An optimal magic cube of order n is a magic cube whose row sums, column sums and oblique sums of 9 n layers are n(n 3+1)/2. The author proved that optimal magic cubes of order n may be constructed as long as n and 2, ...An optimal magic cube of order n is a magic cube whose row sums, column sums and oblique sums of 9 n layers are n(n 3+1)/2. The author proved that optimal magic cubes of order n may be constructed as long as n and 2, 3, 5, 7 are relatively prime, and a formula for making optimal magic cubes by using optimal Latin squares and optimal magic squares was given.展开更多
The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the '...The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the 'loose' ligands are determined. The crystallographic data of the cluster compounds with [W_3S_4]￣(4+) and [W_3CuS_4]￣(5+) cores are compared and their UV-Vis spectra are firstly reported. Thus, the 'quasi-aromaticity' of the [W_3S_4]￣(4+) core of these cluster compounds is discussed.展开更多
文摘An optimal magic cube of order n is a magic cube whose row sums, column sums and oblique sums of 9 n layers are n(n 3+1)/2. The author proved that optimal magic cubes of order n may be constructed as long as n and 2, 3, 5, 7 are relatively prime, and a formula for making optimal magic cubes by using optimal Latin squares and optimal magic squares was given.
文摘The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the 'loose' ligands are determined. The crystallographic data of the cluster compounds with [W_3S_4]￣(4+) and [W_3CuS_4]￣(5+) cores are compared and their UV-Vis spectra are firstly reported. Thus, the 'quasi-aromaticity' of the [W_3S_4]￣(4+) core of these cluster compounds is discussed.
