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Vol. 17, No. 7 (1961)

1961-04-05
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CONTENT
THE CRYSTAL STRUCTURE OF ETHYLENEDIAMINETETRA ACETIC ACID
LU YUN-CHIN, SHAO MEI-CHENG
1961, 75 (7): 304-309. doi: 10.7498/aps.17.304
Abstract +
The crystal structure of ethylenediaminetetraacetic acid has been determined by the method of symmetry elements. The crystal is monoclinic, space group C2h6, with parameters a=13.28?,b=5.64?,c=16.14? and β*=83°45′. Each unit cell has four molecules. The interatomic distances are calculated and discussed.From the result of crystal structure, two carboxyls in the ethylenediaminetetraacetic acid form internal molecular hydrogen bonds with the two nitrogen atoms. Therefore, chemical characters of the ethylenediaminetetraacetic acid can only have those of a dibasic acid. The structure formular of molecule should be
APPLICATION OF SYMMETRY ELEMENTS IN THE INTERPRETA-TION OF PATTERSON DIAGRAM
LU YUN-CHIN
1961, 75 (7): 310-314. doi: 10.7498/aps.17.310
Abstract +
In this paper a new method of interpretation of the Patterson diagram is discribed.. It can be used to determine no-heavy atom crystal structures.Appling this method to determine the structure of E.D.T.A. [CH2N(CH7COOH)2]2 we have obtained a very good result. The crystals are monoclinic, space group C2h6, with parameters a=13.28?,b=5.64?,c=16.14? and β*=83°45′.The plane group of projection on (hol) is P2. Each unit cell has four centres of symmetry.
UP-DOWN ASYMMETRIES OF Λ AND Σ DECAYS
HU NING
1961, 75 (7): 315-320. doi: 10.7498/aps.17.315
Abstract +
It is assumed that the weak interaction Hamiltonian for hyheroas decaying into a mu-cleon and a meson is of the Yukawa type, and that the parity violating factors of the terms involving Λ and Σ hyperons are respectively 1 +εγ5 and 1-εγ5 (ε=±1). The influence of strong interaction is taken into account for the innitial hyheron systems. It is found that the theoretical up-down asymmetries for various hyheron-decays are consistent with the experimental results. The prohabilities of the core of the hyperons being in various bare hyperon states are also estimated.
THE SCATTERING OF AN ARBITRARY UNIFORM PLANE ELECTROMAGNETIC WAVE BY AN INFINITE METAL ROD OF ELLIPTICAL CROSS SECTION IN AN INFINITE HOMOGENEOUS ISOTROPIC MEDIUM WITH FINITE CONDUCTIVITY
JEN LANG
1961, 75 (7): 321-328. doi: 10.7498/aps.17.321
Abstract +
The scattering of an arbitrarily polarized uniform plane electromagnetic wave by an infinite metal rod of elliptical cross section with any eccentricity in a homogeneous isotropic medium of infinite extent with finite conductivity is analized rigorously as a boundary value problem using elliptical cylinder coordinates, the scattered field arround the rod is obtained in terms of calculable Mathieu functions.