长距离柔性接口输水管道试压技术研究

针对大口径柔性接口管道特点和试压难点展开研究,设计专用装配式试压装置,将传统的管道铺设、试压间断施工转变为连续施工。不仅显著地减少了试压用水量,简化了施工程序,而且,完成管道试压后对试压装置进行改装,作为永久性管段加以利用,节约了资源。采用该方法进行压水试验,施工进度快,经济效益显著。     

带钢端部形状双目视觉检测系统的建模仿真

为了实现热轧带钢端部形状检测,利用Matlab中视觉图像处理工具箱,建立了由CCD线阵相机构成的双目立体视觉系统模型和实际带钢生产线上的运动过程模型。热轧带钢在生产过程中会受到粗轧辊的不平均压力的影响,从而造成带钢头尾变形。针对这种情况.提出了一种新的带钢末端形状视觉检测和宽度计算方法。该方法不但可以在带钢发生平移、倾斜等位置和姿态变化情况下仍能够准确测量出带钢宽度,并且可以精确还原出带钢头尾形状。仿真试验结果证实了所提出的视觉模型和算法的有效性.取得的结果令人满意。     

叠板式多缸薄板成型液压机参数化设计

在已有的300 MN多缸薄板成型液压机的基础上,运用基于VB的SolidWorks二次开发方法与自顶向下完全建模技术,通过驱动模型关键尺寸参数,对新产品进行参数化设计,并用ANSYS仿真优化.通过参数化设计可使该类产品系列化,提高新产品研发速度,促进该类型产品的国产化.     

基于STM32的车牌识别模块在烟花溯源系统中的应用

烟花溯源需要对运送烟花的车辆进行监管以便后续追踪定位,所以论文设计了基于STM32的车牌识别模块,结合无线射频模块,利用先进的电子通讯技术对烟花出入库进行严格监管,以STM32F103处理器为控制中心,通过OV7670摄像头采集烟花出库过程中车辆的图像信息,通过RFID模块触发摄像头拍照,并将采集到的图像进行车牌识别,定位出车牌号码,并以文本形式无线上传至上位机,同时将图片信息存入SD卡.该系统硬件体积小,成本低,灵活性好,安装方便,适合出入车辆较少、背景较简单的厂区、仓库的车辆自动监管.     

In-focus electron microscopy of frozen-hydrated biological samples with a Boersch phase plate

We report the implementation of an electrostatic Einzel lens (Boersch) phase plate in a prototype transmission electron microscope dedicated to aberration-corrected cryo-EM. The combination of phase plate, C_s corrector and Diffraction Magnification Unit (DMU) as a new electron-optical element ensures minimal information loss due to obstruction by the phase plate and enables in-focus phase contrast imaging of large macromolecular assemblies. As no defocussing is necessary and the spherical aberration is corrected, maximal, non-oscillating phase contrast transfer can be achieved up to the information limit of the instrument. A microchip produced by a scalable micro-fabrication process has 10 phase plates, which are positioned in a conjugate, magnified diffraction plane generated by the DMU. Phase plates remained fully functional for weeks or months. The large distance between phase plate and the cryo sample permits the use of an effective anti-contaminator, resulting in ice contamination rates of <0.6 nm/h at the specimen. Maximal in-focus phase contrast was obtained by applying voltages between 80 and 700 mV to the phase plate electrode. The phase plate allows for in-focus imaging of biological objects with a signal-to-noise of 5-10 at a resolution of 2-3 nm, as demonstrated for frozen-hydrated virus particles and purple membrane at liquid-nitrogen temperature.     

水轮发电机推力轴承甩油的处理

针对小山电站2号机组推力漏油问题,通过加大稳油板尺寸、加装挡油圈内挡油板、改变油位等方法进行了综合性的处理,弥补了推力轴承甩油导致碳刷打火这一重大缺陷,保证了机组的安全稳定运行.     

面向最终用户编程的服务虚拟化模型

为了解决面向最终用户编程问题,提出了一种基于动态语义的服务虚拟化模型。该模型以SOA思想理论为基础,采用面向服务计算和Web服务技术,结合本体服务描述语言和描述逻辑,建立服务虚拟化模型,从而实现面向最终用户编程。该模型有效地提高了模型的查全率和查准率,能够在一定程度上解决软件危机。     

基于无网格局部Petrov-Galekin法的板结构拓扑优化

为将无网格法的优势集成到结构拓扑优化中,基于无网格局部Petrov-Galerkin(Meshless Local Petrov-Galerkin,MLPG)法进行板结构的拓扑优化.基于带惩罚的各向同性固体微结构(Solid Isotropic Microstructure with Penalization,SIMP...     

Fabrication uncertainties and yield optimization in MEMS tunable capacitors

Intrinsic uncertainties of MEMS fabrication processes can severely affect the performance of devices because the tolerance ranges of these processes are relatively large and improvement of process accuracy is very expensive. Therefore, the analysis of fabrication uncertainties and their outcome on a device performance is a vital task before finalizing the design. In this paper, the effects of process inaccuracy on the performance of MEMS tunable capacitors are studied. Design parameters such as dimensions of electrodes and the initial gap between them and the stiffness of supporting beams are considered as random variables. The variation of these parameters within tolerance ranges drastically alters the capacitor's actual response from the desired one and results in low yield. Hence, design optimization with the objective of maximizing yield in early steps becomes very important. An effective method for yield optimization of MEMS capacitors under given fabrication uncertainties is introduced. The method utilizes aspects of the advanced first-order second-moment (AFOSM) reliability method to find a linearized feasible region to estimate the yield. The yield is calculated directly using the joint cumulative distribution function (CDF) over the tolerance box requiring no numerical integration and avoiding computational complexity. The optimal design verified by Monte-Carlo (M-C) simulation exhibits a significant increase in the yield. The main advantage of this method comparing to other design optimization methods is that the proposed method does not change the design topology or fabrication accuracy. It increases the yield by finding the optimum design variables as demonstrated in this paper.     

模块液体冷却技术及其应用与分析

随着电子技术的迅速发展,电子元器件的总功率密度大幅度增长而物理尺寸却越来越小,而且高温的温度环境会影响电子元器件的性能.有效解决电子元器件的散热问题已成为当前电子元器件和电子设备制造的关键技术,液体冷却技术可在一定程度上适应高热流密度的散热要求.针对模块上电子元器件的液冷问题,该文综述液体冷却的特点,设计不同通道形式的冷板,并进行适当的应用分析.