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   1893篇
  免费   60篇
  国内免费   1篇
  2019年   19篇
  2018年   23篇
  2017年   33篇
  2016年   36篇
  2014年   35篇
  2013年   202篇
  2012年   53篇
  2011年   45篇
  2010年   29篇
  2009年   27篇
  2008年   54篇
  2007年   60篇
  2006年   52篇
  2005年   48篇
  2004年   44篇
  2003年   58篇
  2002年   46篇
  2001年   28篇
  2000年   20篇
  1999年   26篇
  1998年   20篇
  1997年   27篇
  1995年   29篇
  1994年   23篇
  1993年   22篇
  1992年   27篇
  1991年   27篇
  1990年   18篇
  1989年   24篇
  1987年   24篇
  1986年   20篇
  1984年   23篇
  1983年   19篇
  1982年   20篇
  1981年   33篇
  1980年   28篇
  1979年   26篇
  1978年   38篇
  1977年   31篇
  1976年   23篇
  1975年   25篇
  1974年   25篇
  1973年   34篇
  1972年   21篇
  1971年   17篇
  1969年   24篇
  1968年   20篇
  1967年   20篇
  1966年   25篇
  1964年   18篇
排序方式: 共有1954条查询结果,搜索用时 15 毫秒
21.
Using heat as a negative reinforcer was shown to be highly efficient in producing a discriminative response in Long-Evans rats. Heat failed to generate the emotional responses usually associated with shock as an aversive stimulus. In a separate study, using the heat-training procedure, age differences in the learning facility of Swiss/ICR (Ha) mice were detected.  相似文献   
22.
On each of a series of trials, S judged two stimuli to be the same or different. S then made a confidence rating of his judgment. The difficulty of discrimination and feedback of response information (latency and correctness) were manipulated. Feedback had no effect. Latencies conditional on confidence rating decreased with increasing confidence and remained relatively constant with changes in discrimination difficulty. Type II operating characteristics were derived from latencies and from confidence ratings; both appropriately reflected differences in task difficulty.  相似文献   
23.
Previously reported experiments demonstrated changes in the relation of visual direction to retinal locus for stimulation during voluntary saccades as compared to this relation before saccade initiation. The quantitative features of these results led to the prediction, confirmed in the present experiments, that there are shifts in visual direction for stimulation presented before the saccade itself. In the present report, monotonically increasing shifts were mapped with stimuli presented as early as 240 msec before the saccade up to the saccade itself. Such shifts cannot be accounted for readily by “inflowing” processes, and while “outflowing” processes seem to be implicated, their quantitative characteristics would need to be considerably different from those required by classical outflow theories.  相似文献   
24.
Different groups of goldfish were trained to discriminate between a circle and either a square, a diamond, a square with a knob added at the top or a diamond with a knob. All subjects readily mastered the discrimination, and there was no significant difference between the groups in the number of trials taken to criterion. In transfer tests it was found that: (i) while there was no transfer from square to diamond or vice versa, the presence of knobs on these shapes did mediate transfer from one to the other, provided the knob remained in the top part of the shapes; (ii) all groups learned much more about the tops of the shapes than about the bottom halves; (iii) animals discriminated the square from the circle largely by detecting the presence of a strong horizontal edge at the top of the figure; (iv) two features of the diamond were discriminated--the presence of oblique contours and the existence of a point in the upper half of the shape. The results are discussed in terms of a proposed model of shape recognition.  相似文献   
25.
A professional school counselor key was developed on the Strong Vocational Interest Blank using Campbell's revised procedures. Of the 403 counselors initially contacted, 340 responded. Of this number, 203 were identified as professional counselors and were included in the professional school counselor scale. Each of these individuals was fully certified, possessed three or more years' experience as a counselor, was a member of a professional guidance association, and was thoroughly satisfied with his job as a counselor. Differences between professional counselors and non-professional counselors seemed to indicate a greater people-orientation in the professional counselor group. This was further supported by relationships of the professional counselor key with other scales on the SVIB.  相似文献   
26.
The horizontal-vertical illusion was studied as a function of retinal eccentricity. It was found that the relation of illusion magnitude to vertical eccentricity is described by a U-shaped function with large amounts of reversed illusion for the more eccentric positions. Substantial effects due to horizontal eccentricity were also obtained, but these were not consistent across subjects. It is suggested that the flattening of the peripheral zones of the refracting surfaces of the eye may be involved in the variation of the illusion with retinal position, and that the astigmatic properties of the central portions of these surfaces may be a prime factor in the usual horizontal-vertical illusion.  相似文献   
27.
Persistent behavior maintained by unavoidable shocks   总被引:1,自引:1,他引:0       下载免费PDF全文
Squirrel monkeys were trained on a multiple schedule in which 10-min periods on a continuous shock avoidance schedule, indicated by a yellow light, alternated with 10-min periods on a 1.5-min variable interval schedule of food reinforcement (VI 1.5). A white light indicated that VI 1.5 was in effect, except for the middle 2 min of the period on VI 1.5, in which a blue light appeared and terminated with the delivery of a 0.5-sec unavoidable shock. Stable response rates developed in the avoidance and VI 1.5 components. However, the highest response rates occurred in the blue, preshock stimulus. A series of experiments showed that responding in the blue stimulus persisted even when responding had been extinguished on both the VI schedule of food reinforcement and the shock avoidance schedule. Responding in the blue stimulus ceased when the blue stimulus terminated without shock or when it terminated with a response-contingent shock. Each time responding ceased, it was restored by terminating the blue stimulus with an unavoidable shock. When the blue stimulus was on throughout each session and unavoidable shocks were delivered at regular 10-min intervals, responding was well maintained. These results show that in monkeys that have been trained on a continuous avoidance schedule, unavoidable shocks can maintain responding even under conditions where responses have no programmed consequences.  相似文献   
28.
This study examines the geographical distribution of various junior college characteristics. Scores for 6 factors or categories of college characteristics, identified in earlier ACT research, were computed for each of 581 accredited junior colleges. When these junior colleges were classified and analyzed by geographical region, significant differences were found among regions on all 6 factors—Cultural Affluence (or Private Control), Technological Specialization, Size, Age (or Conventionalism), Transfer Emphasis, and Business Orientation (or High Cost). The regional differences are discussed and implications are suggested for research and counseling as well as for junior college planning.  相似文献   
29.
Judgments were made of the size of a small, luminous (inner) square appearing in the center of a somewhat larger, variable (outer) square, the whole pattern appearing in the dark. Accuracy of judgment was greatest when the outer square was constant from trial to trial but deteriorated when the outer square also varied in size, reaching a lower limit less than the accuracy produced under the absolute judgment condition (no outer square presented). An application of multiple discriminant analysis and the use of a maximum likelihood observer model provided estimates of the extent to which Os responded to inner and outer size variation as separate aspects of stimulation. Although Os differed markedly in this respect, their ability to identify inner square size under the various conditions did not reflect this difference.  相似文献   
30.
Tilt invariably involves the factor of displacement. A clockwise rotation of a rod, for example, results in the top being displaced to the right and the bottom to the left. The question was raised as to which is primary, displacement or tilt. Through a series of experiments, apparent tilt was found to be the perceptual outcome of phenomenal displacement. In addition, gravity seemed to play no significant role in determining the visual upright. Therefore, the conventionally accepted field theory of apparent verticality was rejected and the visual upright was interpreted according to principles which govern the perception of motion and radial direction.  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