Fuel retention and recycling in plasma facing materials is a crucial issue for fusion devices, especially for the long pulse discharge devices. In this work, the deuterium retention and the surface erosion of SiC-coat...Fuel retention and recycling in plasma facing materials is a crucial issue for fusion devices, especially for the long pulse discharge devices. In this work, the deuterium retention and the surface erosion of SiC-coated graphite tiles exposed to EAST plasmas have been studied by post-mortem analyses, i.e., thermal desorption spectroscopy （TDS）, secondary ion mass spec- troscopy （SIMS） and scanning electron microscopy （SEM）. The results show that the sample cut from the high field side （HF） tile has been intensely eroded due to deuterium bombardment on plasma facing surfaces in the initial phase of discharges and trapped highest amount of deuterium. Lower deuterium retention has been found in the inner divertor sample, which is presumably due to the particular exposure history in the 2010 spring campaign.展开更多
Poorly-drained, river bottom soils can be high corn (Zea mays L.) yielding environments, but saturated soil conditions often reduce corn yields. Wabash soils located in river bottoms in Northeast Missouri have not bee...Poorly-drained, river bottom soils can be high corn (Zea mays L.) yielding environments, but saturated soil conditions often reduce corn yields. Wabash soils located in river bottoms in Northeast Missouri have not been traditionally tile drained due to high clay content which requires narrow tile drain spacings. Increased land prices in the region have increased interest in tile draining poorly-drained bottom land soils to increase corn yields which could have a deleterious effect on water quality. The objectives of the three-year study were to determine whether use of managed subsurface drainage (MD) in combination with a controlled release N fertilizer could reduce the annual amount of NO3--N loss through tile drainage water compared to free subsurface drainage (FD) with a non-coated urea application. Annual NO3--N loss through tile drainage water with FD ranged from 28.3 to 90.1 kg·N·ha-1. Nitrogen fertilizer source did not affect NO3--N loss through tile drainage water, which was likely due to limited corn uptake over the three-year study due to adverse weather conditions. Averaged over three years, MD reduced tile water drained 52% and NO3--N loss 29% compared to FD. Reduction in NO3--N loss through tile drainage water with MD compared to FD was due to reduced tile flow during the non-cropping period. Annual flow-weighted mean concentration of NO3--N in the tile water was 5.8 mg·N·L-1 with FD and 8.1 mg·N·L-1 with MD. Tile draining river bottom soils at this location for continuous corn production may not pose a health risk over the evaluated duration.展开更多
为探索高分子聚合物用于古建筑琉璃瓦的保护研究,采用所选择的9种有机高分子聚合物对现代黄釉琉璃瓦进行保护处理,分析保护材料的耐光性能及保护后琉璃瓦的憎水性、耐冻融性和化学稳定性等性能,同时选择性能较好的材料用于胎体酥粉古琉...为探索高分子聚合物用于古建筑琉璃瓦的保护研究,采用所选择的9种有机高分子聚合物对现代黄釉琉璃瓦进行保护处理,分析保护材料的耐光性能及保护后琉璃瓦的憎水性、耐冻融性和化学稳定性等性能,同时选择性能较好的材料用于胎体酥粉古琉璃瓦的保护,分析憎水性、耐冻融性、耐折、抗压强度、透气性以及进行保护机理研究。结果表明,保护材料丙烯酸类材料的Prim al SF和B72耐光性能较差;用于现代琉璃瓦保护的Prim al SF憎水性和耐冻融性较差;有机硅的耐酸碱性较差;聚氨酯和硅丙乳液的憎水性和耐碱性能较差;氟碳清漆、氟树脂和复配材料的各项性能相对较好;含氟聚合物及其氟树脂为主的复配材料用于胎体酥粉古琉璃瓦保护的憎水性、耐冻融性、耐折、抗压强度和透气性等性能相对较好,保护材料以良好的渗透能力渗入古琉璃胎体内部,有效提高胎体强度,起到填充空隙和防止水分破坏的作用。综合几项指标,含氟聚合物及其复配材料的各种性能优良,为选择中国古建筑琉璃瓦的保护材料提供科学依据。展开更多
基金supported partially by National Natural Science Foundation of China(Nos.10905070,10875148 and 10728510)the Knowledge Innovation Program of the Chinese Academy of Sciences,the National Magnetic Confinement Fusion Science Program of China(No.2009GB106005)
文摘Fuel retention and recycling in plasma facing materials is a crucial issue for fusion devices, especially for the long pulse discharge devices. In this work, the deuterium retention and the surface erosion of SiC-coated graphite tiles exposed to EAST plasmas have been studied by post-mortem analyses, i.e., thermal desorption spectroscopy （TDS）, secondary ion mass spec- troscopy （SIMS） and scanning electron microscopy （SEM）. The results show that the sample cut from the high field side （HF） tile has been intensely eroded due to deuterium bombardment on plasma facing surfaces in the initial phase of discharges and trapped highest amount of deuterium. Lower deuterium retention has been found in the inner divertor sample, which is presumably due to the particular exposure history in the 2010 spring campaign.
文摘Poorly-drained, river bottom soils can be high corn (Zea mays L.) yielding environments, but saturated soil conditions often reduce corn yields. Wabash soils located in river bottoms in Northeast Missouri have not been traditionally tile drained due to high clay content which requires narrow tile drain spacings. Increased land prices in the region have increased interest in tile draining poorly-drained bottom land soils to increase corn yields which could have a deleterious effect on water quality. The objectives of the three-year study were to determine whether use of managed subsurface drainage (MD) in combination with a controlled release N fertilizer could reduce the annual amount of NO3--N loss through tile drainage water compared to free subsurface drainage (FD) with a non-coated urea application. Annual NO3--N loss through tile drainage water with FD ranged from 28.3 to 90.1 kg·N·ha-1. Nitrogen fertilizer source did not affect NO3--N loss through tile drainage water, which was likely due to limited corn uptake over the three-year study due to adverse weather conditions. Averaged over three years, MD reduced tile water drained 52% and NO3--N loss 29% compared to FD. Reduction in NO3--N loss through tile drainage water with MD compared to FD was due to reduced tile flow during the non-cropping period. Annual flow-weighted mean concentration of NO3--N in the tile water was 5.8 mg·N·L-1 with FD and 8.1 mg·N·L-1 with MD. Tile draining river bottom soils at this location for continuous corn production may not pose a health risk over the evaluated duration.
文摘为探索高分子聚合物用于古建筑琉璃瓦的保护研究,采用所选择的9种有机高分子聚合物对现代黄釉琉璃瓦进行保护处理,分析保护材料的耐光性能及保护后琉璃瓦的憎水性、耐冻融性和化学稳定性等性能,同时选择性能较好的材料用于胎体酥粉古琉璃瓦的保护,分析憎水性、耐冻融性、耐折、抗压强度、透气性以及进行保护机理研究。结果表明,保护材料丙烯酸类材料的Prim al SF和B72耐光性能较差;用于现代琉璃瓦保护的Prim al SF憎水性和耐冻融性较差;有机硅的耐酸碱性较差;聚氨酯和硅丙乳液的憎水性和耐碱性能较差;氟碳清漆、氟树脂和复配材料的各项性能相对较好;含氟聚合物及其氟树脂为主的复配材料用于胎体酥粉古琉璃瓦保护的憎水性、耐冻融性、耐折、抗压强度和透气性等性能相对较好,保护材料以良好的渗透能力渗入古琉璃胎体内部,有效提高胎体强度,起到填充空隙和防止水分破坏的作用。综合几项指标,含氟聚合物及其复配材料的各种性能优良,为选择中国古建筑琉璃瓦的保护材料提供科学依据。
