in this paper we give an elementary argument about the atoms and coatoms of the latticeof all subgroups of a group. it is proved that an abelian group of finite exponent is strongly coatomic.

The intramolecular [4+2] cycloaddition between arenes and allenes first reported by Himbert gives rapid access to rigid polycyclic scaffolds. Herein, we report a one-pot oxyalkynylation/cycloaddition reaction proceeding under mild conditions (23–90 °C) providing complex architectures with high efficiency, atom step economy. bicyclo[2.2.2]octadiene products were obtained wide variety of useful f...

This paper investigates some of the man~estations and major forces driving the emergence of the new economy. A model of the virtual enterprise is proposed and investigated in the context of a virtual industry value chain. The transition to the virtual economy is definitely technology driven but is also shaped by social, economic, institutional forces. As such, it raises a number of significant ...

thirty nine novel 1,2,3,4-tetrahydropyrimidinone (thione)s were subjected to conformational studies. density functional theory at b3lyp/6-31 g* was performed as the computational method of high accuracy. important dihedral angles and bond lengths were investigated and the values obtained were explainable. results of this work confirm a twisted boat tetrahydropyrimidine ring conformation with an...

Inexpensive protic ionic liquids, synthesized from di- or triamines and excess sulfuric acid, were used as solvents catalysts for the Beckmann rearrangement. The use of liquids in place oleum acid allowed base neutralization step, which is required conventional rearrangement, to be entirely avoided, thereby dramatically improving atom economy. Using a biphasic water/organic solvent extraction s...

Density functional theory calculations were carried out to study the interaction of heroin molecule with pristine and N-dopedTiO2 anatase nanoparticles. The oxygen atom of heroin molecule was found to be the binding site on the heroin molecule. In contrast, the binding site of TiO2 nanoparticle was positioned over the fivefold coordinated titanium atoms. The results showed that the adsorption e...