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   3698篇
  免费   181篇
  国内免费   1篇
  2023年   48篇
  2022年   36篇
  2021年   62篇
  2020年   81篇
  2019年   122篇
  2018年   149篇
  2017年   152篇
  2016年   166篇
  2015年   121篇
  2014年   115篇
  2013年   414篇
  2012年   221篇
  2011年   228篇
  2010年   127篇
  2009年   113篇
  2008年   161篇
  2007年   155篇
  2006年   124篇
  2005年   148篇
  2004年   128篇
  2003年   122篇
  2002年   97篇
  2001年   71篇
  2000年   69篇
  1999年   46篇
  1998年   36篇
  1997年   30篇
  1996年   34篇
  1995年   26篇
  1994年   16篇
  1993年   33篇
  1992年   28篇
  1991年   33篇
  1990年   34篇
  1989年   21篇
  1988年   28篇
  1987年   23篇
  1986年   26篇
  1985年   23篇
  1984年   27篇
  1983年   20篇
  1982年   13篇
  1979年   13篇
  1978年   13篇
  1977年   13篇
  1976年   8篇
  1974年   10篇
  1973年   7篇
  1971年   7篇
  1968年   7篇
排序方式: 共有3880条查询结果,搜索用时 23 毫秒
41.
This article presents a series of personal guidelines for promoting the culturally sensitive psychiatric diagnosis of Mexican American/Chicano clients. These guidelines are primarily based on the authors' collective experiences in diagnosing and treating this population.  相似文献   
42.
W. M. de Muynck 《Synthese》1995,102(2):293-318
The axiomatic approaches of quantum mechanics and relativity theory are compared with approaches in which the theories are thought to describe readings of certain measurement operations. The usual axioms are shown to correspond with classes of ideal measurements. The necessity is discussed of generalizing the formalisms of both quantum mechanics and relativity theory so as to encompass more realistic nonideal measurements. It is argued that this generalization favours an empiricist interpretation of the mathematical formalisms over a realist one.  相似文献   
43.
The notion of unsharp orthoalgebra is introduced and it is proved that the category of unsharp orthoalgebras is isomorphic to the category of D-posets. A completeness theorem for some partial logics based on unsharp orthoalgebras, orthoalgebras and orthomodular posets is proved.  相似文献   
44.
This article sets out the overall framework within which American music phenomenologists operates. A widely accepted definition of the word phenomenology, together with a basically eclectic attitude and a boundary issue between musicology and philosophy, is identified. The impetus to the article is provided by an anti-positivistic polemic and a plea in defence of the meaning and concreteness of musical experience. These aspects then combine in a critique of traditional musical analysis in its positivistic matrix. S.K. Langer's philosophy, as the inspiration of this polemic, is examined in the central part of the article. However, the author's distancing from the idealistic aspects of his esthetics is covered, in particular the downplaying of the sound-sensitive level and the condemnation of musicology in general. Sense and sensitive materials, wide philosophical options and concrete procedures of music analysis are what these authors look for in phenomenology as a means to reconcile humanistic and technical culture. Therefore, the article is not so much a condemnation as an attempt to refound musicology in its entirety, with particular reference to contemporary music.  相似文献   
45.
Zellini (1979, Theorem 3.1) has shown how to decompose an arbitrary symmetric matrix of ordern ×n as a linear combination of 1/2n(n+1) fixed rank one matrices, thus constructing an explicit tensor basis for the set of symmetricn ×n matrices. Zellini's decomposition is based on properties of persymmetric matrices. In the present paper, a simplified tensor basis is given, by showing that a symmetric matrix can also be decomposed in terms of 1/2n(n+1) fixed binary matrices of rank one. The decomposition implies that ann ×n ×p array consisting ofp symmetricn ×n slabs has maximal rank 1/2n(n+1). Likewise, an unconstrained INDSCAL (symmetric CANDECOMP/PARAFAC) decomposition of such an array will yield a perfect fit in 1/2n(n+1) dimensions. When the fitting only pertains to the off-diagonal elements of the symmetric matrices, as is the case in a version of PARAFAC where communalities are involved, the maximal number of dimensions can be further reduced to 1/2n(n–1). However, when the saliences in INDSCAL are constrained to be nonnegative, the tensor basis result does not apply. In fact, it is shown that in this case the number of dimensions needed can be as large asp, the number of matrices analyzed.  相似文献   
46.
In the present research, we investigated the modification of the strength of the Poggendortf illusion as a function of different densities ofrandom dot textures failing the space between the verticals. The results ofExperiment 1 show that the illusory effect is a nonlinear function ofthe texture parameterr, the ratio of black pixels to white and black pixels, with a minimum forr=0.5, approximately, and a maximum forr=0 andr=1. The results may be interpreted by an analytical model of perceptual space dynamics, in which the effect dependson the amount of interaction between points of different light intensity. A computer simulation performed by applying the analytical model to different values ofr shows a good agreement between the predictions and the experimental data. To test the hypothesis underlying the model, a second experiment was carried out to measure the magnitude of the expansion ofthe space between the verticals as a function of the parameterr. The results are consistent with the hypothesis of the model. The overall data are discussed in terms of their implications on various theories proposed for the Poggeadorff illusion.  相似文献   
47.
48.
Although there are measurable differences in integrative complexity among solutions that individuals generate in dealing with problems, it is uncertain to what extent people comprehend, recognize, and have preferences among different levels of complexity. Integrative complexity is a function of differentiation (the perception of several attributes within, or perspectives about, a topic) and integration (combining the differentiated characteristics in an interactive or synthesizing solution). The current paper reports two experiments dealing with how university students perceive, interpret, and choose among solutions differing in complexity. Experiment 1 showed that subjects accurately rated the complexity of described solutions differing along the continuum, but that their assessment of their own responses differed from the results of expert scoring. Their self-estimated complexity was highly correlated with their preferences, and preferred complexity was reliably higher than either expert- or self-assessed complexity of subject-generated solutions. Subjects were able to hypothesize quite accurately about environmental and endogenous factors likely to affect complexity. Experiment 2 found that in response to problem scenarios, solutions selected as being potentially most effective were consistently more complex than solutions that participants considered themselves most likely to use. The idea of complexity seems to be intuitively recognizable and understandable by untrained subjects: They can and do distinguish among problem solutions (self-generated or presented) that vary on that dimension, and are able to assess accurately the effects of relevant variables. Such subjects also share the bias shown by experts in favour of the superiority of more complex approaches.  相似文献   
49.
Quantum MV algebras   总被引:1,自引:0,他引:1  
We introduce the notion of quantum MV algebra (QMV algebra) as a generalization of MV algebras and we show that the class of all effects of any Hilbert space gives rise to an example of such a structure. We investigate some properties of QMV algebras and we prove that QMV algebras represent non-idempotent extensions of orthomodular lattices.I should like to thank Prof. M.L. Dalla Chiara and Dr. P. Minari for many interesting comments and remarks. Daniele Mundici  相似文献   
50.
In studies related to human movement, linked segment models (LSM's) are often used to quantify forces and torques, generated in body joints. Some LSM's represent only a few body segments. Others, for instance used in studies on the control of whole body movements, include all body segments. As a consequence of the complexity of 3-dimensional (3-D) analyses, most LSM's are restricted to one plane of motion. However, in asymmetric movements this may result in a loss of relevant information. The aim of the current study was to develop and validate a 3-D LSM including all body segments. Braces with markers, attached to all body segments, were used to record the body movements. The validation of the model was accomplished by comparing the measured with the estimated ground reaction force and by comparing the torques at the lumbo-sacral joint that resulted from a bottom-up and a top-down mechanical analysis. For both comparisons, reasonable to good agreement was found. Sources of error that could not be analysed this way, were subjected to an additional sensitivity analysis. It was concluded that the internal validity of the current model is quite satisfactory.  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