rational formula
4.The tool is used to implement automatic circulation of water and arbitrary adjustment of water head, of which structure is rational, experimental arrangement is proper and experiment of Bernoulli equation, the experiment of constant flow Bernoulli equation of ideal fluid, experiment of Poiseuille formula and the experiment of Pitot line-up measurement flow can be conducted.
6.In order to get more efficient cryptosystem over curves , this paper discussed some basic properties of conic C_n(a,b) over the residue class ring Z_n , where n is the product of two primes . We proved that the rational points of C_n(a,b) form an abelian group, whose operation may be given in two ways: one by reduction map and another by a formula with respect to the coordinates.
