Preservation and deliverability characteristics of coalbed methane,North China;

A Preliminary Discussion on the Relationship between Yanshanian Regional Metamorphism and Ore Deposit Genesis in North China;

Conductivity Structure of Lithosphere in Central North China: Magnetotelluric Study of Yingxian-Shanghe profile;

China' s LPG Market Analysis and Forecast--Northern China to be the Next Booming Area;

Research on Relationship Between Sequence Strata and Coal－accumulation of Late Palaeozoic Coal－accumulating Basin in Northern China;

Carbon content rate in constructive species of main forest types in northern China.;