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Quantitative analysis of microstructure of carbon materials by hrtem

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中国有色金属学会会刊：英文版 2006年第B02期16卷 796-803页

作者： YANG Jan-he CHENG Shu-hui WANG Xia ZHANG Zhuo LIU Xiao-rong TANG Guo-hua Department of Materials Science and Engineering Shanghai Institute of Technology Shanghai 200235 China School of Chemical Engineering East China University of Science and Technology Shanghai 200000 China

The main object of the present research is to make a quantitative evaluation on the microstructure of carbon materials in terms of microcrystal. The digitized images acquired from finely pulverized carbon materials under hrtem at a high magnification were processed by the image processing software so as to extract the fringes of (002) lattice of graphite crystal from the background image, and an FFT-IFFT filtering operation was performed followed by processes as binarization for the image and skeletonization for the fringes. A set of geometrical parameters including position, length and orientation was set up for every lattice fringe by calculating the binarized image. Then, the above obtained fringe parameters were put into an algorithm, which was especially developed for such fringe images so as to find fringes that could be regarded as those belonged to one single graphite microcrystal. The fringe was subjected sequentially to comparing procedures with every other fringe on aspects as parallelism, relative position and spacing, and the above comparisons were repeated till the last fringe. Eventually, the microcrystal size, its stacking number, and the distribution of the microcrystal in the whole sample, as well as other related structure information of such microcrystal in carbon materials were statistically calculated. Such microstructure information at nanometer level may contribute greatly to the interpretation of the properties of carbon materials and a better correlation with the same macrostructure.

关键词：碳材料微晶显微结构定量分析 hrtem

Photocatalytic mechanism of high-activity anatase TiO2 with exposed （001） facets from molecular-atomic scale： hrtem and Raman studies

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Frontiers of Materials Science 2017年第4期11卷 358-365页

作者： Jun WU Chentian SHI Yupeng ZHANG Qiang FU Chunxu PAN School of Physics and Technology and MOE Key Laboratory of Artificial Micro- and Nano-structures Wuhan University Wuhan 430072 China College of Electronic Science and Technology Shenzhen University Shenzhen 518000 China Department of Materials Science and Engineering Monash University Victoria 3800 Australia Center for Electron Microscopy Wuhan University Wuhan 430072 China

Anatase TiO2 with a variant percentage of exposed （001） facets was prepared under hydrothermal processes by adjusting the volume of HF, and the photocatalytic mechanism was studied from atomic-molecular scale by hrtem and Raman spectroscopy. It was revealed that： 1） From hrtem observations, the surface of original TiO2 with exposed （001） facets was clean without impurity, and the crystal lattice was clear and completed; however, when mixed with methylene blue （MB） solution, there were many 1 nm molecular absorbed at the surface of TiO2; after the photocatalytic experiment, MB molecules disappeared and the TiO2 lattice image became fuzzy. 2） The broken path of the MB chemical bond was obtained by Raman spectroscopy, i.e., after the irradiation of the light, the vibrational mode of C-N-C disappeared due to the chemical bond breakage, and the groups containing C-N bond and carbon rings were gradually decomposed. Accordingly, we propose that the driving force for breaking the chemical bond and the disappearance of groups is from the surface lattice distortion of TiO2 during photocatalyzation.

关键词： TiO2 exposed (001)facets hrtem Raman spectroscopy photocatalyticdegradation mechanism

Molecular Structure of Kerogen in the Longmaxi Shale: Insights from Solid State NMR, FT-IR, XRD and hrtem

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Acta Geologica Sinica(English Edition) 2019年第4期93卷 1015-1024页

作者： WANG Xiaoqi ZHU Yanming LIU Yu LI Wu Key Laboratory of Coalbed Methane Resources and Reservoir Formation on Process Ministry of EducationChina University of Mining and TechnologyXuzhou 221008JiangsuChina School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116JiangsuChina

Kerogen plays an important role in shale gas adsorption,desorption and ***,it is necessary to characterize the molecular structure of *** this study,four kerogen samples were isolated from the organic-rich shale of the Longmaxi *** spectroscopy was used to determine the maturity of these kerogen *** transmission electron microscopy(hrtem),13 C nuclear magnetic resonance(13 C NMR),X-ray diffraction(XRD)and Fourier transform infrared(FT-IR)spectroscopy were conducted to characterize the molecular structure of the shale *** results demonstrate that VReqv of these kerogen samples vary from 2.3%to 2.8%,suggesting that all the kerogen samples are in the dry gas *** macromolecular carbon skeleton of the Longmaxi Formation kerogen is mainly aromatic(fa’=0.56).In addition,the aromatic structural units are mainly composed of naphthalene(23%),anthracene(23%)and phenanthrene(29%).However,the aliphatic structure of the kerogen macromolecules is relatively low(fal*+falH=0.08),which is presumed to be distributed in the form of methyl and short aliphatic chains at the edge of the aromatic *** oxygen-containing functional groups in the macromolecules are mainly present in the form of carbonyl groups(fac=0.23)and hydroxyl groups or ether groups(falO=0.13).The crystallite structural parameters of kerogen,including the stacking height(Lc=22.84?),average lateral size(La=29.29?)and interlayer spacing(d002=3.43?),are close to the aromatic structural parameters of anthracite or overmature ***-resolution transmission electron microscopy reveals that the aromatic structure is well oriented,and more than 65%of the diffractive aromatic layers are concentrated in the main *** to the continuous deep burial,the longer aliphatic chains and oxygen-containing functional groups in the kerogen are substantially ***,the ductility and stacking degree of the aromatic structure increases during therm

关键词： organic-rich shale molecular structure kerogen hrtem Sichuan Basin

SAED and hrtem Investigation of Palygorskite

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Acta Geologica Sinica(English Edition) 2008年第2期82卷 385-391页

作者： CHEN Tao WANG Hejing ZHANG Xiaoping ZHENG Nan Institute of Gemology China University of Geosciences Wuhan 430074 Hubei China Key Laboratory of Orogenic Belts and Crustal Evolution （Peking University） Ministry ofEducation of China School of Earth and Space Sciences Peking University Beijing 100871 Electron Microscopy Laboratory School of Physics Peking University Beijing 100871

The microstructure of palygorskite from Longwang Mountain of Xuyu County, Jiangsu Province, was studied by energy dispersive X-ray analysis （EDX）, selected-area electron diffraction （SAED） and high-resolution transmission electron microscopy （hrtem）. The average composition of the palygorskite studied is （Si7.38A10.62）（A10.96Fe^3＋ 0.62Mg2.86 0.56）Ca0.03K0.06O20（OH）2（OH2）4, which is rich in Mg. Several SAED patterns from a single crystal of palygorskite were obtained with different zone axes. The polymorphs （monoclinic and orthorhombic） are unequivocally distinguished by distant interplanar angles, even though they possess similar sets of d-values. High-resolution images of three principal zones （[010], [100] and [110]） were obtained. The lattice fringes on hrtem images along [010] have spacings of 0.319 nm. These fringes are interpreted as periodic alterations of two tetrahedral （T） sheets and one octahedral （O） sheet （-TT-O-TT-O-）. We have directly observed trioctahedral and dioctahedral individual palygorskite particles along [100]. They are all presented as dark lines along [001], but the width of dark lines corresponding to trioctahedral crystals （0.913 nm） is twice that of the dioctahedral ones （0.456 nm）. This is because the *** are occupied by cations in trioctahedral palygorskite. The width of dark lines along [110] is 1.024 nm, a bit thinner than the theoretical spacing （1.044 nm）. This is because water molecules quickly leave the structure upon the irradiation by the electron beam.

关键词： hrtem microstructure palygorskite polymorph SAED

A piece of new hrtem lattice image evidence for P2_1ca hypersthene of Chengde, China

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Chinese Science Bulletin 1996年第12期41卷 1011-1014页

作者：薛纪越罗谷风王启明赵冀徽 Department of Earth Sciences Nanjing University Nanjing 210093 China Laboratory of Electron Microscope Peking University Beijing 100871 China

Traditionally the space group of orthopyroxenes is catalogued into ***,in 1974,Smyth found out that the bronzite from one lunar rock is of P21ca based on thepresence of the 0 kl diffractions with *** it was reported t... 详细信息

关键词： orthopyroxene Chengde of Hebei hrtem lattice image.

7000系铝合金析出相应变的hrtem几何相位分析

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稀有金属材料与工程 2014年第5期43卷 1161-1164页

作者：侯小虎白朴存沈元国李博内蒙古工业大学内蒙古呼和浩特010051

为了研究7000系铝合金时效析出相的应变场分布,利用喷射沉积技术制备了Al-12Zn-2.4Mg合金,使用高分辨透射电子显微镜(high resolution transmission electron microscopy,hrtem)和几何相位分析(geometric phase analysis,GPA)技术对时效析出相(GPII区、η′相)的应变场进行了研究。实验结果表明:GPII区内的应变场为压应变,产生的压应变极值为7.09%;η′相内的应变场为拉应变和压应变,产生的拉应变极值为2.54%﹑压应变极值为2.15%。GPII区和η′相的应变场在不同方向上分布也是不同的,x方向的应变较y方向更大。GPII区转变为η′相是应变能降低的过程,转变后合金达到较稳定的状态。

关键词：应变析出相 GPA技术 hrtem

Quantitative analysis of microstructure of carbon materials by hrtem

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Transactions of Nonferrous Metals Society of China 2006年第S2期 796-803页

作者： YANG Jun-he, CHENG Shu-hui, WANG Xia, ZHANG Zhuo, LIU Xiao-rong, TANG Guo-hua Department of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 200235, China School of Chemical Engineering, East China University of Science and Technology, Shanghai 200000, China

关键词： carbon materials microcrystal digitized images quantitative analysis hrtem

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基于hrtem的煤中不同聚集态结构表征

煤炭学报 2020年第2期45卷 749-759页

作者：王小令李霞曾凡桂边洁晶太原理工大学地球科学与工程系山西太原030024 太原理工大学煤与煤系气地质山西省重点实验室山西太原030024

对曹村2号煤的hrtem图像观察发现,晶格条纹呈现出有序-无序的分布。通过对原始图像的不同区域划分,定义了3种不同类型的聚集态结构区域,分别为具有取向一致的条纹区域,类似环状的条纹区域,取向杂乱的条纹区域。基于hrtem图像处理方法,... 详细信息

对曹村2号煤的hrtem图像观察发现,晶格条纹呈现出有序-无序的分布。通过对原始图像的不同区域划分,定义了3种不同类型的聚集态结构区域,分别为具有取向一致的条纹区域,类似环状的条纹区域,取向杂乱的条纹区域。基于hrtem图像处理方法,对不同类型的聚集态结构进行定量表征,包括晶格条纹的长度及取向,以及曲率特征(分段角度,累积角度及曲折度)。结果表明:具有一致取向的条纹区域中,其单个晶格条纹表现出较大的弯曲,体现在分段角度较大,曲折度较大;对于类似环状的条纹区域,从取向上来看,玫瑰图表现出"十字型"分布的特点;而对于取向杂乱的条纹,却表现出单个条纹较好的线性度,体现在分段角度较小,曲折度较小。3者呈现了较为一致的长度分布,累积角度的分布显示出具有一致取向区域的条纹存在较大的曲率,且短条纹贡献了大部分的弯曲。此外,还对不同区域孔径分布进行了分析,得到3者均发育微孔,取向一致的条纹区域中孔径集中于0.4~0.5 nm,而在取向杂乱的条纹区域中孔径整体稍大。结合煤中不同区域晶格条纹特征、孔径分布,以及FTIR,Raman等分子结构参数探讨了煤中聚集态结构的形成机制:不同的芳香结构,脂肪结构及其他分子之间形成的大分子团,再加上分子团内部的缺陷,孔隙等相互作用的结果。

关键词：煤 hrtem 聚集态结构晶格条纹特征形成机制

湖南湘潭锰矿锰钾矿—天然氧化物八面体分子筛(OMS-2)在hrtem下的微结构特征研究

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矿物岩石 2005年第3期25卷 52-57页

作者：高翔鲁安怀郑辙贾欣欣北京城市学院生物技术学部北京100094 北京大学地球与空间科学学院北京100871

在对湖南湘潭锰矿次生氧化带中天然锰钾矿鉴定的基础上,采用hrtem对该地区结晶程度差、呈隐晶质集合体的天然锰钾矿微结构进行研究,结果表明:M n,K,O为样品的主要元素,还含少量Cu,S i,A l,M g,F e等杂质元素;锰钾矿表现出一维针状的纳米... 详细信息

在对湖南湘潭锰矿次生氧化带中天然锰钾矿鉴定的基础上,采用hrtem对该地区结晶程度差、呈隐晶质集合体的天然锰钾矿微结构进行研究,结果表明:M n,K,O为样品的主要元素,还含少量Cu,S i,A l,M g,F e等杂质元素;锰钾矿表现出一维针状的纳米晶,大多数纳米晶的宽度<100 nm;对选区电子衍射(SAED)计算d值并指标化,确定是锰钾矿,而电子衍射所表现出的弥散环、衍射斑点圆弧化和拉长,均表明该地区样品结晶度差、具有超结构和一定择优取向的特征,这与锰钾矿呈一维针状纳米晶的特征相一致。在锰钾矿的晶格像中,普遍存在晶格畸变、位错缺陷和超结构现象。因此,结晶度较差、颗粒细小至纳米级、结构的有序度较低等是该地区锰钾矿的主要特点。

关键词：湖南湘潭锰矿锰钾矿天然氧化物八面体分子筛 hrtem 微结构