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281.
Two test statistics are proposed for testing the equality of two correlated proportions when some observations are missing
on both responses. The performance of these tests in terms of size and power is compared with other tests by means of Monte
Carlo simulations. The proposed tests are easily computed and compare favorably with other tests. 相似文献
282.
Gunnar Ekbohm 《Psychometrika》1982,47(1):115-118
The problem of testing two correlated proportions with incomplete data is considered by means of Monte Carlo simulations studies. A test proposed in this paper, which can be regarded as a generalization of McNemar's test, is recommended in all cases with incomplete data and not too small samples. 相似文献
283.
汉字部件信息数据库的建立──部件和部件组合频率的统计分析 总被引:5,自引:2,他引:3
用FoxBASE语言统计了6763个基本汉字集合中的部件和部件组合的频度信息,建立了“部件数据库”和“部件组合数据库”。前者包含567个部件;后者包含汉字中实际存在的7583个两部件组合。统计结果表明部件和部件组合均呈偏态分布,绝大多数的频率很低。这两个数据库不仅可应用于研究汉字认知中整体和局部的关系、汉字的学习和记忆,而且也可供汉字学的定量研究、中文信息的计算机处理研究参考。 相似文献
284.
We provide a unified, theoretical basis on which measures of data reliability may be derived or evaluated, for both quantitative and qualitative data. This approach evaluates reliability as the proportional reduction in loss (PRL) that is attained in a sample by an optimal estimator. The resulting measure is between 0 and 1, linearly related to expected loss, and provides a direct way of contrasting the measured reliability in the sample with the least reliable and most reliable data-generating cases. The PRL measure is a generalization of many of the commonly-used reliability measures.We show how the quantitative measures from generalizability theory can be derived as PRL measures (including Cronbach's alpha and measures proposed by Winer). For categorical data, we develop a new measure for the general case in which each of N judges assigns a subject to one of K categories and show that it is equivalent to a measure proposed by Perreault and Leigh for the case where N is 2.Bruce Cooil is an Associate Professor of Statistics, and Roland T. Rust is a Professor and area head for Marketing. The authors thank three anonymous reviewers and an Associate Editor for their helpful comments and suggestions. This work was supported in part by the Dean's Fund for Faculty Research of the Owen Graduate School of Management, Vanderbilt University. 相似文献
285.
Against the backdrop of ancient, mediaeval and modern Catholic teaching prohibiting killing (the rule against killing), the question of assisted suicide and euthanasia is examined. In the past the Church has modified its initial repugnance for killing by developing specific guidelines for permitting killing under strict conditions. This took place with respect to capital punishment and a just war, for example. One wonders why in the least objectionable instance, when a person is already dying, suffering, and repeatedly requesting assistance in dying, there is still such widespread condemnation of assisted suicide and euthanasia. In a Gedankexperiment, I suggest that certain stories of martyrdom in the history of the Christian Church shed some light on the role of taking one's life, or putting one's life in danger out of love. I further suggest that requesting assisted suicide and/or euthanasia from the motive of love of one's family or care givers might possibly qualify as one instance of justifiable euthanasia, although I acknowledge that the Church will not be making changes in its stance any time soon. 相似文献
286.
Negative definability ([18]) is an alternative way of defining classes of Kripke frames via a modal language, one that enables us, for instance, to define the class of irreflexive frames. Besides a list of closure conditions for negatively definable classes, the paper contains two main theorems. First, a characterization is given of negatively definable classes of (rooted) finite transitive Kripke frames and of such classes defined using both traditional (positive) and negative definitions. Second, we characterize the negatively definable classes of rooted general frames. 相似文献
287.
项目在不同间隔时间呈现过程中的系列位置效应 总被引:3,自引:0,他引:3
以中国汉字为材料,考察不同中数比率(0.6,0.8和1.0)时,系列位置曲线不同部分性质的分化,结果说明,系列位置曲线不同部分的性质,是项目间隔时间和其时间变化的中数比率共同作用的结果,发现项目间隔时间变化中数比率所起作用更大,在项目呈现时间相同时,项目隔间的时间长短,决定项目之间的辨别程度,也影响到对项目正确提取的百分数。 相似文献
288.
Minimization of modal contours: an essential cross-species strategy in disambiguating relative depth 总被引:4,自引:2,他引:2
Two chromatically identical patterns, a diamond and a ladder, were shown on a computer touchscreen. Domestic hens were reinforced
for pecking at the pattern that was the highest up on a grid that provided pictorial depth information, i.e. on the pattern
that to a human appears as being the furthest away. Every tenth trial was a non-rewarded probe trial with the two patterns
partially overlapping. In the absence of other cues depth stratification can occur on the basis of a minimization of interpolated
occluding contours. In humans the diamond is usually perceived to be in front of the ladder because shorter interpolated contours
are needed to account for the occlusive effect of the diamond on the ladder. The hens pecked more often at the ladder during
the probe trials. The results suggest that the avian and mammalian visual systems operate along similar principles when dealing
with the problem of solving occlusion indeterminacy in chromatically homogeneous patterns.
Received: 26 March 1999 / Accepted after revision: 17 September 1999 相似文献
289.
CAI下小学低年级学生的学习控制水平与元认知监控水平的关系 总被引:5,自引:1,他引:4
对58名小学三年级学生在CAI(计算机辅助教学)下自学加法法现(规则学习)以及应用法则进行简便计算(技能学习)时学生学习控制水平(即选择学习内容和控制学习步调的适当性)与元认知监控水平(即对自己学习效果进行评价的准确性)之间的关系进行了探讨。结果表明,(1)在规则学习中,CAI学习控制水平与元认知监控水平之间不存在显著性相关,但在技能学习中,两者之间存在显著性相关;(2)规则学习的学习控制水平显著高于技能学习。(3)CAI学习控制水平和元认知监控水平两者与学生的学习成绩和时间两者不存在显著性相关。 相似文献
290.
Why Combine Logics? 总被引:1,自引:0,他引:1
Combining logics has become a rapidly expanding entreprise that is inspired mainly by concerns about modularity and the wish to join together tailor made logical tools into more powerful but still manageable ones. A natural question is whether it offers anything new over and above existing standard languages.By analysing a number of applications where combined logics arise, we argue that combined logics are a potentially valuable tool in applied logic, and that endorsements of standard languages often miss the point. Using the history of quantified modal logic as our main example, we also show that the use of combined structures and logics is a recurring theme in the analysis of existing logical systems. 相似文献