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   2445篇
  免费   511篇
  国内免费   267篇
  2024年   9篇
  2023年   45篇
  2022年   44篇
  2021年   78篇
  2020年   136篇
  2019年   129篇
  2018年   141篇
  2017年   136篇
  2016年   135篇
  2015年   97篇
  2014年   117篇
  2013年   351篇
  2012年   76篇
  2011年   106篇
  2010年   61篇
  2009年   108篇
  2008年   86篇
  2007年   101篇
  2006年   92篇
  2005年   107篇
  2004年   106篇
  2003年   92篇
  2002年   76篇
  2001年   71篇
  2000年   67篇
  1999年   48篇
  1998年   45篇
  1997年   39篇
  1996年   35篇
  1995年   45篇
  1994年   35篇
  1993年   20篇
  1992年   18篇
  1991年   26篇
  1990年   15篇
  1989年   15篇
  1988年   21篇
  1987年   23篇
  1986年   20篇
  1985年   15篇
  1984年   28篇
  1983年   27篇
  1982年   21篇
  1981年   26篇
  1980年   16篇
  1979年   31篇
  1978年   27篇
  1977年   20篇
  1976年   22篇
  1975年   13篇
排序方式: 共有3223条查询结果,搜索用时 15 毫秒
161.
The fixed point combinator (Y) is an important non-proper combinator, which is defhable from a combinatorially complete base. This combinator guarantees that recursive equations have a solution. Structurally free logics (LC) turn combinators into formulas and replace structural rules by combinatory ones. This paper introduces the fixed point and the dual fixed point combinator into structurally free logics. The admissibility of (multiple) cut in the resulting calculus is not provable by a simple adaptation of the similar proof for LC with proper combinators. The novelty of our proof—beyond proving the cut for a newly extended calculus–is that we add a fourth induction to the by-and-large Gentzen-style proof. Presented by Robert Goldblatt  相似文献   
162.
Not only do the writings of Nietzsche – early and late – fail to support the pedagogy of self-reformulation, this doctrine embodies what for him is worst in man and would destroy that which is higher. The pedagogy of self-reformulation is also incoherent. In contrast, Nietzsche offers a fruitful and comprehensive theory of education that, while non-democratic and contemptuous of egalitarian aspirations, emerges consistently from his metaphysics and philosophical anthropology. Whatever, then, we might think of his premises, Nietzsche’s philosophy of education represents an attractive model for those who would develop a meaningful, distinctive, and persuasive educational theory. It defines a domain of the possible and then straightforwardly states what is and is not to be done within it – and why.  相似文献   
163.
Over the last years several European patents were opposed for protecting technology violating the morality requirement under Article 53(a) EPC. Attempts have been made by the Appeal Boards of the European Patent Office (EPO), as well as by amendments introduced into the Implementing Regulations of the European Patent Convention (EPC), to address this sensitive patentability requirement more precisely. The most recent hot topic coming up in this context is the patentability of stem cells. It is to be expected that this discussion will still go on in the field of biotechnological inventions for the next several years. An earlier version of this paper was presented at an international conference, “The Ethics of Intellectual Property Rights and Patents,” held in Warsaw, Poland on 23–24 April, 2004.  相似文献   
164.
In World Poverty and Human Rights, Thomas Pogge argues that the global rich have a duty to eradicate severe poverty in the world. The novelty of Pogges approach is to present this demand as stemming from basic commands which are negative rather than positive in nature: the global rich have an obligation to eradicate the radical poverty of the global poor not because of a norm of beneficence asking them to help those in need when they can at little cost to themselves, but because of their having violated a principle of justice not to unduly harm others by imposing on them a coercive global order that makes their access to the objects of their human right to subsistence insecure. In this paper, I claim that although Pogge is right in arguing that negative duties are crucial in an account of global justice, he is wrong in saying that they are the only ones that are crucial. Harming the global poor by causing their poverty provides a sufficient but not a necessary condition for the global rich to have a duty of justice to assist them. After engaging in a critical analysis of Pogges argument, I conclude by suggesting the need for a robust conception of cosmopolitan solidarity that includes positive duties of assistance which are not mere duties of charity, but enforceable ones of justice.  相似文献   
165.
清代中期“以礼代理”说刍议   总被引:1,自引:0,他引:1  
清代中期,以凌廷堪、焦循、阮元为代表的汉学家提出了“以礼代理”说,即主张用礼学代替理学。他们认为,儒学的中心是“礼”而不是“理”,脱离了“礼”而言“理”,只能导致师心自用以及对人的具体情感的漠视。这一学说是清初顾炎武所倡导的学术方向的继续,它把人们的目光由内在精神变革转向对外在制度的关注;同时,这一学说明确反对以抽象化的“理”来约束人们的行为,它在一定程度上减轻了理学所带来的消极影响。  相似文献   
166.
The effects of two anorectic drugs, dexfenfluramine and phentermine, on food intake under different food-access conditions were examined. Experiment 1 compared the effects of these drugs on food intake under a progressive-ratio (PR) schedule and free-access conditions. Dexfenfluramine decreased food intake under both conditions, but the doses required to decrease intake under free-access conditions were higher than those required to reduce intake under the PR condition. Intermediate doses of phentermine sometimes increased breaking points, and higher doses decreased them. Phentermine decreased food intake at the same doses under both access conditions. Thus the potency of dexfenfluramine, but not phentermine, to decrease food-maintained behavior depended upon the food-access condition. Experiment 2 used a novel mixed progressive-ratio schedule of food delivery to study the duration of drug effects. Sessions consisted of five components separated by 3-hr timeouts. The ratio requirement reset at the beginning of each component and a new breaking point was obtained. Both dexfenfluramine and phentermine dose-dependently decreased breaking points early in the session. In some rats, compensatory increases in breaking point were observed. That is, breaking points later in the session increased over control levels, resulting in no change in the total number of food pellets earned for the session compared to control. The present findings suggest that the effects of some anorectic drugs depend upon the access conditions for food; increasing the effort to obtain food may enhance their ability to decrease food-maintained behavior.  相似文献   
167.
A series of three experiments examined children's sensitivity to probabilistic phonotactic structure as reflected in the relative frequencies with which speech sounds occur and co-occur in American English. Children, ages 212 and 312 years, participated in a nonword repetition task that examined their sensitivity to the frequency of individual phonetic segments and to the frequency of combinations of segments. After partialling out ease of articulation and lexical variables, both groups of children repeated higher phonotactic frequency nonwords more accurately than they did low phonotactic frequency nonwords, suggesting sensitivity to phoneme frequency. In addition, sensitivity to individual phonetic segments increased with age. Finally, older children, but not younger children, were sensitive to the frequency of larger (diphone) units. These results suggest not only that young children are sensitive to fine-grained acoustic-phonetic information in the developing lexicon but also that sensitivity to all aspects of the sound structure increases over development. Implications for the acoustic nature of both developing and mature lexical representations are discussed.  相似文献   
168.
McKinley NM 《Body image》2004,1(2):213-219
Fat women who endorsed fat acceptance (N=128) were recruited from Radiance Magazine. Relationships between objectified body consciousness (OBC), body esteem, and psychological well-being for the mostly European American sample were similar to those found in other samples. OBC was independently related to body esteem when weight dissatisfaction was controlled. Those who endorsed the need for social change in attitudes towards fat people had higher body esteem and self-acceptance, and lower body shame, than those who endorsed personal acceptance of body size only.  相似文献   
169.
Six male albino rats were placed in running wheels and exposed to a fixed-interval 30-s schedule of lever pressing that produced either a drop of sucrose solution or the opportunity to run for a fixed duration as reinforcers. Each reinforcer type was signaled by a different stimulus. In Experiment 1, the duration of running was held constant at 15 s while the concentration of sucrose solution was varied across values of 0, 2.5. 5, 10, and 15%. As concentration decreased, postreinforcement pause duration increased and local rates decreased in the presence of the stimulus signaling sucrose. Consequently, the difference between responding in the presence of stimuli signaling wheel-running and sucrose reinforcers diminished, and at 2.5%, response functions for the two reinforcers were similar. In Experiment 2, the concentration of sucrose solution was held constant at 15% while the duration of the opportunity to run was first varied across values of 15, 45, and 90 s then subsequently across values of 5, 10, and 15 s. As run duration increased, postreinforcement pause duration in the presence of the wheel-running stimulus increased and local rates increased then decreased. In summary, inhibitory aftereffects of previous reinforcers occurred when both sucrose concentration and run duration varied; changes in responding were attributable to changes in the excitatory value of the stimuli signaling the two reinforcers.  相似文献   
170.
Although much social science research has been conducted within American Indian and Alaska Native (AIAN) communities, relatively little research has been conducted by or for those communities. We describe an approach that facilitates the active involvement of AIAN communities in the research process, from conceptualizing the issues to be investigated to developing a research design, and from collecting, analyzing, and interpreting the data to disseminating the results. The Tribal Participatory Research (TPR) approach is consistent with recent developments in psychology that emphasize the inclusion of community members and the social construction of knowledge. We describe the foundations of the approach and present specific mechanisms that can be employed in collaborations between researchers and AIAN communities. We conclude with a discussion of the implications of the use of TPR regarding project timelines and budgets, interpretation of the data, and ultimately the relationships between tribes and researchers.  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