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An experimental study on the self-adaption mechanism used by evolutionary programming

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Progress in Natural science:Materials International 2008年第4期18卷 481-486页

作者： Jingsong He a,b, a Department of Electronic science and technology, University of science and technology of china, Hefei 230027, china b Nature Inspired computation and Application Laboratory, University of science and technology of china, Hefei 230027, china Department of Electronic science and technology University of Science and Technology of China Hefei 230027 China Nature Inspired computation and Application Laboratory University of Science and Technology of China Hefei 230027 China

Evolutionary programming (EP) is one of the most important methods for numerical optimization. Its main technique is the combi- nation of mutations and the self-adaption mechanism. In the past years, studies on EP focused on how to improve the effciency of muta- tions with different probability distributions, and few of them touched on the question that the self-adaption mechanism did not work sometimes, but simply followed the original suggestion. So far, no experimental results have shown why this is a question. This paper firstly gives a primary analysis on the behavior of the self-adaption mechanism, and then presents experimental evidences to show why its adaptive ability is doubtful.

关键词： Evolutionary programming Cauchy mutation Self-adaption mechanism

Analysis and control on Fracture of 20Mn2A High Tensile Steel for Round Link Chain

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Journal of Iron and Steel Research International 2011年第S1期18卷 898-902页

作者： CAO Shu-wei 1,2,KANG Yong-lin 1,3,ZHAO Xian-ping 2,YANG Chang-chun 1 (1.School of Materials science and Engineering,University of science and technology Beijing,Beijing 100083,china 2.technology Center of Anyang Iron & Steel Group co.,ltd.,Anyang 455004,Henan,china 3.State Key Laboratory for Advanced Metals and Materials,University of science and technology Beijing,Beijing 100083,china) Univ Sci & Technol Beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Anyang Iron & Steel Grp co ltd Ctr Technol Anyang 455004 Henan Peoples R China Univ Sci & Technol Beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

Based on the phenomenon of brittle fracture occurred during tensile test for 20Mn2A high strength circular chain used in coal mines,the fracture property is regarded as intercrystalline brittle one after macroscope observation and metallographic *** is analysed that the intercrystalline brittle fracture is due to high tempering temperature and limited processing site where final products are piled together after heat treatment,which lead to a lower cooling rate of internal chain,with Si,Mn and P etc elements segregating and enriching in the austenite grain boundary and forming high tempering *** these circular chains are tempered again for one hour at 670℃,and oil-cooled rapidly,due to the reversibility of high temper brittleness for structural alloy steel,the high temper brittleness can be eliminated and products are completely qualified after tensile inspection.

关键词： high strength circular chain metallographic examination brittle fracture high tempering brittleness improvement measures

Effect of Asymmetry in a Bistable System Subject to Multiplicative colored Noise

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communications in Theoretical Physics 2007年第12期48卷 1059-1062页

作者： ZHOU Yu-Rong~(1,2)GUO Feng~3 and PANG Xiao-Feng~1~1 School of Life science and technology,University of Electronic science and technology of china,Chengdu 610054,china~2 School of Information and Electric Engineering,Panzhihua University,Panzhihua 617000,china~3 School of Automation Engineering,University of Electronic science and technology of china,Chengdu 610054,china School of Life science and technology University of Electronic Science and Technology of China Chengdu 610054 China School of Information and Electric Engineering Panzhihua University Panzhihua 617000 China School of Automation Engineering University of Electronic Science and Technology of China Chengdu 610054 China

By the method of the stochastic energetics,we investigate the stochastic resonance (SR) phenomenon of anoverdamped Brown particle in an asymmetric bistable potential,driven by external periodical signal and *** expressions have been obtained for the quasi-steady-state probability distribution *** is found thatthe input energy (IE) pumped into the system by the external driving shows an SR-like behavior as a function of thenoise strength,whereas the IE turns to be a monotonic function of the correlation time of the *** effect ofpotential asymmetry is also studied on SR and IE.

关键词： asymmetric bistable system stochastic resonance stochastic energetics

Preparation of TiC/Ni_3Al composites by Upward Melt Infiltration

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Journal of Materials science & technology 2000年第4期16卷 387-392页

作者： Yi PAN (Department of Materials science and Engineering, Zhejiang University, hangzhou 310027, china) Kewei SUN (National Engineering Research Center of Solid Waste Resources Recovery, Kunming University of science and technology,Kunming 650093, china) Department of Materials science and Engineering Zhejiang University Hangzhou 310027 China National Engineering Research Center of Solid Waste Resources Recovery Kunming University of Science and Technology Kunming 650093 China

TiC/Ni_3Al composites have been prepared using upward infiltration method. The densification was performed by both Ni_3Al melt filling and TiC sintering during the infiltration. The dissolution of TiC in liquid Ni_3Al has been evidenced by finding Ni_3(Al,Ti)C after fast cooling in the TiC/Ni_3Al composites. The dissolution may be responsible for the infiltration and sintering. compared with downward infiltration, the upward infiltration brought about higher strength and fracture toughness and shorter infiltration time. TiC/20 vol. pct Ni_3Al composite processed by upward infiltration had a flexural strength of 1476 MPa with a statistic Weibull modulus of 20.2 and a fracture toughness of 20.4 MPa . Better mechanical properties may be attributed to melt unidirectional movement in upward infiltration.

关键词： TiC Preparation of TiC/Ni3Al composites by Upward Melt Infiltration Ni Al

Characteristics of fMRI BOLD signal and its neurophysiological mechanism

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Progress in Natural science:Materials International 2007年第6期17卷 630-638页

作者： Zhao Xiaohu1,2, Wu Yigen3 and Guo Shengli3(1. college of Life sciences, Zhejiang University, hangzhou 310058, china 2. Imaging Department of Tongji Hospital of Tongji University, Shanghai 200065, china 3. college of Mathematics and Physics, Nanjing University of Information science and technology, Nanjing 210044, china) college of Life sciences Zhejiang University Hangzhou 310058 China Imaging Department Tongji Hospital Tongji University Shanghai 200065 China college of Mathematics and Physics Nanjing University of Information Science and Technology Nanjing 210044 China

The functional magnetic resonance imaging (fMRI) based on blood oxygen level dependent (BOLD) contrast has emerged as one of the most potent noninvasive tools for mapping brain function and has been widely used to explore physiological, pathological changes and mental activity in the brain. Exploring the nature and property of BOLD signal has recently attracted more attentions. Despite that great progress has been made in investigation of the characteristics and neurophysiological basis, the exact nature of BOLD signal remains unclear. In this paper we discuss the characteristics of BOLD signals, the nonlinear BOLD response to external stimuli and the relation between BOLD signals and neural electrophysiological recordings. Furthermore, we develop our new opinions regarding nonlinear BOLD response and make some perspectives on future study.

关键词： functional magnetic resonance imaging blood oxygen level dependent nonlinear response neural electrophysiological activity.

Effect of rare earths on phase transformation in as-cast ZA27 alloy dur-ing compressive creep

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Rare Metals 2003年第4期22卷 259-264页

作者： WEIXiaowei SHENBaoluo DepamnentofAppliedPhysics UniversityofElectronicScienceandTechnologyofChinaChengdu610045China DeparlanentofMetalscience SichuanUniversityChengdu610065China

The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 27 alloy during compressive was investigated under 37 MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed that the as cast microstructure of ZA 27-RE alloyconsisted of a dendritic Al-rich alpha' surrounded by Zn-rich beta' phase, interdendritic epsilonphase and Zn-rich eta phase together with a complex Z phase which was a complex constitute compound,(RE,Cu)Al_5Zn_(16), dispersed in crystal interfaces or branch crystal interfaces and stable duringcompressive creep test at 160 deg C. The phase transformations of ZA 27-RE alloy, decomposition ofbeta' phase arid four transformation, were delayed by the addition of rare earths, also the lamellarstructure and the spheroidized structure in ZA 27-RE alloy were finer than in ZA 27 alloy duringcompressive creep test at 160 deg C at the same creep time, and the compressive creep resistance ofZA 27-RE alloy was higher than that of ZA 27 alloy.

关键词： microstructure change compressive creep rare earths ZA 27 alloy

A New Clustering Algorithm for Categorical Attributes

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 318-322页

作者： Songfeng Lu, Zhengding Lu (college of computer science and technology, Huazhong University of science and technology, Wuhan 430074, china) college of computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

In traditional data clustering, similarity of a cluster of objects is measured by distance between objects. Such measures are not appropriate for categorical data. A new clustering criterion to determine the similarity between points with categorical attributes is pre- sented. Furthermore, a new clustering algorithm for categorical attributes is addressed. A single scan of the dataset yields a good clus- tering, and more additional passes can be used to improve the quality further.

关键词： data mining clustering similarity Information

Expression and Identification of Mutated Osteoprotegerin in Culture Cells and Larvae of Silkworm

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Acta Biochimica et Biophysica Sinica 2004年第5期36卷 331-335页

作者： Hai-Long XIAO, Yong-Feng JIN, and Yao-Zhou ZHANG1* Institute of Biochemistry, college of Life sciences, Zhejiang University, hangzhou 310029, china college of Life sciences, Zhejiang University of science & technology, hangzhou 310018, china Institute of Biochemistry College of Life Sciences Zhejiang University Hangzhou 310029 China college of Life sciences Zhejiang University of Science & Technology Hangzhou 310018 China

The mutated osteoprotegerin (OPG-372) gene was inserted into the baculovirus transfer vector pBacPAK8, and the recombinant plasmid was co-transfected with linearized Bm-BacPAK6 virus DNA into BmN cells, then homologous recombination occurred inside the cells. The recombinant virus BmNPV-OPG- 372 was screened and identified by Southern blotting. The recombinant human OPG-372 was expressed in cultured cells and the larvae of silkworm by inoculation of recombinant virus. The expression products were run on the SDS-PAGE and their immunoreactivities were determined by Western blotting. It was found that a 42 kD recombinant protein was expressed in BmN cells and a 46 kD one in larvae respectively. The bioactivi- ties of the recombinant proteins were determined by hypocalcemic effect assay in the mice. The results showed that the recombinant proteins had a significant hypocalcemic effect on mice sera.

关键词： OPG-372 silkworm baculovirus expression system hypocalcemic effect

Dynamic behavior of polymer surface and the time dependence of contact angle

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science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2 1. Key Laboratory of Advanced Textile Materials and Manufacturing technology of Education Ministry, Department of Applied Chemistry, Zhejiang Institute of science and technology, hangzhou 310033, china 2. Department of Polymer science and Engineering, Zhejiang University, hangzhou 310027, china Department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry Hangzhou China Department of Polymer science and Engineering Zhejiang University Hangzhou China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.