TheN/D method and the diffraction picture—II.

1965 ◽  
Vol 40 (2) ◽  
pp. 659-661
Author(s):  
P. Olesen ◽  
J. Smitir
Keyword(s):  
Diffraction Picture

MOMENTUM-TRANSFER STRUCTURE OF POMERON AT ACCELERATOR ENERGIES

2004 ◽  
Vol 19 (40) ◽  
pp. 3001-3010 ◽  
Author(s):  
M. KAWASAKI ◽  
T. MAEHARA ◽  
M. YONEZAWA
Keyword(s):  
Experimental Data ◽  
Differential Cross Section ◽  
Momentum Transfer ◽  
Cross Section ◽  
Mass Parameter ◽  
Low Energy ◽  
Peripheral Part ◽  
Wide Range ◽  
Diffraction Picture ◽  
Transfer Structure

A representation of Pomeron amplitude derived asymptotically in the framework of the geometrical diffraction picture is shown to be consistent with the gross feature of the experimental data of the differential cross-section of pp and [Formula: see text] scattering in the low energy region [Formula: see text] over a wide range of momentum transfer. It is found that the most peripheral part of the diffraction interaction is characterized by a mass parameter of 0.4–0.5 GeV indicating the dominance of the two-pion states.

scholarly journals Shape and molecular orientation in lepidopteran scales

1949 ◽  
Vol 234 (608) ◽  
pp. 1-28 ◽  
Keyword(s):  
X Rays ◽  
X Ray Diffraction ◽  
Volume Increase ◽  
Inorganic Systems ◽  
Constant Diameter ◽  
Area Increase ◽  
Different Types ◽  
Diffraction Picture ◽  
Surface Area Increase

The rudiments of all types of scales on the wings of the meal moth, Ephestia sericarium (Scott) ( = E. kühniella Z.), are birefringent from the time of their emergence. Their growth may be regarded as the elongation of a cytoplasm-filled hollow cylinder of oriented protein-polysaccharide. The hair-scales grow as cylinders of approximately constant diameter, but other types of scales dilate progressively towards their distal ends, becoming club-shaped: the rate of volume increase exceeds that of surface-area increase. Dilatation is rapidly followed by flattening of the dilated region; the flattened scale continues to grow in area but undergoes little further change in shape. In spite of these transformations, the mature scale is still largely composed of oriented protein-polysaccharide, the orientation of which can be traced back in time to the earliest phase of development. Even in the mature flattened scales on the wing surfaces, sufficient orientation survives for oriented whole wings to yield a rudimentary chitin fibre-diagram when placed in the path of a beam of X-rays. Hair-scales (the ‘fur’ of moths) give an X-ray diffraction picture showing the principal reflexions of the fibre-diagram of polyacetylglucosamine. Birefringence studies suggest that the earliest rudiments contain more oriented protein than chitin, while in mature scales the chitin fraction is considerably increased. The variations in structure observed in different types of lepidopteran scales are compatible with their properties as fibrillar aggregates, and the final shapes of mature scales result from orderly displacements of the fibrillar organization laid down in the rudiment. The characteristic pattern of longitudinal ridges and transverse rungs may be compared with the patterns that arise in inorganic systems crystallizing out under certain conditions. It is suggested that the ridges compete in situ for the materials of which they are built, and that their regular spacing is an expression of this competition.

TheN/D method and the diffraction picture

1965 ◽  
Vol 39 (3) ◽  
pp. 956-966 ◽  
Author(s):  
P. Olesen ◽  
E. J. Squires
Keyword(s):  
Diffraction Picture

Investigation of Subcontact Layers in SiC after Diffusion Welding

2008 ◽  
Vol 600-603 ◽  
pp. 647-650 ◽  
Author(s):  
Oleg Korolkov ◽  
Natalja Sleptsuk ◽  
Alla A. Sitnikova ◽  
Mart Viljus ◽  
Toomas Rang
Keyword(s):  
Silicon Carbide ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Amorphous Layer ◽  
Interface Layer ◽  
Dark Field ◽  
Diffusion Welding ◽  
Transmission Electron ◽  
First Results ◽  
Diffraction Picture

In our early analytic reports [1,2] has been made the supposition that during the diffusion welding (DW) in subcontact area of SiC is formed the intermediate amorphous layer. In the present work are given the first results of transmission electron microscopy (TEM) and electron diffraction investigations of subcontact layers in n0-n- 4H-SiC. TEM examinations show that the boundary between aluminium and silicon carbide looks like stripy interface layer of ~ 25 nm thickness. This is the evidence that during diffusion welding in subcontact surface layer of SiC the shear micro deformations have been taking place and due to this process the plane inclusions of small-grained phase have been appeared. The image of contact area obtained in diffracted SiC rays (dark field) apparently confirms that stripy zone belongs to silicon carbide because the aluminium (black zone) fell out of contrast. Diffraction picture obtained from bulk zone of silicon carbide looks like monocrystallin, but the micro diffraction pattern obtained from the subcontact (stripy zone) gives a lot of concentric rings, that makes evidential the fact of existence of small-grained inclusions. Deciphering of this electron-diffraction pattern reveals the presence of such elements as residue SiC, Al, Si, as well as inclusions of graphite.

Quasiperiodic Crystals: A Revolution in Crystallography

MRS Bulletin ◽  
1986 ◽  
Vol 11 (2) ◽  
pp. 9-14 ◽  
Keyword(s):  
Electron Diffraction ◽  
Transition Metal ◽  
Rapid Solidification ◽  
Research Society ◽  
Metal Alloys ◽  
Tower Of Babel ◽  
Transition Metal Alloys ◽  
Materials Research ◽  
Diffraction Picture ◽  
At Home

At the beginning of my career, I encountered a book that Professor Von Hippel edited. In the Preface to that book he wrote the following: “Many foresee that science and industry are building a Tower of Babel and thai this undertaking will be halted as in Biblical times: the laborers, more and more specialized, will finally cease to understand each other. The editor, for one, does not share this is gloomy conviction. On the contrary, as our knowledge grows, old boundaries vanish and the view expands to broader horizons. However, people accustomed to boundaries in certain places tend still to respect them after their actual disappearance. To make them feel at home with their new neighbors is a driving motive of this book and its companion volume.”The Materials Research Society, being dedicated to interdisciplinariness, has shared Prof. Von Hippel's optimism, and I hope that in this lecture I can give you a small inkling of how interdisciplinary our current research is and how many different fields it touches.The work that I am going to discuss resulted from the rapid solidification study of aluminum transition metal alloys. One day more than three years ago. Prof. Shechtman, who is the hero of this investigation, came into my office with an electron diffraction picture with ten spots arrayed about the central spots (Figure 1).

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