Additive envelopes of continuous functions

We present an iterative method for constructing additive envelopes of continuous functions on a compact set, with contact at a specified point. For elements of a class of submodular functions we provide closed-form expressions for such additive envelopes.     

Electron paramagnetic resonance study of impurities and point defects in oxide crystals

In this topic review the results of the X-band electron paramagnetic resonance (EPR) measurements of Mn, Co, Cr, Fe ions in YAlO₃ (YAP) crystals and Fe ions in LiNbO₃ (LNO) crystals and of chromium doped Bi₁₂GeO₂₀ (BGO) and Ca₄GdO(BO₃)₃ single crystals, are presented. It is well known that the oxide crystals (for example:YAP, LNO, BGO) are one of the most widely used host materials for different optoelectronic applications. The nature of point defect of impurities and produced in the oxide crystal after irradiation by bismuth ions and after irradiation by the ²³⁵U ions with energy 9.47 MeV/u and fluency 5?×?10¹¹?cm^?1 is discussed. The latter is important for applications of these oxide crystal as laser materials.     

Time shift and superposition method for solving transient radiative transfer equation

Due to the long-time transient response of pulse irradiation, the computational time required for solving transient radiative transfer (TRT) is often very long, especially for the case in which the boundary is subjected to continuous pulse train and the geometry is complicated. In addition, sometimes, before actual experiments are carried out, a suitable pulse shape or type often needs to be selected by numerical simulation and comparison. Because the numerical solution of TRT needs to be repeated many times, the selection processes is very time-consuming. In this paper, by considering that the TRT equation and its initial and boundary conditions are linear, a time shift and superposition method is developed for solving TRT equation in non-emitting media, in which only the transient response of a short square pulse needs to be solved, and the solution of TRT under any pulse shape can be constructed by time shift and then superposition using the basis solution of the short square pulse. Three numerical examples are studied to illustrate the peformance of the superposition method in solving TRT problems. The results show that the superposition is effective, accurate and very suitable for solving TRT in the medium subjected to a series of pulse train.     

q-形变的非简谐振子广义相干叠加态的高阶压缩效应

研究了q-形变的非简谐振子的广义相干态的高阶压缩效应,给出了出现高阶压缩现象的条件.     

多模叠加态光场|ψ5(3)〉q中广义磁场4m次方Y压缩

构造了由多模复共轭相干态|{Z_j^*}〉_q、多模复共轭相干态的相反态|{-Z_j^*}〉_q以及多模虚相干态|{iZ_j^*}〉_q的线性叠加所组成的第Ⅴ类三态叠加多模叠加态光场|ψ₅⁽³⁾〉_q.利用多模压缩态理论研究了态|ψ₅⁽³⁾〉_q中广义磁场分量的等幂次N次方Y压缩特性.结果发现:当压缩次数N=2p且p=2m(m=1,2,3,…,…)时,只要各模的初始相位φ_j(j=1,2,…,…,q)、态间的初始相位差(θ₁-θ₂)、(θ₁-θ₃)和(θ₂-θ₃)以及受各模的初始相位φ_j调制的各单模相干态光场的平均光子数之和 等分别满足一定的取值条件,则态|ψ₅⁽³⁾〉_q的广义磁场分量就可呈现出周期性变化的广义非线性等幂次4m次方Y压缩效应.     

RbCdF_3: Fe~(3+)和CsCdF_3: Fe~(3+)晶体中Fe~(3+)-Li~+缺陷中心结构研究

本文计算了掺入三价Ｆｅ３＋离子和Ｌｉ＋杂质后，晶体ＲｂＣｄＦ３和ＣｓＣｄＦ３中的Ｆｅ３＋－Ｌｉ＋缺陷中心的零场分裂参量，微扰计算进行到第六阶．将计算值与实验值比较，确定了配体的位置，并将本文的计算结果与前人的结果进行了比较     

迭加原理在求边值问题中的应用

本文利用迭加原理求出置于点电荷场中导体球面上感应电荷的分布，提出用“等效电荷”求解空间电势分布的方法，并对有关概念问题作出了讨论     

Formulation DNLR intégrale des lois de comportement : généralisation du principe de superposition de BoltzmannDNLR integral formulation of behaviour laws: generalisation of Boltzmann's superposition principle.

A thermodynamic approach of relaxation phenomena called DNLR (Distribution of Non Linear Relaxations) has been employed for about fifteen years to describe the behaviour of materials. In this Note, we show that different DNLR constitutive equations, initially written in a rate formulation, can be put in a time-integrated (hereditary) form which generalises the superposition principle to non linear fields like viscoplasticity or damage behaviours. To cite this article: B. Martin et al., C. R. Mecanique 332 (2004).     

改进型低纹波Cockcroft-Walton倍压电路及其特性研究

多级倍压整流器倍压纹波和电压跌落分别受级数次方的影响,在级数增加的情况下会明显增加。在最低级数2倍压电路的基础上,采用移相和反相叠加实现2N倍压电路。使用三相组式变压器输出绕组三相独立连接直流二倍压电路,通过并联输入、串联输出实现6脉周期性叠加,构建12倍压电路。通过叠加,大幅度削弱了脉动的幅度。对纹波和电压跌落进行了理论分析和估算,并与经典型和对称型Cockcroft-Walton多级倍压电路进行比较。结果表明,该电路可以显著减小电压纹波和电压跌落,并明显缩短了输出电压稳态建立的时间。