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991.
A general spin S Ising chain interacting with a single phonon mode of the harmonic lattice is studied. The thermodynamics of the spin system is calculated exactly for S = 1, and , while self-consistent equations for the induced lattice distortions are derived. It is demonstrated that for S > there is no second-order phase transition, in contrast to the case S = which was proved to have a tricritical point. This is found to cohere with the previous studies of the dimerized magnetic model chains. 相似文献
992.
Electrical and electrochemical properties of solid LiH2PO4 conductor were investigated in the temperature range from room temperature to 373 K. It was found that high conductivity throughout the temperature range, with activation energy 17.23 kJ/mol, originates from the movement of hydrogen ions (protons). The movement of protons in the correlation with phosphate groups rotation was considered. The slopes of Tafel lines and exchange current densities both for cathodic hydrogen and anodic oxygen evolution were determined (by means of usual electrochemical kinetic methods) at various temperatures. The energy of activation at the equilibrium potentials both for the cathodic and the anodic processes have been assessed to be 17.23 kJ/mol (0.18 eV) and 2.9 kJ/mol (0.03 eV), respectively. 相似文献
993.
994.
The thermochemical behaviour of nitrate inclusion complexes of zeolites of type A was investigated and DTA curves recorded. An attempt was made to identify thermal effects. Supplementary information was obtained from the IR spectra of the solid phase before and after heating as well as from the process of denitration of inclusion complexes. 相似文献
995.
996.
997.
A. Puškár 《Ultrasonics》1977,15(3):124-128
Internal friction, modulus defects and the initial occurrence of slip lines on the surface of armco iron specimens were studied during and after loading at 22.5 kHz, at temperatures of 296, 333, 373 and 423 K and with strain amplitudes ranging from 1.5 × 10-7 to 4 × 10-4. At a particular strain, amplitude dependent internal friction begins, the modulus starts to change and the slip lines may be observed. These strain amplitudes are thermally affected by activation energies of 25.1, 16.7 or 13.6 J kmol-1 as defined by the Arrhenius equation. 相似文献
998.
Derivatives of pyrimido(1,2-b)indazole and s-triazino(1,2-b)indazole were prepared by several different routes and some transformations are described. 相似文献
999.
The magnetostriction constant of three iron-nickel alloys and one Fe-Ni-Co alloy was measured as a function of the plastic elongation up to about 25%. The magnetostriction constant decreases with deformation in all materials. In Fe-Ni-Co alloy the volume magnetostriction also decreases. The influence of crystallographic texture is discussed and it is shown that it is not a decisive factor. The observed decrease is explained by assuming the influence of lattice deformation on spin-orbital interaction.
In conclusion the authors thank Z. Málek and S. Libovický for carefully reading this paper and for remarks, J. Míová for help in the measurements, J. Cáslavský for X-ray determination of the texture and members of the chemical department of the Institute of Physics for thermal treatment and analysis of the samples. 相似文献
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- Fe-Ni-Co 25%. . Fe-Ni-Co . , . .
In conclusion the authors thank Z. Málek and S. Libovický for carefully reading this paper and for remarks, J. Míová for help in the measurements, J. Cáslavský for X-ray determination of the texture and members of the chemical department of the Institute of Physics for thermal treatment and analysis of the samples. 相似文献
1000.
Antonín Rrokeš 《Czechoslovak Journal of Physics》1957,7(3):320-325
50–100 , 1–2 1–10 . - . - . , , - . -. 相似文献