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   28078篇
  免费   1069篇
  国内免费   12篇
  2018年   423篇
  2017年   459篇
  2016年   458篇
  2015年   320篇
  2014年   416篇
  2013年   2193篇
  2012年   690篇
  2011年   744篇
  2010年   507篇
  2009年   470篇
  2008年   751篇
  2007年   673篇
  2006年   624篇
  2005年   559篇
  2004年   544篇
  2003年   551篇
  2002年   556篇
  2001年   669篇
  2000年   687篇
  1999年   542篇
  1998年   312篇
  1997年   310篇
  1996年   314篇
  1995年   291篇
  1992年   535篇
  1991年   468篇
  1990年   479篇
  1989年   455篇
  1988年   471篇
  1987年   436篇
  1986年   489篇
  1985年   462篇
  1984年   421篇
  1983年   369篇
  1981年   308篇
  1980年   289篇
  1979年   432篇
  1978年   367篇
  1977年   329篇
  1976年   338篇
  1975年   393篇
  1974年   474篇
  1973年   513篇
  1972年   375篇
  1971年   398篇
  1970年   369篇
  1969年   389篇
  1968年   468篇
  1967年   422篇
  1966年   429篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
It is argued that the manner in which we teach science in the high schools represents an outdated positivistic conception of science. The standard presentation of a year of each of chemistry, biology and physics should be replaced by an integrated science plus history, philosophy, and sociology of science which would take a total of three years to complete. A proper appreciation for the true nature of science is essential to the continued health of the scientific enterprise.  相似文献   
922.
Converging operations on a basic level in event taxonomies   总被引:1,自引:0,他引:1  
Research on object concepts has identified one level of abstraction as "basic" in cognition and communication. We investigated whether concepts for routine social events have a basic level by replicating the converging operations used to investigate object concepts. In Experiment 1, subjects were presented with event names from a taxonomy and were asked to list the actions comprising the event. Many more actions were listed at the middle than at the highest taxonomic level, without a further increase at the most specific level, paralleling the pattern of superordinate-, basic-, and subordinate-level object concepts. From these action lists, brief stories were composed for each event. In Experiment 2, subjects made pairwise similarity judgments on the stories. The mean similarity of events increased with specificity, as expected. But differentiation of categories (within-category similarity compared to between-category similarity) was highest for super-ordinates, contrary to results with object categories. In Experiment 3, subjects were fastest in recognizing actions as belonging to events named at the basic level. In Experiment 4, subjects predominantly chose basic-level terms to name stories. We conclude that event taxonomies do show basic-level structure, albeit a less sharply defined and less stable structure than in object taxonomies. The benefits and hazards of extending models of object concepts to other entities, such as social events, are discussed.  相似文献   
923.
What do tautological phrases such asBoys will be boys, A promise is a promise, or War is war mean and how are they understood? These phrases literally appear to be uninformative, yet speakers frequently use such expressions in conversation and listeners have little difficulty comprehending them. Understanding nominal tautologies requires that listeners/readers infer the speaker's attitude toward the noun phrase (e.g.,boys) mentioned in the sentence. The purpose of the present studies was to investigate the role of context, syntactic form, and lexical content in the interpretation of nominal tuatologies. Two studies are reported in which subjects rated the acceptability of different tautological constructions either alone (Experiment 1) or with supporting contextual information (Experiment 2). The results of these studies provide evidence that colloquial tautologies can be interpreted differently in different contexts, but that there are important regularities in the syntactic form and lexical content of these phrases which influence how they are understood. Our findings highlight the importance of speakers/listeners' stereotypical understanding of people, activities, and concrete objects in the use and understanding of different tautological expressions. The implications of this research for psycholinguistic theories of conversational inference and indirect language use are discussed.  相似文献   
924.
Do emotional states influence the social judgments made by groups and individuals? Based on affect-cognition theories and research on group judgmental shifts, we predicted that group discussion will enhance positive mood effects on judgments, but inhibit affectively-based distortions in dysphoric moods. Positive, neutral and negative moods were induced using audiovisual presentations. Individual and group consensus judgments of nine person categories on three judgmental dimensions (evaluation, competence and self-confidence) were obtained in two experimental sessions separated by a two-week interval. Results showed that individuals made more positive judgments when happy, and more negative judgments when sad than did controls. Group discussion resulted in a further polarization of positive judgments, and the attenuation of negative judgments. The findings are interpreted as evidence for the important role affect plays in mediating both individual cognitive processes and interactive social behaviours. The implications of the results for contemporary affect-cognition theories and models of group behaviour are considered.  相似文献   
925.
926.
This case study concerns an 18-year-old bilingual girl who suffered a radiation lesion in the left (dominant) thalamic and temporal region when she was 4 years old. Language and memory assessment revealed deficits in auditory short-term memory, auditory word comprehension, nonword repetition, syntactic processing, word fluency, and confrontation naming tasks. Both languages (English and Dutch) were found to be affected in a similar manner, despite the fact that one language (English) was acquired before and the other (Dutch) after the period of lesion onset. Most of the deficits appear to be related to verbal (short-term) memory dysfunction. Several hypotheses of subcortical involvement in memory processes are discussed with reference to existing theories in this area.  相似文献   
927.
Although lexical semantic deficits are postulated to play a prominent role in the anomia of Alzheimer's disease, it is unclear whether the primary disturbance is one of lexical access or one of lexical semantic loss. Response consistency on a naming task is one means of evaluating the underlying source of naming impairment. Access dysfunction usually implies variable word-finding difficulty, while a theory of lexical loss predicts that many word names would be consistently unavailable. Nineteen Alzheimer's disease patients were administered a visual confrontation naming task (the Boston Naming Test) on two occasions 6 months apart. Eighty percent of errors occurred consistently at both times; only 20% of errors occurred on only one occasion. Response consistency occurred significantly more often than expected under the assumption of no response consistency. Findings support the hypothesis that anomia in Alzheimer's disease is in part due to a loss of lexical semantic information.  相似文献   
928.
The purpose of this study was to examine the predictive validity of a teacher nomination procedure for identifying at- risk children. Two hundred and twenty-five children were nominated by their teachers as well- adjusted (n= 75), socially withdrawn (n=76), or socially aggressive (n=74) during the fourth grade. Five years later, 198 of these children (88%) were located and their adjustment evaluated. Significant differences among the nominated children were found on a variety of measures, including academic grades, sociometric status, and social behavior. In addition, differences in school dropout and delinquent offenses were noted. Results are discussed in terms of the validity of teacher nomination procedures and their utility in identifying at- risk youth.  相似文献   
929.
Twenty subjects were presented 240 randomized trials of a lexical decision task (LDT) while connected to a 16-electrode EEG montage. EEG data were acquired for 2 sec prior to the onset of each LDT trial. Alpha (9-13 Hz) coherence, alpha power, and 3- to 30-Hz power from five different combinations of EEG electrodes were used to predict semantic effects in the LDT trials. High pretrial coherence in the Right Hemisphere and Left Posterior-Parietal regions was associated with greater semantic facilitation (faster reaction times) in related-prime trials and greater semantic inhibition (slower reaction times) in unrelated-prime trials, relative to neutral-prime trials. No power variables were associated with semantic effects. Results support an information flow model of the functional significance of EEG coherence to cognitive processing.  相似文献   
930.
Ascertained if being a member of a statistical minority influences children's adjustment in school, as measured by the AML, a teacher-administered adjustment rating scale. Teachers from a southwest school district evaluated elementary students on aggressive, acting-out behaviors, moody-internalized behaviors, and learning difficulties. Analyses conducted on 376 students revealed significant effects of statistical minority status on certain dimensions of adjustment ratings for both Hispanic and Anglo students. Hispanic students in the statistical minority received poorer ratings on the moodiness dimension of the AML than nonminority Hispanic students. Anglo students in the statistical minority received poorer ratings on the aggression dimension of the AML than nonminority Anglo students. These results were interpreted in terms of cultural differences in coping with statistical minority status. Traits commonly exhibited within a culture may intensify and be perceived as maladaptive when stress resulting from being a minority occurs. Implications of the finding that statistical minority status within the school environment influences adjustment are discussed.  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