Ag-Cu-In-Sn合金的结构特性

借助金相、X光衍射及SEM方法研究Ag-Cu-In-Sn合金的结构特性及合金各组元在合金相中的分布规律,还讨论了某些相结构对合金力学性能的影响。四元合金的化学成分是(wt％)57～63Ag,17～23Cu,(20—x)In,xSn,其中:Ag+Cu=80wt％,In+Sn=20wt％,2≤x≤16。     

液态铝合金表面张力快速检测新方法与装置

表面张力是液态合金的重要物性参数之一,铝合金表面张力与其变质处理效果及充型能力等质量参数密切相关,研究铸造铝合金表面张力快速检测方法及装置,对于开发铝合金熔炼质量炉前实时评价系统具有非常重要的实际意义.介绍了一种液态铝合金表面张力快速测试的新方法和新装置,新方法以固定时间内吹入被测液体的气泡个数以及气泡在生长过程中内部压差变化为信息参数,通过回归公式求解表面张力.基于该方法研制的表面张力新型测试装置由单片机测控单元、探头及其锁紧和升降机构、供气单元等部分构成.采用新装置可在5 s内测得铝合金表面张力,且具有较高的测试精度.     

Effect of surface modification of metal hydride electrode on performance of MH/Ni batteries

A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.     

表面氧化层对TiMn1.25Cr0.25储氢合金活化性能的影响

通过TiMn1.25Cr0.25合金粉活化前在空气中暴露不同的时间,探讨了表面氧化层的形成对其活化性能的影响。活化测试结果表明：合金的活化难度随着合金在空气中暴露时间的延长而加大。俄歇电子能谱(AES)结果表明,在空气中暴露后的合金表面形成了一层大约6nm-10nm厚的表面氧化层,正是这层氧化层的形成加大了合金的活化难度。扫描电镜(SEM)结果表明合金的活化过程与合金的碎化有着密切的联系。     

高线粗中轧机"浮动"检测结构设计及故障排除

为克服轧制中因机架锁紧功能降低而产生的机架沿轨座轴向移动的"浮动"现象,对其产生原因进行了分析,并通过改进锁紧装置结构及相关部件,使"浮动"故障得到预防和有效控制并及时排除。     

Atomic force microscopy study of biaxially oriented polypropylene films

Atomic force microscopy (AFM) uses a very sharp pointed mechanical probe to collect real-space morphological information of solid surfaces. AFM was used in this study to image the surface morphology of a biaxially oriented polypropylene film. The polymer film is characterized by a nanometer-scale, fiberlike network structure, which reflects the drawing process used during the fabrication of the film. AFM was used to study polymer-surface treatment to improve wettability by exposing the polymer to ozone with or without ultraviolet (UV) irradiation. Surface-morphology changes observed by AFM are the result of the surface oxidation induced by the treatment. Due to the topographic features of the polymer film, the fiberlike structure has been used to check the performance of the AFM tip. An AFM image is a mixture of the surface morphology and the shape of the AFM tip. Therefore, it is important to check the performance of a tip to ensure that the AFM image collected reflects the true surface features of the sample, rather than contamination on the AFM tip.     

Influencing factors on elastic-plastic deformation of multi-layered surfaces under sliding contact

Stress distribution in the gradient multi-layered surface under a sliding contact was investigated using finite element method(FEM). The main structure parameters of layered surface discussed are total layer thickness,layer number and elastic modulus ratio of layer to the substrate. A model of multi-layered surface contact with rough slider was studied. The effect of the surface structure parameters on the elastic-plastic deformation was analyzed.     

汽车构造实验网络教学辅助系统设计

为切实提高汽车专业教学水平,建立全方位教学体系,设计基于网络的汽车构造实验教学辅助系统。系统充分利用学校现有计算机网络平台,利用多媒体和网络开发技术,开发或整合多媒体资料,开辟学习交流平台,依据课程学习规律和认知特点,建立起方便快捷、生动有趣的实验教学辅助系统。该系统基于现有教材,又高于教学内容,不仅对于传授汽车zai新技术和剖析专业难点,调动学习积极性,具有重要补充和推动作用,而且对于教学示范中心创建工作,也具有重要意义。     

基于贝叶斯的服务通告改装经济性决策方法

改装类服务通告的经济性决策是航空维修企业工程人员的一项重要工作内容。设计了改装类服务通告经济性决策程序;通过服务通告对飞机运营的经济性影响分析构建了成本分解结构,并对不同的成本项目建立了成本评估模型;针对模型的成本影响参数MTBUR和MTBF的估计采用了贝叶斯方法以解决小样本问题;通过投资回收期方法获得评价指标以决定是否进行服务通告改装投资。最后通过实例对决策方法的应用进行说明。此方法能够为航空企业的维修改装决策提供有效的技术支持。