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上海交通大学学报 2007年第S2期41卷 144-149页

作者：武高辉修子扬张强 School of materials science and eng. Harbin Institute of Technology

High reinforcement-content aluminum matrix composite,with a high thermal conductivity,the adjustable coefficient of thermal expansion(CTE),low density and costs,have been extensively applied in electronic *** Sip/Al composites were fabricated by squeeze casting *** microstructure observation showed that the composites were dense and macroscopically homogeneous,with no micro-holes and obvious *** linear CTEs of Sip/Al composites lay between(7.6～8.1)×10^-6 ℃^-1,and the thermal conductivity was larger than 100 W/(m·℃).The composites also had lower density(2.4 g/cm^3),higher special streng.h and special *** electroless nickel method was used to deposit a continuous and uniform layer on the composites surface,which can meet the reliability testing demands of the diodes with Sip/Al composite baseplate.

关键词： Si particles aluminum matrix composite thermal expansion thermal conductivity

RANDOM COPOLYMER OF PROPYLENE OXIDE AND ETHYLENE OXIDE PREPARED BY DOUBLE METAL CYANIDE COMPLEX CATALYST

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Chinese Journal of Polymer science 2002年第5期20卷 453-459页

作者： Yi-jun Huang Guo-rong Qi Guan-xi Chen Department of Polymer science and eng.neering, Zhejiang University Hangzhou 310027,China dept. of Polymer science and eng. Zhejiang University Hangzhou 310027 China

Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.

关键词： propylene oxide ethylene oxide double metal cyanide complex

Active Network Supports for Mobile IP

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Journal of Computer science & Technology 2001年第6期16卷 544-551页

作者： Lu, Y. Qian, D. Xu, B. Wang, L. dept. of Computer science and eng. Xi'an Jiaotong University Xi'an 710049 China

The basic mobile IP protocol is difficult to implement on the traditional IP network and not flexible and efficient under certain conditions. For example, firewalls or bound- ary routers may drop packets sent by mobile nodes for security reasons. Traditional networking devices such as routers cannot dynamically load and unload extended services to achieve differ- ent qualities of services. In this paper, a new scheme of using the active network to support the mobile IP is presented. The Softnet, a prototype of active networks based on mobile agents, is introduced. The active network is characterized by the programmability of its intermediate nodes and therefore presents dynamic and flexible behaviors. Special services can be dynam- ically deployed onto the active nodes in the Softnet. This property is definitely required in implementing the mobile IP protocols. The Softnet supports not only the basic mobile IP pro- tocol but also other extended mobiIe IP protocols. Virtual networks for mobile IP services are dynamically formed by mobile agents in the Softnet to provide different qualities of services.

关键词： mobile IP Softnet active network mobile agent virtual network

Effect of Heat Treatment on High Temperature Stress Rupture Streng.h of Brazing Seam for Nickel-base Superalloy

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Journal of University of science and Technology Beijing 2001年第2期8卷 123-125页

作者： Junying Zhang, Zhongtai Zhang, Jisheng.Sun, Xiaofang Liu, Wei Tian (State Key Laboratory of New Ceramics and Fine Processing, Department of materials science and eng.neering, Tsinghua University, Beijing 100084, China) (Beijing Institute of Aeronautical SKLNCFP Dept. of Materials Sci. and Eng. Tsinghua University Beijing 100084 China

In order to enhance the high-temperature stress rupture streng.h of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of gamma ' phase and boride was observed and the streng.h of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture streng.h by improving the microstructure of brazing seam. The streng.h of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the streng.h of brazing seam.

关键词： wide-gap brazing high temperature stress rupture streng.h microstructure nickel-base superalloy

Allelopathic effect of Acorus tatarinowii upon algae

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Journal of Environmental sciences 2001年第4期13卷 481-484页

作者： He, C.-q. Wang, C.-k. dept. of Environmental science/eng. Shanghai University Shanghai 200072 China

Besides competing with algae for light and mineral nutrients (i. e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in 'A. tatarinowii water', some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A. tatarinowii on algae were obvious and planting A. tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 μl/disc, the inhibitory rate was negative; if it was over 45 μl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 μl/disc and 45 μl/disc.

关键词： Algae Cells Chlorophyll Concentration (process) Deoxidants Photosynthesis

The Application of SCC-DV-X_a Computational Method of Quantum Chemistry in Cement Chemistry

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Journal of Wuhan University of Technology(materials science) 2001年第3期16卷 6-11页

作者：王志 dept. of materials Sci. and eng. Jinan University Shandong 250022 China

It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical streng.h and stabilization, of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

关键词： quantum chemistry cement calculated results hydratian property

Finite Element Analysis for Multi-pass Equal Channel Angular Pressing

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Journal of Shanghai Jiaotong university(science) 2007年第3期12卷 347-351页

作者：王进陈军王经涛 National Die & Mold CAD eng. Research Center Shanghai Jiaotong Univ. dept. of materials science and eng. Nanjing Univ. of Science and Technology

Equal channel angular pressing （ECAP） is an attractive process method to produce bulk uhra-fine grained materials. There are many experiment evidences showing that the nature of the microstructural evolution in multi-pass ECAP depends on process routes. Isothermal three dimensional FEM simulations for muhi-pass ECAP were performed using DEFORM3D finite element code. The material model of 6061A1-T6 was employed. Flow nets, effective strain distribution in the workpiece and loads during multi-pass ECAP using different routes were analysed respectively, The simulations show process routes influence material flow and effective strain distri- bution in the workpiece obviously but have few influence on loads.

关键词： equal channel angular pressing(ECAP) finite element method(FEM) flow nets effective strain

Active Shape Models Using Scale Invariant Feature Transform

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Journal of Shanghai Jiaotong university(science) 2007年第6期12卷 713-718页

作者：史勇红戚飞虎栾红霞吴国荣 dept. of Computer science and eng. Shanghai Jiaotong Univ.

A new active shape models (ASMs) was presented, which is driven by scale invariant feature transform (SIFT) local descriptor instead of normalizing first order derivative profiles in the original formulation, to segment lung fields from chest radiographs. The modified SIFT local descriptor, more distinctive than the general intensity and gradient features, is used to characterize the image features in the vicinity of each pixel at each resolution level during the segmentation optimization procedure. Experimental results show that the proposed method is more robust and accurate than the original ASMs in terms of an average overlap percentage and average contour distance in segmenting the lung fields from an available public database.

关键词： active shape model (ASM) deformable segmentation chest radiograph scale invariant feature transform (SIFT) local descriptor

A Novel Method for Character Segmentation in Natural Scenes

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Journal of Shanghai Jiaotong university(science) 2006年第4期11卷 484-489,497页

作者：徐立戚飞虎蒋人杰朱凯华吴国荣 dept. of Computer science and eng. Shanghai Jiaotong Univ.

A new approach to extract and segment characters in natural scenes was proposed in this paper. First, a set of intrinsic features were calculated based on connected components (CCs) extracted by a non-linear Nilblack algorithm. Then, feature propagation was conducted for feature enhancement, under the constraint of the layout relations. Next, candidate CCs were fed into classifiers with the enhanced feature vector. At last, a model-based hierarchical merging (MHM) procedure was presented to obtain understandable characters. The proposed merging algorithm utilized the constraint of text lines for specific languages and dynamically merges CCs into characters. The whole algorithm was evaluated at both pixel level and character level, experimental results showed that the proposed method is effective in detecting scene characters with significant geometric variations, uneven illumination, extremely low contrast and cluttered background.

关键词： character segmentation feature extraction model-based hierarchical merging (MHM)

Learning Bayesian Networks from Data by Particle Swarm Optimization

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Journal of Shanghai Jiaotong university(science) 2006年第4期11卷 423-429页

作者：杜涛张申生王宗江 dept. of Compute science and eng. Shanghai Jiaotong Univ.

Learning Bayesian network is an NP-hard problem. When the number of variables is large, the process of searching optimal network structure could be very time consuming and tends to return a structure which is local *** particle swarm optimization (PSO) was introduced to the problem of learning Bayesian networks and a novel structure learning algorithm using PSO was proposed. To search in directed acyclic graphs spaces efficiently, a discrete PSO algorithm especially for structure learning was proposed based on the characteristics of Bayesian networks. The results of experiments show that our PSO based algorithm is fast for convergence and can obtain better structures compared with genetic algorithm based algorithms.

关键词： Bayesian networks structure learning particle swarm optimization(PSO)