mpi多线程运用最速下降法求共轭梯度，16个线程，最多循环1000次。-mpi multi-threaded application steepest descent method the conjugate gradient, 16 threads, up to 1000 cycles.

通过最速下降算法研究基于梯度的自适应方法,最速下降是递归的,(Through the study of steepest descent algorithm based on gradient adaptive method, the steepest decline is recursive,)