With a variational method and a modified arrangmement channel quantum mechanics(MACQM) method,the energies of a equilateral triangle H-3 and a tetrahedron H-4 system are calculated.

Fraunhofer diffraction light intensity distribution of the equilateral triangle and the equilateral hexagon pore;

Using the variational method and the modified arrangmement channel quantum mechanics(MACQM) method,the energy curve of the equilateral triangle structure of H_3 has been calculated.

In this paper, we give a method for cutting out a maximal equilateral triangle from a square and a strict proof of this method.

Determination of trace lead in crude oils by trioctylamine extraction-spectrophotometry;

Based on the current situation of the supply and demand of China s medical and health resource, this paper, with the data collected, expounds the inharmonious phenomenon of "upside-down triangle" and "regular triangle" in the first part.