缺血性糖尿病下肢病变的膝下动脉成形术

目的探讨膝下动脉的球囊成形术在治疗糖尿病缺血性下肢病变中的价值。方法对５３例糖尿病合并缺血性下肢病变患者６４侧缺血性下肢进行膝下动脉Deep球囊扩张成形术。对比患者手术前后临床症状的改变及足部溃疡的变化。结果５３例患者共１１９支动脉分支接受PTA治疗，５０例患者的１０１个分支成功地开通，技术成功率为８４．９％，所有５０例患者的临床症状均明显缓解，足部溃疡均变小，无需截肢。结论膝下动脉的球囊成形术是治疗缺血性糖尿病下肢病变安全有效的微创手段     

参数设计法在铝电解电容器设计中的应用探讨

论述了参数设计法在铝电解电容器设计开发阶段的应用。文中阐明了铝电解电容器的主要质量特性(损耗因子、电容量)及芯包外径的参数设计原理,并建立了归一化函数作为优选设计方案的判据。实例证明在铝电解电容器的设计过程中应用参数设计法以减小产品质量特性变异是有效的。     

A local theory of heating in cross-ply carbon fiber thermoplastic composites by magnetic induction

For joining and repair of continuous fiber thermoplastic composites, induction heating has been viewed a strong candidate. Induction heating employs an applied alternating magnetic field, which induces a rotational emf in a grid of conductive carbon fibers, which are then used to carry resulting currents. In continuous carbon fiber crossply composites the available paths for “eddy current” loops are along the network of conductive carbon fibers. For this to occur, an electrical transfer must take place between crossing fibers in adjacent plies. Tests involving variable thicknesses of interply neat film layers have been performed to provide insight into the mechanisms taking place. These tests indicate that the primary mechanism for heating in such laminates is dielectric losses in the polymeric region between fibers in adjacent planes that form the conductive loop. Therefore, heating is not uniform in such composites despite a uniform magnetic flux. Heating patterns were viewed using liquid crystal materials and E-type thermocouples. Several factors leading to nonhomogeneous thermal distributions have been considered, including current density effects, internal emf cancellation, and rotational field effects. Global and local considerations are addressed, a localized model is proposed, and the corresponding theory is developed qualifying the early results. Additional testing has supported the theory.     

东莞市水污染现状及其对策探讨

通过分析东莞市河流、水库、饮用水源地、河库底质污染现状以及1998-2003年部分河道水质变化趋势,找出本地区水污染问题和原因,提出改善水环境的对策措施。     

基于图像处理的炮管轴线直线度检测方法

在分析国内外直线度检测现状和比较了直线度测量的激光准直法、圆度法、杠杆法优缺点的基础上,提出了一种基于图像处理的炮管轴线直线度检测激光反射法.该方法通过激光器发出激光,经准直后射向分光镜,部分反射后射向测量元件.测量元件在炮管内移动并感知炮管实际轴线位置的变化.激光经反射后透射过分光镜到光靶上,CCD摄像机摄得光靶上被测信息的图像.经过图像处理及数据处理得出对应被测截面图像中的激光束中心,按照角度积累的公式计算出轴线直线度误差.同时论述了在Win98和VC++6.0环境下软件实现的步骤.实验结果表明该方法具有灵敏度高、测量速度快,对被测对象尺寸要求较低,适合在工厂内使用等优点.     

一种升压式PFM DC-DC转换器的设计

讨论了一种PFM升压式DC－DC电压转称器的设计，重点对其关键的基准电压产生，振荡控制信号产生及比较器设计进行了分析，并采用3μmCOMOS工艺完成芯片的设计。