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   16096篇
  免费   619篇
  国内免费   4篇
  16719篇
  2019年   213篇
  2018年   258篇
  2017年   219篇
  2016年   257篇
  2015年   169篇
  2014年   261篇
  2013年   1272篇
  2012年   432篇
  2011年   485篇
  2010年   289篇
  2009年   312篇
  2008年   413篇
  2007年   441篇
  2006年   421篇
  2005年   343篇
  2004年   372篇
  2003年   334篇
  2002年   329篇
  2001年   452篇
  2000年   510篇
  1999年   342篇
  1998年   205篇
  1997年   155篇
  1996年   166篇
  1995年   164篇
  1992年   276篇
  1991年   285篇
  1990年   296篇
  1989年   276篇
  1988年   267篇
  1987年   234篇
  1986年   246篇
  1985年   259篇
  1984年   191篇
  1983年   207篇
  1982年   158篇
  1980年   156篇
  1979年   248篇
  1978年   216篇
  1977年   150篇
  1975年   215篇
  1974年   242篇
  1973年   268篇
  1972年   225篇
  1971年   210篇
  1970年   162篇
  1969年   195篇
  1968年   248篇
  1967年   239篇
  1966年   209篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
The author describes mythical beliefs, thinking errors, and faulty attitudes collected from a group of male juvenile sex offenders. Therapists need this information to develop effective treatment strategies for replacing distortions and misperceptions with correct and moral information as a foundation for change.  相似文献   
83.
A running-wheel movement-detection method is described for use with a modified 1350 Commodore mouse and a Commodore 64, is described. The movement-detection method allows for the detection of partial revolutions and direction of movement, but requires no interface equipment. The modified running wheel is discussed as a new technique that may be useful for bridging empirical and theoretical differences between free-operant and discrete-trial runway procedures.  相似文献   
84.
Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged.  相似文献   
85.
This study investigated both an applicant pool and its resulting class of new hires in an attempt to clarify a number of empirical questions concerning recruiting source effectiveness. A pre-established database of applicants and hires for the job of life insurance agent in a large insurance company was analyzed for recruiting activity. Differences in applicant quality and new hire survival were found in favor of the informal recruiting sources. A second measure of hire success, new business commission credits, failed to show differences across recruiting sources. The informal recruiting sources yielded significantly higher selection ratios than did formal sources for all groups. Examination of recruiting source use showed significant group differences, with females and blacks using the formal recruiting sources more frequently than males, non-minorities, and Hispanics. While the informal recruiting sources yielded higher quality applicants and more successful hires for all groups, this research cautions that the implementation of revised recruiting policies must be carefully monitored for adverse effects on protected groups.  相似文献   
86.
Trace mineral analysis of human hair was utilized to determine whether violent and nonviolent criminals could be differentiated on the basis of concentrations of levels of major and trace minerals. 40 violent and 40 nonviolent inmates from a prison population were selected for study. 27 mineral levels were analyzed and a discriminant function analysis correctly classified 86% of the violent and 78% of the nonviolent inmates. The results lent support to the hypothesis that significantly different levels of trace minerals could be found between the two groups.  相似文献   
87.
A case of episodic manifestation of semiparalysis agitans is described, accompanied by severe demential personality change and precursory hallucinatory symptoms, which is made the basis for the discussion of aspects of mental disorders, notably dementia and symptoms resembling schizophrenia, in Parkinsonian patients. By way of allusion to Glass, a diagnosis including a very extensive, complex, symptomatology is made of a Parkinsonian syndrome.  相似文献   
88.
The Psychological Record - The present experiments investigated blocking effects in rhesus monkeys (Macaca mulatta) in a discrimination learning paradigm using a single stimulus modality. Two...  相似文献   
89.
The perspective reversals elicited by a set of drawings based on the Mach truncated pyramid are examined. We obtained each pattern of the set from the previous one by adding to it some graphic cues, which were easily integrated into one of the two competing interpretations, thus reducing step by step the ambiguity of the basic pattern. The phenomenological model, proposed to link the mean times of both alternative interpretations with their complexities, is in close agreement with our experimental data. Furthermore, different aspects of such data are well described by the model equations: The measure of the prevalence of the supported interpretation is well correlated with the difference in complexity between the two alternative interpretations; the two different trends of the mean time of the unfavored interpretation, found in the data obtained from different observers as a function of the various patterns of the set, are well fitted by the model without the need for any specific additional hypothesis.  相似文献   
90.
The effect of prohibiting the use of a preshot routine on free-throw shooting in competitive situations was investigated. 25 male high school basketball players were instructed to attempt 50 free throws alternating in blocks of 10 between the use of their preshot routine and shooting without it. To make the situation competitive, subjects were run in groups of five and their performance was recorded on a large easel placed to the side of the free-throw line. A significantly larger number of baskets were made in the preshot routine condition than without the routine. A competitive situation led to a greater decrement in baskets than had been reported in 1986 by Lobmeyer and Wassermen during noncompetitive free-throw shooting.  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