摘要:

On a étudié la canalisation des fragments de fission dans les métaux, en particulier dans le platine et le tungstène. On montre que cette canalisation est très importante, et que les conditions de canalisation pour les fragments de fission sont plus strictes que pour les particules plus légères, comme les particules α. La bonne définition des images obtenues par “canaligraphie” permet de penser que cette technique sera trés utile pour I'étude des défauts cristallins dans les métaux.

ISSN:0033-7579    

DOI:10.1080/00337576908234450

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The yields of hydrogen, cyclohexene, and bicyclohexyl are lower in gamma irradiated solutions of duroquinone in cyclohexane than they are in cyclohexane alone; duroquinone is consumed during the radiolysis. Product yields are functions of the duroquinone concentration; values at 75 mM duroquinone are: G(H2= 3.50; G(C6H10) = 0.70; G((C6H11)2) = 0.21; G(-DQ) = 7. The product from the quinone is shown to be probabIy a quinone containing a substituted cyclohexyl group. Duroquinone solutions in cyclohexane are photochemically inert, and duroquinone is not consumed in irradiated benzene solution. The reduction of hydrogen yield by duroquinone is attributed to electron scavenging; the reduction of cyclohexene and bicyclohexyl yields and the consumption of duroquinone is attributed to scavenging of cyclohexyl radicals (by hydrogen abstraction from the duroquinone methyl groups). The yield of cyclohexyl radicals in duroquinone-quenched solution is thus found to be 5.5–6.8, and their origin is attributed to the reactions of “hot” (unscavengable) hydrogen atoms.

ISSN:0033-7579    

DOI:10.1080/00337576908234451

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Effects of fast neutrons on the electrical conductivity and thermoelectric power of Cr2O3+xhave been studied. It is shown that both the conductivity and thermoelectric power are reduced after an irradiation of about 1017nvt. This observation is explained in terms of a hole concentration and mobility reduction and by an electron concentration increase. The effect depends on an oxygen excess.

ISSN:0033-7579    

DOI:10.1080/00337576908234452

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

It is shown that the solution of the integral equation governing production of Frenkel pairs in random collision cascades is essentially linear at large energies within the elastic collision region, for a rather general class of scattering cross sections. A standard value for the proportionality constant is suggested, and some implications are discussed.

ISSN:0033-7579    

DOI:10.1080/00337576908234453

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Tris-acetate buffer (0.14 M, pH7), alone or containing Shigella flexneri in suspension, was irradiated with 250 kVp X-rays or 7 MeV electrons in closed vessels or in vessels bubbled with gas containing oxygen. The removal of dissolved oxygen by the radiation was followed with a polarographic electrode.

ISSN:0033-7579    

DOI:10.1080/00337576908234454

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

We have studied the irradiation-produced resistivity recovery of 99.9999% pure annealed and prequenched aluminum foils. The prequenched specimen exhibited two distinct recovery peaks, at 245 °K and 320 °K (Stage IV), whereas the unquenched specimen exhibited only one peak at 255 °K (Stage III). The average activation energy of the Stage III recovery, analyzed by the Meechan-Brinkman method, was found to be 0.58 eV. The order of reaction kinetics was found to be a function of the recovery. The implications of these results on existing recovery models are discussed.

ISSN:0033-7579    

DOI:10.1080/00337576908234455

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

When energetic ions are implanted in Si-crystals an anodization-peeling technique can be used as a precise tool for the determination of the ion concentration profiles, when proper precautions are taken.

ISSN:0033-7579    

DOI:10.1080/00337576908234456

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Infrared absorption measurements were made before and after 90 °K electron irradiations of silicon samples which contained either dispersed oxygen, carbon, or carbon plus oxygen. Irradiation-produced absorption bands associated with two distinctly different defects are observed depending on the oxygen and carbon content of the silicon. One center is the well-known vacancy-oxygen A-center defect (836-cm−1band) and is formed on irradiation in oxygen-containing silicon with a magnitude which is independent of the carbon content. Measurements have correlated the formation of one A-center with the loss of one interstitial oxygen atom, thereby indicating that A-center formation occurs by vacancy trapping at interstitial oxygen atoms. A second center (922-and 932-cm−1bands) is formed only in silicon crystals which containbothoxygen and carbon. The results indicate that this center is formed by the trapping of a silicon interstitial at a carbon-oxygen complex.

ISSN:0033-7579    

DOI:10.1080/00337576908234457

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

A classical mechanical computer simulation of the emission of low energy protons from a single crystal surface of potassium chloride is described. Comparison of the results is made with experimental observations obtained in reflection and transmission at 30 keV. It is concluded that classical mechanics adequately explains the observed features down to energies as low as 5 keV, in keeping with a “correspondence principle” previously outlined. Brief discussion is made of the usefulness of the back scattering technique.

ISSN:0033-7579    

DOI:10.1080/00337576908234458

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Migration energies of vacancies in aluminium and lithium have been calculated using an interatomic potential determined by an OPW pseudopotential method. This differs from potentials of the Born-Mayer and Morse types in that it is an oscillating potential, taking into account directly the ion-electron-ion interactions and stability of the crystal. The method of calculation is that of computer simulation of a section of lattice containing the vacancy in different stages of its migration, convergence and kinetic disturbance propagation criteria determining the volume of lattice permitted to relax around the defect. The effect of the oscillating potential is described and the results are reviewed In the light of its relative accuracy in the two metals chosen.

ISSN:0033-7579    

DOI:10.1080/00337576908234459

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor