Showing papers by "Academy of Sciences of the Czech Republic published in 1969"
TL;DR: In this article, the generalized splittings of dislocations are discussed in detail for {111} planes in f.c.c., and for {110} as well as {112] planes in b.c.c.
Abstract: The concept of splitting of dislocations in generalized by the assumption that generalized intrinsic stacking faults, i.e. faults which are unstable as infinite planar defects, can occur in the dissociation of dislocations. The Burgers vectors of the partials are then not defined on the basis of the geometry of the lattice only, but are determined by the dependence of the energy of the generalized stacking fault on the displacement vector f, i.e. by the γ surface (Vitek 1968). The generalized splittings are discussed in detail for {111} planes in f.c.c. crystals and for {110} as well as {112} planes in b.c.c. crystals.
52 citations
46 citations
TL;DR: In this paper, the authors summarized observations of solar and space phenomena related to the McMath region Number 8461 which passed over the solar disk during the 1966 Proton Flare Project period and produced two important solar particle events on August 28 and September 2.
Abstract: The paper summarizes observations of solar and space phenomena related to the McMath region Number 8461 which passed over the solar disk during the 1966 Proton Flare Project period, from August 21 to September 4, and produced two important solar particle events on August 28 and September 2. The most important results are reviewed and interpretation of some of them is suggested. Items of particular interest: Occurrence of proton-active regions when two or more ‘rows’ of activity approach each other (Section 3). Possible stimulation of activity by magnetic fields of decaying regions that had been active before (4.2a, 5.1a). Significantly increased correlation of flares with X-ray bursts during the proton-active transit of the region (5.3b). Striking difference in the flare response in radio frequency range before and after August 26 (5.2b). Hardening of the X-rays (5.3a), increase in radio flux (5.2a), change in sunspot configuration (5.1c), and increased capability of the region for particle acceleration (5.1b, 5.2b), starting about three days prior to the proton flare. Clear evidence that some flares that occurred on or after August 26, but prior to the proton flare of August 28, already were sources of ≈ 1 MeV protons (5.2b, 8). Anomalous deficiency in metric component of radio bursts produced in the region (5.2c, 9.4d, 11.4b). Strong radio storm on meter waves immediately preceding the proton flare on August 28 (5.2a, 9.1b), coincident with preflare rising dark filament (9.1a) and slight preflare rise in flux of ≈ 1 MeV protons (10.2). Two phases of expansion (fast and slow) of the bright flare ribbons (9.2c). Coincidence of hard X-ray burst with the formation and fast separation of the bright flare ribbons. It is suggested that this is the time of particle acceleration in the flare (9.5b). Short-lived burst of UV radiation (9.6). Visible flare wave in the flare of August 28 (9.3b), and complexity of motions in this flare (9.4b). Suggested electron release by means of a blast wave (10.1a). Electron-proton splitting in the delayed shock-wave-associated maximum of the particle flux on August 29 (10.2c). First brightening of both proton flares in a similar position between the regions 8461 and 8459 (11.2c). Existence of a unique, low elevation coronal condensation three days after proton flare occurrences (7.2). Very strong flux of protons in energy range of the order of 100 MeV producing the largest PCA since July 1961, and unusually steep energy spectrum above 100 MeV in the flare of September 2 (12.2a, b, 12.4). Unusually long rise to the maximum flux, inconsistent with Burlaga's theory of anisotropic diffusion (12.2b). Interpretation of the undisturbed flux decay from September 2 to September 8 (12.2c). A corotating modulation phenomenon on September 8 (12.2d). Detection of medium nuclei, with He/M ratio 50 ± 11 (12.3a). Evidence against a purely velocity-dependent mode of particle propagation (12.3b). Electrons as the possible cause of the first PCA phase (12.4). Plasma disturbance due to permanent proton flux from the region (13.1). Electron injection into inner radiation belt during the geomagnetic storm associated with the September 2 flare (13.3). Section 14 brings a time scheme of the most important phenomena associated with the complex of activity and the active region in question, and some unsolved problems of particular interest are pointed out in Section 15.
41 citations
TL;DR: This report describes the activity of compounds with the farnesane carbon skeleton but differing in the number of double bonds and the presence of halogen atom(s) or oxirane ring(S) in the molecule.
31 citations
TL;DR: The results achieved by the cultivation of the yeast on gas oil were referred in this article, where the optimal condition for biomass production and deparaffination was estimated for various dilution rates and various amounts of gas oil in the medium.
Abstract: The results achieved by the cultivation of the yeast. Candida lipolytica on gas oil are referred. By using a distillation fraction of gas oil distilling between 180–400°C, containing 10–20% of n-alkanes, the optimal condition for biomass production and deparaffination were estimated for various dilution rates and various amounts of gas oil in the medium. The main factor, which influences the yield coefficient by hydrocarbon fermentation is the polyauxie of the hydrocarbon substrate. The penetration of dispersed hydrocarbons into the yeast cell is demonstrated on electron micrographs and the velocity and reversibility of this process is estimated by using tritium-traced hexadecane.
30 citations
TL;DR: In this paper, the temperature dependence of electrical resistivity, Seebeck coefficient, and the saturation magnetization were performed on polycrystals Cu 0.5 Fe 2.5 O 4+γ.
Abstract: The measurements of the temperature dependence of electrical resistivity, Seebeck coefficient, and the saturation magnetization were performed on polycrystals Cu 0.5 Fe 2.5 O 4+γ With all samples the anomalous behavior above 400°C was observed which manifested itself by a sudden increase of electrical resistivity, by the change from n- to p- type of electrical conductivity, and by the irreversible course of the magnetization. Contrary to physical properties, the chemical analysis revealed no significant changes in the composition of ferrites during the transformation. Taking into account the electrical, magnetic, and X-ray investigation it was concluded that in quenched samples (Cu1++ Fe3+) and Cu2++ Fe2+) pairs are more stable in the tetrahedral and the octahedral sites of the spinel lattice, respectively. After the transformation only Cu1+and Fe3+are present in the ferrites which initiates their decomposition into haematite and delafossite.
28 citations
TL;DR: The time course of innervation by nerve implants of the fast contracting flexor digitorum longus and the slow contracting soleus muscles were studied by the recorcling of isometric twitch tensions in response to stimulation of the implanted nerve and by histochemical visualization of newly-formed end-plates.
Abstract: The time course of innervation by nerve implants of the fast contracting flexor digitorum longus and the slow contracting soleus muscles were studied by the recorcling of isometric twitch tensions in response to stimulation of the implanted nerve and by histochemical visualization of newly-formed end-plates. When a foreign motor nerve was implanted into a muscle 30 days prior to sectioning of the original nerve supply, synaptic contacts were established 4–8 days after the section of the nerve, while, with simultaneous implantation and denervation, 16 days were required for the implanted nerve to innervate the muscle. Implantation of the nerve which normally innervates the flexor digitorum longus muscle into the soleus altered the contraction and relaxation speeds of the soleus muscle towards those of a fast contracting muscle, the change being apparent as soon as 4–8 days following sectioning of the original nerve. In muscles with nerve implants and intact normal innervation hypertrophy occurred, amounting to 20–30 per cent within one month.
27 citations
TL;DR: An infusion method for determing the rate constant of drug elimination from the receptor compartment has been developed and compared with methods using single doses and gives results with a lower scatter for the antidiuretic effects of the neurohypophysial hormones and their structural analogues.
24 citations
TL;DR: Four radioactive peptides were isolated from a partial acid hydrolysate of the slightly soluble portion of the tryptic digest and provides evidence of the amino acid sequence Gly-Thr-Ser-Met-Ala around the reactive serine residue of alkaline proteinase.
21 citations
TL;DR: This study isolates from trypsin in parallel experiments all peptides containing tyrosine, both nitrated and unmodified, in order to obtain information on all the ten residues present in the molecule.
20 citations
Book•
01 Jan 1969TL;DR: In this paper, an analysis of the main factors of economic growth, of major growth barriers, and of the interrelation between the factors of growth under specific, though not entirely specific conditions of Czechoslovakia forms the subject matter of this paper, in addition to an investigation of the relations between the strategic parameters of the growth model and the model of functioning of a socialist economy.
Abstract: An analysis of the main factors of economic growth, of major growth barriers, and of the interrelation between the factors of growth (under the specific, though not entirely specific conditions of Czechoslovakia forms the subject matter of this paper, in addition to an investigation of the interdependence between the strategic parameters of the growth model on the one hand and the model of functioning of a socialist economy on the other) It is the intention of its authors that the publication should become part of those contemporary currents of thought which endeavour more fully to understand the reality of socialist construction, using the toolbox of up-to date economic research methods, e An attempt is made to employ the model of economic growth, applied to statistical data, as a criterion of efficiency, under changing conditions, of the traditional system of economic planning and control. It is hoped that this attempt jointly with the efforts of other Czechoslovak economists, will contribute to the determination of the optimum trajectory of transition from economic conditions, prevailing in 1961-1964, onto the time path of balanced economic growth. There are several reasons why not too much hope should be pinned to the expected results and conclusions of our investigation. One of our
TL;DR: In this paper, the temperature dependence of the phonon structure of Mn4+ activator centers in AlN was investigated, and the intensity of individual peaks obtained by graphical decomposition of the emission maxima is in agreement with theory for all measured temperatures.
Abstract: The temperature dependence of the phonon structure of Mn4+ activator centres in AlN was investigated. The spacing of the observed equidistant peaks is −160 cm−1; phonons of this wave number, however, were not found in the lattice vibration spectra. Pseudo-local vibrations are, therefore, presumed to be involved. The intensity of individual peaks obtained by graphical decomposition of the emission maxima is in agreement with theory for all measured temperatures.
TL;DR: This part of the more extensive study on cathepsins was aimed at the isolation of homogeneousCathepsin B and at the determination of the specificity of cleavage of a polypeptide substrate, the B-chain of oxidized insulin, by this enzyme.
TL;DR: In this article, the macroscopic slip plane in solids with undissociated dislocations is determined as the average plane of motion of screw dislocation, assuming that their motion is controlled by thermally activated overcoming of the Peierls potential into different crystallographic planes.
Abstract: The macroscopic slip plane in solids with undissociated dislocations is determined as the average plane of motion of screw dislocations. It is assumed that their motion is controlled by thermally activated overcoming of the Peierls potential into different crystallographic planes. The screw dislocations have a unit motion or jump of one atomic distance and they are free to jump into a number of different positions. Under these circumstances cross slip jumps are frequent and the macroscopic slip plane for a given applied stress is determined by the Peierls potential in the different planes of cross slip. The geometry of slip in b.c.c. metals is discussed in some detail and it is shown that experimental results can be described formally using this approach.
TL;DR: In this article, the theory of elasticity was used to estimate the magnetostrictive deformation at a 180° Bloch wall inside a ferromagnet, which is locally perturbed at the intersection with the surface.
Abstract: While the magnetostrictive deformation at a 180° Bloch wall inside a ferromagnet is homogeneous it is locally perturbed at the intersection with the surface. This perturbation is estimated using the methods of the theory of elasticity.
TL;DR: In this article, an X-ray diffraction image of ferroelectric domain walls in BaTiO3 was studied by Lang's technique, and the visibility of the walls follows, in principle, the same rule that was found to be valid for the viscoelastic domain walls of Fe-Si.
Abstract: An X-ray diffraction image of ferroelectric domain walls in BaTiO3 was studied by Lang's technique. The visibility of the walls follows, in principle, the same rule that was found to be valid for the visibility of ferromagnetic domain walls in Fe-Si. The type of contrast is, however, strongly affected by the relatively large c/a ratio.
TL;DR: Results indicate that the formation of an extracellular proteinase is stimulated by amino acids in one sporogenous strain of Bacillus megaterium KM and the stimulatory effect can be manifested in the absence of glucose only.
TL;DR: In this paper, the origin of hydroxyl in the lattice of barium titanate is described and the defect structure of the sample after prolonged annealing in hydrogen is discussed.
Abstract: The origin of hydroxyl in the lattice of barium titanate as a consequence of the reaction of hydrogen with oxygen ions in the lattice is described. A band at the wave number 1770 cm−1 was assigned to this hydroxyl in the infra-red spectrum. The samples were annealed in a stream of hydrogen and in sealed ampoules containing hydrogen or deuterium at temperatures above 900°C, and at 50 to 500° C when hydrogen plasma was used. The defect structure of the sample after prolonged annealing in hydrogen is discussed.
TL;DR: In this article, the optimum conditions for the preparation of non wedge-shaped KDP and DKDP crystals have been studied and the effect of pH of the crystallisation solution, cation admixtures and speed of agitation on the quality of crystals is presented.
Abstract: Optimum conditions for the preparation of non wedge-shaped KDP and DKDP crystals have been studied. The effect of pH of the crystallisation solution, cation admixtures and speed of agitation on the quality of crystals is presented. The working procedures for the preparation of non wedge-shaped crystals of both species are given.
Es wurde versucht, die optimalen Bedingungen fur das Wachstum nicht keilformiger KDP- und DKDP-Kristalle zu ermitteln. Die Einflusse von Fremdionen, des PH-Wertes der Losungen und der Einflus des Ruhrens auf die Qualitat der Kristalle wurden untersucht. Es werden Arbeitsvorschriften zur Praparation nicht keilformiger KDP- und DKDP-Kristalle angegeben.
TL;DR: In this article, the ultraviolet and red thermoluminescence of manganese-activated aluminium nitride in the temperature range from 100 °K to 700 °K is described.
Abstract: The ultraviolet (u.v.) and red thermoluminescence of manganese-activated aluminium nitride in the temperature range from 100 °K to 700 °K is described. We found more than 12 trap levels, and determined the activation energy for six of them. Some trap levels presumably give the u.v. and others the red luminescence. This is probably due to the fact that some traps are localized in the vicinity of the luminescent centres and the diffusion length of the released carriers is small.
TL;DR: In this paper, a systematic treatment of modifications to the usual form of dispersion relations and sum rules is given, based on the fact that if a function g(z) has analyticity properties analogous to those of a scattering amplitudef (z), the usual dispersion relation for the productf (z)g(z), holds.
Abstract: A systematic treatment of modifications to the usual form of dispersion relations and sum rules is given. The treatment is based on the fact that if a function g(z) has analyticity properties analogous to those of a scattering amplitudef (z), the usual dispersion relation for the productf (z)g(z) holds. After having described the general form of the “weight function” g(z) we concentrate on cases wheng(z) is large in a pre-chosen region and small elsewhere. Weight functions of this type are useful in practical applications where a weight functiong(z) may enhance a contribution of regions where accurate data are available and suppress those of regions with inaccurate or lacking data.
TL;DR: In this article, the authors describe the plastic deformation of a single crystal at room temperature and at −78°C (strain rate = 5·5.10−5 sec−1) by a dynamical yield point followed by a strong workhardening.
Abstract: The stress-strain curves of iron single crystals at room temperature and at −78°C (strain rate\(\dot s\)=5·5.10−5 sec−1) are characterized by a dynamical yield point followed by a strong work-hardening. The plastic deformation starts by the movement ofa/2〈111〉 dislocations from several places of the specimen. Macroscopically, the dislocations move approximately along the planes with maximum resolved shear stress. Slip bands are formed by multiplication of the moving dislocations. They broaden and fill the whole specimen at a strain smaller than 0·1% or 0·2% for the deformation at room temperature and −78°C respectively. The corresponding dislocation densities are <4.106 cm−2 and ≃2.107 cm−2 respectively. At these strains a strong work-hardening begins. The mosaic structure causes an increase of the yield stress and of the difference between the upper and lower yield stress. Differences between iron and iron-3% Si alloy single crystals at the beginning of the plastic deformation have only a quantitative character and can be explained by the fact that the lattice friction stress in iron is approximately 15 times smaller than in iron-3% Si alloy.
TL;DR: In this paper, the overlap and Coulomb integrals with Slater-type orbitals in complexes with rare-earth or transition-metal central ions were computed. But the complexity of computing the overlap was not addressed.
Abstract: Tables are given to enable effective algorithms to be formed for computer calculation of the overlap and Coulomb integrals with Slater-type orbitals in complexes with rare-earth or transition-metal central ions
TL;DR: In this paper, the spin arrangement of the Ni-I boracite is discussed from a microphysical point of view, and the rotation of the spontaneous magnetization by 90° with reversal of spontaneous polarization is explained.
Abstract: Possible spin arrangements of the ferromagnetoelectric Ni-I boracite are discussed from a microphysical point of view. Rotation of the spontaneous magnetization by 90° with reversal of the spontaneous polarization is explained.
TL;DR: Calculations of activation energies suggest that there is an enzymatic system which maintains Ca in the cell membrane which is apparently activated by oestrogen, since in tissue from castrated animals there was no biphasic temperature effect on the reactivity decline rate.