we classify the paracontact riemannian manifolds that their rieman-nian curvature satisfies in the certain condition and we show that thisclassification is hold for the special cases semi-symmetric and locally sym-metric spaces. finally we study paracontact riemannian manifolds satis-fying r(x, ξ).s = 0, where s is the ricci tensor.

In his article, Gáspár Jékely praises the role that chemistry played in elucidating the structure of DNA. Rightly so, I must say, being educated as a chemist myself. However, I believe that some modesty is quite appropriate in this case and I would like to explain briefly why chemistry initially failed to grasp the real nature of DNA. While reflecting on the sequencing of the human genome, Jéke...

We classify the paracontact Riemannian manifolds that their Riemannian curvature satisfies in the certain condition and we show that this classification is hold for the special cases semi-symmetric and locally symmetric spaces. Finally we study paracontact Riemannian manifolds satisfying R(X, ξ).S = 0, where S is the Ricci tensor.

the automatic assignment of protein secondary structure from three dimensional coordinates is an essentialstep in the characterization of protein structure.although, the recognition of secondary structures suchas alpha-helices and beta-sheets seem straightforward, but there are many different definitions, eachregarding different criteria. we have developed a newalgorithm for protein helix assig...

As a novel topological state, higher-order insulator has attracted enormous interest, which in d spatial dimensions gapless boundary states at (d−n) (integer n is larger than 1). Until now, merely few two-dimensional (2D) materials have been identified as insulators and their experimental confirmations are still absent. Here we propose universal strategy of antidot engineering to realize second...

iranian popular films, as a type of national culture, are consumed vastly iran. although they are neglegted in common cultural studies is iran, according to recent culture theories , they are some cultural texts including the ideological cods that they have an important role in the constrution of collective social perception. therefore, a quastion that can be addressed is what the narrative and...