摘要:

A directional Čerenkov counter has been used at latitude 52° N to separate shower directions into two classes, incident from North and South of the East-West plane through the zenith. Evidence from some previous experiments indicates a Northern excess of approximately 30%. No excess has been observed; out of 526 showers, each containing at least 3 × 106particles at sea level, 261 were incident from the North, and 265 from the South. The apparent direction of a shower was found to be dependent on the position of its axis relative to the detector. A directional radius of curvature was measured, making reasonable assumptions, and found to be 1625 ±505290metres.

ISSN:0031-8086    

DOI:10.1080/14786436008235847

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

In an attempt to resolve the present controversy about the relative abundances of the heavy, Z≤6, nuclei in the primary cosmic radiation, the magnitude of the corrections introduced by the overlying atmosphere has been redetermined. For this reason it has been necessary to use nuclear emulsions to determine the fragmentation parameters of nuclei having 20≤Z≤28. The results of this work show that the relative abundances calculated previously by considering the diffusion of nuclei through the atmosphere were not seriously in error, and that outside the atmosphere the ratio ofH, Z≤10, toM, 6≤Z≤9, nuclei is 0.38 ± 0.04. The significance of this result is considered briefly.

ISSN:0031-8086    

DOI:10.1080/14786436008235848

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Measurements have been made as a function of strain and temperature with specimens of commercially pure beryllium. Very sharp internal friction peaks were observed which are similar to those reported as occurring in aluminium. The previously suggested mechanism giving rise to these maxima is discussed in terms of the evidence obtained here.

ISSN:0031-8086    

DOI:10.1080/14786436008235849

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Ferromagnetism has hen detected in disordered solid solution alloys of Fe in Pd at compositions down to 1.25 atomic % of iron. Data are presented on magnetic moments and on Curie points. It is shown that part of the observed magnetic moment must be associated with the Pd atoms, and cannot be completely localized on iron atoms.

ISSN:0031-8086    

DOI:10.1080/14786436008235850

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The resistance changes produced by thermal treatment of Fe3Al have been measured and the annealing kinetics analysed. It was found that an increase in long-range order produced a large decrease in resistance. It was found that the rate at which ordering takes place is a function of the initial quenching temperature. All curves were fitted to the standard rate equation giving an order of reactionn=2.2 for specimens quenched from 620°c andn =1.5 for specimens quenched from 530°c. The activation energy obtained from resistivity kinetics was found to be much lower than the mean activation energy for diffusion.

ISSN:0031-8086    

DOI:10.1080/14786436008235851

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The refractive indices of liquid and solid argon have been measured as a function of temperature between 74° and 95°k. The results, represented by the Lorentz-Lorenz function, are expressed as a function of density, and their significance discussed.

ISSN:0031-8086    

DOI:10.1080/14786436008235852

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The status of the possible E1-E3 cascade between the 2 + state at 6.92 mev, the 3- state at 6.14 mev and the 0+ ground state of16O is reviewed in the light of recent improvements in our knowledge of radiative transitions and isotopic spin impurities. It is concluded that the present limit of 5 × 10−3on the relative intensity, although clearly demonstrating the efficacy of the isotopic spin selection rule, is not sharp enough to be a significant test for detailed models of the nuclear structure, for which purpose an improvement by an order of magnitude would be required. It is shown by a coincidence method, wing the reaction19F(p, α)16O, that the relative intensity is less than 4 × 10−4. This corresponds to α02(1) < 2 × 10−3, a low figure.

ISSN:0031-8086    

DOI:10.1080/14786436008235853

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The 3.68 mev 3/2 - state of13C is shown, by a coincidence technique to cascade via the 3.09 mev 1/2+ state with a probability of (6−5±1.0) × 10−3. The rule that Corresponding E1 transitions in mirror nuclei have the same reduced speed, i.e. are mirror transitions, is used to deduce the speed of this weak branch from data available in13N and hence to determine the radiative width of the M1 transition to ground from the 3.68 mev state. This is (0.40–0.75) ev. The speed of this transition, which is not a mirror transition to the corresponding one in13N, is compared with the prediction of the independent particle model. Agreement is obtained within the range of the intermediate coupling parametera/Kthat satisfies other data in theA =13 system.

ISSN:0031-8086    

DOI:10.1080/14786436008235854

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Thin films of permalloy (81% Ni, 19% Fe) grown by evaporation on rock salt cleavage faces have been studied in the electron microscope. Selected area diffraction patterns indicate the presence of microtwinning on all types of {111} planes. The diffratction pattern are also subject to the effects of multiple diffraction, film deformation, and an' effective aperture' in the optical behaviour of the electron microscape when used for selected area diffraction. Electron micrographs reveal a' film' that consists of discrete particles, three-dimensional in character, with irregular shapes suggestive of hemispheres of various sizes which have coalesced, side by side. The irregular shapes fit together like pieces of a jig-saw puzzle to cover the film area. Twinned components can be identified with dark field illumination. The three-dimensional particles seem to be a consequence of isotropic growth of crystal nuclei that are in epitaxial orientation but distributed at random over the substrate surface. Microtwinning appears to be a relief mechanism for reduction of the strain energies which accumulate at the boundaries between growing crystal nuclei.

ISSN:0031-8086    

DOI:10.1080/14786436008235855

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

An examination is made of the compositions of eutectic points in the metallurgical equilibrium diagrams given in Hansen's text-book onThe Constitution of Binary Alloys. A large number of eutectics occur at almost 0% of the solute element. With increasing atomic percentage of solute, the number of eutectics in a given composition range diminishes rapidly, until a recovery sets in at 8–10 atomic % solute. There are very few eutectics in the equiatomic region, and at intermediate compositions the eutectic composition distribution curves show a series of peaks at intervals of 7–8 atomic %. Stockdale's suggestion that eutectic points occur at whole number ratios of the two kinds of atom is not confirmed, but certain regions of composition are favoured, and these include the atomic ratios of approximately 1:6, 1:3, 1: 2 and 2:3. The reason for this is discussed, and free energy curves are described; some of these lead to liquid immiscibility. and examples of this are discussed.

ISSN:0031-8086    

DOI:10.1080/14786436008235856

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor