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921.
We examine differences between3H binding energies obtained by solving the Faddeev equations using standard partial-wave expansion procedures and results from solving the Schrödinger equation by means of the coupled-rearrangement-channel variational method. Variational bounds generated from Faddeev solutions for several contemporary, realistic potential models are presented as a function of the number of partial waves retained in the potential expansion. We demonstrate that the Faddeev wave function yields an optimal variational bound for the partial-wave truncated potential from which it is generated, but it does not yield optimal bounds for the full Hamiltonian or when the potential is partial-wave truncated at a different level. Finally, qualitative differences between3H solutions for static models such as the AV14 and RSC potentials and for momentum-dependent models such as the Nijmegen soft-core and Paris potentials are explored, and comparison is made with solutions for the RSC/TM two-body-force plus three-body-force model. 相似文献
922.
I. Havezov 《Fresenius' Journal of Analytical Chemistry》1996,355(5-6):452-456
AAS as a highly sensitive and specific single element technique is ideally suited as a detector for speciation analysis. The combinations of chromatographic separation with element specific detectors (flame AAS, electrothermal AAS (ETAAS), hydride generation AAS (HGAAS)) provide powerful approaches to the determination of all species. Sample stabilisation is the area that requires most attention as it still represents the main source of problems encountered in speciation work. The correct speciation depends on how the sample is handled prior to analysis. Unfortunately, no universal procedure has been found. Anything that changes redox conditions, pH or complexation equilibrium is clearly unacceptable. 相似文献
923.
用闪光蒸镀法在77K制备了NdxFe1-x(x=0.06-0.80)非晶薄膜,原位测定了其电阻随温度的变化。结果表明:在0.192和ρ(T)∝T。晶化不是在一个固定的温度,而是在一个温度区间发生。 相似文献
924.
925.
The possibilities and the limitations of 2D NMR for the structural characterization of paramagnetic metalloproteins are reviewed. We survey the general strategies for 2D1H NMR investigations of hyperfine shifted signals. Careful adaptation of classical 2D NMR experiments to fast relaxing systems results in the detection of previously not observed scalar and dipolar connectivities, thus leading to the specific assignment of selected resonances. The approach is of general applicability for paramagnetic metalloproteins. We report here on the application of the application of the method to an iron sulfur protein and a heme protein. In both cases specific assignment of several hyperfine shifted signals, corresponding to active site protons, were obtained; this allowed significant insight into the structure-function relationships of these metalloproteins. 相似文献
926.
I. Yu. Chudinovich 《Mathematical Methods in the Applied Sciences》1993,16(3):217-227
This work considers the methods for solving approximately the four types of boundary equations arising when the third initial boundary value problem of the theory of elasticity is solved with the help of retarded elastic potentials. The convergence of these methods is proved. 相似文献
927.
A. I. Podgorny 《Radiophysics and Quantum Electronics》1996,39(11-12):912-915
We have developed the Peresvet program for numerical simulation of energy accumulation above active regions. This program solves 3D MHD equations for the compressible plasma with allowance for the dissipative terms. It is shown that the energy can be stored in a layer of current by focusing the photospheric disturbances. 相似文献
928.
M. U. Belyi N. E. Bartnitskaya I. F. Mel'nik B. A. Okhrimenko S. M. Yablochkov 《Journal of Applied Spectroscopy》1995,62(3):564-567
T. Shevchenko Kiev University, 252022 Kiev, Pr. Akad. Glushakova, 6, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 62, No. 3, pp. 192–196, May–June, 1995. 相似文献
929.
Methods are proposed for determining the diffusion coefficients of adsorbed molecules and the adsorption isotherms from given concentrations of the solutes in the external solution. The methods are based on a comparison of experimental data with the numerical results produced by a mathematical model of internal-diffusion kinetics of adsorption from a constant bounded volume.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 66, pp. 41–46, 1988. 相似文献
930.
In this paper we propose time-optimal convex hull algorithms for two classes of enhanced meshes. Our first algorithm computes the convex hull of an arbitrary set ofn points in the plane inO (logn) time on a mesh with multiple broadcasting of sizen×n. The second algorithm shows that the same problem can be solved inO (1) time on a reconfigurable mesh of sizen×n. Both algorithms achieve time lower bounds for their respective model of computation.This work was supported by NASA under grant NCCI-99.Additional support by the National Science Foundation under grant CCR-8909996 is gratefully acknowledged. 相似文献