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   6271篇
  免费   185篇
  国内免费   3篇
  2019年   61篇
  2018年   117篇
  2017年   91篇
  2016年   103篇
  2015年   70篇
  2014年   83篇
  2013年   489篇
  2012年   178篇
  2011年   173篇
  2010年   92篇
  2009年   102篇
  2008年   141篇
  2007年   160篇
  2006年   138篇
  2005年   140篇
  2004年   130篇
  2003年   110篇
  2002年   124篇
  2001年   217篇
  2000年   208篇
  1999年   149篇
  1998年   61篇
  1996年   61篇
  1993年   57篇
  1992年   121篇
  1991年   125篇
  1990年   122篇
  1989年   101篇
  1988年   93篇
  1987年   104篇
  1986年   109篇
  1985年   109篇
  1984年   96篇
  1983年   84篇
  1980年   61篇
  1979年   99篇
  1978年   75篇
  1977年   68篇
  1976年   60篇
  1975年   73篇
  1974年   97篇
  1973年   104篇
  1972年   77篇
  1971年   73篇
  1970年   81篇
  1969年   83篇
  1968年   106篇
  1967年   83篇
  1966年   98篇
  1958年   62篇
排序方式: 共有6459条查询结果,搜索用时 15 毫秒
941.
Studies of tachistoscopic word perception were reviewed under two theoretical headings: the structural approach, in which the variables of interest are linguistic relations among letters, and the lexical approach, where the interest is in the availability of words in lexical memory. The results of a recent tachistoscopic recognition study question the importance of lexical availability by finding no difference in performance between meaningful words and well-structured, pronounceable nonwords. In the present study, further comparisons between words and pronounceable nonwords were performed, and a meaningfulness effect was demonstrated. The generality of this finding was discussed, and alternative models accounting for the effect were considered. Two of these were capable of explaining structural effects as well as the meaningfulness effect: a translation model and a lexical discrimination net.  相似文献   
942.
943.
Using different warning signals and threshold stimuli, the thresholds, as determined by a method of limits, were found to rise monotonically as the interval between warning signal and threshold stimulus increased from I to 9 sec. It was found that the variability of the threshold did not increase as the threshold increased. Similar results were obtained for phosphene and auditory thresholds and with visual and auditory warnings; therefore the effect was considered to be central. Motokawa's finding of a minimum in the phosphene threshold 2 sec. after a flash of white light was not repeated. The rise in threshold was not obtained when the warning intervals were randomized and so seemed to depend on the use of fixed warning intervals. A model was developed relating threshold level to accuracy of anticipation of the end of the warning interval.  相似文献   
944.
This paper presents a test for determining significance of differences between means of samples which are drawn from positively skewed populations, more specifically, those having a Pearson Type III distribution function. The quantity 2npx g /x p (wherep equals the mean squared divided by the variance andn is the number of cases in the sample), which distributes itself as Chi Square for 2np degrees of freedom, may be referred to the tables of Chi Square for testing hypotheses about the value of the true mean. For two independent samples, the larger mean divided by the smaller mean, which distributes itself asF for 2n 1 p 1 and 2n 2 p 2 degrees of freedom, may be referred to theF distribution tables for testing significance of difference between means. The test assumes that the range of possible scores is from zero to infinity. When a lower theoretical score limit (c) exists which is not zero, the quantity (Mean —c) should be used instead of the mean in all calculations.  相似文献   
945.
946.
Visual reinforcement in fighting cocks   总被引:2,自引:0,他引:2       下载免费PDF全文
Fighting cocks were conditioned to emit a key-pecking response on a fixed ratio reinforcement schedule leading to the visual image of another fighting cock. In addition, the relative reinforcing properties of the visual reinforcer were compared with food and water reinforcers in a three-choice, non-reversible option situation. The relative reinforcing effects of mirror presentation and another rooster visually presented through a window, were compared. The mirror maintained a relatively lower response output.  相似文献   
947.
948.
Background and Objectives: In this research, we tested the role of cognitive appraisals in explaining why harmonious and obsessive passion dimensions are related to distinct forms of coping and explored if performance was impacted by these appraisal and coping processes. Design: Undergraduate students (N = 489) participated in a longitudinal study and completed three surveys throughout the course of an academic year. Methods: Participants completed assessments of both passion dimensions (Time 1), reported how they were appraising and coping with the mid-year examination period (Time 2), and provided consent to obtain their final grade in Introductory Psychology (Time 3). The hypothesized model was tested using structural equation modeling. Results: Harmonious and obsessive passion dimensions were linked with approach and avoidant coping responses, respectively. Cognitive appraisals, particularly appraisals of challenge and uncontrollability, played an indirect role in these relationships. In addition, both appraisals and coping responses had an indirect effect in the relationship between passion dimensions and final grade. Conclusions: These results identify cognitive appraisal as a reason why passion dimensions are linked with distinct coping tendencies and demonstrate the role of appraisal and coping processes in the journey to passionate goal attainment.  相似文献   
949.
950.
Between 65 and 75 % of juvenile-justice involved (JJI) youth present with at least one behavioral health disorder. Many communities have developed diversion programs that provide behavioral health services to JJI youth, often in lieu of detention. A key component of successful diversion programming is accurate screening and assessment. The Ohio Scales, a validated instrument designed to track service effectiveness in clinical samples of youth, are now being used with juvenile justice populations. The purpose of this study is to validate the Ohio Scales in a JJI youth population (N = 2246). The population (ages 12–18) is derived from Ohio’s Behavioral Health Juvenile Justice Initiative, a diversion program for JJI youth with behavioral health issues. We conducted Confirmatory Factor Analyses (CFA) on all forms of the Ohio Scales (parent, youth and worker) to measure fit for one factor, four factor and four factor second order solutions. We also conducted an Exploratory Factor Analysis (EFA) on the Problem Severity factor in the youth form to determine the number of appropriate sub-factors. The EFA indicated that the Problem Severity factor should be broken into three hypothesized sub-factors: Externalizing, Internalizing and Delinquency. The CFA confirmed this solution. CFA results indicated the four factor second order solution fits superior to the other two solutions. Using the Ohio Scales Problem Severity measure as a three sub-factor measure may increase clinical applicability by allowing a clinician to specifically measure and target externalizing or internalizing issues during treatment.  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