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   1893篇
  免费   119篇
  国内免费   1篇
  2023年   26篇
  2022年   17篇
  2021年   29篇
  2020年   50篇
  2019年   65篇
  2018年   93篇
  2017年   88篇
  2016年   90篇
  2015年   51篇
  2014年   79篇
  2013年   242篇
  2012年   115篇
  2011年   122篇
  2010年   74篇
  2009年   70篇
  2008年   103篇
  2007年   79篇
  2006年   92篇
  2005年   60篇
  2004年   61篇
  2003年   60篇
  2002年   50篇
  2001年   26篇
  2000年   17篇
  1999年   23篇
  1998年   19篇
  1997年   23篇
  1996年   6篇
  1995年   12篇
  1994年   14篇
  1992年   10篇
  1991年   8篇
  1990年   7篇
  1989年   4篇
  1987年   5篇
  1986年   7篇
  1985年   9篇
  1984年   13篇
  1983年   6篇
  1982年   9篇
  1981年   10篇
  1980年   5篇
  1979年   7篇
  1978年   8篇
  1977年   4篇
  1976年   4篇
  1975年   4篇
  1974年   6篇
  1971年   3篇
  1970年   4篇
排序方式: 共有2013条查询结果,搜索用时 31 毫秒
21.
Two dogs were maintained on a multiple schedule having both a food reinforced and an avoidance component (Mult VI 1′ SΔ AvoidSS20 RS20 SΔ). The effects of superimposing an Estes-Skinner procedure for delivering unavoidable shocks on all components of the multiple schedule were observed. The buzzer-shock pairing of the Estes-Skinner procedure produced an increased rate of responding on the avoidance component of the schedule and also on the SΔ components. No persistent change in rate was observed on the food component during the pre-shock stimulus. Control performances on all components could be regained by either extinguishing or eliminating the buzzer-shock pairing. Extinction of the avoidance responding had little effect on the increased rates of responding produced by the Estes-Skinner procedure on the SΔ and avoidance extinction components and did not lead to a conditioned suppression of the food reinforced responding. Rate of responding during the pre-shock stimulus was observed to be relatively independent of changes in the maintaining schedules. Responding during the pre-shock stimulus could be conditioned and maintained after an extensive history of avoidance extinction.  相似文献   
22.
23.
Given a normal (multi-)modal logic a characterization is given of the finitely presentable algebras A whose logics L A split the lattice of normal extensions of . This is a substantial generalization of Rautenberg [10] and [11] in which is assumed to be weakly transitive and A to be finite. We also obtain as a direct consequence a result by Blok [2] that for all cycle-free and finite A L A splits the lattice of normal extensions of K. Although we firmly believe it to be true, we have not been able to prove that if a logic splits the lattice of extensions of then is the logic of an algebra finitely presentable over ; in this respect our result remains partial.  相似文献   
24.
Canadian Workers Compensation Boards have recently been confronted with claims for compensation for disability related to workplace stress. Rules of adjudication applied to such claims are currently evolving in the 11 Canadian jurisdictions studied. This article describes the Canadian Workers' Compensation schemes and then proceeds to analyse the approach of the various provincial Boards to mental-mental claims. It explores some of the differences between the Canadian and American approaches to the issue of compensation for psychological workplace stress, offers hypotheses as to the reasons for the disparities, and looks at the future of such claims.  相似文献   
25.
26.
Kracht  Marcus  Wolter  Frank 《Studia Logica》1997,59(2):149-177
This papers gives a survey of recent results about simulations of one class of modal logics by another class and of the transfer of properties of modal logics under extensions of the underlying modal language. We discuss: the transfer from normal polymodal logics to their fusions, the transfer from normal modal logics to their extensions by adding the universal modality, and the transfer from normal monomodal logics to minimal tense extensions. Likewise, we discuss simulations of normal polymodal logics by normal monomodal logics, of nominals and the difference operator by normal operators, of monotonic monomodal logics by normal bimodal logics, of polyadic normal modal logics by polymodal normal modal logics, and of intuitionistic modal logics by normal bimodal logics.  相似文献   
27.
The development of attitudes and activities of newcomers in the 18 months following the first period of socialization was investigated. At two points in time, persons' preferences for seven work climates were compared with perceived climate. Changes in person-climate fit were assessed, using a squared difference index, after alternative fit-indices were tested with hierarchical regression analysis. Person-climate fit and work attitudes at T1 (eight to ten months after entry) were examined by comparing three groups of respondents who did not change jobs, changed jobs within the organization or changed organizations. Results showed no alpha, beta or gamma changes for the total group of 108 respondents. Alpha changes were only found for respondents who changed jobs. They showed higher ratings for job satisfaction at T2. Finally, work attitudes at T1 were related to turnover. Organizational changers showed higher turnover intentions and higher discrepancies between preferred and perceived risk orientation and work pressure at T1.  相似文献   
28.
Role of siblings in adult daughters' anticipation of caregiving   总被引:1,自引:0,他引:1  
Despite extensive research regarding adult daughters' experiences as caregivers to aging parents, little attention has been paid to how adult daughters anticipate future caregiving roles. The current study examines the impact of sibling networks on the caregiving anticipation of 103 adult daughters. Factors influencing the expectation and amount of support adult daughters anticipate include daughters' birth order and proximity to their mothers. Characteristics of the sibling networks, including percentage of sisters within the family, are also important to care anticipation.  相似文献   
29.
A mother's (prenatal) wish for a girl has, at times, been implicated as an etiological factor for boyhood femininity or its DSM-III-R diagnostic equivalent, the Gender Identity Disorder of Childhood. In one sample of 52 feminine and 52 nonclinical control boys from Los Angeles, the proportion of mothers who recalled a wish for a girl during the pregnancy did not differ significantly between groups (26.9% vs. 19.2%, respectively); however, in both groups, the maternal wish for a girl was significantly more common in sibships in which all of the proband's older siblings were male. In a second sample of 103 feminine boys from Toronto, the maternal wish for a girl was significantly higher than that found in the Los Angeles sample (43.7% vs. 26.9%), but a control group was not available; as in the Los Angeles sample, the maternal wish for a girl was significantly more common in sibships in which all of the proband's older siblings were male. Implications of these findings for further study of maternal influences on boyhood femininity are discussed.  相似文献   
30.
The study examines the relative merits of a noncompatibility and a restructuring explanation of the recurrent empirical finding that a prominent attribute looms larger in choices than in judgments. Pairs of equally attractive options were presented to 72 undergraduates who were assigned to six conditions in which they performed (1) only preference judgments or choices, (2) preference judgments or choices preceded by judgments of attractiveness of attribute levels, or (3) preference judgments or choices accompanied by think-aloud reports. The results replicated the prominence effect for choices, but a prominence effect was also found for preference judgments. In accordance with the restructuring explanation, the think-aloud protocols indicated that options were more often restructured in choices than in preference judgments. However, restructuring could not explain the prominence effect observed for preference judgments. A modified compatibility hypothesis is offered as an alternative explanation.  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