Ferroelectric materials are promising candidates for ultraviolet photodetectors due to their ferroelectric effect.In this work,a BaTiO_(3)/p-GaN/Au hybrid heterojunction-Schottky self-driven ultraviolet photodetector ...Ferroelectric materials are promising candidates for ultraviolet photodetectors due to their ferroelectric effect.In this work,a BaTiO_(3)/p-GaN/Au hybrid heterojunction-Schottky self-driven ultraviolet photodetector was fabricated with excellent bipolar photoresponse property.At 0 V bias,the direction of the photocurrent can be switched by flipping the depolarization field of BaTiO_(3),which allows the performance of photodetectors to be controlled by the ferroelectric effect.Meanwhile,a relatively large responsivity and a fast response speed can be also observed.In particular,when the depolarization field of BaTiO_(3) is in the same direction of the built-in electric field of the Au/p-GaN Schottky junction(up polarized state),the photodetector exhibits a high responsivity of 18 mA/W at 360 nm,and a fast response speed of<40 ms at 0 V.These findings pave a new way for the preparation of high-performance photodetectors with bipolar photocurrents.展开更多
针对目前大型地下工程在复杂地质环境条件下硬岩隧道掘进机(tunnel boring machine,TBM)施工的安全保障工作存在“缺数据、缺平台、缺分析”以及海量数据难以挖掘与计算分析的问题,提出了TBM施工数据“Born by digit,Born in format,Bor...针对目前大型地下工程在复杂地质环境条件下硬岩隧道掘进机(tunnel boring machine,TBM)施工的安全保障工作存在“缺数据、缺平台、缺分析”以及海量数据难以挖掘与计算分析的问题,提出了TBM施工数据“Born by digit,Born in format,Born to the cloud”的理念,研究构建了基于云计算和大数据挖掘技术的复杂地质环境状态TBM施工信息综合管理平台,该平台通过环境地质分析以及数据采集、存储和计算分析,建立基于TBM锚杆钻机随钻测量系统和岩体渣片图像识别系统实时采集岩体数字化信息,并实时采集TBM施工过程中PLC(可编程逻辑控制器)数据,建立Mongo DB TMB多源施工信息大数据仓库,同时基于Openstack技术搭建私有云计算平台以及在SaaS层部署算法组件开展TBM大数据挖掘。该平台的搭建不仅能提供基础信息,帮助提升安全管控水平,更重要的是可为TBM在复杂地质环境条件下对于各类瓶颈问题的研究解决提供数据挖掘和计算分析的支撑,并通过其所建立的知识库和规则库指导TBM设计、选型、控制。该研究成果在中国吉林引松供水工程项目上得到应用,并取得了较好的效益。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.62074148,61875194,11727902,12204474,12304111,and 12304112)the Youth Innovation Promotion Association,Chinese Academy of Sciences (Grant No.2020225)+1 种基金Jilin Province Science Fund (Grant Nos.20220101053JC and 20210101145JC)Jilin Province Young and Middle-Aged Science and Technology Innovation Leaders and Team Project (Grant No.20220508153RC)。
文摘Ferroelectric materials are promising candidates for ultraviolet photodetectors due to their ferroelectric effect.In this work,a BaTiO_(3)/p-GaN/Au hybrid heterojunction-Schottky self-driven ultraviolet photodetector was fabricated with excellent bipolar photoresponse property.At 0 V bias,the direction of the photocurrent can be switched by flipping the depolarization field of BaTiO_(3),which allows the performance of photodetectors to be controlled by the ferroelectric effect.Meanwhile,a relatively large responsivity and a fast response speed can be also observed.In particular,when the depolarization field of BaTiO_(3) is in the same direction of the built-in electric field of the Au/p-GaN Schottky junction(up polarized state),the photodetector exhibits a high responsivity of 18 mA/W at 360 nm,and a fast response speed of<40 ms at 0 V.These findings pave a new way for the preparation of high-performance photodetectors with bipolar photocurrents.
文摘针对目前大型地下工程在复杂地质环境条件下硬岩隧道掘进机(tunnel boring machine,TBM)施工的安全保障工作存在“缺数据、缺平台、缺分析”以及海量数据难以挖掘与计算分析的问题,提出了TBM施工数据“Born by digit,Born in format,Born to the cloud”的理念,研究构建了基于云计算和大数据挖掘技术的复杂地质环境状态TBM施工信息综合管理平台,该平台通过环境地质分析以及数据采集、存储和计算分析,建立基于TBM锚杆钻机随钻测量系统和岩体渣片图像识别系统实时采集岩体数字化信息,并实时采集TBM施工过程中PLC(可编程逻辑控制器)数据,建立Mongo DB TMB多源施工信息大数据仓库,同时基于Openstack技术搭建私有云计算平台以及在SaaS层部署算法组件开展TBM大数据挖掘。该平台的搭建不仅能提供基础信息,帮助提升安全管控水平,更重要的是可为TBM在复杂地质环境条件下对于各类瓶颈问题的研究解决提供数据挖掘和计算分析的支撑,并通过其所建立的知识库和规则库指导TBM设计、选型、控制。该研究成果在中国吉林引松供水工程项目上得到应用,并取得了较好的效益。
