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981.
T. Yamaguchi 《Journal of Physics and Chemistry of Solids》1974,35(4):479-500
Mechanisms of the temperature-induced spin-reorientation in rare-earth orthochromites (and orthoferrites) are examined. It is concluded that the anisotropic parts of the magnetic interactions between Cr3+ (or Fe3+) and rare-earth ions, the antisymmetric and the anisotropic-symmetric exchange interactions, are generally responsible for both the rotational and the abrupt types of the spin-reorientations. These anisotropic exchange interactions produce an effective field for the Cr3+ up-spins in the direction perpendicular to that of these spins and an effective field for the Cr3+ down-spins in the direction opposite to the above. These effective fields favor rotation of the Cr3+ spins, retaining their original antiferromagnetic configuration. Thus, as the temperature is lowered, this effective field increases due to the increase of the rare-earth magnetization, and when the interaction energy of the Cr3+ spins with these effective fields exceeds the anisotropy energy of the Cr3+ ion, spin-reorientation. takes place. At the beginning and ending of the spin-reorientation a second-order phase-transition occurs. The first-order nature of the abrupt spin-reorientation is stressed. Anisotropic exchange interactions between Cr3+ and rare-earth ions also play an important role in inducing the abrupt spin-reorientation. 相似文献
982.
983.
The microwave spectrum of cis-thiopropionic acid in the ground vibrational state has been observed in the frequency range between 10 and 35 GHz. The rotational and centrifugal distortion constants, and the dipole moments have been determined. The conformation of this molecule is discussed on the basis of the observed results. 相似文献
984.
N. Nishida M. Yamaguchi T. Furubayashi K. Morigaki H. Ishimoto K. Ono 《Solid State Communications》1982,44(2):305-309
Electrical conductivity of metallic amorphous Si1?xAux films was measured down to 10 mK. Superconducting transition was observed in a certain range of Au content. In the normal state, the temperature variation of electrical conductivity showed √T-dependence at higher temperatures and ln T-dependence at lower temperatures. This crossover is interpreted as being due to a change of sample dimensionality. 相似文献
985.
Masaru Yamaguchi 《Journal of Mathematical Analysis and Applications》2005,303(2):643-660
We shall be concerned with the behavior of a suspended string to which a time-periodic or time-quasiperiodic outer force works. We shall deal with IBVP for a linear equation of a suspended string, and show that every solution is almost periodic in time. The result shall be shown under the assumptions that the basic periods (the period), the length of the string and the zero points of the Bessel functions of the first kind satisfy the Diophantine type number-theoretic condition and the forcing term is smooth. In order to deal with the problems we shall develop some well-matched function spaces and solve the eigenvalue problem for suspended string operator. 相似文献
986.
987.
Kazuo Yamaguchi Gabriel Rokicki Wataru Kawanobe Seiichi Nakahama Noboru Yamazaki 《Journal of polymer science. Part A, Polymer chemistry》1982,20(5):1185-1191
Direct polycondensation of various dicarboxylic acids and diamines was effected under mild conditions by using an enol phosphite, diethyl 1-methyl-3-oxo-1-butenyl phosphite (I), in the presence of imidazole. To check the activity of the enol phosphite and various organic bases in an amidation reaction, the model reaction of acetic acid and aniline was carried out, and the yield of acetanilide was estimated by means of gas chromatography. Among organic bases, imidazole was the best in terms of yield of acetanilide. Polycondensation performed by varying solvents, temperature, and amount of imidazole resulted in high yields of polyamides with inherent viscosities of 0.1-0.25. 相似文献
988.
Six varieties of liquid-crystalline side-chain polymers, poly (cholesteryl ω-(methacryloyloxy)alkanoates) (p-ChMO-n, n = 1,2,3,4,5,7, the carbon number of the alkyl chain), were studied by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). On and after the first cooling run from the isotropic state, these polymethacrylates gave the same smectic phase. However, on the first heating run for virgin samples, unique phenomena were observed, similar to those frequently observed on the first heating run for thermotropic liquidcrystalline polymers. The thermal properties of the first heating run for these six polymers showed different tendencies between pChMO-n (n-1-3) and pChMO-n (4-7). Although the DSC curve of pChMO-n (n = 4, 5 and 7) exhibited the melting and clearing points on the first heating run, the DSC curve of pChMO-n (n = 1,2 and 3) exhibited an exothermal peak between the glass transition and the clearing point on the first heating run. This difference, probably due to the difference in the spacer length of these polymers, was investigated quantitatively by small-angle X-ray scattering by which the micro-change of the packing structure of the side chains of the polymers was traced. 相似文献
989.
S. Yamaguchi 《Fresenius' Journal of Analytical Chemistry》1971,256(3):200
990.
K. Albrecht D. Fleischer A. Kane C. Rentscb O. Van Tran Thi H. Yamaguchi und R. C. Schulz 《Colloid and polymer science》1979,257(1):109
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