Mg-(6～8)A1-0.7Si合金的组织和力学性能分析

通过金相观察、扫描电镜、X衍射分析和拉伸实验等方法,研究了Mg-(6~8)A1-0.7Si合金的铸态组织和力学性能.研究结果表明:添加了少量Sb和RE的Mg-(6~8)%A1-0.7%Si的铸态组织主要由α-Mg基体、Mg17A l12相、Mg2Si相、Mg3Sb2相和少量针状A l4Si2Mn2Y相组成,并且随着A l含量的增加,试验合金组织中的Mg17A l12相增多,共晶析出物变得更加连续.同时,力学性能的测试结果表明:A l含量变化对于试验合金抗拉强度、屈服强度和延伸率的影响呈现出不同的变化规律.     

Multicast routing algorithm of multiple QoS based on widest-bandwidth

1 .INTRODUCTIONA mobile Ad hoc network refers to a temporal multi-hop autonomy system,whichis constituted by a groupof mobile nodes containing wireless send-receive equip-ments[1].It possesses manycharacteristics-fast-deploy-able,self-organized,acentric , movable and of multi-hop.It can be wildly applied to many fields ,such asnational defense,emergency and disaster ,scientificin-vestigation and exploration etc .,and uponthat ,it hasgreat prospects[1 ,3 6]. With the wide spread of mo-bile…     

Research on system-of-systems combat simulation model formal specification and representation

1. INTRODUCTION Weapon equipments acquisition and demonstration has become more and more prominent in the informationalized war conditions while operational effectiveness evaluation is its core part. The compl- exity and uncertainty of weapon systems operational effectiveness evaluation make traditional analysis methods or expert evaluation methods less effective to solve problems. Simulation based operational effe- ctiveness evaluation is an efficient solution. The increased complexity o…     

试论电子货币对货币政策的影响

电子货币的广泛应用和普及,对现有货币金融体系提出了挑战,对中央银行的地位、货币发行、金融控制和货币供给等都将产生直接或间接的影响。货币政策的制定应具有前瞻性,因此,必须深入研究电子货币对货币政策的影响。这是制定电子货币时代货币政策的必然要求。     

幽门螺杆菌粘附素基因的原核表达

目的：构建幽门螺杆菌粘附素（hpaA）基因的原核表达载体，并诱导表达。方法：用PCR扩增hpaA目的基因片段，克隆至pQE-30表达载体中，构建含目的基因的表达质粒pQE-hpaA，转化E．coli DH5α，经IPTG诱导表达蛋白HpaA；Western blot分析其免疫反应性。结果：经测序hpaA基因片段由783bp组成，可编码260氨基酸残基的多肽。经SDS—PAGE分析相对分子量（Mr）约为30000。可溶性表达占全菌的42％以上。Western blot分析能与Hp全菌抗血清反应。结论：成功构建了粘附素hpaA基因的原核表达载体并能高效表达，为研制Hp疫苗提供理论依据。     

白色念珠菌基因分型方法研究进展

目的：探讨近年来白色念珠菌基因分型方法研究的新进展。方法：查阅相关文献资料，归纳总结。结果：白色念珠菌基因分型是近年来白色念珠菌分子生物学研究中的一个热点和主要方向，其方法很多。常用的分子生物学技术各有千秋，目前倾向于计算机辅助分析，多种分型技术合用。结论：白色念珠菌基因分型方法研究有新进展，对临床念珠菌病的诊断、治疗及分子流行病学研究等具有重要意义，同时，理想的分型技术还有待进一步研究。     

模糊控制在双闭环调速系统中的应用

应用模糊自适应对直流双闭环调速系统中的转速调节器的比例、积分参数进行整定。仿真结果表明,用这种控制方法得到的转速调节器参数比传统的工程整定方法得到的参数控制性能好,响应快,过渡过程时间短,基本无超调。     

用MATLAB制作迂回相位编码的傅立叶变换计算全息图

本文用MAT—LAB语言制作了一个迂回相位编码的傅立叶变换全息图。在实验中，观察到了全息图的再现。     

平面六杆机构的运动分析及仿真

采用杆组法建立机构运动分析的数学模型。基于Ture Basic编程计算机构的运动参数,为动力学分析提供依据。使用虚拟样机技术对机构进行运动学仿真,计算结果及仿真结果相互验证,证明了杆组法分析的有效性和仿真结果的可靠性。     

A Project Risk Ranking Approach Based on Set Pair Analysis

Set Pair Analysis （SPA） is a new methodology to describe and process system uncertainty. It is different from stochastic or fuzzy methods in reasoning and operation, and it has been applied in many areas recently. In this paper, the application of SPA in risk ranking is presented, which includes review of risk ranking, introduction of Connecting Degree （CD） that is a key role in SPA., Arithmetic and Tendency Grade （TG） of CDs, and a risk ranking approach proposed. Finally a case analysis is presented to illustrate the reasonability of this approach. It is found that this approach is very convenient to operate, while the ranking result is more comprehensible.