Josephson plasmon and inhomogeneous superconducting state in La2-xSrxCuO4

We report on the interlayer far infrared response for a series of La2-xSrxCuO4 crystals with 0.08相似文献   

Theoretical investigation of promising methods of improving the energy characteristics of CW industrial electron-beam-controlled lasers

The thermodynamic gasdynamic parameters of the active media of subsonic and supersonic open- and closed-cycle electron-beam-controlled lasers (EBCL) are theoretically calculated. The optimal characteristics of the pumping system and of the thermal regimes of the active medium, which permit a considerable improvement of the energy characteristics of the EBCL, are calculated. The investigations make it possible to increase the efficiency and the working-medium pressure of cw electron-beam-controlled lasers and decrease the dimensions of the laser installations.Translated from Trudy Ordena Lenina Fizicheskogo Instituta im. P. N. Lebedeva, Vol. 142, pp. 95–116, 1983.     

Trends in electronic-transition chemical lasers

A new class of chemical lasers based on electronic transitions of atoms, radicals, or molecules excited via oxidation chain reactions in the presence of catalysts is proposed and discussed. The possibility is considered of using these processes to realize four lasing schemes: directly via transitions of excited intermediate products, in an exchange chemical laser, using narrowband chemical lamps, and in chemical-excimer lasers. A number of specific active mixtures are proposed. The gain of a realizable chemical Na-BaOlaser is calculated. The possibility of using chemical reactions with participation of cluster molecules are analyzed. The use of atoms as acceptor (emitting) particles is discussed. Two methods of obtaining increased atom densities are proposed. Certain possibilities of obtaining cw lasing on self-limiting atom transitions are considered.This preprint is the text of a paper delivered at the 3rd International Conference on Trends in Quantum Electronics, Bucharest, 29 August-3 September 1988.Translated from Preprint No. 36 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1989.     

Two-dimensional homogeneous cubic systems: Classification and normal forms. I

This work is the first in a series of papers devoted to classifying of two-dimensional homogeneous cubic systems based on partitioning into classes of linear equivalence. Principles have been developed that are capable of constructively distinguishing the structure of a simplest system in each class and a canonical set that defines the admissible values that can be assumed by its coefficients. The polynomial vector in the right-hand part of this system identified with a 2 × 4 matrix is called the canonical form (CF) and the system itself is called the normal cubic form. One of the main objectives of this series of papers is to maximally simplify the reduction of a system with a homogeneous cubic polynomial in the unperturbed part to the various structures of a generalized normal form (GNF). Generalized normal form refers to a system in which the perturbed part has the simplest form in some sense. The constructive implementation of the normalization process depends on the ability to explicitly specify the conditions of compatibility and possible solutions of the so-called bonding system, which is understood to be a countable set of linear algebraic equations that specify the normalizing transformations of the perturbed system. The above principles are based on the idea of the maximum possible simplification of the bonding system. This will allow one to first reduce the initial perturbed system by an invertible linear substitution of variables to a system with some CF in the unperturbed part, then reduce the resulting system, which is optimal for normalization, by almost identical substitutions to various structures of the GNF. In this paper, the following tasks are carried out: (1) the general problem is set, close problems are formulated, and the available results are described; (2) a bonding system is derived that is capable of determining the equivalence of any two perturbed systems with the same homogeneous cubic part, the possibilities of its simplification are discussed, the GNF is defined, and the method of resonant equations is given allowing one to constructively obtain all its structures; (3) special forms of recording homogeneous cubic systems in the presence of a common homogeneous factor in their right-hand parts with a degree of 1–3 are introduced, and the linear equivalence of these systems, as well as of systems without a common factor is studied, and key linear invariants are offered.     

Two-dimensional homogeneous cubic systems: Classification and normal forms II

This work is the second in a series of papers concerning two-dimensional homogeneous cubic systems. In the first paper of the series, structural principles were developed to introduce a total order on the set of structural forms, i.e., vector polynomials with a fixed number of zero coefficients that are right-hand sides of two-dimensional homogeneous cubic systems of ODEs. Among them, structural forms normalized on the basis of normalization principles and canonical forms (CFs) that are linearly nonequivalent to each other and are the simplest in their class were sequentially distinguished. In this paper, for above-mentioned systems with proportional right-hand side components, all CFs with their canonical sets of permissible values are distinguished. For each CF, (a) conditions on the coefficients of the original system, (b) linear substitutions that reduce the right-hand side of a system under these conditions to the chosen CF, and (c) the resulting values of the CF’s coefficients are given.     

High-power 20-channel neodymium glass laser and combined laser and beam heating of a plasma

A high-power 20-channel neodymium-glass laser is described (energy i kJ, pulse duration 2 nsec). It is part of the Flora facility intended for combined simultaneous heating of a plasma by powerful laser radiation (PLR) and by a relativistic electron beam (REB) produced in a facility of the plasma focus type. The paper deals theoretically with the processes of combined interaction of PLR and REB with a current plasma and a solid target.Translated from Trudy Ordena Lenina Fizicheskogo Instituta im. P. N. Lebedeva, Vol. 103, pp. 202–230, 1978.     

Electronic correlations and unconventional spectral weight transfer in the high-temperature pnictide BaFe(2-x)Co(x)As(2) superconductor using infrared spectroscopy

We report an infrared optical study of the pnictide high-temperature superconductor BaFe(1.84)Co(0.16)As(2) and its parent compound BaFe(2)As(2). We demonstrate that electronic correlations are moderately strong and do not change across the spin-density wave transition or with doping. By examining the energy scale and direction of spectral weight transfer, we argue that Hund's coupling J is the primary mechanism that gives rise to correlations.