全文获取类型
收费全文 | 542篇 |
免费 | 70篇 |
国内免费 | 67篇 |
专业分类
679篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 24篇 |
2019年 | 32篇 |
2018年 | 27篇 |
2017年 | 28篇 |
2016年 | 24篇 |
2015年 | 16篇 |
2014年 | 25篇 |
2013年 | 86篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 14篇 |
2009年 | 30篇 |
2008年 | 25篇 |
2007年 | 36篇 |
2006年 | 33篇 |
2005年 | 25篇 |
2004年 | 20篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 16篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
排序方式: 共有679条查询结果,搜索用时 0 毫秒
31.
Algebras of Intervals and a Logic of Conditional Assertions 总被引:1,自引:0,他引:1
Intervals in boolean algebras enter into the study of conditional assertions (or events) in two ways: directly, either from intuitive arguments or from Goodman, Nguyen and Walker's representation theorem, as suitable mathematical entities to bear conditional probabilities, or indirectly, via a representation theorem for the family of algebras associated with de Finetti's three-valued logic of conditional assertions/events. Further representation theorems forge a connection with rough sets. The representation theorems and an equivalent of the boolean prime ideal theorem yield an algebraic completeness theorem for the three-valued logic. This in turn leads to a Henkin-style completeness theorem. Adequacy with respect to a family of Kripke models for de Finetti's logic, ukasiewicz's three-valued logic and Priest's Logic of Paradox is demonstrated. The extension to first-order yields a short proof of adequacy for Körner's logic of inexact predicates. 相似文献
32.
Little is known about the acoustic cues infants might use to selectively attend to one talker in the presence of background noise. This study examined the role of talker familiarity as a possible cue. Infants either heard their own mothers (maternal-voice condition) or a different infant's mother (novel-voice condition) repeating isolated words while a female distracter voice spoke fluently in the background. Subsequently, infants heard passages produced by the target voice containing either the familiarized, target words or novel words. Infants in the maternal-voice condition listened significantly longer to the passages containing familiar words; infants in the novel-voice condition showed no preference. These results suggest that infants are able to separate the simultaneous speech of two women when one of the voices is highly familiar to them. However, infants seem to find separating the simultaneous speech of two unfamiliar women extremely difficult. 相似文献
33.
Lip reading is the ability to partially understand speech by looking at the speaker's lips. It improves the intelligibility of speech in noise when audio-visual perception is compared with audio-only perception. A recent set of experiments showed that seeing the speaker's lips also enhances sensitivity to acoustic information, decreasing the auditory detection threshold of speech embedded in noise [J. Acoust. Soc. Am. 109 (2001) 2272; J. Acoust. Soc. Am. 108 (2000) 1197]. However, detection is different from comprehension, and it remains to be seen whether improved sensitivity also results in an intelligibility gain in audio-visual speech perception. In this work, we use an original paradigm to show that seeing the speaker's lips enables the listener to hear better and hence to understand better. The audio-visual stimuli used here could not be differentiated by lip reading per se since they contained exactly the same lip gesture matched with different compatible speech sounds. Nevertheless, the noise-masked stimuli were more intelligible in the audio-visual condition than in the audio-only condition due to the contribution of visual information to the extraction of acoustic cues. Replacing the lip gesture by a non-speech visual input with exactly the same time course, providing the same temporal cues for extraction, removed the intelligibility benefit. This early contribution to audio-visual speech identification is discussed in relationships with recent neurophysiological data on audio-visual perception. 相似文献
34.
Nonparametric tests for testing the validity of polytomous ISOP-models (unidimensional ordinal probabilistic polytomous IRT-models) are presented. Since the ISOP-model is a very general nonparametric unidimensional rating scale model the test statistics apply to a great multitude of latent trait models. A test for the comonotonicity of item sets of two or more items is suggested. Procedures for testing the comonotonicity of two item sets and for item selection are developed. The tests are based on Goodman-Kruskal's gamma index of ordinal association and are generalizations thereof. It is an essential advantage of polytomous ISOP-models within probabilistic IRT-models that the tests of validity of the model can be performed before and without the model being fitted to the data. The new test statistics have the further advantage that no prior order of items or subjects needs to be known. 相似文献
35.
On the lateralization of emotional prosody: an event-related functional MR investigation 总被引:11,自引:0,他引:11
In order to investigate the lateralization of emotional speech we recorded the brain responses to three emotional intonations in two conditions, i.e., "normal" speech and "prosodic" speech (i.e., speech with no linguistic meaning, but retaining the 'slow prosodic modulations' of speech). Participants listened to semantically neutral sentences spoken with a positive, neutral, or negative intonation in both conditions and judged how positive, negative, or neutral the intonation was on a five-point scale. Core peri-sylvian language areas, as well as some frontal and subcortical areas were activated bilaterally in the normal speech condition. In contrast, a bilateral fronto-opercular region was active when participants listened to prosodic speech. Positive and negative intonations elicited a bilateral fronto-temporal and subcortical pattern in the normal speech condition, and more frontal activation in the prosodic speech condition. The current results call into question an exclusive right hemisphere lateralization of emotional prosody and expand patient data on the functional role of the basal ganglia during the perception of emotional prosody. 相似文献
36.
小学儿童空间物体位置编码(Ⅰ) 总被引:3,自引:0,他引:3
采用找物范式研究小学7、9、11岁儿童利用点与点之间的关系对目标物位置进行编码的认知发展。结果表明:两点距离编码和三点共线编码认知成绩的年龄效应显著,9岁组和11岁组儿童的认知成绩显著好于7岁组儿童的认知成绩。两个不同实验任务对儿童认知成绩的影响不同,7岁组儿童两点距离编码认知成绩显著好于三点共线编码认知成绩,9岁组和11岁组两个任务的认知成绩差异不显著。提供编码线索后,认知成绩有了较大的改善。 相似文献
37.
Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules 下载免费PDF全文
Foster TA Hackenberg TD Vaidya M 《Journal of the experimental analysis of behavior》2001,76(2):159-178
Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens. 相似文献
38.
Eric Mack 《Ethical Theory and Moral Practice》1999,2(2):87-115
This paper offers a programmatic philosophical articulation of moral and political individualism. This individualism consists of two main components: value individualism and rights individualism. The former is the view that, for each individual, the end which is of ultimate value is his own well-being. Each individual's well-being has ultimate agent-relative value and the only ultimate values are these agent-relative values. The latter view is that individuals possess moral jurisdiction over themselves, i.e., rights of self-ownership. These rights (along with other rights individuals may come to possess) constrain the manner in which agents may pursue value. For this reason, the articulated individualism is an constrained individualism. Sketches of arguments are offered for both value and rights individualism. And it is argued that the sole legitimate function of legal/political institutions is to further delineate and protect the rights of individuals. However, the paper is also concerned to indicate why this radical moral and political individualism does not have many of the features or implications that are commonly ascribed to it. In this connection, I seek to show how this social doctrine accords with individuals' having concern for the well-being of others, with the emergence of relationships among individuals that have both instrumental and non-instrumental value, with a degree of responsibility for self and others that is often thought to be antithetical to individualism and, in general, with a flourishing of civil order. 相似文献
39.
Mutsumi Imai 《The Japanese psychological research》1999,41(1):5-20
Many researchers have agreed that word learning in young children is guided by so-called "word-learning principles." However, these principles may make it difficult to learn a substantial part of the lexicon unless they are appropriately controlled. To learn proper names, the taxonomic assumption and/or the shape bias must be overridden; to learn names for substances, withdrawal of the whole-object assumption and/or the shape bias is required; and to learn lexical hierarchies, the mutual exclusivity assumption must be suspended. In certain languages, syntax can provide useful information in this situation. For example, if a novel noun is given to an object for which the name is known in the syntactic frame "This is X," English-speaking children may assume the noun to be a proper noun, and this will help them override the taxonomic assumption. However, this information is not available to Japanese children, since the Japanese language does not have grammatical markers to flag the distinction between count nouns and mass nouns, or the distinction between proper nouns and common nouns. In this paper, I discuss how Japanese children get around this problem. 相似文献
40.
王夫之阴阳十二位向背是根据乾坤并建之体的性质及体用一源的原理引申、推论出来的,他用这一原理来批评象数学的机械排比和框定,并用事物的自然自足、自立自全的性质,证明《序卦传》的三种卦序说不能成立,为自己独特的卦序说奠立基础。他要证明的哲学原理是,显现有向背,阳阳无或缺;本体所具有的性质与功能,同时就具于个体之中,个体因此而有了主体性、能动性,和自由地独立活动的品格。 相似文献