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   49572篇
  免费   2074篇
  国内免费   18篇
  2020年   615篇
  2019年   698篇
  2018年   935篇
  2017年   1068篇
  2016年   1081篇
  2015年   775篇
  2014年   957篇
  2013年   4462篇
  2012年   1671篇
  2011年   1684篇
  2010年   1120篇
  2009年   1097篇
  2008年   1564篇
  2007年   1539篇
  2006年   1414篇
  2005年   1280篇
  2004年   1227篇
  2003年   1164篇
  2002年   1207篇
  2001年   1362篇
  2000年   1277篇
  1999年   1050篇
  1998年   576篇
  1997年   563篇
  1996年   520篇
  1995年   533篇
  1994年   505篇
  1993年   517篇
  1992年   907篇
  1991年   798篇
  1990年   855篇
  1989年   723篇
  1988年   752篇
  1987年   722篇
  1986年   714篇
  1985年   674篇
  1984年   674篇
  1983年   649篇
  1982年   517篇
  1981年   480篇
  1980年   472篇
  1979年   697篇
  1978年   565篇
  1977年   499篇
  1975年   575篇
  1974年   629篇
  1973年   628篇
  1972年   468篇
  1968年   535篇
  1967年   479篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
A study was conducted with 104 hospital employees to assess the relationship between pay-for-performance perceptions and pay satisfaction. Unlike previous research examining this relationship, a multi-item measure of pay-for-performance perceptions and a multidimensional measure of pay satisfaction were used. As hypothesized, the results indicated a positive relationship between pay-for-performance perceptions and pay-raise satisfaction, pay-level satisfaction, and overall pay satisfaction even after the effects of salary level, salary increases, performance ratings, job tenure, job satisfaction, and promotions were controlled. The importance of gathering perceptual data on characteristics of the pay system believed to have differential relationships with the subdimensions of pay satisfaction are discussed.  相似文献   
212.
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   
213.
This paper discusses least squares methods for fitting a reformulation of the general Euclidean model for the external analysis of preference data. The reformulated subject weights refer to a common set of reference vectors for all subjects and hence are comparable across subjects. If the rotation of the stimulus space is fixed, the subject weight estimates in the model are uniquely determined. Weight estimates can be guaranteed nonnegative. While the reformulation is a metric model for single stimulus data, the paper briefly discusses extensions to nonmetric, pairwise, and logistic models. The reformulated model is less general than Carroll's earlier formulation.The author is grateful to Christopher J. Nachtsheim for his helpful suggestions.  相似文献   
214.
215.
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   
216.
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   
217.
After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.  相似文献   
218.
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   
219.
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   
220.
The purpose of the present study was to determine whether the sex role orientations of male and female collegiate athletes were more similar in team sports than in individual sports. It was predicted that females in masculine-oriented team sports (basketball and volleyball) would exhibit sex role orientations more similar to those of their male counterparts than would females in individual sports (track/field and swimming). To test this notion the S. L. Bem (The Measurement of Psychological Androgyny, Journal of Consulting and Clinical Psychology, 1974, 42, 155–167) Sex Role Inventory was administered to 381 athletes from 37 National Collegiate Athletic Association institutions. The median-split procedure (S. L. Bem, On the Utility of Alternative Procedures for Assessing Psychology Androgyny, Journal of Consulting and Clinical Psychology, 1977, 45, 196–205) was used to classify subjects as masculine, feminine, androgynous, or undifferentiated. Separate Gender × Sex Role Orientation chi square tests were performed on the frequency data of team and individual sport athletes. The results indicated no significant differences in the sex role orientations of male and female team sport performers, with the greatest proportion (66%) having a masculine (33%) or androgynous (33%) orientation. For individual sports there was a significant difference in the sex role orientations of males and females. The highest proportion of females were classified as feminine (37%) and the lowest proportion were classified as masculine (11%). Individual sport males were somewhat evenly distributed among the four sex role orientation categories, with the highest proportion classified as undifferentiated (36%). It was concluded that sex role orientation of elite female athletes may be associated with the male appropriateness of the sport in which they participate.  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