Let Γd2n be the set of trees with a given diameter d having a perfect matching,where 2n is the number of vertex.For a tree T in Γd2n,let Pd+1 be a diameter of
On December 19, 2009, each party of the United Nations Climate Change Conference was to "record" a way to save the "Copenhagen agreement" in Copenhagen. However, th
Based on the principle of general relativity,geometrization of interaction,the interaction of the inhomogeneous isotropic medium to light can be equated to a no