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   794篇
  免费   38篇
  2023年   6篇
  2022年   15篇
  2021年   16篇
  2020年   22篇
  2019年   26篇
  2018年   41篇
  2017年   42篇
  2016年   24篇
  2015年   11篇
  2014年   12篇
  2013年   85篇
  2012年   42篇
  2011年   57篇
  2010年   35篇
  2009年   27篇
  2008年   48篇
  2007年   29篇
  2006年   35篇
  2005年   29篇
  2004年   18篇
  2003年   32篇
  2002年   27篇
  2001年   10篇
  2000年   12篇
  1999年   9篇
  1998年   12篇
  1997年   7篇
  1996年   7篇
  1995年   5篇
  1994年   6篇
  1993年   4篇
  1992年   7篇
  1991年   4篇
  1990年   6篇
  1989年   4篇
  1988年   6篇
  1987年   4篇
  1986年   3篇
  1985年   5篇
  1984年   5篇
  1983年   3篇
  1982年   7篇
  1981年   3篇
  1980年   3篇
  1976年   4篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1971年   2篇
  1968年   3篇
排序方式: 共有832条查询结果,搜索用时 62 毫秒
41.
In this paper, I reconstruct Quine?s arguments against quantified modal logic, from the early 1940?s to the early 1960?s. Quine?s concerns were not technical. Quine was looking for a coherent interpretation of quantified-in English modal sentences. I argue that Quine?s main thesis is that the intended objectual interpretation of the quantifiers is incompatible with any semantic reading of the modal operators, for example as expressing analytic necessity, unless the entities in the domain of quantification are intensions, i.e. definitional entities. The difficulty is that it makes no sense to say of an ordinary object that it bears a property necessarily or contingently when the necessity or contingency in question is analytic. However, starting in 1960, Quine claims that quantified-in modal sentences can be coherently interpreted only as essentialist predications. When we say about an object that it necessarily F?s, we can only coherently mean that it essentially F?s. In the paper, I argue that adequately qualified the thesis is plausible. Two important qualifications are needed. The first is the assumption that satisfaction is an irreducibly predicative notion, making any explication of satisfaction in terms of truth inadequate. The second is the ontological rejection of purely semantic, i.e. merely definitional, entities. With these qualifications in place, Quine?s rejection of the combination of objectual quantifiers and semantic modalities can be upheld. In this way, we vindicate a qualified version of Quine?s conjecture that quantified modal logic is committed to essentialism.  相似文献   
42.
Some evidence suggests that the cerebellum participates in the complex network processing emotional facial expression. To evaluate the role of the cerebellum in recognising facial expressions we delivered transcranial direct current stimulation (tDCS) over the cerebellum and prefrontal cortex. A facial emotion recognition task was administered to 21 healthy subjects before and after cerebellar tDCS; we also tested subjects with a visual attention task and a visual analogue scale (VAS) for mood. Anodal and cathodal cerebellar tDCS both significantly enhanced sensory processing in response to negative facial expressions (anodal tDCS, p=.0021; cathodal tDCS, p=.018), but left positive emotion and neutral facial expressions unchanged (p>.05). tDCS over the right prefrontal cortex left facial expressions of both negative and positive emotion unchanged. These findings suggest that the cerebellum is specifically involved in processing facial expressions of negative emotion.  相似文献   
43.
The objective of this study was to validate in a sample of 205 coronary patients a factor model for the BDI-II, especially a model that would allow for modeling of depressive symptoms after explicitly removing bias related to somatic symptoms of depression that would overlap those of heart disease. Exploratory and confirmatory factor analyses for ordinal data were conducted. A one-factor model, six correlated two-factor models and, derivatives thereof, seven models with a single General Depression factor and two uncorrelated factors, were analyzed. Exploratory analysis extracted two factors, Somatic-affective and Cognitive. Confirmatory factor analyses showed the worst fit for the one-factor model. Two-factor models were surpassed in goodness of fit by the models of general-factor and group factors. Among these, the General, Somatic-affective and Cognitive (G-Sa-C) model of Beck with students is noteworthy. The reduced General, Somatic and Cognitive (G-S-C) model of Ward showed the worst goodness of fit. Our model surpasses the cutoff criteria of all fit indexes. We conclude that the inclusion of a general-factor and group factors in all the models surpasses the results of G-S-C model and, therefore, questions it. The G-Sa-C model is strengthened.  相似文献   
44.
Wu B  Klatzky RL  Stetten GD 《Cognition》2012,123(1):33-49
We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object representation. Participants used a hand-held device to reveal a hidden object as a sequence of cross-sectional images. The process of localization was manipulated by contrasting two displays, in situ vs. ex situ, which differed in whether cross sections were presented at their source locations or displaced to a remote screen. The process of integration was manipulated by varying the structural complexity of target objects and their components. Experiments 1 and 2 demonstrated visualization of 2D and 3D line-segment objects and verified predictions about display and complexity effects. In Experiments 3 and 4, the visualized forms were familiar letters and numbers. Errors and orientation effects showed that displacing cross-sectional images to a remote display (ex situ viewing) impeded the ability to determine spatial relationships among pattern components, a failure of integration at the object level.  相似文献   
45.
The objective of this study is to analyze the mediating role of intrinsic and extrinsic job satisfaction in the relationship between the 2 dimensions of work-family conflict-family interfering with work (FIW) and work interfering with family (WIF)-and general job satisfaction. Step-by-step hierarchical regression analyses were carried out on a sample of 151 men and women from a Spanish public organization. The results confirmed the mediating role of intrinsic job satisfaction in the case of FIW. This highlights the importance of taking into account the level of satisfaction with the intrinsic facets of one's job as a measure for understanding why FIW has a negative impact on general job satisfaction.  相似文献   
46.
The aim of this study was to evaluate a procedure to reveal the emergence of full naming in typically developing children. In Experiment 1, five 6-year-old children (a) learned tacts of pictures and the emergence of the selection of these pictures upon hearing their names was tested; and (b) the selection of other pictures was taught and the emergence of the tacts was tested. All children showed the emergence of picture selection and 3 children showed the emergence of the tacts. In Experiment 2a, the children's correct repetition of the names of 3 pictures was verified first, then the experimenter presented the pictures with their names without requiring any behavior other than attending. Finally, the emergence of picture selection and the tacts was tested. Experiment 2b replicated Experiment 2a with words that were easier to pronounce. Picture selection and the tacts emerged; this performance documented full naming for the first time with typically developing children. These procedures can be used to induce naming capacity in children who lack it; hence, they can be applied to teach children with learning delays.  相似文献   
47.
This paper presents two experiments on nutrient-based flavor conditioning with rats as subjects and sucrose as the unconditioned stimulus (US). Experiment 1 was aimed at establishing an optimal control for conditioning, comparing simultaneous and serial presentations of a flavor and the US. The results showed that simultaneous, but not serial training, produced conditioning. Experiment 2 was designed to obtain evidence of summation as an index of both conditioned inhibition and predictive learning. Group Simultaneous received Pavlovian conditioned inhibition training during which flavor A was simultaneously paired with sucrose on excitatory trials (A+), and forming an unreinforced compound with flavor B on inhibitory trials (AB-). An independent excitor for the summation test was also trained by simultaneous pairings with sucrose (C+). In the control group (Blocked), the AB- trials were presented forming a block at the beginning of training to avoid a negative contingency-relationship with sucrose, and flavor A received serial rather than simultaneous pairing with sucrose (A --> +). On the summation test, only in group Simultaneous was consumption of the CB compound lower than that of flavor C alone, suggesting that, during training, flavor A activated an expectancy of the US occurrence.  相似文献   
48.
We present a study that investigates changes in the acquisition and development of morphological awareness in children from 5 to 7 years old. This investigation was carried out on three separate occasions over two academic years, in which morphological awareness was assessed according to two levels. The data indicate an increase in the morphological awareness development from the kindergarten to primary education, verifying the acquisition in the first instance of the morphological judgment level and secondly, of morphological production level. It also generates a pattern of acquisition of the various parameters that make up morphology.  相似文献   
49.
Several ethological reports have indicated that cooperative behaviors play an adaptive role. However, research has focused on competition in men, and there have been few studies on cooperation. This study aims to analyze the cortisol and psychological responses in women to a cooperative situation compared with a competitive situation in a laboratory context. The sample was distributed into four groups depending on the task and the outcome obtained: Positive cooperation, negative cooperation, competition with victory, and competition with defeat. Our results show that, in comparison with competition, cooperation produces different effects in cortisol, but not in psychological states. Nevertheless, these effects occur only when the task outcome and its appraisal are considered. Only the participants who cooperated and obtained a positive outcome and those who competed and lost showed significant decrements of cortisol. Internal attribution was higher in groups with more stable cortisol levels, suggesting a possible modulator effect of controllability in the way the situation was experienced. These results could be generalized to situations in which negotiation, mediation, and cooperative strategies are relevant for making decisions and/or solving problems.  相似文献   
50.
Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes, cognitive abilities (Wechsler Intelligence Scale for Children-Revised, WISC-R), and serum inflammatory mediators were collected in 20 Mexico City (MC) children (10 with white matter hyperintensities, WMH+, and 10 without, WMH) and 10 matched controls (CTL) from a low polluted city. There were significant differences in white matter volumes between CTL and MC children - both WMH+ and WMH - in right parietal and bilateral temporal areas. Both WMH and WMH+ MC children showed progressive deficits, compared to CTL children, on the WISC-R Vocabulary and Digit Span subtests. The cognitive deficits in highly exposed children match the localization of the volumetric differences detected over the 1 year follow-up, since the deficits observed are consistent with impairment of parietal and temporal lobe functions. Regardless of the presence of prefrontal WMH, Mexico City children performed more poorly across a variety of cognitive tests, compared to CTL children, thus WMH+ is likely only partially identifying underlying white matter pathology. Together these findings reveal that exposure to air pollution may perturb the trajectory of cerebral development and result in cognitive deficits during childhood.  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