Effects of land use change on light fractions of organic carbon in soil water-stable aggregates;

In Quzhou County,Hebei Province where now intensive farming system is operated,original grassland and farming land under different tillage,crop straw return and fertilization measures were studied for the analysis of the impact on soil organic carbon properties,espe cially on light fraction organic carbon,sand and particle organic carbon.

No effect is acted on colour APHA and volume resistivity of dioctyl phathalate when a little of light component of phthalic anhydride was added to the fine phthalic anhydride,but the addition of light component can affect the purity of dioctyl phthalate(DOP).

Through design and test,we have modified waste oil recovery system to separate the heavy component,the light component and water from waste oil,This modification increased the use value of waste oil and reduced the pollution .

A new type of light weight and small size machine with sprinkling irrigation and hose irrigation was introduced.

The wings of light weight and small size machine for sprinkling irrigation and hose irrigation adopt multi-strides truss with fast disassembling & connection structure.