检索结果-南通市图书馆

PROPERTIES OF W/cu FGMs cONTAINING 1%Tic OR 1%La_2O_3 PREPARED USING GSUHP

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 59-64页

作者： K. Zhang W.P. shen c.c. Ge Laboratory of Special ceramics and Powder Metallurgy University of Science and Technology Beijing Beijing 100083 China

W/ cu functionally gradient materials （FGMs） containing 1% La2O3 and 1% Tic were prepared using graded sintering under tdtra-high pressure （GSUHP）. The specimens have been found to exhibit low porosity （11.57% and 11.35%, respectively）. Shearing strength of the specimens between layers is good. Moreover, the specimens have still demonstrated good performance in testing thermal-shock resistance. When power density of laser is 200MWm^-2, the specimens have been tested for thermal-shock resistance （1000 times）; the specimens that contained 1%La2O3 were not subjected to damage, whereas those that contained 1%Tic began to crack. Finally, effect of additives on thermal-shock resistance was also preliminarily discussed.

关键词： W/cu FGMs (functionally gradient materials) GSUHP (graded sintering under ultra-high pressure) shearing strength, thermal-shock resistance

colloidally deposited nanoparticle wires for biophysical detection

在线全文

学校读者我要写书评

暂无评论

chinese Physics B 2015年第12期24卷 87-90页

作者： Sophie c.shen 刘文韬刁佳杰 University of North carolina at chapel Hill college of Environmental Science and Forestry State University of New York center for Mitochondrial Biology and Medicine The Key Laboratory of Biomedical Information Engineering of Ministry of EducationSchool of Life Science and Technology and Frontier Institute of Life Science Frontier Institute of Science and Technology (FIST)Xi’an Jiaotong University

Among the techniques developed to prepare nanoparticle wires for multiple applications, the colloidal deposition method at interface has been regarded as cost-efficient and eco-friendly, and hence has attracted an increasing amount of research attention. In this report, the recent developments in preparing nanoparticle wires and integrated nanoparticle wire arrays using this technique have been reviewed. Furthermore, we have also discussed the application of these nanoparticle structures in detecting chemical and biological molecules.

关键词： nanoparticle biomolecule electronic detection

Effects of Mixing Volume and Initial Particle Size Distribution of Fly Ash on Pore Solution of cement Paste

在线全文

学校读者我要写书评

暂无评论

武汉理工大学学报 2010年第17期32卷 112-116页

作者： SHUI Z H DUAN P shen c H School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China center of Materials Research and Analysis Wuhan University of TechnologyWuhan 430070China

The effects of fly ash with different mixing volume and different particle sizes on pore solution of cement-based materials were studied. The pore solution was extracted by squeezing at scheduled ages. The particle size distribution of fly ash was classified as smaller than 45 μm and 45～80 μm,and the mixing volume was classified as 10% and 20%. The concentrations of K+,Na+ and ca2+ were measured using Inductively coupled Plasma Emission Spectrometer (IcP),and the pH was measured by acid-base titration. The results indicate that the concentrations of various ions were prompted at the initial time of the hydration. With further hydration,ion concentrations of K+ and Na+ raise again and finally stabilized,but there is a certain decline on ca2+ later on. It also shows that fly ash exhibited great effect on the hydration of cement,it can lower the concentration of ca2+ and pH of the pore solution,but raise the concentrations of K+ and Na+. More importantly,ion concentrations of K+,Na+ and ca2+ reduced with smaller particle sizes of fly ash.

关键词： cement-based materials pore solution ion concentration squeeze

coercivity mechanisms in nanostructured permanent magnets

在线全文

学校读者我要写书评

暂无评论

chinese Physics B 2019年第7期28卷 1-13页

作者： G P Zhao L Zhao L c shen J Zou L Qiu college of Physics and Electronic Engineering & Institute of Solid State Physics Sichuan Normal UniversityChengdu 610066 China State Key Luboratory of Metastablc Materials Science and Technology Yunshnn University.Qinhuangdao 066004China collaborative Innovation center for Shunxi Advanced Permanent Materials and Technology Lint'en 041004 China

coercivity mechanism in permanent magnets has been debated for many *** this paper, various models of the coercivity mechanism are classified and re-examined by the comparison and *** rotation and curling models can reveal the underlying reversal mechanism clearly based on isolated grains with elliptic *** contrast, the numerical methods consider inter-grain interactions while simulating the evolution of the spins and hysteresis loops with complicated ***, an exact simulation of magnetic reversal in permanent nanomagnets requires many meshes to mimic the thin domain wall *** and pinning are the two main coercivity mechanisms in permanent *** former signifies the beginning of the magnetic reversal, whilst the latter completes ***, it is proposed that the large difference between the intrinsic magnetic properties of the nucleation centers and those of the main phase can result in a large pinning field(self-pinning), which has the attributes of both traditional nucleation and *** a pinning explains the experimental data of permanent magnets very well, including the enhancement of the coercivity by the grain boundary pinning.

关键词： coercivity mechanism permanent nanomagnets self-pinning

ON THE RELATIONSHIP BETWEEN THE EMBEDDED-ATOMMETHOD FUNcTION OF TITANIUM AND TEMPERATURE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1999年第2期12卷 143-148页

作者： shen, c. Zhang, H.T. Lu, M. Bai, X.M. Zhang, Q.J. Fudan Univ Shanghai China

Temperature-dependent Embedded-Atom-Method (EAM) functions of hcp titanium have been determined by fitting to the lattice constants and elastic constants, measured at various temperatures as well as by considering the universal Rose's relation. The EAM functions thus obtained satisfy the stable structure requirement and cauchy discrepancy. The results show that the EAM functions do have temperature-dependence, and in the meanwhile it also provides EAM functions of titanium for the study of Ti-based metallic materials at various temperatures. (Author abstract) 16 Refs.

关键词： computer simulation crystal atomic structure Elastic moduli Free energy Metallic matrix composites Thermal effects

Rational Solutions of First Order Algebraic Ordinary Differential Equations

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & complexity 2024年第2期37卷 567-580页

作者： FENG Shuang shen Liyong School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Let f(t,y,y')=∑ _(i=0)^(n )a_(i)(t,y)y'^(i)=0 be an irreducible first order ordinary differential equation with polynomial *** in 1998 proved that there exists a constant c such that every rational solution of f(t,y,y')=0 is of degree not greater than *** show that this degree bound c depends not only on the degrees of f in t,y,y' but also on the coefficients of f viewed as the polynomial in t,y,y'.In this paper,the authors show that if f satisfies deg(f,y)0,then the degree bound c only depends on the degrees of f in t,y,y',and furthermore we present an explicit expression for c in terms of the degrees of f in t,y,y'.

关键词： Degree bound first order AODE height rational solution

Near Earth Vortices Driving of Field Aligned currents Based on Magnetosphere Multiscale and Swarm Observations

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2019年第1期39卷 9-17页

作者： ZHANG c shen c YANG Y Y DUNLOP M W TI S RUSSELL c T LüHR H BURcH J L LINDQVIST P A TORBERT R B FRIIS-cHRISTENSEN E State Key Laboratory of Space Weather National Space Science Center college of Earth Science University of Chinese Academy of Sciences college of Science Harbin Institute of Technology Institute of china Seismological Bureau Crustal Stress Space Science Institute School of Astronautics Beihang University Rutherford Appleton Laboratory University of california German Research center For Geosciences German Research Center for Geosciences Southwest Research Institute Royal Institute of Technology University of New Hampshire Danish National Space center

A long-standing mystery in the study of Field-Aligned currents(FAcs) has been that: how the currents are generated and why they appear to be much stronger at high altitudes than in the ionosphere. Here we present two events of magnetotail FAcs observed by the Magnetospheric Multiscale Spacecraft(MMS) on 1 st July and 14 th July 2016, to show how the Substorm current Wedges(ScW) were formed. The results show that particles were transferred heading towards the Earth during the expansion phase of *** azimuthal flow formed clockwise(counter-clockwise) vortex-like motion, and then generated downward(upward) FAcs on the tailward/poleward side of the distorted field with opposite vorticity on their Earthward/equatorward side. We also analyzed the Region 1 FAcs observed by the Earth Explorer Swarm spacecraft on 1 st July 2016 and found that they were associated with FAcs observed by MMS, although differing by a factor of 10. This difference suggests that either there was the closure of the currents at altitudes above 500 km or the currents were not strictly parallel to B and closed at longitudes away from where they were generated.

关键词： Substorm current wedge Magnetosphere Field-aligned currents Flow vorticity Multiple spacecraft measurements

Decision and coordination of an E-commerce Supply chain considering Returns and Network Externalities

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2024年第5期33卷 552-575页

作者： Liang shen Fei Lin Yuyan Wang Luping Ding T.c.E.cheng Dexia Wang School of Public Finance and Taxation Shandong University of Finance and Economicsjinan 250014China bschool of Management Science and Engineering Shandong University of Finance and EconomicsJinan 250014China PolyU Business School The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077China

considering the large number of returns in online sales and the network externalities of e-platforms,we develop a decentralized model and a centralized model to explore the impacts of returns and network externalities on e-commerce supply chain(EcSc)*** show that in the decentralized model,the service level,price,market demand,and EcSc members’profits increase with the network externality ***,the service level and price increase,while the market demand and EcSc members’profits decrease with the product return *** centralized model is the optimal operating mode when it is properly *** design the“commission and return cost-sharing”contract to optimize EcSc,in which the proportion of the e-platform’s sharing of the return handling cost is exactly equal to the proportion of the system profit after *** on the decentralized model,we develop two extended models in which we endogenize the impacts of the service level and return rate on the network externality *** comparisons between the extended and decentralized models,we show that high-quality service can improve EcSc’s profitability,while a high return rate hurts its economic performance.

关键词： E-commerce supply chain coordination mechanism network externalities return products

The Mechanism of Internal Friction Peak Associated with the Subboundaries

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

苏州市职业大学学报 1997年第1期8卷 10-12页

作者： Z.c.shen

It has been indicated that subboundaries apperar to have difficulty in sliding. This paper propose three mechanisms of the internal friction peak associated with subboundaries:diffusion *** and climb of the jogged dislocations in subboundaries and the interaction of subboundaries and dislocations. We have analysed and calculated the internal friction.

关键词：职业大学学报王二苏州飞花田七