Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether

Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.

PRESTABILIZATION FOR K_1U~ε OF A-2-FOLD RINGS

Vaserstein introduced the K1-functor for the unitary groups over the associative ring with involution, studied the stabilization of unitary K1 for some rings with the stable range condition; and particularly described the prestabilization for K1Uε of local rings. In this report, we study the prestabilization for K1Uε of a class of rings satisfying the condition Sr（R） ≤1 which is introduced by Vaserstein and Bass.

球形向列相液滴新缺陷态的研究

基于Landau-de Gennes理论,利用二维有限差分迭代法,研究了相同条件下环(ring)结构与三缺陷结构之间的能量对比。探究了三缺陷结构稳定存在的尺寸范围、边界条件对于缺陷位置的影响以及三缺陷结构转变为环结构的动力学过程。结果表明:环结构能量最低为基态,而三缺陷结构能量相对较高为亚稳态。研究中选取固定温度并做单一弹性常数近似。对于均匀垂面锚定且锚定强度系数为w = 10−3 J/m2时,三缺陷结构在R ≥ 1.17 μm范围内稳定;w = 10−4 J/m2时,三缺陷结构在R ≥ 1.16 μm范围内稳定;w = 10−5 J/m2时,存在的范围为R ≥ 0.95 μm。进一步改变边界锚定强度系数,使其在边界不再是定值,而是线性变化的。在球的两极点处取最大值wmax,并取半径为26.4 μm进行研究。其他条件相同只改变wmax的值,我们发现,wmax取10−3 J/m2与取10−4 J/m2、10−5 J/m2相比,缺陷反而向中心轴收缩,出现反常现象。在较小的半径下,三缺陷态中的两个缺陷靠近并湮灭,最终形成环结构。