К ВОПРОСУ О ФОТОПРОВО ДИМОСТИ ФОТОГРАФИЧЕСКОЙ ЭМУ ЛьСИИ

) . , , , ; , , . . , .     

The formation of dislocations by a spark discharge

The arrangement of dislocations formed in a single crystal of the alloy Fe-4·2% Si by a spark discharge in air is studied. The dislocations are made visible by etching on the surfaces perpendicular and parallel to the axis of the crater. The results of the observations are explained on the basis of microphysical conceptions of plastic deformation.

---

, Fe— 4,2% Si . , . .

     

ОПРЕДЕЛЕНИЕ ПОСТОЯН НЫХ ДВУХПАРАМЕТРОВЫ Х РЕШЕТОК МЕТОДОМ ОТНО ШЕНИЙ

. . - 10^–4.     

РЕАКЦИЯ (γ, р) НА КОБАЛЬ ТЕ

- , Li(, ) ( =17,6. 14,8 MeV). , u . , gQ=0,74+-0,16 MeV ⁵⁸Fe E ^* : 6,76; 6,44; 5,90; 5,47; 4,98; 4,35; 3,50; 3,20 MeV. , .     

The collisions of two plasma streams

The mutual interaction of two colliding plasma streams is investigated by means of the perturbation method. The disordered random motions of electrons are taken into account. It is shown that electron oscillations occur only when certain conditions as to the density and relative velocity of the colliding streams are fulfilled. The order of magnitude of the thickness of the shock generated by the initial relative motion is estimated on various assumptions.

---

. . , , . , , .

     

КРУЧЕНИЕ СТЕРЖНЕЙ С С ЕЧЕНИЕМ ФОРМЫ ПРЯМОУГОЛЬНИКА С ВЫР ЕЗОМ

[1] , 1) . [2].

---

Twisting of notched rectangularly-shaped bars

It was pointed out in paper [1] that special cases of this solution are the problems of the torsion of a notched and unnotched rectangularly-shaped bar. Here, some results obtained earlier are generalized and in one concrete case very good agreement is obtained with the results of Sapondjan [2].

     

СВЯЗЬ МЕЖДУ МЕТОДОМ С ФЕРИЧЕСКИХ ГАРМОНИК И МЕТОДОМ ДИСКРЕТНЫХ КООРДИНАТ

, .

---

On the relation between the method of spherical harmonics and the method of discrete coordinates

The relation between the method of spherical harmonics and the method of discrete coordinates is studied from the point of view of the integral Boltzmann equation for neutron diffusion problems which have full plane and cylindrical symmetry.

     

ГАЛЬВАНОМАГНИТНЫЙ Э ФФЕКТ В ОБЛАСТИ ТЕМПЕРАТУРЫ КЮРИ

. - II- . .     

ВЛИЯНИЕ ПРЕДВАРИТЕЛ ЬНОГО ОСВЕЩЕНИЯ ha ХАРАКТЕРИСТИКИ МЕДН ОЗАКИСНЫХ ВЫПРЯМИТЕ ЛЕЙ

, 150° , . - . -. . ( ).     

ИССЛЕДОВАНИЕ ЭРОЗИЙ НОГО ДЕЙСТВИЯ ИМПУЛЬ СНЯХ ЭЛЕКТРИЧЕСКИХ РАЗРЯ ДОВ С СЛАБЫМ ТОКОМ

50–100 , 1–2 1–10 . - . - . , , - . -.     

On the photo-electroluminescence of ZnS-Cu

The influence of weak ultra-violet irradiation on the brightness waves of electroluminescence is investigated for two types of ZnS-Cuphosphors. The observed effects (increase in brightness in the primary peak and its phase shift, the disappearance of the secondary peak) are explained on the basis of present-day conceptions on electroluminescence.

---

ZnS-Cu

ZnS-Cu. ( , ) .

     

Ferromagnetic resonance in thin cobalt films

The paper gives the results of measuring ferromagnetic resonance on thin cobalt films, vacuum deposited on unheated glass slides. The values of the (g-factor, the width of the curve, the effective stress and uniaxial induced anisotropy were determined as a function of the thickness of the film from measurements of the ferromagnetic absorption in a magnetic field normal and parallel to the surface of the film. Measurements were carried out on a frequency of 9200 MHz and on film thicknesses of 180 to 1800 Å. A qualitative explanation of the observed dependences is given.

---

, . , , g-, , , . 9200 MHz 180–1800 Å. .

---

---

The author thanks V. Kamberský and Z. Málek, C. Sc., for providing some of the cobalt films and for help in depositing and measuring the thicknesses, S. Kadeková and M. Polcarová for valuable advice in determining the structure of the films, J. Míová for carefully plotting the results of measurements and Z. Málek and O. tirand for carefully reading the paper and for valuable discussions.     

An attempt at a phenomenological interpretation of the influence of a polarizing field on piezoelectric resonators

The change in frequency of quartz piezoelectric resonators in a d-c electric polarizing field cannot be explained merely by a change in the dimensions of the resonator due to the polarizing field caused by the inverse piezoelectric effect and electrostriction. We are forced to admit that the elastic constants also change in a polarizing field. A phenomenological interpretation of the influence of a d-c electric polarizing field on the frequency of quartz resonators is proposed here, based on newly introduced quantities characterizing such a change. In conclusion it is shown in what way the quantities, on which the phenomenological theory is based, can be determined experimentally.

---

, . , . , , . , , .

---

---

The author would like to thank Dr. J. Tichý for carefully reading the paper, for valuable discussion and numerous remarks on style and subject matter, which greatly helped to improve the text. He is also indebted to V. Janovec, C. Sc., for some new aspects and the exceptional interest with which he reviewed the paper.     

ПЛОТНОСТЬ ТОКА В КАТО ДНЫХ ПЯТНАХ В КОНДЕНСИРОВАННОМ Р АЗРЯДЕ

- . , .     

ЗАТУХАНИЕ КОЛЕБАНИЙ ЧАСТИЦ В ОБЩЕМ ПОЛЕ С ПЕРИОДИЧЕСКОЙ СТРУКТУРОЙ I

, , . , . .

---

The damping of particle oscillations in a general field with periodic structure I

A liner theory is derived, discussing the dynamics of particles in the region of an equilibrium orbit in a general electromagnetic field, which forms a periodic system. The total particle damping is determined from the Hamiltonian found and from dissipative forces brought out by a classical reaction radiation. Relations for the damping of the synchrotron oscillations are derived from the study of the appropriate phase space.

     

The movement of single 90° domain walls of BaTiO3 in an alternating electric field

Single crystals of BaTiO₃, containing one 90° domain wall, were used to study the origin and character of the movement of such a wall in an alternating electric field having a frequency of 50 c/s. The experimental results are discussed from the phenomenological point of view.

---

90- BaTiO₃

iO₃, 90- , 50 Hz. .

---

---

The authors would like to thank A. Glanc for preparing the crystals for measurement, V. Dvoák, J. Kaczér and V. Janovec for fruitful discussions.     

ПРИГОТОВЛЕНИЕ И ХАРА КТЕР ПОВЕРХНОСТИ ПЛАСТИНОК AgBr

AgBr . , .     

Method of moments in analysis of x-ray diffraction lines

A general relation between the moments of the functionsf,g, andh, in the integral equationh(x)=f(y)g(x–y) dy, is derived. This enables any moment of the unknown functionf to be calculated from the moments of the functionsg andh. In particular, if certain assumptions are fulfilled, the moments of the components of the doublet can be calculated with advantage from the moments of the total profile. The statistical significance of the moment characteristics is also emphasized.

---

f, g, h h(x)=f(y)g(x–) dy, f g h. , . .

     

Change in primary extinction during decomposition of supersaturated solid solution II. Al-Cu 4% alloy-formation of G.P. zones

The change in integrated intensity of the (200) reflections of a solid solution during the formation of G.P. zones was measured and compared with the change in the character of the diffuse streaks corresponding to them. It was found that the. formation of G.P. zones does not lead to a decrease in primary extinction despite the great changes in the distribution of the copper atoms. It was shown that the formation of a precipitate accompanied by the formation of crystallographically incoherent boundaries greatly decreases the primary extinction.

---

. II. 1-u 4%: [. . ]

(200) . . , . , . . , . , , , .

     

Two-barrier detector

The paper describes the principle of a detector with two opposite surface barriers and the experimental verification of its functioning. The detector permits double the effective depth to be attained on the material with a given bias voltage. The principle of opposite barriers also permits a reduction in the system of dE/dx andE detectors to one detector.

---

. . dE/dx E .

---

---

The authors thank A. Irra for carefully preparing the plates, K. Putz and J. imková for very effective help in measuring on the cyclotron and the members of of the cyclotron staff for their cooperation.