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   4034篇
  免费   402篇
  国内免费   703篇
  2023年   52篇
  2022年   89篇
  2021年   104篇
  2020年   128篇
  2019年   125篇
  2018年   168篇
  2017年   160篇
  2016年   155篇
  2015年   122篇
  2014年   127篇
  2013年   365篇
  2012年   224篇
  2011年   295篇
  2010年   243篇
  2009年   224篇
  2008年   260篇
  2007年   355篇
  2006年   347篇
  2005年   251篇
  2004年   170篇
  2003年   121篇
  2002年   108篇
  2001年   90篇
  2000年   86篇
  1999年   83篇
  1998年   48篇
  1997年   35篇
  1996年   22篇
  1995年   32篇
  1994年   24篇
  1993年   28篇
  1992年   26篇
  1991年   27篇
  1990年   46篇
  1989年   29篇
  1988年   21篇
  1987年   25篇
  1986年   19篇
  1985年   29篇
  1983年   13篇
  1982年   21篇
  1980年   13篇
  1979年   14篇
  1978年   14篇
  1976年   12篇
  1975年   13篇
  1973年   15篇
  1970年   13篇
  1969年   11篇
  1968年   14篇
排序方式: 共有5139条查询结果,搜索用时 15 毫秒
151.
The purpose of this study was to assess the reliability and validity of a single-item measure of Usual Physical Activity and to assess its usefulness as a physical activity tool for perimenopausal women. 188 perimenopausal women participated (age: M = 47 yr., SD = 3; range = 40-55). Data were collected using the Women's Health Assessment Scale, the Physical Activity Questionnaire, the Perimenopause-related Quality of Life Scale, a health history and demographic questionnaire, and the rater. Scores were stable over a 2-wk. interval. Convergent validity was supported by a correlation of .66 between ratings on Usual Physical Activity and the Physical Activity Questionnaire. Concurrent validity was supported by the association of the rating of Usual Physical Activity with three parameters of Body Mass Index, psychosomatic symptoms, and perimenopause related quality of life, known to be associated with physical activity. Highly active women had a lower Body Mass Index than less active and inactive women. Active women tended to report fewer and less distressing psychosomatic symptoms and better quality of life. These findings support the use of rating of Usual Physical Activity to classify perimenopausal women into categories of physical activity.  相似文献   
152.
Although the vagus nerve has traditionally been considered to perform efferent functions, in reality it performs significant afferent functions as well, carrying information from the body, head, and neck to the brain. Preliminary studies examining this afferent activity led to the theory that vagus nerve stimulation (VNS) could successfully control seizure activity in persons who are refractory to antiepileptic medications. Unlike other forms of brain stimulation, VNS is unable to directly stimulate multiple discrete areas of the brain; however, through several pathways, it is able to relay sensory information to higher brain regions. An implantable VNS device known as the VNSTM NeuroCybernetic Prosthesis (NCP) System has been used in approximately 9,000 epilepsy patients in Europe and the United States since 1994. The implant has reduced seizure frequency by an average of 25% to 30%, with minimal side effects. Studies underway are also showing some degree of success in the management of treatment-refractory depression. The future efficacy of the implantable system in other disorders may depend on whether the implant can be more precisely focused to affect different brain regions. Research in this area is underway.  相似文献   
153.
"中小学生心理健康"公众观的调查和分析   总被引:15,自引:3,他引:12  
李凌  缪小春 《心理科学》2000,23(5):537-541
本研究调查分析了家长、教师对中小学生心理健康判断标准的认识.因素分析表明,家长主要强调四个因素"精神和神经病症"、"良好品行"、"健康人格"和"循环性";教师则强调五个因素"精神分裂症状"、"神经质"、"好学生标准"、"不良人格"和"不良品行".公众对于情、意、个性及社会适应等同心理健康的关系认识较为清楚,但对认知、品行及体征与之的关系认识则片面和模糊."好学生标准"对判断有重要影响.  相似文献   
154.
Response time (RT) distributions from three fixed foreperiod conditions (2, 4, and 8 s) in a warned four-choice RT task were obtained for a group of boys with attention-deficit/hyperactivity disorder, combined type (ADHD; n = 17) and for two groups of normal control boys (age-matched, n = 18, and younger-aged, n = 10). Quantitative measures of distributional shape were derived by fitting the ex-Gaussian distributional model to the individual RT data. Statistical results indicate that the ADHD distributions differ from the age-matched control distributions with respect to the size of the tail (larger for the ADHD boys), but differ from the younger control distributions with respect to the location of the leading edge (slower for the younger control boys). Receiver operating characteristic (ROC) results reveal that the ex-Gaussian exponential component is highly diagnostic of the ADHD boys.  相似文献   
155.
The present study evaluated the singular and interactive effects of a functional polymorphism (variation) in the serotonin transporter (5-HTT) gene and a psychological trait (anxiety sensitivity [AS], i.e., fear of arousal symptoms) in predicting subjective and physiological responses to a 35% carbon dioxide (CO2) challenge in a community sample (N = 72). Genotypes were divided into 2 groups in accord with prior research. Findings were partially supportive of the hypothesized risk model. These indicated that the Group L genotype (homozygous for the 1 allele), compared with the Group S genotype (homozygous for the s allele plus heterozygous individuals), predicted greater fearful response to the biological challenge. There was also an AS x Genotype interaction predicting heart rate variability (HRV) in response to the CO2, suggesting that high AS plus Group L status predicts decreased HRV.  相似文献   
156.
We investigated the regulation of sequential action using a new paradigm. Participants learned a sequence of seven stimulus categories and then monitored for them during successive displays. All displays were instances of these categories, presented in pseudorandom order. On each trial, participants monitored for an instance of Category 1, pressed a key on a computer keyboard, then monitored for an instance of Category 2, pressed a key on the keyboard, and so on for all seven categories. Thus, a perfect trial contained exactly seven responses. Intrusion errors were classified as a function of ordinal distance from the current serial position ( n ). Fewer intrusion errors were made at near serial positions than at far ones, suggesting a gradient of lateral inhibition. In addition, more intrusions were made on n + 1 categories than n − 1 categories, suggesting greater availability of intended than completed goals. In accord with current models of sequential action, the results indicate lateral and self-inhibition as important mechanisms in regulation of sequential action.  相似文献   
157.
158.
Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically coded. No opiate-exposure effects were detected. However, mothers of cocaine-exposed infants showed more negative engagement than other mothers. The cocaine-exposed dyads also showed higher overall levels of mismatched engagement states than other dyads, including more negative engagement when the infants were in states of neutral engagement. Infants exposed to heavier levels of cocaine showed more passive-withdrawn negative engagement and engaged in more negative affective matching with their mothers than other infants. Although effect sizes were small, cocaine exposure, especially heavy cocaine exposure, was associated with subtly negative interchanges, which may have a cumulative impact on infants' later development and their relationships with their mothers.  相似文献   
159.
From among the diverse meanings of stability, the one the author adopts here is that the effects of a perturbation are opposed, and therefore small effects remain small. Except in linear systems, however, instability need not lead to unbounded motion and may actually be desirable when maneuverability is important. Moreover, properties of nerves, muscles, and tendons present serious challenges to stabilization. A review of observations from the motor control literature reveals that responses to perturbations in many common situations assist rather than resist the perturbation and are therefore presumably destabilizing. The observations encompass situations of position maintenance as well as impending or ongoing movement. The author proposes that the motor control system responds to a sudden perturbation by a pattern of muscle activity that mimics an accustomed voluntary movement, oblivious of stability considerations. What prevents runaway motion in the face of short-term instability appears to be voluntary intervention.  相似文献   
160.
The authors examined the stability and dynamic structure of negative cognitions made to naturalistic stressors and the prediction of depressive symptoms in a daily diary study. Young adults reported on dispositional depression vulnerabilities at baseline, including a depressogenic cognitive style, dysfunctional attitudes, rumination, neuroticism, and initial depression, and then completed short diaries recording the inferences they made to the most negative event of the day along with their experience of depressive symptoms every day for 35 consecutive days. Daily cognitions about stressors exhibited moderate stability across time. A traitlike model, rather than a contextual one, explained this pattern of stability best. Hierarchical linear modeling analyses showed that individuals' dispositional depressogenic cognitive style, neuroticism, and their daily negative cognitions about stressors predicted fluctuations in daily depressive symptoms. Dispositional neuroticism and negative cognitive style interacted with daily negative cognitions in different ways to predict daily depressive symptoms.  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