全文获取类型
收费全文 | 3480篇 |
免费 | 656篇 |
国内免费 | 171篇 |
出版年
2024年 | 7篇 |
2023年 | 50篇 |
2022年 | 31篇 |
2021年 | 69篇 |
2020年 | 161篇 |
2019年 | 246篇 |
2018年 | 208篇 |
2017年 | 257篇 |
2016年 | 236篇 |
2015年 | 175篇 |
2014年 | 189篇 |
2013年 | 614篇 |
2012年 | 158篇 |
2011年 | 147篇 |
2010年 | 90篇 |
2009年 | 152篇 |
2008年 | 164篇 |
2007年 | 159篇 |
2006年 | 122篇 |
2005年 | 159篇 |
2004年 | 119篇 |
2003年 | 109篇 |
2002年 | 103篇 |
2001年 | 102篇 |
2000年 | 71篇 |
1999年 | 51篇 |
1998年 | 58篇 |
1997年 | 40篇 |
1996年 | 32篇 |
1995年 | 57篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 3篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 4篇 |
排序方式: 共有4307条查询结果,搜索用时 15 毫秒
141.
A finitary characterization for non-well-founded sets with finite transitive closure is established in terms of a greatest fixpoint formula of the modal -calculus. This generalizes the standard result in the literature where a finitary modal characterization is provided only for wellfounded sets with finite transitive closure. The proof relies on the concept of automaton, leading then to new interlinks between automata theory and non-well-founded sets. 相似文献
142.
Slavoj iek's writings on Krzysztof Kies´lowski and Andrej Tarkovskij represent direct challenges to the Central and Eastern European tradition of spiritual art and to dominant aesthetic concepts as such. He refuses to separate the solemn films of Kies´lowski and Tarkovskij from popular culture and stresses their import as ethical statements by their directors. Despite this ethical emphasis, iek makes an important contribution to philosophical aesthetics. He implicitly defines art as a suspension of reality which reveals time in its fragility and potentiality. Defining iek's aesthetics in terms of suspension helps to explain his partiality for Kies´lowski and Tarkovskij and bears comparison to the Russian tradition of philosophical aesthetics, in particular Aleksej Losev and Alexander Bakshy. 相似文献
143.
A series of three experiments examined children's sensitivity to probabilistic phonotactic structure as reflected in the relative frequencies with which speech sounds occur and co-occur in American English. Children, ages 212 and 312 years, participated in a nonword repetition task that examined their sensitivity to the frequency of individual phonetic segments and to the frequency of combinations of segments. After partialling out ease of articulation and lexical variables, both groups of children repeated higher phonotactic frequency nonwords more accurately than they did low phonotactic frequency nonwords, suggesting sensitivity to phoneme frequency. In addition, sensitivity to individual phonetic segments increased with age. Finally, older children, but not younger children, were sensitive to the frequency of larger (diphone) units. These results suggest not only that young children are sensitive to fine-grained acoustic-phonetic information in the developing lexicon but also that sensitivity to all aspects of the sound structure increases over development. Implications for the acoustic nature of both developing and mature lexical representations are discussed. 相似文献
144.
Free Łukasiewicz and Hoop Residuation Algebras 总被引:2,自引:1,他引:1
Hoop residuation algebras are the {, 1}-subreducts of hoops; they include Hilbert algebras and the {, 1}-reducts of MV-algebras (also known as Wajsberg algebras). The paper investigates the structure and cardinality of finitely generated free algebras in varieties of k-potent hoop residuation algebras. The assumption of k-potency guarantees local finiteness of the varieties considered. It is shown that the free algebra on n generators in any of these varieties can be represented as a union of n subalgebras, each of which is a copy of the {, 1}-reduct of the same finite MV-algebra, i.e., of the same finite product of linearly ordered (simple) algebras. The cardinality of the product can be determined in principle, and an inclusion-exclusion type argument yields the cardinality of the free algebra. The methods are illustrated by applying them to various cases, both known (varieties generated by a finite linearly ordered Hilbert algebra) and new (residuation reducts of MV-algebras and of hoops). 相似文献
145.
Four-month-olds' memory for surface feature and location information was tested following brief occlusions. When the target objects were images of female faces or monochromatic asterisks infants showed increased looking times following a change in identity or color but not following a change in location or combinations of feature and location information. When the target objects were images of manipulable toys, the infants showed increased looking times following a change in location but not identity or the binding of location and identity information. This evidence is consistent with the idea that young infants are unable to maintain the information processed separately in both the dorsal and ventral visual streams during occlusions. Our results suggest that it is the target's affordance for action that determines whether the dorsal or ventral information is selectively maintained during occlusion. 相似文献
146.
Thompson RH Iwata BA Hanley GP Dozier CL Samaha AL 《Journal of applied behavior analysis》2003,36(2):221-238
Several techniques have been used in applied research as controls for the introduction of a reinforcement contingency, including extinction, noncontingent reinforcement (NCR), and differential reinforcement of other behavior (DRO). Little research, however, has examined the relative strengths and limitations of these "reversal" controls. We compared the effects of extinction with those of NCR and DRO in both multi-element and reversal designs, with respect to (a) rate and amount of response decrement, (b) rate of response recovery following reintroduction of reinforcement, and (c) any positive or negative side effects associated with transitions. Results indicated that extinction generally produced the most consistent and rapid reversal effects, with few observed negative side effects. 相似文献
147.
Functional analysis and treatment of self-injurious behavior in young children a summary of 30 cases
Kurtz PF Chin MD Huete JM Tarbox RS O'Connor JT Paclawskyj TR Rush KS 《Journal of applied behavior analysis》2003,36(2):205-219
The assessment and treatment of self-injurious behavior (SIB) has received much attention in the literature; however, few studies have focused on early intervention for this behavior. In the current study, functional analyses with developmentally appropriate modifications were conducted in an outpatient clinic with 30 children (aged 10 months to 4 years 11 months) to assess SIB and problem behavior in its early stages. The reported mean age of SIB onset was 17 months, and head banging was the most prevalent topography. Functional analyses identified sources of reinforcement for SIB in 62.1% of cases; with the inclusion of all forms of problem behavior, sources of reinforcement were identified for 87.5% of cases. Function-based treatments were developed for 24 cases, with functional communication training prescribed most often (70.8% of cases). Implications of these findings for the development of early intervention programs for SIB are discussed. 相似文献
148.
In this study, students worked independently by setting goals, selecting assignments, and recording and evaluating their results after receiving one of two different types of self-management training. During teacher-directed training, the teacher set goals, assigned work, and recorded and evaluated results for students. During student-directed training, students performed those tasks themselves. The results indicated that students engaged in the self-management behaviors more frequently during independent work following student-directed instruction than following teacher-directed instruction. 相似文献
149.
The present study evaluated the effects of noncontingent escape and differential negative reinforcement of other behavior in reducing problem behaviors and increasing compliance in 2 children with disabilities. Results showed that both methods reduced problem behavior and increased compliance for both children. 相似文献
150.
The paper discusses the similarity between geometry, arithmetic, and logic, specifically with respect to the question of whether applied theories of each may be revised. It argues that they can - even when the revised logic is a paraconsistent one, or the revised arithmetic is an inconsistent one. Indeed, in the case of logic, it argues that logic is not only revisable, but, during its history, it has been revised. The paper also discusses Quine's well known argument against the possibility of logical deviancy. 相似文献