首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5674篇
  免费   741篇
  国内免费   718篇
  2024年   12篇
  2023年   120篇
  2022年   116篇
  2021年   198篇
  2020年   331篇
  2019年   311篇
  2018年   266篇
  2017年   362篇
  2016年   362篇
  2015年   221篇
  2014年   283篇
  2013年   912篇
  2012年   198篇
  2011年   227篇
  2010年   203篇
  2009年   270篇
  2008年   324篇
  2007年   282篇
  2006年   291篇
  2005年   258篇
  2004年   227篇
  2003年   197篇
  2002年   182篇
  2001年   135篇
  2000年   122篇
  1999年   106篇
  1998年   74篇
  1997年   75篇
  1996年   52篇
  1995年   56篇
  1994年   53篇
  1993年   32篇
  1992年   22篇
  1991年   33篇
  1990年   26篇
  1989年   21篇
  1988年   22篇
  1987年   17篇
  1986年   13篇
  1985年   16篇
  1984年   20篇
  1983年   8篇
  1982年   7篇
  1981年   8篇
  1980年   13篇
  1979年   8篇
  1978年   12篇
  1977年   12篇
  1976年   7篇
  1975年   8篇
排序方式: 共有7133条查询结果,搜索用时 15 毫秒
991.
Algorithmic procedures have been devised for constructing a knowledge space by querying experts. The queries submitted to the expert consist of assertions that are to be accepted or rejected. The present paper provides a characterization of the algorithms that may be used to draw inferences from previously collected answers. It is based on the notion of a closure on the set of all assertions, and its extension to a set containing for each assertion a positive and a negative instance, representing acceptance and rejection, respectively. The developed characterization emphasizes the significance of the well-known QUERY and PS-QUERY procedures. Potential applications of the presented results in contexts other than knowledge space theory are pointed out.  相似文献   
992.
Computer Implication and the Curry Paradox   总被引:2,自引:2,他引:0  
There are theoretical limitations to what can be implemented by a computer program. In this paper we are concerned with a limitation on the strength of computer implemented deduction. We use a version of the Curry paradox to arrive at this limitation.  相似文献   
993.
Abstract: The Bush administration's military war on terrorism is a blunt, ineffective, and unjust response to the threat posed to innocent civilians by terrorism. Decentralized terrorist networks can only be effectively fought by international cooperation among police and intelligence agencies representing diverse nation‐states, including ones with predominantly Islamic populations. The Bush administration's allegations of a global Islamist terrorist threat to the national interests of the United States misread the decentralized and complex nature of Islamist politics. Undoubtedly there exists a “combat fundamentalist” element within Islamism. But the threat posed to U.S. citizens by Islamist terrorism neither necessitates nor justifies as a response massive military invasions of other nations. Not only does the Bush administration's war on alleged “terrorist states” violate the doctrine of just war, but in addition these wars arise from a new, unilateral, imperial foreign‐policy doctrine of “preventive wars.” Such a doctrine will isolate the United States from international institutions and long‐standing allies. The weakening of these institutions and alliances will only weaken the ability of the international community to deter terrorism.  相似文献   
994.
Higher-order latent trait models for cognitive diagnosis   总被引:9,自引:0,他引:9  
Higher-order latent traits are proposed for specifying the joint distribution of binary attributes in models for cognitive diagnosis. This approach results in a parsimonious model for the joint distribution of a high-dimensional attribute vector that is natural in many situations when specific cognitive information is sought but a less informative item response model would be a reasonable alternative. This approach stems from viewing the attributes as the specific knowledge required for examination performance, and modeling these attributes as arising from a broadly-defined latent trait resembling theϑ of item response models. In this way a relatively simple model for the joint distribution of the attributes results, which is based on a plausible model for the relationship between general aptitude and specific knowledge. Markov chain Monte Carlo algorithms for parameter estimation are given for selected response distributions, and simulation results are presented to examine the performance of the algorithm as well as the sensitivity of classification to model misspecification. An analysis of fraction subtraction data is provided as an example. This research was funded by National Institute of Health grant R01 CA81068. We would like to thank William Stout and Sarah Hartz for many useful discussions, three anonymous reviewers for helpful comments and suggestions, and Kikumi Tatsuoka and Curtis Tatsuoka for generously sharing data.  相似文献   
995.
The Implications of Prospect Theory for Human Nature and Values   总被引:1,自引:0,他引:1  
Central to prospect theory are far-reaching claims about what people fear and what gratifies them. Subjective well-being is a topic that social science has been reluctant to discuss in recent years, but it is central to much of our lives. A loss inflicts more harm than a comparable gain produces pleasure; this fact and the related endowment effect are important parts of our psychological makeup. The importance of change rather than absolute value position, and the related significance of the reference point and how it can be altered, can be seen as integral to human nature.  相似文献   
996.
An actor's frame of reference significantly affects that actor's risk attitude. Although the frame of reference is often taken as a given, earlier work shows it to be the result of an actor's assumptions and beliefs, which can be manipulated by a second actor in a bargaining situation. As modeled here, confidence in selected assumptions can be manipulated by one of two means: changing the confidence of the actor about the future domain, and getting the actor to adopt a particular domain by discounting the utility of a course of action. Both methods force a change in the perceived domain and a shift in risk attitude. In addition to showing manipulation of an actor's frame, the model adds to our understanding of Kahneman and Tversky's original expression of prospect theory.  相似文献   
997.
Expected utility theory explains collective action as an attempt by individuals to maximize their gains. In contrast, my application of prospect theory to collective action suggests that people are motivated to participate in collective action by a fear of loss. These alternative rationalities are considered in the context of the successful cooperative effort of four economic groups in Chile during 1973–75, the first years of the Pinochet military regime. In this case, the logic of prospect theory better captures how actors made decisions about whether or not to engage in collective action. Of the four groups that did join the 1973–75 economic coalition, only one (the mineowners) appears to have maximized its net asset level, as expected utility theory predicts. All four groups seem to have been motivated to cooperate because they found themselves in the domain of losses and expected that cooperation with other, even rival, economic groups might help them recoup their recent losses.  相似文献   
998.
The theory has been misconstrued in four primary ways, which are often expressed as the claims of psychological reductionism, conceptual redundancy, biological reductionism, and hierarchy justification. This paper addresses these claims and suggests how social dominance theory builds on and moves beyond social identity theory and system justification theory.  相似文献   
999.
This study examined the influence of affect, curiosity, and socialization-related learning on job performance, with 233 service industry employees from a diverse variety of occupations completing surveys at their places of work. Both state and trait curiosity and socialization-related learning (learning associated with employee socialization) were hypothesized to mediate the relationship between affect (operationalized as state and trait anxiety and anger) and job performance. Structural equation analyses indicate that the data are consistent with the theoretical models proposed. As expected, anxiety negatively influences curiosity, socialization-related learning, and job performance; conversely, anger positively influences curiosity, socialization-related learning, and job performance. Overall, the findings suggest that affects indeed predict perception of job performance, but through the mediation of curiosity and the learning associated with the socialization process. These results highlight the importance of the complex interplay between affect, curiosity, and learning when thinking about successful employee socialization and best possible job performance.  相似文献   
1000.
Is there a duty to respond to objections in order to present a good argument? Ralph Johnson argues that there is such a duty, which he refers to as the “dialectical tier“ of an argument. I deny the (alleged) duty primarily on grounds that it would exert too great a demand on arguers, harming argumentation practices. The valuable aim of responding to objections, which Johnson 's dialectical tier is meant to satisfy, can be achieved in better ways, as argumentation is a social-epistemic activity.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号