检索结果-南通市图书馆

Resistive field generation in intense proton beam interaction with solid targets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第1期9卷 35-43页

作者： W.Q.Wang J.J.Honrubia y.y.n X.H.y.ng F.Q.shao Department of Phy.ics National University of Defense TechnologyHunanChina ETSI Aeronáutica y.del Espacio Universidad Politécnica de MadridMadridSpain Department of Nuclear Science and Technology National University of Defense TechnologyHunanChina

The Brown-Preston-Singleton(BPS)stopping power model is added to our previously.developed hy.rid code to model ion beam-plasma *** simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target,in which they.compete with each *** the target is not completely.ionized,the self-generated resistive field effect dominates over the ion scattering ***,when the target is completely.ionized,this situation is ***,it is found that Ohmic heating is important for higher current densities and materials with high *** energy.fraction deposited as Ohmic heating can be as high as 20%-30%.Ty.ical ion divergences with half-angles of about 5°-10°will modify.the proton energy.deposition substantially.and should be taken into account.

关键词： interaction beam intense

Multi-circular formation control with reinforced transient profiles for nonholonomic vehicles:A path-following framework

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology.防务技术） 2024年第1期31卷 278-287页

作者： Jintao Zhang Xingling shao Wendong Zhang Zongy. Zuo School of Instrument and Electronics North University of ChinaTaiyuan 030051China State Key.Laboratory.of Dy.amic Measurement Technology North University of ChinaTaiyuan 030051China Seventh Research Division School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100191China

This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by.a digraph.A multi-circular formation controller endowed with the feature of spatial-temporal decoupling is devised for a group of vehicles guided by.a virtual leader evolving along an implicit path,which allows for a circumnavigation on multiple circles with an anticipant angular *** addition,notice that it ty.ically.imposes a stringent time constraint on time-sensitive enclosing scenarios,hence an improved prescribed performance control(IPPC)using novel tighter behavior boundaries is presented to enhance transient capabilities with an ensured appointed-time convergence free from any.*** significant merits are that coordinated circumnavigation along different circles can be realized via executing geometric and dy.amic assignments independently.with modified transient ***,all variables existing in the entire sy.tem are analy.ed to be *** and experimental results are provided to validate the utility.of suggested solution.

关键词： Multi-circular formation Reinforced transient profiles Nonholonomic vehicles Path following

From risk control to resilience: developments and trends of urban roads designed as surface flood passages to cope with extreme storms

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第2期18卷 103-120页

作者： Zhiy. shao y.exin Li Huafeng Gong Hongxiang Chai College of Environment and Ecology Chongqing UniversityChongqing 400030China Key.Laboratory.of Ecological Environment of Ministry.of Education of Three Gorges Reservoir Area Chongqing UniversityChongqing 400030China T.y.Lin International Engineering Consulting(China)Co.Ltd. Chongqing 400045China

Urban roads can be designated as surface flood passages to transport excess runoff during extreme storms, thereby.preventing local flooding, which is known as the major drainage sy.tem. However, this practice poses significant risks, including human loss and property.damage, due to the high flow rate and velocity.carried by.roads. Moreover, urban roads with low flood-resilience may.significantly.hamper the transportation function during severe storms, leading to dy.function of the city. Therefore, there is an urgent need to transform risk-oriented flood passages into resilient urban road-based flood passages. This paper presents a sy.tematic review of existing methodologies in designing a road network-based flood passage sy.tem, along with the discussion of new technologies to enhance sy.tem resilience. The study.also addresses current knowledge gaps and future directions. The results indicate that flood management measures based on the urban road network should integrate accessibility.assessment, lifeline and emergency.planning to ensure human well-being outcomes. Furthermore, the special needs and features of vulnerable groups must be taken into serious consideration during the planning stage. In addition, a data-driven approach is recommended to facilitate real-time management and evaluate future works.

关键词： Major drainage Flood mitigation Resilient city Stormwater model Urban flooding

The Distances of Subclusters in the Virgo Area

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

天文研究与技术 1999年第S1期 260-263页

作者： shao Z. y. (Shanghai Astronomical Observatory. The Chinese Academy.of Sciences, 80 Nandan RD. Shanghai 200030, China) (E-mail: zy.0} center. shao. ac. cn)

By.using the Mixture Model and radial velocity.data from CfA redshift catalogue, we resolve the substructures of the Virgo cluster. Distances of three main subclusters are determined by.the Tully.Fisher galaxies, they.are 18.0±1.3Mpc, 25.0±2 3Mpc and 30.9±3.1Mpc respectively. which implicate that they.are independent clusters, and the Virgo area has a significant depth in the line-of -sight direction.

关键词： Cluster of Galaxies Virgo Substructure Distance

Development of space virtual laboratory.and simulation sy.tem

在线全文

学校读者我要写书评

暂无评论

Development of space virtual laboratory and simulation syste...

Strain Gradient Finite Element Formulation of Flexoelectricity.in Ferroelectric Material Based on Phase-Field Method

第十一届全国日地空间物理学术讨论会

作者： R.X. y.ng, X.H. Deng, R.X. Tang, y.C. shao, y. Ma, M. Zhou, y. Pang and K. y.an Institute of Electronics and Information, Wuhan University. Wuhan, Hubei, P.R.China, 430079

＜正＞Space scientists use vast quantities of data for their research. The data is obtained from many.different kinds of instruments situated on the ground and on satellites in space. Because of the rapid advance in instruments and detector technology.there has been a phenomenal increase in the quantity.of data, both from observation of specific objects as well as from survey. which cover entire areas of the study. Because of the large volume of data, and the many.different forms in which it is available, the storage and retrieval of data have become difficult tasks. It has also become very.challenging for Space scientists to use the vast storehouse of data to produce exciting new scientific discoveries. On the other hands, Numerical simulation has become a powerful tool to analy.e various plasma phenomena occurring in the solar-terrestrial environment as well as spacecraft observations and theoretical analy.is. The ultimate aim of the project is for users to be able to extract data from observation and simulation archives, develop strategies for distribution of data in the most efficient possible manner and to provide for high speed data transfer between the different data centers, develop technique for bringing together the different structures to efficiently.utilize the data through the establishment of a Virtual laboratory. and run different analy.is tools. It will also provide on-line space simulation support sy.tem, which enables us to perform simulation runs by.providing or selecting plasma parameters through Web-based interface on the internet, compare observations directly.to different simulations and models

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第4期37卷 570-579页

作者： Shuai Wang Hengchang Su Min y. Li-Hua shao National Key.Laboratory.of Strength and Structural Integrity Institute of Solid MechanicsSchool of Aeronautic Science and EngineeringBeihang UniversityBeijing100191People’s Republic of China State Key.Laboratory.of Mechanics and Control for Aerospace Structures and Institute for Frontier Science and Key.Laboratory.for Intelligent Nano Materials and Devices of Ministry.of Education and College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China

Flexoelectricity.is a two-way.coupling effect between the strain gradient and electric field that exists in all dielectrics,regardless of point group ***,the high-order derivatives of displacements involved in the strain gradient pose challenges in solving electromechanical coupling problems incorporating the flexoelectric *** this study.we formulate a phase-field model for ferroelectric materials considering the flexoelectric effect.A four-node quadrilateral element with 20 degrees of freedom is constructed without introducing high-order shape *** microstructure evolution of domains is described by.an independent order parameter,namely.the spontaneous polarization governed by.the time-dependent Ginzburg–Landau *** model is developed based on a thermody.amic framework,in which a set of microforces is introduced to construct the constitutive relation and evolution *** the flexoelectric part of electric enthalpy.the strain gradient is determined by.interpolating the mechanical strain at the node via the values of Gaussian integration points in the isoparametric *** model is shown to be capable of reproducing the classic analy.ical solution of dielectric materials incorporating the flexoelectric *** model is verified by.duplicating some ty.ical phenomena in flexoelectricity.in cy.indrical tubes and truncated py.amids.A comparison is made between the polarization distribution in dielectrics and *** model can reproduce the solution to the boundary.value problem of the cy.indrical flexoelectric tube,and demonstrate domain twisting at domain walls in ferroelectrics considering the flexoelectric effect.

关键词： Flexoelectricity Phase-field method Ferroelectrics Domain configuration

In situ TEM investigation of electron irradiation and aging-induced high-density.nanoprecipitates in an Mg-10Gd-3y.1Zn-0.5Zr alloy

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 Magnesium and Alloy. 2024年第5期12卷 1841-1853页

作者： M.Lv H.L.Ge Q.Q.Jin X.H.shao y.T.Zhou B.Zhang X.L.Ma Sheny.ng National Laboratory.for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density.precipitates in an Mg-10Gd-3y.1Zn-0.5Zr(GWZ1031K,wt.%)alloy.to improve the *** results show that the hardness of the Mg alloy.after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately.64% higher than that of the samples before being *** is mainly.attributed to γ'precipitates on the basal plane after irradiation and the high-density.nanoscale β'precipitates on the prismatic plane after aging,which should be closely.related to the irradiation-induced homogenous *** latter play. a key.role in precipitation *** result paves a way.to improve the mechanical properties of metallic materials by.tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM

Graphdiy.e oxide substrate-enhanced peroxidase-mimicking performance of Ru nanoparticles with phy.iological pH preference

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1123-1131页

作者： Cong Xu Wenjie Ma Haozhi Wang Leihou shao Weiqi Li Ping y. Lanqun Mao Beijing National Laboratory.for Molecular Science Key Laboratory of Analytical Chemistry for Living BiosystemsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University.of Chinese Academy.of Sciences Beijing 100049China State Key.Laboratory.of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China College of Chemistry Beijing Normal UniversityBeijing 100875China

Modulating electronic structure of metal nanoparticles via metal–support interaction has attracted intense interest in the field of cataly.ic ***,the roles of supporting substrates in regulating cataly.ic properties of nanozy.es remain *** this study.we find that the use of graphdiy.e oxide(GDy.)as the substrate for self-terminating growth of Ru nanoparticles(Ru@GDy.)endows the peroxidase-like activity.of Ru nanoparticles with intrinsic phy.iological pH preference and natural horseradish peroxidase(HRP)comparable *** nanoparticles electrolessly.deposited onto GDy. possess a partially.oxidized electronic structure owing to limited charge transfer between Ru and GDy.,contributing to the intrinsic phy.iological pH preference of the peroxidase-mimicking *** importantly.the substrate GDy. play. an influential factor in enhancing cataly.ic activity.that is,the activity.of Ru@GDy. is much higher than that of Ru nanoparticles deposited on other carbon substrates including graphene oxides and *** demonstrate the application of Ru@GDy. nanozy.e in neutral solutions,we employ.Ru@GDy. with nicotinamide adenine dinucleotide(NAD+)-dependent dehy.rogenases in phy.iological conditions to realize a sustainable cascade reaction by.means of forming continuous NAD^(+)/dihy.ronicotiamide adenine dinucleotide(NADH)*** finding represents a promising perspective on designing high-performance peroxidase-mimicking nanozy.es with broader applicability.raising fundamental understanding of structure–activity.relationship,and investigating new applications of nanozy.es in biological sy.tems.

关键词： nanozy.e graphdiy.e reactive oxy.en species electroless deposition metal–support interaction

The influence of y.trium and manganese additions on the degradation and biocompatibility.of magnesium-zinc-based alloy.:In vitro and in vivo studies

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 Magnesium and Alloy. 2024年第2期12卷 608-624页

作者： Lei Shi y.ng y.n Chun-sheng shao Kun y. Bo Zhang Liang-jian Chen Third Xiangy. Hospital Central South UniversityChangsha 410013China State Key.Laboratory.of Powder Metallurgy Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Mechanical Engineering City University of Hong KongHong KongChina

The repair and regeneration of bone defects are highly.challenging orthopedic ***,Mg-based implants have gained popularity.due to their unique biodegradation and elastic modulus similar to that of human *** aim of our study.is to develop a magnesium alloy.with a controllable degradation that can closely.match bone tissue to help injuries heal in vivo and avoid cy.otoxicity.caused by.a sudden increase in ion *** this study.we prepared and modified Mg-3Zn,Mg-3Zn-1y.and Mg-2Zn-1Mn by.hot extrusion,and used Mg-2.5y.2.5Nd was as a *** then investigated the effect of additions of y.and Mn on alloy.'*** results show that Mn and y.can improve not only.compression strength but also corrosion *** alloy.Mg-2Zn-1Mn demonstrated good cy.ocompatibility.in vitro,and for this reason we selected it for implantation in *** degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory.reaction,and the degradation products left no signs of damage to the heart,liver,kidney.or ***,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.

关键词： Magnesium alloy Biodegradation Biocompatibility Bone regeneration Bone defect repair