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   20900篇
  免费   41篇
  20941篇
  2023年   11篇
  2020年   18篇
  2019年   10篇
  2018年   3499篇
  2017年   2822篇
  2016年   2256篇
  2015年   201篇
  2014年   85篇
  2013年   110篇
  2012年   584篇
  2011年   2388篇
  2010年   2526篇
  2009年   1478篇
  2008年   1710篇
  2007年   2186篇
  2006年   47篇
  2005年   235篇
  2004年   180篇
  2003年   133篇
  2002年   83篇
  2001年   38篇
  2000年   60篇
  1999年   25篇
  1998年   24篇
  1997年   22篇
  1996年   16篇
  1993年   11篇
  1992年   9篇
  1991年   17篇
  1990年   12篇
  1989年   7篇
  1988年   4篇
  1986年   4篇
  1985年   5篇
  1983年   5篇
  1982年   5篇
  1981年   4篇
  1980年   5篇
  1978年   12篇
  1977年   13篇
  1976年   5篇
  1975年   10篇
  1974年   8篇
  1972年   3篇
  1971年   6篇
  1970年   5篇
  1969年   4篇
  1968年   4篇
  1967年   6篇
  1966年   3篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
121.
Linguistics must again concentrate on the evolutionary nature of language, so that language models are more realistic with respect to human natural languages and have a greater explanatory force. Multi-agent systems are proposed as a possible route to develop such evolutionary models and an example is given of a concrete experiment in the origins and evolution of word-meaning based on a multi-agent approach.  相似文献   
122.
In recognition tasks where Signal Detection Theory (SDT) is applied, a suitable decision variable is required. This variable is typically assumed to be a global assessment of memory strength. A further assumption is that factors such as old-new, serial position (SP), and word frequency (WF) simply act to change the value of strength across levels within the factor. In terms of SDT, the decision variable is assumed to be uni-dimensional. Four experiments are reported that provide a direct empirical assessment of this assumption for SP and WF. Judgements of items (JOI), recency (JOR), and primacy (JOP) were measured for SP; and subjective frequency (JOF) was measured for WF. Multiple dimensions imply non-additive effects across factor levels and different retrieval processes or the influence of an extra process. A single dimension is consistent with an additive effect of factor levels and current theorizing. The data are in fairly good agreement with the uni-dimensional assumption across all four factors with the exception of JOR and JOP. These showed less uni-dimensionality for comparisons between beginning vs. end list items. The implications of this are discussed.  相似文献   
123.
Data from a survey of 869 students aged 11 to 15 years and attending six urban middle schools were analyzed to identify differences in sex attitudes and behaviors between self-reported very religious students and their less religious peers. The two groups were demographically similar. They differed on only two attitude items, one suggesting that intercourse was a normal part of teenage dating and the other suggesting intercourse was alright if the two people were in love. The groups did not differ in their estimation of their peers' sexual activity or attitude or in terms of their own intercourse behavior or future intentions.  相似文献   
124.
What are moral principles? In particular, what are moral principles of the sort that (if they exist) ground moral obligations or—at the very least—particular moral truths? I argue that we can fruitfully conceive of such principles as real, irreducibly dispositional properties of individual persons (agents and patients) that are responsible for and thereby explain the moral properties of (e.g.) agents and actions. Such moral dispositions (or moral powers) are apt to be the metaphysical grounds of moral obligations and of particular truths about what is morally permissible, impermissible, etc. Moreover, they can do other things that moral principles are supposed to do: explain the phenomena “falling within their scope,” support counterfactuals, and ground moral necessities, “necessary connections” between obligating reasons and obligations. And they are apt to be the truthmakers for moral laws, or “lawlike” moral generalizations.  相似文献   
125.
Why do people express moral outrage? While this sentiment often stems from a perceived violation of some moral principle, we test the counter-intuitive possibility that moral outrage at third-party transgressions is sometimes a means of reducing guilt over one’s own moral failings and restoring a moral identity. We tested this guilt-driven account of outrage in five studies examining outrage at corporate labor exploitation and environmental destruction. Study 1 showed that personal guilt uniquely predicted moral outrage at corporate harm-doing and support for retributive punishment. Ingroup (vs. outgroup) wrongdoing elicited outrage at corporations through increased guilt, while the opportunity to express outrage reduced guilt (Study 2) and restored perceived personal morality (Study 3). Study 4 tested whether effects were due merely to downward social comparison and Study 5 showed that guilt-driven outrage was attenuated by an affirmation of moral identity in an unrelated context.  相似文献   
126.
We examined associations between children’s peer relationships and (a) their parents’ social competence as well as (b) their parents’ behaviors during the children’s peer interactions. Participants were families of 124 children ages 6–10 (68% male), 62 with ADHD and 62 age- and sex-matched comparison youth. Children’s peer relationships were assessed via parent and teacher report, and sociometric nominations in a lab-based playgroup. Parental characteristics were assessed via parent self-report and observations of behavior during their child’s playgroup. After statistical control of relevant covariates, parents of children with ADHD reported poorer social skills of their own, arranged fewer playdates for their children, and displayed more criticism during their child’s peer interaction than did parents of comparison youth. Parents’ socialization with other parents and facilitation of the child’s peer interactions predicted their children having good peer relationships as reported by teachers and peers, whereas parental corrective feedback to the child and praise predicted poor peer relationships. Parents’ ratings of their child’s social skills were positively associated with ratings of their own social skills, but negatively associated with criticism and facilitation of the child’s peer interactions. Relationships between parental behaviors and peer relationships were stronger for youth with ADHD than for comparison youth. The relevance of findings to interventions is discussed.  相似文献   
127.
RESUMEN

En una amplia variedad de tareas de detección de objetivos auditivos y visuales, la ejecución era escasamente influida por el número de no-objetivos simultáneos, pero le afectaba si los objetivos simultáneos debían ser detectados por separado. Se ha sugerido que sólo los objetivos necesitan pasar por un sistema de capacidad limitada que conduce a la conciencia; los no-objetivos pueden ser identificados y rechazados por un procesamiento paralelo e inconsciente. Puesto que las palabras no- objetivo, por ejemplo, se pueden rechazar en base al significado, el estímulo debe ser completamente analizado antes de pasar por el sistema de capacidad limitada. De modo general, la disminución en la ejecución debida a la atención dividida es acusada siempre que la estimulación simultánea (psicofísica, verbal, etc.) se deba identificar por separado, puesto que bajo estas circunstancias cualquier estimulación debe pasar por un sistema de capacidad limitada hasta la conciencia.  相似文献   
128.
Parenting and family interventions have repeatedly shown effectiveness in preventing and treating a range of youth outcomes. Accordingly, investigators in this area have conducted a number of studies using statistical mediation to examine some of the potential mechanisms of action by which these interventions work. This review examined from a methodological perspective in what ways and how well the family-based intervention studies tested statistical mediation. A systematic search identified 73 published outcome studies that tested mediation for family-based interventions across a wide range of child and adolescent outcomes (i.e., externalizing, internalizing, and substance-abuse problems; high-risk sexual activity; and academic achievement), for putative mediators pertaining to positive and negative parenting, family functioning, youth beliefs and coping skills, and peer relationships. Taken as a whole, the studies used designs that adequately addressed temporal precedence. The majority of studies used the product of coefficients approach to mediation, which is preferred, and less limiting than the causal steps approach. Statistical significance testing did not always make use of the most recently developed approaches, which would better accommodate small sample sizes and more complex functions. Specific recommendations are offered for future mediation studies in this area with respect to full longitudinal design, mediation approach, significance testing method, documentation and reporting of statistics, testing of multiple mediators, and control for Type I error.  相似文献   
129.
The goal of the study was to examine the dimensionality of the Career Decision Self-Efficacy Scale Short Form (CDSES-SF, Betz et al. 1996). Integrating several previous findings from different cultures, we found that the bifactor structure of the CDSES-SF on a Hungarian sample of 649 respondents showed the best model fit. This structure includes a general CDSE factor covering 15 items and the original five specific factors (self-appraisal, occupational information, goal selection, planning, and problem solving) covering three items each. This short form of CDSES shows an acceptable model fit and appropriate reliability in terms of the Cronbach’s alpha and omega values. Regarding career decision self-efficacy, a large proportion of variance was explained by the general factor and to a smaller extent by the specific factors. These results can be considered as a first step in resolving the paradox of the dimensionality of CDSES-SF.  相似文献   
130.
This study investigated how various risk and protective factors interface with child health and well-being at the population level. Specifically, we examined the association of income, social-contextual variables, and indicators of health-related habits and activities to children’s life satisfaction and perceived overall health. Child data were collected via a self-report survey, the Middle Years Development Instrument, which was administered in three demographically diverse Canadian school districts to 5026 grade 4 students (83 % of the students had complete data and were included in the analyses). Multiple regression and mediation analyses were conducted to examine the joint associations of social relationships with adults and peers, nutrition and sleep habits, and after school sports activities with children’s satisfaction with life and perceived health. Results indicate that peer belonging and relationships with adults at home and school were the strongest predictors of life satisfaction. Furthermore, the (small) association between income and life satisfaction was mediated by social relationship variables. Child reports of perceived health were predicted by peer belonging, adult relationships (home, school, neighborhood), after-school team sports, and nutrition habits. The (small) association between income and health was mediated by social relationships and team sports participation. Findings are discussed in light of previous research on social determinants and socio-economic gradients of children’s health and life satisfaction.  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