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Wyszukujesz frazę "electron scattering" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
Secondary electron interactions in materials with environmental and radiological interest
Autorzy:
García, G.
Blanco, F.
de Pablos, J.
Pérez, J.
Williart, A.
Powiązania:
https://bibliotekanauki.pl/articles/148529.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron scattering
energy deposition
Opis:
Important environmental and radiological applications require energy deposition models including the interactions between the secondary electrons and the atoms or molecules of the medium. In this work we propose a method to obtain reliable cross-section data to be used in these models by combining total and ionisation cross-section measurements with simple calculations of the differential and integral elastic cross sections. The energy loss spectra obtained in this experiment have been also used to derive the stopping power of the considered materials for electrons. Some examples of results for atomic (Xe) and molecular (CF4) targets are presented and discussed in this paper.
Źródło:
Nukleonika; 2003, 48, 2; 103-107
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resonance contributions to low-energy electron collisions with molecular hydrogen
Autorzy:
Horácek, J.
Cížek, M.
Houfek, K.
Kolorenc, P.
Pichl, L.
Powiązania:
https://bibliotekanauki.pl/articles/148461.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron scattering
molecules
attachment
vibrational excitation
Opis:
Calculations of electron dissociative attachment and vibrational excitation of molecular hydrogen by low-energy electrons based on an improved nonlocal resonance model are reported. The role of the rotational excitation of the target molecules is discussed.
Źródło:
Nukleonika; 2003, 48, 2; 109-112
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron elastic collisions with C3F6 molecule
Autorzy:
Możejko, P.
Szmytkowski, Cz.
Powiązania:
https://bibliotekanauki.pl/articles/1954668.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
electron scattering
elastic cross section
hexafluoropropene
independent atom method
Opis:
We report calculations of differential and integral cross sections for intermediate- and high-energy (50-1000eV) elastic collisions of electrons with hexafluoropropene (C3F6) molecules. The calculations have been carried out using the independent atom model with static-polarization model potential. The present results are compared with elastic cross sections estimated from total and ionization experiments. Agreement between present calculations and the "experiment" is good for energies above 70eV.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 2; 171-178
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron-argon scattering: a high angle minimum in differential cross sections
Autorzy:
Konopińska, V.
Telega, S.
Sienkiewicz, J. E.
Powiązania:
https://bibliotekanauki.pl/articles/1964089.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
scattering
atomic physics
relativistic theory
electron-Ar scattering
Opis:
Ab initio relativistic calculations of the high angle differential cross section minimum have been presented. Theoretical method is based on the Dirac-Hartree-Fock scattering equation. Ab initio polarization and exact exchange have been included. Calculations have been performed for the low energy elastic electron scattering from argon. A very good agreement with the recent experimental data has been found.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 1; 13-16
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Components for differential cross-section with taking into account the polarization effects in elastic electron-deuteron scattering
Autorzy:
Zhaba, V. I.
Powiązania:
https://bibliotekanauki.pl/articles/1066249.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
cross-section
deuteron
deuteron wave function
electron-deuteron scattering
Opis:
The components for differential cross-section was considered with taking into account the polarization effects in elastic electron-deuteron scattering. These characteristics are analyzed for angle of electron scattering θ = 70º and different momentums. The angular-momentum dependence of values components for differential cross-section have been evaluated in 3D format. The wave function of the deuteron in the coordinate representation for the Reid93 potential was applied to numerical calculations.
Źródło:
World Scientific News; 2019, 131; 279-286
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
JMATRIX - package for relativistic J-MATRIX calculations in elastic scattering of electrons from model potentials
Autorzy:
Syty, P.
Sienkiewicz, J. E.
Powiązania:
https://bibliotekanauki.pl/articles/1940696.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska
Tematy:
J-matrix method
relativistic
electron elastic scattering
phase shifts
Dirac partial-waves analysis
differential
total
momentum transfer
spin polarization cross sections
Opis:
We present a software package JMATRIX, consisting of two computer codes written in FORTRAN 95 and parallelized with OpenMP, implementing the so-called J-matrix method, applied to elastic scattering of electrons on the radial potential, vanishing faster than the Coulomb potential. In the J-matrix method, the physical scattering problem is replaced by using a well-defined model which is solved analytically. The presented software implements both non-relativistic and relativistic versions of the method, and allows calculations of scattering phase shifts as well as cross sections, in cases when the scattering potential is given through an analytical formula. We performed test calculations for the scattering potential modeled as a truncated Coulomb potential. We show that the numerical phase shifts to converge as we increase the size of the basis used to truncate the scattering potential, and that the method is suitable for calculating the total differential momentum transfer and spin polarization cross sections, using the partial-wave analysis.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2017, 21, 1; 17-42
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scattering mechanisms in MOS/SOI devices with ultrathin semiconductor layers
Autorzy:
Walczak, J.
Majkusiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/308021.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
ultrathin SOI
scattering mechanisms
electron mobility
Opis:
Main scattering mechanisms affecting electron transport in MOS/SOI devices are considered within the quantum-mechanical approach. Electron mobility components (i.e., phonon, Coulomb and interface roughness limited mobilities) are calculated for ultrathin symmetrical DG SOI transistor, employing the relaxation time approximation, and the effective electron mobility is obtained showing possible mobility increase relative to the conventional MOSFET in the range of the active semiconductor layer thickness of about 3 nm.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 1; 39-49
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniqueness of studies on electron densities in the extended momentum space
Autorzy:
Kontrym-Sznajd, G.
Powiązania:
https://bibliotekanauki.pl/articles/148018.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron-positron momentum densities
Compton scattering
extended momentum space
positron annihilation
Opis:
This work draws attention to the fact that by measuring electronic structure via angular correlation of positron radiation (ACAR) and Compton scattering experiments one probes electron densities in the extended momentum space, directly related to the electron Bloch wave functions. Presenting some examples of electron densities in the extended and reduced momentum spaces, it is demonstrated what kind of information concerning the electronic structure can be obtained depending on the considered space. It is also shown how the knowledge of the symmetry selection rules allows to separate various Fermi surfaces and establish Fermi momenta.
Źródło:
Nukleonika; 2013, 58, 1; 203-206
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of symmetry of solids in some experiments
Autorzy:
Kontrym-Sznajd, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/971520.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Brillouin zone (BZ)
Compton scattering experiment
crystal symmetry
electron momentum densities
lattice harmonics
Opis:
It is known that some anisotropic quantities, that describe the properties of solids, can be determined, to a reasonable accuracy, by a limited number of data along the "special directions" (SD). SDs are very useful in various theoretical and experimental investigations. Among other things, they define projections which are the most efficient to reconstruct three-dimensional (3-D) electron momentum densities from Compton scattering spectra. The concept of SDs and their power is illustrated by comparing an isotropic average of the function based on either three high-symmetry directions or even only one, but SD.
Źródło:
Nukleonika; 2013, 58, 1; 207-210
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic-assisted synthesis of reactive carboxymethyl cellulose stabilized nano zero-valent iron and its application for removal of Cr6+ and Cu2+ ions
Autorzy:
Ayob, A.
Santiagoo, R.
Amneera, W. A.
Ismail, N.
Abdullah, A. Z.
Powiązania:
https://bibliotekanauki.pl/articles/207403.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high resolution transmission
electron microscopy
light scattering
transmission electron microscopy X ray diffraction
zero-valent iron
wysoka rozdzielczość transmisyjna
mikroskopia elektronowa
dyfrakcja rentgenowska
żelazo
Opis:
Carboxymethyl cellulose (CMC) was used in the chemical reduction using sodium borohydride to yield dispersive nano zero-valent iron (nZVI) particles as reactive and stable adsorbents. CMC- -stabilized nZVI particles were characterized via UV-visible light spectroscopy, X-ray diffraction, dynamic light scattering, transmission electron microscopy, and specific surface area assisted using a probe ultrasonication dispersing tool at 50% amplitude power. High catalytic reactivity obtained in pseudo-first order reaction for Cr6+ (rate constant K1 = 0.0311 min–1) and pseudo-second order for Cu2+ (rate constant K2 = 0.0946 g·mg–1·min–1) indicated that colloidal stability of nZVI particles can be achieved with a stabilizer for the removal of toxic contaminants.
Źródło:
Environment Protection Engineering; 2016, 42, 2; 55-79
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Znaczenie i przykłady zastosowania banków pseudoatomów asferycznych w krystalografii małych cząsteczek i ich potencjalne wykorzystanie w krystalografii makromolekuł
The importance and examples of application of aspherical pseudoatom databanks in small-molecule crystallography and their potential use in makromolecular crystallography
Autorzy:
Dominiak, P. M.
Powiązania:
https://bibliotekanauki.pl/articles/171730.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
asferyczne atomowe czynniki rozpraszania
gęstość elektronowa
rentgenowskie dane dyfrakcyjne
struktura krystaliczna
aspherical atomic scattering factors
electron density
X-ray diffraction data
crystal structure
Opis:
X-rays are diffracted by the electron density of crystals. Thus, the correct analysis of a single crystal X-ray diffraction pattern can provide information about the distribution of the electron density. How precise and accurate the information could be is largely determined by the resolution of the data collected. The majority of X-ray diffraction data is collected at and below the standard resolution, dmin= 0.84 Å. Before the development of pseudoatom databases, such resolution permitted to carry out X-ray refinement only with the use of simple model of electron density called the Independent Atom Model (IAM). In the IAM, individual atoms are represented by the spherically averaged electron density distributions obtained by theoretical methods for isolated atoms in the ground state. The IAM does not take into account changes in the density distribution of individual atoms caused by such phenomena as chemical bond formation, charge transfer, lone electron pairs, etc. Only the geometrical information of the crystal structure is obtained from the IAM refinement. A more physical model has been introduced in which an atom is represented as a finite spherical harmonic expansion of the electron density around each atomic center and is called a pseudoatom. Such definition allows the pseudoatom electron density to be individually adjusted (by changing values of pseudoatom parameters) to account for density departure from spherical and neutral model. However, to refine pseudoatom parameters with experimental data subatomic resolution is required. It has been shown that the values of pseudoatom parameters are almost identical for atoms in similar chemical environments, i.e. atoms having similar local topology of connecting chemical bonds. Therefore it was possible to build a databank of different types of pseudoatoms and to use the bank to generate the Transferable Aspherical Atom Model (TAAM) for any organic molecule, including proteins and nucleic acids. There are three different pseudoatom databanks being developed: ELMAM2, GID and UBDB. They differ by the source of pseudoatom parameters and by the way how atom types are defined. Replacement of the IAM model by the TAAM in the refinement procedure of standard diffraction data leads to more accurate geometrical information and provide access to quantitative estimation of the electron density distribution and properties derived from it (dipole moment, electrostatic potential, etc.) for molecules in a crystalline environment. The review summarizes the research on the verification and application of pseudoatom databases.
Źródło:
Wiadomości Chemiczne; 2014, 68, 5-6; 429-455
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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