A general finite element model for numerical simulation of structure dynamics
作者:Fujun Wang、Yaojun Li、K. Han、Y. T. Feng
DOI:10.1007/s11433-006-2011-1
日期:2006.8
A finite element model used to simulate the dynamics with continuum and discontinuum is presented. This new approach is conducted by constructing the general contact model. The conventional discrete element is treated as a standard finite element with one node in this new method. The one-node element has the same features as other finite elements, such as element stress and strain. Thus, a general finite element model that is consistent with the existed finite element model is set up. This new model is simple in mathematical concept and is straightforward to be combined into the existing standard finite element code. Numerical example demonstrates that this new approach is more effective to perform the dynamic process analysis in which the interactions among a large number of discrete bodies and continuum objects are included.
Metal-free Synthesis of 2,4,6-Trisubstituted Pyrimidines using α,β.- Unsaturated Ketones and Benzamidine via Tandem Annulation-Oxidation Pathway
作者:Kamlesh S. Vadagaonkar、Hanuman P. Kalmode、Kaliyappan Murugan、Atul C. Chaskar
DOI:10.2174/1570178612666150425000023
日期:2015.7.8
A tandem metal-free synthesis of partly and fully substituted pyrimidines has been
accomplished from α,β-unsaturated ketones and benzamidine in presence of triethyl amine. The
reaction proceeds via [3+3] annulation-oxidation sequence and the protocol has been found successful
for the synthesis of a wide range of pyrimidine derivatives.
Substrate-Controlled Synthesis of Functionalized Cyclohexanes with Four Stereocenters by Organocatalytic Asymmetric Domino Reactions Between γ-Nitro Ketone and Enone
作者:Lu Yu、Zhen Yang、Jianzhao Peng、Pengfei Li
DOI:10.1002/ejoc.201501303
日期:2016.1
Organocatalytic asymmetric dominoreactions of γ-nitroketones and enones have been developed for the construction of functionalized cyclohexane skeletons with four stereogenic carbon atoms, including one tetrasubstituted carbon stereocenter. 5-Nitropentan-2-one and 6-nitrohexan-3-one reacted with chalcone to afford six-membered carbocycles with four consecutive stereocenters in yields of 51–91 % with