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排序方式: 共有18条查询结果,搜索用时 510 毫秒
1.
作者观察了平溃散对多种实验性胃溃疡模型的作用。结果表明:平溃散可非常显著的对抗束缚应激法和消炎痛加乙醇所致的小鼠胃溃疡;对幽门结扎法及HCl损伤法所致大鼠胃溃疡模型也有明显对抗作用。各组分研究表明:平溃散基础方组、全方组、绞股蓝组和沙棘组均有显著的抗溃疡作用,但以全方组抗溃疡作用最佳。  相似文献   
2.
Li  Jianling  Wachs  Martin 《Transportation》2004,31(1):43-67
In the United States, federal funding for public transit often accounts for a large proportion of a local agency's budget, especially for capital investments. For this reason, local governments can be expected to plan a portfolio of projects that maximize federal contributions. This study examines the financial effects of federal transit subsidy policy on local transit investment decisions. Data from a System Planning Study for the Geary Corridor in San Francisco are used as an illustration. It is found that federal transit subsidy policy provides financial incentives for local decision-makers to select capital-intensive investment options that may not be efficient or effective. While federal financial incentives are not the only factor influencing local investment decisions, some reform of the current subsidy policy may be necessary to reduce the incentive for ineffective use of public resources.  相似文献   
3.
文章结合三岸邕江特大桥工程实例,对比分析了悬臂拼装钢桁拱的施工监控特点,阐述了悬臂拼装钢桁拱施工监控的主要内容及组织实施流程。  相似文献   
4.
介绍了机车乘务员出乘时“三交三问”培训、考试系统,系统有机地将“三交三问”培训考试、用户管理、题库管理、成绩查询、考试分析、数据备份与还原等模块集成在一起,充分利用了模块化的设计思想和开发方法,探索出机车乘务员班前针对性教育的新路子。  相似文献   
5.
从集计角度分析了运行多种交通方式的城市交通系统。利用目前已受关注的宏观基本图(简称MFD),描述城市交通的整体特性。以旧金山某区为例,使用现有数据,通过仿真论证如何应用MFD监管真实交通网络。然后讨论了同一路网中不同交通方式间如何相互作用,以及如何将这些作用纳入包含多种交通方式路网的MFD。研究得到的两个主要结论是:1)证实了已有研究猜想——对市区拥挤区域限行,可提高包括被限行者在肉的所有出行者的机动性;2)公交方式提供专用道路空间可提高所有交通方式的可达性。  相似文献   
6.
This article presents the results of a three-year effort at applying information technology to the problem of collaborative natural resource management in San Diego Bay. As such, it represents an approach to integrated coastal zone management (ICZM). This effort resulted from a collaboration between the San Diego Supercomputer Center at the University of California, San Diego and the San Diego Bay Interagency Water Quality Panel for the purpose of (1) developing an environmental data repository to facilitate the acquisition and sharing of data and (2) the development of a visual model of the bay in support of the development of a comprehensive, coordinated management plan for San Diego Bay. It was determined from this study that information technology is an important and key component to ICZM but that sociopolitical factors may override the benefits of decision-support systems and should be considered at the outset of any project of this kind.  相似文献   
7.
Establishment of marine reserves or marine protected areas (MPAs) has emerged as a major coastal resource management tool in the Philippines. A major sustainability constraint is the enforcement of MPA and fisheries regulations. We contribute to the literature of using stated preference methods to investigate the local residents’ willingness to work (WTW) and willingness to pay (WTP) for the continued existence of the San Miguel Island (SMI) fishery reserve in Bicol Region, Philippines. We surveyed 435 respondents in three villages. The lower-bound mean WTW is 3.5 days/mo for residents in the “owner” village and 1.9 days/mo for residents in adjacent villages. Using a fraction of mean daily income to impute the monetary equivalent of WTW, the result is more than 3 times higher than the Php16 to 25/mo (US$0.34 to 0.75/mo) estimated mean WTP. We hypothesize that labor market in this rural village is incomplete so residents have stronger preference for money than for time. However, further investigation on the opportunity cost of time and understanding the labor market is warranted when using WTW in a valuation framework. Some policy implications are: (1) considering use of voluntary labor as management option for MPAs and (2) establishing “own village” MPAs may increase residents’ conservation value.  相似文献   
8.
Mehndiratta  Shomik  Kemp  Michael  Pierce  Sean  Lappin  Jane 《Transportation》2000,27(4):391-417
This paper reports the results of a 1998 survey carried out among a small sample of people who had called the TravInfo Travel Advisory Telephone System (TATS) in April 1997 looking for current information about traffic conditions in the San Francisco Bay Area. The survey employed a series of tradeoff questions designed to identify the specific attributes of the information that the respondents felt to be most important, and to estimate the relative values that these users had for various possible information improvements. Despite the small size of the sample, it proved feasible to investigate how the implicit valuations placed on each attribute of the service (update frequency, extent of road coverage, and level of customization) varied among different user segments. For the most part, respondents appeared to value basic enhancements – those that establish an initial quality differential above the baseline set by free broadcast traffic information – more than they value further subsequent improvements. Overall, more frequent information updates are the highest priority among the range of possible enhancements explored in the survey, followed by an extension of coverage to include major arterials in addition to freeways. However, the evidence suggests relatively little value in door-to-door coverage – that is, coverage of streets beyond the freeway and major arterial networks. This research produced some estimates of the average monetary values ("willingness to pay") that the sample of current users attached to information improvements of various kinds. While these values varied among subgroups in ways that fit a priori expectations, it is not clear whether they provide an unbiased picture of the users' absolute levels of willingness to pay, such that they could be used reliably to inform (for example) information pricing decisions. The value of this research lies more clearly in the light it sheds on the relative structure of user preferences, and on the variations in preferences between information attributes and market segments. Overall, the authors conclude that the prospects for self-sustaining ATIS services are unclear. In response to a direct question, a majority of users (perhaps influenced by a strategic bias) indicated that they were unwilling to pay for ATIS services; some of these same people, however, indicated later that they might indeed be willing to buy a particular enhanced ATIS package, in direct competition with free broadcast services.  相似文献   
9.
为了解加利福尼亚州HOV系统的运行效果,基于交通量检测器收集的数据,对HOV系统进行全面分析、评价。最终得到4个主要结论:1)与多条普通车道构成的高速公路相比,包含1条HOV车道的高速公路损失了20%的通行能力;2)HOV车道通常处于两种运行状态,一种是HOV车道未被充分利用,另一种是HOV车道处于超负荷、降级运行状态;3)HOV车道未显著提高小汽车合乘比例;4)在一个相当出色的交通管理系统中,HOV车道并未从整体上缓解道路交通拥堵状况。  相似文献   
10.
作者叙述了自己研制的中药新药—平溃散(陕卫药准字[1992—L00601])治疗胃脘痛(消化性溃疡病),结果表明:平溃散配方合理,服用方便,可选择性拮抗组胺和乙酰胆碱受体,使胃酸分泌明显降低;并可使胃粘液分泌增加,在溃疡表面形成保护膜,促其愈合。与雷尼替丁相对照,疗效显著增加。3周痊愈率92%,有效率99%。  相似文献   
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