<正> Referring to GB5618-1995 about heavy metal pollution,and using statistical analysis SPSS,the major pollutants of mine area farmland heavy metal pollution w
<正> The coal hydrogenation reaction process is simply considered as three steps.In the first step,the smaller molecules associated with coal structure units ar
<正> Summarized the four main sources of CO gas on the working face based on investigation and local observation: firstly,it analyzed the mechanism that CO gas