Details

Titel

Societies and Academies

Ist Teil von

• Nature (London), 1929-06, Vol.123 (3110), p.894-895

Erscheinungsjahr

1929

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• LONDON. Royal Society, May 30.-O. W. Richardson and P. M. Davidson: The energy functions of the H2 molecules. The terms in the expansion of the force function are determined for certain states by various methods and show satisfactory agreement. Negative total energies, heats of dissociation and other constants of about thirty H2 states are tabulated. Curves are drawn for the mean kinetic energy of the electrons of certain states at various nuclear separations. An appendix contains a theorem on the mean energy of a system of particles in any condition of periodic motion, when some of the particles are fixed.-E. K. Rideal, C. P. Snow, F. I. G. Rawlins, and A. M. Taylor:-Infrared investigations of molecular structure (1).-C. P. Snow, F. I, G. Rawlins, and E. K. Rideal: Infra-red investigations of molecular structure (2). The vibration-rotation band spectrum of nitric oxide proves to be a fundamental, with its centre at 1882-9 cm., with the fine-structure consisting of P, Q, and B branches with at least 42 rotation bands in each of the P and R branches. The molecular constants derived from the separation of the fine-structure bands (3-35 cm.″1) corresponds almost exactly with those obtained from electronic band spectral data. The presence of a Q branch is in accordance with the gyroscopic character of an odd-electron molecule. The facts relating to the ground state of nitric oxide, its physical magnitudes, and its electronic angular momentum about the nuclear axis, form a consistent whole.-A. Miiller: The connexion between the zigzag structure of the hydrocarbon chain and the alternations in the properties of odd and even numbered chain compounds. Starting from the fact that the CH2-groups are arranged in a zigzag line, it is shown that there must exist an essential difference in the structure of the odd and even numbered substances. This difference accounts for the alternations of properties.-O. W. Richardson and F. S. Robertson: The emission of soft X-rays by different elements at higher voltages.-L. P. Davies: The soft X-ray emission from various elements after oxidation. The effect of oxidation on the total soft X-ray emission from the following elements has been studied: Silicon, manganese, iron, cobalt, nickel, copper, molybdenum, palladium, and tungsten. The efficiency of the oxide seems to be the average efficiency of the oxygen and element present.-D. L. Chapman and W. K. Hall: A study of the catalysis by silver of the union of hydrogen and oxygen. The new method of Hughes and Bevan was used and the conclusions confirmed by direct measurements of the falls of pressure which occur when the gases, separately and mixed together, are brought into contact with a large surface of silver. The mechanism of the action seems to be one of alternate reduction and re-oxidation of an oxide film. The fact that a film formed at low temperature is more effective than one formed at a higher temperature suggests that some of the molecules of silver oxide in the former are in relatively unstable positions, and therefore more active chemically.-R. H. Fowler and A. H. Wilson: A detailed study of the 'radio-active decay' of, and the penetration of a-particles into, a simplified one-dimensional nucleus. The authors solve exactly for a simplified nucleus the problem of a-particle disintegration (determination of the complex characteristics of the wave-equation with the proper boundary conditions), and discuss the converse problem of the penetration of an a-particle into the nucleus from without.-G. I. Finch and D. L. Hodge: Gaseous combustion in electric discharge (3).bustion of dry detonating gas in the direct current discharge is primarily determined by the ionisation of both the constituent molecules of the gas. Electrostatic forces keep apart positively charged ions, unless such forces are counteracted by some other agency; one such agency is negatively charged metal atoms sputtered from the cathode which, by forming electrically neutral metal-gas complexes with positive ions, overcome electrostatic repulsion and thus enable combustion to proceed.-G. I. Finch and J. C. Stimson: The electrical condition of hot surfaces during the adsorption of gases (3). A hot platinum surface exhibits a charge when in vacuo or in contact with gases. With alternate treatment with oxygen and hydrogen at 500° C., it will exhibit a charge in hydrogen or in vacuo at room temperature. Heating at 850° destroys such superactivity. The charge due to any gas can be rapidly removed by evacuation at 850°. The destruction of the superactive condition is due to a structural change in the arrangement of the surface atoms akin to sintering.-J. M. Robertson: An X-ray investigation of the structure of naphthalene and anthracene. Using the rotating crystal photographic method, the general and statistical considerations of the reflections indicate a periodic structure parallel to the c axes of the crystals. Geometrical structure factors are developed and the dimensions of the molecules calculated differ only slightly from those of Bragg's tetrahedral structure. Thus the tetrahedral properties of the carbon atom are maintained in aromatic structures.-K. Majumdar: The arc spectrum of chlorine. The spectrum has been photographed in the region X6400-8700. The ionisation potential is calculated as 13-1 volts.-K. R. Rao: The arc spectrum of germanium. Observations have been extended to X1630 and about fifty new lines have been added, most of which have been classified. The ionisation potential of Ge I is 8-09 volts approximately.-U. Nakaya: On the emission of soft X-rays by different elements, with reference to the effect of adsorbed gas. The absorption of these rays increases with the amount of the adsorbed gas molecules on the photoelectric plate, while the excitation decreased with the presence of gas molecules. Reliable data were secured by bombarding the photoelectric plate and target to red heat in the highest vacuum and afterwards reducing the oxide films on these surfaces with hydrogen.-N. F. Mott: The scattering of fast electrons by atomic nuclei. The scattering of electrons by an atomic nucleus is investigated, using the wave equation of Dirac and a scattering formula obtained which gives the spin-relativity correction to be applied, for fast 3-particles, to the usual Rutherford formula.-L. J. Freeman: Further investigations of the spectrum of ionjsed nitrogen (N II). Nine terms belonging to a quintet system have been identified and two new terms of the triplet system. Some 75 lines have been newly classified.-A. E. Gillam and R. A. Morton: The absorption spectra of halogens and inter-halogen compounds in solution in carbon tetrachloride.-R. A. Frazer and A. J. Duncan: On the criteria for the stability of small motions.-R. A. Frazer and W. J. Duncan: On the numerical solution of equations with complex roots.-G. C. McVitie: On Einstein's unified field theory.