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The lithium (Li) metal anode is an integral component in an emerging high-energy-density rechargeable battery. A composite Li anode with a three-dimensional (3D) host exhibits unique advantages in suppressing Li dendrites and maintaining dimensional stability. However, the fundamental understanding and regulation of solid electrolyte interphase (SEI), which directly dictates the behavior of Li plating/stripping, are rarely researched in composite Li metal anodes. Herein, the interaction between a polar polymer host and solvent molecules was proposed as an emerging but effective strategy to enable a stable SEI and a uniform Li deposition in a working battery. Fluoroethylene carbonate molecules in electrolytes are enriched in the vicinity of a polar polyacrylonitrile (PAN) host due to a strong dipole–dipole interaction, resulting in a LiF-rich SEI on Li metal to improve the uniformity of Li deposition. A composite Li anode with a PAN host delivers 145 cycles compared with 90 cycles when a non-polar host is employed. Moreover, 60 cycles are demonstrated in a 1.0 Ah pouch cell without external pressure. This work provides a fresh guidance for designing practical composite Li anodes by unraveling the vital role of the synergy between a 3D host and solvent molecules for regulating a robust SEI.

The lithium-sulfur (Li-S) battery is regarded as a promising secondary battery. However, constant parasitic reactions between the Li anode and soluble polysulfide (PS) intermediates significantly deteriorate the working Li anode. The rational design to inhibit the parasitic reactions is plagued by the inability to understand and regulate the electrolyte structure of PSs. Herein, the electrolyte structure of PSs with anti-reductive solvent shells was unveiled by molecular dynamics simulations and nuclear magnetic resonance. The reduction resistance of the solvent shell is proven to be a key reason for the decreased reactivity of PSs towards Li. With isopropyl ether (DIPE) as a cosolvent, DIPE molecules tend to distribute in the outer solvent shell due to poor solvating power. Furthermore, DIPE is more stable than conventional ether solvents against Li metal. The reactivity of PSs is suppressed by encapsulating PSs into anti-reductive solvent shells. Consequently, the cycling performance of working Li-S batteries was significantly improved and a pouch cell of 300 Wh kg-1 was demonstrated. The fundamental understanding in this work provides an unprecedented ground to understand the electrolyte structure of PSs and the rational electrolyte design in Li-S batteries.

This paper considers the time difference of arrival (TDOA) and frequency difference of arrival (FDOA) estimation problem for joint localization using unmanned aerial vehicles (UAVs), involving range migration (RM) and Doppler ambiguity within observation interval. A robust estimation method based on interpolation and resampling is proposed. Specifically, the interpolation artificially increases the pulse repetition frequency (PRF). After that, the resampling eliminates the coupling between range frequency and slow time. Finally, a coherent integration step based on inverse discrete Fourier transform (IDFT) is used to achieve parameter estimation and suppress the grating lobes caused by interpolation. The proposed method could be efficiently implemented by fast Fourier transform (FFT), inverse FFT (IFFT) and non-uniform FFT (NUFFT) without parameter searching procedures. Numerical experiments indicate that the proposed method has nearly optimal anti-noise performance but much lower computational complexity than the maximum likelihood estimator, which makes it more competitive in practical applications.

The lithium–sulfur (Li–S) battery has raised great expectations as a next-generation high-energy-density energy storage system. The multielectron dissolution–precipitation redox conversion of S affords a great contribution to its high specific energy. Spontaneously, the highly reactive Li metal anode always confronts soluble Li polysulfides (LiPSs) in a working Li–S battery, and parasitically side reactions occur inevitably. The challenges of the Li metal anode induced by soluble LiPSs emerge as roadblocks for practical Li–S batteries with the development of the S cathode from its infancy into growth stage. Therefore, the fundamental understanding of Li anode in the electrolyte with LiPSs and the targeted protection strategies are urgently required. In this review, the challenges of the Li metal anode in the presence of LiPSs are systematically analyzed. Then, the preliminary advances in Li metal anode protection to deal with LiPSs are summarized. Finally, an insightful outlook is put forward through both a fundamental understanding and a practical exploration of the Li metal anode to promote the development of practical Li–S batteries.

Lithium (Li) metal attributes to the promising anode but endures the low Columbic efficiency (CE) and safety issues from the inactive Li accumulation. The metallic Li which is isolated from the lithium anode (named dead Li0) consists the major component of the inactive Li. We systematically and meticulously investigated the formation and evaluation of dead Li0 during stripping process from electron transfer, the oxidation of Li0 to Li+ and the diffusion of Li+ through solid electrolyte interphase (SEI). The above-mentioned processes were regulated by adjusting the contact sites of electron channels, the dynamic rate of conversion from Li0 to Li+, and the structure as well as components of SEI. The design principles for achieving less dead Li0 and higher CE are proposed as a proof of concept in lithium metal batteries. This new insight sheds a comprehensive light on dead Li0 formation and guides the next-generation safe batteries for future application.

Severe soil erosion occurs on the Loess Plateau in China, which makes the Yellow River the most sediment-laden river in the world. Construction of about 60,000 sediment check dams has remarkably controlled soil erosion on the Loess Plateau and reduced the sediment load of the middle and lower Yellow River. Nonetheless, little is known about the mechanism of erosion control and vegetation development of sediment check dams. The function of a single check dam mainly is trapping sediment, while the function of a train of check dams comprising dozens of or over hundreds of check dams in a gully encompasses controlling bed incision and reducing erosion energy. A formula was proposed to calculate the potential energy of bank failure and slope failure in a gully, which essentially constitutes the erosion energy. The erosion energy increases when gully incision occurs, which is induced by the incision of the Yellow River and its tributaries on the Loess Plateau. Sediment deposition in many gullies due to construction of check dams reduces the erosion energy to almost zero, which in turn greatly reduces soil erosion and sediment yield. Construction of check dams promotes vegetation development. The vegetation-erosion dynamics model was used to study the effect of check dams on vegetation development. Simulation results show that reforestation without check dam construction might result in an increase of vegetation cover in the first ten years and then a drop of vegetation cover to less than 10% in the later years. The check dams provide a foundation for vegetation development.

International audience; New alkylimidazoles functionalized with a homoserine lactone or an alkyloxycarbonyl moiety have been synthesized as N-acylhomoserine lactones (AHL) analogues. The 1,4-disubstituted imidazole derivatives were prepared by alkylation of 4(5)alkylimidazoles with α-bromo-γ-butyrolactone or ethyl α-bromoacetate. An alternative route was preferred for the synthesis of their 1,5-disubstituted counterparts based on the use of a N1protected alkylimidazole, its alkylation to an N3-imidazolyl-α-acetate and deprotection to the desired 1,5-disubstituted esters and subsequent alkylation of the acetate moiety with cyclic ethylene sulfate followed by acid catalyzed cyclization. The ability to modulate bacterial quorum sensing of all new compounds was compared to that of previously reported AHL analogues in which the amide bond is replaced by a heterocyclic group.

The machinability of hard brittle polycrystalline ceramic has a strong correlation with internal microstructures and their accommodated deformation behavior. In the present work, we investigate the mechanisms governing the brittle-to-ductile transition behavior of polycrystalline 3C–SiC in diamond cutting by means of molecular dynamics simulations. Simulation results reveal the co-existence of dislocation slip and amorphization-dominated ductile deformation and cracking along grain boundaries-mediated brittle fracture, as well as the correlation of individual deformation modes with machining force variation and machined surface morphology. In addition, inter-granular fracture, grain boundary sliding and grain pull-up are also operating brittle deformation modes of polycrystalline 3C–SiC. The strong competition between above heterogeneous deformation modes determines the brittle-to-ductile transition behavior in grooving of polycrystalline 3C–SiC. Simulation results also demonstrate that grain size has a strong impact on the brittle-to-ductile transition and material deformation behavior of polycrystalline 3C–SiC under diamond cutting.

As an important horticultural plant, the orchid is widely distributed in its natural habitat and faces various environmental stresses, among which nutrient recycling and stress resistance are of great concern. During these processes, autophagy is an essential pathway, which is a conserved self-eating process that degrades macromolecular components and recycles cell materials or nutrients during developmental processes or under stress conditions. Two ubiquitin-like systems (UBLs) play a major role in the initiation of autophagy and are associated with two key proteins: ATG8 and ATG12. In this study, we identified and refined the UBL-related genes in orchids and performed phylogenetic reconstruction together with other plant species. We found that the orchid had unique domains in UBL-related genes, indicating potential functional diversification in the ATG8 system in plants. Transcriptome and protein tertiary structure prediction indicated that conserved domains that are vital for the canonical function of ATG12 are incomplete in orchids, in which a novel mechanism of autophagy may have evolved.

Lithium–sulfur (Li–S) batteries have long been expected to be a promising high-energy-density secondary battery system since their first prototype in the 1960s. During the past decade, great progress has been achieved in promoting the performances of Li–S batteries by addressing the challenges at the laboratory-level model systems. With growing attention paid to the application of Li–S batteries, new challenges at practical cell scales emerge as the bottleneck. In this Outlook, the key parameters for practical Li–S batteries to achieve practical high energy density are emphasized regarding high-sulfur-loading cathodes, lean electrolytes, and limited excess anodes. Subsequently, the key scientific problems are redefined in practical Li–S batteries beyond the previous ones under ideal conditions. Finally, viable strategies are proposed to address the above challenges as future research directions., This Outlook emphasizes the key parameters and redefines the fundamental scientific problems of practical Li−S batteries, and further proposes viable strategies to address the emerging challenges as future research directions.

Stable operation at elevated temperature is necessary for lithium metal anode. However, Li metal anode generally has poor performance and safety concerns at high temperature (>55 °C) owing to the thermal instability of the electrolyte and solid electrolyte interphase in a routine liquid electrolyte. Herein a Li metal anode working at an elevated temperature (90 °C) is demonstrated in a thermotolerant electrolyte. In a Li|LiFePO4 battery working at 90 °C, the anode undergoes 100 cycles compared with 10 cycles in a practical carbonate electrolyte. During the formation of the solid electrolyte interphase, independent and incomplete decomposition of Li salts and solvents aggravate. Some unstable intermediates emerge at 90 °C, degenerating the uniformity of Li deposition. This work not only demonstrates a working Li metal anode at 90 °C, but also provides fundamental understanding of solid electrolyte interphase and Li deposition at elevated temperature for rechargeable batteries.

High-energy-density Li metal batteries suffer from a short lifespan under practical conditions, such as limited lithium, high loading cathode, and lean electrolytes, owing to the absence of appropriate solid electrolyte interphase (SEI). Herein, a sustainable SEI was designed rationally by combining fluorinated co-solvents with sustained-release additives for practical challenges. The intrinsic uniformity of SEI and the constant supplements of building blocks of SEI jointly afford to sustainable SEI. Specific spatial distributions and abundant heterogeneous grain boundaries of LiF, LiNx Oy , and Li2 O effectively regulate uniformity of Li deposition. In a Li metal battery with an ultrathin Li anode (33 μm), a high-loading LiNi0.5 Co0.2 Mn0.3 O2 cathode (4.4 mAh cm-2 ), and lean electrolytes (6.1 g Ah-1 ), 83 % of initial capacity retains after 150 cycles. A pouch cell (3.5 Ah) demonstrated a specific energy of 340 Wh kg-1 for 60 cycles with lean electrolytes (2.3 g Ah-1 ).

Lithium–metal batteries (LMBs) comprising a lithium anode and high-specific-capacity manganese (Mn)-based cathode provide a promising high-energy-density system. However, this full cell suffers from poor cycling life under practical conditions. In this contribution, the effect of transition metal ions, e.g., Mn ions, dissolved from the cathode on the failure of lithium anodes was investigated in a working cell. Mn ions are involved in the formation of the solid electrolyte interphase (SEI), inducing the emergence of Mn content and a decrease in the Li2O and LiF components in the SEI; this results in inhomogeneous lithium nucleation. Furthermore, the direct chemical reaction between Mn ions and lithium anodes results in anode corrosion. For the crossover shielding of Mn ions, a graphene-coated separator was proposed to obstruct Mn ions by adsorption for lithium protection, prolonging the lifespan of LMBs under harsh conditions. This study not only highlights the impact of dissolved transition metal ions, such as Mn ions, on the stability of lithium anodes but also affords a practical strategy to shield the crossover of transition metal ions for anodic protection in both present lithium-ion and next-generation batteries.

Adenosine 5'-triphosphate (ATP) is a central extracellular signaling agent involved in various physiological and pathological processes. However, precise measurements of the temporal and spatial components of ATP dynamics are lacking due primarily to the limitations of available methods for ATP detection. Here, we report on the first effort to design a self-phosphorylating DNAzyme (SPDz) sensor for fluorescence imaging of ATP. In response to ATP, SPDz sensors exhibit subsecond response kinetics, extremely high specificity, and micromolar affinities. In particular, we demonstrate cell-surface-anchored SPDz sensors for fluorescence imaging of both stress-induced endogenous ATP release in astrocytes and mechanical stimulation-evoked ATP release at the single-cell level. We also validated their utility for visualizing the rapid dynamic properties of ATP signaling upon electrical stimulation in astrocytes. Thus, SPDz sensors are robust tools for monitoring ATP signaling underlying diverse cellular processes.

Non-layered two-dimensional (2D) carbon complexes manifest great potential in energy-related applications owing to their exotic electronic structures, large electrochemically active surface, and intriguing synergistic effects. However, reliable method for mass production and thickness manipulation of 2D carbon complexes remains great challenges. Here, inspired by blowing chewing gum into bubbles, a “tailored gel expanding” strategy is proposed for high-yield synthesis of non-layered 2D carbon complexes with tailored thickness from ~12 nm to ~1 μm, by controllable pyrolysis of metal-polymeric gel with adequate crosslinking degree. The key feature for thickness manipulation is introducing NH4NO3 in sol–gel process, which tailors the expansion behavior of gel precursor during subsequent pyrolysis. Various of 2D sheets with intimately coupled N,O-doped carbon (NOC) and NiCo-based (NiCo, (NiCo)S2, (NiCo)Se2, NiCo2O4, (NiCo)(PO3)2) nanocrystals are obtained on a large scale and without any impurities. Moreover, these 2D products are branched with in-situ grown CNTs on the surface, accelerating electrons transfer and preventing the nanosheets from stacking. As a demonstration, the 2D (NiCo)S2/NOC with optimized thickness manifests excellent lithium storage properties in both half and full cells. This method paves a new path for massive and controlled production of non-layered 2D materials with tailored thickness and robust structure stability for energy-related applications.

Dose–response modelling was performed for several infectious disease viruses using the exponential, exact beta-Poisson, and approximate beta-Poisson models using existing datasets of animal infections. The exact beta-Poisson model was found to provide the best fit of the three models. The aerosol transmission route was found to require the lowest dose to cause infection compared to the intra-nasal and oral transmission routes for porcine reproductive and respiratory syndrome virus (PRRSV) and H9N2 avian influenza virus. Foot and mouth disease virus required lower doses with the aerosol transmission route than the intra-nasal transmission route. Liquid oral transmission required lower doses than feed transmission to cause infection for African swine fever virus and overall oral transmission required low doses to cause infection by porcine epidemic and diarrhoea virus. A computational fluid dynamics simulation was coupled with the dose–response modelling to simulate aerosol transmission of PRRSV in two experimental case studies. The coupled model predicted a probability of infection between 82% and 100% using the exact beta-Poisson model, which was in good agreement with the observed rate of infections in the two experimental case studies (84% and 90%).

At the post-transcriptional level, microRNAs (miRNAs) play an important role in the regulation of gene expression, thereby influencing the outcome of many biological processes in insects, such as development, reproduction, metamorphosis, immunity, and insecticide resistance. The alteration of miRNA expression by mimic/agomir or inhibitor/antagomir via injection/feeding can lead to pest developmental abnormalities, death, or reduced pesticide resistance, indicating that miRNAs are potential targets for pest control. This review provides an overview of recent advances in understanding the regulatory roles of miRNA in agricultural and public health insect pest, and further highlights the potential of miRNAs as prospective targets in pest control.

Many end-to-end approaches have been proposed to detect predefined keywords. For scenarios of multi-keywords, there are still two bottlenecks that need to be resolved: (1) the distribution of important data that contains keyword(s) is sparse, and (2) the timestamps of the detected keywords are inaccurate. In this paper, to alleviate the first issue and further improve the performance of the end-to-end ASR front-end, we propose the biased loss function for guiding the recognizer to pay more attention to the speech segments containing the predefined keywords. As for the second issue, we solve this problem by modifying the force alignment applied to the end-to-end ASR front-end. To get the frame-level alignment, we utilize a Gaussian Mixture Model-Hidden Markov Model (GMM-HMM) based acoustic model (AM) for auxiliary. The proposed system is evaluated in the OpenSAT20 held by the National Institute of Standards and Technology (NIST). The performance of our end-to-end KWS system is comparable to the conventional hybrid KWS system, sometimes even slightly better. With fusion results of the end-to-end and conventional KWS systems, we won the first prize in the KWS track. On the dev dataset (a part of SAFE-T corpus), the system outperforms the baseline by a large margin, i.e., our system with GMM-HMM aligner has a lower segmentation-aware word error rates (relatively 7.9–19.2% decrease) and higher overall Actual term-weighted values (relatively 3.6–11.0% increase), which demonstrates the effectiveness of the proposed method. For more precise alignments, we can use DNN-based AM as alignmentor at the cost of more computation.

The liver is an important organ for drugs disposition, and thus how to accurately evaluate hepatic clearance is essential for proper drug dosing. However, there are many limitations in drug dosage adjustment based on liver function and pharmacogenomic testing. In this study, we evaluated the ability of endogenous glycochenodeoxycholate-3-sulfate (GCDCA-S) and 4β-hydroxycholesterol (4β-HC) plasma levels to evaluate organic anion-transporting polypeptide (Oatps)-mediated hepatic uptake and Cyp3a-meidated metabolism of atorvastatin (ATV) in rats. The concentration of ATV and its metabolites, 2-OH ATV and 4-OH ATV, was markedly increased after a single injection of rifampicin (RIF), an inhibitor of Oatps. Concurrently, plasma GCDCA-S levels were also elevated. After a single injection of the Cyp3a inhibitor ketoconazole (KTZ), plasma ATV concentrations were significantly increased and 2-OH ATV concentrations were decreased, consistent with the metabolism of ATV by Cyp3a. However, plasma 4β-HC was not affected by KTZ treatment despite it being a Cyp3a metabolite of cholesterol. After repeated oral administration of RIF, plasma concentrations of ATV, 2-OH ATV and 4-OH ATV were markedly increased and the hepatic uptake ratio of ATV and GCDCA-S was decreased. KTZ did not affect plasma concentrations of ATV, 2-OH ATV and 4-OH ATV, but significantly decreased the metabolic ratio of total and 4-OH ATV. However, the plasma level and hepatic metabolism of 4β-HC were not changed by KTZ. The inhibition of hepatic uptake of GCDCA-S by RIF was fully reversed after a 7-d washout of RIF. Plasma concentration and hepatic uptake ratio of GCDCA-S were correlated with the plasma level and hepatic uptake of ATV in rats with ANIT-induced liver injury, respectively. These results demonstrate that plasma GCDCA-S is a sensitive probe for the assessment of Oatps-mediated hepatic uptake of ATV. However, Cyp3a-mediated metabolism of ATV was not predicted by plasma 4β-HC levels in rats., Graphical abstract Image, graphical abstract

The thick cloud coverage phenomenon severely disturbs optical satellite observation missions (covering approximately 40–60% areas in the global scale). Therefore, the manner by which to eliminate thick cloud in remote sensing imagery is greatly significant and indispensable. In this study, we combine the deep spatio-temporal prior with low-rank tensor singular value decomposition (DP-LRTSVD) for thick cloud removal in multitemporal images. On the one hand, DP-LRTSVD utilizes the low-rank characteristic of multitemporal images via the third-order tensor SVD and completion. On the other hand, DP-LRTSVD employs the deep spatio-temporal feature expression ability by 3D convolutional neural network. The proposed framework can effectively eliminate thick cloud in multitemporal images through combining the model-driven and data-driven strategies. Moreover, DP-LRTSVD outperforms on thick cloud removal in the simulated and real multitemporal Sentinel-2/GF-1 experiments compared with model-driven or data-driven methods. In contrast with most methods that can only use a single reference image for thick cloud removal, the proposed method can simultaneously eliminate thick cloud in time-series images.

Carbon dioxide reforming of methane can reduce emissions of greenhouse gases, and has been extensively studied. The conventional Ni-based catalysts easily coke, sinter, and deactivate in the CRM reaction. The studies suggested that the cold plasma treatment can improve the structure of Ni-based catalysts, and so enhance coke resistance of the catalysts. The review summarized the effect of cold plasma treatment on the coke resistance of Ni-based catalysts for the CRM reaction. The main goal of the paper was to illuminate: the structure change of catalysts treated by cold plasma, such as crystal planes of Ni particles, the particles size of Ni, the Ni dispersion, the metal-support interaction, and CO2 absorption capacity; the correlation between plasma treatment conditions (treatment way and parameters) and coke resistance of the catalyst treated by cold plasma; and the mechanism of plasma treatment to improve the coke resistance of the catalysts.

The contribution of meteorology and emissions to long-term PM 2.5 trends is critical for air quality management but has not yet been fully analyzed. Here, we used the combination of a machine learning model, statistical method, and chemical transport model to quantify the meteorological impacts on PM 2.5 pollution during 2000–2018. Specifically, we first developed a two-stage machine learning PM 2.5 prediction model with a synthetic minority oversampling technique to improve the satellite-based PM 2.5 estimates over highly polluted days, thus allowing us to better characterize the meteorological effects on haze events. Then we used two methods to examine the meteorological contribution to PM 2.5 : a generalized additive model (GAM) driven by the satellite-based full-coverage daily PM 2.5 retrievals and the Weather Research and Forecasting/Community Multiscale Air Quality (WRF/CMAQ) modeling system. We found good agreements between GAM estimations and the CMAQ model estimations of the meteorological contribution to PM 2.5 on a monthly scale (correlation coefficient between 0.53–0.72). Both methods revealed the dominant role of emission changes in the long-term trend of PM 2.5 concentration in China during 2000–2018, with notable influence from the meteorological condition. The interannual variabilities in meteorology-associated PM 2.5 were dominated by the fall and winter meteorological conditions, when regional stagnant and stable conditions were more likely to happen and when haze events frequently occurred. From 2000 to 2018, the meteorological contribution became more unfavorable to PM 2.5 pollution across the North China Plain and central China but were more beneficial to pollution control across the southern part, e.g., the Yangtze River Delta. The meteorology-adjusted PM 2.5 over eastern China (denoted East China in figures) peaked in 2006 and 2011, mainly driven by the emission peaks in primary PM 2.5 and gas precursors in these years. Although emissions dominated the long-term PM 2.5 trends, the meteorology-driven anomalies also contributed −3.9 % to 2.8 % of the annual mean PM 2.5 concentrations in eastern China estimated from the GAM. The meteorological contributions were even higher regionally, e.g., − 6.3 % to 4.9 % of the annual mean PM 2.5 concentrations in the Beijing-Tianjin-Hebei region, − 5.1 % to 4.3 % in the Fenwei Plain, − 4.8 % to 4.3 % in the Yangtze River Delta, and − 25.6 % to 12.3 % in the Pearl River Delta. Considering the remarkable meteorological effects on PM 2.5 and the possible worsening trend of meteorological conditions in the northern part of China where air pollution is severe and population is clustered, stricter clean air actions are needed to avoid haze events in the future.

Bioaerosols containing pathogenic microorganisms have posed a great threat to human and animal health. Effective monitoring of bioaerosols containing pathogenic viruses and bacteria is of great significance to prevent and control infectious diseases. This Feature summarizes recent advances on bioaerosol collection and detection based on microfluidic chips. Besides, the challenges and trends for bioaerosol collection and detection were also discussed.

The effect of solution temperature and aging temperature on mechanical properties and microstructure of the new ultrahigh strength stainless steel S280 was investigated by heat treatment process experiment. The results showed that the optimal heat treatment process was as follows: heating to 1080 °C，holding for a hour, and quenching in oil; cooling to -73 °C, holding for 2 hour, and warming in air to room temperature; heating to 540~550 °C, holding for 4 hour, and cooling in air. Choosing this heat treatment process, the steel can get good coordination between strength and toughness. Analyzed by HREM, the steel had desirable microstructures, which were fine lath martensite matrix with high density dislocation and finely dispersed precipitate strengthening phase, and film-like reversed austenite precipitated from the boundary of martensite.

Sex dimorphism is ubiquitous in the animal kingdom and can be influenced by environmental factors. However, relatively little is known about how the degree and direction of sex difference vary with environmental factors, including food quality and temperature. With the spider mites from the family Tetranychidae as subjects, the sex difference of life-history traits in responses to host plant and temperature were determined in this meta-analytic review. Across the 42 studies on 26 spider mite species (N = 8057 and 3922 for female and male mites, respectively), female spider mites showed longer developmental duration than the males in all except two species. The direction of sex difference in development was consistent regardless of temperature and host plant. The 16 spider mite species in 33 studies generally showed female-biased longevity, with an overall effect size of 0.6043 [95%CI = 0.4054–0.8031]. Host plant significantly influenced the sex difference in longevity, where the males lived longer than females below 22.5 ℃, but the reverse was true at higher and fluctuating temperature. Host plant also influenced the magnitude of sex difference in longevity, with females living longer than males when reared on herbs but not on trees. This study indicated that life-history traits are highly variable between sexes under temperature and host plant influence, highlighting that environmental conditions can significantly shape the direction and magnitude of sexual dimorphism of life-history traits.

Two new zirconium MOFs, WSU-6 and WSU-7, were synthesized through postsynthetic modifications. In both cases, linker insertion was conducted on a MOF consisting of eight-connected (8-c) Zr6 cluster and four-connected (4-c) ETTC linker, WSU-5, which possesses the uncommon 4, 8-c scu-c topology. The insertion of 1, 4-benzenedicarboxylate into the MOF formed the new 4, 12-c mjh topology, WSU-6. Interestingly, when 2, 6-naphthalenedicarboxylate was inserted, WSU-7 can be formed, which possesses a new 4, 14-c jkz topology. WSU-7 contains very rare 14-c Zr6 secondary building units (SBUs) and is the first MOF to have a Zr6 SBUs with connectivity greater than 12. The three Zr-MOFs were structurally characterized, and the photoluminescence properties of the materials were also studied.

Recent radiations provide excellent models to gain more insights into evolution, speciation and adaptation. To this end, a well-resolved phylogenetic tree is needed. However, resolving phylogenetic relationships within recent radiations has been difficult as traditional phylogenetic markers failed to provide enough information. We here use plastome data to test their capacity in resolving phylogenetic relationships among a recent rapidly diverging group, Rhodiola, on the Qinghai-Tibetan Plateau. We reconstructed a robust phylogenetic backbone of Rhodiola using 23 plastomes representing all subgenera and sections in previous taxonomic treatments. Based on the backbone, we inferred the spatio-temporal pattern of diversification of the genus. We also traced evolution of five important morphological characters of Rhodiola, including sexual system, inflorescence type and flowering stem, based on the maximum likelihood and the threshold models. Two well-supported clades were revealed in Rhodiola, and the two clades were distinguished by sexual system: species in clade I are mostly hermaphrodite (except R. stapfii and R. integrifolia), and those in clade II are all dioecious. Biogeographic analysis showed that Rhodiola probably originated in the Qinghai-Tibetan Plateau and the Hengduan Mountains. The two major clades diverged c. 6.34 Mya, corresponding to a period of rapid uplift of the Hengduan Mountains and intensification of the Asian monsoon. Character evolution analysis confirmed parallel evolution of dioecy and other adaptive traits, such as marcescent flowering stems, in the genus. We demonstrate that plastome data could significantly improve phylogenetic resolution in plant groups resulting from recent radiations. Our results not only shed new light on the evolutionary history of Rhodiola, but also indicate that more plastome data should be used in resolving phylogenetic relationship in plant groups that have undergone recent radiations.

Sixteen metabolites, including seven C7-alkylated salicylaldehyde derivatives (1-7) and nine prenylated indole alkaloids (8-16), three of which are new, namely, asperglaucins A and B (1 and 2) and neoechinulin F (8), were separated from the endolichenic fungus Aspergillus chevalieri SQ-8. Asperglaucin A (1) represents an unusual phthalide-like derivative with a benzo[c]thiophen-1(3H)-one scaffold. All compounds were assessed in vitro for antibacterial, antineuroinflammatory, and antioxidant activities. Notably, asperglaucins A and B exhibited potent antibacterial activities against two plant pathogens Pseudomonas syringae pv actinidae (Psa) and Bacillus cereus, with an MIC value of 6.25 μM; further SEM analyses illustrated that the possible bacteriostatic mechanisms for compounds 1 and 2 were to alter the external structure of B. cereus and Psa, and to cause the rupture or deformation of the cell membranes, respectively, and the results suggest that compounds 1 and 2 may serve as potential promising candidates for lead compounds of agrochemical bactericides. Furthermore, compounds 6 and 10 significantly inhibited nitric oxide production with an IC50 value of ca. 12 μM, and the possible anti-inflammatory mechanisms involved were also studied by molecular docking. Finally, the tested phenolics 3-5 showed significant antioxidative effects. Thus, strain SQ-8 represents a novel resource of these bioactive metabolites to be utilized.

Titanium-oxide or polyoxotitanate clusters are a new type of inorganic host materials that can encapsulate inorganic molecules or ions. We report herein a (NH4)4(enH2)[Ti18O27(PhCOO)24(en)9] molecular cage (Ti18) that encapsulates an entire organic ethylenediamine (en) ion. A thorough investigation has revealed the extraordinary versatility of en. Besides being a guest cation, it also functions as chelating and bridging ligand. It balances the charge of the negative Ti18 cage and facilitates the deprotonation of benzoic acid at the early stage of the reaction as well. DFT calculation and a derivative of Ti18 with open sites at its equatorial position shed further light on the formation mechanism. Ti18 strongly absorbs visible light as a result of en coordination, and it exhibits superior photocatalytic activity compared to anatase TiO2.

Summary Background The health impacts of ambient air pollution impose large costs on society. Although all people are exposed to air pollution, the older population (ie, those aged ≥60 years) tends to be disproportionally affected. As a result, there is growing concern about the health impacts of air pollution as many countries undergo rapid population ageing. We investigated the spatial and temporal variation in the economic cost of deaths attributable to ambient air pollution and its interaction with population ageing from 2000 to 2016 at global and regional levels. Methods In this global analysis, we developed an age-adjusted measure of the value of a statistical life-year (VSLY) to estimate the economic cost of deaths attributable to ambient PM2·5 pollution using Global Burden of Diseases, Injuries, and Risk Factors Study 2017 data and country-level socioeconomic information. First, we estimated the global age-specific and cause-specific mortality and years of life lost (YLLs) attributable to PM2·5 pollution using the global exposure mortality model and global estimates of exposure at 0·1° × 0·1° (about 11 km × 11 km at the equator) resolution. Second, for each year between 2000 and 2016, we translated the YLLs within each age group into a health-related cost using a country-specific, age-adjusted measure of VSLY. Third, we decomposed the major driving factors that contributed to the temporal change in health costs related to PM2·5. Finally, we did a sensitivity test to analyse the variability of the estimated health costs to four alternative valuation measures. We identified the uncertainty intervals (UIs) from 1000 draws of the parameters and concentration–response functions by age, cause, country, and year. All economic values are reported in 2011 purchasing power parity-adjusted US dollars. All simulations were done with R, version 3.6.0. Findings Globally, in 2016, PM2·5 was estimated to have caused 8·42 million (95% UI 6·50–10·52) attributable deaths, which was associated with 163·68 million (116·03–219·44) YLLs. In 2016, the global economic cost of deaths attributable to ambient PM2·5 pollution for the older population was US$2·40 trillion (1·89–2·93) accounting for 59% (59–60) of the cost for the total population ($4·09 trillion [3·19–5·05]). The economic cost per capita for the older population was $2739 (2160–3345) in 2016, which was 10 times that of the younger population (ie, those aged Interpretation The economic cost of ambient PM2·5 borne by the older population almost doubled between 2000 and 2016, driven primarily by GDP growth, population ageing, and population growth. Compared with younger people, air pollution leads to disproportionately higher health costs among older people, even after accounting for their relatively shorter life expectancy and increased disability. As the world's population is ageing, the disproportionate health cost attributable to ambient PM2·5 pollution potentially widens the health inequities for older people. Countries with severe air pollution and rapid ageing rates need to take immediate actions to improve air quality. In addition, strategies aimed at enhancing health-care services, especially targeting the older population, could be beneficial for reducing the health costs of ambient air pollution. Funding National Natural Science Foundation of China, China Postdoctoral Science Foundation, and Qiushi Foundation.

Background Plant-based meat analogues (PBMA) are promising to address the issue of imbalance between global meat supply and demand. PBMA can contribute to an environmentally friendly and sustainable food production. As one of the main raw materials in PBMA, the naturally occurring beany flavor in soybean restricts their further development and consumer acceptance. To enhance the application of soybean as an ingredient in PBMA as well as improve consumer acceptability, the beany flavor should be effectively eliminated. Scope and approach In the present review, the main beany flavor compounds, their formation mechanism, the interaction between soybean protein and off-flavor compounds, the detection methods, and the removal methods were systematically reviewed. Notably, the main removal approaches for beany flavor of soybean can be divided into three categories, namely biotechnological, physical and chemical methods. The different removal methods of beany flavor in soybean protein were compared and discussed. Key findings and conclusions Application of biotechnological methods to eliminate beany flavor in soybean is challenging. Although enzymatic method is safe and clean, its catalytic efficiency is relatively low. Chemical modification methods possess food safety threats. By contrast, physical processing is relatively effective in removing beany flavor, while heating may exert a negative impact on the functional properties of soybean protein. Collectively, enzymatic modification combined with novel non-thermal processing as well as the optimized texturization process of soybean protein is of great significance to elimination of beany flavor in PBMA.

This research first verified that prokaryotic algae are more sensitive to toxicity of CuO nanoparticles (CuO NPs) than eukaryotic algae and that CuO NPs damaged photosynthesis of prokaryotic algae (Arthrospira sp.) but had no effect on respiration. The Cu2+ released by CuO NPs caused a bending deformation of the thylakoid, which was an important cause of the decline in photosynthetic capacity. In addition, the D1 protein was the most susceptible site to CuO NPs. The degradation of D1 protein reduced photosynthetic electron transport, which enhanced the excess excitation energy to cause the accumulation of reactive oxygen species (ROS) to further result in oxidative stress on algae. Dissolved organic matter (DOM) increased the toxicity of CuO NPs to photosynthesis of Arthrospira sp. The damage of photosynthesis caused by CuO NPs is an important reason why CuO NPs have a serious toxicity to algae.

Noncollinear spin textures have attracted much attention due to their novel physical behaviors in heavy/ferromagnetic metal (HM/FM) systems. The transport anomaly, appearing as contrast humps in Hall resistivity curves, is the mark of noncollinear spin textures. Here, the epitaxial Pt/γ'-Fe4N bilayers with noncollinear spin textures were obtained by facing target sputtering. Large micromagnetic Dzyaloshinskii-Moriya interaction coefficient D of 2.90 mJ/m2 appears in Pt/γ'-Fe4N/MgO systems, which is larger than 2.05 mJ/m2 of Pt/Co/MgO systems with skyrmionic states. Moreover, at 300 K, magnetic bubble-like domains appear in Pt/γ'-Fe4N bilayers that just possess a 3 nm thick ferromagnetic layer instead of [HM/FM]n or [HM1/FM/HM2]n multilayers. Additionally, a room-temperature transport anomaly appears in Pt/γ'-Fe4N/MgO systems. The contrast humps of Pt(3 nm)/γ'-Fe4N(tFe4N ≤ 4 nm)/MgO heterostructures are not sharp due to the nonuniform distributions of the magnetic bubble-like domains with various sizes and irregular shapes, as observed by the magnetic force microscopy. The discovery of epitaxial Pt/γ'-Fe4N bilayers with noncollinear spin states is more crucial than that of polycrystalline or amorphous HM/FM systems for reducing ohmic heating, which provides a candidate for noncollinear spintronic applications.

Bismuth telluride alloys have dominated the industrial application of thermoelectric cooling, but the relatively poor mechanical performance of commercial zone-melting material seriously limits the device integration and stability. Here, we exhibit synergistically enhanced thermoelectric and mechanical performances of sintered Bi0.48Sb1.52Te3-AgSbSe2 composites. It is found that the increased hole concentration improves the S2σ to 40 μW cm-1 K-2 at room temperature, and the emerged various defects effectively suppress the κl to 0.57 W m-1 K-1 at 350 K. All effects harvest a highest ZT = 1.2 at 350 K along with an average ZT = 1.0 between 300-500 K in the x = 0.2 sample. Notably, AgSbSe2 addition not only optimizes the thermoelectric properties, but also enhances the mechanical performance with a Vickers hardness of 0.75 GPa. Furthermore, the isotropy of thermoelectric properties is also observably promoted by solid-phase reaction combined with high-energy ball milling and hot pressing. Our study reveals a viable strategy to improve the comprehensive performance of sintered bismuth telluride materials.

The production of bimetallic nanoparticles with ultrasmall sizes is the constant pursuit in chemistry and materials science because of their promising applications in catalysis, electronics and sensing. Here we report ambient-temperature preparation of bimetallic NPs with tunable size and composition using microfluidic-controlled co-reduction of two metal precursors on silicon surface. Instead of free diffusion of metal ions in bulk system, microfluidic flow could well control the local ions concentration, thus leading to homogenous and controllable reduction rate among different nucleation sites. By controlling precursor concentration, flow rate and reaction time, we rationally design a series of bimetallic NPs including Ag-Cu, Ag-Pd, Cu-Pt, Cu-Pd and Pt-Pd NPs with ultrasmall sizes (∼ 3.0 nm), tight size distributions (relative standard deviation (RSD) < 21%), clean surface, and homogenous elemental compositions among particles (standard deviation (SD) of weight ratios < 3.5%). This approach provides a facile, green and scalable method toward the synthesis of diverse bimetallic NPs with excellent activity.

Powdery mildew resistance gene MlIW39, originated from wild emmer wheat accession IW39, was mapped to a 460.3 kb genomic interval on wheat chromosome arm 2BS. Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is destructive disease and a significant threat to wheat production globally. The most effective way to control this disease is genetic resistance. However, when resistance genes become widely deployed in agriculture, their effectiveness is compromised by virulent variants that were previously minor components of the pathogen population or that arise from mutation. This necessitates continual search for new sources of resistance in both wheat and its near relatives. In this study, we produced a common wheat line 8D49 (87-1/IW39//2*87-1), which has all-stage immunity to Bgt isolate E09 and many other Chinese Bgt isolates, by transferring powdery mildew resistance from Israeli wild emmer wheat (WEW) accession IW39 to the susceptible common wheat line 87-1. Genetic analysis indicated that the powdery mildew resistance in 8D49 was controlled by a single dominant gene, temporarily designated MlIW39. Genetic linkage analyses with molecular markers showed that MlIW39 was located in a 0.7 cm genetic region between markers QB-3-16 and 7Seq546 on the short arm of chromosome 2B. Fine mapping using three large F2 populations delimited MlIW39 to a physical interval of approximately 460.3 kb region in the WEW reference genome (Zavitan v1.0) that contained six annotated protein-coding genes, four of which had gene structures similar to known disease resistance genes. This provides a foundation for map-based cloning of MlIW39. Markers 7Seq622 and 7Seq727 co-segregating with MlIW39 can be utilized for marker-assisted selection in further genetic studies and wheat breeding.

A stereospecific convergent peptide arginine glycosylation method is reported for the first time. A recently discovered arginine glycosylation invigorated the interests of arginine modification, which has been challenging, because of the inertness of the guanidino side chain. The approach renders the arginine glycoside construction convergently. Catalyzed by palladium complex, glycals modify arginine guanidino groups in one step with high functional group tolerance at ambient temperature. The glycosylated products may be converted to glycopeptide analogues in few steps.

Background With the development of rapid resistance, new modes of action for pesticides are needed for insect control, such as RNAi-based biopesticides targeting essential genes. To explore the function of Argonaute-1 (Ago-1) and potential miRNAs in ovarian development of Bactrocera dorsalis, an important agricultural pest, and to develop a novel control strategy for the pest, BdAgo-1 was first identified in B. dorsalis. Results Spatiotemporal expression analysis indicated that BdAgo-1 had a relatively high transcriptional level in the ovarian tissues of adult female B. dorsalis during the sexual maturation period. RNA interference (RNAi) experiment showed that BdAgo-1 knockdown significantly decreased the expression levels of ovarian development-related genes and delayed ovarian development. Although RNAi-mediated silencing of Ago-1 led to a reduced ovary surface area, a subsequent oviposition assay revealed that the influence was minimal over a longer time period. Small RNA libraries were constructed and sequenced from different ovarian developmental stages of B. dorsalis adults. Among 161 identified miRNAs, 84 miRNAs were differentially expressed during the three developmental stages of the B. dorsalis ovary. BdAgo-1 silencing caused significant down-regulation of seven differentially expressed miRNAs (DEMs) showing relatively high expression levels (>1000 TPM (Transcripts per kilobase of exon model per million mapped reads)). The expression patterns of these seven core DEMs and their putative target genes were analyzed in the ovaries of B. dorsalis. Conclusion The results indicate that Ago-1 and Ago-1-dependent miRNAs are indispensable for normal ovarian development in B. dorsalis and help identify miRNA targets useful for control of this pest.

Uncontrolled Li plating in graphite electrodes endangers battery life and safety, driving tremendous efforts aiming to eliminate Li plating. Herein we systematically investigate the boundary of Li plating in graphite electrode for safe lithium-ion batteries. The cell exhibits superior safety performance than that with Li dendrites by defining the endurable amount of uniform Li plating in graphite anode. The presence of "dead Li" can be eliminated owing to the uniform distribution of Li plating, and the average Coulombic efficiency for deposited Li during reversible plating/stripping process is decoupled as high as about 99.5 %. Attributing to the limited Li plating with superior Coulombic efficiency, the LiNi0.5 Mn0.3 Co0.2 O2 | graphite cell achieves a high capacity retention of 80.2 % over 500 cycles. This work sheds a different light on further improving the fast-charging capability, low-temperature performance, and energy density of practical lithium-ion batteries.

Background Paphiopedilum is the largest genus of slipper orchids. Previous studies showed that the phylogenetic relationships of this genus are not well resolved, and sparse taxon sampling documented inverted repeat (IR) expansion and small single copy (SSC) contraction of the chloroplast genomes of Paphiopedilum. Results Here, we sequenced, assembled, and annotated 77 plastomes of Paphiopedilum species (size range of 152,130 – 164,092 bp). The phylogeny based on the plastome resolved the relationships of the genus except for the phylogenetic position of two unstable species. We used phylogenetic and comparative genomic approaches to elucidate the plastome evolution of Paphiopedilum. The plastomes of Paphiopedilum have a conserved genome structure and gene content except in the SSC region. The large single copy/inverted repeat (LSC/IR) boundaries are relatively stable, while the boundaries of the inverted repeat and small single copy region (IR/SSC) varied among species. Corresponding to the IR/SSC boundary shifts, the chloroplast genomes of the genus experienced IR expansion and SSC contraction. The IR region incorporated one to six genes of the SSC region. Unexpectedly, great variation in the size, gene order, and gene content of the SSC regions was found, especially in the subg. Parvisepalum. Furthermore, Paphiopedilum provides evidence for the ongoing degradation of the ndh genes in the photoautotrophic plants. The estimated substitution rates of the protein coding genes show accelerated rates of evolution in clpP, psbH, and psbZ. Genes transferred to the IR region due to the boundary shift also have higher substitution rates. Conclusions We found IR expansion and SSC contraction in the chloroplast genomes of Paphiopedilum with dense sampling, and the genus shows variation in the size, gene order, and gene content of the SSC region. This genus provides an ideal system to investigate the dynamics of plastome evolution.

Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle (WHTC) urea deposits are urea, cyanuric acid (CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cuβ and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cuβ, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline.

Lithium–sulfur (Li–S) battery is regarded as one of the most promising next-generation energy storage systems due to the ultra-high theoretical energy density of 2600 Wh kg−1. To address the insulation nature of sulfur, nanocarbon composition is essential to afford acceptable cycling capacity but inevitably sacrifices the actual energy density under working conditions. Therefore, rational structural design of the carbon/sulfur composite cathode is of great significance to realize satisfactory electrochemical performances with limited carbon content. Herein, the cathode carbon distribution is rationally regulated to construct high-sulfur-content and high-performance Li–S batteries. Concretely, a double-layer carbon (DLC) cathode is prepared by fabricating a surface carbon layer on the carbon/sulfur composite. The surface carbon layer not only provides more electrochemically active surfaces, but also blocks the polysulfide shuttle. Consequently, the DLC configuration with an increased sulfur content by nearly 10 wt% renders an initial areal capacity of 3.40 mAh cm−2 and capacity retention of 83.8% during 50 cycles, which is about two times than that of the low-sulfur-content cathode. The strategy of carbon distribution regulation affords an effective pathway to construct advanced high-sulfur-content cathodes for practical high-energy-density Li–S batteries.

Claw injuries of pigs due to inadequate floor surface conditions are a major concern in pig operations. Rough and slippery concrete floor surfaces can result in claw disorders. In this paper, the surface roughness and dynamic coefficient of friction (DCOF) of concrete floors used in two sow gestation rooms were studied. The first room had a slatted concrete floor with 105-mm wide slats and 19-mm wide gaps, and the second room had a floor with 125-mm wide slats and 25-mm wide gaps. A portable tester was designed and built to measure the surface roughness and friction of concrete floors. Measurements were conducted weekly during two gestation cycles for a total of 21 weeks. Based on the observations of sow activities, the floor in each room was virtually divided into four areas, namely dunging, high traffic, low traffic and sleeping areas. Surface roughness and friction were measured in the four areas in directions both parallel and perpendicular to the slats. The results showed that the length of time of floor usage by sows had a significant effect on the roughness and DCOF of concrete floors, with a sharp reduction in the DCOF after the first two weeks of use because manure stuck in the pores of the concrete surface reduced the interlocking between the asperities of the contact surfaces. No significant differences in the roughness and DCOF were found among different areas of floor (dunging, high traffic, low traffic and sleeping) or between the two floor configurations in the first 21 weeks of floor usage.

Cationic glycopolymers with structures similar to those of typical poly(ionic liquid)s (PILs) were synthesized via the quaternization reaction of poly(4-vinyl pyridine) with halogen-functionalized d-mannose and tetraphenylethylene units. Such postpolymerization modification provided PILs with aggregation-induced emission effect as well as specific carbohydrate-protein recognition with lectins such as concanavalin A. The interactions between cationic glycopolymers and different microorganisms, including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, were used for the killing, imaging, and detection of bacteria. Besides, these sugar-containing PILs showed a relatively low hemolysis rate due to the presence of saccharide units, which may have potential application in the field of biomaterials.

Silk-based scaffolds with hierarchical structure possess the capacities of promoting cells adhesion, proliferation and neotissue formation, which have been one of the candidates in tissue engineering. However, the ways to construct hierarchical structures in scaffolds are very limited, rather than introducing other nanoscale components. In this study, a hierarchical porous structure was directly established in silk fibroin/hyaluronic acid (SF/HA) scaffold through slight degradation technique. The resulting SF/HA scaffold presented desirable microarchitecture and appropriate porosity attribute to partial hydrolysis of SF molecules. The compression test showed that the SF/HA scaffolds was better than SF scaffolds in terms of compression stress and Young’s modulus. More importantly, the SF/HA scaffolds displayed good cytocompatibility as to supporting cells adhesion and proliferation. This paper provides a new strategy for preparing SF-based scaffolds with hierarchical porous structure in tissue engineering.

The concentration of fine particulate matter (PM2.5) across China has decreased by 30–50% over the period 2013–2018 due to stringent emission controls. However, the nitrate component of PM2.5 has not responded effectively to decreasing emissions of nitrogen oxides and has actually increased during winter haze pollution events in the North China Plain. Here, we show that the GEOS-Chem atmospheric chemistry model successfully simulates the nitrate concentrations and trends. We find that winter mean nitrate would have increased over 2013–2018 were it not for favourable meteorology. The principal cause of this nitrate increase is weaker deposition. The fraction of total inorganic nitrate as particulate nitrate instead of gaseous nitric acid over the North China Plain in winter increased from 90% in 2013 to 98% in 2017, as emissions of nitrogen oxides and sulfur dioxide decreased while ammonia emissions remained high. This small increase in the particulate fraction greatly slows down deposition of total inorganic nitrate and hence drives the particulate nitrate increase. Our results suggest that decreasing ammonia emissions would decrease particulate nitrate by driving faster deposition of total inorganic nitrate. Decreasing nitrogen oxide emissions is less effective because it drives faster oxidation of nitrogen oxides and slower deposition of total inorganic nitrate. Reduction of ammonia emissions may be effective in reducing the nitrate component of fine particulate matter air pollution across the North China Plain, according to the simulation of nitrate trends using the GEOS-Chem atmospheric chemistry model.

The effect of additional dl-methionine (Met) on the thermal degradation of a methionine-glucose-derived Amadori rearrangement product (MG-ARP) was investigated under different reaction conditions. The resulting color formation and changes in the concentrations of MG-ARP, Met, and α-dicarbonyl compounds were investigated. Additional Met did not affect the degradation rate of MG-ARP but got involved in subsequent reactions and resulted in a decrease in the contents of C6-α-dicarbonyl compounds. During MG-ARP degradation, the formation of glyoxal (GO) and methylglyoxal (MGO) was facilitated by additional Met, through retro-aldolization reaction of C6-α-dicarbonyl compounds. This effect of Met addition was dependent on the reaction temperature, and the consistent conclusion could be made in a buffer system. The improvement of GO and MGO formation as color precursors caused by the additional Met contributed to the acceleration of browning formation.

Due to the intrinsic poor ionic/electronic conductivities of Li2S, it is a great challenge to realize high-rate all-solid-state lithium-sulfur batteries (ASSLSBs) with long cyclic performance. Herein, ultrasmall Li2S (∼15 nm) is evenly deposited on a carbon nanotube (CNT) via a facile liquid-phase method to address these issues. The unique structure of the Li2S deposited on a CNT composite cathode can improve ionic/electronic conductivities of Li2S effectively and relieve the generated internal stress/strain during cycling. Specifically, the resultant Li/75%Li2S-24%P2S5-1%P2O5/Li10GeP2S12/Li2S-53%CNT ASSLSBs show a reversible capacity of 651.4 mAh g-1 under 1.0C at 60 °C after 300 cycles and even at a much higher cathode load of 5.08 mg cm-2, a high discharge capacity of 556 mAh g-1 can still be obtained under 0.1C after 20 cycles. The outstanding electrochemical performances are also attributed to the high diffusion coefficient of Li2S-53%CNT, which is 39 times that of pristine Li2S. This work presents an efficient procedure to design cathode materials with high ionic/electronic conductivities and paves the way for the successful commercialization of high-rate ASSLSBs.

Chemical reaction pathways and product state correlations of gas-phase ion-molecule reactions are governed by the involved potential energy surfaces (PESs). Here, we report the photodissociation dynamics of charge-transfer complex [Ar-N2]+, which is the intermediate of the model system of the Ar+ + N2 → Ar + N2+ reaction. High-resolution recoiling velocity images of photofragmented N2 and N2+ from different dissociation channels exhibit a vibrational state-specific correlation, revealing the nonadiabatic charge-transfer mechanisms upon the photodissociation of [Ar-N2]+. The state-resolved product branching ratios have yielded an accurate determination of the resonant charge-transfer probabilities. This work provides a powerful approach to elucidating the detailed dynamics of chemical events of charge-transfer complex [Ar-N2]+ and to probing the state-to-state charge-transfer PESs.