The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and...The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.展开更多
全球价值链分工格局的深刻变化、日益复杂的全球经贸形势,对中国对外贸易、产业转型发展、"一带一路"倡议等海外发展战略将会产生极其深远的影响。东北亚区域在中国价值链合作中一直占有十分重要的地位,本文首先分析传统贸易...全球价值链分工格局的深刻变化、日益复杂的全球经贸形势,对中国对外贸易、产业转型发展、"一带一路"倡议等海外发展战略将会产生极其深远的影响。东北亚区域在中国价值链合作中一直占有十分重要的地位,本文首先分析传统贸易统计下东北亚区域贸易态势,进而基于亚洲发展银行——多区域投入产出表(ADB-MRIO)数据,借鉴Koopman et al.(2014)、王直等(2015)的增加值贸易核算方法,改进及构建相关指标,从增加值贸易角度对中国与东北亚区域价值链合作中各国的产业贸易平衡、贸易关联与需求依赖度等进行深入剖析,探明中国与各国的价值链合作关联机制、地位变化趋势、真实的贸易收益,为中国东北亚区域外经贸战略调整和产业转型升级提供参考依据。相应提出以下对策建议:正确审视贸易差额,更加关注增加值贸易结构和贸易收益变化趋势;制定差异化的国别产业贸易政策、促进高技术产业贸易关联和需求依赖度的提升;增强政治互信,推进中日韩自贸区建设,塑造国际贸易新动能;梯度强化优势产业竞争力,促进全球价值链地位提升以及重构。展开更多
基金Project supported by the Science and Technology Major Project of Shanxi Province,China (Grant No.20181102013)the “1331 Project” Engineering Research Center of Shanxi Province,China (Grant No.PT201801)the Natural Science Foundation of Shanxi Province,China (Grant No.201801D221131)。
文摘The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.
基金supported by the National Natural Science Foundation of China(81921004,T2122019,51973096,and 32171325)Tianjin Municipal Science and Technology Bureau(20JCQNJC01720)the Fundamental Research Funds for the Central Universities,Nankai University.
文摘全球价值链分工格局的深刻变化、日益复杂的全球经贸形势,对中国对外贸易、产业转型发展、"一带一路"倡议等海外发展战略将会产生极其深远的影响。东北亚区域在中国价值链合作中一直占有十分重要的地位,本文首先分析传统贸易统计下东北亚区域贸易态势,进而基于亚洲发展银行——多区域投入产出表(ADB-MRIO)数据,借鉴Koopman et al.(2014)、王直等(2015)的增加值贸易核算方法,改进及构建相关指标,从增加值贸易角度对中国与东北亚区域价值链合作中各国的产业贸易平衡、贸易关联与需求依赖度等进行深入剖析,探明中国与各国的价值链合作关联机制、地位变化趋势、真实的贸易收益,为中国东北亚区域外经贸战略调整和产业转型升级提供参考依据。相应提出以下对策建议:正确审视贸易差额,更加关注增加值贸易结构和贸易收益变化趋势;制定差异化的国别产业贸易政策、促进高技术产业贸易关联和需求依赖度的提升;增强政治互信,推进中日韩自贸区建设,塑造国际贸易新动能;梯度强化优势产业竞争力,促进全球价值链地位提升以及重构。
