原子转移自由基聚合与“Click”反应相结合制备Fe3O4@SiO2-g-PDMAEMA及其性质研究

结合原子转移自由基聚合（ATRP）与点击反应（＂Click＂reaction）,在SiO2包裹的Fe3O4磁性纳米粒子（Fe3O4@SiO2）表面接枝聚[甲基丙烯酸-2-（N,N-二甲氨基）乙酯]（PDMAEMA）,得到了表面接枝PDMAEMA的磁性纳米粒子（Fe3O4@SiO2-g-PDMAEMA）.通过1H NMR...     

Hamilton formalism and Noether symmetry for mechanico—electrical systems with fractional derivatives

This paper presents extensions to the traditional calculus of variations for mechanico-electrical systems containing fractional derivatives.The Euler-Lagrange equations and the Hamilton formalism of the mechanico-electrical systems with fractional derivatives are established.The definition and the criteria for the fractional generalized Noether quasisymmetry are presented.Furthermore,the fractional Noether theorem and conseved quantities of the systems are obtained by virtue of the invariance of the Hamiltonian action under the infinitesimal transformations.An example is presented to illustrate the application of the results.     

具有接种和非局部扩散的流行病模型的行波解（英文）

An epidemic model with vaccination and nonlocal diffusion is proposed, and the existence of traveling wave solutions of this model is studied. By the cross-iteration scheme companied with a pair of upper and lower solutions and Schauder’s fixed point theorem,sufficient conditions are obtained for the existence of a traveling wave solution connecting the disease-free steady state and the endemic steady state.     

N-氧化吡啶-2-甲醛缩二胍合铜配合物的合成、表征及磁性

合成了N-氧化吡啶-2-甲醛缩二胍合铜的新型配合物,通过元素分析、红外光谱、电导、热重测定,对配合物进行了表征,并测定了配合物的变温磁化率,表明双核配合物中铜离子间存在反铁磁性交换作用.     

关于[Co(NH3)5NO2]Cl2键合异构体相互转化的研究

[Co(NH_3)_5NO_2]Cl_2是最早发现和首先分离得到的第一个键合异构体。长期被认为只有氧配位的[Co(NH_3)_5ONO]Cl_2异构体会向氮配位的[Co(NH_3)_5NO_2]Cl_2异构体转化。本文认为氮配位的异构体也会向氧配位的异构体转化,并测定和报导了这种转化的速率常数。