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In this paper, we examine a novel generalized (2 + 1) -dimensional Bogoyavlensky–Konopelchenko (gBK) model analytically via application of five mathematical methods, namely called Extended Simple Equation (ESE) method, Modified Extended Auxiliary equation mapping (MEAEM) method, (G ′ / G) -expansion method, Exp (− Ψ (ϕ)) -expansion method and modified F-expansion method, respectively, to obtain different types solitary wave solutions in the form of trigonometric, hyperbolic, rational and exponential functions as compared to solutions exist in [S. T. Chen and W. X. Ma, Math. China 13 (2018) 525; A. Sonia, A. Jamshad, S.-U. Rehman and A. Ali, Int. J. Appl. Comput. Math. 9 (2023)]. The research focuses on physical systems, physiology, mathematical applications, engineering fields, and the chemical processes of species in the porous nanoparticles, examining the impact of various parameters on the nonlinear model. The graphs of some solutions are plotted in the form of two-dimensional and three-dimensional by assigning the particular values to the paraments with the assistance of mathematica software which illustrated the physical behavior of the concern model. The derived solution has numerous applications in fluid dynamics and the interaction of Riemann waves and long waves. [ABSTRACT FROM AUTHOR]

Process safety management (PSM) is a proven and effective management approach that has been validated through practical experience. In recent years, China has been actively exploring advanced PSM methods and has implemented several regulations and standards related to chemical PSM. This article begins with a review of chemical PSM development in China and the United States. It then conducts a comparative analysis of the quantity and content of elements in the PSM systems of both countries. Based on the analysis results, suggestions for improving PSM in China are presented. [ABSTRACT FROM AUTHOR]

Ozone (O3) pollution is a severe air quality issue in China, posing a threat to human health and ecosystems. The climate change will affect O3 levels by directly changing physical and chemical processes of O3 and indirectly changing natural emissions of O3 precursors. In this study, near‐surface O3 concentrations in China in 2030 and 2060 are predicted using the process‐based interpretable Extreme Gradient Boosting (XGBoost) model integrated with multi‐source data. The results show that the climate‐driven O3 levels over eastern China are projected to decrease by more than 0.4 ppb in 2060 under the carbon neutral scenario (SSP1‐1.9) compared with the high emission scenario (SSP5‐8.5). Among this reduction, 80% is attributed to the changes in physical and chemical processes of O3 related to a cooler climate, while the remaining 20% is attributed to the reduced biogenic isoprene emissions. Plain Language Summary: O3 pollution is a severe air quality issue in China that threatens human health and ecosystem. Under the background of climate change, O3 pollution will continue to evolve in the future. Here, we predict near‐surface O3 concentrations in China in 2030 and 2060 based on an interpretable machine learning method, integrated with physical and chemical processes of O3, natural emissions of O3 precursors, and other multi‐source data. The direct (via changing physical and chemical processes of O3) and indirect (via changing natural emissions of O3 precursors) impacts of future climate change on O3 concentrations are quantitatively analyzed. It demonstrates that the climate‐driven O3 levels are projected to decrease by more than 0.4 ppb in 2060 over eastern China under a carbon neutral scenario relative to a high emission scenario. The changes in physical and chemical processes under climate change play a more important role in regulating O3 concentrations in the future than the changes in natural emissions. Key Points: Climate change influences O3 pollution in China through changing physical and chemical processes and natural precursor emissions of O3Physical and chemical processes play a dominant role in regulating future near‐surface O3 concentrations over eastern ChinaCarbon neutral scenario is an ideal pathway for China to mitigate both climate change and O3 pollution in 2060 [ABSTRACT FROM AUTHOR]

The Erlian Basin is a Mesozoic–Cenozoic rift basin with a large thick Pliocene sandstones deposit, which has important oil, gas, and uranium resources exploration potential. The paleo-sedimentary environment plays an important role in controlling the development of mineral resource. However, provenance and depositional environment of the Pliocene sandstones remain enigmatic. To address it, this study reports the whole rock geochemical compositions of sandstones from the Youqi and Siziwangqi regions to reflect the paleo-sedimentary environment. The Youqi sandstones are classified as litharenite-arkose, whereas the Siziwangqi sandstones exhibit a graywacke affinity. Furthermore, both the Youqi and Siziwangqi sandstones exhibit low CIA, PIA, ICV, and Th/U values, suggesting that their source rocks were of great maturation and experienced low to moderate chemical weathering processes. The Ni/Co, U/Th, and Ce/Ce* values in these sandstones range from 0.4 to 5.9, 0.20 to 0.37, and 0.80 to 1.09, respectively, indicating that these sandstones were formed in an oxygen-rich depositional environment. Additionally, interelement ratios such as Sr/Cu, SiO2/Al2O3, and Rb/Sr suggest a hot and arid paleoclimate during the deposition of these sandstones. Tectonic discrimination diagrams reveal a continental arc environment for the studied sandstones, Combining regional structural background, implying that the Erlian Basin was influenced by both Himalayan and the Pacific-Ocean-surrounding tectonism during the Pliocene period. [ABSTRACT FROM AUTHOR]

Methylene diphenyl diisocyanate (MDI) serves as a primary component of polyurethane in various applications, including household appliances, architectural structures, automobiles, and adhesives. A recent MDI plant explosion in China highlighted the importance of studying MDI's thermal stability and parameters to prevent accidental thermal decomposition. In this study, an extensive array of analytical techniques, including differential scanning calorimetry, thermogravimetric analysis, and adiabatic accelerating calorimeter, was employed to determine the thermokinetic constants of MDI, providing a solid foundation for further in-depth investigations. The findings revealed that MDI containing water reacts at substantially lower temperatures, while pure MDI can release heat and gases in an adiabatic environment, posing a considerable explosion risk. The kinetic constant of MDI was calculated using the Flynn–Wall–Ozawa method, yielding apparent activation energy values ranging from 51.78 to 96.70 kJ mol−1 across a conversion degree range of 0.05–0.70. The Coats–Redfern model pinpointed the kinetic reaction mechanism as a two-stage chemical process based on the apparent activation energy. Molecular optimization, following the energy minimisation principle, was conducted using Gaussian 09 software, which led to the identification of the optimal pathway for generating carbodiimide and carbon dioxide. This investigation offers valuable insights for the effective management of MDI during production, transportation, and storage, contributing to improve loss prevention practices in the industry. [ABSTRACT FROM AUTHOR]

To investigate the optical characteristics and sources of brown carbon (BrC) in North China, where the atmospheric aerosol loadings are high and have severe impacts on Earth's climate system, we collected fine aerosols (PM 2.5) at an urban site in Tianjin over a 1-year period. We measured the ultraviolet (UV) light absorption and excitation emission matrix (EEM) fluorescence of the water-soluble BrC (WSBrC) and the water-insoluble but methanol-soluble BrC (WI-MSBrC) in the PM 2.5 using a three-dimensional fluorescence spectrometer. The average light absorption efficiency of both WSBrC (Abs365, WSBrC) and WI-MSBrC (Abs365, WI-MSBrC) at 365 nm was found to be highest in winter (10.4 ± 6.76 and 10.0 ± 5.13 Mm-1 , respectively) and distinct from season to season. The averages of the fluorescence index (FI) and the biological index (BIX) of WSBrC were lower in summer than in the other seasons and opposite to that of the humification index (HIX), which implied that the secondary formation and further chemical processing of aerosols were more intensive during the summer period than in the other seasons. However, in winter, the higher HIX together with the higher FI and BIX of WI-MSBrC suggested that the BrC loading was mainly influenced by primary emissions from biomass burning and coal combustion. Based on the EEM, the types of fluorophores in WSBrC were divided into humic-like substances (HULIS), including low-oxygenated and high-oxygenated species and protein-like compounds (PLOM), though mostly PLOM in the WI-MSBrC. The direct radiation absorption by both WSBrC and WI-MSBrC in the range of 300–400 nm accounted for ∼ 40 % of that (SFEAbs , 4.97 ± 2.71 and 7.58 ± 5.75 Wg-1 , respectively) in the range 300–700 nm. [ABSTRACT FROM AUTHOR]

In the chemical flooding process, the premature breakthrough of chemical agents in production wells results in a large waste of chemical agents and increases the volume and processing difficulty of the produced fluids. The early warning method of chemical agent channeling can predict the strength of agent channeling in advance. The practice of chemical flooding shows that the production performance can be used for early warning of chemical agent channeling. In this paper, we analyze the relationship between cumulative oil production and cumulative polymer production of production wells in polymer–surfactant flooding. Three types of curves according to the enhanced oil production characteristics of chemical flooding, including convex type, S‐type, and concave type. We use the drop speed of the water–oil ratio and the rapid‐decline speed of water cut as early warning indicators to predict the channeling coefficient. A Latin hypercube experimental design method is used to design a polymer–surfactant flooding scheme with the main control factors of the channeling coefficient and early warning indicators. Numerical simulation is used to calculate samples of the channeling coefficient and early warning indicators under various conditions. The drop speed of the water–oil ratio reference value model and the rapid‐decline speed of the water cut reference value model are determined with a multiple regression method. A prediction model for the chemical agent channeling coefficient is established using the deviation coefficient of an early warning index. The method is applied in the Ng54‐61 polymer–surfactant flooding pilot area in the west of the Gudong Seventh District, Shengli Oilfield, China, and the error between the predicted result and the actual value is less than 10%. This research is helpful in taking effective antichanneling measures and improving the oil recovery degree of chemical flooding reservoirs. [ABSTRACT FROM AUTHOR]

Since the distinct thermostability difference of sulfate ammonium and nitrate ammonium aerosols, their distributions, evolutions and sources could be unpredictable on a long‐range transport condition. Here, we highlighted the 3‐D structures and sources of SO42−, NO3− and NH4+ (SNA) during two cold front episodes in east China. Cold fronts effectively uplift and transport PM2.5 and its precursors from upstream sources to the Yangtze River Delta (YRD). Specifically, in the YRD, surface SO42− is mostly imported from the upstreams, accounting for ∼48%, significantly higher than the contribution from the YRD itself (∼29%). In contrast, NH4NO3 is thermally unstable and more easily lost in the warmer and lower boundary layer (BL) ahead of cold front. Consequently, only 20% of the total NO3− originates from upstreams, while the YRD contributes 28%. In the upper BL, the contribution of SO42− from upstreams remain high (∼49%), with only 18% originating from the YRD. However, due to the intense thermostability of NH4NO3 in colder and wetter air, the YRD's contribution to NO3− is 27%, and upstreams contribute 20%. The physical processes exert relatively consistent effects on variations of PM2.5 and SNA concentrations. The aerosol chemical process (AERO) of (NH4)2SO4 consistently contributes positively throughout the entire BL. Conversely, the temperature‐sensitive NH4NO3 undergoes repeated dissociation/condensation and deposition, causing positive AERO contributions in upper BL and negative contributions in lower BL. Results indicate that one difference in physicochemical property of species could induce their distinct distributions and sources in large scale, and should be considered in regional air pollution control. Plain Language Summary: Long‐range transport of PM2.5 by cold frontal passage is an important haze formation mechanism. Previous field and modeling studies have revealed that the vertical distribution of particle sulfate and particle nitrate concentrations varied significantly. However, few studies have explored the 3‐D structures and sources of particle sulfate and nitrate under a long‐range transport conditions. In this study, we used combined observations and model simulations during cold front events to address the unrevealed inconsistent 3‐D structures and sources of sulfate and nitrate resulting from temperature stability differences. Cold front episodes redistribute SNA and precursors in three dimensions, driven by drastic meteorology changes and long range transport. Consequently, the distributions, variations and sources of SNA may exhibit complexity and unpredictablility during long‐range transport. Specificlly, (NH4)2SO4 is mostly imported from the upstream in the whole boundary layer (BL), but NH4NO3 is dominant by local source. Moreover, uplifting by cold front, temperature‐sensitive NH4NO3 form in the upper BL and dissociation in the lower BL, whereas (NH4)2SO4 forms uniformly across the whole BL. These findings suggest that one difference in physicochemical property of species can induce distinct distributions and sources in large scale, highlighting the importance of considering such differences in regional air pollution control. Key Points: Uplifted by cold fronts, the temperature‐sensitive NH4NO3 forms in the upper BL and dissociates in the lower BL(NH4)2SO4 forms in the whole BL because it is highly thermally stable and impervious to dissociationThe differences in thermostability and lifetime result in local sources being dominant for NH4NO3, while upstream sources dominate for (NH4)2SO4 [ABSTRACT FROM AUTHOR]

Bilirubin, a key active ingredient of bezoars with extensive clinical applications in China, is produced through a chemical process. However, this method suffers from inefficiency and adverse environmental impacts. To address this challenge, we present a novel and efficient approach for bilirubin production via whole-cell transformation. In this study, we employed Corynebacterium glutamicum ATCC13032 to express a β-glucuronidase (StGUS), an enzyme from Staphylococcus sp. RLH1 that effectively hydrolyzes conjugated bilirubin to bilirubin. Following the optimization of the biotransformation conditions, a remarkable conversion rate of 79.7% in the generation of bilirubin was obtained at temperate 40 °C, pH 7.0, 1 mM Mg2+ and 6 mM antioxidant NaHSO3 after 12 h. These findings hold significant potential for establishing an industrially viable platform for large-scale bilirubin production. [ABSTRACT FROM AUTHOR]

Two-way coupled meteorology and air quality models, which account for aerosol–radiation–cloud interactions, have been employed to simulate meteorology and air quality more realistically. Although numerous related studies have been conducted, none have compared the performances of multiple two-way coupled models in simulating meteorology and air quality over eastern China. Thus, we systematically evaluated annual and seasonal meteorological and air quality variables simulated by three open-source, widely utilized two-way coupled models (Weather Research and Forecasting (WRF)–Community Multiscale Air Quality (WRF–CMAQ), WRF coupled with chemistry (WRF–Chem), and WRF coupled with a regional chemistry-transport model named CHIMERE (WRF–CHIMERE)) by validating their results with surface and satellite observations for eastern China in 2017. Although we have made every effort to evaluate these three coupled models by using configurations that are as consistent as possible, there are still unavoidable differences between them in their treatments of physical and chemical processes. Our thorough evaluations revealed that all three two-way coupled models captured the annual and seasonal spatiotemporal characteristics of meteorology and air quality reasonably well. Notably, the role of the aerosol–cloud interaction (ACI) in improving the models' performances was limited compared to that of the aerosol–radiation interaction (ARI). The sources of uncertainties and bias in the different ACI schemes in the two-way coupled models were identified. With sufficient computational resources, these models can provide more accurate air quality forecasting to support atmospheric environment management and deliver timely warnings of heavy air pollution events. Finally, we propose potential improvements to two-way coupled models for future research. [ABSTRACT FROM AUTHOR]

The onset of the South China Sea summer monsoon (SCSSM) has profound impacts on meteorological conditions over East Asia. However, whether the interannual variability in monsoon onset date impacts ozone (O3) pollution remains unclear. Here, we investigate the relationship between early onset of SCSSM and late spring O3 in southern China. Our results show notable differences in surface O3 concentrations before and after SCSSM onset during early onset events in southern China. The enhanced O3 of 11.1 μg m−3 is supported by increased air temperature and solar radiation of 1.1 K and 30.9 W m−2 and reduced relative humidity of −5.7%. Both observation and model simulations confirm that O3‐favorable meteorological conditions modulated by early SCSSM onset can be found in May. It increases the boundary layer height and biogenic emissions of volatile organic compounds, enhancing O3 by 10 μg m−3 over southern China. Chemical processes dominate such increases in O3 with enhanced chemical production of 0.27 Tg month−1. Descending motion in southern China vertically transports O3 to surface by 0.10 Tg month−1, whereas horizontal advection reduces O3 concentration by 0.12 Tg month−1. The meteorological responses to colder sea surface temperature (SST) in the central equatorial Pacific are pronounced, leading to higher O3 concentrations over the Yangtze River Delta, while warmer SST in the Philippine Sea contributes O3 over the Pearl River Delta and eastern China. This study highlights the importance of SCSSM onset with respect to O3 in southern China, with promising applications in management of air pollution and agriculture. Plain Language Summary: The onset of the South China Sea summer monsoon (SCSSM), a spectacular feature of the Asian summer monsoon, has significant impacts on meteorological conditions over East Asia. It remains unclear whether the interannual variability in monsoon onset date affects ozone (O3) pollution. In this study, we demonstrated that the early onset of SCSSM can create warmer and drier conditions with enhanced solar radiation in May, which increases boundary layer height, boosts biogenic emissions of volatile organic compounds and worsens O3 pollution in southern China. By integrating reconstructed O3 data set and meteorological reanalysis together with model simulations, we found that increased O3 concentrations of approximately 10 μg m−3 over southern China were dominated by enhanced chemical production. Both sea surface temperature anomalies in the central equatorial Pacific and Philippine Sea contributed to the O3‐favorable meteorological conditions modulated by early SCSSM onset. Our study emphasizes the importance of considering the SCSSM onset in understanding O3 pollution in southern China, with promising applications in air pollution management and agriculture. Key Points: Early onset of the South China Sea summer monsoon can create warmer and drier conditions with enhanced solar radiation in MayEnhanced chemical production dominates the worsening late spring ozone pollution in southern China during early onset eventsBoth sea surface temperature anomalies in the central equatorial Pacific and Philippine Sea contribute to higher ozone in southern China [ABSTRACT FROM AUTHOR]

Purpose: The extensive invasion of Spartina alterniflora in coastal wetlands of China has posed a ruinous risk to biodiversity and ecosystem constancy. Sulfur is an essential nutrient, while sulfide is biologically toxic and could couple with iron. The influence of S. alterniflora invasion on sulfur and iron cycling in sediment remains poorly understood. Hence, the purpose of this study is to investigate how the invasion of S. alterniflora affects the sulfur and iron cycles in sediments in coastal wetlands. Methods: Field investigations were conducted in the Jiuduansha Wetland to examine the different sulfur and iron components, microbial communities, and functional genes related to the sulfur cycle in soils colonized by S. alterniflora and in native coenosis. Results: The invasion of S. alterniflora caused the accumulation of reduced inorganic sulfur (RIS) in the sediments, and the RIS components were stratified at different sediment depths. The activity of S. alterniflora roots and the presence of low-elevation tides promoted sulfate reduction and the accumulation of acid volatile sulfide (AVS), primarily through abiotic chemical processes. These processes facilitated the invasion and expansion of S. alterniflora. Meanwhile, S. alterniflora could promote sulfate reduction by altering sediment physicochemical properties, such as pH. However, the correlation between RIS components and salinity or Eh in the low-intertidal zones was not significant due to the influence of tidal action. Nevertheless, S. alterniflora could buffer sulfide by enriching Fe, rapidly reducing Fe(III) and forming pyrite, thus mitigating sulfide stress. Conclusion: The invasion of S. alterniflora in tidal environments increased sediment sulfide levels, while S. alterniflora is able to mitigate the effects of sulfide stress on itself by efficiently utilizing iron. [ABSTRACT FROM AUTHOR]

Modeling air quality has always been a challenge in global models constrained by coarse grids. Here, the variable‐resolution Community Atmosphere Model with full chemistry based on the scalable spectral element (SE) dynamical core (MUSICAv0) is applied in simulating air pollution with a finer grid resolution of ∼0.25° over East Asia (SE_VR), in contrast to the same model with a uniform resolution of ∼1.0° (SE_UR). Two nudging experiments and four free‐running experiments are conducted to investigate the capabilities of SE_VR in modeling the air pollution and aerosol‐planetary boundary layer (PBL) interactions over China. Results show the regional refinement in SE_VR is essential for simulating haze events over complex terrain areas attributed to its better performance in representing the local vertical and horizontal dispersion conditions. SE_VR shows prominent advantages over SE_UR in simulating surface ozone because of better resolving spatial segregation of NOx and volatile organic compounds (VOC) chemical regimes and subsequently representing more detailed chemical processes related to ozone formation, although the model generally overestimates surface ozone over China. Further analysis of SE_VR shows the daytime radiative effect of black carbon (BC) aerosols lowers PBL height by 12.0% (17.9%), and leads to an increase of PM2.5 by 14.5% (10.8%) under the moderate (severe) air pollution conditions over Sichuan Basin. However, SE_UR has deficiencies in simulating BC‐PBL interactions due to its inability to reproduce the strong inverse temperature structure caused by BC aerosols in the lower atmosphere layer. Our results highlight the value of variable‐resolution global models for simulating air pollution and its interactions with climate. Plain Language Summary: Air pollution has been demonstrated to be harmful to humans and the living environment over East Asia. Simulations of air pollution are traditionally performed with regional or global models. However, uncertainties remain in air quality simulations due to insufficient resolution to resolve the regional‐scale processes in global models or the inconsistency of chemical and physical schemes between regional and global models. In this work, we conduct experiments using a variable‐resolution global climate model to explore the improvement of regional refinement in simulating the air quality and aerosol‐PBL interactions over China. The experiment with grid refinement over East Asia simulates PM2.5 and ozone concentrations better, as well as improving the aerosol‐PBL interaction simulations. The finer grids are more essential in improving the haze event simulation at the complex terrain regions due to better presenting the local vertical and horizontal dispersion conditions associated with the accumulation and aggregation of pollutants. Finer grids show prominent advantages in the representation of spatial segregation of NOx and VOC chemical regimes, improving the ozone simulation over China. Moreover, refinement grids reproduce the strong inverse temperature structure caused by BC aerosols in the low atmosphere and improve simulations of the impacts of BC‐PBL interactions on air quality. Key Points: The MUSICAv0 model with regional refinement over East Asia improves haze event simulations, especially in complex terrain areasFiner grids can resolve a greater range of NOx and volatile organic compounds (VOC) chemical regimes, significantly reducing the ozone overestimation in coarser gridsFiner grids improve the boundary layer representation of black carbon featured by stronger inverse temperature structure in the lower atmosphere [ABSTRACT FROM AUTHOR]

Radiative absorption of black carbon (BC) is of great importance in air quality and climate change. Simultaneous mitigation of haze pollution and climate warming requires an in‐depth understanding of haze‐BC‐climate connections based on direct observations. We simultaneously performed measurements in the North China Plain (NCP) and the Yangtze River Delta (YRD) during the winter of 2018–2019, when cross‐regional haze transport frequently occurred. We found that BC particles exhibited a thick coating thickness (100–120 nm) under haze pollution conditions in the NCP and were then transported to the YRD with regional haze development. BC particles in the downwind region showed a bimodal distribution of core‐size‐resolved aging degree, which can be used to separate and quantify local and regional BC. The results showed that the regional haze transport from the NCP brought 1–3 μg m−3 BC into the YRD. These regional BC particles exhibited ∼1.6 times stronger absorption efficiency than locally emitted BC. The direct radiative effects of BC in the downwind region were estimated to be enhanced by ∼2 times when regional haze pollution was transported from the NCP to the YRD. The amplification of BC's climate effect during regional haze pollution was attributed to the increases in both the mass concentrations and light absorption efficiency of BC, which were responsible for 40%–50% and 50%–60%, respectively. Our work identified strong haze‐BC‐climate connections across the NCP and YRD and highlighted the importance of BC in the effects of haze pollution on regional climate. Plain Language Summary: Black carbon (BC) aerosols strongly absorb solar radiation and have a large contribution to both haze pollution and climate warming. The model estimates of BC radiative effects during their lifecycle have considerable uncertainties due to the complex physical and chemical processes of BC aerosols from local emissions to long‐range transport in the atmosphere. Improving estimates of BC radiative effects requires some direct measurements of BC absorption properties to constrain model predictions. However, it challenges field measurements to obtain this information at the regional scale. Our simultaneous observations in the North China Plain and the Yangtze River Delta using a single‐particle technique helped to distinguish the regional origins of BC. Based on field measurements, we quantified the optical properties of BC at local and regional scales. The results showed that the radiative effects of BC at the regional scale were significantly amplified by haze formation and transport, indicating the important role of BC in haze‐climate interactions. The work provides a clue for the simultaneous mitigation of haze pollution and climate warming. Key Points: Bimodal coating feature of black carbon (BC) was found when cross‐regional haze transport occurredCross‐regional haze transport brought 1–3 μg m−3 BC with higher absorption efficiency than locally emitted BCA case study identified strong haze‐BC‐climate connections across northern and eastern China [ABSTRACT FROM AUTHOR]

A field campaign (29 May to 14 June 2018) was conducted at a mountain site in central China. The chemical composition of non‐refractory submicron particulate matter (NR‐PM1) and the particle number size distribution (PNSD) were measured, respectively. The mean NR‐PM1 mass concentration was 20.94 ± 10.14 μg m−3, among which organics (47%) was the most abundant component, followed by sulfate (37%), ammonium (11%), nitrate (4%), and chloride (1%). Notably, sulfate accounted for more than 70% of the secondary inorganic aerosols. Positive matrix factorization (PMF) analysis of the composition data resulted in three organic aerosol (OA) factors: hydrocarbon‐like OA (HOA), oxygenated OA I (OOA‐I), and oxygenated OA II (OOA‐II). The secondary organic aerosol (SOA) composed of the latter two factors (SOA: OOA‐I + OOA‐II) was dominant in OA (80.7%). The PMF analysis of the PNSD data yielded three factors: new particle formation related mode, growth mode, and accumulation mode, among which the last factor dominated both number and volume ratios. The sulfate formation was characterized by the sulfur oxidation ratio (SOR), heterogeneous sulfate production rate (Phet), and gaseous sulfuric acid concentration, representing secondary sulfate transformation, heterogeneous reactions, and gas phase reactions, respectively. The results showed that Phet was well correlated with both sulfate concentrations and SOR, especially during the polluted periods. Our study demonstrates that photochemically‐driven heterogeneous reactions contribute dominantly to the sulfate formation and SOA is formed predominantly by photochemical oxidation of volatile organic compounds under high temperatures and ultraviolet (UV) intensities, and NOX concentrations on Mt. Wudang during the campaign period. Plain Language Summary: In this study, the chemical composition and size distribution of submicron aerosols were measured at a mountain site in central China (Mt. Wudang), and the sources as well as controlling factors were further investigated. Our results reveal that photochemical reactions play an important role in both sulfate and secondary organic aerosol formation. For sulfate, heterogeneous reactions were dominant during the polluted periods, whereas gas‐phase reactions are more pronounced during the clean periods. Key Points: Organics and sulfate account for more than 80% mass concentration of submicron aerosols on Mt. WudangHeterogenous reactions lead to sulfate formation on Mt. Wudang during the polluted periodsSecondary organic aerosol was mainly formed by photochemical reactions on Mt. Wudang [ABSTRACT FROM AUTHOR]

Iron isotopes of magnetite have been used to unravel the sources and evolutionary processes of magma and ore deposits, but most studies have focused on bulk-rock samples, which possibly provide mixed information. Magnetite is susceptible to fluid-induced metasomatism, e.g., recrystallization and coupled dissolution-reprecipitation (CDR) processes in magmatic-hydrothermal systems, resulting in textural and chemical modification and re-equilibration. The behaviors of Fe isotopes during fluid metasomatism, however, are poorly understood. Magnetite from iron oxide-apatite (IOA) deposits commonly shows multi-generation and metasomatic textures, which have been suggested to form from magmatic melts/fluids to low-temperature hydrothermal processes. In this study, we carried out in situ Fe isotopic and chemical analyses on texturally constrained magnetite from ores and their hosting trachyandesite of the giant Luohe IOA deposit, eastern China, to assess the effect of fluid-assisted metasomatic processes on both chemical and Fe isotopic compositions, and to constrain the ore-forming processes. The ores contain three types of magnetite (Mag1, Mag2 and Mag3), all of which are texturally later than albite and diopside. Pristine Mag1 grains, formed at high temperatures (>700 °C), have ilmenite exsolution lamellae, and have lower Ti (0.61–1.55 wt%) but higher Ni/Cr ratios (mostly > 1) than those of magmatic magnetite (MagM) in the hosting trachyandesite. They also have δ56Fe values (0.12–0.52‰) lower than those of MagM (0.54–0.65‰), which overlap with those of high-temperature hydrothermal magnetite from iron-oxide copper–gold (IOCG), iron skarn, and porphyry Cu deposits, indicating that they were precipitated from high-temperature hypersaline fluids, as recorded by fluid inclusions within early-formed garnet, diopside, and coeval titanite. The heavy Fe isotope compositions of Mag1 are interpreted to be due to fluid exsolution under high temperatures and the preference of isotopically light Fe for earlier diopside (δ56Fe = −0.19 to −0.02‰). Mag2 grains, which show triple junction textures, were formed through a fluid-induced recrystallization process at relatively lower temperatures (∼480 °C). They have δ56Fe values (0.29–0.53‰) similar to those of Mag1 and previously reported high-temperature hydrothermal magnetite in other deposits. In contrast, Mag3 grains, which occur as rims on Mag1 grains, were formed via CDR at much lower temperatures (<300 °C). They have δ56Fe values (−0.15 to 0.22‰) significantly lower than those of pristine Mag1 and overlap those of reported low-temperature hydrothermal magnetite. Decreasing formation temperatures from Mag1 to Mag3 are consistent with the decreasing trace element concentrations (Ti, Al, and V). Our study demonstrates that IOA deposits are formed from high-temperature hypersaline magmatic fluids and that the Fe isotopes of magnetite can be significantly modified during fluid metasomatism and ore-forming processes. Therefore, trace element and in situ Fe isotopic analyses on texturally well-constrained magnetite grains are crucial for determining the origin and evolution of magmatic-hydrothermal systems. [ABSTRACT FROM AUTHOR]

Photooxidants drive many atmospheric chemical processes. The photoexcitation of light-absorbing organic compounds (i.e., brown carbon, BrC) in atmospheric waters can lead to the generation of reactive organic triplet excited states (3C∗), which can undergo further reactions to produce other photooxidants such as singlet oxygen (1O2∗). To determine the importance of these aqueous photooxidants in secondary organic aerosol (SOA) formation and transformation, we must know their steady-state concentrations and quantum yields. However, there have been limited measurements of aqueous 3C∗ and 1O2∗ in atmospheric samples outside of North America and Europe. In this work, we report the first measurements of the steady-state concentrations and quantum yields of 3C∗ and 1O2∗ produced in aerosols in South China. We quantified the production of 3C∗ and 1O2∗ in illuminated aqueous extracts of PM 2.5 collected in different seasons at two urban sites and one coastal semi-rural site during a year-round study conducted in Hong Kong SAR, South China. The mass absorption coefficients at 300 nm for BrC in the aqueous PM 2.5 extracts ranged from 0.49 to 2.01 m 2 g-C -1 for the three sites. Both 1O2∗ and 3C∗ were produced year-round. The steady-state concentrations of 1O2∗ ([1O2∗]ss) in the illuminated aqueous extracts ranged from 1.56×10-14 to 1.35×10-12 M , with a study average of (4.02±3.52)×10-13 M. At nearly 2 orders of magnitude lower than [1O2∗]ss , the steady-state concentrations of 3C∗ ([3C∗]ss) ranged from 2.93×10-16 to 8.08×10-14 M , with a study average of (1.09±1.39)×10-14 M. The quantum yields of 1O2∗ and 3C∗ also spanned wide ranges across samples, with a range of 1.19 % to 13.74 % and an average of (5.19±2.63) % for 1O2∗ and a range of 0.05 % to 3.24 % and an average of (0.56±0.66) % for 3C∗. The [1O2∗]ss and [3C∗]ss correlated with the concentration and absorbance of BrC , thus implying that the amount of BrC drives the steady-state concentrations of these photooxidants. The locations (urban vs. semi-rural) did not have a significant effect on [3C∗]ss and [1O2∗]ss , which indicated that BrC from local sources did not have a significant influence on the year-round 3C∗ and 1O2∗ production. 3C∗ and 1O2∗ production were found to be the highest in winter and the lowest in summer for all three sites. The observed seasonal trends of 1O2∗ and 3C∗ production could be attributed to the seasonal variations in the long-range air mass transport. Our analysis highlighted the key role that regional sources play in influencing the composition and concentrations of water-soluble BrC in winter PM 2.5 in Hong Kong SAR, which contributed to their highest 3C∗ and 1O2∗ production. The current results will be useful for modeling seasonal aqueous organic aerosol photochemistry in the South China region. [ABSTRACT FROM AUTHOR]

As an important consideration in the chemical industry, chemical process safety has received notable attention in China. However, catastrophic chemical accidents still occur. To better understand why accidents continue to occur, this paper presented a diagnostic analysis of 14 major chemical accidents in China from 2012 to 2022 based on VOSviewer software. The authors analysed the correlation between the accident causation and their relationship with the safety management elements. The study observed that inferior process safety culture, intentional violation (rule-breaking) of procedure, inadequate safety training, and illegal operations were the most frequent causes of accidents. These causes highlighted the prominent gaps in PSM in China in the process safety culture, compliance with standards, the conduct of operations, process safety competency, and training & performance assurance. The results based on co-occurrence analysis indicated a strong correlation between these gaps in PSM. Enterprises should pay attention to collaborative management among them. These deficiencies in the enterprise's PSM system showed that the essential defects in China's chemical industry are a poor safety culture, inadequate accident investigation, inadequate training, and a lack of chemical safety personnel. The study recommended that the chemical industry establish superior process safety culture and competency for all personnel, monitor leading and lagging process safety indicators, apply inherent safety, and practice advanced safety management concepts. We hope that the findings can provide China's perspectives and strengths for global chemical safety. [ABSTRACT FROM AUTHOR]

Groundwater heat pumps (GWHP) are an efficient utilisation of shallow geothermal energy technology and of great significance in terms of promoting energy conservation and reducing emissions. However, recharge clogging has been a key problem restricting the continuous operation of GWHP. In this study, a simulation test device for sand column was designed with the aim of addressing chemical clogging induced by heat pump reinjection in a porous saline aquifer in the Huaibei Plain, China. The trend in the variation of the permeability coefficient was studied based on the detection of the sand sample composition, recharge water quality, and sand layer temperature, and the cause of formation was analysed using the saturation index (SI) and ion ratio method. The results indicated that the permeability coefficient in the sand column decreased exponentially, with a maximum and minimum decrease of 8.14% and 71.65% of the original coefficient, respectively, found in sections P2–P3 and P8–P9. Therefore, the clogging effect of the aquifer at approximately 200–400 mm from the recharge well was significant. Water–rock interactions predominantly involved the dissolution of halite, albite, chlorite, anhydrite, and dolomite and the precipitation of calcite, as well as the exchange adsorption of Ca2+ and Mg2+ to Na+, which were the key sources of ions during the water chemical evolution process. Finally, quartz was formed by the weathering and dissolution of aluminosilicate minerals such as albite, and particle migration and precipitation during the hydrodynamic disturbance were the primary causes of the front-end blockage of the column. [ABSTRACT FROM AUTHOR]

To investigate the physicochemical characteristics and sources of brown carbon (BrC) in North China, we collected fine aerosols (PM2.5) at an urban site in Tianjin over a 1-year period. We measured the ultraviolet (UV) light absorption and excitation emission matrix (EEM) fluorescence of the water-soluble BrC (WSBrC) and the water-insoluble but methanol-soluble BrC (WI-MSBrC) in the PM2.5 using a three-dimensional fluorescence spectrometer. Average light absorption efficiency of both WSBrC (Abs365, WSBrC) and WI-MSBrC (Abs365, WI-MSBrC) at 365 nm was found to be highest in winter and distinct from season to season. The biological index (BIX) and fluorescence index (FI) of WSBrC showed an opposite seasonal pattern to that of the humification index (HIX) with lower values in summer, implying that the secondary formation and further chemical processing of aerosols were intensive in summer than in other seasons. Whereas in winter, the higher HIX together with the higher BIX and FI of WI-MSBrC suggested that the BrC loading was mainly influenced by primary emissions and was relatively water-soluble. Based on EEM, the types of chromophores in BrC were divided into humic-like substances (HULIS), including low-oxygenated and high-oxygenated species, and protein like compounds (PLOM). The direct radiation absorption caused by WSBrC and WI-MSBrC combinedly in the range of 300–400 nm was accounted for about 40 % to the total radiation (range, 300–700 nm), which emphasizes that the radiation balance of the Earth's climate system is substantially affects by the BrC and should be considered in the radiative forcing models. [ABSTRACT FROM AUTHOR]

Though China's air quality has been improved in the past decade, haze still engulfs megacities in winter with fast increasing secondary aerosol like nitrate. Given that aerosol and its precursors exhibit great vertical heterogeneity, we conducted airship measurements at Shanghai in December 2017 to understand the critical drivers for the rapidly increased secondary pollution. By integrating in‐situ observations and model simulations, we found that cold front favors the long‐range transport of pollutants, during which chemical formation of nitrate in residual layer was faster than near the surface due to concentrated precursors and sufficient oxidation. The nitrate aloft would be entrained down once the daytime convective boundary layer develops, thereby deteriorating near‐surface air pollution. It is shown that the local surface‐level chemical production played a minor role, whereas the synoptic weather and boundary layer evolution largely contributed to enhanced secondary aerosol pollution (>60%). This study demonstrates that weather systems, boundary layer evolution, and chemical processes could jointly shape secondary aerosol production, highlighting the importance of a vertical understanding of haze pollution. Plain Language Summary: Severe haze events occur frequently in eastern China during winter, mainly caused by secondary aerosol like nitrate. Given that aerosol and its precursors feature great vertical heterogeneity, it is of great significance to understand the critical drivers for secondary pollution from a vertical perspective. By conducting airship measurements in Shanghai, high loading of secondary aerosols was observed in the upper air. It is revealed that cold fronts promoted the transport of pollution, resulting in the accumulation and rapid oxidation of precursors in residual layer. Nitrate aloft mixed downward with the development of boundary layer, which leads to enhanced secondary pollution near thesurface. This work sheds light on the importance of a vertical understanding of haze pollution. Key Points: Cold‐front driven regional transport of pollutants aloft was observed by a tethered airshipConcentrated precursors and rapid oxidation promote secondary aerosol formation in residual layerSecondary aerosols in the upper air make a significant impact on surface air quality through vertical mixing process [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) have crucial influences on atmospheric chemistry. Accurate quantification of the VOC emissions is critical for air pollution research, especially when applying to air quality models. However, current bottom‐up emission inventories have biases, making observational constraints of VOC emissions necessary. We conducted concurrent VOC measurements in the Pearl River Delta (PRD) region during the summer of 2018 and found large discrepancies in the spatiotemporal variations of VOCs between observations and model simulations when using the priori VOC emission inventory (Multi‐resolution Emission Inventory for China). The normalized biases of total VOC concentrations ranged from −55% to 85% across the PRD cities in the study period. To improve the simulations, we constrained the anthropogenic VOC emissions based on their measured concentrations. The observation‐constrained VOC emissions showed clear diurnal variations and resolved the spatially‐concentrated priori emissions by reducing the high emissions by 15%–36% in the central PRD cities while elevating the sparse emissions in other cities. After employing the observation‐constrained VOC emissions, the model better reproduced the spatiotemporal variations of VOCs in the PRD region, alleviating the biases to −13%–13%. Furthermore, simulations of peak ozone (O3) concentrations were amended to reduce the mean normalized bias by 5%–12% on high O3 days. Our work has effectively combined VOC field measurements with air quality modeling to achieve better simulations of VOCs and O3. Besides, the observational‐constrained emissions are flexible for studying short‐term emission changes and their subsequent impacts on air quality. Plain Language Summary: Air quality models are important tools for studying the physical and chemical processes of air pollution. Model simulations rely heavily on the input emission profiles. Despite efforts to establish accurate and model‐ready emission inventories, biases persist, which further affects model results. Volatile organic compounds (VOCs) emitted from various anthropogenic sources are key precursors to ozone (O3) and secondary organic aerosols. In this study, we constructed an observational constraint to validate current VOC emission inventories against observations in nine cities. Constrained emission profiles revealed more pronounced spatiotemporal variations in VOC emissions across cities. Furthermore, since VOC emissions were constrained by observations, air quality model simulations of VOCs and O3 were significantly improved and more consistent with observations in terms of chemical composition, diurnal variation, and spatial variation. Our proposed approach is efficient and flexible in updating VOC emissions and is suitable for air quality modeling. The improved simulations of VOCs and O3 provide scientific support for further studies on the impacts of emission changes on air pollution and pollution control strategies. Key Points: Discrepancies found in spatiotemporal variations of volatile organic compounds (VOCs) between field measurements and model simulationsAnthropogenic VOC emissions in the Pearl River Delta region quantitatively estimated through observationsSimulations of spatiotemporal variations of VOCs and ozone improved by observation‐constrained emissions [ABSTRACT FROM AUTHOR]

Water pollution has been one of the most serious environmental issues worldwide, due partly to the excess emissions of heavy metals. Among them, chromium (Cr) is one of the most important raw materials in a variety of industries, including metal mining, tanneries, electroplating, chrome plating, and dye manufacturing. The accumulation of Cr(VI) in the human body cannot be biodegraded, leading to various diseases, such as dermatitis, rhinitis, and even cancer. Thus, the World Health Organization (WHO) has recommended that the permissible limit of Cr for potable water of 0.05 mg/L. The trivalent (III) and hexavalent (VI) Cr forms can often be found in aqueous solutions. Cr(VI) has much higher toxicity, solubility, and mobility than Cr(III). Therefore, it is urgent to remove Cr(VI) from the water environment. Alternatively, the ZVI-embedded biochar can be expected to efficiently remove Cr(VI), due to the synergetic effect of adsorption and reduction. Generally, the ZVI-embedded biochar is produced to load Fe2+/Fe3+ onto precursor biochar, and then reduce the costly chemical reagents (such as NaBH4). However, the conventional processes of ZVI-embedded biochar can often be verbose, expensive, and/or release toxic byproducts. Therefore, it is a high demand for a cheap and convenient strategy to produce the ZVI/biochar. Meanwhile, more than one million tons of branches and leaves are pruned from tea trees each year in China, in order to improve branch growth and tea quality. Most residues are discarded or burned, leading to plant diseases and insect pests, or severe air contamination. Hence, it is imperative to develop new applications of pruned tea residues for environmental protection. Pruned tea residues with a rich number of cellulosic and polyphenolic components can be expected to serve as the biomass feedstocks and reducing agents, and then to synthesize the ZVI-embedded biochar. In this work, an inexpensive and convenient approach was developed for the synthesis of nanoscale zero-valent iron-embedded biochar (TLBC-nZVI) using pruned tea residues as biomass feedstocks and reducing agents. A series of batch experiments were carried out to explore the adsorption characteristics of TLBC-nZVI for Cr(VI). Scanning electron microscope with energy dispersive spectrometer (SEM-EDS), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS) were applied to characterize the microscopic morphology and physicochemical properties of TLBC-nZVI before and after reaction with Cr(VI). The results showed that the nZVI was embedded successfully with the TLBC. Batch adsorption experiments demonstrated that the low pH value, high temperature, and a large amount of adsorbent were beneficial to the removal of Cr(VI). Batch adsorption experiments showed that the TLBC-nZVI shared excellent performance in the Cr(VI) removal (164.7 mg/g) from aqueous solutions. The kinetic studies showed that the Cr(VI) removal was also fit better with the pseudo-second-order model and intra-particle diffusion model. Therefore, the process of adsorption was mainly through chemical adsorption, such as surface complexation, electrostatic interactions, and ion exchange processes. The first region line cannot pass the origin in the intra-particle diffusion model, indicating the limited rate by the diffusion of the boundary layer. The second region fitting demonstrated that intraparticle diffusion was the limiting step. The Freundlich model was utilized to better simulate the isothermal adsorption behavior, indicating the adsorption under chemical action. The adsorption thermodynamics showed that the removal process was a chemical, spontaneous and endothermic reaction. The removal mechanisms were as follows: (i) the protonated TLBC-nZVI adsorbed anionic Cr(VI) by electrostatic interaction under acidic conditions; (ii) Fe0, Fe(II), and some surface functional groups (such as –NH2 and –OH) reduced Cr(VI) to Cr(III); and (iii) Cr(III) were removed through complexation, physical adsorption and coprecipitation. The finding can be served as a potential theoretical reference for the resource utilization of pruned tea wastes and the remediation of heavy metal pollution in water. [ABSTRACT FROM AUTHOR]

Odor pollution has become one of the important environmental problems in China. In this study, Gas Chromatography Ion Mobility Spectrometry (GC-IMS), Gas Chromatography Mass Spectrometer (GC-MS) and Flame Ionization Detector (FID) were combined to obtain comprehensive information of the odor produced during the production of Captan, a common pesticide, and to evaluate the efficiency of the odorant treatment techniques utilized by the manufacturer studied. Based on our findings, refining, an important phase during the production process of Captan, was found to be the most important factor in determining the type and the concentration of the odorant produced. Of the odorants found during the production process, perchloromethylmercaptan (CCl 3 SCl) and other chlorine-containing compounds are the key odorants during the production process based on the calculation of odor activity value (OAV). The current odorant treatment utilized by the manufacturer studied showed about 40 % removal rate. However, the odorant treatment produced a new odorant, dimethyl disulfide. Therefore, a much more targeted odorant treatment technique without the production of new odorants is desired and should be utilized. [Display omitted] [ABSTRACT FROM AUTHOR]

Photooxidants drive many atmospheric chemical processes. The photoexcitation of light-absorbing organic compounds (i.e., brown carbon (BrC)) in atmospheric waters can lead to the generation of reactive organic triplet excited states (3C∗), which can undergo further reactions to produce other photooxidants such as singlet oxygen (1O2). To determine the importance of these aqueous photooxidants in SOA formation and transformation, we must know their steady-state concentrations and quantum yields. However, there has been limited measurements of aqueous 3C∗ and 1O2 in atmospheric samples outside of North America and Europe. In this work, we report the first measurements of the steady-state concentrations and quantum yields of 3C∗ and 1O2 produced in aerosols in South China. We quantified the production of 3C∗ and 1O2 in illuminated aqueous extracts of PM2.5 collected in different seasons at two urban sites and one coastal semi-rural site during a year-round study conducted in Hong Kong, South China. The mass absorption coefficients at 300 nm for BrC in the aqueous PM2.5 extracts ranged from 0.49 × 104 to 2.01 × 104 cm2 g-C−1 for the three sites. Both 1O2 and 3C∗ were produced year-round. The steady-state concentrations of 1O2 ([1O2]ss) in the illuminated aqueous extracts spanned two orders of magnitude, ranging from 1.56 × 10−14 to 1.35 × 10−12 M, with a study average of (4.02 ± 3.52) × 10−13 M. The steady-state concentrations of 3C∗ ([3C∗]ss) in the illuminated aqueous extracts spanned two orders of magnitude, ranging from 2.93 × 10−16 to 8.08 × 10−14 M, with a study average of (1.09 ± 1.39) × 10−14 M. The [1O2]ss and [3C∗]ss correlated with the concentration and absorbance of BrC, thus implying that the amount of BrC drives the steady-state concentrations of these photooxidants. The locations (urban vs. semi-rural) did not have a significant effect on [3C∗]ss and [1O2]ss, which indicated that BrC from local sources did not have a significant influence on the year-round 3C∗ and 1O2 production. 3C∗ and 1O2 production were found to be the highest in winter and the lowest in summer for all three sites. The observed seasonal trends of 1O2 and 3C∗ production could be attributed to the seasonal variations in long-range air mass transport. Our analysis highlighted the key role that regional sources play in influencing the composition and concentrations of water-soluble BrC in winter PM2.5 in Hong Kong, which contributed to their highest 3C∗ and 1O2 production. The current results will be useful for modeling seasonal aqueous organic aerosol photochemistry in the South China region. [ABSTRACT FROM AUTHOR]

Radioactive cobalt release poses concerns since the attention to radiation safety. In this work, soil and groundwater sampled from the surroundings of the long-distance pipeline of a proposed nuclear power plant were used to assess radiation safety by studying Co(II) adsorption. The Freundlich and Langmuir models fitted the experimental data well. The results indicated that Co adsorption was an entropy-driven, spontaneous, endothermic and chemical process. The adsorption mechanism was mainly the inner-sphere complexation, and CoSO4(aq) contributed to the partially reversible occurrence. This study provided fundamental information about the environmental behaviours and adsorption mechanism of radioactive Co(II) surrounding the effluent pipeline. [ABSTRACT FROM AUTHOR]

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This work investigated seasonal variation of aerosol iron (Fe) solubility for coarse (>1 µ m) and fine (<1 µ m) particles at Xi'an, a megacity in northwestern China impacted by anthropogenic emission and desert dust. Total Fe concentrations were lowest in summer and were similar in other seasons for coarse particles but lowest in summer and highest in spring for fine particles; for comparison, dissolved Fe concentrations were higher in fall and winter than spring and summer for coarse particles but highest in winter and lowest in spring and summer for fine particles. Desert-dust aerosol was always the major source of total Fe for both coarse and fine particles in all four seasons, but it may not be the dominant source of dissolved Fe. Fe solubility was lowest in spring for both coarse and fine particles and highest in winter for coarse particles and in fall for fine particles. In general, aerosol Fe solubility was found to be higher in air masses originating from local and nearby regions than those arriving from desert regions after long-distance transport. Compared to coarse particles, Fe solubility was similar for fine particles in spring but significantly higher in the other three seasons, and at a given aerosol pH range, Fe solubility was always higher in fine particles. Aerosol Fe solubility was well correlated with relative abundance of aerosol acidic species, implying aerosol Fe solubility enhancement by acid processing; moreover, such correlations were better for coarse particles than fine particles in all four seasons. Fe solubility was found to increase with relative humidity and acid acidity for both coarse and fine particles at Xi'an, underscoring the importance of aerosol liquid water and aerosol acidity in regulating Fe solubility via chemical processing. [ABSTRACT FROM AUTHOR]

The Artemisia argyi Lévl. et Van. growing in the surrounding areas of Qichun County in China are called Qiai (QA). Qiai is a crop that can be used both as food and in traditional folk medicine. However, detailed qualitative and quantitative analyses of its compounds remain scarce. The process of identifying chemical structures in complex natural products can be streamlined by combining UPLC-Q-TOF/MS data with the UNIFI information management platform and its embedded Traditional Medicine Library. For the first time, 68 compounds in QA were reported by the method in this study. The method of simultaneous quantification of 14 active components in QA using UPLC-TQ-MS/MS was reported for the first time. Following a screening of the activity of QA 70% methanol total extract and its three fractions (petroleum ether, ethyl acetate, and water), it was discovered that the ethyl acetate fraction enriched with flavonoids such as eupatilin and jaceosidin had the strongest anti-inflammatory activity, while the water fraction enriched with chlorogenic acid derivatives such as 3,5-di-O-caffeoylquinic acid had the strongest antioxidant and antibacterial activity. The results provided the theoretical basis for the use of QA in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

This paper investigates weathering pits at three granite sites located on mountain tops, in a former river bed, and on the coastline of an island, respectively, from north to south in eastern China and aims to characterize weathering pit formation in the above settings in terms of mineral weathering and elemental transport. In these settings, the main elements, and mineral groups in the debris in the weathering pits and the fragments of the rock surface directly adjacent to the pits were analyzed. The chemical index of alteration (CIA), the quartz/feldspar (Q/F) ratio and the Na/K (Na2O/K2O) ratio were applied to identify the chemical origin of the weathering pits and assess the difference in the chemical weathering processes of the weathering pits in the different settings; the mass transfer coefficient was used to measure the characteristics of element migration during weathering pit formation at the three sites. The result of CIA, Q/F, and Na/K analysis shows that debris in a weathering pit suffered from higher chemical weathering intensity than nearby rock surfaces, indicating that the weathering pits of the study sites originated from chemical weathering. However, the differences in the CIA values of weathering pits in different areas are only the result of different chemical weathering durations and cannot be used to identify the climate types of the areas. The calculation of element mass transfer indicates that only Na and K are continuously leached during the formation process of weathering pits regardless of whether in valleys, mountains or on the coast. Other elements may or may not be the external source for the formation of weathering pits resulting in different natural tendencies for element mass transfer in weathering pits. Seawater can also be a factor contributing to the different patterns of element migration in weathering pits in coastal and inland areas. In addition, the environment of river valleys is more conducive to weathering pit formation than mountain tops. [ABSTRACT FROM AUTHOR]

Reservoir dams alter the nutrient composition and biogeochemical cycle. Thus, dual isotopes of δ18O-NO3− and δ15N-NO−3 and geochemical signatures were employed to study the NO3− pollution and chemical weathering in the Three Gorges Reservoir (TGR), China. This study found that the TGR dam alters the δ15N-NO3− composition and is enriched in the recharge period. Values of δ15N-NO3− varied from 4.5 to 12.9‰ with an average of 9.8‰ in the recharge period, while discharge period δ15N-NO3− ranged from 3.2 to 12.5‰, with an average of 9.3‰. δ18O-NO3− varies (1.2–11.3‰) with an average of 6.5‰ and (2.4–12.4‰) with an average of 7.5‰, in the recharge and discharge periods, respectively. Stable isotopic values sharply decreased from upstream to downstream, indicating the damming effects. δ18O-NO3− and δ15N NO3− confirm that sewage effluents, nitrification of soil organic material, and NH4+ fertilizers were the primary sources of NO3− in the reservoir. Carbonate weathering mainly provides ions to the reservoir. HCO3− + SO42− and Ca2+ + Mg2+ represent 90% of major ions in the TGR. Downstream sampling sites showed low solute concentration during the recharge period, indicating the dam effect on solute concentration. Ca–Mg–Cl−, Ca–HCO3− and Ca–Cl− were the main water types in the TGR. The average percentage of solutes contribution revealed the carbonate weathering, evaporites dissolution, silicate weathering, and atmospheric input were 51.9%, 41%, 7.8%, and 1.7% for the recharge period. In contrast, the discharge period contributed 66.4%, 29.2%, 10%, and 4.3%, respectively. TGR water is moderately suitable for irrigation, and hardness is high in drinking water. This study provides new insight into the dual isotopic approach and geochemical signatures to interpret the NO3− cycle and chemical weathering process under dam effects in the TGR. However, this isotopic application has some limitations in source identification, isotope fractionation, and transformation mechanisms of nitrate. Thus, further studies need to be done on these topics for a better undestanding. [ABSTRACT FROM AUTHOR]

In recent years, ground‐level ozone (O3) has been one of the main pollutants hindering air quality compliance in China's large city‐clusters including the Yangtze River Delta (YRD) region. In this work, we utilized the process analysis (PA) and the higher‐order decoupled direct method (HDDM‐3D) tools embedded in the Community Multiscale Air Quality model (CMAQ) to characterize O3 formation and sensitivities to precursors during a typical O3 pollution episode over the YRD region in July 2018. Results indicate that gas‐phase chemistry contributed dominantly to the ground‐level O3 although a significant proportion was chemically produced at the middle and upper boundary layer before reaching the surface via diffusion process. Further analysis of the chemical pathways of O3 and Ox formation provided deep insights into the sensitivities of O3 to its precursors that were consistent with the HDDM results. The first‐order sensitivities of O3 to anthropogenic volatile organic compounds (AVOC) were mainly positive but small, and temporal variations were negligible compared with those to NOx. During the peak O3 time in the afternoon, the first‐ and second‐order sensitivities of O3 to NOx were significantly positive and negative, respectively, suggesting a convex response of O3 to NOx over most areas including Shanghai, Hangzhou, Nanjing and Hefei. These findings further highlighted an accelerated decrease in ground‐level O3 in the afternoon corresponding to continuous decrease of NOx emissions in the afternoon. Therefore, over the YRD region including its metropolises, NOx emission reductions will be more important in reducing the afternoon peak O3 concentration compared with the effect of VOC emission control alone. Plain Language Summary: Ground‐level ozone (O3) is formed primarily from photochemical reactions between volatile organic compounds (VOCs) and nitrogen oxides (NOx). Besides, O3 and other pollutants also frequently undergo various other processes such as vertical/horizontal transport and deposition. These chemical and physical processes cause the complexity of O3 formation and pose challenges to its mitigation. For instance, in the Yangtze River Delta (YRD) region of eastern China, ground‐level O3 has been among the main pollutants hindering air quality compliance. In this study, advanced modeling techniques based on the state‐of‐science community multiscale air quality model were utilized to understand at a regional scale the nonlinear response of O3 to NOx and VOCs, as well as to explore the contributions of these processes to O3 during the pollution episode between 24th and 31th July 2018 over this region. The results emphasized that O3 sensitivity to NOx was high and positive in the afternoon over most areas including the urban cores. This strongly indicates that NOx emission reductions could be an important way to reduce peak O3 and the more the reduction of NOx, the faster the decrease of peak O3. These findings provide important insights into the formulation of policies and regulations to mitigate O3 pollution. Key Points: The O3 chemically produced in the zone above 40 m contributed significantly to the surface O3 through vertical transportO3 sensitivity to NOx was high and positive in the afternoon over most of Yangtze River Delta region, including urban areasControlling NOx emissions is an important way to reduce peak O3, and the more NOx is reduced, the faster the decrease of peak O3 [ABSTRACT FROM AUTHOR]

In this study, the influence of pH on the moisture-absorbing swelling cracks of red mudstone in southwest China was studied and its microscopic mechanism was revealed. A self-designed water absorption device combined with digital speckle correlation (DSCM), scanning electron microscope, XRD diffraction experiment, mercury injection experiment and other means were used. The results indicated that compared with an alkaline environment, an acidic environment resulted in the self-absorption and cracking of mudstone. The maximum water absorption rate of mudstone and crack rate in a pH of 3 were determined as 15.77 and 18.91%, respectively; whereas for pH = 11, they were 11.71 and 7.11%, respectively. In the acidic environment, the maximum combined displacement value and maximum principal strain value of mudstone self-priming and swelling evolution were both greater than in an alkaline environment. Simultaneously, in the former, the moisture absorption failure characteristics of mudstone exhibited increased swelling strain zones and swelling cores. The three possible mechanisms by which pH affects the expansion of mudstone hygroscopic cracks were proposed: hydration-expansion softening, adsorption-wedge failure, and humidity stress field. However, it was found that the solutions with different pH values may affect these three microscopic mechanisms through the following four physical or chemical processes: mineral dissolution, ion absorption and exchange, particle association, and pore change. The results of this study are expected to be of significance and aid in roadbed design, tunnel support, slope treatment, and other projects in the southwest region. [ABSTRACT FROM AUTHOR]

The Pushi area of South‐west China features a large area of purple soil that formed by the weathering of Cretaceous terrigenous clastic rocks. In this study, four vertical profiles of the purple soil (P1, P2, P3, and P4) derived from different pedogenic parent rocks were investigated. Specifically, the chemical weathering intensity and element migration, enrichment, and differentiation characteristics were analysed and the influencing factors of chemical weathering were explored. According to the discrimination map of major and trace elements and content characteristics of rare earth elements, the soil profiles are controlled by complex chemical weathering processes. Various geochemical parameters and indicators exhibited good correlation, and the chemical weathering intensity of the profiles followed the order P1 (mudstone) > P3 (silty mudstone) > P4 (argillaceous siltstone) > P2 (sandstone). The overall chemical weathering intensity of argillaceous rocks was slightly higher than that of sandstone, and the four profiles generally reflected medium to strong chemical weathering. The migration, enrichment, and differentiation characteristics of geochemical elements were found to be mainly affected by different chemical weathering intensities and stages, followed by leaching deposition. The chemical weathering characteristics varied for the four profiles with different pedogenic parent rocks, which could be mainly attributed to internal factors such as the lithology of the pedogenic parent rock and external topographic factors such as altitude. [ABSTRACT FROM AUTHOR]

Scrophulariae Radix (SR) is one of the oldest and most frequently used Chinese herbs for oriental medicine in China. Before clinical use, the SR should be processed using different methods after harvest, such as steaming, "sweating", and traditional fire-drying. In order to investigate the difference in chemical constituents using different processing methods, the two-dimensional (2D) 1H-13C heteronuclear single quantum correlation (1H-13C HSQC)-based metabolomics approach was applied to extensively characterize the difference in the chemical components in the extracts of SR processed using different processing methods. In total, 20 compounds were identified as potential chemical markers that changed significantly with different steaming durations. Seven compounds can be used as potential chemical markers to differentiate processing by sweating, hot-air drying, and steaming for 4 h. These findings could elucidate the change of chemical constituents of the processed SR and provide a guide for the processing. In addition, our protocol may represent a general approach to characterizing chemical compounds of traditional Chinese medicine (TCM) and therefore might be considered as a promising approach to exploring the scientific basis of traditional processing of TCM. [ABSTRACT FROM AUTHOR]

Haze is the phenomenon of visibility degradation caused by extinction effects related to the physicochemical properties of atmospheric particulate matter (APM). Atmosphere heterogeneous reactions can alter the physicochemical properties of APM. Therefore, it is important to understand the atmospheric heterogeneous reactions of APM in order to reveal the cause of haze. Herein, the current situation, developmental trend, source, and composition of APM pollution in China are reviewed. Additionally, we introduce the reaction characteristics and key chemical processes of common inorganic, organic, and mixed pollutant gases on the surface of mineral particles. The effects of mineral particulate matter on aggregation, regulation, and catalysis in the formation of atmospheric aerosols and the synergistic reaction mechanism of SO2, NO2, O3, and VOCs on the surfaces of different mineral particles are summarized. The problems existing in the current research on heterogeneous reactions on the surfaces of mineral particles are also evaluated. This paper aims to gain a deep understanding of the mechanism of mineral particulate matter promoting the formation of secondary aerosols and attempts to provide theoretical support for effective haze control. [ABSTRACT FROM AUTHOR]

In spite of the fact that rock weathering performs an essential task in the evolution of the Earth's surface, the quantitative assessment between pH and rates of chemical weathering remain unclear. This study aims to characterize the chemical weathering rate of purple rocks and then develops a model to calculate the release rates of cations (K+, Na+, Ca2+ and Mg2+) under various pH conditions. Two types of purple rock were sampled from the Shaximiao Group (J2s) and Penglaizhen Group (J3p), and a series of laboratory experiments were performed by soaking the purple rocks in solutions with pHs from 2.5 to 7.0, over 24 treatment cycles. The results showed that the release rates of cations apparently increased as the pH decreased. The release of Ca2+ was the dominant process of chemical weathering in J3p under various pH treatments, while K+ and Na+ were remarkably high in J2s (with the exception of the pH 2.5 treatment). Quantitative analysis revealed that the rate of cation release was significantly related to the H+ concentration (p < 0.001) and the air temperature (p < 0.001). The relationship between cation release and acidity was found to be an exponential function. Our results suggested that solution acidity serves as an important driving force for cation release rates from purple rocks and that environmental acidification would enhance rock weathering. [ABSTRACT FROM AUTHOR]

Silver-bearing manganese ore (Mn-Ag ore) is an important resource for the extraction of the precious metal Ag. However, the efficient and economical utilization of low-grade Mn-Ag ore poses challenges due to its polymetallic co-occurrence, complex associated mineral structures, and lower Ag grade compared to an industrial Ag grade of 80 g/t. In contrast, the Ag grade of commercially viable concentrate, achieved through physicochemical beneficiation, generally exceeds 1000 g/t. This work briefly discusses the metallogeny and resource characteristics and the processing technologies of Mn-Ag ore to produce high grade Ag concentrates. Based on the metallogeny characteristics of Mn-Ag deposits, this work delves into the challenges and difficulties in the physical separation of Ag and Mn. By regulating the differences in the chemical properties of Mn and Ag constituents, chemical beneficiation processes, including unit operations of pyrometallurgy and hydrometallurgy, result in favorable Ag and Mn enrichment and separation. The chemical principles, technical parameters, Mn-Ag separation efficiency, and advantages and disadvantages of chemical beneficiation (blast furnace smelting, chlorination roasting, one-step leaching, and two-step leaching) were systematically summarized and discussed. This work can provide theoretical and technical guidance for the effective treatment of low-grade Mn-Ag ores. [Display omitted] • Diverse processes for pyro- and hydro- separation of Ag and Mn are reviewed. • Metallurgical properties of Mn-Ag ores and the characteristics of silver resources are introduced. • Separation methods based on the differences in reduction, volatility, fusibility and selective solubility are highlighted. • Advantages and disadvantages of separation methods for Ag and Mn are discussed. [ABSTRACT FROM AUTHOR]

Sediments in deltaic tidal flats regulate physical and chemical processes. Grain‐size distribution plays an important role in determining sediment dynamics and substrate properties. However, it is challenging to quantify large‐scale depositional environments in intertidal flats, due to time‐consuming grain‐size analyses and sparse sedimentary information extracted from scattered sediment samples. In this study, a novel terrestrial laser scanner (TLS) based method was developed to characterize the substrate of an intertidal flat. Surface sediment samples in the Nanhui flats in the Yangtze Delta, China, and the corresponding waveform amplitudes of TLS echoes at fixed sampling sites were collected for a total of 22 months. A negative logarithmic relationship was found between the sediment sand fraction, average grain size, D50, and corrected waveform amplitude of TLS echo in different hydro‐meteorological conditions. The mean of average grain size of five sediment sampling sites along a transect was 58.78 μm when measured by traditional grain‐size analysis, and 49.48 μm when calculated with the proposed logarithmic equation. The mean error at each site was up to 21.77%. The mean error for the sand and silt fraction at each location was as high as 27.28% and 21.75%, respectively. The spatial distribution pattern of TLS‐based average grain size in the entire study area was consistent with the measured pattern with a Root Mean Square Error of 13.83 μm. These errors could be caused by the accuracy of the TLS waveform amplitude correction and by limits of the method in recognizing different substrates. The effects produced by the presence of microphytobenthos (for example, cyanobacterial mats or diatom biofilms) or bedforms have not been investigated and may have affected the results. The TLS‐based grain‐size measurements can rapidly and effectively discriminate sediment characteristics, thus avoiding traditional time‐consuming measurements. It is expected that the TLS‐based method proposed here will have wide applications in shoreline studies, especially in inaccessible tidal flats. [ABSTRACT FROM AUTHOR]

Geological processes alter pore spaces over time, and their analysis can shed light on the dynamic fractal structure and fluid flow of rocks over time. This study presents experimental evidence to illustrate that the pore fractal structure evolves with sedimentation, carbonate cementation, clay growth, and dissolution. It examines, describes and characterizes a suite of core samples from the Gaotaizi oil layer of the second and third members of the Qingshankou Formation, Songliao Basin, China. The effects of mechanical compaction and other diagenesis effects on fractal pore structure on sedimentary rocks are discussed. A schematic diagram is proposed that describes the impacts of these diagenetic processes on fractal pore structure at the microscopic scale in sedimentary rocks. This work links the state of diagenetic alteration and fractal pore structure, which can guide practical applications such as predicting the permeability of sedimentary rocks. Plain Language Summary: Mechanical compaction or chemical alteration process will change the pore space of the rock, including pore size and grain‐pore interface properties. We present the evidence that geological processes alter the "roughness" amplitude of grain‐pore interface (fractal pore structure) in sedimentary rock, and discuss the evolutionary mechanism of the "roughness" amplitude of grain‐pore interface. This work links the state of diagenetic alteration and fractal properties of rocks, which can guide practical applications such as predicting permeability of sedimentary rocks for any historical period. Key Points: Evolution of fractal dimension with diagenesis was revealedEffects of diagenesis on fractal upper and lower limits were discussedEffect mechanism of fractal pore structure was revealed in sedimentary rocks [ABSTRACT FROM AUTHOR]

Relationships between oceanic emissions and air chemistry are intricate and still not fully understood. For regional air chemistry, a better understanding of marine halogen emission on the hydroxyl (OH) radical is crucial. The OH radical is a key species in atmospheric chemistry because it can oxidize almost all trace species in the atmosphere. In the marine atmosphere, OH levels could be significantly affected by the halogen species emitted from the ocean. However, due to the complicated interactions of halogens with OH through different pathways, it is not well understood how halogens influence OH and even what the sign of the net effect is. Therefore, in this study, we aim to quantify the impact of marine-emitted halogens (including Cl, Br, and I) through different pathways on OH in the high OH season by using the WRF-CMAQ model with process analysis and state-of-the-art halogen chemistry in East Asia and near the western Pacific. Results show a very complicated response of the OH production rate (P OH) to marine halogen emissions. The monthly P OH is generally decreased over the ocean by up to a maximum of about 10 %–15 % in the Philippine Sea, but it is increased in many nearshore areas by up to about 7 %–9 % in the Bohai Sea. In the coastal areas of southern China, the monthly P OH could also decrease 3 %–5 %, but hourly values can decrease over 30 % in the daytime. Analysis of the individual reactions using the integrated reaction rate shows that the net change in P OH is controlled by the competition of three main pathways (OH from O 3 photolysis, OH from HO 2 conversion, and OH from HO X , X=Cl , Br, I) through different halogen species. Sea spray aerosol (SSA) and inorganic iodine gases are the major species influencing the strengths of these three pathways and therefore have the most significant impacts on P OH. Both of these two types of species decrease P OH through physical processes, while generally increasing P OH through chemical processes. In the ocean atmosphere, inorganic iodine gases determine the basic pattern of Δ P OH through complicated iodine chemistry, which generally positively influences P OH near O 3 sources while negatively influencing it when O 3 experiences longer transport over the ocean. Over the continent, SSA is the controlling species, and the SSA extinction effect leads to the negative Δ P OH in southern China. Our results show that marine-emitted halogen species have notable impacts over the ocean and potential impacts on coastal atmospheric oxidation by species (SSA, inorganic iodine, and halocarbons), processes (chemistry, radiation, and deposition), and main pathways. The notable impacts of the marine-emitted halogen species on the atmospheric oxidation capacity have further implications for the lifetime of long-lived species such as CH 4 in the long term and the quantity of air pollutants such as O 3 in the episodic events in East Asia and in other circumstances (e.g., different domains, regions, and emission rates). [ABSTRACT FROM AUTHOR]

Tropospheric ozone, as a critical atmospheric component, plays an important role in influencing radiation equilibrium and ecological health. It is affected not only by anthropogenic activities but also by natural climate variabilities. Here we examine the tropospheric ozone changes in China associated with the eastern Pacific (EP) and central Pacific (CP) El Niño using satellite observations from 2007 to 2017 and GEOS-Chem simulations from 1980 to 2017. GEOS-Chem reasonably reproduced the satellite-retrieved lower tropospheric ozone (LTO) changes despite a slight underestimation. In general, both types of El Niño exert negative impacts on LTO concentration in China, except for southeastern China during the pre-CP El Niño autumn and post-EP El Niño summer. Ozone budget analysis further reveals that for both events, LTO changes are dominated by the transport processes controlled by circulation patterns and the chemical processes influenced by local meteorological anomalies associated with El Niño, especially the changes in solar radiation and relative humidity. The differences between EP- and CP-induced LTO changes mostly lie in southern China. The different strengths, positions, and duration of the western North Pacific anomalous anticyclone induced by tropical warming are likely responsible for the different EP and CP LTO changes. During the post-EP El Niño summer, the Indian Ocean capacitor effect also plays an important role in mediating LTO changes over southern China. [ABSTRACT FROM AUTHOR]

Oxaziclomefone is an organic heterocyclic herbicide which has been widely used in rice fields. The aim of this paper is to investigate the adsorption–desorption and migration of oxaziclomefone in four Chinese agricultural soils. All the four soils show high adsorption capacity for oxaziclomefone, with similar adsorption rates at 84.48%–96.70%. Four adsorption kinetic models were used to fit the adsorption kinetic characteristics and the elovich model was the best, indicating that chemical processes were involved in adsorption. For the isothermal adsorption behavior of oxaziclomefone, the Freundlich model shows the best, indicating that the adsorption sites for oxaziclomefone in soil were heterogeneous. The retention factor in the soil thin-layer plates ranges from 0.083 to 0.250 and the retention factor 0–10 cm layer of the soil column was > 50, indicating that the herbicide was not easily migration from all four soils. Because oxaziclomefone has low mobility in different soils and is not easily leached, it poses a low potential threat of contaminating surface water and groundwater. [ABSTRACT FROM AUTHOR]

Anthropogenic emission inventory for aerosols and reactive gases is crucial to the estimation of aerosol radiative forcing and climate effects. Here, the anthropogenic emission inventory for AerChemMIP, endorsed by CMIP6, is briefly introduced. The CMIP6 inventory is compared with a country-level inventory (i.e., MEIC) over China from 1986 to 2015. Discrepancies are found in the yearly trends of the two inventories, especially after 2006. The yearly trends of the aerosol burdens simulated by CESM2 using the two inventories follow their emission trends and deviate after the mid-2000s, while the simulated aerosol optical depths (AODs) show similar trends. The difference between the simulated AODs is much smaller than the difference between model and observation. Although the simulated AODs agree with the MODIS satellite retrievals for country-wide average, the good agreement is an offset between the underestimation in eastern China and the overestimation in western China. Low-biased precursor gas of SO2, overly strong convergence of the wind field, overly strong dilution and transport by summer monsoon circulation, too much wet scavenging by precipitation, and overly weak aerosol swelling due to low-biased relative humidity are suggested to be responsible for the underestimated AOD in eastern China. This indicates that the influence of the emission inventory uncertainties on simulated aerosol properties can be overwhelmed by model biases of meteorology and aerosol processes. It is necessary for climate models to perform reasonably well in the dynamical, physical, and chemical processes that would influence aerosol simulations. [ABSTRACT FROM AUTHOR]

The demand together with the urgency of phosphogypsum (PG) treatment will pose significant challenges for many countries. This research aims to explore the research progress of PG, including basic status, cooperation situation, research fields, and development trends, based on the Web of Science database through bibliometric analysis of publications (articles and patents) from 1990 to 2020. The results show that academic research on PG originated early, but the number of patents grew quickly. China is a global leader in terms of the number of publications and plays a significant role in international cooperation. The knowledge of PG has remained concentrated in the fields of natural radioactivity, cement paste backfilling, soil, crystal morphology, and synthetic gas. However, academic hotspots focus on the microstructure of chemical processes and various environmental impacts; patents and hot technologies are based on the production of refractory materials, ceramics, surface materials, cement mortar, and composite materials. The academic frontiers of PG will be centered on exploiting the methods of recovering rare earth elements from PG, the conditions of ion solidification/stabilization in PG, the impact of reaction conditions on product quality, and the reaction mechanism at the micro-level. The frontiers of patents need to focus on the improvement of manufacturing equipment, new wall materials, and chemically modified polymer materials. Envisaging the number of articles and patents to be published in the future, architectural research has a large room for improvement. This paper conducts an in-depth analysis of PG and provides information on the technological development prospects and opportunities, which is helpful for researchers engaged in PG management. [ABSTRACT FROM AUTHOR]

Correct description of the boundary layer mixing process of particle is an important prerequisite for understanding the formation mechanism of pollutants, especially during heavy pollution episodes. Turbulent vertical mixing determines the distribution of momentum, heat, water vapor and pollutants within the planetary boundary layer (PBL). However, what is questionable is that the turbulent mixing process of particles is usually denoted by turbulent diffusion of heat in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). With mixing-length theory, the turbulent diffusion relationship of particle is established, embedded into the WRF-Chem and verified based on long-term simulations from 2013 to 2017. The new turbulent diffusion coefficient is used to represent the turbulent mixing process of pollutants separately, without deteriorating the simulation results of meteorological parameters. The new turbulent diffusion improves the simulation of pollutant concentration to varying degrees, and the simulated results of PM 2.5 concentration are improved by 8.3 % (2013), 17 % (2014), 11 % (2015) and 11.7 % (2017) in eastern China, respectively. Furthermore, the pollutant concentration is expected to increase due to the reduction of turbulent diffusion in mountainous areas, but the pollutant concentration did not change as expected. Therefore, under the influence of complex topography, the turbulent diffusion process is insensitive to the simulation of the pollutant concentration. For mountainous areas, the evolution of pollutants is more susceptible to advection transport because of the simulation of obvious wind speed gradient and pollutant concentration gradient. In addition to the PM 2.5 concentration, the concentration of CO as a primary pollutant has also been improved, which shows that the turbulent diffusion process is extremely critical for variation of the various aerosol pollutants. Additional joint research on other processes (e.g., dry deposition, chemical and emission processes) may be necessary to promote the development of the model in the future. [ABSTRACT FROM AUTHOR]

As one of the most important staple crops in China,wheat production target both high yield and high quality is very essential to simultaneously meeting the demands for food security and life quality. It has been found that both contents of key chemicals and processing quality vary greatly within different layers of wheat kernels. This provides a potential approach to achieve both high-yield and high-quality of wheat. In this paper,we detailly reviewed the spatial distributions of protein and its components,starch,dietary fiber and microelements. We further discussed the underlying mechanisms on the formation of protein and starch spatial distribution in the views of supply of substrate and synthetic capacity of protein and starch. The paper also summarized the regulation effects of cultivation practices on quality spatial distribution. Finally,we proposed the breakthrough solutions for exploring the underlying mechanisms on quality spatial distribution. This paper will provide research views for achieving the production of wheat with both high yield and high quality. [ABSTRACT FROM AUTHOR]

Biogenic volatile organic compounds (BVOCs) simulated by current air quality and climate models still have large uncertainties, which can influence atmospheric chemistry and secondary pollutant formation. These modeling sensitivities are primarily due to two sources. One originates from different treatments in the physical and chemical processes associated with the emission rates of BVOCs. The other is errors in the specification of vegetation types and their distribution over a specific region. In this study, the version of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) updated by the University of Science and Technology of China (USTC version of WRF-Chem) from the public WRF-Chem(v3.6) is used. The modeling results over eastern China with different versions (v1.0, v2.0, v3.0) of the Model of Emissions of Gases and Aerosols from Nature (MEGAN) in WRF-Chem are examined or documented. Sensitivity experiments with these three versions of MEGAN and two vegetation datasets are conducted to investigate the difference of three MEGAN versions in modeling BVOCs and its dependence on the vegetation distributions. The experiments are also conducted for spring (April) and summer (July) to examine the seasonality of the modeling results. The results indicate that MEGAN v3.0 simulates the largest amount of biogenic isoprene emissions over eastern China. The different performance among MEGAN versions is primarily due to their different treatments of applying emission factors and vegetation types. In particular, the results highlight the importance of considering the sub-grid vegetation fraction in estimating BVOC emissions over eastern China, which has a large area of urbanization. Among all activity factors, the temperature-dependent factor dominates the seasonal change of activity factor in all three versions of MEGAN, while the different response to the leaf area index (LAI) change determines the difference among the three versions in seasonal variation of BVOC emissions. The simulated surface ozone concentration due to BVOCs can be significantly different (ranging from 1 to more than 10 ppbv in some regions) among the experiments with three versions of MEGAN, which is mainly due to their impacts on surface VOCs and NO x concentrations. Theoretically MEGAN v3.0 that is coupled with the land surface scheme and considers the sub-grid vegetation effect should overcome previous versions of MEGAN in WRF-Chem. However, considering uncertainties of retrievals and anthropogenic emissions over eastern China, it is still difficult to apply satellite retrievals of formaldehyde and/or limited sparse in situ observations to constrain the uncertain parameters or functions in BVOC emission schemes and their impacts on photochemistry and ozone production. More accurate vegetation distribution and measurements of biogenic emission fluxes and species concentrations are still needed to better evaluate and optimize models. [ABSTRACT FROM AUTHOR]

Sewage treatment is an important public service, but it consumes a lot of energy and chemicals in the process of removing wastewater pollutants, which may cause the risk of pollution transfer. To find the corresponding hot issues, this paper took the lead in integrating life cycle assessment (LCA) with life cycle costing (LCC) to evaluate four most typical sewage treatment technologies with more than 85% share in China. It is found that anaerobic/anoxic/oxic (AAO) was the optimal treatment scheme with relatively small potential environmental impact and economic load. The normalized results show that the trends of the four technologies on eleven environmental impact categories were basically the same. Marine aquatic ecotoxicity potential accounted for more than 70% of the overall environmental impact. Contribution analysis indicates that electricity and flocculant consumption were the main processes responsible for the environmental and economic burden. Overall, electricity consumption was the biggest hot spot. Sensitivity analysis verifies that a 10% reduction in electricity could bring high benefits to both the economy and the environment. These findings are expected to provide effective feedback on the operation and improvement of sewage treatment. [ABSTRACT FROM AUTHOR]