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Wyszukujesz frazę "78.70." wg kryterium: Temat


Tytuł:
Studies of Solids and Adsorbates in Synchrotron Radiation Excited Soft X-Ray Fluorescence
Autorzy:
Nordgren, J.
Wassdahl, N.
Powiązania:
https://bibliotekanauki.pl/articles/1920879.pdf
Data publikacji:
1992-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
Opis:
A progress report is presented on recent developments in soft X-ray emission spectroscopy using synchrotron radiation. Some key experiments are discussed demonstrating that new information can be gained by using synchrotron radiation for this purpose. Recent work on highly resolved soft X-ray emission from monolayers of adsorbed species is commented on and some perspectives are given regarding further developments expected from the third generation sources that are underway.
Źródło:
Acta Physica Polonica A; 1992, 82, 2; 251-262
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of Painting Layers of Sennefer Tomb by Ion Beam Analysis
Autorzy:
Abd El Aal, S.
Powiązania:
https://bibliotekanauki.pl/articles/1504061.pdf
Data publikacji:
2011-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
07.60.Pb
Opis:
Egypt has many pharaonic tombs for kings, queens and noblemen. The Sennefer tomb, one of the most important nobleman tombs, is located in the southern hillside of Sheikh Abd El-Qurna - west side of Luxor. It is dated back to 1439-1413 B.C. (18th Dynasty) and is usually referred as the Tomb of Vines, due to the large part of the ceiling of the burial chamber. The vine tomb was carved inside a mountain, its walls are covered with plaster and were painted using the tempera technique (pigments mixed with organic binding medium). The analysis was performed by using particle-induced X-ray emission, microbeam particle-induced X-ray emission and optical microscope for the six samples from the Vine tomb such as white, black, red, yellow, blue and green pigments and for the ground layers of the tomb in order to identify the composition of plaster layers and pigments. The data about the nature of these materials are indispensable for conservation and cleaning.
Źródło:
Acta Physica Polonica A; 2011, 120, 1; 144-148
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of Analytical Methods in Evaluation of Coptic Wall Paintings Conservation - A Case Study
Autorzy:
Ali, M.
Abd El Aal, S.
Mahgoub, G.
Sihame, A.
Turos, A.
Korman, A.
Stonert, A.
Powiązania:
https://bibliotekanauki.pl/articles/1504111.pdf
Data publikacji:
2011-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
07.60.Pb
Opis:
Egypt has a lot of ancient monasteries and churches, which were decorated with different kinds of wall paintings. Structure of these wall paintings consists of support, plaster and painting layers. Paintings deterioration is primarily due to physicochemical, natural and human factors. The most detrimental factors are bat patches, old varnish and organic waste of birds. All these lead to the gradual disappearance of paintings. Modern technology of conservation is focused on application of new materials for cleaning of wall paintings. Here we report on the use of enzymes, for cleaning surface of coptic wall paintings. Analytical techniques such as particle induced X-ray emission, Fourier transform infrared and optical microscopy were used to evaluate the enzymatic cleaning processes of coptic wall paintings and to identify the chemical composition of red, yellow and white pigments. Particle induced X-ray emission results indicated that there is no change in the chemical composition of the materials and pigments due to enzymatic cleaning. Fourier transform infrared and optical microscopy results confirmed the stability of organic medium before and after treatment of different kind of patches.
Źródło:
Acta Physica Polonica A; 2011, 120, 1; 171-176
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchrotron Radiation Induced X-Ray Emission - SRIXE
Autorzy:
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1920883.pdf
Data publikacji:
1992-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
87.15.Mi
Opis:
The synchrotron radiation induced X-ray emission (SRIXE) technique was found very useful and sensitive for determination of trace elements content and distribution in different types of materials. Due to properties of synchrotron radiation the SRIXE technique became very unique and powerful for trace elements analysis. This paper describes the phenomena related to production of characteristic X-rays and principles of the method. The properties of SRIXE such as minimum detectable limit, spatial resolution, radiation damage, and depth sensitivity are also discussed. Selected applications are given to emphasize the usefulness of the technique.
Źródło:
Acta Physica Polonica A; 1992, 82, 2; 263-271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recombination Processes in $PbWO_{4}:Tb^{3+}$ Crystals
Autorzy:
Novosad, S.
Kostyk, L.
Novosad, I.
Tsvetkova, O.
Powiązania:
https://bibliotekanauki.pl/articles/1550389.pdf
Data publikacji:
2010-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Hx
78.60.Kn
78.70.En
Opis:
In the paper the results of investigations of X-ray excitation spectra, thermostimulated luminescence and the influence of light illumination on the thermoluminescence glow curves of pure and Tb-doped $PbWO_{4}$ crystals are presented. It is suggested that the $F^{-}$-centres are formed in $PbWO_{4}$ crystals at filling oxygen vacancies near $Pb^{3+}$ ions to three electrons under X-ray irradiation at 90 K. The nature of 108 K thermostimulated luminescence peak is connected with the $[(WO_{3} + F^{-})-Pb^{3+}]$ associations. It was established that thermal or optical destruction of this peak leads to appearance of the radiative transitions of excitons localized near the $[(WO_{3} + F)-Pb^{2+}]$ complex centres.
Źródło:
Acta Physica Polonica A; 2010, 117, 1; 143-145
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Europium Impurity on the Recombination Luminescence in Y₂O₃
Autorzy:
Novosad, S.
Novosad, I.
Bordun, O.
Kostyk, L.
Bordun, I.
Tuzyak, O.
Powiązania:
https://bibliotekanauki.pl/articles/1029724.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Hx
78.60.Kn
78.70.En
Opis:
In this work the researched results of the spectral characteristics of the luminescence and the thermostimulated luminescence curves of Y₂O₃ and Y₂O₃:Eu ceramic materials at the X-ray excitation in the 85-295 K range were generalized. Considering the features of Y₂O₃ crystal structure and the possibility of the formation of the short-lived and stable hole and electron centers of V- and F-type by the ionizing radiation X-ray luminescence spectrum of ceramics at 85 K is fitted into the elementary Gaussian shape bands with the maxima near 3.40, 3.06, 2.67, 2.33, 2.09, and 1.91 eV. The main 3.40 and 3.06 eV bands of the luminescence are caused by the self-trapped excitons of (YO₆)⁹¯ complex, when the cation is localized in the field of the trigonal (C_{3i}) and monoclinic (C₂) symmetries. The emission at 2.67 eV and the weak bands in the 1.65-2.61 eV region are considered as the radiation of excitons localized on the anion vacancies and the electron centers of F-type (F⁺, F and F¯). The thermoluminescence of Y₂O₃ in the 186 and 204 K main peaks range is connected with the thermal destruction of the self-trapped states of O¯ ions that located in the field of the trigonal and monoclinic symmetries. The activator bands caused by ⁵D→ ⁷F_{j} electronic transitions in Eu³⁺ are only observed in the X-ray and thermostimulated luminescence spectra of Y₂O₃:Eu ceramics. It was assumed that both at the X-rays irradiation and an optical excitation in the band of the charge transfer of Y₂O₃:Eu sample the energy goes to Eu³⁺ through (Eu²⁺O¯) complexes (states) of the charge transfer.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 806-810
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Luminescence and Luminescence Kinetics of $Gd_{3}Ga_{5}O_{12}$ Polycrystals Doped with $Cr^{3+}$ and $Pr^{3+}$
Autorzy:
Mahlik, S.
Kukliński, B.
Grinberg, M.
Kostyk, Ł.
Tsvetkova, O.
Powiązania:
https://bibliotekanauki.pl/articles/1550204.pdf
Data publikacji:
2010-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Hx
78.60.Kn
78.70.En
Opis:
In this paper spectroscopic investigations of $Gd_3Ga_5O_{12}$ (GGG) polycrystals, containing $Cr^{3+}$ and intentionally doped with $Pr^{3+}$ of concentrations 0.5, 1 and 1.5 mol% are presented. We have measured the steady state luminescence and luminescence excitation spectra, as well as the time resolved spectra and luminescence kinetics. The main goal was to investigate the excitation energy transfer from lattice to impurity and between impurities. We found that relative intensity of $Cr^{3+}$ and GGG lattice luminescence decreased when material was doped with $Pr^{3+}$. On the other hand, time resolved spectroscopy and luminescence decay measurements showed that the $Cr^{3+}$ and GGG lattice luminescence decays were independent of $Pr^{3+}$ content. The lifetime of $Pr^{3+}$ luminescence related to $\text{}^{1}D_{2} \rightarrow \text{}^{3}H_{4}$ and $\text{}^{3}P_{0} \rightarrow \text{}^{3}H_{4}$ transitions decreased with concentration of $Pr^{3+}$, which was attributed to the concentration luminescence quenching. No energy transfer between GGG lattice defects and $Cr^{3+}$, and $Pr^{3+}$ ions was observed. We proposed the model of radiative recombination of electron and hole, which took place through three independent pathways: by GGG host emission that peaked at 12750 $cm^{-1}$, by $Cr^{3+}$ luminescence that peaked at 15400 $cm^{-1}$, and by $Pr^{3+}$ luminescence.
Źródło:
Acta Physica Polonica A; 2010, 117, 1; 117-121
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recombination Luminescence in $Ca_{3-x}Cd_xGa_2Ge_3O_{12}$ Garnets Doped with $Eu^{3+}$ Ions
Autorzy:
Kostyk, L.
Luchechko, A.
Novosad, S.
Panasyuk, M.
Rudko, M.
Tsvetkova, O.
Powiązania:
https://bibliotekanauki.pl/articles/1398246.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Hx
78.60.Kn
78.70.En
Opis:
The results of the investigations of X-ray excitation spectra, thermostimulated luminescence and influence of light illumination on the thermoluminescence glow curves of $Eu^{3+}$-doped $Ca_{3-x}Cd_xGa_2Ge_3O_{12}$ garnet polycrystalline samples are presented. It is shown that $Ca_{3-x}Cd_xGa_2Ge_3O_{12}$ polycrystalline samples are characterized by intrinsic luminescence, which consists of several components. The nature of intrinsic luminescence is discussed. It is suggested that the nature of thermoluminescence glow peak near 150 K is connected with the $[(V_{Ge}+V_{O})^{-}-F^+]$ associations formed under X-ray irradiation at 85 K. The influence of light illumination on the TSL intensity of the preliminary X-ray irradiated samples is shown.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 943-947
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fluorescence Processes and Scintillation of CeF$\text{}_{3}$ Crystal Excited by UV and X-Ray Synchrotron Radiation
Autorzy:
Pédrini, C.
Belsky, A. N.
Moine, B.
Bouttet, D.
Powiązania:
https://bibliotekanauki.pl/articles/1929797.pdf
Data publikacji:
1993-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.+z
78.55.Hx
78.70.En
Opis:
Photoluminescence properties of CeF$\text{}_{3}$ have been investigated. Two kinds of emitting centers have been identified: regular Ce$\text{}^{3+}$ sites exhibiting two close emission bands (285 and 300 nm) and a fast fluorescence (20 ns) and several physically different perturbed Ce$\text{}^{3+}$ sites giving rise to a broad emission band near 340 nm and a longer fluorescence (30-40 ns) the decay time of which varies with wavelength. An energy transfer occurs between these two kinds of centers. Scintillation properties have been studied under UV and X-ray excitation. The additional fast decay always observed at short time under ionizing radiation is interpreted by a temperature dependent luminescence quenching phenomenon due to high excitation density.
Źródło:
Acta Physica Polonica A; 1993, 84, 5; 953-957
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Iron Containing Supplement Biofer Investigated by X-ray Fluorescence, Energy Dispersive X-Ray Spectroscopy and Mössbauer Spectroscopy
Autorzy:
Brzozowski, R.
Szałański, P.
Kaźmierczak, J.
Polański, K.
Pruba, M.
Moneta, M.
Powiązania:
https://bibliotekanauki.pl/articles/1402229.pdf
Data publikacji:
2015-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.Qr
78.70.En
87.14.Pq
Opis:
Iron, an important microelement essential to the functioning of the body, plays a special role in the process of respiration. There are more and more new products available on the pharmaceutical market. Some of them were the subject of previous studies, especially by using the Mössbauer spectroscopy. One of the latest is Biofer. For the present tests three tablets from three different production series of Biofer were used for examination of elemental composition using the X-ray fluorescence and energy dispersive X-ray spectroscopy methods. Information about oxidation of iron contained in the tablets was obtained with by means of the Mössbauer spectroscopy.
Źródło:
Acta Physica Polonica A; 2015, 128, 5; 905-907
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compensation of Roentgen Exciting System Instability in Conducting X-Ray Fluorescence Analysis of Bioassays
Autorzy:
Galchenko, S.
Kirilenko, E.
Fokov, G.
Powiązania:
https://bibliotekanauki.pl/articles/1493666.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
82.80.Ej
87.10.Rt
Opis:
Detailed analysis of the backscattering peak in the X-ray fluorescence spectrum was carried out using the Monte Carlo method which is the base of the computer code "SNEGMONT" for simulating the transport of electrons and photons. The calculations show that the intensity of the backscattering peak is directly proportional to the intensity of the exciting radiation. It was found that the intensity of analyzed elements' lines has a strict relation with the intensity of the backscattering peak. The example of determination of lead and zinc concentrations in bioassay is presented. The simulation of an eightfold change of the exciting X-rays intensity which taking into account the obtained strict relation allows to determine the true concentration of elements with an error of no more than 3%.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 531-535
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Mo-Ni Alloys by X-Ray Spectroscopies
Autorzy:
Ławniczak-Jabłońska, K.
Heinonen, M.
Inoue, J.
Tohyama, T.
Powiązania:
https://bibliotekanauki.pl/articles/1924333.pdf
Data publikacji:
1993-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Cf
78.70.En
79.60.-i
Opis:
Band structure investigations of the random MoNi$\text{}_{4}$ and MoNi$\text{}_{3}$ alloys, performed by emission and photoelectron spectroscopy, is reported. The X-ray emission and X-ray photoelectron spectra allowed to study the occupied valence band states below Fermi level. These techniques gave the full description of changes in the density of valence electron states distribution due to substitution of Mo atoms into the fcc Ni lattice up to 25 at%. The analysis of the emission and photoelectron spectra led to clear distinction between the changes in spectra caused by density of states structure and by additional effects involved in creation of the particular spectra. The experimental data are compared with the density of states calculated using coherent potential approximation and linear muffin-tin orbital methods.
Źródło:
Acta Physica Polonica A; 1993, 83, 1; 115-124
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Trace Element Concentration in Diabetic Rats Tissues
Autorzy:
Kowalska, J.
Krośniak, M.
Gryboś, R.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1809705.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.30.Ep
78.70.En
87.19.X-
Opis:
Diabetes is one of the most frequent diseases in developing countries and thus there is a significant interest in diabetes related studies. It was found that vanadium compounds have glucose-lowering properties in diabetes and therefore it is very important to estimate the vanadium dose in diabetes treatment. On the other hand, the proper estimation of vanadium concentration is important due to side effects that occur in vanadium supplementation. In this study the influence of V(IV) and V(V) compounds with different ligands on the concentration of K, Ca, Mn, Fe, Cu, and Zn in selected rat's tissues was investigated by means of proton induced X-ray emission technique. As a result of the measurements it was found that the concentration of vanadium depends on the organ. The highest value was determined in spleen while the lowest in pancreas. It was also found that the concentration of other elements depends on the presence of vanadium and its concentration. The most meaningful influence of vanadium presence was on iron concentration in spleen, on copper and zinc in kidney, and on manganese in pancreas.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 556-560
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Structure of ZnS:Co Semiconductors: X-ray and Optical Spectroscopy Studies
Autorzy:
Surkova, T. P.
Galakhov, V. R.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2036872.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
78.70.En
79.60.-i
Opis:
Experimental studies of X-ray photoelectron and Co L$\text{}_{α}$ X-ray emission spectra of the ZnS:Co semiconductor were carried out. It was established that Co ions are in a Co$\text{}^{2+}$ configuration and that the Co 3d impurity states are localized above the top of the valence band by 1.0±0.2 eV.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 703-708
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Atmospheric Aerosols Using the Lisbon Nuclear Microprobe
Autorzy:
Rita, E. M. C.
Alves, L. C.
Reis, M. A.
Rodrigues, F.
Fialho, P.
Soares, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/2029003.pdf
Data publikacji:
2001-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
92.20.Bk
92.60.Mt
78.70.En
82.80.Yc
Opis:
The nuclear microprobe installed at Instituto Tecnológico e Nuclear, in Lisbon, was used in the analysis of aerosols collected at the Azores islands. Samples from two different aerosol groups were analysed. One referred to aerosols that were carried from North America and the other one contained aerosols that were carried from the Sahara desert and crossed over Europe. Coarse and fine fractions were analysed for each aerosol group and two-dimensional elemental maps were constructed, which allowed the identification of several individual particles. For particles of interest, elemental spatial correlations and dimensions were determined and point analysis was also carried out (depth information was achieved by fitting Rutherford backscattering spectra). Some of these particles are quite interesting. For instance, in the fine fraction of the aerosols that were carried from North America, particles were found with Cu and Cl in the atomic proportion 1:2 and with dimensions 15×15×15μm$\text{}^{3}$, and in the corresponding coarse fraction a particle with K and S was identified, with dimensions 28×35×30μm$\text{}^{3}$. Some differences were found between the aerosols groups. One example of these are Ti particles (fine fraction) and Rb (coarse fraction) that were identified in one group (Sahara desert and Europe), but not in the other
Źródło:
Acta Physica Polonica A; 2001, 100, 5; 781-788
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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