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Experimental study on hydrodynamic effect of orientation micro-pored surfaces

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Science china(Technological Sciences) 2011年第3期54卷 659-662页

作者： BAI ShaoXian1,2. PENG XuDong1,2. LI JiYun1,2.& MENG XiangKai1,2.1college of Mechanical engineering, {2. University of technology, hangzhou 310032. china 2.ey Laboratory of Special Purpose Equipment and Advanced Processing technology, Ministry of Education, {2. University of technology, hangzhou 310032. china college of Mechanical engineering Zhejiang University of Technology Hangzhou China Key Laboratory of Special Purpose Equipment and Advanced Processing technology Ministry of Education Zhejiang University of Technology Hangzhou China

The orientation of the dimple increases the flow distance in the dimple and produces fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect as a result. In order to investigate the hydrodynamic effect of orientation dimples, a series of experiments was carried out on a ring-on-ring test. Multi-pored faces were tested with different dimple inclination angles and slender ratios. Film thickness and frictional torque were measured under different conditions of load and rotation speed. Experimental results showed that the orientation dimple could produce obvious dynamic effect by change of the flow direction and the increasing dimple orientation leads to increase of the load capability. The hydrodynamic effect strongly depends on dimple orientation parameters such as inclination angle and slender ratio. A larger load capability can be available by increasing dimple orientation and rotation speed. Experimental results agreed well with the theory that orientation micro-pores can significantly improve hydrodynamic performance of surfaces.

关键词： orientation micro-pore multi-pored face hydrodynamic effect

Fractal Characteristic of Pits Distribution on 304 Stainless Steel Corroded Surface and Its Application in Corrosion Diagnosis

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Journal of Wuhan University of technology(Materials Science) 2007年第3期22卷 389-393页

作者：梁成浩 Electromechanics & Materials engineering college Dalian Maritime University

Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2.back-propagation （BP） artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62., respectively.

关键词： 304 stainless steel pits distribution fractal neural network diagnosis

Experimental study on pressurized activated sludge process for high concentration pesticide wastewater

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Journal of Environmental Sciences 2010年第9期22卷 1342-1347页

作者： Zanfang Jin, Zhiyan Pan, Shangqin Yu, Chunmian Lin college of Biological and Environmental engineering, {2. University of technology, hangzhou 310032. china. college of Biological and Environmental engineering Zhejiang University of Technology Hangzhou 310032 China

Pressurized biochemical process derived from traditional activated sludge processes is an innovative technology for wastewater treatment. The main advantage of the pressurized process is that the oxygen transfer barrier can be overcome by increasing the dissolved oxygen level. In this study, high concentration pesticide wastewater was treated by pressurized activated sludge process. It was found that the removal of chemical oxygen demand （COD） increased steadily with the increase of operating pressure, aeration time, and sludge concentration. When the operation pressure was 0.30 MPa and the aeration time was 6 hr, 85.0%-92.5% COD, corresponding to an effluent COD of 2.0-370 mg/L, was removed from an influent COD of 2.00-5000 mg/L. The obtained outlet COD concentration was lower than 350-450 mg/L for the identical process operated under the atmospheric pressure. In addition, pressurized biochemical process could produce a higher COD volumetric loading rate at 5.8-7.6 kg COD/（m^***）, compared with 2.0-2.8 kg COD/（***） using the same equipment at the atmospheric pressure. The COD concentration followed a modified Monod model with Vmax 2.31 day-1 and Ks 487 mg/L.

关键词： pressurized biochemical process pesticide wastewater activated sludge kinetics

Group sparse representation for image categorization and semantic video retrieval

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Science china(information Sciences) 2011年第10期54卷 2051-2063页

作者： LIU YaNan 1,2.,WU Fei 2.& ZHUANG YueTing 2.1 School of information,zhejiang University of Finance & Economics,{2.,310018,china 2.college of Computer Science and technology,zhejiang University,{2.,310012.china School of information Zhejiang University of Finance & Economics Hangzhou China college of Computer Science and technology Zhejiang University Hangzhou China

Multimedia content analysis and management are a promising and challenging *** this paper we develop a novel approach to image representation,which we call group sparse representation (GSR),for image classification and video *** basic idea is to represent a test image as a weighted combination of all the training *** particular,we introduce two sets of weight coefficients,one for each training image and the other for each ***,we formulate our concern as a group nonnegative garrote *** resulting representations are sparse,and they are appropriate for discriminant *** on Caltech101 and PASCAL VOC2.08 image dataset and TRECVID2.05 video corpus testify that our proposed approach is efficient and effective.

关键词： compressive sensing group sparse representation bag-of-SIFT-words nonnegative garrote l1-minimization apcluster

A New (t, n) Threshold Signature Scheme Withstanding the Conspiracy Attack

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Wuhan University Journal of Natural Sciences 2005年第1期10卷 107-110页

作者： XIE Qi 1,2. YU Xiu-yuan 3 1.Department of Mathematics, zhejiang University, hangzhou 31002., zhejiang,china 2.School of information and engineering, hangzhou Teachers college, hangzhou 310012. zhejiang, china 3.hangzhou Teachers college, hangzhou 310012. zhejiang, china Dept. of Math. Zhejiang Univ. Hangzhou 310027 China Sch. of Info. and Eng. Hangzhou Teachers Coll. Hangzhou 310012 China hangzhou Teachers Coll. Hangzhou 310012 China

A ccmspiracy attack is proposed to show that Wang-Li's scheme is instcure,because any t or more group members can impersonate other t member to sign any message withoutholding the responsibility. To avoid the conspiracy attack, this paper prestentsa new (t,n)threshold signature scheme with traceablt signers. A (t. n) threshold signature scheme allows t ormore group members of the group lo generate a signature on behalf of the group, Any less than tmembers cannot generate a valid signature, andany set of the group cannot impersonate another set ofmembers to sign any message without holding the responsibility. In case of disputes., the thresholdsignature can be opened, so that the original signers ean be traced without repealing the secretkeys.

关键词： cryptography threshold signature conspiracy attack identifier tracing

New Method for Constructing Comparison Matrix Based on the Proportion Scales in the AHP

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Journal of Systems engineering and Electronics 2003年第3期14卷 8-13页

作者： Huang Decai & Shen Liangzhong college of Informaton engineering, {2. University of technology, hangzhou 310032. P. R. china college of Informaton engineering Zhejiang University of Technology Hangzhou 310032 P. R. China

The main faults existing in current scale methods are that the scales do not represent the real importance of alternatives and their relations. This paper presents a proportion judgment scale and introduces a new method based on the proportion scale for construction comparison matrix in the analytic hierarchy process (AHP). The proportion judgment scales do not have the faults existing in current scale methods and the comparison matrix constructed by the new scale

关键词： AHP Judgment scales Comparison matrix Consistency checking.

Optimizing aerobic biodegradation of dichloromethane using response surface methodology

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Journal of Environmental Sciences 2009年第9期21卷 1276-1283页

作者： WU Shijin,YU Xiang,HU Zhihang,ZHANG Lili,CHEN Jianmeng college of Biological and Environmental engineering,{2. University of technology,hangzhou 310032.china college of Biological and Environmental engineering Zhejiang University of Technology Hangzhou 310032 China. E-mail: wujan28@***

Response surface methodology （RSM） was employed to evaluate the optimum aerobic biodegradation of dichloromethane （DCM） in pure culture. The parameters investigated include the initial DCM concentration, glucose as an inducer and hydrogen peroxide as terminal electron acceptor （TEA）. Maximum aerobic biodegradation efficiency was predicted to occur when the initial DCM concentration was 380 mg/L, glucose 13.72.mg/L, and H2.2.115 mg/L. Under these conditions the aerobic biodegradation rate reached up to 93.18%, which was significantly higher than that obtained under original conditions. Without addition of glucose degradation efficiencies were ≤ 80% at DCM concentrations ≤ 32. mg/L. When concentrations of DCM were more than 480 rag/L, the addition of hydrogen peroxide did not help to significantly increase DCM degradation efficiency. When DCM concentrations increased from 2.0 to 480 rag/L, the overall DCM degradation efficiency decreased from 91% to 60% in the presence of HaO2.for 12. mg/L.

关键词： biodegradation dichloromethane response surface methodology

A general communication performance evaluation model based on routing path decomposition

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Journal of zhejiang University-Science C(Computers and Electronics) 2011年第7期12卷 561-573页

作者： Ai-lian CHENG 1,Yun PAN 1,2.Xiao-lang YAN 2.Ruo-hong HUAN 3 (1 Department of information Science and Electronic engineering,{2. University,hangzhou 31002.,china) (2.Institute of VLSI Design,{2. University,hangzhou 31002.,china) (3 college of Computer Science and technology,{2. University of technology,hangzhou 31002.,china) Department of information Science and Electronic engineering Zhejiang University Hangzhou China Institute of VLSI Design Zhejiang University Hangzhou China college of Computer Science and technology Zhejiang University of Technology Hangzhou China

The network-on-chip (NoC) architecture is a main factor affecting the system performance of complicated multi-processor systems-on-chips (MPSoCs).To evaluate the effects of the NoC architectures on communication efficiency,several kinds of techniques have been developed,including various simulators and analytical *** simulators are accurate but time consuming,especially in large space explorations of diverse network configurations;in contrast,the analytical models are fast and flexible,providing alternative methods for performance *** this paper,we propose a general analytical model to esti-mate the communication performance for arbitrary NoCs with wormhole routing and virtual channel flow *** resolve the inherent dependency of successive links occupied by one packet in wormhole routing,we propose the routing path decomposition approach to generating a series of ordered link *** we use the traditional queuing system to derive the fine-grained transmission latency for each network *** to our experiments,the proposed analytical model provides a good approximation of the average packet latency to the simulation results,and estimates the network throughput precisely under various NoC configurations and ***,the analytical model runs about 10 5 times faster than the cycle-accurate NoC *** applications of the model including bottleneck detection and virtual channel allocation are also presented.

关键词： Analytical model Communication performance Network-on-chip (NoC) Queuing system Routing path decom-position Virtual channel

Understanding the endocrine disruption of chiral pesticides:The enantioselectivity in estrogenic activity of synthetic pyrethroids

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Science china Chemistry 2010年第5期53卷 1003-1009页

作者： WANG Cui 1,ZHANG Quan 1,ZHANG XiaoFeng 1,LIU Jing 2.& LIU WeiPing 2.1college of Biological and Environmental engineering,{2. University of technology,hangzhou 310032.china 2.ey Laboratory of Environmental Remediation and Ecosystem Health,Ministry of Education college of Environmental and Resource Sciences,{2. University,hangzhou 31002.,china college of Biological and Environmental engineering Zhejiang University of Technology Hangzhou China Key Laboratory of Environmental Remediation and Ecosystem Health Ministry of Education College of Environmental and Resource Sciences Zhejiang University Hangzhou China

Synthetic pyrethroids(SPs) ,a family of chiral insecticides consisting of multiple stereoismers,have been regarded as estrogenic endocrine-disrupting chemicals(EDCs) .In this study,we applied the yeast two-hybrid and molecular docking(MD) assay to assess the enantioselective estrogenic activities of three commonly used SPs,bifenthrin(cis-BF) ,permethrin(PM) and fenvalerate(Fen) .The β-galactosidase analyses indicated that all of the testing pyrethroids displayed significant(p2.-Fen and αS-2.-Fen also induced the β-galactosidase *** inability to initiate the reporter gene expression by the racemic chemicals may be due to the low ratios of these isomers or the antagonism among *** strong hydrophobic interaction and the hydrogen bond between positive estrogenic isomers and ERα support our biological testing *** research demonstrated that the enantioselective estrogenic activity of chiral SPs was due to selective binding between their isomers and the ERα*** data suggests that enantioselectivity of these chiral pesticides is significant to their estrogenic activities.

关键词： enantioselectivity synthetic pyrethroids (SPs) endocrine disruption yeast molecular docking