Second order parabolic equations in Banach spaces with dynamic boundary conditions

In this paper, we exhibit a unified treatment of the mixed initial boundary value problem for second order (in time) parabolic linear differential equations in Banach spaces, whose boundary conditions are of a dynamical nature. Results regarding existence, uniqueness, continuous dependence (on initial data) and regularity of classical and strict solutions are established. Moreover, several examples are given as samples for possible applications.

     

三量子位Heisenberg XX 链中杂质对纠缠的影响

研究了有杂质时三量子位Heisenberg-XX链中正常格点之间的热纠缠情况，给出了Concurrence的解析表达式.进一步的讨论发现，杂质对正常格点的热纠缠有着重要的影响，甚至能够改变纠缠在反铁磁区的特性.理论表明，可以通过调节温度和杂质参数来控制纠缠. 关键词： Heisenberg -XX链 热纠缠 杂质格点     

质子化丙酮分子团簇的结构和振动光谱

用密度泛函B3LYP/ 6 3 1G(d)方法 ,对质子化丙酮分子团簇 (CH3COCH3) nH+ (n =1～ 7)弱相互作用体系进行了全自由度能量梯度优化 ,得到了该系列团簇的稳定结构及其对应的体系能量 .通过对构型的分析得出了质子化丙酮分子团簇 (CH3COCH3) nH+ (n =1～ 7)的生长规律 .计算了中性丙酮分子团簇体系的质子亲合能并总结出其变化趋势 .分析讨论了质子化团簇的红外振动光谱 ,发现质子化团簇的振动光谱普遍较中性环型团簇的振动光谱复杂 ,最强的振动峰来源于质子在溶剂壳中两个氧原子之间的振动 ,而且随着团簇尺寸的增加羰基的伸缩振动峰的数目也随之增多     

An efficient synthesis of cyanoarenes and cyanoheteroarenes via lithiation followed by electrophilic cyanation

A one-pot procedure for the conversion of mono-substituted arenes and heteroarenes into the ortho-cyano derivatives was achieved through directed lithiation followed by electrophilic cyanation with phenyl cyanate. This reaction method proved to be applicable to halogen-lithium exchanged intermediates, so especially useful for the synthesis of benzonitriles. The scope of the reaction sequence was explored using a number of substrates.     

Synthesis and adsorption properties of gold nanoparticles within pores of surface‐functional porous polymer microspheres

Mesoporous polymer microspheres with gold (Au) nanoparticles inside their pores were prepared considering their surface functionality and porosity. The Au/polymer composite microspheres prepared were characterized by transmission electron microscope (TEM), X‐ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) techniques. The results showed that the adsorption of Au nanoparticles could be increased by imparting the pore structure and surface‐functional groups into the supporting polymer microspheres (in this study, poly (ethylene glycol dimethacrylate‐co‐acrylonitrile) and poly (EGDMA‐co‐AN) system). Above all, from this study, it was established that the porosity of the polymer microspheres is the most important factor that determines the distribution and adsorption amount of face‐centered cubic (fcc) Au nanoparticles in the final products. Our study showed that the continuous adsorption of Au nanoparticles with the aid of the large surface area and surface interaction sites formed more favorably the Au/polymer composite microspheres. The BET measurements of Au/poly(EGDMA‐co‐AN) composite microspheres reveals that the adsorption of Au nanoparticles into the pores kept the pore structure intact and made it more porous. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5627–5635, 2004     

高阶线性微分方程的解及其解的导数的不动点

研究了复域齐次和非齐次线性微分方程的解及其解的导数的不动点与超级问题,得到了整函数系数的齐次和非齐次线性微分方程的解及其解的导数的不动点的两个结果,所得结果推广了一些相关结果.     

非平稳NA序列部分和的精确渐近性

本文探讨了非平稳NA序列部分和的精确渐近性．以前的文献在讨论NA序列此类极限性质时都附加有强平稳条件的限制,这必然会给一些问题的研究带来不便．周知,非平稳NA序列在许多实际问题中是大量存在的,所以解除强平稳条件的束缚具有较大的理论和实际意义,这正是本文的目的之所在,同时本文也将已有的一些结果包含成为特殊情形．     

Ag-Bi高温超导线材转变温度的测量

介绍了 Bi系银包套高温超导线材的电阻温度特性 ,用测电阻和电磁感应两种方法分别测量了材料的超导转变温度 ,电磁感应法测量曲线上台阶的出现表明材料中 Bi(2 2 2 3)和 Bi(2 2 12 )两相的存在。     

Crystallization process of Bi(Pb)-Sr-Ca-Cu-O glass

A crystallization study has been carried out for rapidly solidified Bi₂Pb_0.5Sr₂Ca₄Cu₅O_x glass. Glass transition temperature T _g, crystallized superconducting phases and microstructural changes were measured and analysed by differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The crystallization mechanism of the three superconducting phases — (2201) 20 K phase, (2212) 80 K phase, and (2223) 110 K phase — has been discussed, and a time-temperature-transformation diagram for the glass has been constructed.     

液态铅的电阻率

采用精确的结构因数实验数据和Ｂｅｈａｖｉ模型赝势，用Ｚｉｍａｎ理论计算了液态铅的电阻率．计算结果和实验数据符合很好．讨论了Ｚｉｍａｎ理论对液态铅的适用性以及适合于液态铅的赝势的特征．