2019年10月8日,欧盟委员会联合研究中心(Joint Research Centre,JRC)发布了《区块链的现在和未来——评估分布式账本技术的多维影响》(Blockchain Now and Tomorrow——Assessing Multidimensional Impacts of Distributed Ledger Techn...2019年10月8日,欧盟委员会联合研究中心(Joint Research Centre,JRC)发布了《区块链的现在和未来——评估分布式账本技术的多维影响》(Blockchain Now and Tomorrow——Assessing Multidimensional Impacts of Distributed Ledger Technologies)。首先,该报告概述了区块链技术的工作原理,以便更好地了解其技术优势和局限性。其次,报告基于欧洲和全球的区块链初创企业的数量、产品和资金,讨论了这一新兴技术的投资创业热潮,并总结了欧盟基于政策层面的主要举措和活动,展示了欧盟对区块链的发展和内在潜力的态度。最后,分析了区块链在发展和应用过程中面临的机遇和挑战,以及其可能会给行业、经济和社会带来的重大变化。本报告就其主要内容进行了摘编。展开更多
A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge co...A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.展开更多
文摘2019年10月8日,欧盟委员会联合研究中心(Joint Research Centre,JRC)发布了《区块链的现在和未来——评估分布式账本技术的多维影响》(Blockchain Now and Tomorrow——Assessing Multidimensional Impacts of Distributed Ledger Technologies)。首先,该报告概述了区块链技术的工作原理,以便更好地了解其技术优势和局限性。其次,报告基于欧洲和全球的区块链初创企业的数量、产品和资金,讨论了这一新兴技术的投资创业热潮,并总结了欧盟基于政策层面的主要举措和活动,展示了欧盟对区块链的发展和内在潜力的态度。最后,分析了区块链在发展和应用过程中面临的机遇和挑战,以及其可能会给行业、经济和社会带来的重大变化。本报告就其主要内容进行了摘编。
基金Supported by the National Natural Science Foundation of China under Grant No.69686002the‘Talents Across the Century’of Education Ministry of Chinathe Natural Science Fund of Zhejiang Province.
文摘A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.
