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The Tibetan Plateau (TP) plays a key role in the regional environment and global climate change; however, the lack of vertical observations of atmospheric species, such as HONO and O3, hinders a deeper understanding of the atmospheric chemistry and atmospheric oxidation capacity (AOC) on the TP. In this study, we conducted multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements at Nam Co, the central TP, to observe the vertical profiles of aerosol, water vapor (H2O), NO2, HONO and O3 from May to July 2019. In addition to NO2 mainly exhibiting a Gaussian shape with the maximum value appearing at 300=-400 m, the other four species all showed an exponential shape and decreased with the increase in height. The maximum values of monthly averaged aerosol (0.17 km−1) and O3 (66.71 ppb) occurred in May, H2O (3.68 × 1017 molec. cm−3) and HONO (0.13 ppb) appeared in July, and NO2 (0.39 ppb) occurred in June at the 200–400 m layer. H2O, HONO and O3 all exhibited a multi-peak pattern, and aerosol appeared to have a bi-peak pattern for its averaged diurnal variations. The averaged vertical profiles of OH production rates from O3 and HONO all exhibited an exponential shape decreasing with the increase in height, with maximum values of 2.61 and 0.49 ppb h−1 at the bottom layer, respectively. The total OH production rate contributed by HONO and O3 on the TP was obviously larger than that in low-altitude areas. In addition, source analysis was conducted for HONO and O3 at different height layers. The heterogeneous reaction of NO2 on wet surfaces was a significant source of HONO. The maximum values of HONO/NO2 appeared when H2O concentrations were approximately 1.0 × 1017 molec. cm−3 and aerosol concentrations were larger than 0.15 km−1 below 1.0 km. The maximum values were usually accompanied by H2O concentrations of 1.0–2.0 × 1017 molec. cm−3 and aerosol concentrations greater than 0.02 km−1 at 1.0–2.0 km. O3 was potentially sourced from the South Asian subcontinent and Himalayas through long-range transport. Our results contribute to the new understanding of vertical distribution of atmospheric components and explain the strong AOC on the TP.

Atmospheric particles can impact cloud formation and play a critical role in regulating cloud properties. However, particle characteristics at the single-particle level and their ability to act as ice-nucleating particles (INPs) over the marine atmosphere are poorly understood. In this study, we present micro-spectroscopic characterizations and ice nucleation properties of particles collected during a cruise from South Korea to Antarctica in 2019. Most of the samples were dominated by fresh sea salt, aged sea salt, and sea salt mixed with sulfate particles, with total number percentages ranging from 48 % to 99 % over the western Pacific and the Southern Ocean. The mixing-state index of the particle population ranged from 50 % to 95 % over the Northern Hemisphere and Southern Hemisphere. Multiphase processes on sea salt particles resulted in chlorine deficiency. This selective aging process made the marine particle population more externally mixed. Ice nucleation onset conditions primarily for the deposition mode were measured and the investigated particles showed diverse ice nucleation abilities. The fresh sea salt particles with organic coatings exhibited the highest ice nucleation ability at a relative humidity with respect to ice as low as 121 %. The sea salt mixed sulfate particle was enriched in INPs by a factor of 1.9. Aging processes affected both the mixing state of the particles and their ice nucleation abilities. Our analysis shows that assuming an internally mixed particle population in the marine atmosphere can lead to errors of several orders of magnitude in predicting ice nucleation rates.

The Antarctic Ice Sheet (AIS) holds the potential to raise global sea levels by a staggering 57 m. Ice shelves, extensions of these ice sheets into the ocean, play a crucial role in stabilizing the upstream ice sheet. The Brunt Ice Shelf (BIS), located in the Southern Weddell Sea region and proximal to the continental shelf break, stands as a vital indicator for the region's response to global climate warming. Hence, this study systematically employs a range of remote sensing and field data, including remote sensing data from 1963 to 2023 (ARGON images, Landsat1-9 images, Sentinel-1 images, ICESat-2 altimetry data, etc.) and in-situ ice flow velocity data since 1956, to conduct a comprehensive analysis of the BIS's calving cycle and evolution over nearly six decades. The results reveal a significant exacerbation of both dynamical and structural instabilities in the BIS compared to the calving cycle in the 1970s. Combining analyses of air temperature from meteorological station, water temperature from ocean models and in-situ measurements such as Conductivity-Temperature-Depth profiles, the study suggests that the increased instability of the BIS is likely linked to the intrusion of warmer currents over the continental shelf. This research provides valuable insights into the evolving behavior of the BIS in response to changing climate conditions, underscoring the critical role of remote sensing data in advancing our understanding of these processes on a global scale.

Amid global warming, the timely supplementation of soil water is crucial for the effective restoration and protection of the ecosystem. It is therefore of great importance to understand the temporal and spatial variations of soil water sources. The research collected 2451 samples of soil water, precipitation, river water, ground ice, supra-permafrost water, and glacier snow meltwater in June, August, and September 2020. The goal was to quantify the contribution of various water sources to soil water in the Three-Rivers Headwater Region (China) during different ablation periods. The findings revealed that precipitation, ground ice, and snow meltwater constituted approximately 72 %, 20 %, and 8 % of soil water during the early ablation period. The snow is fully liquefied during the latter part of the ablation period, with precipitation contributing approximately 90 % and 94 % of soil water, respectively. These recharges also varied markedly with altitude and vegetation type. The study identified several influencing factors on soil water sources, including temperature, precipitation, vegetation, evapotranspiration, and the freeze–thaw cycle. However, soil water loss will further exacerbate vegetation degradation and pose a significant threat to the ecological security of the “Chinese Water Tower”. It emphasizes the importance of monitoring soil water, addressing vegetation degradation related to soil water loss, and determining reasonable soil and water conservation and vegetation restoration models.

As the transition zone between the Tibetan Plateau and arid region, the Qilian Mountains are important ecological barriers and source regions of inland rivers in northwest China. In recent decades, drastic changes in the cryosphere have had a considerable impact on the formation process of water resources in the Qilian Mountains. In this study, 2164 environmental isotope samples were used to quantify the runoff components of 11 major rivers in the Qilian Mountains and investigate the influence of cryosphere changes on mountain runoff. The results show that the mountain runoff primarily originates in the cryosphere belt, which contributes approximately 82 %, 71 %, and 80 % to the Hexi inland water system, the upper stream of the Yellow River system, and the Qinghai inland river system, respectively. The maximum contribution ratio of glacier and snow meltwater to runoff occurred in May. The contribution of supra-permafrost water to runoff gradually increased from May and reached approximately 40 % in some rivers in October. Cryosphere degradation in the Qilian Mountains after the 1990s has caused a rapid increase in runoff, changes in the peak runoff time, and an increase in winter runoff. These changes in the hydrological processes bring opportunities and challenges to managing inland river water resources, and various adaptive measures to seek advantages and avoid disadvantages have been proposed. The findings from the environmental isotope analysis provide insights into understanding water resources and realizing the nexus of life, agriculture, industry, and ecological water use.

To evaluate whether ontogenetic development over the grow-out culture period can cause geographical plasticity of carapace shape in a certain region, geometric morphometric analysis was used, in this study, to determine the ontogenetic changes in the carapace morphology of Chinese mitten crabs (Eriocheir sinensis) originating from Yangcheng Lake, China, during a year of growth from coin-sized juveniles to market-sized adults. The morphological differences in the carapace throughout the year of culture were characterized using a 35-landmark point system. We used principal component analysis and linear discriminant analysis to determine morphological variation using thin-plate spline analysis and mesh deformation. During the growth process, the changes in the carapace were mainly concentrated in the third and fourth anterolateral teeth and on the M-shaped pattern. During the growth of male and female crabs throughout the year, the shape of the carapace changed considerably over the first six months. Afterwards, the shape of the carapace began to stabilize and could not be differentiated through discriminant analysis. This study is the first to use geometric morphometrics to analyze the ontogenetic changes in the carapace shape of E. sinensis crabs native to Yangcheng Lake. The results demonstrate that it takes a long time for the carapace morphology of native crabs to stabilize.

The atmospheric chemistry of organic nitrogen compounds (ONCs) is of great importance for understanding the formation of carcinogenic nitrosamines, and ONC oxidation products might influence atmospheric aerosol particle formation and growth. Indole is a polyfunctional heterocyclic secondary amine with a global emission quantity almost equivalent to that of trimethylamine, the amine with the highest atmospheric emission. However, the atmospheric chemistry of indole remains unclear. Herein, the reactions of indole with ⚫OH and ⚫Cl, and subsequent reactions of resulting indole radicals with O2 under 200 ppt NO and 50 ppt HO2⚫ conditions, were investigated by a combination of quantum chemical calculations and kinetics modeling. The results indicate that ⚫OH addition is the dominant pathway for the reaction of ⚫OH with indole. However, both ⚫Cl addition and H abstraction are feasible for the corresponding reaction with ⚫Cl. All favorably formed indole radicals further react with O2 to produce peroxy radicals, which mainly react with NO and HO2⚫ to form organonitrates, alkoxy radicals and hydroperoxide products. Therefore, the oxidation mechanism of indole is distinct from that of previously reported amines, which primarily form highly oxidized multifunctional compounds, imines or carcinogenic nitrosamines. In addition, the peroxy radicals from the ⚫OH reaction can form N-(2-formylphenyl)formamide (C8H7NO2), for the first time providing evidence for the chemical identity of the C8H7NO2 mass peak observed in the ⚫OH + indole experiments. More importantly, this study is the first to demonstrate that despite forming radicals by abstracting an H atom at the N site, carcinogenic nitrosamines were not produced in the indole oxidation reaction.

The shearer cutting drum plays an important role in improving the mining efficiency of the coal mine. Starting from the basic theoretical mechanics, this paper analyzes the force on the shearer cutting drum of a certain model, establishes the mathematical model of the force on the cutting drum, sets the shearer calculation parameters, and calculates the load of the cutting tooth on the shearer cutting drum. Through the analysis, it is concluded that the threeway instantaneous load of the drum cutting tooth is irregularly distributed, and the axial force has sudden changes in magnitude and direction. The research content of this paper has certain guiding significance for the layout design of shearer drum and cutting tooth.

The cause of crankshaft fracture crack of a certain vehicle has been analyzed through macroscopic analysis, microstructure analysis, mechanical properties test and dimension inspection. The analysis results show that: the fatigue strength of the crankshaft is reduced due to spheroidization recession, low strength and shallow nitriding layer of the fillets.

Taking a certain type of shearer as the research object, using the large-scale Finite Element Analysis (FEA) software ANSYS, according to the actual situation of load distribution, the stress model of the shearer body is established, the stress and deformation of the shearer body are analyzed, and the deformation curve and equivalent stress nephogram of the shearer body under working state are fitted, The stress and strain distribution of fuselage structure under working conditions are analyzed. The calculation results show that the structural design of the shearer body is more reasonable and has better stiffness and strength under normal working conditions. The calculation results have a certain reference value for the analysis and research of high-power shearer.

The gas-liquid two-phase flow with interfacial behaviors and bubble-liquid interactions is widely encountered in industrial processes such as that in gas-liquid reactors. The complicated phase structure makes it difficult to be modeled. The present work proposes a multi-scale mathematical model to simulate the bubbly flow in a square column. The volume of fluid (VOF) method is applied to treat the separated interface, and the discrete bubble model (DBM) is incorporated to handle the dynamics of dispersed bubbles. The hybrid model is validated against the benchmark experimental data to study the accuracy and suitability of the modeling framework for bubbly flows. And the influence of interphase forces on bubbly flow patterns and velocity profiles is investigated. It is found that the employment of both pressure gradient force and Ishii-Zuber drag model provides fairly good agreements with experimental data for velocity profiles.

Background and Aims. Aeration, an important operation in winemaking, cannot be controlled accurately based on dissolved oxygen for ester production in wine alcohol fermentation. The following study describes an aeration control method with oxidation-reduction potential (ORP) in alcohol fermentation and investigates its effect on ester production in fermentations with different starter cultures. Methods and Results. The proposed method is based on using ORP as a switch for aeration timing. Different aeration levels driven by ORP were performed in wine alcohol fermentation with different starter cultures including Saccharomyces cerevisiae (Sc), Pichia fermentans (Pf), Hanseniaspora uvarum (Hu), and their mixes (Pf/Sc and Hu/Sc). The accumulated aeration volume, residual sugar concentration, viable cell number, and ester concentration were analyzed. Results showed that aeration levels could be controlled effectively with an ORP value, and aeration with higher ORPs triggered faster sugar utilization in Sc and Hu/Sc fermentation. Pf and Hu survived one day less in their respective cofermentation with aeration when ORP was −100 mV or −50 mV compared to the natural ORP (−150 mV∼−105 mV in Pf/Sc and −141 mV∼−107 mV in Hu/Sc, respectively). Aeration driven by ORP changed ester profiles in cofermentations. With the aeration levels increasing, the proportion of medium-chain fatty acid ethyl esters in the concentration of total esters first increased and then decreased in Hu/Sc fermentation. When ORP was −100 mV in Pf/Sc fermentation, the proportion of higher alcohol acetates to total esters was highest (8.14%), while that of ethyl acetate to total esters was lowest (87.35%). Conclusions. Aeration driven by ORP improved wine ester profiles by increasing the proportion of medium-chain fatty acid ethyl esters or reducing that of ethyl acetate in cofermentations. Significance of the Study. The present study will allow wineries and researchers to optimize the aeration process in alcohol fermentation and develop a scientific aeration strategy to improve the wine ester profile and aroma quality.

Heat stress limits wheat production and trehalose can improve stress tolerance. How trehalose affects wheat respiration is unclear. In this study, we investigated the effects of exogenous trehalose on the respiration of wheat seedlings during heat stress and the subsequent recovery period. Trehalose pretreatment significantly increased the expression of the alternative oxidase genes AOX1a and AOX1c under heat stress, indicating that trehalose pretreatment increased the capacity of the alternative respiration pathway (AP) in response to heat stress. Trehalose pretreatment also enhanced the activity of the malate-oxaloacetate (Mal-OAA) shuttle and ameliorated the decrease in photosynthetic activity caused by heat stress. However, when the AP was inhibited by salicylhydroxamic acid under heat stress, both Mal-OAA shuttle activity and photosynthetic efficiency were substantially reduced in the control and trehalose pretreatment groups. In addition, trehalose pretreatment helped to maintain inner mitochondrial respiratory activity and the activity of Complex II during heat stress, particularly the coupling of oxidative phosphorylation with the Complex II electron transport chain, thereby mitigating heat-related damage to the cytochrome pathway (CP). Taken together, these results suggest that exogenous trehalose enhanced the AP and reduced damage to the CP under heat stress in wheat seedlings, thus maintaining cellular energy metabolism. Up-regulation of the AP by trehalose pretreatment may improve the heat tolerance of wheat seedlings by dissipating excess reducing equivalents transported through the Mal-OAA shuttle, thereby protecting photosynthetic performance.

The previous comparative studies on watersheds were mostly based on the comparison of dispersive characteristics, which lacked systemicity and causality. We proposed a causal structure-based framework for basin comparison based on the Bayesian network (BN) and focus on the basin-scale water–energy–food–ecology (WEFE) nexus. We applied it to the Syr Darya River basin (SDB) and the Amu Darya River basin (ADB), of which poor water management caused the Aral Sea disaster. The causality of the nexus was effectively compared and universality of this framework was discussed. In terms of changes in the nexus, the sensitive factor for the water supplied to the Aral Sea changed from the agricultural development during the Soviet Union period to the disputes in the WEFE nexus after the disintegration. The water–energy contradiction of the SDB is more severe than that of the ADB, partly due to the higher upstream reservoir interception capacity. It further made management of the winter surplus water downstream of the SDB more controversial. Due to this, the water–food–ecology conflict between downstream countries may escalate and turn into a long-term chronic problem. Reducing water inflow to depressions and improving the planting structure prove beneficial to the Aral Sea ecology, and this effect of the SDB is more significant. The construction of reservoirs on the Panj River of the upstream ADB should be cautious to avoid an intense water–energy conflict such as the SDB's. It is also necessary to promote the water-saving drip irrigation and to strengthen the cooperation.

This study focused on the hydrological and runoff formation processes of river water by using stable isotope tracing in the source regions of the Yangtze River during different ablation episodes in 2016 and the ablation period from 2016 to 2018. The effects of altitude on stable isotope characteristics for the river in the glacier permafrost area were greater than for the main stream and the permafrost area during the ablation period in 2016. There was a significant negative correlation (at the 0.01 level) between precipitation and δ18O, while a significant positive correlation was evident between precipitation and d-excess. More interestingly, significant negative correlations appeared between δ18O and temperature, relative humidity, and evaporation. A mixed segmentation model for end-members was used to determine the proportion of the contributions of different water sources to the target water body. The proportions of precipitation, supra-permafrost water, and glacier and snow meltwater for the main stream were 41.70 %, 40.88 %, and 17.42 %, respectively. The proportions of precipitation, supra-permafrost water, and glacier and snow meltwater were 33.63 %, 42.21 %, and 24.16 % for the river in the glacier permafrost area and 20.79 %, 69.54 %, and 9.67 %, respectively, for that in the permafrost area. The supra-permafrost water was relatively stable during the different ablation periods, becoming the main source of runoff in the alpine region, except for precipitation, during the ablation period.

Tomato is an economically important vegetable. Tomato chlorosis virus (ToCV) and Tomato yellow leaf curl virus (TYLCV) are two major viruses that cause serious losses to tomato production. The effective method to control these two viruses is to breed antiviral species by genetic engineering techniques. In order to obtain the RNA interference (RNAi) expression vector of tomato, the coat protein (CP) genes of ToCV and TYLCV were selected in this study. The tandem sequences of the two CP genes were obtained using the recombinant PCR technique. Using Gateway cloning technology, the RNAi expression vector pRNAi-ToCV-TY including the two CP genes was constructed by attB×attP and attL×attR recombination reactions. Polymerase chain reaction and sequencing analysis confirmed that the vector was obtained successfully and contained the ToCV and TYLCV CP genes. The RNAi expression vector pRNAi-ToCV-TY was transformed into Agrobacterium strain GV3101. The RNAi vector was then used to transform tomato. The objective fragments were successfully transformed into a tomato by PCR identification. At the fourth-leaf stage, the positive transgenic plants were challenged with ToCV and TYLCV. Out of 15 transgenic plants, 33 % showed early symptoms within 4 weeks post-infection (WPI); 20 % showed delayed symptoms (5 - 7 WPI); and the remaining 47 % were symptomless even after 9 WPI. The untransformed control plants (90 %) showed severe symptoms within 2 - 4 WPI, whereas 10 % delayed symptoms.

The temporal and spatial distributions of regional irrigation water productivity (RIWP) are crucial for making decisions related to agriculture, especially in arid irrigated areas with complex cropping patterns. Thus, in this study, we developed a new RIWP model for an irrigated agricultural area with complex cropping patterns. The model couples the irrigation- and drainage-driven soil water and salinity dynamics and shallow groundwater movement in order to quantify the temporal and spatial distributions of the target hydrological and biophysical variables. We divided the study area into 1 km × 1 km hydrological response units (HRUs). In each HRU, we considered four land use types: sunflower fields, wheat fields, maize fields, and uncultivated lands (bare soil). We coupled the regional soil hydrological processes and groundwater flow by taking a weighted average of the water exchange between unsaturated soil and groundwater under different land use types. The RIWP model was calibrated and validated using 8 years of hydrological variables obtained from regional observation sites in a typical arid irrigation area in North China, the Hetao Irrigation District. The model simulated soil moisture and salinity reasonably well as well as groundwater table depths and salinity. However, overestimations of groundwater discharge were detected in both the calibration and validation due to the assumption of well-operated drainage ditch conditions; regional evapotranspiration (ET) was reasonably estimated, whereas ET in the uncultivated area was slightly underestimated in the RIWP model. A sensitivity analysis indicated that the soil evaporation coefficient and the specific yield were the key parameters for the RIWP simulation. The results showed that the RIWP decreased from maize to sunflower to wheat from 2006 to 2013. It was also found that the maximum RIWP was reached when the groundwater table depth was between 2 and 4 m, regardless of the irrigation water depth applied. This implies the importance of groundwater table control on the RIWP. Overall, our distributed RIWP model can effectively simulate the temporal and spatial distribution of the RIWP and provide critical water allocation suggestions for decision-makers.

ABSTRACT The objective of the study was to investigate the mechanism by which dietary energy concentration regulates laying performance in geese. Eighty 558-day-old female Sichuan White geese were randomly allotted to two dietary treatments, each treatment was fed 1 of 2 experimental diets containing 10.00 (deficient) or 11.80MJ/kg metabolizable energy (sufficient) for 30 days. Laying performance, hormone concentration and gene expressions in hypothalamus-pituitary-gonadal axis were examined in geese. Birds fed the sufficient-energy diet had significantly higher average egg weight, daily laying rate, and lower feed to egg ratio than those fed the deficient-energy (p

A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.

This paper reviews the development of the global navigation satellite system (GNSS) radio occultation (RO) observations assimilation in the Global/Regional Assimilation and PrEdiction System (GRAPES) of China Meteorological Administration, including the choice of data to assimilate, the data quality control, the observation operator, the tuning of observation error, and the results of the observation impact experiments. The results indicate that RO data have a significantly positive effect on analysis and forecast at all ranges in GRAPES, not only in the Southern Hemisphere where conventional observations are lacking but also in the Northern Hemisphere where data are rich. It is noted that a relatively simple assimilation and forecast system in which only the conventional and RO observation are assimilated still has analysis and forecast skill even after nine months integration, and the analysis difference between both hemispheres is gradually reduced with height when compared with NCEP (National Centers for Environmental Prediction) analyses. Finally, as a result of the new on-board payload of the Chinese FengYun-3 (FY-3) satellites, the research status of the RO of FY-3 satellites is also presented.

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD), Landrace (CL) and Yorkshire (CY) swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.