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971.
972.
973.
Studies of the influence of plastic deformation and the straining temperature on the temperature dependence of the stresses
developed in titanium nickelide shape memory alloys are described.
Zh. Tekh. Fiz. 68, 141–142 (July 1998) 相似文献
974.
975.
Yu. I. Bespyatykh V. Vasilevskii É. G. Lokk V. D. Kharitonov 《Physics of the Solid State》1998,40(6):975-981
Specific models of domain walls are used to investigate conditions for the single-domain state and quasi-single-domain states
in structures with magnetic materials having a quality factor higher than one. It is shown that the critical thickness of
the magnetic film in a tangentially magnetized system decreases monotonically as the magnetizing field increases from zero
to the transition from the collinear to the homogeneous angular phase and then increases monotonically with increasing external
field. In a thin isolated magnetic film, the size of the domains increases exponentially with decreasing thickness. This dependence
is logarithmic near the transition to the single-domain state for a film coated on two sides and obeys a power law for a film
coated on one side. The establishment of a single-domain state and characteristic features in the asymptotic behavior of the
domain structure in magnetic films with and without coatings can be attributed to differences in the asymptotic behavior of
the field of a single domain wall.
Fiz. Tverd. Tela (St. Petersburg) 40, 1068–1074 (June 1998) 相似文献
976.
采用循环伏安法,对SPEPt电极以及SPEAu-Pt电极上还原态CO2的电化学氧化行为研究表明,此类电极的电化学特性与光滑Pt电极一致:CO2在氢原子吸附电位区0~250mV(vs.RHE)处,可与电极上化学吸附的氢反应,生成还原态的CO2,通过线性扫描,还原态CO2即发生一不可逆电化学氧化过程(阳极剥离).在SPEPt系列及SPEAu-Pt系列上CO2的电化学行为表明,当SPEPt系列上Pt的载量为2.5mL的0.01mol·L-1H2PtCl6的Pt时,对还原态CO2的电催化活性最好,当Pt的载量相同时,在SPEAu-Pt上,催化剂对还原态CO2的电化学氧化行为比SPEPt电极更强,这是由于预先沉积的Au对后沉积的Pt有调制作用. 相似文献
977.
The magnetic phase diagrams of a two-sublattice ferrimagnet with a magnetically unstable subsystem are calculated taking account
of the susceptibility. Analytic expressions are obtained for the phase-transition fields and critical values of the parameters
of the ferrimagnet. The evolution of the magnetic phase diagrams as the susceptibility of the unstable sublattice increases
is analyzed. 相似文献
978.
We show that when a three-level laser is excited by Poisson light the lasing remains sub-Poisson, as asserted by H. Ritsch,
M. A. M. Marte, and P. Zoller [Europhys. Lett. 19, 7 (1992)], only if there is no reciprocal action on the exciting laser (weak coupling). In cascade schemes in which each
three-level Λ-laser excites each succeeding Λ-laser with its light, any desired degree of shot-noise suppression can be achieved.
Zh. éksp. Teor. Fiz. 114, 1971–1992 (December 1998) 相似文献
979.
Nikolai Yu. Bakaev 《BIT Numerical Mathematics》1998,38(3):462-485
We consider a Cauchy problem for the sectorial evolution equation with generally variable operator in a Banach space. Variable
stepsize discretizations of this problem by means of a strongly A(φ)-stable Runge-Kutta method are studied. The stability
and error estimates of the discrete solutions are derived for wider families of nonuniform grids than quasiuniform ones (in
particular, if the operator in question is constant or Lipschitz-continuous, for arbitrary grids). 相似文献
980.
An analysis is made of a two-electron system of two adjacent quantum dots (QD) with a two-dimensional parabolic lateral confining
potential, and of two coupled or double, spatially separated QDs (a “horizontal” and a “vertical” QD molecule), and of their
behavior in an external transverse magnetic field. The ground-state energies and energy spectra of the system have been determined
by various methods (Heitler-London, molecular-orbital, variational approach, and numerical diagonalization of Hamiltonian),
with inclusion of electron-electron interaction, and for a broad range of confining-potential steepness, QD-center spacing
(interlayer distance), and external magnetic field.
Fiz. Tverd. Tela (St. Petersburg) 40, 2127–2133 (November 1998) 相似文献