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Construction of an Hα diagnostic system and its application to determine neutral hydrogen densities on the Keda Torus eXperiment

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Chinese Physics B 2019年第10期28卷 428-434页

作者： Junfeng Zhu Tao Lan Ge Zhuang Tijian Deng Jie Wu hangqi xu Chen Chen Sen Zhang Jiaren Wu Yiming Zu Hong Li Jinlin Xie Ahdi Liu Zixi Liu Zhengwei Wu Hai Wang Xiaohui Wen Haiyang Zhou Chijin Xiao Weixing Ding Wandong Liu KTX Laboratory and Department of Engineering and Applied Physics University of Science and Technology of ChinaHefei 230026China Plasma Physics Laboratory University of SaskatchewanSaskatoonSK S7N 5E2Canada

A 10-channel Hα diagnostic system has been designed with the rapid response rate of 300 kHz, spatial resolution of about 40 mm, and overlap between adjacent channels of about 3%, and it has been implemented successfully on Keda Torus eXperiment(KTX), a newly constructed, reversed field pinch(RFP) experimental device at the University of Science and Technology of China(USTC). This diagnostic system is a very important tool for the initial KTX operations. It is compact,with an aperture slit replacing the traditional optical lens system. A flexural interference filter is designed to prevent the center wavelength from shifting too much as the increase of angle from vertical incidence. To eliminate the stray light,the interior of the system is covered with the black aluminum foil having a very high absorptivity. Using the Hαemission data, together with the profiles of electron temperature and density obtained from the Langmuir probe, the neutral density profiles have been calculated for KTX plasmas. The rapid response rate and good spatial resolution of this Hαdiagnostic system will be beneficial for many studies in RFP plasma physics.

关键词： Hα diagnostic neutral density Keda Torus eXperiment(KTX) device

Development of a compact torus injection system for the Keda Torus eXperiment

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Plasma Science and Technology 2022年第4期24卷 114-123页

作者： Chen CHEN Tao LAN Chijin XIAO Ge ZHUANG Defeng KONG Shoubiao ZHANG Sen ZHANG Weixing DING Zhengwei WU Wenzhe MAO Jie WU hangqi xu Jiaren WU Yiming ZU Dong ZHANG Zian WEI Xiaohui WEN Chu ZHOU Ahdi LIU Jinlin XIE Hong LI Wandong LIU Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People's Republic of China Department of Physics and Engineering Physics University of SaskatchewanSaskatoon SK S7N 5E2Canada Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People's Republic of China

A compact torus injection system,KTX-CTI,has been developed for the planned injection experiments on the Keda Torus e Xperiment(KTX)reversed field pinch(RFP)device to investigate the physics and engineering issues associated with interaction between a compact torus(CT)and *** key interests include fueling directly into the reactor center,confinement improvement,and the injection of momentum and helicity into the RFP *** CT velocity and mass have been measured using a multichannel optical fiber interferometer,and for the first time the time evolution of the CT density profile during CT propagation is *** effects of discharge parameters on the number of injected particles,CT velocity and CT density have been characterized:the maximum hydrogen CT plasma mass,m,CTis 50μg,corresponding to 30%of the mass in a typical KTX plasma;the CT velocity exceeds 120 km *** is observed for the first time that multiple CTs can be produced and emitted during a very short period(<100μs)in one discharge,which is significant for the future study of repetitive CT injection,even with an ultra-high frequency.

关键词： compact torus injection central fueling reversed field pinch

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

Laboratory evaluation of high-friction thin overlays for pavement preservation

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 936-948页

作者： Ouming xu Rentao xu Lintong JIN School of Highway Chang’an UniversityXi’an 710064China School of Materials Science and Engineering Chang’an UniversityXi’an 710061China

Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and ***,several studies have used a novel asphalt mixture known as a high-friction thin overlay(HFTO)to improve surface ***,it remains uncertain whether the laboratory properties of HFTO differ significantly from those of conventional *** study aims to evaluate the laboratory properties of HFTO mixtures and compare them with those of AC and *** mixtures with nominal maximum size of 9.5 mm were produced in the laboratory,and performance tests were conducted,including wheel tracking test,low temperature flexural creep test,moisture susceptibility test,Cantabro Abrasion Test,Marshall Test,sand patch test,British pendulum test,and indoor tire-rollingdown *** results showed that the HFTO exhibited a lower tire/pavement noise than the AC and ***,HFTO had superior high-temperature stability,larger macro texture,and higher skid resistance in comparison to those of AC,but lower than those of ***,HFTO mixtures may be considered a suitable replacement for traditional AC mixtures in regions where skid resistance and noise reduction are concerns.

关键词： road engineering pavement maintenance high friction thin overlay performance skid resistance tire/pavement noise

Granting strength to aerogel fibers through encapsulation

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Science China Materials 2024年第4期67卷 1365-1366页

作者： Wenhui xu Department of Basic Chemistry School of PharmacyJiangxi University of Chinese MedicineNanchang 330004China

Aerogel fibers, distinguished by their lightweight nature, pronounced porosity, large surface area, and superior thermal insulation properties, have diversified applications in thermal management, energy devices, and environmental remediation[1]. However, compared with monolithic ones, these fibershaped aerogels exhibit limited mechanical strength and resilience due to their one-dimensional small size.

关键词： strength fibers thermal

Aldehyde oxidase mediated enantioselective metabolic health risk of dinotefuran

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Science China Chemistry 2024年第6期67卷 2079-2091页

作者： Liwei xu Xinxin xu Hua Kuang Chuanlai xu Xiaoling Wu State Key Laboratory of Food Science and Resources Jiangnan UniversityWuxi214122China International Joint Research Laboratory for Biointerface and Biodetection and School of Food Science and Technology Jiangnan UniversityWuxi214122China Collaborative Innovation center of Food Safety and Quality Control in Jiangsu Province Jiangnan UniversityWuxi214122China

Chiral pollutants often pose significant differential environmental health *** this study,the biotransformation of chiral dinotefuran(DIN)and its enantioselective metabolic toxicity mechanisms have been systemically ***,reversedphase chromatography-high resolution mass spectrometry was developed to quantify the content of DIN R/S chiral enantiomer with pg level sensitivity,revealing a lower elimination rate constant(K_(e))of S-DIN(0.730 h^(-1))than R-DIN(0.746 h^(-1)).Secondly,the interaction mechanism between DIN metabolism and important endogenous bioactive molecules,such as aldehyde oxidase(AOX)and neurotransmitters,was *** DIN nitro-group was converted into a guanidine group by the reducing site of nearby flavin adenine dinucleotide(FAD)in AOX with the preferred higher affinity of ***,the endogenous tryptophan(Trp)aldehyde metabolic intermediate,5-hydroxyindoleacetaldehyde(5-HIAL),provides a persistent electron donor for DIN reduction via the oxidation-catalyzed site in AOX,resulting in remarkable up-regulation of monoamine neurotransmitters such as serotonin and ***,the higher level of neurotransmitters further mediated dysregulation of oxylipin homeostasis via the serotonergic pathway,where S-DIN exhibited more pronounced liver lipid damage and environmental health risk with the accumulated lipid biomarkers,oxidized triglyceride(OxTG)and oxidized sphingomyelin(OxSM).This study elucidates the AOX-mediated enantioselectivity metabolic pathway of DIN,providing a new analytical method for chiral pollutants and paves the way for their health risk assessments.

关键词： neonicotinoid dinotefuran enantiomer aldehyde oxidase metabolomics health risk

Skeletal interoception in osteoarthritis

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Bone Research 2024年第2期12卷 241-254页

作者： Dinglong Yang Jiawen xu Ke xu Peng xu Department of Joint Surgery Honghui HospitalXi’an Jiaotong UniversityXi’an 710054China Department of Orthopedic Surgery and Orthopedic Research Institute West China HospitalSichuan UniversityChengdu 610041China

The interoception maintains proper physiological conditions and metabolic homeostasis by releasing regulatory signals after perceving changes in the internal state of the *** its various forms,skeletal interoception specifically regulates the metabolic homeostasis of ***(OA)is a complex joint disorder involving cartilage,subchondral bone,and *** subchondral bone undergoes continuous remodeling to adapt to dynamic joint *** findings highlight that skeletal interoception mediated by aberrant mechanical loads contributes to pathological remodeling of the subchondral bone,resulting in subchondral bone sclerosis in *** skeletal interoception is also a potential mechanism for chronic synovial inflammation in *** this review,we offer a general overview of interoception,specifically skeletal interoception,subchondral bone microenviroment and the aberrant subchondral *** also discuss the role of skeletal interoception in abnormal subchondral bone remodeling and synovial inflammation in OA,as well as the potential prospects and challenges in exploring novel OA therapies that target skeletal interoception.

关键词： homeostasis inflammation releasing

Surface Polarization Effects on Collapse Transition of Polyelectrolyte Brushes

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Chinese Journal of Polymer Science 2024年第9期42卷 1313-1320,I0006页

作者： Xiao-Fei xu State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai200237China

Polyelectrolyte brushes(PEBs)are commonly used to modify surface that have attracted great research *** dielectric permittivity of the grafted surface is typically significantly different from that of solution,which results in surface polarization(SP)effect with a jump of electric *** is thus important to study how SP alters the PEB’s structure and *** this work,the SP effects on PEB structure was studied using a statistical thermodynamic *** free energy functional to describe SP effect was constructed by using the image-charge ***,the electrostatic potential was solved from a modified Poisson-Boltzmann equation taking the ion solvation effect into *** the absence of SP,the thickness of PEB exhibited a continuous collapse transition when decreasing the solvent *** the presence of SP,the collapse became a jump-like *** energy analysis showed that the long-range Coulombic interaction dominated the transition because of the enhanced counterion condensation in the presence of *** theory provides an effective tool to study SP effect on PEBs,and the results explain the underlying physics in PEB collapse transition.

关键词： Surface polarization Polyelectrolyte brush Image charge Ion solvation Polyelectrolyte collapse transition

Malware Evasion Attacks Against IoT and Other Devices: An Empirical Study

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Tsinghua Science and Technology 2024年第1期29卷 127-142页

作者： Yan xu Deqiang Li Qianmu Li Shouhuai xu School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Department of Computer Science University of Colorado Colorado SpringsColorado SpringsCO 80918USA

The Internet of Things(loT)has grown rapidly due to artificial intelligence driven edge *** enabling many new functions,edge computing devices expand the vulnerability surface and have become the target of malware ***,attackers have used advanced techniques to evade defenses by transforming their malware into functionality-preserving *** systematically analyze such evasion attacks and conduct a large-scale empirical study in this paper to evaluate their impact on *** specifically,we focus on two forms of evasion attacks:obfuscation and adversarial *** the best of our knowledge,this paper is the first to investigate and contrast the two families of evasion attacks *** apply 10 obfuscation attacks and 9 adversarial attacks to 2870 malware *** obtained findings are as follows.(1)Commercial Off-The-Shelf(COTS)malware detectors are vulnerable to evasion attacks.(2)Adversarial attacks affect COTS malware detectors slightly more effectively than obfuscated malware examples.(3)Code similarity detection approaches can be affected by obfuscated examples and are barely affected by adversarial attacks.(4)These attacks can preserve the functionality of original malware examples.

关键词： Android malware obfuscation adversarial examples