Living cationic ring‐opening polymerization of five‐membered cyclic dithiocarbonate controlled by neighboring group participation of carbamate group

A five‐membered cyclic dithiocarbonate having phenylcarbamate moiety 1 underwent cationic ring‐opening polymerization by using methyl trifluoromethanesulfonate as an initiator in nitrobenzene at 60 °C. Both of the corresponding first‐order kinetic plot and conversion‐molecular weight plot showed linearity to suggest the living fashion of the polymerization, which was then supported by two‐stage polymerization experiment. The living fashion as well as the regioselective formation of the repeating unit suggested significant contribution of the neighboring group participation of the carbamate group to form a stabilized cationic propagating end, of which structure was confirmed by performing an equimolar reaction of 1 and methyl trifluoromethanesulfonate with analyzing the resulting species by NMR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4459–4464, 2007     

保特征2域上上三角矩阵群逆的线性映射

设F是一个特征2且至少含有5个元素的域,n≥2是一个正整数．令Mn（F）和Tn（F）分别F上的全矩阵空间和上三角矩阵空间．我们首先刻划从Tn（F）到Mn（F）的保矩阵群逆的所有线性单射，由此从Tn（F）到自身的所有保矩阵群逆的线性双射被刻划．     

Computing test rank for a free solvable group

It is proved that test rank of a free solvable non-Abelian group of finite rank is 1 less than the rank of that group. This gives the answer to Question 14.88 posed in the Kourovka Notebook by Fine and Shpilrain, asking whether or not a free solvable group of rank 2 and solvability index n ≥ 3 has test elements. Supported by RFBR grant No. 05-01-00292. __________ Translated from Algebra i Logika, Vol. 45, No. 4, pp. 447–457, July–August, 2006.     

偏振模色散补偿控制中偏振度技术的性能

基于主偏振态理论，导出了光信号偏振度的解析表达式.并对40 Gb/s光传输系统中的信号偏振度受各种因素的影响进行了数值模拟，包括啁啾、脉冲形状、脉冲宽度、自发辐射噪声以及消光比等.结果表明，偏振度技术能有效地监测和控制40 Gb/s系统中小于37.5 ps的偏振模色散.而且发现就最大化偏振度技术对差分群延时的容许范围而言，脉冲的1/e强度半宽取0.45个位宽（11.25 ps）是最优的.     

Minimality conditions on circularly ordered structures

We explore analogues of o‐minimality and weak o‐minimality for circularly ordered sets. Much of the theory goes through almost unchanged, since over a parameter the circular order yields a definable linear order. Working over ?? there are differences. Our main result is a structure theory (with infinitely many doubly transitive examples related to Jordan permutation groups) for ?₀‐categorical weakly circularly minimal structures. There is a 5‐homogeneous (or ‘5‐indiscernible’) example which is not 6‐homogeneous, but any example which is k‐homogeneous for some k ≥ 6 is k‐homogeneous for all k. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Separation of unitary representations of connected Lie groups by their moment sets

We show that every unitary representation π of a connected Lie group G is characterized up to quasi-equivalence by its complete moment set.Moreover, irreducible unitary representations π of G are characterized by their moment sets.     

密集波分复用薄膜滤光片的群延迟补偿设计

设计了一种基于薄膜干涉理论的反射式相位补偿器件，用以补偿密集型波分复用窄带滤光片所产生的群延迟，使50GHz薄膜滤光片的群延迟特性适应于40Gb／s系统的要求，在0．2nm带宽下群延迟波动从10ps左右下降到0．76ps以下。     

Isolated complex singularities and their CR links

In this paper, we discuss some recent studies on the complex structure of an isolated normal singularity by using the information from its link. We also give some open problems to be further pursued. Dedicated to Professor Sheng GONG on the occasion of his 75th birthday     

Solvable quadratic Lie algebras

A Lie algebra endowed with a nondegenerate, symmetric, invariant bilinear form is called a quadratic Lie algebra. In this paper, the author investigates the structure of solvable quadratic Lie algebras, in particular, the solvable quadratic Lie algebras whose Cartan subalgebras consist of semi-simple elements, the author presents a procedure to construct a class of quadratic Lie algebras from the point of view of cohomology and shows that all solvable quadratic Lie algebras can be obtained in this way.