It is difficult to establish a simple model which the mathematic or mechanical method can be used in the selection lf mining method, due to many influence and constraint factors.
由于采矿方法选择受诸多因素影响和制约，难于建立一个用数学或力学模型的方法加以处理。
2
Discusses the influence of parameters in equations of constraint upon the motion of mechanical systems.
研究约束方程中参数对力学系统运动的影响。
3
In this paper two erroneous formulas, which discuss constraint forces of mechanical system in Theoretical Mechanics second edition write by Zhou Yengbor, have been indicated and analyzed.