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   24528篇
  免费   1017篇
  国内免费   17篇
  2021年   189篇
  2020年   299篇
  2019年   344篇
  2018年   630篇
  2017年   620篇
  2016年   690篇
  2015年   484篇
  2014年   460篇
  2013年   1763篇
  2012年   1037篇
  2011年   1107篇
  2010年   504篇
  2009年   515篇
  2008年   722篇
  2007年   688篇
  2006年   593篇
  2005年   1775篇
  2004年   1122篇
  2003年   885篇
  2002年   575篇
  2001年   762篇
  2000年   749篇
  1999年   518篇
  1998年   231篇
  1997年   213篇
  1996年   170篇
  1995年   168篇
  1993年   166篇
  1992年   387篇
  1991年   362篇
  1990年   390篇
  1989年   374篇
  1988年   341篇
  1987年   323篇
  1986年   340篇
  1985年   331篇
  1984年   261篇
  1983年   222篇
  1979年   218篇
  1978年   168篇
  1975年   206篇
  1974年   270篇
  1973年   217篇
  1972年   221篇
  1971年   180篇
  1970年   162篇
  1969年   212篇
  1968年   214篇
  1967年   173篇
  1966年   194篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
911.
The detectability of a target pattern presented briefly with a number of similar nontarget patterns varies as a function of the spatial location of the target. Previous work attributes these detectability gradients to a visual search process--a non-eye movement serial scan--that examines a decaying neural representation of the image. (Heron, 1957; Efron, Yund, & Nichols, 1987, 1990a,b,c; Yund, Efron, & Nichols, 1990a,b,c). The results reported in the companion paper (Ostrosky-Solis, Efron, & Yund, 1991) indicated that literacy did not affect overall performance levels but did influence scanning behavior: "...reading, or learning to read, caused the scanning mechanisms of literate subjects to adopt more consistent scan paths, from subject to subject, than they would have adopted without this reading experience." The purpose of the present experiment was to determine the effect on this scanning mechanism, if any, of an entirely different type of visual experience--the high-speed visual processing required of tennis players. Unlike reading which requires the linguistic interpretation of a highly structured visual input, tennis skill requires rapid target detection and tracking in three-dimensional visual space as well as large scale visual-motor coordination. As in the previous experiments, subjects were required to detect a vertical stripe pattern among a number of similar non-target patterns. The experiment was performed on a group of 52 tennis players and on an age- and sex-matched group of 52 non-tennis players. The overall accuracy of target detection was greater among the tennis players than among the non-tennis players and, of more interest, there was a significant difference in the detectability gradients. The detection advantage of the tennis group seemed to reach its maximum in the first half of the scan and then to deteriorate as the scan proceeded. These results indicate that visual experience other than reading can affect the habitual activity of the scanning mechanism.  相似文献   
912.
Maximizing the potential of worksites for smoking intervention remains elusive. We hypothesized that long-term effectiveness of group intervention would be enhanced when offered within an "enriched milieu" (full program) compared with relative isolation (group only). The data failed to support the hypothesis. Although sustained abstinence rates were higher at full-program sites (50%) than at group-only sites (44%), the difference did not achieve statistical significance. Initial (35% vs. 47%) and 12-month (18% vs. 22%) quit rates at full-program and group-only sites also failed to demonstrate the "benefit" of the "enriched milieu."  相似文献   
913.
Self-management of diabetes mellitus: a critical review   总被引:5,自引:0,他引:5  
Diabetes has no known cure and is a leading source of morbidity and mortality. Clinical management involves patients managing a complex and variable regimen. This article reviews the determinants of effective self-management and the methods of promoting better self-management. Trait variables (e.g., personality and demographics) have been presumed to affect self-management, but evidence suggests they have little impact. The important determinants of self-management are transient situational factors such as psychological stress and social pressure to eat. Interventions to promote better self-management have reported initial improvements in blood glucose control, but the long-term effects are unclear. We conclude that self-management has been inadequately assessed and that attempts to improve self-management have relied excessively on providing information. More research is needed to clarify determinants of self-management, and interventions to improve self-management will need to change these determinants.  相似文献   
914.
The purpose of this study was to investigate the effect of cosmetics use on attributions concerning the likelihood of provoking sexual harassment and of being sexually harassed. Subjects were 85 female and 76 male undergraduate volunteers. The study was a 3×2 between-subjects design with three levels of cosmetics use (heavy, moderate, no cosmetics) and two levels of sex of subject (male, female). Each subject viewed one of three colored photographs of a model wearing either heavy, moderate, or no cosmetics, and then indicated how likely the model was to provoke sexual harassment and to be sexually harassed. Data were analyzed using analyses of variance and the Newman-Keuls test. When the model wore heavy cosmetics, she was rated as more likely to provoke sexual harassment than when she wore moderate cosmetics. Similarly, when the model wore moderate cosmetics, she was rated as significantly more likely to provoke sexual harassment than when she was not wearing cosmetics. When the model wore either heavy or moderate cosmetics, she was also rated as more likely to be sexually harassed than when she did not wear cosmetics. In addition, male subjects rated the model as more likely to provoke and to be sexually harassed than did female subjects. Results are discussed in terms of sex role spillover.  相似文献   
915.
The present investigation focused upon the impact of gender and various powerful and less powerful linguistic features on the communication of unfamiliar male and female college students. Same-sex and mixed-sex dyads were recorded as they engaged in discussions regarding suggestions for a bogus freshman orientation booklet. Although few gender differences were found, the result of a factor analysis yielded three factors: questions, suggestions, and process variables. These factors are consistent with a power perspective in the use of various linguistic features. However, the present findings suggest that gender and power alone cannot explain differences in communication styles. Rather, the results suggest the need to consider other aspects of the speaker to explain differences that occur in the use of language.  相似文献   
916.
Very few behavioral patterns generalize across human and nonhuman species. We describe washing, drying, and anointing sequences in humans (Homo sapiens) that may have analogies with other species. The rank ordering of washing, drying, and anointing body parts was obtained over 3 successive days for 37 men and 60 women. Variation in rank ordering of body parts was nonrandom, and a cephalocaudal progression was evident for each behavior. Reliability of the behaviors as well as the correlations across rankings were highly significant, which indicates a generalized cephalocaudal progression for all 3 behaviors. Women's anointing was most variable, which suggests a more specific function. The cephalocaudal action pattern described for humans is similar to that for Mongolian gerbils and laboratory rats. Cross-species functions, such as these, may add to our understanding of common developmental and learning processes.  相似文献   
917.
The present study examined the differences in internal and external locus of control and imposter phenomenon among persons with alcoholic and non-alcoholic parents. The subjects were 48 college students and 21 members of local Adult Children of Alcoholic groups. The students were further divided into those with alcoholic parents and non-alcoholic parents. The subjects were administered the following three instruments: the Nowicki-Strickland Internal-External Control Scale for Adults (Nowicki & Duke, 1973), the Imposter Test (Chance & O’Toole, 1987), and a family history survey. Analysis of locus of control scores revealed a highly significant (p<.01) difference for externality, with Adult Children being most external and students with non-alcoholic parents least external. Similarly, internality scores differed significantly (p<.0001), with Adult Children being least, and the non-alcoholic group being most internally oriented. Analysis of variance for imposter phenomenon revealed a significant (p<.05) difference among the three groups, with the Adult Children of Alcoholics group having the highest scores and students with non-alcoholic parents having the lowest. These findings are consistent with the idea that parental alcoholism interferes with nurturing and consistent reinforcement, and with the development of personal adaptability.  相似文献   
918.
The mental health service delivery system is experiencing a transformation attendant to rapidly developing cost containment mechanisms. This article reviews various aspects of the new managed mental health care systems and details the gains and losses the various mental health service provider professions may experience depending upon how each responds to the changing demands of alternate service delivery systems. Recommendations are presented regarding how counselors can establish a solid base in the new managed mental health care system.  相似文献   
919.
The interrelationship of measures of rigidity-flexibility and of psychometric intelligence is examined. The latent factors of Attitudinal Flexibility, Motor-Cognitive Flexibility, and Psychomotor Speed are derived from the Test of Behavioral Rigidity, and factors of Inductive Reasoning, Spatial Orientation, Verbal Ability, Numeric Ability, Verbal Memory, and Perceptual Speed are derived from the Thurstone Primary Mental Abilities Test and the Educational Testing Service Kit of Factor-Referenced Tests. The data base in this study comes from the fifth wave of the Seattle Longitudinal Study (N = 1,628; age range, 22-95 years). The Rigidity-Flexibility factors were found to be independent of the cognitive domain. Also, longitudinal stability of the factor structure of the rigidity-flexibility domain was confirmed for 837 participants tested in both 1977 and 1984.  相似文献   
920.
Thirty community-dwelling, moderately depressed elderly were randomly assigned to 1 of 3 interventions: experimenter-accompanied exercise in the form of walking, a social contact control condition, and a wait-list control. Exercise and social contact both resulted in significant reductions in both the total and the psychological subscale of the Beck Depression Inventory (BDI). The exercise condition, however, unlike the control conditions, resulted in decreased somatic symptoms of the BDI. These results indicate that, at least in the short term, exercise has a broader effect compared with control conditions in reducing depressive symptoms in the moderately depressed elderly.  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