全文获取类型
收费全文 | 530篇 |
免费 | 33篇 |
出版年
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 21篇 |
2020年 | 26篇 |
2019年 | 25篇 |
2018年 | 36篇 |
2017年 | 31篇 |
2016年 | 40篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 42篇 |
2012年 | 18篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 5篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 8篇 |
1969年 | 10篇 |
1968年 | 6篇 |
1967年 | 5篇 |
1964年 | 4篇 |
1961年 | 5篇 |
1960年 | 4篇 |
1958年 | 12篇 |
1955年 | 6篇 |
1953年 | 6篇 |
排序方式: 共有563条查询结果,搜索用时 15 毫秒
101.
Sorokowski P 《Perceptual and motor skills》2008,106(3):737-744
An experimental study was undertaken to assess the phenomenon of male preference for blondes. In the first study, 360 Polish men ages 18 to 46 years were asked to assess the attractiveness of the presented stimuli using a 9-point scale. Stimuli were 9 different pictures of the same women whose ages (about 20, 30, and 40 years old) and hair colors (blonde, brown, and brunette) were manipulated. Pictures of blonde-haired women were generally rated as younger than the others. The attractiveness ratings of female faces changed with age and hair color. Still, only the 30-yr.-old woman with blonde hair was rated as significantly more attractive than those with brown or brunette hair. In a second study (the analysis of 500 Internet advertisements) mature women dyed their hair blonde more frequently. These results are analyzed with regard to the evolutionarily formed male preference for younger females. 相似文献
102.
Iwanowski PS 《Science and engineering ethics》2007,13(3):333-336
Setting reasonable and fair limits of emergency research acceptability in ethical norms and legal regulations must still adhere
to the premise of well-being of the research subject over the interests of science and society. Informed consent of emergency
patients to be enrolled in clinical trials is a particularly difficult issue due to impaired competencies of patients’ to
give consent, short diagnostic and therapeutic windows, as well as the requirement to provide detailed information to participants.
Whereas the Declaration of Helsinki, Good Clinical Practice guideline, Additional Protocol to the European Bioethical Convention
concerning Biomedical Research, as well as appropriate regulations adopted by the Food and Drugs Administration (USA) allow
waivers from participants’ consent or deferred consent for emergency research, the regulations of most European Community
countries following the Clinical Trial Directive (2001/20/EC) do not give space for a deferred consent or a waiver from consent
for adult patients (unless surrogate consent is made use of). This is even more confusing in case of Poland, where conflicting
regulations on a waiver from a participant’s consent in emergency research exist and the regulations on surrogate consent
of temporarily incompetent adults are too restrictive and authorise only the guardianship courts to consent, which is not
or hardly feasible in practice. European Community regulations need to be amended to allow for implementation of the deferred
consent or waivers from consent for emergency research in order to enable ethical research of emergency conditions that should
become a large part of important public health priorities. 相似文献
103.
In the current paper we consider theories with vocabulary containing a number of binary and unary relation symbols. Binary relation symbols represent labeled edges of a graph and unary relations represent unique annotations of the graph’s nodes. Such theories, which we call annotation theories, can be used in many applications, including the formalization of argumentation, approximate reasoning, semantics of logic programs, graph coloring, etc. We address a number of problems related to annotation theories over finite models, including satisfiability, querying problem, specification of preferred models and model checking problem. We show that most of considered problems are NPTime- or co-NPTime-complete. In order to reduce the complexity for particular theories, we use second-order quantifier elimination. To our best knowledge none of existing methods works in the case of annotation theories. We then provide a new second-order quantifier elimination method for stratified theories, which is successful in the considered cases. The new result subsumes many other results, including those of [2, 28, 21]. 相似文献
104.
Jaskowski P 《Journal of experimental psychology. Human perception and performance》2007,33(2):456-468
Masked stimuli (primes) can affect the preparation of a motor response to subsequently presented target. In numerous studies, it has been shown that the compatibility effect is biphasic as it develops over time: positive (benefits for compatible trials and costs for incompatible trials) for short prime-target temporal distances and negative (benefits for incompatible trials and costs for compatible trials) for long ones. What triggers the 2nd phase is the matter of the current debate. According to the self-inhibition hypothesis, the motor response elicited by a prime is automatically followed by an inhibition phase. The object-updating and mask-triggered inhibition hypotheses assume that this phase is triggered by the mask, provided that it contains features calling for the alternative response. In the present study, the author shows that the compatibility effect is modulated on the temporal position of a nonmasking distractor presented after the prime and before the target. With a distractor possessing task-relevant features, the compatibility effect was found to be negative for short prime- distractor intervals and for moderate prime-target intervals. The consequences of these results for the 3 hypotheses are discussed. 相似文献
105.
Journal of Happiness Studies - The article concentrates on regulatory focus (promotion and prevention) as a factor involved in the relationships between materialism and well-being alongside two... 相似文献
106.
107.
108.
Jarosław Achinger 《Studia Logica》1986,45(3):281-292
In the paper [2] the following theorem is shown: Theorem (Th. 3,5, [2]), If α=0 or δ=∞ or α?δ, then a closure space X is an absolute extensor for the category of 〈α, δ〉 -closure spaces iff a contraction of X is the closure space of all 〈α, δ〉-filters in an 〈α, δ〉-semidistributive lattice. In the case when α=ω and δ=∞, this theorem becomes Scott's theorem: Theorem ([7]). A topological space X is an absolute extensor for the category of all topological spaces iff a contraction of X is a topological space of “Scott's open sets” in a continuous lattice. On the other hand, when α=0 and δ=ω, this theorem becomes Jankowski's theorem: Theorem ([4]). A closure space X is an absolute extensor for the category of all closure spaces satisfying the compactness theorem iff a contraction of X is a closure space of all filters in a complete Heyting lattice. But for separate cases of α and δ, the Theorem 3.5 from [2] is proved using essentialy different methods. In this paper it is shown that this theorem can be proved using, for retraction, one uniform formula. Namely it is proved that if α= 0 or δ= ∞ or α ? δ and \(F_{\alpha ,\delta } \left( L \right) \subseteq B_{\alpha ,\delta }^\mathfrak{n} \) and if L is an 〈α, δ〉-semidistributive lattice, then the function $$r:{\text{ }}B_{\alpha ,\delta }^\mathfrak{n} \to F_{\alpha ,\delta } \left( L \right)$$ such that for x ε ? ( \(\mathfrak{n}\) ): (*) $$r\left( x \right) = inf_L \left\{ {l \in L|\left( {\forall A \subseteq L} \right)x \in C\left( A \right) \Rightarrow l \in C\left( A \right)} \right\}$$ defines retraction, where C is a proper closure operator for \(B_{\alpha ,\delta }^\mathfrak{n} \) . It is also proved that the formula (*) defines retraction for all 〈α, δ〉, whenever L is an 〈α, δ〉 -pseudodistributive lattice. Moreover it is proved that when α=ω and δ=∞, the formula (*) defines identical retraction to the formula given in [7], and when α = 0 and δ=ω, the formula (*) defines identical retraction to the formula given in [4]. 相似文献
109.
Małgorzata Porębska 《Studia Logica》1986,45(1):35-38
Important positive as well as negative results on interpolation property in fragments of the intuitionistic propositional logic (INT) were obtained by J. I. Zucker in [6]. He proved that the interpolation theorem holds in purely implicational fragment of INT. He also gave an example of a fragment of INT for which interpolation fails. This fragment is determined by the constant falsum (), well known connectives: implication () and conjunction (), and by a ternary connective defined as follows: (p, q, r)=
df
(pq)(pr).Extending this result of J. I. Zucker, G. R. Renardel de Lavalette proved in [5] that there are continuously many fragments of INT without the interpolation property.This paper is meant to continue the research mentioned above. To be more precise, its aim is to answer questions concerning interpolation and amalgamation properties in varieties of equivalential algebras, particularly in the variety determined by the purely equivalential fragment of INT. 相似文献
110.
Bronisław Tembrowski 《Studia Logica》1986,45(2):167-179
The first part of the paper deals with some subclasses of B-algebras and their applications to the semantics of SCI
B
, the Boolean strengthening of the sentential calculus with identity (SCI). In the second part a generalization of the McKinsey-Tarski construction of well-connected topological Boolean, algebras to the class of B-algebras is given. 相似文献