Shallow underground water in south of Boxing county has the characteristics of wide distribution, stable reentry and alimetation condition and complicated hydrochemical characteristics.
博兴县南部浅层地下水具有埋藏分布广泛、补排径条件稳定、水化学特征复杂等特点。
2
The optimal high altitude guidance law with reentry constraint condition is derived by using the optimal control theory, and the algorithm of time to go is also given.