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971.
The asymptotic value of the melting entropy, i.e. ΔSf = R ln 2 for vanishing relative change of volume on melting, can be derived from the vibrational entropy due to vibrating dislocations, which are introduced into a material on melting. 相似文献
972.
We have developed a sensitive method for the measurement of rhodanese activity in human serum which is based on the colorimetric method for the determination of thiocyanate produced from methanethiosulfonate and cyanide as substrates. Thiocyanate gives a red complex with ferric ion in an acidic condition. The present method is about 70-fold more sensitive than the conventional method using cyanide and thiosulfate as substrates and correlates well (r = 0.997) with the conventional method in bovine liver rhodanese. Within-run precision of the method is 0.91% for 420 units/l serum and the calibration curve is linear up to 1850 units/l. The normal value for human serum, determined by the present method on 31 healthy persons, was 20.9 +/- 20.0 units/l (mean +/- 2S.D.). Rhodanese activity was clearly elevated in some serum samples which were observed at abnormal values in some biochemical diagnostic tests and showed significant positive correlations with guanase activity (r = 0.728, p less than 0.01) and glutamic-oxalacetic transaminase activity (r = 0.625, p less than 0.01). 相似文献
973.
Translated from Programmnoe Oborudovanie i Voprosy Prinyatiya Reshenii, pp. 152–184, 1989. 相似文献
974.
V. K. Mel'nikov 《Communications in Mathematical Physics》1991,137(2):359-381
It is shown that the nonlinear Schroedinger equation with a self-consistent source admits investigation by the inverse scattering method for the Dirac operator. The conditions are found under which the solutions of the nonlinear Schroedinger equation with a self-consistent source describe the creation and annihilation of solitons. 相似文献
975.
Modeling synchronization and suppression of spontaneous otoacoustic emissions using Van der Pol oscillators: effects of aspirin administration 总被引:1,自引:0,他引:1
Many of the aspects of the interaction of spontaneous otoacoustic emissions with external tones (suppression and synchronization) can be qualitatively simulated by the behavior of a single driven Van der Pol oscillator. Analytical and numerical investigations of a model of spontaneous otoacoustic emissions based on such an oscillator (with appropriate parametric changes in the nonlinear and negative damping components) lead to predictions of the nature of the changes in suppression and synchronization (frequency-locking) tuning curves when the levels of spontaneous otoacoustic emissions are modified. Observations of the suppression and synchronization of spontaneous otoacoustic emissions by external tones of different frequencies and levels were obtained while the levels of spontaneous emissions were altered by aspirin administration. Modeling an emission as a single Van der Pol oscillator qualitatively accounts for: (1) the reduction of the level of an external tone required to suppress the emission by a decibel amount equivalent to the level reduction induced by aspirin administration; (2) the broadening of the frequency-locking tuning curve of an emission whose level is reduced; and (3) the pulling of the emission frequency by an external tone. It does not account for: (1) the observed asymmetry in the slopes of the external-tone suppression curves (more gradual for frequencies of the suppressor tone higher, rather than lower, than that of the emission); and (2) the frequency pushing of the emission by an external tone. 相似文献
976.
977.
K. Naito 《Journal of Optimization Theory and Applications》1989,60(1):57-65
We treat an abstract semilinear control system and study the controllability problem for its trajectories. Assuming a range condition of the control action operator and an inequality condition on the system parameters, we can show that the reachable trajectory set of the semilinear system is equivalent to that of its corresponding linear system.The author wishes to express his deep appreciation to Prof. T. I. Seidman for his many helpful suggestions and to Prof. W. Takahashi for many stimulating conversations. 相似文献
978.
J. Pill J. Aufenanger K. Stegmeier F. H. Schmidt D. Müller 《Fresenius' Journal of Analytical Chemistry》1987,327(5-6):558-560
Summary The investigation methods of the action of xenobiotics on sterol biosynthesis from 14C-acetate in rat hepatocyte cultures can be developed, with regard to extraction using Extrelut and the separation of the sterol pattern by thin-layer chromatography, in such a way that they are suitable for wider application, e.g., screening. Good visualisation and recognition of changes in the sterol pattern are possible using autoradiography of the thin-layer chromatogram.
Dedicated to Dr. E. Roesch on occasion of his 65th birthday 相似文献
Dünnschicht-Chromatographie von radioaktiv markiertem Cholesterin und Vorstufen aus biologischem Material. Eine einfache und empfindliche Methode zur Untersuchung einer Beeinflussung des Sterolbiosynthesewegs
Dedicated to Dr. E. Roesch on occasion of his 65th birthday 相似文献
979.
980.