Microscopy最新文献_第5页

Improving the depth resolution of STEM-ADF sectioning by 3D deconvolution 利用三维反褶积提高STEM-ADF剖面的深度分辨率

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa056

A Ishizuka;K Ishizuka;R Ishikawa;N Shibata;Y Ikuhara;H Hashiguchi;R Sagawa

{"title":"Improving the depth resolution of STEM-ADF sectioning by 3D deconvolution","authors":"A Ishizuka;K Ishizuka;R Ishikawa;N Shibata;Y Ikuhara;H Hashiguchi;R Sagawa","doi":"10.1093/jmicro/dfaa056","DOIUrl":"10.1093/jmicro/dfaa056","url":null,"abstract":"Although the possibility of locating single atom in three dimensions using the scanning transmission electron microscope (STEM) has been discussed with the advent of aberration correction technology, it is still a big challenge. In this report we have developed deconvolution routines based on maximum entropy method (MEM) and Richardson–Lucy algorithm (RLA), which are applicable to the STEM-annular dark-field (ADF) though-focus images to improve the depth resolution. The new three-dimensional (3D) deconvolution routines require a limited defocus-range of STEM-ADF images that covers a whole sample and some vacuum regions. Since the STEM-ADF probe is infinitely elongated along the optical axis, a 3D convolution is performed with a two-dimensional (2D) convolution over xy-plane using the 2D fast Fourier transform in reciprocal space, and a one-dimensional convolution along the z-direction in real space. Using our new deconvolution routines, we have processed simulated focal series of STEM-ADF images for single Ce dopants embedded in wurtzite-type AlN. Applying the MEM, the Ce peaks are clearly localized along the depth, and the peak width is reduced down to almost one half. We also applied the new deconvolution routines to experimental focal series of STEM-ADF images of a monolayer graphene. The RLA gives smooth and high-P/B ratio scattering distribution, and the graphene layer can be easily detected. Using our deconvolution algorithms, we can determine the depth locations of the heavy dopants and the graphene layer within the precision of 0.1 and 0.2 nm, respectively. Thus, the deconvolution must be extremely useful for the optical sectioning with 3D STEM-ADF images.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":"70 1","pages":"241-249"},"PeriodicalIF":1.8,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38484133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Advances in cryo-EM and ED with a cold-field emission beam and energy filtration —Refinements of the CRYO ARM 300 system in RIKEN SPring-8 center— 冷场发射束和能量过滤低温EM和ED的研究进展——日本理工大学SPring-8中心cryo ARM 300系统的改进--

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa052

Saori Maki-Yonekura;Tasuku Hamaguchi;Hisashi Naitow;Kiyofumi Takaba;Koji Yonekura

引用次数: 14

Recent advances in small-angle electron diffraction and Lorentz microscopy 小角度电子衍射和洛伦兹显微术的最新进展

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa048

Shigeo Mori;Hiroshi Nakajima;Atsuhiro Kotani;Ken Harada

引用次数: 2

Transport of intensity equation method and its applications 强度方程输运法及其应用

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa053

Masanori Mitome

引用次数: 8

Practical implementation of high-resolution electron ptychography and comparison with off-axis electron holography 高分辨率电子ptychography的实际实现及其与离轴电子全息术的比较

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa055

Arthur M Blackburn;Robert A McLeod

{"title":"Practical implementation of high-resolution electron ptychography and comparison with off-axis electron holography","authors":"Arthur M Blackburn;Robert A McLeod","doi":"10.1093/jmicro/dfaa055","DOIUrl":"10.1093/jmicro/dfaa055","url":null,"abstract":"Ptychography is a coherent diffractive imaging technique that can determine how an electron wave is transmitted through an object by probing it in many small overlapping regions and processing the diffraction data obtained at each point. The resulting electron transmission model describes both phase and amplitude changes to the electron wave. Ptychography has been adopted in transmission electron microscopy in recent years following advances in high-speed direct electron detectors and computer algorithms which now make the technique suitable for practical applications. Its ability to retrieve quantitative phase information at high spatial resolution makes it a plausible alternative or complement to electron holography. Furthermore, unlike off-axis electron holography, it can provide phase information without an electron bi-prism assembly or the requirement of a minimally structured region adjacent to the region of interest in the object. However, it does require a well-calibrated scanning transmission electron microscope and a well-managed workflow to manage the calibration, data acquisition and reconstruction process to yield a practical technique. Here we detail this workflow and highlight how this is greatly assisted by acquisition management software. Through experimental data and modelling we also explore the similarities and differences between high-resolution ptychography and electron holography. Both techniques show a dependence of the recovered phase on the crystalline orientation of the material which is attributable to dynamical scattering. However, the exact nature of the variation differs reflecting fundamental expectations, but nonetheless equally useful information is obtained from electron holography and the ptychographically determined object transmission function.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":"70 1","pages":"131-147"},"PeriodicalIF":1.8,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38431030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Local structure analysis of amorphous materials by angstrom-beam electron diffraction 用埃束电子衍射分析非晶材料的局域结构

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa075

Akihiko Hirata

引用次数: 9

Novel −75°C SEM cooling stage: application for martensitic transformation in steel 新型−75°C SEM冷却阶段：在钢中马氏体相变中的应用

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa051

Kaneaki Tsuzazki;Motomichi Koyama;Ryosuke Sasaki;Keiichiro Nakafuji;Kazushi Oie;Akinobu Shibata;Takashi Gondo;Hiroya Miyazaki;Hiroshi Akamine;Minoru Nishida

引用次数: 1

Magnetic flux density measurements from narrow grain boundaries produced in sintered permanent magnets 烧结永磁体中产生的窄晶界磁通密度测量

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa032

Youngji Cho;Sujin Lee;Yasukazu Murakami

引用次数: 1

Visualization of microstructural change affected by mechanical stimulation in tendon healing with a novel tensionless model 用一种新的无张力模型可视化肌腱愈合过程中受机械刺激影响的微观结构变化

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa043

Junya Oshima;Kaoru Sasaki;Naoto Yamamoto;Tomoharu Kiyosawa;Mitsuru Sekido

{"title":"Visualization of microstructural change affected by mechanical stimulation in tendon healing with a novel tensionless model","authors":"Junya Oshima;Kaoru Sasaki;Naoto Yamamoto;Tomoharu Kiyosawa;Mitsuru Sekido","doi":"10.1093/jmicro/dfaa043","DOIUrl":"10.1093/jmicro/dfaa043","url":null,"abstract":"Since the majority of a tendon’s dry weight is collagen fibers, tendon healing consists mainly of collagen repair and observing three-dimensional networks of collagen fibers with scanning electron microscopy (SEM) is optimal for investigating this process. In this report, a cell-maceration/SEM method was used to investigate extrasynovial tendon (unwrapped tendon in synovial tissue such as the tendon sheath) healing of an injured Achilles tendon in a rat model. In addition, since mechanical stimulation is important for tendon healing, a novel, tensionless, rat lower leg tendon injury model was established and verified by visualizing the structural change of collagen fibers under tensionless conditions by SEM. This new model was created by transplanting the leg of a rat with a tendon laceration to the back, removing mechanical stimulation. We then compared the process of tendon healing with and without tension using SEM. Under tension, collagen at the tendon stump shows axial alignment and repair that subsequently demarcates the paratenon (connective tissue on the surface of an extrasynovial tendon) border. In contrast, under tensionless conditions, the collagen remains randomly arranged. Our findings demonstrate that mechanical stimulation contributes to axial arrangement and reinforces the importance of tendon tension in wound healing.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":"70 1","pages":"186-191"},"PeriodicalIF":1.8,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38230199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase plates in the transmission electron microscope: operating principles and applications 透射电子显微镜中的相位板：工作原理和应用

IF 1.8 4区工程技术

Microscopy Pub Date : 2020-11-01 DOI: 10.1093/jmicro/dfaa070

Marek Malac;Simon Hettler;Misa Hayashida;Emi Kano;Ray F Egerton;Marco Beleggia

引用次数: 21