检索结果-南通市图书馆

microscopic stresses in carbon nanotube reinforced aluminum matrix composites determined by in-situ neutron diffraction

引用

Journal of materials Science & Technology 2020年第19期54卷 58-68页

作者： X.X.Zhang J.F.Zhang Z.Y.Liu w.m.gan m.Hofmann H.Andrä B.L.Xiao Z.Y.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China German Engineering materials Science Centre at mLZ Helmholtz-Zentrum GeesthachtD-85747 GarchingGermany Heinz maier-Leibnitz Zentrum(mLZ) Technische Universität MünchenD-85747 GarchingGermany Fraunhofer Institute for Industrial mathematics Fraunhofer-Platz 1Kaiserslautern 67663Germany

One of the most desired strengthening mechanisms in the carbon nanotube reinforced aluminum matrix composites(CNT/Al)composites is the load transfer strengthening mechanism(LTSm).However,a fundamental issue concerning the LTSm is that quantitative measurements of load partitioning in these composites during loading are very *** this study,in-situ neutron diffraction study on the tensile deformation of the 3 vol.%CNT/2009 Al composite and the unreinforced 2009 Al alloy was ***{311}and{220}diffraction elastic constants(DECs)of the 2009 Al alloy were *** those DECs the average stress in the 2009 Al matrix of the composite was *** the average stress in the CNTs was separated by using the stress equilibrium *** homogenization models were also applied to explain the stress evolution in each *** results agree with experimental *** the present case,the average stress in the CNTs reaches 1630 mPa at the yield strength of the composite based on linear regression of the measured data,which leads to an increment of yield strength by about 37 *** the result of this work,an approach to quantify load partitioning in the CNTs is developed for the CNT/Al composites,which can be applied to optimize the mechanical properties of the composites.

关键词： Carbon nanotubes Aluminum matrix composites In-situ neutron diffraction Load partitioning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of welding speed on the multiscale residual stresses in frictionstir welded metal matrix composites

引用

Journal of materials Science & Technology 2019年第5期35卷 824-832页

作者： X.X.Zhang L.H.wu H.ANDra w.m.gan m.Hofmann D.wang D.R.Ni B.L.Xiao Z.Y.ma Shenyang National Laboratory for materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Fraunhofer Institute for Industrial mathematics Fraunhofer-Platz 1 Kaiserslautern 67663 Germany German Engineering materials Science Centre Helmholtz-Zentrum Geesthacht D-21502 Geesthacht Germany Heinz maier-Leibnitz Zentrum (mLZ) Technische Universitat Munchen D-85747 Garching Germany

The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled hierarchical multiscale modeling methods. measurements showed that the macroscopic and total RSes had the largest variations in the longitudinal direction(LD). Increasing the welding speed led to higher values of measured LD macroscopic and total RSes in the matrix. The welding speed also significantly influenced the distributions and magnitudes of the microscopic RSes. The RSes were predicted via an improved hierarchical multiscale model, which includes a constant coefficient of friction based thermal model. The RSes in the composite plates before friction stir welding(FSw) were computed and then set as the initial states of the FSw process during modeling. This improved decoupled multiscale model provided improved predictions of the temperature and RSes compared with our previous model.

关键词： metal-matrix composites (mmCs) Friction stir welding Residual/internal stress Neutron diffraction Finite element analysis (FEA) multiscale simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Bulk and local textures of pure magnesium processed by rotary swaging

引用

Journal of magnesium and Alloys 2013年第4期1卷 341-345页

作者： w.m.gan Y.D.Huang R.wang Z.Y.Zhong N.Hort K.U.Kainer N.Schell H.-G.Brokmeier A.Schreyer Institute of materials Research Helmhlotz-Zentrum GeesthachtMax-Planck-Str.1D-21502 GeesthachtGermany Institute for materials Science and Engineering Clausthal University of TechnologyAgricolastrasse 6D-38678 Clausthal-ZellerfeldGermany

Rotary swaging processing on commercial as-cast pure mg has been carried out. Bulk texture variation with the processing passes was investigated using large gauge volume by neutron diffraction, of which results showed a combination of different components such as {00.2} basal fibre and two weak {10.0} and {11.0} fibres. Asymmetric distribution of the basal fibre around swaging direction was observed and being related to the processing parameters. Texture gradient analysis by synchrotron radiation demonstrates a non-uniform deformation of the RS processed pure mg from surface to the centre.

关键词： Rotary swaging Pure magnesium Bulk and local textures

来源：

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

Queue reduction in discrete-event systems by relabeling

引用

Control Theory and Technology 2018年第3期16卷 232-240页

作者： Yongmei gan Ting JIAO w. m. wONHAm School of Electrical Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 China Department of Automation Shanxi University Taiyuan Shanxi 030006 China Department of Electrical and Computer Engineering University of Toronto Toronto ON M5S 3G4 Canada

The customer population of entities potentially requesting to join a queue for service often have identical structure, i.e., the same state set and isomorphic transitions. The state size of the automaton modeling a queue will grow rapidly with increase of the size of this population. However, by relabeling the queue arrival events and service events to the same symbols respectively, the automaton model of a queue will be converted to the structure of a buffer, which is proved to be independent of the total size of the customer population, as long as the queue size is held fixed. we propose the model of a dynamic buffer to embody order and shift of a queue. The result is applied to a manufacturing facility with a dynamic buffer to manage the repair of broken down machines.

关键词： Queue relabeling identical structures invariance property discrete-event systems

来源：

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

Atomically dispersed materials:Ideal catalysts in atomic era

引用

Nano Research 2024年第1期17卷 18-38页

作者： Tao gan Dingsheng wang Department of Chemistry Tsinghua UniversityBeijing 100084China

Catalysts can accelerate the chemical reaction rate and effectively promote the molecules transformation,which is of great significance in the research of chemical industry and material *** extreme utilization of reactive sites has led to the emergence and development of atomically dispersed materials(ADms).The highly active coordination unsaturated metal sites and fully utilized metal atoms make ADms show great potential in catalytic *** adjustment of coordination environment and electronic structure provides more possibilities for constructing reactive centers with different *** review summarized the application and research progress of ADms in different *** design strategy and structure–activity relationship of ADms for specific reactions were summarized and ***,we also provided advices for the challenges and opportunities faced by ADms in catalytic reactions.

关键词： atomically dispersed materials catalysis organic synthesis battery sensor enzyme

来源：

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

Fractional Stokes–Einstein relation in TIP5P water at high temperatures

引用

Chinese Physics B 2018年第6期27卷 307-314页

作者： gan Ren Ge Sang Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908 China

Fractional Stokes–Einstein relation described by D ～（τ/T）~ξ is observed in supercooled water, where D is the diffusion constant, τ the structural relaxation time, T the temperature, and the exponent ξ =τ^（-1）. In this work, the Stokes–Einstein relation in TIP5 P water is examined at high temperatures within 400 K–800 K. Our results indicate that the fractional Stokes–Einstein relation is explicitly existent in TIP5P water at high temperatures, demonstrated by the two usually adopted variants of the Stokes–Einstein relation, D ～τ^（-1）τand D ～ T/τ, as well as by D ～ T/η, where η is the shear viscosity. Both D ～τ^（-1）τand D ～ T/τ are crossed at temperature Tx= 510 K. The D ～τ^（-1）τis in a fractional form as D ～ τ ξwith ξ =-2.09 for T ≤ Txand otherwise ξ =τ^（-1）.25. The D ～ T/τ is valid with ξ =τ^（-1）.01 for T ≤ Txbut in a fractional form for T Tx. The Stokes–Einstein relation D ～ T/η is satisfied below Tx = 620 K but in a fractional form above Tx. we propose that the breakdown of D ～ T/η may result from the system entering into the super critical region, the fractional forms of D ～τ^（-1）τand D ～ T/τ are due to the disruption of the hydration shell and the local tetrahedral structure as well as the increase of the shear viscosity.

关键词： Stokes-Einstein relation TIP5P water molecular dynamics hydration shells

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ventilation of the Sulu Sea retrieved from historical data

引用

Acta Oceanologica Sinica 2014年第9期33卷 1-11页

作者： LI Li gan Zijun Third Institute of Oceanography State Oceanic Administration State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanoglogy

Based on historical observations, ventilation of the Sulu Sea （SS） is investigated and, its interbasin exchange is also partly discussed. The results suggest that near the surface the water renewal process not only occurs through the mindoro Strait （mS） and the Sibutu Passage, but also depends on the inflows through the Surigao Strait and the Bohol Sea from the Pacific and through the Balabac Strait from the South China Sea （SCS）. Both inflows are likely persistent year round and their transports might not be negligible. Below the surface, the core layer of the Subtropical Lowerwater （SLw） lies at about 200 m, which enters the SS through the mindoro Strait not hampered by topography. moreover, there is no indication of SLw inflow through the Sibutu Passage even though the channel is deep enough to allow its passage. The most significant ventilation process of the SS takes place in depths from 20a m to about 1200 m where intermediate convection driven by quasi-steady inflows through the mindoro and Panay straits （mS-PS） dominates. Since the invaded water is drawn from the upper part of the North Pacific Intermediate water （NPIw） of the SCS, it is normally not dense enough to sink to the bottom. Hence, the convective process generally can only reach some intermediate depths resulting in a layer of weak salinity minimum （about 34.45）. Below that layer, there is the Sulu Sea Deep water （SSDw） homogeneously distributed from 1200 m down to the sea floor, of which the salinity is only a bit higher （about 34.46） above the minimum. Observational evidence shows that hydrographic conditions near the entrance of the mS in the SCS vary significantly from season to season, which make it possi- ble to provide the mS-PS overflowwith denser water of higher salinity sporadically. It is hence proposed that the SSDw is derived from intermittent deed convection resulted from DroDertv changes of the mS-PS inflow.

关键词： Sulu Sea ventilation overflow interbasin exchange

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fast m-fold matching pursuit algorithm for image approximation

引用

Journal of Systems Engineering and Electronics 2009年第4期20卷 883-888页

作者： gan Tao He Yanmin Zhu weile School of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China.

A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. First, it iteratively finds an approximation by selecting m atoms instead of one at a time. Second, the inner product computations are confined within only a fraction of dictionary atoms at each iteration. The modifications are implemented very efficiently due to the spatial incoherence of the dictionary. Experimental results show that compared with full search matching pursuit, the proposed algorithm achieves a speed-up gain of 14.4-36.7 times while maintaining the approximation quality.

关键词： greedy algorithm image approximation matching pursuit

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A micromechanical model for efective conductivity in granular electrode structures

引用

Acta mechanica Sinica 2013年第5期29卷 682-698页

作者： Julia Ott Benjamin Vlker Yixiang gan Robert m.mc meeking marc Kamlah Institute of Applied materials Karlsruhe Institute of Technology76131 Karlsruhe Germany Department of mechanical Engineering University of CaliforniaSanta BarbaraCA 93106 USA School of Civil Engineering The University of SydneyNSW 2006 Australia materials Department University of CaliforniaSanta BarbaraCA 93106 USA School of Engineering University of AberdeenKing’s CollegeAberdeenAB24 3UE Scotland UK INm-Leibniz Institute for New materials Campus D22 66123 Saarbrücken Germany

Optimization of composition and microstructure is important to enhance performance of solid oxide fuel cells （SOFC） and lithium-ion batteries （LIB）. For this, the porous electrode structures of both SOFC and LIB are modeled as a binary mixture of electronic and ionic conducting particles to estimate effective transport properties. Particle packings of 10000 spherical, binary sized and randomly positioned particles are created numerically and densified considering the different manufacturing processes in SOFC and LIB： the sintering of SOFC electrodes is approximated geometrically, whereas the calendering process and volume change due to intercalation in LIB are modeled physically by a discrete el- ement approach. A combination of a tracking algorithm and a resistor network approach is developed to predict the con- nectivity and effective conductivity for the various densified structures. For SOFC, a systematic study of the influence of morphology on connectivity and conductivity is performed on a large number of assemblies with different compositions and particle size ratios between 1 and 10. In comparison to percolation theory, an enlarged percolation area is found, es- pecially for large size ratios. It is shown that in contrast to former studies the percolation threshold correlates to varying coordination numbers. The effective conductivity shows not only an increase with volume fraction as expected but also with size ratio. For LIB, a general increase of conductivity during the intercalation process was observed in correlation with increasing contact forces. The positive influence of cal- endering on the percolation threshold and the effective conductivity of carbon black is shown. The anisotropy caused by the calendering process does not influence the carbon black phase.

关键词： Granular electrode structures Effective conductivity - Percolation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Identifying influential nodes in social networks via community structure and influence distribution difference

引用

Digital Communications and Networks 2021年第1期7卷 131-139页

作者： Zufan Zhang Xieliang Li Chenquan gan School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Chongqing Key Laboratory of mobile Communications Technology Chongqing400065China Engineering Research Center of mobile Communications Ministry of EducationChongqing400065China

This paper aims to effectively solve the problem of the influence maximization in social *** this purpose,an influence maximization method that can identify influential nodes via the community structure and the influence distribution difference is ***,the network embedding-based community detection approach is developed,by which the social network is divided into several high-quality ***,the solution of influence maximization is composed of the candidate stage and the greedy *** candidate stage is to select candidate nodes from the interior and the boundary of each community using a heuristic algorithm,and the greedy stage is to determine seed nodes with the largest marginal influence increment from the candidate set through the sub-modular property-based Greedy ***,experimental results demonstrate the superiority of the proposed method compared with existing methods,from which one can further find that our work can achieve a good tradeoff between the influence spread and the running time.

关键词： Social network Community detection Influence maximization Network embedding Influence distribution difference

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：