Nb在高Ti中Al铁基高温合金的作用

探讨Nb在高Ti中Al铁基高温合金的作用，认为Nb参与了γ-相形成，增加γ-相数量，生成Ni3（Al、Ti、Nb）提高γ-相的固溶温度，从而实现第二相强化。同时，Nb促使碳化物相处于均匀弥散分布状态使合金组织均匀化并显著提高室温、700℃拉伸和持久强度，改善塑性。当Nb含量超过1．38％时γ-相析出达到平衡，μ-相结构发生变化，且数量增加，晶界小颗粒状、块状、链状、μ相析出脆化了晶界，降低合金塑性。     

新时期地方高校教育多元质量观与人力培养

人才培养质量是高校发展的永恒主题.针对我国高等教育正向大众化阶段迈进的现状,本文提出要发展多种教育模式,建立多种质量标准,让更多的人接受高等教育,确保高校人才培养质量能够与时俱进,满足社会发展需求.     

以创新谋求企业经济增长质的飞跃

建设节约型企业,就要树立和落实科学发展观,坚持资源开发与节约并重,把节约放在首位。27 a来,江西铜业集团公司以提高资源利用效率为核心,以节能、节水、降耗、资源综合利用和发展循环经济为重点,加快结构调整,推进技术进步,强化节约意识,以创新实现了企业经济增长质的飞跃。     

Over-relaxation effect of deformed austenite on ageing behavior of an Nb-bearing microalloyed steel

The ageing behavior of an Nb-bearing microalloyed steel at 525℃was investigated by thermo-simulation test, hardness measurements and transmission electron microscopy (TEM). Prior to ageing, the steel was deformed in austenite zone followed by a long relaxation. Experimental results indicate that the hardness decreases gradually in the initial stage until ageing for 120 min, and then increases continuously until 1200 min. The coarsened precipitates (>10 nm) formed in deformed austenite remain nearly unchanged in size, even after ageing for long time, while the further precipitates, which nucleate in a phase, contribute to the increasing of hardness. By comparison, the undeformed samples in austenite subjected to the same ageing process display a very similar hardness change trend to that of over-relaxation ones and have higher hardness values at each corresponding period.     

Drag characteristics of power law fluids on an upstream moving surface

The specific problem to be considered here concerns the boundary layer problem of a non-Newtonian fluid on a flat plate in length, whose surface has a constant velocity opposite in the direction to that of the mainstream with Uw 〉〉 U∞, or alternatively when the plate surface velocity is kept fixed but the stream speed is reduced to zero. A theoretical analysis for a boundary layer flow is made and the self-similar equation is determined. Solutions are presented numerically for special power index and the associated transfer behavior is discussed.     

聚烯烃纳米复合材料研究进展

综述了近年来国内外聚烯烃纳米复合材料的制备方法 ,研究进展和结构与表征。     

离子络合法制备ZnO纳米线

通过高聚物PAM与锌盐发生离子络合反应 ,将络合溶液涂膜在单晶硅片上 ,再通过烧结使之生长出ZnO纳米线。用场发射扫描电子显微镜 (FE SEM )、X射线衍射 (XRD)、红外光谱 (IR)对所得样品的结构与形貌进行分析表征 ,结果表明ZnO纳米线直径约 6 0～ 80nm、长度约 1～ 2 μm ,单晶 ,为六方晶系 ,且沿c轴方向优先生长。     

HYSYS过程模拟软件在空分设备操作中的应用

描述了HYSYS过程模拟软件在空分设备操作中的应用,并介绍了软件应用过程中的体会。     

文检课个性化教学设计

提出了文检课个性化教学的观点，讨论了实施个性化教学的必要性，指出在网络环境下，如何构建多维的个性化智能教学系统，探讨了个性化的教学方案及基于此的教学内容及考试制度。     

万能轧机水平辊辊环应力分析和直径优化

对H型钢轧机万能轧机水平辊辊环的各种应力分析比较得出,对万能轧机镶套水平轧辊辊环作 用最大的应力为热装应力,并对辊环的直径进行了优化,提高辊环与辊芯之间的摩擦系数,减少热装过盈量是改善辊环受力状态的有效途径.