In this paper, an experimental method was described for measuring very slight wear of polymer by using neutron activation analysis (NAA). By means of adopting appropriate neutron flux suitable experimental parameters ...In this paper, an experimental method was described for measuring very slight wear of polymer by using neutron activation analysis (NAA). By means of adopting appropriate neutron flux suitable experimental parameters and measuring technique, the method was performed under the condition without any effect upon the mechanical properties of wearing. The sensitivity of the wear measurements reached the order of magnitude of 10-7g for engineering plastics containing about 1 wt% of zinc. The comparison could be made rapidly between different materials with different resistance to wear. The results were free from the influence of vibration of test systems, elastic deformation of materials, media and moisture absorption, and etc. Combined with autoradiograph, the present technique can be used to investigate the backtransfer of ground debris of metallic fillers from the counter part to the specimen. A multifunctional plane wear testing machine was set up for obtaining wear data and friction coefficient. The present work provides a new, rapid and sensitive measuring technique and also a screening method for the wear of polymers.展开更多
The growth of Arthrospira platensis and physiological changes in biomass under the effects of six rare earth elements Dy,Sm,Tb,La,Nd and Yb were evaluated.Elements were tested by three concentrations of 10,20 and 30 m...The growth of Arthrospira platensis and physiological changes in biomass under the effects of six rare earth elements Dy,Sm,Tb,La,Nd and Yb were evaluated.Elements were tested by three concentrations of 10,20 and 30 mg/L.According to neutron activation analysis data A.platensis’s accumulation capacity toward studied elements changes in the following order of La>Dy>Nd>Sm>Yb>Tb.The results show that Dy and La ions stimulate biomass growth and Yb ions inhibit it,while Sm,Tb and Nd ions do not affect biomass accumulation.The contents of proteins and chlorophyll a are not affected by the presence of rare earth elements in the cultivation medium.Studied elements affect to different extents carbohydrates,phycobilins,β-carotene,lipids and MDA contents in spirulina biomass.Changes in the antioxidant activity under applied metal loads reveal a moderate stress in exposed A.platensis.Cyanobacterium A.platensis can be successfully used for bioremediation of natural water contaminated with REEs as well as REEs recovery from low polluted industrial effluents.展开更多
文摘In this paper, an experimental method was described for measuring very slight wear of polymer by using neutron activation analysis (NAA). By means of adopting appropriate neutron flux suitable experimental parameters and measuring technique, the method was performed under the condition without any effect upon the mechanical properties of wearing. The sensitivity of the wear measurements reached the order of magnitude of 10-7g for engineering plastics containing about 1 wt% of zinc. The comparison could be made rapidly between different materials with different resistance to wear. The results were free from the influence of vibration of test systems, elastic deformation of materials, media and moisture absorption, and etc. Combined with autoradiograph, the present technique can be used to investigate the backtransfer of ground debris of metallic fillers from the counter part to the specimen. A multifunctional plane wear testing machine was set up for obtaining wear data and friction coefficient. The present work provides a new, rapid and sensitive measuring technique and also a screening method for the wear of polymers.
文摘The growth of Arthrospira platensis and physiological changes in biomass under the effects of six rare earth elements Dy,Sm,Tb,La,Nd and Yb were evaluated.Elements were tested by three concentrations of 10,20 and 30 mg/L.According to neutron activation analysis data A.platensis’s accumulation capacity toward studied elements changes in the following order of La>Dy>Nd>Sm>Yb>Tb.The results show that Dy and La ions stimulate biomass growth and Yb ions inhibit it,while Sm,Tb and Nd ions do not affect biomass accumulation.The contents of proteins and chlorophyll a are not affected by the presence of rare earth elements in the cultivation medium.Studied elements affect to different extents carbohydrates,phycobilins,β-carotene,lipids and MDA contents in spirulina biomass.Changes in the antioxidant activity under applied metal loads reveal a moderate stress in exposed A.platensis.Cyanobacterium A.platensis can be successfully used for bioremediation of natural water contaminated with REEs as well as REEs recovery from low polluted industrial effluents.
