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   36490篇
  免费   1494篇
  国内免费   8篇
  2020年   366篇
  2019年   476篇
  2018年   646篇
  2017年   682篇
  2016年   730篇
  2015年   481篇
  2014年   638篇
  2013年   2880篇
  2012年   1107篇
  2011年   1188篇
  2010年   698篇
  2009年   736篇
  2008年   1055篇
  2007年   1031篇
  2006年   1001篇
  2005年   851篇
  2004年   872篇
  2003年   786篇
  2002年   812篇
  2001年   1082篇
  2000年   986篇
  1999年   764篇
  1998年   445篇
  1997年   366篇
  1992年   587篇
  1991年   575篇
  1990年   555篇
  1989年   569篇
  1988年   569篇
  1987年   533篇
  1986年   551篇
  1985年   612篇
  1984年   491篇
  1983年   463篇
  1982年   402篇
  1981年   377篇
  1979年   549篇
  1978年   419篇
  1977年   357篇
  1976年   402篇
  1975年   470篇
  1974年   516篇
  1973年   529篇
  1972年   424篇
  1971年   395篇
  1970年   385篇
  1969年   421篇
  1968年   493篇
  1967年   427篇
  1966年   427篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The present study evaluated the efficacy of a new intervention, Guided Imaginal Coping (GIC), compared to imaginal exposure (IEX), and a waiting-list control (WLC) condition among 24 clinic outpatients meeting DSM-III-R criteria for panic disorder (PD) or PD with agoraphobia. GIC was the more consistently effective intervention, with individuals demonstrating significant improvement in frequency and severity of panic attacks (Pas) as well as significant reductions in physiological and subjective arousal to provocative imagery. Individuals in the IEX intervention demonstrated less consistent improvement on the dependent measures, while individuals in the WLC condition essentially remained unchanged. Both GIC and IEX were effective according to a composite measure of clinically significant improvement. However, only GIC was superior to the WLC condition when clinical improvement was defined as zero PAs at follow-up. These findings, while preliminary, suggest that GIC can be added to the armamentarium of effective approaches to treating PD.  相似文献   
992.
We examined the effects of a self-monitoring program on reducing the frequency of negative statements of a student with mild mental retardation who was enrolled in a self-contained classroom at a middle school. A changing criterion design was used within a multiple baseline design across two classroom periods. Additionally, the frequency of positive statements was reported. The results showed a decrease in the number of negative statements, and an increase in the number of positive statements. Maintenance data collected up to 8 weeks after the program ended indicated that the student continued to emit positive rather than negative statements. The use of this procedure to decelerate undesirable behavior is discussed.  相似文献   
993.
To determine the frequency and correlates of nonsuicidal physically self-damaging acts in 12–14 year olds, a two stage epidemiologic survey with a self-administered questionnaire (N=3283) followed by a psychiatric interview of a subsample of the adolescents and their parents (N=444) was used. Prevalence estimates of interview validated nonsuicidal physically self-damaging acts were 2.46% in males and 2.79% in females. Significant relationships were found between nonsuicidal physically self-damaging acts and suicidal ideation, major depression and undesirable life events. Data suggest that physically self-damaging acts occur at substantial rates during early adolescence. The strong correlation between nonsuicidal self-destructive acts and both suicidal ideation and major depression clarifies prior conflicting reports in the literature and suggests that a history of self-damaging acts should be taken into consideration when evaluating for possible depression and suicide risk.  相似文献   
994.
This study emanated from the long-standing question of whether a maternal bonding process similar to other mammalian species occurs in humans. The perceptions of adult adoptees and a matched sample of non-adoptees about their parents' behaviours towards them were compared on an original Parental Solicitude Scale. As hypothesized, birth children perceived their mothers as the more solicitous parent, but ratings of adoptive mothers showed a unilateral decline. Further, the differential ratings for birth and adoptive mothers occurred mostly for the factors labelled benignity vs abuse and tolerance vs control, rather than caretaking vs neglect, which was congruent to reported effects in prior studies of lack of mother-infant contact during the sensitive period for bonding. An alternative explanation of the data was also tested but not substantiated.  相似文献   
995.
A critical problem in most real-time programming tasks is the verification that timing of the presented displays and recorded events occur at the expected times. It is often difficult for psychologists to verify critical timing because of the lack of costly specialized tools and technicians to measure events with millisecond accuracy. Algorithms utilized in a new Time Audit mechanism, added to the Micro Experimental Laboratory, are described. This new mechanism involves the recording and time stamping of all input and output events with 0.1-msec accuracy. This allows the experimenter to determine the initiation, duration, and termination of each event and also makes it possible to relate these events to the synchronization of the screen refresh cycle. A customized user interface provides a time log and event-tracing feature that enables nonprogrammers to determine the duration of command execution to the .1-msec level, allowing rapid, precise assessment of program execution. The resulting time log provides a detailed specification of the experimental events for debugging and a permanent record of the experimental procedure.  相似文献   
996.
The relationship between local/global and high/low spatial-frequency processing in hemispheric asymmetries was explored. Subjects were required to judge the orientation of a high- or low-spatial-frequency component of a compound grating presented in the left visual field (LVF) or right visual field (RVF). In Experiment 1, attention was focused on one or the other component. A signal detection analysis indicated that sensitivity (d′) to the high-spatial-frequency target was reduced more by the presence of the low-spatial-frequency component when both were presented in the LVF rather than in the RVF. In Experiment 2, subjects determined whether a target orientation was present, independent of spatial frequency at only a single level (i.e., at the high- or low-spatial-frequency level), as opposed to both or neither level. An RVF/LH (left hemisphere) advantage was found when the decision was based on the orientation of the high-frequency component. The asymmetrical influence of visual field of presentation and spatial frequency upon sensitivity is discussed in terms of hemispheric differences in the magnitude of inhibition between spatial-frequency channels and in the role of transient channel activity to capture and direct higher order attentional processes.  相似文献   
997.
Can spatial frequency differences between local and global forms account for differences in the way different levels of structure are analyzed? We examined this question by having subjects identify local or global forms of hierarchical stimuli that had beencontrast balanced. Contrast balancing eliminates low spatial frequencies, so that both local and global forms must be identified on the basis of high spatial frequency information. Response times (RTs) to global (but not local) forms were slowed for contrast-balanced stimuli, suggesting that low spatial frequencies mediate the global RT advantage typically found. In contrast, interference between local and global forms was little affected by contrast balancing or by shifts of attention between local and global forms, suggesting that it does not result from inhibitory interactions between spatial frequency channels or from temporal precedence of low versus high spatial frequency information. Finally, shifts of attention between local and global forms were also little affected by contrast balancing, suggesting that they were not based on spatial frequency.  相似文献   
998.
Two experiments compared rates of solving simple and complex addition and multiplication problems in groups of speakers of French or English in Experiment 1 (n = 35) and Spanish or English in Experiment 2 (n = 84). Subjects were divided into groups of English unilinguals, weak bilinguals, and strong bilinguals according to their performance on a naming task. In both experiments, simple problems consisted of two single-digit numbers. At least three single-digit numbers were used for complex problems in Experiment 1 and double-digit numbers in Experiment 2. Mean solution times, particularly for complex problems, were lowest for the monolingual group, followed in turn by the weak bilingual and strong bilingual groups, but these differences were not statistically reliable in either experiment. In Experiment 2, however, componential analyses of solution times indicated that strong bilingual subjects were slower at executing the carry operation when solving complex problems, relative to the two remaining groups. Results were interpreted in terms of the relationship between bilingualism and the representation and processing of numerical information.  相似文献   
999.
1000.
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