大型计算机的环境要求—兼谈机房设计中的若干问题

本文根据大、中、小型计算机对环境的要求和建设大型计算机机房的经验,总结了在设计计算机机房时必须考虑的若干问题;其中重点介绍了机房和机器的温度调节系统,不间断供电电源(UPS)及其联接方式,机房的安全措施,接地线的方式,防静电的方法及机房的环境监测.     

浅谈计算机机房的建设与维护

计算机机房管理是一项系统的工作,任何一个环节都会影响到机房的管理效率.本文通过对计算机机房的建设、硬件设备的管理、系统的维护等方面的阐述,提出了科学有效的机房管理技术和措施.     

关于新校区建设机房管理的研究

职业学校计算机机房是学生学习计算机的重要场所,只有科学地管理机房才能让学生利用计算机高效而健康地学习.本文对我校计算机机房管理的问题进行了探讨.     

计算机机房电气安全设计

由于计算机的广泛应用，社会已开始步入智能化、网络化的新时代。对计算机机房电气设计的要求也越来越高。本文主要对计算机机房的供电系统、接地系统及安保措施做一些探讨，以供参考。     

基于桌面虚拟化技术的实验机房改造

随着计算机虚拟化技术的日益发展,计算机硬软件更新换代进程的加速,绿色环保理念的增强,较高的维护成本给现代高校实验机房的建设带来了极大的挑战。结合现代IT界焦点云计算技术特点和现代高校实验机房的现状进行分析,重点对云桌面技术在高校实验机房的应用进行讨论,并通过测试对现存问题和未来发展提出了现代高校实验机房改造的想法和建议。     

涟钢计算机机房集中监控系统的设计

针对涟钢机房比较分散的情况，设计了计算机机房集中监控系统，阐述了该系统的结构、目标及其软硬件设计。     

机房管理的关键

由于学生的好奇和恶作剧,使得机房管理工作非常繁琐,严重影响了机房教学。本文阐述了要管理好一间机房,使其在计算机教学工作中发挥应有的作用,所应该采取的措施。     

浅谈学校机房软件维护技术的实现

随着计算机的大量普及和在教学中的广泛应用,各个学校都建立了大量基于局域网的多媒体教室.计算机机房和电子阅览室,这些地方由于每天开放时间长,人员流动大,应用需求复杂,使得计算机系统的维护十分繁杂.传统的机房维护是采用单台计算机的系统重装,一个管理员要面对的是几十台微机,工作量巨大,因而设计高效可靠的机房软件维护系统是非常必要的.     

多民族贫困山区学校如何上好信息技术课

在多民族贫困山区学校,大约有95%学生在读初中以前没见过计算机,少部分即便见到了也不知道那就是计算机,计算机一词只是在书本上见过,认为计算器就是计算机,计算机对他们来说是神秘而陌生的,第一次接触计算机就是进初中以后在学生机房.     

典型数据中心机房气流组织模拟测试与分析

针对某典型数据中心机房冷通道隔离方式下的气流组织,采用CFD(Computational Fluid Dynamics)计算机数值模拟商用软件对现有机房结构相关区域的流场和温度场进行数值模拟分析,得到现有送风工况下的冷通道及机柜周边区域的速度场和温度场,并与实测值进行比较分析。验证了现有机房典型模块的冷通道结构合理性,并对机房制冷管理提出相应改进建议,以达到最佳的送回风状态,使机柜中的热量能够及时散发,降低空调负荷,达到节能的效果。     

Number of Cable Effects on Buckling Analysis of Cable-Stayed Bridges

Cables instead of interval piers support cable-stayed bridges, and the bridge deck is subjected to strong axial forces due to the horizontal components of cable reactions. The structural behavior of a bridge deck becomes nonlinear because of the axial forces, large deflection, and nonlinear behavior of the cables and the large deformation of the pylons as well as their interactions. The locations and amplitude of axial forces acting on the bridge deck may depend on the number of cables. Agrawal indicated that the maximum cable tension decreases rapidly with the increase in the number of cables. This paper investigates the stability analysis of cable-stayed bridges and considers cable-stayed bridges with geometry similar to those proposed in Agrawal's paper. A digital computer and numerical analysis are used to examine 2D finite element models of these bridges. The eigen buckling analysis has been applied to find the minimum critical loads of the cable-stayed bridges. The numerical results indicate that the total cumulative axial forces acting on the bridge girder increase as the number of cables increases, yet because the bridge deck is subjected to strong axial forces, the critical load of the bridges decreases. Increasing the number of cables may not increase the critical load on buckling analysis of this type of bridge. The fundamental critical loads increase if the ratio of Ip∕Ib increases until the ratio reaches the optimum ratio. If the ratio of Ip∕Ib is greater than the optimum ratio, depending on the geometry of an individual bridge, the fundamental critical load decreases for all the types of bridges considered in this paper. In order to make the results useful, they have been normalized and represented in graphical form.     

Comparison between Shape Memory Alloy Seismic Restrainers and Other Bridge Retrofit Devices

Strong earthquakes can result in large longitudinal displacements in multiple-frame bridges. This could lead to excessive displacements/openings at the intermediate joints. Bridges with small seat widths are vulnerable to the unseating of their superstructure. Seismic steel restrainers are currently used to limit the joint openings in bridges. However, past earthquakes have shown that restrainer cables have limitations in regards to preventing unseating in bridges. Other devices have been proposed to limit joint displacements, including metallic dampers, viscoelastic dampers, and shape memory alloys (SMAs), which are known for their ability to recover their original shape after being deformed. A sensitivity study and a case study are conducted using computer simulations to compare the effectiveness of SMA retrofit devices with other devices. The results show that the effectiveness of the devices is a function of the characteristics of the bridge frames and the ground motion characteristics. In all cases, the steel restrainer cables were the least effective in limiting joint displacements. The SMA devices have the additional benefit of significantly limiting the residual joint displacement in bridges.     

变电站直流电源模块易损分析及处理

智能高频开关直流电源是利用高频开关电源技术、应用电子技术及计算机技术集成的电源装置,具有高精度、低纹波及高效率的特点。由于工作环境及外部干扰过电压等因素,造成直流电源模块故障率较高,使用寿命降低。通过详细分析直流模块易损的原因,提出处理办法,有效地降低模块的损失率,从而保证变电站安全运行。     

Effects of armrests on workload with ten-key operation

In radiation oncology the computer has its confirmed importance for many activities and now appears indispensable. Many applications in treatment planning and during treatment are only possible with its support. The most important applications of the computer in a radiation oncology centre are reviewed. A computer-network of the different subsystems involves advantages and improves work flow security. Two future applications under development are presented: dynamic treatment, and inverse treatment planning. Treatment of the individual patient is a matter of co-decision by all concerned. The computer is an auxiliary resource which offers greater facility, increases safety and improves accuracy.     

全自动位移监测系统在南芬露天矿的应用

随着多年的采掘,在南芬露天矿底盘形成300多米高的边坡,多次发生滑坡,严重影响滑体下方开采,为了能对下方开采及时预警,需对滑体位移实时采集,因此南芬露天矿组建了全自动位移监测系统。此监测系统由TCA2003全站仪、监测分析软件GEOMOS、计算机及专用通讯供电电缆构成。自动完成测量周期、实时评价测量成果、实时显示变形趋势等智能化的功能合为一体,可24h不间断对监测目标实时测量。测量结果显示在时间—位移图上,据此可以判断出监测对象的变化趋势,发出预警信息,指导生产。     

Assembly and function of the actin cytoskeleton of yeast: relationships between cables and patches

Actin in eukaryotic cells is found in different pools, with filaments being organized into a variety of supramolecular assemblies. To investigate the assembly and functional relationships between different parts of the actin cytoskeleton in one cell, we studied the morphology and dynamics of cables and patches in yeast. The fine structure of actin cables and the manner in which cables disassemble support a model in which cables are composed of a number of overlapping actin filaments. No evidence for intrinsic polarity of cables was found. To investigate to what extent different parts of the actin cytoskeleton depend on each other, we looked for relationships between cables and patches. Patches and cables were often associated, and their polarized distributions were highly correlated. Therefore, patches and cables do appear to depend on each other for assembly and function. Many cell types show rearrangements of the actin cytoskeleton, which can occur via assembly or movement of actin filaments. In our studies, dramatic changes in actin polarization did not include changes in filamentous actin. In addition, the concentration of actin patches was relatively constant as cells grew. Therefore, cells do not have bursts of activity in which new parts of the actin cytoskeleton are created.     

通过期铜规避电缆成本中铜价波动风险及实证分析

合理量的期铜操作能够降低或锁定一段时期电缆生产和库存成本,解决销售、投标过程中因铜价上涨给企业带来的履约困惑,且占用资金不多,是规避因铜价波动给电缆成本带来风险的有效途径之一。本文简述电缆生产企业在期铜市场不同情况操作的一些实战方法。     

Tropomyosin-containing actin cables direct the Myo2p-dependent polarized delivery of secretory vesicles in budding yeast

The actin cytoskeleton in budding yeast consists of cortical patches and cables, both of which polarize toward regions of cell growth. Tropomyosin localizes specifically to actin cables and not cortical patches. Upon shifting cells with conditionally defective tropomyosin to restrictive temperatures, actin cables disappear within 1 min and both the unconventional class V myosin Myo2p and the secretory vesicle-associated Rab GTPase Sec4p depolarize rapidly. Bud growth ceases and the mother cell grows isotropically. When returned to permissive temperatures, tropomyosin-containing cables reform within 1 min in polarized arrays. Cable reassembly permits rapid enrichment of Myo2p at the focus of nascent cables as well as the Myo2p- dependent recruitment of Sec4p and the exocyst protein Sec8p, and the initiation of bud emergence. With the loss of actin cables, cortical patches slowly assume an isotropic distribution within the cell and will repolarize only after restoration of cables. Therefore, actin cables respond to polarity cues independently of the overall distribution of cortical patches and are able to directly target the Myo2p-dependent delivery of secretory vesicles and polarization of growth.     

变电所仿真培训系统

本文介绍了采用全数字仿真方式的变电所仿真培训系统。仿真培训系统以实时计算机网络为核心，对一个２２０ｋＶ枢纽变电所及所在的区域电力网进行全物理过程的逼其仿真，为变电运行岗位培训提供了一个与真实变电所相似的运行环境，以及全方位的模拟操作。     

变频器故障与变频器工作原理

变频器性能稳定,运行故障相对较少,在行车交流调速中得到广泛应用。然而,变频器集成了计算机、微电子、电力电子、光缆等技术,结构复杂,产生故障后原因往往难以判断。而运用变频器工作原理处理故障,可使故障处理时间缩短,忽视变频器工作原理的运用,容易使故障扩大,使故障发生成为事故。