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   18381篇
  免费   1473篇
  国内免费   1135篇
  20989篇
  2024年   29篇
  2023年   304篇
  2022年   283篇
  2021年   341篇
  2020年   647篇
  2019年   656篇
  2018年   640篇
  2017年   747篇
  2016年   752篇
  2015年   493篇
  2014年   667篇
  2013年   2072篇
  2012年   411篇
  2011年   561篇
  2010年   432篇
  2009年   657篇
  2008年   813篇
  2007年   847篇
  2006年   780篇
  2005年   686篇
  2004年   593篇
  2003年   484篇
  2002年   458篇
  2001年   279篇
  2000年   260篇
  1999年   233篇
  1998年   185篇
  1997年   147篇
  1996年   129篇
  1995年   113篇
  1994年   107篇
  1993年   84篇
  1992年   69篇
  1991年   48篇
  1990年   49篇
  1989年   28篇
  1988年   43篇
  1985年   378篇
  1984年   424篇
  1983年   348篇
  1982年   451篇
  1981年   442篇
  1980年   442篇
  1979年   394篇
  1978年   445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 0 毫秒
991.
The present study explored the intrinsic event-related potential (ERP) features of the effects of acute psychological stress on the processing of motion-in-depth perception using a dual-task paradigm. After a mental arithmetic task was used to induce acute psychological stress, a collision task was used to evaluate motion-in-depth perception. The error value and average amplitude of late slow waves (SW) were significantly larger for the earlier colliding spheres’ than for the later colliding spheres. The P1 peak latency in the left occipital region was significantly shorter than that of the right occipital region in the motion-in-depth perception task. Compared to the control condition, the estimated value of residual time-to-collision and error value were significantly reduced, and the N1 peak amplitude and the SW averaged amplitude were significantly increased in the stress condition. Longer motion-in-depth time improved discrimination accuracy and decreased the investment of cognitive resources. Acute psychological stress increased behavioral performance and enhanced attention resources on the motion-in-depth perception task together with greater investment of cognitive resources.  相似文献   
992.
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   
993.
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   
994.
The purpose of this study was to examine children's reported experiences of anger and their means of expressing anger in their interactions with high versus equal status individuals. Parents and teachers represented high status while siblings and peers represented equal status. Sixth grade children were asked to cite situations in which they experience anger in interaction with peers versus adults and to indicate their typical responses to these situations. We identified 13 categories of situations in which anger was experienced and 11 categories of response to these situations. Anger was experienced in interaction with both high and equal status provokers but of the situations that were identified as producing experiences of anger, nine were reported as occurring differentially in interaction with adults versus peers of the responses to the experience of anger, seven responses were cited differentially in interaction with peers versus adults. The typical responses to adult provoked anger were generally more passive than those to peer provoked anger. Girls more than boys indicated experiencing anger due to adult's task demands but tended to express less overt anger in their interactions with adults than did boys. These findings are consistent with the view that high status of the provoker servers only to inhibit the expression of anger but does not lessen the anger experience itself.  相似文献   
995.
Social diffusion theory has recently been recognized as a promising approach for large-scale disease prevention and health promotion efforts. This paper describes how principles and tactics from social cognitive theory, operant psychology, social psychology, social marketing, and the overarching stages of change model can be used to further develop the conceptual and strategic (technological) bases of social diffusion theory. Within an integrative framework, we discuss in detail more effective ways to train peer mediators of behavior change as one example of how social diffusion theory can benefit from this conceptual and strategic reformulation. We then further illustrate the use of peer mediators of change in human immunodeficiency virus (HIV) and cancer prevention intervention studies with both interventions training peer mediators to diffuse information, norms, and risk reduction strategies. Although the results of these studies showed reductions in high-risk behaviors across population segments, more closely following the framework discussed in this article should further increase the behavior change potential of future interventions based on social diffusion theory.  相似文献   
996.
Despite the lack of invariance problem (the many-to-many mapping between acoustics and percepts), human listeners experience phonetic constancy and typically perceive what a speaker intends. Most models of human speech recognition (HSR) have side-stepped this problem, working with abstract, idealized inputs and deferring the challenge of working with real speech. In contrast, carefully engineered deep learning networks allow robust, real-world automatic speech recognition (ASR). However, the complexities of deep learning architectures and training regimens make it difficult to use them to provide direct insights into mechanisms that may support HSR. In this brief article, we report preliminary results from a two-layer network that borrows one element from ASR, long short-term memory nodes, which provide dynamic memory for a range of temporal spans. This allows the model to learn to map real speech from multiple talkers to semantic targets with high accuracy, with human-like timecourse of lexical access and phonological competition. Internal representations emerge that resemble phonetically organized responses in human superior temporal gyrus, suggesting that the model develops a distributed phonological code despite no explicit training on phonetic or phonemic targets. The ability to work with real speech is a major advance for cognitive models of HSR.  相似文献   
997.
Studies have shown that performance-dependent monetary rewards facilitate visual perception. However, no study has examined whether such a positive effect is limited to the rewarded task or may be generalized to other tasks. In the current study, two groups of people were asked to perform two visual perception tasks, one being a reward-relevant task and the other being a reward-irrelevant task. For the reward-relevant task, the experimental group received performance-dependent monetary rewards, whereas the control group did not. For the reward-irrelevant task, both groups were not rewarded. The two tasks were randomly intermixed trial by trial (Experiment 1) or presented block by block (Experiment 2) or session by session (Experiments 3a, 3b, and 3c). Results showed that performance-dependent monetary rewards improved participants' performance on the relevant task in all experiments and impaired their performance on the irrelevant task in Experiments 2, 3a, 3b, and 3c. These results suggested that monetary rewards might incur a cost on reward-irrelevant tasks. Finally, the benefit of monetary rewards disappeared when they were no longer provided during the final session. This is the first study that reveals both the bright and dark sides of the performance-dependent monetary rewards in visual perception.  相似文献   
998.
Previous research has shown that there is higher tolerance of violence against women in cultures with salient gender-specific honor norms, especially when the violence occurs in intimate relationships and in response to threat to male honor. The present cross-cultural study (N = 398) extended these findings to sexual aggression (i.e., marital rape) by comparing participants from a culture that emphasizes honor (Turkey) and participants from cultures without strong honor traditions (Germany and Britain). Turkish participants blamed the victim and exonerated the perpetrator more than did German and British participants. In all cultural groups, participants blamed the victim and exonerated the perpetrator more when the husband's reputation was threatened than in the absence of such threat, and in all cultural groups, men blamed the victim and exonerated the perpetrator more than women. Yet, the effect of masculine reputation threat and this pattern of gender differences were somewhat more pronounced among Turkish than German or British participants. Results exploring the predictive role of honor norms at the individual level beyond rape myth acceptance and traditional gender role attitudes revealed that honor norms were the primary predictor of rape perceptions and blame attributions in Turkey (an honor culture), but not in Germany and Britain (dignity cultures) where rape myth acceptance was the strongest predictor. These results provide insights into the cultural factors influencing marital rape judgments in ways that may undermine victim's well-being and fair handling of rape cases, and highlight the domains most urgently in need of potential intervention.  相似文献   
999.
Our objective was to examine the differential effects of antenatal breastfeeding intention (BI) and breastfeeding practice (BP) on maternal postnatal responsiveness. We conducted a secondary analysis of longitudinal data from a subsample of 962 mother–infant dyads from a U.K.-based birth cohort study the Avon Longitudinal Study of Parents and Children. Exposures were BI and BPs measured at 32 weeks of gestation and 18 months’ postpartum. The outcome was maternal responsiveness assessed at 12 months’ postpartum. We used logistic regression analyses unadjusted and adjusted for confounders. Intention to breastfeed was associated with increased odds of postnatal maternal responsiveness independent of BP, adjusted odds ratio (OR) = 2.34, 95% CI [1.42, 3.86]. There was no evidence that BP was an independent predictor of maternal responsiveness, OR = 0.93, 95% CI [0.55, 1.57]. Life-course epidemiology analyses demonstrated that maternal responsiveness is most positive when both BI and BP are present. This is the first population-based study to provide evidence that BI during pregnancy is more strongly associated with maternal postnatal responsiveness than is BP. Further research is needed to understand the determinants of BI in pregnancy and its relationships with maternal responsiveness.  相似文献   
1000.
Qualitative interviews were conducted with nine members of the Islamic State of Iraq and Syria (ISIS) and Al-Qaeda currently incarcerated in Kuwait's Central Prison. The semistructured interviews attempted to understand psychosocial factors in Kuwait that contributed to their decision to join extremist organizations. Interviews were analyzed using Interpretive Phenomenological Analysis (IPA) and the emergent themes identified the following core themes explaining their involvement: (1) religious identity development; (2) personal connections; (3) propaganda; (4) defense of Islam; and (5) social marginalization. Participants described a process whereby their religion became a central part of their personal identity. As their religious identity developed, they became involved in Islamic organizations where they met people involved with ISIS or Al-Qaeda. These social connections exposed them to jihadi propaganda which, in addition to increased military conflict in the Middle East, crystallized their beliefs that Islam is under attack, and they were religiously obligated to defend it. The results also identified societal factors that increased the probability of engaging in terrorism including relatively low levels of education, coming from low socioeconomic groups in Kuwait, and feeling socially marginalized by broader Kuwaiti society.  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