High-quality AlN/sapphire templates were fabricated by the combination of sputtering and high-temperature(HT)annealing.The influence of sputtering parameters including nitrogen flux,radio frequency power,and substrate...High-quality AlN/sapphire templates were fabricated by the combination of sputtering and high-temperature(HT)annealing.The influence of sputtering parameters including nitrogen flux,radio frequency power,and substrate temperature on the crystalline quality and surface morphology of annealed AlN films were investigated.With lower substrate temperature,lower power,and lower N2 flux,the full width at half maximum of the X-ray rocking curve for AlN(0002)and(102)were improved to 97.2 and 259.2 arcsec after high-temperature annealing.This happens because the increased vacancy concentration of sputtered AlN films can facilitate the annihilation of dislocations by increasing the recovery rate during HT annealing.Step and step-bunching morphologies were clearly observed with optimized sputtering conditions.展开更多
Taking the traditional fruit pear as the example, this paper analyzes labor cost for pome production in Hebei Province, based on the representative cases and the research of pome production in different cultivation mo...Taking the traditional fruit pear as the example, this paper analyzes labor cost for pome production in Hebei Province, based on the representative cases and the research of pome production in different cultivation modes. Firstly, it conducts cost analysis for medium-density pome production in Xinji City, focusing on the comparison of the costs for the main production labor in standard thin planting mode and dwarf close planting mode. According to the research results, labor cost has a great influence on the total production cost of pome. The methods to reduce labor cost include: adopting dwarfing rootstock close planting and intensively efficient pome cultivation method; simplifying the pruning method when matching up the shape of tree; improving soil by the methods of natural grasses and addition of organic materials, and increasing mechanized operation.展开更多
基金This work was supported by the National Key R&D Program of China(Nos.2016YFB0400800 and 2017YFB0404202)the National Natural Sciences Foundation of China(Grant Nos.61527814,61674147,61904176,U1505253)+1 种基金Beijing Nova Program Z181100006218007Youth Innovation Promotion Association CAS 2017157.
文摘High-quality AlN/sapphire templates were fabricated by the combination of sputtering and high-temperature(HT)annealing.The influence of sputtering parameters including nitrogen flux,radio frequency power,and substrate temperature on the crystalline quality and surface morphology of annealed AlN films were investigated.With lower substrate temperature,lower power,and lower N2 flux,the full width at half maximum of the X-ray rocking curve for AlN(0002)and(102)were improved to 97.2 and 259.2 arcsec after high-temperature annealing.This happens because the increased vacancy concentration of sputtered AlN films can facilitate the annihilation of dislocations by increasing the recovery rate during HT annealing.Step and step-bunching morphologies were clearly observed with optimized sputtering conditions.
文摘Taking the traditional fruit pear as the example, this paper analyzes labor cost for pome production in Hebei Province, based on the representative cases and the research of pome production in different cultivation modes. Firstly, it conducts cost analysis for medium-density pome production in Xinji City, focusing on the comparison of the costs for the main production labor in standard thin planting mode and dwarf close planting mode. According to the research results, labor cost has a great influence on the total production cost of pome. The methods to reduce labor cost include: adopting dwarfing rootstock close planting and intensively efficient pome cultivation method; simplifying the pruning method when matching up the shape of tree; improving soil by the methods of natural grasses and addition of organic materials, and increasing mechanized operation.