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   75536篇
  免费   1493篇
  国内免费   77篇
  77106篇
  2020年   853篇
  2019年   1020篇
  2018年   1382篇
  2017年   1424篇
  2016年   1513篇
  2015年   1111篇
  2014年   1336篇
  2013年   6560篇
  2012年   2268篇
  2011年   2325篇
  2010年   1559篇
  2009年   1458篇
  2008年   2087篇
  2007年   2017篇
  2006年   1858篇
  2005年   1591篇
  2004年   1497篇
  2003年   1466篇
  2002年   1435篇
  2001年   2171篇
  2000年   2062篇
  1999年   1591篇
  1998年   781篇
  1996年   835篇
  1995年   806篇
  1994年   803篇
  1993年   765篇
  1992年   1499篇
  1991年   1359篇
  1990年   1376篇
  1989年   1213篇
  1988年   1238篇
  1987年   1204篇
  1986年   1215篇
  1985年   1176篇
  1984年   1062篇
  1983年   916篇
  1982年   735篇
  1979年   1095篇
  1978年   804篇
  1975年   934篇
  1974年   956篇
  1973年   1057篇
  1972年   900篇
  1971年   845篇
  1970年   749篇
  1969年   775篇
  1968年   932篇
  1967年   829篇
  1966年   749篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
From Dialog's PsychINFO database the number of studies with 6 species reported in the Psychological Abstracts was calculated for each year from 1967 to 1988. Also, the number of studies with an additional 11 species were calculated for each year from 1973 to 1988. A hand search in the Journal of the Experimental Analysis of Behavior and Learning and Motivation was also conducted to explore trends in studies on 12 species from 1970 to 1987. The numbers of studies on many species (e.g., baboons, bats, chimpanzees, dolphins, gerbils, guinea pigs, gorillas, hamsters, lemurs, mice, pigeons, rats, seals, and snakes) have remained stable. There has, however, been a steady decline in the numbers of studies on selected species (e.g., cats, dogs, and rabbits). Possible reasons for changing trends in studies on selected species include: increased costs, the cognitive emphasis in psychology, and arguably, animal rights activism.  相似文献   
932.
Feigned insanity in nineteenth-century America is appraised through a review of the medical and legal literature. The authors focus on the explanations for feigning, procedures used in uncovering feigning, and the role of feigning in the courtroom. This discussion of feigned insanity demonstrates the remarkable consistency of approach to this form of malingering over the past 200 years.  相似文献   
933.
Human interaction and communication involve space in multiple ways. This paper examines the spatial and interactional order of a covertly video-taped police interrogation. When the participants enter the interrogation room and become engaged in the interrogation process, the room itself is a constraint and a resource for interaction. While interacting within a built environment, the participants appropriate their material surroundings in ways that constitute a spatial order and make possible certain arguments. This paper examines how the physical structure of the interrogation room is differentially appropriated, used, and filled in by the participants'; territorial and postural manoeuvers over the course of their interaction; and how the spatial structures thus created by the bodily appropriation of the physical locale are subsequently formulated by talk and thereby used as a metaphorical resource to frame the participants' situated experience. Through this embedded process, the interrogators move the suspect toward confession.  相似文献   
934.
The cloning of BRCA1, a susceptibility gene for inherited breast cancer, has made genetic screening possible for individuals and families whose medical histories are suggestive of an inherited predisposition to breast cancer. To date, few systematic attempts have been made to determine the level of knowledge about breast cancer genetics among women who are likely to seek BRCA1 screening when it becomes widely available. The present study attempted to assess the general knowledge about BRCA1 mutations in two groups: (1) first-degree relatives (FDRs) of breast cancer patients; and (2) women with a previous diagnosis of breast cancer. A self-administered, thirty-item questionnaire was developed through a pilot study. Ten of the items were objective, factual questions about breast cancer genetics. Responses to these questions were used to generate an overall knowledge score for each respondent. The study population was moderately knowledgeable about breast cancer genetics, with an average score of 5.35 out of 10. Counselors should not underestimate the importance of evaluating each counselee's existing knowledge about breast cancer, which can affect the provision and reception of genetic information. In particular, specific areas of knowledge that may be confusing or misunderstood were identified and these topics are discussed in detail.  相似文献   
935.
Dienes and Berry (1997) argue that there really are two kinds of knowledge, implicit and explicit, that can be characterized through a subjective threshold. We argue that the subjective threshold does not separate two forms of knowledge, but instead two uses of knowledge, for two different purposes. With Neal and Hesketh (1997), we suggest that an understanding of learning will be better served by investigating the processing that occurs under various circumstances than by attempting to isolate learning that occurs with awareness from that which occurs without it.  相似文献   
936.
After a short introduction into the changing nature of our society and organizations, we outline two kinds of flexibility of labor: qualitative flexibility, that is the degree to which people who work in or for a certain organization can and do perform different tasks, and quantitative flexibility, that is, varying the quantity of personnel and their working hours. Then, the different ways in which we organize our work and organizations are dealt with in terms of quantitative and qualitative flexibility. Next, we survey these ways of organizing on the degree to which they moderate the positive individual outcomes, or individual goals, of work. It can be concluded that quantitatively flexible work, besides some minor positive consequences, may have serious negative consequences for one's well-being, health, and personal development, while qualitative flexibility may have many more advantages, though it may lead to a devastating task overload. Last, we explore some ways to alleviate these negative effects.  相似文献   
937.
Control theory was used to investigate identity microprocesses (i.e., self-verification)within the context of serious dating relationships. Forty-two college women importance for, and certainty about, their future career identities served as targets in the study. The targets and their dating partners participated in a procedure in which the targets received career information that was contrary to their beliefs about their future identities. Results revealed that women who were highly certain about their future career identity, regardless of its importance level, engaged in more self-verification efforts than did women who were uncertain. A comparison of congruent (partner herself) and incongruent dating partners revealed that congruent partners were the most overt in their disagreement with the contrary information. Certainty and partner congruence predicted the target's self-rating change following the identity disruption. Partner congruence accounted for a substantial amount of variance in self-rating change, indicating that close relationships provide an influential context for identity development.  相似文献   
938.
The major challenge facing today’s biomedical researchers is the increasing competition for available funds. The competitive review process, through which the National Institutes of Health (NIH) awards grants, is built upon review by a committee of expert scientists. The NIH is firmly committed to ensuring that its peer review system is fair and objective. Wendy Baldwin, Ph.D., is Deputy Director for Extramural Research, National Institutes of Health. This paper is based on a presentation at a workshop, “Advances in Peer Review Research”, American Association for the Advancement of Science Meeting, Baltimore, MD, February 9, 1996.  相似文献   
939.
Empirical research with young people in Finland, Germany, Spain and Britain was carried out as part of the BIOCULT project funded by the European Union. The project focused on their attitudes to biotechnology and, in particular, the formation of arguments about risk and safety. This paper looks at the responses of 14–18 year olds to a story about the so called anti-obesity gene, in the form of advice to a friend who is taking it. The majority advised against taking it with some differences by gender and country. Most reservations were on grounds of safety and the feeling that ‘natural’ ways to lose weight are better: A minority questioned the idea of striving for a ‘perfect’ body. The types of arguments used by the young people reveal underlying perspectives on the place of human beings in the world and whether they have a right to manipulate nature and their own bodies. Marie Levitt is a sociologist with research interests in attitudes and values in relation to biotechnology, health and religion.  相似文献   
940.
A literature search was conducted on studies of new drugs used with patients with schizophrenia reported by U.S. and non-U.S. researchers from 1966–1993, yielding 41 U.S., and a total of 24 other non-U.S. studies, among them 11 British studies. Results of the U.S. and non-U.S. studies were pooled separately and compared. Among several comparable conditions discussed, the lack of any data on suicides in the U.S. studies was observed. For a second statistical analysis of suicide rates ‘person-years’ were calculated to adjust for differing washout durations. The results obtained include findings that the percentage of patients relapsing in U.S. studies was slightly lower (37.9%) than in non-U.S. studies (46%); the percentage of patients dropping out in U.S. studies (10.5%) was higher than in non-U.S. studies (7.6%); known location of dropout patients in U.S. studies was 1.7%, compared to 2.6% in non-U.S. studies. The most interesting finding was that no suicides were reported in U.S. studies, compared to 0.6% of patients reported in British studies. Some U.S. studies used ‘challenge doses’, such as amphetamines or L-dopa; no non-U.S. studies reported their use. Compared to U.S. studies, those by non-U.S., and particularly British, researchers appeared to report adverse events in their studies. ‘Challenge’ drugs were not used; suicides were reported. It is estimated that the probability that no patients suicided who participated in the U.S. is small—one in 500.  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