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   4861篇
  免费   70篇
  4931篇
  2024年   43篇
  2023年   63篇
  2022年   67篇
  2021年   105篇
  2020年   147篇
  2019年   122篇
  2018年   231篇
  2017年   235篇
  2016年   199篇
  2015年   125篇
  2014年   168篇
  2013年   670篇
  2012年   350篇
  2011年   331篇
  2010年   199篇
  2009年   123篇
  2008年   297篇
  2007年   241篇
  2006年   196篇
  2005年   123篇
  2004年   103篇
  2003年   109篇
  2002年   87篇
  2001年   43篇
  2000年   70篇
  1999年   43篇
  1998年   37篇
  1997年   23篇
  1996年   23篇
  1995年   18篇
  1994年   27篇
  1993年   17篇
  1992年   14篇
  1991年   34篇
  1990年   19篇
  1989年   19篇
  1988年   16篇
  1987年   16篇
  1986年   10篇
  1985年   14篇
  1984年   13篇
  1983年   9篇
  1981年   8篇
  1980年   8篇
  1979年   12篇
  1977年   8篇
  1975年   9篇
  1968年   11篇
  1966年   9篇
  1965年   8篇
排序方式: 共有4931条查询结果,搜索用时 15 毫秒
151.
A simple method was designed to evaluate visual abilities such as disance visual acuity, binocular horizontal visual field, simple and choice visual reaction times, and stereoscopic vision in skilled 11- to 13-yr.-old basketball players participating in a 15-day summer training camp. On a test battery, visual abilities were monitored in 473 players of the Spanish Basketball Federation over a 5-yr. period. The players showed outstanding scores on distance visual acuity and stereoscopic vision, and good visual reaction times and horizontal visual fields. When scores were compared by sex and age, significant differences on certain visual measures were observed. Many layers showed crossed eye-hand dominance. Visual screening programs may help promote visual health among junior basketball players and could be used for performance training.  相似文献   
152.
Causal judgment is assumed to play a central role in prediction, control, and explanation. Here, we consider the function or functions that map contingency information concerning the relationship between a single cue and a single outcome onto causal judgments. We evaluate normative accounts of causal induction and report the findings of an extensive meta-analysis in which we used a cross-validation model-fitting method and carried out a qualitative analysis of experimental trends in order to compare a number of alternative models. The best model to emerge from this competition is one in which judgments are based on the difference between the amount of confirming and disconfirming evidence. A rational justification for the use of this model is proposed.  相似文献   
153.
This study is composed of 233 adult nonpatients, all from Peru. Inclusion/exclusion criteria are described. Interrater reliability statistics at the response level are presented along with scores for the Rorschach Comprehensive System (CS; Exner & Erdberg, 2005). Considering the results of this investigation, the researcher suggests a line of multicultural research. The differences between the United States and Peru strengthen the psychometric and qualitative value of this line of investigation.  相似文献   
154.
The present work sets out to study the internal structure of the Torrance Test of Creative Thinking (TTCT) and to establish standardised scores that will enable the test to be used in both a diagnostic and educational context. 649 students (319 girls and 330 boys), aged 5 to 12 years from various schools in Murcia and Alicante (SE Spain), took part in the study. The findings suggest that the psychometric characteristics of TTCT are satisfactory, and its internal structure can be attributed to three factors that are responsible for a high percentage of the variance (73.8%). The standardised score tables, which are provided for first time in this context, will be useful in the evaluation of creativity and the identification of students with high intellectual abilities.  相似文献   
155.
Systems biology is the rapidly growing and heavily funded successor science to genomics. Its mission is to integrate extensive bodies of molecular data into a detailed mathematical understanding of all life processes, with an ultimate view to their prediction and control. Despite its high profile and widespread practice, there has so far been almost no bioethical attention paid to systems biology and its potential social consequences. We outline some of systems biology's most important socioethical issues by contrasting the concept of systems as dynamic processes against the common static interpretation of genomes. New issues arise around systems biology's capacities for in silico testing, changing cultural understandings of life, synthetic biology, and commercialization. We advocate an interdisciplinary and interactive approach that integrates social and philosophical analysis and engages closely with the science. Overall, we argue that systems biology socioethics could stimulate new ways of thinking about socioethical studies of life sciences.  相似文献   
156.
This paper analyzes the modulator role of job involvement in the relationship between stress and job satisfaction, using the OSI (Occupational Stress Indicator) model. For this purpose, we analyzed: six sources of stress, the OSI job satisfaction results, and a job involvement scale. The sample consisted of 779 professional soldiers from the Spanish Army. The results show that when the levels of the two dimensions job involvement (psychological identification and job-related feelings of duty-obligation are high, stress due to achievements and career development and social relationships will have no influence on job satisfaction. However, we found higher job satisfaction, even when stress is high, in those situations where psychological identification is low and job-related feelings of duty-obligation are high.  相似文献   
157.
158.
Whereas the unique axes properties of PARAFAC1 have been examined extensively, little is known about uniqueness properties for the PARAFAC2 model for covariance matrices. This paper is concerned with uniqueness in the rank two case of PARAFAC2. For this case, Harshman and Lundy have recently shown, subject to mild assumptions, that PARAFAC2 is unique when five (covariance) matrices are analyzed. In the present paper, this result is sharpened. PARAFAC2 is shown to be usually unique with four matrices. With three matrices it is not unique unless a certain additional assumption is introduced. If, for instance, the diagonal matrices of weights are constrained to be non-negative, three matrices are enough to have uniqueness in the rank two case of PARAFAC2. The authors are obliged to Richard Harshman for stimulating this research, and to the Associate Editor and reviewers for suggesting major improvements in the presentation.  相似文献   
159.
An injection olfactometer for human psychophysical experiments is described. The olfactometer is capable of presenting, either mono- or birhinally, single odorants and binary mixtures. The pulse form of the olfactory stimulus at the exit of the olfactometer approaches a rectangular form, which makes the olfactometer well suited for olfactory reaction time measurements. Since stimulation periods are independent of the subject’s inhalation, time-intensity measurements over prolonged periods of time are possible as well. In the second part of this paper, a new technique is described for the measurement of the stimulus pulse form at the exit of the olfactometer.  相似文献   
160.
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