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   7694篇
  免费   271篇
  国内免费   13篇
  2023年   65篇
  2021年   66篇
  2020年   127篇
  2019年   134篇
  2018年   164篇
  2017年   165篇
  2016年   204篇
  2015年   235篇
  2014年   265篇
  2013年   927篇
  2012年   366篇
  2011年   359篇
  2010年   320篇
  2009年   313篇
  2008年   330篇
  2007年   295篇
  2006年   263篇
  2005年   210篇
  2004年   180篇
  2003年   176篇
  2002年   138篇
  2001年   112篇
  2000年   88篇
  1999年   68篇
  1998年   60篇
  1997年   69篇
  1996年   65篇
  1995年   88篇
  1994年   82篇
  1993年   68篇
  1992年   85篇
  1991年   82篇
  1990年   80篇
  1989年   85篇
  1988年   90篇
  1987年   65篇
  1986年   69篇
  1985年   69篇
  1984年   70篇
  1983年   62篇
  1982年   81篇
  1981年   63篇
  1980年   81篇
  1979年   81篇
  1978年   91篇
  1977年   87篇
  1976年   88篇
  1975年   88篇
  1974年   86篇
  1973年   55篇
排序方式: 共有7978条查询结果,搜索用时 15 毫秒
131.
Tolbutamide has previously been shown to amplify the pressor effects of “exogenous” catecholamines in conscious dogs, possibly due to sensitization of the α1-adrenoreceptor-mediated vasoconstriction. The objective of this study was to examine if tolbutamide also amplifies the pressor effects of “endogenous” catecholamines released during psychological stress (classical Pavlovian aversive conditioning). Experiments were conducted in β-adrenoreceptor-blocked (propranolol, 1 mg/kg, i.v.) conscious dogs (n=4) trained in classical aversive conditioning. Conditioning was accomplished by following a tone (CS+) with a 1/2 second shock; another tone (CS-) was not followed by any shock and served as control. With saline pretreatment, aversive conditioning (i.e., CS+) increased mean arterial pressure (MAP) only by approximately 4.7% when compared to CS-, whereas with tolbutamide (45 mg/kg, i.v.) pretreatment, the increase in MAP induced by CS+ beyond what was induced by the CS- (approximately 6.2%) was significantly (p<0.05) larger than that with saline pretreatment. In isolated canine femoral arterial segments (n=4), the vasoconstrictor effect of phenylephrine (an α1-agonist) at 5×10?6M (which was the EC50 value) was amplified by 2×10?2M of tolbutamide from 54.0±2.0% to 66.9±2.1%. In conclusion, tolbutamide amplifies the pressor effects of “endogenous” catecholamines in conscious dogs, possibly by sensitization of the α1-adrenoreceptor-mediated vasoconstriction. This mechanism of action is novel and has not been reported with other agents.  相似文献   
132.
133.
The expressed affect of clinically depressed and nondepressed mothers as measured by the Schedule for Affective Disorders and Schizophrenia: Lifetime Version (SADSL) and their children (1 1/2 to 3 1/2 years) was observed in seminatural situations. The objectives were to investigate how maternal depression enters into affective interactions between mother and child and how the affect patterns of mother and child are related. Fortynine unipolar and 24 bipolar depressed mothers and 45 nondepressed mothers were observed on 2 days, 2 weeks apart, for a total of 5 h. Each minute was coded for the predominant affect of mother and child. Affects relevant to depression (anxioussad, irritableangry, downcast, pleasant, tenderaffectionate) were coded. Depressed mothers expressed significantly more negative affect than did control mothers. Mothers' expressed affect and their selfreports of affect on days of observation were unrelated. Mother's and child's affects, measured on different days, were significantly correlated. Unipolar mothers and mothers severely depressed spent significantly more time in prolonged bouts of negative affect. There was significant synchrony between their bouts and the negative bouts of their daughters. Gender of child was related to mother's and child's affect, and to relations between mother's and child's affect.  相似文献   
134.
Sixty-nine Cambodian adolescents and young adults were interviewed to determine their experience as children surviving the Pol Pot regime (1975–1979);their first-year experience of resettlement in this country; and their experience of stressful events during the past year. Current DSM-III-R diagnostic status was also determined. A strong relationship between earlier war trauma, resettlement strain, and symptoms of posttraumatic stress disorder (PTSD) was found. In contrast, the strongest relationship with depressive symptoms was found for recent stressful events. These results are discussed in light of current findings from stress and PTSD research.Dr. Clarke is Assistant Professor of Psychiatry in the Division of Child Psychiatry, Oregon Health Sciences University, Portland, Oregon. Dr. Sack is Director of the Division of Child Psychiatry and Principal Investigator of the Khmer Adolescent Project. Brian Goff is a Research Assistant.This project was supported by the National Institutes of Mental Health [NIMH] grant #5-RO1-MH42927-02, Dr. William H. Sack, M.D., Principal Investigator.  相似文献   
135.
This section draws attention to occupational stress and suggests ways in which psychologists can apply their knowledge of research methods and treatment to this issue. In this article, the past and present role of psychologists in occupational stress is examined and ways in which psychologists might play a more central role are proposed. Although industrial/organizational and health psychology are most obviously applicable to the study of workplace wellness, more focused attention and wider application of knowledge from other subspecialities are also examined. The need for increased attention to work and family; race, class, and gender; and training and public policy issues are also discussed.  相似文献   
136.
137.
Mutual influencing processes are assumed to be the basic building blocks in establishing parentchild bonding and in influencing cognitive and language behavior. A study by Jasnow and Feldstein (1986) revealed that, within the temporal domain of speech, preverbal (9-month-old) infants and their mothers exhibit a pattern of mutual influence (attunement) in their average durations of switching pauses. The general purpose of this research was to extend those findings to children with higher verbal functioning. In addition, parent and child genders, nature of the interaction, and specific aspects of parents' personalities, expressiveness, and instrumentality were considered. Each parent interacted with their 4-or 5-year-old son or daughter in each of two conversations—unstructured (social conversation) and structured (task activity). Conversations were processed by an automated computer system yielding objective measure of turns, vocalizations, pauses, and switching-pause durations. To examine interspeaker influence or attunement of temporal speech patterns, influence coefficients were computer for each speaker on a turn-by-turn basis using time series regression. Analysis of these coefficients revealed that: (1) Mutual influence is most evident with switching-pause duration. (2) Structure in the conversation (as defined by the task or parental instrumentality) seems to facilitate attunement for vocalization and switching pause duration. (3) Attunement with girls seems to occur equally well with both parents, while boys exhibit a style of temporal patterning influence which suggests greater identification with the father. (4) Expressiveness seems to facilitate attunement to the child's switching-pause duration.  相似文献   
138.
Some hypotheses concerning the evolution of polysemous words   总被引:1,自引:0,他引:1  
The evolution of polysemous words is examined in three studies. Study 1 indicates that older words are more polysemous than recent words, and that frequently used words are more polysemous than infrequently used words. These effects were replicated, controlling for word concreteness (Study 2) and evaluation (Study 3), using two other samples of words. If words evolve additional meanings through metaphor (MacCormac, 1985), then variables (such as concreteness and evaluation) that play a role in metaphor may mediate the evolution of polysemy. The correlation between concreteness and polysemy was negligible (Study 2). As hypothesized, evaluation is a significant predictor of polysemy: Negative words are more polysemous than positive words, and relatively neutral words are more polysemous than evaluatively extreme words. These findings are consistent with the notion that polysemous words evolve, in part, through metaphor.  相似文献   
139.
Compared four treatment conditions to test their ability to enhance compliance with vascular access cleansing (VAC) procedures in a group of 56 hemodialysis patients. The conditions were patient education, behavioral management with monetary incentive, patient education/behavioral management, and attention control. Behavioral observers rated VAC behavior at pretreatment, posttreatment 1-month follow-up, and 1-year follow-up. Knowledge of VAC procedures was also assessed via a questionnaire at pretreatment and posttreatment. Data were analyzed using repeated-measures multivariate analyses of variance. Results indicated that the patients in the education/behavioral, behavioral, and education groups gave significantly more correct answers on our VAC knowledge questionnaires at posttreatment than did patients in the attention control group. Further, patients in the education/behavioral and behavioral groups completed significantly more VAC steps at posttreatment and 1-month follow-up than did patients in the education group and in the attention control group. Differences were not maintained at 1-year follow-up, although more than 50% of the patients were lost to follow-up. Implications of the present findings for behavioral and educational interventions are discussed.  相似文献   
140.
The purpose of this study is to examine the relationships among sex, sex role orientation, and friendship. Based on the Bem Sex Role Inventory, 164 participants were categorized as either androgynous (17 males; 29 females), traditional (36 males; 39 females), or undifferentiated (26 males; 17 females) in their sex role orientation. Participants reported the number of close male and female friends, and responded to several questionnaires: interpersonal trust of male and female friends, communal and exchange orientations, affective and activity attributes associated with male and female friends, loneliness, and friendship satisfaction. Results indicate that close friends tended to be same sex, even though females had more close friends overall than did the males. Androgyny was related to characteristics that enhance the development and maintenance of close friendships, such as a communal orientation and positive conceptions of friends, while the undifferentiated orientation was related to less relationship enhancing orientations and a less rewarding interpersonal milieu. The study confirms that sex and sex role orientation are important factors in both quantitative and qualitative aspects of friendship during young adulthood.Portions of this paper were presented at the annual convention of the Southwestern Psychological Association, Houston, Texas, April 13, 1989. We appreciate the extensive help of an anonymous reviewer on earlier versions of this paper.  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