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   6474篇
  免费   156篇
  国内免费   189篇
  2015年   37篇
  2014年   29篇
  2013年   35篇
  2012年   379篇
  2011年   448篇
  2010年   123篇
  2009年   70篇
  2008年   350篇
  2007年   378篇
  2006年   378篇
  2005年   303篇
  2004年   275篇
  2003年   244篇
  2002年   276篇
  2001年   200篇
  2000年   177篇
  1999年   95篇
  1998年   57篇
  1996年   41篇
  1994年   72篇
  1993年   86篇
  1992年   87篇
  1991年   96篇
  1990年   95篇
  1989年   92篇
  1988年   107篇
  1987年   124篇
  1986年   85篇
  1985年   109篇
  1984年   107篇
  1983年   138篇
  1982年   88篇
  1981年   89篇
  1980年   72篇
  1979年   78篇
  1978年   66篇
  1966年   49篇
  1965年   132篇
  1964年   106篇
  1963年   126篇
  1962年   54篇
  1958年   115篇
  1957年   116篇
  1956年   76篇
  1955年   43篇
  1954年   62篇
  1953年   50篇
  1952年   56篇
  1951年   40篇
  1950年   43篇
排序方式: 共有6819条查询结果,搜索用时 15 毫秒
981.
Although analogical reasoning has long been a popular method of reasoning in bioethics, current literature does not sufficiently grasp its variety. We assert that the main shortcoming is the fact that an analogy’s value is often judged on the extent of similarity between the source situation and the target situation, while in (bio)ethics, analogies are often used because of certain dissimilarities rather than in spite of them. We make a clear distinction between dissimilarities that aim to reinforce a similar approach in the source situation and the target situation and dissimilarities that aim to undermine or denounce a similar approach. The former kind of dissimilarity offers the analogy more normative force than if there were no dissimilarities present; this is often overlooked by authors who regard all relevant dissimilarities as detrimental to the analogy’s strength. Another observation is that an evaluation of the normative force of an analogy cannot be made independently of moral principles or theories. Without these, one cannot select which elements in an analogy are morally relevant nor determine how they should be interpreted.  相似文献   
982.
Two studies examined how individuals' perceptions of self and others are associated with different emotional traits. Study 1 (N = 386) used structural equation modeling of questionnaire data to examine the relations between emotional traits (i.e., affect intensity, affect variability, and trait pleasant and unpleasant affect) and self- and other-perceptions (i.e., self-instability, self-esteem, other-instability, and perceived treatment by others). Study 2 (N = 99) used path analyses of data collected using an event sampling method in which online measures of emotional experiences (i.e., intensity, frequency, and variability of pleasant and unpleasant affect) as well as perceptions of self and others (i.e., self-instability, self-esteem, other-instability, perceived treatment by others) were collected. The strongest and most consistent finding was that affect variability was associated with both self- and other-instability. The results linking affect intensity with self- and other-instability were limited to negative intensity. There was also evidence of pleasant affect being associated with both self-esteem and perceived treatment by others, and unpleasant affect being associated with self-esteem and other-instability.  相似文献   
983.
This study examined neural features of emotional responses to errors. We specifically examined whether directed emotion regulation of negative emotion associated with error modulates action-monitoring functions of anterior cingulate cortex, including conflict monitoring, error processing, and error prevention. Seventeen healthy adults performed a continuous performance task during assessment by fMRI. In each block, participants were asked either to increase or decrease their negative emotional responses or to react naturally after error commission. Emotion regulation instructions were associated with modulation of rostral and dorsal anterior activity and of their effective connectivity following errors and conflict. Cingulate activity and connectivity predicted subsequent errors. These data may suggest that responses to errors are affected by emotion and that aspects of emotion and cognition are inextricably linked, even during a nominally cognitive task.  相似文献   
984.
Easterners tend to process information more holistically than Westerners. Kim and Markman (J Exp Soc Psychol 42(3):350–364, 2006) suggest that these differences are rooted in higher chronic levels of Fear of Isolation (FOI) for those cultures that process information more holistically. The goal of this study was to determine if these differences and their suggested cause could be found with two different Western cultures. Testing Italian (IT) and US American (US) adults, we found that IT participants processed information more holistically and had a higher chronic level of FOI than US participants; furthermore, the manipulation of FOI affected context sensitivity more for IT than for US participants. The results demonstrate that IT participants were more similar to previous research with Eastern populations than with Western populations (Kim and Markman in J Exp Soc Psychol 42(3):350–364, 2006) and indicate a within-Western culture difference for reasoning styles and support the hypothesis that this difference is due to different chronic levels of FOI.  相似文献   
985.
Age-related degeneration of intracortical inhibition could underlie declines in cognitive function during senescence. Based on a hypothesis that a decrease in basal concentration of ambient (extrasynaptic) GABA with aging leads to depressing intracortical inhibition, we investigated how the basal concentration affects stimulus-evoked activity (as signal), ongoing-spontaneous activity (as noise) of neurons and their (signal-to-noise) ratio S/N. We simulated a neural network model equipped with a GABA transport system that regulates ambient GABA concentration in a neuronal activity-dependent manner. An increase in basal concentration augmented ambient GABA, increased GABA-mediated inhibitory current, and depressed ongoing-spontaneous activity while still keeping stimulus-evoked activity. This led to S/N improvement, for which it was necessary for the reversal potential of GABA transporter to be close to the resting potential of neurons. Above the resting potential, ongoing-spontaneous activity was predominantly enhanced due to excessive GABA-uptake from the extracellular space by transporters. Below the resting potential, stimulus-evoked activity was predominantly depressed, caused by excessive GABA-release. We suggest that the insufficient augmentation of ambient GABA due to a decrease in its basal concentration may be one of the possible causes of cognitive deficit with aging, increasing ongoing-spontaneous neuronal activity as noise. GABA transporter may contribute to improving S/N, provided that its reversal potential is close to the resting potential.  相似文献   
986.
Sensorimotor synchronization is a crucial function for human daily activities, which relies on the ability of predicting external events. Synchronization performance, as assessed in finger-tapping (FT) tasks, is characterized by an anticipation tendency, as the tap generally precedes the pacing event. This synchronization error (SE) depends on many factors, in particular on the features of the pacing stimulus. Interest is growing in the facilitation effect that action observation has on motor execution. So far, neuroimaging and neurophysiology studies of motor priming via action observation have mainly employed tasks requiring single action instances. The impact of action observation on motor synchronization to periodic stimuli has not yet been tested; to this aim, a synchronization FT task may be an eligible probing task. The purpose of this study was to characterize a biological pacer at the behavioral level and provide information for those interested in studying the brain processes of continuous observation/execution coupling in timed actions using FT tasks. We evaluated the influence of the biological appearance of a pacer (a tapping finger) on SE, when compared to an abstract, kinematically equivalent pacer (a tilting hinged bar) and a more standard stimulus (a pulsating dot). We showed that the continuous visual display of a biological pacer yields comparable results to the abstract pacer, and a more robust performance and larger anticipations than a traditional pulsating stimulus.  相似文献   
987.
Episodic memory was assessed using Virtual Reality (VR). Forty-four (44) subjects visualized a target virtual apartment containing specific objects in each room. Then they visualized a second virtual apartment comprised of specific objects and objects shared by the two apartments. Subjects navigated in the virtual apartments in one of the following two conditions: active and passive. Four main episodic memory components were scored from the VR exposures: (1) learning effect; (2) active forgetting effect; (3) strategies at encoding and at retrieval; and (4) false recognitions (FRs). The effect of navigation mode (active vs. passive) on each memory component was examined. Active subjects had better learning and retrieval (recognition hits) performances compared to passive subjects. A beneficial effect of active navigation was also observed on the source-based FR rates. Active subjects made fewer source-based FRs compared to passive subjects. These overall results for the effect of active navigation are discussed in terms of the distinction between item-specific and relational processing.  相似文献   
988.
In Indo-European languages, letter position coding is particularly noisy in middle positions (e.g., judge and jugde look very similar), but not in the initial letter position (e.g., judge vs. ujdge). Here we focus on a language (Thai) which, potentially, may be more flexible with respect to letter position coding than Indo-European languages: (i) Thai is an alphabetic language which is written without spaces between words (i.e., there is a degree of ambiguity in relation to which word a given letter belongs to) and (ii) some of the vowels are misaligned (e.g., [see text] ε:bn/ is pronounced as /bε:n/), whereas others are not (e.g., [see text]/a:p/ is pronounced as /a:p/). We conducted a masked priming lexical decision experiment with 3-4 letter Thai words (with vs. without an initial misaligned vowel) in which the prime was: (i) identical to the target, (ii) a nonword generated by transposing the two initial letters of the target, or (iii) a replacement-letter control nonword. Results showed a significant masked transposed-letter priming effect in the initial letter positions, which was similar in size for words with and without an initial misaligned vowel. These findings reflect that: (i) letter position coding in Thai is very flexible and (ii) the nature of the obtained priming effects is orthographic rather than phonological.  相似文献   
989.
Procedural justice concerns play a critical role in economic settings, politics, and other domains of human life. Despite the vast evidence corroborating their relevance, considerably less is known about how procedural justice judgments are formed. Whereas earlier theorizing focused on the systematic integration of content information, the present contribution provides a new perspective on the formation of justice judgments by examining the influence of accessibility experiences. Specifically, we hypothesize that procedural justice judgments may be formed based on the ease or difficulty with which justice-relevant information comes to mind. Three experiments corroborate this prediction in that procedures were evaluated less positively when the retrieval of associated unfair aspects was easy compared to difficult. Presumably this is because when it feels easy (difficult) to retrieve unfair aspects, these are perceived as frequent (infrequent), and hence the procedure as unjust (just). In addition to demonstrating that ease-of-retrieval may influence justice judgments, the studies further revealed that reliance on accessibility experiences is high in conditions of personal certainty. We suggest that this is because personal uncertainty fosters systematic processing of content information, whereas personal certainty may invite less taxing judgmental strategies such as reliance on ease-of-retrieval.  相似文献   
990.
In this paper we briefly describe preliminary data from two experiments that we have carried out to investigate the relationship between visual encoding and memory for objects and their locations within scenes. In these experiments, we recorded participants′ eye movements as they viewed a photograph of a cubicle with 12 objects positioned pseudo-randomly on a desk and shelves. After viewing the photograph, participants were taken to the actual cubicle where they undertook two memory tests. Participants were asked to identify the 12 target objects(from the photograph)presented amongst 12 distractors. They were then required to place each of the objects in the location that they occupied in the photograph. These tests assessed participants′ memory for identity of the objects and their locations. In Experiment 1, we assessed the influence of the encoding period and the test delay on object identity and location memory. In Experiment 2 we manipulated scanning behaviour during encoding by "boxing"some of the objects in the photo. We showed that using boxes to change eye movement behaviour during encoding directly affected the nature of memory for the scene. The results of these studies indicate a fundamental relationship between visual encoding and memory for objects and their locations. We explain our findings in terms of the Visual Memory Model(Hollingworth & Henderson, 2002).  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