全文获取类型
收费全文 | 16632篇 |
免费 | 1377篇 |
国内免费 | 975篇 |
出版年
2023年 | 208篇 |
2022年 | 193篇 |
2021年 | 279篇 |
2020年 | 509篇 |
2019年 | 589篇 |
2018年 | 556篇 |
2017年 | 659篇 |
2016年 | 674篇 |
2015年 | 420篇 |
2014年 | 535篇 |
2013年 | 1774篇 |
2012年 | 350篇 |
2011年 | 443篇 |
2010年 | 367篇 |
2009年 | 565篇 |
2008年 | 741篇 |
2007年 | 785篇 |
2006年 | 746篇 |
2005年 | 633篇 |
2004年 | 544篇 |
2003年 | 453篇 |
2002年 | 430篇 |
2001年 | 262篇 |
2000年 | 248篇 |
1999年 | 212篇 |
1998年 | 174篇 |
1997年 | 146篇 |
1996年 | 121篇 |
1995年 | 110篇 |
1994年 | 98篇 |
1993年 | 81篇 |
1992年 | 61篇 |
1991年 | 45篇 |
1990年 | 48篇 |
1989年 | 26篇 |
1988年 | 40篇 |
1987年 | 27篇 |
1985年 | 368篇 |
1984年 | 417篇 |
1983年 | 344篇 |
1982年 | 450篇 |
1981年 | 441篇 |
1980年 | 442篇 |
1979年 | 394篇 |
1978年 | 444篇 |
1977年 | 349篇 |
1976年 | 353篇 |
1975年 | 272篇 |
1974年 | 278篇 |
1973年 | 236篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Cognitive inhibition has been suggested to deteriorate in Alzheimer’s disease. While numerous studies with different experimental paradigms found evidence on impaired inhibition in attention and memory, evidence in favour of intact memory inhibition has been reported with regard to the phenomenon of retrieval-induced forgetting (Moulin et al., 2002). Here, we adapted the previously used paradigm in order to reduce the contribution of non-inhibitory processes and examined whether retrieval-induced forgetting could still be observed in a sample of participants with diagnosed Alzheimer’s disease. In contrast to the previous finding, we found that retrieval-induced forgetting only occurred in an age-matched control group. These results suggest that inhibitory deficits in Alzheimer’s disease also generalize to memory inhibition that resolves interference occurring during retrieval, whereas effects of retrieval-induced forgetting may still occur when non-inhibitory causes, such as, blocking by previously retrieved content, are not precluded. 相似文献
993.
Male and female college students were instigated to aggression by a confederate's shocks during a preliminary task. The confederate informed half of the treatment subjects of the response strategy which he intended to adopt. The other half received an irrelevant message. All subjects then competed against the confederate, who employed one of the following five response consequence strategies: a) set a maximum shock on all trials; b) set a minimum shock on all trials; c) set shocks identical to the subject's response on the preceding trial; d) set shocks two settings below the subject's response; or e) set shocks two settings above the subject's. The subject's latency to setting a shock, the intensities of the shocks set, the durations of the shock settings, and the subject's reaction times were recorded. When an irrelevant message was delivered, passive responses, well below those of the opponent, resulted in the lowest level of retaliation. In the presence of a relevant message, the match-same strategy emerged as an effective deterrent to aggressive behavior. The results were found to be consistent with predictions derived from an application of the norm of reciprocity and research demonstrating the enhancing effects achieved through the communication of existing contingencies. 相似文献
994.
人与自然关系是文学表现的重要母题。透过文学的发展,可以窥视出人类社会在社会实践推动下所走过的历史道路。本文意在通过中西文学发展中人与自然关系的描写,揭示人与自然关系的变化过程,并在历史的视野中审视生态批判的当代意义。 相似文献
995.
996.
997.
Electrical stimulation of the region of the lateral hypothalamus produced a consistent form of quiet-biting attack behavior in cats. In one series of experiments, cats, implanted with electrodes from which attack had been elicited, were anesthetized and then were injected with a bolus of 14C-2-deoxyglucose at the same time as electrical stimulation was delivered through the attack electrodes. Brains prepared for X-ray autoradiography revealed that lateral hypothalamic stimulation activated the classical medial forebrain bundle pathway supplying the septal region, diagonal band, lateral preoptic area, and ventral tegmental region. Stimulation of quiet-attack sites in perifornical hypothalamus resulted in the activation of a much more extensive projection system which included the central and lateral tegmental fields of the midbrain and pons, and central gray region, as well as the structures described above. In a second series of experiments, 3H-leucine was placed into the region of the electrode tip from which attack was elicited in order to identify more precisely the pathways arising from that site. In general, tritiated amino acid radioautography replicated the 14C-2-deoxyglucose findings. In addition, the amino acid radioautographic data revealed the presence of extensive projections from perifornical hypothalamus to such pontine structures as the nucleus locus coeruleus, motor nucleus of NV , and the lateral pontine tegmental field. The functional connections between the lateral hypothalamic “attack region” and lateral preoptic zone were also confirmed by electrophysiological methods. 相似文献
998.
An explanation-approach within the frame of a universal and integrating theory of aggression is favored for understanding the effects of exposure to violence. Kornadt's Motivation Theory of Aggression is used to generate several hypotheses concerning the effects of aggressive movies on a viewer's expectancy-value-cognitions and these are tested in an experiment. The experiment suggests that aggressive stimulation is able to change aggression-related expectancy-value-cognitions in an aggression-facilitating direction. Based on these results, an attempt is made to explain increases in the aggression of viewers in terms of the Motivation Theory of Aggression. © 1993 Wiley-Liss, Inc. 相似文献
999.
商周文化东渐是山东地区商周考古的一个重要课题,淄潍河流域则是山东地区商周考古的一个关键性区域,随着考古资料的日益丰富,从考古学角度探讨淄潍河流域商周文化东渐及其历史背景已成为可能。 相似文献
1000.
Rainer Dyckerhoff 《Journal of Multi-Criteria Decision Analysis》1994,3(1):41-58
In expected utility many results have been derived that give necessary and/or sufficient conditions for a multivariate utility function to be decomposable into lower-dimensional functions. In particular, multilinear, multiplicative and additive decompositions have been widely discussed. These utility functions can be more easily assessed in practical situations. In this paper we present a theory of decomposition in the context of nonadditive expected utility such as anticipated utility or Choquet expected utility. We show that many of the results used in conventional expected utility carry over to these more general frameworks. If preferences over lotteries depend only on the marginal probability distributions, then in expected utility the utility function is additively decomposable. We show that in anticipated utility the marginality condition implies not only that the utility function is additively decomposable but also that the distortion function is the identity function. We further demonstrate that a decision maker who is bivariate risk neutral has a utility function that is additively decomposable and a distortion function q for which q(½) = ½. 相似文献