道路交通事故受害者生活质量的损失计量方法

生活质量的损失是道路交通事故经济损失的重要部分，文章分析了国际上道路交通事故受害者生活质量损失的研究，提出了适合我国国情的生活质量损失综合评价指标体系，构造了生活质量经济损失的计量模型，并对北京市１９９３年道路交通事故受害者的生活质量的损失进行了实际测算。     

基于BP神经网络的交通事故预测

本文利用神经网络具有描述非线性特性的能力，将影响交通事故的多种因素综合起来建立了BP神经网络的道路交通事故预测模型。选取人口数量、公路里程数和客运量作为神经网络的输入神经元，道路交通死亡人数和交通事故经济损失作为网络的输出神经元，对道路交通事故进行预测。     

混凝土路面裂缝控制技术

在市政道路工程施工中,水泥混凝土道路路面经常出现裂缝类质量问题,有些裂缝甚至还很严重,影响使用功能,造成不必要的经济损失和工期损失。本文阐述了水泥混凝土道路路面三种常见裂缝的现象、成因与防治措施。     

道路照明设计中的若干问题分析

道路交通事故统计表明,夜间发生的交通事故约占全天事故的３０％左右。因此,研究道路照明中存在的问题,提高道路照明的质量,对于预防道路交通事故是很必要的。文章从驾驶员对道路照明的视觉要求出发,在分析道路照明质量指标的基础上,提出了一般道路照明的质量要求,即有足够的平均亮度,较好的亮度均匀度,而且不产生刺眼的眩光。同时,要考虑道路照明对景观美化的积极作用。针对道路照明设计中容易忽视的心理问题,提出几点注意事项,希望能为完善和改进道路照明提供参考。     

高速公路交通事故原因的探讨

交通事故是一种世界性的公害,道路交通事故给家庭、集体和国家都会带来巨大的损失,成为世界性的严重社会问题。预计至2020年,交通事故将成为继心血管病和精神压力症之后造成人类非正常死亡的第三大直接原因。本文针对高速公路交通事故的原因进行分析,并对此提出预防措施。     

浅谈当前高速公路安全评价及原则

高速公路交通安全关系到道路的正常运作,一旦发生重大交通事故,就会给人民群众造成极大的生命财产损失和恶劣的社会影响.因此.从交通系统安全管理角度出发,对高速公路交通安全状况进行科学评价,提出尽量减少高速公路交通事故及损失的对策,这对在复杂的交通环境下妥善预防和处理交通事故具有直接操作价值,并且对构建高速公路现代化的管理机制和提高管理水平具有现实意义.而建立高速公路交通安全评价体系是系统安全评价的基础.     

浅议道路施工的几种常见质量问题

伴随着我国经济的迅速腾飞,道路的建设也迈上了快车道,并且其建设对国家的发展意义也是决定性的。道路反映一个国家的面貌,同时也是国家的动脉,是城市的骨架。但在道路施工的过程中,各种质量问题却让我们头疼不已。这些问题不仅降低了道路施工的效率和质量,而且还会给居民生活,国家的发展带来诸多不便,造成巨大的经济损失。本文提出了一些常在道路施工中出现的质量问题,并给出了自己的建议。     

道路交通事故救援体系探讨

利用现有的检测设备和驾驶员情报系统，以交通安全地理信息系统与最优路径算法为核心，构筑了以提高效率、减少延误与事故损失为目的的道路交通事故救援体系。     

试论道路交通事故紧急救援现状与对策

介绍了国内外道路交通事故救援现状,重点对当前国内道路交通事故救援系统存在的问题进行分析,对道路交通事故救援工作提出了改进对策。     

谈谈公路几何设计

随着国民经济和公路交通建设的快速发展,人民物质生活水平的不断提高,交通安全越来越受到重视。通过完善的道路设计,来有效地控制交通安全,减少交通事故,减少经济损失。     

A validated stable isotope dilution liquid chromatography tandem mass spectrometry assay for the trace analysis of cocaine and its major metabolites in plasma.

A validated method has been developed for the simultaneous quantitation of cocaine and its major metabolites (ecgonine methyl ester, benzoylecgonine, and norcocaine) in rat plasma. The method is based upon the use of stable isotope dilution liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Previously reported methods do not have the sensitivity and specificity that can be attained with this method. Plasma samples required no cleanup apart from protein precipitation, and no derivatization was required. Selected reaction monitoring was performed on the transitions of m/z 200 to m/z 182 (ecgonine methyl ester), m/z 290 to m/z 168 (benzoylecgonine), m/z 304 to m/z 182 (cocaine), and m/z 290 to m/z 168 (norcocaine). The standard curves were linear over the range from 2 ng/mL (benzoylecgonine, cocaine, and norcocaine) or 5 ng/mL (ecgonine methyl ester) to 1000 ng/mL in rat plasma. The lower limit of quantitation (LLQ) for benzoylecgonine, cocaine, and norcocaine was 2 ng/mL, and for ecgonine methyl ester, the LLQ was 5 ng/mL for plasma. This simple, rapid, reliable, and sensitive method of quantitation had excellent accuracy and precision for the four analytes. The method was sensitive enough to permit a detailed study of the pharmacokinetics of cocaine and its metabolites after administration of a bolus intravenous dose to rats.     

Network visualisation: a review

As communication networks increase in performance and complexity, and more dependence is placed upon them, it becomes ever more important that their behaviour is understood in an efficient and timely manner. Visualisation is an established technique for the presentation of the vast volume of data yielded in monitoring such networks. It is apparent, however, that much of the work in this area has been performed in isolation, and it is timely that a review of this research is conducted. The techniques for the visualisation of communication networks and related measurements are surveyed. The research is classified by the type of visualisation used and is separated into three classes: geographic visualisations, in which the data are presented with respect to the physical location of nodes in the network; abstract topological visualisations, in which the relationships between nodes are presented independently of physical location; and plot-based visualisation, in which the focus is a single point in the network, often presented with respect to time. The research in this area is reviewed and the techniques proposed are discussed in terms of these three classes     

'Arching' effect in elastic polycrystals: implications for the variability of fatigue lives

ABSTRACT The paper deals with a study of heterogeneous stress and strain distribution in polycrystals in relation with elastic anisotropy of grains. A similitude with the arching effect widely studied in granular materials is proposed and this concept is extended to heterogeneous polycrystals in which the load transfer is not binary in the way it is in granular media but may vary significantly and suddenly from one grain to another according to the crystal orientation to the load direction. Experiments and 3D finite element analyses show that though the individual orientation of grains is random, the strain and stress distribution is not. A network is formed inside the polycrystal whose scale is larger than the grain size. The load percolation network consists in heavily loaded links whose direction is coincident with the direction of the principal stresses. So, the typical scale for the variability of the local stresses is not the grain size but the size of the load percolation network. Since this scale is found to be rather large in particular for iron, zinc and copper, this effect should contribute significantly to the variability of the fatigue lives of notched vs. smooth components.     

基于并联机构及MR阻尼器的多维减振平台半主动控制研究

分析了磁流变阻尼器的力学特性,将其应用于多维减振系统中。采用经典的三平移并联机构作为多维减振平台的主体机构,推导出其位置逆解公式;建立了系统动力学状态方程模型,以运动学方程得到的支路加速度作为输入信号,控制器采用了基于线性二次型最优控制理论的半主动控制算法。考虑到动态过程中机构动力学方程的复杂性,采用稳态方法对并联机构处于某一运动姿态的支路移动副振动进行控制,从而控制了整个平台的振动。仿真结果表明,所采取的控制算法有较好的控制效果。     

Measurements of the thermal magnetoresistance of aluminum

The transverse thermal magnetoresistance of single-crystal plates of pure aluminum has been measured at liquid helium temperatures. It is shown that the high field Lorentz ratio is practically independent of field in agreement with theoretical predictions, and the value of the Lorentz ratio in high fields is discussed in terms of thermal and electrical relaxation times. It is also shown that the previously observed linear increase of the electrical resistivity in high fields is reflected in the thermal resistivity, and the origin of this effect is discussed. It is believed that the linear behavior is not caused by a magnetic breakdown effect in this case, but is due to other intrinsic or nonintrinsic effects.     

基于双寡头竞争的航空客运模糊销售定价决策

针对近年来航空公司机票销售领域流行的模糊分销模式,利用Hotelling模型建立了季末单一模糊销售以及直销与模糊销售共存的双寡头竞争模型,求解供大于求和供小于求下两种销售模式各利益主体的均衡价格及收益,旨在发现哪种销售模式更有利于提高航空公司的收益。研究表明,当市场竞争激烈时,模糊分销模式存在,且季末共同销售策略下航空公司的期望总收益高于单一模糊销售,同时模糊中介商有动力实施该模式,凸显了双渠道同期销售对市场需求的引导作用。该研究结果可为航空公司竞争环境下的均衡定价决策和销售模式选择提供理论参考。     

A fuzzy logic-controlled thermal process for simultaneous pasteurization and cooking of soft-boiled eggs

A fuzzy logic-based design of control for a unique thermal process in the food industry is presented. Products of the thermal process are pasteurized soft-boiled eggs. The function of temperature vs. time is unique in its shape and in its required precision, since the constraints of pasteurization and cooking of soft-boiled eggs are technically contradictory. Both processes can coexist only in a quite narrow temperature range, which is a nonlinear function of egg processing time. Precision in temperature control is essential. The thermal process is implemented in an apparatus that presents a novelty on the market of industrial kitchen appliances.A precondition for the present work was simulation of thermal energy propagation in hens' eggs of different sizes and ages. A function of temperature vs. time for the media in which eggs are immersed was defined. The function is piecewise linear in time, with horizontal and near vertical sections and abrupt transitions between them.The process is patented and the quality of pasteurization is certified by the corresponding institutes. The result is pasteurized soft-boiled eggs for consumption in hospitals, schools and hotels. The presented fuzzy control implementation of the thermal process meets the requirements, and thus the implication is that the design and implementation of temperature control based on fuzzy logic is suitable for processes where precision is required.     

陀螺系统特征值问题的一些探讨

陀螺系统特征值问题是在转子动力学中提出的一个典型的数学问题。它的研究一直受到力学界的重视。研究它具有较大的理论意义和工程应用价值。作为本专题的第一部分，本文探讨三维旋转法本身存在的问题。指出三维旋转法不是对任何反对称矩阵都是合适的，而应有条件地应用它。     

空调排风显热回收技术在办公建筑中的节能应用

在提出显热回收装置及其系统基本性能参数和节能性指标的基础上,以北京地区某办公建筑板式显热回收系统为例,分析该显热回收系统夏季及冬季运行情况。分析结果表明,显热回收装置冬季运行效果好于夏季:冬季显热效率高于60%,逐时热回收量平均值为40.8 kW,具有较高的系统能效比;夏季运行收支几乎相抵。投资回收期约为3年,适宜在北京地区采用。