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101.
S. M. Jeong S.-B. Park S.-S. Hong C.-S. Seo S.-W. Park 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(2):349-356
Summary The
electrolytic reduction of U3O8 powder was carried out
using LiCl-Li2O molten salt in a 20-kg U3O8
batch cell to verify the feasibility of the process. As the current passes the
cell, the decomposition of Li2O and the reduction of U3O8
occur simultaneously in a cathode assembly and oxygen gas evolvs at the anode.
The results from a 20-kg U3O8 scale cell were compared
with data obtained from a bench scale cell. The results suggest a successful
demonstration of this process, exhibiting a reduction conversion of U3O8
of more than 99% in a batch.</p>
</p> 相似文献
102.
The electrophoretic motion of two charged colloidal spheres with very thin electrical double layers in a constant applied electric field along their line of centers is considered. The particles may differ in radius and in zeta potential at the surface. The electrostatic and hydrodynamic governing equations are solved in the quasi-steady situation using bipolar coordinates and the electrophoretic velocities of particles are calculated for various cases. The interaction effect between particles can be very significant when the distance between particle surfaces gets close to zero. The particle with smaller zeta potential is speeded up by the motion of the other, which is retarded at the same time by the motion of the former one, if the two spheres have unequal zeta potentials of the same electrical sign. For two particles of different signs in zeta potential, motions of both are hindered by each other. The influence of the interaction between particles in general is stronger on the smaller one than on the larger one. For the special case of two electrophoretic spheres with identical zeta potentials, there is no particle interaction for all particle sizes and separations. 相似文献
103.
Won Young Jung Seung Hee Baek Seong Soo Park Gun-Dae Lee Euh Duck Jeong Hyun Gyu Kim Seong-Soo Hong 《Reaction Kinetics and Catalysis Letters》2007,91(2):233-240
The nanosized titania and TiO2/SiO2 particles were prepared by the microwave-hydrothermal method. The effect of physical properties TTIP/TEOS ratio and calcination
temperature has been investigated. The major phase of the pure TiO2 particle is of the anatase structure, and a rutile peak was observed above 800°C. In TiO2/SiO2 particles, however, no significant rutile phase was observed, although the calcination temperature was 900°C. No peaks for
the silica crystal phase were observed at either silica/titania ratio. The crystallite size of TiO2/SiO2 particles decreases as compared to pure TiO2 at high calcination temperatures. The TiO2/SiO2 particles show higher activity on the photocatalytic decomposition of orange II as compared to pure TiO2 particles. 相似文献
104.
New (diamine)platinum(II) complexes A(2)PtX(2) (A(2) = trans-(+/-)-1,2-diaminocyclohexane (DACH), tetrahydro-4H-pyran-4,4-diylbis(methylamine)(THPDMA); X(2) = 9-fluorenylidenemalonate(FM), benzhydrylidenemalonate(BHM)) have been synthesized and characterized by means of multinuclear NMR spectroscopy and X-ray analysis. (DACH)Pt(FM) crystallizes in space group P2(1)/c with eight formula units in a cell of dimensions a = 20.071(7) ?, b = 12.717(3) ?, c = 24.512(6) ?, beta = 103.25(2) degrees, and V = 6090(3) ?.(3) (DACH)Pt(BHM) crystallizes in space group P&onemacr; with four molecular units in a cell of dimensions a = 11.048(3) ?, b = 13.639(3) ?, c = 14.043(6) ?, alpha = 90.17(3) degrees, beta = 91.31(4) degrees, gamma = 89.98(3) degrees, and V = 2116(1) ?(3). The platinum atom in both complexes adopts a typical square planar arrangement with two nitrogen atoms in cis position. The 9-fluorenylidene and benzhydrylidene groups of the amine ligands chelated to platinum are strikingly bent up by 88.8(3) and 80.8(2) degrees, respectively, from the platinum square plane in the solid state. Variable temperature (1)H NMR spectra of the title complexes in dimethyl sulfoxide solution reveals that the amine proton resonances are sensitive to the fluxional motion of the remote arylidene groups, and suggests that interconversion occurs between two "bent-up" and "bent-down" forms. The prominent difference between the FM and BHM complexes is observed in solution, due to the presence or absence of the angle constraint of the anionic coligands. 相似文献
105.
Hwang S Lee KH Ryu GH Jang YH Lee SB Lee WY Hong JI Chung DS 《The Journal of organic chemistry》2000,65(2):536-542
The binding affinity and selectivity of a new ionophore, [1(8)]starand (1), toward alkali metal cations in methanol were examined through NMR titration experiments and free energy perturbation (FEP) and molecular dynamics simulations. The preference was determined to be K(+) > Rb(+) > Cs(+) > Na(+) > Li(+) in both FEP simulations and NMR experiments. The FEP simulation results were able to predict the relative binding free energies with errors less than 0.13 kcal/mol, except for the case between Li(+) and Na(+). The cation selectivity was rationalized by analyzing the radial distribution functions of the M-O and M-C distances of free metal cations in methanol and those of metal-ionophore complexes in methanol. 相似文献
106.
Oh JY Moon JH Lee YH Hyung SW Lee SW Kim MS 《Rapid communications in mass spectrometry : RCM》2005,19(10):1283-1288
Photodissociation (PD) tandem mass spectra have been obtained at 266 nm for the protonated molecules of a tryptic peptide, ASHLGLAR, and of its phenyl isothiocyanate and 4-sulfophenyl isothiocyanate derivatives, generated by matrix-assisted laser desorption/ionization. Derivatization with the aromatic chromophores greatly reduced the intensity of the laser required for efficient PD. Major fragment ions observed in the three spectra are quite similar. General features of the PD tandem mass spectra and their potential utility for analytical purposes are discussed. 相似文献
107.
Lee CS Kim KY Im JB Choi JW Kim HK Park JS Shin EY Kim SR Kim EG 《Experimental & molecular medicine》2004,36(6):582-587
p21-activated kinase (PAK)-interacting exchange factor (PIX) is known to be involved in regulation of Cdc42/Rac GTPases and PAK activity. PIX binds to the proline-rich region of PAK, and regulates biological events through activation of Cdc42/Rac GTPase. To further investigate the role of PIX we produced monoclonal antibodies (Mab) against bPIX. Three clones; N-C6 against N-terminal half and C-A3 and C-B7 against C- terminal half of bPIX were generated and characterized. N-C6 Mab detected bPIX as a major band in most cell lines. C-A3 Mab recognizes GIT-binding domain (GBD), but it does not interfere with GIT binding to bPIX. Using C-A3 Mab possible bPIX interaction with actin in PC12 cells was examined. bPIX Mab (C-A3) specifically precipitated actin of the PC12 cell lysates whereas actin Mab failed to immunoprecipitate bPIX. Co-sedimentation of PC12 cell lysates with the polymerized F-actin resulted in the recovery of most of bPIX in the cell lysates. These results suggest that bPIX may not interact with soluble actin but with polymerized F-actin and revealed that bPIX constitutes a functional complex with actin. These data indicate real usefulness of the bPIX Mab in the study of bPIX role(s) in regulation of actin cyoskeleton. 相似文献
108.
[reaction: see text] Unusual palladium-catalyzed arylative fragmentations of acyclic 3-allen-1-ols were observed. Oxidative addition of Pd(0) to aryl halides would form the arylpalladium halides, which added to the central carbon of allenes via carbopalladation to form the pi-allylpalladium intermediates. The pi-allylpalladium intermediates would be reductively eliminated via carbon-carbon cleavage to give the arylated dienes and the alpha-hydroxyalkylpalladium intermediates, which were further reductively eliminated to the corresponding aldehydes. 相似文献
109.
Moon Jeong Park Jongnam Park Taeghwan Hyeon Kookheon Char 《Journal of polymer science. Part A, Polymer chemistry》2006,44(24):3571-3579
We investigated the effect of hard additives, that is, magnetic nanoparticles (NPs) and metal NPs, on the ordered morphology of block copolymers by varying the NP concentration. To characterize the structural changes of a block copolymer associated with different NP loadings, small-angle X-ray scattering and transmission electron microscopy were performed. Monodisperse maghemite (γ-Fe2O3) NPs (7 nm in diameter) and silver (Ag) NPs (6 nm in diameter) with surfaces modified with oleic acids were synthesized, and a cylinder-forming poly(styrene-block-isoprene) diblock copolymer was used as a structure-directing matrix for the NPs. As the NP concentration increased, domains of NP aggregates were observed for both magnetic and metal NPs. In the case of mixtures of cylinder-forming poly(styrene-block-isoprene) and Ag NPs with weak particle–particle interactions, random aggregates of Ag NPs were observed, and the ordered morphology of the block copolymer lost its long-range order with an increase in the NP concentration. However, regular, latticelike aggregates obtained with γ-Fe2O3 NPs, because of the strong interparticle interactions, induced an intriguing morphological transformation from hexagonal cylinders to body-centered-cubic spheres via undulated cylinders, whereas the neat block copolymer did not show such a morphological transition over a wide range of temperatures. The interplay between magnetic NPs and the block copolymer was also tested with magnetic NPs of different sizes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3571–3579, 2006 相似文献
110.
Kwon M Jeong S Lee KH Park YK Yu J 《Journal of the American Chemical Society》2002,124(47):13996-13997
Our approach to multivalent peptide construction relies on tentacle peptides, also known as a multiple antigenic peptides, which contain two and four repeats of a selected peptide. In this communication, we report the results of preliminary studies aimed at (1) the selection of short peptides against the carbohydrate, sLeX, (2) the synthesis of tentacle dimers and tetramers of the selected peptides, and (3) the determination of affinities and specificities of the peptides to several related carbohydrates by using the surface plasmon resonance (SPR) and the equilibrium dialysis techniques. Binding affinity studies, as well as assays of in vitro binding of the peptides to a sLeX-specific cell line, have shown that the tetrameric peptides bind to the cell surface sugars. 相似文献