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1.
František Lukeš 《Czechoslovak Journal of Physics》1959,9(1):118-123
, , . .
A new method of measuring the reflectivity factor
A new method is given of measuring reflectivity and compared with methods known up to now, which are characterized briefly. The applicability and suitability of the given method is shown on an example of measurement of the reflectivity of germanium in the ultra-violet and visible regions.相似文献
2.
J. Čermák 《Czechoslovak Journal of Physics》1960,10(3):215-224
Wavelength distribution in the focus of a Johansson type monochromator is computed assuming the tube focus emissivityG(), reflection curveR() and wavelength distribution of the incident radiationJ(-0) are known. It is shown e.g. that the centre of gravity may be shifted in accordance with the position of the crystal on the focal circle which may considerably influence precision measurements of lattice parameters.
The author is grateful to Z. Hemanová for carrying out all the computations very carefully. 相似文献
, G(,) R() J(-0) . , , , .
The author is grateful to Z. Hemanová for carrying out all the computations very carefully. 相似文献
3.
A. Ja. Režnikova 《Journal of statistical physics》1981,25(2):291-308
Let HL = –d2/dt2+q(t,) be an one-dimensional random Schrödinger operator in 2(–L, L) with the classical boundary conditions. The random potential q(t,) has a form q(t, )=F(xt), where xt is a Brownian motion on the Euclidean v-dimensional torus, FSv R1 is a smooth function with the nondegenerated critical points, mins
v F = 0. Let
are the eigenvalues of HL) be a spectral distribution function in the volume [– L,L] and N() = limL(1/2L)NL() be a corresponding limit distribution function.Theorem 1. If L then the normalized difference N
L
*
()=[NL() -2L·N()]2L tends (in the sense of Levi-Prokhorov) to the limit Gaussian process N*(); N*()0, 0, and N*() has nondegenerated finitedimensional distributions on the spectrum (i.e., > 0). Theorem 2. The limit process N*() is a continuous process with the locally independent increments. 相似文献
4.
Y. Last 《Communications in Mathematical Physics》1994,164(2):421-432
We study the almost Mathieu operator: (H
, ,
u)(n)=u(n+1)+u(n-1)+ cos (2n+)u(n), onl
2
(Z), and show that for all ,, and (Lebesgue) a.e. , the Lebesgue measure of its spectrum is precisely |4–2|. In particular, for ||=2 the spectrum is a zero measure cantor set. Moreover, for a large set of irrational 's (and ||=2) we show that the Hausdorff dimension of the spectrum is smaller than or equal to 1/2.Work partially supported by the GIF 相似文献
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To determine the mechanism of the amplification of moving striations one starts out from the processes which [3] showed to be decisive for the production of stratification of the plasma of a positive column. An analysis of the influence of other processes shows that the main processes leading to the decay of space charges and thus to a smoothing out of the inhomogeneities and thereby to the attenuation of the periodic structure, cannot by overcome by ionization phenomena caused by changes in the concentration of electrons but only partially compensated.It was found that the process which can lead to the predomination of the processes of amplification over the attenuation is the process of the spatial shift of the temperature deflections of the electrons with respect to the additional electric field, which is expressed in a simplified way by Eq. (12).By solving the extremely simplified basic equations it is proved that under favourable conditions this displacement can lead to both a time and a spatial amplification of the striations. Such a possibility is also verified quantitatively by substituting numerical values into the formulae obtained.
, [3] . , , , , , ., , (12). , , . .相似文献
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9.
An analytical expression for the two-frequency correlation function of reflected radiation
is derived in the framework of the Kirchhoff approximation, assuming that the mean square roughness heights 1,2 of the upper (1) and lower (2) boundaries are large compared to the wavelength and taking account of large-scale permittivity fluctuations in the layer. The condition under which p cannot be small when
i
2
2 is specified. In particular, it is shown that if the scattering is only at the upper boundary of the layer (when 1 0, 2 = = 0), then this condition is
, where m, n=0, 1,.... The potential of the layered medium sounding methods based on the relations obtained is estimated.Institute of Physics, State University, Rostov-on-Don. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 7, pp. 619–630, July, 1995. 相似文献
10.
The spectrum of the mass operator on the soliton sectors of the anisotropic (|ø|4)2—and the (ø4)2—quantum field models in the two phase region is analyzed. It is proven that, for small enough >0, the mass gapm
s() on the soliton sector is positive, andm
s()=0(–1). This involves estimatingm
s() from below by a quantity () analogous to the surface tension in the statistical mechanics of two dimensional, classical spin systems and then estimating () by methods of Euclidean field theory. In principle, our methods apply to any two dimensional quantum field model with a spontaneously broken, internal symmetry group.A Sloan Foundation Fellow; Research supported in part by the U.S. National Science Foundation under Grant No. MPS 75-11864.Supported in part by the National Science Foundation under Grant No. PHY 76-17191 相似文献
11.
Jiří Teichman 《Czechoslovak Journal of Physics》1959,9(3):388-394
. .
The influence of fringing on betatron oscillations in an accelerator with a sectioned magnet II
The influence of stray fields at the edges of pole pieces on the deformation of equilibrium trajectory and betatron oscillations is studied. A new definition of the effective length of segments for the approximative solution is given.相似文献
12.
Zdeněk Knittl 《Czechoslovak Journal of Physics》1959,9(1):91-94
The paper deals with the problem of the anomalous divergence of an infinite geometric series of complex amplitudes, pointed out by Berning. It is shown that the paradox is of a formal mathematical nature and has no consequences for multiple beam interference as a method of derivation.
, . , - .相似文献
13.
, , . , . .
The damping of particle oscillations in a general field with periodic structure I
A liner theory is derived, discussing the dynamics of particles in the region of an equilibrium orbit in a general electromagnetic field, which forms a periodic system. The total particle damping is determined from the Hamiltonian found and from dissipative forces brought out by a classical reaction radiation. Relations for the damping of the synchrotron oscillations are derived from the study of the appropriate phase space.相似文献
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E. F. Ter-Ovanesov 《Russian Physics Journal》1972,15(8):1099-1103
The method of complex angular moments is used to analyze the experimental data on the inelastic reactions p ()K, taking into account branch cuts in the j-plane in the eikonal approximation. An optical model for the backward scattering is considered. Agreement with experiment is obtained in the region of small angles for the reactions (0)K0. In the case of –P K0(–K+) processes, agreement is obtained with the experimental results for large (180) scattering angles.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 26–30, August, 1972. 相似文献
16.
A. Angeletti 《Letters in Mathematical Physics》1980,4(6):495-504
Let (x) be the Dirac's delta,q(x)L
1
(R)L
2
(R) be a real valued function, and , R; we will consider the following class of one-dimensional formal Schrödinger operators on
. It is known that to the formal operator
may be associated a selfadjoint operatorH(,) onL
2(R). Ifq is of finite range, for >0 and || is small enough, we prove thatH(,) has an antibound state; that is the resolvent ofH(,) has a pole on the negative real axis on the second Riemann sheet.Work done while the author was supported by an undergraduate fellowship of the (Italian) National Research Council (CNR). 相似文献
17.
The arrangement of dislocations formed in a single crystal of the alloy Fe-4·2% Si by a spark discharge in air is studied. The dislocations are made visible by etching on the surfaces perpendicular and parallel to the axis of the crater. The results of the observations are explained on the basis of microphysical conceptions of plastic deformation.
, Fe— 4,2% Si . , . .相似文献
18.
Zusammenfassung Es werden Versuchsergebnisse des Studiums der Röntgenolumineszenz (RL) von NaCl-Kristallen mit Beimengungen von Elementen der Eisengruppe (Fe, Co, Ni) angeführt. Die Kristalle wurden aus der Lösung und aus der Schmelze gezüchtet. Das Vorkommen und das Höhenverhältnis der einzelnen Emissionsbanden werden diskutiert.
NaCl
NaCl Fe, Co, Ni. . .相似文献
19.
Zusammenfassung Aus den Projektionen der Elektronendichten in drei voneinander unabhÄngigen kristallographischen Ebenen wird die Funktion (2) zusammengesetzt, die das übliche Darstellungsverfahren mit Hilfe der dreidimensionalen Fourierreihe ersetzt.
(2), .相似文献