水利政府网站的功能作用及建设

文章介绍了政府网站的作用及功能,国家对政府网站绩效评估的内容以及水利政府网站建设的实践.     

A framework for a limitation policy of the population exposure to natural radiation in Belgium

The conclusions are put forward that are adopted by a discussion group preparing the framework for a limitation policy of the radon problem in Belgium. Existing and future situations are treated in a coherent policy that is adequate for practical implementation. An action level is defined, together with a hierachy of levels for new constructions. The decision logic for the acceptance of building materials is explained.     

The forward muon detector of the DELPHI experiment at LEP

The layout and construction of the muon drift chambers equipping the end caps of the DELPHI detector are described. The performance of this forward muon detection system, determined from cosmic ray tests and data collected during the first year of LEP operation, is presented.     

Cyclic variations in the permeability of the cell wall of Saccharomyces cerevisiae.

To study cell-cycle-related variations in wall permeability of Saccharomyces cerevisiae, two approaches were used. First, an asynchronous culture was fractionated by centrifugal elutriation into subpopulations containing cells of increasing size. The subpopulations represented different stages of the cell cycle as judged by light microscopy. Cell wall porosity increased when these subpopulations became enriched with budded cells. Secondly, synchronous cultures were obtained by releasing MATa cells from alpha-factor induced G1-arrest. These cultures grew synchronously for at least two generations. The cell wall porosity increased sharply in these cultures, shortly before buds became visible and was maximal during the initial stages of bud growth. It decreased in cells which had completed nuclear migration and before abscission of the bud had occurred. The porosity reached its lowest value during abscission and in unbudded cells. We examined the incorporation of mannoproteins into the wall during the cell cycle. SDS-extractable mannoproteins were incorporated continuously. However, the incorporation of glucanase-extractable mannoproteins, which are known to affect cell wall porosity, showed cyclic oscillations and reached its maximum after nuclear migration. This coincided with a rapid decrease in cell wall porosity, indicating that glucanase-extractable mannoproteins might contribute to this decrease.     

明渠湍流床面附近跃移层面颗粒浓度垂线分布

本文以动理学理论的Boltzmann方程为基础，考虑明渠湍流床面附近猝发喷射和清扫运动对跃移层内运动颗粒的不同作用，分析了明渠中泥沙颗粒浓度垂线分布问题，得到了适用于包括跃移层、悬移层在内的统一浓度垂线分布公式。文中着重研究了跃移层内运动颗粒的浓度垂线分布，并将本文结果与实测跃移层内浓度垂线分布及实测跃移层顶部浓度进行了对比，结果表明理论与实验两者符合较好。     

彩色等离子体显示器的新进展

扼要地介绍了近年来世界上各大公司对彩色PDP的结构和驱动方法的改进 ,将现今彩色PDP的亮度、对比度和色纯度等主要性能与过去相比 ,得到明显的改善 ,达到了与高清晰度CRT相当的性能。     

光纤专用网中基于DSP的Q值在线检测模块的设计

基于误码率与Q值的对应关系，本文介绍一种Q值在线检测方法，模块设计采用DSP技术，并讨论了该模块在光纤工业专用网（FIN）中的应用。     

锅炉炉膛红外成像温度实时检测系统研究

说明电厂锅炉炉膛温度及结焦直接影响锅炉正常运行及安全；给出了基于多探测器的锅炉反应温度红外成像实时测温系统的系统结构、系统原理、系统标定和温度测定方法。     

关于知识团队特性的研究

章从商业环境的变化分析入手，指出由知识工作为主体构成的知识团队将成为企业运作的重要形式。知识团队与传统的、特别是基于某项单一职能或成员来自某一知识领域的团队有着许多显的不同。通过分析认为，这些不同点主要体现在团队目标的模糊性、团队成员的动态性和团队管理手段的协定性等方面。     

近非临界相位匹配温度调谐MgO：LiNbO3OPO

通过对MgO:LiNbO3参量过程温度相位匹配及走离角，允许参量等运转参数的理论计算与分析，确定了晶体的切割角度θ=82℃，以近非临界相位匹配（NCPM）取代NCPM，将温度调节范围控制在较低的温度上，研制了532nm泵浦的MgO:LiNbO3温度调谐脉冲光学参数振荡器（OPO），在800～1700nm波段实现连续调谐输出。参量泵浦功率密度阈值为57.3MW/cm^2，泵浦能量约2倍阈值处，单谐振（SRO）参量转换效率为11%以上。