572 research outputs found

    Calculation of francium hyperfine anomaly

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    The Dirac-Hartree-Fock plus many-body perturbation theory (DHF+MBPT) method has been used to calculate hyperfine structure constants for Fr. Calculated hyperfine structure anomaly for hydrogen-like ion has been shown to be in good agreement with analytical expressions. It has been shown that the ratio of the anomalies for ss and p1/2p_{1/2} states is weakly dependent on the principal quantum number. Finally, we estimate Bohr--Weisskopf corrections for several Fr isotopes. Our results may be used to improve experimental accuracy for the nuclear gg factors of short-lived isotopes.Comment: 5 pages, 3 tables, 2 figures. arXiv admin note: text overlap with arXiv:1703.1004

    Soliton-antisoliton pair production in particle collisions

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    We propose general semiclassical method for computing the probability of soliton-antisoliton pair production in particle collisions. The method is illustrated by explicit numerical calculations in (1+1)-dimensional scalar field model. We find that the probability of the process is suppressed by an exponentially small factor which is almost constant at high energies.Comment: 4 pages, 3 figures, journal versio

    Use of accelerated helium-3 ions for determining oxygen and carbon impurities in some pure materials

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    Methods are developed for the determination of O impurity in Be and Si carbide and concurrent determination of C and O impurities in Si and W by irradiation with accelerated He-3 ions and subsequent activity measurements of C-11 and F-18 formed from C and O with the aid of a gamma-gamma coincidence spectrometer. Techniques for determining O in Ge and Ga arsenide with radiochemical separation of F-18 are also described

    Magnetic anisotropy in strained manganite films and bicrystal junctions

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    Transport and magnetic properties of LSMO manganite thin films and bicrystal junctions were investigated. Manganite films were epitaxially grown on STO, LAO, NGO and LSAT substrates and their magnetic anisotropy were determined by two techniques of magnetic resonance spectroscopy. Compare with cubic substrates a small (about 0.3 persentage), the anisotropy of the orthorhombic NGO substrate leads to a uniaxial anisotropy of the magnetic properties of the films in the plane of the substrate. Samples with different tilt of crystallographic basal planes of manganite as well as bicrystal junctions with rotation of the crystallographic axes (RB - junction) and with tilting of basal planes (TB - junction) were investigated. It was found that on vicinal NGO substrates the value of magnetic anisotropy could be varied by changing the substrate inclination angle from 0 to 25 degrees. Measurement of magnetic anisotropy of manganite bicrystal junction demonstrated the presence of two ferromagnetically ordered spin subsystems for both types of bicrystal boundaries RB and TB. The magnitude of the magnetoresistance for TB - junctions increased with decreasing temperature and with the misorientation angle even misorientation of easy axes in the parts of junction does not change. Analysis of the voltage dependencies of bicrystal junction conductivity show that the low value of the magnetoresistance for the LSMO bicrystal junctions can be caused by two scattering mechanisms with the spin- flip of spin - polarized carriers due to the strong electron - electron interactions in a disordered layer at the bicrystal boundary at low temperatures and the spin-flip by anti ferromagnetic magnons at high temperatures.Comment: 26 pages, 10 figure

    The Bohr-Weisskopf effect in the potassium isotopes

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    The magnetic hyperfine structure constants have been calculated for low-lying levels in neutral potassium atom taking into account the Bohr--Weisskopf (BW) and Breit--Rosenthal (BR) effects. According to our results the 4p1/24p_{1/2} state of K~I is free from both BR and BW corrections on the level of the current theoretical uncertainties. Using this finding and the measured values of the A(4p1/2)A(4p_{1/2}) constants, we corrected the nuclear magnetic moments for several short-lived potassium isotopes. The BW correction is represented as a product of atomic and nuclear factors. We calculated the atomic factor for the ground state of K I, which allowed us to extract nuclear factors for potassium Iπ=3/2+I^\pi = 3/2^+ isotopes from the experimental data. In this way the application range of the single-particle nuclear model for nuclear-factor calculation in these isotopes has been clarified

    Remote results of pathogenetic therapy of cystic breast disease

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    With 2000 year of pathogenetic treatment of fibrocystic breast disease preventing cystadenocarcinoma has led to positive results. In 2000–2001 years the percentage devoted to oncological indications for surgical treatment of patients with fibrocystic disease of the breast, was less than 3 % of the total number of operated on for various diseases of the breast

    Therapy of pathology secretory disease of the breast

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    Pathogenesis of serous discharge from the nipples of the breast is complex and includes the following components: hormonal imbalance as a backdrop, stimulating increased secretion in the ducts of serous content, resorption of the liquid component of a secret, resulting in local pathological effects of protein resorption, hormone content, autoimmune reactions ductless with subsequent development of proliferative processes in them. Under adverse conditions, infection occurs from an external or internal source of microorganisms. The presence of fluid in the ducts, mammary system ductal communication with the external environment, is an “open gate” for content ductal infection of the mammary glands. This creates the prerequisites for the development of proliferative processes in the first phase of the inflammatory origin. Application of 194 women with serous secretions from the nipples of the breast combined combinations of enzymes, glucocorticoids, progestogens, gonadoliberins and other agonists, suppress the proliferation of drugs that helped to put an end to abnormal secretion and prevent changes in the walls of the ducts and periductal breast tissue at different stages of disease
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