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   1455篇
  免费   73篇
  国内免费   1篇
  2023年   10篇
  2022年   19篇
  2021年   32篇
  2020年   35篇
  2019年   49篇
  2018年   72篇
  2017年   58篇
  2016年   70篇
  2015年   42篇
  2014年   72篇
  2013年   161篇
  2012年   113篇
  2011年   109篇
  2010年   58篇
  2009年   63篇
  2008年   74篇
  2007年   72篇
  2006年   56篇
  2005年   56篇
  2004年   47篇
  2003年   47篇
  2002年   39篇
  2001年   17篇
  2000年   13篇
  1999年   16篇
  1998年   17篇
  1997年   10篇
  1996年   8篇
  1995年   5篇
  1994年   4篇
  1993年   3篇
  1992年   5篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1987年   4篇
  1983年   3篇
  1982年   5篇
  1981年   3篇
  1978年   4篇
  1977年   3篇
  1975年   4篇
  1973年   3篇
  1971年   2篇
  1969年   4篇
  1968年   2篇
  1967年   3篇
  1966年   2篇
  1965年   2篇
  1963年   2篇
排序方式: 共有1529条查询结果,搜索用时 178 毫秒
841.
The study was designed to investigate changes in how children are interviewed in cases of child sexual abuse over a fairly long period of time. The interviewers' utterances were analysed in a large sample of forensic interviews conducted in Norway during the period of 1990–2002. The results indicate that interviewer strategies have improved during this period; there is a decrease in the proportion of suggestive, yes/no and option‐posing utterances, accompanied by a comparable increase in directive utterances. However, the frequency of open‐ended utterances is low, and has not changed much over time. An index of the overall quality of the interviews likewise showed a positive trend, with an increase in the proportion of interviews that were labelled ‘good’. However, even in recent years, interviews rated as ‘inadequate’ or ‘poor’ constituted half of the interviews conducted. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
842.
The China Puzzle: Falling Happiness in a Rising Economy   总被引:4,自引:0,他引:4  
Over the 1990–2000 decade happiness in China plummeted despite massive improvement in material living standards. This finding contradicts the notion that income growth at low living standards leads to gains, not losses, in happiness. We explain this puzzle by drawing on a specific version of relative deprivation theory, the concept of “frustrated achievers.” Our major finding is that income inequality in China became increasingly skewed towards the upper income strata, so that related to the average income the financial position of most Chinese worsened. Consequently, financial dissatisfaction rose and became an increasingly important factor in depressing happiness. Other negative feelings emerging with rapid transitions, such as anomie and disaffection, show a less depressive effect on Chinese happiness. We conclude with some speculations about the applicability of our findings to transition economies in general.
Jan DelheyEmail:
  相似文献   
843.
In the field of cognitive ergonomics, research on car drivers requires multimodal in-vehicle systems for recording not only driving-related behavior, but also contextual information from their surroundings. In addition, reliable information concerning a driver’s functional state should be obtained. In this article, we describe an integrated device simultaneously recording specific physiological data, video recordings of the driver and environment, parameters from the vehicle, and contextual data. Physiological signals from the autonomic nervous system provide objective and quantitative information on the driver’s alertness and his/her ability to process specific driving-related stimuli or other nonspecific information. Consequently, recorded physiological responses can be related to individual driving events. Electrodermal and cardiac activities are sensitive to time-dependent variations in arousal level and to certain external stimuli, so there is great interest in studying drivers’ behavior via measured physiological signals that have been established as suitable behavioral indicators. The present integrated device is capable of processing the relevant indices from raw measured data in real time.  相似文献   
844.
I first summarize the central issues in the debate about the empirical adequacy of virtue ethics, and then examine the role that social psychologists claim positive and negative mood have in influencing compassionate helping behavior. I argue that this psychological research is compatible with the claim that many people might instantiate certain character traits after all which allow them to help others in a wide variety of circumstances. Unfortunately for the virtue ethicist, however, it turns out that these helping traits fall well short of exhibiting certain central features of compassion.  相似文献   
845.
This study evaluates how different aspects of travel socialization during childhood and adolescence contribute to the explanation of travel mode choice in young adulthood. In an online survey with 2612 students who had access to a car three different socialization aspects were measured retrospectively: communication with parents about the environmental impact of travel mode choice at the participants’ age of 15, the symbolic-affective importance of driving and acquisition of a driver’s license at the age of 18, and finally multi-mobility in the peer group at the age of 18. It was expected that socialization constructs would have a direct effect on social and personal norm as wells as on car use habit and an indirect effect on car use, mediated by norms, habit and intention. Structural equation modelling showed a significant impact of all socialization constructs on either norms or car use habit or both. Moreover, the postulated mediator effect could be confirmed. The paper encourages widening the perspective of transport studies by aspects of socialization, which have been neglected in former research on adults mobility behaviour.  相似文献   
846.
The fact that we ought to prefer what is comparatively more likely to be good, I argue, does, contrary to consequentialism, not rest on any evaluative facts. It is, in this sense, a deontological requirement. As such it is the basis of our valuing those things which are in accordance with it. We value acting (and believing) well, i.e. we value acting (and believing) as we ought to act (and to believe). In this way, despite the fact that our interest in justification depends on our interest in truth, we value believing with justification on non-instrumental grounds. A deontological understanding of justification, thus, solves the Value of Knowledge Problem.
Christian PillerEmail:
  相似文献   
847.
The subjective impression that statements are true increases when statements are presented repeatedly. There are two sources for this truth effect: An increase in validity based on recollection (a controlled process) and increase in processing fluency due to repeated exposure (an automatic process). Using multinomial processing trees (MPT), we present a comprehensive model of the truth effect. Furthermore, we show that whilst the increase in processing fluency is indeed automatic, the interpretation and use of that experience is not. Experiment 1 demonstrates the standard use of the fluency experience and Experiment 2 demonstrates that people can change the interpretation of the experience according to its ecological validity. By implication, the truth effect represents the adaptive usage of feedback received from internal processes.  相似文献   
848.
The NMDA receptor (NMDAR) subunit GluN1 is an obligatory component of NMDARs without a known functional homolog and is expressed in almost every neuronal cell type. The NMDAR system is a coincidence detector with critical roles in spatial learning and synaptic plasticity. Its coincidence detection property is crucial for the induction of hippocampal long-term potentiation (LTP). We have generated a mutant mouse model expressing a hypomorph of the Grin1N598R allele, which leads to a minority (about 10%) of coincidence detection-impaired NMDARs. Surprisingly, these animals revealed specific functional changes in the dentate gyrus (DG) of the hippocampal formation. Early LTP was expressed normally in area CA1 in vivo, but was completely suppressed at perforant path-granule cell synapses in the DG. In addition, there was a pronounced reduction in the amplitude of the evoked population spike in the DG. These specific changes were accompanied by behavioral impairments in spatial recognition, spatial learning, reversal learning, and retention. Our data show that minor changes in GluN1-dependent NMDAR physiology can cause dramatic consequences in synaptic signaling in a subregion-specific fashion despite the nonredundant nature of the GluN1 gene and its global expression.According to Hebb''s postulate, neurons require a molecular mechanism to detect synchronous activity in order to change the strength of synaptic connectivity (Hebb 1949). NMDA receptors (NMDARs) are molecular coincidence detectors, and selective NMDAR antagonists block the induction of long-term potentiation (LTP) in both the dentate gyrus (DG) and CA1 regions of the hippocampus (Bliss and Collingridge 1993; Martin et al. 2000). NMDARs have been long known for their role in spatial learning, but more recently have been implicated in other forms of cognitive function and dysfunction (Gruart et al. 2006; Whitlock et al. 2006; Castner and Williams 2007; Kristiansen et al. 2007; Wilson and Linster 2008).Neuronal NMDARs are hetero-tetrameric ligand-gated ion channels typically comprised of two types of subunits. Two copies of the mandatory GluN1 subunit (or NR1 subunit [Collingridge et al. 2009] encoded by Grin1) are associated with two copies from the GluN2 family, GluN2A–D (or NR2A–D). The GluN1 subunit is expressed ubiquitously both spatially and temporally throughout the developing and adult brain. Global knockout mice models of the GluN1 subunit are postnatally lethal within hours after birth (Forrest et al. 1994; Li et al. 1994), and cell-specific GluN1 mice knockouts (Tsien et al. 1996; Nakazawa et al. 2002; McHugh et al. 2007; Niewoehner et al. 2007) have provided insights on how specific synapses and regional neuronal networks are dependent on NMDAR function.The early postnatal lethality of the global GluN1 knockout is in contrast to the null mutants of the four AMPA receptor genes and other major synaptic proteins, such as αCaMKII (Silva et al. 1992a,b; Jia et al. 1996; Zamanillo et al. 1999; Meng et al. 2003). This can be at least partially explained by the absence of any close GluN1 homologs, which could functionally compensate for the absence of the GluN1 subunit. Recombinant expression studies defined the GluN1 subunit as a mandatory component of NMDARs. This constellation provides a specific opportunity to test whether different local neuronal subnetworks are affected differentially by mutant Grin1 alleles associated with subtle alterations of the functional properties of NMDARs.GluN1 subunits with the N598R point mutation (GluN1R) yield functional NMDARs that are Mg2+ insensitive and Ca2+ impermeable (Burnashev et al. 1992; Mori et al. 1992). The Grin1N598R allele that codes for GluN1R subunits is a gain-of-function mutation that is dominant lethal, even in heterozygous and hemizygous lines (Single et al. 2000; Rudhard et al. 2003). NMDARs with GluN1R subunits do not act as coincidence detectors and, interestingly, mice expressing exclusively the GluN1R allele lack whisker-related pattern formation in the neonate brainstem (Rudhard et al. 2003).To investigate the functional importance of GluN1 subunits with the N598R point mutation, we took advantage of the generation of a variant mutant line of mice (GluN1Rneo/+) expressing a minority (around 10%) of these mutant NMDARs. Even though the majority of the NMDARs are normal, all neurons expressing NMDARs will contain a subset of receptors carrying this mutation.Therefore, this mouse model is an ideal candidate to study the impact of subtle alterations of NMDAR function on different neuronal networks, such as those comprising the hippocampal formation.Studies examining region-specific targeted disruption of GluN1 expression in subregions of the hippocampus have revealed subtle yet important contributions of this NMDAR subunit in synaptic plasticity and spatial learning and memory. CA1-restricted knockout of GluN1 expression in the hippocampus caused impaired spatial learning and memory as well as reduced CA1-LTP (Tsien et al. 1996). In the case of the disruption of GluN1 expression in the DG region of the hippocampus, more subtle behavioral impairments were apparent, including the inability to discriminate between two similar contexts (pattern separation) and deficits in spatial working memory despite normal LTP in the CA1 region (McHugh et al. 2007; Niewoehner et al. 2007).Our GluN1Rneo/+ mice differ from the region-specific GluN1 mutant mice in that they express the mutant hypomorph at the same level in different subregions of the hippocampus. Interestingly, we found that this allele leads to substantial differences in short- and long-term plasticity between area CA1 and the DG of the hippocampus. The specific impairment in the DG was accompanied by impaired spatial recognition, spatial learning, reversal learning, and retention. Our data establish the possibility of a circuit-specific phenotype caused by a mutant variant of a globally expressed major nonredundant synaptic protein.  相似文献   
849.
In the 1970s, Robin Giles introduced a game combining Lorenzen-style dialogue rules with a simple scheme for betting on the truth of atomic statements, and showed that the existence of winning strategies for the game corresponds to the validity of formulas in Łukasiewicz logic. In this paper, it is shown that ‘disjunctive strategies’ for Giles’s game, combining ordinary strategies for all instances of the game played on the same formula, may be interpreted as derivations in a corresponding proof system. In particular, such strategies mirror derivations in a hypersequent calculus developed in recent work on the proof theory of Łukasiewicz logic. Presented by Daniele Mundici  相似文献   
850.
This research explores the possibility that changes in attitude certainty can affect general self-certainty and, thus, have consequences that extend beyond the attitude domain. Across two studies, attitude certainty is manipulated using repeated attitude expression and attitude consensus paradigms. The implications of these manipulations are tested for feelings of general self-uncertainty (Study 1) and global self-doubt about one’s abilities (Study 2). In each study, it is demonstrated that participants feel greater self-certainty under conditions of high rather than low attitude certainty, but only when they view aspects of the attitude as central to their self-concept.  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