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   794篇
  免费   17篇
  国内免费   1篇
  2024年   1篇
  2023年   2篇
  2022年   3篇
  2021年   5篇
  2020年   8篇
  2019年   7篇
  2018年   14篇
  2017年   13篇
  2016年   13篇
  2015年   4篇
  2014年   10篇
  2013年   46篇
  2012年   4篇
  2011年   4篇
  2009年   11篇
  2008年   18篇
  2007年   8篇
  2006年   13篇
  2005年   5篇
  2004年   8篇
  2003年   3篇
  2002年   6篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1994年   2篇
  1993年   3篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
  1985年   45篇
  1984年   50篇
  1983年   39篇
  1982年   41篇
  1981年   53篇
  1980年   48篇
  1979年   51篇
  1978年   55篇
  1977年   42篇
  1976年   49篇
  1975年   32篇
  1974年   44篇
  1973年   42篇
排序方式: 共有812条查询结果,搜索用时 15 毫秒
151.
Although theoretical results for several algorithms in many application domains were presented during the last decades, not all algorithms can be analyzed fully theoretically. Experimentation is necessary. The analysis of algorithms should follow the same principles and standards of other empirical sciences. This article focuses on stochastic search algorithms, such as evolutionary algorithms or particle swarm optimization. Stochastic search algorithms tackle hard real-world optimization problems, e.g., problems from chemical engineering, airfoil optimization, or bio-informatics, where classical methods from mathematical optimization fail. Nowadays statistical tools that are able to cope with problems like small sample sizes, non-normal distributions, noisy results, etc. are developed for the analysis of algorithms. Although there are adequate tools to discuss the statistical significance of experimental data, statistical significance is not scientifically meaningful per se. It is necessary to bridge the gap between the statistical significance of an experimental result and its scientific meaning. We will propose some ideas on how to accomplish this task based on Mayo’s learning model (NPT*).  相似文献   
152.
在1973年的"致列泽克·科拉克夫斯基的公开信"中,汤普森通过给科拉克夫斯基这个受到第二代英国新左派热捧、然而在他看来已经出现背叛迹象的东欧马克思主义者写公开信,向第二代英国新左派阐发了他对在英国如何才能成为一个真正的马克思主义者这个重大问题的基本理解.  相似文献   
153.
山东省某县农民参加新农合意愿及受益公平分析   总被引:1,自引:1,他引:0  
通过调查农民参加新型农村合作医疗(新农合)意愿选择及受益程度,对影响参合因素及政府补助分配的公平性进行研究,认为:影响参合因素主要有家庭收入、家庭医疗支出、补偿比例等;从受益角度看,总补助的集中指数是负值,不同人群的受益趋于公平。从不同服务看,住院的公平程度好于门诊。  相似文献   
154.
Changes in migrants' backgrounds and societies sending and receiving migrants might increase adaptation issues and reduce retention. To enhance migrants' well‐being/health and their likelihood of staying it is necessary to gain an understanding of psychological and social factors that contribute to resilience and adaptation. This paper presents findings from a qualitative study that investigated the experiences, interpretations and actions of German migrant couples to New Zealand throughout the whole migration process to identify these factors. In depth, episodic interviews were conducted with four couples who decided to stay in New Zealand and four couples who decided to return to Germany. Interview data were complemented with participant observation. This paper provides insights into how the pre‐migration experiences, interpretations and actions of German migrants to New Zealand influenced their establishment, their interpretations and actions and consequently adaptation, well‐being/health and the decision whether to stay in New Zealand or to return to Germany. The findings illuminate the influence of psychological and social factors on migration experiences, interpretations and actions throughout the migration process. The paper offers some solutions for addressing the identified barriers to successful migration and integration into host societies. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
155.
This paper presents an analysis of everyday understandings of the law, within the context of a dispute between colonial and indigenous land interests in New Zealand. The analysis is informed by developments in the areas of critical legal studies, methodological critique of legal psychology, the social constructionist movement within social psychology, and the application of discursive psychology to understandings of racism. Data for this work was drawn from a corpus of letters to the editor of a newspaper, published in the city where the land dispute took place. Writers constructed the dispute as a legal issue and deployed two divergent constructions of the law. When the ‘primacy’ of the law was invoked, indigenous interests and the protesters were positioned as lawbreakers. When ‘the law in context’ was the resource used, protesters became positioned as seekers of justice. These variable constructions are discussed in terms of the social practices they engender and their wider contribution to debates regarding indigenous and colonial interests. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
156.
New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
157.
Maureen C. McHugh 《Sex roles》2006,54(5-6):361-369
Recent attempts to medicalize women’s sexual “dysfunction” are critiqued and a “New View” of women’s sexual problems is introduced. The author argues for a female-centered perspective on women’s sexual desires and problems, based on a review of the literature on women’s sexuality and her observations of young women’s sexual experiences from 25 years of teaching Human Sexuality to undergraduate women. The review suggests that a pill or a patch cannot adequately address the sexual problems commonly experienced by US women.  相似文献   
158.
This paper presents Automath encodings (which are also valid in LF/λP) of various kinds of foundations of mathematics. Then it compares these encodings according to their size, to find out which foundation is the simplest.

The systems analyzed in this way are two kinds of set theory (ZFC and NF), two systems based on Church's higher order logic (Isabelle/Pure and HOL), three kinds of type theory (the calculus of constructions, Luo's extended calculus of constructions, and Martin-Löf's predicative type theory) and one foundation based on category theory.

The conclusions of this paper are that the simplest system is type theory (the calculus of constructions), but that type theories that know about serious mathematics are not simple at all. In that case the set theories are the simplest. If one looks at the number of concepts needed to explain such a system, then higher order logic is the simplest, with twenty-five concepts. On the other side of the scale, category theory is relatively complex, as is Martin-Löf's type theory.

(The full Automath sources of the contexts described in this paper are one the web at http://www.cs.ru.nl/~freek/zfc-etc/.)  相似文献   

159.
Using the socialization and attraction-selection-attrition (ASA) frameworks, this study examined the relation between employees’ work values and their organization’s values (person-organization fit). With a two year time interval, 140 respondents participated in a longitudinal study. After entry, socialization served to enhance homogeneity. The work values underwent small changes and the perception of fit with the organization grew. Despite high retention rates results confirmed the attrition effect. Results indicated that the lower the perceived match between own and organizational values at entry, the more likely it was that someone left the organization over time. We concluded that socialization as well as attrition mechanisms were present at the same time.  相似文献   
160.
Using the example of the Catholic Church in Papua New Guinea (PNG), I detail how, through praxis, it has brought to life a living theology of HIV and AIDS. In this way, the Catholic Church in PNG is responding faithfully to the epidemic. As a Christian country with a generalised HIV epidemic, where the body of an individual is reconstituted through the liturgical practices of baptism and Eucharist, theologically, in PNG the body of Christ has AIDS. In order to examine the ways in which the Catholic Church in PNG has responded faithfully to the Christian body with AIDS, I do so in relation to the three theological virtues of faith, hope and love.
Angela KellyEmail:
  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