Numerical Solution of Viscoplastic Flow Problems by Augmented Lagrangians

This paper describes an application of augmented Lagrangiantechniques to the numerical solution of quasistatic flow problemsin incompressible viscoplasticity, focusing on cases where theinternal viscoplastic dissipation potential is not a differentiablefunction of the material deformation rate. The stresses of elasticorigin are neglected, and the variational formulation of theseproblems is approximated via low-order mixed finite elements,which reduces the original problems to the constrained minimizationof a convex, but possibly not differentiable functional. Convergenceresults are proved or recalled, both for the finite elementapproximation and for the augmented Lagrangian algorithm. Adetailed study of the local minimization problems which occurin the augmented Lagrangian decomposition of the above problemsis also presented, together with several numerical results.     

实二次域Q(P(1/2))(p≡3(mod 4))类数的上界

设p是适合p≡3（Pod4）的奇素数,h,ε分别是实二次域Q的类数和基本单位．本文运用初等方法证明了：εh＜（p a 2)a 2/4(a 2)!,其中     

L-脯氨酸对离子液体介质中的不对称Michael反应催化性能研究

研究了L-脯氨酸对离子液体介质中醛(酮)与β-硝基烯烃的不对称Michael加成反应的催化性能, 利用X射线单晶衍射对Michael产物结构进行了表征. 结果表明, 反应在遵循胺催化机理的同时, 烯胺是从Re面对β-硝基烯烃进行加成, 产物的优势结构为(1R,2S)的syn型. 脯氨酸在离子液体1-正己基-3-甲基咪唑氯盐中显示良好的催化性能, 室温反应3～5 h, 得到89%以上收率的Michael产物, 其ee值最高70%. 脯氨酸与离子液体形成的催化体系具有良好的重复使用性能, 可至少稳定地重复使用6次.     

ChemInform Abstract: Polymorphism of CsAlF4. Synthesis and Structure of Two New Crystalline Forms.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

三元混配铜(Ⅱ)配合物的晶体结构、DNA作用及其生物活性

利用溶剂缓慢挥发法合成了以5-氯-2-(2'-吡啶基)苯并咪唑为主配体、L-苯丙氨酸根为辅助配体的三元混配铜(I)配合物:[Cu(HPBC)(L-Phe)(H2O)]C1O4(简称为1,HPBC=5-氯-2-(2'-吡啶基)苯并咪唑,L-Phe=L-苯丙氨酸根).采用元素分析、红外光谱、紫外可见光谱、摩尔电导率测定和电...