EFFECT OF COMPOSITION ON PHYSICAL PROPERTIES OF AMORPHOUS Fe-Si-B ALLOYS

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管材外高压成型工艺研究现状及应用

管材液压成型是一种生产中空轴类零件的成型技术,其在汽车和航空领域有广泛的应用前景.本文介绍了一种新的液压成型工艺--管材外高压成型;并综述了外高压成型(EHF)的基本原理、外高压成型优点、研究现状、应用范围、适用材料.     

Ti-Mo-Zr-Fe合金的微观结构与纳米压入特性的关系

通过不同的热处理制度控制TMZF合金中的相组成和含量，利用XRD分析确定各种相结构。利用纳米压入测量仪测试了不同组织结构下的硬度和弹性模量。结果表明，当合金中存在ω相时，合金的的硬度和弹性模量最高，随着热处理温度的提高，合金中的ω相消失，代之而来的是α相，而且越接近β转变温度，α相含量越少，对应的弹性模量和硬度越来越低。对于Ti—Mo—Zr-Fe合金来说压入性能（硬度、弹性模量）与相成分之间存在着良好的匹配关系。     

稀土Ce和Y在ZK60合金中的分布、演变及其对性能的影响

用熔铸法制备了两类8种镁-稀土合金，通过力学性能试验，X射线衍射（XRD）、扫描电子显微（SEM）分析确定了稀土元素Ce、Y在ZK60镁合金中的分布、演化规律及其不同状态时所发挥的作用。结果表明：ZK60-1．5Ce和ZK60-1．0Y分别在两类合金中具有最佳的力学性能；Ce和Y在铸态时都分布在晶界上，在基体镁中的分布极少，经挤压变形后，Ce和Y沿挤压方向分布：无论合金处于什么状态，Ce和Y都以化合物的形式存在为主。试验合金的力学性能都高于ZK60合金本身。     

改革开放以来我国高等教育管理研究回顾与展望

我国高等教育管理研究是在改革开放以后正式开始起步的，其研究沿着两条并行而又有所交叉的轨道发展。其一是高等教育管理学学科的建设；其二是结合中国高等教育管理改革与发展的实际，为解决高等教育管理实践中所提出的问题而进行的应用性研究。尽管改革开放以来短短几十年我国高等教育管理研究取得了令人瞩目的成就，但也存在着一些问题。展望21世纪，我国高等教育管理研究必然在重视自身问题的基础上，以更加积极、开放、严谨的姿态在学科建设和应用研究方面迈上一个新的台阶。     

多点成形压力机中基本体群安装模板的有限元分析

应用ANSYS商业软件，对多点成形压力机基本体群安装模板的强度与刚度进行了分析，获得了不同厚度、不同载荷工况下的应力分布规律和变形状况，为多点成形压力机的设计提供了重要的参考依据。     

Hydrogen sorption properties of Mg-20wt.%Fe 23 Y8 composite prepared by reactive mechanical alloying

Mg-20wt.% Fe23Y8 composite was successfully prepared by reactive mechanical alloying (RMA). X-ray diffraction (XRD) measurement shows that the main phases of composite are MgH2 and Mg2FeH6. The composite exhibits excellent hydrogen abs/desorption properties and can absorb 4.36wt.% and 5.72wt.% hydrogen at 473 and 573 K in 10 min under 3.0 Mpa hydrogen pressure, respectively. The composite can desorb 5.27wt.% hydrogen at 573 K in 30 min under 0.02 Mpa hydrogen pressure. Compared with the pure MgH2, the hydrogen desorption temperature of Mg-20wt.% Fe23Y8 composite is decreased about 40 ℃. It is supposed that both the catalyst effect of Fe-Y distributed in Mg substrate and the crystal defects play the main role in improving hydrogen sorption properties of Mg-20wt.% Fe23Y8 composite.     

移动式冲孔翻边复合模设计

深拉伸件冲底孔翻边,冲压力不大,但由于拉伸件较高,为了取放工件,需要选用行程较大的大吨位冲床,为了解决这个矛盾,本文介绍了一种在小吨位小行程压力机上使用的下模移动式冲孔翻边复合模。为类似零件的冲压探索出了一条行之有效的途径。     

A projection-based decomposition for the scalability of evolvable hardware

Scalability is a main and urgent problem in evolvable hardware (EHW) field. For the design of large circuits, an EHW method with a decomposition strategy is able to successfully find a solution, but requires a large complexity and evolution time. This study aims to optimize the decomposition on large-scale circuits so that it provides a solution for the EHW method to scalability and improves the efficiency. This paper proposes a projection-based decomposition (PD), together with Cartesian genetic programming (CGP) as an EHW system namely PD-CGP, to design relatively large circuits. PD gradually decomposes a Boolean function by adaptively projecting it onto the property of variables, which makes the complexity and number of sub-logic blocks minimized. CGP employs an evolutionary strategy to search for the simple and compact solutions of these sub-blocks. The benchmark circuits from the MCNC library, \(n\)-parity circuits, and arithmetic circuits are used in the experiment to prove the ability of PD-CGP in solving scalability and efficiency. The results illustrate that PD-CGP is superior to 3SD-ES in evolving large circuits in terms of complexity reduction. PD-CGP also outperforms GDD+GA in evolving relatively large arithmetic circuits. Additionally, PD-CGP successfully evolves larger \(n\)-even-parity and arithmetic circuits, which have not done by other approaches.     

Network Characterizations for Excluding Braess’s Paradox

Braess’s paradox exposes a counterintuitive phenomenon that when travelers selfishly choose their routes in a network, removing links can improve the overall network performance. Under the model of nonatomic selfish routing, we characterize the topologies of k-commodity undirected and directed networks in which Braess’s paradox never occurs. Our results strengthen Milchtaich’s series-parallel characterization (Milchtaich, Games Econom. Behav. 57(2), 321–346 (2006)) for the single-commodity undirected case.