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   70894篇
  免费   2940篇
  国内免费   25篇
  73859篇
  2020年   698篇
  2019年   887篇
  2018年   1206篇
  2017年   1209篇
  2016年   1298篇
  2015年   966篇
  2014年   1134篇
  2013年   5248篇
  2012年   2119篇
  2011年   2237篇
  2010年   1418篇
  2009年   1390篇
  2008年   1999篇
  2007年   2043篇
  2006年   1840篇
  2005年   1660篇
  2004年   1522篇
  2003年   1398篇
  2002年   1537篇
  2001年   2374篇
  2000年   2357篇
  1999年   1775篇
  1998年   822篇
  1997年   726篇
  1996年   739篇
  1993年   651篇
  1992年   1478篇
  1991年   1365篇
  1990年   1365篇
  1989年   1241篇
  1988年   1208篇
  1987年   1148篇
  1986年   1220篇
  1985年   1232篇
  1984年   1043篇
  1983年   946篇
  1982年   675篇
  1981年   656篇
  1979年   1092篇
  1978年   794篇
  1975年   902篇
  1974年   991篇
  1973年   1067篇
  1972年   892篇
  1971年   851篇
  1970年   745篇
  1969年   799篇
  1968年   1005篇
  1967年   919篇
  1966年   774篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
251.
We studied the correlation of one measure of imagery ability, the Visual Elaboration Scale, with two others, absorption of image and effort required to form a mental image. Significant correlations were obtained between the Visual Elaboration Scale and the other scales, with the exception of Absorption for women.  相似文献   
252.
253.
Ratings of pre-morbid intelligence level, derived from the hospital charts of 26 chronic schizophrenics, were correlated with the post-mortem brain volume measures of cortex, white matter, central grey matter, and ventricles. Contrary to hypothesis, no significant correlations were found.  相似文献   
254.
The IES Arrow-Dot was administered to 41 cocaine detoxification patients. This group's scores indicated lower ego functioning and higher impulsivity and superego functioning than other clinical samples. No significant differences were noted between the Arrow-Dot scores of patients who successfully completed the program and those who did not.  相似文献   
255.
30 subjects volunteered from three sources: community adults (M age = 32.8, SD = 13.4), college adults (M age = 23.8, SD = 8.3), and children (M age = 9.5, SD = 1.7) and were categorized as 'left-' and 'right-dominant' by scores on Your Style of Thinking and Learning. They reported the number of Necker cube reversals perceived in 90 sec., attempted to locate four embedded figures, and blindly traversed a 16-choice point finger maze in that order. 'Right-dominant' subjects located more embedded figures and made fewer errors on the finger maze than did 'left-dominant' subjects. College adults reported more Necker cube reversals than did community adults and children, and community adults reported more reversals than did children. Confounds of performance measures with fatigue and/or practice require further research.  相似文献   
256.
Under simple- and choice-RT conditions, the biceps brachii muscle was examined in 8 healthy male subjects to determine how the temporal and spatial characteristics of elbow flexion and forearm supination differed at the initial phase of EMG activity and whether preparation or the presence of response uncertainty influenced the EMG outputs of the two movements. In the simple-RT condition, RT of supination was significantly faster than that of flexion but EMG activity of supination was less than that of flexion. In contrast, in the choice-RT condition, RT of flexion was significantly faster than that of supination but EMG activity of flexion was significantly reduced compared to supination. These findings indicate that advanced preparation or motor set facilitates the differentiation of RTs and EMG activities of the response movements and that response uncertainty causes a significant change in the temporal and spatial specificity of both elbow flexion and forearm supination.  相似文献   
257.
258.
Multidimensional studies of Munsell color solid   总被引:1,自引:0,他引:1  
  相似文献   
259.
This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.  相似文献   
260.
Stress in time     
The goals of this research were to determine whether speakers adjust the stress patterns of words within sentences to create an alternation between strong and weak beats and to explore whether this rhythmic alternation contributes to the characteristics stress differences between two major lexical categories of English. Two experiments suggested that speakers do alter lexical stress in accordance with rhythmic biases. When speakers produced disyllabic pseudowords in sentence contexts, they were more likely to place stress on the first syllable when the pseudoword was preceded by a weak stress and followed by a strong one than when the strong stress preceded and the weak followed. This occurred both when the pseudowords served as nouns and when they served as verbs. Text analyses further revealed that weakly stressed elements precede nouns more often than verbs, whereas such elements follow verbs more often than nouns. Thus, disyllabic nouns are more likely than disyllabic verbs to occupy contexts biased toward trochaic rhythm, a finding consistent with leftward dominant stress in disyllabic English nouns. The history of stress changes in English nouns and verbs also conforms with the view that rhythmic context may have contributed to the evolution of stress differences. Together, the findings suggest that the citation stress patterns of words may to some degree reflect adaptations of lexical knowledge to conditions of language performance.  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