光点与会聚测试系统的设备需求与配置

光点测试和会聚测试是验证CPT电子枪偏转线圈性能的重要手段之一。本提出基于合理的测试方法、有效适当的测试设备，建立最佳的测试系统。针对光点测试和会聚测试系统中的各种设备，介绍它们的应用原理及应用效果，从而了解在测试CPT光点质量和会聚误差过程中测试系统的设计原理及设备配置原理。     

一种精确的光点测试系统

介绍了一种精密光点测试系统。它采用脉冲方法刷新光点,并且刷新频率和电源频率保持同步,从而避免了扫描及视频方法引起的测量误差,同时避免了散逸电磁场的影响;并克服了采用扫描光栅、通过信号发生器或者测试软件产生测试信号来进行测试的系统存在的问题。该测试系统尤其适合电子枪和偏转线圈设计人员进行精密的光点测试分析。     

一种精确的光点测试系统

介绍了一种精密光点测试系统,它采用脉冲方法刷新光点,并且刷新率和电源频率保持同步,从而避免了扫描及视频方法引起的测量误差,同时避免了散兔电磁场的影响,并克服了采用扫描光栅,通过信号发生器或测试信号来进行测试的系统存在的问题,该测试系统尤其适合电子枪的偏转线圈设计人员进行精密的光点测试分析。     

一种新型彩色显像管会聚测量系统

本文在系统分析会聚测量方法的基础上 ,着重对我们开发的一套新型的会聚测量设备进行了介绍和研究。该系统采用栅极脉冲电流、脉冲偏转 ,用微移动法消除荫罩影响修复光点。整套系统由计算机控制、采集、分析。该系统很好地满足了CRT研究开发的需要     

如何确定测量设备的配置需求

本文从实践的角度阐述了如何确定测量设备配置需求的方法 ,以及测量配置需求的作用。举例说明确定测量误差的方法。     

浅谈特效影院系统设备的配置

伴随我国科技馆(包括近年新建的博物馆及各类专业场馆)的不断兴建和发展,特效影院即特种电影影院大有与日俱增、不断发展之趋势.为此,笔者根据多年的研究和工作实践,对特效影院系统设备的配置谈些粗浅认识,以期和同行共同探讨:     

自会聚偏转系统中磁滞损耗的估测

通过空间磁场和感应电压的测量，对自会聚偏转移系统偏转磁芯中的二极场、六极场磁通密度的分布进行了计算，并根据磁滞损耗的经验公式对Philips 17英寸CMT的磁滞损耗进行了估测。该方法适用于估测高次谐波场对磁滞损耗的影响，降低能量损耗的偏转系统磁芯结构的优化，磁性材料的选择等。     

彩色显像管静会聚漂移问题的研究

在采用传统精密一字形电子枪的彩色显像管中，若聚焦电压发生变化，静会聚将产生漂移。如果聚焦电压变化700V，那么21英寸彩管将有大约0．3mm的静会聚漂移。由于静会聚漂移值超过荧光粉节距的50％，所以，静会聚漂移对彩色显像管的分辨率影响很大（若彩色显示管有更精细的荧光粉节距和更高的分辨率，对其影响更大），在高质量彩管设计中必须克服静会聚漂移。对此讨论了产生静会聚漂移的原因，提出了一种克服静会聚漂移的电子枪，并通过数值计算获得了较理想的结果。如果聚焦电压变化700V，采用新枪的21英寸彩管的静会聚漂移仅0．006mm，与原枪相比，屏上电子束斑变化很小。     

谈检测实验室设备配置与管理

本文阐述了如何配置与管理检测实验室的设备,使设备指标满足检测要求,保证检测数据的准确性.     

浅谈国产冻干机的设备配置

详细分析了国产冻干机与进口冻干机在制冷系统、真空系统及无菌干燥箱等设备配置及其性能上优缺点，提出了国产机相应的改进措施与建议，以尽快赶上国际先进水平。     

Laser Spot Welding of Thermoplastic and Ceramic: An Experimental Investigation

Laser welding of dissimilar materials classes has vast potential in a variety of applications due to the non-contact nature of the process. This study investigates the effects of CO₂ laser process parameters on the characteristics of spot welded joint between ceramic and thermoplastic. Using a full-factorial design an experimental investigation is carried out studying the effect of welding parameters (laser exposure, number of spots, stand-off distance) on the tensile strength and the diameter of spot weld. The study reveals an increase of joint tensile strength with the increase in the number of spots and the duration of exposure. However at low laser power, the effect of stand-off distance on the spot weld diameter is found to be inconclusive. Optimal process parameters are estimated using the multi-objective optimization on the basis of ratio analysis. The analysis shows that the higher number of spots and the longest duration of laser exposure result in optimal weld characteristics. Alongside these conditions, a larger stand-off distance is seen to have beneficial impact on the weld characteristics.     

GGREADA: A graph grammar-based machine design algorithm

A class of graph grammar-based design algorithms for the generation of near-optimal machine designs is proposed. The GGREADA algorithm is implemented to design scale model carts from Meccano^® Set components. A graph grammar for the carts is defined. GGREADA successfully designs minimum-weight carts that provide specified load-bed areas. GGREADA's exploration capability is also demonstrated by creating probability frequency plots of likely cart surface areas and weights from random samples taken from the space of all possible cart designs. The advantages that a designer may gain from grammar-based design tools are discussed along with the representational challenges that remain in exploiting grammars for this purpose.     

遗传算法用于电子枪发射系统的全局最优化设计

常用的优化设计方法 ,如单纯形法、Powell法等 ,易陷入局部最优解。而遗传算法是一种新兴的直接搜索最优化算法 ,它模拟达尔文遗传选择与自然进化的理论 ,根据“适者生存”和“优胜劣汰”的原则 ,借助“复制”、“交换”、“突变”等操作可以得到全局最优解。本文将遗传算法运用于电子枪发射系统的最优化设计 ,得到了使交叠点半径尽可能小的发射系统的最佳结构和相应电参量     

Microstructural and Mechanical Observations of Galvanized TRIP Steel after Friction Stir Spot Welding

Friction stir spot welding was done in transformation-induced plasticity steel sheets coated with zinc. The influence of tool rotational speed and dwell time on the microstructure and mechanical properties of lap-joints were investigated. After processing, different zones were formed in the joints. Microstructures in each zone depended on the welding conditions employed. Higher dwell time coupled with higher rotational speed promoted the deposition of a large amount of allotriomorphic ferrite beside the keyhole left by the pin. Coalesced bainite formation was stimulated by the deformation. Mechanical and chemical stabilization of the austenite occurred in different welding zones. Some zinc from the coating remained in the joint, in the stirring zone, representing a partial bonding between the steel sheets. The strength of the welds depended on a complex interaction between geometrical features, such as bonding ligament length and distance between the zinc and the keyhole left by the pin and the resultant microstructure in the stirring zone. The highest joint strength was observed for the “lowest tool rotational speed–highest dwell time” combination of welding parameters.     

基于性能曲线的冷水机组配置和运行优化

在设计中引入简单有效的计算手段,对冷水机组配置和运行的优化进行节能分析是必要的,本文分析了与冷水机组节能相关的因素,介绍了常用冷水机组典型性能特征,举例分析常用冷水机组COP-PLRC-tc曲线,提出了基于性能曲线的冷水机组配置和优化运行方法,阐述了运用该方法对进行冷水机组配置和运行优化的步骤,最后为采用该方法的应用实例。     

相关要求与边界设计

相关要求是一种边界控制的公差设计方法。用最大实体边界( MMB) 或最小实体边界( LMB) 及综合公差( T t ) , 来满足装配或强度要求, 并为制造提供更好的经济效益。此方法应该在公差设计中积极推广应用。     

Normalization and Technical Variation in Gene Expression Measurements

Using data from the Microarray Quality Control (MAQC) project, we demonstrate two data-analysis methods that shed light on the normalization of gene expression measurements and thereby on their technical variation. One is an improved method for normalization of multiple assays with mRNA concentrations related by a parametric model. The other is a method for characterizing limitations on the effectiveness of normalization in reducing technical variation. We apply our improved normalization to the four project materials as part of testing the linearity of the probe responses. We find that the lack of linearity is statistically significant but small enough that its sources cannot be easily identified. Applying our characterization method to assays of the same material, we show that there is a source of variation that cannot be eliminated by normalization and therefore must be dealt with by other means. Four high-density, single probe, one-color microarray platforms underlie our demonstration.     

Importance measures in risk-informed decision making: Ranking, optimisation and configuration control

This paper describes roles, extensions and applications of importance measures of components and configurations for making risk-informed decisions relevant to system operations, maintenance and safety. Basic importance measures and their relationships are described for independent and mutually exclusive events and for groups of events associated with common cause failures. The roles of importances are described mainly in two groups of activities: (a) ranking safety significance of systems, structures, components and human actions for preventive safety assurance activities, and (b) making decisions about permissible permanent and temporary configurations and allowed configuration times for regulation, technical specifications and for on-line risk monitoring. Criticality importance and sums of criticalities turn out to be appropriate measures for ranking and optimization. Several advantages are pointed out and consistent ranking of pipe segments for in-service inspection is provided as an example.Risk increase factor and its generalization risk gain are most appropriately used to assess corrective priorities and acceptability of a situation when components are already failed or when planning to take one or more components out of service for maintenance. Precise definitions are introduced for multi-failure configurations and it is shown how they can be assessed under uncertainties, in particular when common cause failures or success states may be involved. A general weighted average method is compared to other candidate methods in benchmark cases. It is the preferable method for prediction when a momentary configuration is known or only partially known. Potential applications and optimization of allowed outage times are described.The results show how to generalize and apply various importance measures to ranking and optimization and how to manage configurations in uncertain multi-failure situations.     

企业资源需求建模及其资源规划分析

分析了目前国际上各种企业资源建模方法，提出企业资源建模的过程框架，构造了企业资源能力描述模板，建立了基于过程分解的企业资源需求模型及其分析方法，针对企业经营管理目标提出了企业资源规划决策的规则。     

LNG工程用大截面高压板翅式换热器的技术发展与现状

随着国内外LNG工业的高速发展,对铝制板翅式换热器提出了新的要求,以往小截面、多只并/串连的板翅式换热器组合方案已不能满足大、中型液化天然气工业发展的需要。大截面高压板翅式换热器的换热单元个数少,承压能力高,能够尽量减少气流分配的不均性。大截面高压板翅式换热器的应用,也使得LNG冷箱内管道布置简单,安全性、可靠性大大提高,冷箱体积减小,满足了液化天然气工业发展的需要,也降低了用户投资成本。简介板翅式换热器的技术发展与现状,阐述大截面高压板翅式换热器的热力设计与结构优化。