Polymer networks based on α,ω-methacrylate-terminated poly(1,3-dioxolane)

α,ω-Methacrylate-terminated poly(1,3-dioxolane)s (polyDXL) were synthesized by cationic ring-opening polymerization of DXL in the presence of methylene-bis(oxyethylmethacrylate) as transfer agent. If the initiator concentration is small compared with the transfer agent concentration, the molecular weights of the polymers are governed by the ratio of the reacted monomer to the reacted transfer agent. The α,ω-methacrylate-terminated polyDXLs obtained undergo free radical polymerization with formation of polyacetal networks. The properties of the networks as function of the molecular weight of the corresponding prepolymers are reported.     

核电材料在模拟反应堆环境中应力腐蚀破裂测试技术与性能评价

简要介绍了采用慢应变速率试验，Ｕ型弯曲和Ｃ形环试验等技术，分别对８００合金，３０４和３１６及３１６Ｔｉ不锈钢Ａ５３３Ｂ压力容器用多在模拟核反应堆环境中的应力腐蚀破裂敏感性性进行的试验研究的一些主要结果；并结合电化学测试和表面膜俄歇电子能谱分析结果进行了讨论。     

Unperturbed dimension of poly(4-acetoxystyrene) measured in good and theta solvents

In order to obtain the additional data concerning the unperturbed dimension of poly-4-substituted styrene, light scattering measurements are performed on the twenty-two fractions with molecular weight of (0.91–352)·10⁴ of poly(4-acetoxystyrene) in dioxan at 25°C, from which the molecular weight obtained was found easily to be evaluated with the gel permeation chromatography using THF. Phase separation experiments for this polymer indicate that the theta state is attained in isopropyl acetate at 19.7°C and butyl acetate at 26.8°C. By making viscosity measurements at that state, the value of K_Θ is directly evaluated as 5.4·10^?4 dl g^?1. The limiting viscosity number is also obtained in good solvents, THF and dioxan, at 25°C and constants of the Mark-Houwink-Sakurada equation in each solvent are determined. Further, approximately the same K_Θ as above is obtained from these data with the Stockmayer-Fixman plot. The calculated value of steric factor, 2.37, on this polymer may be plausible, compared with those of polyvinylaromatic derivatives.     

Ionic transport in amorphous anodic titania stabilised by incorporation of silicon species

Incorporation of silicon species from an alloy substrate into anodic titania is shown to stabilise the structure of the film, facilitating investigation of the ionic transport processes in amorphous titania grown at high efficiency. Thus, an amorphous anodic film developed on a sputtering-deposited Ti-6 at.%Si alloy formed to 100 V in phosphoric acid electrolyte in contrast to a partially crystalline film developed on relatively pure titanium at <20 V. Silicon species, which are immobile and act as marker species in the growing film, are present in the inner 58% of the film thickness. Evidently, the film material forms simultaneously at the film/electrolyte and alloy/film interfaces by co-operative transport of cations and anions, as is usual in amorphous anodic oxides. The phosphate anions incorporated from the electrolyte migrate inward at 0.34 times the rate of O²⁻ ions and hence are present in the outer 62% of the film thickness.     

IPv6与欧洲

在推进IPv6的问题上,亚洲表现的最为积极,这是因为亚洲各国承受着巨大的IP地址方面的压力。欧洲虽然在这方面没有这样大的压力,但在互联网方面一直落后于美国,这是欧洲所不甘心的。因此,欧洲在推进IPv6方面也做了许多工作。欧洲推进IPv6的基本策略是先移动,后固定,并实施了一系列的行动计划和项目。欧洲面临的挑战主要是已经部署了数量巨大的网元、操作系统与软件应用必须予以更新、互通或取代,需要仔细规划和大量投资。     

WDM传输系统中泵浦配置对光纤拉曼放大器增益特性的影响

通过理论分析和模拟运算,研究了光纤拉曼放大器泵浦优化的一般规律。     

数字散斑干涉技术及应用

介绍了数字散斑干涉技术在位移、应变、振动和医学诊断等领域中的应用和国内外发展状况。提出了一种新的应用领域—数字散斑干涉技术在语音识别中的应用,并对该方法作了介绍,讨论了它的特点。     

数据采集与监控软件Genie

Genie是具有国际先进水平的数据采集与监控软件，它提供了一个面向对象的图形化用户界面，因此简化了数据采集过程、控制应用程序开发和操作员界面。本文介绍了Genie的特点、功能、基本用途以及VISUALBA－SIC在设计这类监控软件中的作用。     

激光晶体Nd:YVO4的形貌及生长缺陷

本文报道了应用环境扫描电镜（ESEM）和同步辐射X射线白光形貌术对采用提拉法生长出的Nd:YVO4晶体进行的形貌及生长缺陷的分析,获得了该晶体的开裂表面的ESEM形貌像以及取自晶体肩部和中间部位的（001）面的同步辐射白光形貌像,观察到了位错、包裹物等缺陷,可为生长高质量的Nd:YVO4晶体提供重要的启示.     

头盔显示器的关键技术及有关设计问题综述

头盔显示器可以提高驾驶员的态势感知能力，红外传感器提供的信息，使驾驶员的态势感知能力大大加强，头盔显示器提供的红外图像，使恶劣的天气和黑夜不再成为驾驶员作战的障碍，概述了头盔显示器的发展过程和关键技术，介绍了当前空军用头盔显示器的技术问题，解决方法，设计示例。