THE COMPACTION OF TIME-DEPENDENT VISCOUS GRANULAR MATERIALS CONSIDERING INERTIAL FORCES

In the present paper, compactions of time-dependent viscous granular materials are simulated step by step using the automatic adaptive mesh generation schemes. Inertial forces of the viscous incompressible aggregates are taken into account. The corresponding conservation equations, the weighted-integral formulations, and penalty finite element model are investigated. The fully discrete finite element equations for the simulation are derived. Polygonal particles of aggregates are simplified as mixed three-node and four-node elements. The automatic adaptive mesh generation schemes include contact detection algorithms, and mesh upgrade schemes. Solutions of the numerical simulation are in good agreement with some results from literatures. With minor modification, the proposed numerical model can be applied in several industries, including the pharmaceutical, ceramic, food, and household product manufacturing.     

奇闻一页谈

谜之岛最不可思议奇闻摘，挑战你的想象极限！ 谜之岛“不得不看榜”排名第一！ 世界真奇妙，此谜解不了！     

一种烟气冷却器的研制

介绍了某型烟气冷却器的设计思路,主要从结构的紧凑性、制冷系统的匹配等方面给予了阐述,通过实际应用说明了其设计的可行性,证明设计是成功的.     

Theoretical Analysis of Interference Nanolithography of Surface Plasmon Polaritons without a Match Layer

Interference nanolithography techniques based on long-range surface plasmon polaritons （LR-SPP） are hardly ever achieved by experiments at present. One key reason is that suitable liquid materials are difflcult to find as the match layer connects the metal film and the resist. We redesign a Kretschmann-Raether structure for interference lithography. A polymer layer is coated under the metal film, and an air layer is placed between the polymer layer and the resist layer. This design not only avoids the above-mentioned question of the match layer, but also can form a soft contact between the polymer layer and the resist layer and can protect the exposure pattern. Simulation results confirm that a device with an appropriately thick polymer layer can form high intensity and contrast interference fringes with a critical dimension of about λ/7 in the resist. In addition, the fabrication of the device is very easy.     

基于ST7单片机的液体电导率传感器

基于ST7LITEF15B单片机研制了用于实验教学的低成本液体电导率传感器. 介绍了测试方案、系统的硬件结构和软件的设计思路,进行了典型标样的测量实验,结果表明该液体电导率传感器的研制是成功的.     

碘量测测定低硫

硫是钢中有害元素 ,随着工厂的发展和对材料质量要求的提高 ,需对低硫进行精确测定。本法用HV- 1 1高速自动定碳定硫仪进行了一系列的分析试验。试验证明 ,可以满足钢中低硫 (特别是 ws<0 .0 1 % )测定精度的要求 ,克服了正常分析范围内该仪器对低硫测定精度的要求的不足 ,做到了碳、硫同时测定。1　试验部分1 .1　仪器与试剂HV- 1 1高速自动定碳定硫仪管式炉 ,电阻炉变压器碘酸钾标准溶液 :称取碘酸钾 0 .1 78g,溶于水后稀释至 1 L,浓度为 0 .0 0 5mol· L-1。分取此液50 ml,稀释至 1 L,加碘化钾 1 g,摇匀 ,配成0 .0 0 0 2 5mol·L-1碘…     

重力匹配导航的影响模式分析

从重力场匹配导航的改进TERCOM算法入手,针对采样长度、采样间隔以及重力测量误差对匹配结果的影响进行了系统分析,并在此基础上利用海洋年度重力测量数据设计了准实时仿真试验,结果表明:(1)采样长度对匹配结果有重要的影响,采样长度与重力基准图的分辨率比值在10~20之间时,能够获得较好的匹配效果;(2)适当增加采样间隔可以在一定程度上提高匹配的整体精度,但增加了匹配失效的风险,实际应用中采样间隔以2~4 min为宜;(3)重力测量白噪声误差对匹配结果影响相对较大,过大的误差将不能得到有效匹配,水下重力测量误差最好能控制在2 mGal以内。     

半导体所国内首台48片MOCVD样机研发工作取得重大进展

在中国科学院和广东省共同支持下,由中科院半导体研究所负责研制开发的国内首台48片MOCVD样机取得重大进展。样机不仅经过了真空、压力、温度、旋转、自动传输等一系列设备性能指标实验考核,还进行了氮化镓以及氮化物LED的外延工艺考核。所外延的氮化物材料分别由山东华光、杭州士兰明芯、武汉迪源、上海蓝     

光纤干涉投射实时傅里叶轮廓术的研究

基于光纤干涉投射技术,采用马赫-曾德尔光纤干涉仪结构产生杨氏双孔干涉条纹,同时通过高速CMOS相机采集变形条纹图像,并传输至计算机,利用实时视觉库OpenCV实现了自动化的高速条纹图像处理.采用旋转矩形窗算法实现滤波窗口自动选择,对多种相位解包裹算法进行了探讨,总体时间算法复杂度为O(nlg n),测量时间小于200 ...