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electron microscopy observations of surface morphologies and particle arrangement behaviors of magnetic fluids

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Science China Technological Sciences 2003年第2期46卷 168-172页

作者：沈辉徐雪青王伟 Center for Nanotechnology Research Zhongshan University Guangzhou 510275 China Guangzhou 510070 China Center for Nanotechnology Research Zhongshan University Guangzhou 510275 China Zhongshan 528411 China Guangzhou Institute of Energy Conversion Guangzhou Institute of Energy ConversionHawley & Hazel Chemical Co. Ltd. Guangzhou 510070 China

The surface morphology of quasi-periodic stripe-shaped patterns of magnetite fluids was observed in applied perpendicular magnetic fields by means of scanning electron microscopy. The nanoparticles of the magnetite fluids are arranged in oriental quasilinear chains in applied perpendicular magnetic fields as observed using transmission electron microscopy. This arrangement results from particle-particle interactions and particle-carrier liquids interactions, which are eventually controlled by the magnetic fields distribution.

关键词： magnetic fluids electron microscopy surface morphology nanoparticle arrangement behavior.

Revealing structural degradation in layered structure oxides cathode of lithium ion batteries via in-situ transmission electron microscopy

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Journal of Materials Science & Technology 2023年第23期154卷 189-201页

作者： Fanjie Xia Weihao Zeng Haoyang Peng Hong Wang Congli Sun Ji Zou Jinsong Wu State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Nanostructural Research Center (NRC) Wuhan University of Technology Wuhan 430070 China Hubei Longzhong Laboratory Xiangyang 441000 China

Transition metal oxides with layered structure have been widely used as cathode materials for lithium-ion batteries(LIBs)which have relatively high energy density,large capacity and long ***,in the long-term electrochemical cycle,the inevitable degradation of performance of LIBs due to structural degradation in cathodes severely restricts their large-scale practical *** the underlying mechanism of structural degradation is the most critical scientific ***,in situ transmission electron microscopy(TEM)has become a useful tool to study the structural and compositional evolutions at atomic scale in electrochemical reactions,which provided a unique and in-depth understanding of the structural *** this review,we discuss the recent advances in the in situ TEM,focusing on its role in revealing the structural degradation mechanisms in the four key places:(1)the interface between the cathodes and electrolyte;(2)the cathode surface;(3)the particle interior and(4)those induced by thermal *** insight gained by the in-situ TEM which is still developing at its fast pace is unique and expected to provide guidance for designing better layered cathode materials.

关键词： Li-ion battery Layered cathodes Structural degradations electron microscopy In-situ

A transmission electron microscopy study of microscopic causes for localized-corrosion morphology variations in the AA7055 Al alloy

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Journal of Materials Science & Technology 2018年第10期34卷 1719-1729页

作者： X.B. Yang J.H. Chen G.H. Zhang L.P. Huang T.W. Fan Y. Ding X.W. Yu Center for High-Resolution electron microscopy College of Materials Sdence and Engineering Hunan University Changsha Hunan 410082 China Department of Applied Physics School of Physics and Electronics Hunan University Changsha Hunan 410082 China

By Using （scanning） transmission electron microscopy, localized-corrosion morphology variations of the AA7055 AIZn（Cu）Mg alloy with different thermal processes and their underlying microscopic causes were investigated systematically. Our study shows that the corrosion resistance of the nanoscale precipitates varies with their structure type and Cu-content. Just like the Al-matrix, the early-stage precipitates are corrosion resistant, as compared with the ηp/η-precipitates without high Cu-content. With a high Cu-content, however, the η-precipitates become most corrosion resistant among all phases involved. Hence, tailoring the precipitate microstructure and chemistry though thermal processes may change the overall corrosion morphology and improve corrosion resistance property of the alloy.

关键词： Aluminum alloys Precipitates Corrosion electron microscopy

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High-resolution electron microscopy for heterogeneous catalysis research

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Chinese Physics B 2018年第5期27卷 33-48页

作者： Yong Zhu Mingquan Xu Wu Zhou School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100049 China

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.

关键词： atomic resolution electron microscopy three-dimensional (3D) reconstruction in-situ heterogeneous catalysts

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Microstructural investigation of Nd-rich phase in sintered Nd-Fe-B magnets through electron microscopy

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Journal of Rare Earths 2013年第8期31卷 765-771页

作者： FU Xin HAN Xiaolei DU Zhiwei FENG Haibo LI Yanfeng National Center of Analysis and Testing for Non-ferrous Metals & electronic Materials General Research Institute for Nonferrous Metals Beijing 100088 China Division of Functional Materials Central Iron and Steel Research Institute Beijing 100081 China

The distribution, morphologies and structures of intergranular Nd-rich phase in sintered Nd-Fe-B magnets were studied through electron microscopy. Backscattered electron （BSE） imaging revealed that Nd-rich particles with various morphologies and sizes were randomly distributed at the grain boundaries and the triple junctions of the tetragonal Nd2FelnB matrix. Through selected area electron diffraction （SAED） analysis under a systematic tilting condition, most intergranular Nd-rich phase particles, with sizes ranging from hundreds of nanometres to several micrometres, were identified as face-centred cubic （FCC） structure. Such particles possessed several approximate orientation relationships with their adjacent Nd2FelaB matrix grains, such as （002）Nd2Fe14B/ （200）FCC_Nd-rieh [120] Nd2Fe14B//[001]FCC Nd-fich, （002）Nd2Fe14B//（220）FCC_Nd-rich [110] Nd2Fe14B//[l12]FCC_Nd-rich, as well as （011）Nd2Fe14B// （13 1 ）rcc Nd-rich [111 ] Nd2Fe14B//[ 114]FCC Nd_rich, which could be attributed to minimising interracial energy. The combination of high- resolution electron microscopy with energy-dispersive X-ray spectroscopy revealed the internal inhomogeneous nature of Nd-rich phases. The large lattice distortion and nanoscale-ordered structures within a single Nd2rich grain were observed.

关键词： Nd-rich phases Nd-Fe-B magnets electron microscopy rare earths

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18,X,Y aneuploidies and transmission electron microscopy studies in spermatozoa from five carriers of different reciprocal translocations

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Asian Journal of Andrology 2009年第3期11卷 325-332页

作者： Elena Moretti Nicola Antonio Pascarelli Valentina Giannerini Michela Geminiani Cecilia Anichini Giulia Collodel Department of Biomedical Sciences Applied Biology Section University of Siena Siena 53100 Italy Department of Pediatrics Obstetrics and Reproductive Medicine University of Siena Siena 53100 Italy

We analysed ejaculated spermatozoa from five infertile men with different balanced reciprocal translocations to contribute to the study of meiotic segregation of chromosomes 18, X and Y and also to evaluate sperm morphology by transmission electron microscopy （TEM） analysis. Conventional lymphocyte karyotype analyses highlighted dif- ferent reciprocal balanced translocations： t（12; 13）, t（4;9）, t（X;8）, t（8; 10） and t（3; 16）. Semen analysis was performed by light and TEM. Fluorescence in situ hybridization was performed directly on sperm nuclei using centromeric probes for chromosomes 18, X and Y. The carriers of the balanced reciprocal translocations considered in the present study showed a very similar pattern of sperm pathologies： diffused presence of apoptosis and immaturity. All patients showed meiotic segregation derangements, highlighted by the presence of sperm diploidies and sex chromosome disomies particularly related to the failure of the first meiotic division. However, an increased incidence of chromosome 18 aneuploidy was detected in spermatozoa from t（X;8） and t（8;10） carriers. We have also reported values from sex chromosomes such as t（X;8）, although the X chromosome was involved in translocation. Since patients with reciprocal translocations and spermatogenetic impairment are candidates for intracytoplasmic sperm injection cycles, the study of sperm parameters, and particularly of the level of aneuploidy rates, would provide better information for couples at risk and would contribute to the data in the literature for a better understanding of the effects of chromosomal rearrangement on the whole meiotic process and, in particular, on chromosomes not involved in translocation.

关键词： electron microscopy fluorescence in situ hybridization altered karyotype spermatozoa reciprocal translocation

electron microscopy combined with spatial analysis:quantitative mapping of the nano-assemblies of plasma membrane-associating proteins and lipids

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Biophysics Reports 2018年第6期4卷 320-328页

作者： Yong Zhou John F.Hancock Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston

The plasma membrane(PM) is a complex environment consisting of [ 700 species of lipids and many different types of membrane-associating proteins. These lipids and membrane proteins are distributed heterogeneously into nanometer-sized domains, called nanoclusters. The lateral spatial segregation in the PM gives rise to different curvature and lipid composition, which determines the efficiency of effector binding and signal transmission. Here, we describe an electron microscopy(EM)-spatial mapping technique to quantify the extent of nanoclusters formation in the PM. The nano-assemblies in the PM are quantified via expressing the GFP-tagged proteins or lipid-binding domains in the cells,which are then immunolabeled with the gold nanoparticles pre-coupled to the anti-GFP antibody. The gold nanoparticles are visualized via the transmission EM at high magnification. The statistical analysis of the Ripley's K-function calculates the spatial distribution of the gold nanoparticles. Important spatial parameters, such as the extent of nanoclustering, the clustered fraction, the number of proteins per cluster, the optimal size of a nanocluster, and the number of proteins localized to the PM, can be calculated. Further detailed aggregation pattern, such as the populations of monomers, dimers, trimers,and higher ordered oligomers, can also be extracted from the spatial analysis. The EM-bivariate analysis quantifies the extent of co-localization between two different components in the PM and provides key information on the protein–protein and the protein–lipid interactions over a long-distance scale from 8 to 240 nm.

关键词： electron microscopy Lipid-anchored proteins Nanoclustering Ripley’sK-function Signal transduction Spatial distribution

Advanced Transmission electron microscopy for Identification of Atomic-Scale Configurations of Zeolite-Supported Metal Catalysts

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Chinese Journal of Chemistry 2022年第19期40卷 2371-2373页

作者： Xuan Tang Jiajie Ye Yun Guo Sheng Dai Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Frontiers Science Center for Materiobiology and Dynamic ChemistryEast China University of Science and TechnologyShanghai200237 China Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and Technology130 Meilong RoadShanghai200237 China

Zeolite-supported metal catalysts have important applications in various catalytic reactions,but unveiling their atomic-scale structures is always a grand *** developed transmission electron microscopy(TEM)characterization techniques,e.g.,integrated differential-phase contrast(iDPC)scanning transmission electron microscopy(STEM)is emerging as a powerful tool for visualizing the electron beam-sensitive materials at atomic resolution,thus,providing new opportunities for imaging the exact configurations of metal species in the various channels of *** emerging topic summarizes recent progress utilizing iDPC-STEM-related technique for determination of the structures of metal species in zeolites that should offer insights into the structure-property relationships of zeolite-supported metal catalysts.A brief perspective about the new TEM technique is also presented,showing prospects in this field that will stimulate further scientific research in zeolite-supported metal catalysts.

关键词： Metal-zeolite Catalyst structure Heterogeneous catalysis TEM characterization electron microscopy

Fixation methods for electron microscopy of human and other liver

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World Journal of Gastroenterology 2010年第23期16卷 2851-2866页

作者： Eddie Wisse Filip Braet Hans Duimel Celien Vreuls Ger Koek Steven WM Olde Damink Maartje AJ van den Broek Bart De Geest Cees HC Dejong Chise Tateno Peter Frederik electron Microscope Unit University of Maastricht Australian Key Center for microscopy and Microanalysis Sydney University Department of Internal Medicine University of Maastricht Department of Surgery University of Maastricht Center for Molecular and Vascular Biology University of Leuven PhoenixBio Co.

For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is *** interpretation of electron microscopy(EM) images requires knowledge of the liver fine structure and experience with the numerous artifacts in fixation,embedding,sectioning,contrast staining and microscopic ***,the aim of this paper is to present a detailed summary of different methods for the preparation of hepatic cells and tissue,for the purpose of preserving long-standing expertise and to encourage new investigators and clinicians to include EM studies of liver cells and tissue in their projects.

关键词： Liver Tissue fixation Perfusion electron microscopy Biopsy