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91.
Eiji Nishibori Masaki Takata Makoto Sakata Hiroshi Tanaka Masaki Hasegawa Hisanori Shinohara 《Chemical physics letters》2000,330(5-6):497-502
An anomalous charge density distribution of La atom encapsulated in a C82 cage has been revealed for La@C82 by the maximum entropy method (MEM)/Rietveld analysis using synchrotron powder diffraction data. The obtained La atom charge density shows a feature almost like a bowl or a hemisphere, suggesting that the La atom has a giant motion (large amplitude motion) inside the C82 cage at room temperature. From the obtained MEM charge density, the main results are (1) the cage structure of La@C82 (I) has C2V symmetry; (2) La atom locates at an off-centered position adjacent to a six-membered ring of the carbon cage; (3) the nearest La–C distance is 2.55(8)
and (4) the amount of charge transfer from the La atom to the carbon cage is about 3.2 e, which corresponds to the nominal electronic structure, La3+@C823−. 相似文献
92.
S. Sakata F. Ashida T. Kojima 《International Journal of Solids and Structures》2008,45(25-26):6553-6565
This paper describes a methodology for evaluation of influence of microscopic uncertainty in material properties and geometry of a microstructure on a homogenized macroscopic elastic property of an inhomogeneous material. For the analysis of the stochastic characteristics of a homogenized elastic property, the first-order perturbation method is used. In order to analyze the influence of microscopic geometrical uncertainty, the perturbation-based equivalent inclusion method is formulated. In this paper, an analytical form of the perturbation term using the equivalent inclusion method is provided.As a numerical example, macroscopic stochastic characteristics such as an expected value or variance of the homogenized elastic tensor of a unidirectional fiber reinforced plastic, which is caused by microscopic uncertainty in material properties or geometry of a microstructure, are estimated with computing the first order perturbation term of the homogenized elastic tensor. Compared the results of the proposed method with the results of the Monte-Carlo simulation, validity, effectiveness and a limitation of the perturbation-based homogenization method is investigated. 相似文献
93.
Activation by cathepsin G of latent gelatinase secreted from rat polymorphonuclear leukocytes 总被引:1,自引:0,他引:1
Rat polymorphonuclear leukocytes secrete a latent gelatinase with a molecular weight of about 96 kilodaltons (kDa). Activation of the latent 96-kDa gelatinase by cathepsin G was studied by using sodium dodecyl sulfate-substrate polyacrylamide gel electrophoresis. Cathepsin G activated the 96-kDa gelatinase by converting it to two lower molecular-weight species of 76 and 61 kDa, which were slightly different from the gelatinase species generated by treatment with 4-aminophenylmercuric acetate, an activator of latent gelatinase. 相似文献
94.
Minoru Funakubo Sadahisa Sakata 《Journal of Mathematical Analysis and Applications》2006,324(2):1036-1049
In this paper, we give a necessary and sufficient condition on the uniform asymptotic stability of the zero solution of a linear integro-differential equation of Volterra type where the ordinary part is ax(t). We put emphasis on the case a>0. The proofs of our results are carried out by using the root analysis of the characteristic equation. In Section 5 we give some conjectures. 相似文献
95.
Toshihide Kawashima Katsutoshi Yoshida Yasuo Tohda Masahiro Ariga Yutaka Mori Yoshiteru Sakata Soichi Misumi 《Tetrahedron letters》1984,25(15):1585-1586
A novel derivative of methylviologen, prepared by transannular reaction of [2.2] (3,5) pyridinophane, shows large bathochromic shift in the electronic spectrum and nearly equal redox potential compared with methylviologen. 相似文献
96.
97.
H. Sakata 《Optical and Quantum Electronics》1996,28(9):1129-1138
Wavelength-selective photodetectors employing vertically grating-coupled optical filters are designed with a straightforward waveguide structure in order to improve wavelength selectivity. By arranging stacked layer formation for the absorption layer, we can greatly reduce the cross-talk absorption from unselected light down to -40 dB while keeping high selective absorption efficiency. Such photodetectors with a weighted coupling-assisted grating achieve an excellent bandpass filter-detector response which shows a steep transition between stopband and passband. 相似文献
98.
We have carried out the field emission experiments to measure the temperature dependence of the work function of Pt field emitter and found that the work function steeply decreases more than 2 eV by annealing at relatively low temperature above about 500 K in ultra high vacuum. The maximum reduction of the work function was 2.59 eV. The reduced work function was restored the original value of Pt clean surface by applying high voltage of only 20% of Pt evaporation field. The experimental results are tentatively interpreted in terms of the formation of complex cyanides on the emitter shank during the electrochemical etching in KCN solution and the surface diffusion of potassium atoms formed by the thermal decomposition of the complex cyanides to the emitter cap. 相似文献
99.
M. Sakata M. Nakayama T. Fujisaki S. Morimura M. Kunitake C. Hirayama 《Chromatographia》2005,62(9-10):465-470
This paper describes a method for selective removal of DNA from various cellular products using columns packed with cross-linked poly(ethyleneimine) (PEI) beads or cross-linked N,N-dimethylaminopropylacrylamide (DMAPAA) beads. Each bead type showed a high DNA-adsorbing activity under experimental conditions of pH 5.0–9.0 and ionic strength of μ = 0.05–0.4. When γ-globulin was present in solution with DNA under physiological conditions (pH 7.2, μ = 0.17), DNA-removing activity of PEI columns was unsatisfactory because both the DNA and the γ-globulin were adsorbed onto the column. In contrast, DMAPAA columns allowed removal of DNA from various protein solutions contaminated with DNA. DNA concentration in each treated protein solution was below 10 ng mL?1, and high recovery of proteins was obtained. 相似文献
100.
Sakata M Nakayama M Kamada T Kunitake M Mizokami H Hirayama C 《Journal of chromatography. A》2004,1030(1-2):117-122
To remove nucleic acids from cellular products as drugs, cross-linked N,N-dimethylaminopropylacrylamide (DMP) particles with cationic functional groups were prepared. The particle's hydrophobicity and its anion-exchange capacity were easily adjusted by changing the cross-linking agent and the DMP ratio in the cross-linking, respectively. When divinylbenzene (DVB) was used as a cross-linking agent and the DMP ratio (in the cross-linking) was adjusted to 90 mol%, the particles (DMP-DVB, 90:10) showed the highest adsorbing activity of DNA (salmon spermary). Its adsorption capacity was 54 mg/ml adsorbent. On the other hand, the adsorption of bovine serum albumin (BSA) to the DMP-DVB extremely increased with increase in the adsorbent's pore size (molecular mass exclusions; M(lim)) from 2 x 10(3) to 1 x 10(4), but decreased with increase in the buffer's ionic strength (mu) to 0.2 or stronger. As a result, when the DMP-DVB (80:20) with M(lim) 2 x 10(3) was used as adsorbent by a column method at pH, 7.2 and mu = 0.17, it only selectively removed DNA from a BSA solution, including 1000 microg/ml of BSA and 10 microg/ml of DNA. The adsorbent decreased the concentration of DNA in the BSA solution to < 10 ng/ml, and the recovery rate of BSA was more 98%. 相似文献