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   2068篇
  免费   252篇
  国内免费   170篇
  2024年   5篇
  2023年   23篇
  2022年   29篇
  2021年   58篇
  2020年   76篇
  2019年   85篇
  2018年   81篇
  2017年   82篇
  2016年   91篇
  2015年   60篇
  2014年   76篇
  2013年   220篇
  2012年   61篇
  2011年   74篇
  2010年   46篇
  2009年   69篇
  2008年   73篇
  2007年   67篇
  2006年   64篇
  2005年   46篇
  2004年   47篇
  2003年   52篇
  2002年   39篇
  2001年   39篇
  2000年   29篇
  1999年   21篇
  1998年   12篇
  1997年   13篇
  1996年   18篇
  1995年   19篇
  1994年   19篇
  1993年   20篇
  1992年   20篇
  1991年   12篇
  1990年   9篇
  1988年   6篇
  1986年   8篇
  1985年   68篇
  1984年   79篇
  1983年   60篇
  1982年   54篇
  1981年   51篇
  1980年   60篇
  1979年   59篇
  1978年   78篇
  1977年   58篇
  1976年   48篇
  1975年   42篇
  1974年   39篇
  1973年   19篇
排序方式: 共有2490条查询结果,搜索用时 15 毫秒
61.
This paper tests a meta-model of youthful marijuana use on students in Grades 11, 12 and 13. Although the specific models for each grade varied in detail, all followed a meta-model making the following assumptions: (1) that use or nonuse of marijuana depends primarily on attitude towards use; (2) that attitude largely reflects the perceived functional and dysfunctional consequences of use; and (3) that what people perceive as functional or dysfunctional depends on relevant personality characteristics. All three models showed satisfactory goodness-of-fit in terms of nonsignificant overidentification tests (minimum P > 0.25) and small discrepancies between observed correlations and the corresponding theoretically implied correlations. A notable feature of the Grade 13 data in contrast to those for Grade 12 and previously reported findings was the seeming unimportance of the perceived value of marijuana use for gaining acceptance from peers. It was suggested that this might reflect the selective survival into Grade 13 in the sampled community of more independently-oriented students.  相似文献   
62.
This research compared the retention of nouns, adjectives and verbs of sentences. A model of the structure underlying the retention of sentences and in which deep structure constituent propositions are hierarchically related, was used to make predictions concerning the retention of these word classes. The model was not supported by the data and it was determined that latencies to recognize the words of a previously presented sentence were the same for all classes of words. This result indicated that for recognition (but not necessarily for other memory tasks), each word of a sentence is seperately or equally accessible (as long as inter-word imagery is the same). However, a further experiment showed that, although word class is not a variable, the image-arousing capacity of a word is. Latencies and error rates were much lower for high-imagery words than for low-imagery ones. The findings on error rates in recognizing words were interesting and pointed to a different model where the meaning representations and syntatic functions of words have an active role in sentence retention.  相似文献   
63.
64.
65.
Nondepressed human subjects were divided into seven groups. On a series of discrimination problems, a helplessness group received insoluble problems, a solvable group received contingent feedback, and a no treatment control group received no feedback. For two other groups insoluble problems were preceded by success feedback on a different task presented according to a fixed ratio (FR) or variable ratio (VR) schedule of reinforcement. Two control groups received either FR or VR schedules of success but were not examined on the discrimination problems. All groups were tested for escape/avoidance performance on a human shuttle box. Both FR and VR schedules produced an inoculation against learned helplessness; escape performance by the helplessness group was significantly worse than that of FR and VR inoculation groups. These latter groups performed similar to the solvable and three control groups. Significantly worse than that of FR and VR inoculation groups. These latter groups performed similar to the solvable and three control groups. Significantly fewer subjects in the VR inoculation group exhibited avoidance responses than their counterparts in the FR inoculation group. despite similar escape performance. The findings indicate that learned helplessness can be prevented in humans and suggest different sources of interference produced by unpredictable and uncontrollable events.  相似文献   
66.
The background and development of a multicategory direct observation system, the Behavior Observation Instrument (BOI), is described. This time-sampling procedure for recording the behavior of persons is demonstrated in several treatment settings and the results applied to issues of program evaluation. Elements that have prevented direct observation from being widely adopted, such as costs, manpower, and training requirements, are systematically analyzed. A basic psychometric analysis of the instrument is used to determine optimum frequency and duration of observation intervals as well as observer agreement. The results imply that direct observation methods, once assumed by some to belong to the special province of the single-subject design, can be used to assess the effects of programs on groups of psychiatric clients in an efficient and economic manner.  相似文献   
67.
A model of subjective magnitude comparisons is explored, which assumes that subjects compare symbolic stimulus magnitudes with respect to a reference point. The reference point may be established implicitly by the question (e.g., “Which is larger?” vs “Which is smaller?”) or be presented explicitly (e.g., “Choose the stimulus closer to X.”). The model was tested in five experiments in which subjects judged which of two comparison digits was closer to (or further from) a reference digit. Regression analyses in three experiments revealed that reaction time depended on the ratio of the distances from the comparison items to the reference point. The other two experiments provided evidence that subjects can strategically vary the processes by which they compare stimuli to a reference point. The results indicated that subjects can perform various types of “analog arithmetic” using either the linear number scale or a nonlinear scale of subjective digit magnitude.  相似文献   
68.
Second- and sixth-grade (ages 7 and 11 years, respectively) subjects were instructed to learn simple Spanish vocabulary nouns using the keyword method. To remember a foreign word translation the keyword method user must: (1) associate the foreign word to an English word (the keyword) that sounds like part of the foreign word; and (2) remember an image of the keyword and translation referents interacting. Second-grade keyword users who were provided with interactive pictures remembered more vocabulary items than those who generated their own imagery links when given separate pictures of the keyword and translation referents. Second graders who generated their own linking images when given only the keywords and translation words recalled fewer items than both picture groups, and were not significantly different from control subjects. Sixth graders in the three imagery-link variations performed at comparable levels and better than control subjects. The results are in complete accord with previous speculations about the development of imagery strategies in children.  相似文献   
69.
The discriminative learning and transfer of compound and component problems were assessed in retarded subjects at two levels of intelligence. It was found that brighter subjects (MA = 10 years) found the component problems relatively easier than the compound problems to a greater extent than did the less developed subjects (MA = 5 years). The learning of compound solutions was shown to transfer positively to other compound problems and negatively to component problems. Component solutions were found to transfer positively to other component solutions and negatively to compound solutions. These dimensional transfer effects were interpreted to mean that both compound and component solutions were mediated and conceptual in nature. The developmental differences in relative usages of compound and component aspects of stimuli were viewed as the result of differences in direction of attention rather than of differences in complexity of processing.  相似文献   
70.
The effect of having a child serve as a rule-following model for other children on the model's own subsequent rule-following was investigated in a resistance to deviation situation. First- and second-grade boys (age range 73 to 94 months) who were told they would serve as self-controlling models for others and who actually served in this capacity touched prohibited toys less than did boys who were not told they would serve as models. Boys told they were to serve as models but who were prevented from performing deviated at a level between the models and boys given no responsibility. Having children serve as rule-following models for others is suggested as an effective, non-punitive technique to increase their self-control.  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