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   719篇
  免费   105篇
  国内免费   39篇
  863篇
  2024年   13篇
  2023年   19篇
  2022年   21篇
  2021年   18篇
  2020年   32篇
  2019年   28篇
  2018年   30篇
  2017年   19篇
  2016年   36篇
  2015年   24篇
  2014年   37篇
  2013年   57篇
  2012年   32篇
  2011年   54篇
  2010年   41篇
  2009年   50篇
  2008年   65篇
  2007年   58篇
  2006年   64篇
  2005年   51篇
  2004年   37篇
  2003年   16篇
  2002年   11篇
  2001年   9篇
  2000年   5篇
  1999年   12篇
  1998年   5篇
  1997年   4篇
  1994年   1篇
  1993年   3篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1984年   1篇
  1983年   1篇
  1971年   1篇
排序方式: 共有863条查询结果,搜索用时 0 毫秒
821.
Previous research has established that people can implicitly learn chunks, which (in terms of formal language theory) do not require a memory buffer to process. The present study explores the implicit learning of nonlocal dependencies generated by higher than finite-state grammars, specifically, Chinese tonal retrogrades (i.e. centre embeddings generated from a context-free grammar) and inversions (i.e. cross-serial dependencies generated from a mildly context-sensitive grammar), which do require buffers (for example, last in-first out and first in-first out, respectively). People were asked to listen to and memorize artificial poetry instantiating one of the two grammars; after this training phase, people were informed of the existence of rules and asked to classify new poems, while providing attributions of the basis of their judgments. People acquired unconscious structural knowledge of both tonal retrogrades and inversions. Moreover, inversions were implicitly learnt more easily than retrogrades constraining the nature of the memory buffer in computational models of implicit learning.  相似文献   
822.
传统的迫选量表得分是自模式数据,最近提出的Thurstone IRT模型建构了被试对迫选量表反应的数学模型,能够更精确地度量被试的特质水平.研究自编了神经质人格迫选量表,与常用的测量神经质的Likert量表一起,在无压力、模拟应聘和实际应聘三种情境下进行施测.结果发现,迫选量表的实测数据能够较好地拟合Thurstone IRT模型,该模型估计的特质得分不具有自模式数据的性质,比传统计分更能够抵抗作假.无论采用哪种计分方式,迫选量表都比Likert量表更能够抵抗作假.  相似文献   
823.
已婚少数民族妇女的性生活和谐程度和夫妻交流性感受程度较高.民族、年龄、职业、家庭年收入、小孩数目、因避孕不适的治疗、身体健康状况、参加生殖健康培训以及与配偶讨论性是少数民族已婚妇女性生活是否和谐的影响因素.少数民族地区的生殖健康干预措施要结合各民族文化习俗,才能保证其有效实施.  相似文献   
824.
胰岛β细胞数量减少和功能障碍是糖尿病的根本原因,现有的治疗手段主要以维持正常血糖水平为主要目的,尚无有效恢复受损胰岛功能的治愈性治疗手段。胰岛再生治疗将是一种可以恢复受损胰岛功能、改变糖尿病自然病程的崭新治疗手段。目前现有的噻唑烷二酮、肠促胰岛素及类似物、二肽基肽酶-4抑制剂等治疗,虽然不是一类新的胰岛再生药物,但其具有一定的促进胰岛再生、改善胰岛功能的作用。体外诱导β细胞再生也将为胰岛移植提供新的来源,为治愈糖尿病带来曙光。  相似文献   
825.
Male–male vocal competition in anuran species is critical for mating success; however, it is also highly time-consuming, energetically demanding and likely to increase predation risks. Thus, we hypothesized that changes in the social context would cause male vocal competition to change in real time in order to minimize the costs and maximize the benefits of competition. To test this hypothesis, we assessed the effect of repeating playbacks of either white noise (WN) or male advertisement calls on male call production in the Emei music frog (Babina daunchina), a species in which males build mud-retuse burrows and call from within these nests. Previous studies have shown that calls produced from inside burrows are highly sexually attractive (HSA) to females while those produced outside nests are of low sexual attractiveness (LSA). Results showed that most subjects called responsively after the end of WN playbacks but before the onset of conspecific call stimuli although call numbers were similar, indicating that while males adjusted competitive patterns according to the biological significance of signals, their competitive motivation did not change. Furthermore, these data indicate that the frogs had evolved the ability of interval timing. Moreover, when the inter-stimulus interval (ISI) between playbacks was varied, the subjects preferentially competed with HSA calls when the ISI was short (<4 s) but responded equally to HSA and LSA calls if the ISI was long (≥4 s), suggesting that males allocate competitive efforts depending on both the perceived sexual attractiveness of rivals and the time available for calling. Notably, approximately two-thirds of male calls occurred in response to HSA calls, a preference rate comparable to that previously found for females in phonotaxis experiments and consistent with the idea that the mechanisms underlying both the male’s competitive responses to rivals and the female’s preferences toward potential mates coevolved under the same selective pressure.  相似文献   
826.
Rejection sensitivity (RS) can be defined as the disposition that one tends to anxiously expect, readily perceive, and intensely react to rejection. High-RS individuals are more likely to suffer mental disorders. Previous studies have investigated brain activity during social rejection using different kinds of rejection paradigms and have provided neural evidence of individual differences in response to rejection cues, but the association between individual differences in RS and brain structure has never been investigated. In this study, voxel-based morphometry (VBM) was used to investigate the relationship between gray matter volume (GMV) and RS in a large healthy sample of 150 men and 188 women. The participants completed the RS Questionnaire and underwent an anatomical magnetic resonance imaging scan. Multiple regression was used to analyze the correlation between regional GMV and RS scores, adjusting for age, sex, and total brain GMV. These results showed that GMV in the region of the posterior cingulate cortex/precuneus was negatively associated with RS, and GMV in the region of the inferior temporal gyrus was positively correlated with RS. These findings suggest a relationship between individual differences in RS and GMV in brain regions that are primarily related to social cognition.  相似文献   
827.
828.
Abstract

Dislocations and dislocation networks in superconducting Bi-Pb-Sr-Ca-Cu-O have been observed by means of TEM, confirming that this compound is a layer structure with low stacking fault energy. On the basal plane, dislocations and dislocation networks dissociate into partial dislocations and partial dislocation networks. However, the dissociation of [010] dislocations is hardly observed, which is related to the structural characteristics of the compound.  相似文献   
829.
Perceptual grouping is usually defined by principles that associate distinct elements by virtue of image properties, such as proximity, similarity, and occurrence within common regions. What role does learning play in forming a perceptual group? This study provides evidence that learning of shape associations leads to perceptual grouping. Subjects were repeatedly exposed to pairs of unique shapes that co-occurred within a common region. The common region cue was later removed in displays composed of these shapes, and the subjects searched the display for two adjacent shapes of the same color. The subjects were faster at locating the color repetition when the adjacent shapes with the same color came from the same trained groups than when they were composed of two shapes from different trained groups. The effects were perceptual in nature: Learned pairings produced spatial distortions similar to those observed for groups defined by perceptual similarity. A residual grouping effect was observed even when the shapes in the trained group switched their relative positions but was eliminated when each shape was inverted. These results indicate that statistical co-occurrence with explicit grouping cues may form an important component of perceptual organization, determining perceived scene structure solely on the basis of past experience.  相似文献   
830.
本研究选取Anderson1968年研究中的200个核心人格特质词汇,请165名在校大学生对词汇进行喜好度评定.对比Anderson(1968)的研究结果,发现:1)中西方被试均将真诚评定为最受欢迎的个性品质;2)中国被试作答较少出现极端值;3)中国被试评出的前10位积极品质均与人际和谐有关;而西方被试评出的前10位积极品质主要涉及诚信和个人能力两方面;4)中西方被试评出的前10位消极词汇均为他相关词汇,并和积极词汇相对应.  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