Modified Born-Jordan Method For Constructing The Commutation Relation Of   Coordinate and Momentum
  The Born-Jordan method for constructing the quantum condition of the Matrix Mechanics is pointed out to be inappropriate in the present work. We modify this method and reconstruct the quantum condition by setting up a new expression for the Bohr quantum condition with the help of the (n,n) elements of the matrix $\oint\hat{p}(t){\rm d}\hat{x}(t)$. 
Ze-Sen Yang (Institute of Theoretical Physics, Peking University)
quant-ph