Showing papers in "Physics-Uspekhi in 1960"
TL;DR: In this paper, the double-time temperature-dependent Green functions are used in the theory of irreversible processes, and the relation between the two functions and the Spectral Representation of Spectral Spectral Functions is discussed.
Abstract: 1. Introduction 320 2. Double-time temperature-dependent Green functions 321 3. Spectral representations 324 4. Green functions in the theory of irreversible processes 326 5. Perfect quantum gases 328 6. Application to the theory of superconductivity 330 7. Application to the theory of ferromagnetism 336 8. Electron-lattice interaction 338 9.Conclusions 342
1,577 citations
TL;DR: In this article, the principle properties of the two-period Green's function and their simplest application in irreversible process theory, in the theory of superconductors, in ferromagnetics, and in electron- lattice reactions in common metals and semiconductors are discussed.
Abstract: Various aspects of the application of Green's functions in statistical physics are reviewed, and the future applications of two-period functions (retarding and advancing) are analyzed. The principle properties of the two- period Green's function and their simplest application in irreversible process theory, in the theory of superconductors, in ferromagnetics, and in electron- lattice reactions in common metals and semiconductors are discussed. It is also shown that the causal Green's functions can be successfully replaced with retarding and advancing Green's functions in the analytical expansion of the complex plane. Statistical mechanics sometimes employs the Motsubara temperature Green's functions which are not related to time; however, they are less adaptable than the temperature-time Green's functions. (R.V.J.)
933 citations
396 citations
TL;DR: In this paper, the authors investigated the role of self-action in the propagation of a radio wave in the ionosphere of a homogeneous electric field and showed that the effect of cross-modulation in Isotropic Plasmas can be seen as a function of the number of collisions with neutral particles.
Abstract: Introduction 139 1. Plasma in a Homogeneous Electric Field (Elementary Theory) 141 1.1. Electron Current. Dielectric Permittivity and Conductance of Plasma 141 1.2. Electron Temperature 143 2. Plasma in Homogeneous Electric Fields (Kinetic Theory) 147 2.1. Kinetic Equation 147 2.2. Transformation of the Collision Integral 150 a) Elastic Collisions with Neutral Particles (Molecules) 150 b) Inelastic Collisions with Neutral Particles 152 c) Collisions with Ions 153 d) Collisions between Electrons 154 2.3. Solution of Kinetic Equation. Stronglyionized Plasma 155 a) Distribution Function (Maxwellian Distribution) 156 b) Effective Number of Collisions 158 c) Relative Fraction of Energy Transfer 158 d) Electron Current. Dielectric Permittivity and Conductance of Plasma 159 e) Electron Temperature 162 2.4. Weakly-ionized Plasma 163 a) Case of Elastic Collisions 163 b) Molecular Plasma 164 c) Inert Gases 165 d) Electron Current and Average Electron Energy 166 2.5. Arbitrary Degree of Ionization. Elementary Theory 166 a) Transition for Strongly-ionized to Weakly-ionized Plasma 166 b) Conditions of Validity of Elementary Theory 168 3. Nonlinear Effect in the Propagation of Radio Waves in a Plasma (Ionosphere) 3.1. Propagation of a Radio Wave in a Plasma with Allowance for Nonlinearity (Self Action of the Plasma) 3.2. Role of Self Action of a Plasma in the Propagation of Waves in the Ionosphere a) Short Waves (λ≤ 200 m; ω ≥ 107). b) Average Waves (200 2000 m; ω < 106). d) Resonant Self-remodulation near the Gyro Frequency 3.3. Nonlinear Interaction of Modulated Radio Waves (Cross Modulation), a) Cross Modulation in Isotropic Plasma, b) Calculation of the Effect of a Permanent Magnetic Field. Resonant Effects near the Gyro Frequency 3.4. Results of Experimental Investigations of Cross Modulation in the Ionosphere. a) Absolute Value of Depth of Cross Modulation, b) Dependence of μΩ and ΦΩ on μ0 and Ω, n) Dependence of μΩ on the Power of the Interfering Station, d) Dependence of μΩ on the Frequencies ω1 and ω2. e) Resonance of Cross Modulation at ω1 ~ ωH. 3.5. Nonlinear Interaction of Unmodulated Radio Waves, a) Variation of Conditions of Wave Propagation, b) Sideband Waves (Waves with Combination Frequencies). c) Nonlinear Effects Connected with Variation of the Electron Concentration Concluding Remarks Literature Cited
204 citations
89 citations
TL;DR: In this paper, the quantum theory of scattering of Electrons with an Abritrary Dispersion Law has been studied in the context of quantum mechanics of a particle with an arbitrary Dispersion law.
Abstract: 1. Introduction 831 2. Geometry of Constant-Energy Surfaces for Electrons 833 3. Classical Mechanics of a Particle with an Arbitrary Dispersion Law 835 4. Collisions of Quasiparticles. Scattering 841 5. Quasiclassical Energy Levels 843 6. Quantum Mechanics of an Electron with an Arbitrary Dispersion Law 848 7. Quantum Theory of Scattering of Electrons with an Abritrary Dispersion Law 853
67 citations
TL;DR: In this paper, Cerenkov Radiation and Absorption of Waves in an Isotropic Magneto-Active Plasma (IMP) is discussed. But this is not the case in the case of superlight motion.
Abstract: Introduction 874 1. Characteristic Features of Radiation Due to Superlight Motion (Classical Theory) 874 2. Quantum Theory of Radiation and Absorption Due to Superlight Motion 876 3. Radiation Reaction Force for Motion of a Charge in a Medium 880 4. Cerenkov Radiation and Absorption of Waves in an Isotropic Magnetoactive Plasma 883 5. Cerenkov Radiation of Dipole Moments in a Continuous Medium and in Channels and Slits 87 Literature References 891
61 citations
TL;DR: In this article, collective excitation spectra in systems of interacting particles and energy losses in the excitation (within Bose statistics) of collective oscillations during the passage of particles through substances are discussed.
Abstract: Collective excitation spectra in systems of interacting particles and energy losses in the excitation (within Bose statistics) of collective oscillations during the passage of particles through substances are discussed. Kinetic equations for the distribution quantum function, the collective oscillation spectra in self-consistent field approximation, the influence of particle correlation on collective oscillation and excitation spectra, and the phenomenological theory of degenerate electron Fermi liquid are analyzed. Energy losses related to the excitation of collective oscillations in the medium and the non-linear effects in charged particle passage through plasma are also considered 109 references. (R.V.J.)
48 citations
25 citations
22 citations
TL;DR: A review of available data on the formation of multi-charged particles in nuclear fission and on the mecharism of nuclear Fission at high excitation energies is presented in this article.
Abstract: A review is presented of available data on the formation of multi- charged particles in nuclear fission and on the mecharism of nuclear fission at high excitation energies, a phenomena of special interest among the processes eccurring during high-energy particle interactions with nuclei. (R.V.J.)
TL;DR: In this article, the authors describe light and the properties of the medium in the Scattering Act and the Polarization Map of the Sky; the Anisotropy of Molecules and Multiple Scattering 358 6.
Abstract: 1. Introduction 346 2. The Puzzle of the Daytime Sky and the Discovery of Light Scattering 347 3. Description of Light and the Properties of the Medium in the Scattering Act 352 4. Atmospheric Transmission and the Aerosol 354 5. The Polarization Map of the Sky; the Anisotropy of Molecules and Multiple Scattering 358 6. The Brightness Map of the Sky and the Scattering Function 361 7. Optical Probing of the Atmosphere and the Problem of Interpretation of the Data 364 8. Propagation of Light in Clouds and Fogs and Similar Problems 368 9. Radiation Climatology and the Optics of the Aerosol 368
TL;DR: In this article, an analysis is made of the two separate high-intensityradiation regions discovered by artificial satellites and cosmic rockets, where gas discharge and scintillation counters were used for recording cosmic radiations.
Abstract: An analysis is made of the two separate high-intensityradiation regions discovered by artificial satellites and cosmic rockets. Gas discharge and scintillation counters were used for recording cosmic radiations. The design of the instrumentation is presented. Data recorded by the second and third "Sputniks" show the presence of an outer radiation belt consisting of electrons with energies of 100 kev. It was also shown that the belt is strongly limited by a high latitude region.
TL;DR: In this paper, the shape of the sigma curve (v) as a function of the properties of the interacting particle pair is analyzed and the dependence of the cross section maximum on the various factors.
Abstract: The apparatus and methods used for measuring effective cross sections of negative ion prcduction in nuclear collisions are described. Measurements of various effective cross sections are discussed. Problems which include the shape of the sigma curve (v) as functions of the properties of the interacting particle pair, the interpretation of the sigma (v) curve shape based on the adiabatic Messi criteria with consideration of the participation of excited particle in the process; and the sigma (v) curve at small velocities STA(a/ DELTA E/ hv >> 1)! and at vc > v/max are analyzed as well as the dependence of the cross section maximum on the various factors. Data are presented on slow negative ion prcduction in nuclear collisions. (R.V.J.)
TL;DR: A general analysis and evaluation of data, presented at the International Conference on Cosmic Radiation in Moscow, July 1959, on the origin of cosmic rays is made of data as mentioned in this paper, which includes basic and new data on primary cosmic radiation, life-time and motion of the cosmic rays, on cosmic ray sources and the mechanism of their acceleration.
Abstract: A general analysis and evaluation are made of data, presented at the International Conference on Cosmic Radiation in Moscow, July 1959, on the origin of cosmic rays. Basic and new data on primary cosmic radiation, on the life-time and motion of cosmic rays, on cosmic ray sources and the mechanism of their acceleration, and on the transformation of nuclear component in cosmic radiation are discussed. 144 references. (R.V.J.)
TL;DR: In this article, the authors proposed a solution of the basic Equations of the Theory for light and heavy components. But the solution was not suitable for the case of heavy components, and the results were unsatisfactory.
Abstract: I. Basic Equations of the Theory 912 1. Basic Equations of the Theory 912 2. The Probabilities of the Basic Processes 914 II. Solution of the Basic Equations of the Theory. The method of functional transformations 916 3. Solution by the Double Functional Transformation Method 916 4. S. Z. Belen'kiĭ's method 918 5. The Scott, Snyder, Bhabha, and Chakrabarty Method 922 6. The Gupta and Chakrabarty Method 929 7. The Solution of Generalized Equations of the Theory 931 8. Other Methods of Solution 933 9. The Cascade Theory for Heavy Substances 934 III. Solution of the Basic Equations of the Theory. The Method of Moments 936 10. Calculating the Moments of the Distribution Functions of Cascade Particles 936 11. The Electron and Photon Equilibrium Spectrum 938 12. Regular Method of Plotting Cascade Curves by Moments 941 13. Cascade Curves and Energy Spectra in Light Substances 943 14. Cascade Curves and Energy Spectra in Heavy Substances 951
TL;DR: In this paper, the authors examine present physical ideas about the strength of crystalline materials, the reasons for the low strength of real materials, and also the main ways of increasing their strength.
Abstract: Present-day technology makes greater and greater demands on the strength properties of materials. A physical theory of strength has not yet been developed, although the last 30 or 40 years have seen the development of a new branch of molecular physics which is concerned with the study of the deformation and fracture of solid materials. In this review we examine present physical ideas about the strength of crystalline materials, the reasons for the low strength of real materials, and also the main ways of increasing their strength.
TL;DR: In this article, a review is given of various radio methods in investigating the electromagnetic properties of the ionosphere and interplanetary gas (at 300 to 400 km) by means of artificial satellites and cosmic rockets.
Abstract: A review is given of various radio methods in investigating the electromagnetic properties of the ionosphere and interplanetary gas (at 300 to 400 km) by means of artificial satellites and cosmic rockets. Special attention is paid to interactions of moving bodies with plasma. An account is satellites and cosmic rockets. Special attention is paid to interactions of moving bodies with plasma. An account is given of the data on the electromagnetic properties of the media (the density of charged particles, elastic interactions between particles, electron and ion heterogeneous formations, plasma waves, electromagnetic particle emission. etc.) 49 references. (R.V.J.)
TL;DR: In this article, an analysis was made of complex heavy-nucleus fission in which three charged particles are emitted, and the probabilities of complex fission and the energy and angular distributions of the long range alpha particle were discussed.
Abstract: S>An analysis was made of complex heavy-nucleus fission in which three charged particles are emitted. The threeparticle event is rare in the binary fission background. A thind long range alpha particle was observed, in a photographic film saturated with uranium salt and irradiated by thermal neutrons. The probabilities of complex fission and the energy and angular distributions of the long range alpha particle are discussed, as well as the energy spectrum of triple-fission fragments and the hypothesis on triplefission mechanisms. 31 references. (R.V.J.)
TL;DR: In this paper, overhauser effect in liquid and solid Diamagnets with Paramagnetic Impurities is discussed. But the authors focus on the point of view of Statistical Physics and Thermodynamics.
Abstract: 1. Introduction 285 2. Contact Interaction between the Electron and Nuclear Spins 286 3. Saturation of Paramagnetic Resonance 288 4. Hyperfine Structure of Paramagnetic Resonance 290 5. Overhauser Effect with Complete Saturation of all Components 291 6. Overhauser Effect in Metals 293 7. Overhauser Effect in Liquid and Solid Diamagnets with Paramagnetic Impurities 298 8. Overhauser Effect in Paramagnetic Salts and Semiconductors 304 9. Overhauser Effect in Alkali-Halide Crystals and Alkali-Ammonia Solutions 308 10. Overhauser Effect from the Point of View of General Principles of Statistical Physics and Thermodynamics 309 11. Nonstationary Methods 310 12. Conclusion 317