The complex resins prepared from macroporous sulfonated resin D72(H^+ form) with ferric chloride or ferric chloride hexahydrate have both sites of Bronsted acid
D-ribose is a unique ,5-carbon sugar that occurs naturally in all living cells,D-ribose has been used as a staring material for preparation of some certain medic
A t-(v,k,λ)design(X,B)is a set X of points,of cardinality v,and a collection B of k-subsets of X called blocks,with the property that every t-subset of X is co