4045铝合金热变形行为及其加工图

采用Gleeble-3500热模拟试验机对4045铝合金在变形速率为0.01~10 s-1，变形温度为300~450 ℃条件下进行等温热压缩实验，研究了该合金的热变形行为及其热加工特性.结果表明：4045铝合金热变形过程的流变行为可用双曲正弦模型来描述，其平均激活能为189.93 kJ/mol.基于动态材料模型(DMM)获得了4045铝合金的热加工图，并结合热加工图和金相显微组织分析得到了该合金在实验参数范围内较优的热加工工艺参数范围：加工温度为380~450℃，变形速率为0.1~0.3 s-1.     

基于概念设计的客车车身结构设计与优化系统

针对客车车身结构概念设计的特点，开发了客车车身结构概念设计与优化系统（简称BCD），建立了参数化的客车车身结构概念模型.以该模型为模板，实现了新客车车身结构概念几何模型的创建和车身尺寸参数调整，同时建立了车身系统的静态刚度分析、低阶模态分析、灵敏度计算和优化设计计算的自动化过程，对车身的结构性能和低阶模态进行了有效的预估.最后，本文使用该系统计算了某客车车身结构的刚度和低阶模态，并在保证车身质量降低的情况下实现了刚度和低阶模态的提高，有效的改善该车身结构性能，实现了车身轻量化，验证了BCD系统的有效性和可靠性.     

Field Emission Characterization of 1D-Nanostructural ZnO Grown at Low Temperature

Ondeu-ctdio rmse nhsaivoen aaltt rwaicdteed b aan gdr-egaatp d neaaln oosft uartctteunrtialon se bmeiccaounse-of their remarkable physical and chemical properties[1 ,2].Amongthose properties ,the highaspect ratio of these materi-als makes them genuine can…     

Manufacturing Communication： DCOM-MMS-based Approach for Flexible Manufacturing System

A design approach of manufacturing communication is presented for flexible manufacturing system in this paper. The primary objective aims at making the flexible manufacturing ,control system provided with interoperability and reconfigurability. Based on describing manufacturing message specification （MMS） and distributed component object model （DCOM）, a client/server manufacturing communication model is built with MMS standard and DCOM middleware, and the communication interfaces between MMS client and MMS server are designed with Microsoft interface definition language （MIDL） and abstract syntax notation one （ASN. 1） of MMS services. As a result, DCOM and MMS integration leads to such client/ server communication capabilities independent of different operating systems and manufacturing devices in flexible manufacturing automation environment. Finally, to verify the new design approach, a prototype system of robot control system has been implemented in MS 2000 Server/Professional Operating System and VC ＋ ＋ 6.0 Developer Environments.     

A Parallel Genetic Simulated Annealing Hybrid Algorithm for Task Scheduling

0 IntroductionGrid computingis a hot topic inthe current internet research,and a developing direction of the parallel and distributedprocess[1 ,2].Since the task scheduling in grid computing faces aNP-hard problem[3];it has drawn attention from many scholarsand become the focusinthe field of the current grid computing re-search.In recent years , two global random and opti mal algorithmhave been widelystudiedandappliedinthefield of the gridcompu-ting research: GA(Genetic Algorithm) and SA( …     

Merkle Tree Digital Signature and Trusted Computing Platform

0 IntroductionDigital signatureis a key technique to provide datainteg-rity andsource authenticationcapabilities to enhance da-ta trustworthiness in trusted computing platform. Most cur-rent digital signature schemes are based on complex mathe-matical problems , such as integer factoring, discrete log-arithm,and discrete logarithm on elliptic curves . The hard-ness of these underlying mathematical problems is really un-certain at present . Merkle treeis a method used for authenti-cation and di…     

Improvement of Identity-Based Threshold Proxy Signature Scheme with Known Signers

0 IntroductionIdentity-based (ID-based) cryptography[1]is rapidly emer-gingin recent years .The concept of the proxy signature scheme was first in-troduced by Mamboet al[2]in 1996 .The concept of thresholdproxy signature was proposed[3 ,4]. Apractical and secure (t,n) threshold proxy signature scheme should satisfy the secre-cy,the proxy protected,the unforgeability,the non-repudia-tion,the ti me constraint ,andthe known signers[5].In 2006 , Baoet al[6]proposed an ID-based thresholdproxy si…     

基于过滤定向搜索的柔性制造系统动态调度优化

针对柔性制造环境中内外扰动的动态随机发生和快速、高效的重调度需求,构建了动态调度决策系统结构模型,提出了一种基于过滤定向搜索的启发式算法作为模型的核心算法.为了更好地搜索调度解空间和更好地集成作业的交货期、优先权重和资源负载平衡,算法改进了节点分枝策略和局部、全局评价函数.以作业交货延迟时间加权平方和最小为性能指标,通过实例仿真,对算法性能进行了分析评价和比较,结果表明了该算法对实现柔性制造系统动态调度的有效性和实用性.     

A Beam Search-based Algorithm for Flexible Manufacturing System Scheduling

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Fluorescence spectra and enzymatic property of hemoglobin as mimetic peroxidase

0　IntroductionHemoglobin(Hb)isthemajorhemeproteinofredbloodcells(RBCs)andisresponsibleforthetransportofoxygentothetissues.ThefunctionofHbdependsupontheabilityoffer rousironinthehemegrouptobindandreleaseoxygen .Despiteitsprincipalroleasanoxygen carrier,theHbmoleculepossessesdifferentenzymaticactivities[1 ] andamethodwasdevelopedforthedeterminationofHbbasedonitsenzymaticactivityfortheox idationofo phenylenediamine (OPDA)withH2 O2 asanoxi dant[2 ] .Hbasamimeticenzymeofperoxidase ,cancataly…