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   43201篇
  免费   992篇
  国内免费   8篇
  2020年   269篇
  2019年   313篇
  2018年   3810篇
  2017年   3164篇
  2016年   2666篇
  2015年   543篇
  2014年   525篇
  2013年   2026篇
  2012年   1314篇
  2011年   3065篇
  2010年   2944篇
  2009年   1917篇
  2008年   2359篇
  2007年   2805篇
  2006年   647篇
  2005年   802篇
  2004年   716篇
  2003年   609篇
  2002年   637篇
  2001年   803篇
  2000年   811篇
  1999年   592篇
  1998年   317篇
  1997年   295篇
  1996年   274篇
  1995年   258篇
  1994年   236篇
  1992年   461篇
  1991年   433篇
  1990年   446篇
  1989年   377篇
  1988年   352篇
  1987年   343篇
  1986年   324篇
  1985年   342篇
  1984年   338篇
  1983年   312篇
  1982年   262篇
  1981年   268篇
  1979年   339篇
  1978年   288篇
  1977年   259篇
  1976年   228篇
  1975年   290篇
  1974年   330篇
  1973年   295篇
  1972年   244篇
  1969年   230篇
  1968年   253篇
  1967年   224篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Julesz (1975) proposed a theory of texture discrimination, based on an order statistics principle, which states that no two textures can be perceptually discriminated if they have identical second-order statistics. The experiments reported here demonstrate that this principle is not adequate to predict visual texture discriminability. Both letter and dot micropatterns were used to create texture pairs that either differed or were identical with respect to secondorder statistics. The subject’s task was to decide which quadrant of an array contained a disparate texture. In Experiments 1, 2, and 3, when controlling for spatial overlap, texture pairs having identical second-order statistics were discriminated more quickly than similar texture pairs having different second-order statistics, in contradiction to the principle. Although a significant effect in the direction predicted by the order statistics principle was found in Experiment 4 for texture pairs created from the dot micropatterns, other factors, such as spatial overlap, border differences, and goodness of pattern, must also be considered in predicting texture discriminability.  相似文献   
952.
Subjective estimates of McCollough aftereffect strength are significantly reduced when certain spatial features of the line grating patterns are manipulated. Results are dependent upon whether the spatial parameters of the test or inspection patterns are altered. Changing the angular slant, contour sharpness, or contour completeness of the inspection gratings does not affect aftereffect strength, but changing the spatial frequency, contour sharpness, or contour completeness of the test gratings does. The implications of these results are discussed with regard to theories offered to explain the McCollough effect.  相似文献   
953.
Redundancy gain and orthogonal interference for height and width were demonstrated in two experiments using a relative coding task with number of intertrial repetitions controlled. Orthogonal interference was shown to be perceptually based rather than simply an intertrial repetitions effect as suggested by Felfoldy (1974). These results from a relative coding task were discussed in terms of the previous multidimensional processing literature. It was concluded that Lockhead’s (1972t model has been applied too generally. An alternative model (a parallel, dimensional analysis stage followed by a stage in which dimensional information is integrated) was suggested.  相似文献   
954.
The effect of sorrounding context on the recognition of objects from briefly presented pictures was investigated. Forty-eight undergraduates saw 100 msec displays of either line drawings containing several objects embedded in context or drawings of object arrays without background context. Following each exposure they were required to select from among four objects the one that had been contained in the picture. Presentation of objects in context aided recognition only when incorrect response alternatives were inconsistent with the picture context. The results suggest that context contributes to the construction of a general characterization of the pictures which provides expectancies regarding the identity of specific objects.  相似文献   
955.
This study purports to test a theory of life and career stages developed by Daniel Levinson and his associates. The theory suggests four distinct stages between ages 20 and 45 each with their own developmental tasks and related behaviors and attitudes. Subjects (759 managerial, professional, and technical employees) were selected randomly from levels and departments of a major public sector employer in the midwest United States. The measure of career stage asked respondents to indicate whether they had passed through, were still in, or had not yet reached each stage as operationalized by a short vignette. Attitudinal and behavioral measures were abstracted from previously developed instruments. Only moderate support for the theory was found with little or no evidence to support the age-linked notion of these stages. Stages were found to be discriminable in terms of certain attitudes (upward mobility, career and overall job satisfaction, and job commitment) as predicted. Suggestions are given for improvements in measurement, research design, and theory refinement.  相似文献   
956.
Previous research has demonstrated the relationship of work stress to indices of job strain, as well as underscoring the importance of moderating variables. In the present study of a mining organization it was hypothesized that personnel associated with actual mining operations would demonstrate stress-strain relationships different from those associated with administrative and staff work. Measures of stress and strain were obtained from management staff of blue-collar and white-collar groups to assess the moderating influence of collar color. Results strongly support collar color as a moderator variable. In particular, the two groups differ significantly with respect to how role conflict, job security, quantitative work load, variation in work load, and utilization of skills impact various strains. The effect of job function on stress and strain and possible practical implications of these results are discussed.  相似文献   
957.
Building on Watzlawick's observations of certain similarities between judo and brief strategic therapy, this paper develops theoretic and pragmatic parallels between brief strategic therapy and a sophisticated martial art system, Aikido. After presenting the contextual similarities of the two conceptual systems as parallel “challenges” to the therapist and Aikidoist to effect change, the similarities in basic principles of practice are presented. The similarities in the philosophical and attitudinal positions of these conceptual systems are then delineated, followed by a case example that integrates the various concepts in the paper.  相似文献   
958.
A review of the literature indicates that methods of skill acquisition based on the operant paradigm have been scientifically validated with many motor behaviors. However, these procedures have been limited to the use of positive reinforcement for correct performance when applied to the acquisition of complex sports skills in natural settings. To find complementary procedures to enhance skill acquisition, a coaching method involving several behavioral techniques was developed that focused on remediation of errors. This coaching method combined the following components: (1) systematic use of verbal instructions and feedback, (2) positive and negative reinforcement, (3) positive practice, and (4) time out. Three sports, football, gymnastics, and tennis, were selected to determine the effectiveness and generality of this behavioral coaching method. A total of 23 male and female subjects, ranging in age from 11 to 35, was included in this study. Baseline data were first collected for each sport under standard coaching conditions. Next, the behavioral coaching method was evaluated depending on the sport in either a multiple baseline or a reversal design. The behavioral dimensions selected were blocking in football; backward walkovers, front hand springs, and reverse kips in gymnastics; and the forehand, backhand, and serve in tennis. Behavioral coaching was immediately effective in increasing the correct execution of complex skills in all three sports. Gains of up to 10 times the baseline performance were achieved in each sport. In football, behavioral coaching resulted in an increase in correct blocking performance from a baseline average of 5% to 51.3%. Gymnasts' performances increased from baseline averages of 2.7% to 52.6% across the three skills. In tennis, standard coaching produced an average of 6% correct performance which increased dramatically under behavioral coaching to 57% across the three strokes. The success of the behavioral coaching package used here suggests that a technology of behavior may offer additional and complementary strategies to the acquisition of motor skills in the natural environment.  相似文献   
959.
The purpose of the present study was to better understand the development of children's occupational knowledge, as assessed by their ability to give ratings to jobs along various dimensions that were similar to ratings given by adults, and to investigate differences in boys' and girls' ratings. Overall, younger students gave higher ratings to the jobs pictured than did older students. Also, females gave higher ratings to three of the four dimensions investigated. Girls rated traditionally female jobs higher on respect and service, while boys rated traditionally male jobs higher on respect and service. Both males and females agreed that more education would be required for the female jobs pictured, but that males would be paid more money for the male jobs pictured.  相似文献   
960.
Self-control continues to develop as a major source of explanatory concepts within cognitive behavior therapy. The recent history of self-control is reviewed, and three related areas of disagreement between radical behaviorists and cognitive behaviorists are discussed. The logical status of self-reinforcement, reciprocity, and private events is examined and evaluated. This review suggests that a radical behavioral approach continues to offer psychology the most effective program for the analysis of behavior.  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