A framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance

Mechanical mechanisms with clearance abound in technological fields such as robotics, machine and steam turbine industry. The dynamic performance of these mechanisms in working condition can be achieved provided that the effects of the different on the mechanisms (such as mechanism dynamics, technological effects and thermal behaviour) are thoroughly understood. Virtual prototyping provides an integration of multi-domain dynamic simulation for the design and analysis process. In the current paper, a framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance is presented. A case study with such a simulation strategy is studied for the optimum design and analysis of the technological parameter.     

The new structure of fibre glass reinforced plastics bolt

The develop actuality and direction of FRP (fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country stand-ard, substitute present metal bolt, wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce ef-ficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.     

论剪切质量的提高

通过对飞剪剪切长度，精度，剪刃间隙和压板机构等参数的优化，来提高钢板的剪切质量。     

大孔径石蜡加氢精制催化剂的制备

采用氨吸附-程序升温脱附(NH3-TPD)、低温N2吸附(BET)、压汞法以及加氢精制活性评价等技术,探索SiO2-Al2O3载体在制备过程中孔结构和表面性质的变化。实验结果表明,采用特殊扩孔剂制备载体,当焙烧温度为700℃时,平均孔径可达到17.3nm,其中孔径大于20nm的孔占总孔体积的13.2%;同时载体表面上的中、强酸中心也全部丧失,均为弱酸中心。采用该载体制备的MoNiP/SiO2-Al2O3石蜡加氢精制催化剂,在MoO3用量减少了约1/4的情况下,比目前工业上使用的催化剂具有更高的脱金属能力和加氢精制活性。     

松软厚煤层轻放工作面切眼锚杆支护实践

针对朱仙庄矿 84 15工作面切眼特殊的地质条件 ,介绍了高强锚杆 (索 )支护技术成功应用于特厚极软煤层的经验 ,并对巷道支护成本进行了分析     

A new stereological principle for test lines in three-dimensional space

A new principle is presented to generate isotropic uniform random (IUR) test lines hitting a geometric structure in three-dimensional space (3D). The principle therefore concerns the estimation of surface area, volume, membrane thickness, etc., of arbitrary structures with piecewise smooth boundary. The principle states that a point-sampled test line on an isotropic plane through a fixed point in 3D is effectively an invariant test line in 3D. Particular attention is devoted to the stereology of particles, where an alternative to the surfactor method is obtained to estimate surface area. An interesting case arises when the particle is convex. The methods are illustrated with synthetic examples.     

锚索锚杆联合支护在破碎顶板中的应用

结合工程工作面概况，就锚索和锚杆补强加固支护参数的选择进行了介绍，并指出锚索、锚杆的联合支护，保证了顶板的完整性，有效地控制了巷道的变形。     

施肥模型研究综述

对施肥模型和参数研究的历史、现状和趋势进行了综述,并指出今后定量施肥研究的关键问题。     

Optimization of support positions to maximize the fundamental frequency of structures

In this paper, the position optimization of simple supports is implemented to maximize the fundamental frequency of a beam or plate structure. Both elastic and rigid supports are taken into account. First, the frequency sensitivity with respect to the movement of a simple support is derived using the discrete method. By means of the shape functions of the finite element method, closed‐form sensitivity formulations are developed straightforwardly. Then, a heuristic approach, called evolutionary shift method, is presented for optimizing support positions with a fixed grid mesh scheme. Based on the design sensitivity analysis, the support with the highest efficiency is shifted in priority along the elementary edges with the interval (step) of the elementary size. To facilitate the convergence of the process, the interpolation technique is employed to evaluate the solution more accurately. Finally, three numerical examples are presented to demonstrate the validity of the sensitivity analysis and the effectiveness of the optimization method. Copyright © 2004 John Wiley & Sons, Ltd.     

区域可持续发展决策支持模拟系统研究

本文先给出区域可持续发展指标体系；讨论了区域可持续发展决策支持模拟系统及其组成部分，给出区域可持续发展决策支持模拟系统的总体构架，数据库、模型库管理系统及其设计。最后以广州市为例，给出可持续发展决策支持模拟系统的使用效果。