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   22878篇
  免费   438篇
  国内免费   8篇
  23324篇
  2022年   175篇
  2021年   237篇
  2020年   378篇
  2019年   379篇
  2018年   614篇
  2017年   599篇
  2016年   591篇
  2015年   423篇
  2014年   473篇
  2013年   2014篇
  2012年   963篇
  2011年   1043篇
  2010年   623篇
  2009年   514篇
  2008年   784篇
  2007年   705篇
  2006年   619篇
  2005年   540篇
  2004年   461篇
  2003年   446篇
  2002年   444篇
  2001年   755篇
  2000年   773篇
  1999年   506篇
  1998年   206篇
  1997年   192篇
  1996年   159篇
  1993年   156篇
  1992年   390篇
  1991年   340篇
  1990年   363篇
  1989年   357篇
  1988年   341篇
  1987年   303篇
  1986年   320篇
  1985年   310篇
  1984年   251篇
  1983年   210篇
  1979年   206篇
  1978年   172篇
  1975年   194篇
  1974年   254篇
  1973年   208篇
  1972年   213篇
  1971年   177篇
  1970年   161篇
  1969年   207篇
  1968年   213篇
  1967年   169篇
  1966年   191篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
211.
Two experiments are reported, which examined the relative contributions of preload (resting force level), change of force, and the time taken to achieve the force in determining isometric force variability. The findings showed that change of force is the strongest determiner of peak force variability but that preload and time to peak force have smaller though systematic effects. A formula that predicts peak force variability is proposed, with preload as an additive effect to the ratio between the change of force level and the square root of time to peak force. These findings confirm that these three impulse variables are significant in predicting force variability and that the impact of rate of force on peak force variability is nonlinear.  相似文献   
212.
213.
The purpose of this study was to examine the relationship between learned resourcefulness and two common addictive behaviors, namely, drinking and smoking. Male and female college students (N = 175) completed the Self-Control Schedule (SCS), the Quantity-Frequency-Variability questionnaire, and a smoking history form. Learned resourcefulness was related to self-reported patterns of alcohol consumption; specifically, heavy drinking subjects were lower in learned resourcefulness than were light and moderate drinkers who, in turn, were lower in learned resourcefulness than were infrequent drinkers and abstainers. Learned resourcefulness was only modestly related to smoking, with students who had never smoked evidencing somewhat higher learned resourcefulness than ex-smokers and current smokers. Overall, these data provide correlational support for the notion that learned resourcefulness may protect young adults against substance abuse.  相似文献   
214.
It has recently been claimed (Geiger & Lettvin, 1987; Perry, Dember, Warm, & Sacks, 1989) that the acuity/eccentricity function is flatter in dyslexics than in normal subjects, with dyslexics showing better performance in the periphery and worse performance at fixation. In these studies, all target letters were presented to the right of fixation, a procedural flaw inviting subjects to optimize performance by directing attention and/or gaze to the right of the designated fixation point. It is suggested that dyslexic and normal readers may differ in the degree to which they might adopt the optimal strategy in this situation. To overcome this problem, target letters were briefly presented at 16 randomly intermixed locations derived from the orthogonal combination of four eccentricities and four directions from fixation (above, below, right, left). The accuracy of letter identification declined with increasing eccentricity at the same rate for good and poor adult readers and dyslexic teenagers. This finding provides no support for the view that the acuity/eccentricity function might vary with and possibly cause differences in reading level.  相似文献   
215.
This study investigated effects of the target-background luminance ratios upon the autokinetic illusion, with special emphasis on manipulation of the background intensity. Exp. 1, in which the effects of four levels of target luminance were examined against the completely dark background, showed that the target luminance did not affect the illusion as long as the target was small enough in size (0.17 degrees in visual angle). This result confirmed the suggestion by Edwards in 1954. In Exp. II effects of the target-background luminance ratios were examined by varying the luminance of target and background independently. Dominant illusory patterns at the luminance ratio 1 were "pendulum-like" and "bobbing"; these differed from those at higher ratios ("winding"). On the other hand, latency and duration were not affected by the ratios. These findings suggest that the movement pattern is effective in specifying the autokinetic illusion, if it is appropriately categorized and represented.  相似文献   
216.
Conclusion Given my dilemma, then, we should think twice before following Putnam away from metaphysical realism. Internal realism can offer only a false sense of philosophical security. And now we may doubt that it can offer even that.  相似文献   
217.
The paper introduces a catalog of symptoms to promote in the field of endogenous psychoses differentiated diagnosis, at the same time constituting a prognosis. Symptoms should be more minutely differentiated than is customary in psychiatric questionnaires. Manic-depressive disorders and purely phasal psychoses are distinguished solely in the clinical evaluation. Thus benign cycloid psychoses can be distinguished from malignant unsystematic schizophrenia.  相似文献   
218.
The effects of Type A behavior and hardiness on depression and physical symptoms in the face of hassles were examined in 107 Japanese female college students. Analysis of variance indicated that Type A females had less depression under low hassles. There were no hardiness main effects or interactions. Neither Type A behavior nor hardiness moderated the adverse effect of hassles for Japanese women. An implication for research is suggested.  相似文献   
219.
Ratings during acute and follow-up care by 35 families having members with traumatic brain injury showed none of the medical facilities met families' needs though some aspects of patients' care were rated higher in hospitals. Findings suggest comprehensive surveys are needed.  相似文献   
220.
B Küppers 《Psyche》1990,44(4):343-355
The author is an internist in a non-university hospital. He discusses the possibilities and limits of dealing with patients suffering from ulcerative colitis and Crohn's disease. He demonstrates the clinical importance of a psychoanalytic perspective with three case illustrations.  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