bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inelastic Scattering and Interference
Authors: Van Dyck D 
Published: July 2020

Abstract
Recently it has been a matter of controversy whether inelastically scattered electrons can yield interference fringes so as to obtain holograms, and in particular whether compensation of energy loss in the object by energy gain in the source will maintain coherence [1]. In discussions about coherence (and wave mechanisms in general) it is always dangerous to rely on intuitive arguments (exchange of energy, time of interaction, etc.). In this work we will start from the most general approach, which is inspired by the treatment of inelastic electron diffraction crystals by Yoshioka in 1957 [2]. Energy exchanges are always described quantummechanically by an Hamiltonian. Therefore we can only investigate the balance between energy exchange properly if electron, object, and source are described by one global Hamiltonian. With source we mean the whole electron generating system (emitter, accelerator, condensor).
Consider a global system consisting of an electron, with position vector r, an object with particle vectors ri, and a source with particles at rα.
Models of Magnesium Oxide (111) Surface Reconstructions Obtained from Direct Phasing of Transmission Electron Diffraction Data
Authors: Plass R , Egan K , Collazo-Davila C , Grozea D , Landree E , Marks L D , Gajdardziska-Josifovska M 
Published: July 2020

Abstract
It has long been thought that (111) surfaces of rock salt oxides microfacet to neutral surfaces upon annealing because of the very large energies involved in bulk terminating a layer of like ions. However in a recent reflection electron microscopy (REM) study Gajdardziska-Josifovska et al. found that MgO(lll) surfaces annealed in flowing oxygen furnaces at 1500°C not only did not microfacet, but displayed a √3×√3R30° surface periodicity that was stable in air. To determine the structure of this unusually stable surface MgO (111) transmission electron microscopy (TEM) samples were annealed in a vacuum furnace in the present study and their transmission electron diffraction (TED) patterns were analyzed with direct phasing methods.
The TEM samples were prepared by orienting a MgO single crystal and sawing lmm wafers along a (111) plane. Disk samples were then ultrasonically drilled, dimpled, mechanically polished and/or hot nitric acid etched, and milled with 5 KeV Ar+ ions.
Structure of the in on SI(111)4X1 Surface Determined by Applying Direct Phasing Methods to Transmission Electron Diffraction Data
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Collazo-Davila C , Marks L D , Nishii K , Tanishiro Y 
Published: July 2020

Abstract
Direct methods were applied to transmission electron diffraction data to solve the previously unknown In on Si(111)4x1 surface structure. The structure consists of zig-zag chains of In atoms separated by regions of silicon including dimer chains (Fig 1.). The 4x1 structure is one of several stable surface structures formed with increasing In coverages on the Si(111) surface. The √3x√3 structure consists of 1/3 of a monolayer of In, the √31x√31 occurs at a slightly higher coverage and the 4x1 structure appears before the formation of In islands on the surface. While the √3x√3 surface has been extensively studied, relatively little is known about the √31x√31 and 4x1 structures. Knowledge of the atomic positions in the 4x1 structure is an important step in understanding metal/semiconductor epitaxy and interface formation.
Two data sets were used in this study -- the first recorded on film and reduced in Tokyo, the second recorded on Imaging Plate in Tokyo and reduced at Northwestern. Twenty-seven independent intensities were measured.
Electron Holography of Electromagnetic Fields
Authors: Bonevich JE 
Published: July 2020

Abstract
Electron holography can lend crucial insights to understanding the subtle manifestations of electro-magnetism in a wide range of materials. Whereas conventional microscopy is sensitive only to the intensity, holography reveals the phase changes in coherent electron wavefronts making it a unique tool to probe electric and magnetic fields on the nanometer scale. We have employed electron holography to characterize materials for mean inner potential measurements and also their electric and magnetic properties.
Electron holograms were acquired in a 300 kV FE-TEM under two optical conditions: the standard high resolution mode was employed for mean inner potential measurements; to examine the intrinsic electromagnetic states, a lower resolution mode was used whereby the objective lens is turned off and the diffraction lens images the specimen. Digitally acquired holograms were reconstructed with the HolograFREE software package.
Nanophase TiO2 particles generated in a flame burner system were found to have unusual central features. The rutile particles appear to contain faceted voids, raising the question whether the feature is truly a void or a secondary amorphous phase.
Reference Electron Energy Spectra for Quantitative Auger Electron Spectroscopy (AES) : Cu(100), (110), and (111)
Authors: Goto Keisuke 
Published: July 2020

Abstract
We have developed a novel cylindrical mirror analyzer (CMA) for the quantitative Auger electron spectroscopy (AES) to obtain reference electron spectra. This CMA was defined in all respects, thus it yields an absolute electron energy distribution ; the energy resolution of 0.25% for 42.3° ± 6° of incidence angles (theoretically obtainable resolution), the estimated transmission of 6.2% (assuming cosine law), and the signal detection by the combination of Faraday cup and electrometer (SI traceable). The acceleration voltages for the primary electron beam were ranging 1 through 5000 volts and the energy range of the sweep was 0 through 5000 eV in 0.1 eV(min)/step for the whole range and 10 meV or even 0.1 meV/step for the limited narrow range. The energy calibration by using the primary acceleration voltage (SI traceable) and the spectral intensity correction for the relativity have been performed.
The spectra for typical samples have already been published, i.e., C's(soot and graphite), Al(poly), Si(100and 111), Cr(poly), Fe(poly), Ni(poly), Cu(poly), Ga(liquid), Ag(poly), and Au(poly). Among the samples C's and Ga(liquid) seem to be convincing materials.
Design, Construction and Applications of a Low Temperature (5 K) Combined Scanning Cathodoluminescence and WDS X-ray Spectroscopy and Imaging System
Authors: Phillips MR , Moon A R , Stevens Kalceff M A , Remond G 
Published: July 2020

Abstract
Recently there has been a renaissance in scanning cathodoluminescence (CL) microscopy and microanalysis primarily brought about by the analytical demands of the semiconductor industry in addition to significant advances in photonics technology (high efficiency PMTs, CCDs and CL collectors). The strength of the CL analysis technique lies in its ability to provide high spatial (lateral and depth) resolution concentration and distribution information about: (i) the chemical state (identity, oxidation state and co-ordination) of trace level impurities and (ii) point / extended structural defects (vacancies and dislocations) in both semiconductors and insulators.
For many materials, interpretation of CL spectra and images measured at low temperature (5 K) is quite straightforward. However CL generation via recombination of electron / hole pairs is a competitive process. Consequently in some specimens the measured CL intensity is not directly proportional to the concentration of the particular luminescent center but relates to the concentration of other radiative or non-radiative centers. In these cases it is difficult to decide whether contrast in the CL image is due to variation in the concentration of the radiative center or the competitive center.
Use of Polycapillary Optics to Increase the Effective Area of Microcalorimeter Spectrometers
Authors: Wollman D A , Jezewski Christopher , Hilton G C , Xiao Qi-Fan , Irwin K D , Dulcie L L , Martinis John M 
Published: July 2020

Abstract
Although the performance of high-energy-resolution microcalorimeter spectrometers for x-ray microanalysis is encouraging, the future widespread acceptance of these spectrometers as valuable microanalysis instruments depends on improvements in both achievable count rate and geometrical x-ray collection efficiency. While the maximum output count rate of our microcalorimeter (∼160 s−1) is much less than that of conventional EDS detectors operating at their highest energy resolution (∼3000 s−1), we are confident that we can significantly improve the count rate without loss of energy resolution (∼10 eV FWHM over a broad energy range). Increasing the area (and thus solid angle) of the microcalorimeter is a more difficult problem, however, as the best microcalorimeter performance is achieved using small-area (typically 250 μm by 250 μm) absorbers with low heat capacity.
This problem can be solved by using an x-ray lens to increase the collection efficiency of the microcalorimeter spectrometer. A polycapillary optic consisting of tens of thousands of fused capillaries can collect x-rays from a point x-ray source over a large solid angle and focus the x-rays onto the small-area absorber of the microcalorimeter.
In-column energy filtering transmission electron microscope (EFTEM) optimum contrast without disadvantages for all modes of imaging and all kinds of detectors
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Bauer R , Benner G , Seybold V , Zellmann E , Probst W 
Published: July 2020

Abstract
The major demand for imaging light element specimens in the TEM is to achieve the appropriate contrast. This is particularly true in biomedical and also in polymer fields of application. The main reason for contrast being challenging is the correlation between the atomic number of the constituting elements and the scattering angle and thus the very low scattering absorption contrast achievable.
Different conventional methods or combinations of them can be used to overcome the problem. 1) Contrast is created chemically by staining with heavy elements. Disadvantages besides the high level of preparational efforts are the artificial unnatural view in general and the high potential of artifacts in particular. 2) Contrast is created physically using small objective apertures and/or long focal length objective lenses. Disadvantages are clearly increased alignment and cleaning efforts for small apertures and the complete loss of high frequency/high resolution information. Moreover, some elastic scattering is still required. 3) Contrast is created physically converting phase contrast into absorption contrast using the phase contrast transfer function of the microscope and high defocus values.
Design of an Objective Lens with Minimum Chromatic Aberration Coefficient
Authors: Tsuno K , Jefferson D A 
Published: July 2020

Abstract
The Schelzer resolution is defined as the highest spatial frequency which is transferred into the image with the same phase as all lower frequencies. The resolution of the information limit is, however, determined by the information from the specimen which is equal to the degree of noise. The Schelzer resolution is determined by the wave length and the spherical aberration coefficient Cs of the objective lens. It reached 0.1 nm at 1250 kV. The limit of the resolution has been calculated numerically and it is written as d = 4.65(BsVr)−1/4 (nm), where Bs (in T) is the saturation magnetic flux density of the pole-piece material and Vr the relativistically corrected accelerating voltage. The resolution of the information limit is determined by the axial chromatic aberration coefficient Cc and incoherent effects such as the finite size of the source, beam divergence, energy spread, instabilities of the high voltage and lens current. The limit of the resolution is not clear. Most of the objective lenses of commercial microscopes are designed to optimize Cs rather than Cc. In this investigation, however, we describe the limit of Cc for 200 kV microscopes.
Development of a Double Tilt Specimen Heating Holder and its Application for the Study of Phase Transformation of Si3N4 During Sintering
Authors: Kamino T , Yaguchi T , Tomita M , Yasutomi Y , Hidaka K 
Published: July 2020

Abstract
The results of our previous studies revealed that the specimen heating holder with the heating elements of spiral shaped fine metal wires of high melting point enable us to observe high resolution transmission electron microscopy(TEM) images at elevated temperatures.
In fact, the holder was applied for high resolution TEM study of a formation of SiC crystal at 1500°C and a surface reconstruction of Au deposited Si particle at 1000°C successfully. However, because the heating holder was single tilt type, there was a certain limitation in its application.
In this paper, development of a double tilt specimen heating holder with a heating element of spiral shaped fine metal wire and its application for the study of microstructural changes of Si3N4 during sintering at very high temperature.
Photograph of the newly developed double tilt specimen heating holder is shown in Fig. 1. The heating element is mounted on the electrically isolated tilting frame of the holder and the heating current is supplied via tilting rod which is also electrically isolated from other parts of the holder.
Event-Driven 2D Detector for Digital Electron Imaging
Authors: Fan G Y , Beuville E , Datte P , Beche J-F , Millaud J , Ellisman M H , Xuong N-H 
Published: July 2020

Abstract
An event-driven 2D pixel array detector designed for protein crystallography is being tested to determine its suitability as a direct electron detector for digital imaging in electron microscopy. The detector prototype consists of an 8×8 pixel array with an 150 μm pitch. The device configuration is illustrated in Fig. 1. The detector module consists of a reverse-biased 300 μm thick monolithic silicon diode array which is bump-bonded to an Application Specific Integrated Circuit (ASIC) which instruments each diode in the array. Each pixel cell of the ASIC forms a pixel processor which consists of an amplifier, discriminator, prescalar and readout circuit.
When an incident electron enters the detector, a group of electron-hole pairs is created in the silicon. The detector bias of the diode array is such that holes are collected at the input to the amplifier where the signal is then amplified and shaped. When the output signal pulse height is greater than the discriminator threshold, the event is then registered in the prescalar, causing one count to be accumulated.
Current Trends in Digital Imaging for Optical Microscopy
Authors: Cheng Ping-chin 
Published: July 2020

Abstract
Digital imaging has provided a number of possibilities in optical microscopy which can not be achieved easily by traditional methods. These include the possibility of low-light imaging, ease of image manipulation (processing and analysis) and transmission via electronic communication channels. Recently, digital imaging has become the buzz-word in photography. Therefore, it is the intent of this article to evaluate the current state of digital imaging technologies for optical microscopy, both pro and con.
There are certain applications where digital imaging is the only feasible way to gather image data, examples include laser scanning confocal microscopy and low-light CCD microscopy. Based on the nature of image acquisition methods, one can classify digital imaging into two major domains: (1) sequential and (2) parallel data acquisition. The sequential data acquisition method is generally used in scanning devices such as the confocal laser scanning microscopes (CLSM). Photomultipliers and solid state devices are generally used as the photon detector(s) and the analog signals are subsequently digitized. On the other hand, the use of 2D array detectors such as CCDs falls into the parallel acquisition category. Although, the data from a CCD is read-out sequentially, all the pixels on a CCD chip acquire the image simultaneously. Depending on the dynamic range of the photon detector and needs of the application, the digitized image generally has a dynamic range of 8, 12 or 16 bits.
Integration of a Spatial Map with the Images of Polytene Chromosomes
Authors: Heckman C A , Olesen J B 
Published: July 2020

Abstract
The principle of spatial mapping is familar to microscopists. It is, for example, employed in conjunction with x-ray fluorescence spectrometry to draw up maps showing the distribution of elements in a materials surface. Although widely exploited in scanning electron microscopy, the technique of spatial mapping is rarely applied to other types of images. With the recent development of automated methods for recognizing and extracting details from digital images, however, it has become feasible to extract patterns from the transmission electron microscope image and overlay the original image with representations from the data. Pattern extraction, executed in a data mining scheme, is an area of common interest to researchers in machine discovery, data visualization, and high performance computing. Since the resolution of an electron microscopic image, if completely conserved in the conversion into digital format, can range into many millions of pixels, microscopy is one of the most promising areas for data mining applications.
This capability is particularly well-suited to investigating the problem of chromatin higher order structure. The highest order of packing that is readily seen in transmission electron micrographs of chromatin is the 30 nm fiber, the approximate size of which has been confirmed by x-ray diffraction studies.
Automatic Hough Transform-Based 3D Segmentation of Cell Nuclei in Thick Tissue Sections
Authors: Lockett SJ , Rodriguez EG , Ortiz de Solorzano C , Sudar D , Pinkel D , Gray JW 
Published: July 2020

Abstract
Combining pathology, which reports the structural features of individual cells and their spatial organi-zation in a tissue specimen, with molecular biology techniques (immunocytochemistry and fluores-cence in situ hybridization, FISH) for detecting the distribution of specific molecular species in individual cells is a powerful approach for gaining insight into the underlying disease mechanisms of carcinogenesis. This approach requires analysis of thick (&gt;20 ¼m) tissue sections in which cells are preserved intact within the context of their environment. 3D (confocal) microscope image acquisition followed by 3D image analysis (IA) for extracting quantitative information are then used for quantita-tive analysis of tissue features such as nuclear and/or cell volume, shape, total fluorescence or FISH signal number. An essential component of the IA is detection of the individual cells, or their nuclei since many molecular species of interest are localized within the nucleus (e.g. genetic aberrations). We present here a completely automatic, 3D algorithm for this task, which based on the Hough transform (HT).
Use of High-Performance Computing Algorithms in Combination With Parallel Computing for Tomography
Authors: Perkins GA , Renken CW , Young SJ , Lindsey S , Ellisman MH , Frey TG 
Published: July 2020

Abstract
The electron microscope is essential for resolving complex biological structures, such as mitochondria, which are too small to be viewed in detail with the light microscope. In contrast to a conventional instrument, the High-Voltage Electron Microscope (HVEM) located at the National Center for Microscopy and Imaging Research (NCMIR) can obtain images from relatively thick specimens that contain substantial three-dimensional structure. Though a single image acquired with the HVEM represents a projection through the specimen, tomographic methods can be applied to a set of images acquired from different orientations to derive a three-dimensional representation of its biological structure. Tomography requires extensive computation and considerable processing time on conventional workstations in order to reconstruct the typically large HVEM volumes from the tilt series.
In order to expedite tomographic processing, we have implemented both the commonly used singleaxis tilt, R-weighted backprojection algorithm and two iterative reconstruction methods, algebraic reconstruction (ART) and simultaneous iterative reconstruction (SIRT) on the massively parallel Intel Paragon at the San Diego Supercompter Center.
Recent Development of Cone-Beam X-Ray Microtomography at Sunyab
Authors: Pan SJ , Shih A , Liou WS , Park MS , Wang G , Bohne BA , Newberry SP , Kim H , Cheng PC 
Published: July 2020

Abstract
An experimental X-ray cone-beam microtomographic imaging system utilizing a generalized Feldkamp reconstruction algorithm has been developed in our laboratory. This microtomographic imaging system consists of a conventional dental X-ray source (Aztech 65, Boulder, CO), a sample position and rotation stage, an X-ray scintillation phosphor screen, and a high resolution slow scan cooled CCD camera (Kodak KAF 1400). A generalized Feldkamp cone-beam algorithm was used to perform tomographic reconstruction from cone-beam projection data. This algorithm was developed for various hardware configuration to perform reconstruction of spherical, rod-shaped and plate-like specimen.
A test sample consists of 8 glass beads (approx. 800μm in diameter) dispersed in an epoxy-filled #0 gelatin capsule. One hundred X-ray projection images were captured equal angularly (at 3.6 degree spacing) by the cooled CCD camera at a of 1317×967 (17×17mm2) pixels with 12-bit dynamic range. Figure 1 shows a 3D isosurface rendering of the test sample. The eight glass beads and trapped air bubbles (arrows) in the epoxy resin (e) are clearly visible.
Computer Graphics Challenges in Electron Microscope Tomography Visualization
Authors: Durkin James W 
Published: July 2020

Abstract
We are developing a collaborative research environment, the Collaboratory for Microscopic Digital Anatomy (CMDA), to provide remote access to the sophisticated instrumentation located at the Na-tional Center for Microscopy and Imaging Research (NCMIR). The project’s initial focus is the col-lection and analysis of data from NCMIR’s unique intermediate-high voltage transmission electron microscope (HVEM), an instrument expressly designed to obtain images from thick specimens con-taining substantial 3-D structure. Because of the electron optical characteristics of the microscope, its images represent a 2-D projection of the specimen’s 3-D structure. 3-D data is derived, using axial tomography, from a series of projections acquired as the specimen is successively tilted in small angu-lar increments. Visualizing the 3-D volume data generated by this procedure is a key challenge facing the project. Our experience suggests that existing visualization mechanisms are limited in their ability to fully access the data’s biologically interesting information.
What is the Future for Image Simulation?
Authors: Van Dyck D 
Published: July 2020

Abstract
The ultimate goal of high resolution electron microscopy is to determine quantitatively the atomic structure of an object. In this respect the electron microscope can be considered as an information channel that carries this information from the object to the observer. High resolution images are then to be considered as data planes from which the structural information has to be extracted.
However this structural information is usually hidden in the images and cannot easily be assessed. Therefore, a quantitative approach is required in which all steps in the imaging process are taken into account. Two main approaches have been followed so far in the literature: the indirect approach in which the images are simulated for various plausible trial structures of the object and compared with the experimental images, and the direct approach in which the lost phase information is retrieved using holographic techniques so as to “deblur” the effect of the microscope and to reveal directly the atomic structure of the object.