Self-consistent field theory and calculation for gyromonotron

A self consistent field large signal theory of gyromonotron is studied in this paper. The RF field profile function satisfies a wave equation. The field is determined by cavity geometry and AC electron beam current. The RF field not only satisfies the boundary conditions at the ends of the cavity but also obeys conservation of energy for steady state interaction between electron beam and field. The parameters of a particular gyrotron are calculated numerically using present theory. Effect of some factors on gyrotron characteristic is discussed. Comparison is made between the results of the self consistent field calculations with and without conservation of energy.     

On the consistent histories approach to quantum mechanics

We review the consistent histories formulations of quantum mechanics developed by Griffiths, Omnès, and Gell-Mann and Hartle, and describe the classification of consistent sets. We illustrate some general features of consistent sets by a few simple lemmas and examples. We consider various interpretations of the formalism, and examine the new problems which arise in reconstructing the past and predicting the future. It is shown that Omnès' characterization of true statements—statements which can be deduced unconditionally in his interpretation—is incorrect. We examine critically Gell-Mann and Hartle's interpretation of the formalism, and in particular their discussions of communication, prediction, and retrodiction, and conclude that their explanation of the apparent persistence of quasiclassicality relies on assumptions about an as-yetunknown theory of experience. Our overall conclusion is that the consistent histories approach illustrates the need to supplement quantum mechanics by some selection principle in order to produce a fundamental theory capable of unconditional predictions.     

Non-equilibrium Thermodynamic Analysis of The Transport Properties of Formed-in-Place Zirconium (Ⅳ) Hydrous Oxide-Polyacylate Membranes in aqueous NaNO_3 solution

Recently,membranescontinuetobethesubjectofcomPrehensivereseachbecauseoftheirwiderangeofapplicationsinindustrialprocessesandscientificinvestigation.Thetransportpropertiesofformed-in-place(i.e.dynaInicallyformed)Zr(IV)hydrousoxide-PAAmembranesinaqueousNaNO3soIutionwasinverstigatedinIhiswork.ThemembranesweredyndricallyformedonesofthetypeoriginallydevelopedbyMarcinkowskyetall.Themembraneusedinthispaperwaspreparedessentia1lyaccordingtoThomas2andexhibitednanofiltfationpropertiescharacteristico…     

A finite volume method for viscous incompressible flows using a consistent flux reconstruction scheme

An incompressible Navier–Stokes solver using curvilinear body‐fitted collocated grid has been developed to solve unconfined flow past arbitrary two‐dimensional body geometries. In this solver, the full Navier–Stokes equations have been solved numerically in the physical plane itself without using any transformation to the computational plane. For the proper coupling of pressure and velocity field on collocated grid, a new scheme, designated ‘consistent flux reconstruction’ (CFR) scheme, has been developed. In this scheme, the cell face centre velocities are obtained explicitly by solving the momentum equations at the centre of the cell faces. The velocities at the cell centres are also updated explicitly by solving the momentum equations at the cell centres. By resorting to such a fully explicit treatment considerable simplification has been achieved compared to earlier approaches. In the present investigation the solver has been applied to unconfined flow past a square cylinder at zero and non‐zero incidence at low and moderate Reynolds numbers and reasonably good agreement has been obtained with results available from literature. Copyright © 2006 John Wiley & Sons, Ltd.     

Spectral analysis of the covariance of the almost periodically correlated processes

This paper deals with the spectrum of the almost periodically correlated (APC) processes defined on . It is established that the covariance kernel of such a process admits a Fourier series decomposition, K(s+t, s) , whose coefficient functions b are the Fourier transforms of complex measures m, , which are absolutely continuous with respect to the measure m_o. Considering the APC strongly harmonizable processes, the spectral covariance of the process can be expressed in terms of these complex measures m.

The usual estimators for the second order situation can be modified to provide consistent estimators of the coefficient functions b from a sample of the process. Whenever the measures m are absolutely continuous with respect to the Lebesgue measure, so m(dλ)=f(λ) dλ, the estimation of the corresponding density functions f is considered. Under hypotheses on the covariance kernel K and on the coefficient functions b, we establish rates of convergence in quadratic mean and almost everywhere of these estimators.     

Theory of polymer brushes grafted to finite surfaces

In this work, a model based in strong‐stretching theory for polymer brushes grafted to finite planar surfaces is developed and solved numerically for two geometries: stripe‐like and disk‐like surfaces. There is a single parameter, , which represents the ratio between the equilibrium brush height and the grafting surface size, that controls the behavior of the system. When is large, the system behaves as if the polymer were grafted to a single line or point and the brush adopts a cylindrical or spherical shape. In the opposite extreme when it is small, the brush behaves as semi‐infinite and can be described as a planar undeformed brush region and an edge region, and the line tension approaches a limiting value. In the intermediate case, a brush with non‐uniform height and chain tilting is observed, with a shape and line tension depending on the value of . Relative stability of disk‐shaped, stripe‐shaped, and infinite lamellar micelles is analyzed based in this model. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 663–672     

KINETIC MODEL FOR DIFFUSION-CONTROLLED INTERMOLECULAR REACTION OF HOMOGENOUS POLYMER UNDER STEADY SHEAR

The kinetic model for diffusion-controlled intermolecular reaction of homogenous polymer under steady shear was theoretically studied. The classic formalism and the concept of conformation ellipsoids were integrated to get a new equation, which directly correlates the rate constant with shear rate. It was found that the rate constant is not monotonic with shear rate. The scale of rate constant is N^-1.5 （N is the length of chains）, which is in consistent with de Gennes＇s result.     

6-硫代黄嘌呤互变异构体的密度泛函理论计算

在密度泛函B3LYP/6-311G**水平下,对14种气相和水相中可能存在的6-硫代黄嘌呤异构体进行了几何构型的全自由度优化,并计算出它们的总能量、焓、熵、吉布斯自由能。Onsager反应场溶剂模型用于水相的计算.计算结果表明,6-硫代黄嘌呤在气相中和水相中主要以硫酮的形式存在.在气相和水相中,硫酮-N7(H)均比硫酮-N9(H)更稳定.计算结果同已有实验结果一致.6-硫代黄嘌呤异构化的熵效应小,对互变异构平衡几乎没有显著的影响,而焓变对互变异构产生了主要的影响.较详细地讨论了水溶剂化作用对异构体的能量、几何结构、电荷分布和偶极矩的影响.     

A model study of the intermolecular interactions of amino acids in aqueous solution: The glycine-water system

We have performed calculations of the glycine zwitterion surrounded by water molecules with the help of the mutually consistent field (MCF) method and perturbation theoretical expressions. Two different models for the hydration shell have been chosen, the glycine·6H₂O and glycine·12H₂O complexes, representing the most probable first and second solvation shell, respectively. To calculate the exchange and charge transfer energy contributions we have applied approximative expressions derived from perturbation theory for weakly overlapping subunits. For the sake of comparison we also calculated the interaction energy in the supermolecule approach for the smaller of the two solvation complexes. Furthermore, we have investigated the part of the potential energy surface which is determined by varying the lengths of the hydrogen bonds between glycine and water in the complex glycine·12H₂O using the electrostatic approach. The exchange energy contribution to the interaction energy for different points on the surface was approximated with the help of an analytical expression fitted to three directly calculated points. For the charge transfer energy a polynomial expansion of second order was established on the basis of five values, computed with the aid of the perturbation theoretical expression. To get a more detailed insight in the relatively strong hydrogen bonds between the water molecules and the ionic hydrophilic parts of glycineab initio model studies on NH ₄ ⁺ ·3H₂O and HCOO⁻·3H₂O systems are reported.