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   26734篇
  免费   1111篇
  国内免费   15篇
  27860篇
  2021年   240篇
  2020年   328篇
  2019年   380篇
  2018年   615篇
  2017年   624篇
  2016年   624篇
  2015年   450篇
  2014年   502篇
  2013年   2401篇
  2012年   997篇
  2011年   1025篇
  2010年   623篇
  2009年   520篇
  2008年   799篇
  2007年   794篇
  2006年   681篇
  2005年   634篇
  2004年   530篇
  2003年   521篇
  2002年   553篇
  2001年   793篇
  2000年   775篇
  1999年   582篇
  1998年   239篇
  1996年   241篇
  1995年   216篇
  1992年   476篇
  1991年   463篇
  1990年   448篇
  1989年   423篇
  1988年   440篇
  1987年   389篇
  1986年   395篇
  1985年   397篇
  1984年   321篇
  1983年   285篇
  1979年   366篇
  1978年   262篇
  1977年   216篇
  1976年   211篇
  1975年   287篇
  1974年   364篇
  1973年   375篇
  1972年   297篇
  1971年   288篇
  1970年   286篇
  1969年   257篇
  1968年   358篇
  1967年   315篇
  1966年   291篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Two experiments were conducted using an autoshaping procedure with pigeons to examine whether dimensional stimulus control by a Pavlovian facilitator parallels the control established following operant discrimination training. Facilitation training consisted of the presentation of a black vertical line on a white background as the B stimulus in a feature-positive discrimination in which the A stimulus (white keylight) was followed by grain presentation only if preceded by B. In this way, B facilitates or sets the occasion for pecking at A. Subsequent testing for generalization along the line-orientation dimension produced decremental gradients when the facilitation paradigm incorporated an explicit feature-negative stimulus (B−). These results parallel the decremental control obtained following operant discrimination training and suggest that Pavlovian facilitators and instrumental discriminative stimuli are functionally equivalent.  相似文献   
982.
983.
The purposes of this study were to (1) describe errors in weightbearing at three target levels for patients with neuropathic feet and control subjects, (2) compare the absolute errors at the three target levels between groups, and (3) identify predictor variables of errors in weightbearing by the neuropathic group. The groups of 26 subjects were matched for age and height. Weightbearing was measured with digital scales while subjects attempted to adjust their weight through a designated lower extremity to each target level (25, 50, and 75% of body weight). Analysis of variance indicated no significant difference in the percentage weightbearing between groups at the three target levels. There was a significant difference in errors made in weightbearing by the groups at the three target levels. Mean errors ranged from 8.5 to 9.7% for the neuropathic group and from 2.4 to 6.6% for the control group. The findings cast doubt on the utility (in the absence of feedback) of requesting individuals, particularly those with neuropathic feet, to weightbear at specific target levels.  相似文献   
984.
A 3-mo. follow-up was made of 64 male veterans who were discharged from a 21-day Alcohol Detoxification Treatment Program at the Veterans Affairs Medical Center at Lyons, NJ. Scores on the Rotter I-E and Alcohol Responsibility Scales were significantly correlated with tendencies toward a more external direction among the 13% who relapsed, significant on the I-E scale and nonsignificant on the Alcohol Responsibility Scale. When tests were compared as possible predictor variables of alcoholic relapse, the difference in favor of the I-E scale was statistically nonsignificant.  相似文献   
985.
The aim of this study was to investigate the possible relations between specific personality variables and the effect of subliminal stimulation on choice behavior. It was hypothesized that subjects with low anxiety, less neuroticism, and external locus of control and the trait of extraversion would be more susceptible to subliminal stimulation. 38 undergraduate students were exposed to subliminal messages urging them to choose symbols instead of numbers or letters. Analysis showed that subliminal stimulation did not generate a preference for symbols over numbers or letters. No support was observed for the hypothesis of an association between susceptibility and personality variables. These results may be explained in terms of symbol choice being a neutral message that did not relate to the subjects' needs and motivation.  相似文献   
986.
Responsiveness of 1-, 3-, and 5-year-old children and adults to octave-band noises at .4 and 10 kHz was assessed with a go/no-go version of visual reinforcement audiometry (VRA) (Moore, Thompson, & Thompson, 1975) and a two-alternative, forced-choice version (Suzuki & Ogiba, 1961; Trehub, Schneider, & Endman, 1980). Infants performed better on the two-alternative, forced-choice version in quiet and in noisy backgrounds, and adults performed better on the two-alternative, forced-choice version in quiet but not in noisy backgrounds. Performance on the two tasks was essentially equivalent for 3- and 5-year-old children. Superior performance on two-alternative VRA over go/no-go may be due to lesser cognitive demands in the case of infants and to the engagement of superior decision strategies in the case of adults.  相似文献   
987.
An article by Leigh (1989d) examined certain substantive and measurement-related limitations of research on alcohol outcome expectancies. Leigh (1989d) criticized research in this field on both conceptual and methodological grounds and speculated on future theoretical directions for research in the field. In their response, Goldman, Brown, Christiansen, and Smith (1991) contended that Leigh's critique is faulty in important respects. However, some of their points are based on misinterpretations of Leigh's comments, and they appear to have insufficient appreciation of conditions necessary for comprehensive measurement validation and for meaningful application of theories of memory to alcohol expectancy research. Despite the limitations of expectancy research, exciting avenues exist for further work.  相似文献   
988.
Essential hypertension is a chronic disorder having many potential physical and behavioral sequelae. This article evaluates the impact of hypertension on neuropsychological test performance. First, cross-sectional and longitudinal studies that examine the neuropsychological correlates of hypertension are reviewed. In general, hypertensives are found to perform more poorly than normotensives, particularly on tests of memory, attention, and abstract reasoning, and less consistently on tests of perception, constructional ability, mental flexibility, and psychomotor speed. Next, the influence of variables that may moderate relationships between hypertension and neuropsychological performance--such as age, education, and medication usage--are examined. Finally, potential mechanisms, both physiological and psychological, underlying associations between hypertension and neuropsychological performance are discussed.  相似文献   
989.
Analyses of interpersonal behavior within a borderline population usually focus on object relations variables. In contrast, this preliminary research focuses on the nature of attachment styles and its relation to behavioral pathology. 24 hospitalized borderline patients were administered an Attachment Style Inventory and Millon Clinical Multiaxial Inventory. Analysis confirms predicted differences in attachment style between the borderline and normal control samples as well as indicates that a dependent style of attachment within this borderline sample is associated with less pathology than an avoidant, hostile, or resistant/ambivalent style. The implications of this preliminary work for full-scale research are addressed.  相似文献   
990.
Childhood peer rejection, aggression, withdrawal, and perceived competence were compared as predictors of self-reported behavior problems. Peer sociometric status (Coie, Dodge, and Coppotelli, 1982), teacher ratings of behavior problems (Lorion, Cowen, & Caldwell, 1975), and perceived competence ratings (Harter, 1982) were obtained for 613 second-through fourth-grade children. Two years later, these students completed a modified version of the Youth Self-Report form (Achenbach & Edelbrock, 1987). Rejected children and neglected girls were more likely to have a self-reported nonspecific negative outcome than others. Neglected girls were at heightened risk for depression. A varied set of predictors obtained from different informants emerged for each sex for each of the specific self-reported outcomes of depression, unpopularity, delinquency, aggression, and self-destructive/identity problems. Results are discussed in terms of future directions for longitudinal research on the consequences of poor peer relationships in childhood.This research was supported in part by a grant from the W. Alton Jones Foundation and in part from Cooperative Agreement (G0087C3033) between the U.S. Department of Education, Office of Special Education and Rehabilitative Services, and the University of Virginia. However, the opinions expressed herein do not necessarily represent the opinions of the funding agencies. Portions of this paper were presented at the First Annual Meeting of the Society for Research in Child and Adolescent Psychopathology, Miami, Florida. The authors would like to thank Robert Terry, Ruth Axman, Pamela Griesler, Melissa DeRosier, Nancy Vaden, Charlene Eickholt, Amy Young, Emily Burhans, Eric Johnson, Renee Lorio, and Karen Welke for their assistance in conducting this research project.  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