The influence of dielectric properties on the emission of a metal-dielectric-metal system: Angular distribution of emitted electrons

In two previous papers [1,2] the emission current from a sandwich cathode was calculated under various assumptions about the properties of the dielectric layer. The angular distribution of electrons emitted from this cathode is calculated in the present paper. The derived characteristics for the case of ideal dielectrics, dielectrics with phonons and traps are then compared with the experimental results from papers [3–5] and some conclusions are drawn about the dielectric layer. It is shown that isotropic angular distribution requires extraordinarily short mean free paths for elastic interactions (equal to several Å) and large mean free paths for collisions with traps (at least larger than several tens Å).     

Extended frequency range measurements for determining the Kneser-type acoustic relaxation time

In the present paper, the authors discuss studies carried out for many years dealing particularly with two compounds: benzene and carbon disulphide and compare them with the results obtained by numerous acoustics researchers. These compounds are typical liquids in which acoustic Kneser-type relaxation occurs, caused by an irreversible vibrational and translational (VT) transition. Since magnitudes describing the relaxation process were diverse in many papers, we have undertaken an attempt to clarify these differences and to indicate how to avoid errors resulting from instrumental imperfections and the disregard of the considerable measurement errors when investigating velocity dispersion in the hypersonic (GHz) range. The results of these researches changed the interpretation of previous papers.     

On contour crossings in contour-advective simulations – part 2 – analysis of crossing errors and methods for their prevention

This is the second of two papers devoted to the analysis of contour crossing errors that occur in contour-advective simulations of fluid motion, where either vorticity or potential vorticity is represented by contours. We begin with a detailed discussion on some of the potential mechanisms for contour crossing. Past work has suggested that the formation of contour crossings is due to inadequate spatial resolution of contours [1]. The implementation of two schemes for preventing contour crossings within the framework of the Contour-Advective Semi-Lagrangian (CASL) algorithm is detailed here. We then present an analysis of contour crossing errors in simulations of quasigeostrophic turbulence on the f-plane and the quasigeostrophic motion of an initially circular vortex patch on the β-plane using the algorithm detailed in Part 1. We find that in general individual crossings occur at scales smaller than the inversion grid scale on which velocity is calculated, but at scales larger than that of the surgical scale that defines the smallest resolved features (vorticity) of a flow. If the resolution of a quasigeostrophic turbulence simulation on the f-plane is increased by doubling the number of grid points in each coordinate direction used in the calculation of the velocity field, then the total area in error due to contour crossings remains unchanged; a smaller number of crossings introducing larger scale area errors is replaced by a greater number of smaller local errors. Uniformly increasing the density of nodes along all contours and placement of nodes at points of close approach on contours are both effective methods for limiting contour crossings.     

On the dependence of the laser-induced incandescence (LII) signal on soot volume fraction for variations in particle size

“The laser-induced incandescence (LII) signal is proportional to soot volume fraction” is an often used statement in scientific papers, and it has – within experimental uncertainties – been validated in comparisons with other diagnostic techniques in several investigations. In 1984 it was shown theoretically in a paper by Melton that there is a deviation from this statement in that the presence of larger particles leads to some overestimation of soot volume fractions. In the present paper we present a detailed theoretical investigation of how the soot particle size influences the relationship between LII signal and soot volume fraction for different experimental conditions. Several parameters have been varied; detection wavelength, time and delay of detection gate, ambient gas temperature and pressure, laser fluence, level of aggregation and spatial profile. Based on these results we are able, firstly, to understand how experimental conditions should be chosen in order to minimize the errors introduced when assuming a linear dependence between the signal and volume fraction and secondly, to obtain knowledge on how to use this information to obtain more accurate soot volume fraction data if the particle size is known. PACS 42.62.-b; 44.40.+a; 61.46.Df; 78.70.-g; 65.80.+n     

Quantized Flag Manifolds and Irreducible *-Representations

In this paper we fill some gaps in the arguments of our previous papers [1,2]. In particular, we give a proof that the L operators of Conformal Field Theory indeed satisfy the defining relations of the Yang–Baxter algebra. Among other results we present a derivation of the functional relations satisfied by T and Q operators and a proof of the basic analyticity assumptions for these operators used in [1,2]. Received: 20 May 1998 / Accepted: 7 July 1998     

Foundations of Quantum Mechanics: The Connection Between QM and the Central Limit Theorem

In this paper we unravel the connection between the quantum mechanical formalism and the Central limit theorem (CLT). We proceed to connect the results coming from this theorem with the derivations of the Schrödinger equation from the Liouville equation, presented by ourselves in other papers. In those papers we had used the concept of an infinitesimal parameter x that raised some controversy. The status of this infinitesimal parameter is then elucidated in the framework of the CLT. Finally, we use the formal apparatus developed in our previous papers and the results of the present one to advance an alternative objective interpretation of quantum mechanics in which its relations with the classical framework are made explicit. The relations between our approach and those using the Wigner–Moyal transformation are also addressed.     

Effects of circuit parameters on the electrical explosion of wires

The numerous papers [1–4] on exploding wires give mainly qualitative explanations of some of the processes and inadequate quantitive evidence, in spite of the practical importance of the technique. The present paper reports the effects of source parameters (voltage, capacity, inductance, stored energy) and of load parameters (specific resistance, diameter, resistance) on the energy deposited in the wire before rupture, and on the time and rate of deposition.We are indebted to Professor A. A. Vorob'ev for his interest in this work.     

Does the onset of epileptic seizure start from a bifurcation point?

Detection of epileptic seizures is a major challenge of these days. There are lots of papers which pay their attention to this subject. Recently, some dynamical disease with attacks such as epilepsy are considered as a system in which critical slowing down can be seen before their attacks (seizure). Although there are not many researches on the prediction of seizures using this phenomenon. Recently [P. Milanowski, P. Suffczynski, Int. J. Neural Syst. 26, 1650053 (2016)] have investigated the application of critical slowing down indicators and surprisingly they found that only in 8% of nearby 300 epileptic patients have the evidence of critical slowing down before seizures. The main goal of this paper is finding the answer of the important question “can we trust that epileptic seizures are bifurcations in the neural system”. In order to find the answer, different studies on the prediction of seizure are investigated and we prove that features which are used in those papers are critical slowing down indicators although they are not aware of it. So we present some reasons for the occurrence of critical slowing down before the seizure. We hope that this study will be a motivation of future studies on the application of critical slowing down indicators for predicting epileptic seizures.     

The Arithmetic Mirror Symmetry and¶Calabi–Yau Manifolds

We extend our variant of mirror symmetry for K3 surfaces [GN3] and clarify its relation with mirror symmetry for Calabi-Yau manifolds. We introduce two classes (for the models A and B) of Calabi-Yau manifolds fibrated by K3 surfaces with some special Picard lattices. These two classes are related with automorphic forms on IV type domains which we studied in our papers [GN1]-[GN6]. Conjecturally these automorphic forms take part in the quantum intersection pairing for model A, Yukawa coupling for model B and mirror symmetry between these two classes of Calabi-Yau manifolds. Recently there were several papers by physicists where it was shown on some examples. We propose a problem of classification of introduced Calabi-Yau manifolds. Our papers [GN1]-[GN6] and [N3]-[N14] give hope that this is possible. They describe possible Picard or transcendental lattices of general K3 fibers of the Calabi-Yau manifolds.     

解不可压缩流体力学问题的降阶法Ⅲ、二阶有限元格式

在本系列文章里,我们提出一种新的求解不可压缩流体力学问题的有限元方法——降阶法。这种算法是通过寻找零散度空间V^h的一组简单的基函数从而对原来的混合有限元问题降阶来实现的。本文对于一人类解Ω⊂<R²上的Navier-Stokes方程的有限元格式(包括一些二阶格式和[4]中讨论的一阶格式)给出了空间V^h的基函数。最后给出几个算例。     

Corrections to “Space-like submanifolds in de Sitter spaces”: [J. Geom. Phys. 40 (2002) 370–378]

In this paper, we corrected some errors in [J. Geom. Phys. 40 (2002) 370]. In [J. Geom. Phys. 40 (2002) 370], the errors in Eqs. (32) and (44) influenced the conclusion of Theorem 3.1, Corollary 3.1 and Theorem 3.2.     

Experimental investigation of non-linear processes in quasi-optical resonator with paramagnetic

The following papers [1,2] are devoted to the experimental investigations of electron system in polarized nuclear target (PNT) materials and in particular in such substance as a paramagnetic complex HMBA (Cr^v). The processes of electron and nuclear system interactions in these matters were also considered [3,4].The purpose of a present paper is the study of a nuclear system paramagnetic complex HMBA (Cr^v) in a 1,2 - propylene glycol. The super high frequency (SHF) power of saturation is changed during our experiment.     

Corrected potential energy functions for constrained molecular dynamics

Atomic oscillations present in classical molecular dynamics restrict the step size that can be used. Multiple time stepping schemes offer only modest improvements, and implicit integrators are costly and inaccurate. The best approach may be to actually remove the highest frequency oscillations by constraining bond lengths and bond angles, thus permitting perhaps a 4-fold increase in the step size. However, omitting degrees of freedom produces errors in statistical averages, and rigid angles do not bend for strong excluded volume forces. These difficulties can be addressed by an enhanced treatment of holonomic constrained dynamics using ideas from papers of Fixman (1974) and Reich (1995, 1999). In particular, the 1995 paper proposes the use of “flexible” constraints, and the 1999 paper uses a modified potential energy function with rigid constraints to emulate flexible constraints. Presented here is a more direct and rigorous derivation of the latter approach, together with justification for the use of constraints in molecular modeling. With rigor comes limitations, so practical compromises are proposed: simplifications of the equations and their judicious application when assumptions are violated. Included are suggestions for new approaches.     

Bestimmung des Abschirmtensors der magnetischen Kernresonanz und des Tensors der magnetischen Suszeptibilität durch numerische Berechnung der Stromdichte in der Ladungsverteilung diamagnetischer Moleküle

Determination of the NMR Shielding Tensor and of the Tensor of Magnetic Susceptibility by Numerical Calculation of the Current Density in the Chargedistribution of Diamagnetic Molecules In papers [1] and [2] a semiclassical approach for calculation of the NMR shielding tensor and of the tensor of magnetic susceptibility of diamagnetic molecules was represented by SCHMIEDEL. In this method the equation of continuity for the currents in the electronic cloud induced by an external magnetic field must be solved. In this paper a method of numerical solution of this partial differential equation is developed. The H₂-molecule serves as an example to present the possibilities of this method.     

Kubo线性输运系数公式

在这篇短文中,作者对霍裕平等和陈式刚在文[1]—[4]中,提出的和争论的问题,陈述一些不同的看法。 关键词：     

Numerical studies of hyperbolic manifolds supporting diffusion in symplectic mappings

Diffusion in generic quasi integrable systems at small values of the perturbing parameters has been a very studied subject since the pioneering work of Arnold [3]. For moderate values of the perturbing parameter a different kind of diffusion occurs, the so called Chirikov diffusion, since the Chirikov’s papers [11, 13]. The two underlying mechanisms are different, the first has an analytic demonstration only on specific models, the second is based on an heuristic argument. Even if the relation between chaos and diffusion is far to be completely understood, a key role is played by the topology of hyperbolic manifolds related to the resonances. Different methods can be found in the literature for the detection of hyperbolic manifolds, at least for two dimensional systems. For higher dimensional ones some sophisticated methods have been recently developed (for a review see [55]). In this paper we review some of these methods and an easy tool of detection of invariant manifolds that we have developed based on the Fast Lyapunov Indicator. The relation between the topology of hyperbolic manifolds and diffusion is discussed in the framework of Arnold diffusion.     

D s lifetime,m b,m c and |V cb | in the heavy quark expansion

Zeitschrift für Physik C Particles and Fields - We present some straightforward applications of the QCD heavy quark expansion, stated in previous papers [1–3], to the inclusive widths of...