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   3952篇
  免费   1422篇
  2023年   13篇
  2021年   86篇
  2020年   94篇
  2019年   391篇
  2018年   286篇
  2017年   409篇
  2016年   394篇
  2015年   350篇
  2014年   309篇
  2013年   588篇
  2012年   297篇
  2011年   222篇
  2010年   253篇
  2009年   231篇
  2008年   215篇
  2007年   137篇
  2006年   119篇
  2005年   128篇
  2004年   103篇
  2003年   111篇
  2002年   123篇
  2001年   88篇
  2000年   80篇
  1999年   42篇
  1998年   16篇
  1997年   22篇
  1996年   11篇
  1995年   12篇
  1994年   12篇
  1993年   13篇
  1992年   16篇
  1991年   20篇
  1990年   14篇
  1989年   9篇
  1988年   8篇
  1987年   11篇
  1986年   11篇
  1985年   9篇
  1984年   8篇
  1983年   15篇
  1981年   5篇
  1979年   7篇
  1978年   7篇
  1977年   9篇
  1975年   5篇
  1974年   7篇
  1973年   6篇
  1971年   6篇
  1970年   7篇
  1967年   8篇
排序方式: 共有5374条查询结果,搜索用时 16 毫秒
151.
This article argues for two related theses. First, it defends a general thesis: any kind of necessity, including metaphysical necessity, can only be known a priori. Second, however, it also argues that the sort of a priori involved in modal metaphysical knowledge is not related to imagination or any sort of so‐called epistemic possibility. Imagination is neither a proof of possibility nor a limit to necessity. Rather, modal metaphysical knowledge is built on intuition of philosophical categories and the structures they form.  相似文献   
152.
This longitudinal study among ethnic migrants from Russia to Finland (N = 127) examined the relationships between anticipated and perceived discrimination, ethnic and national identities, and outgroup attitudes towards the national majority group. The study included one pre‐migration and two post‐migration assessments. First, associations between the variables studied were tested using a conventional autoregressive sample‐level modelling approach. Second, individual trajectories and the associations between the individual‐level changes in the variables included in the models were tested. Although there were no sample‐level effects over time, there were significant relationships between changes in discrimination and changes in identification and outgroup attitudes at the individual level. The results indicated that changes in perceived discrimination were not reflected in increased ethnic identification. However, participants who perceived higher levels of discrimination after migration than they anticipated before migration were, in the post‐migration stage, more likely to disidentify from and to increasingly show negative attitudes towards the national majority group. The study complements previous research by examining the identity and attitudinal reactions to perceived ethnic discrimination starting from the pre‐migration stage and highlights the value of incorporating both group and individual perspectives to the research on perceived discrimination. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
153.
The coincidence of historical trends in youth antisocial behavior and change in family demographics has led to speculation of a causal link, possibly mediated by declining quality of parenting and parent–child relationships. No study to date has directly assessed whether and how parenting and parent–child relationships have changed. Two national samples of English adolescents aged 16–17 years in 1986 (N = 4,524 adolescents, 7,120 parents) and 2006 (N = 716 adolescents, 734 parents) were compared using identical questionnaire assessments. Youth-reported parental monitoring, expectations, and parent–child quality time increased between 1986 and 2006. Ratings of parental interest did not change. Parenting differences between affluent and disadvantaged families narrowed over time. There was thus little evidence of a decline in quality of parenting for the population as a whole or for disadvantaged subgroups. Parent-reported youth conduct problems showed a modest increase between 1986 and 2006. Findings suggested that the increase in youth conduct problems was largely unrelated to observed change in parent–child relationships.  相似文献   
154.
Although children born preterm or low birth weight (PT LBW) are more likely to exhibit behavior problems compared to children born at term, developmental and family processes associated with these problems are unclear. We examined trajectories of maternal depressive symptoms in relation to toddler compliance and behavior problems in families with PT LBW infants. A total of 177 infants (93 boys, 84 girls) and their mothers enrolled in the study during the infant's NICU stay. Data were collected at five time points across 2 years. Assessments of maternal depressive symptoms were conducted at all time points, and toddler compliance and opposition to maternal requests and behavior problems were assessed at 2 years. Toddlers born earlier with more health problems to mothers whose depressive symptoms increased over time exhibited the most opposition to maternal requests during a cleanup task at 24 months, consistent with multiple risk models. Mothers with elevated depression symptoms reported more behavior problems in their toddlers. The study has implications for family‐based early intervention programs seeking to identify PT LBW infants at highest risk for problem behaviors.  相似文献   
155.
Socially disinhibited or indiscriminate behavior (IB) has traditionally been investigated using caregiver reports. More recently, an observational measure based on the Strange Situation Procedure (M. Ainsworth, M. Blehar, E. Waters, & S. Wall, 1978), the Rating of Infant and Stranger Engagement (RISE; C. Riley, A. Atlas‐Corbett, & K. Lyons‐Ruth, 2005), was validated in home‐reared at‐risk children. The present study aimed to validate the RISE in an institutionally reared sample using the caregiver report, to assess whether IB assessed with the RISE was elevated among the institutionalized children, and to explore potential risk factors associated with IB. The study was conducted among 74 institutionalized toddlers aged 11 to 30 months. Sociodemographic questionnaires were used to assess pre‐admission experiences, and aspects of institutional placement were coded from the children's files in the institution and staff's report. Institutionalized children displayed high frequencies of IB as assessed on the RISE, and this instrument was validated against caregiver report. Pre‐admission experiences of the institutionalized children in their biological families—namely, prenatal risk and maternal emotional neglect risk—predicted IB. Results suggest that the RISE is adequate to use among institutionally reared toddlers and point to aspects of the early familial environment that may be implicated in IB.  相似文献   
156.
Both negative and idealized maternal prenatal representations may constitute a risk for mother–infant interaction. This study analyzed the role of maternal prenatal representations and pre‐ to postnatal representational change in predicting mother–infant emotional availability (EA) among 51 drug‐abusing mothers and their infants who participated in either psychodynamic group therapy (PGT) or received psychosocial support (PSS) and among 50 nonusing comparison dyads. Maternal representations of her child, the child's father, her own mother, self‐as‐mother, and self‐as‐woman were measured during pregnancy and at 4 and 12 months' postpartum with the Interview of Maternal Representations (M. Ammaniti et al., 1992 ; M. Ammaniti, R. Tambelli, & P. Perucchini, 1998). EA was measured with the Emotional Availability Scales, fourth edition (Z. Biringen, 2008 ) at 4 and 12 months. The results showed that drug‐abusing mothers had more negative prenatal representations of the self‐as‐woman and of the child's father. Postnatally, PSS mothers tended to first idealize their child, but later to experience disillusionment of idealization. Both negative and idealized prenatal representations of the self‐as‐mother predicted mother–infant EA problems, but only among the PGT mothers. For all mothers, negative representational change was detrimental for the mother–infant EA whereas for drug‐abusing mothers, also increasing idealization from the prenatal period to the postnatal period was harmful. Clinicians working with drug‐abusing mothers should aim at supporting the development of a realistically positive view of motherhood.  相似文献   
157.
Underlying deficits in self‐regulation and sensory processing are seen in children with regulation disorders (RD) and might lead to emotional and behavioral problems as the child develops. However, little is known about the specific developmental course of RD. This follow‐up study was conducted to investigate the development of a clinical sample of RD children, diagnosed by means of the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood, Revised (DC:0–3R; ZERO TO THREE, 1994), toward specific psychopathology 4 to 10 years later based on parent‐ and teacher‐reports on the Child Behavior Checklist (T.M. Achenbach & L.A. Rescorla, 2007). Parental reports showed that 39 to 69% of children with RD had internalizing, externalizing, and total problems above borderline cutoffs, as compared to norm group data (16%). In addition, higher rates of affective, anxiety, attention deficit/hyperactivity, oppositional defiant, and conduct problems were reported. Analyses between RD subtypes showed significant differences on future attention problems and rule‐breaking behavior, wherein less favorable results were found for the Hypersensitive subtype Type A (fearful/cautious) in comparison to the sensory stimulation‐seeking/impulsive subtype. The current results indicate persistence of emotional and behavioral problems into middle childhood and adolescence in children with preschool RD diagnoses. More attention should be paid to differentiation of psychopathology in these children since developmental outcomes may differ between RD subtypes.  相似文献   
158.
This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to influence estrogen levels across the life span, and performance on prospective and retrospective memory measures in a group of 50 postmenopausal women (mean age=69.3years) who, if they were current or former users of estrogen therapy, had started therapy within 5years of menopause. The ICEE was found to be a significant predictor of performance on the Prospective Memory task (F(1)=4.21, p=.046, η(p)(2)=.084). No significant relationship was noted between the ICEE and performance on measures of retrospective memory. The results suggest that the level of cumulative lifetime exposure to estrogen a woman has influences her prospective memory performance later in life and that the influence of reproductive and biological markers of endogenous estrogen exposure are relevant factors to consider when studying the effect of estrogen therapy on cognitive functioning in postmenopausal women. In addition, the finding that performance on a measure of prospective memory, but not performance on measures of retrospective memory, was associated with the ICEE adds further support to the theory that the frontal cortex may be especially sensitive to estrogen.  相似文献   
159.
The purpose of this article is to present the current status of the literature related to stress in clinical psychology trainees (CPTs), and to offer research directions for investigating stress in this population and ways to enhance self‐care in these individuals. The following conclusions emerge from the review: (1) CPTs are vulnerable to elevated stress; (2) undue stress can negatively impact CPTs' personal and professional functioning and, in turn, result in less than optimal standards of care for clients; (3) there is a dearth of studies on stress in this population and no published intervention studies; (4) incorporating self‐care strategies into clinical psychology training is recommended; and (5) “third‐wave” cognitive behaviour therapy stress management interventions have been efficacious in comparable populations. In view of the potential costs of elevated stress to trainees themselves and their clients, research on stress and stress management in this population is of a high priority. Broad research agendas are proposed for these two domains. Modifications to clinical training programmes to reduce trainee stress are required and should be evidence‐based and systematically revaluated.  相似文献   
160.
Background. A key learning outcome in problem‐solving domains is the development of procedural flexibility, where learners know multiple procedures and use them appropriately to solve a range of problems (e.g., Verschaffel, Luwel, Torbeyns, & Van Dooren, 2009 ). However, students often fail to become flexible problem solvers in mathematics. To support flexibility, teaching standards in many countries recommend that students be exposed to multiple procedures early in instruction and be encouraged to compare them. Aims. We experimentally evaluated this recommended instructional practice for supporting procedural flexibility during a classroom lesson, relative to two alternative conditions. The alternatives reflected the common instructional practice of delayed exposure to multiple procedures, either with or without comparison of procedures. Sample. Grade 8 students from two public schools (N= 198) were randomly assigned to condition. Students had not received prior instruction on multi‐step equation solving, which was the topic of our lessons. Method. Students learned about multi‐step equation solving under one of three conditions in math class for about 3 hr. They also completed a pre‐test, post‐test, and 1‐month‐retention test on their procedural knowledge, procedural flexibility, and conceptual knowledge of equation solving. Results. Novices who compared procedures immediately were more flexible problem solvers than those who did not, even on a 1‐month retention test. Although condition had limited direct impact on conceptual and procedural knowledge, greater flexibility was associated with greater knowledge of both types. Conclusions. Comparing procedures can support flexibility in novices and early introduction to multiple procedures may be one important reason.  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