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1.
研究了用电加热法解决用于动态气流温度测量的小惯性热电偶时间常数的实验测定问题。提出采取在稳定气流场中用电加热热电偶然后迅速切断电源的方法 ,获取较为理想的负温度阶跃 ,进而由热电偶的阶跃响应曲线求得时间常数。设计了相应的设备 ,并进行了实验测定 ,获得了较好的结果。  相似文献   
2.
植物液泡膜H+-ATPase及其在胁迫中的响应   总被引:4,自引:0,他引:4  
V-ATPase存在于所有已知的真核生物中,在植物的生长、发育、信号转导和胁迫适应过程中发挥着重要的作用.近年来对V-ATPase的结构、功能和调节机制的研究进展较快,V-ATPase主要亚基已经完成序列测定及分析,并对各亚基生理功能、V-ATPase全酶复合体的组装、调控也有了较为深入的研究.该文在阐述植物细胞液泡膜H -ATPase的基本结构的基础上,介绍V-ATPase亚基组成、编码基因及在胁迫应答中的响应.  相似文献   
3.
读者接受理论为文学翻译提供了一个更为开放的视角,值得重视和借鉴。然而,如果全盘接受读者接受理论的观点,把文学翻译仅仅看作一种译者主体行为,势必会导致不准确的翻译。读者对于文化空缺词的接受能力是一个历史的动态变化过程。  相似文献   
4.
Low dose risk estimation via simultaneous statistical inferences   总被引:2,自引:0,他引:2  
Summary.  The paper develops and studies simultaneous confidence bounds that are useful for making low dose inferences in quantitative risk analysis. Application is intended for risk assessment studies where human, animal or ecological data are used to set safe low dose levels of a toxic agent, but where study information is limited to high dose levels of the agent. Methods are derived for estimating simultaneous, one-sided, upper confidence limits on risk for end points measured on a continuous scale. From the simultaneous confidence bounds, lower confidence limits on the dose that is associated with a particular risk (often referred to as a bench-mark dose ) are calculated. An important feature of the simultaneous construction is that any inferences that are based on inverting the simultaneous confidence bounds apply automatically to inverse bounds on the bench-mark dose.  相似文献   
5.
Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances.  相似文献   
6.
Summary.  Official employment-related performance indicators in UK higher education are based on the population of students responding to the 'First destination supplement' (FDS). This generates potentially biased performance indicators as this population of students is not necessarily representative of the full population of leavers from each institution. University leavers who do not obtain qualifications and those who do not respond to the FDS are not included within the official analysis. We compare an employment-related performance indicator based on those students who responded to the FDS with alternative approaches which address the potential non-random nature of this subgroup of university leavers.  相似文献   
7.
章建立了雷诺润滑系统中的流体瞬态压力方程和镜板的运动方程,分析了该系统的瞬态响应和相对阻尼系数以及特征值,结果表明,雷诺润滑系统不会处于负阻尼运动状态,且系统是稳定的。  相似文献   
8.
文学翻译的创造性叛逆与读者接受   总被引:4,自引:0,他引:4  
文学翻译是译者在理解、解释原文基础上的创造性叛逆与读者对译文创造性叛逆的理解和反应的过程。文学翻译活动中的创造性叛逆的程度与可接受性必须以如下标准为依据:符合知识的客观性,符合理解的合理性、解释的普遍有效性,符合原文文本的定向性。  相似文献   
9.
关于外语专业题库建设范式的探讨   总被引:2,自引:0,他引:2  
本文通过对当前国内外语教育形式的综览 ,指出了外语专业的题库建设已成为当务之急 ,并通过对各种考试形式的分析 ,提出了外语题库建设的具体理论模式———以项目反应理论为基础的计算机自适应测试。文章就有关方面的实施提出了自己的看法。  相似文献   
10.
Terrorist actions are aimed at maximizing harm (health, psychological, economical, and political) through the combined physical impacts of the act and fear. Immediate and effective response to a terrorist act is critical to limit human and environmental harm, effectively restore facility function, and maintain public confidence. Though there have been terrorist attacks in public facilities that we have learned from, overall our experiences in restoration of public facilities following a terrorist attack are limited. Restoration of public facilities following a release of a hazardous material is inherently far more complex than in industrial settings and has many unique technical, economic, social, and political challenges. For example, there may be a great need to quickly restore the facility to full operation and allow public access even though it was not designed for easy or rapid restoration, and critical information is needed for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm for restoration of public facilities that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Similarities between natural resource management and restoration of a public facility after a terrorist attack suggest that integration of adaptive management principles explicitly into restoration processes will result in substantially enhanced and flexible responses necessary to meet the uncertainties of potential terrorist attacks.  相似文献   
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