Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "angular distribution" wg kryterium: Wszystkie pola


Wyświetlanie 1-12 z 12
Tytuł:
Angular Distribution of Photoemission from Surfaces of Amorphous Solids
Autorzy:
Jabłoński, A.
Powiązania:
https://bibliotekanauki.pl/articles/1931731.pdf
Data publikacji:
1994-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.80.Bm
72.10.-d
79.60.-i
Opis:
As follows from the formalism of X-ray photoelectron spectroscopy, knowledge of the angular distribution of photoemission is crucial for certain applications of quantitative X-ray photoelectron spectroscopy analysis. In the present work, the experimental data on the relative angular distribution of photoemission from solid materials are reviewed and compared with theoretical predictions. Noticeable discrepancies are usually observed. It has been proved that major part of the observed discrepancies can be ascribed to elastic photoelectron scattering. The commonly used formalism, where the elastic collisions are neglected, may be of insufficient reliability for certain solids, or in certain experimental geometries. This formalism can be easily extended to account for elastic photoelectron collisions by introducing two correction factors, Q$\text{}_{X}$ and β$\text{}_{eff}$. The second parameter, called the effective asymmetry parameter, describes the observed decrease in anisotropy of photoemission. Determination of the correction factors requires a reliable theory describing elastic electron scattering in the solid. A need arises for accurate differential and total elastic electron scattering cross-sections pertinent to kinetic energies of considered photoelectrons or the Auger electrons. The increasingly important role of electron transport in surface analysis has stimulated an effort to construct a complete database containing the differential and total atomic elastic scattering cross-sections.
Źródło:
Acta Physica Polonica A; 1994, 86, 5; 787-798
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Angular Distribution of Bremsstrahlung Photons in Ta Target for 40 MeV Electron Beam
Autorzy:
Demir, N.
Kuluöztürk, Z.
Akkurt, İ.
Powiązania:
https://bibliotekanauki.pl/articles/1402503.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Jj
23.20.En
Opis:
Bremsstrahlung photons are created by electron beams de-accelerating in electric field (coupling with a thin radiator) and are used in a variety of different fields. In nuclear physics experiments it is important to transport and focus the created photon beam into the experimental cavity. Here angular distribution of the photon beam is one of the important parameters, which should be known. In this study a FLUKA simulation has been done to obtain angular distribution of photon beam created by interaction of 40 MeV electron beam with the tantalum (Ta) radiator of varied thickness, which is planned to be used in bremsstrahlung photon facility at TARLA (Turkish Accelerator and Radiation Laboratory in Ankara). TARLA will be the first facility of Turkish Accelerator Center project.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-443-B-444
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary determination of angular distribution of neutrons emitted from PF-1000 facility by indium activation
Autorzy:
Jednoróg, S.
Szydłowski, A.
Scholz, M.
Paduch, M.
Bienkowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/146918.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
neutron activation technique
plasma diagnostics
Opis:
This paper presents a new method applied to measure the angular neutron emission from Plasma Focus (PF) - type deuterium discharges performed within the PF-1000 facility. Neutrons were recorded by activation of especially optimized (mass and shape) indium samples with subsequent gamma spectrometry to measure the induced activity of the samples. The neutron fluence rate on every indium sample used was determined using neutron transport calculation and measured activity of the samples.
Źródło:
Nukleonika; 2012, 57, 4; 563-568
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model angular distribution functions in CA3, CA4 and CA6 structural units of glassy systems
Autorzy:
Bergmański, G.
Feliziani, S.
Rybicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1933172.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska
Tematy:
structure of matter
disordered systems
short-range order
stochastic geometry
Opis:
We have calculated model partial angular distribution functions (pADFs) in CA3, CA4 and CA6 structural units, i. e. an equilateral triangle with three vertical anions, A, and a central cation, C, a regular tetrahedron with four vertical anions, A, and a central cation, C and a square bipyramid with six vertical anions, A, and a central cation, C. The model pADFs were calculated employing a simple Monte Carlo procedure: the ions were being shifted at random within 3D spheres of radius r with uniform probability density and the AAA, ACA and CAA angles were calculated for each random configuration. Repeating the calculation 10(8) - 10(9) times produced smooth probability densities for the angles' values. Conventional reference data so obtained can be applied to estimate the overall degree of deformation of the considered structural units in numerically simulated materials.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 3; 185-195
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Angular Distribution of N-Doped Carbon Nanotubes in Alumina Membrane Channels: A High-Energy X-ray Diffraction Study
Autorzy:
Hawelek, L.
Brodka, A.
Dore, J.
Honkimäki, V.
Kyotani, T.
Yang, Q.
Burian, A.
Powiązania:
https://bibliotekanauki.pl/articles/1538877.pdf
Data publikacji:
2010-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
61.48.De
Opis:
An alignment study of multi-wall N-doped carbon nanotubes prepared by a template pyrolytic carbon deposition method inside channels of an alumina membrane has been performed using high-energy X-ray diffraction on the ID15B beamline at the European Synchrotron Radiation Facility (ESRF, Grenoble). The two-dimensional diffraction pattern of the deposited carbon nanotubes, recorded directly, within the alumina membrane, using an image plate detector, exhibits two non-continuous arcs corresponding to the 002 graphitic reflection. The following values of the angle between the axis of the carbon nanotubes lying along the membrane channels and the incident beam were taken for five positions: 0°, 30°, 45°, 60° and 90°. The anisotropic scattering distribution of the two-dimensional patterns indicates an orientational alignment of the nanotubes. The one-dimensional intensity patterns obtained by scanning around the circumference of the (0 0 2) ring have allowed an estimation of the angular distribution of the nanotubes axes.
Źródło:
Acta Physica Polonica A; 2010, 117, 2; 302-306
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo study of medium-energy electron penetration in aluminium and silver
Autorzy:
Aydın, A.
Peker, A.
Powiązania:
https://bibliotekanauki.pl/articles/146550.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
angular distribution
electron
energy spectra
penetration
transmission
Opis:
Monte Carlo simulations are very useful for many physical processes. The transport of particles was simulated by Monte Carlo calculating the basic parameters such as probabilities of transmitted–reflected and angular-energy distributions after interaction with matter. Monte Carlo simulations of electron scattering based on the single scattering model were presented in the medium-energy region for aluminium and silver matters. Two basic equations are required the elastic scattering cross section and the energy loss. The Rutherford equation for the different screening parameters is investigated. This scattering model is accurate in the energy range from a few keV up to about 0.50 MeV. The reliability of the simulation method is analysed by comparing experimental data from transmission measurements.
Źródło:
Nukleonika; 2015, 60, 2; 361-366
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo calculations of low energy positrons in silicon
Autorzy:
Aydin, A.
Powiązania:
https://bibliotekanauki.pl/articles/148795.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Monte Carlo method
positron transmission
backscattering
angular distribution
energy distribution
Opis:
Theoretical data for positron scattering from a thin silicon film and semi-infinite silicon are presented as a function of incident and outgoing angles and energies. These theoretical data of the scattering processes of low energy positrons penetrating into silicon were performed by Monte Carlo simulation. The simulation is based on the use of different types of differential cross sections for individual elastic and inelastic scattering i) inelastic scattering; Gryzinski's excitation function to simulate the energy loss and Liljequist's model to calculate the inelastic scattering cross section, ii) elastic scattering; the screened Rutherford differential cross section with the spin-relativistic factor. In calculations on positron traversing matter, it is important to know the transmission through medium, their path lengths, and their energy and angular distribution through matter. The simulation results are well agreed with experiments.
Źródło:
Nukleonika; 2005, 50, 1; 37-42
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revisiting the role of oceanic phase function in remote sensing reflectance
Autorzy:
Freda, W.
Piskozub, J.
Powiązania:
https://bibliotekanauki.pl/articles/48003.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine optics
remote sensing
scattering
backscattering
volume scattering function
angular variation
scattering light intensity
inherent optical property
sea surface
solar radiation
angular distribution
Opis:
The effect of angular structure differences between measured and best-fit analytical phase functions of the equivalent backscattering ratio on calculated reflectance values was studied and shown to be significant. We used a Monte Carlo radiative transfer code to check the effect of choosing different analytical (several Fournier- Forand (1994) and Henyey-Greenstein (1941)) phase functions with backscattering ratios identical to the ‘classical’ average Petzold function. We show that the additional variability of the resulting water leaving radiance is about 7% (4% between the Fournier-Forand functions themselves) for most scenarios. We also show a previously unknown maximum of the discrepancy (up to 10%) for highly scattering waters. We discuss the importance of relative differences in phase function for different angular ranges to this maximum and to the behaviour of the discrepancy as a function of solar zenith angle.
Źródło:
Oceanologia; 2012, 54, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rozkład sił i ich wpływ na prawidłową pracę kulkowych łożysk skośnych
Distribution of forces and their impact on the proper work of angular contact ball bearings
Autorzy:
Turek, P.
Piórkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/134798.pdf
Data publikacji:
2017
Wydawca:
ADVSEO
Tematy:
preload of angular contact bearings
machine tool spindles
Opis:
The paper presents the dependence that exists between the bearing preload, and its maximum speed. It discusses the distribution of forces within the bearing and behavior of the rolling element (ball) with increasing spindle speed. The definitions of slow and fast speed bearings commonly used in the literature are presented. It explained the need for systems with variable preload of angular contact ball bearings especially in systems operating over a wide speed range. Further we described the influence of preload on the bearing life and the influence of centrifugal force on the rigidity and accuracy of the spindle.
Źródło:
Technical Issues; 2017, 2; 35-41
2392-3954
Pojawia się w:
Technical Issues
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Channel cross-section influence on effective strain distribution in ECAP process
Wpływ przekroju kanału kątowego na rozkład intensywności odkształcenia w procesie ECAP
Autorzy:
Chyła, P.
Bednarek, S.
Łukaszek-Sołek, A.
Powiązania:
https://bibliotekanauki.pl/articles/263794.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
effective strain
homogeneity of strain
equal-channel angular pressing
intensywność odkształcenia
jednorodność odkształcenia
przeciskanie przez kanał kątowy
Opis:
This study compares the numerically determined strain distributions after the application of the method of equal-channel angular pressing. The calculations were performed for four variants of the channel cross-sectional shapes – square, circular, and two rectangular ones with the same transverse surface area. The calculation results have been demonstrated as maps of effective strain distribution in the stabilized process.
W pracy porównano wyznaczone numerycznie rozkłady odkształceń po zastosowaniu procesu przeciskania przez kanał kątowy. Obliczenia wykonano dla czterech wariantów przekroju kanału – kwadratowego, kołowego i dwóch prostokątnych, o takim samym polu powierzchni poprzecznej. Wyniki obliczeń przedstawiono w postaci map rozkładu intensywności odkształcenia w procesie ustalonym.
Źródło:
Metallurgy and Foundry Engineering; 2017, 43, 1; 31-40
1230-2325
2300-8377
Pojawia się w:
Metallurgy and Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grain refinement, microhardness distribution, strain hardening behaviour and mechanical proprieties of RD-ECAPed AA 1050
Autorzy:
Halimi, A.
Hemmouche, L.
Chettah, I. E.
Louchene, Z. A.
Powiązania:
https://bibliotekanauki.pl/articles/38697115.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
aluminium alloys
Rotary Die Equal Channel Angular Pressing
microstructure
longitudinal microhardness
compression test
Opis:
This study aims to investigate the evolution of mechanical and microstructural characteristics of the 1050 aluminium alloy processed by Rotary Die Equal Channel Angular Pressing (RD-ECAP). The RD-ECAPed specimens were analysed after each pass using optical microscopy, quasi-static compression test and microhardness measurements. The results revealed a reduction in grain size from 29 _m before the RD-ECAP process to a minimum value of 2 _m at the second pass, corresponding to the maximum value of compressive yield strength, reaching 184MPa. Furthermore, there was an increase in hardness from 30 Hv to 63 Hv with a homogeneous distribution along the longitudinal surface, especially in the initial four RD-ECAP passes. Additionally, the appearance of a 45_ shear plane was observed at the last fifth pass, coinciding with the region of maximum microhardness.
Źródło:
Archives of Mechanics; 2023, 75, 6; 647-672
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies