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   4246篇
  免费   433篇
  国内免费   953篇
  5632篇
  2024年   11篇
  2023年   75篇
  2022年   97篇
  2021年   155篇
  2020年   184篇
  2019年   155篇
  2018年   201篇
  2017年   185篇
  2016年   195篇
  2015年   134篇
  2014年   145篇
  2013年   375篇
  2012年   251篇
  2011年   315篇
  2010年   287篇
  2009年   287篇
  2008年   329篇
  2007年   427篇
  2006年   388篇
  2005年   335篇
  2004年   238篇
  2003年   167篇
  2002年   105篇
  2001年   69篇
  2000年   70篇
  1999年   63篇
  1998年   60篇
  1997年   43篇
  1996年   27篇
  1995年   32篇
  1994年   27篇
  1993年   18篇
  1992年   18篇
  1991年   16篇
  1990年   11篇
  1989年   24篇
  1988年   12篇
  1987年   14篇
  1986年   9篇
  1985年   12篇
  1984年   12篇
  1983年   6篇
  1982年   8篇
  1981年   11篇
  1980年   8篇
  1979年   11篇
  1976年   2篇
  1973年   2篇
  1972年   2篇
  1966年   1篇
排序方式: 共有5632条查询结果,搜索用时 15 毫秒
221.
222.
In reading music, the acquisition of pitch information depends mostly on the spatial position of notes, hence more spatial processing, whereas the acquisition of temporal information depends mostly on the visual features of notes and object recognition. This study used both electrophysiological and behavioral methods to compare the processing of pitch and duration in reading single musical notes. It was observed that in the early stage of note reading, identification of pitch could elicit greater N1 and N2 amplitude than identification of duration at the parietal lobe electrodes. In the later stages of note reading, identifying pitch elicited a greater negative slow wave at parietal electrodes than did identifying note duration. The sustained contribution of parietal processes for pitch suggests that the dorsal pathway is essential for pitch processing. However, the duration task did not elicit greater amplitude of any early ERP components than the pitch task at temporal electrodes. Accordingly, a double dissociation, suggesting involvement of the dorsal visual stream, was not observed in spatial pitch processing and ventral visual stream in processing of note durations.  相似文献   
223.
This paper first discusses the relationship between Kullback–Leibler information (KL) and Fisher information in the context of multi-dimensional item response theory and is further interpreted for the two-dimensional case, from a geometric perspective. This explication should allow for a better understanding of the various item selection methods in multi-dimensional adaptive tests (MAT) which are based on these two information measures. The KL information index (KI) method is then discussed and two theorems are derived to quantify the relationship between KI and item parameters. Due to the fact that most of the existing item selection algorithms for MAT bear severe computational complexity, which substantially lowers the applicability of MAT, two versions of simplified KL index (SKI), built from the analytical results, are proposed to mimic the behavior of KI, while reducing the overall computational intensity.  相似文献   
224.
Twin and family studies have shown that genetic factors play a role in the development of conduct disorder (CD). The purpose of this study was to identify genetic variants associated with CD using a family-based association study. We used 4,720 single nucleotide polymorphisms (SNPs) from the Illumina Panel and 11,120 SNPs from the Affymetrix 10K GeneChips genotyped in 155 Caucasian nuclear families from Genetic Analysis Workshop (GAW) 14, a subset from the Collaborative Study on the Genetics of Alcoholism (COGA). 20 SNPs had suggestive associations with CD (p < 10−3), nine of which were located in known genes, including ADAM10 (rs383902, p = 0.00036) and CAMK2A (rs2053053, p = 0.00098). Our results were verified using the International Multi-Center ADHD Genetics Project (IMAGE) dataset. In conclusion, we identified several loci associated with CD. Especially, the two genes (ADAM10 and CAMK2A) have been reported to be associated with Alzheimer’s disease, bipolar disorder and depression. These findings may serve as a resource for replication in other populations.  相似文献   
225.
Using a speeded word fragment completion task, we assessed age differences in the automatic accessibility of emotional versus neutral words from semantic memory. Participants were instructed to complete a series of single-solution word fragments as quickly as possible. The results demonstrate that older adults are biased against accessing both positive and negative words relative to neutral words, whereas young adults are biased against accessing positive words only. These findings suggest an arousal-based accessibility bias favouring neutral stimuli in older adults coupled with a valence-based bias accessing negative and neutral stimuli for young adults.  相似文献   
226.
Yang H  Jin G  Ren D  Luo S  Zhou T 《Brain and cognition》2011,76(1):206-210
This study investigated the effect of isoflavone aglycone (IA) on the learning and memory performance of senescence-accelerated mice, and explored its neural protective mechanism. Results showed that SAM-P/8 senescence-accelerated mice treated with IA performed significantly better in the Y-maze cognitive test than the no treatment control (P<0.05). The cortex AchE activity, serum SOD and GSH-Px activities were notably higher (P<0.05). MDA concentration and the β-secretase activity in the hippocampal tissue were both lower (P<0.05). Additionally, the number of hippocampal neurons was increased and cell morphology was significantly improved. Data suggested that IA could indirectly increase concentration of the cholinergic neural transmitter Ach through regulation of AchE, therefore improving the central cholinergic function and enhancing the learning and memory ability. By reducing the β-secretase activity, IA could decrease the formation and deposition of insoluble Adebris, relieve the resulted toxicity and damage to neurons, and thereby effectively protect the nervous system.  相似文献   
227.
228.
To explore the relationship between parental phubbing (PP) and adolescent online hostility and its' psychological mechanism, 689 Chinese adolescents were recruited to complete a paper-and-pencil questionnaire. We took cyber flaming (CF) as an overall category for hostile online communication to investigate the relationship between PP and CF and the mediating role of perspective-taking (PT) in this relationship and examined whether there is a sex difference in this process. After controlling the average daily online time, the results showed that PP predicted adolescent CF positively. The relationship between PP and CF was partially mediated by PT. The effect of PP on PT was moderated by sex, with the result being significant only for boys. Related findings and future directions were discussed.  相似文献   
229.
Multifunctional products are ubiquitous in consumers' daily lives. However, scant research has examined whether and how the presence of multifunctional products systematically alters consumer behavior beyond product evaluations and adoption. Across four experiments and three supplementary studies, the authors identify a multifunction-impatience effect. They show that after exposure to multifunctional (vs. single-function) products, consumers are more likely to choose a smaller but sooner (vs. a larger but later) reward (Study 1), report more impatience when waiting for the web search results to load and perceive the loading time as longer (Study 2), and are willing to pay more for expedited shipping (Study 3). The authors further show that the effects occur because multifunctional products activate an efficiency goal among consumers, which renders them less patient (studies 2 and 3). In addition to the regular, “sequential” multifunctional products for which each of the functions has a specific usage situation, the proposed effect also applies to “simultaneous” multifunctional products whose functions operate simultaneously during consumption (Study 4). Taken together, this research broadens the scholarly understanding of the effects of multifunctional products from consumers' responses to these products to the unintended impact of such products on consumer impatience.  相似文献   
230.
Given the prevalence of imagery appeals in today’s marketplace, the current research studies the role of mental imagery in how consumers process and react to advertisements with different numbers of ad claims. Past research has proposed “three” as the magical number of ad claims that maximizes persuasion, with more than three ad claims increasing skepticism and reducing evaluation. In the current research, we replicate this so-called “charm of three” effect, but only when consumers do not engage in mental imagery; when they do, however, we find that the effect is moderated, in that more ad claims beyond three produces more favorable product evaluation. Additionally, we provide evidence that the moderating effect of mental imagery is driven by transportation and skepticism toward the ad claims, with mental imagery increasing transportation and decreasing skepticism when there are more than three ad claims. Our research contributes to a better understanding of the “charm of three” effect, its boundary conditions, and underlying mechanism.  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