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   4098篇
  免费   499篇
  国内免费   518篇
  5115篇
  2024年   8篇
  2023年   91篇
  2022年   102篇
  2021年   131篇
  2020年   236篇
  2019年   289篇
  2018年   296篇
  2017年   300篇
  2016年   260篇
  2015年   190篇
  2014年   196篇
  2013年   736篇
  2012年   145篇
  2011年   160篇
  2010年   143篇
  2009年   134篇
  2008年   166篇
  2007年   222篇
  2006年   158篇
  2005年   151篇
  2004年   116篇
  2003年   102篇
  2002年   104篇
  2001年   81篇
  2000年   68篇
  1999年   54篇
  1998年   60篇
  1997年   36篇
  1996年   40篇
  1995年   38篇
  1994年   30篇
  1993年   29篇
  1992年   13篇
  1991年   9篇
  1990年   9篇
  1989年   9篇
  1987年   9篇
  1985年   17篇
  1984年   22篇
  1983年   13篇
  1982年   15篇
  1981年   15篇
  1980年   14篇
  1979年   16篇
  1978年   16篇
  1977年   20篇
  1976年   12篇
  1975年   11篇
  1974年   9篇
  1973年   5篇
排序方式: 共有5115条查询结果,搜索用时 15 毫秒
141.
Amso D  Johnson SP 《Cognition》2005,95(2):B27-B36
We used a spatial negative priming (SNP) paradigm to examine visual selective attention in infants and adults using eye movements as the motor selection measure. In SNP, when a previously ignored location becomes the target to be selected, responses to it are impaired, providing a measure of inhibitory selection. Each trial consisted of a prime and a probe, separated by 67, 200, or 550 ms interstimulus intervals (ISIs). In the prime, a target was accompanied by a distractor. In the probe, the target appeared either in the location formerly occupied by the distractor (ignored repetition) or in another location (control). Adults exhibited the SNP effect in all three ISI conditions, producing slower saccade latencies on ignored repetition versus control trials. The SNP effect obtained for infants only under 550 and 200 ms ISI conditions. These results suggest that important developments in visual selection are rooted in emerging inhibitory mechanisms.  相似文献   
142.
In face-to-face conversation speech is perceived by ear and eye. We studied the prerequisites of audio-visual speech perception by using perceptually ambiguous sine wave replicas of natural speech as auditory stimuli. When the subjects were not aware that the auditory stimuli were speech, they showed only negligible integration of auditory and visual stimuli. When the same subjects learned to perceive the same auditory stimuli as speech, they integrated the auditory and visual stimuli in a similar manner as natural speech. These results demonstrate the existence of a multisensory speech-specific mode of perception.  相似文献   
143.
Simultaneous visual discrimination in Asian elephants   总被引:3,自引:0,他引:3  
Two experiments explored the behavior of 20 Asian elephants (Elephas aximus) in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3 sessions and 293 trials. One elephant failed to reach criterion in the white+/black- task in 9 sessions and 549 trials, and 2 elephants failed to reach criterion in the black+/white- task in 9 sessions and 452 trials. In Experiment 2, 3 elephants learned a large/small transposition problem, reaching criterion within a mean of 1.7 sessions and 58 trials. Four elephants failed to reach criterion in 4.8 sessions and 193 trials. Data from both the black/white and large/small discriminations showed a surprising age effect, suggesting that elephants beyond the age of 20 to 30 years either may be unable to acquire these visual discriminations or may require an inordinate number of trials to do so. Overall, our results cannot be readily reconciled with the widespread view that elephants possess exceptional intelligence.  相似文献   
144.
Two experiments examined whether postsample signals of reinforcer probability or magnitude affected the accuracy of delayed matching to sample in pigeons. On each trial, red or green choice responses that matched red or green stimuli seen shortly before a variable retention interval were reinforced with wheat access. In Experiment 1, the reinforcer probability was either 0.2 or 1.0 for both red and green responses. Reinforcer probability was signaled by line or cross symbols that appeared after the sample had been presented. In Experiment 2, all correct responses were reinforced, and the signaled reinforcer durations were 1.0 s and 4.5 s. Matching was more accurate when larger or more probable reinforcers were signaled, independently of retention interval duration. Because signals were presented postsample, the effects were not the result of differential attention to the sample.  相似文献   
145.
The current paper introduces the special issue on research attempting to extend the construct of psychopathy to child and adolescent samples. Past special sections and reviews have typically focused on the implications of this research for forensic research and practice. The current special issue focuses on topics relevant for integrating this research within the broader literature on childhood psychopathology. Papers included in this special issue focus on the structure of psychopathic traits in youth, the relation of these traits to other important psychopathological and personality constructs in children and adolescents, and the utility of these traits for identifying a distinct subgroup of antisocial youth who differ on important cognitive processes and on the severity and stability of their problem behavior. These empirical works are followed by commentary provided by two prominent scholars who outline the potential importance of the construct for advancing our understanding of childhood psychopathology. In addition, these scholars provide a discussion of important directions for future research.  相似文献   
146.
The study examines a recurrent interactional pattern in genetic counseling. It describes clinical geneticists' responses in situations in which clients have presented information from other sources that is potentially discrepant with information given by the doctor. The data consists of 12 video-recorded sessions of genetic counseling in Finland, and the method is conversation analysis. There are two primary ways the doctors respond: either they accept the client's information as such, but show that it is not discrepant with the doctor's information, or they reject the client's information. In the latter case they mitigate the ‘wrongness’ of the client's information. The clinical geneticists seem to be working with a dilemma: they need to find a balance between ensuring correct understanding of the information and showing respect for the expertise of others. A particularly complex case is also analyzed and reflected on.  相似文献   
147.
Critics of genetic discourse are concerned that deterministic and discriminatory views of genetics are increasingly becoming adopted. These views argue that current genetic discourse becomes a source of power whereby powerful institutions harm people with so-called “bad” genes. This essay argues that current analyses of the power of genetics discourse are grounded in an improper reading that disempowers patients. Deploying Michel Foucault's concept “care of the self,” this essay claims that genetics discourse is better understood as a way that patients take on power through rhetoric rather than a force that has power over patients. Through a close reading of the “My Family Health Portrait” program, this paper argues that patients experience a process of “subjection” wherein they become agents of and objects of genetics discourse both. This alternative mode of analyzing the power of genetics discourse has implications for our collective understanding of the operations of the care of the self and the uses of genetic information that we propose.  相似文献   
148.
This multicenter study aimed to assess (i) whether individual clinical geneticists and genetic counselors vary in their communication skills and (ii) whether this variation in communication impacts on patient outcomes, such as anxiety, depression, genetics knowledge, and satisfaction. One hundred and fifty women from high-risk breast cancer families attending their first genetic counseling consultation completed pre and post-consultation self-report questionnaires. The consultations were audiotaped and transcribed verbatim. Univariate analyses showed highly significant differences between individual clinical geneticists and genetic counselors in: facilitating understanding (p 0.001); facilitating active involvement (p 0.001); facilitating partnership building (p = 0.003); addressing emotional concerns (p 0.001); and discussing prophylactic mastectomy (p = 0.017). Multivariate linear regressions showed that this variation in communication resulted in a greater change in patients depression 4 weeks after the counseling session (p = 0.017). These findings suggest clinical geneticists and genetic counselors have achieved some standardization in communicating information, but showed diversity in their facilitation skills. Communication skills may be a useful area to explore further in this field.  相似文献   
149.
The question of the morality of war is something of an embarrassment to liberal political thinkers. A philosophical tradition which aspires to found its preferred institutions in respect for individual autonomy, contract, and voluntary association, is naturally confronted by a phenomenon that is almost exclusively explained and justified in the language of States, force and territory. But the apparent difficulties involved in providing a convincing account of nature and ethics of war in terms of relations between individuals has not prevented liberal theorists from attempting this task. This paper examines a recent attempt by Igor Primoratz to sketch out the implications of a consistent liberalism for just war doctrine and, in particular, as regards the question of who may be a legitimate target of attack in wartime. Primoratz’s paper itself is a critique of Michael Waltzer’s authoritative exposition of just war theory for failing to be sufficiently and consistently liberal. The debate between these two authors is a productive site for investigating the potential and limitations of liberal theories of just war.  相似文献   
150.
2003年诺贝尔医学奖给科学界的多重启示(上)   总被引:1,自引:0,他引:1  
2003年诺贝尔医学奖授予了两位美英物理学家,劳特布尔和曼斯菲尔德,表彰他们在磁共振成像方面的发现.这些发现导致现代磁共振技术的开发,这一技术标志着医学诊断学和科学研究中的一项突破.该项发现建筑在核磁和核磁共振现象被发现的基础之上.核磁现象的发现及其应用导致了1943、1944和1952年诺贝尔物理学奖的获得.核磁共振现象的发现及其应用导致了1991年和2002年诺贝尔化学奖的获得.这意味着,2003年诺贝尔医学奖是该系列发现中第六个诺贝尔科学奖.  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