La部分取代MI混合稀土贮氢合金的电化学性能     

赵东江  马松艳 《实验技术与管理》2007,24(1):26-28

金属La部分取代MI（混合稀土）的贮氢合金电极Ml0.8La0.2Ni4.0Mn0.4Co0.4Al0.1（A）容易活化，其充电效率、放电容量、快速放电能力以及荷电保持能力比电极MlNi4.0Mn0.4Co0.4Al0.1（B）分别提高5．5％、7．0％、4．0％和8．2％。电极A放电过电位比电极增大，且循环稳定性下降。  相似文献   

螺旋支架治疗前列腺增生的适应症探讨     

马建国  王寿祥  刘春霞 《河北北方学院学报(医学版)》1999,(1)

自1992年6月至1994年10月,收治了10例记忆金属螺旋支架管治疗前列腺增生所致排尿困难的患者.采用耻骨上经膀胱开放手术,取出金属螺旋支架管,摘出前列腺。分析了10例置管失败的原因。就金属螺旋支架管治疗前列腺增生的作用、适应症进行了探讨,认为合并膀胱颈部纤维化、前列腺中叶增生及以纤维组织增生为主的良性前列腺增生者不适宜这种治疗。  相似文献   

Preparation and characterization of TiO₂/expanded graphite     

赖奇  朱世富  刘国钦  邹敏  李玉峰  罗学萍 《天津大学学报(英文版)》2010,16(2):156-159

In order to obtain anatase TiO2/expanded graphite with high expansion volume, titania gel was introduced to expandable graphite surface by sol-gel process, and then the composite was expanded and calcined at high temperature. The samples were analysed by using scanning electron microscope (SEM), X-ray diffraction(XRD), energy disperse spectroscopy(EDS), and differential scanning calorimetry(DSC). The optimal conditions for preparation are as follows: the molar ratio of tetrabutyl orthotitanate to triethanolamine is 1∶0.4, and the calcination and expansion temperature is in the range of 650-750 °C. Under such conditions, the expansion volume of composites could reach 98 mL/g, and the mass loss ratio is less than 5%. The analysis shows that lower temperature and smaller particle size of graphite are helpful to the formation of anatase-type of TiO2, but larger particle size will lead to lower mass loss ratio, and higher temperature and larger particle size will lead to higher expansion volume.  相似文献   

Treating dye wastewater by TiO2 coated on coal cinder     

LIU Jian-hu  WANG Hai-jun 《重庆大学学报(英文版)》2009,8(3):165-169

We investigated the photocatalytic degradation of dye wastewater by using titanium dioxide （TiO2） coated on a coal cinder. The coal cinder was used as the carrier, with a thin film of TiO2 coated on it by using the sol-gel method. Using the Congo red as the model pollutant for dye wastewater, we studied the decolorization efficiency, and effects of TiO2 film thickness and roasting temperature on the efficiency. We also evaluated the recycling and regeneration of the immobilized TiO2 （TiO2/cinder）. Results show that the decolorization rate of Congo red solution was more than 98% after 2.h treatment when we used TiO2/cinder calcined at 500 ℃ for 2 h and coated four times as the photocatalyst. At the same time, the TiO2/cinder remained high catalytic activity after being reused and regenerated for many times.  相似文献   

Morphology evolution of two-phase Cu-Ag alloys under different conditions     

Jin-li Hu  Jin-dong Zhang  Liang Meng 《浙江大学学报(A卷英文版)》2009,10(3):458-463

Cu-Ag filamentary microcomposites with different Ag contents were prepared by cold drawing and intermediate heat treatments. The microstructure characterization and filamentary distribution were observed for two-phase alloys under different conditions. The effect of heavy drawing strain on the microstructure evolution of Cu-Ag alloys was investigated. The results show that the microstructure components consist of Cu dendrites, eutectic colonies and secondary Ag precipitates in the alloys containing 6%-24% （mass fraction） Ag. With the increase in Ag content, the eutectic colonies in the microstructure increase and gradually change into a continuous net-like distribution. The Cu dendrites, eutectic colonies and secondary Ag precipitates are elongated in an axial direction and developed into the composite filamentary structure during cold drawing deformation. The eutectic colonies tend to evolve into filamentary bundles. The filamentary diameters decrease with the increase in drawing strain degree for the two-phase alloys, in particular for the alloys with low Ag content. The reduction in filamentary diameters becomes slow once the drawing strain has exceeded a certain level.  相似文献   

掺钕TiO2的固载化及其光催化活性的研究     

计兵  杨金田  张林萍 《湖州师范学院学报》2006,28(1):64-67

以膨润土为载体,用离子交换法制备负载型掺钕TiO2光催化剂.用X射线衍射、紫外可见分光光度计及降解苯酚的催化活性评价对掺钕TiO2/膨润土进行了表征,结果表明:掺杂0.1%Nd的TiO2/膨润土对苯酚有最高的光催化降解效率,500℃为掺杂Nd的TiO2/膨润土光催化剂的最佳热处理温度,离子交换法制备TiO2/膨润土光催化剂的最佳温度、酸度、交换时间分别为45℃、1.5mol/L(H )、3h.  相似文献   

轴瓦的合理浇注及废品分析     

王桂杰  赵强 《鸡西大学学报》2001,(3)

详细介绍了轴瓦浇注的过程、废品产生的原因及有效防止缺陷的方法,从实践出发,对轴瓦的浇注工艺做了详细论述.  相似文献   

Study on Moving Principle of Colonoscopic Robot     

MIZhi－nan  GONGZhen－bang 《上海大学学报(英文版)》2001,5(2):143-146

The moving principle of a colonoscopic robot is presented in this paper.The robot mainly consists of soft mobile mechanism for earthworm locomotion and turning mechanism based on shape memory effect.The soft mobile mechanism contacts colon wall with air-in inflatable balloons.so the robot has better soft and non-invasive properties.The turning mechanism can be actively bent by shape memory alloy components.It ensures the robot to adapt to the tortuous shape of colon.Therefore,the colonoscopic robot has good safety,lower working strength of surgeon and higher efficiency of colonooscopy.  相似文献   

铁碳合金相图分析     

李鹏志 《石家庄职业技术学院学报》2006,18(4):51-53

铁碳合金相图是研究在平衡状态下铁碳合金成分、组织和性能之间的关系及其变化规律的重要工具,掌握铁碳相图对于制定钢铁材料的热加工工艺具有重要的指导意义.通过分析铁碳合金相图的主要特性点和主要特性线,解决了“金属工艺学“教学与研究中的重点和难点问题.  相似文献   

钛合金表面激光熔覆氧化锆陶瓷涂层的显微组织     

李平  邓永瑞 《洛阳工业高等专科学校学报》1995,(3)

本文采用激光熔覆技术,探讨制备ZrO_2/Ti梯度功能材料,利用SEM和EPMA分析激光熔覆层,过渡层、热影响区的组织形貌和各组元的成份分布。用X射线衍射和微区X射线衍射技术分析激光熔覆区的氧化锆相变及各区域的相组成。得到:经过激光熔覆处理,熔覆区氧化锆由C—ZrO_2和T—ZrO_2组成,激光熔覆层、过渡区,热影响区的组织分别为ZrO_2枝晶 Ti_2O、粒状Z_rO_2 α相、片状α组成,在过渡区内成份是渐变的,组织为陶瓷相ZrO_2和塑性相α相混合。此工艺是制备ZrO_2/Ti梯度功能材料有前途的方法。  相似文献