Superplasticity and deformation mechanisms in NiAl(- Mo) alloy

Abstract

The mechanical behaviour and microstructural evolution in tension of NiAl - 9Mo eutectic alloy at 1100 ° C and strain rates from 10^-5 to 10^-3 s^-1 have been investigated. High values of strain rate sensitivity index, but relatively small elongations between 150 and 200%, have been observed. Tensile specimens with various strains were quenched in water to preserve the dislocation structures for TEM examination. The TEM results show that the dislocation configuration and density change significantly with an increase in strain rate, and therefore correspond to different deformation mechanisms. At a low strain rate (5.5 × 10^-5 s^-1), the dislocation density is relatively low and dislocation activity is regarded as an accommodation mechanism for grain boundary sliding. In contrast, the high density of dislocations as well as clear subboundaries observed in grains at a high strain rate (5.5 × 10^-4 s^-1) suggest that the dislocations are active directly in response to the applied stress as well as participating in the relaxation process of grain boundary sliding by subboundary formation. Thus, grain boundary sliding is mainly responsible for superplastic deformation at a low strain rate, while superlastic deformation at a high strain rate is controlled by the combined operation of both grain boundary sliding and dynamic recovery.     

新型的热致收缩化合物和材料

介绍了近5年引起国际科技界兴趣的Sc2(WO4)3,AM2O7和立方ZrW2O8三种结构类型的热致收缩化合物和材料。特别是对在1000多度温度范围内都表现为各向性的高热致收缩化合物－－立方ZrW2O8进行了较全面的介绍，对立方ZrW2O8的改进了探讨。     

基于数据库的网管系统的设计与实现

网络管理系统以数据为中心。文章提出了基于数据库的多域网管系统的思想及模型。根据管理需求将被管对象ＭＯ（Ｍａｎａｇｅｄ　Ｏｂｊｅｃｔ）划分成域（Ｄｏｍａｉｎ）,每个域内实施特殊的管理政策模型以数据库为中心,将ＭＯ、ＭＩＢ以及采集到的数据全部映射到数据库中,可以将高层应用与Ｄｏｍａｉｎ　Ｍａｎａｇｅｒ分离,使高层应用全部建立在对数据库数据分析的基础上。     

Sodium retention in rats with cadmium-induced hypertension

Chronic feeding of non-toxic doses of cadmium induces an average increase of 15 to 20 mm Hg in indirectly measured systolic pressure of lightly anaesthetized rats. The mechanism of this increase is not known, but cadmium has several potentially pressor effects, including increased sodium retention. This report describes both sodium balance and blood pressure in a pair of experiments where cadmium was fed and in a pair where it was injected. All four cadmium challenges induced sodium retention and also induced hypertension. Thus, rats with either low or moderate chronic exposure to fed cadmium (well below the exposures required to induce toxicity) retained more intraperitoneally injected radiosodium than controls and at the same time developed higher systolic pressures than controls. Immediately following intraperitoneally injected cadmium, rats lost a radiosodium load more slowly than controls or alternately accumulated dietary radiosodium more rapidly than controls; in both situations the blood pressure was higher than in controls. These data indicate that some of the pressor effect associated with cadmium exposure could result from its concomitant antinatriuretic effect.     

某低品位铜钼矿石混浮捕收剂替代试验

内蒙古某低品位斑岩型铜钼矿选矿厂以酯105+煤油为捕收剂进行铜钼混合浮选,不仅分选指标不太理想,而且煤油采购越来越困难,价格也越来越高,严重影响了正常生产和经济效益的提高。为解决生产中面临的这些问题,采用从美国引进的新型高效捕收剂替代原浮选药剂对该矿石进行了选矿试验。结果表明：以MO+CO-47为铜钼混浮捕收剂,在工艺流程不变的情况下,获得了铜、钼品位分别为1970%、0339%,铜、钼回收率分别为9264%、8034%的铜钼混合精矿,与现场生产指标相比,精矿铜、钼品位分别提高145、0009个百分点,回收率分别提高706、1005个百分点。因此,用MO+CO-47替代原捕收剂酯105+煤油可以取得理想的降本增效效果。     

Investigation of thermal effects on mechanical properties of 9Cr-1Mo to 9Cr-1Mo welded joints for high-temperature applications

Modified 9CR-1MO usage has been highly increased in recent years mainly under high-temperature application. This paper focusses on microstructure without post heat treatment and hardness, stress analysis of weld zone, heat affected zone and parent metal with and without post heat treatment. Here, among many suitable welding processes, we have been chosen Tungsten Inert Gas Welding with an appropriate filler rod ER308L.The post heat treatment is been carried out by an annealing process. The study of microstructure for 9cr-1mo steel mainly describes size and shape of grains by the Scanning Electronic Microscope, micro, and macro structure examination. The tensile and hardness strength of the 9cr-1mo steel has been determined by using suitable equipment throughout the base metal and weld zone. The microstructure is uniform and free from a dendritic pattern, the ductility of material more after annealing and the hardness of material become uniform overall except in HAZ.     

"放逸"建筑论

讨论了中国古代美学中“放逸”的哲学基础与美学特征,比较了其与解构主义的主要异同;通过以“放逸”的美学精神对解构主义建筑的解读,提出除了理性主义以外,二者的精神比较接近,认为依据“放逸”精神的中国新地域主义建筑创作,可以参照解构主义建筑,本着理性主义精神进行。     

空间治理之“道”:源自老子哲学的启示

按照国家提出的推进国家治理体系和治理能力现代化的战略要求,作为空间治理政策工具的城市规划也纳入到了治理现代化改革的时代背景中。通过分析主流城市规划的历史嬗变,认为西方现代城市规划作为一门解决城市问题的学问,必然从属于问题导向,且整体上具有城市问题—孕育新理论—产生新问题循环的特点。改革开放30多年来,中国城市规划也被带入了问题导向发展的循环圈中。本文引入老子哲学,从本体论、认识论、方法论和人性论方面构建了一个整体性的理论框架,为规划转型提供了本土哲学的探索。     

基于老子生命哲学的高校教职工生命教育研究

老子的生命哲学以其博大精深的生命智慧引发了弥久不衰的思想魅力.文章结合时下我国高校教职工生命状况和职业发展态势,着重发掘和整理老子生命哲学中的“贵生轻物”的人文关怀、“贵柔不争”的处世艺术、“生死自然”的达观态度、“死而不亡”的终极超越等独特的生命智慧.认为一名优秀的高校教职工,应既“育人”也“育己”,把握自己的定位,顺应生命的本性,纯真而自然地让个体生命之花自由而全面地绽放.     

渔子溪水电站水轮机技术改造

根据渔子溪水电站的实际参数,采用数值和实验研究,提出了改造水轮机过流部件的方案,改造后的水轮机,改善了叶片的空蚀和机组运行的稳定性,提高了水轮机效率,增大了机组出力。