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   169209篇
  免费   7604篇
  国内免费   155篇
  176968篇
  2021年   1501篇
  2020年   2777篇
  2019年   3434篇
  2018年   3433篇
  2017年   3895篇
  2016年   4564篇
  2015年   3917篇
  2014年   4793篇
  2013年   23500篇
  2012年   4376篇
  2011年   3395篇
  2010年   3802篇
  2009年   4715篇
  2008年   3653篇
  2007年   3171篇
  2006年   3845篇
  2005年   3854篇
  2004年   3340篇
  2003年   2963篇
  2002年   2819篇
  2001年   3097篇
  2000年   2991篇
  1999年   3027篇
  1998年   2810篇
  1997年   2644篇
  1996年   2558篇
  1995年   2396篇
  1994年   2384篇
  1993年   2310篇
  1992年   2524篇
  1991年   2342篇
  1990年   2223篇
  1989年   2155篇
  1988年   2115篇
  1987年   2138篇
  1986年   2133篇
  1985年   2342篇
  1984年   2476篇
  1983年   2256篇
  1982年   2369篇
  1981年   2324篇
  1980年   2159篇
  1979年   2157篇
  1978年   2153篇
  1977年   2130篇
  1976年   1905篇
  1975年   1966篇
  1974年   2035篇
  1973年   1864篇
  1972年   1495篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
831.
Summary Four experiments are reported that examine performance on a complex reasoning task. Subjects have to determine which factory has polluted a river by ordering a series of tests for the presence or absence of various pollutants. Previous research has shown that people typically employ a non-optimal exhaustive search stragegy on this task. Experiments 1 and 2 attempt to identify some of the boundary conditions of this strategy. It is found that the order in which pollutants appear on the matrix list does not seem to be a critical factor, whereas the overall size of the factory-pollutant matrix is. Experiments 3 and 4 attempt to deter people directly from adopting the exhaustive strategy. The results show that even when people are deterred from using the exhaustive method, this will not necessarily result in their adopting a more efficient strategy.  相似文献   
832.
Summary This study investigated the relative importance of perceptual and motor factors in the imitation of simple temporal patterns. Previous research in which subjects tap out interval sequences using one finger has suggested that perceptual factors play an important role in response timing. Studies of bimanual tapping, in contrast, stress the importance of motor interactions between the two hands. In this experiment we compared the ability of subjects to tap out two-interval sequences using one finger, two fingers on one hand, and two fingers on opposite hands. The results showed almost identical performance under the three response conditions. It is suggested that the perceptual relations between intervals in a pattern were the main determinant of performance in this experiment.  相似文献   
833.
Summary Three experiments investigated whether learning action phrases by enacting the denoted action enhances organization or not. In the first experiment it was shown that, compared to a standard learning instruction, enacting did not enhance the clustering of episodic and taxonomic lists, but it did enhance memory performance. Furthermore, the enacting effect was strongest with an unrelated list; in all lists, organization and recall correlated only under a verbal instruction and not under an enacting instruction. In the second experiment, subjects were also informed about the categories of the lists and instructed to use them to learn the items. The organization was enhanced in all cases by this procedure, but the recall performance was enhanced only with a standard learning instruction. Under enacting, information about the categories had no influence. In the third experiment this effect was replicated for a taxonomic list and could be generalized for a motor list, in which categories were in accordance with the similarities of the movement pattern. Here too the explicit category information had an effect only under a standard learning instruction, but not with enacting. We interpret these effects as support for the assumption that enacting does not enhance memory performance by better relational information. Relational information is, on the contrary, less important for recall under enacting than under a standard learning instruction.  相似文献   
834.
835.
Research conducted primarily in the United States suggests that the combination of Type A behaviour, high instrumentality, and low expressiveness may place individuals at relatively high risk for coronary-artery and heart disease. The present research investigates the trans-societal generalizability of the structure, reliability, relationships among, and distributional characteristics of these measures for 117 college students in Athens, Greece. As hypothesized, the Greek students were significantly less instrumental and less expressive than the American students, and scored significantly higher on the measure of Type A. Although there were significant mean differences between these samples, the results suggest that many of the interscale relationships are comparable, supporting an etic (universal) interpretation of the findings. Nevertheless, the results suggested several emic (unique) characteristics of these measures and their interrelationships.  相似文献   
836.
Using recall of clinical protocols as a measure of expertise in medicine has yielded disappointingly small effects. Experiments using recall of clinical laboratory data are presented to provide an explanation. In one experiment, subjects either deliberately memorized or first diagnosed and then were incidentally asked for memory. With incidental instructions, experts recalled over twice as much data as did students, but with memorization instructions, student performance approximated that of experts. Experts also showed a large advantage over students in incidental recall of data that were not relevant to the problem solution. These results suggest that expert processing in this "discrete, independent inputs" domain requires effortful analysis with minimal reliance on default values, rather than relatively effortless pattern perception reported in highly visual areas of expertise. For this area, intentional memory is a misleading measure of expertise. However, incidental memory is a valuable measure of processing during diagnosis.  相似文献   
837.
Recent reports have indicated similarities between patients with persistent chest pain of nonorganic origin and patients with panic disorder. In order to explore this association further, we administered a structured interview and three self-report measures (State-Trait Inventory, Beck Depression Inventory, and SCL90-R) to three subject groups: (1) a sample with persistent chest pain (CP; n=14) who had been screened and found to have normal coronary arteries, (2) a sample of patients with panic disorder (PD; n=14), and (3) a sample of matched normals (n=14). CP patients were considered to be free of coronary artery disease (CAD) following normal cardiac catheterization and/or normal thallium stress tests and were not diagnosed initially with panic disorder. PD patients were diagnosed with a standardized psychiatric interview and were free of organic causes of panic. Using an exploratory data analytic approach, the results indicated that both CP and PD samples reported increased levels of state and trait anxiety (p <.0001), depression (p <.01), and somatization (p <.0001) compared with normals. CP patients differed from PD patients in their less frequent use of anxiolytic medication (p <.01) and lower levels of reported panic anxiety and phobic avoidance (p <.0001). These data suggest that persistent chest pain in the absence of CAD shares some features with panic disorder, yet differs from panic in key ways as well. The results are discussed in light of the role of anxiety in contributing to symptom labeling.This research was supported by Grant 86G-491 from the American Heart Association, Texas Affiliate, to J.G.B. H.T. is the recipient of USPHS Research Career Development Award K04-HL-0122246.  相似文献   
838.
839.
In order to guarantee that each individual is free to pursue his/her potential, each member of AACD is charged to (a) engage in ongoing examination of his/her own attitudes, feelings, stereotypic views, perceptions and behaviors that might have prejudicial or limiting impact on women, ethnic, minorities, elderly persons, gay/lesbian persons and persons with handicapping conditions; (b) contribute to an increased sensitivity on the part of other individuals, groups or institutions to the barriers to opportunity imposed by discrimination; (c) advocate equal rights for all individuals through concerted personal, professional and political activity. (Position paper of the Human Rights Committee of the American Association for Counseling and Development, 1987, p.1)  相似文献   
840.
There is little available literature on gay and lesbian identity among Black Americans. This exploratory study involved interviewing a total of six Black-American gay men and lesbian women regarding gay identity development issues. Data pertaining to the interviewees' experiences of gay identity development were obtained through a questionnaire of six open-ended questions and an interview with each participant lasting 1 to 2 hours. This article presents some of the significant challenges faced by those who were interviewed regarding their sense of self-acceptance, both as Blacks in the predominantly White gay and lesbian community and as gay men and lesbian women in the predominantly heterosexual Black community. The implications of these issues for future research and counseling intervention are discussed. In this article the term gay identity is generally used in reference to both men and women. When women are being discussed exclusively, however, the term lesbian identity is used.  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