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   1514篇
  免费   44篇
  1558篇
  2024年   8篇
  2023年   12篇
  2022年   19篇
  2021年   24篇
  2020年   54篇
  2019年   57篇
  2018年   75篇
  2017年   63篇
  2016年   86篇
  2015年   68篇
  2014年   74篇
  2013年   190篇
  2012年   117篇
  2011年   89篇
  2010年   76篇
  2009年   69篇
  2008年   85篇
  2007年   54篇
  2006年   36篇
  2005年   36篇
  2004年   59篇
  2003年   35篇
  2002年   28篇
  2001年   15篇
  2000年   15篇
  1999年   9篇
  1998年   9篇
  1997年   5篇
  1996年   3篇
  1994年   4篇
  1993年   5篇
  1992年   4篇
  1991年   4篇
  1990年   5篇
  1988年   4篇
  1986年   2篇
  1984年   2篇
  1983年   2篇
  1982年   4篇
  1981年   3篇
  1980年   5篇
  1979年   4篇
  1978年   3篇
  1977年   2篇
  1976年   9篇
  1975年   2篇
  1974年   4篇
  1973年   4篇
  1971年   2篇
  1966年   4篇
排序方式: 共有1558条查询结果,搜索用时 0 毫秒
31.
For 19 mating-relevant traits, single males (N= 53) and single females (N= 86) rated (a) themselves relative to their same-sex peers, (b) their perceptions of the qualities desired by members of the opposite sex in an ideal partner, and (c) the qualities desired in their own ideal romantic partner. Several themes emerged from the data. First, males’ and females’ judgments of what members of the opposite-sex seek were generally accurate. Second, males and females both feel that they fall short of perceived opposite-sex expectations in a few areas. Third, both males and females desire an ideal partner better than themselves, but this is especially true for females. These findings are discussed in terms of evolutionary social psychological principles.  相似文献   
32.
The concept of informed consent was one of the most fruitful ideas that deeply changed the relationships between physicians and their patients from paternalism to respect for the personal autonomy of subjects needing professional medical care. The great progress in medicine, also involving the pharmaceutical industry, has created an increasing need to perform different clinical and experimental trials. The evolution of clinical research in the last decades has influenced strongly the design of these studies. One of the most important changes in this field has been the use of placebo groups in double-blind controlled studies. The controversies have involved not only the use of placebo when standard or proven treatment was available, but also some specific problems concerning the procedure of obtaining informed consent in such trials. This paper briefly presents the evolution of informed consent in Poland as well as different ethical and legal problems concerning informed consent and the use of placebo controls in clinical trials. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.  相似文献   
33.
Neurophysiological experiments with monkeys have demonstrated that working memory (WM) is associated with persistent neural activity in multiple brain regions, such as the prefrontal cortex (PFC), the parietal cortex, and posterior unimodal association areas. WM maintenance is believed to require the coordination of these brain regions, which do not function in isolation but, rather, interact to maintain visual percepts that are no longer present in the environment. However, single-unit physiology studies and traditional univariate analyses of functional brain imaging data cannot evaluate interactions between distant brain regions, and so evidence of regional integration during WM maintenance is largely indirect. In this study, we utilized a recently developed multivariate analysis method that allows us to explore functional connectivity between brain regions during the distinct stages of a delayed face recognition task. To characterize the neural network mediating the on-line maintenance of faces, the fusiform face area (FFA) was defined as a seed and was then used to generate whole-brain correlation maps. A random effects analysis of the correlation data revealed a network of brain regions exhibiting significant correlations with the FFA seed during the WM delay period. This maintenance network included the dorsolateral and ventrolateral PFC, the premotor cortex, the intraparietal sulcus, the caudate nucleus, the thalamus, the hippocampus, and occipitotemporal regions. These findings support the notion that the coordinated functional interaction between nodes of a widely distributed network underlies the active maintenance of a perceptual representation.  相似文献   
34.
The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.  相似文献   
35.
Substantial variation exists in the importance of olfaction in influencing individuals' preferences, yet the sources of this variation remain elusive. The authors explored responsivity to 2 odorants as 1 potential source. Participants (N = 258) completed the Affective Impact of Odor Scale and were assessed for responsivity to the putative human pheromone androstenone and amyl acetate. Results showed a significant relationship between odorant responsivity and self-reports of the influence of odors. People able to smell androstenone more commonly reported odors as having a negative effect on interpersonal relationships than did people anosmic to androstenone, whereas responsivity to amyl acetate was associated with positive effects of odors on relationships. Responsivity to certain odorants may be an important factor affecting human social interactions.  相似文献   
36.
37.
Operant devices have been used for many years in animal behavior research, yet such devices a regenerally highly specialized and quite expensive. Although commercial models are somewhat adaptable and resilient, they are also extremely expensive and are controlled by difficult to learn proprietary software. As an alternative to commercial devices, we have designed and produced a fully functional, programmable operant device, using a PICmicro microcontroller (Microchip Technology, Inc.). The electronic operant testing apparatus (ELOPTA) is designed to deliver food when a study animal, in this case a bird, successfully depresses the correct sequence of illuminated keys. The device logs each keypress and can detect and log whenever a test animal i spositioned at the device. Data can be easily transferred to a computer and imported into any statistical analysis software. At about 3% the cost of a commercial device, ELOPTA will advance behavioral sciences, including behavioral ecology, animal learning and cognition, and ethology.  相似文献   
38.
In the absence of relevant information in working memory during decision consideration, respondents tend to rely on a style of cognitive processing that may result in premature or inaccurate decision making (M. J. Sharps, 2003). M. J. Sharps and S. S. Martin (2002) demonstrated this effect in executive decision making. In the present study, the authors extended these methods to decisions about environmental issues. Respondents rated decisions about issues such as overpopulation, energy policy, and food production in the presence or absence of simple pertinent information. The presence of such information in the immediate context of environmental decisions, and therefore in working memory, significantly improved respondents' ability to understand negative decision consequences. These results demonstrate the importance of contextual information in environmental decision making.  相似文献   
39.
Observers viewed briefly presented target dot patterns, either at low contrast without a mask (no mask, or NM) or at high contrast and followed by a long-lasting patterned mask (backward masking, or BM). Experiment 1 demonstrated independent processing of NM target dots but limited capacity processing of BM target dots. Experiments 2 and 3 showed that visual images may radically change sensitivity (d′) in BM but not in NM. Results suggest that d′ is reduced if the image suppresses dots relevant for the detection task, but that d′ is raised if the image suppresses dots that compete for processing with those the observer must detect.  相似文献   
40.
The authors investigated whether expertise is more likely to mitigate age declines when experts rely on environmental support in a pilot/Air Traffic Control (ATC) communication task. Pilots and nonpilots listened to ATC messages that described a route through an airspace, while they referred to a chart of the airspace. They read back (repeated) each message and then answered a probe question about the route. In a preliminary study, participants could take notes while listening to the messages and performing the read-back and probe tasks. In Experiment 1, opportunity to take notes was manipulated. Note taking determined when expertise mitigated age differences on the read-back task. With note taking, read-back accuracy declined with age for nonpilots but not for pilots. Without note taking, similar age-related declines occurred for pilots and nonpilots. Benefits of expertise, younger age, and note taking occurred for probe accuracy, but mitigation did not occur. The findings suggest that older adults take advantage of a domain-relevant form of environmental support (note taking) to maintain performance on some complex tasks despite typical age-related declines in cognitive ability.  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