构建媒体网络信息安全体系

通过对广州市电视台综合信息平台网络系统的应用现状及安全风险进行分析,提出基于网络层、系统层、用户层和安全策略管理全方位的网络信息安全体系.     

一种具有带孔补偿过滤器的γ剂量计的能响补偿计算

对在低能区有过高响应的γ辐射剂量计可采用带孔补偿过滤器进行能响补偿。本文介绍了对这类补偿过滤器选择最佳补偿参数(材料厚度和孔隙率)的近似求解方法;并对 CaSO:Tm 热释光剂量计用此方法作了实例计算。文中还计算了自制带有鼠笼结构的这类补偿过滤器的 CaSO:,Tm热释光剂量计对照射量的能量响应,与实测结果比较,各能量点响应的最大相差为10%。     

Indicators for inspection and maintenance planning of concrete structures

Based on an idea introduced by Benjamin and Cornell (1970. Probability, statistics and decision for civil engineers. New York: McGaw Hill) and previous works by the authors it is demonstrated how condition indicators may be formulated for the general purpose of quality control and for assessment and inspection planning in particular. The formulation facilitates quality control based on sampling of indirect information about the condition of the considered components. This allows for a Bayesian formulation of the indicators whereby the experience and expertise of the inspection personnel may be fully utilized and consistently updated as frequentistic information is collected. The approach is illustrated on an example considering a concrete structure subject to corrosion. It is shown how half-cell potential measurements may be utilized to update the probability of excessive repair after 50 years. Furthermore in the same example it is shown how the concept of condition indicators might be applied to develop a cost optimal maintenance strategy composed of preventive and corrective repair measures.     

Application of stochastic filtering for lifetime prediction

This paper introduces a stochastic filtering modeling approach for predicting the remaining lifetime of a component based on information on the stochastic degradation process and uncertain condition monitoring measurements. The model is illustrated by a case study, where the degradation is assumed to be a simplified fatigue crack growth process. The model accounts for uncertainties in both degradation process and condition measurements in a sound way. If completed with information on costs of monitoring, failure and replacement, such model could be used in optimizing both the condition monitoring intervals and, e.g. the replacement time for the component.     

State observability and condition observability for a class of interacting discrete event systems

This paper introduces the concepts of state observability and condition observability for condition systems, a class of systems composed of discrete state components which interact via discrete binary signals called conditions. Given a set of externally observed conditions, state observability implies that the state of the system can be determined from the observations, and condition observability implies that all unobserved input and output conditions of the system can be determined from the observations. In this paper, we present a class of systems which is state observable and condition observable. We present a method to synthesize an observer system to provide state and condition signal estimates for a single component subsystem.     

增力式夹具的设计与应用

增力式夹具结构紧凑，夹紧迅速可靠。它可以用较少的原动力获得较大的夹紧力，其增力倍数据实际须要同设计者调整。而且，若按机构自锁条件设计，该夹具夹紧之后，实现自锁。本文对该夹具结构做了介绍，并通过理论分析，指出增力系数和夹具自锁的设计条件。     

基于接地弹簧及配点法的系统动态特性分析

核电设备和部件的动态特性包括其固有频率和相应模态。对于动态特性受支承条件影响的核电设备,将之简化为带接地弹簧的质量一弹簧系统．并分析接地弹簧刚度的变化对该系统动态特性的影响。在此基础上,从带罚数的有限元配点法出发,推导接地弹簧的有限元等价形式,证明接地弹簧刚度与罚数的等价性,并由此等价性,阐明支承条件在施加设备边界条件过程中所起的作用。     

江汉盆地盐湖碳酸盐岩成藏条件及潜力——以新沟地区新沟嘴组下段Ⅱ油组为例

在物源、古地形、古气候的控制下,江汉盆地新沟嘴组下段Ⅱ油组自北而南发育有砂岩相、泥岩相、碳酸盐岩相、硫酸盐以及氯化盐岩相,盆地中南部斜坡带为碳酸盐岩的主要分布区,具有碳酸盐岩与薄层泥岩频繁互层沉积特征;其中碳酸盐岩晶间孔发育,具有较好的储集条件,泥岩有机质丰度高,具有较好的生烃能力,生储配置关系良好;新沟嘴组下段Ⅱ油组碳酸盐岩成藏条件优越,油气成藏主要受有利烃源岩分布范围、岩性岩相、物性控制,具有烃源岩控藏、岩性物性控富的特征;江汉盆地碳酸盐岩油藏分布广泛,具有较好的勘探开发前景。     

基于容积效率的液压齿轮泵状态监测与故障诊断

阐述了容积效率作为特征信息进行液压齿轮泵状态监测与故障诊断的原理,分析了液压齿轮泵中流量信号以及容积效率与齿轮泵工况之间的关系,指出了容积效率是状态信息的丰富载体,讨论了利用容积效率进行液压齿轮泵状态监测与故障诊断的可行性及方法.     

装甲车辆柴油机使用期内的振动信号分析

对不同使用期的柴油机进行测试，利用加速度传感器测取了柴油机机体的表面振动信号。经过信号处理，较好地解决了实车测试信噪比差的问题。分析结果表明，柴油机的机体振动信号能够反映柴油机的技术状况，为柴油机的技术状况检测及故障诊断奠定了基础。