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31.
基于番茄红素有防癌抑癌的生理功能,使之成为具有广阔应用前景的天然色素。该文针对番茄红素生产过程中产品产率低、纯度差的现状,对番茄红素的稳定性、生产方法、纯化方法、异构体的分离以及检测进行阐述。为番茄红素工业生产提供理论和实践依据。  相似文献   
32.
The family of decision analysis techniques can be applied effectively to support practical negotiators in international settings. These techniques are most appropriate in support of the prenegotiation phase, when parties are diagnosing the situation, assessing their own plans and strategies, and evaluating likely reactions and outcomes. The paper identifies how these approaches have and can be used to assist negotiation practitioners, offers a rationale for the application of decision analytic approaches in terms of the particular analytical requirements of the prenegotiation period, suggests how these process-oriented tools can be integrated with substantive tools, and discusses ways in which these tools can be presented and delivered to practitioners in a practical and confidence-building manner.  相似文献   
33.
介绍了在工程界已广泛应用的信号分析诊断及尚停留在实验室探索的裂纹分析诊断,模糊分析诊断的工作原理和应用实例。  相似文献   
34.
从移民的基本政策、移民安置规划、公众参与、移民的组织机构及责任四个方面 ,对中国移民政策与亚洲银行移民政策进行了对比分析 ,找出之区别 ,以便更好地与国际接轨  相似文献   
35.
Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.  相似文献   
36.
To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure.  相似文献   
37.
语篇分析与机器翻译   总被引:2,自引:0,他引:2  
机译系统应该建立在具有语篇分析的大型语料库基础之上,语篇语料库内的原语和目的语文本不是单向、而应是双向或多向流动的网络系统。文本的译文也应该有历时和共时的区别,因为互文性已是翻译的某种本质特征。  相似文献   
38.
随着对管理会计理论及实践方法的不断探讨和研究,管理会计对提高企业内部管理水平的作用日益突出。本文主要分析、论述了管理会计面临的挑战及存在的主要问题,并对管理会计今后的发展和应用前景进行了探索和思考。  相似文献   
39.
This article explores two problems analysts face in determining how to estimate values for children's health and safety risk reductions. The first addresses the question: Do willingness‐to‐pay estimates for health risk changes differ across children and adults and, if so, how? To answer this question, the article first examines the potential effects of age and risk preferences on willingness to pay. A summary of the literature reporting empirical evidence of differences between willingness to pay for adult health and safety risk reductions and willingness to pay for health and safety risk reductions in children is also provided. The second dimension of the problem is a more fundamental issue: Whose perspective is relevant when valuing children's health effects—society's, children's, adults‐as‐children, or parents'? Each perspective is considered, followed ultimately by the conclusion that adopting a parental perspective through an intrahousehold allocation model seems closest to meeting the needs of the estimation problem at hand. A policy example in which the choice of perspective affects the outcome of a regulatory benefit‐cost analysis rounds out the article and emphasizes the importance of perspective.  相似文献   
40.
文章选取广东省 2 1个行政区 1996至 2 0 0 2年的数据 ,采用主因子分析和多元统计回归分析对影响外资在广东聚集的因素进行分析 ,因子分析从 11个解释变量中提取出五个主因子 ,它们分别是经济发展规模和水平、产业聚集、劳动力聚集、经济开放度和政策因子。回归分析表明了每个解释变量对利用外资额的弹性。文章最后提出了产业聚集的引资策略。  相似文献   
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