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   1798篇
  免费   464篇
  国内免费   217篇
  2479篇
  2024年   7篇
  2023年   49篇
  2022年   36篇
  2021年   68篇
  2020年   103篇
  2019年   120篇
  2018年   87篇
  2017年   100篇
  2016年   104篇
  2015年   55篇
  2014年   87篇
  2013年   254篇
  2012年   58篇
  2011年   73篇
  2010年   55篇
  2009年   67篇
  2008年   64篇
  2007年   74篇
  2006年   70篇
  2005年   60篇
  2004年   66篇
  2003年   45篇
  2002年   44篇
  2001年   41篇
  2000年   37篇
  1999年   29篇
  1998年   44篇
  1997年   31篇
  1996年   34篇
  1995年   33篇
  1994年   33篇
  1993年   33篇
  1992年   23篇
  1991年   29篇
  1990年   23篇
  1989年   26篇
  1988年   20篇
  1987年   30篇
  1986年   16篇
  1985年   24篇
  1984年   17篇
  1983年   20篇
  1982年   23篇
  1981年   21篇
  1980年   26篇
  1979年   23篇
  1978年   24篇
  1977年   31篇
  1976年   34篇
  1975年   8篇
排序方式: 共有2479条查询结果,搜索用时 15 毫秒
121.
The goal of this study was to test the response styles theory of depression in a sample of 3rd- and 7th-grade children. In addition, we examined whether the relationship between rumination and increases in depressive symptoms is mediated by hopelessness and low self-esteem. The procedure involved an initial assessment in which depressive symptoms, response styles, hopelessness, and self-esteem were assessed. The procedure also involved a follow-up assessment, 6 weeks later, in which depressive symptoms, hopelessness, and self-esteem were reassessed. Children with a ruminative response style exhibited increases in depressive symptoms over the 6-week period. In addition, the relationship between rumination and increases in depressive symptoms was mediated by both hopelessness and low self-esteem. Last, contrary to our hypotheses, neither distraction nor problem-solving response styles predicted decreases in depressive symptoms over the course of the study.  相似文献   
122.
We examine the hypothesis that the efficiency of executive control processes is less stable over time in older than younger adults. An age-related decrease in the efficiency of executive control should result in an increase in performance variability in task conditions requiring the recruitment of executive control processes and not in task conditions requiring minimal involvement of executive control. Performance variability was similar for younger and older adults in task conditions requiring minimal executive control and greater for older than younger adults in task conditions requiring executive control. These and other data are consistent with the proposal that aging is associated with a decrease in the stability of executive control over time.  相似文献   
123.
Five adolescents with autism, 5 adult control participants, and 4 child controls received rewards for varying their sequences of responses while playing a computer game. In preceding and following phases, rewards were provided at approximately the same rate but were independent of variability. The most important finding was that, when reinforced, variability increased significantly in all groups. Reinforced variability could provide the necessary behavioral substrate for individuals with autism to learn new responses.  相似文献   
124.
Evidence has been mixed on whether speakers spontaneously and reliably produce prosodic cues that resolve syntactic ambiguities. And when speakers do produce such cues, it is unclear whether they do so "for" their addressees (the audience design hypothesis) or "for" themselves, as a by-product of planning and articulating utterances. Three experiments addressed these issues. In Experiments 1 and 3, speakers followed pictorial guides to spontaneously instruct addressees to move objects. Critical instructions (e.g., "Put the dog in the basket on the star") were syntactically ambiguous, and the referential situation supported either one or both interpretations. Speakers reliably produced disambiguating cues to syntactic ambiguity whether the situation was ambiguous or not. However, Experiment 2 suggested that most speakers were not yet aware of whether the situation was ambiguous by the time they began to speak, and so adapting to addressees' particular needs may not have been feasible in Experiment 1. Experiment 3 examined individual speakers' awareness of situational ambiguity and the extent to which they signaled structure, with or without addressees present. Speakers tended to produce prosodic cues to syntactic boundaries regardless of their addressees' needs in particular situations. Such cues did prove helpful to addressees, who correctly interpreted speakers' instructions virtually all the time. In fact, even when speakers produced syntactically ambiguous utterances in situations that supported both interpretations, eye-tracking data showed that 40% of the time addressees did not even consider the non-intended objects. We discuss the standards needed for a convincing test of the audience design hypothesis.  相似文献   
125.
To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions.  相似文献   
126.
Neural correlates of a default response in a delayed go/no-go task   总被引:3,自引:0,他引:3  
Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with increasing delay duration, indicating that working memory fades across a delay. However, no such performance decrease has been found when the sample cues exist of present vs. absent stimuli, suggesting that pigeons do not rely on working memory, but seem to respond by default in those trials. We trained 3 pigeons in a DGNG task and found a similar default response pattern: The diverging slopes of the retention functions on correct Go and No-Go trials suggested that pigeons by default omitted their response following No-Go stimuli, but actively retained task-relevant information across the delay for successful responses on Go trials. We conducted single-cell recordings in the avian nidopallium caudolaterale, a structure comparable to the mammalian prefrontal cortex. On Go trials, many neurons displayed sustained elevated activity during the delay preceding the response, replicating previous findings and suggesting that task-relevant information was neurally represented and maintained across the delay. However, the same units did not show enhanced delay activity preceding correct response suppressions in No-Go trials. This activation-inactivation pattern presumably constitutes a neural correlate of the default response strategy observed in the DGNG task.  相似文献   
127.
Organizational measurement is necessary for managing incremental improvements or change efforts. Some have argued that indicators of financial performance measure the past and should be joined by "lead" measures such as management development and customer relations, assumed to be drivers of performance. Approaches of "lead" measures have met criticism for not contributing to operational management. The present is an empirical case study where measures from a customer satisfaction survey and a management assessment instrument were analyzed and compared to actual measures of financial performance. The effects of measures obtained seem to depend on the interpretations and reflection taking place in the organization. The pursuit of "lead" indicators did not seem to drive results. Counter-intuitively, higher scores on these measures were related to poorer financial performance. The explication of and reflection on the underlying dynamic seemed to turn the development in a profitable direction.  相似文献   
128.
The majority of scholarly management studies are based on self-report surveys. Consequently, the need to control for social desirability response is important, although few management studies in fact include the use of relevant scales commonly incorporated in psychology research. The full Marlowe–Crowne scale is disaffectingly long for senior-manager sample usage, so one of its short forms is more practical. However, the reliability of the most popular of these, the Strahan–Gerbasi scale, has not been tested with senior-manager samples. This study tests the scale amongst several senior-manager samples and finds it consistently lacks adequate reliability and unidimensionality.  相似文献   
129.
The aim of this study was to examine differences in responses to the Caregiver Strain Questionnaire (CGSQ) between African American and White caregivers of children with emotional and behavioral challenges. Significant item- and scale-level differences were detected across groups with African Americans consistently reporting less strain. We examined whether these differences were more likely due to nonequivalent measurement than to real differences in the experience of caregiver strain. Confirmatory factor analysis showed that the model fit the data well for both racial groups, but there were some differences in structural components. Internal consistency was equivalent across the groups. In an examination of criterion validity, regression analyses showed that African American caregivers experienced a slower rate of increase in objective caregiver strain at a given increase in child internalizing problems. No other race differences were found in the regression analyses. In general, we conclude that the CGSQ can be useful for detecting caregiver strain and identifying family support needs for both White and African American caregivers. Differences across groups in reports of caregiver strain, however, call for more research on racial differences in the impact on the family of caring for a child with emotional and behavioral disorders.  相似文献   
130.
Cruelty to animals may be a particularly pernicious aspect of problematic child development. Progress in understanding the development of the problem is limited due to the complex nature of cruelty as a construct, and limitations with current assessment measures. The Children and Animals Inventory (CAI) was developed as a brief self- and parent-report measure of F. R. Ascione's (1993) 9 parameters of cruelty. The CAI emerged as a reliable, stable, and readily utilized measure of cruelty using parent and child reports. Children (especially the older children) reported higher rates of cruelty than their parents and boys reported more cruelty than girls. Self- and parent-reports showed good convergence with independent observations of cruelty versus nurturance during free interactions with domestic animals. The results indicate that cruelty to animals can be reliably measured using brief child and parent report measures.  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