基于负压波的管道泄漏检测与定位技术研究

管道输送因其具有独特的优点已经在各行各业中得到了广泛应用，但日益严重的泄漏问题不仅影响了管输的正常运行，也给人类的生命财产造成了极大的损失。探索一种有效的检测方法已经迫在眉睫。文章对基于负压波的管道泄漏检测与定位技术的方法进行了研究，说明了其优缺点，指出了基于负压波法的管道泄漏检测与定位结构模式识别系统具有很好的发展前景。     

用Origin 6.0绘制波函数平面图形

Origin6．0作为一个数学软件平台，集数据管理与分析、二维及三维函数和离散数据绘图、程序开发等多功能于一体，广泛用于科学研究和工程计算。本文利用Origin6．0软件的函数绘图功能，绘制氢原子径向波函数、径向密度函数、径向分布函数、氢原子轨道及电子云的角度分布、杂化轨道等二维图形。给出了波函数的软件可读化形式和绘图的实际操作过程。与其它函数绘图方法相比，界面更友好，操作更方便。     

用Origin 6.0绘制波函数立体图形

Origin6．0作为一个数学软件平台，具有数据管理与分析、二维及三维函数和离散数据绘图、程序开发等多种功能，广泛用于工程设计和科学研究。本文利用Origin6．0软件的三维函数绘图功能，绘制势箱波函数、氢原子轨道、及其电子云密度函数的立体图形、等值线图和等密度线图。详细给出了各类绘图函数的程序可读化形式、图形及操作过程。该绘图方法操作界面更友好，适用于一般化学化工过程中的三维解析函数可视化。     

Business process management—the third wave: business process modelling language (bpml) and its pi-calculus foundations

This paper introduces the ideas behind BPML, the business process modelling language published by BPMI. BPML provides a process-centric (as opposed to a datacentric) metalanguage and execution model for business systems. It is underpinned by a strong mathematical foundation, the pi-calculus. The current paper is derived from supplementary appendices to a book which describes a ‘third wave’ approach to business process management [Business Process Management: The Third Wave, 2003]. The aim is to model business processes directly in an executable form, so that the mobility and mutability inherent in business behaviour is reflected and supported in the corresponding IT systems, erasing the present IT-business divide.     

Velocity-Guided Tracking of Deformable Contours in Three Dimensional Space

This paper presents a 3D active contour model for boundary detection and tracking of non-rigid objects, which applies stereo vision and motion analysis to the class of energy-minimizing deformable contour models, known as snakes. The proposed contour evolves in three-dimensional space in reaction to a 3D potential function, which is derived by projecting the contour onto the 2D stereo images. The potential function is augmented by a kinetic term, which is related to the velocity field along the contour. This term is used to guide the inter-image contour displacement. The incorporation of inter-frame velocity estimates in the tracking algorithm is especially important for contours which evolve in 3D space, where the added freedom of motion can easily result in loss of tracking. The proposed scheme incorporates local velocity information seamlessly in the snake model, with little computational overhead, and does not require exogenous computation of the optical flow or related quantities in each image. The resulting algorithm is shown to provide good tracking performance with only one iteration per frame, which provides a considerable advantage for real time operation.     

强脉冲离子束在金属中引起的应力波效应

金属在强脉冲离子束辐照及其后的快速冷却过程中所经历的应力过程是强脉冲离子束金属材料改性的最重要的机制之一。对应于这种过程，金属材料的微观结构和微硬度发生了改变。本文以45＃钢和纯铝为样品，将实验中测量到的不同强度的强脉冲辐照后样品微硬度和微观结构的变化与热力学计算所描述的热力学过程相对照，解释了出现微硬度双峰是由于应力波的形成和传播使然，并预言了由于应力波的在样品背面的反射，在较强能通量的强脉冲离子束辐照下样品背表面一定深度处也会出现微硬度增加的现象，该现象已被实验所证实。     

Modification of Boundary Parameters and Fluctuations by IBW and LHCD in the HT-7 Tokamak

Measurements of boundary parameters and their fluctuations have been performed in ohmic (OH) plasma and Ion Bernstein Wave (IBW) and Lower Hybrid Current Drive (LHCD) enhanced confinement plasma using a pneumatically driven Langmuir probe array on HT-7 toka-maX. In the enhanced confinement plasma~ the gradients of electron density and temperature become higher and a transport barrier comes into being in the vicinity of the limiter. The boundary potential shows a clear modification in the same region. The fluctuation levels are significantly depressed and the coherences between fluctuations are reduced evidently in the enhanced plasma.Meanwhile, we obtained the spectral features and the poloidal phase velocity of fluctuations us-ing a two-point correlation technique and found obvious modifications of the turbulence and the poloidal flow. The results suggest that the improved confinement in the IBW and LHCD enhanced plasma is at least partially due to the modification of the boundary parameters and the suppression of the boundary fluctuations and fluctuation induced fluxes.     

Propagation Properties of Electromagnetic Wave in a Plasma Slab

In this paper, the calculated results about the propagation properties of electromag-netic wave in a plasma slab are described. The relationship of the propagation properties with frequencies of electromagnetic wave, and parameters of plasma (electron temperature, electron density, dimensionless collision frequency and the size of the plasma slab) is analyzed.     

双馈电机转子交流励磁矢量控制电压波形分析

以矢量控制作为转子交流励磁控制方法，建立了双馈电机在变速恒压、恒频发电机运行时的数学模型和仿真模型。对启动和较大转速扰动时的动态过程进行了计算机仿真，得出了转速变化时转子交流励磁电压和定子输出电压的动态波形。结果表明，双馈电机采用转子交流励磁的矢量控制后，具有良好的动态特性，但又存在值得注意的问题。为励磁变频器的设计和控制提供了有意义的依据，对风力机的选用也十分有用。     

互相关函数法在声学测温技术中的应用研究

该文介绍了利用声学方法测量烟气温度的基本原理，并对声波飞渡时间的测量进行了计算机模拟分析和实验研究。利用信号处理技术中的互相关函数分析方法，计算声波发射端和接收端两路信号之间的时间延迟。采用计算机模型进行的研究表明，当接收端背景噪声和接收的信号水平相当时，在不作降噪处理的情况下，也能得到比较满意的分析结果。由于稳定周期信号作为测温声源在技术处理上有难度，该文设计了500—2000Hz范围内的扫频声波作为声源，对声波飞渡时间的测量进行了实验研究，结果表明该种声源和信号处理方法可以满足声学测温的技术要求。