In situ polyurethane/silica composite formation via a sol‐gel process

Polyurethane acrylate anionomer (PUAA)/silica composite gels were prepared by the sol‐gel reaction of tetraethoxysilane (TEOS) and methacryloxypropyl trimethoxysilane (MPTS) incorporated to PUAA gels by using a swelling method. The formation and structure of composites were confirmed by FTIR, X‐ray diffraction, and SEM. As a result, we found that silica components in composites are located within the ionic domains of their gels and interacted with PUAA via hydrogen bonding. This drastically enhanced the mechanical properties of the composites. Mechanical properties are also improved by MPTS, because MPTS improves the dispersibility and adhesion of silica components in PUAA/silica composite gels. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2327–2334, 2002     

短波长相干光与原子团受激发射

多种原子团及其离子已具有在VUV/XUV波段产生受激发射的能力。本文介绍了产生短波长相干辐射的方法、研究现状、研究方法和原子团的结构与受激发射。     

The polar cluster like behavior in Ti substituted BaZrO3 ceramics

In this paper we report the evolution of the polar cluster like behavior with the incorporation of Ti⁴⁺ ion in BaZrO₃ Ceramics. Dielectric behavior of BaZr_xTi_(1−x)O₃ (x = 1.00, 0.95, 0.90, 0.85) ceramics is studied in the temperature range from 300 to 30 K. Polar cluster like behavior becomes more prominent with the increase in content of Ti⁴⁺ ion. The dielectric relaxation is analyzed by Vogel–Fulcher relation and Arrhenius law. Frequency dependence of dielectric constant and low loss tangent of these materials can be useful for the potential applications at low temperature.     

Action strategies for strengthening industrial clusters in southern Taiwan

For the past decade, the Taiwanese government has applied the policy of “North heavy, South light” to put more emphasis on development in northern Taiwan instead of the south. This has resulted in uneven development between the northern and southern regions, especially when introducing, developing, and supporting high technology and resource allocation in education. Industry clusters have become the centerpiece of economic development policy in many parts of the world. In this study, it is assumed that there are two categories of less-advantaged regions in Taiwan: (1) older industrialized regions dominated by labor-intensive/capital-intensive industries, and (2) industrial regions that have merged with potential high-technology small firms but still lack infrastructure. This study discusses the following points: (a) How do industrial clusters work in action? (b) What barriers do less-advantaged industrial clusters face? (c) What action strategies promote less-advantaged industrial clusters?     

示例学习的扩张矩阵理论

本文提出示例学习的一种计算理论,扩张矩阵论.根据这个理论,示例学习中一些主要最优化问题被证明是NP难题,并给出这些难题的近似解法及下界的估计.     

分流液压转向牵引计算的展开图及其应用

本文论及分流液压转向牵引计算的概念,方法及其展开图,并且提供了计算机绘制的展开图和应用实例。     

基于模糊神经网络对经济的聚类分析

在现实生活中具有同等人力资本的劳动者在不同的生产力环境下的经济贡献率是不同的 ,有时甚至不可比较的。利用人工神经网络 (SOM网络 ) ,通过 Matlab语言编程 ,根据技术进步增长率对整个经济进行模式分类。分类的结果是大致把 2 9个省市分为 6个类 ,反映了各地区的经济与技术进步增长率情况     

Multidimensional Personality Questionnaire profiles of veterans with traumatic combat exposure: Externalizing and internalizing subtypes.

This study used the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, in press) to identify personality-based subtypes of posttraumatic response. Cluster analyses of MPQs completed by combat veterans revealed subgroups that differed on measures relating to the externalization versus internalization of distress. The MPQ profile of the externalizing cluster was defined by low Constraint and Harmavoidance coupled with high Alienation and Aggression. Individuals in this cluster also had histories of delinquency and high rates of substance-related disorder. In comparison, the MPQ profile of the internalizing cluster was characterized by lower Positive Emotionality, Alienation, and Aggression and higher Constraint, and individuals in this cluster showed high rates of depressive disorder. These findings suggest that dispositions toward externalizing versus internalizing psychopathology may account for heterogeneity in the expression of posttraumatic responses, including patterns of comorbidity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

聚合物包覆热分解法制备纳米氧化锌的工艺研究

采用聚合物包覆热分解法化学工艺制备了纳米氧化锌，对其工艺进行系统的比较研究，对所得粉体进行XRD与SEM表征。发现利用该工艺所得粉体为六方晶系纤锌矿结构（空间群为P63mc）的纳米氧化锌。该方法制备的氧化锌衍射峰尖锐，表明此种方法合成的氧化锌结晶程度高。所得的氧化锌粉体XRD图谱中没有杂质衍射峰，说明产物纯度都很高。产品SEM表征结果显示了此工艺产物在形貌方面的高度一致性——为菊花状氧化锌纳米杆团簇，对产物形貌形成的原因做了探讨。     

Heavy arsenic doping of silicon grown by atmospheric pressure selective epitaxial chemical vapor deposition

Selective epitaxial Si with a high arsenic concentration of 2.2×10¹⁹ atoms/cm³ was deposited at a high growth rate of 3.3 nm/min under atmospheric pressure. It was confirmed that this method had excellent selectivity and produced films having good crystalline quality, abrupt dopant profiles at the interfaces, and smooth surfaces. The growth mechanism is discussed in terms of the relationship between the effects of arsenic surface segregation and etching by hydrogen chloride.