全文获取类型
收费全文 | 34960篇 |
免费 | 649篇 |
国内免费 | 13篇 |
出版年
2023年 | 82篇 |
2021年 | 129篇 |
2020年 | 234篇 |
2019年 | 279篇 |
2018年 | 3744篇 |
2017年 | 3116篇 |
2016年 | 2567篇 |
2015年 | 482篇 |
2014年 | 437篇 |
2013年 | 1820篇 |
2012年 | 1186篇 |
2011年 | 2997篇 |
2010年 | 2841篇 |
2009年 | 1871篇 |
2008年 | 2236篇 |
2007年 | 2704篇 |
2006年 | 642篇 |
2005年 | 760篇 |
2004年 | 669篇 |
2003年 | 646篇 |
2002年 | 593篇 |
2001年 | 294篇 |
2000年 | 287篇 |
1999年 | 251篇 |
1998年 | 237篇 |
1997年 | 244篇 |
1996年 | 219篇 |
1995年 | 183篇 |
1994年 | 178篇 |
1993年 | 169篇 |
1992年 | 166篇 |
1991年 | 182篇 |
1990年 | 155篇 |
1989年 | 133篇 |
1988年 | 102篇 |
1987年 | 136篇 |
1986年 | 152篇 |
1985年 | 185篇 |
1984年 | 187篇 |
1983年 | 164篇 |
1982年 | 162篇 |
1981年 | 165篇 |
1980年 | 151篇 |
1979年 | 131篇 |
1978年 | 142篇 |
1977年 | 132篇 |
1976年 | 130篇 |
1975年 | 112篇 |
1974年 | 134篇 |
1973年 | 108篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Vance DE 《Perceptual and motor skills》2004,98(2):647-655
Given pharmaceutical advancements, more people with HIV will be living to old age. Cognitive declines have been observed both during normal aging and in people with HIV; whether there are cumulative cognitive declines in adults aging with HIV remains unknown. Based on current literature, adults aging with HIV may be at risk for psychomotor declines that resemble parkinsonianism. 相似文献
942.
High cognitive effort has been frequently related to better indices of motor learning through the study of many different paradigms. However, automaticity presumably invokes minimal cognitive processing but has often been related to high-level motor performance, which suggests a paradox. The objective of this study was to approach this paradox by examining the viability of the use of different cognitive strategies during practice and performance which promote the benefits of high cognitive effort and automaticity. Members of the university community (14 men and 15 women) divided into 3 groups practiced a discrete precision task. All participants completed four sessions totaling 320 trials and were tested on retention and transfer seven days later. Findings suggest that it is indeed possible to benefit from both effortful and minimal cognitive processing strategies and that they should be used complementarily. 相似文献
943.
Significance of Childhood Conduct Problems to Later Development of Conduct Disorder Among Children With ADHD: A Prospective Follow-Up Study 总被引:3,自引:0,他引:3
This study investigates whether low to moderate levels of childhood oppositional defiant disorder (ODD) and conduct disorder (CD) behaviors contribute to the development of clinically diagnosed CD in adolescence, in children with attention deficit hyperactivity disorder (ADHD). Participants were 207 White boys (ages 6-12) with ADHD free of conduct disorder diagnoses. Parent and teacher ratings were obtained. Participants were assessed at mean age 18 by clinicians blind to childhood status. A non-ADHD group (recruited in adolescence) was also studied. ODD behavior ratings did not predict CD in adolescence, whereas CD behavior ratings did. No single ODD or CD behavior predicted adolescent outcome. ADHD probands with very low ratings (Not at all, Just a little) by parents and teachers on all CD behaviors were still at significantly increased risk for CD in adolescence, compared to non-ADHD controls. The same relationships were found between childhood ODD and CD behaviors, and antisocial personality disorder in adulthood (mean age, 25). We conclude that childhood ADHD is a developmental precursor of later antisocial disorder, even in the absence of comorbid ODD or CD in childhood. However, low levels of CD-type problems are not innocuous, because they predict later CD among children with ADHD without comorbid CD. 相似文献
944.
Parental Discipline and Externalizing Behavior Problems in Early Childhood: The Roles of Moral Regulation and Child Gender 总被引:4,自引:0,他引:4
We tested whether individual differences in a component of early conscience mediated relations between parental discipline and externalizing behavior problems in 238 3.5-year-olds. Parents contributed assessments of discipline practices and child moral regulation. Observations of children's behavioral restraint supplemented parental reports. Parents and teachers reported on child externalizing symptoms. Parental induction, warm responsiveness, and less frequent use of physical punishment generally were associated with higher levels of moral regulation and fewer externalizing problems. Moreover, moral regulation partially mediated relationships between discipline and externalizing symptoms, with the clearest case of mediation involving induction. However, relationships were found for boys only. Results support a mediation model wherein inductive and physical discipline may influence the expression of boys' externalizing behavior through effects on conscience. Finally, results suggest that different developmental processes may be associated with early externalizing problems in boys and girls, and confirm that fathers' reports contribute to our understanding of the origins of child externalizing problems. 相似文献
945.
The current article is an analysis of the research represented in American Journal of Community Psychology (AJCP) from 1993 to 1998, including a comparison to two previously published analytic reviews by Lounsbury et al. (J. W. Lounsbury, D. S. Leader, E. P. Meares, & M. P. Cook, 1980) and Speer et al. (P. Speer, A. Dey, P. Griggs, C. Gibson, B. Lubin, & J. Hughey, 1992), respectively. Observed trends are examined with references to major epistemological frameworks and methods used to define community psychology. Four guiding principles were examined to determine the representation of the epistemological frameworks of the articles published in the journal. The frameworks include social action, human diversity and cultural relativity, person–environmental fit, and methodological procedures. The results document the transition of community psychology from its early beginnings to an independent field conducting research consistent with the values articulated at the Swampscott Conference. This paper also comments on how well, after three decades of publication, the journal has served as a vehicle for improving community life. 相似文献
946.
This study explored the applicability of previous research (obtained with groups of college-educated women) about the subjective experience of aging in midlife to men and less-educated people. Two-hundred fifty-nine men and women who graduated from a public high school in 1955-1957 retrospectively assessed their feelings of identity certainty, confident power, generativity, and concern about aging for their 60s, 40s, and 20s. Participants reported higher levels of identity certainty, confident power, and concern about aging at each age, and a leveling off of generativity in their 60s. There were some gender and social class differences. Although men and women recalled the same trajectory of these feelings, men reported higher levels of identity certainty and confident power across age. Non-college-educated men recalled the highest levels of concern about aging across age. We discuss how these findings add to our understanding of the experience of aging in these domains. 相似文献
947.
948.
Does intentional car following capture visual attention to the extent that driving may be impaired? We tested fifteen participants on a rudimentary driving simulator. Participants were either instructed to follow a vehicle ahead through a simulated version of London, or were given verbal instructions on where to turn during the route. The presence or absence of pedestrians, and the simulated time of the drive (day or night) were varied across the trials. Eye movements were recorded along with behavioural measures including give-way violations, give-way accidents, and kerb impacts. The results revealed that intentional car following reduced the spread of search and increased fixation durations, with a dramatic increase in the time spent processing the vehicle ahead (controlled for exposure). The effects were most pronounced during nighttime drives. During the car-following trials participants were also less aware of pedestrians, produced more give-way violations, and were involved in more give-way accidents. The results draw attention to the problems encountered during car following, and we relate this to the cognitive demands placed on drivers, especially police drivers who often engage in intentional car following and pursuits. 相似文献
949.
Jobes DA Nelson KN Peterson EM Pentiuc D Downing V Francini K Kiernan A 《Suicide & life-threatening behavior》2004,34(2):99-112
Given the incidence and seriousness of suicidality in clinical practice, the need for new and better ways to assess suicide risk is clear. While there are many published assessment instruments in the literature, survey data suggest that these measure are not widely used. One possible explanation is that current quantitatively developed assessment instruments may fail to capture something essential about the suicidal patient's experience. The current exploratory study examined a range of open ended qualitative written responses made by suicidal outpatients to five assessment prompts from the Suicide Status Form (SSF)--psychological pain, press, perturbation, hopelessness, and self-hate. Two different samples of suicidal outpatients seeking treatment, including suicidal college students (n = 119) and active duty U.S. Air Force personnel (n = 33), provided a wide range of written responses to the five SSF prompts. A qualitative coding manual was developed through a step-by-step methodology; two naive coders were trained to use the coding system and were able to sort all the patients' written responses into the content categories with very high interrater reliability (Kappa > .80). Certain written qualitative responses of the patients were more frequent than others, both within and across the five SSF constructs. Among a range of specific exploratory findings, one general finding was that two thirds of the 636 obtained written responses could be reliably categorized under four major content headings: relational (22%), role responsibilities (20%), self (15%), and unpleasant internal states (10%). Theoretical, research, and clinical implications of the methodology and data are discussed. 相似文献
950.
Throughout the U.S., state laws require professionals who work with children to report cases of suspected child abuse to child protection services. Both practically and conceptually, however, significant problems arise from a lack of clarity regarding the threshold that has been set for reporting. Specifically, there is no consensus as to what constitutes reasonable suspicion, and little direction for how mandated reporters should gauge their legal and professional responsibilities when they harbor suspicion. In this paper we outline the context of the problem, discuss the nature and scope of its conceptual underpinnings, and offer recommendations for moving towards a concrete, practical solution. 相似文献