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   2673篇
  免费   387篇
  国内免费   537篇
  2024年   5篇
  2023年   77篇
  2022年   100篇
  2021年   134篇
  2020年   169篇
  2019年   167篇
  2018年   145篇
  2017年   152篇
  2016年   158篇
  2015年   147篇
  2014年   139篇
  2013年   385篇
  2012年   121篇
  2011年   129篇
  2010年   115篇
  2009年   138篇
  2008年   148篇
  2007年   125篇
  2006年   138篇
  2005年   120篇
  2004年   107篇
  2003年   91篇
  2002年   77篇
  2001年   54篇
  2000年   55篇
  1999年   39篇
  1998年   30篇
  1997年   35篇
  1996年   31篇
  1995年   28篇
  1994年   18篇
  1993年   20篇
  1992年   28篇
  1991年   12篇
  1990年   14篇
  1989年   15篇
  1988年   16篇
  1987年   18篇
  1986年   12篇
  1985年   11篇
  1984年   13篇
  1983年   14篇
  1982年   8篇
  1981年   3篇
  1980年   9篇
  1979年   4篇
  1978年   13篇
  1977年   7篇
  1976年   3篇
排序方式: 共有3597条查询结果,搜索用时 15 毫秒
141.
To expand the collection of instruments available for assessment of anxiety in the elderly, this report examined the original and revised Hamilton anxiety scales in a sample of 50 older adults diagnosed with Generalized Anxiety Disorder (GAD) and 93 normal community participants (ages 55–82). Although the revised anxiety scale had better discriminant validity (lower correlation with the revised Hamilton depression scale) than the original anxiety and depression scales, a considerable amount of shared variance still existed (41% shared variance, GAD sample alone; 17% control sample alone; 74% shared variance, both samples combined). Near-perfect group classification was possible using 7 items from the original anxiety scale and 10 items from the revised anxiety scale. Results are discussed in light of their implications for use of the Hamilton anxiety rating scale with older anxiety-disordered patients.  相似文献   
142.
Honeybees were trained to find sugar water in the middle of an array of two landmarks of different colours. Unrewarded tests compared searching on the training array with searching on rotated arrays. On rotated tests, a system using the angles between landmarks would continue to search in the middle. A system using vectors to individual elements would search at locations outside the rotated array at which the distances and compass directions to a subset of landmarks matched. Results indicated that bees used both elements and interlandmark angles, but they relied most on one favourite landmark element. Results support the template model of landmark use in honeybees, with the minor parametric modification that weights given to different elements may be unequal. Received:6 July 1998 / Accepted after revision:7 December 1998  相似文献   
143.
In this paper, the constrained maximum likelihood estimation of a two-level covariance structure model with unbalanced designs is considered. The two-level model is reformulated as a single-level model by treating the group level latent random vectors as hypothetical missing-data. Then, the popular EM algorithm is extended to obtain the constrained maximum likelihood estimates. For general nonlinear constraints, the multiplier method is used at theM-step to find the constrained minimum of the conditional expectation. An accelerated EM gradient procedure is derived to handle linear constraints. The empirical performance of the proposed EM type algorithms is illustrated by some artifical and real examples.This research was supported by a Hong Kong UCG Earmarked Grant, CUHK 4026/97H. We are greatly indebted to D.E. Morisky and J.A. Stein for the use of their AIDS data in our example. We also thank the Editor, two anonymous reviewers, W.Y. Poon and H.T. Zhu for constructive suggestions and comments in improving the paper. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.  相似文献   
144.
Demri  Stéphane  Orłowska  Ewa 《Studia Logica》1999,62(2):177-200
In this paper a unified framework for dealing with a broad family of propositional multimodal logics is developed. The key tools for presentation of the logics are the notions of closure relation operation and monotonous relation operation. The two classes of logics: FiRe-logics (finitely reducible logics) and LaFiRe-logics (FiRe-logics with local agreement of accessibility relations) are introduced within the proposed framework. Further classes of logics can be handled indirectly by means of suitable translations. It is shown that the logics from these classes have the finite model property with respect to the class of -formulae, i.e. each -formula has a -model iff it has a finite -model. Roughly speaking, a -formula is logically equivalent to a formula in negative normal form without occurrences of modal operators with necessity force. In the proof we introduce a substantial modification of Claudio Cerrato's filtration technique that has been originally designed for graded modal logics. The main core of the proof consists in building adequate restrictions of models while preserving the semantics of the operators used to build terms indexing the modal operators.  相似文献   
145.
A dynamical model of the movements of the platform of a ski-simulator was derived from experimental data, using the graphical and statistical methods developed by Beek and Beek (Beek, P. J., & Beek, W. J. (1988). Human Movement Science, 7, 301–342). The data were collected in an experiment in which both amplitude and practice were manipulated. The data were filtered and further reduced to normalised cycles that were averaged within and across subjects. Graphical methods were applied to these averaged normalised cycles to determine the stiffness and friction terms to be included in the model. The relative contribution of each term was assessed by means of multiple regression. The model, which included cubic and quintic Duffing terms and one or two dissipative Van der Pol terms, accounted on average for 99.2% of the variance. The exact parameter setting of the model differed considerably across subjects. For one subject, a qualitatively different model, including Rayleigh instead of Van der Pol terms, provided a better account of the data. Systematic changes of the coefficients in the model, related to amplitude and the duration of practice, were evident.  相似文献   
146.
Using consensual qualitative research, the authors examined the treatment planning process of experienced counselors (N = 9). The data analysis resulted in 4 domains: assessment steps, clinical impressions, treatment factors, and treatment strategies. These domains describe the process used by experienced counselors in making clinical decisions and offer insight into the nature of clinical expertise and the need for further research on treatment planning.  相似文献   
147.
The present study illustrates the usefulness of finite mixture of generalized linear models (GLMs) to examine variability in cognitive strategies during childhood. More precisely, it addresses this variability in set-shifting situations where task-goal updating is endogenously driven. In a task-switching paradigm 5–6-year-olds had to switch between color- and shape-matching rules as a function of a predetermined, predictable task sequence. A finite mixture of GLMs was fitted to explore individual differences in performance. The statistical model revealed five response profiles, defined by accuracy and response times. These response profiles likely correspond to different cognitive strategies with varying efficiency and differential relations to working memory capacity (assessed by backward digit span). These results illustrate the heuristic value of statistical modeling to reveal the behavioral and cognitive variability in the temporal dynamics of children's cognitive functioning.  相似文献   
148.
Judges often evaluate stimulus series on dimensions for which no physical scale exists; for example, when judging academic ability in oral examinations. We propose that judges deal with this problem by calibrating an internal judgment scale that maps stimulus input onto available judgment categories. This calibration process implies serial position effects: Judges should initially avoid extreme categories, because using extreme categories reduces judgmental degrees of freedom, thereby increasing the possibility of internal consistency violations. In four experiments, we show that judgments become indeed more extreme later in a series of judgments. Judges evaluated the same good (poor) performances more positive (negative) at the end of a sequence compared to the beginning. Judges’ expertise did not prevent the effect, but allowing end-of-sequence judgments reduced serial position effects. We discuss the implications and possible remedies of these calibration effects on judgment extremity.  相似文献   
149.
This study investigated the role of adolescents' cognitive ability, personality traits and school success in predicting later criminal behaviour. Cognitive ability, the five‐factor model personality traits and the school grades of a large sample of Estonian schoolboys (N = 1919) were measured between 2001 and 2005. In 2009, judicial databases were searched to identify participants who had been convicted of misdemeanours or criminal offences. Consistent with previous findings, having a judicial record was associated with lower cognitive ability, grade point average, agreeableness, and conscientiousness and higher neuroticism. In multivariate path models, however, the contributions of cognitive ability and conscientiousness were accounted for by school grades and the effect of neuroticism was also accounted for by other variables, leaving grade point average and agreeableness the only independent predictors of judicial record status. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
150.
传统的心理素质结构研究模式不经济,研究结果出现纵向断裂横向分裂的趋势.从进化心理学的视角来看,心理素质结构的最终功能均指向个体的适应性,其形成是与周围环境不断排斥和融合的过程.建构的心理素质结构融合模型能在一定程度上解决传统研究模式的弊端,并建议今后的研究应以分析人为主导转而分析人及其所处的文化环境并重,进而引导人的心理素质结构的不断发展.  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