三峡水电站ALSTOM机组低水头运行稳定性分析

混流式水轮机的水力稳定性与机组水力工况密切相关。以三峡电站左岸6号机组稳定性试验为例，分析了ALSTOM机组的低水头运行稳定性。根据试验分析结果，可将机组运行工况划分为小负荷区、涡带振动区、大负荷运行区。小负荷区机组效率较低，机组不宜在此区间运行；大负荷区机组运行稳定性最佳，但机组应避开强涡带工况区和特殊频率振动区运行。     

Dye-sensitized solar cell based on nanocrystalline TiO<Subscript>2</Subscript> with 3–10 nm in diameter

Nanocrystalline TiO₂ with 3–10 nm in diameter was prepared with a surfactant-template method. Dye-sensitized solar cells were assembled using the prepared nanocrystalline TiO₂ with large surface area and high crystallinity, which achieved significant higher Jsc when compared to cells fabricated with bigger particles of 25 nm in diameter. In the cells with nanocrystalline TiO₂, the sintering temperature drastically affected the conversion performance of the cells.     

海底管道系统失效故障树的建立及定性分析

受自然环境、管道腐蚀、第三方破坏及管理不善等因素的影响,海底管道系统在铺设及运行过程中常常会失效。文中以海底管道穿孔、凝管、断裂和设备故障等主要失效形式为顶事件建立了海底管道系统失效故障树,通过系统的定性分析得到了海底管道系统失效故障树的37个一阶最小割集,进而确定了影响海底管道系统失效的4项主要因素,并针对这些主要因素提出了相应的解决问题的措施。     

Aging response of the young’s modulus and mechanical properties of Ti-29Nb-13Ta-4.6Zr for biomedical applications

Alloys for implant devices require improved strength but a reduced Young’s modulus, in order to become mechanically more compatible with adjacent bone tissues. In this study, a new metastable β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr (wt pct), was subjected to aging treatment to produce different microstructures, and the resulting mechanical properties, including the Young’s modulus, were measured. The Young’s modulus of this alloy is found to be sensitive to microstructures generated by various heat treatments. For microstructures varying from (α + β) to (α + β + ω) and (β + ω), the Young’s modulus increases with an accompanying increase in tensile strength and hardness, but decreases in ductility. The (β + ω) microstructure has a low strength, high modulus, and poor ductility and cannot be used for biomedical applications. For an (α + β) microstructure, the volume fraction of the phases is shown to be the main factor that determines the mechanical properties.     

水系统的积垢及其物理控制技术

主要综述了水系统中水垢的种类、形成机理及其物理防治方法。详细阐述了静电、电子以及磁化等物理控垢法的工作原理及技术要点,并指出了其发展方向。     

A distributed adverse drug reaction detection system using intelligent agents with a fuzzy recognition‐primed decision model

Discovering unknown adverse drug reactions (ADRs) in postmarketing surveillance as early as possible is highly desirable. Nevertheless, current postmarketing surveillance methods largely rely on spontaneous reports that suffer from serious underreporting, latency, and inconsistent reporting. Thus these methods are not ideal for rapidly identifying rare ADRs. The multiagent systems paradigm is an emerging and effective approach to tackling distributed problems, especially when data sources and knowledge are geographically located in different places and coordination and collaboration are necessary for decision making. In this article, we propose an active, multiagent framework for early detection of ADRs by utilizing electronic patient data distributed across many different sources and locations. In this framework, intelligent agents assist a team of experts based on the well‐known human decision‐making model called Recognition‐Primed Decision (RPD). We generalize the RPD model to a fuzzy RPD model and utilize fuzzy logic technology to not only represent, interpret, and compute imprecise and subjective cues that are commonly encountered in the ADR problem but also to retrieve prior experiences by evaluating the extent of matching between the current situation and a past experience. We describe our preliminary multiagent system design and illustrate its potential benefits for assisting expert teams in early detection of previously unknown ADRs. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 827–845, 2007.     

网上考试系统中指纹验证模块的研究与算法实现

网上考试中运用指纹认证方法,可以有效地杜绝代考现象的发生.文中探讨了网上指纹验证过程中的算法实现,综合运用图像处理和模式识别技术,研究了指纹识别的理论和技术,建立了一对一的指纹识别系统.整个系统框架采用浏览器/服务器(B/S)结构,用户在客户端提交指纹图像,而服务器端则完成指纹图像的预处理、匹配算法等,再将识别信息反馈给客户端.     

蓝牙智能车载卡的软件实现

介绍一个具有蓝牙通信功能的小型嵌入式系统--蓝牙智能车载卡的软件实现方案.描述了蓝牙智能车载卡在车辆信息化管理系统中的应用,介绍了蓝牙智能车载卡的系统设计方案,重点是软件设计和实现,分析了软件开发中遇到的一些问题及其解决方法,最后给出了实测结果,指出存在的不足之处和改进目标.     

低云中短波红外表观辐射模型研究

在对空红外系统的多光谱探测和红外仿真中，云的干扰不可忽略，所以，对云的辐射特性的研究至关重要。在不同的波段，云的辐射特性会有很大的差异，为了研究各个不同波段云的表现辐射特性．需要计算云的光谱辐射量。在典型观测模式下建立了低云的表观光谱辐射模型，研究了对云背景辐射有贡献的各个辐射分量的计算方法。基于传统的二流近似模型获取各个参数，引入云的光谱光学厚度的经验公式。进而获得了低云在中短波段的光谱辐射特性，有效地计算出了云背景在1-5μm的中短波段内的表现光谱辐亮度数据，并且节省了计算时间。经过比较发现，该模型的计算结果与实测结果有较好的一致性。可以为云背景多光谱分析、探测及仿真提供背景数据。