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   8601篇
  免费   799篇
  国内免费   398篇
  2024年   43篇
  2023年   202篇
  2022年   144篇
  2021年   172篇
  2020年   451篇
  2019年   428篇
  2018年   415篇
  2017年   428篇
  2016年   388篇
  2015年   256篇
  2014年   358篇
  2013年   1130篇
  2012年   165篇
  2011年   286篇
  2010年   249篇
  2009年   338篇
  2008年   417篇
  2007年   439篇
  2006年   446篇
  2005年   359篇
  2004年   321篇
  2003年   260篇
  2002年   226篇
  2001年   150篇
  2000年   119篇
  1999年   128篇
  1998年   100篇
  1997年   83篇
  1996年   55篇
  1995年   73篇
  1994年   50篇
  1993年   42篇
  1992年   40篇
  1990年   19篇
  1989年   27篇
  1988年   17篇
  1987年   17篇
  1985年   133篇
  1984年   125篇
  1983年   106篇
  1982年   87篇
  1981年   68篇
  1980年   75篇
  1979年   65篇
  1978年   95篇
  1977年   59篇
  1976年   42篇
  1975年   31篇
  1974年   24篇
  1973年   28篇
排序方式: 共有9798条查询结果,搜索用时 15 毫秒
91.
It is argued that the manner in which we teach science in the high schools represents an outdated positivistic conception of science. The standard presentation of a year of each of chemistry, biology and physics should be replaced by an integrated science plus history, philosophy, and sociology of science which would take a total of three years to complete. A proper appreciation for the true nature of science is essential to the continued health of the scientific enterprise.  相似文献   
92.
Kevin J. Sharpe 《Zygon》1990,25(1):105-122
Abstract. David Bohm's thinking has become widely publicized since the 1982 performance of a form of the Einstein-Podolsky- Rosen (EPR) experiment. Bohm's holomovement theory, in particular, tries to explain the nonlocality that the experiment supports. Moreover, his theories are close to his metaphysical and religious thinking. Fritjof Capra's writings try something similar: supporting a theory (the bootstrap theory) because it is close to his religious beliefs. Both Bohm and Capra appear to use their religious ideas in their physics. Religion, their source for physical hypotheses, provides the motivation to develop and uphold them.  相似文献   
93.
A multidisciplinary group of genetic and other professionals discuss a complex case of familial conflict over access to genetic information. One twin wishes to know the results of her deceased mother's tests for BRCA1 mutations; a second twin objects to researchers making this information available. As the case discussion unfolds, the apparent facts of this case are called into question and the lines of ethical certainty become less clear.  相似文献   
94.
95.
自由回忆和线索回忆测验中的系列位置效应   总被引:3,自引:1,他引:2  
吴艳红  朱滢 《心理科学》1997,20(3):217-221
本文以96个中国汉字为材料,使用自由回忆和线索回忆测验方法,对20名被试进行6组分测验和最后所有汉字的总测验。发现自由回忆分测验中存在明显的系列位置效应,总测验出现负近因现象;线索回忆分测验也表现出明显的系列位置效应,但最后的总测验没有出现负近因现象。上述结果验证了Bjork和Whitten(1974)提出的顺序或情景理论。  相似文献   
96.
大学生解决物理问题的表征层次的实验研究   总被引:12,自引:1,他引:11  
廖伯琴  黄希庭 《心理科学》1997,20(6):494-498
设计了两个实验,探讨优、差生物理问题表征层次的特点。结果表明,优、差生物理问题表征层次有差异。优生侧重于科学理论表征,表现为以物理原理分类,在科学理论表征层次上多为正向推理:差生则受初始表征的影响,以表面特征分类,在科学理论表征层次上多为逆向推理。  相似文献   
97.
This paper discusses two forms of separability of item and person parameters in the context of response time (RT) models. The first is separate sufficiency: the existence of sufficient statistics for the item (person) parameters that do not depend on the person (item) parameters. The second is ranking independence: the likelihood of the item (person) ranking with respect to RTs does not depend on the person (item) parameters. For each form a theorem stating sufficient conditions, is proved. The two forms of separability are shown to include several (special cases of) models from psychometric and biometric literature. Ranking independence imposes no restrictions on the general distribution form, but on its parametrization. An estimation procedure based upon ranks and pseudolikelihood theory is discussed, as well as the relation of ranking independence to the concept of double monotonicity.I am indebted to Wim van der Linden for bringing Thissen's (1983) paper to my notice, and to Martijn Berger, Frans Tan, and the anonymous reviewers for their constructive comments on earlier drafts of this paper.  相似文献   
98.
Shrinkage estimation of linear combinations of true scores   总被引:1,自引:0,他引:1  
This paper is concerned with combining observed scores from sections of tests. It is demonstrated that in the presence of population information a linear combination of true scores can be estimated more efficiently than by the same linear combination of the observed scores. Three criteria for optimality are discussed, but they yield the same solution which can be described and motivated as a multivariate shrinkage estimator.Input from Eric Bradlow, Charles Lewis, and Linda Zeger is acknowledged. Research for this paper was funded by the Program Research Council (ETS). Suggestions of the Editor and of anonymous referees were instrumental in several improvements of the paper.  相似文献   
99.
Konikowska  Beata 《Studia Logica》1997,58(1):185-226
A similarity relation is a reflexive and symmetric binary relation between objects. Similarity is relative: it depends on the set of properties of objects used in determining their similarity or dissimilarity. A multi-modal logical language for reasoning about relative similarities is presented. The modalities correspond semantically to the upper and lower approximations of a set of objects by similarity relations corresponding to all subsets of a given set of properties of objects. A complete deduction system for the language is presented.  相似文献   
100.
医学伦理学概念之探究   总被引:5,自引:1,他引:4  
医学伦理学的概念看起来很简单,一般情况下人们便习以为常地接受了作为应用规范伦理学的一个分支的科学地位,而忽视了医学对医学伦理学所起的作用。本文认为:医学伦理学的具体内容是医学科技与伦理道德两因素相互作用的产物,对其相互作用的形式和产物的具体分析和总结便可构成这门学科的理论体系。  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