裂解炉下集气锥形接管失效分析

通过化学成份分析、金相的宏微观考察、Manson-Haferd参数对锥形接管持久寿命的估算,以及热应力的计算,对锥形接管的失效原因进行了分析,认为是由温差应力导致失效。所以应该充分注意高温构件保温措施的有效性,避免非正常温差应力的产生。     

Self-scaling cooperative discovery of service compositions in unstructured P2P networks

We propose an efficient technique for improving the performance of automatic and cooperative compositions in unstructured Peer-to-Peer networks during service discovery. The technique exploits a probabilistic forwarding algorithm that uses different sources of knowledge, such as network density and service grouping, to reduce the amount of messages exchanged in the network. The technique, analysed in several network configurations by using a simulator to observe resolution time, recall and message overhead, presents good performance especially in dense and large-scale service networks.     

工业自动化仪表的可靠性及维修

本文叙述有关国内外自动化仪表在工业生产流程中的可靠性，维修性及安全性。     

Synthesis and electrochemical characteristics of Al2O3-coated LiNi1/3Co1/3Mn1/3O2 cathode materials for lithium ion batteries

LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials have been coated with Al₂O₃ nano-particles using sol-gel processing to improve its electrochemical properties. The X-ray diffraction (XRD) pattern of the as-prepared Al₂O₃ nano-particles was indexed to the cubic structure of the γ-Al₂O₃ phase and had an average size of ∼4 nm. The XRD showed that the structure of LiNi_1/3Co_1/3Mn_1/3O₂ was not affected by the Al₂O₃ coating. However, the Al₂O₃ coatings on LiNi_1/3Co_1/3Mn_1/3O₂ improved the cyclic life performance and rate capability without decreasing its initial discharge capacity. These electrochemical properties were also compared with those of LiAlO₂-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathode material. The electrochemical impedance spectroscopy (EIS) was studied to understand the enhanced electrochemical properties of the Al₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ compared to uncoated LiNi_1/3Co_1/3Mn_1/3O₂.     

Web Service性能测试的两种测试脚本设计方法

Web Service接口技术越来越广泛地应用到信息系统之中,Web Service接口的性能测试需求也越来越多。给出使用LoadRunner和SOAP UI工具进行Web Service接口性能测试的两种测试脚本设计方法,即Service Call方式的测试脚本设计方法和SOAP方式的测试脚本设计方法。     

大型矿车用减速机齿轮系统的疲劳分析

提出一种基于"放大因子"、采用二维平面单元模拟三维实体动态工况的计算疲劳的方法,对某矿车减速机齿轮系统进行疲劳分析,得到太阳轮、行星轮和扭力管在不同抗拉强度下的疲劳寿命.结果表明:太阳轮和扭力管最易发生疲劳破坏;齿轮寿命对抗拉强度的依赖性较敏感;得出的齿轮系统热处理后的抗拉强度建议值能为设计提供参考,且该方法能大大提高计算效率.     

聚氨酯橡胶摩擦轮有限元及疲劳寿命分析

针对汽车滑板输送机聚氨酯橡胶摩擦轮的开裂问题,对摩擦轮与滑板之间的相互作用进行预压紧力和接触摩擦驱动有限元分析,获得摩擦轮的应力和变形分布等结果.在获得摩擦轮周向应力分布的基础上,根据疲劳裂纹扩展公式对聚氨酯橡胶部分进行疲劳寿命分析,验证是否满足设计要求.分析过程和结果能为聚氨酯橡胶摩擦轮的详细设计提供参考.     

Contourlet变换与生命游戏置乱相结合的视频零水印

为了达到版权保护的目的,提出一种Contourlet变换与生命游戏置乱相结合的视频零水印,Contourlet被誉为处理二维信号的最优解,算法利用其优势对关键帧处理得到低频系数,再经过核心算法处理,最后结合生命游戏规则生成特征图像,并运用加密算法对水印进行预处理以加强安全性。实验结果表明本算法较好地折中了数字水印的不可见性和鲁棒性,并能有效地抵抗常见的几何攻击和视频攻击。     

Relationship between chemical degradation and thickness loss of an amine-cured epoxy coating exposed to different UV environments

The relationship between chemical degradation and thickness loss of an unpigmented, non UV-stabilized, crosslinked amine-cured epoxy coating exposed to three UV conditions was investigated. Spin-coated samples having a thickness of approximately 7 μm on an Si substrate were prepared from a stochiometric mixture of a bisphenol A epoxy resin and a tetra-functional amine curing agent. Samples were exposed outdoors and to two accelerated laboratory UV environments. Chemical degradation and thickness loss were measured by transmission Fourier transform infrared spectroscopy (FTIRS) and laser scanning confocal microscopy (LSCM), respectively. In addition, surface roughness and morphological changes were measured by atomic forcemicrosocopy (AFM) and LSCM. Substantial chemical degradation, thickness loss, and morpholocal changes occurred in the exposed films, and the rate of chemical degradation was greater than that due to the thickness loss. This additional chemical loss was attributed to an inhomogeneous degradation process in which nanoscale localized depressions initiate at certain sites on the surface, which then enlarge and deepen with exposure time. The results of this study provide a better understanding of the degradation mechanism and should lead to the development of scientific-based models for predicting the service life of crosslinked amine-cured epoxy coatings. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL     

A trustworthy QoS-based collaborative filtering approach for web service discovery

Many network services which process a large quantity of data and knowledge are available in the distributed network environment, and provide applications to users based on Service-Oriented Architecture (SOA) and Web services technology. Therefore, a useful web service discovery approach for data and knowledge discovery process in the complex network environment is a very significant issue. Using the traditional keyword-based search method, users find it difficult to choose the best web services from those with similar functionalities. In addition, in an untrustworthy real world environment, the QoS-based service discovery approach cannot verify the correctness of the web services’ Quality of Service (QoS) values, since such values guaranteed by a service provider are different from the real ones. This work proposes a trustworthy two-phase web service discovery mechanism based on QoS and collaborative filtering, which discovers and recommends the needed web services effectively for users in the distributed environment, and also solves the problem of services with incorrect QoS information. In the experiment, the theoretical analysis and simulation experiment results show that the proposed method can accurately recommend the needed services to users, and improve the recommendation quality.