nitrogen content of coal

• 煤中氮

nitrogen content of coal的用法和样例：

例句

1. After harvesting the crops, he tested them for nitrogen content.
   作物收获后，他测定了作物中氮的含量。
2. The Kjeldahl is a general analysis method for determining nitrogen in rubber.
   凯氏定氮法是测定橡胶中氮含量的常规分析方法。