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861.
Márcio Ferrari Monica Maruno Adelino K. Nakano Pedro A. Rocha-Filho 《Journal of Dispersion Science and Technology》2013,34(9):1203-1208
Stable multiple emulsions containing andiroba oil and sunscreen have been formulated. These were prepared using the two-step procedure. The formulations were characterized and their stability over the time was evaluated by centrifugation, macroscopic, and microscopic analyses, and rheological measurements. The photoprotective efficacy of the O/W and O1/W/O2 containing or not andiroba oil was evaluated by in vivo sun protection factor determination according to the FDA method. The formulations exhibited good stability during 30 days after preparation at different temperatures. These presented pseudoplastic flow behaviour and thixotropy. The increase of in vivo SPF value was not observed when andiroba oil was incorporated into emulsions containing ethylhexyl methoxycinnamate. These multiple emulsions can be utilized as an interesting topical vehicle. 相似文献
862.
With the aim of developing new oligothiophene-based liquid crystals involving hydrogen bonding, new terthiophene derivatives containing an alkylamide group, N,N'-distearyl-2,2' : 5',2"-terthiophene-5,5"-dicarboxamide (DNC183T) and N,N'-dialkyl-5,5"-dibromo-2,2' : 5',2"-terthiophene-4,4"-dicarboxamides (DNCnDBr3T, n = 5, 8, 16, 18), were designed and synthesized, and their thermal behaviour examined. While DNC183T did not exhibit liquid crystallinity, DNCnDBr3T compounds with n = 8, 16, 18 were found to form smectic A phases. In addition to liquid crystal behaviour, crystal polymorphism was also observed for DNC16DBr3T. It is shown that both the position of the amido group and the alkyl chain length greatly affect liquid crystal phase formation. The absence of liquid crystallinity in the corresponding ester derivatives suggests that intermolecular hydrogen bonding also plays a role in the formation of liquid crystal phases in the DNCnDBr3T system. 相似文献
863.
864.
A grid drawing of a plane graph G is a drawing of G on the plane so that all vertices of G are put on plane grid points and all edges are drawn as straight line segments between their endpoints without any edge-intersection.
In this paper we give a very simple algorithm to find a grid drawing of any given 4-connected plane graph G with four or more vertices on the outer face. The algorithm takes time O(n) and yields a drawing in a rectangular grid of width \lceil n/2 \rceil - 1 and height \lfloor n/2\rfloor if G has n vertices. The algorithm is best possible in the sense that there are an infinite number of 4-connected plane graphs, any
grid drawings of which need rectangular grids of width \lceil n/2 \rceil - 1 and height \lfloor n/2\rfloor .
Received October 13, 1999, and in revised form July 18, 2000. Online publication February 26, 2001. 相似文献
865.
Takumi Kataishi Kotaro Kato Yoshiaki Makihara Yuichi Kitashima Sigeru Ohara Fumiaki Anzai Seiich Inokuma Hiroyuki Oku Masa‐aki Ubukata Yutaka Takahashi Taichi Nakano 《应用有机金属化学》2008,22(12):665-670
A combination catalyst of Pd(dba)2‐PPh3‐CuI‐LiCl or Pd(dba)2‐P(2‐furyl)3‐CuI‐LiCl effectively catalyzed the cross‐coupling of (Z)‐germyl(stannyl)ethenes with aryl halides, providing novel triethyl(2,2‐diarylethenyl)germanes in good to high yields. The reaction proceeds with retention of configuration. Cross‐coupling results in the formation of phenylene or phenyleneethynylene derivatives with terminal stereochemically defined vinylgermane unit(s). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
866.
Xiao Zhou Shin-ichi Nakano Takao Nishizeki 《Journal of Algorithms in Cognition, Informatics and Logic》1996,21(3):598-617
Many combinatorial problems can be efficiently solved for partialk-trees (graphs of treewidth bounded byk). The edge-coloring problem is one of the well-known combinatorial problems for which no efficient algorithms were previously known, except a polynomial-time algorithm of very high complexity. This paper gives a linear-time sequential algorithm and an optimal parallel algorithm which find an edge-coloring of a given partialk-tree with the minimum number of colors for fixedk. 相似文献
867.
We propose a method to integrate many games into one in order to analyse effectively a complex situation in which various types of games which are mutually interactive can be perceived. Applying the concept of integration of games into the theory of hypergames, we obtain the concepts of integration of hypergames and hypergames generated from a class of games. Simple examples of competitive situations are given and analysed to clarify the concepts. 相似文献
868.
David J. Benson Daniel K. Nakano 《Proceedings of the American Mathematical Society》2003,131(11):3395-3405
The nucleus was a concept first developed in the cohomology theory for finite groups. In this paper the authors investigate the nucleus for restricted Lie algebras. The nucleus is explicitly described for several important classes of Lie algebras.
869.
Eriko Ohshima Masae Kikuchi Masayasu Nagoshi Yasuo Fukuda Yasuhiko Syono 《Physica C: Superconductivity and its Applications》1995,250(3-4):320-324
The superconductivity of Tl0.5Pb0.5Sr2−xNdxCuO5−δ was observed for x ≥ 0.3, although the calculated Cu valence assuming Tl3+ and Pb4+ is slightly above or below 2.0. The binding energy of the Tl and Pb 4f core levels measured by XPS shifted to higher energy than those of Tl3+ and Pb4+ in the reference materials, showing that the Tl and Pb valences are lower than 3 + and 4 +, respectively. These observations strongly suggest that holes in the CuO2 sheet are created by charge transfer from the (Tl,Pb)O layer, similar to the double-layered Tl---Ba cuprates.
In contrast, the temperature variation of electrical conductivity of Tl0.5Pb0.5Sr2CuO5−δ changed from metallic to semiconducting with increasing oxygen deficiency, δ, and no superconductivity was observed through any control of δ. Although XPS measurement also suggested that Tl and Pb valences lowered with increasing oxygen deficiency, δ, the reason why the system did not show superconductivity can be understood by the depletion of oxygen from the CuO2 plane during deoxygenation. 相似文献
870.
Kuniko Nasu Tetsuya Taketsugu Takashi Nakano Umpei Nagashima Haruo Hosoya 《Theoretical chemistry accounts》1995,90(2-3):75-86
Summary By semi-empirical molecular orbital calculations stability of fullerenes was analyzed in terms of topological parameters, such as the number of special fragments and the number of three types of abutting bonds between two 5-membered rings. Relative stability was compared by AM1 method for all spectrally distinct closed-shell isomers of C36 and C40 fullerenes, and for some closed-shell isomers of C60 fullerene. Molecular geometries of these fullerenes were also optimized. Their relative stabilities were well explained by the instability of abutting bonds. 相似文献