Normal Vibrations of the Polymer Molecules of Helical Configuration. II. A Simple Method of Factoring of the Secular Equation

1961 ◽  
Vol 35 (3) ◽  
pp. 1050-1054 ◽  
Author(s):  
Hiroyuki Tadokoro
Keyword(s):  
Secular Equation ◽  
Simple Method ◽  
Normal Vibrations ◽  
Polymer Molecules ◽  
Helical Configuration

Normal Vibrations of the Polymer Molecules of Helical Configuration. III. Polyoxymethylene and Polyoxymethylene‐d2

1963 ◽  
Vol 38 (3) ◽  
pp. 703-721 ◽  
Author(s):  
Hiroyuki Tadokoro ◽  
Masamichi Kobayashi ◽  
Yôichi Kawaguchi ◽  
Akira Kobayashi ◽  
Shunsuke Murahashi
Keyword(s):  
Normal Vibrations ◽  
Polymer Molecules ◽  
Helical Configuration

Normal Vibrations of the Polymer Molecules of Helical Conformation. V. Isotactic Polypropylene and Its Deuteroderivatives

1965 ◽  
Vol 42 (4) ◽  
pp. 1432-1449 ◽  
Author(s):  
Hiroyuki Tadokoro ◽  
Masamichi Kobayashi ◽  
Minoru Ukita ◽  
Katsutoshi Yasufuku ◽  
Shunsuke Murahashi ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Helical Conformation ◽  
Normal Vibrations ◽  
Polymer Molecules

Normal Vibrations of the Polymer Molecules of Helical Conformation. VI. Polytetrahydrofuran and Deuterated Polytetrahydrofurans

1965 ◽  
Vol 42 (8) ◽  
pp. 2807-2816 ◽  
Author(s):  
Kiyohisa Imada ◽  
Hiroyuki Tadokoro ◽  
Akira Umehara ◽  
Shunsuke Murahashi
Keyword(s):  
Helical Conformation ◽  
Normal Vibrations ◽  
Polymer Molecules

scholarly journals On the planarity of the NSi3 skeleton in the trisilylamine molecule. A normal coordinate analysis involving complex symmetry coordinates

1979 ◽  
Vol 57 (14) ◽  
pp. 1779-1784 ◽  
Author(s):  
H. F. Shurvell ◽  
A. Dunham ◽  
S. J. Cyvin ◽  
J. Brunvoll
Keyword(s):  
Secular Equation ◽  
Point Group ◽  
Irreducible Representations ◽  
Complex Numbers ◽  
Normal Coordinate ◽  
Energy Distributions ◽  
Normal Vibrations ◽  
Interaction Terms ◽  
Symmetry Coordinates ◽  
Unusual Problem

Normal coordinate calculations have been carried out for the N(SiH3)3 molecule. A model with C3h symmetry was used, which is based on a planar NSi3 skeleton. The presence of complex numbers for the characters of degenerate irreducible representations of the point group C3h leads to an unusual problem when factoring the G and F matrices. A set of real degenerate symmetry coordinates for the E′ and E′′ species can be constructed, but these are not true symmetry coordinates under the C3h point group. However, they can be obtained from the genuine (complex) symmetry coordinates by a unitary transformation. For a degenerate species, this procedure leads to a and b blocks of the factored G and F matrices, which contain interaction terms. Consequently both blocks must be taken together when forming the secular equation, and subsequently the calculated frequencies appear as pairs of identical numbers.A valence force field that includes all reasonable interactions has been obtained and used to predict the wavenumbers of the 15N and d9 isotopic molecules. Details of the normal vibrations in the three molecules have been obtained from potential energy distributions. The results show reasonable agreement with the limited experimental data available for the isotopic molecules.

The orientation of sickle hemoglobin fibers within fascicles

1988 ◽  
Vol 46 ◽  
pp. 400-401
Author(s):  
Christopher A. Miller ◽  
Bridget Carragher ◽  
William A. McDade ◽  
Robert Josephs
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Relative Orientation ◽  
Unit Cell ◽  
Red Cell ◽  
High Ph ◽  
Sickle Hemoglobin ◽  
Polar Crystal ◽  
Helical Configuration

Highly ordered bundles of deoxyhemoglobin S (HbS) fibers, termed fascicles, are intermediates in the high pH crystallization pathway of HbS. These fibers consist of 7 Wishner-Love double strands in a helical configuration. Since each double strand has a polarity, the odd number of double strands in the fiber imparts a net polarity to the structure. HbS crystals have a unit cell containing two double strands, one of each polarity, resulting in a net polarity of zero. Therefore a rearrangement of the double strands must occur to form a non-polar crystal from the polar fibers. To determine the role of fascicles as an intermediate in the crystallization pathway it is important to understand the relative orientation of fibers within fascicles. Furthermore, an understanding of fascicle structure may have implications for the design of potential sickling inhibitors, since it is bundles of fibers which cause the red cell distortion responsible for the vaso-occlusive complications characteristic of sickle cell anemia.

A simple way for producing holographic filters suitable for image improvement

1978 ◽  
Vol 36 (1) ◽  
pp. 226-227
Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske
Keyword(s):  
Transfer Functions ◽  
Diffraction Order ◽  
Lateral Position ◽  
Simple Method ◽  
Spatial Frequencies ◽  
Resolution Electron ◽  
Wiener Filters ◽  
Image Improvement ◽  
Optical Reconstruction ◽  
Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Sign in / Sign up

Export Citation Format

Share Document