Natural gas has multi-origin compared with oil,which can be expressed as multiple genetic types,multiple gas genetic models and multiple occurrences of gas-generating material.

The research demonstrated that Cd highly concentrated assumes the punctual distribution,its distribution situation is been limited by the parent material,the high content in soil mainly caused by the human factors.

pH and the exchangeable aluminum content in acid soils as affected by parent materials and cropping systems;

Comparative study of red earth grain-size from different parent materials in Zhejiang Province;