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   32893篇
  免费   540篇
  国内免费   2篇
  2020年   141篇
  2019年   175篇
  2018年   3658篇
  2017年   3025篇
  2016年   2471篇
  2015年   385篇
  2014年   341篇
  2013年   1548篇
  2012年   1000篇
  2011年   2804篇
  2010年   2757篇
  2009年   1744篇
  2008年   2125篇
  2007年   2568篇
  2006年   461篇
  2005年   638篇
  2004年   597篇
  2003年   537篇
  2002年   514篇
  2001年   257篇
  2000年   241篇
  1999年   220篇
  1998年   251篇
  1997年   227篇
  1996年   176篇
  1995年   178篇
  1994年   164篇
  1993年   179篇
  1992年   170篇
  1991年   148篇
  1990年   156篇
  1989年   134篇
  1988年   128篇
  1987年   137篇
  1986年   121篇
  1985年   155篇
  1984年   194篇
  1983年   195篇
  1982年   196篇
  1981年   176篇
  1980年   142篇
  1979年   138篇
  1978年   179篇
  1977年   158篇
  1976年   163篇
  1975年   143篇
  1974年   161篇
  1973年   112篇
  1969年   80篇
  1968年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Whose job is it to discover and manage patients' sexual concerns? If you believe that you have a role to play, just what is that role and how will you perform it? Sexual disorders are common, yet infrequently diagnosed. A willingness to inquire about sexual function is the most critical diagnostic step for clinicians. Once a problem is discovered, a systematic diagnostic process can uncover etiologic organic and psychogenic factors using customary diagnostic tools, including taking a psychosexual and medical history, comprehensive and focused physical examinations, psychological assessment instruments, laboratory tests, and special procedures.  相似文献   
972.
In a recent article, Howard H. Kendler (2002) criticized Kenneth B. Clark and the other social scientists who worked in Brown v. Board of Education for polluting their science with value judgments. This article argues that Kendler's critique is misguided because it conflates a policy judgment with a value judgment. In addition, Kendler inconsistently applied his own standard of objectivity when he examined in the social science used in Brown.  相似文献   
973.
This paper informally summarizes a two-day symposium held at the U.S. National Academy of Sciences in Washington, D.C., September 5–6, 2002. The issue was to what extent the progress of science and societal capacity for continued technological innovation are threatened by excessive protection of intellectual property. Excessive protection creates disadvantages not only for scientists and inventors but also for educators/students and for librarians/clientele. Speakers from a variety of disciplines and institutions agreed unanimously that scientific and technological progress is, indeed, under serious threat. Various opinions were expressed about the degree of threat, currently and prospectively, as well as what counter-measures are best suited to resist undue restrictions on creative uses of scientific and technical data and information. This summary is based entirely on the author’s notes from the symposium, and the commentary offered is his alone. My apologies to the speakers if this paper does not accurately reflect the primary intent of their presentations. The “Suggested Readings” offered at the end are not specific to the speakers’ statements but rather are offered as a general resource to aid further research. The definitive record of the symposium is planned to be available from the National Academies Press as a Proceedings publication in the summer of 2003. John Gardenier is an independent researcher, ethicist and science writer.  相似文献   
974.
This paper was presented at a seminar that outlined the work of the Surrey Ethics Forum. The Forum provides an opportunity for reflection by staff of the Federal University of Surrey and its Associated Institutions on ethical questions, the place of ethics in the curriculum and the role of ethics in the life of future graduates. The purpose of this paper is to argue that openness to the relationship between ethics and faith is itself an ethical task because both ethics and faith claim to protect human dignity and give meaning to the concept of "human flourishing". Analysis of the relationship between ethics, faith, flourishing and narrative can lead to clearer understanding of differences in ethical debates.  相似文献   
975.
976.
Research scientists are trained to produce specialised bricks of knowledge, but not to look at the whole building. Increasing public concern about the social role of science is forcing science students to think about what they are actually learning to do. What sort of knowledge will they be producing, and how will it be used? Science education now requires serious consideration of these philosophical and ethical questions. But the many different forms of knowledge produced by modern science cannot be covered by any single philosophical principle. Sociology and cognitive psychology are also needed to understand what the sciences have in common and the significance of what they generate. Again, traditional modes of ethical analysis cannot deal adequately with the values, norms and interests activated by present-day technoscience without reference to its sociological, political and economic dimensions. What science education now requires is ‘metascience’, a discipline that extends beyond conventional philosophy and ethics to include the social and humanistic aspects of the scientific enterprise. For example, students need to learn about the practices, institutions, career choices, and societal responsibilities of research scientists, and to rehearse in advance some of the moral dilemmas that they are likely to meet. They need also to realise that science is changing rapidly, not only in its research techniques and organisational structures but also in its relationships with society at large.  相似文献   
977.
In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus–response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus–response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus–response mappings, causing a compatibility effect from the avatar’s point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants’ sense of agency over the avatar, a spatial compatibility effect from the avatar’s perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.  相似文献   
978.
The use of diagrams in analogical problem solving   总被引:2,自引:0,他引:2  
In four experiments, we examined the impact of perceptual properties on the effectiveness of diagrams in analogical problem solving, using variants of convergence diagrams as source analogues for the radiation problem. Static diagrams representing the initial problematic state (one large line directed at a target) and the final state for a convergence solution (multiple converging lines) were not accessed spontaneously but were often used successfully once a hint to consider the diagram had been provided. The inaccessibility of static diagrams was not alleviated by adding additional diagrams to represent intermediate states (Experiment 1), but spontaneous access was improved by augmenting static diagrams with a verbal statement of the convergence principle (Experiment 3). Spontaneous retrieval and noticing were increased markedly by animating displays representing converging forces and thereby encouraging encoding of the lines as indicating motion toward a target (Experiments 3 and 4). However, neither static nor animated diagrams were effective when the arrows were reversed to imply divergence rather than convergence (Experiment 2). The results indicate that when animation encourages the interpretation of a diagram as a helpful source analogue, it can greatly enhance analogical transfer.  相似文献   
979.
Interlimb coordination is subject to constraints. One major constraint has been described as a tendency for homologous muscle groups to be activated simultaneously. Another has been described as a biasing of limb segments to movement in the same direction. In 2 experiments, the 2 constraints were placed in opposition: In-phase or antiphase contraction of homologous muscles of contralateral limbs produced movement that was spatially antiphase or in-phase, respectively. Probability distributions of relative phase were obtained under manipulations of phase detuning and movement speed. They revealed that the equilibrium and stability of coordination were related, respectively, to spatial relative phase and muscular relative phase. Previously observed spatial and muscular constraints reflect a (possibly very general) factorization of attractor location and attractor strength in the dynamics of interlimb coordination.  相似文献   
980.
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