全文获取类型
收费全文 | 5182篇 |
免费 | 875篇 |
国内免费 | 318篇 |
出版年
2024年 | 29篇 |
2023年 | 144篇 |
2022年 | 93篇 |
2021年 | 182篇 |
2020年 | 289篇 |
2019年 | 307篇 |
2018年 | 242篇 |
2017年 | 285篇 |
2016年 | 291篇 |
2015年 | 200篇 |
2014年 | 223篇 |
2013年 | 655篇 |
2012年 | 160篇 |
2011年 | 199篇 |
2010年 | 136篇 |
2009年 | 206篇 |
2008年 | 202篇 |
2007年 | 203篇 |
2006年 | 187篇 |
2005年 | 179篇 |
2004年 | 152篇 |
2003年 | 132篇 |
2002年 | 134篇 |
2001年 | 131篇 |
2000年 | 105篇 |
1999年 | 106篇 |
1998年 | 97篇 |
1997年 | 71篇 |
1996年 | 82篇 |
1995年 | 78篇 |
1994年 | 72篇 |
1993年 | 80篇 |
1992年 | 57篇 |
1991年 | 62篇 |
1990年 | 57篇 |
1989年 | 47篇 |
1988年 | 44篇 |
1987年 | 45篇 |
1986年 | 30篇 |
1985年 | 40篇 |
1984年 | 30篇 |
1983年 | 30篇 |
1982年 | 36篇 |
1981年 | 30篇 |
1980年 | 37篇 |
1979年 | 36篇 |
1978年 | 48篇 |
1977年 | 40篇 |
1976年 | 42篇 |
1975年 | 10篇 |
排序方式: 共有6375条查询结果,搜索用时 296 毫秒
921.
922.
It is well known that minimum-diameter partitioning of symmetric dissimilarity matrices can be framed within the context of coloring the vertices of a graph. Although confusion data are typically represented in the form of asymmetric similarity matrices, they are also amenable to a graph-coloring perspective. In this paper, we propose the integration of the minimum-diameter partitioning method with a neighborhood-based coloring approach for analyzing digraphs corresponding to confusion data. This procedure is capable of producing minimum-diameter partitions with the added desirable property that vertices with the same color have similar in-neighborhoods (i.e., directed edges entering the vertex) and out-neighborhoods (i.e., directed edges exiting the vertex) for the digraph corresponding to the minimum partition diameter. 相似文献
923.
Higher-order latent trait models for cognitive diagnosis 总被引:9,自引:0,他引:9
Higher-order latent traits are proposed for specifying the joint distribution of binary attributes in models for cognitive
diagnosis. This approach results in a parsimonious model for the joint distribution of a high-dimensional attribute vector
that is natural in many situations when specific cognitive information is sought but a less informative item response model
would be a reasonable alternative. This approach stems from viewing the attributes as the specific knowledge required for
examination performance, and modeling these attributes as arising from a broadly-defined latent trait resembling theϑ of item response models. In this way a relatively simple model for the joint distribution of the attributes results, which
is based on a plausible model for the relationship between general aptitude and specific knowledge. Markov chain Monte Carlo
algorithms for parameter estimation are given for selected response distributions, and simulation results are presented to
examine the performance of the algorithm as well as the sensitivity of classification to model misspecification. An analysis
of fraction subtraction data is provided as an example.
This research was funded by National Institute of Health grant R01 CA81068. We would like to thank William Stout and Sarah
Hartz for many useful discussions, three anonymous reviewers for helpful comments and suggestions, and Kikumi Tatsuoka and
Curtis Tatsuoka for generously sharing data. 相似文献
924.
925.
应用Markov模型进行临床决策分析的思考 总被引:2,自引:0,他引:2
应用模型进行临床决策分析的研究日益增多,Markov模型就是近年来用于临床决策分析的一种.它优于传统的决策树分析方法,能应用于疾病预后影响因素的研究、筛查试验的评价、疾病治疗结局预测、纵向生命质量资料分析等多个方面.Markov模型用于临床决策分析,是创新思维的体现,是实事求是的典范,体现了认识的辩证过程. 相似文献
926.
我国传染病防治面临的形势与对策 总被引:1,自引:0,他引:1
长期以来由于种种原因对新发传染病和再发传染病防控方面存在许多问题,比如认识上不足、缺乏投入、设施陈旧、专业人员短缺、农村是薄弱环节等,在SARS暴发过程中表现更为严重,迫切地要求建立一完整套的、科学的、符合中国国情的应对各种新发或再发传染病的公共卫生应急系统. 相似文献
927.
认知需要与战略决策过程之间的关系 总被引:2,自引:0,他引:2
认知需要指人们在信息加工过程中是否愿意投入周密的心考以及能否从深入的思考中获得享受.它反映的是人的认知动机。由于企业管理者在决策过程中涉及诸多处理信息和思考问题的环节,认知需要必然在这一过程中起作用。本研究运用情境案例法探讨了在不确定环境下决策者的认知需要与其在战略决策过程中分析环境和判断战略导向的关系。通过相关分析发现高认知需要者在决策过程中更倾向于关注环境、对环境做出积极判断、强调从长远和全面的角度去分析企业战略。 相似文献
928.
929.
Sherwood Waldron Robert D. Scharf David Hurst Stephen K. Firestein Anna Burton 《The International journal of psycho-analysis》2004,85(2):443-466
A group of experienced analysts has developed scales and a coding manual illustrated with clinical examples to evaluate recorded analyses and psychodynamic therapies. The analytic process scales (APS) assesses three dimensions: (1) the contribution of the analyst: helping to develop a relationship in which the analyst can provide clarification and interpretation of transference and resistance; (2) the contribution of the patient: the communication of experience and the expression of feeling in ways which provide information about needs, wishes and conflicts, accompanied by self-reflection; and (3) interactional characteristics of the emerging relationship, explored by studying sessions divided into psychoanalytically coherent segments. A preliminary study of nine sessions has established that the variables assessed by the APS can be rated reliably. Study of the analysts' contributions illuminated their varied and complexstructure. Important differences emerged among the three patient-analyst pairs studied, and changes in scores over time tracked developments in the analytic work which would imply different treatment outcomes. The APS appears to be a reliable tool facilitating the systematic study of psychoanalyses. 相似文献
930.
In the early history of psychoanalysis, the work of Wilhelm Stekel (1868-1940) was by and large neglected, even though he wrote a considerable number of psychoanalytic studies, some of which should be considered to have had a major influence on Freud's early thought. Freud, in turn, had much greater influence on Stekel than is commonly believed. In this article, the authors aim to uncover some of these mutual influences, in particular in the field of practice, by focusing on the elements of autobiography and self-analysis. The authors have identified a number of covert autobiographical passages in the work of Stekel, and attempt to link one of these 'revelations' to an equally covert response to it by Freud. In the closing section of this article, the authors argue that Stekel's attempt to imitate Freud's self-analysis contributed to the fracture between the two of them. 相似文献