Maifanite is a nature medicinal stone used in many fields for long time. Theresearch on it showed that there are many trace elements in maifanite. In this paper, 36 traceelements in maifanite were determined by outer ...Maifanite is a nature medicinal stone used in many fields for long time. Theresearch on it showed that there are many trace elements in maifanite. In this paper, 36 traceelements in maifanite were determined by outer cover electrode atomic emission spectrometry, and thedetermination conditions were studied systematically. The results show that the concentrations ofelements, which are beneficial to human health, are higher, and the elements harmful to peoplehealth such as As, Cd, Hg, Cr, and Pb are tiny in maifanite. The precision and the accuracy werealso discussed.展开更多
This study investigates the optimization of physical parameters in a parabolic trough collector receiver unit to improve its thermal and optical performance.The parameters include the transmissivity,reflectivity,absor...This study investigates the optimization of physical parameters in a parabolic trough collector receiver unit to improve its thermal and optical performance.The parameters include the transmissivity,reflectivity,absorptivity,emissivity and thermal conductivity of the outer cover and absorber pipe.This study utilizes a novel experimental design and a simulation model that accounts for the infrared reflectivity inside the receiver.The simulation results were validated by the experimental data,with a maximum deviation of 8%.The study analyses the effects of varying the physical parameters on the heat transfer fluid temperature,total plant efficiency,temperature profiles,temperature gradients and thermal stress.The study finds that increasing the reflectivity and decreasing the emissivity of the outer cover and the absorber pipe significantly enhance the performance,with maximum increases of 25.8%and 26.5%in total efficiency,respectively.The study also finds that increasing the thermal conductivity of the absorber pipe reduces the temperature gradients and thermal stress,with maximum decreases of 42.2%and 29%,respectively.This study provides valuable insights for optimizing the receiver design and operation in solar-thermal systems.展开更多
文摘Maifanite is a nature medicinal stone used in many fields for long time. Theresearch on it showed that there are many trace elements in maifanite. In this paper, 36 traceelements in maifanite were determined by outer cover electrode atomic emission spectrometry, and thedetermination conditions were studied systematically. The results show that the concentrations ofelements, which are beneficial to human health, are higher, and the elements harmful to peoplehealth such as As, Cd, Hg, Cr, and Pb are tiny in maifanite. The precision and the accuracy werealso discussed.
基金following entities for their kind support:Engineering and Natural Sciences Department at SDU UniversityMITP(Mandelstam Institute for Theoretical Research)at the University of the Witwatersrand.
文摘This study investigates the optimization of physical parameters in a parabolic trough collector receiver unit to improve its thermal and optical performance.The parameters include the transmissivity,reflectivity,absorptivity,emissivity and thermal conductivity of the outer cover and absorber pipe.This study utilizes a novel experimental design and a simulation model that accounts for the infrared reflectivity inside the receiver.The simulation results were validated by the experimental data,with a maximum deviation of 8%.The study analyses the effects of varying the physical parameters on the heat transfer fluid temperature,total plant efficiency,temperature profiles,temperature gradients and thermal stress.The study finds that increasing the reflectivity and decreasing the emissivity of the outer cover and the absorber pipe significantly enhance the performance,with maximum increases of 25.8%and 26.5%in total efficiency,respectively.The study also finds that increasing the thermal conductivity of the absorber pipe reduces the temperature gradients and thermal stress,with maximum decreases of 42.2%and 29%,respectively.This study provides valuable insights for optimizing the receiver design and operation in solar-thermal systems.
