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   3716篇
  免费   247篇
  国内免费   2篇
  2023年   41篇
  2022年   31篇
  2021年   45篇
  2020年   95篇
  2019年   131篇
  2018年   143篇
  2017年   164篇
  2016年   151篇
  2015年   106篇
  2014年   140篇
  2013年   488篇
  2012年   189篇
  2011年   224篇
  2010年   123篇
  2009年   142篇
  2008年   196篇
  2007年   138篇
  2006年   146篇
  2005年   130篇
  2004年   142篇
  2003年   126篇
  2002年   110篇
  2001年   44篇
  2000年   49篇
  1999年   27篇
  1998年   42篇
  1997年   39篇
  1996年   35篇
  1995年   24篇
  1994年   21篇
  1993年   15篇
  1992年   28篇
  1991年   23篇
  1990年   22篇
  1989年   21篇
  1988年   19篇
  1987年   26篇
  1986年   28篇
  1985年   25篇
  1984年   31篇
  1983年   33篇
  1982年   22篇
  1981年   17篇
  1980年   27篇
  1979年   20篇
  1978年   16篇
  1977年   20篇
  1976年   17篇
  1975年   8篇
  1974年   9篇
排序方式: 共有3965条查询结果,搜索用时 15 毫秒
171.
The association of college attendance with alcohol use and alcohol use disorders was examined in a population-based young adult female twin sample identified from a systematic search of birth records. College-attending women consumed a larger overall volume of alcohol than did their non-college-attending peers, but they were not more likely to be diagnosed with an alcohol use disorder. Significant associations between college attendance and alcohol involvement were probed using 3 different complementary research designs: multivariate cross-sectional analyses, longitudinal analyses of the precollege and college years, and cotwin-control analyses of twin pairs discordant for attending college. Although demographic and lifestyle characteristics accounted for most or all of the association between college attendance and alcohol involvement, there was 1 aspect of drinking behavior, occasionally consuming large quantities of alcohol, that remained significantly associated with college attendance even after controlling for these characteristics or for genetic and family background factors. These results are consistent with the conclusion that some aspect of the college experience may be an important environmental risk factor for this pattern of drinking among young adults.  相似文献   
172.
The authors examined the core characteristics, component processes, antecedents, and function of state inspiration. In Studies 1 and 2, inspiration was contrasted with baseline experience and activated positive affect (PA) using a vivid recall methodology. Results supported the tripartite conceptualization of inspiration. Confirmatory factor analysis indicated that inspiration may be decomposed into separate processes related to being inspired "by" and being inspired "to." Study 3 found that daily inspiration is triggered by illumination among individuals high in receptive engagement, whereas activated PA is triggered by reward salience among individuals high in approach temperament. Approach temperament was also implicated in being inspired "to." Inspiration and activated PA appear to serve different functions: transmission and acquisition, respectively.  相似文献   
173.
Catatonia, long viewed as a motor disorder, may be better understood as a fear response, akin to the animal defense strategy tonic immobility (after G. G. Gallup & J. D. Maser, 1977). This proposal, consistent with K. L. Kahlbaum's (1874/1973) original conception, is based on similarities between catatonia and tonic immobility ("death feint") as well as evidence that catatonia is associated with anxiety and agitated depression and responds dramatically to benzodiazepines. It is argued that catatonia originally derived from ancestral encounters with carnivores whose predatory instincts were triggered by movement but is now inappropriately expressed in very different modern threat situations. Found in a wide range of psychiatric and serious medical conditions, catatonia may represent a common "end state" response to feelings of imminent doom and can serve as a template to understand other psychiatric disorders.  相似文献   
174.
A semantic differential scale was administered to 208 school children when they were in the second, fourth, sixth, eighth, tenth, and twelfth grades. Their perceptions towards two concepts were measured, Education (going to school) and Work (having a job). Each semantic differential scale had 15 adjective pairs and reflected the three underlying factors of Evaluative, Potency, and Activity. Because the study was conducted for 10 years (ages seven to 18), the changing cognitive developmental stages of the children were expected to influence factor analytic and reliability results. Confirmatory factor analysis, which forced the data into three factors, did not clearly identify the expected three factors, although more items loaded on the three factors with age. An exploratory factor analysis identified a trend across grades from six to four factors over time. Reliability also improved across age groups. Caution should be exercised when using the semantic differential with young children in investigations of abstract concepts.  相似文献   
175.
Cortical reorganization in poststroke aphasia is not well understood. Few studies have investigated neural mechanisms underlying language recovery in severe aphasia patients, who are typically viewed as having a poor prognosis for language recovery. Although test-retest reliability is routinely demonstrated during collection of language data in single-subject aphasia research, this is rarely examined in fMRI studies investigating the underlying neural mechanisms in aphasia recovery. The purpose of this study was to acquire fMRI test-retest data examining semantic decisions both within and between two aphasia patients. Functional MRI was utilized to image individuals with chronic, moderate-severe nonfluent aphasia during nonverbal, yes/no button-box semantic judgments of iconic sentences presented in the Computer-assisted Visual Communication (C-ViC) program. We investigated the critical issue of intra-subject reliability by exploring similarities and differences in regions of activation during participants' performance of identical tasks twice on the same day. Each participant demonstrated high intra-subject reliability, with response decrements typical of task familiarity. Differences between participants included greater left hemisphere perilesional activation in the individual with better response to C-ViC training. This study provides fMRI reliability in chronic nonfluent aphasia, and adds to evidence supporting differences in individual cortical reorganization in aphasia recovery.  相似文献   
176.
At the centenary of Spearman's seminal 1904 article, his general intelligence hypothesis remains one of the most influential in psychology. Less well known is the article's other hypothesis that there is "a correspondence between what may provisionally be called 'General Discrimination' and 'General Intelligence' which works out with great approximation to one or absoluteness" (Spearman, 1904, p. 284). Studies that do not find high correlations between psychometric intelligence and single sensory discrimination tests do not falsify this hypothesis. This study is the first directly to address Spearman's general intelligence-general sensory discrimination hypothesis. It attempts to replicate his findings with a similar sample of schoolchildren. In a well-fitting structural equation model of the data, general intelligence and general discrimination correlated .92. In a reanalysis of data published byActon and Schroeder (2001), general intelligence and general sensory ability correlated .68 in men and women. One hundred years after its conception, Spearman's other hypothesis achieves some confirmation. The association between general intelligence and general sensory ability remains to be replicated and explained.  相似文献   
177.
Following F. Zaal and R. J. Bootsma (1995), the authors studied whether the decelerative phase of a reaching movement could be modeled as a constant tau-dot strategy resulting in a soft collision with the object. Specifically, they investigated whether that strategy is sustained over different viewing conditions. Participants (N = 11) were required to reach for 15- and 50-mm objects at 2 different distances under 3 conditions in which visual availability of the immediate environment and of the reaching hand were varied. Tau-dot estimates and goodness-of-fit were highly similar across the 3 conditions. Only within-participant variability of tau-dot estimates was increased when environmental cues were removed. That finding suggests that the motor system uses a tau-dot strategy involving the intermodal (i.e., visual, proprioceptive, or both) specification of information to regulate the decelerative phase of reaching under restricted viewing conditions. The authors provide recommendations for improving the derivation of tau;(x) estimates and stress the need for further research on how time-to-contact information is used in the regulation of the dynamics of actions such as reaching.  相似文献   
178.
A very powerful form of preoedipal guilt stems from a sense of having damaged the life-giving parent with one's most basic needs. A related phenomenon is the child's sense that another subjectivity has deliberately chosen to give and sustain the child's life. This experience gives rise to a compelling mixture of awe, reverence, and obligation, a sense of guilt about being born, of debt concerning the gift of life. This sense of guilt and debt are part of every child's development. Depending on how conflicts surrounding them are negotiated, the child can come to feel either an appetite for living or a crushing sense of selfishness and unworthiness. Such forms of guilt and debt may lead not only to masochism generally, but to a particularly pernicious form of negative therapeutic reaction that can sabotage psychoanalytic work. A patient may feel, for instance, that a successful psychoanalysis is a selfish indulgence and an immoral betrayal of a sacred duty to rescue his or her parents from their misery. Guilt about being born and the sense of debt concerning the gift of life are linked to various developmental, psychodynamic, interpersonal, and cultural phenomena.  相似文献   
179.
Potential problems with "well fitting" models   总被引:1,自引:0,他引:1  
  相似文献   
180.
Several techniques have been used in applied research as controls for the introduction of a reinforcement contingency, including extinction, noncontingent reinforcement (NCR), and differential reinforcement of other behavior (DRO). Little research, however, has examined the relative strengths and limitations of these "reversal" controls. We compared the effects of extinction with those of NCR and DRO in both multi-element and reversal designs, with respect to (a) rate and amount of response decrement, (b) rate of response recovery following reintroduction of reinforcement, and (c) any positive or negative side effects associated with transitions. Results indicated that extinction generally produced the most consistent and rapid reversal effects, with few observed negative side effects.  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