A theory of double exchange in infinite dimensions

This paper gives a simplified model of the double exchange which is a kind of indirect exchange interaction between localized magnetic moments. The presented model is solved exactly in the case of infinite - dimensional space. Equations for single-particle Green's function and magnetization of the localized spins subsystem are obtained. It is shown that our simple double exchange model reveals an instability to the ferromagnetic ordering of localized moments. Magnetic and electric properties of this system on Bethe lattice with are investigated in detail. Received: 24 January 1997 / Revised: 14 February 1997 / Received in final form: 18 August 1997 / Accepted: 25 August 1997     

Atomic beam deflection by coherent momentum transfer and the dependence on weak magnetic fields

The deflection of Ne atoms in the metastable state ³ P ₂ by coherent transfer of the momenta of 4 or 8 photons is demonstrated, based on the technique developed for coherent population transfer with delayed pulses (STIRAP). After deflection the intensity profile of the isotope of mass 20 is fully seperated from that for the undeflected atoms of mass 22. It is furthermore shown, how the interplay of Larmor precession of the electronic magnetic moment and the sequential deflection in two spatially separated zones can be used to measure the magnetic field, integrated over the flight-path between the transfer zones. Received: 1 October 1997 / Revised: 22 December 1997 / Accepted: 11 March 1998     

A lattice gas model for enzyme kinetics (a correlated walks' theory and variational procedures)

Summary We have shown that, by using a correlated walks' theory or variational procedures, for the lattice gas model we can find for enzyme kinetics some new equations, which in the limit of no interactions between sites reduce to the classical Michaelis-Henri equation. These new equations can be useful for the experimental investigation.     

On the formation of dissipative spatial patterns of charge carriers in biosystems

Summary It is shown that in systems like large aggregates of biological molecules, population inversion of charge carriers, for example as produced by photoexcitation processes, may have competitive advantage beyond critical levels of excitation to produce ordered spatial structures (morphological transitions). In our analysis electromagnetic radiation transfers electrons from bonding states into a continuum of itinerant antibonding states in ap-type doped sample. In this system, in which energy is pumped continuously by an external source, the interplay of collective and dissipative processes can be responsible for the condensation of a self-organized spatially ordered structure. The study we present here is carried out resorting to the powerful nonequilibrium statistical operator method, thus showing that it can be provide a mechano-statistical formalism at the microscopic level for the treatment of Prigogine's synergetic dissipative structures. The authors of this paper have agreed to not receive the proofs for correction     

Modulated Weiner process

Summary We define and develop a novel process, related to stochastic resonance, in which a particle experiences three forces: a constant drift, a zero-mean white noise, and a time-periodic modulation. Upon reaching a threshold, the particle immediately returns to the starting point. The resulting process exhibits multiple maxima in the output power at the modulation frequency as a function of the white-noise variance, multimodal first-passage-time densities, and evidence of phase locking. Our model is an extension of the Gerstein-Mandelbrot model of neuron firing to the case of periodic stimuli, and therefore has applications in neural modeling. Paper presented at the International Workshop ?Fluctuations in Physics and Biology: Stochastic Resonance, Signal Processing and Related Phenomena?, Elba, 5–10 June 1994.     

三值线性时序机(TLSM)及其在三值序列滤波器与发生器中的应用

本文提出了三值线性时序机(TLSM)模型.并提出了基于文献[4]的三值D型触发器的三值序列滤波器与三值序列发生器的设计,讨论了三值序列发生器在保密通信中的应用.     

Semantics and factor analysis: An approach to the interpretation of factors

The interpretation of factors constitutes a major problem in factor analysis. Until now the underlying semantic aspects of the question have been studied only occasionally. However, there are some indications that the mechanical interpretation of the results may constitute in the immediate future a real need in the realm of very large problems. On the other hand, the semantic study of multivariate statistical methods is the only way to warrant the validity of the mechanization procedures and the means to identify their limits.     

大型精密仪器的在线测试维修技术

本文概述了国内外大型智能仪器维修工作的现场在线测试方法,介绍了各种主要新技术及方法的特点,谈了实际工作中的一些体会和看法,强调了在维修工作中采用新技术、新设备的重要性。     

Optical stack filters using parallel fuzzy logic

Stack filters are more general and robust nonlinear filters than median filter, which possess threshold decomposition and stacking properties. Stack filters can be carried out one step using optical parallel fuzzy logic technique instead of three steps in threshold decomposition. All window, width 3 stack filters but two trivial stack filters are expressed in unified expression with coefficiencies to choose desired stack filter, so they are realized by an optical approach, window 3×3 separable stack filters can be realized by cascading the window width 3 stack filters. Window width 5 stack filters can be realized using the same method.     

基于开关信号理论的三值IZL单变贵电路设计

本文应用开关信号理论的基本思想，分别用开关变量及三值信号变量来描写IZL电路!}?地开关晶体管的开关状态与三值电流信号·联结这两类变量的!}J比较运算和接地运算则用于描写电路内部开关元件与信号的相互作用过程，从而引入了适用于IzL电路的接地电流开关理论.基于该理论，本文对几类重要的三值IzL单变量电路进行了设计，结果表明，借助该理论能获得较简单的电路设计.