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chinese Journal of Polymer Science 2005年第2期23卷 137-145页

作者： J.YangandP.H.Geil t.c.longandp.xu DepartmentofMaterialsScienceandEngineering UniversityoflUinois1304W.GreenSt.UrbanaIL61801 W.L.Gore＆Assocs. Inc.W.L.Gore＆Assocs.Inc.P.O.Box1220ElktonMD21921USA

the effect of sintering dispersed and bulk,low molecular weight(M_n=50,000 Da),nano-emulsionpolytetrafluoroethylene(PtFE)particles near their melting point is *** the nascent particles consisting of ca.75 nm diameter,hexagonal,single crystals,sintering at,e.g.,350℃,results,initially,in merger of neighboring particles,followed by individual molecular motion on the substrate and the formation of folded chain,lamellar single crystals andspherulites,and on-edge *** is suggested these structures develop,with time,in the mesomorphic“melt”.Sintering ofthe bulk resin yields extended chain,band structures,as well as folded chain lamellae;end-surface to end-surface merger,possibly by end-to-end polymerization,occurs with increasing time.

关键词： Polytetrafluoroethylene Nano-emulsion Single crystals Spherulites Banded structures Extended chain crystals Sintering.

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.xu t.W.Huang K.Jiang c.N.Wu H.Peng P.c.hen R.Li H.B.Zhuo c.t.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Recent advances on bismuth oxyhalides for photocatalytic cO_(2)reduction

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Journal of Environmental Sciences 2024年第6期140卷 183-203页

作者： Liangpang xu Jimmy c.Yu Ying Wang Department of chemistry The Chinese University of Hong KongShatinNew TerritoriesHong Kong 999077China

Photocatalytic conversion of cO_(2)into fuels such as cO,cH_(4),and cH_(3)OH,is a promising approach for achieving carbon *** oxyhalides(BiOX,where X=cl,Br,and I)are appropriate photocatalysts for this purpose due to the merits of visible-light-active,efficient charge separation,and easy-to-modify crystal structure and surface *** practical applications,multiple strategies have been proposed to develop high-efficiency BiOX-based *** review summarizes the development of different approaches to prepare BiOX-based photocatalysts for efficient cO_(2)*** the review,the fundamentals of photocatalytic cO_(2)reduction are ***,several widely used modification methods for BiOX photocatalysts are systematacially discussed,including heterojunction construction,introducing oxygen vacancies(OVs),Bi-enrichment,heteroatom-doping,and morphology ***,the challenges and prospects in the design of future BiOX-based photocatalysis for efficient cO_(2)reduction are examined.

关键词： Bismuth oxyhalides Photocatalysis cO_(2)reduction Modification methods

Design,simulation,and testing of a tunable MEMS multi-threshold inertial switch

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Microsystems & Nanoengineering 2024年第2期10卷 37-46页

作者： Qiu xu Rodrigo t.Rocha Yousef Algoos Eric Feron Mohammad I.Younis Faculty of Electronic Information Engineering Huaiyin Institute of TechnologyHuai’an223003PR China computer Electrical and Mathematical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia Piezoelectric Microsystem technologies Silicon Austria LabsVillach9524Austria Physical Sciences and Engineering Division King Abdullah University of Science and TechnologyThuwal23955Saudi Arabia Mechanical Engineering Department State University of New YorkBinghamtonNY13902USA

this paper presents a tunable multi-threshold micro-electromechanical inertial switch with adjustable threshold *** demonstrated device combines the advantages of accelerometers in providing quantitative acceleration measurements and g-threshold switches in saving power when in the inactive state upon experiencing acceleration below the *** designed proof-of-concept device with two thresholds consists of a cantilever microbeam and two stationary electrodes placed at different positions in the sensing *** adjustable threshold capability and the effect of the shock duration on the threshold acceleration are analytically investigated using a nonlinear beam *** are shown for the relationships among the applied bias voltage,the duration of shock impact,and the tunable *** fabricated prototypes are tested using a shock-table *** analytical results agree with the experimental *** designed device concept is very promising for the classification of the shock and impact loads in transportation and healthcare applications.

关键词： tunable acceleration testing

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

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

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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

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

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

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