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   1313篇
  免费   123篇
  2023年   12篇
  2021年   13篇
  2020年   35篇
  2019年   17篇
  2018年   29篇
  2017年   58篇
  2016年   44篇
  2015年   32篇
  2014年   34篇
  2013年   135篇
  2012年   46篇
  2011年   50篇
  2010年   42篇
  2009年   49篇
  2008年   52篇
  2007年   40篇
  2006年   36篇
  2005年   32篇
  2004年   38篇
  2003年   31篇
  2002年   27篇
  2001年   36篇
  2000年   51篇
  1999年   36篇
  1998年   19篇
  1997年   17篇
  1996年   19篇
  1995年   16篇
  1994年   16篇
  1993年   16篇
  1992年   17篇
  1991年   21篇
  1990年   17篇
  1989年   16篇
  1988年   12篇
  1987年   19篇
  1986年   11篇
  1985年   15篇
  1984年   12篇
  1983年   10篇
  1981年   10篇
  1980年   11篇
  1979年   12篇
  1977年   15篇
  1974年   16篇
  1971年   13篇
  1968年   11篇
  1967年   10篇
  1966年   17篇
  1965年   14篇
排序方式: 共有1436条查询结果,搜索用时 406 毫秒
131.
This study examined concordance between adult and child reports of child suicidality using a sample of 1,046 8-year-old children at risk for, or having experienced, maltreatment. Concordance was low with both caregivers and teachers. For children reporting no suicidality, caregiver-child agreement was associated with few transitions in caregiver and low social withdrawal and aggression, and teacher-child agreement was associated with non-White ethnicity, good academic performance, and low thought problems. For children reporting suicidality, care-giver-child agreement was associated with perceptions of child mental health needs, aggression, and somatic complaints, and teacher-child agreement was associated with thought problems.  相似文献   
132.
In two experiments, we investigated the ability of younger and older observers to perceive and discriminate 3-D shape from static and dynamic patterns of binocular disparity. In both experiments, the younger observers' discrimination accuracies were 20% higher than those of the older observers. Despite this quantitative difference, in all other respects the older observers performed similarly to the younger observers. Both age groups were similarly affected by changes in the magnitude of binocular disparity, by reductions in binocular correspondence, and by increases in the speed of stereoscopic motion. In addition, observers in both age groups exhibited an advantage in performance for dynamic stereograms when the patterns of binocular disparity contained significant amounts of correspondence "noise." The process of aging does affect stereopsis, but the effects are quantitative rather than qualitative.  相似文献   
133.
This study examined the impact of changes in level of current grief over time on changes in memory for past grief. Following from previous work on the impact of current affective state on memory for past affectively salient events, bereaved individuals who underwent a greater reduction in grief over time were expected to show a similar pattern of changes in memory for past grief. A sample of conjugally bereaved participants completed measures of current grief and memory for past grief at the time of the loss of their spouse at each of the 2, 6, 13, and 30 month post-loss time periods. As predicted, those who reported greater reduction in grief over the course of the study were more likely to remember their past grief as progressively less severe relative to those who underwent less reduction in grief over time. A nonrecursive causal model analysis verified that changes in memory for past grief were explained by changes in current grief. These results were discussed in terms of contemporary reconstructive memory accounts of the effect of affective state on memory.  相似文献   
134.
The current study explored the relationship between religious coping and cumulative health risk associated with health behavior patterns in a sample of 256 Latina and Caucasian female caregivers of elderly relatives with dementia. Primary analyses examined the relationship between religious coping (both positive and negative) and an overall index of cumulative health risk. Secondary analyses were conducted on the individual health behaviors subsumed in the broader index. Findings revealed that negative religious coping was significantly associated with increased cumulative health risk. Positive religious coping was predictive of decreased cumulative health risk among Latina caregivers but not among Caucasians. Negative religious coping was significantly associated with both an increased likelihood for weight gain and increased dietary restriction. Positive religious coping was associated with decreased likelihood for weight gain in Latinas. Implications for both caregivers and clinicians are discussed.  相似文献   
135.
ABSTRACT We examined mothers' ratings of children's affective and behavioral aspects of approach tendencies and links with overt aggressive behavior problems while considering the genetic etiology of these processes. Approach/positive anticipation (AP), frustration/anger (FA), and overt aggression in 4–9‐year‐olds were assessed using mothers' reports in a diverse national sample (n=992) and a sample of same‐sex twins (n=195 pairs). AP and FA were positively correlated with each other and with overt aggression (r from .2 to .5), and these associations were very similar for boys and girls. AP and FA provided overlapping as well as independent statistical prediction of aggression. AP statistical prediction of aggression was substantially mediated by FA, an effect that was accounted for by underlying genetic and nonshared environmental influences.  相似文献   
136.
Individual vocal recognition behaviors in songbirds provide an excellent framework for the investigation of comparative psychological and neurobiological mechanisms that support the perception and cognition of complex acoustic communication signals. To this end, the complex songs of European starlings have been studied extensively. Yet, several basic parameters of starling individual vocal recognition have not been assessed. Here we investigate the temporal extent of song information acquired by starlings during vocal recognition learning. We trained two groups of starlings using standard operant conditioning techniques to recognize several songs from two conspecific male singers. In the first experiment we tested their ability to maintain accurate recognition when presented with (1) random sequences of 1–12 motifs (stereotyped song components) drawn from the training songs, and (2) 0.1–12-s excerpts of continuous song drawn from the training songs. We found that song recognition improved monotonically as more vocal material is provided. In the second experiment, we systematically substituted continuous, varying length regions of white noise for portions of the training songs and again examined recognition accuracy. Recognition remained above chance levels for all noise substitutions tested (up to 91% of the training stimulus) although all but the smallest substitutions led to some decrement in song recognition. Overall, above chance recognition could be obtained with surprisingly few motifs, short excerpts of song, and in the absence of large portions of the training songs. These results suggest that starlings acquire a representation of song during individual vocal recognition learning that is robust to perturbations and distributed broadly over large portions of these complex acoustic sequences.  相似文献   
137.
Magnesium oxide (MgO) films and particles have been collected by pressurised filtration of a Mg-8.6wt%Al-0.67wt%Zn (AZ91D) alloy melt. The morphology of the oxides and their interfaces with the α-Mg phase were investigated by high-resolution transmission electron microscopy. It was found that the oxide films consisted of large numbers of sub-micrometre-sized MgO particles, and that melt shearing can effectively break up the oxide films and disperse the oxide particles. For the first time, orientation relationships (ORs) of OR I: [1?1?1]MgO~2° from (0?0?0?1)α-Mg and (0?1?1)MgO?//[2?1?1?0)α-Mg; and OR II: (1?1?1)MgO//(1?1?0?1)α-Mg and [0?1?1]MgO//[1?2?1?1]α-Mg, were observed between the MgO particles and the α-Mg matrix. The calculated Bramfitt planar disregistries were 5.5% and 2.5% for the two ORs, respectively, indicating good lattice matching between MgO and α-Mg at the interface. With the evidence of grain refinement effect observed in the sheared AZ91D magnesium alloy, the possibility of MgO particles to act as potent nucleants for heterogeneous nucleation of α-Mg grains is discussed in terms of the crystallographic criterion.  相似文献   
138.
Peri-traumatic information processing is thought to affect the development of intrusive trauma memories. This study aimed to replicate and improve the study by Holmes, Brewin, and Hennessy (2004, Exp. 3) on the role of peri-traumatic verbal processing in analogue traumatic intrusion development. Participants viewed an aversive film under one of three conditions: counting backwards in 3s (“verbal interference”), verbalising emotions and thoughts (“verbal enhancement”), or without an extra task. A dual-process account of PTSD would predict that verbal interference would increase intrusion frequency compared to no task, whereas verbal enhancement would lead to a decrease. In contrast, mainstream memory theory predicts a decrease in intrusion frequency from any concurrent task that diverts attention away from the trauma film. The main finding was that the verbal interference task led to a decrease in intrusive memories of the film compared to the other two conditions. This finding does not support a dual-process account of PTSD, but is in line with general theories of memory and attention.  相似文献   
139.
This study examined the impact of changes in level of current grief over time on changes in memory for past grief. Following from previous work on the impact of current affective state on memory for past affectively salient events, bereaved individuals who underwent a greater reduction in grief over time were expected to show a similar pattern of changes in memory for past grief. A sample of conjugally bereaved participants completed measures of current grief and memory for past grief at the time of the loss of their spouse at each of the 2, 6, 13, and 30 month post-loss time periods. As predicted, those who reported greater reduction in grief over the course of the study were more likely to remember their past grief as progressively less severe relative to those who underwent less reduction in grief over time. A nonrecursive causal model analysis verified that changes in memory for past grief were explained by changes in current grief. These results were discussed in terms of contemporary reconstructive memory accounts of the effect of affective state on memory.  相似文献   
140.
Second-grade, fourth-grade, sixth-grade, high school, and college students (N = 140) were asked to describe situations in which they would not help someone else and their reasons for not helping in those situations. Younger subjects used perceived self-incompetence as a reason for not helping more frequently than did older subjects. In contrast, older subjects more frequently cited a desire not to violate another's personal situation and/or their own internalized values, laws, and rules as reasons not to help than did their younger counterparts. For a majority of the not-helping categories, however, no significant effect of age level was found, and indeed, some individuals in even the youngest age group expressed subtle and insightful reasons for not helping.  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