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   1297篇
  免费   130篇
  国内免费   35篇
  1462篇
  2025年   2篇
  2024年   23篇
  2023年   17篇
  2022年   18篇
  2021年   39篇
  2020年   66篇
  2019年   81篇
  2018年   47篇
  2017年   66篇
  2016年   66篇
  2015年   63篇
  2014年   61篇
  2013年   154篇
  2012年   60篇
  2011年   68篇
  2010年   35篇
  2009年   61篇
  2008年   65篇
  2007年   79篇
  2006年   58篇
  2005年   63篇
  2004年   40篇
  2003年   40篇
  2002年   34篇
  2001年   28篇
  2000年   16篇
  1999年   15篇
  1998年   17篇
  1997年   7篇
  1996年   6篇
  1995年   9篇
  1994年   8篇
  1993年   4篇
  1992年   9篇
  1991年   3篇
  1990年   8篇
  1989年   3篇
  1988年   5篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1982年   1篇
  1980年   4篇
  1979年   3篇
  1978年   1篇
  1976年   3篇
排序方式: 共有1462条查询结果,搜索用时 0 毫秒
241.
This research project proposes the modeling of collective behaviors such as flocks, industrial districts, and markets. Unlike many other approaches, the aim is to identify ways to recognize, change, and maintain the coherence of collective behaviors, as well as inducing their emergence in configurations of elements that only interact without acquiring properties. The basic assumption is that currently collective behavior is not adequately modeled for the purpose described above when intended as given by sequences of states adopted by the same system over time. Here the sequence of states of a collective behavior in time is considered as corresponding to sequences of different states adopted by systems made up of the same elements interacting with different structures. Sequences of structures are considered to establish meta-structures and their properties correspond to the coherence acquired. The project is based on the use of mesoscopic variables to represent such structural dynamics considered in turn to represent the continuous emergence of coherent collective behavior. Mesoscopic variables are specified and their properties considered as meta-structural properties (properties of sequences of structures). The purpose of this research project is to search for meta-structural properties within processes of computational emergence (computer simulated). I discuss the problem of prescribing meta-structural properties to non-coherent, disordered collective behaviors. I introduce possible approaches for applications to social systems.  相似文献   
242.
A general factor (gp) at the apex of personality has been suggested to account for the correlations between the Big Five. Although the gp has received ample support from monomethod studies, results from studies incorporating different methods have remained rather ambiguous; some have identified a gp across different informants, whereas others have not. It was hypothesized that these divergent findings are a result of varying lengths of acquaintance between raters. To this end, the current study presents a multitrait multi‐informant meta‐analysis (total N = 11 941) that found weak support for a gp as a substantive trait of personality. Evidence for a gp was susceptible to the length of acquaintance between informants. Although a gp could be identified for short‐term acquaintances, it remained elusive at long‐term acquaintance. Thus, the gp in other ratings more likely reflects normative ratings of an average individual rather than ratings of the specific target person. Copyright © 2013 European Association of Personality Psychology  相似文献   
243.
With data from the middle cohort of the Pittsburgh Youth Study, a prospective longitudinal study of inner-city boys, we examined whether Big Five agreeableness facets could be reliably recovered in this sample, and whether facets predicted educational, occupational, social, and antisocial life outcomes assessed a decade later. Caregivers described their adolescent boys’ personalities using the Common California Q-Set; twelve years later, participants were interviewed and court records were obtained. Factor analyses recovered two facets: compliance and compassion. Compliance predicted more schooling and lower risk of unemployment, teenage fatherhood, and crime; compassion related to longer committed relationships. Findings highlight the value of studying personality at the facet level.  相似文献   
244.
Spearman's Law of Diminishing Returns (SLODR) is the idea that the structure of human cognitive ability is more differentiated and g a weaker determinant of cognitive performance at higher levels of ability. In this study, we distinguish between ‘traditional’ methods of testing SLODR and ‘contemporary’ methods of testing SLODR. It is the former set of methods from which the vast majority of the evidence base for SLODR derives. We demonstrated that it is easy to mimic SLODR and reverse SLODR effects in these traditional methods of assessing SLODR by using data with skewed observed variable distributions. The skewness magnitudes did not need to be large to produce these effects and they fell well within the range of values that are usually considered unproblematic for parametric statistic analysis. In simulated datasets, positive subtest skewness resulted in SLODR and negative subtest skewness resulted in reverse SLODR. In contemporary methods of testing SLODR, non-linear g-loadings or a skewed g are assumed to reflect evidence for SLODR. When we applied contemporary methods of testing SLODR to these data, there was evidence of heteroscedastic residuals but no evidence of non-linear g-loadings or skewed g distributions. We broadly replicated the effects of subtest skew from these simulated datasets in real data from the Minnesota Study of Twins Reared Apart. Results imply that traditional methods of assessing SLODR cannot distinguish between effects due to subtest characteristics that have nothing to do with differences in ability structure at different levels of g and true SLODR effects. This calls into question the empirical support for SLODR.  相似文献   
245.
ABSTRACT

We present results for the structural, electronic, vibrational, and electron-phonon coupling properties of LaSn3 and CaSn3 adopting the simple cubic AuCu3-type structure obtained using the the generalised gradient approximation of the density functional theory and plane wave ab initio pseudopotential method. Our electronic results show that both materials display metallic character with several bands, which have mainly Sn 5p character, crossing the Fermi level. The calculated phonon spectrum of LaSn3 accords very well with reported experimental measurements. The weights of the peaks in the Eliashberg spectral function of both compounds are enhanced with the use of experimental lattice constant in our electron-phonon calculation, increasing the value of average electron phonon coupling parameter from 0.876 to 0.937 for LaSn3 (by 7%) and from 0.642 to 0.725 for CaSn3 (by 13%). The use of experimental lattice constant also improves the agreement between theoretical and experimental values of the superconducting temperature for both compounds.  相似文献   
246.
The structural validity of the Personal Globe Inventory (PGI, Tracey, 2002) as applied to a Caribbean sample of university students in Jamaica (N = 103) and Trinidad (N = 118) was examined. The fit of the data to Holland's six-type RIASEC, the PGI eight-type model, and the PGI spherical structure was examined using the randomized test of hypothesized order relations. The results demonstrated that the circular structure (i.e. RIASEC and the eight-type model), unlike the spherical structure, fits the Caribbean data well. No structural differences were found between gender and nationality. Further examination of the cultural perception of prestige in a Caribbean sample is warranted. Overall, the results support the structural validity of the PGI in Caribbean applications.  相似文献   
247.
248.
Abstract: The diversity in the morphological structure of two‐kanji compound words is a matter of special concern for models of the Japanese mental lexicon. This study discusses two proposals for models of the Japanese mental lexicon – Hirose’s (1992, 1994, 1996 ) hypotheses and a Japanese lemma‐unit version of the multilevel interactive‐activation framework – in terms of their ability to cope with this diversity. As the proposals make different predictions concerning constituent‐morpheme priming, patterns of facilitation were examined in two experiments with five word‐formation principles as experimental conditions. Experiment 1, using the long stimulus onset asynchrony (SOA) of 3000 ms employed by Hirose (1992 ), only found significant differences between the first‐ and second‐element conditions in one of the word‐formation conditions. Experiment 2, using a short SOA of 250 ms, confirmed the pattern of priming obtained in Experiment 1. These results are more consistent with the prediction from the Japanese lemma‐unit model.  相似文献   
249.
正如不同的病症需要使用不同的医疗技术方法来诊断一样, 不同的认知结构也需要设计对应的测验模式来进行诊断, 从而保证测验具有高质量的诊断评估效果。但传统测验形式未考虑不同认知结构的针对性诊断测验需求, 导致“千人一卷”在测验效率上有所不足; 认知诊断计算机化自适应测验虽可针对不同认知结构的被试施测不同的项目, 然而支持自适应过程的题库却没有针对不同认知结构被试设计对应的项目, 导致题库使用效率较低。要解决上述问题的关键在于, 探索如何针对不同认知结构设计相对应的测验模式。本研究采用Monte Carlo模拟, 对六种属性层级关系下, 不同认知结构的测验设计模式进行探讨。实验结果表明(1)同一属性层级关系下, 不同认知结构的最佳测验设计模式不同; (2)依据不同认知结构的最佳测验设计模式构建的题库具有更高的使用效率。测验编制者可以根据实验结果针对不同认知结构优化对应的测验设计模式, 并用于指导题库建设。  相似文献   
250.
句法优先理论假设词类加工功能上优先于语义、动词论元结构和话语信息加工。来自德语和法语的证据显示, 词类违反阻断语义整合和动词论元结构加工, 因而词类优先于语义和动词论元结构。关于词类加工在功能上是否优先于话语信息加工, 尚无来自任何语言的证据。汉语证据尽管显示词类并不优先于语义, 但未充分讨论任务因素的影响。将来研究有必要使用ERP技术和违反范式, 从语义整合、动词论元结构加工和话语水平加工等多个层面, 同时操纵词类的正确性和非句法因素, 考察句法特性上与德语和法语不同的语言, 如汉语和韩语。这方面研究将有助于洞察一个语言的语言学特性如何制约或调整词类加工的功能性质。  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