Coating of carbon-fiber surface by silicon carbide via sol-gel mixtures of tetraethyl orthosilicate and phenolic resin

The preparation of a SiC coating on a carbon fiber surface using a sol-gel mixture of tetraethyl orthosilicat (TEOS) and phenolic resin was studied. FTIR and SEM investigations indicated that the SiC coating can be formed by carbothermal reduction of the sol-gel mixture at 1420°C for 15–20 min in an argon atmosphere. TGA of the coated fiber was also performed, showing that the SiC coating improves the thermooxidative stability of the carbon fiber. With the thickness of the obtained coating of 0.47 μm using a C/Si ratio of 4, this treatment does not affect the carbon fiber strength.     

Novel polymeric aromatic lithium sulfonylimides as salts for polymer electrolytes

Three new polymeric aromatic lithium sulfonylimides were used as salts in high molecular weight poly(ethylene oxide) (PEO) electrolytes. Their conductivity and electrochemical stability behaviors were investigated. The electrolytes with lithium poly[4,4′‐(hexafluoroisopropylidene)diphenoxy]sulfonylimide (LiPHFIPSI) showed a better conductive performance compared with the other two lithium salts. The best conductivity was obtained for PEO/LiPHFIPSI EO/Li = 16 (1.90 × 10^?4 S/cm at 60°C). Thermal analysis indicated that the salts effectively decreased the crystallinity of PEO. Moreover, the electrolytes also had good electrochemical stability and their oxidative potential was to 5.5 V versus Li/Li⁺. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1802–1805, 2002     

Bone replacement in head and neck surgery: a biocompatible alternative

BACKGROUND: Defects in the skull have presented difficult reconstructive problems. Recently glass-ionomer cement and preformed. implants have been used to repair bony defects in the skull base and in cranio-facial surgery. Three patients are reported to illustrate possible applications for this new material. METHODS: Ionocap cement and Ionoroc-skull standardized implants have been used. The cement is available as a two component blister pack. When mixed and blended a gel is produced which can be worked for approximately 5 min before hardening. It can then be contoured and drilled to the required shape. The resultant material is biocompatible and biostable, is non-toxic and permanently bonds to bone with no increase in temperature or shrinkage. RESULTS: The material has been used to fill the temporal defect left by transplantation of the temporalis muscle for oral reconstruction, the anterior and lateral walls of the maxilla and following craniofacial resection, the posterior wall of the frontal sinus and anterior skull base. CONCLUSIONS: Three patients with different reconstructive problems have been presented to illustrate the use of an alloplastic material that has a tensile strength similar to bone and firmly adheres to it. The material was found to be safe and easy to use. All three patients have now been followed for 12 months with no adverse affects.     

A priori ordering protocols to support consensus-building in multiple stakeholder contexts

In a complex social, political, economic, technological, and/or environmental context, corporate, military, government, and other organizations are often faced with collective decision-making situations. The rationale for group decision exercises is that the judgment of many will usually prove superior to the judgment of one. However, it has been shown that collective decision exercises are often highly dependent on matters of perspective, values and opinion, all of which - being essentially subjective in nature - are beyond the reach of existing formal decision technology. Furthermore, it can be expected that many collective decision exercises - particularly those of strategic import - will not lend themselves to the quantitative analysis instruments that have long dominated the management and decision science repertoire. This does not, however, mean that they must remain entirely and forever outside the bounds of scientific rationality. The ordering protocols which are currently available do not have enough technical mechanics to be relied upon to bring us to any satisfying resolution of a priori disputation. Hence, we propose an a priori ordering reference model that might support consensus-building in a multiple stakeholders context. In order to detect whether the subjective arguments are products of proper reasons or merely instances of raw rhetoric and to suggest how any logical or syntactical flaws might best be repaired, we propose logical ordering facilities and protocols for integrating procedural and instrumental provisions for a group-decision process with two lines of technical innovation: the superimpositional ordering function and the logical ordering support facilities.     

高温超导红外探测器的电极工艺探讨

介绍了高温超导红外探测器电极材料的选择和制备。选用先蒸、后蒸金，再合金化的电极工艺。芯片装配成器件后，器件性能稳定，膜层牢固，接触电阻小。     

ConcurrentC语言在分布式系统上的一种高效实现

本文介绍了ＣｏｎｃｕｒｒｅｎｔＣ语言在一分布式系统上的实现。该实现使用了不同于预编译法的编译器的构造方法，同时将Ｃｏｎｃｕｒｒｅｎｔ Ｃ语言中的进程实现为ＵＮＩＸ进程中的用户级线索，是ＣｏｎｃｕｒｒｅｎｔＣ语言在分布式系统上的一种高效实现。     

用于计算机教育的Android实验软件(英文)

In this paper,we address the need for better hands-on learning materials in computing education and the need for integrating mobile computing education into computing curricular.We propose an innovative learning approach that uses state-of-the-art mobile computing technologies and devices to design a highly accessible and real-world relevant hands-on labware for computing education.The labware employs a modular design such that the learning materials can both be combined together into a single course of mobile program development and be integrated into the related computing courses as building blocks.The labware will help students understand the concepts,improve their problem solving skills,and prepare them for the mobile computing industrial workforce.The pilot modules of the labware have been presented to undergraduate students and have received positive feedbacks.     

集成电路测试系统中波形数字化仪的校准研究

文章介绍了波形数字化仪的原理、结构、工作方式及特点,并针对其校准技术进行了深入的研究。通过多功能校准源、示波器及测试系统数字模块实现波形数字化仪模块的精确校准,解决了波形数字化仪模块的校准问题。校准结果表明,该校准装置及校准方法能够满足集成电路测试系统任意波形发生器的校准要求。     

网络对抗训练混合虚拟化平台设计研究

讨论了虚拟化技术实现原理及其在网络对抗教学中的应用上,分析了各类虚拟化技术的优缺点和构建网络对抗训练环境存在的问题。提出了一种混合虚拟化平台设计,该平台利用Libvirt虚拟化的应用程序编程接口（API）调用两种虚拟化技术同时运行在同一物理主机上。并详细叙述了混合虚拟化平台的实现过程和方法,并在多个虚拟机内同时运行测试基准,分析其可扩展性。多种虚拟化技术在同一物理机上的混合,实现了复杂实验环境的创建,对构建大规模的网络实验平台具有一定的参考价值。