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181.
Electromagnetic fields are often used industrially to controlthe flow of liquid metal, and in particular this review is concernedwth applications of alternating fields. An alternating fieldinduces eddy currents in liquid metal which interact with thefield to give a Lorentz body force which is generally rotationaland which must therefore drive fluid motion. We derive generalexpressions for the Lorentz force, showing that it consistsof both steady and oscillatory components. The flow in a circularcylinder due to a rotating field is discussed in detail, sincethis problem is simple to analyse and illustrates several importantgeneral principles. In the high-frequency limit, the field isconfined to a narrow layer on the surface of the conductor,and we derive approximate methods for calculating the surfacemagnetic pressure andthe induced flow. We also examine the otherextreme of slowly alternating fields. As each problem is studied,we discuss practical applications. 相似文献
182.
P. Tekely V. G rardy P. Palmas D. Canet A. Retournard 《Solid state nuclear magnetic resonance》1995,4(6):361-367
A simple modification of the standard cross-polarization method designed for quenching the proton T1ρ dependence when studying polarization transfer is presented. It is demonstrated that by using this simple procedure, new and subtle details of cross-polarization dynamics, previously hidden by the T1ρ(1H) effect, can be observed in dipolar-coupled spin systems. 相似文献
183.
M. J. Gaylard G. C. MacLeod D. P. Smits M. E. West D. J. Walt 《Journal of chemical crystallography》1993,23(9):763-763
Future contributions toJournal of Crystallographic and Spectroscopic Research 相似文献
184.
We propose a complex approach to evaluating afunction sum of two noncommuting non-Hermitianoperators. We propose an explicit expansion of theevolution operator in the case of the neutral K-mesonsystem influenced by an external interaction. Theimportance is pointed out of considering the algebraicexpansion of the time evolution operator whenever thedynamics decouples the internal transitions andcenter-of-mass motion. 相似文献
185.
186.
Polarization dynamics are considered in the presence of an anisotropic Kerr non-linearity in the most common semiconductor waveguide geometry. The equations of motion are formulated in terms of Stokes polarization parameters and their Hamiltonian form is derived. Stationary solutions and their stability are found for plane-wave propagation. It is found that the non-integrable problem of mixed-polarization spatial soliton dynamics can be largely explained in terms of the equivalent plane-wave solutions. 相似文献
187.
D. B. Saakian 《JETP Letters》1998,67(6):440-444
A layered random spin model, equivalent to the generalized random energy model (GREM), is introduced. In analogy with diluted
spin systems, a diluted GREM (DGREM) is constructed. It can be applied to calculate approximately the thermodynamic properties
of spin glass models in low dimensions. For the Edwards-Anderson model it gives the correct critical dimension and 5% accuracy
for the ground state energy in two dimensions.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 6, 415–419 (25 March 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
188.
The 351 nm laser-damage thresholds (at 0.7 nm pulse length) of monomeric liquid crystals are reported and results from aromatic-core samples are compared with those from fully saturated systems. The role of π-electron conjugation is examined and identified as the key cause for laser damage. For UV laser compatibility of devices, the damage behaviour of an alignment-layer polymer (nylon 6/6) was also investigated. 相似文献
189.
Translated from Vychislitel'nye Kompleksy i Modelirovanie Slozhnykh Sistem, pp. 138–141, Moscow State University, 1989. 相似文献
190.
Two organic scintillators — NE104 and a liquid solution of 2,5 diphenyloxazole (PPO) — were investigated through positron annihilation spectroscopy to study the influence of the structural order on the magnetic quenching effect on positron bound systems in solids.Preliminary note in [11] 相似文献