一种D_4型Dynkin图所有自函子的矩阵刻画

引入几个偏序范畴的相关概念,如链、偏序范畴之间的函子的矩阵表示等。首先解决了两个n秩偏序范畴之间函子的矩阵表示的存在性问题,其次给出了D4型Dynkin图作为偏序范畴上所有自函子的矩阵刻画。

关于左三角范畴定义的一个等价条件

本文给出了左三角范畴定义的一个等价条件,得出可以替代八面体公理的一个交换图。

Evaluation of Phonon-level Density of UO2 by Molecular Dynamics Simulation

Molecular dynamics calculation of UO2 in a wide temperature range are presented and dis- cussed. The calculated lattice parameters, mean square displacements, and dynamic prop- erty of phonon-level density of the velocity auto-correlation functions for UO2 are provided. The Morelon potential and the Basak potential are employed. It confirms that the cal- culated lattice parameters using the Basak potential are in nearly perfect agreement with the reported values. The models successfully predict mean square displacement and Bredig transition. Furthermore, the phonon-level density of uranium dioxide are discussed. The intensity of phonon-level density increases with temperature, and the properties of UO2 are characterized by large thermal vibrations rather than extensive disorder.

An Estimate of the Enumeration Function of Multiplicative Partitions

Let f(n) denote the number of multiplicative partitions of a positive intger. We prove that if n is an odd number,then f(n)≤n/15+7/5.

Wavefunctions for Particles with arbitrary Spin

By solving rigorously the relativistic wave equations derived from Bargmann–Wigner equation for arbitrary spin, the relativistic wavefunctions in momentum representation for particles with arbitrary spin are deduced.

A new phenomenon of quantum-dot cellular automata

If an external point charge and the movable charges of an isolated quantum-dot cellular automata (QCA) cell have the same polarity, the point charge greatly affects the polarization (P) of the cell only when it is in a narrow band with periodically changing width. The center of the band is on a radius R circle. The ratio of R to the electric charge (q) is a constant determined by the parameters of the cell. A QCA cell can be used as charge detector based on the above phenomenon.

Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors. Both the quantum wire and conductors are described by a hard-wall confining potential. Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density j^Ts,xi and j^Ts,yi（i=x, y, z）. We find that the elements j^Ts,xx and j^Ts,yy have a antisymmetrical relation and the element j^Ts,yz has the same amount levelas j^Ts,xx and j^Ts,yy. We also find a net linear spin current density, which has peaks at the center of quantum wire. The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

Bloom-Gilman Duality of Nucleon Spin Structure Function and Elastic Peak Contribution

By employing the parametrization form of the nucleon spin structure functionin the resonance region, which includes the contributions of the resonance peaks and of nonresonancebackground, we study Bloom—Oilman quark-hadron duality of g_1 both in the inelastic resonanceregion and elastic one.

Density Functional Theory Study on Spin States of LaCoO3 at Room Temperature

The electronic structure of the perovskite LaCoO3 at room temperature structure （293 K） was calculated by using PBE, PBE＋U and HSE. Different spin configurations have been considered. Our calculations showed that the choice of the Hubbard U parameter in DFT＋U and mixing factor α in HSE significantly influenced the band gap as well as relative energies. For the spin exited states, the optimal value for U and α were 3.0 eV and 0.05, respectively. Our calculation also emphasized that when U〉5.0 eV, PBE＋U would lead to unreasonable electronic structure and energy order.

Spin Transport in a Rashba Ring-Quantum Dot System Pumped by Microwave Fields

We report a theoretical study on producing electrically spin-polarized current in the Rashba ring with parallel double dots embedded, which are subject to two time-dependent microwave fields. By means of the Keldysh Green＇s function method, we present an analytic result of the pumped current at adiabatic limit and demonstrate that the interplay between the quantum pumping effect and spin-dependent quantum interference can lead to an arbitrarily controllable spin-polarized current in the device. The magnitude and direction of the charge and spin current can be effectively modulated by system parameters such as the pumping phase difference, Rashba precession phase, and the dynamic phase difference of electron traveling in two arms of ring; moreover, the spin-polarization degree of the charge current can also be tuned in the range [-∞, ＋∞]. Our findings may shed light on the all-electric way to produce the controllable spin-polarized charge current in the field of spintronics.

Four-Electron Quantum Ring in a Magnetic Field

We study a quantum ring （QR） with four electrons in a perpendicular external magnetic field B by exact diagonalization. The low-lying spectra of the QR as a function orb are obtained. A phase diagram is presented indicating that the angular momentum and the spin of the ground state of the QR may jump when B and/or the radius of the QR vary, and a corresponding analysis is performed. By plotting the density functions of the QR, the ground-state configuration is found to be a regular quadrangle. Furthermore, the features of the ground-state persistent current are revealed.

D型箭图的有界导出范畴的Frobenius-Perron维数

设M是D型箭图的一个不可分解表示, s是一个整数,[s]表示范畴中的平移函子.本文研究一类D型箭图的表示范畴及其有界导出范畴的不可分解表示的砖块集,给出这类D型箭图的不可分解表示M与M[s]的Frobenius-Perron维数.

一类D型箭图的表示的Frobenius-Perron维数

本文通过研究一类D型箭图的不可分解表示的砖块(brick)集,给出这些不可分解表示的Frobenius-Perron维数.

Some Results on Dual Cosine Operator Function

Some basic properties of dual cosine operator function are given. The concept and characterization of θ reflexivity with respect to cosine operator function are first studied.

MASLOV-TYPE INDEX THEORY FOR SYMPLECTIC PATHS AND SPECTRAL FLOW (Ⅰ)

The spectral flow for paths of admissible operators in arbitrary Banach space is defined, and some properties of the spectral flow is studied.

A Lower Bound on Longitudinal Structure Function at Small x from a Self-Similarity Based Model of Proton

Self-similarity based model of proton structure function at small x was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region 6.2 × 10-7 ≤ x ≤ 10-2 and 0.045 ≤ Q2 ≤ 120 GeV2. We use momentum sum rule to pin down the corresponding self-similarity-based gluon distribution function valid in the same kinematical region. The model is then used to compute bound on the longitudinal structure function FL（X, Q2） for A1tarelli-Martinelli equation in QCD and is compared with the recent HERA data.

Anti-(conjugate) linearity

This is an introduction to antilinear operators. In following Wigner the terminus antilinear is used as it is standard in Physics.Mathematicians prefer to say conjugate linear. By restricting to finite-dimensional complex-linear spaces, the exposition becomes elementary in the functional analytic sense. Nevertheless it shows the amazing differences to the linear case. Basics of antilinearity is explained in sects. 2, 3, 4, 7 and in sect. 1.2: Spectrum, canonical Hermitian form, antilinear rank one and two operators,the Hermitian adjoint, classification of antilinear normal operators,(skew) conjugations, involutions, and acq-lines, the antilinear counterparts of 1-parameter operator groups. Applications include the representation of the Lagrangian Grassmannian by conjugations, its covering by acq-lines. As well as results on equivalence relations. After remembering elementary Tomita-Takesaki theory, antilinear maps, associated to a vector of a two-partite quantum system, are defined. By allowing to write modular objects as twisted products of pairs of them, they open some new ways to express EPR and teleportation tasks. The appendix presents a look onto the rich structure of antilinear operator spaces.

Dependence of Spin-orbit Parameters in AlxGa1-xN/GaN Quantum Wells on the Al Composition of the Barrier

In this paper, we obtain considerable spin-orbit （SO） parameters in AlxGa1-xN/GaN quantum wells （QWs） with sheet carrier concentration N8 = 120 × 10^11/cm^2. With increasing AI content （x） of the barrier, the SO parameters increase as a whole, and the two major contributions are found to be the decrease of the expansion region of the envelope functions and the increase of the polarized electric field in the well. Compared with the Rashba parameters for the first two subbands, the intersubband SO parameter is a bit smaller and varies more slowly with x. The results indicate the SO parameters, especially the Rashba parameters can be engineered by the AI composition of the barrier, which may be helpful to the spin manipulation of III-nitride low-dimensional heterostructures.

ALMOST PERIODIC SOLUTIONS OF NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATIONS WITH NONAUTONOMOUS OPERATOR

This paper presents some existence theorems on almost periodic solutions for almost periodicneutral functional differential equation and its perturbed systems by means of Liapunov functional, and extends the corresponding results in 12,4,5,10,11].

Effects of Ionic Dependence of DNA Persistence Length on the DNA Condensation at Room Temperature

DNA persistence length is a key parameter for quantitative interpretation of the conformational properties of DNA and related to the bending rigidity of DNA.A series of experiments pointed out that,in the DNA condensation process by multivalent cations,the condensed DNA takes elongated coil or compact globule states and the population of the compact globule states increases with an increase in ionic concentration.At the same time,single molecule experiments carried out in solution with multivalent cations(such as spermidine,spermine)indicated that DNA persistence length strongly depends on the ionic concentration.In order to revolve the effects of ionic concentration dependence of persistence length on DNA condensation,a model including the ionic concentration dependence of persistence length and strong correlation of multivalent cation on DNA is provided.The autocorrelation function of the tangent vectors is found as an effective way to detect the ionic concentration dependence of toroidal conformations.With an increase in ion concentration,the first periodic oscillation contained in the autocorrelation function shifts,the number of segment contained in the first periodic oscillation decreases gradually.According to the experiments,the average long-axis length is defined to estimate the ionic concentration dependence of condensation process further.The relation between long-axis length and ionic concentration matches the experimental results qualitatively.