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   57577篇
  免费   1487篇
  国内免费   16篇
  59080篇
  2020年   449篇
  2019年   556篇
  2018年   4016篇
  2017年   3416篇
  2016年   2915篇
  2015年   756篇
  2014年   773篇
  2013年   3070篇
  2012年   1811篇
  2011年   3546篇
  2010年   3188篇
  2009年   2194篇
  2008年   2766篇
  2007年   3235篇
  2006年   1059篇
  2005年   1127篇
  2004年   1035篇
  2003年   932篇
  2002年   899篇
  2001年   1202篇
  2000年   1168篇
  1999年   890篇
  1998年   406篇
  1997年   402篇
  1996年   367篇
  1995年   366篇
  1994年   358篇
  1993年   361篇
  1992年   747篇
  1991年   655篇
  1990年   734篇
  1989年   617篇
  1988年   639篇
  1987年   603篇
  1986年   613篇
  1985年   552篇
  1984年   518篇
  1983年   492篇
  1982年   359篇
  1980年   357篇
  1979年   580篇
  1978年   420篇
  1975年   463篇
  1974年   512篇
  1973年   540篇
  1972年   404篇
  1971年   392篇
  1969年   404篇
  1968年   471篇
  1967年   428篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
162.
163.
The IES Arrow-Dot was administered to 41 cocaine detoxification patients. This group's scores indicated lower ego functioning and higher impulsivity and superego functioning than other clinical samples. No significant differences were noted between the Arrow-Dot scores of patients who successfully completed the program and those who did not.  相似文献   
164.
165.
We obtain in this paper a representation of the formulae of extensions ofL by generalized quantifiers through functors between categories of first-order structures and partial isomorphisms. The main tool in the proofs is the back-and-forth technique. As a corollary we obtain the Caicedo's version of Fraïssés theorem characterizing elementary equivalence for such languages. We also discuss informally some geometrical interpretations of our results.  相似文献   
166.
This article is concerned with the use of base-rate information that is derived from experience in classifying examples of a category. The basic task involved simulated medical decision making in which participants learned to diagnose hypothetical diseases on the basis of symptom information. Alternative diseases differed in their relative frequency or base rates of occurrence. In five experiments initial learning was followed by a series of transfer tests designed to index the use of base-rate information. On these tests, patterns of symptoms were presented that suggested more than one disease and were therefore ambiguous. The alternative or candidate diseases on such tests could differ in their relative frequency of occurrence during learning. For example, a symptom might be presented that had appeared with both a relatively common and a relatively rare disease. If participants are using base-rate information appropriately (according to Bayes' theorem), then they should be more likely to predict that the common disease is present than that the rare disease is present on such ambiguous tests. Current classification models differ in their predictions concerning the use of base-rate information. For example, most prototype models imply an insensitivity to base-rate information, whereas many exemplar-based classification models predict appropriate use of base-rate information. The results reveal a consistent but complex pattern. Depending on the category structure and the nature of the ambiguous tests, participants use base-rate information appropriately, ignore base-rate information, or use base-rate information inappropriately (predict that the rare disease is more likely to be present). To our knowledge, no current categorization model predicts this pattern of results. To account for these results, a new model is described incorporating the ideas of property or symptom competition and context-sensitive retrieval.  相似文献   
167.
Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972).  相似文献   
168.
This article examines how values, as orienting beliefs about what is good for a client, group of clients, or a nation, affect the delivery of counseling services. Specifically, this article explores the role of value assumptions within such areas as counselor-client interactions, psychometrics, career services, and the transportability of counseling theories across national boundaries.  相似文献   
169.
This research was designed to investigate development and behavioral mediation in lines of ICR mice that have been selectively bred for aggressive behavior. General behavioral reactivity and behavioral immobility have been implicated as potential mediators by prior analyses of preattack interactions. To evaluate the separate roles of these dispositions, the emergence of attacks in genetically selected lines was tracked for 11 years by three levels of analysis: over successive generations, over development, and over dyadic interactions. Convergent outcomes were observed in all three levels with respect to two findings: (a) Robust line differences were obtained in attack behaviors, and (b) strong associations were found between line differences in attacks and line differences in behavioral immobility. Conversely, all three levels of analysis indicated a weak and inconsistent association between line differences in attacks and measures of social and nonsocial reactivity.  相似文献   
170.
Computerized career information and guidance systems, although now commonplace, have received little psychometric scrutiny. The authors argue for examining these systems in the same way in which paper and pencil instruments are assessed. Consideration is also given to issues related to programming, technical-service problems, and staffing.  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