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   56138篇
  免费   2197篇
  国内免费   25篇
  2020年   589篇
  2019年   750篇
  2018年   1031篇
  2017年   1127篇
  2016年   1153篇
  2015年   831篇
  2014年   992篇
  2013年   4446篇
  2012年   1777篇
  2011年   1793篇
  2010年   1146篇
  2009年   1088篇
  2008年   1546篇
  2007年   1600篇
  2006年   1401篇
  2005年   1276篇
  2004年   1197篇
  2003年   1157篇
  2002年   1197篇
  2001年   1747篇
  2000年   1682篇
  1999年   1309篇
  1998年   568篇
  1997年   548篇
  1996年   540篇
  1995年   519篇
  1992年   1106篇
  1991年   1015篇
  1990年   1045篇
  1989年   941篇
  1988年   997篇
  1987年   913篇
  1986年   932篇
  1985年   869篇
  1984年   759篇
  1983年   710篇
  1982年   528篇
  1979年   856篇
  1978年   625篇
  1977年   532篇
  1975年   693篇
  1974年   809篇
  1973年   838篇
  1972年   660篇
  1971年   637篇
  1970年   591篇
  1969年   621篇
  1968年   769篇
  1967年   696篇
  1966年   611篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
Theories of observing differ in predicting whether or not a signal for absence of reinforcement (S−) is capable of reinforcing observing responses. Experiments in which S− was first removed from and then restored to the procedure have yielded mixed results. The present experiments suggest that failure to control for the direct effect of presenting S− may have been responsible. Pigeons and operant procedures were used. Experiment 1 showed that presentations of S−, even when not contingent on observing, can raise the rate of an observing response that was reinforced only by presentations of a signal (S+) that accompanied a schedule of food delivery. Experiment 2 showed that this effect resulted from bursts of responding that followed offsets of S−. Experiment 3 showed that, when the presence of S− was held constant, lower rates occurred when S− was dependent on, rather than independent of, observing. These results support theories that characterize S− as incapable of reinforcing observing responses.  相似文献   
902.
Syntactic decoding reaction times of 20 learning disabled children comprising two groups of subjects (mean age of 8 and 13 yr., respectively) were compared to the responses of normal controls matched for age and sex. An analysis of variance procedure showed that the learning disabled children and their normal peers did not differ significantly in responses to the experimental stimuli. This held true regardless of linguistic complexity, suggesting that delays in processing elementary syntactic constructions are not a concomitant of learning disabilities.  相似文献   
903.
In previous studies subjects who have learned a positioning response with kinesthetic feedback tended to make greater errors when visual feedback was provided during later trials. These subjects have always performed with both kinesthetic and visual feedback available. This study determined whether subjects with only visual feedback would produce errors similar to those who received kinesthetic plus visual feedback. Blindfolded subjects learned to move a handle to a criterion location with knowledge of results following each trial. Subjects then were assigned to one of three experimental groups, with only kinesthetic feedback, with kinesthetic plus visual feedback, or with only visual feedback. Subjects had 9 trials without knowledge of results in these feedback conditions. When visual feedback was available, subjects tended to make longer response errors. This finding replicates previous studies. Also, the similarity of performances from the conditions with visual feedback indicated the dominance of visual information in the condition with kinesthetic plus visual feedback.  相似文献   
904.
The count of publications on geometric-optical illusions and the bibliography of extant books on the topic are brought up to date. The number of publications now exceeds 1100 and the number of books is 35.  相似文献   
905.
Visual correction of a rapid goal-directed response   总被引:1,自引:0,他引:1  
The purpose of this study was to investigate the role of dynamic and static visual cues in improvement of accuracy during a pointing movement. In the experiment, subjects were required to point finger rapidly at visual targets as accurately as possible. Movement amplitude was 15 cm, and movement times ranged from 100 to 190 msec. Three visual feedback conditions were applied: no feedback, dynamic ongoing feedback on the complete hand trajectory, and static error feedback on the movement end-point. Two spatial movement outcomes were considered, mean constant error and intraindividual dispersion of pointings. Data were analyzed with regard to effects of feedback and speed. Under the no-feedback condition, accuracy was lowest; constant error was not speed-dependent, whereas dispersion increased with speed of movement. Accuracy was highest under the complete feedback condition and was speed-dependent, as shown by both constant error and dispersion. Under error feedback, accuracy was intermediate and was also speed-dependent. The results are discussed in terms of the interchange between correcting mechanisms vs delayed control within the motor regulatory processes.  相似文献   
906.
The comparable worth controversy has generated much discussion about the appropriate valuation of job worth. To date, academic inquiries into the measurement of job worth have focused primarily on job evaluation; however, recent court decisions suggest that market wages are a more compelling indicator of job worth than are job evaluation results. This paper examines the construct of "market wage" and the process by which it is measured (wage surveys). It is argued that both the construct and the measurement of the market wage have not been sufficiently examined by either academics or the courts. Implications for pay administration and future research are noted.  相似文献   
907.
VALIDITY GENERALIZATION RESULTS FOR LAW ENFORCEMENT OCCUPATIONS   总被引:1,自引:0,他引:1  
The Schmidt-Hunter interactive validity generalization procedure was applied to validity data for cognitive abilities tests for law enforcement occupations. Both assumed artifact distributions, and distributions of artifacts constructed from information contained in the current sample of studies were used to test the hypothesis of situational specificity and to estimate validity generalizability. Results for studies using a criterion of performance in training programs showed that validities ranged from .41 to .71, and for four test types the hypothesis of situational specificity could be rejected using the 75% decision rule. For the remaining test types, validity was generalizable, based on 90% credibility values ranging from .37 to .71. Results for studies using a criterion of performance on the job indicated that the hypothesis of situational specificity was not tenable for three test types, which had validities between .17 and .31. For the remaining test types, estimated mean true validities ranged from .10 to .26 and were generalizable to a majority of situations. Results for both groups of studies were essentially identical for the two types of artifact distribution. Possible reasons for the apparently lower validities and lesser generalizability for job performance criteria are discussed, including possible low validity of the criterion (due to lack of opportunity by supervisors to observe behavior) and the potential role of noncognitive factors in the determination of law enforcement job success. Suggestions for specifically targeted additional research are made.  相似文献   
908.
INFLUENCE OF ASSESSMENT CENTER METHODS ON ASSESSORS'RATINGS   总被引:2,自引:0,他引:2  
Recently a number of authors have argued persuasively that performance ratings are influenced to a large extent by the way the rater selects, organizes, stores, and recalls information. Although the influence of the rater's cognitive processes on the obtained ratings has been considered in the job-performance evaluation literature, this issue has not been considered in the assessment center literature. The purpose of the present study was to examine how assessment center methods affect the way assessors organize and process assessment center information and affect the ratings they make. Independent groups of assessors underwent one of two methods for evaluating candidates in an assessment center. Data indicated differences in the convergent and discriminant validities and differences in the factor structures of the ratings for the two methods. The pattern of results suggested that the two methods for evaluating assessment center candidates affected the way the assessors organized the assessment center information and affected the obtained ratings. Future research should consider assessment center methods and assessors as sources of variation in assessment center ratings.  相似文献   
909.
910.
Psychic findings of 266 patients suffering from cerebral tumor have been analysed. Psychopathological findings, therefore, were among the most frequent symptoms, at the same time being the second most frequent primary symptom after headache. Disturbance of consciousness and orientation were primarily an indication of malign tumors with increase in cerebral pressure whereas disturbance of motive and cognitive functions were more an indication of slowly growing tumors. Despite the same kind of tumors, same localisation and same duration of anamnesis psychic primary symptoms and disturbance of consciousness and orientation have been found considerably more frequently in older patients than in younger patients.  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