全文获取类型
收费全文 | 3547篇 |
免费 | 2174篇 |
国内免费 | 60篇 |
专业分类
5781篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 137篇 |
2020年 | 147篇 |
2019年 | 565篇 |
2018年 | 469篇 |
2017年 | 590篇 |
2016年 | 555篇 |
2015年 | 483篇 |
2014年 | 406篇 |
2013年 | 512篇 |
2012年 | 287篇 |
2011年 | 249篇 |
2010年 | 196篇 |
2009年 | 163篇 |
2008年 | 140篇 |
2007年 | 143篇 |
2006年 | 136篇 |
2005年 | 105篇 |
2004年 | 83篇 |
2003年 | 93篇 |
2002年 | 86篇 |
2001年 | 81篇 |
2000年 | 62篇 |
1999年 | 36篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有5781条查询结果,搜索用时 0 毫秒
1.
Self‐explaining is an effective metacognitive strategy that can help learners develop deeper understanding of the material they study. This experiment explored if the format of material (i.e., text or diagrams) influences the self‐explanation effect. Twenty subjects were presented with information about the human circulatory system and prompted to self‐explain; 10 received this information in text and 10 in diagrams. Results showed that students given diagrams performed significantly better on post‐tests than students given text. Diagrams students also generated significantly more self‐explanations that text students. Furthermore, the benefits of self‐explaining were much greater in the diagrams condition. To discover why diagrams can promote the self‐explanation effect, results are interpreted with reference to the multiple differences in the semantic, cognitive and affective properties of the texts and diagrams studied. 相似文献
2.
Quantification of a chaotic system can be made by calculating the correlation dimension (D2) of the data that the system generates
(Packard et al., 1980). The D2 algorithm, however, requires stationarity of the generator, a feature that biological data
rarely reflect (Mayer-Kress et al., 1988). So we developed the “point correlation dimension” (PD2), an algorithm that accurately
tracks D2 in linked data of different dimensions (Carpeggiani et al., 1991). We now present a mathematical argument that,
for stationary data, individual PD2s converge to D2 and we demonstrate that the algorithm rejects contributions made by bursts
of noise. Data were obtained from the surface of the olfactory bulb of the conscious rabbit (64 electrodes, 640 Hz each, 1.3
sec epochs) before and after presentation of a novel or habituated odor. D2 could be calculated in only 1 of 10 novel-odor
trials, whereas PD2 could be calculated in all. Both algorithms indicated that a novel odor evokes a spatially uniform dimensional
increase. The PD2 uniquely exhibited the dimensional decreases that occur during inspiration and the gradients of mean dimension
present during the nonstimulated control state. These control gradients remained unchanged without odor experience, but showed
spatially specific PD2 increases following odor habituation. It is interpreted that, 1) the PD2 issensitive, accurate, and appropriate for dimensional assessment of biological data, 2) that during analysis of unfamiliar information a singleglobal process is transiently evoked in the neuropil, and 3) after experience multiplespatially specific processes tonically map the sites of learning.
Grant Support: National Institutes of Health, HL 31164 and NS27745 相似文献
3.
4.
Gabriel Oak Rabin 《Metaphilosophy》2023,54(2-3):352-358
This paper draws a distinction between the existential quantifier and the symbol ‘∃’ used to express it, on the one hand, and existence and ‘exists’, on the other. It argues that some popular arguments in metaphysics, including arguments against vague existence and arguments against deflationary metaontology (which views ontological disputes as lacking substance), are guilty of fudging this distinction. The paper draws some lessons for metaphysical debate about existence and highlights some heretofore ignored and attractive positions in logical space. 相似文献
5.
Philip Clayton 《Zygon》1993,28(3):361-369
Abstract. The present article continues an earlier critique of Robbins's and Rorty's neopragmatism. Their skepticism about the traditional concept of correspondence and about the criteria for truth are both unjustified, and their own assertion of meaning as usefulness either presupposes a prior notion of linguistic reference or fails to qualify as a sufficient criterion for knowledge. The difficulties with neopragmatism have implications for two other areas of the religion/science discussion, postmodernism and empirical Theology. Postmodernism shares neopragmatism's mistakes regarding the philosophy of language and can be rejected without endangering one's empiricism, humanism, or naturalism. By contrast, the strengths of empirical Theology, and of religious empiricism in general, can be preserved without Robbins's proposed ban on metaphysics. 相似文献
6.
7.
8.
Terrence W. Deacon 《Zygon》1996,31(4):635-670
Abstract. Language and information processes are critical issues in scientific controversies regarding the qualities that epitomize humanness. Whereas some theorists claim human mental uniqueness with regard to language, others point to successes in teaching language skills to other animals. However, although these animals may learn names for things, they show little ability to utilize a complex framework of symbolic reference. In such a framework, words or other symbols refer not only to objects and concepts but also to sequential and hierarchical relationships with other symbols. This process is essential to human mental operations, including language, mathematics, and music. In humans, these operations may have coevolved with the prefrontal area of the cerebral cortex, which is proportionately much larger in humans than in other animals and more intricately linked with other areas of the brain. Analysis of the structure and function of the prefrontal area suggests that it is centrally involved in the operation of higher-order associative relationships involving the subordination of one set of associations to another. This alternate learning strategy apparently appeared at the cost of certain sensory, motor, or limbic abilities. The payoff was symbolic thinking. Humans thus are unique among species, not just for their highly developed language ability but for their odd style of thinking and learning. 相似文献
9.
The polyserial correlation coefficient 总被引:1,自引:0,他引:1
The polyserial and point polyserial correlations are discussed as generalizations of the biserial and point biserial correlations. The relationship between the polyserial and point polyserial correlation is derived. The maximum likelihood estimator of the polyserial correlation is compared with a two-step estimator and with a computationally convenient ad hoc estimator. All three estimators perform reasonably well in a Monte Carlo simulation. Some practical applications of the polyserial correlation are described.By coincidence, the first author and the second and third authors learned that they were working independently on closely related problems and, consequently, decided to write a jointly authored paper. 相似文献
10.
Weiner H 《Journal of the experimental analysis of behavior》1977,27(3):515-528
Human altruistic responding (called give responding), which delivered a reinforcer to someone other than the responder, was compared to responding where the responder was the recipient of the reinforcer (called earn responding). The same type of response (button pressing), the same reinforcer (a point representing a penny), and the same reinforcer contingency (a 40-response fixed-ratio schedule) were used for both give and earn responding. Since points representing pennies were used to reinforce give and earn responding, responding for points not worth money was also assessed. Give, earn, and point responding were arranged as concurrent incompatible operants. Lowest rates were obtained for point responding. Compared to earn responding, give responding occurred at lower rates, was more susceptible to cessation when point responding was possible, extinguished more rapidly in the absence of money, and produced less responding during reconditioning compared to conditioning when reconditioning followed a period of nonreinforcement. Give responding was less when it reduced the giver's opportunity to earn. Finally, histories of getting reinforcement from others were shown to determine give responding. 相似文献