全文获取类型
收费全文 | 6399篇 |
免费 | 386篇 |
国内免费 | 2篇 |
专业分类
6787篇 |
出版年
2021年 | 57篇 |
2020年 | 112篇 |
2019年 | 131篇 |
2018年 | 171篇 |
2017年 | 217篇 |
2016年 | 216篇 |
2015年 | 157篇 |
2014年 | 187篇 |
2013年 | 741篇 |
2012年 | 302篇 |
2011年 | 327篇 |
2010年 | 200篇 |
2009年 | 212篇 |
2008年 | 262篇 |
2007年 | 281篇 |
2006年 | 235篇 |
2005年 | 234篇 |
2004年 | 227篇 |
2003年 | 201篇 |
2002年 | 213篇 |
2001年 | 103篇 |
2000年 | 112篇 |
1999年 | 107篇 |
1998年 | 92篇 |
1997年 | 85篇 |
1996年 | 94篇 |
1995年 | 87篇 |
1994年 | 78篇 |
1993年 | 62篇 |
1992年 | 81篇 |
1991年 | 61篇 |
1990年 | 52篇 |
1989年 | 50篇 |
1988年 | 48篇 |
1987年 | 42篇 |
1986年 | 46篇 |
1985年 | 62篇 |
1984年 | 59篇 |
1983年 | 50篇 |
1982年 | 72篇 |
1981年 | 71篇 |
1980年 | 52篇 |
1979年 | 52篇 |
1978年 | 44篇 |
1977年 | 66篇 |
1976年 | 40篇 |
1975年 | 46篇 |
1974年 | 39篇 |
1973年 | 45篇 |
1972年 | 35篇 |
排序方式: 共有6787条查询结果,搜索用时 31 毫秒
991.
Research misconduct—Have we reached the turning point at last? 总被引:1,自引:0,他引:1
Jay P 《Science and engineering ethics》1999,5(1):119-122
The laissez-faire attitude towards dishonesty in research has simply created an environment for widespread escalation of the problem. Can we now believe anything we read? Why should we have confidence in an author because of his eminence? Should we automatically accept that clinical trials are always conducted with total integrity? Why have we been afraid to tackle this crisis head-on? 相似文献
992.
Medical students are exposed to demanding academic workloads and are often under considerable psychological strain. This study examined important person and environmental variables that might predict their psychological well-being. Participants were 755 students in years 2-6 from 11 Australian medical schools. A web-based survey assessed well-being, personality, professional expectations, lifestyle expectations, barriers, academic stress, and debt. A hierarchical regression analysis demonstrated that extraversion, conscientiousness, professional expectations, and lifestyle expectations were positively associated with well-being, while academic stress, which was the strongest predictor, neuroticism, and concern about debt were negatively associated. Medical students who displayed a disposition that was outgoing, conscientious, and stable, who were less stressed about their academic workload and their level of debt, and who held higher expectations for their future professional career, and expectations of a balanced lifestyle, had better well-being. Medical educators should be aware of these factors and provide support and strategies that promote well-being to students during medical training. 相似文献
993.
Humans imitate each other during social interaction. This imitative behavior streamlines social interaction and aids in learning to replicate actions. However, the effect of imitation on action comprehension is unclear. This study investigated whether vocal imitation of an unfamiliar accent improved spoken-language comprehension. Following a pretraining accent comprehension test, participants were assigned to one of six groups. The baseline group received no training, but participants in the other five groups listened to accented sentences, listened to and repeated accented sentences in their own accent, listened to and transcribed accented sentences, listened to and imitated accented sentences, or listened to and imitated accented sentences without being able to hear their own vocalizations. Posttraining measures showed that accent comprehension was most improved for participants who imitated the speaker's accent. These results show that imitation may aid in streamlining interaction by improving spoken-language comprehension under adverse listening conditions. 相似文献
994.
995.
Peter Jones 《Res Publica》2011,17(1):75-90
An objection frequently brought against critical or satirical expressions, especially when these target religions, is that
they are ‘offensive’. In this article, I indicate why the existence of diverse and conflicting beliefs gives people an incentive
to formulate their complaints in the language of offence. But I also cast doubt on whether people, in saying they are offended
really mean to present that as the foundation of their complaint and, if they do, whether their complaint should weigh with
us. These doubts do not apply to everything we might find offensive; in particular, they do not apply to simple cases of ‘sensory
offence’; but they do apply to ‘belief-based offence’. Relying on offence also implies, inequitably, that different faiths
should be differently protected depending on their susceptibility to offence; and the faithful themselves should worry about
the flimsiness of claims based on ‘bare knowledge’ offence. I propose a principle of respect for beliefs as a differently
grounded and more plausible reason for curbing our treatment of others’ beliefs. However, that principle has a limited compass
and is hemmed in by the claims of free expression. It is also less suited to dictating the content of law than to influencing
our conduct within the law. 相似文献
996.
Loughnan S Kuppens P Allik J Balazs K de Lemus S Dumont K Gargurevich R Hidegkuti I Leidner B Matos L Park J Realo A Shi J Sojo VE Tong YY Vaes J Verduyn P Yeung V Haslam N 《Psychological science》2011,22(10):1254-1258
People's self-perception biases often lead them to see themselves as better than the average person (a phenomenon known as self-enhancement). This bias varies across cultures, and variations are typically explained using cultural variables, such as individualism versus collectivism. We propose that socioeconomic differences among societies--specifically, relative levels of economic inequality--play an important but unrecognized role in how people evaluate themselves. Evidence for self-enhancement was found in 15 diverse nations, but the magnitude of the bias varied. Greater self-enhancement was found in societies with more income inequality, and income inequality predicted cross-cultural differences in self-enhancement better than did individualism/collectivism. These results indicate that macrosocial differences in the distribution of economic goods are linked to microsocial processes of perceiving the self. 相似文献
997.
A considerable body of kinematic data supports the proposal that independent visuomotor channels are involved in the control of the transport and grip components of reach and grasp. These channels are seen as having separate perceptual inputs, outputs and internal processing and are thought by some to correspond to independent neuroanatomical pathways. The idea that different groups of muscles and biomechanical structures can be controlled independently is attractive, but this kinematically-inspired hypothesis fails to take into account the complexity of the dynamic relationships and their interactions within the neuromusculoskeletal system. Inertial, viscous, centrifugal, coriolis, gravitational and reflex cross couplings exist between efferent drives to muscles and resulting body movements. Rotation at even a single joint generates a complex set of dynamic reaction forces and requires coordinated activation of many muscles throughout the body to maintain posture and balance. In this theoretical paper we present a new view of independent visuomotor channels in the form of an adaptive neural controller that can compensate for the above interactions and decouple the relationships between efferent drives to muscles and resulting body movements. At the same time, the neural controller renders all the dynamics (linear and nonlinear), other than time delays, of the neuromusculoskeletal system, unobservable in the visuomotor relationships. Using the geometry of nonlinear dynamical systems we show that, providing certain constraints on the structure of time delays within the system are satisfied, there exists a neural controller that can render all the dynamics of the neuromusculoskeletal system (except for time delays) unobservable in the responses. The controller simultaneously decouples all the interactive dynamics so that each of the m independent inputs controls one and only one degree of freedom of the response. This means that each degree of freedom in a multi-joint response can be controlled by an independent component of the visual input, a behaviour that has long been observed in visual tracking experiments. The controller effectively establishes m independent visuomotor channels. However, rather than reflecting separate neuroanatomical pathways, the independent channels result from a neural controller with convergent and divergent connections to compensate for the interactive nonlinear dynamics within the neuromusculoskeletal system. This new view of visuomotor channels has implications for neural control processes involved in the acquisition and adaptability of skilled perceptual-motor behaviour in general, as well as for the design of robotic controllers. 相似文献
998.
999.
Fischer H Fransson P Wright CI Bäckman L 《Cognitive, affective & behavioral neuroscience》2004,4(3):326-334
Blood-oxygenation-level-dependent signal was measured with functional magnetic resonance imaging in 24 healthy young subjects
(12 men and 12 women) during viewing of angry, fearful, and neutral male and female face pictures. Exposure to angry male
as opposed to angry female faces activated the visual cortex and the anterior cingulate gyrus significantly more in men than
in women. A similar sex-differential brain activation pattern was present during exposure to fearful but not neutral faces.
Previous behavioral studies indicate enhanced physiological arousal in men but not in women during exposure to angry male
as opposed to female faces, and brain imaging studies have shown that the occipital cortex and the anterior cingulate gyrus
are influenced by activity in the autonomic nervous system as well as by visual attention. Hence, we suggest that the elevated
occipital and anterior cingulate activation in men during confrontation with other angry and fearful males may reflect enhanced
vigilance in a potentially dangerous situation. 相似文献
1000.