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   7717篇
  免费   294篇
  国内免费   2篇
  2021年   61篇
  2020年   114篇
  2019年   134篇
  2018年   171篇
  2017年   197篇
  2016年   183篇
  2015年   164篇
  2014年   190篇
  2013年   934篇
  2012年   303篇
  2011年   308篇
  2010年   195篇
  2009年   229篇
  2008年   321篇
  2007年   305篇
  2006年   276篇
  2005年   295篇
  2004年   272篇
  2003年   251篇
  2002年   249篇
  2001年   111篇
  2000年   109篇
  1999年   118篇
  1998年   140篇
  1997年   95篇
  1996年   94篇
  1995年   98篇
  1994年   87篇
  1993年   79篇
  1992年   79篇
  1991年   78篇
  1990年   59篇
  1989年   71篇
  1988年   66篇
  1987年   57篇
  1986年   57篇
  1985年   77篇
  1984年   83篇
  1983年   74篇
  1982年   62篇
  1981年   69篇
  1980年   72篇
  1979年   51篇
  1978年   70篇
  1977年   68篇
  1976年   67篇
  1975年   62篇
  1974年   60篇
  1973年   44篇
  1972年   38篇
排序方式: 共有8013条查询结果,搜索用时 15 毫秒
51.
The primary care setting is seen by many to be at the forefront of the attempt to encourage people to follow healthier diets. Conducted in a single practice, the present study firstly considered the effectiveness of three ‘healthy eating’ clinics for patients found to have elevated cholesterol levels at screening. Through the use of a randomised trial, these patients received either basic dietay information or were invited back more frequently and requested to complete food diaries, half of which were then analysed through a computer program. At one year follow up the three programmes were found to have produced a 6.7% reduction in cholesterol levels. However, no differences were found between the three programmes. The study secondly examined a range of health belieji, based on the health belief model, as predictors of reductions in cholesterol levels. These were generally found to be poor predictors, with only the belief that one's diet is related to the chances of developing a number of major conditions and the perception of bam'ers dealing with confidence predicting these reductions. Finally, the case for incorporating self-efficacy beliefs into the healh belief model is outlined and the need for health counsellors to tailor their messages to the pre-existing beliefi and behaviours of patients is highlighted.  相似文献   
52.
Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.  相似文献   
53.
Retrospective and prospective reports of the onset of disruptive child behaviors were analyzed in a sample of clinic-referred boys. The younger boys (ages 7–9 years), compared with the older boys (ages 10–12 years), showed the highest level of disruptive behavior and, judging from mothers' reports, had the fastest progression of onsets from less serious to more serious problem behaviors. Despite some overlap, developmental sequences in problem behavior within the domains of hyperactivity/inattention, oppositional behavior, and conduct problems were similar across the two age groups. This was also the case for developmental sequences of overt or confrontive problem behaviors and covert or concealing conduct problems. Sequences of the onset of oppositional behavior and conduct problems were validated through prospective data, based on the information from mothers, teachers, and boys themselves. The implications of the findings are discussed for the formulation of developmental pathways of behavior and the analysis of causal factors.  相似文献   
54.
Working in the fragment of Martin-Löfs extensional type theory [12] which has products (but not sums) of dependent types, we consider two additional assumptions: firstly, that there are (strong) equality types; and secondly, that there is a type which is universal in the sense that terms of that type name all types, up to isomorphism. For such a type theory, we give a version of Russell's paradox showing that each type possesses a closed term and (hence) that all terms of each type are provably equal. We consider the kind of category theoretic structure which corresponds to this kind of type theory and obtain a categorical version of the paradox. A special case of this result is the degeneracy of a locally cartesian closed category with a morphism which is generic in the sense that every other morphism in the category can be obtained from it via pullback.The financial support of the Royal Society in London is gratefully acknowledged.  相似文献   
55.
Two experiments were conducted to examine the hypothesized differential effectiveness of two attentional focusing strategies in pain perception. In the first experiment, subjects (72 male college students) rated their levels of pain after being exposed to either low- or high-intensity pressure stimulation for 75 s. Subjects were instructed to use either an external or internal focus of attention during the pain induction. Results revealed that external focusing was more effective for coping than internal focusing across both levels of stimulus intensity. The second experiment was a replication of the first, and featured bolstered internal focusing and stimulus intensity manipulations. Results showed that high-intensity stimulation produced higher pain ratings than did low-intensity stimulation for subjects in the internal focusing conditions, but not for those in the external focusing conditions. The findings support the power of distraction strategies for dealing with short-term pain with a rapid onset. Theoretical implications are discussed.The authors thank Darwyn E. Linder and Daniel M. Landers for their help in development of this research. The authors are also indebted to Sarah Colley, Jona Davis, Nanci Neuberger, and Rebecca Roberts for their assistance in data collection.  相似文献   
56.
Established results on latent variable models are applied to the study of the validity of a psychological test. When the test predicts a criterion by measuring a unidimensional latent construct, not only must the total score predict the criterion, but the joint distribution of criterion scores and item responses must exhibit a certain pattern. The presence of this population pattern may be tested with sample data using the stratified Wilcoxon rank sum test. Often, criterion information is available only for selected examinees, for instance, those who are admitted or hired. Three cases are discussed: (i) selection at random, (ii) selection based on the current test, and (iii) selection based on other measures of the latent construct. Discriminant validity is also discussed.This work was supported in part by Grant SES-87-01890 from the Measurement Methods and Data Improvement Program of the U.S. National Science Foundation.  相似文献   
57.
Three experiments were designed to investigate the influence of initial recall on memory by assessing delayed recall after different immediate cued-recall tests. In all experiments, subjects performed semantic and phonemic encoding tasks on a word list. The subjects then received a cued-recall test that cued the target using the same word as the context word in the encoding task, a test that cued the target with a word from the same level at which the target was encoded, a test that cued the target with a cue from a different level at which the target was encoded, or no immediate-recall test. One day later, the subjects performed a final cued-recall test in which the type of cue (semantic or phonemic) was varied. Consistently, delayed recall was facilitated primarily when the cue on the immediate test was from the same level as the cue on the delayed test. This pattern of facilitation suggests that immediate cued-recall produces an elaboration of an existing memory representation that is closely tied to the type of cue used on the immediate test.  相似文献   
58.
Research conducted primarily in the United States suggests that the combination of Type A behaviour, high instrumentality, and low expressiveness may place individuals at relatively high risk for coronary-artery and heart disease. The present research investigates the trans-societal generalizability of the structure, reliability, relationships among, and distributional characteristics of these measures for 117 college students in Athens, Greece. As hypothesized, the Greek students were significantly less instrumental and less expressive than the American students, and scored significantly higher on the measure of Type A. Although there were significant mean differences between these samples, the results suggest that many of the interscale relationships are comparable, supporting an etic (universal) interpretation of the findings. Nevertheless, the results suggested several emic (unique) characteristics of these measures and their interrelationships.  相似文献   
59.
60.
While psychologists have recognized the importance of cultural differences in many areas, multicultural ethical guidelines for psychology are still lacking. This article will review some of the controversial issues that cultural differences raise and discuss literature published on multicultural ethics. The existing American Psychological Association Ethical Principles will be reviewed with suggestions for specific changes to meet the needs of a multicultural society.  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