铸钢件冒口离开热节动态顺序凝固补缩的计算机数值模拟

采用计算机三维热场数值计算法模拟了铸钢件-冒口系统的凝固补缩过程。结果表明，冒口安放处铸件的凝固时间延长80％以上，尤以热节处安放冒口凝固时间延长率最大。冒口放在热节上，冒口根部铸件发生缩松的可能性最大；冒口离开热节又不远离热节，冒口附近的温度梯度在形成缩松的固相率范围内都比较陡，铸件发生缩松的可能性很小。     

Mapping of the rice （Oryza sativa L.） thermo-sensitive genic male sterile gene tms5 with EST and SSR markers

VELOPING“TWO-LINE”HYBRID RICE.THE POLLEN FERTILITY OF TGMS IS REGULATED BY THE TEMPERATURE OF ENVIRONMENT.THE POLLENS OF TGMS LINES ARE STERILE WHEN THE ENVI-RONMENT TEMPERATURE IS ABOVE A CRITICAL POINT,BUT FERTILE BELOW THIS POINT.SO FAR,A NUMBER OF T…     

基于NET的Web服务安全验证

NET平台简化了Web服务的创建和使用，然而需要服务开发自己选择一种安全策略来保护Web服务，验证SOAP消息中凭证的安全性，这篇章在介绍几种WEB服务自份认证的同时．提出了一种基于数字签名技术、信任凭证、soap头的用户自定义的两因素动态加密认证方法。     

论文化诗学的价值向度

文化诗学作为文学理论研究的一个视角是可能且现实的,它旨在解脱诗学的现实困境,并赋予其新的价值功能.文化诗学有其存在的根据、存在的形式和功能价值.对诗学自律与文化他律的研究后,我们认为它还应有文化批判的价值向度,并主张诗学家与诗人一起追寻文学背后的文化意义和人之存在的终极价值.     

改进数学形态方法及其在电能质量监测中的应用

在分析传统形态滤波方法缺陷的基础上，提出一种改进的数学形态方法来处理电能质量监测中采集数据的噪声问题．通过选取合适的结构元素，并利用不同的结构元素及其自适应的加权组合方式，设计了性能优异的电能质量扰动信号的处理方法，该方法能在保证信号局部特征的前提下对信号进行有效的去噪．文中介绍了算法的设计要点和步骤，并从仿真计算和实验设计两方面来分析所提方法的性能和效率．结果表明，该方法设计简单、计算速度快、易于硬件实现，是一种切实可行的方法。     

Enhanced performance of nano-sized SiC reinforced Al metal matrix nanocomposites synthesized through microwave sintering and hot extrusion techniques

In the present study, nano-sized SiC (0, 0.3, 0.5, 1.0 and 1.5 vol%) reinforced aluminum (Al) metal matrix composites were fabricated by microwave sintering and hot extrusion techniques. The structural (XRD, SEM), mechanical (nanoindentation, compression, tensile) and thermal properties (co-efficient of thermal expansion- CTE) of the developed Al-SiC nanocomposites were studied. The SEM/EDS mapping images show a homogeneous distribution of SiC nanoparticles into the Al matrix. A significant increase in the strength (compressive and tensile) of the Al-SiC nanocomposites with the addition of SiC content is observed. However, it is noticed that the ductility of Al-SiC nanocomposites decreases with increasing volume fraction of SiC. The thermal analysis indicates that CTE of Al-SiC nanocomposites decreases with the progressive addition of hard SiC nanoparticles. Overall, hot extruded Al 1.5 vol% SiC nanocomposites exhibited the best mechanical and thermal performance as compared to the other developed Al-SiC nanocomposites.     

属性约简的两阶段遗传算法

属性约简是数据挖掘的一个重要研究内容. 为了解决具有多种属性类型的决策表约简问题,在粗集和二元关系聚合理论的基础上,利用属性重要性作为评价标准,提出了一种两阶段遗传约简算法. 算法的第一阶段是为了找出尽可能多的约简,第二阶段力求寻找最小约简. 根据算法每个阶段的目标设计了编码方案、种群规模、适应度函数、终止条件、选择、变异和修正操作. 实验表明,与标准遗传算法相比,两阶段算法在计算最小约简时更为准确和稳定.     

High-performance flexural fatigue of carbon nanotube yarns

Carbon nanotube yarns （CNTY） possess good specific strength and specific conductivity. As such, their potential for commercial applications is significant. Fatigue performance is a significant consideration in yarn/wire applications. In this study, the flexural fatigue performance of CNTY spun from super-aligned carbon nanotube arrays was investigated using a reversed bending test. The results showed that CNTY exhibited excellent resistance to pure flexural fatigue, significantly outperforming stainless steel wire; CNTY failed where a combination of flexural fatigue and tension-tension fatigue had special hollow fracture morphology, and CNTY resistance remained fundamentally unchanged in the combination fatigue process.     

The predictability of stock market volatility in emerging economies: Relative roles of local,regional, and global business cycles

This paper explores the role of business cycle proxies, measured by the output gap at the global, regional, and local levels, as potential predictors of stock market volatility in the emerging BRICS nations. We observe that the emerging BRICS nations display a rather heterogeneous pattern when it comes to the relative role of idiosyncratic factors as a predictor of stock market volatility. While domestic output gap is found to capture significant predictive information for India and China particularly, the business cycles associated with emerging economies and the world in general are strongly important for the BRIC countries and weakly for South Africa, especially in the postglobal financial crisis era. The findings suggest that despite the increase in the financial integration of world capital markets, emerging economies can still bear significant exposures to idiosyncratic risk factors, an issue of high importance for the profitability of global diversification strategies.