IF 1.8 4区工程技术

Microscopy Pub Date : 2024-05-17 DOI: 10.1093/jmicro/dfae027

Motoki Shiga, Taisuke Ono, Kenichi Morishita, Keiji Kuno, Nanase Moriguchi

{"title":"Fast computational approach with prior dimension reduction for three-dimensional chemical component analysis using CT data of spectral imaging.","authors":"Motoki Shiga, Taisuke Ono, Kenichi Morishita, Keiji Kuno, Nanase Moriguchi","doi":"10.1093/jmicro/dfae027","DOIUrl":"https://doi.org/10.1093/jmicro/dfae027","url":null,"abstract":"Spectral image (SI) measurement techniques, such as X-ray absorption fine structure (XAFS) imaging and scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) or electron energy loss spectroscopy (EELS), are useful for identifying chemical structures in composite materials. Machine-learning techniques have been developed for automatic analysis of SI data, and their usefulness has been proven. Recently, an extended measurement technique combining SI with a computed tomography (CT) technique (CT-SI), such as CT-XAFS and STEM-EDS/EELS tomography, was developed to identify the three-dimensional (3D) structures of chemical components. CT-SI analysis can be conducted by combining CT reconstruction algorithms and chemical component analysis based on machine learning techniques. However, this analysis incurs high computational costs owing to the size of the CT-SI datasets. To address this problem, this study proposed a fast computational approach for 3D chemical component analysis in an unsupervised learning setting. The primary idea for reducing the computational cost involved compressing the CT-SI data prior to CT computation and performing 3D reconstruction and chemical component analysis on the compressed data. The proposed approach significantly reduced the computational cost without losing information about the 3D structure and chemical components. We experimentally evaluated the proposed approach using synthetic and real CT-XAFS data, which demonstrated that our approach achieved a significantly faster computational speed than the conventional approach while maintaining analysis performance. As the proposed procedure can be implemented with any CT algorithm, it is expected to accelerate 3D analyses with sparse regularized CT algorithms in noisy and sparse CT-SI datasets.","PeriodicalId":48655,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140966117","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

Spin polarization of photoelectrons emitted from spin-orbit coupled surface states of Pb/Ge(111). Pb/Ge(111) 自旋轨道耦合表面态发射的光电子的自旋极化。

IF 1.8 4区工程技术

Microscopy Pub Date : 2024-04-25 DOI: 10.1093/jmicro/dfae021

K. Yaji, Kenta Kuroda, Shunsuke Tsuda, Fumio Komori

引用次数: 0

Optimization of method for cross section hydrogels preparation using high-pressure freezing. 优化使用高压冷冻法制备横截面水凝胶的方法。

IF 1.8 4区工程技术

Microscopy Pub Date : 2024-04-24 DOI: 10.1093/jmicro/dfae020

Shuichi Ichihashi, Masahiko Kuwata, Kodai Kikuchi, Tatsushi Matsuyama, Akio Shimizu

{"title":"Optimization of method for cross section hydrogels preparation using high-pressure freezing.","authors":"Shuichi Ichihashi, Masahiko Kuwata, Kodai Kikuchi, Tatsushi Matsuyama, Akio Shimizu","doi":"10.1093/jmicro/dfae020","DOIUrl":"https://doi.org/10.1093/jmicro/dfae020","url":null,"abstract":"High-pressure water freeze fracturing (HPWFF) is a method for preparing water-containing samples such as hydrogels for scanning electron microscopy, in which a sample is placed in a divisible pressure vessel, filled with water, sealed, frozen with liquid nitrogen, then vacuum dried after the vessel is divided. The pressure (about 200 MPa) generated by the phase transition from water to ice is expected to inhibit ice crystal formation that causes large deformation of microstructure in the sample. To maximize the useable sample size, where SEM observation is not affected by ice crystal growth, preparation conditions including the size of pressure vessel were examined in this work. Using pressure vessels 8.0 mm, 5.5 mm and 4.5 mm in diameter, agarose gel, gelatin gel, wheat starch hydrogel, wheat flour noodle and cellulose hydrogel were used to prepare SEM samples. With agarose gel, an area of 3.6 mm in diameter in the 5.5 mm vessel was achieved as the maximum size of the area observable without ice crystal growth. The observable size of other samples was comparable, except for gelatin gel. As a result, observation of the three-dimensional network structure of hydrogels could be performed over a wider range than with the conventional method without shredding or chemical treatment of the samples. Additionally, usability of agarose gel for sample support matrix in HPWFF was demonstrated.","PeriodicalId":48655,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140665050","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

Diffraction contrast of ferroelectric domains in DPC STEM images. DPC STEM 图像中铁电畴的衍射对比。

IF 1.8 4区工程技术

Microscopy Pub Date : 2024-04-17 DOI: 10.1093/jmicro/dfae019

Masaya Takamoto, T. Seki, Y. Ikuhara, Naoya Shibata

{"title":"Diffraction contrast of ferroelectric domains in DPC STEM images.","authors":"Masaya Takamoto, T. Seki, Y. Ikuhara, Naoya Shibata","doi":"10.1093/jmicro/dfae019","DOIUrl":"https://doi.org/10.1093/jmicro/dfae019","url":null,"abstract":"Differential phase contrast scanning transmission electron microscopy (DPC STEM) is a powerful technique for directly visualizing electromagnetic fields inside materials at high spatial resolution. Electric field observation within ferroelectric materials is potentially possible by DPC STEM, but concomitant diffraction contrast hinders the quantitative electric field evaluation. Diffraction contrast is basically caused by the diffraction-condition variation inside a field-of-view, but in the case of ferroelectric materials, the diffraction conditions can also change with respect to the polarization orientations. To quantitatively observe electric field distribution inside ferroelectric domains, the formation mechanism of diffraction contrast should be clarified in detail. In this study, we systematically simulated diffraction contrast of ferroelectric domains in DPC STEM images based on the dynamical diffraction theory, and clarify the issues for quantitatively observing electric fields inside ferroelectric domains. Furthermore, we conducted experimental DPC STEM observations for a ferroelectric material to confirm the influence of diffraction contrast predicted by the simulations.","PeriodicalId":48655,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140693104","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

Correction to: Electron holography observation of electron spin polarization around charged insulating wire. 更正：带电绝缘线周围电子自旋极化的电子全息观测。

IF 1.8 4区工程技术

Microscopy Pub Date : 2024-04-11 DOI: 10.1093/jmicro/dfae014

引用次数: 0

Editorial: In-situ microscopy. 社论：原位显微镜。

IF 1.8 4区工程技术

Microscopy Pub Date : 2024-04-01 DOI: 10.1093/jmicro/dfae006

Toshie Yaguchi, Ayako Hashimoto, Junko Matsuda

引用次数: 0

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IF 1.8 4区工程技术