Atomic resolution improvement by a new method using the second derivative of the intensity function of the reconstructed exit wave of electrons for a thin β-Si3N4 crystal

2010 ◽  
Vol 63 (5) ◽  
pp. 524-527 ◽  
Author(s):  
Hwang Su Kim
Keyword(s):  
Intensity Function ◽  
New Method ◽  
Atomic Resolution ◽  
Second Derivative ◽  
Resolution Improvement

scholarly journals Second Derivative Free Eighteenth Order Convergent Method for Solving Non-Linear Equations

2017 ◽  
Vol 10 (04) ◽  
pp. 829-835
Author(s):  
V.B. Kumar Vatti ◽  
Ramadevi Sri ◽  
M.S.Kumar Mylapalli
Keyword(s):  
Linear Equations ◽  
Efficiency Index ◽  
Subject Classification ◽  
New Method ◽  
Second Derivative ◽  
Numerical Examples ◽  
Derivative Free ◽  
Convergent Method ◽  
And Performance ◽  
Non Linear Equations

In this paper, the Eighteenth Order Convergent Method (EOCM) developed by Vatti et.al is considered and this method is further studied without the presence of second derivative. It is shown that this method has same efficiency index as that of EOCM. Several numerical examples are given to illustrate the efficiency and performance of the new method. AMS Subject Classification: 41A25, 65K05, 65H05.

scholarly journals Hosoya polynomial of zigzag polyhex nanotorus

2008 ◽  
Vol 73 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Mehdi Eliasi ◽  
Bijan Taeri
Keyword(s):  
Molecular Graph ◽  
Wiener Index ◽  
New Method ◽  
Second Derivative ◽  
First Derivative ◽  
Hosoya Polynomial

The Hosoya polynomial of a molecular graph G is defined as H(G,?)=?{u,v}V?(G) ?d(u,v), where d(u,v) is the distance between vertices u and v. The first derivative of H(G,?) at ?=1 is equal to the Wiener index of G, defined as W(G)?{u,v}?V(G)d(u,v). The second derivative of 1/2 ?H(G, ?) at ?=1 is equal to the hyper-Wiener index, defined as WW(G)+1/2?{u,v}?V(G)d(u,v)?. Xu et al.1 computed the Hosoya polynomial of zigzag open-ended nanotubes. Also Xu and Zhang2 computed the Hosoya polynomial of armchair open-ended nanotubes. In this paper, a new method was implemented to find the Hosoya polynomial of G = HC6[p,q], the zigzag polyhex nanotori and to calculate the Wiener and hyper Wiener indices of G using H(G,?).

scholarly journals Automatic local resolution-based sharpening of cryo-EM maps

2018 ◽  
Author(s):  
Erney Ramírez-Aportela ◽  
Jose Luis Vilas ◽  
Roberto Melero ◽  
Pablo Conesa ◽  
Marta Martínez ◽  
...  
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
New Method ◽  
Atomic Resolution ◽  
Atomic Model ◽  
Artificial Structure ◽  
Technological Advances ◽  
Fully Automatic

AbstractRecent technological advances and computational developments, have allowed the reconstruction of cryo-EM maps at near-atomic resolution structures. Cryo-EM maps benefit significantly of a “postprocessing” step, normally referred to as “sharpening”, that tends to increase signal at medium/high resolution. Here, we propose a new method for local sharpening of volumes generated by cryo-EM. The algorithm (LocalDeblur) is based on a local resolution-guided Wiener restoration approach, does not need any prior atomic model and it avoids artificial structure 1 factor corrections. LocalDeblur is fully automatic and parameter free. We show that the new method significantly and quantitatively improving map quality and interpretability, especially in cases of broad local resolution changes (as is often the case of membrane proteins).

scholarly journals A New Three Step Iterative Method without Second Derivative for Solving Nonlinear Equations

2015 ◽  
Vol 12 (3) ◽  
pp. 632-637 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Finite Difference Method ◽  
Iterative Method ◽  
Nonlinear Equations ◽  
Linear Interpolation ◽  
New Method ◽  
Second Derivative ◽  
Third Order ◽  
Numerical Examples ◽  
Newton Equation ◽  
Interpolation Analysis

In this paper , an efficient new procedure is proposed to modify third –order iterative method obtained by Rostom and Fuad [Saeed. R. K. and Khthr. F.W. New third –order iterative method for solving nonlinear equations. J. Appl. Sci .7(2011): 916-921] , using three steps based on Newton equation , finite difference method and linear interpolation. Analysis of convergence is given to show the efficiency and the performance of the new method for solving nonlinear equations. The efficiency of the new method is demonstrated by numerical examples.

A New Method for Solving the Constraint Multibody System Dynamic Equation

2011 ◽  
Vol 345 ◽  
pp. 361-364
Author(s):  
Ding Xuan Zhao ◽  
Yu Xin Cui ◽  
Tao Ni ◽  
Ying Zhao ◽  
Chao Fei Wang
Keyword(s):  
Dynamic Equation ◽  
Multibody System ◽  
Linear Equations ◽  
Constraint Equation ◽  
System Dynamic ◽  
New Method ◽  
Taylor Formula ◽  
Second Derivative ◽  
System Constraint ◽  
Non Linear Equations

Aiming at the problem of solving the constraint multibody system dynamic equation, a new method is proposed. This method takes the function of general coordinates to replace the second derivative of the general coordinates in the dynamic equation according to Taylor formula, and considers the converted dynamic equation and system constraint equation as a system of non-linear equations to find the solution by Newton method. Experimental results show that the proposed method is efficient and accurate for solving the constraint multibody system dynamic equation.

A new method for estimating the morphometric size at maturity of crabs

1998 ◽  
Vol 55 (3) ◽  
pp. 704-714 ◽  
Author(s):  
George Watters ◽  
Alistair J Hobday
Keyword(s):  
Body Size ◽  
A Priori ◽  
Smoothing Splines ◽  
The Body ◽  
New Method ◽  
Second Derivative ◽  
Size At Maturity ◽  
Relative Growth ◽  
Wide Range ◽  
Body Sizes

Existing techniques for estimating the morphometric size at maturity of crabs are based on assumptions that may be unnecessary. Here we demonstrate a new method of detecting changes in relative growth (or allometric) relationships and estimating morphometric size at maturity. This method involves fitting several smoothing splines to relationships between body size and claw size, selecting the "best" spline, and finding this spline's maximum second derivative. The body size where the second derivative of the best spline is maximized estimates the morphometric size at maturity. Monte Carlo simulations suggest that uncertainty and bias in the estimate of morphometric size at maturity can be decreased by measuring a large number of crabs from a wide range of body sizes. Our spline method does not require a priori assumptions about the shape of the relative growth relationship; it can detect multiple changes in the relative growth rate; and it is robust to outliers. The modeling technique may also be used to identify regions of allometric change in other types of relationships. We demonstrate the new technique by estimating the morphometric size at sexual maturity for males of both brachyuran (Chionoecetes tanneri) and anomuran (Paralomis spinosissima and P. formosa) crabs.

Effect of strain on ADF-STEM high-resolution images

1991 ◽  
Vol 49 ◽  
pp. 666-667
Author(s):  
M. Kelly ◽  
D.M. Bird
Keyword(s):  
High Resolution ◽  
Strong Influence ◽  
Intensity Variation ◽  
Dark Field ◽  
Atomic Resolution ◽  
Strain Fields ◽  
High Resolution Image ◽  
Annular Dark Field ◽  
High Resolution Images ◽  
Interesting Alternative

It is well known that strain fields can have a strong influence on the details of HREM images. This, for example, can cause problems in the analysis of edge-on interfaces between lattice mismatched materials. An interesting alternative to conventional HREM imaging has recently been advanced by Pennycook and co-workers where the intensity variation in the annular dark field (ADF) detector is monitored as a STEM probe is scanned across the specimen. It is believed that the observed atomic-resolution contrast is correlated with the intensity of the STEM probe at the atomic sites and the way in which this varies as the probe moves from cell to cell. As well as providing a directly interpretable high-resolution image, there are reasons for believing that ADF-STEM images may be less suseptible to strain than conventional HREM. This is because HREM images arise from the interference of several diffracted beams, each of which is governed by all the excited Bloch waves in the crystal.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Electron crystallographic determination of the 3-D structure of staurolite at atomic resolution

1991 ◽  
Vol 49 ◽  
pp. 540-541
Author(s):  
Kenneth H. Downing ◽  
Hu Meisheng ◽  
Hans-Rudolf Went ◽  
Michael A. O'Keefe
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Dimensional Structure ◽  
Structure Information ◽  
Resolution Electron ◽  
Scattering Effects ◽  
High Resolution Images ◽  
Effects Of Radiation

With current advances in electron microscope design, high resolution electron microscopy has become routine, and point resolutions of better than 2Å have been obtained in images of many inorganic crystals. Although this resolution is sufficient to resolve interatomic spacings, interpretation generally requires comparison of experimental images with calculations. Since the images are two-dimensional representations of projections of the full three-dimensional structure, information is invariably lost in the overlapping images of atoms at various heights. The technique of electron crystallography, in which information from several views of a crystal is combined, has been developed to obtain three-dimensional information on proteins. The resolution in images of proteins is severely limited by effects of radiation damage. In principle, atomic-resolution, 3D reconstructions should be obtainable from specimens that are resistant to damage. The most serious problem would appear to be in obtaining high-resolution images from areas that are thin enough that dynamical scattering effects can be ignored.

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