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材料科学中的高分辨电子显微学—发展历史、现状与展望 被引量:12
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作者 李斗星 《电子显微学报》 CAS CSCD 2000年第2期81-103,共23页
本文综述了材料科学中的高分辨电子显微学发展历史、现状与展望。重点讨论了在高分辨电子显微学中能直接观察物质中原子排列的直接成像法 ,能区分原子种类的选择成像法、能量过滤选择成像法和 Z-衬度像 ,能研究物质结构变化动态过程的... 本文综述了材料科学中的高分辨电子显微学发展历史、现状与展望。重点讨论了在高分辨电子显微学中能直接观察物质中原子排列的直接成像法 ,能区分原子种类的选择成像法、能量过滤选择成像法和 Z-衬度像 ,能研究物质结构变化动态过程的分辨时间高分辨电子显微学 。 展开更多
关键词 原子尺度分辨度 电子显微学 晶界结构 材料科学
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原子力显微镜在粘土矿物学研究中的应用 被引量:6
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作者 吴平霄 张惠芬 郭九皋 《地球科学进展》 CAS CSCD 1998年第4期351-355,共5页
研究粘土矿物表面组成与表面结构的手段和方法多种多样,但由于粘土矿物特殊的晶体结构,这些手段和方法都有一定的局限性和不足。原子力显微镜是近年来发展起来的一种能达到原子分辨能力的表面结构分析仪器,能够分辨粘土矿物硅氧四面... 研究粘土矿物表面组成与表面结构的手段和方法多种多样,但由于粘土矿物特殊的晶体结构,这些手段和方法都有一定的局限性和不足。原子力显微镜是近年来发展起来的一种能达到原子分辨能力的表面结构分析仪器,能够分辨粘土矿物硅氧四面体片上的六方环结构及八面体片的羟基团,是研究粘土矿物表面反应、表面改性及表面溶蚀作用的重要手段。 展开更多
关键词 粘土矿物 原子力显微镜 原子分辨 表面结构
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Atomic level deposition to extend Moore’s law and beyond 被引量:9
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作者 Rong Chen Yi-Cheng Li +2 位作者 Jia-Ming Cai Kun Cao Han-Bo-Ram Lee 《International Journal of Extreme Manufacturing》 2020年第2期29-52,共24页
In the past decades,Moore’s law drives the semiconductor industry to continuously shrink the critical size of transistors down to 7 nm.As transistors further downscaling to smaller sizes,the law reaches its limitatio... In the past decades,Moore’s law drives the semiconductor industry to continuously shrink the critical size of transistors down to 7 nm.As transistors further downscaling to smaller sizes,the law reaches its limitation,and the increase of transistors density on the chip decelerates.Up to now,extreme ultraviolet lithography has been used in some key steps,and it is facing alignment precision and high costs for high-volume manufacturing.Meanwhile,the introduction of new materials and 3D complex structures brings serious challenges for top-down methods.Thus,bottom-up schemes are believed to be necessary methods combined with the top-down processes.In this article,atomic level deposition methods are reviewed and categorized to extend Moore’s law and beyond.Firstly,the deposition brings lateral angstrom resolution to the vertical direction as well as top-down etching,such as double patterning,transfer of nanowires,deposition of nanotubes,and so on.Secondly,various template-assisted selective deposition methods including dielectric templates,inhibitors and correction steps have been utilized for the alignment of 3D complex structures.Higher resolution can be achieved by inherently selective deposition,and the underlying selective mechanism is discussed.Finally,the requirements for higher precision and efficiency manufacturing are also discussed,including the equipment,integration processes,scale-up issues,etc.The article reviews low dimensional manufacturing and integration of 3D complex structures for the extension of Moore’s law in semiconductor fields,and emerging fields including but not limited to energy,catalysis,sensor and biomedicals. 展开更多
关键词 Moore’s law atomic level deposition high resolution selective deposition ALIGNMENT
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基于RD-ANM的毫米波雷达动目标超分辨DOA估计方法 被引量:5
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作者 舒月 傅东宁 +4 位作者 陈展野 黄岩 张彦君 谭晓衡 陶俊 《雷达学报(中英文)》 EI CSCD 北大核心 2023年第5期986-999,共14页
超分辨波达方位角估计是车载毫米波雷达实现目标精准定位及跟踪需要解决的关键问题。针对车载场景中常见的阵列孔径受限、少快拍、低信噪比以及信源相干的情况,该文提出了一种基于距离多普勒域原子范数最小化(RD-ANM)的车载毫米波雷达... 超分辨波达方位角估计是车载毫米波雷达实现目标精准定位及跟踪需要解决的关键问题。针对车载场景中常见的阵列孔径受限、少快拍、低信噪比以及信源相干的情况,该文提出了一种基于距离多普勒域原子范数最小化(RD-ANM)的车载毫米波雷达动目标超分辨DOA估计方法:首先,构建了基于动目标雷达回波的距离多普勒域阵列接收信号;其次,设计了动目标多普勒耦合相位补偿矢量,用以削弱目标运动对DOA估计的影响;最后,提出了基于原子范数框架的多目标超分辨DOA估计方法。相较于车载毫米波雷达现使用的DOA估计算法,该文算法能够在基于低信噪比条件和单快拍处理前提下获得较高的测角分辨率和估计精度,以及拥有不牺牲阵列孔径对相干信号进行处理的稳健性能。理论分析、数值仿真以及实测实验验证了该文算法的有效性。 展开更多
关键词 毫米波雷达 动目标DOA估计 原子范数 单快拍 超分辨
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Field emission patterns with atomic resolution of single-walled carbon nanotubes by field emission microscopy 被引量:3
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作者 侯士敏 张兆祥 +7 位作者 刘惟敏 罗骥 张耿民 顾镇南 赵兴钰 彭练矛 吴锦雷 薛增泉 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2003年第1期33-40,共8页
Electron emission properties of single-walled carbon nanotubes (SWCNTs) assembled on a tungsten tip were investigated using field emission microscopy (FEM). The transmission electron microscopy (TEM) micrograph confir... Electron emission properties of single-walled carbon nanotubes (SWCNTs) assembled on a tungsten tip were investigated using field emission microscopy (FEM). The transmission electron microscopy (TEM) micrograph confirmed the existence of an SWCNT bundle on the W tip. Under appropriate experimental conditions,a series of FEM patterns with atomic resolution were obtained. These patterns arose possibly from the field emission of the open end of an individual (16,0) SWCNT protruding from the SWCNT bundle. The magnification factor and the resolution under our experimental conditions were calculated theoretically. If the value of the compression factor β was set at β= 1.76, the calculated value of the magnification factor was in agreement with the measured value. The resolving powerof FEM was determined by the resolution equation given by Gomer. The resolutionof 0.277 nm could be achieved under the typical electric field of 5.0×107 V/cm, which was close to the interatomic separation 0.246 nm between carbon atoms along the zigzag edge at the open end for the (16, 0) SWCNT. Consequently, our experimental results were further supported by our theoretical calculation. 展开更多
关键词 field emission microscope SINGLE-WALLED carbon nanotubes resolving power atomic resolution.
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原子力显微镜(AFM)应用于纳米科学中的研究进展 被引量:5
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作者 于凉云 张奇 袁淑军 《山东化工》 CAS 2016年第24期39-43,共5页
原子力显微镜由于其操作简便,对样品要求不高,可检测绝缘样品,具有原子级的分辨率等优点,在纳米科学中的应用前景越来越广阔。本文简要介绍原子力显微镜的工作基本原理,并结合国内外最近的研究动态,重点阐述了纳米材料的外貌特征观察、... 原子力显微镜由于其操作简便,对样品要求不高,可检测绝缘样品,具有原子级的分辨率等优点,在纳米科学中的应用前景越来越广阔。本文简要介绍原子力显微镜的工作基本原理,并结合国内外最近的研究动态,重点阐述了纳米材料的外貌特征观察、力学分析、纳米材料加工等三个方面的研究进展。 展开更多
关键词 原子力显微镜 原子级的分辨率 机理 纳米材料
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透射电镜电子能量损失振动谱的研究进展 被引量:5
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作者 黄思瑜 时若晨 +5 位作者 李跃辉 武媚 李宁 杜进隆 俞大鹏 高鹏 《真空科学与技术学报》 CAS CSCD 北大核心 2021年第3期213-224,共12页
近年来,透射电子显微镜在球差矫正器、单色仪等方面取得了长足的发展,使得它在材料科学和凝聚态物理等研究中发挥越来越大的作用。本文简要介绍近十年透射电子显微镜电子能量损失谱技术在声子物理研究方面的进展。目前,基于这一技术,可... 近年来,透射电子显微镜在球差矫正器、单色仪等方面取得了长足的发展,使得它在材料科学和凝聚态物理等研究中发挥越来越大的作用。本文简要介绍近十年透射电子显微镜电子能量损失谱技术在声子物理研究方面的进展。目前,基于这一技术,可以开展实空间和倒空间同时分辨的电子能量损失谱测量(简称四维电子能量损失谱,4D-EELS),在纳米尺度上绘制空间分辨声子色散分布图;能实现原子尺度上声子谱的测量,得到声子态密度的信息。此外,电子散射在能量匹配、动量匹配方面都与光子散射有很强的互补性,因此为声子极化激元的测量提供了一个新的手段。最后,本文简要展望电镜能损振动谱的研究前景。 展开更多
关键词 扫描透射电子显微镜 振动谱 原子分辨 声子色散 四维电子能量损失谱
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Cu在HOPG上电化学沉积的原子分辨ECSTM现场观测 被引量:4
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作者 李春增 谢兆雄 +5 位作者 毛秉伟 卓向东 穆纪千 叶建辉 冯祖德 田昭武 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1993年第5期706-707,共2页
电化学扫描隧道显微镜(ECSTM)因其能提供真实空间的原子分辨图象而成为现场研究电极表面结构的最强有力的手段之一。近来,欠电位沉积(UPD)得到日益广泛的研究,人们观察到了Cu在Au(111)和Pt(111)上的UPD层的原子结构。而在金属体相沉积的... 电化学扫描隧道显微镜(ECSTM)因其能提供真实空间的原子分辨图象而成为现场研究电极表面结构的最强有力的手段之一。近来,欠电位沉积(UPD)得到日益广泛的研究,人们观察到了Cu在Au(111)和Pt(111)上的UPD层的原子结构。而在金属体相沉积的ECSTM研究中所得图象的分辨率较低。我们用ECSTM在控电位下对Cu在高序石墨(HOPG) 展开更多
关键词 原子分辨 电沉积 ECSTM
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Mechanocatalysis of CO to CO_(2)on TiO_(2)surface controlled at atomic scale
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作者 Yuuki Adachi Robert Turanský +6 位作者 Ján Brndiar Kamil Tokár Qiang Zhu Huan Fei Wen Yasuhiro Sugawara IvanŠtich Yan Jun Li 《Nano Research》 SCIE EI CSCD 2024年第7期5826-5834,共9页
The common ways to activate a chemical reaction are by heat,electric current,or light.However,mechanochemistry,where the chemical reaction is activated by applied mechanical force,is less common and only poorly unders... The common ways to activate a chemical reaction are by heat,electric current,or light.However,mechanochemistry,where the chemical reaction is activated by applied mechanical force,is less common and only poorly understood at the atomic scale.Here we report a tip-induced activation of chemical reaction of carbon monoxide to dioxide on oxidized rutile TiO_(2)(110)surface.The activation is studied by atomic force microscopy,Kelvin probe force microscopy under ultrahigh-vacuum and liquid nitrogen temperature conditions,and density functional theory(DFT)modeling.The reaction is inferred from hysteretic behavior of frequency shift signal further supported by vector force mapping of vertical and lateral forces needed to trigger the chemical reaction with torque motion of carbon monoxide towards an oxygen adatom.The reaction is found to proceed stochastically at very small tip-sample distances.Furthermore,the local contact potential difference reveals the atomic-scale charge redistribution in the reactants required to unlock the reaction.Our results open up new insights into the mechanochemistry on metal oxide surfaces at the atomic scale. 展开更多
关键词 atomic resolution MECHANOCHEMISTRY atomic force microscopy Kelvin probe force microscopy density functional theory(DFT)simulation CO oxidation catalysis rutile TiO_(2)surface
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Three-dimensional crystal defect imaging by STEM depth sectioning
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作者 Ryo Ishikawa Naoya Shibata Yuichi Ikuhara 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期2-7,共6页
One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic resolution.Despite the success of aberration correction to deep sub-angstrom lateral resolution,spatial resoluti... One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic resolution.Despite the success of aberration correction to deep sub-angstrom lateral resolution,spatial resolution in depth is still far from atomic resolution.In scanning transmission electron microscopy(STEM),this poor depth resolution is due to the limitation of the illumination angle.To overcome this physical limitation,it is essential to implement a next-generation aberration corrector in STEM that can significantly improve the depth resolution.This review discusses the capability of depth sectioning for three-dimensional imaging combined with large-angle illumination STEM.Furthermore,the statistical analysis approach remarkably improves the depth resolution,making it possible to achieve three-dimensional atomic resolution imaging at oxide surfaces.We will also discuss the future prospects of three-dimensional imaging at atomic resolution by STEM depth sectioning. 展开更多
关键词 atomic-resolution STEM STEM depth sectioning depth resolution DOPANTS surface topography
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A High-Resolution Measurement Method for Inner and Outer 3D Surface Profiles of Laser Fusion Targets Using a Laser Differential Confocal–Atomic Force Probe Technique
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作者 Weiqian Zhao Zihao Liu Lirong Qiu 《Engineering》 SCIE EI CAS CSCD 2024年第10期51-60,共10页
The high-resolution and nondestructive co-reference measurement of the inner and outer threedimensional(3D)surface profiles of laser fusion targets is difficult to achieve.In this study,we propose a laser differential... The high-resolution and nondestructive co-reference measurement of the inner and outer threedimensional(3D)surface profiles of laser fusion targets is difficult to achieve.In this study,we propose a laser differential confocal(LDC)–atomic force probe(AFP)method to measure the inner and outer 3D surface profiles of laser fusion targets at a high resolution.This method utilizes the LDC method to detect the deflection of the AFP and exploits the high spatial resolution of the AFP to enhance the spatial resolution of the outer profile measurement.Nondestructive and co-reference measurements of the inner profile of a target were achieved using the tomographic characteristics of the LDC method.Furthermore,by combining multiple repositionings of the target using a horizontal slewing shaft,the inner and outer 3D surface profiles of the target were obtained,along with a power spectrum assessment of the entire surface.The experimental results revealed that the respective axial and lateral resolutions of the outer profile measurement were 0.5 and 1.3 nm,while the respective axial and lateral resolutions of the inner profile measurement were 2.0 nm and approximately 400.0 nm.The repeatabilities of the rootmean-square deviation measurements for the outer and inner profiles of the target were 2.6 and 2.4 nm,respectively.We believe our study provides a promising method for the high-resolution and nondestructive co-reference measurement of the inner and outer 3D profiles of laser fusion targets. 展开更多
关键词 Laser fusion targets Laser differential confocal-atomic force probe HIGH-resolution Nondestructive Co-reference
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On-Surface Stereochemical Characterization of a Highly Curved Chiral Nanographene by Noncontact Atomic Force Microscopy and Scanning Tunneling Microscopy 被引量:2
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作者 Qigang Zhong Viktor Barat +8 位作者 Daniel Csokas Kaifeng Niu Marcin Gorecki Animesh Ghosh Jonas Bjork Daniel Ebeling Lifeng Chi Andre Schirmeisen Mihaiela C.Stuparu 《CCS Chemistry》 CSCD 2023年第12期2888-2896,共9页
A highly distorted chiral nanographene structure composed of triple corannulene-fused[5]helicenes is prepared with the help of the Heck reaction and oxidative photocyclization with an overall isolated yield of 28%.The... A highly distorted chiral nanographene structure composed of triple corannulene-fused[5]helicenes is prepared with the help of the Heck reaction and oxidative photocyclization with an overall isolated yield of 28%.The complex three-dimensional(3D)structure of the bowl-helix hybrid nanostructure is studied by a combination of noncontact atomic force microscopy(AFM)and scanning tunneling microscopy(STM)on the Cu(111)surface,density functional theory calculations,AFM/STM simulations,and high-performance liquid chromatography-electronic circular dichroism analysis.This examination reveals a molecular structure in which the three bowl-shaped corannulene bladesd position themselves in a C3-symmetric fashion around a highly twisted triphenylene core.The molecule appears to be shaped like a propeller in which the concave side of the bowls face away from the connected[5]helicene motif.The chirality of the nanostructure is confirmed by the direct visualization of both MMM and PPP enantiomers at the single-molecule level by scanning probe microscopies.These results underline that submolecular resolution imaging by AFM/STM is a powerful real-space tool for the stereochemical characterization of 3D curved chiral nanographene structures. 展开更多
关键词 chirality at surfaces noncontact atomic force microscopy scanning tunnelling microscopy submolecular resolution imaging single-bond resolution curved nanographenes multiple helicenes chiral nanostructures bowl-helix hybrids scanning probe microscopy
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qPlus型原子力显微镜技术 被引量:1
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作者 彭金波 江颖 《物理》 CAS 北大核心 2023年第3期186-195,共10页
扫描探针显微镜主要包括扫描隧道显微镜和原子力显微镜,其利用尖锐的针尖逐点扫描样品,可在原子和分子尺度上获取表面的形貌和丰富的物性,改变了人们对物质的研究范式和基础认知。近年来,qPlus型高品质因子力传感器的出现将扫描探针显... 扫描探针显微镜主要包括扫描隧道显微镜和原子力显微镜,其利用尖锐的针尖逐点扫描样品,可在原子和分子尺度上获取表面的形貌和丰富的物性,改变了人们对物质的研究范式和基础认知。近年来,qPlus型高品质因子力传感器的出现将扫描探针显微镜的分辨率和灵敏度推向了一个新的水平,为化学结构、电荷态、电子态、自旋态等多自由度的精密探测和操控提供了前所未有的机会。文章首先简要介绍原子力显微镜的发展历史和基本工作原理,然后重点描述qPlus型原子力显微镜技术的优势及其在单原子、单分子和低维材料体系中的应用,最后展望该技术的未来发展趋势和潜在应用。 展开更多
关键词 扫描探针显微镜 原子力显微镜 qPlus力传感器 高分辨成像 原子分辨
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面心立方结构金属纳米线弯曲变形机制研究进展 被引量:2
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作者 赵玉峰 李雪峤 +1 位作者 王立华 韩晓东 《电子显微学报》 CAS CSCD 北大核心 2023年第2期238-251,共14页
弯曲变形是金属纳米材料最常见的变形方式之一。揭示金属纳米材料弯曲状态下的变形机制,建立微观结构、变形机制与力学性质之间的关联性,可为材料设计提供重要的理论依据。本文综述了面心立方(FCC)单晶金属纳米线在弯曲变形下力学性质... 弯曲变形是金属纳米材料最常见的变形方式之一。揭示金属纳米材料弯曲状态下的变形机制,建立微观结构、变形机制与力学性质之间的关联性,可为材料设计提供重要的理论依据。本文综述了面心立方(FCC)单晶金属纳米线在弯曲变形下力学性质与变形机制研究的主要进展:介绍了尺寸效应对弯曲应变下的材料力学性能的影响,概述了弯曲应变的大小对变形机制的影响;总结了金属纳米线中孪晶厚度对位错滑移,相变等塑性变形机制的影响;对比了金属纳米线弯曲与拉伸,压缩中变形机制的异同。最后对金属纳米线弯曲塑性变形机制研究所面临的难题以及有望解决该难题的原位实验技术的发展进行了展望。 展开更多
关键词 金属纳米线 弯曲 原子分辨率 孪晶结构 变形机制
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g-框架的摄动和原子分解 被引量:3
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作者 王静 高德智 《数学物理学报(A辑)》 CSCD 北大核心 2010年第6期1451-1456,共6页
该文完善了g-框架的稳定性理论.首先给出了g-框架摄动的几个结果,其中包括g-框架的紧摄动性.其次,讨论了g-框架和单位原子分解的关系.
关键词 G-框架 摄动 单位原子分解
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High-resolution electron microscopy for heterogeneous catalysis research 被引量:1
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作者 Yong Zhu Mingquan Xu Wu Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第5期33-48,共16页
Heterogeneous catalysts are the most important catalysts in industrial reactions. Nanocatalysts, with size ranging from hundreds of nanometers to the atomic scale, possess activities that are closely connected to thei... Heterogeneous catalysts are the most important catalysts in industrial reactions. Nanocatalysts, with size ranging from hundreds of nanometers to the atomic scale, possess activities that are closely connected to their structural characteristics such as particle size, surface morphology, and three-dimensional topography. Recently, the development of advanced analytical transmission electron microscopy(TEM) techniques, especially quantitative high-angle annular darkfield(HAADF) imaging and high-energy resolution spectroscopy analysis in scanning transmission electron microscopy(STEM) at the atomic scale, strengthens the power of(S)TEM in analyzing the structural/chemical information of heterogeneous catalysts. Three-dimensional reconstruction from two-dimensional projected images and the real-time recording of structural evolution during catalytic reactions using in-situ(S)TEM methods further broaden the scope of(S)TEM observation. The atomic-scale structural information obtained from high-resolution(S)TEM has proven to be of significance for better understanding and designing of new catalysts with enhanced performance. 展开更多
关键词 atomic resolution electron microscopy three-dimensional (3D) reconstruction IN-SITU heterogeneous catalysts
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Cryo-EM for nanomaterials:Progress and perspective 被引量:2
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作者 Jingchao Zhang Jie Wen +2 位作者 Wei-Di Liu Xiaoya Cui Yanan Chen 《Science China Materials》 SCIE EI CAS CSCD 2022年第10期2613-2626,共14页
Cryogenic electron microscopy(cryo-EM)has extensively boosted structural biology research since the“resolution revolution”in the year of 2013 which was soon awarded the Nobel Prize in Chemistry in 2017.The advances ... Cryogenic electron microscopy(cryo-EM)has extensively boosted structural biology research since the“resolution revolution”in the year of 2013 which was soon awarded the Nobel Prize in Chemistry in 2017.The advances in camera techniques and software algorithms enabled cryoEM to routinely characterize the three-dimensional structures of biomolecules at near-atomic resolution.Biomolecules are basically sensitive to electron irradiation damage,which can be minimized at cryo-temperature.This principle has inspired material scientists to characterize electron beam-or air-sensitive materials by cryo-EM,such as the electrodes in the lithium-ion battery,metal-organic frameworks(MOFs),covalent-organic frameworks(COFs)and zeolites.In addition,the reaction systems can be fast-frozen at vitreous ice in cryoEM,which correspondingly preserves the materials at the close-to-native state.Herein,we summarized the development and applications of both the cryo-EM technique and other emerging cryo-techniques in materials science,and energy storage and conversion.Cryo-EM techniques,capable of the direct observation of sensitive materials and electrochemical reaction processes,will greatly renew our understanding of materials science and related mechanisms. 展开更多
关键词 cryogenic electron microscopy structural biology 3D reconstruction atomic resolution NANOMATERIALS
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原子探针的发展及其对金属内界面的研究 被引量:2
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作者 朱逢吾 职任涛 张瑗 《物理》 CAS 1999年第10期624-629,共6页
简要介绍了原子探针,特别是三维原子探针(3 D A P) 的最新发展及其特点.3 D A P 在探测到单个原子位置的同时能鉴别其种类,因而几乎能以原子分辨力显示出材料中大部分原子在实空间中的三维分布.文章举例说明了常规 A ... 简要介绍了原子探针,特别是三维原子探针(3 D A P) 的最新发展及其特点.3 D A P 在探测到单个原子位置的同时能鉴别其种类,因而几乎能以原子分辨力显示出材料中大部分原子在实空间中的三维分布.文章举例说明了常规 A P 和3 D A P 展开更多
关键词 三维 原子探针 金属内界面 原子分辨力
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拓宽具有原子分辨率的ECSTM研究至多晶电极表面 被引量:1
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作者 施财辉 蔡雄伟 +2 位作者 陈燕霞 田中群 毛秉伟 《物理化学学报》 SCIE CAS CSCD 北大核心 1997年第12期1061-1064,共4页
Electrochemical Scanning TUnneling Microscopy (ECSTM) has been extended to characterizc polycrystalline silver electrode surfaces in iodide solution. Potential-dependcnt ordered and disordered structures of the silver... Electrochemical Scanning TUnneling Microscopy (ECSTM) has been extended to characterizc polycrystalline silver electrode surfaces in iodide solution. Potential-dependcnt ordered and disordered structures of the silver electrode as well as the iodine adsorption layer have been obscrved to coexist on polycrystalline silver electrode surfaces, for the first time. A very special column arrangement of the iodine adsorption layer, similar to the so called "ndssing row" type of structure has been obseryed. Some columns of the iodine adsorption layer roll over from one place to another along with the time and changing potential. A proposed model has been given to better describe the structure. The highly corrugated and loose surface structure of the polycrystalline surface are responsible for this special phenomenon. 展开更多
关键词 STM ECSTM 原子分辨率 多晶电极 吸附
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Towards quantitative determination of atomic structures of amorphous materials in three dimensions
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作者 Zhiheng Xie Yao Zhang +3 位作者 Siwei Huang Zezhou Li Qi Cheng Jihan Zhou 《National Science Open》 2023年第3期1-26,共26页
Amorphous materials such as glass,polymer and amorphous alloy have broad applications ranging from daily life to extreme conditions due to their unique properties in elasticity,strength and electrical resistivity.A be... Amorphous materials such as glass,polymer and amorphous alloy have broad applications ranging from daily life to extreme conditions due to their unique properties in elasticity,strength and electrical resistivity.A better understanding of atomic structure of amorphous materials will provide invaluable information for their further engineering and applications.However,experimentally determining the three-dimensional(3D)atomic structure of amorphous materials has been a long-standing problem.Due to the disordered atomic arrangement,amorphous materials do not have any translational and rotational symmetry at long-range scale.Conventional characterization methods,such as the scattering and the microscopy imaging,can only provide the statistic structural information which is averaged over the macroscopic region.The knowledge of the 3D atomic structure of amorphous materials is limited.Recently atomic resolution electron tomography(AET)has proven an increasingly powerful tool for atomic scale structural characterization without any crystalline assumptions,which opens a door to determine the 3D structure of various amorphous materials.In this review,we summarize the state-of-art characterization methods for the exploration of atomic structures of amorphous materials in the past few decades,including X-ray/neutron diffraction,nano-beam and angstrom-beam electron diffraction,fluctuation electron microscopy,high-resolution scanning/transmission electron microscopy,and atom probe tomography.From experimental data and theoretical descriptions,3D structures of various amorphous materials have been built up.Particularly,we introduce the principles and recent progress of AET,and highlight the most recent groundbreaking feat accomplished by AET,i.e.,the first experimental determination of all 3D atomic positions in a multi-component glass-forming alloy and the 3D atomic packing in amorphous solids.We also discuss the new opportunities and challenges for characterizing the chemical and structural defects in amorphous materials. 展开更多
关键词 amorphous solid atomic structure 3D reconstruction atomic resolution electron tomography short-range order medium-range order
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