生命周期评价及其在汽车排放领域的应用

介绍了生命周期评价(LCA)的定义、评估对象、范围、评价思路、步骤及其体系框架,说明了汽车排放分析中存在的两种循环(燃料循环和车辆循环)。通过分析汽车生命周期排放模型及其在CATCH(Clean A ccessible Transport for Community Health)研究中的一个实际应用案例,进一步阐明了生命周期评价在对各种燃料进行排放分析过程中的实际应用价值,最后介绍了生命周期评价在国外汽车企业中的研究发展情况、实际产品以及应用前景。     

Road Pricing models with maintenance cost

According to the Federal Highway Administration of the United States, maintenance expenditure takes up more than 25% of road revenue disbursement and this percentage has been increasing gradually. The reason for the increment in maintenance cost is that there lacks incentives for road users to take this cost component into their driving behavior. That is, different classes of vehicles should be levied different levels of congestion tax due to the different degrees of damage on the highway if a road pricing policy is implemented. This paper intends to incorporate this concept into road pricing literature by introducing two types of vehicles. After the analysis of the problem, we find that different types of vehicles should be charged different tolls. The toll includes not only the travel delay cost of one's own vehicle and the other types of vehicles, but also the marginal maintenance cost that is dependent on the traffic flow. A set of numerical examples is provided to demonstrate the theoretical analyses. The result shows that both the welfare and cost coverage rate will increase when the road pricing mechanism takes the maintenance cost factor into account.     

The analysis of regulation on private highway investment under a build-operate-transfer scheme

The build-operate-transfer (BOT) approach has become an attractive instrument for public facility provision, especially for a project that faces difficulty with public finance. This study analyzes the regulation alternatives on private highway investment under a BOT scheme and their impacts on traffic flows, travel costs, toll, capacity, and social welfare (total user-benefit in the traffic system including congestion). For comparison, five cases are analyzed: (1) No BOT with maximizing welfare, (2) No BOT with breaking even on finance, (3) BOT without regulation, (4) BOT with a minimum flow constraint (the total users will not be less than those in Case 1), and (5) BOT with a maximum travel cost constraint (the travel cost for users on a non-tolled road will not exceed the maximum tolerance). After each case is modeled and simulated on some functional forms, we find that the case of BOT with regulations performs between the cases of maximizing welfare and that of maximizing profit. From the perspective of the government, regulation has less power in a project with low elastic demand. Furthermore, even when the regulation is strict, a high cost-efficient firm with BOT could result in a higher level of social welfare than that without a BOT scheme.     

应用PCR方法检测人乳头瘤病毒的E_7转化基因

应用聚合酶链反应技术（ＰＣＲ）检测５４份子宫颈癌活检标本中人乳头瘤病毒１６型（ＨＰＶ－１６）Ｅ７转化基因的存在情况，结果显示阳性率为７２．２％（３９／５４）。ＨＰＶ－１６Ｅ７转化基因在人子宫颈癌组织中的高检出率，证实该转化基因与其发生关系密切。本研究同时证明，ＰＣＲ方法具有敏感、特异、快速和实用特点，值得推广。     

月桂氮酮对消炎痛体外透皮吸收的促进作用

本文研究了含乙醇、三乙醇胺、pH7.2磷酸缓冲液的水溶液系统中,0.5%月桂氮酮可使消炎痛溶液的体外透皮吸收增加3倍,且0.5%～10%的浓度促进消炎痛吸收的作用几无区别(P>0.05)。     

一种新型船舶压载水管理系统的设计

本文设计一套压载水管理系统,该系统能方便地进行液位遥测和阀门遥控,友好地实现对船舶压载水的监测和管理。论文介绍了计算机工作站的结构和基于Usual Basic的软件功能．     

船用锅炉主过热蒸汽管路破损的贝叶斯网络安全性定量分析

针对贝叶斯网络方法在处理大规模复杂系统上的优点,结合当前船用锅炉的安全性定量分析特点,提出将贝叶斯网络方法应用于船用锅炉的安全性分析。通过探讨贝叶斯网络及故障树分析方法原理,尝试将贝叶斯网络与故障树分析方法结合起来,主要突出贝叶斯网络方法可以实现数据的自动更新及由后验信息到先验信息的反向推理能力。最后将该方法应用于船用锅炉的安全性定量分析中,通过更新观测部件故障状态实现了整个系统的自动更新,并自动查找出最大概率事件,证实该方法提高了安全性分析效率,使实际操作更加准确、快捷,极大地的降低了事故带来的风险。     

高温季节桥上CRTSⅡ型板式无砟轨道温度分布试验研究

为研究高温季节高速铁路桥上CRTSⅡ型板式无砟轨道的温度分布规律,制作CRTSⅡ型板式无砟轨道-预应力混凝土简支箱梁1:4缩尺试验模型.通过开展夏季典型高温天气的温度试验,分析高速铁路桥上CRTSⅡ型板式无砟轨道结构的温度分布变化规律,研究无砟轨道横、竖向温度分布型式.结果表明:在非阳光直射条件下,高速铁路桥上C RT...     

氰基桥联配合物的溶剂热合成研究进展

介绍了以MCN（M=Na,K）和K3[M’（CN）6]（M’=Fe,Co）为氰基来源的氰基桥联配合物溶剂热合成的研究进展。讨论了影响溶剂热合成氰基桥联合物的主要因素,如：反应条件、有机配体、氰基来源、平衡离子、溶剂种类及摩尔比等．最后指出了目前存在的问题,并对今后的研究趋势进行了展望．     

公路工程中软基的鉴别和处治

针对公路工程中难以确定软基变更的问题,阐述了试验数据分析的方法及规律。从工程施工实际案例中总结了鉴别软基的有关要点,通过比较各种软基处治的运用特点,探讨了软基鉴别方法与施工技术。