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91.
The viscoelastic behavior of aqueous solutions of an ionic complex formed from poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) and rodlike mixed micelles of dimethyloleylamine oxide (DMOAO) and hexadecyltrimethylammonium chloride (CTAC) was investigated under oscillatory conditions. The DMOAO/CTAC mixed micelles exhibited high zero-shear viscosities (eta0) depending on the mole fraction of CTAC in the mixed micelle (Y) in the range 0Y0.25. The addition of the polyanion had no effect on the rheological behavior of the mixed micelles when Y<0.02 at an ionic strength (mu) of 0.2. However, when Y was increased to a certain level (Yc), eta0 decreased drastically; Yc depended on mu but not on the polymer concentration. These observations indicate the formation of an ionic complex between the polymer and micelle when YYc. The reciprocal of steady-state compliance (Je(-1)) began to decrease gradually at Y approximately Yc and then leveled off at Y>0.06. The relaxation time (tau) was found to be more strongly dependent on Y. Thus, the large decrease in eta0 was attributed mainly to a decrease in tau while the number density of junctions decreased only slightly. Therefore, it is concluded that polymer-micelle complex maintains a rodlike structure with some entanglements remaining at Y<0.12. 相似文献
92.
The complete solid solution of Fe(Sb1?xTex)2 with the marcasite structure was synthesized. Electrical and magnetic measurements showed that the substitution of tellurium for antimony in the diamagnetic semiconductor FeSb2 resulted in metallic and paramagnetic behavior in the composition range 0.1 ? x ? 0.3, but in 0.4 ? x ? 0.6 the products belonged to the arsenopyrite structure and were diamagnetic and semiconductive. The samples whose compositions were in the range 0.7 ? x ? 1.0 were semiconductors. Mössbauer effect measurements showed that the isomer shift did not change, but the quadrupole splitting changed significantly from 1.28 mm/sec for FeSb2 to 0.50 mm/sec for FeTe2 in this solid solution. 相似文献
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96.
Imanishi A Suzuki H Murakoshi K Nakato Y 《The journal of physical chemistry. B》2006,110(42):21050-21054
Dye-sensitized photocurrents at (100)-, (001)-, and (110)-cut TiO(2) rutile surfaces were increased by photoetching of TiO(2), but the increasing ratio strongly depended on the cut crystal faces and the illumination intensity for the photoetching. For the (110)-cut surface, the photocurrent increase was moderately large and in proportion to the increase in the surface area of TiO(2) induced by the photoetching, irrespective of the illumination intensity for the photoetching. On the other hand, the photocurrent increases for the (001)- and (100)-cut surfaces, especially that for the (001)-cut surface, were prominent and largely exceeded the increases in the surface area. The results were explained by taking into account the following factors: (1) The (001)- and (100)-cut surfaces were thermodynamically unstable in contrast to the (110)-cut surface and had thicker inactive surface layers (or higher densities of surface defects), produced by surface reconstruction during heat treatment of TiO(2) at 550 degrees C in a hydrogen atmosphere for getting n-type semiconductivity. (2) Photoetching not only increased the surface area through formation of nanoholes and grooves at the surface but also effectively removed the thin inactive surface layers (or surface defects). 相似文献
97.
Yusuke Hamabe Sungbong Jung Hikotaro Suzuki Naoto Koizumi Muneyoshi Yamada 《Journal of synchrotron radiation》2010,17(4):530-539
Ni species on the spent NiMo catalyst from ultra‐deep hydrodesulfurization of gas oil in a commercial plant were studied by Ni K‐edge EXAFS and TEM measurement without contact of the catalysts with air. The Ni–Mo coordination shell related to the Ni–Mo–S phase was observed in the spent catalyst by quasi in situ Ni K‐edge EXAFS measurement with a newly constructed high‐pressure chamber. The coordination number of this shell was almost identical to that obtained by in situ Ni K‐edge EXAFS measurement of the fresh catalyst sulfided at 1.1 MPa. On the other hand, large agglomerates of Ni3S2 were observed only in the spent catalyst by quasi in situ TEM/EDX measurement. MoS2‐like slabs were sintered slightly on the spent catalyst, where they were destacked to form monolayer slabs. These results suggest that the Ni–Mo–S phase is preserved on the spent catalyst and Ni3S2 agglomerates are formed by sintering of Ni3S2 species originally present on the fresh catalyst. 相似文献
98.
K. Koizumi M. Shoji Y. Kitagawa H. Ohoyama T. Kasai K. Yamaguchi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(1):193-197
The electronic structure and effective exchange integrals (J ab)
between two manganese (III) ions of porphyrin dimer (PPMn(III)–OH–Mn(III)PP)
were examined by using unrestricted hybrid DFT (UHDFT) methods. The
dependence of Jab on bond angle between two manganese (
Mn–OH–Mn) is
also calculated to elucidate orbital overlap effect for Jab value in the system. Natural orbital analysis is performed to explain the overlap effect in terms of the instability of the
π, σ and δ orbitals by using diradical character. 相似文献
99.
We introduce the k-strong Lefschetz property and the k-weak Lefschetz property for graded Artinian K-algebras, which are generalizations of the Lefschetz properties. The main results are: 1. Let I be an ideal of R = K[x 1, x 2,…, x n ] whose quotient ring R/I has the n-SLP. Suppose that all kth differences of the Hilbert function of R/I are quasi-symmetric. Then the generic initial ideal of I is the unique almost revlex ideal with the same Hilbert function as R/I. 2. We give a sharp upper bound on the graded Betti numbers of Artinian K-algebras with the k-WLP and a fixed Hilbert function. 相似文献
100.
Akihito Ebisu 《The Ramanujan Journal》2013,32(1):101-108
In a series of letters to D. Stanton, R.W. Gosper presented many strange evaluations of hypergeometric series. Recently, we rediscovered one of the strange hypergeometric identities appearing in (Gosper: A letter to D. Stanton, XEROX Palo Alto Research Center, 1977). In this paper, we prove this identity and derive its generalization using contiguity operators. 相似文献