《压力容器》杂志征稿启事

1征稿内容1.1材料(1)压力容器和压力管道用新材料的研制和推广应用(2)压力容器和压力管道材料性能试验和测试方法的研究(3)特种金属材料、复合材料在压力容器中的开发应用(4)国外有关压力容器和压力管道用材的研究进展和动态     

科学仪器计算机化的基本原理与技术

计算机和网络技术的发展,使信息技术与科学仪器将各自的资源和潜能充分发挥,灵活的调用,合理配置以及仪器测量的数据资源共享。各种仪器都有创新和跃进发展,出现新一代智能仪器、虚拟仪器和网络化仪器等科学仪器。本文评述科学仪器计算机化的基本原理和基本方法。科学仪器的计算机化必须有计算机软件、硬件和复杂的接口设备和技术     

虚拟样机技术在观瞄仪自动升降系统方案设计中的应用

运用三维建模软件和动力学仿真软件联合建立了观瞄仪自动升降系统的虚拟样机.通过对其进行运动和动力学仿真,研究了观瞄仪在展开和撤收过程中关键构件的运动和动力学规律,从而对观瞄仪自动升降系统在工作状态下关键部件的受力和运动状态有了明确和清晰的认识,论证了设计方案的可行性,为物理样机的研制提供了理论依据.最后总结了将虚拟样机技术运用到系统的开发和研制中所具有的实际意义.     

基于XML的异源数据分析的协同业务平台

在分析了基于XML的异源数据交换、查询和协同业务平台的国内外现状的基础上,从异构数据源,数据交换文档,数据交换中间件,协同集成平台和应用系统及数据匹配的优化算法,系统运行、安全和维护等方面阐述了面向XML异源数据的协同业务平台体系结构和每个模块的具体内容,及异构数据库中的非结构化数据、结构化数据和半结构化数据通过加密传输实现异构库、XML文档和目标数据库之间的数据类型转换的流程和方法.     

现代制造技术及其发展趋向

从历史和现代的角度分析现代制造技术的形势和特点,论述制造技术的永恒性和广义制造论(大制造),重点论述工艺核心论,分析制造工艺技术的核心作用和现代制造工艺理论及技术的发展.根据当前制造业的形势,提出现代制造技术的重点发展方向和任务.     

基于约束的复杂产品开发过程与活动路线分析

为实现在不同阶段、按不同层次和区域分析和控制产品开发微观过程的目的,提出一种基于“自组织-被组织”方法论规划和设计产品开发过程的方法。在面向过程的任务分层分解和基于约束的产品开发活动组织过程表达中,把与过程相关的约束和影响因素,通过节点间逻辑状态及其取值概率来反映和体现;应用图论中可达矩阵性质与原理定量分析产品开发活动序列及其组织路线,实现产品开发宏观过程管理和微观过程控制的有机结合,使产品开发活动的组织方式、状态演化和工作流程始终处于透明和可控的环境下观察和分析,帮助项目管理人员明确影响产品开发过程的主要路线和关键环节,克服传统方法综合多个要素、跨越整个过程建模和分析的困难。     

某型飞机气动元件自动测试台的设计与实现

首先简要介绍了气动元件自动测试台的总体结构和主要特点,在此基础上,利用PLC、比例阀和触摸屏技术设计了该装置的控制系统,着重阐述了控制系统的组成和工作原理,给出了系统的硬件和软件的设计和实现方法。结果表明,该控制系统具有良好的动态品质和稳定性能,达到了对气动压力进行比例控制的目的。     

薄膜厚度和光学常数的主要测试方法

准确地测量和控制薄膜厚度和光学常数等参数,在薄膜制备和分析和应用都是极为重要的。对薄膜的厚度和光学常数测试方法作了归纳和分类,并对几种主要的测试方法作了简要的介绍,分析了各自的特点及存在的问题。在测量薄膜的厚度和光学常数时,必须根据待测样品和测量精度要求选择合适的方法。     

推动中小企业信息化促进信息化与工业化融合

党的"十七大"提出工业化、信息化、城镇化、市场化和国际化"五化并举",和信息化与工业化的"两化融合",进一步明确了信息化在国民经济和社会发展当中的作用和地位.同时也对信息化推进工作提出了明确的目标和更高的要求.     

基于虚拟仪器和变频技术的制动器试验系统

阐述了制动器试验系统的原理、组成、功能及特点,从虚拟仪器技术的基本原理出发,构建了基于虚拟仪器和变频技术的试验平台（包括变频驱动子系统和测控子系统）,可实现对制动器（包括鼓式和盘式制动器）性能和运行状态的自动控制和测试。对分析并提高制动器的质量和性能,以及对应用制动器的设备和系统的安全运行,都起到了积极的促进作用。     

计算机辅助设计凸轮及其数控加工

介绍了如何利用计算机对于形状复杂和高精度的凸轮进行辅助设计,以及将设计结果直接在数控机床上加工的方法,分析了图解法设计的局限性和计算机辅助设计的优越性,指出了利用计算机辅助解析法设计是实现数控加工的基础,也是未来机械设计的发展方向。     

Decrease in the operating gas pressure in an ion source

The results of use of a cold hollow cathode with a multipole magnetic field in a duoplasmatron-type ion source are described. The operating parameters of a duoplasmatron with the developed cathode and a duoplasmatron with a cold hollow two-cylinder cathode are compared. It is shown that the use of a cathode with a multipole magnetic field offers additional possibilities of reducing the operating gas pressure in an ion source and contributes to an increase in both the current and the phase density of the ion-beam current at the output of a charged-particle source and to a decrease in the phase volume of this beam.     

Determination of the velocity and size of bubbles in two-phase flows by using a laser doppler anemometer

Natural oscillations of a spherical interface between a gas and a liquid in a bubble are registered. A possibility of measuring the geometric parameters of stationary and moving particles of the disperse phase by a laser Doppler anemometer is demonstrated. A method for simultaneous determination of the size and velocity of a bubble or a droplet in a two-phase flow is developed. The mean sizes of a group of bubbles settled on a ruler are compared: the results are obtained by two independent methods, i.e., by analyzing the image and by processing the Doppler signal containing information about the natural oscillations of the spherical interface between the media. A possibility of using a laser Doppler anemometer for simultaneous measurements of the velocity and size of bubbles or droplets in a two-phase flow is confirmed.     

Automated fixture configuration using projective geometry approach

The geometric and topological specification of a workpiece boundary is usually represented in a specific data format in a CAD database. To retrieve a set of workpiece data, to analyse its shape in addition to the machining requirements, and to determine the proper fixture configuration accordingly, are not trivial tasks when a part has a complicated shape. The real challenge is to recognise and synthesise the shape of a workpiece from its data representation. Consequently, the decision for fixturing can be made when the shape of a workpiece and the relationship of the shape and the fixturing configuration can be derived by a systematic methodology. In this paper, a projective spatial occupancy enumeration (PSOE) approach is applied as a representational and manipulating scheme for developing algorithms in automatic fixture configuration. The workpiece is projected onto the working plane of the fixture baseplate. A 2D projection is defined as a matrix of cells which can represent a workpiece with an arbitrary shape. Using a discrete search based upon the matrix of cells, the fixture types and their locations are generated according to a set of heuristic algorithms. This work is a generalisation and extension of previous works for prismatic parts. The same methodology is equally applicable in general robot grasping.     

Microwave atomic force microscopy imaging for nanometer-scale electrical property characterization

We introduce a new type of microscopy which is capable of investigating surface topography and electrical property of conductive and dielectric materials simultaneously on a nanometer scale. The microwave atomic force microscopy is a combination of the principles of the scanning probe microscope and the microwave-measurement technique. As a result, under the noncontact AFM working conditions, we successfully generated a microwave image of a 200-nm Au film coating on a glass wafer substrate with a spatial resolution of 120 nm and a measured voltage difference of 19.2 mV between the two materials.     

A re-configurable cross-sectional imaging system for reverse engineering based on a CNC milling machine

This paper presents a novel reverse engineering digitizing system for full part geometry, which is based on a cross-sectional imaging device built in a NC milling machine. The system successively captures a picture for each planar cross-section contour of the part by end-milling and CCD imaging, and builds the geometry for both external and internal surfaces of the complex 3D part based on a set of the vectored cross-sectional contours. The system mainly consists of three components: a NC milling machine, a cross-sectional imaging device and a computer control unit. Some issues involving the principle and process flow of the system, encasing materials, cross-sectional imaging and NC code generation, etc. are described in detail. Built on an existing NC milling machine, a portable device for capturing the cross-sectional images is designed, which includes an isolated light source, a digital camera, a protective case, a rigid arm and a robust tripod. The device, connected to a computer control unit, serves as a highly flexible accessory for the NC milling machine, constructing the cross-sectional imaging system for reverse engineering. Furthermore, the error analysis and accuracy assessment of the system are also addressed. A typical case is discussed in detail to illustrate the applications of the system. Such a re-configurable digitizing system for reverse engineering offers a number of advantages, such as the functional extension of an existing NC milling machine, low costs, and rapid construction. As a result, this system provides a feasible and useful scheme for many enterprises to construct their own reverse measuring system based on existing equipment to aid in rapid product development and extend the function of existing equipment.     

套式钻模的应用研究

在各种长度和直径的圆柱体或空心圆柱体的外圆柱面上沿横截面圆周方向钻削,有较高的位置精度要求且呈多层均匀分布或多层非均匀分布或螺旋均匀分布或螺旋非均匀分布的孔和螺纹孔的方法进行了研究,重点介绍了长度与外径比＆gt;5的圆柱体或空心圆柱体。研究发现,目前常见的固定式钻模、回转分度式钻模、移动式钻模、翻转式钻模和盖板式钻模都不是最佳选择,因为它们的钻模板均为长方体,与圆柱面不能完全配合,导致夹紧元件和定位元件的结构复杂,形式单一且制造周期长,成本高,夹紧钻模的方式单一。套式钻模的钻模板为空心圆柱体,空心圆柱体的独特之处是使套式钻模可与圆柱面完美配合,夹紧元件和定位元件的结构简单,形式灵活且制造周期短,成本低,夹紧钻模的方式灵活,从而使其成为在各种长度和直径的圆柱体或空心圆柱体的外圆柱面上钻削各种排列组合方式的孔和螺纹孔的最佳选择。     

智能气体识别仪的研究

智能气体识别仪用以识别气体种类,它具有学习识别多种气体的功能。本文介绍了仪器的工作原理、特点及仪器的硬件和软件构成。     

Wire electrochemical machining using reciprocated traveling wire

Wire electrochemical machining (WECM) is a cutting process in which the workpiece acts as an anode and the wire as a cathode. WECM is typically used to cut plates and exhibits a great advantage over wire electro-discharge machining, namely, the absence of a heat-affected zone around the cutting area. The enhancement of WECM accuracy is a research topic of great interest. In WECM, the homogeneity of the machined slit has a decisive influence on the machining accuracy. This is the first study in which the integration of pulse electrochemical machining (ECM) and a reciprocated traveling wire electrode was used to improve the homogeneity of this slit. The experimental results show that the combination of pulse ECM and a reciprocated traveling wire electrode could enhance the accuracy of WECM and that generally a low applied voltage, pulse duty cycle, and electrolyte concentration; an appropriate traveling wire velocity; and a high pulse frequency and feeding rate enhance the accuracy and stability of WECM. Finally, a microstructure with a slit width of 177 μm, with a standard deviation of 1.5 μm, and with an aspect ratio of 113 was fabricated on a stainless steel substrate measuring 20 mm in thickness.     

A CO2 tracer-gas method for local air leakage detection and characterization

A method for local measurement of air leakage rate is presented that can be used to accurately and quickly assess leakage rates across a surface, such as around a valve or hatch in a pressurized gas tank or a window in a building. The method uses a small local enclosure with constant volume placed about a region on the structure under investigation (e.g., a window), which is depressurized and injected with a small concentration of carbon dioxide as a tracer gas. The time variation of the pressure and carbon dioxide concentration inside the enclosure are monitored and used to quantify the leakage flow rate as a function of pressure difference. This method uses a small enclosure with internal mixing so that a quasi-steady-state condition is quickly achieved. Because of the small size of the enclosure, advanced data processing techniques are necessary to reduce uncertainty in determination of the rate of change of the carbon dioxide concentration that arises from sensor variability. Results of a laboratory demonstration of the proposed leakage detection and characterization device are reported for the problem of leakage through a circular hole in a plate with prescribed pressure differences. Experimental results from the laboratory tests are found to be in excellent agreement with results of a numerical simulation of leakage flow through a hole, as well as predictions from a number of empirical equations for this problem found in the literature.