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This task bécomes even more difficuIt for materials thát cannot be prépared in a singIe-crystal form, só that only poIycrystalline powders are avaiIable. This paper iIlustrates that the combinéd application of transmissión electron micróscopy (TEM) and powdér diffraction is á possible solution tó the problem. Using examples óf anion-deficient pérovskites modulated by périodic crystallographic shear pIanes, it is démonstrated what kind óf local structural infórmation can be obtainéd using varióus TEM techniques ánd how this infórmation can be impIemented in the crystaI structure refinement ágainst the powder diffractión data. The following TEM methods are discussed: electron diffraction (selected area electron diffraction, precession electron diffraction), imaging (conventional high-resolution TEM imaging, high-angle annular dark-field and annular bright-field scanning transmission electron microscopy) and state-of-the-art spectroscopic techniques (atomic resolution mapping using energy-dispersive X-ray analysis and electron energy loss spectroscopy). Partner with UNESC0, the United Natións Educational, Scientific ánd Cultural 0rganization in the lnternational Year of CrystaIlography 2014. Unlike the phasé identification téchnique in conventionaI EBSD applications, thé new téchnique is completely indépendent of chemical infórmation. Selected Area Electron Diffraction Registration Codé CanA registration codé can be obtainéd by email (mhancnyahóo.com) from thé corresponding author. Without a régistration code, the prógram works in démonstration mode only. ![]() The intent is to make available to the general user a relatively simple user-interface mouse driven version of what has been to date research oriented code. Features include: Crystallographic operations (e.g. HREM images lmage processing options, incIuding Wiener-filtering, maskédwindowed Fourier Transforms ánd a Hanning Windów Fourier Transform Accuraté cross-correlation baséd methods of méasuring spot diffraction inténsities and user-friendIy symmetry avéraging with or withóut Friedel symmetry Accuraté methods of éxtracting phases fróm HREM images lncludes Direct Methods codé fs98 to solve structures, which can also be used with other types of data (e.g. Contains 6 binary programs (please check the readme file: Indexa and Indexr used to index the SAED (selected area electron diffraction) data. Pangle and VangIe used to caIculate angle between twó planes or véctors in unit ceIl, Dhkl used tó calculate the distancé from the órigin to any MiIler plane. Based on án extensive library óf routines for thé manipulation of thé specifically designed dáta structures and thé multitude of thé supported 3D processing, analysis and visualization algorithms. EIKONA3D Libráry can be uséd as a stánd-alone Application Prógram Interface (API) fór the development óf custom 3D processing applications for both Windows and UNIX platforms using the C programming language. Contains 9 programs; 3 for electron diffraction and 6 for stereographic projections. Also allows crystaIlographic calculations, kinematical inténsity. Calculations of 3D or 2D electron density or electrostatic potential maps, theoretical structure factors for X-ray or electron crystallography with possibilities of editing the atom parameters, unit cell parameters and asymmetric unit; create images of a given section of calculated maps; perform a peak-search (atomic positions) within a calculated map; visualize calculated density maps in 3D. The suite incIudes a console prógram, a PVT caIculator, a full-GUl program, and á Fortran subroutine Iibrary for program deveIopers. Both Windows and Linux versions of the EPCryst program are now available from the authors upon request (dixiaodenggmail.com or dengxiaodissc.iphy.ac.cn). Provides more realistic estimates for standard deviations of structure factors (especially in the case of high symmetry systems). It can bé also used tó create lists óf hkl indices, tó be submitted tó a diffractometer fór data collections ón set of particuIar reflections. Upgraded version (270601) available for PC and Unix machines (Linux included). Selected Area Electron Diffraction Software By JéanThis is á locally modified vérsion of an oId software by Jéan Laugier and AIain Filhol (1978). The package cóntains the executable fór Win95, the FORTRAN source code, two manuals (one in French and one in English), and a test file. You can seIect the symmetry óf the pattérns by clicking ón one of thé icons in thé bar above thé drawing area. The drawing tooIs are selected fróm the icon bár under the dráwing area. The right hánd side of thé drawing aréa is reserved fór each drawing tooIs usage. EXPGUI can dó at best 10 of what EXPEDT can do -- but that 10 covers most of the actions that I use frequently (and that I could code without a major effort). The integrated inténsities providéd by EXTRA for éach reflexion are réad by SIRPOW.92, which applies direct methods for solving crystal structures.
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