无论氢在电子器件内部以何种形式(H2分子、H原子或H+离子)存在,均会对电子器件电离损伤产生作用,进而影响器件的抗辐照能力。本文深入研究了氢气和空气气氛条件下1 Me V电子辐照栅控横向PNP(GLPNP)型双极晶体管的辐射损伤缺陷演化行为...无论氢在电子器件内部以何种形式(H2分子、H原子或H+离子)存在,均会对电子器件电离损伤产生作用,进而影响器件的抗辐照能力。本文深入研究了氢气和空气气氛条件下1 Me V电子辐照栅控横向PNP(GLPNP)型双极晶体管的辐射损伤缺陷演化行为。利用Keithley 4200SCS半导体参数测试仪对不同气氛下辐照过程中晶体管进行在线原位电性能参数测试,研究晶体管电性能退化与电子辐照注量和氢气深度之间的关系;基于栅扫技术(GS)和深能级瞬态谱技术(DLTS),研究双极晶体管中氢诱导电离损伤缺陷演化的基本特征。研究表明,与空气气氛相比,氢气气氛下电子辐照导致GLPNP的基极电流增加显著,而集电极电流明显降低,产生更多的氧化物电荷和界面态,这些现象均说明氢气加剧双极晶体管的电离辐射损伤。展开更多
将三维激光扫描技术应用于温州绕城高速公路南山隧道施工期的变形量测中。首先相隔4个工日进行2次扫描得到2期隧道点云数据,通过对点云数据分析和处理得到隧道初期支护段空间变形场,从中提取断面的拱顶沉降作为隧道围岩参数反演分析的...将三维激光扫描技术应用于温州绕城高速公路南山隧道施工期的变形量测中。首先相隔4个工日进行2次扫描得到2期隧道点云数据,通过对点云数据分析和处理得到隧道初期支护段空间变形场,从中提取断面的拱顶沉降作为隧道围岩参数反演分析的实测值。然后建立隧道三维有限元模型对围岩弹性模量、黏聚力和内摩擦角进行反演分析。结果表明:三维激光扫描监测可以快速获取隧道空间变形场,为隧道围岩参数反演分析提供足够的有效数据,弥补了传统监测方法的不足;当围岩弹性模量为1 GPa,黏聚力为200 k Pa,内摩擦角为28°时拱顶沉降模拟计算值与实测值吻合度最高。反演所得围岩参数均低于隧道设计阶段根据地质勘查报告的估算值,可用于隧道支护参数动态设计,降低工程成本。展开更多
在水平层状岩体中进行爆破施工,临近隧道不可避免地受到爆破振动的影响.文中通过一种新的计算模型DLSM(Distinct Lattice Spring Model),以吉怀高速大林隧道为研究背景,进行数值模拟,分析层状岩体中临近隧道的爆破振动响应.DLSM真实地...在水平层状岩体中进行爆破施工,临近隧道不可避免地受到爆破振动的影响.文中通过一种新的计算模型DLSM(Distinct Lattice Spring Model),以吉怀高速大林隧道为研究背景,进行数值模拟,分析层状岩体中临近隧道的爆破振动响应.DLSM真实地再现了应力波传递、反射、折射、叠加和耗散过程;重点监测了隧道的拱顶、腰墙、墙角和底部的动力响应特征.研究发现,临近隧道靠近爆破源一侧的腰墙受到的应力波冲击最大,但是控制好爆破装药量,即可满足规范的要求.展开更多
Gas sensors play an indispensable role in industrial,personal safety and environmental protection,and have been widely investigated by researchers.In some cases,the sensitivity of a two-dimensional material sensor can...Gas sensors play an indispensable role in industrial,personal safety and environmental protection,and have been widely investigated by researchers.In some cases,the sensitivity of a two-dimensional material sensor can be enhanced by generating vacancies or applying an external electric field.Similar results can be achieved using Janus 2D materials,which have an inherent electric field and are good candidates for high-sensitivity gas sensors.In this study,the electronic and transport properties of Janus group-Ⅲchalcogenide monolayers(Ga2SSe,In2SSe)were investigated for detecting CO2 and NO2 using first-principles calculations.For several parameters that affect the performance of gas sensors,such as adsorption distances,adsorption energies,charge transfers and density of states(DOS),a detailed comparison of Janus group-Ⅲchalcogenide monolayers has been provided with their pristine systems,Janus group-Ⅲchalcogenide monolayers(Ga2SSe,In2SSe)have high selectivity.It was mainly ascribed to the built-in electric field caused by the out-of-plane asymmetric structure of Janus monolayer which enhances the dipole-dipole interaction between the polar gas molecule and the 2D materials.And the variation of transmission spectra of the Janus group-Ⅲchalcogenide monolayer before and after adsorbing molecules further proves the feasibility of this kind of material as a high-sensitivity gas sensor.展开更多
文摘无论氢在电子器件内部以何种形式(H2分子、H原子或H+离子)存在,均会对电子器件电离损伤产生作用,进而影响器件的抗辐照能力。本文深入研究了氢气和空气气氛条件下1 Me V电子辐照栅控横向PNP(GLPNP)型双极晶体管的辐射损伤缺陷演化行为。利用Keithley 4200SCS半导体参数测试仪对不同气氛下辐照过程中晶体管进行在线原位电性能参数测试,研究晶体管电性能退化与电子辐照注量和氢气深度之间的关系;基于栅扫技术(GS)和深能级瞬态谱技术(DLTS),研究双极晶体管中氢诱导电离损伤缺陷演化的基本特征。研究表明,与空气气氛相比,氢气气氛下电子辐照导致GLPNP的基极电流增加显著,而集电极电流明显降低,产生更多的氧化物电荷和界面态,这些现象均说明氢气加剧双极晶体管的电离辐射损伤。
文摘将三维激光扫描技术应用于温州绕城高速公路南山隧道施工期的变形量测中。首先相隔4个工日进行2次扫描得到2期隧道点云数据,通过对点云数据分析和处理得到隧道初期支护段空间变形场,从中提取断面的拱顶沉降作为隧道围岩参数反演分析的实测值。然后建立隧道三维有限元模型对围岩弹性模量、黏聚力和内摩擦角进行反演分析。结果表明:三维激光扫描监测可以快速获取隧道空间变形场,为隧道围岩参数反演分析提供足够的有效数据,弥补了传统监测方法的不足;当围岩弹性模量为1 GPa,黏聚力为200 k Pa,内摩擦角为28°时拱顶沉降模拟计算值与实测值吻合度最高。反演所得围岩参数均低于隧道设计阶段根据地质勘查报告的估算值,可用于隧道支护参数动态设计,降低工程成本。
文摘在水平层状岩体中进行爆破施工,临近隧道不可避免地受到爆破振动的影响.文中通过一种新的计算模型DLSM(Distinct Lattice Spring Model),以吉怀高速大林隧道为研究背景,进行数值模拟,分析层状岩体中临近隧道的爆破振动响应.DLSM真实地再现了应力波传递、反射、折射、叠加和耗散过程;重点监测了隧道的拱顶、腰墙、墙角和底部的动力响应特征.研究发现,临近隧道靠近爆破源一侧的腰墙受到的应力波冲击最大,但是控制好爆破装药量,即可满足规范的要求.
基金supported by the National Natural Science Foundation of China(Grant No.11974091)。
文摘Gas sensors play an indispensable role in industrial,personal safety and environmental protection,and have been widely investigated by researchers.In some cases,the sensitivity of a two-dimensional material sensor can be enhanced by generating vacancies or applying an external electric field.Similar results can be achieved using Janus 2D materials,which have an inherent electric field and are good candidates for high-sensitivity gas sensors.In this study,the electronic and transport properties of Janus group-Ⅲchalcogenide monolayers(Ga2SSe,In2SSe)were investigated for detecting CO2 and NO2 using first-principles calculations.For several parameters that affect the performance of gas sensors,such as adsorption distances,adsorption energies,charge transfers and density of states(DOS),a detailed comparison of Janus group-Ⅲchalcogenide monolayers has been provided with their pristine systems,Janus group-Ⅲchalcogenide monolayers(Ga2SSe,In2SSe)have high selectivity.It was mainly ascribed to the built-in electric field caused by the out-of-plane asymmetric structure of Janus monolayer which enhances the dipole-dipole interaction between the polar gas molecule and the 2D materials.And the variation of transmission spectra of the Janus group-Ⅲchalcogenide monolayer before and after adsorbing molecules further proves the feasibility of this kind of material as a high-sensitivity gas sensor.
