共查询到20条相似文献,搜索用时 171 毫秒
1.
L. Trlifaj 《Czechoslovak Journal of Physics》1962,12(9):653-659
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Partially inserted block in square lattice
The paper gives a theory of the partially inserted block (control rod) in a reactor of finite height, consisting of a square lattice of fuel blocks and a moderator. The partially inserted block replaces the block of the original lattice which was located in the axis of cylindrical symmetry of the reactor. The results obtained agree with the relations for a homogeneous medium in paper [1] and are thereby justified for homogeneized reactors.相似文献
2.
V. Sochor 《Czechoslovak Journal of Physics》1964,14(10):786-795
The paper explains the theory of modelling electrostatic fields by a resistance network. The conditions, which the resistance network must satisfy, are derived and the question of modelling electrodes of different shapes is solved. The finished network and the results obtained on it when modelling a jet for a linear h-f accelerator of electrons are described. Particular attention is paid to the influence of a space charge, the modelling of which is an advantage of this method.
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3.
We study the Sine-Gordon field theory at 2=8. We prove that the theory is renormalizable but not superrenormalizable and we show how the perturbative renormalization procedure works in this case where the interaction is not polynomial. To go beyond the perturbative results we investigate the -functional equation for this theory and discuss in what sense at 2=8 the theory is lacking the asymptotic freedom and how it is asymptotic free for 2<8 in a appropriate region of the coupling constants. 相似文献
4.
Ivan Šantavý 《Czechoslovak Journal of Physics》1955,5(3):340-367
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5.
J. Schnakenberg 《Zeitschrift für Physik B Condensed Matter》1980,38(4):341-349
The fluctuations in limit cycles of second-order bifurcation (transition from a stable to an unstable focus) are investigated near the bifurcation point c, being an external control parameter. Two different methods are applied: a time- and space-dependent Fokker-Planck equation obtained from an 1/2-expansion of the master equation ( being the volume) and a time- and space-dependent Langevin equation. Both methods give the same results. It is shown that the dependence of the radial correlation on 2 = | – c| and the time-behaviour of the phase correlation (ensemble dephasing) are determined by the dimensionality of space. 相似文献
6.
F. Janouch 《Czechoslovak Journal of Physics》1960,10(1):1-6
Double beta decay is discussed in relation to parity non-conservation. Two possible ways of neutrino-less double beta decay (allowed and forbidden) are investigated and the half-life of decay is calculated. For allowed transitions we obtain for Ca48 an estimatedT1/2=2×1019 years. The negative results of the experiments by Lukjanov et al., who give the valueT1/2=0.7×1019 years for the lower limit of the half-life of double beta decay of Ca48, cannot therefore be regarded as a definitive solution of the question, whether the neutrino is a Dirac or Majorana particle. Further study of double beta decay, aimed at finding higher values of the lower limit of half-life, are of considerable importance for theory.
In conclusion the author thanks Prof. I. S. apiro for suggesting this work and help in elaborating it. 相似文献
-
- . - ( ) . 48 T1/221019 . - . [1] ( - 48 T1/2 0,71019 ), , . - .
In conclusion the author thanks Prof. I. S. apiro for suggesting this work and help in elaborating it. 相似文献
7.
As is known, the second approximation in the calculation of the partition function by the traces method of ferromagnetic thin films gives wrong results for the coordination number equal to eight. In order to obtain correct results even for this case, the third order approximation of the partition function is developed and thus the magnetic properties of body-centred cubic iron thin films are studied. The dependence of the Curie temperature on the thickness, for different values of the ratio between the anisotropy constant and the exchange energy between two neighbours, is discussed. A value can be chosen for this ratio such that the thin film becomes ferromagnetic only for a thickness greater than a definite value.
, . , , (Fe). . , - .相似文献
8.
Arnošt Hladík 《Czechoslovak Journal of Physics》1955,5(4):502-513
- [3], [4], U(x, y) . - U(x, y) -, . B § 10 - . , - , - D, . - . 相似文献
9.
J. Pastrňták 《Czechoslovak Journal of Physics》1962,12(8):614-620
The paper describes microscopic investigation into the spectral distribution of photo-luminescence and its polarization on hexagonal ZnS monocrystals in relation to the structural defects of such crystals. These observations, as well as birefringent observations, show that the values of the birefringence and the degree of polarization in different stripes of the same crystal are the same within the limits of observational errors.
In conclusion the author would like to thank K. Pátek, L. Souková and M. Mokonová for providing the monocrystals and for fruitful discussions. 相似文献
ZnS: Cu
ZnS . , , , .
In conclusion the author would like to thank K. Pátek, L. Souková and M. Mokonová for providing the monocrystals and for fruitful discussions. 相似文献
10.
11.
Qj , i 4 ISb, - N , –180° +400°C. , ISb zi, - ; -m
n
=3,6. 10–, n . menem , , - .eue . - - . 相似文献
12.
Bohumil Jurek 《Czechoslovak Journal of Physics》1954,4(1):97-97
13.
K. Pátek 《Czechoslovak Journal of Physics》1960,10(9):679-683
The influence of a small electric perturbation of variable phase on the brightness wave of alternating electroluminescence of ZnS-Cu is investigated. The results are compared with the model described in [1]. The increase in the number of ionized activators after switching on the electric field is studied and is found to reach equilibrium. after about 50 to 150 sec.
In conclusion the author thanks M. Mokonová for cooperation in evaluating the results of measurement. 相似文献
ZnS-Cu
ZnS-Cu. , [1]. , 50–150 s.
In conclusion the author thanks M. Mokonová for cooperation in evaluating the results of measurement. 相似文献
14.
A. Corciovei 《Czechoslovak Journal of Physics》1960,10(8):568-578
In this paper the magnetic properties of ferromagnetic thin layers are studied by calculating the partition function for the magnetic system inKirkwood's approximation of the second order. The results obtained for the Curie temperature and the magnetization are in somewhat better agreement with the experiment than those obtained by Valenta.
The author extends his thanks to the group of research workers who performed the numerical calculation of the Curie temperatures on the computer CIFA 1, as well as gratitude to Dr. l. Valenta for so kindly supplying information on the results of his investigations on the same subject. 相似文献
. , , .
The author extends his thanks to the group of research workers who performed the numerical calculation of the Curie temperatures on the computer CIFA 1, as well as gratitude to Dr. l. Valenta for so kindly supplying information on the results of his investigations on the same subject. 相似文献
15.
J. Teichman 《Czechoslovak Journal of Physics》1960,10(2):144-157
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Betatron oscillations in an accelerator with a general field I
The paper gives a linear theory of equilibrium trajectories in an accelerator with a generalized magnetostatic field, the components of which are defined on a general rotation surface. Equations of motion of the particles in natural coordinates are derived with respect to the change in energy and dissipative force. A system of equilibrium trajectories is found in the general form. Conditions for the field components on the reference surface, necessary for the existence of equilibrium trajectories, for the conservation of their geometric similarities and for maintaining the constancy of the frequencies of the betatron oscillations, are derived. A condition is also derived which must be satisfied by the reference surface in order to conserve constant circular frequency of the particles. It is seen that it is not possible to find a field for an accelerator with an exactly constant circular frequency and with constant frequencies of the betatron oscillation in the relativistic energy region. An ultra-relativistic cyclotron with such properties is realizable.相似文献
16.
The paper describes a new experimentally found phenomenon of the effect of standing stratification on the parameters of moving striations in the positive column of a glow discharge.
. . M. Hobaky 相似文献
. . M. Hobaky 相似文献
17.
18.
M. Blažek 《Czechoslovak Journal of Physics》1962,12(7):497-507
It is shown that by solving the linear integral Agranovi-Marenko equation for potentials-scattering one can obtain: 1) in the simplest case, when the scattering matrixS has one redundant pole in the upper half-plane of the impulse, the Bargmann potentials; 2) if theS-matrix hasn redundant poles — the equations, which Petras derived fors-scattering using an adapted and simplified Bargmann method; 3) if theS-matrix is discontinuous on a certain interval — the non-relativistic Noyes-Wong equation and 4) further relations — for combinations of isolated poles and discontinuities of theS-matrix on intervals. The former equations can be obtained from the latter as specific cases. In the discussion, the relation between the value of the residuum of theS-matrix in the redundant poles and the number of bound states is shown and the solution of the inverse problem for a band spectrum is sketched.
, - s-, : 1) , S — . 2) , S-n — , , s-. 3) S- — . 4) — S- . . S- .相似文献
19.
The magnetostriction constant of nickel was measured as a function of plastic deformation up to an elongation of 30%. The values of the magnetostriction constant in deformed samples deviate considerably, a fact which cannot be explained by errors of measurement. The absolute value of the magnetostriction constant decreases with increasing plastic deformation (by around 5%).
In conclusion the authors thank J. Kaczér, C. Sc. and B. esták, C. Sc. for carefully reading the paper and for their remarks, J. Míová for help in the measurements and workers of the chemical department of our Institute for careful preparation of the samples. 相似文献
30% . , . ( 5%).
In conclusion the authors thank J. Kaczér, C. Sc. and B. esták, C. Sc. for carefully reading the paper and for their remarks, J. Míová for help in the measurements and workers of the chemical department of our Institute for careful preparation of the samples. 相似文献
20.
V. Prosser 《Czechoslovak Journal of Physics》1960,10(4):306-316
The optical constants of single crystals of hexagonal selenium in the region of the intrinsic absorption edge in polarized light were investigated. The absorption edge for light polarized normal to the optical axis of the crystal is displaced towards longer wavelengths. The absorption maximum of hexagonal selenium for a wavelength of 0·6 is interpreted as the maximum corresponding to interaction between neighbouring chains and in connection with this the position of the absorption edge of different modifications of selenium is discussed.
In conclusion the author wishes to thank Dr. E. Klier and R. Kuel for valuable discussions and advice. He thanks laboratory assistants J. Ontl and O. Kundrátová for help in the work. 相似文献
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In conclusion the author wishes to thank Dr. E. Klier and R. Kuel for valuable discussions and advice. He thanks laboratory assistants J. Ontl and O. Kundrátová for help in the work. 相似文献