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Slice Thickness Optimization for the Focused Ion Beam-SCANNING electron microscopy 3D Tomography of Hierarchical Nanoporous Gold

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Nanomanufacturing and Metrology 2022年第2期5卷 112-118页

作者： Alexander Shkurmanov Tobias Krekeler Martin Ritter electron microscopy Unit Hamburg University of Technology(TUHH)Eißendorfer Straße 4221073HamburgGermany

The combination of focused ion beam (FIB) with SCANNING electron microscopy (SEM), also known as FIB-SEM tomography, has become a powerful 3D imaging technique at the nanometer scale. This method uses an ion beam to mill away a thin slice of material, which is then block-face imaged using an electron beam. With consecutive slicing along the z-axis and subsequent imaging, a volume of interest can be reconstructed from the images and further analyzed. Hierarchical nanoporous gold (HNPG) exhibits unique structural properties and has a ligament size of 15–110 nm and pore size of 5–20 nm. Accurate reconstruction of its image is crucial in determining its mechanical and other properties. Slice thickness is one of the most critical and uncertain parameters in FIB-SEM tomography. For HNPG, the slice thickness should be at least half as thin as the pore size and, in our approach, should not exceed 10 nm. Variations in slice thickness are caused by various microscope and sample parameters, e.g., converged ion milling beam shape, charging effects, beam drift, or sample surface roughness. Determining and optimizing the actual slice thickness variation appear challenging. In this work, we examine the influence of ion beam scan resolution and the dwell time on the mean and standard deviation of slice thickness. After optimizing the resolution and dwell time to achieve the target slice thickness and lowest possible standard deviation, we apply these parameters to analyze an actual HNPG sample. Our approach can determine the thickness of each slice along the z-axis and estimate the deviation of the milling process along the y-axis (slow imaging axis). For this function, we create a multi-ruler structure integrated with the HNPG sample.

关键词： Focused ion beam SCANNING electron microscopy Tomography Hierarchical nanoporous gold

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Comparison of SCANNING electron microscopy findings regarding biofilm colonization with microbiological results in nasolacrimal stents for external, endoscopic and transcanalicular dacryocystorhinostomy

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International Journal of Ophthalmology(English edition) 2014年第3期7卷 534-540页

作者： Melike Balikoglu-Yilmaz Tolga Yilmaz Sule Cetinel Umit Taskin Ayse Banu Esen Muhittin Taskapili Timur Kose Department of Ophthalmology Bagcilar Education and Research Hospital Department of Histology & Embryology Marmara UniversityFaculty of Medicine Department of Otorhinolaryngology Bagcilar Education and Research Hospital1Istanbul 34200 Turkey Department of Microbiology and Clinical Microbiology Bagcilar Education and Research Hospital Department of Biostatistics and Medical Informatics Ege University Faculty of Medicine

AIM:To compare bacterial biofilm colonization in lacrimal stents following external dacryocystorhinostomy(EX-DCR),endoscopic dacryocystorhinostomy(EN-DCR),and transcanalicular dacryocystorhinostomy(TC-DCR)with multidiode laser.METHODS:This prospective study included 30consecutive patients with nasolacrimal duct obstruction who underwent EXT-,EN-,or TC-DCR.Thirty removed lacrimal stent fragments and conjunctival samples were cultured.The lacrimal stent biofilms were examined by SCANNING electron microscopy(SEM).RESULTS:Eleven(36.7%)of the 30 lacrimal stent cultures were positive for aerobic bacteria(most commonly Staphylococcus epidermidis and Pseudomonas aeruginosa).However anaerobic bacteria and fungi were not identified in the lacrimal stent cultures.Twenty-seven(90%)patients had biofilmpositive lacrimal stents.The conjunctival culture positivity after the DCR,biofilm positivity on stents,the grade of biofilm colonization,and the presence of mucus and coccoid and rod-shaped organisms did not significantly differ between any of the groups(P>0.05).However,a significant difference was found when the SEM results were compared to the results of the lacrimal stent and conjunctival cultures(P<0.001).CONCLUSION:Type of dacryocystorhinostomy(DCR)surgery did not affect the biofilm colonization of the lacrimal stents.SEM also appears to be more precise than microbiological culture for evaluating the presence of biofilms on lacrimal stents.

关键词： biofilms nasolacrimal duct obstruction epiphora dacryocystitis SCANNING electron microscopy

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A different approach for determining the responsivity of n^+p detectors using SCANNING electron microscopy

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Journal of Semiconductors 2012年第7期33卷 29-33页

作者： Omeime Xerviar Esebamen Gran Thungstrm Hans-Erik Nilsson Department of Information Technology and Media Mid Sweden UniversityHolmgatan 10SE-851 70SundsvallSweden

This paper explores an alternative to the standard method of studying the responsivities （the input-output gain） and other behaviours of detectors at low electron energy. The research does not aim to compare the results of differently doped n＋p detectors; its purpose is to provide an alternative characterization method （using SCANNING electron microscopy） to those used in previous studies on the responsivity ofn＋p doped detectors as a function of the electron radiation energy and other interface oarameters.

关键词： SCANNING electron microscopy responsivity n＋p detector

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SCANNING electron microscopy(SEM) Observations of Antennal Sensilla of Chrysopa pallens Rambur(Neuroptera：Chrysopidae)

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Plant Diseases and Pests 2017年第4期8卷 1-4,19页

作者： Wang Juan Chen Hongyin Wang Mengqing Liu Chenxi Zhang Haiping Zhang Lisheng Key Laboratory of Integrated Pest Management in Crops the Ministry of Agriculture/Institute of Plant ProtectionChinese Academy of Agricultural Sciences

[Objectives]The paper was to provide background information for ongoing research on relationship between smell and behavior of the green lacewing Chrysopa pallens（ Rambur）（ Neuroptera： Chrysopidae）. [Methods]The submicroscopic structure of antennal sensilla of C. pallens was examined using SCANNING electron microscopy. [Results]Antennae of female and male C. pallens were linear in shape and（ 1. 52 ± 0. 08） and（ 1. 58 ± 0. 23） cm in length,respectively. The scape and pedicel were composed of single sub-segment,while the flagellum consisted of 116 sub-segments,on which most sensilla distributed. The flagella of female and male antennae were（ 1. 44 ± 0. 04） and（ 1. 47 ± 0. 13） cm in length,respectively. Nine morphological sensilla types were recorded in both sexes,including four types of highly abundant and widely distributed sensilla trichodea（ ST Ⅰ,ST Ⅱ,ST Ⅲ and ST Ⅳ）,three types of sensilla basiconica（ SB Ⅰ,SB Ⅱ,and SB Ⅲ）,and one of each type of sensilla chaetica and B9 hm bristles. Although the shape,structure,numbers,and distribution of antennae of females and males were basically similar,major differences were recorded between the sexes in the length of some sensilla types. Both the ST Ⅲ and SB Ⅰ in female adults were significantly longer than that in male ones. Notably,SB Ⅱ was found only in female. [Conclusions]The paper laid a foundation for revealing the relationship between smell and behavior,playing a crucial role in promoting the important biological control effect of C. pallens in farmland ecological system.

关键词： Chrysopa pallens Antenna Sensilla Ultrastructure SCANNING electron microscopy

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Analysing Imaging Signals of Negative－Charging Contrast in SCANNING electron microscopy ＊

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Chinese Physics Letters 2003年第11期20卷 2011-2014页

作者：张海波冯仁剑 KatsumiURA DepartmentofelectronicScienceandTechnology Xi'anJiaotongUniversityXi’an710049 ProfessorEmeritusofOsakaUniversity Takakura-cho1-14-9Miyakojima-kuOsaka534-0011Japan

Negative charging of a specimen may produce the image contrast of yielding the information under the insulating thin film in SCANNING electron microscopy. To clarify and make good use of the recently developed negative-charging contrast (NCC), we propose a simplified procedure for quantifying secondary electron (SE) imaging signals and report the calculated results. The theoretical considerations and calculations are validated by comparing the calculated relation between the SE signal and the surface potential with measured dynamic characteristics of the NCC images. The results show that in the region of weak negative charging the NCC formation is due to the SE redistribution. The intensity of SE signals decreases with increasing the amount of the SEs returning to the negatively charged surface whose local electric field may attract electrons. This results in the NCC transient characteristics.

关键词： SCANNING electron microscopy

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Nucleation and Growth of Thallium on Thin Film Mercury Electrode: Voltammetric, SCANNING electron microscopy, Chronoamperometric and Electrochemical Impedance Studies

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American Journal of Analytical Chemistry 2022年第11期13卷 415-430页

作者： Abdoulkadri Ayouba Mahamane Boubié Guel Paul-Louis Fabre Laboratoire Matériaux Eaux Environnement (LAMEE) Faculté des Sciences et Techniques Université Abdou Moumouni Niamey Niger Laboratoire de Chimie Moléculaire et des Matériaux Equipe Chimie Physique et Electrochimie Département de Chimie UniversitéJoseph KI ZERBO Ouagadougou Burkina Faso Unité Mixte de Recherche (UMR CNRS 5503) Laboratoire de Génie Chimique Toulouse France

Thallium is a heavy metal highly toxic to the biosphere. It can be determined by anodic stripping voltammetry after deposition on mercury film. The aim of this work is to study the conditions and mechanisms of deposition of Hg on glassy carbon electrode and Tl on Hg film by cyclic voltammetry, SCANNING electron microscopy, chronoamperometry and impedance techniques. The results showed a germination and growth of a 3D Hg phase on glassy carbon electrode. Similarly, the electrodeposition of Tl on Hg follows a 3D three-dimensional nucleation with diffusion controlled growth. The impedance measurements reveal an easier charge transfer on the Tl film.

关键词： Thallium Mercury Film Cyclic Voltammetry SCANNING electron microscopy Impedance Measurements

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SCANNING electron microscopy (SEM) of the Bug Eye and Sand Coral

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microscopy Research 2020年第1期8卷 1-7页

作者： Sayid Ali Sayid Aliyu Dadan-Garba Daniel Elaigwu Enenche Barnabas Achakpa Ikyo Harkness Screens Stevenage United Kingdom Department of Geography Nigerian Defence Academy Kaduna Nigeria Department of Chemistry Benue State University Makurdi Nigeria Department of Physics Benue State University Makurdi Nigeria

We present a SCANNING electron microscopy (SEM) technique for the characterisation of biological and non-biological samples at nano-scale level. SCANNING electron microscopy has been around for a long while especially in material science laboratories in developed countries. The SEM has enabled scientist to have a better understanding of microstructure by providing unsurpassed optical magnifications of samples. In this introductory paper, we introduce the techniques of using SEM to capture highly magnified microstructure of a fly found on an African soybean (Glycine max) seed. We are able to estimate the number of lenses in each eye and zoom into features that could describe its life characteristics. Hexagonal lenses are estimated to have sizes ranging from 14 um to 19 um. This paper also presents a finding of a sea coral “pie like structure” on a single grain of sand used for water filtration.

关键词： Bug Eye Sand Coral SCANNING electron microscopy

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SCANNING electron microscopy STUDY OF FILLED SILICONE RUBBER

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Chinese Journal of Polymer Science 1988年第3期6卷 230-235页

作者：李玉福杨啓云李光亮 Institute of Chemistry Academia Sinica Beijing

The fracture surfaces of a number of silicone vulcanizates were investigated by the use of SCANNING electron microscopy (SEM). It was found that the difference in the presence and absence of filler, the variation of its surface modification as well as the history of thermal aging of the vulcanizates, all of these factors made difference in surface morphology of the fractured surface. This was correlated with the strength of the vulcanizates. The reinforcing effect of filler and the process of fracture were discussed.

关键词： SCANNING electron microscopy Silicone rubber Filler effect Silica Fracture of polymer.

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SCANNING electron microscopy OF MALIGNANT BRENNER TUMORS OF THE OVARY

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北京大学学报(医学版) 1991年第5期23卷 409-411+421页

作者：唐素恩王素霞 Beijing Medical University Department of electron microscopy The First School of Clinical Medicine

Six cases of malignant Brenner tumors of the ovary were observed by lightmicroscopy (LM) and scanning electon microscopy (SEM). The histologic features of the tu-mors revealed nonkeratinized squamous cell carcinoma. The SEM showed the tumor nests werecomposed of squamous cells, accompanied with a few ciliated cells. These findings evide-nced that malignant Brenner tumor like the other epithelial tumors of ovary originated fromthe same Mullerian epithelium, but recapitulated the vagino cervical epithelium. The histoge-nesis of different types of ovarian epithelial tumors corresponded to the development oforgans of female genital tract differentiating from Mallerian epithelium in embryo. It dosenot conform to fact to think that there were present transitional cell carcinomas in ovarianepithelial tumors, or the malignant Brenner tumors were composed of transitional epithelium.

关键词： Brenner tumor SCANNING electron microscopy Mullerian epithelial system

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A Hybrid Optimization Approach of Single Point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with Principal Component Analysiss

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 160-166页

作者： A Visagan P Ganesh Department of Production Technology Madras Institute of TechnologyChennai-600044India

We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.

关键词： single point incremental forming AISI 316L taguchi grey relation analysis principal component analysis surface roughness SCANNING electron microscopy

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