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981.
982.
This paper is contributed to the combinatorial properties of the periodic kneading words of antisymmetric cubic maps defined on a interval. The least words of given lengths, the adjacency relations on the words of given lengths and the parity-alternative property in some sets of such words are established. 相似文献
983.
Xue Sen FAN Yan Zhen LI Xin Ying ZHANG Xue Yuan HU Jian Ji WANG School of Chemical Environmental Sciences Henan Key Laboratory for Environmental Pollution Control Henan Normal University Xinxiang 《中国化学快报》2005,(7)
Room temperature ionic liquids with low melting point (<100℃) salts represent a new class of non-molecular, ionic solvents. Especially those based on the 1-N-alkyl-3- methylimidazolium cations, have shown great promise as an attractive alternative to conventional solvents for catalytic reactions1. On the other hand, FeCl3·6H2O was considered to be an environmentally benign Lewis acid and has been used successfully in several kinds of organic reactions2. Recently we have focused our interes… 相似文献
984.
Kang Ji Wang 《Applied Surface Science》2008,254(7):1981-1985
Deposition of HfO2 films on n-type 4H-SiC substrates by sol-gel spin-on coating technique has been performed and the physical and electrical characteristics of this film as a function of annealing temperature (550, 750, and 850 °C for 30 min) have been reported. The physical properties of the film have been characterized using a Filmetrics and X-ray diffractometer, while conduction atomic force microscope and semiconductor parameter analyzer were used for electrical characterization. Phase transformation has been revealed in the oxide as the annealing temperature changed. Refractive index, relative density, dielectric constant of the film, and oxide-semiconductor interface trap density have been extracted and related to the leakage current through the oxide. It has been recorded that, oxide annealed at 700 °C has demonstrated the lowest leakage current and the best oxide reliability. The reasons of these observations have been explained. 相似文献
986.
987.
A simplicial complex
K\mathsf{K}
is called d
-representable if it is the nerve of a collection of convex sets in ℝ
d
;
K\mathsf{K}
is d
-collapsible if it can be reduced to an empty complex by repeatedly removing a face of dimension at most d−1 that is contained in a unique maximal face; and
K\mathsf{K}
is d
-Leray if every induced subcomplex of
K\mathsf{K}
has vanishing homology of dimension d and larger.
It is known that d-representable implies d-collapsible implies d-Leray, and no two of these notions coincide for d≥2. The famous Helly theorem and other important results in discrete geometry can be regarded as results about d-representable complexes, and in many of these results, “d-representable” in the assumption can be replaced by “d-collapsible” or even “d-Leray.” 相似文献
988.
Plasma Chemistry and Plasma Processing - 相似文献
989.
990.