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91.
Let {ø n (dμ)} be a system of orthonormal polynomials on the unit circle with respect to a measuredμ. Szegö's theory is concerned with the asymptotic behavior ofø n (dμ) when logμ′∈L 1. In what follows we will discuss the asymptotic behavior of the ratioø n (dμ 2)/ø n (dμ 1) on the unit circle whendμ 1 anddμ 2 are close in a sense (e.g.,dμ 2=gdμ 1, where g≥0 is such thatQ(e it )g(t) andQ(e it )/g(t) are bounded for a suitable polynomialQ) and μ 1 ′ >0 almost everywhere or (a somewhat weaker requirement) lim n→∞Φ n (dμ 1,0)=0 for the monic polynomial Φ n . The asymptotic behavior of the same fraction outside the unit circle was discussed in an earlier paper. 相似文献
92.
I. Pelant M. N. Popova J. Hála M. AmbroŽ V. Lhotská K. Vacek 《Czechoslovak Journal of Physics》1987,37(10):1183-1197
Dependence of two-photon absorption (TPA) rate on the state of polarization of a laser beam is investigated in the low-temperature orthorhombic modification of Hg2Cl2 crystals. Theoretical calculations of the dependence of TPA rate on the direction of polarization vector of the beam are performed for centrosymmetric points, Y, Z, T, R andS of the Brillouin zone. The domain structure of real crystals is taken into consideration and it is shown that periodicity of the polarization dependence may indicate whether TPA is due to transitions either at, Y, Z, T orR, S points. The polarization dependence of TPA cannot, however, distinguish between points inside these two groups. Comparison of theory with a low-temperature (T 8·5 K) experimental curve of polarization dependence is discussed. It is shown that the experiment can be explained in main features by a model of noninteracting oriented linear dipoles. Further, on the basis of TPA measurements, a simple energy band structure of Hg2Cl2 is proposed regarding Hg2Cl2 crystal as a linear chain of molecules.The authors express thanks to Dr. . Barta for supplying the Hg2Cl2 crystals, Dr. Z. Bryknar for critical comments and Dr. B. Velický for stimulating discussion. We thank also Dr. V. Kohlová for assistance during measurement. 相似文献
93.
B. Barabás 《Periodica Mathematica Hungarica》1987,18(2):115-122
The properties of the empirical density function,f
n(x) = k/n(
j
+
–
j-1
+
) if
j-1
+
< x + where
j-1
+
and
j
+
are sample elements and there are exactlyk – 1 sample elements between them, are studied in that practical point of view how to choose a suitablek for a good estimation. A bound is given for the expected value of the absolute value of difference between the empirical and theoretical density functions. 相似文献
94.
L. Eckertová 《Czechoslovak Journal of Physics》1987,37(6):749-758
A simple model including different processes important for the creation of APS signals formed by electrons is proposed. Mean probabilities of elastic and inelastic interactions of electrons with individual atom layers in the solid are introduced. The contribution of different layers to the DAPS and AEPS signals and the dependence of these signals on the interaction parameters are calculated.I am indebted to dr. J. Pavluch for valuable discussions. 相似文献
95.
L. Avanov N. Borodkova Z. NĚmeček A. Omeltchenko J. Šafránková A. Skalski Yu. Yermolaev G. Zastenker 《Czechoslovak Journal of Physics》1987,37(6):759-774
The paper describes the results of investigations of the solar wind ions, carried out on board the high apogee Prognoz 7 and Prognoz 8 Earth's satellites with the aid of an SKS instrument (USSR) and a Monitor instrument (USSR-SSR). Behaviour of proton and that of components on the front of Earth's bow and interplanetary shock waves were compared by means of the energoanalysis and energy-mass analysis techniques. In several long-term periods of observation the solar wind heavy ions — oxygen, silicon and iron were determined. It enabled us to estimate the solar corona chemical composition and electron temperature.Presented at the 5th General Assembly IAGA/IAMAP August 5–17, 1985, Prague, Czechoslovakia. 相似文献
96.
The dependence of the flow stress and the slip band density on the plastic strain has been measured at 201 K, 293 K and 363 K. The growth of deformation concentrated in an average slip band has been stated. The types of obstacles acting against the rise and development of a slip band and the temperature dependence of the strain hardening in AgCl crystals are discussed. An equation stating the dependence of the flow stress on the slip band density is presented. The hardening in AgCl crystals is classified as the stage III — hardening. 相似文献
97.
A hybrid method for measuring the electron distribution function in the low temperature plasma is described. The time resolution of the measurement is of the order of several sec. 相似文献
98.
99.
O. Čermáková 《Czechoslovak Journal of Physics》1986,36(9):1058-1062
This contribution presents birefringence spectra for orthorhombic YAlO3Ce single crystal in the region 2–5 eV. The spectra were measured by means of a reflection method of null ellipsometry and were compared with spectra of YAlO3:Nd determined from values measured in the region of lower energies (1·1–2·2 eV). We have found that there are differences between the spectra of YAlO3Nd and YAlO3:Ce which are most pronounced in thea-axis direction.The author is most grateful to Ing. . Viovský CSc. for helpful discussions during the course of this work and to Monokrystaly Turnov for preparation of the samples. 相似文献
100.
Multiplicity distributions up to the Collider energies could be described by various two-parameter compounded distributions having in common Poisson distributed number of clusters. Among them the logarithmic distribution for hadronization via decaying clusters leads to energyindependent number of clusters above the ISR energies, replacing the previous KNO-scaling.Dedicated to the 30th anniversary of the Joint Institute for Nuclear Research. 相似文献