Sn及其氧化物超微粉的制备与测试

本文采用气体蒸发法制备出粒度不到５ｎｍ的Ｓｎ及其氧化物的超微粉。利用热重，差热分析和Ｘ射线衍射谱等测试方法研究了热处理制度对其粒度，成份和气敏特性的影响，发现了ＳｎＯ_２正交相的存在。     

编制快走丝线切割3B程序的技巧

对传统的3B编程方法进行了新的探索和实践,在传统的3B手工编程的基础上总结出了易掌握、不易出错、高效的编程技巧即“终-终-终”;“起-终-起”的方法。通过比较教学证实,它是一种高效实用的新方法。     

Classification and prediction of burr formation in micro drilling of ductile metals

In the micro drilling of precision miniature holes, the formation of exit burrs is a topic of interest, especially for ductile materials. Because such burrs are difficult to remove, it is important to be able to predict various burr types and to employ burr minimisation schemes that consider burrs’ micro-scale characteristics. In the present work, an artificial neural network (ANN) was used to predict the formation of burrs in the micro drilling of copper and brass, along with burr formation/optimisation analysis specialised for micro drills. The influence of cutting conditions, including cutting speed, feed and drill diameter, upon exit micro burr characteristics such as burr size and type was observed, analysed and classified. Based on the results, an empirical equation to predict micro burr height is proposed herein. The classification results were compared with conventional burr cases using burr control charts. Then, micro burr types were predicted by means of an ANN, using the influential parameters as input vectors. The usefulness of the proposed scheme was demonstrated by comparing the experimental and prediction/analysis results.     

J-K旋转坐标轴定向的矢量控制策略

考虑到传统矢量控制在空载或轻载时励磁电流损耗较大会导致运行效率降低,研究了一种基于j-k坐标轴的新型矢量控制方法。j-k坐标轴的定向角度超前传统的d-q坐标轴45°。在空载或轻载运行时,控制j轴一个方向的电流大小即可达到控制磁链和转矩的目的。励磁电流不再一直维持在额定值,而是随输出转矩的变化而变化。实验结果表明,可以减小励磁电流损耗,具有控制简单,动态性能良好的优点。     

白藜芦醇糖苷类衍生物的设计与合成

以白藜芦醇及其类似物紫檀芪为原料,采用Schmidt成苷法、相转移催化法,分别与溴代糖和乙酰氨基糖反应,得紫檀芪乙酰葡萄糖苷和(E)-5,4'-二叔丁基二甲基硅基-3-(2"-乙酰氨基-3",4",6"-三乙酰葡萄糖二苯乙烯,其结构经红外光谱、核磁共振氢谱和质谱表征.     

黄河某水电站库区泥石流特征及工程影响研究

黄河某水电站库区泥石流沟道发育,对该水电站运行安全带来不利影响。结合国内外有关研究成果,根据库区内泥石流的具体特征,以杏儿沟、官亭沟和喇家沟为重点研究对象,分析研究了这几条沟泥石流的形成条件及运动特征,包括泥石流的流速、流量等,并将泥石流对工程的危害作出评价。研究成果对水电站建设具有重要指导意义。     

多功能油层保护剂JQD的研制与应用

针对新疆小拐油田裂缝-孔隙型储层特点,开发研制了一种新型的兼具防漏堵漏及油层保护功能的JQD处理剂。该处理剂具有较好的油溶率、酸溶率,与现有钻井完井液体系配伍性良好,加工粒径可调,对1—4mm的裂缝堵漏效果良好。动态损害实验表明,JQD体系的岩心渗透率恢复值不小于80％。现场试验三口表明,JQD与钻井液配伍性良好,防漏堵漏效果显著,性能调整及维护方便,起下钻及电测顺利。三口井投产后,两口井产量分别为30和28t/d,一口井产气量为1.1×10~4m~3/d,说明储层得到了有效的保护,实现了“堵得住、解得开”的目标。     

循环水的电子—化学协合处理

简述循环水电子-化学协合处理的基本原理及应用现状,通过电厂的应用实例,分析节能减排降耗的成效,对取得的经济效益进行了比较。     

The thermochemical behavior of some binary shape memory alloys by high temperature direct synthesis calorimetry

The standard enthalpies of formation of some shape memory alloys have been measured by high temperature direct synthesis calorimetry at 1373 K. The following results (in kJ/mol of atoms) are reported: CoCr (−0.3 ± 2.9); CuMn (−3.7 ± 3.2); Cu₃Sn (−10.4 ± 3.1); Fe₂Tb (−5.5 ± 2.4); Fe₂Dy (−1.6 ± 2.9); Fe₁₇Tb₂ (−2.1 ± 3.1); Fe₁₇Dy₂ (−5.3 ± 1.7); FePd₃ (−16.0 ± 2.7); FePt (−23.0 ± 1.9); FePt₃ (−20.7 ± 2.3); NiMn (−24.9 ± 2.6); TiNi (−32.7 ± 1.0); TiPd (−60.3 ± 2.5). The results are compared with some earlier experimental values obtained by calorimetry and by EMF technique. They are also compared with predicted values on the basis of the semi empirical model of Miedema and co-workers and with ab initio calculations when available. We will also assess the available information regarding the structures of these alloys.     

Crystallization and infrared radiation properties of iron ion doped cordierite glass-ceramics

Heterogeneous ion solution is an important method to improve the wanted property of polycrystalline materials. In this paper, for the purpose of infrared radiation property modification, different contents Fe₂O₃ were doped in MgO-Al₂O₃-SiO₂ system glasses. The effects of Fe₂O₃ doping on nucleation mechanism, crystallization behaviors and especially infrared radiation properties of this cordierite-crystalline based glass-ceramics were systematically investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that, the doping of iron ion can promote the phase separation of this magnesium aluminosilicate glass, and therefore change the crystallization mechanism of this glass from surface crystallization to bulk crystallization. The iron ion incorporates into the crystal structure of cordierite by mean of substituting Mg²⁺ in M site. The substitution of Fe³⁺ to Mg²⁺ can form the vacant site of Mg²⁺ cations. For the effects of lattice distortion, impurity and vacancy defects which caused by the incorporation of iron ion, the infrared radiation performance of cordierite based glass-ceramics can be improved effectively.