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   1527篇
  免费   89篇
  国内免费   2篇
  2023年   11篇
  2022年   14篇
  2021年   23篇
  2020年   31篇
  2019年   44篇
  2018年   33篇
  2017年   69篇
  2016年   54篇
  2015年   41篇
  2014年   48篇
  2013年   177篇
  2012年   61篇
  2011年   50篇
  2010年   32篇
  2009年   41篇
  2008年   52篇
  2007年   60篇
  2006年   71篇
  2005年   55篇
  2004年   52篇
  2003年   35篇
  2002年   44篇
  2001年   37篇
  2000年   35篇
  1999年   30篇
  1998年   21篇
  1997年   28篇
  1996年   31篇
  1995年   30篇
  1994年   10篇
  1993年   18篇
  1992年   11篇
  1991年   18篇
  1990年   20篇
  1989年   14篇
  1988年   9篇
  1987年   10篇
  1986年   17篇
  1984年   14篇
  1981年   12篇
  1980年   9篇
  1979年   11篇
  1978年   9篇
  1977年   11篇
  1975年   10篇
  1974年   12篇
  1973年   8篇
  1972年   9篇
  1970年   9篇
  1968年   11篇
排序方式: 共有1618条查询结果,搜索用时 15 毫秒
91.
There are specific challenges to studying the design of pharmacologic trials in child/adolescent and adult autism, such as subject stratification and parallel versus crossover designs. This article describes how optimal study design is influenced by subject selection and outcome measures chosen. Lessons learned in study design from the Research Units on Pediatric Psychopharmacology Autism Network trial with risperidone, Seaver Center trials with fluoxetine and valproate, Dartmouth trials with amantadine, and National Institutes of Health secretin trials are highlighted. The Internet System for Assessing Autistic Children system for managing multicenter clinical trials in autism and statistical issues in autism research are also described.  相似文献   
92.
The experiment was setup to examine the coordination changes in assembling the movement form of 3-ball cascade juggling. Eight adult participants learned to juggle over 4 weeks of practice. Juggling scores were recorded at each session and performance was videotaped at eight selected sessions for purposes of movement analysis. Once the basic spatial and temporal constraints on cascade juggling were satisfied, and the figure-8 juggling mode was established, temporal modulations of the relative motions of the hands were emphasized. All participants learned to juggle and the increase over practice in the number of consecutive balls caught was best fit with a power law. The non-proportional rate of performance increment was consistent with the qualitative changes in the form of the hand and ball movement kinematics that occurred over practice.  相似文献   
93.
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   
94.
In a speeded choice reaction time task, responses to centrally presented letter targets can be altered by the identity of surrounding task-irrelevant letters (flankers). In the standard flanker effect, flankers associated with the same response as the target lead to faster and more accurate responses, whereas flankers associated with a different response lead to slower and more error-prone responses. B. A. Eriksen and C. W. Eriksen (1974, pp. 143-149) have argued that these flanker effects occur through response competition. We present data from a novel version of the Eriksen task, in which some targets and flankers consist of letter forms that are morphed versions of target letters. In this paradigm, flankers induce classic flanker effects on well-formed targets. But flankers induce an opposite effect, termed a negative flanker effect on morphed letter targets. For example, targets that are morphs between the letters "A" and "H" are more likely to be identified as an "A" when flanked by an "H." The interpretation advanced here is that there are two distinct kinds of flanker effects contrast enhancement in perceptual processes and response competition in response selection processes.  相似文献   
95.
Traditional methods for analyzing trends in longitudinal data have typically emphasized average group change over time. In this article, we propose multilevel, regression-based methods for examining inter-individual differences in intra-individual change and apply these methods to research in trauma and posttraumatic stress disorder (PTSD). The outcome or dependent variable of interest is reconceptualized as an index of dynamic change reflecting the trend or trajectory of an individual's PTSD symptom severity scores across time. A basic statistical model is presented, and analyses and findings are demonstrated with an existing database used in previously published studies. The methods offer promise for future study of the natural course of PTSD chronicity or recovery, risk and resilience factors that influence individual growth or decline, and critical timepoints for intervention.  相似文献   
96.
The present study investigated nighttime fears in normal school children aged 4 to 12 yr (N=176). Children and their parents were interviewed about the frequency, content, origins, coping behaviors and severity of children's nighttime fears. Results showed that 73.3% of the children reported nighttime fears, indicating that these fears are quite prevalent. Inspection of the developmental course of nighttime fears revealed that these fears are common among 4- to 6-year-olds, become even more frequent in 7- to 9-year-olds and then remain relatively stable in 10- to 12-year-olds. Inspection of the origins of nighttime fears revealed that most of the children (i.e., almost 80%) attributed their fear to negative information; conditioning and modeling were endorsed less frequently (25.6% and 13.2%, respectively). A substantial percentage of the children (24.0%) indicated that learning experiences had not played a role in the acquisition of their nighttime fears. Children reported a variety of coping strategies in order to deal with their nighttime fears and generally rated these strategies as helpful in reducing anxiety. Furthermore, children's nighttime fears were associated with moderate levels of anxiety. Moreover, in about 10% of the children, nighttime fears were related to one or more DSM-III-R anxiety disorders. Finally, parental reports of children's nighttime fears substantially deviated from children's reports. Most importantly, parents provided a marked underestimation of the frequency of nighttime fears, at least as reported by their children.  相似文献   
97.
This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.  相似文献   
98.
99.
Data from two multi-ethnic prospective studies of African American, Latina, and non-Hispanic White pregnant women were used to examine the influence of contextual factors on social support processes during pregnancy. Multiple types of support (perceived support, received support, support satisfaction, network support) and sources of support (baby's father, family, friends) were assessed. The role of ethnicity in social support was examined after controlling for the contribution of related contextual factors (SES, marital status, age, parity, employment) to these processes. The impact of ethnicity and related contextual factors differed across sources of social support. Ethnic differences in support from family and friends, but not from the baby's father, emerged. However, marital status was a consistent predictor of support from the baby's father, and SES was a consistent predictor of support from friends. Overall, the findings of two studies suggest that although ethnicity is associated with support from friends and family, other contextual factors, such as marital status and SES, influence support processes during pregnancy.  相似文献   
100.
The author's experience of reflection-on-action and reflection-in-action in clinical supervision for counseling provides the basis for an analogous experience in the classroom that promotes the teaching of the practice of general pastoral care. A classroom ritual of role play within a specific process for reflection provides the basis for integrating theory and practice.  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