电磁泄放阀辅阀改进

通过对电磁泄放阀辅阀泄漏原因的分析，提出了相应的改进措施：(1)改进辅助阀瓣结构；(2)改动辅阀位置；(3)改变试验方法；(4)加强锅炉起动时的检查。珠江电厂3号、4号炉电磁泄放阀采取这些措施后已运行近两年，效果良好，辅阀未再泄漏，确保了机组的安全运行。     

异步电动机矢量控制系统Simulink仿真

作者提出异步电动机矢量控制系统方案 ,在此基础上设计了一个矢量控制系统 ,并结合具体实例 ,在Simulink中给出了仿真框图及仿真结果     

谈现代小说中人力车夫形象

通过《一件小事》、《薄奠》和《骆驼祥子》三部作品中的比较分析,从“人力车夫”这一都市劳动人民的主人公形象,我们可以看到其工人阶级的友爱精神和高尚品质,同时,要清醒认识到在旧制度下劳动者的悲剧命运是无法避免的。     

Three-dimensional porous composite framework assembled withCuO microspheres as anode current collector for lithium-ionbatteries

The surface structure and material composition of current collectors have significant effects on the electrochemical performances of lithium-ion batteries(LIBs). In this work, a three-dimensional(3D) porous composite framework is applied as the anode current collector in LIBs. This unique 3D skeleton is composed of conductive carbon fiber/Cu core/shell fibrous structure. With an oxidation treatment upon the copper shell, the porous framework is assembled with CuO microspheres. Using mesocarbon microbead(MCMB) graphite powders as the active material, the cell with this 3D porous composite current collector shows an improved reversible discharge-charge capacity of 415 mAh g~(–1) at a current rate of 0.1 C after 50 cycles, which is much higher than that of the cell with a flat Cu foil(127 mAh g~(–1)). It is demonstrated that this unique fibrous network of the 3D current collector coupled with the morphological effects of the CuO microspheres greatly improve the cell performance in terms of electrical conductivity, reversible capacity and cycling stability.     

感应电机无速度传感器直接转矩控制的智能优化设计

在一些特定作业环境中,需要对电机转速进行精确调控.为了改善直接转矩控制系统低速时常规PI调节器带来的转速脉动,设计了基于模糊神经网络的新型PI调节器,改进后的转速调节器具有快速自整定、微超调的特性.针对MARS转速观测器低速时的不稳定性,设计了基于人工神经网络的模型参考自适应速度观测器,改进后的转速观测器具有良好的动、静态特性.仿真结果表明:智能优化设计使得直接转矩控制系统的控制效果明显提高,且有更好的鲁棒性和自适应性.     

Experimental investigation and numerical simulation of large-sized aluminum tube extrusion forming

Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variation and velocity effect is difficult to control. The extrusion forming of large-sized aluminum tube was researched and simulated. Three-dimensional thermo-mechanical coupled finite element model was constructed and appropriate boundary conditions were given out. The results show that large-sized aluminum tube can be formed by isothermal extrusion through controlling the extrusion velocity and founding the relationship between extrusion velocity and extrusion temperature.     

废树脂苯乙烯固化研究(Ⅱ)

本文研究废离子交换树脂苯乙烯固化的工艺条件和固化产品性能鉴定。该法能包容62％(W)废树脂。固化产品均匀、坚韧、抗压强度239kg/cm~2。在去离子水中浸泡120d,浸出率对于~(137)Cs为10~(-6)cm/d,对于~(60)Co和~(85)Sr为10~(-7)-10~(-8)cm/d。长期水浸不溶胀。承受辐照剂量>10~8rad。闪点270℃,燃点290℃左右。加热到450℃不自燃,DTA曲线上235℃前无放热峰。     

维生素对螺旋霉素发酵的影响

研究了单独添加和组合添加VB1、VB1。和硫辛酸对发酵合成螺旋霉素的影响。结果显示,组合添加0．96mg·L^-1VB1和0．35mg·L^-1硫辛酸时,螺旋霉素产量提高30％。测定结果显示维生素的添加显著增加了乙酸等前体物质的浓度,提高了发酵过程中乙酰激酶、乙酰磷酸转移酶与乙酰CoA合成酶的酶活。由此表明维生素的添加促进螺旋霉素发酵合成可能是因为维生素促进了过程中前体物质的合成,从而增进了内酯环的形成。     

生成长寿命放射性核的（n，γ）截面测量

生成长寿命放射性核的（ｎ，γ）截面测量夏宜君，龙先灌，王春浩，杨志华，罗小兵杨经福，刘漫天，彭秀峰，何福庆（四川大学原子核科学技术研究所，成都，６１００６４）卢涵林（中国原子能科学研究院，北京，１０２４１３）低放射性水平作为聚变堆发展的重要目标，对聚...     

嵌入式数据库SQLite在核仪器数据管理中的应用

针对核仪器中采用文件方式管理二进制谱线数据块时操作繁杂、格式不一、升级困难等问题,本项目通过嵌入体积小、速度快、稳定可靠的SQLite数据库,采用BLOB类型存储二进制谱线数据块,利用事务传输批量数据,提高了谱线数据管理性能与安全性。根据谱线数据管理要求,设计实用的谱线数据管理系统,验证SQLite数据库在核仪器数据管理中高效、便捷、可靠等优势。