检索结果-南通市图书馆

Defence Technology（防务技术） 2024年第2期32卷 644-654页

作者： yabei xu Jiankun Shao Wei Wang Shengliang xu Dongping Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyXiangyang 441003China

The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical ***,the impact of the above coupling on thermal hazard assessment is not considered in the literature *** this work,nitroguanidine(NQ)and 1,3,5-trinitro-1,3,5-triazine(RDX)are selected as representative materials to explore the influence of the coupling effect on the thermal hazard assessment of chemical *** linear heating experiments of NQ and RDX are carried out by a microcalorimeter and synchronous thermal *** thermal decomposition curves are decoupled by advanced thermokinetics *** thermal decomposition and kinetic parameters before and after decoupling are *** results of TG experiment show that both NQ and RDX began to lose mass during the endothermic *** endothermic melting and exothermic decomposition of NQ and RDX are coupled within this *** coupling effect has different degrees of influence on its initial decomposition temperature and safety *** with the parameters in the coupling state,the initial decomposition temperature and adiabatic induction period after decoupling *** self-accelerating decomposition temperature increases,and internal thermal runaway time *** the thermal hazard assessment of chemical materials with coupling effects,the calculated parameters after decoupling should be taken as an important safety index。

关键词： Calorimetric technologies Kinetics Thermal hazard Phase transformation Thermal decomposition

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Granting strength to aerogel fibers through encapsulation

在线全文

学校读者我要写书评

暂无评论

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

Skeletal interoception in osteoarthritis

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

Experimental study on performance of spring damping support structure system for large deformation tunnel in soft rock

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Underground Space 2024年第2期15卷 221-243页

作者： Jinfeng xu Xiongyao Xie Zhou Shi Wuqiang Cai Dinglun xu Chen xu Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji UniversityShanghai 200092China Zhaotong City Zhaolu Expressway Investment and Development Co. ZhaotongYunnan Province 657000China Institute of Rock Mechanics Ningbo UniversityNingboZhejiang 315211China

According to the convergence confinement theory,it is an effective measure to control the large deformation of high ground stress in fractured soft rock tunnels by using yielding *** yielding support can be classified as either radial or circumferential yielding *** yielding support is achieved by transforming radial displacement into circumferential tangential closure without compromising the support capacity of the primary lining support *** on this,and inspired by the design principle of dampers,a yielding support structure system with spring damping elements as its core was developed,based on the connection characteristics of steel arches in highway tunnel,which can provide increasing support resistance in the yielding deformation *** the mechanical properties of spring damping elements were obtained through indoor axial pressure and flexural *** addition,according to these results with numerical calculations,the yielding support structure system with embedded spring damping elements can reduce the internal force of the support structure by approximately 10%and increase the area of the plastic zone of the surrounding rock by 11.23%,which can fully utilize the self-bearing capacity of surrounding rock and verify the effectiveness of circumferential yielding ***,the spring damping support structure system was designed with reference to the construction process of the tunnel excavated by drilling and blasting method,and the transformation of the spring damping element to spring damping support structure was *** on field test results,surrounding ground pressure for the yielding support optimization scheme was reduced by 40%and more evenly distributed,resulting in the successful application and a reduction in the construction cost of large deformation tunnels in soft rock.

关键词： Soft rock Highway tunnel Convergence confinement method Circumferential yielding support with spring damping element Numerical calculations Field test

From 0D to 3D:Hierarchical structured high-performance free-standing silicon anodes based on binder-induced topological network architecture

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 16-23,I0002页

作者： Yihong Tong Ruicheng Cao Guanghui xu Yifeng Xia Hongyuan xu Hong Jin Hui xu Xi’an Jiaotong University Suzhou Academy Suzhou 215123JiangsuChina Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215123JiangsuChina

Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely ***,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is ***,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking *** which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of *** from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical ***,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization ***,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.

关键词： Topological network Self-stabilization Flexibility Free-standing Silicon anode

How to build a habitable planet:an interview with Charles H. Langmuir

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 76-80页

作者： Yi-Gang xu the Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Earth is the only known habitable planet in the solar system. Understanding how Earth developed its unique habitability has been the frontier of Earth sciences and has become one of the main themes of current deep-space explorations. What are the decisive factors that led to a habitable planet? What is the role of solid Earth processes in the origin of life and in modulating the surface environment? Are Earth’s habitability studies relevant to current challenges that human beings face? These questions have attracted the interest of both scientists and the public alike.

关键词： Earth (planet)