微型同轴脉管制冷机最低制冷温度影响因素的实验研究

本文对微型同轴脉管制冷机最低制冷温度的影响因素进行了实验研究。试验结果表明:在其他运行参数不变的情况下,随着氢浓度的逐渐减少,最低制冷温度也逐渐降低,当氢的摩尔浓度小于20％时,其最低制冷温度和纯氦相差不大。不同的氢氦配比下,该脉管制冷机的最佳运转频率为16.7 Hz。随着系统平均压力的提高,最低制冷温度也随之下降,但变化幅度越来越小。     

Forecasting of precipitation occurrence in long-range trajectory climatology

Summary A procedure to include a way for forecasting the precipitation occurrence in the air mass trajectory computation for climatological studies in order to compute the wet deposition of airborne pollutants is presented. It is based on a technique proposed by Moscoet al., Riv. Meteorol. Aeronaut.,33, 229 (1973). Its performance is tested comparing the forescen occurrence of either precipitation or no precipitationversus the actual one for two stations, Parma and Vipiteno, for a period of four years. In more than 80% of the cases the forecasting was correct.     

阴极荧光光谱有效收集效率的计算与测量（I）

从点光源均匀发光模型出发,重点导出了回转半椭球面镜的阴极荧光(Cathodoluminescence,简称CL)光谱有效收集效率η_λ~(eff)的计算公式,分析讨论了收集效率η_λ~(eff)与椭球参数e、收集角、Δφ出射角Δ(?)以及出射光束方位角θ_N的关系,给出了相应的理论计算和模拟实验结果.研究表明,理论计算与实验结果一致.     

基于第一性原理的石墨吸附一氧化碳倾向性研究

利用基于量子力学的第一性原理计算方法,从微观角度研究煤层对一氧化碳气体的吸附机理.根据煤层的基本成分及结构特点,用结构类似的石墨模拟复杂的煤层,建立石墨吸附一氧化碳分子的模型,讨论石墨表面的三种高对称吸附位置,分别是顶位（top位）、桥位（bridge位）、洞位（hollow位）对一氧化碳分子的吸附.结果表明：当一氧化碳分子垂直于石墨表面,且碳原子端靠近碳层时,在石墨（001）表面的桥位（bridge位）有较强的吸附能.     

The Ablowitz–Ladik hierarchy integrability analysis revisited: the vertex operator solution representation structure

A regular gradient-holonomic approach to studying the Lax type integrability of the Ablowitz–Ladik hierarchy of nonlinear Lax type integrable discrete dynamical systems in the vertex operator representation is presented. The relationship to the Lie-algebraic integrability scheme is analyzed and the connection with the τ-function representation is discussed.     

Rainfalls during great Forbush decreases

Summary The changes of rainfall values during great Forbush decreases recorded by the low-latitudinal neutron monitor of Huancayo (47 events from 1956 through 1992) were examined. The data on precipitations were taken from the State of S?o Paulo and from the Amazonian region, Brazil. As a rule, the data from more than 50 meteorological stations were used for each events. The main result is the following: during strong decreases of cosmic-ray flux in the atmosphere (great Forbush decreases) the precipitation value is decreased. The effect of rainfall changes is seen more distinctly if wet seasons are considered.     

自然地面背景下红外目标检测算法

为了快速准确地检测出以地面物体为背景的红外序列图像中的目标,结合小波变换的特点及其应用于图像边缘检测的优点,提出了一种基于小波技术的图像预处理算法。该方法利用图像边缘在目标识别中的重要作用,讨论了基于小波变换的图像边缘检测方法,并结合地面背景红外图像自身的特点,大大地提高了单帧的检测概率。     

Axiomatic Geometric Formulation of Electromagnetism with Only One Axiom: The Field Equation for the Bivector Field <Emphasis Type="Italic">F</Emphasis> with an Explanation of the Trouton-Noble Experiment

In this paper we present an axiomatic, geometric, formulation of electromagnetism with only one axiom: the field equation for the Faraday bivector field F. This formulation with F field is a self-contained, complete and consistent formulation that dispenses with either electric and magnetic fields or the electromagnetic potentials. All physical quantities are defined without reference frames, the absolute quantities, i.e., they are geometric four-dimensional (4D) quantities or, when some basis is introduced, every quantity is represented as a 4D coordinate-based geometric quantity comprising both components and a basis. The new observer-independent expressions for the stress-energy vector T(n) (1-vector), the energy density U (scalar), the Poynting vector S and the momentum density g (1-vectors), the angular momentum density M (bivector) and the Lorentz force K ((1-vector) are directly derived from the field equation for F. The local conservation laws are also directly derived from that field equation. The 1-vector Lagrangian with the F field as a 4D absolute quantity is presented; the interaction term is written in terms of F and not, as usual, in terms of A. It is shown that this geometric formulation is in a full agreement with the Trouton-Noble experiment.     

The Difference Between the Standard and The Lorentz Transformations of the Electric and the Magnetic Fields

In this paper it is shown by using the Clifford algebra formalism that the usual Lorentz transformations of the three-dimensional (3D) vectors of the electric and magnetic fields E and B (which will be named as standard transformations (ST)) are different than the Lorentz transformations (LT) of well-defined quantities from the 4D spacetime. This difference between the ST and the LT is obtained regardless of the used algebraic objects (1-vectors or bivectors) for the representation of the electric and magnetic fields in the usual observer dependent decompositions of F. The LT correctly transform the whole 4D quantity, e.g., E_f : F · γ₀, whereas the ST are the result of the application of the LT only to the part of E_f, i.e., to F, but leaving γ₀ unchanged. The new decompositions of F in terms of 4D quantities that are defined without reference frames, i.e., the absolute quantities, are introduced and discussed. It is shown that the LT of the 4D quantities representing electric and magnetic fields correctly describe the motional electromotive force (emf) for all relatively moving inertial observers, whereas it is not the case with the ST of the 3D E and B.     

对《二维六角形晶格伊辛模型的重正化群解》一文的进一步计算

针对《二维六角形晶格伊辛模型的重正化群解》一文中有关〈V〉0的计算进行了修正,给出了新的重正化群的变换、重正化群的线性化变换矩阵以及临界指数.