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Study on the stability and 3-dimensional character for natural convection in a rectangular cavity heated from below

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science china(Technological sciences) 2010年第6期53卷 1647-1654页

作者： ZHAN NaiYan1,2,XU PeiWei1,SUN ShiMei,YANG Mo2 & LIU Jun3 1 Scool of Municipal and Environmental Engineering,Jilin Institute of Architectural and Civil Engineering,Changchun 130021,china 2 college of Power Engineering,university of shanghai for science and technology,Shanghiai 200093,china 3 college of Power Engineering,Jilin university,Changchun 130000,china 1. Scool of Municipal and Environmental Engineering Jilin Institute of Architectural and Civil Engineering Changchun 130021 China2. College of Power Engineering University of Shanghai for Science and Technology Shanghiai 200093 China3. College of Power Engineering Jilin University Changchun 130000 China

Natural convection of air is numerically simulated in a 3-dimensional rectangular cavity heated from below using SIMPLE algorithm with a QUICK *** results suggest that when all lateral walls are adiabatic,the fluid rolls occur along the long *** the Rayleigh number is smaller,the flow is of 2-dimensional character,and the rolls shapes are *** average Nusselt numbers in the central part of the cavity are *** average Nusselt numbers in the part near by the cavity are *** to the comparison of 3-dimensional results with 2-dimensional results,the flow patterns and heat transfer in the central part of the cavity can be assumed as a 2-dimensional flow,While those in the part near by the cavity can *** increasing Rayleigh number,the flow is 3-dimensional *** 3-dimensional result accords with the experimental *** all lateral walls are adiabatic,the ten rolls occur along the long *** when lateral walls are heated or cooled,the rolls disappear along the long axis and two rolls occur along the short *** rotation direction of the rolls is *** Rayleigh number is over some critical value,flow and heat transfer will be asymmetry,indicating unsteady oscillation *** nonlinear analyses,it is shown that with increasing Rayleigh number,flow and heat transfer will change from steady state to unsteady state through HOPF bifurcation,and transition to chaos will occur through multi-periodical oscillation.

关键词： Critical Raleigh number 3-dimensional character lateral boundaries nonlinear characteristic bifurcation

The Properties of Native Silk Fibroin (SF) Solution/Gel from Bombyx mori Silkworms during the Full Fifth Instar Larval Stage

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Journal of Wuhan university of technology(Materials science) 2011年第2期26卷 263-269页

作者：王洪 Key Laboratory of Textile science & technology Ministry of EducationDonghua University

The properties of native silk fibroin （SF） solution in the gland of silkworms during the full fifth instar larval stage were examined in an attempt to elucidate the mechanism of natural silk spinning in the *** flow and gelation behavior,birefringence phenomenon,rheological properties,specific viscosity and conformation of SF solutions from the gland of silkworms were measured by polarized light microscope,HAKKE rheometer,Ubbelohde viscometer and Solid-state 13C NMR,*** comparing their properties with regenerated SF solutions from natural silk fibers,it is believed that there exists a progressive maturation process favorable to spin silk fibers with excellent properties from native SF solution and a weak bonded and highly oriented SF gel network with SF molecules partly extended in α-helix conformation is formed in the middle section of the gland of *** suggests that a biomimetic maturation process for making spinnable solution might be necessary for artificial silk fiber spinning in order to obtain improved fiber properties.

关键词： silk fibre spin viscosity sol/gel

Nine Pathogenic Fungi of Waterhyacinth Isolated in china

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Journal of shanghai jiaotong university(science) 2008年第5期13卷 617-622页

作者：丁义赵楠褚建君 School of life sciences & Biotechnology Shanghai Jiaotong University

The native pathogens of waterhyacinth in china, were studied and compared on pathogenicity by Koch＇s postulate. Nine pathogenic fungi, YBH, YBB, YB, YYX, YY, YBA1, YBA2, YBA3 and YYB12, were isolated from diseased waterhyacinth plants, and collected from Zhejiang province and shanghai. According to cultural characteristics, the nine isolates were preliminarily identified. Isolates YBH and YBB were Collectotrichum sp.; YB, YYX and YY were placed in fungi imperfecti; the isolates YBA1, YBA2, YBA3 and YYB12 were Alternaria sp. The isolate YBH was the highly virulent with a disease index （DI） of 65.28% after one month inoculation. The isolate YBA3 was equily virulent, with the disease index of 6770 after 7 day introduction. These two pathogens appear to have the potential as biocontrol agents and they deserve further study.

关键词： waterhyacinth pathogenic fungi disease index (DI) virulence

Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay

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science china(Information sciences) 2011年第4期54卷 861-872页

作者： YUE WenJing 1,2,ZHENG BaoYu 1,2,MENG QingMin 1,YUE WenJie 3 & CUI JingWu 1 1 Institute of Signal Processing and Transmission,Nanjing university of Posts and Telecommunications,Nanjing 210003,china 2 Department of Electronic Engineering,shanghai jiaotong university,shanghai 200240,china 3 Shanxi Institute of Educational science,Taiyuan 030009,china 1. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China2. Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China3. Shanxi Institute of Educational Science Taiyuan 030009 China

We consider a cognitive relay network which is defined by a source,a destination,and cognitive relay nodes and primary user *** this network,a source is assisted by cognitive relay nodes which allow coexisting with primary user nodes by imposing severe constraints on the transmission power so that they operate below the noise floor of primary user *** this paper,we mainly study the power allocation strategies of this system to minimize the outage probability subject to total and individual power constraints for cognitive relay nodes and subject to interference constraints for primary user nodes.A relay transmission scheme,namely amplify-and-forward (AF),is *** first present an optimal power allocation (OPA) scheme to minimize the system outage probability,based on instantaneous channel state information among the source,destination and relay nodes and mean channel gains between primary user nodes and cognitive ***,we propose a selection AF scheme (S-AF) where the single best relay is chosen to assist in the transmission and study power allocation strategy for S-AF to minimize outage *** analytical power allocation strategies have been validated through numerical *** results indicate that the AF with OPA and S-AF with OPA have significantly better outage behavior and average throughput than AF and S-AF schemes *** also find that S-AF with OPA achieves a higher throughput,and hence lower outage probability than AF with OPA.

关键词： cognitive radio (CR) relay networks power allocation outage probability

Dynamic learning rates algorithm for BPNN to forecast time series of dam security

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Progress in Natural science:Materials International 2007年第12期17卷 1527-1530页

作者： Hu Daiping1, Wu Ruiming1, Lei Aizhong1 and Wang Qi2(1. Antai college of Economics & Management, shanghai jiaotong university, shanghai 200052, china 2. Graduate School, Lanzhou university, Lanzhou 730000, china) Antai college of Economics & Management Shanghai Jiaotong University Shanghai 200052 China Graduate School Lanzhou University Lanzhou 730000 China

Time series data of dam security have a large number of observed values and should be forecasted accurately in time. Neural networks have the powerful approach ablilities of arbitrary functions and have been broadly utilized in many domains. In this paper, a dynamic learning rate training algorithm of back-propagation neural networks for time series forecasting is proposed and the networks with this algorithm are built to forecast time series of dam security. The application results demonostrate the efficiency of modelling and the effictiveness of forecasting.

关键词： neural network dynamic learning rate forecasting dam security.

EXPERIMENTAL STUDY ON INSTANTANEOUS DISCHARGE OF UNSORTED PARTICLE CLOUD IN CROSS-FLOW

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Journal of Hydrodynamics 2008年第1期20卷 10-16页

作者： GU Jie HUANG Jing LIC. W. college of Marine science and technology Shanghai Fisheries University Shanghai 200090 China Department of Civil and Structural Engineering The Hong Kong Polytechnic University Hong Kong China

A series of extensive laboratory experiments were conducted to investigate the transport and mixing of instantaneous discharge of unsorted particle cloud in cross-flow. The following experimental results were obtained：（1） the vertical frontal position and the longitudinal width of the particle cloud in the cross-flow is much larger than those in stagnant water, （2） the smaller cross-flow velocity will normally cause the larger non-dimensional frontal position for the same particle size range and initial volume, （3） the non-dimensional longitudinal width of the particle cloud in the cross-flow increases with the increase of cross-flow velocity. The empirical constants （α1, α3 and α2） and their variance range, which can be used to determine the relationships of non-dimensional vertical frontal position and time, longitudinal width and time, and vertical frontal position and longitudinal width were also obtained through the analysis of experimental data.

关键词： instantaneous discharge particle cloud cross-flow buoyancy hydrodynamic behavior

Recognition of Gene Acceptor Site Based on Multi-objective Optimization

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Acta Biochimica et Biophysica Sinica 2005年第7期37卷 435-439页

作者： Jing ZHAO~(1,3,4) Yue-Min ZHU~2 Pei-Ming SONG~1 Qing FANG~1 Jian-Hua LUO~(1,3) 1 School of life science & technology,shanghai jiaotong university,shanghai 200240,china 2 CREATIS,CNRS UMR 5515,INSA Lyon,69621 Villeurbanne Cedex,France 3 shanghai Center for Bioinformation and technology,shanghai 200235,china 4 Logistical Engineering university,Chongqing 400016,china Schooloflifescience&technology ShanghaiJiaotongUniversityShanghai200240China

A new method for predicting the gene acceptor site based on multi-objective optimization isintroduced in this *** models for the acceptor,branch and distance between acceptor site andbranch site were constructed according to the characteristics of the sequences from the exon-intron databaseand using common biological *** acceptor function,branch function and distance functionwere defined respectively,and the multi-objective optimization model was constructed to recognize thesplice *** test results show that the algorithm used in this study performs better than the SplicePredictor,which is one of the leading acceptor site detectors.

关键词： multi-objective optimization acceptor site recognition

Research on Digitalization of High Frequency Microplasma Arc Welding Machine with Small Welding Current

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稀有金属材料与工程 2011年第S4期40卷 79-83页

作者： He Jianping1,Huang Chen1,Jiao Fujie1,You Zhichun2 1college of Materials Engineering,shanghai university of Engineering science,shanghai 201620,china2shanghai WTL Welding Equipment Manufacture Co.Ltd.,shanghai 201620,china shanghai Univ Engn Sci Coll Mat Engn Shanghai 201620 Peoples R China shanghai WTL Welding Equipment Mfg Co Ltd Shanghai 201620 Peoples R China

The problem of digital controlling of high frequency microplasma arc welding machine has been solved through Fujitsu 16-bits single-chip processor *** welding power sources and their control systems,digital sequential control system,and digital man-machine interaction system were included in digital microplasma arc welding machine ***,which is about digital sequential control system,digital man-machine interaction system,digital controller and its interface,and controlling software program,were *** has been showed that full digitalization of high frequency microplasma arc welding machine was fulfilled,minimum welding current of the machine is 0.05A,and arc is stable and can been started unfailingly.

关键词： digitalization microplasma arc welding machine single-chip processor

The Computer Analysis of the Excimer Laser Beam Intensity Uniformization by Rotational Lens Array

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光学学报 2003年第S1期23卷 869-870页

作者： Xu Huabin Chen Lin Chen Baoxue The Physics Department of shanghai Second Polytechnic university, china,E-mail:hbhbxu@*** college of Optic and Electron Information Engineering, university of shanghai for science and technology The Physics Department of shanghai Second Polytechnic university China college of Optic and Electron Information Engineering University of Shanghai for Science and Technology

The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity di... 详细信息

关键词： of on by The Computer Analysis of the Excimer Laser Beam Intensity Uniformization by Rotational Lens Array have for