基于ASP.NET的图书馆志愿者考勤系统

针对图书馆志愿者管理工作需要,利用ASP.NET开发平台和SQL后台数据库开发出一套便于操作和维护的图书馆志愿者考勤系统,系统从需求分析、柜架设计、数据库设计、数据流程图及模块的实现等方面进行介绍。     

面向船舶运动控制仿真的网络数据库系统

构建一个基于JSP+JavaBean的B/S体系结构的船舶运动的网络数据库,给船舶仿真提供一个与用户交互的平台,使用SQL Server 2005,结合Ajax+JavaScript技术,主要采集模拟船舶运动仿真过程所需的参数、显示船舶运动状态参数以及运行轨迹,并可以方便地对船舶、操舵员(用户)等进行信息管理.     

基于降雨资料的雨量预警指标阈值求解模型

为保证雨量预警指标阈值在有效周期范围内发挥预警作用,通过分析现有雨量预警指标阈值的确定方法,提出了基于区域临界雨量法-降雨灾害同频率法-R/S分析法的雨量预警指标阈值求解模型。将该模型应用于江苏省泰兴市降雨时间序列的分析,对最大日降水量时间序列进行阈值确定、趋势分析,并用指标阈值进行预警验证。结果表明,该模型的雨量预警指标阈值确定结果相较单一模型更为准确,且具有一定的时效性,可为农村基层防汛预报预警提供参考。     

1957-2017年泾河流域降雨量及降雨侵蚀力时空变化分析

泾河流域受土壤侵蚀的影响,水土流失较为严重,为对流域水土流失风险评估和防治等提供参考依据,根据1957-2017年泾河流域5个气象站点的日降水资料,运用ArcGIS空间插值、小波分析、R/S分析等方法,分析了该时段降雨量及降雨侵蚀力时空变化规律。结果表明:泾河流域及各气象站点的降雨量与降雨侵蚀力均呈显著正相关关系;泾河流域降雨量与降雨侵蚀力年内分布不均,主要集中在夏季,分别占全年的67.80%和52.86%;泾河流域年均降雨量和降雨侵蚀力分别为496.83 mm和1 481.24 (MJ·mm)/(hm~2·h),年际总体呈波动上升趋势且未来降雨侵蚀力将延续增加趋势,两者均在1996和2009年出现突变点且第一主周期分别为27和17 a;泾河流域降雨量和降雨侵蚀力在空间上均呈从西北到东南递增的趋势。     

微结构量子器件

微结构量子器件是八十年代中期伴随着微结构物理的发展而出现的一种新的半导体器件,这种器件以量子力学原理工作,具有常规“经典”器件无法比拟的优异特性。本文在简要介绍了微结构系统电子状态的基础上,较详细地描述了量子谐振隧道器件以及量子线和量子点激光器的基本原理、特点及其应用前景。     

Searching minimax game trees under memory space constraint

Games such as CHESS, GO and OTHELLO can be represented by minimax game trees. Among various search procedures to solve such game trees,- and SSS^* are perhaps most well known. Although it is proved that SSS^* explores only a subset of the nodes explored by-, - is commonly believed to be faster in real applications, since it requires very little memory space and hence its storage management cost is low. Contrary to this folklore, however, this paper reports, using the OTHELLO game as an example, that SSS^* is much faster than-. It is also demonstrated that SSS^* can be modified to make the required memory space controllable to some extent, while retaining the high efficiency of the original SSS^*.This research was partially supported by the Ministry of Education, Science and Culture of Japan, under a Scientific Grant-in-Aid.     

Elimination of dislocations in heteroepitaxial MBE and RTCVD Ge x Si1-x grown on patterned Si substrates

We have grown Ge _x Si_1-x (0 <x < 0.20,1000–3000Å thick) on small growth areas etched in the Si substrate. Layers were grown using both molecular beam epitaxy (MBE) at 550° C and rapid thermal chemical vapor deposition (RTCVD) at 900° C. Electron beam induced current images (EBIC) (as well as defect etches and transmission electron microscopy) show that 2800Å-thick, MBE Ge_0.19Si_0.81 on 70-μm-wide mesas have zerothreading and nearly zero misfit dislocations. The Ge_0.19Si{0.81} grown on unpatterned, large areas is heavily dislocated. It is also evident from the images that heterogeneous nucleation of misfit dislocations is dominant in this composition range. 1000Å-thick, RTCVD Ge_0.14Si_0.86 films deposited on 70 μm-wide mesas are also nearly dislocation-free as shown by EBIC, whereas unpatterned areas are more heavily dislocated. Thus, despite the high growth temperatures, only heterogeneous nucleation of misfit dislocations occurs and patterning is still effective. Photoluminescence spectra from arrays of GeSi on Si mesas show that even when the interface dislocation density on the mesas is high, growth on small areas results in a lower dislocation density than growth on large areas.     

Consequences of the formation of Cooper-pairs near oxygen-deficient sites

In this investigation we consider the formation of Cooper pairs near the oxygen-deficient sites in Y-Ba-Cu-O ceramic superconductors which would give rise to an energy-dependent potential as seen by conduction charge carriers. It is shown that Cooper pairs could be formed under such conditions, resulting in a supercurrent. We use the Bogoliubov transformation technique to calculate the energy gap, the energy difference, and the transition temperature of the model superconductor using certain data obtained from previous experiments. Numerical analysis shows that the superconducting current can be explained by the presence of such oscillating Cooper pairs.     

The effects of long-term VDT usage on the nature and incidence of asthenopic symptoms

An opportunity arose in 1985 to become involved in a transition of working practice from hard copy to VDT. Over a two-year period, 161 VDT users and 65 control subjects in the same office environment were regularly and routinely examined for symptoms of asthenopia. The analysis of data shows that there are no significant differences in type, number and frequency of the work-related symptoms between VDT users and non-VDT users. It appears that reporting of symptoms within the group may be random, although certain symptoms do appear more frequently than others. Additionally, it appears that there is a significant difference between male and female users in the frequency of symptom reporting.     

关于工控系统信息安全的思考与建议

文章在介绍工控系统的发展历程后,分析了工控信息网络安全隐患的本质与根源,在建议借鉴国外相关规范和经验的同时强调国内重要工程产品引入的约束性,提出了大力支持国内自主核心工控产品的必要洼。