k（k〉2）光子Jaynes—Cummings模型中自发辐射场的位相演化特性

应用Ｐｅｇｇ－Ｂａｒｎｅｔ（ＰＢ）位相理论，研究了ｋ光子Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ（Ｊ－Ｃ）模型中自发辐射场的位相演化特性，计算了辐射场的位相几率分布函数与位相涨落，给出了在极坐标中位相几率分布演化曲线。     

小型自冷式油扩散泵

在真空实验中,要想使系统获得高真空(10~(-2)Pa以下的气压),除用机械泵对系统进行排气外还必须加高真空泵,其中最常用的就是扩散泵。一般商品扩散泵都是多级泵,是由几个单级泵串联而成。泵的外形有立式、卧式;泵体材料有玻璃的、金属的;使用的工作液有汞、油等。但它体积大、自身重、需水冷,如果被排气的系统或容器容积不大,使用这种扩散泵无论从经济上还是从实用上考虑都显得大才小用。我们在实验中使用自己设计制做的二级自冷卧式玻璃油扩散泵。它的结构如图1所示,此扩散泵     

强$J$-Semiclean环

We in this note introduce a new concept, so called strongly J-semiclean ring, that is a generalization of strongly J-clean rings. We first observe the basic properties of strongly J-semiclean rings, constructing typical examples. We next investigate conditions on a local ring R that imply that the upper triangular matrix ring T_n(R) is a strongly J-semiclean ring. Also,the criteria on strong J-semicleanness of 2 × 2 matrices in terms of a quadratic equation are given. As a consequence, several known results relating to strongly J-clean rings are extended to a more general setting.     

将生产资料分类的社会扩大再生产图解法

运用空间解析几何的作图方法,直观并且简便地获得将生产资料分类的社会扩大再生产的解,以及有解的充分必要条件.     

浅谈排列组合中的分书问题

引例1停车场上有7个空位,3辆车去停,有几种方法？     

非线性脉冲向量双曲型微分方程解的H-振动性

研究一类具脉冲时滞的非线性双曲型向量泛函微分方程解的H-振动性.方法是采用由Domslak引进的H-振动性的概念,将向量微分方程解的振动问题转化为纯量微分不等式正解和负解的不存在性问题.得到了解的H-振动性的若干判别准则.     

The stability of a non-extensive relativistic Fermi system

Based on the statistical theory of non-extensive relativity,and using theoretical analysis and numerical simulation,the non-extensive mechanical stability of ultra-relativistic free Fermi gas is investigated.The expressions of the stability conditions under high and low temperatures are given,and the mechanisms of the influences of temperature,ultrarelativistic effect,and non-extensive parameter q on stability are analysed.Our results show that at high temperature and under the condition of q < 1,the stability of a non-extensive system is weaker than that of an extensive system,and the relativistic effect reduces system stability as compared with a non-relativistic system.However,under the condition of q > 1,the stability of the non-extensive system is stronger than that of the extensive system,and the relativistic effect strengthens the system stability as compared with the non-relativistic system.In addition,under the condition of low temperature,the variation of the stability of the non-extensive system with temperature has a turning point.     

超细碳酸钙微球的制备

采用乳状液膜与共沉淀结合法制备超细碳酸钙微球,考察了不同反应条件对碳酸钙形貌的影响。获得的试样使用X-射线衍射(XRD)、场发射扫描电镜(FESEM)、红外光谱(FT-IR)以及激光粒度仪等手段予以表征。结果表明,吐温-80和PVP的添加量分别为4 mL和0.5 g时,制备出了颗粒大小约为5μm的碳酸钙微球;碳酸钙材料的物相组成和形貌与溶液中吐温-80体积含量以及PVP含量密切相关。     

ZnSe-ZnS多层量子阱光学双稳态器件

本文报道了以YAG三倍频激光为光源时,在用MBE生长的ZnSe-ZnS多量子阱材料制成的F—P标准具光双稳器件上观察到的脉冲压缩效应。根据入射脉冲波形和透射脉冲波形得到了该器件的双稳回线。