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Science Letters:Research on 3D fiber orientation distribution in arbitrary planar flows

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 1021-1025页

作者： ZHOU Kun lin jian-zhong State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China China Jiliang University Hangzhou 310018 China

A non-stretchable fiber rotation in planar flows has been solved. The fiber will rotate periodically or run to the asymptotical direction decided by a discriminant defined in the paper involving the fiber aspect ratio and the flow characteristics. Subsequently the fiber orientation distribution is derived directly without the bother of solving the Fokker-Planck equation. The research clearly indicates the overall configuration of a fiber rotation movement in planar flows.

关键词： Fiber suspension flow Jeffery orbit Fiber orientation distribution

Influence of Electroshocking Treatment on Microstructure and Mechanical Properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Thin-Wall Specimen Manufactured by Laser Melting Deposition

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 145-158页

作者： Yan Wen Xuan Sun jian Zhou Bingliang Liu Haojie Guo Yuxin Li Fei yin Liqiang Wang Lechun Xie lin Hua Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan430070China Hubei Longzhong Laboratory Xiangyang441000China Shanghai Aircraft Manufacturing Co. Ltd.Commercial Aircraft Corporation of ChinaLtd.Shanghai201324China State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China

In order to improve the properties of titanium alloys manufactured by laser melting deposition(LMD),the electroshocking treatment(EST)was proposed in this *** effects of EST on microstructure and mechanical properties of LMD Ti-6.5Al-3.5Mo-1.5Zr-0.3Si were *** results showed that the width of the heat affected band decreased and disappeared under the thermal and athermal effects of EST,resulting in the uniform *** the microstructure,theαlaths became coarser gradually,and the quantity ofα/βinterface was *** reduction of the quantity ofα/βinterface leads to make less resistant to dislocation,resulting in the reduction in hardness and *** discontinuous grain boundaryαphase and nucleationαcolony near grain boundary inhibited the crack propagation and improved the ***,EST can manipulate the microstructure and improve the mechanical properties of LMD titanium alloys.

关键词： Electroshocking treatment(EST) Laser melting deposition(LMD) Titanium alloy Microstructure Mechanical properties

Critical fluctuations upon photoinduced phase transition in manganite strips

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维普期刊数据库

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Science China(Physics,Mechanics & Astronomy) 2018年第9期61卷 86-90页

作者： HanXuan lin Tian Miao Qian Shi Yang Yu Hao Liu Kai Zhang WenBin Wang LiFeng yin jian Shen State Key Laboratory of Surface Physics and Department of Physics Fudan University Advanced Materials Laboratory Fudan University Collaborative Innovation Center of Advanced Microstructures Fudan University

Light,acting as an external stimulus to induce various intriguing phenomena ranging from photovoltaics to photoinduced catalysis,exerts prominent effects in strongly correlated *** would be of particular interest to investigate photon-induced emerging phenomena in spatially confined strongly correlated systems,which are important for applications of these materials in future electronic *** magnetoresistive manganites materials offer an ideal platform for such study due to their sensitivity to ***,we fabricated 900 nm wide La_(0.325)Pr_(0.3)Ca_(0.375)Mn O_3strips,whose width is comparable to the size of the electronic phase separation(EPS)domains in this *** observed the photoinduced critical fluctuations in the strips,where abrupt resistivity jumps occurred upon photoinduced phase transition depending sensitively on the light *** on the microscopic views of the EPS domains under photoexcitation,we conclude that such photo-induced resistivity fluctuations originate from the photoinduced phase fluctuations of individual EPS domains when their size becomes comparable to the strip width.

关键词： photo-induced phase transition resistivity critical fluctuation electronic phase separation magnetic force microscope manganite strip optolithorgraphy

Decoding the Moon Phase Display Device over the Front Dial of the Antikythera Mechanism

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 676-683页

作者： lin jian Liang YAN Hong Sen Department of Mechanical Engineering and University Museum National Cheng Kung University

The Antikythera mechanism is the most famous ancient astronomical calculator. The damaged excavation is a critical constraint for decoding the mechanism completely. By the systematic reconstruction design methodology, all feasible designs of the moon phase display device, which is one of the unclear mechanisms of the Antikythera mechanism, are reconstructed. These designs, including ordinary gear trains and epicyclic gear trains, are the simplest designs and satisfy the surviving evidence. The Antikythera mechanism and its reconstruction designs presented by lin and YAN are introduced first. Three pointer types of the Antikythera mechanism are concluded based on their display motions and the orientation of the mechanism. In accordance with the analysis of the available interior reconstruction designs and the surviving evidence, four feasible designs of the moon phase display device are generated. All of them utilize the ball pointer with black and white that rotates around the radial axis to show cyclic moon phase. Two of these four feasible reconstruction designs are driven by one input source, and their bronze disks are fixed and rotatable respectively. Both of the remaining reconstruction designs are driven by two input sources, and their bronze disks are rotatable. Therefore, the four reconstruction designs of the moon phase display device reveal all possible display conditions of the moon phase pointers and the possible purposes of the bronze disk.

关键词： Antikythera mechanism moon phase display device reconstruction design gear train

Optimal distributed resource allocation in a wireless sensor network for control systems

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第1期8卷 106-112页

作者： MAO jian-lin WU Zhi-ming Department of Automation Shanghai Jiao Tong University Shanghai 200240 China School of Information Engineering and Automation Kunming University of Science and Technology Kunming 650093 China

Wireless technology is applied increasingly in networked control systems. A new form of wireless network called wireless sensor network can bring control systems some advantages, such as flexibility and feasibility of network deployment at low costs, while it also raises some new challenges. First, the communication resources shared by all the control loops are limited. Second, the wireless and multi-hop character of sensor network makes the resources scheduling more difficult. Thus, how to effectively allocate the limited communication resources for those control loops is an important problem. In this paper, this problem is formulated as an optimal sampling frequency assignment problem, where the objective function is to maximize the utility of control systems, subject to channel capacity constraints. Then an iterative distributed algorithm based on local buffer information is proposed. Finally, the simulation results show that the proposed algorithm can effectively allocate the limited communication resource in a distributed way. It can achieve the optimal quality of the control system and adapt to the network load changes.

关键词： Wireless sensor networks (WSN) Distributed resource allocation Control systems Optimization.

Nanoparticle nucleation and coagulation in a mixing layer

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Acta Mechanica Sinica 2010年第4期26卷 521-529页

作者： jian-Zhong lin Yan-Hua Liu China Jiliang University 310018 Hangzhou China Department of Mechanics Zhejiang University310027 Hangzhou China

Numerical simulation of nanoparticle nucleation and coagulation in a mixing layer with sulfuric acid vapor binary system is performed using the large eddy simulation and the direct quadrature method of moment. The distributions of number concentration, volume concentration, and average diameter of nanoparticles are obtained. The results show that the coherent structures have an important effect on the distributions of number concentration, volume concentration and average diameter of nanoparticles via continuously transporting and diffusing the nanoparticles to the area of low particle concentration. In the streamwise direction, the number concentration of nanoparticles decreases, while the volume concentration and the average diameter increase. The distributions of number concentration, volume concentration and average diameter of nanoparticles are spatially inhomogeneous. The characteristic time of nucleation is shorter than that of coagulation. The nucleation takes place more easily in the area of low temperature because where the number concentration of nanoparticles is high, while the intensity of coagulation is mainly affected by the number concentration. Both nucleation and coagulation result in the variation of average diameter of nanoparticles.

关键词： Nanoparticles Nucleation - Coagulation Mixing layer Direct quadrature method of moment

Packet： a privacy-aware access control policy composition method for services composition in cloud environments

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Frontiers of Computer Science 2016年第6期10卷 1142-1157页

作者： Li lin jian HU jianbiao ZHANG College of Computer Science Beijing University of Technology Beijing 100124 China Beijing Key Laboratory of Trusted Computing Beijing 100124 China National Engineering Laboratory for Classified Information Security Protection Beijing 100124 China

Combining different independent cloud services must coordinate their access control policies. Otherwise unauthorized access to composite cloud service can occur when there＇s a conflict among different cloud service providers＇ access control policies, and then it will bring serious data security and privacy issues. In this paper, we propose Packet, a novel access control policy composition method that can detect and resolve policy conflicts in cloud service composition, including those conflicts related to privacyaware purposes and conditions. The Packet method is divided into four steps. First, employing a unified description, heterogeneous policies are transformed into a unified attributebased format. Second, to improve the conflict detection ef- ficiency, policy conflicts on the same resource can be eliminated by adopting cosine similarity-based algorithm. Third, exploiting a hierarchical structure approach, policy conflicts related to different resources or privacy-aware purposes and conditions can be detected. Fourth, different conflict resolution techniques are presented based on the corresponding conflict types. We have successfully implemented the Packet method in Openstack platform. Comprehensive experiments have been conducted, which demonstrate the effectiveness of the proposed method by the comparison with the existing XACML-based system at conflict detection and resolution performance.

关键词： cloud service composition access control privacy policy composition unified policy format conflict detection similarity analysis conflict resolution

Numerical Study of Controlling Jet Flow and Noise using Pores on Nozzle Inner Wall

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Journal of Thermal Science 2018年第2期27卷 146-156页

作者： lin jian SHI Zhixiao LAI Huanxin School of Mechanical and Power Engineering East China University of Science and Technology

In this paper, the feasibility of controlling the subsonic jet flow and its noise using pores of blind holes added on the nozzle inner wall is explored numerically. These pores are intended to introduce disturbances to the shear layer so as to change the flow mixing. This passive strategy has not been attempted so far. A convergent nozzle with a cylindrical extension is selected as the baseline case. Three nozzles with pores on the inner wall are set up. Validations of the numerical settings are carried out, then the compressible turbulent jets at the exit Math number Mj = 0.6 in the four nozzles are calculated by large eddy simulations （LES）, while the ra-diated sounds are predicted by the FW-H acoustic analogy. The results show that the blind holes have produced some effects on weakening the turbulence intensity in the shear layer. Comparison reveals that both temporal and spatial correlations of the turbulent fluctuations in the modified cases are suppressed to some extent. Meanwhile, the porous nozzles are shown to suppress the pairing of vortices and enhance the flow mixing, and therefore, the development of shear layer and the fragmentation of large scale vortices are accelerated.

关键词： noise of jet flow pores of blind holes passive method nozzle wall treatment

BACKBONE OF TECHNOLOGY EVOLUTION IN THE MODERN ERA AUTOMOBILE INDUSTRY: AN ANALYSIS BY THE PATENTS CITATION NETWORK

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Journal of Systems Science and Systems Engineering 2011年第4期20卷 416-442页

作者： Yan lin jian CHEN Yan CHEN Department of Management Science and Engineering Dalian Maritime University Dalian 116026 China School of Economics and Management Tsinghua University Beijing 10084 China

In the automobile industry, especially in its modem era, large amount of technologies have been generated to produce automobiles. The technological evolution in this industry is formed by complicated effects of the emergence of some milestone inventions and interaction, integration, and succession among diverse technologies. It＇s a big challenge to sort out crucial inventions and technologies progresses that mainly form this industry＇s technological evolution. We use patent citation data and apply network analytical techniques to reveal characteristics of the ＂backbone＂ in the automobile industry＇s technological evolution. We employ three algorithms respectively to explore the main path of the technological evolution, the most important subnetwork which outlines the main characteristics of the industry＇s technological evolution, and the most important technological inventions （act as authorities and hubs of the technological evolution） in the industry. Main results are reported in detail by tables, figures and interpretations to disclose the most influential technologically developing path, pivotal transfers in technological trajectories, and important technological convergences and divergences over time, of the modem era automobile industry.

关键词： Technology evolution automobile industry patent citation network analysis