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41.
An approach to analysis of pigment release from microcapsules with size distribution 总被引:2,自引:0,他引:2
Takao Yamamoto Toshiaki Dobashi Miho Kimura Chih Pong Chang 《Colloids and surfaces. B, Biointerfaces》2002,25(4):305-311
We have studied the release curve for microcapsules with size distribution. On the basis of an analogy to the relaxation phenomena with multiple characteristic times, we propose a stretched exponential release curve for the system with size distribution and relate the release curve to the size distribution function of the microcapsule. This method was successfully applied to the transfer of azo-pigments from inner medium of dioctyl phthalate to dispersing medium of methanol through poly(ureaurethane) microcapsule membrane. 相似文献
42.
Mugishima T Tsuda M Kasai Y Ishiyama H Fukushi E Kawabata J Watanabe M Akao K Kobayashi J 《The Journal of organic chemistry》2005,70(23):9430-9435
[Structure: see text]. Citrinadin A (2) is a pentacyclic indolinone alkaloid isolated from the cultured broth of a fungus, Penicillium citrinum, which was separated from a marine red alga. The absolute stereochemistry of the pentacyclic core in 2 and its new congener, citrinadin B (1), was elucidated by analysis of the ROESY spectrum for the chlorohydrin derivative (3) of 1 as well as comparison of the electronic circular dichroism (ECD) spectra for 1 and 2 with those of known spirooxiindole alkaloids. On the other hand, the absolute configuration at C-21 bearing an epoxide ring was assigned as S by comparison of the vibrational circular dichroism (VCD) spectra of 1 with those of model compounds 2S- and 2R-2,3-epoxy-3,3-dimethyl-1-phenylpropan-1-one (4a and 4b, respectively). 相似文献
43.
To provide theoretical insight into the structures and properties of Sc3N@C80, which has been isolated in high yield and purity as a new stable endohedral metallofullerene, density functional calculations are carried out for the Sc3?nLanN@C80 (n=0–3) series. Because of electron transfer from Sc3N to C80, the electronic structure of Sc3N@C80 is formally described as (Sc3N)6+C$_{80}^{6-}$. The encapsulated Sc3N cluster takes a planar structure with long Sc–Sc distances and is highly stabilized inside the Ih cage of C80, which rotates rapidly. As the number of La atoms increases, the Sc3?nLanN cluster is forced to maintain a pyramidal structure in Sc3?nLanN@C80. In addition, the C80 cage takes an open‐shell electronic structure due to an increase in the number of electrons transferring from Sc3?nLanN. These make the endohedral structure less stable and more reactive. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1353–1358, 2001 相似文献
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Complexes of the type (n-C
n
H2n
+1NH3)2SnX6 (0n 4 and X=Cl or Br) have been investigated with a variety of physico-chemical techniques. The structural phase transitions were found in some of these complexes. The temperature dependence of the Mössbauer spectral absorption area for (C2H5NH3)2SnCl6 and (C2H5NH3)2SnBr6 changed sharply at phase transition temperatures. The temperature dependences for (n-C4H9NH3)2SnCl6 and (n-C4H9NH3)2SnBr6 decreased gradually with an increase in temperature. The correlation between the temperature dependence of the spectral absorption area and the motion of n-C
n
H2n+1NH3
+ ions is discussed. 相似文献
46.
Mao Guangjun Li Zhuxia Zhuo Yizhong Han Yinlu Yu Ziqiang M. Sano 《Zeitschrift für Physik A Hadrons and Nuclei》1994,347(3):173-179
The collision term has been deduced based on the effective Lagrangian in addition to the mean-field. We propose the momentum- and density-dependent coupling strengths for scalar and vector fields. The saturation properties of nuclear matter, the experimental data of the energy-dependent optical potential and the mean free path in the nuclei can be reproduced simultaneously. The in-mediumn–n cross section has also been calculated for different densities and energies, our results are consistent with Dirac-Brueckner-Hartree-Fock calculations.Supported by National Natural Science Foundation of China 相似文献
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