Our Knowledge of the Fundamental Constants of Physics and Chemistry in 1965

“…COS 0 B Thus, equation (3) (5), (6) and (7) we have used the values t = 0.82 cm, e TM = 0.9125 nominated by Schneider and the values r 0 = e2/mc 2 = 2.8178 x 10 -13 cm, a = 3-615 fi~ and 2 = 0.030105 A obtained respectively from Cohen & DuMond (1965, p. 590), Landolt-B6rnstein (1971, and Muller, Hoyt, Klein & DuMond (1952, p. 790).…”

Section: Theorymentioning

confidence: 99%

The absolute measured value off(220) for Cu –the importance of extrapolation to zero extinction

Mackenzie¹,

Mathieson²

1979

Acta Cryst Sect A

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A method of deriving an extinction-free estimate of an X-ray structure-factor value is outlined. The method is based on the availability of experimental estimates of the level of extinction from the mosaic distribution of the crystal. A plot of the diffracted intensity or its corresponding structure factor (uncorrected or nominally corrected for extinction) against the percentage extinction effect yields an extinction-free value in the limit on extrapolation to zero level. Such a procedure can also reveal any inadequacy in the correction procedures by lack of internal consistency. An illustration of the potential of this procedure is given using the set of 11 experimental values off for the 220 reflexion of Cu derived by Schneider [Acta Cryst. (1977), A33, 235-243] from y-ray diffractometry. Use of the experimental estimates of the level of extinction together with the nominally corrected f data indicates the presence of systematic residual error. Linear extrapolation of these f values to zero extinction yields an estimate off(220) in the region of 16.77. A value in this region is more in accord with a Hartree-Fock value than with the band-structure value, which was favoured by Schneider's original estimate of 16.46.

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“…The relation forn = 127, bn = 1, u = 0 ·15 is given by the dotted line (B). The values used in the calculations were taken from the report on fundamental-constants by Cohen and Du Mond (1965).…”

Section: Theoretical Relationships Between the Quantities Measuredmentioning

confidence: 99%

The Excited Atomic Hydrogen Lines 126a and 127a in HII Regions

McGee¹,

Gardner²

1968

Aust. J. Phys.

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SummaryForty radio sources have been observed for the presence of the hydrogen recombination lines 126", at 3248·708 MHz and 127", at 3172·864 MHz with a 6' arc aerial beam and a receiver with 48 channels of 37 kHz bandwidth each. Detections were made in 34 sources, all of which were either HI! regions or optically unidentified thermal sources.The mean ratio of line intensity to thermal continuum intensity was 3·4% (± 1· 3 % s.d.); the mean halfwidth of the lines was 340 kHz (± 50 kHz s.d.), which is equivalent to 31·5 km/sec in radial velocity.It is suggested that many of the profiles are complex and contain two or more major components that represent large·scale motions in the HI! regions. The Orion and Omega nebulae are shown to have this type of profile and are discussed in some detail.

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Our Knowledge of the Fundamental Constants of Physics and Chemistry in 1965

Cited by 388 publications

References 125 publications

Photoionization of atoms and molecules

Photoionization of atoms and molecules

The absolute measured value off(220) for Cu –the importance of extrapolation to zero extinction

The Excited Atomic Hydrogen Lines 126a and 127a in HII Regions

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