掺杂WRe3、WRe25合金的高温电阻－温度特性

本文报导了采用一种新型高温陶瓷发热体高温管状炉，通以氩气保护，测量ＷＲｅ合金丝的电阻－温度（１６００℃）特性试验方法，该方法较真空炉简便、实用且试验费用低而准确，测量数据与美国研究报导一致。     

Introductory Paper

In today’s competitive market designing of digital systems (hardware as well as software) faces tremendous challenges. In fact, notwithstanding an ever decreasing project budget, time to market and product lifetime, designers are faced with an ever increasing system complexity and customer expected quality. The above situation calls for better and better formal verification techniques at all steps of the design flow. This special issue is devoted to publishing revised versions of contributions first presented at the 12th Advanced Research Working Conference on Correct Hardware Design and Verification Methods (CHARME) held 21–24 October 2003 in L’Aquila, Italy. Authors of well regarded papers from CHARME’03 were invited to submit to this special issue. All papers included here have been suitably extended and have undergone an independent round of reviewing.     

MetateM: An introduction

In this paper a methodology for the use of temporal logic as an executable imperative language is introduced. The approach, which provides a concrete framework, calledMetateM, for executing temporal formulae, is motivated and illustrated through examples. In addition, this introduction provides references to further, more detailed, work relating to theMetateM approach to executable logics.     

An improved BioHashing for human authentication

Given the recent explosion of interest in human authentication, verification based on tokenized pseudo-random numbers and the user specific biometric feature (BioHashing) has received much attention. These methods have significant functional advantages over sole biometrics i.e. zero equal error rate. The main drawback of the base BioHashing method proposed in the literature relies in exhibiting low performance when an “impostor” B steals the pseudo-random numbers of A and he tries to authenticate as A. In this paper, we introduce some ideas to improve the base BioHashing approach in order to maintain a very low equal error rate when nobody steals the Hash key, and to reach good performance also when an “impostor” steals the Hash key.     

Two-class fingerprint matcher

We present a system for fingerprint verification that approaches the problem as a two-class pattern recognition problem. The features extracted by “FingerCode” are used to capture the ridge strength. This feature vector is then classified as genuine or impostor according to a novel approach to handle the fingerprint verification as a two-class problem. Moreover, we show that extracting the features from sub-images around the core permits to better represent the local information.     

高校实验材料的计算机化管理

主要阐述了高校实验材料实行计算机化管理的必要性及全面介绍了自行开发设计的高校实验材料计算机管理系统．     

板式薄层膜通道中压力行为的实验研究

对层流状态下膜分离装置内膜通道中压力行为的特性进行了研究，理论分析了膜通道中出现该压力行为的原因，并用根式膜进行了验证．实验结果证实了理论分析的正确性。     

挤压六通管及其连接结构的安全性研究

六通管是石油化工设备及压力管道中的重要元件,传统的制作及连接方法是在集流管上开孔,然后将支管插入并焊接而成或采用锻制的方法制成。采用挤压的方法制作六通管,将其与支管对接焊接。并通过试验及数值模拟对该结构的安全性进行了研究,实践证明,这种挤压六通管的强度性能优于普通的焊接六通管,可以广泛应用于工业生产。     

试验模态分析技术的进展

本文对试验模态分析技术的进展,特别是80年代发展起来的有关新技术进行了综合评述。主要内容有:试验激振技术、频响函数估计方法、试验测试设备、以及各种模态识别方法,包括单输入/多输出和多输入/多输出识别的时域和频域方法。文中强调了试验模态分析技术各环节之间的相互联系、相互影响,对于80年代已成为模态识别主流的多输入/多输出各种方法(包括作者发展的几种方法),用统一方法作了描述。最后提出了若干值得进一步研究的方向。     

Three-Dimensional Solution and Experimental Confirmation for the Electric Resistivity Testing of Surface-Breaking Defects in Green-State Powder Metallurgy Compacts

This paper investigates electrostatic voltage distributions around a surface-breaking flaw due to an injected current of known strength. The direct 3-D solution of the voltage behavior over the flawed surface is obtained numerically by the use of a boundary integral formulation. A novel iteration method is applied to solve the resulting electrostatic integral equation for the unknown surface voltage distribution. In addition to investigating the sensitivity of different flaw sizes to the observed surface voltage distribution, important issues such as suitable probe spacing and current flow orientation are studied. For sufficiently small surface-breaking flaws, a simple image source model is developed to evaluate the voltage response of hairline cracks. The model is tested by comparing it with the developed numerical solution. Experiments aimed at establishing the validity of the modeling approach show remarkable agreement with the theoretical model.