全文获取类型
收费全文 | 26866篇 |
免费 | 139篇 |
国内免费 | 1篇 |
专业分类
27006篇 |
出版年
2024年 | 54篇 |
2023年 | 74篇 |
2022年 | 58篇 |
2021年 | 97篇 |
2020年 | 162篇 |
2019年 | 219篇 |
2018年 | 3643篇 |
2017年 | 2997篇 |
2016年 | 2446篇 |
2015年 | 392篇 |
2014年 | 283篇 |
2013年 | 790篇 |
2012年 | 886篇 |
2011年 | 2712篇 |
2010年 | 2695篇 |
2009年 | 1672篇 |
2008年 | 1959篇 |
2007年 | 2403篇 |
2006年 | 271篇 |
2005年 | 416篇 |
2004年 | 346篇 |
2003年 | 304篇 |
2002年 | 227篇 |
2001年 | 111篇 |
2000年 | 117篇 |
1999年 | 78篇 |
1998年 | 100篇 |
1997年 | 95篇 |
1996年 | 79篇 |
1995年 | 53篇 |
1994年 | 65篇 |
1993年 | 50篇 |
1992年 | 51篇 |
1991年 | 50篇 |
1990年 | 68篇 |
1989年 | 36篇 |
1988年 | 38篇 |
1987年 | 40篇 |
1986年 | 39篇 |
1985年 | 54篇 |
1984年 | 52篇 |
1982年 | 66篇 |
1981年 | 45篇 |
1980年 | 50篇 |
1979年 | 45篇 |
1978年 | 48篇 |
1977年 | 52篇 |
1976年 | 51篇 |
1975年 | 45篇 |
1974年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Warren R. Stanton 《Current psychology (New Brunswick, N.J.)》2002,21(2):176-198
Stage theories are commonly used to represent the structure of cognitive processes in the domains of cognitive processing
and cognitive development. Hierarchical unidimensional theories consisting of a single sequence of stages through which development
proceeds in one direction only have predominated. However, a review of stage theories revealed that a two-dimensional, interactive
(multidimensional) structure is warranted. Particularly in the area of cognitive development, results of research have supported
subdivision of the stages of prominent unidimensional theories. Following this trend a small number of theorists have developed
multidimensional theories, most of which consist of a sequence of stages in which each stage contains a number of subsidiary
stages or levels. The emergence of a similar trend in other domains is examined, and the prospects of using an existing multidimensional
framework to enable future comparisons and integration of different stage theories is explored. 相似文献
102.
Kaufer DI 《CNS spectrums》2002,7(10):742-750
Historically, drugs that increase central cholinergic transmission have primarily been investigated for relieving cognitive symptoms in mild-to-moderate Alzheimer's disease. These efforts have led to the somewhat unexpected findings that cholinergic therapy has a beneficial effect on selected neuropsychiatric symptoms in AD across disease stages. In Parkinson's disease with dementia and dementia with Lewy bodies, cholinergic deficits are more severe than in AD, and there is emerging evidence that cholinesterase inhibitors are efficacious in treating core symptoms of attentional disturbance and psychosis. Recent data also suggest a rational basis for cholinergic therapy in vascular dementia. The cognitive and neuropsychiatric effects of cholinergic therapy observed in AD and other dementias form the crux of an integrative model of cholinergic therapeutic efficacy that encompasses the diverse central nervous system actions of acetylcholine and its complementary interactions with central monoamine transmitters. This heuristic framework highlights the broader therapeutic potential of cholinergic therapy for symptom-based indications in other neuropsychiatric disorders. 相似文献
103.
104.
Jonathan James McCreadie Lillie 《Sexuality & culture》2002,6(2):25-48
This article presents theoretical considerations based on cultural analysis approaches to studying pornography and sexuality
as a means of starting to suggest a new agenda for cyberporn research. By bringing to the forefront concepts of how subjectivity
and sexuality are produced within the computer/Internet apparatus, I hope to diversify the focus in cyberporn research away
from social science approaches and pre-Foucaultian assumptions of the subject which obscure understandings of new media and
cyberporn use. Through a summary of visual culture studies and reception studies of pornography, I argue that cyberporn must
be understood as contingent within the encoding and decoding processes and discourses of sexuality (Foucault) in which it
is produced and consumed. My focus here is the home office/terminal as the site of reception/cyberporn use. While there is
potential for a great variety of cultural analytic approaches to the study of cyberporn and how new media use influences sexuality,
I end with specific suggestions for researching cyberporn reception in the home.
The computer’s allure is more than utilitarian or aesthetic; it is erotic. Instead of a refreshing play with surfaces, as
with toys or amusements, our affair with information machines announces a symbiotic relationship and ultimately a mental marriage
to technology. Rightly perceived, the atmosphere of cyberspace carries the scent that once surrounded Wisdom. The world rendered
as pure information not only fascinates our eyes and minds, but also captures our hearts. We feel augmented and empowered.
Our hearts beat in the machines. This is Eros. (Michael Heim, The Metaphysics of Virtual Reality) 相似文献
105.
106.
107.
Baguley T 《Behavior research methods》2012,44(1):158-175
The psychological and statistical literature contains several proposals for calculating and plotting confidence intervals
(CIs) for within-subjects (repeated measures) ANOVA designs. A key distinction is between intervals supporting inference about
patterns of means (and differences between pairs of means, in particular) and those supporting inferences about individual
means. In this report, it is argued that CIs for the former are best accomplished by adapting intervals proposed by Cousineau
(Tutorials in Quantitative Methods for Psychology, 1, 42–45, 2005) and Morey (Tutorials in Quantitative Methods for Psychology, 4, 61–64, 2008) so that nonoverlapping CIs for individual means correspond to a confidence for their difference that does not include zero.
CIs for the latter can be accomplished by fitting a multilevel model. In situations in which both types of inference are of
interest, the use of a two-tiered CI is recommended. Free, open-source, cross-platform software for such interval estimates
and plots (and for some common alternatives) is provided in the form of R functions for one-way within-subjects and two-way
mixed ANOVA designs. These functions provide an easy-to-use solution to the difficult problem of calculating and displaying
within-subjects CIs. 相似文献
108.
Welch’s (Biometrika 29: 350–362, 1938) procedure has emerged as a robust alternative to the Student’s t test for comparing the means of two normal populations with unknown and possibly unequal variances. To facilitate the advocated
statistical practice of confidence intervals and further improve the potential applicability of Welch’s procedure, in the
present article, we consider exact approaches to optimize sample size determinations for precise interval estimation of the
difference between two means under various allocation and cost considerations. The desired precision of a confidence interval
is assessed with respect to the control of expected half-width, and to the assurance probability of interval half-width within
a designated value. Furthermore, the design schemes in terms of participant allocation and cost constraints include (a) giving
the ratio of group sizes, (b) specifying one sample size, (c) attaining maximum precision performance for a fixed cost, and
(d) meeting a specified precision level for the least cost. The proposed methods provide useful alternatives to the conventional
sample size procedures. Also, the developed programs expand the degree of generality for the existing statistical software
packages and can be accessed at brm.psychonomic-journals.org/content/ supplemental. 相似文献
109.
Køppe’s proposition of four layers in theoretical building are used here in the exploration of a specific case of eclectic combination, the use of Piagetian and Vygotskian general approaches to the analysis of proportional reasoning as a cognitive mathematical ability. It is proposed here that the eclectic consideration of these contributions depends on the consideration of their specificity, in the sense that they highlight different aspects of the phenomenon under scrutiny, and also on the consideration of the coherence between this eclectic convergence and premises in terms of schools of thought under which each contribution is framed. We conclude proposing in accordance to S. Køppe’s proposal that eclecticism can be valuable and heuristic in theory development, but this contribution will depend largely on the effort in establishing careful relations between the four layers of theory-building. 相似文献
110.
Callahan D 《Theoretical medicine and bioethics》2012,33(1):11-20
The Hastings Center was founded in 1969 to study ethical problems in medicine and biology. The Center arose from a confluence
of three social currents: the increased public scrutiny of medicine and its practices, the concern about the moral problems
being generated by technological developments, and the desire of one of its founders (Callahan) to make use of his philosophical
training in a more applied way. The early years of the Center were devoted to raising money, developing an early agenda of
issues, and identifying a cadre of people around the country interested in the issues. Various stresses and strains in the
Center and the field are identified, and some final reflections are offered on the nature and value of the contributions made
by bioethics as an academic field. 相似文献