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101.
On the basis of polarization studies, grain boundary corrosion rate measurements and metallographic results, a corrosion mechanism is advanced which allows for a full explanation of the corrosion behaviour of zin—aluminium alloys. Explanations are provided for the well-known detrimental effects of lead additions, and the beneficial effects of copper and magnesium additions to these alloys. 相似文献
102.
103.
104.
Maria C. F. Ferreira Delia Kesner Laurence Puel 《Applicable Algebra in Engineering, Communication and Computing》1999,9(4):333-371
This paper studies preservation of β-strong normalization by two different confluent λ-calculi with explicit substitutions
defined in [96]; the particularity of these calculi, called λ
d
and λ
dn
respectively, is that both have a (weak) composition operator for substitutions. We apply an abstract simulation technique
to reduce preservation of β-strong normalization of λ
d
and λ
dn
to that of another calculus, called λ
f
having no composition operator. Then, preservation of β-strong normalization of λ
f
is shown using the same technique as in [2]. As a consequence, λ
d
and λ
dn
become the first λ-calculi with explicit substitutions having (weak) composition and preserving β-strong normalization. As
an aside, we also show how to apply our technique to reduce preservation of β-strong normalization of the calculus λ
v
in [20] to that of λ
f
.
Received: August 19, 1997; revised version: November 13, 1998 相似文献
106.
107.
Takagi S Frukhtbeyn S Chow LC Sugawara A Fujikawa K Ogata H Hayashi M Ogiso B 《Journal of research of the National Institute of Standards and Technology》2010,115(4):267-276
This study reports for the first time in vitro and in vivo properties of fluorapatite (FA)-forming calcium phosphate cements (CPCs). The experimental cements contained from (0 to 3.1) mass % of F, corresponding to presence of FA at levels of approximately (0 to 87) mass %. The crystallinity of the apatitic cement product increased greatly with the FA content. When implanted subcutaneously in rats, the in vivo resorption rate decreased significantly with increasing FA content. The cement with the highest FA content was not resorbed in soft tissue, making it the first known biocompatible and bioinert CPC. These bioinert CPCs might be useful for applications where slow or no resorption of the implant is required to achieve the desired clinical outcome. 相似文献
108.
109.
110.
A central question in psycholinguistic research is how listeners isolate words from connected speech despite the paucity of clear word-boundary cues in the signal. A large body of empirical evidence indicates that word segmentation is promoted by both lexical (knowledge-derived) and sublexical (signal-derived) cues. However, an account of how these cues operate in combination or in conflict is lacking. The present study fills this gap by assessing speech segmentation when cues are systematically pitted against each other. The results demonstrate that listeners do not assign the same power to all segmentation cues; rather, cues are hierarchically integrated, with descending weights allocated to lexical, segmental, and prosodic cues. Lower level cues drive segmentation when the interpretive conditions are altered by a lack of contextual and lexical information or by white noise. Taken together, the results call for an integrated, hierarchical, and signal-contingent approach to speech segmentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献