The influences of filter unit on lubricating oil properties were studied by the simulation of wear conditions.The oil samples under different conditions were analyzed using ferrography.The results show that the filter unit can effectively improve the properties of lubricating oil,decrease the mechanical wear of devices,and extend the life of lubricating oil.

A method for the determination of selenium in plant samples by hydride generation-atomic fluorescence spectrometry(HG-AFS) was developed.The samples are treated with microwave digestion in HNO3 medium.The detection limit of the method for Se is 0.008 mg/kg and the precision is 4.36%RSD(n=12).The method has been applied to the determination of Se in National Standard Reference plant samples and the results are in agreement with certified values.Selenium in 5 kinds of 42 plant samples are determined by the method and the results are in agreement with external examination results.