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421.
To obtain evidence linking long-term potentiation (LTP) and memory, we examined whether LTP induction modifies functional relationship among neurons in the rat hippocampus. In contrast to neurons in low-frequency stimulated or AP5-treated slices, LTP induction altered 'functional connectivity,' as defined by the degree of synchronous firing, among simultaneously recorded neurons in the CA3 region. Interestingly, functional connectivity changed bidirectionally so that the total sum of functional connectivity remained constant. These results demonstrate LTP-induced changes in neuronal functional connectivity and suggest the existence of a normalization mechanism for the total sum of functional connectivity.  相似文献   
422.
Although previous researchers found that several individual, family, and school characteristics influenced adolescents' academic performance, religion‐related factors have not typically been considered for models of bachelor's degree attainment. Using longitudinal data in a national database, the authors examined the relationship between high school students' religiosity and bachelor's degree attainment. The results indicate that high school students' religiosity was significantly related to bachelor's degree attainment when other variables (i.e., locus of control, self‐concept, parental involvement, and prior academic performance) were controlled for.  相似文献   
423.
图片和汉字的激活水平及知觉干扰效应的比较   总被引:5,自引:1,他引:4  
王权红  李菲菲  何敏 《心理科学》2007,30(2):332-336
研究使用8个残缺水平下的图片及其中文名(汉字双字词)为实验材料.试图比较图片与汉字双字词识别激活水平的差异,接着比较二者产生知觉于扰效应的条件,并把二者产生知觉于扰的条件与英文单词产生知觉于扰的条件进行比较。实验一结果发现,在材料较清晰的条件下,汉字双字词的命名成绩高于图片,表明汉字双字词的激活水平不比图片低,但在材料很残缺的条件下,汉字双字词的命名成绩低于图片。实验二发现双字词和图片在没有事先学习情况下都产生知觉干扰效应,已有研究表明单个汉字无需事先学习也可以产生干扰效应,而英文单词需要事先学习。因此,图片和汉字的干扰效应与英文单词的差别跟图片、汉字的激活水平比英文单词高有关。  相似文献   
424.
This study examines the potential encoding in long-term memory of subphonemic, within-category variation in voice onset time (VOT) and the degree to which this encoding of subtle variation is mediated by lexical competition. In 4 long-term repetition-priming experiments, magnitude of priming was examined as a function of variation in VOT in words with voiced counterparts (cape-gape) and without (cow-*gow) and words whose counterparts were high frequency (pest-best) or low frequency (pile-bile). The results showed that within-category variation was indeed encoded in memory and could have demonstrable effects on priming. However, there were also robust effects of prototypical representations on priming. Encoding of within-category variation was also affected by the presence of lexical counterparts and by the frequency of counterparts.  相似文献   
425.
Wang M  Koda K  Perfetti CA 《Cognition》2003,87(2):129-149
Different writing systems in the world select different units of spoken language for mapping. Do these writing system differences influence how first language (L1) literacy experiences affect cognitive processes in learning to read a second language (L2)? Two groups of college students who were learning to read English as a second language (ESL) were examined for their relative reliance on phonological and orthographic processing in English word identification: Korean students with an alphabetic L1 literacy background, and Chinese students with a nonalphabetic L1 literacy background. In a semantic category judgment task, Korean ESL learners made more false positive errors in judging stimuli that were homophones to category exemplars than they did in judging spelling controls. However, there were no significant differences in responses to stimuli in these two conditions for Chinese ESL learners. Chinese ESL learners, on the other hand, made more accurate responses to stimuli that were less similar in spelling to category exemplars than those that were more similar. Chinese ESL learners may rely less on phonological information and more on orthographic information in identifying English words than their Korean counterparts. Further evidence supporting this argument came from a phoneme deletion task in which Chinese subjects performed more poorly overall than their Korean counterparts and made more errors that were phonologically incorrect but orthographically acceptable. We suggest that cross-writing system differences in L1s and L1 reading skills transfer could be responsible for these ESL performance differences.  相似文献   
426.
Wang M  Perfetti CA  Liu Y 《Cognition》2005,97(1):67-88
This study investigated cross-language and writing system relationship in biliteracy acquisition of children learning to read two different writing systems-Chinese and English. Forty-six Mandarin-speaking children were tested for their first language (Chinese-L1) and second language (English-L2) reading skills. Comparable experiments in Chinese and English were designed focusing on two reading processes-phonological and orthographic processing. Word reading skills in both writing systems were tested. Results revealed that Chinese onset matching skill was significantly correlated with English onset and rime matching skills. Pinyin, an alphabetic phonetic system used to assist children in learning to read Chinese characters, was highly correlated with English pseudoword reading. Furthermore, Chinese tone processing skill contributed a moderate but significant amount of variance in predicting English pseudoword reading even when English phonemic-level processing skill was taken into consideration. Orthographic processing skill in the two writing systems, on the other hand, did not predict each other's word reading. These findings suggest that bilingual reading acquisition is a joint function of shared phonological processes and orthographic specific skills.  相似文献   
427.
428.
It is shown that pre-straining with deformation twinning is a novel approach to enhancing the uniform elongation of a high-strength β-type Ti–15Mo alloy (mass%) with isothermal ω-phase precipitation. Pre-existent mechanical {3?3?2}?1?1?3? twins hinder the early onset of plastic instability (necking) after yielding, which is often caused by the presence of the isothermal ω-phase, and enhance the uniform elongation markedly from 0% to 13% at a yield strength level of 900?MPa.  相似文献   
429.
When Darwin wrote his ‘On the origin of species…” (1859) he focused on evolution as a property of living organisms in interaction with abiotic and biotic elements in the world. This viewpoint is still dominant amongst biologists. For particle physicists and cosmologists evolution refers to a larger scale, ranging from quarks and atoms to galaxies, stars and planets (i.e. Pagels 1985, Hawking 1988). To close the gap between such different viewpoints, a wide range of perspectives on an interdisciplinary understanding of system development has been published (i.e. Teilhard de Chardin 1966, von Bertalanffy 1968, Varela 1979, Prigogine and Stengers 1984, Laszlo 1996). As an integrative concept, the construction of nature from a hierarchy of system layers forms a central tenet in general system research and the stepwise construction of this layered hierarchy can be regarded as an interdisciplinary evolution theory. Surprisingly, the literature offers no unequivocal rules to recognise a multilayer hierarchy in nature. This presents an obstacle for interdisciplinary approaches to evolution.

Searching a solution to part of the above hierarchy problem, the present paper is dedicated to the analysis of a special kind of layering in natural systems, which is based on transitions between ‘building block’ systems. To identify these building blocks, and the transitions from building block x at level A, to building block y at level B, the focus of this study is further limited to ‘hypercydic dynamics’ and ‘containment’. On the basis of these criteria, a hierarchy is created which shows no possibilities for ‘bypasses’. It connects hadrons to atoms, atoms to cells, and cells to neural networks. Implications of this hierarchy for system studies and evolution are discussed.  相似文献   
430.
According to hedonic approaches to psychological health, healthy individuals should pursue pleasant and avoid unpleasant emotions. According to instrumental approaches, however, healthy individuals should pursue useful and avoid harmful emotions, whether pleasant or unpleasant. We sought to reconcile these approaches by distinguishing between preferences for emotions that are aggregated across contexts and preferences for emotions within specific contexts. Across five days, we assessed daily confrontational and collaborative demands and daily preferences for anger and happiness. Somewhat consistent with hedonic approaches, when averaging across contexts, psychologically healthier individuals wanted to feel less anger, but not more happiness. Somewhat consistent with instrumental approaches, when examined within contexts, psychologically healthier individuals wanted to feel angrier in more confrontational contexts, and some wanted to feel happier in more collaborative contexts. Thus, although healthier individuals are motivated to avoid unpleasant emotions over time, they are more motivated to experience them when they are potentially useful.  相似文献   
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