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Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu bing.xu Zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

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Compliance motion control of the hydraulic dual-arm manipulator with adaptive mass estimation of unknown object

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Frontiers of Mechanical Engineering 2024年第1期19卷 35-52页

作者： Bolin SUN Min CHENG Ruqi DING bing.xu State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China Key Laboratory of Conveyance and Equipment(Ministry of Education) East China Jiaotong UniversityNanchang 330013China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China

Given the limited operating ability of a single robotic arm,dual-arm collaborative operations have become increasingly *** with the electrically driven dual-arm manipulator,due to the unknown heavy load,difficulty in measuring contact forces,and control complexity during the closed-chain object transportation task,the hydraulic dual-arm manipulator(HDM)faces more difficulty in accurately tracking the desired motion trajectory,which may cause object deformation or even *** overcome this problem,a compliance motion control method is proposed in this paper for the *** mass parameter of the unknown object is obtained by using an adaptive method based on velocity *** to the difficulty in obtaining the actual internal force of the object,the pressure signal from the pressure sensor of the hydraulic system is used to estimate the contact force at the end-effector(EE)of two hydraulic manipulators(HMs).Further,the estimated contact force is used to calculate the actual internal force on the ***,a compliance motion controller is designed for HDM closed-chain *** position and internal force errors of the object are reduced by the feedback of the position,velocity,and internal force errors of the object to achieve the effect of the compliance motion of the HDM,i.e.,to reduce the motion error and internal force of the *** required velocity and force at the EE of the two HMs,including the position and internal force errors of the object,are inputted into separate position *** addition,the position controllers of the two individual HMs are designed to enable precise motion control by using the virtual decomposition control ***,comparative experiments are carried out on a hydraulic dual-arm test *** proposed method is validated by the experimental results,which demonstrate improved object position accuracy and reduced internal force.

关键词： hydraulic dual-arm manipulator compliance motion control unknown object adaptive mass estimation nonlinear control

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A robust vector tracking loop structure based on potential bias analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 405-420页

作者： Qiongqiong JIA Yiran LUO bing.xu Li-Ta HSU Renbiao WU Tianjin Key Lab for Advanced Signal Processing Civil Aviation University of ChinaTianjin 300300China Interdisciplinary Division of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University999077Hong KongChina Department of Geomatics Engineering University of CalgaryCalgary T2N1N4Canada

This paper proposes a robust vector tracking loop structure based on potential bias analysis. The influence of four kinds of biases on the existing two implementations of Vector Tracking Loops(VTLs) is illustrated by theoretical analysis and numerical simulations, and the following findings are obtained. Firstly, the initial user state bias leads to steady navigation solution bias in the relative VTL, while new measurements can eliminate it in the absolute VTL. Secondly, the initial code phase bias is transferred to the following navigation solutions in the relative VTL, while new measurements can eliminate it in the absolute VTL. Thirdly, the user state bias induced by erroneous navigation solution of VTLs can be eliminated by both of the two VTLs. Fourthly,the multipath/NLOS likely affects the two VTLs, and the induced tracking bias in the duration of the multipath/NLOS would decrease the performance of VTLs. Based on the above analysis,a robust VTL structure is proposed, where the absolute VTL is selected for its robustness to the two kinds of initialization biases;meanwhile, the instant bias detection and correction method is used to improve the performance of VTLs in the duration of the multipath/NLOS. Numerical simulations and experimental results verify the effectiveness of the proposed robust VTL structure.

关键词： Global Navigation Satellite System(GNSS) Vector Tracking Loop(VTL) Multipath Non-Line-of-Sight(NLOS) Tracking bias propagation Least Absolute Shrinkage and Selection Operator(LASSO)

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Catalytically generated noncovalent ammonium dienolate:a versatile platform for the development of organocatalytic asymmetric cascade reactions

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Science China Chemistry 2024年第8期67卷 2524-2546页

作者： Jun-bing Lin Dong-Sheng Ji Peng-Fei xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Shaanxi Key Laboratory of Chemical Reaction Engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China

Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.

关键词： organocatalysis asymmetric catalysis ammonium dienolate cascade reaction difunctionalization

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Real-time arrival picking of rock microfracture signals based on convolutional-recurrent neural network and its engineering application

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 761-777页

作者： bing-Rui Chen xu Wang Xinhao Zhu Qing Wang Houlin Xie State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Accurately picking P-and S-wave arrivals of microseismic(MS)signals in real-time directly influences the early warning of rock mass failure.A common contradiction between accuracy and computation exists in the current arrival picking ***,a real-time arrival picking method of MS signals is constructed based on a convolutional-recurrent neural network(CRNN).This method fully utilizes the advantages of convolutional layers and gated recurrent units(GRU)in extracting short-and long-term features,in order to create a precise and lightweight arrival picking ***,the synthetic signals with field noises are used to evaluate the hyperparameters of the CRNN model and obtain an optimal CRNN *** actual operation on various devices indicates that compared with the U-Net method,the CRNN method achieves faster arrival picking with less performance *** application of large underground caverns in the Yebatan hydropower station(YBT)project shows that compared with the short-term average/long-term average(STA/LTA),Akaike information criterion(AIC)and U-Net methods,the CRNN method has the highest accuracy within four sampling points,which is 87.44%for P-wave and 91.29%for S-wave,*** sum of mean absolute errors(MAESUM)of the CRNN method is 4.22 sampling points,which is lower than that of the other *** the four methods,the MS sources location calculated based on the CRNN method shows the best consistency with the actual failure,which occurs at the junction of the shaft and the second ***,the proposed method can pick up P-and S-arrival accurately and rapidly,providing a reference for rock failure analysis and evaluation in engineering applications.

关键词： Rock mass failure Microseismic event P-wave arrival S-wave arrival Deep learning

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Chemoselective labeling-based spermatozoa glycan imaging reveals abnormal glycosylation in oligoasthenotspermia

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Chinese Chemical Letters 2024年第4期35卷 475-480页

作者： Lijia xu Tong Zhong Wei Zhao bing Yao Lin Ding Huangxian Ju State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Department of Reproductive Medical Center Jinling HospitalSchool of MedicineNanjing UniversityNanjing 210002China Chemistry and Biomedicine Innovation Center(ChemBIC) Nanjing UniversityNanjing 210023China Center of Clinical Laboratory Science The Affiliated Cancer Hospital of Nanjing Medical University&Jiangsu Cancer Hospital&Jiangsu Institute of Cancer ResearchNanjing 210009China

Spermatogenesis, maturation, capacitation and fertilization are precisely regulated by glycosylation. However, the relationship between altered glycosylation patterns and the onset and development of reproductive disorders is unclear, mainly limited by the lack of in situ imaging techniques for spermatozoa glycosylation. We developed an efficient and highly specific spermatozoa glycan imaging technique based on the robust chemoselective labeling of sialic acid(Sia) and N-acetyl-D-galactosamine(Gal/GalNAc). We further proposed a “tandem glycan chemoselective labeling” strategy to achieve simultaneous imaging of two types of glycans on spermatozoa. We applied the developed method to the spermatozoa from oligozoospermic patients and diabetic mice and found that these spermatozoa showed higher levels of Sia and Gal/Gal NAc expression than the normal groups. Moreover, spermatozoa from diabetic mice showed a severe decrease in number, viability, and forward motility, suggesting that in vivo glucose metabolism disorders may lead to an elevated level of spermatozoa glycosylation and have a correlation with the development of oligoasthenotspermia. Our work provides a research tool to reveal the relationship between glycosylation modification and spermatozoa quality, and a promising clue for the development of glycan-based reproductive markers.

关键词： Spermatozoa Glycan Chemoselective labeling Oligoasthenotspermia Fluorescence imaging

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Abnormal grain growth induced byδ→γphase transformation in Fe-based shape memory alloys

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Journal of Materials Science & Technology 2024年第5期172卷 196-201页

作者： Huabei Peng Liqiu Yong Gaixia Wang Jiazhen Yan bing.xu Yuhua Wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Grain boundaries,including low-angle,high-angle,and coinci-dence boundaries,are intrinsic interfaces in polycrystalline *** heat-treatment at sufficiently high temperatures,grain boundary migration occurs because the grain boundaries are ther-modynamically ***,grain growth occurs due to a decrease in grain boundary area after heat-treatment[1].In general,there are two types of grain growth:normal grain growth,where grains grow uniformly,and abnormal grain growth,where one or a few grains selectively grow and engulf surround-ing smaller grains,leading to the formation of large grains,some-times several millimeters or greater in size[2].The classical tech-nique to achieve abnormal grain growth is the strain-annealing method,which involves subjecting the material to a small strain followed by annealing[3,4].This method has been reported to ob-tain single-crystal wires or plates[1].Additionally,abnormal grain growth can be achieved by plastic straining at high temperatures,resulting in the fabrication of large grains or single crystals[5].However,the above methods are not applicable to components with complicated shapes due to the inevitable deformation ***,Omori et *** a simply method of abnor-mal grain growth to fabricate ultra-large grains,even single crys-tals,in Cu-Al-Mn[1],Fe-Mn-Al-Ni[2],and Fe-Mn-Al-Ni-Cr[6]*** method involves applying cyclic heat treatment between a high temperature BCC single-phase region and a low tempera-ture BCC+FCC two-phase region[1,2,6-12].Note that the cyclic heat treatment resulted in the formation of BCC sub-grain struc-tures responsible for abnormal grain growth[1,2,6-12].In addition,Yang et *** that abnormal grain growth occurred at above 900℃,and large-grains,even single crystals,were obtained only through annealing cast Cu-based polycrystalline alloys contained coherent nano-particles[13,14].Notably,the cyclic heat treatment and annealing cast alloys are deform

关键词： grain alloys deformation

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Rapid health estimation of in-service battery packs based on limited labels and domain adaptation

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Journal of Energy Chemistry 2024年第2期89卷 345-354,I0009页

作者： Zhongwei Deng Le xu Hongao Liu Xiaosong Hu bing Wang Jingjing Zhou School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina School of Sustainability Stanford UniversityStanfordCA 94305USA College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China China Automotive Engineering Research Institute Co.Ltd. Chongqing 401122China

For large-scale in-service electric vehicles(EVs)that undergo potential maintenance,second-hand transactions,and retirement,it is crucial to rapidly evaluate the health status of their battery ***,existing methods often rely on lengthy battery charging/discharging data or extensive training samples,which hinders their implementation in practical *** address this issue,a rapid health estimation method based on short-time charging data and limited labels for in-service battery packs is proposed in this ***,a digital twin of battery pack is established to emulate its dynamic behavior across various aging levels and inconsistency ***,increment capacity sequences(△Q)within a short voltage span are extracted from charging process to indicate battery ***,data-driven models based on deep convolutional neural network(DCNN)are constructed to estimate battery state of health(SOH),where the synthetic data is employed to pre-train the models,and transfer learning strategies by using fine-tuning and domain adaptation are utilized to enhance the model ***,field data of 10 EVs exhibiting different SOHs are used to verify the proposed *** using the△Q with 100 m V voltage change,the SOH of battery packs can be accurately estimated with an error around 3.2%.

关键词： Lithium-ion battery Electric vehicles Health estimation Feature extraction Convolutional neural network Domain adapatation

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Achieving high-performance sodium metal anodes: From structural design to reaction kinetic improvement

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Nano Research 2024年第3期17卷 1288-1312页

作者： Jing xu Jianhao Yang Yashuang Qiu Yang Jin Tianyi Wang bing Sun Guoxiu Wang Research Center of Grid Energy Storage and Battery Application School of Electrical and Information EngineeringZhengzhou UniversityZhengzhou 450001China College of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225009China Centre for Clean Energy Technology School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNSW 2007Australia

Sodium metal is one of the ideal anodes for high-performance rechargeable batteries because of its high specific capacity(~1166 mAh·g^(-1)),low reduction potential(-2.71 V compared to standard hydrogen electrodes),and low ***,the unstable solid electrolyte interphase,uncontrolled dendrite growth,and inevitable volume expansion hinder the practical application of sodium metal *** present,many strategies have been developed to achieve stable sodium metal ***,we systematically summarize the latest strategies adopted in interface engineering,current collector design,and the emerging methods to improve the reaction kinetics of sodium deposition ***,the strategies of constructing protective layers are reviewed,including inorganic,organic,and mixed protective layers through electrolyte additives or ***,the classification of metal-based,carbon-based,and composite porous frames is discussed,including their function in reducing local deposition current density and the effect of introducing sodiophilic ***,the recent progress of alloys,nanoparticles,and single atoms in improving Na deposition kinetics is systematically ***,the future research direction and the prospect of high-performance sodium metal batteries are proposed.

关键词： sodium metal anodes interface engineering current collector design reaction kinetics sodium deposition processes

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Acute upper gastrointestinal bleeding due to portal hypertension in a patient with primary myelofibrosis:A case report

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World Journal of Clinical Cases 2024年第15期12卷 2621-2626页

作者： Yu Chen bing-bing Kong He Yin Hao Liu Sheng Wu Ting xu Department of Emergency Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Pathology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China

BACKGROUND Acute upper gastrointestinal bleeding is a common medical emergency that has a 10%hospital mortality *** to the etiology,this disease can be divided into acute varicose veins and nonvaricose *** from esophageal varices is a life-threatening complication of portal *** hypertension is a clinical syndrome defined as a portal venous pressure that exceeds 10 *** is the most common cause of portal hypertension,and thrombosis of the portal system not associated with liver cirrhosis is the second most common cause of portal hypertension in the Western *** myeloproliferative disorders are the main cause of portal venous thrombosis,and somatic mutations in the Janus kinase 2 gene(JAK2 V617F)can be found in approximately 90% of polycythemia vera,50% of essential thrombocyrosis and 50% of primary *** SUMMARY We present a rare case of primary myelofibrosis with gastrointestinal bleeding as the primary manifestation that presented as portal-superior-splenic mesenteric vein *** blood tests revealed the presence of the JAK2 V617F *** marrow biopsy ultimately confirmed the diagnosis of myelofibrosis(MF-2 grade).CONCLUSION In patients with acute esophageal variceal bleeding due to portal hypertension and vein thrombosis without cirrhosis,the possibility of myeloproliferative neoplasms should be considered,and the JAK2 mutation test should be performed.

关键词： Acute esophageal variceal bleeding Portal hypertension Myelofibrosis JAK2 V617F mutation Case report

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