The potential use of nanosilver-decorated titanium dioxide nanofibers for toxin decomposition with antimicrobial and self-cleaning properties

While chemical and biological attacks pose risk to human health, clean air is of scientific, environmental and physiological concerns. In the present contribution, the potential use of nanosilver-decorated titanium dioxide (TiO₂) nanofibers for toxin decomposition with antimicrobial activity and self-cleaning properties was investigated. Titanium dioxide nanofibers were prepared through sol-gel reaction followed by an electrospinning process. Following the Japan Industrial Standard (JIS) protocol, decompositions of nitrogen oxide (NOx) and volatile organic compound (VOC) by the TiO₂ nanofibers suggested that these materials were capable of air treatment. To further enhance their anti-microbial activity, silver nanoparticles were decorated onto the TiO₂ nanofibers’ surfaces via photoreduction of silver ion in the presence of the nanofibers suspension. Furthermore, tests of photocatalytic activity of the samples were performed by photodegrading methylene blue in water. The nanofibrous membranes prepared from these nanofibers showed superhydrophilicity under UV. Finally, the possibility of using these hybrid nanofibers in environmental and hygienic nanofiltration was proposed, where the self-cleaning characteristics was expected to be valuable in maintenance processes.     

一种新型的统一认证平台的设计与实现

传统的电子认证服务,由于服务水平、证书策略、风险防控能力的差异,不仅增加了资源投入,也给用户带来不便。本文提出了一种基于数字证书的统一身份认证的实现方案,使得数字证书的一证多用成为可能,能让数字证书得到更广泛的应用。实践证明,采用本文的技术路线,可以实现数字证书的统一认证,行之有效并给用户带来便利。     

分布式CA下空间网络认证密钥安全度量方法

基于分布式CA的密钥管理策略解决了空间网络中不易实施集中式密钥管理的难题,但也给认证密钥的安全带来了新的威胁。该文在描述和分析空间网络中认证密钥的安全威胁的基础上,提出了一种度量认证密钥安全强度的方法。该方法可根据系统门限值、密钥更新周期等参数的设置情况,定量度量认证密钥的安全强度。通过分析系统门限值和密钥分量更新周期对安全强度的影响,给出了合理设置这两个网络安全参数的方法。     

全球FTTH的发展及前景预测

目前全球FTTH的发展现状是日本发展最快,被认为已进入大规模发展阶段;美国紧跟其后,成为继日本之后的第二大市场;欧洲主要国家由于ADSL和ISDN使用较多,FTTH在很长时间内发展较慢,但目前已经开始升温。各国FTTH发展的动因和特点基本一致,主要是市场和技术竞争、业务需求、政府推动,各国根据自己人口分布、城市格局等情况采取不同的发展策略和技术方案。未来几年,全球FTTH的发展格局不会有大的变化;但其成本将进一步下降,GPON和EPON技术将成为主流。     

从日本3G市场看cdma2000与WCDMA之争

日本是当今WCDMA和edma2000两大阵营直接对垒的国家。与WCDMA相比，cdma2000 1x推出较晚．技术和性能也不及前者，但却后来居上．发展规模大大超过了前者，这主要是因为这种技术更容易平滑过渡、与2G网容易兼容、建网初期成本低、终端与2G终端配套且价格低廉。加上公司营销策略对路、能与高通公司密切合作等。从长远来看，GSM运营商选择WCDMA比较适当。而对那些非GSM的潜在运营商．选择cdma2000则可能更有利。     

日本未来信息通信技术发展动向

介绍了日本“日本通信研究开发基本计划”该计划勾画了２１世纪日本在信息通信领域中的发展趋势，对我国信息通信技术的发展具有一定的借鉴意义。     

基于多认证方式的Mobile VPN系统

文章介绍了一个Mobile VPN应用系统的认证框架及相应的技术特点。通过对现有移动通信网络的分析．以及针对这些特点提出一些与之相应的适合服务。同时结合其他相关技术构架设计出了一个具体的认证服务系统，为移动用户的访问时提出了多认证方法，并阐述了其实现过程和应用价值。最后提出本系统的服务易扩充性．以及在未来移动通信中的应用前景。     

智能3P控制器(三)--参数整定

本文是在文^[1]和文^[2]研究分析的基础上，具体分析了智能3P控制器的参数整定及方法，通过理论分析说明了本智能3P控制器具有优良控制品质的本质原因。     

对日本PCB业新观念新战略的综述与思考（下）

该文综述了日PCB业近期的新思路、新战略,并联系我国PCB业的现状,作以思考与综述。     

An arbitrarily oriented crack in a semi-infinite medium with a surface layer under tension

The title problem is analyzed by the use of the continuous distribution of dislocations in the framework of plane elastostatics. A set of singular integral equations for the dislocation density is readily set up, whose solution is obtained in the form of the product of the series of Chebyshev polynomials of the first kind and their weight function. The variation of the stress intensity factor due to the geometrical configuration and the material combination is shown in graphs. The probable angle of crack growth due to Erdogan-Sih criterion for brittle materials is also shown.