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   55742篇
  免费   2330篇
  国内免费   21篇
  58093篇
  2020年   675篇
  2019年   791篇
  2018年   1129篇
  2017年   1139篇
  2016年   1194篇
  2015年   854篇
  2014年   1032篇
  2013年   4822篇
  2012年   1928篇
  2011年   1928篇
  2010年   1152篇
  2009年   1182篇
  2008年   1663篇
  2007年   1627篇
  2006年   1490篇
  2005年   1234篇
  2004年   1277篇
  2003年   1221篇
  2002年   1161篇
  2001年   1921篇
  2000年   1795篇
  1999年   1341篇
  1998年   616篇
  1997年   530篇
  1996年   606篇
  1995年   549篇
  1994年   541篇
  1993年   528篇
  1992年   1105篇
  1991年   1016篇
  1990年   997篇
  1989年   957篇
  1988年   934篇
  1987年   862篇
  1986年   857篇
  1985年   903篇
  1984年   729篇
  1983年   627篇
  1979年   758篇
  1978年   562篇
  1975年   601篇
  1974年   679篇
  1973年   701篇
  1972年   604篇
  1971年   561篇
  1970年   483篇
  1969年   478篇
  1968年   609篇
  1967年   530篇
  1966年   506篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
A square-wave grating from which the fundamental harmonic has been subtracted (missing fundamental grating) when viewed from a suitable distance appears similar to another grating of periodicity three times higher. The neurons of the visual cortex of the cat, in a given range of spatial frequencies characteristic of each cell, give similar responses to the two gratings.  相似文献   
62.
63.
64.
A Black feminist model was used to investigate rape myth acceptance between African American antirape activists and a comparison group of nonactivists using Cross's (1991) racial identity model and Downing and Roush's (1985) feminist identity model. As predicted, activists rejected rape myths more than nonactivists; the earlier stages of both models were associated with rape myth acceptance; the later stages were associated with rape myth rejection; and activists evidenced more sociopolitical maturity (race and gender consciousness) than nonactivists. The findings suggest that researchers may need to investigate to what degree rape myth acceptance serves an overarching system of social domination where racism and sexism overlap.  相似文献   
65.
Previous research has revealed that individuals have expectations for the development of romance based on personal experience and cultural images. A series of research questions and hypotheses was generated and a sequence of hierarchical log-linear analysis models axis developed to test (a) the effect of gender and knowledge of relational stage and relationship type on prediction of next-occurring actions in the development of a romance, (b) the use of compliance-gaining strategies intended to advance a relationship to the next stage, and (c) justification of secondary goals in which participants reported why they chose the strategies they did as opposed to other alternatives. The data revealed effects for relational stage progression on prediction of ensuing actions. Ingratiation, explanation, and direct requests were popular strategies for developing intimacy. Gender differences in terms of secondary goals were reported. Results are discussed in terms of relational memory structures for the development of intimacy.  相似文献   
66.
The purpose of this meta-analysis of randomized controlled trials was to evaluate the efficacy of psychological interventions for adults with noncancerous chronic low back pain (CLBP). The authors updated and expanded upon prior meta-analyses by using broad definitions of CLBP and psychological intervention, a broad data search strategy, and state-of-the-art data analysis techniques. All relevant controlled clinical trials meeting the inclusion criteria were identified primarily through a computer-aided literature search. Two independent reviewers screened abstracts and articles for inclusion criteria and extracted relevant data. Cohen's d effect sizes were calculated by using a random effects model. Outcomes included pain intensity, emotional functioning, physical functioning (pain interference or pain-specific disability, health-related quality of life), participant ratings of global improvement, health care utilization, health care provider visits, pain medications, and employment/disability compensation status. A total of 205 effect sizes from 22 studies were pooled in 34 analyses. Positive effects of psychological interventions, contrasted with various control groups, were noted for pain intensity, pain-related interference, health-related quality of life, and depression. Cognitive-behavioral and self-regulatory treatments were specifically found to be efficacious. Multidisciplinary approaches that included a psychological component, when compared with active control conditions, were also noted to have positive short-term effects on pain interference and positive long-term effects on return to work. The results demonstrated positive effects of psychological interventions for CLBP. The rigor of the methods used, as well as the results that reflect mild to moderate heterogeneity and minimal publication bias, suggest confidence in the conclusions of this review.  相似文献   
67.
68.
69.
70.
Visual acuity for the detection of gratings at four orientations was measured for groups of ten boys and ten girls aged five to seven years, from the following four populations: Scots in Glasgow, Pakistanis in Glasgow, Gaels in Stornoway (Outer Hebrides) and East Anglians in Littleport (Cambridgeshire fenlands). The Glaswegians, both Scottish and Pakistani, showed the normal pattern of anisotropy, with poorest acuity for oblique orientations; the East Anglians showed no significant anisotropy; while the Gaels were unusual in showing poorest horizontal acuity. A group of fourteen Pakistani children in Stornoway differed slightly from a matched group of Gaels. The group differences bore little relation to the visual environments, and were probably due to genetic or cultural factors. The relatively poor horizontal acuity of the Gaels was not correlated with astigmatism. Sex differences were also found, with the boys showing higher mean acuity and a higher ratio between vertical and oblique acuity.  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