共查询到20条相似文献,搜索用时 31 毫秒
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Results of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of
the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric
depositional fluxes of 7Be, 60Co and 137Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated
Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the 137Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the 137Cs activity concentration of up to 17.4 μBq m−3 on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium
resuspension from the Chernobyl NPP accident polluted regions are sources of 137Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols — carriers of 137Cs — are discussed. 相似文献
3.
A. Ghosh S.K. Adhikari 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(1):31-36
The solutions of a renormalized BCS equation are studied in three space dimensions in s, p and d waves for finite-range separable
potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model yields a small coherence
length and a large critical temperature, , appropriate for some high- materials. The BCS gap, , and specific heat as a function of zero-temperature condensation energy are found to exhibit potential-independent universal scalings. The
entropy, specific heat, spin susceptibility and penetration depth as a function of temperature exhibit universal scaling below
in p and d waves.
Received: 18 July 1997 / Revised: 8 September 1997 / Accepted: 29 September 1997 相似文献
4.
The thermal instability of a layer of Rivlin-Ericksen elastico-viscous fluid in porous medium acted on by a uniform magnetic field is considered. For stationary convection, Rivlin-Ericksen elastico-viscous fluid behaves like a Newtonian fluid. The magnetic field is found to have stabilizing effect whereas medium permeability has destabilizing effect. The magnetic field introduces oscillatory modes in the system, A sufficient condition for the non-existence of overstability is also obtained. 相似文献
5.
It is shown that bulk semiconductors exhibit strongly asymmetric Fano-type resonance profiles in magnetoabsorption processes
involving the formation of hot electron-hole pairs (EHPs) and accompanied by the scattering of the EHPs by defects. This result
is valid for transitions to electronic states with large Landau quantum numbers, when the Coulomb interaction plays a small
role. The physical reason for such a sharp change in the magnetoabsorption coefficient as compared with the expected result
for the ordinary density of states in a quantizing magnetic field is that the electronic excitations are quasi-one-dimensional.
The form of the resonance absorption is in good qualitative agreement with the experimental data.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 8, 619–622 (25 April 1996) 相似文献
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The concepts of uncertainty in prediction and inference are introduced and illustrated using the diffraction of light as an example. The close relationship between the concepts of uncertainty in inference and resolving power is noted. A general quantitative measure of uncertainty in inference can be obtained by means of the so-called statistical distance between probability distributions. When applied to quantum mechanics, this distance leads to a measure of the distinguishability of quantum states, which essentially is the absolute value of the matrix element between the states. The importance of this result to the quantum mechanical uncertainty principle is noted. The second part of the paper provides a derivation of the statistical distance on the basis of the so-called method of support. 相似文献
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We present the action and transformation laws of supergravity in 11 dimensions which is expected to be closely related to the O(8) theory in 4 dimensions after dimensional reduction. 相似文献
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S. Maslowski 《Optical and Quantum Electronics》1973,5(4):275-284
This paper offers a review of the contributions of German research groups in the field of fibre-optical communications until now. Since the latest publications are also taken into account which in part are not yet printed, a survey is given at the same time of current activities in this field in Germany. 相似文献
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M. N. Vinoslavskiĭ P. A. Belevskii A. V. Kravchenko 《Journal of Experimental and Theoretical Physics》2006,102(3):417-430
The self-organization of an electron-hole plasma (EHP) heated by an electric field in pure p-Ge samples at T = 77 K has been studied experimentally. The derived current-voltage characteristics (CVCs) and the distributions of the electric
field and IR emission of the hot carriers along the samples show that the segments of a steep rise or the S-shaped segments of the CVCs in samples with n-p junctions are related to the formation of longitudinal thermal-diffusion autosolitons (AS‖); as a result, thin (d = 2–20 μm in diameter), melted-through current channels appear. Such AS‖ are formed at high EHP densities (n ≥ 1 × 1016 cm−3), when the electron-hole scattering is dominant, and at electron temperatures T
e
= (2–4.5)T
0 (T
0 is the lattice temperature). The saturation segments and the N-shaped segments in the CVCs are attributable to the generation of transverse thermal-diffusion high-field autosolitons (AS⊥) in the form of narrow strata with electric field strengths
= 1–20 kV cm−1. High-field AS⊥ are formed at EHP densities n = 5 × 1013−1 × 1016 cm−3, when the electron-phonon scattering is dominant, and at electron temperatures T
e
∼ Θ ≥ 5T
0 (Θ is the Debye temperature). The generated longitudinal and transverse autosolitons have high temperatures (T
e
≥ 1000 K) and reduced carrier densities and can exist simultaneously in different parts of the sample.
Original Russian Text ? M.N. Vinoslavskiĭ, P.A. Belevskii, A.V. Kravchenko, 2006, published in Zhurnal éksperimental’noĭ i
Teoreticheskoĭ Fiziki, 2006, Vol. 129, No. 3, pp. 477–492. 相似文献
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In this paper, we investigate the data of industries in China and find that the frequency distributions of fixed assets and fixed-assets’ investment of industries obey power laws. We show that these power-law modes can be explained by the rules of the Simon Model, rather than the existing investment theories such as the classical investment theory or acceleration principle. Moreover, the mechanism of the investment distribution may be similar to the forest-fire model of self-organizing criticality. By introducing the complex system methods, this research changes the traditional opinion of the investment and gains some meaningful understanding in the dynamics of industries and the economic cycle. 相似文献
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I. N. Wischnewski H. V. Klapdor H. Fromm P. Herges 《Zeitschrift für Physik A Hadrons and Nuclei》1981,301(1):29-34
High spin states have been investigated by the reaction90Zr(19F, 3nγ), using an Anticompton spectrometer device, for the nucleus106In, for which no in-beamγ-spectroscopic information was available up to now. A level scheme has been constructed up to anI =(13,14) state. 相似文献
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V. I. Nazaruk 《The European Physical Journal A - Hadrons and Nuclei》2007,31(2):177-183
The role of strong absorption of particles in intermediate and final states has been considered. The range of applicability
of phenomenological models of absorption has been studied. This model is nonuniversal. Its applicability depends on the type
of interaction Hamiltonian and matrix element used. We also demonstrate that the violation of the unitarity condition can
produce a qualitative error in the results. The absorption (decay) in the final state does not tend to suppress the total
process probability as well as the probability of the channel corresponding to absorption. This is true for the reactions,
decays and nˉ conversion in the medium. 相似文献
18.
S. Gershman A. Belkind 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,60(3):661-672
A phenomenological picture of a pulsed electrical discharge in gas bubbles
in water is produced by combining electrical, spectroscopic, and imaging
characterization methods. The discharge is generated by applying 1 m\mu s
pulses of 5 to 20 kV between a needle and a disk electrode submerged in
water. An Ar gas bubble surrounds the tip of the needle electrode. Imaging,
electrical characteristics, and time-resolved optical emission spectroscopic
data suggest a fast streamer propagation mechanism and the formation of a
plasma channel in the bubble. Comparing the electrical and imaging data for
consecutive pulses applied to the bubble at a frequency of 1 Hz indicates
that each discharge proceeds as an entirely new process with no memory of
the previous discharge aside from the presence of long-lived chemical
species, such as ozone and oxygen. Imaging and electrical data show the
presence of two discharge events during each applied voltage pulse, a
forward discharge near the beginning of the applied pulse depositing charge
on the surface of the bubble and a reverse discharge removing the
accumulated charge from the water/gas interface when the applied voltage is
turned off. The pd value of ~ 300–500 torr cm, the 1 μs long pulse duration, low repetition rate, and unidirectional character of
the applied voltage pulses make the discharge process here unique compared
to the traditional corona or dielectric barrier discharges. 相似文献
19.
On phase-coherence in rescattering in multiphoton ionization and in higher-order harmonic generation
Summary The recently discovered plateau and rings in high-order multiphoton ionization apparently have their origin in rescattering.
Similarly, rescattering is involved in higher-order harmonic generation. Using a simple one-dimensional model, it is shown
that the phase-coherence in this rescattering process is of considerable importance.
The authors of this paper have agreed to not receive the proofs for correction.
This work has been supported by the East-West Program of the Austrian Academy of Sciences and by the Austrian Ministry of
Science and Transportation under project no. 45.372/2-IV/6/97. One of us (JZK) acknowledges the support of the Polish Committee
of Scientific Research (grant KBN 2 P03B 007 13). 相似文献
20.
Vibro-acoustography is an imaging method based on audio-frequency harmonic vibrations induced in the object by the radiation force of focused ultrasound. The purpose of this study is to investigate features of vibro-acoustography images and manifestation of various tissue structures and calcifications in such images. Our motivation for this study is to pave the way for further in vitro and in vivo applications of vibro-acoustography. Here, vibro-acoustography images of excised prostate and in vivo breast are presented and compared with images obtained with other modalities. Resulting vibro-acoustography images obtained with a 3 MHz ultrasound transducer and at a vibration frequency of 50-60 kHz show soft tissue structures, tissue borders, and microcalcifications with high contrast, high resolution, and no speckle. It is concluded that vibro-acoustography offers features that may be valuable for diagnostic purposes. 相似文献