Topology optimization for crashworthiness of thin-walled structures under axial crash considering nonlinear plastic buckling and locations of plastic hinges

Although topology optimization is established for linear static problems, more effort is required for solving nonlinear plastic problems. A new topology optimization approach with equivalent static loads (ESLs) is suggested to find the optimum topologies and locations of plastic hinges of thin-walled crash boxes by considering crash-induced deformation, the main crash energy-absorbing mechanism. Together with finite element method crashworthiness analyses, considering all nonlinearities with rate-dependent plasticity, the method was developed using an appropriate time-incremental scheme of ESLs without removing any high values of loads. Analyses show that the crash boxes with optimum topologies have energy-absorbing capabilities equivalent to the original structure. The proposed method is evaluated for two crashes: a crash box at low speed and a double cell subjected to high-speed collision. The results indicate that this method captures nonlinear crushing behaviours and accurate locations of plastic hinges where, if proper reinforcements are made, energy absorption can be enhanced.     

运营商内部数据通信网的VPN技术

针对电信运营商在构建内部数据通信网(DCN)时遇到的各应用系统的隔离问题，详细介绍了目前几种主流的虚拟专用网(VPN)技术，并进行分析比较，最后提出了运营商内部数据通信网的VPN解决方案。     

Poly(Styrene‐Divinylbenzene) Based Media for Liquid Chromatography

The latest developments and in particular important synthetic aspects for the preparation of modern poly(styrene‐divinylbenzene) (PS‐DVB) based liquid chromatography (LC) supports are reviewed. In this context, the chemistry of particular porous and nonporous, functionalized, monolithic, coated silica and more specialized mixed organic PS‐DVB media is covered. Special consideration is given to modern approaches such as micro‐(μ)‐HPLC and coating techniques and their most important applications. Synthetic particularities relevant to the corresponding applications are outlined.     

斗南锰矿选矿厂设计中几个问题的处理

作者在斗南锰矿选矿厂设计中,针对当前锰选厂生产的经验和存在的问题,从工艺角度分别对干、湿筛分、CS-2强磁机的处理量、矿泥强磁选机的选型、以及在强磁选前设置脱除强磁性物质装置等作了分析,并提出了作者的看法。     

Issues in nonlinear stochastic grey box identification

Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings.     

具多件内装物的瓦楞纸箱尺寸优化设计

跳出传统的设计思路，提出装多件内装物的瓦楞纸箱尺寸优化设计方法，建立优化设计模型，编写程序用于生产，节省纸用量，降低成本。     

靖边气田分离器分离效果对比分析

从理论计算分离器处理能力和现场开展试验两方面入手，对靖边气田目前在用的不同规格分离器的分离效果进行了对比分析，通过对现场数据统计和整理，得到了靖边气田不同规格分离器合理的处理气量，给气田开发建设中分离器的选型和维护改造中分离器的调整提供了依据。     

百万吨级乙烯冷箱的设计

分析了百万吨级乙烯冷箱的设计难点和采取的对策，介绍杭氧设计、制造的乙烯冷箱的技术参数和设计方案，与国外公司设计方案的比较，说明杭氧乙烯冷箱的设计、制造技术与世界先进水平的差距大大缩小。     

加氢反应器内构件—急冷箱的试验研究

急冷箱是加氢反应器的重要内件。洛阳石化工程公司设备研究所在认真分析UOP急冷箱的基础上,对其结构进行了改进,开发出了新型急冷箱(已获专利)。经过流体力学、传质、传热性能对比试验、分析,新型急冷箱结构性能优良。     

VOD在有线电视网的实现

从视频点播系统的结构及组成和在有线电视网络中VOD系统的结构模式与应用两个方面，详细地阐述了如何利用有线电视网络实现视频点播，主要从以下3个方面介绍关于视频点播系统VOD技术：①视频点播VOD的技术原理；②视频点播系统的结构及组成；③有线电视视频点播系统的结构模式与应用。