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排序方式: 共有459条查询结果,搜索用时 15 毫秒
171.
172.
Michio Nishioka 《General Relativity and Gravitation》1983,15(6):591-593
Recently a geometrical gravitational theory based on the coefficients of connection with two gauge fields was proposed. The objective of the present paper is to show that the geometry based on the coefficients of connection with two gauge fields can be obtained by the successive operations of conformal and projective transformations on Riemannian metric. 相似文献
173.
174.
Shigeyoshi Watanabe Masashi Nishioka Kiyomi Okamoto Mitsuru Awano 《Physics letters. A》1979,74(6):441-442
The resistive superconducting transition of vanadium films is studied experimentally. The behavior of the resistance is well explained by fluctuation theory. In parallel magnetic fields the pair-breaking parameter increases with the increase of the strength of the magnetic field. 相似文献
175.
[reaction: see text] N-Alkyl-4-boronopyridinium salts are highly effective and reusable catalysts for the dehydrative amide condensation reaction between equimolar mixtures of carboxylic acids and amines. N-Alkylboronopyridinium salts are thermally stabilized in the order N-alkyl-2-boronopyridinium salt < N-alkyl-3-boronopyridinium salt < N-alkyl-4-boronopyridinium salt. Homogeneous catalysts, such as 4-borono-N-methylpyridinium iodide, are more effective in the presence of ionic liquid and can be recovered by extraction with ionic liquid. In contrast, heterogeneous catalysts, such as polystyrene-bound 4-boronopyridinium salts, are effective even in the absence of ionic liquid and can be recovered by filtration. 相似文献
176.
Toshikatsu Sata Yukio Mizutani 《Journal of polymer science. Part A, Polymer chemistry》1979,17(4):1199-1213
When a cation exchange membrane is immersed in a cationic polyelectrolyte solution to form a thin layer on the membrane surface, the membrane properties are changed: permselectivity between cations with different electric charges (a relative transport number of the calcium ions to sodium ions, P), current efficiency, and electric resistance of the membrane. Here the more compact the cationic polyelectrolyte layer, the more outstanding the change in permselectivity. To make a more compact layer, an electrodeposition method was adopted and a change in the permselectivity of the resultant cation exchange membrane was investigated. By using the electrodeposition method a strongly basic polyelectrolyte with a larger molecular weight effectively changed the permselectivity of the cation exchange membrane: the P value dropped to about 0.3 from about 2.5 of the P of the untreated membrane during electrodialysis of the sodium chloride—calcium chloride system, and an increase in the electric resistance of the membrane (i.e., organic fouling) due to a cationic surface-active agent could be prevented. It is noteworthy that by using the strongly basic polyelectrolyte with a larger molecular weight the electrodeposition method was effective, whereas the immersion method was ineffective. Furthermore, even with the electrodeposition method the cationic polyelectrolyte which had a relatively smaller molecular weight resulted in a more remarkable change in the P value than did that with a larger molecular weight. In the electrodeposition method the amount of polyelectrolyte cohered onto the membrane surface in creased with an increase in the concentration of the polyelectrolyte, and weakly basic polyelectrolyte, and weakly basic polyelectroyte (polyethyleneimine) was also available independent of its molecular weight. 相似文献
177.
Toshikatsu Koga Akihiro Hirashima Yuji Ueda Mutsuo Morita 《Theoretical chemistry accounts》1982,62(1):55-67
For a one-electron homonuclear diatomic system with arbitrary nuclear charge Z, the change in the nature of diatomic interaction and its density origin are quantitatively examined as a function of Z by the method of binding/antibinding analyses based on the Hellmann-Feynman theorem. In the Isg ground state, two energy extrema, potential barrier at a large internuclear distance and potential minimum at a smaller distance, appear for 1<Z<1.44. The binding part of the partitioned Hellmann-Feynman forces suffers little effect of Z, and these two extrema are attributed respectively to the increase in the nuclear repulsion and to the decrease in the antibinding part of the partitioned forces. In the antibonding 2pu state, a stable molecule is formed for Z<1. This appearance of the bonding nature is shown to have its origin in the binding part which is almost unchanged by the decrease of Z. 相似文献
178.
A Sawada S Yoshida O Kamiike M Morita M Nishioka T Inomata T Hamada S Ohara Y Ogawa T Maeda 《Radioisotopes》1986,35(9):473-477
During the past 3 years, we have performed 1525 studies of 67Ga scintigraphy and 38 cases of these showed suppressed liver uptake; 19 cases after chemotherapy, 13 cases with liver dysfunction and 6 cases with competitive blockade. Many cases in chemotherapy used cyclophosphamide and vincristine, and were performed 67Ga scan within 1 week after chemotherapy. In cases showed suppressed uptake by liver after chemotherapy, serum Fe was markedly increased and UIBC was markedly decreased (p less than 0.01). This suggested that serum Fe influenced suppressed uptake by liver more than carrier-protein, disturbed hepatic cells, and receptors. 相似文献
179.
E. Romera Toshikatsu Koga J. S. Dehesa 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,42(4):251-257
The present paper addresses the controversial problem on the nonmonotonic behavior of the spherically-averaged momentum density γ(p) observed previously for some ground-state atoms based on the Roothaan-Hartree-Fock (RHF) wave functions of Clementi and Roetti. Highly accurate RHF wave functions of Koga et al. are used to study the existence of extrema in the momentum density γ(p) of all the neutral atoms from hydrogen to xenon. Three groups of atoms are clearly identified according to the nonmonotonicity parameter μ, whose value is either equal to, larger, or smaller than unity. Additionally, it is found that the function p?α γ(p) is (i) monotonically decreasing from the origin for α ≥ 0.75, (ii) convex for α ≥ 1.35, and (iii) logarithmically convex for α ≥ 3.64 for all the neutral atoms with nuclear charges Z = 1–54. Finally, these monotonicity properties are applied to derive simple yet general inequalities which involve three momentum moments 〈p t≥. These inequalities not only generalize similar inequalities reported so far but also allow us to correlate some fundamental atomic quantities, such as the electron-electron repulsion energy and the peak height of Compton profile, in a simple manner. 相似文献
180.
Michael S. Hansen Hidetoshi Nishioka 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,28(1):73-80
Hartree-Fock calculations are done for finite number of valence electrons (8, 20, 40, and 58) in a positively charged uniform background (jellium) with the density of bulk sodium. Differences and similarities with the results of Kohn-Sham local-density calculations are discussed. State-dependence and suppression of the wave functions are the two important effects coming from the nonlocality of the Hartree-Fock potential. These two effects, however, cancel in the density profile of electrons. The Kohn-Sham calculations consequently produce similar density profiles as in the Hartree-Fock calculations. The dipole polarizability is also calculated for 8-mers. The calculated value is still smaller than the measured one and is not an improvement of the insufficient Kohn-Sham result.deceased 相似文献