High Temperature Oxidation Behavior of La2O3-MosSi3/MoSi2 Composites

The oxidation behavior of 0. 8% La2O3- Mo5Si3/MoSi2 composites at 1200℃ in air was investigated. The results reveal that the oxidation resistance of the material with 0. 8% La2O3 and Mo5Si3 is impaired. The oxidation resistance is decreased with increasing Mo5Si3 content. The mass loss follows a linear law in the initial oxidation. With oxidation time prolonging, a continuous and dense oxidation scale prevents oxygen from diffusing increasing when and leads to mass change a Mo5Si3 content is less than 30%. However, the composite shows ＂PEST＂ with the addition of 40% Mo5Si3. With increasing Mo5Si3 content, the oxidation resistance of 0.8% La2O3- Mo5Si3/MoSi2 decreases. This attributes to the poor oxidation resistance of M05Si3 and the relative density decreasing of 0. 8% La2O3-Mo5Si3/MoSi2 composite.     

转炉吹炼时造渣动力学研究的新方法

转炉炼钢过程中钢渣数量的变化和化学成分的变化，取决于吹氧期氧化—还原反应的复杂作用；取决于熔炼过程中吸收的加入材料和吸收转炉炉衬侵蚀物的情况；以及废钢的熔化情况。弄清这些变化的规律性，不仅是理论上的需要，同时也是实践提出的需求。     

PyGC/FTIR在丁苯胶表面氧化产物分析中的应用

提出了一种利用控制热裂解温度分析丁苯胶表面氧化产物的裂解气相色谱/红外光谱(PyGC/FTIR)分析方法.借助热重分析结果确定了合适的热裂解温度,PyGC/FTIR分析结果表明丁苯胶表面氧化主要是由于丁二烯聚合所余双键和苯乙烯末端双键不稳定性所致.利用PyGC/FTIR法不但可以进行高分子单体组成分析,通过控制热解温度还可以用于其表面氧化产物的分析.     

丁二烯经环氧丁烯制四氢呋哺新工艺

本项目采用改进的银催化体系，以丁二烯为原料，通过气相环氧化一步制备新型精细化工原料——环氧丁烯。由环氧丁烯出发，经过2，5-二氢呋喃，再加氢得到四氢呋喃（THF）。     

单微乳液中制备Ag/TS-1及丙烯气相环氧化

采用N2H4还原含AgNO3的单微乳液制备了Ag／TS-1催化剂。TEM表征结果表明，Ag高度分散于TS-1之上。以H2、O2存在下的丙烯气相环氧化为探针反应，考察了Ag／TS-1的催化性能。结果表明，采用Ag／TS-1为催化剂，Ag的负载量为1％（质量分数，下同），823 K焙烧后，373 K下反应30 min时，丙烯转化率为1．69％，环氧丙烷（Propylene oxide，PO）选择性为93．2％。当Ag的负载量超过2％时，反应过程中生成大量的热，造成PO的选择性下降。采用Ag的负载量为8％的Ag／TS-1催化剂，消除热效应后，丙烯的转化率为2．46％．PO的选择性为79．2％。     

氧化镐氧量计在优化锅炉燃烧过程中的应用

介绍了氧化镐氧量计的发展、测量原理以及在锅炉优化燃烧中的应用。重点论述了氧化镐氧量计在130t／h煤粉锅炉优化燃烧应用的实现过程和方法，氧体积分数是锅炉优化燃烧控制最重要的参数之一，是锅炉燃烧控制的依据，氧体积分数测量的可靠性直接影响锅炉的燃烧效率，对经济、环保等方面起到很好的效果和作用。     

Spin Dependent Hopping in Ti Doped La0.67 Ca0.33 MnO3

A systematic investigation of the magnetic and transport properties of Ti doped La0.67Ca0.33MnO3 was reported. The Ti substitution for Mn ions results in a reduction in ferromagnetism and conductivity. The metal-insulator transition temperature is close to Curie temperature which decreases from 274 to 82 K as x increases from 0 to 0.17. The most important effect of Ti doping is to introduce spin clusters in the samples due to the distortion of local lattice and the inhomogeneous magnetic structure induced primarily by the random distribution of Mn ions. A maximum magnetoresistance ratio as large as 90% in 1 T at 122 K was obtained for the sample with x =0. 055, which is four times larger than that obtained for LCMO sample at 272 K. There is a remarkable field-history dependent MR in the cooling process for the doped samples while such phenomenon disappears in the warming run. The resistivity follows well the variable range hopping behavior in paramagnetic state. Both the size effect and spin dependent hopping of carriers between the spin clusters should be considered in this system.     

纯度极高的钼材

法国一家公司制成了一种新型的耐高温合金。该合金以钼为主要成分,含有一定比例的三氧化二钇和钾。这种合金的再结晶温度高,且再结晶后的组织结构良好。试验表明,该合金在1750℃温度下加热差半小时后形成长而大的再结晶组织,同时能够承受3次以上的90度钳口弯折。此外,这种合金还具有延伸率高、容易工成型、抗高温变形性好、尺寸稳定、使用寿命长等优点,是一种理想的耐高温结构材料。新型耐高温合金@李有观