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191.
O. Ya. Savchenko 《Optics and Spectroscopy》2006,101(2):179-182
The efficiency with which a magnetic field acts on sublevels of the first and second doublets of a hydrogen-like atom is shown to vary because of relativistic effects by a factor of 1 ? 2γ(l + 1)/(2l + 3) and 1 ? 2γl/(2l ? 1), respectively, where γ is the ratio of the electron binding energy to the rest energy and l is the quantum number of the orbital angular momentum. 相似文献
192.
S. K. Godunov V. T. Zhukov O. B. Feodoritova 《Computational Mathematics and Mathematical Physics》2006,46(6):971-982
An algorithm is constructed for calculating invariant subspaces of symmetric hyperbolic systems arising in electromagnetic, acoustic, and elasticity problems. Discrete approximations are calculated for subspaces that correspond to minimal eigenvalues and smooth eigenfunctions. Difficulties related to the presence of an infinite-dimensional kernel in the differential operator are successfully handled. The efficiency of the algorithm is demonstrated using acoustics equations. 相似文献
193.
Multi-quantum well heterostructures (MQWHs) of the novel Ga(NAsP)/GaP material system have been grown, pseudomorphically strained to GaP-substrate. The crystalline perfection is verified by transmission electron microscopy (TEM). For As-concentrations in excess of about 70%, a direct band structure and adequate luminescence efficiency for laser device application is observed. Temperature-dependent photoluminescence (PL) investigations show the influence of carrier localisation and non-radiative recombination processes typical for dilute nitride materials. With rising N content in the active material, the emission wavelength shifts towards longer wavelength, leading to Ga(NAs)/GaP MQW structures with photon energies below the indirect band gap of silicon (Si). At the same time the luminescence intensity drops due to an increase in non-radiative carrier traps and/or structural degradation. 相似文献
194.
Bajdik J. Pintye-Hódi K. Novák Cs. Kelemen A. Regdon G. Erős I. 《Journal of Thermal Analysis and Calorimetry》2002,68(2):613-627
The extents of the protective effects of coating films on the surface of crystals were determined. Three different samples
were made with different quantities of coating fluid (Sepifilm LP 010 in 10% aqueous solution). Since the atomizing rate was
constant, the coating time increased in parallel with the volume of coating fluid applied. The direct measurement of film
thickness and smoothness is very difficult, and therefore indirect methods were used. Dimenhydrinate was chosen as model drug;
this is a heat-sensitive antihistamine with a low melting point. This temperature can be reached during the tableting process.
The behaviour of samples on exposure to heat was examined by differential scanning calorimetry. The water uptakes of the samples
were determined with an Enslin apparatus. Plasticity was studied with an instrumented tablet machine. These indirect methods
(thermal conductivity, water uptake and plasticity measurements) revealed connections between the results of the various experiments.
An overlong coating time decreased the protective effect of the coating film.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
195.
Bairamov R. K. Ermakov A. I. Vedernikova N. R. 《Russian Journal of Applied Chemistry》2002,75(3):408-410
The influence exerted by the nature and concentration of a number of organic and mineral acids on the composition of products formed in electric-spark dispersion of aluminum was studied. 相似文献
196.
Shunin D. G. Filippova A. G. Okhotina N. A. Liakumovich A. G. Samuilov Ya. D. 《Russian Journal of Applied Chemistry》2002,75(6):1020-1023
Procedures are discussed for production of rubber-bitumen compounds based on spent rubber items. A possibility of using these binders for paving is studied experimentally. 相似文献
197.
Using Brown's construction (J. Algebra 15 (1970) 103) of an exact 6-term sequence for a fibration of groupoids we show how an exact 9-term sequence can be associated to a fibration of bigroupoids. Applications to topology and algebra are given. 相似文献
198.
A nonlinear, compressible, non-isothermal gravity wave model that involves photochemistry is used to study the effects of gravity wave on atmospheric chemical species distributions in this paper. The changes in the distributions of oxygen compound and hydrogen compound density induced by gravity wave propagation are simulated. The results indicate that when a gravity wave propagates through a mesopause region, even if it does not break, it can influence the background distributions of chemical species. The effect of gravity wave on chemical species at night is larger than in daytime. 相似文献
199.
E. C. Ferreira J. A. P. da Costa J. A. K. Freire G. A. Farias V. N. Freire 《Applied Surface Science》2002,190(1-4):191-194
Confined excitons in non-abrupt GaAs/AlxGa1−xAs single quantum wells are studied. The graded interfaces are described taking into account fluctuations in their thickness a and positioning with respect to the abrupt interface picture. Numerical results for confined (0,0),(1,1) and (0,2) excitons in GaAs/Al0.3Ga0.7As quantum wells show that while the interfacial fluctuations produce small changes (<0.5 meV) in the exciton binding energies, the confined exciton energies can be red- or blue-shifted as much as 25 meV for wells with mean width of 50 Å and 2 ML wide interfaces. 相似文献
200.
S.K. HAY.H. KIM 《Journal of sound and vibration》2002,253(5):1001-1014
Impedance and admittance matrices are presented for the analysis of the beam-type piezoelectric multimorph (PM). Each piezoelectric layer is polarized in the thickness direction. The stacking sequence can be arbitrary, and both the extensional and flexural motions are considered. The variational principle is used for deriving the lumped conjugate parameters: two mechanical ports for the extensional motion, four mechanical ports for the flexural motion, and m electrical ports for the m piezoelectric layers. The resonance and antiresonance frequencies are then easily calculated from the admittance matrices. For the case of all the piezoelectric layers either in series or parallel connection, them +6 ports reduce to the seven ports, and its impedance and admittance matrices are presented. The present methods are applied to the cantilevered PM and their electromechanical behavior is studied. The tip trajectory of the cantilevered piezomotor is also investigated using the presented matrices. It is found that the present methods are very effective in analyzing the multilayer piezoelectric transducers. 相似文献