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Wyświetlanie 1-45 z 45
Tytuł:
Extended X-Ray Bremsstrahlung Isochromat Fine Structure
Autorzy:
Sobczak, E.
Powiązania:
https://bibliotekanauki.pl/articles/1928257.pdf
Data publikacji:
1993-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
79.20.Kz
78.70.Dm
Opis:
Main aspects concerning a new method of extended X-ray bremsstrahlung isochromat fine structure (EXBIFS) are specified and discussed. The EXBIFS effect is studied here by application of a single-scattering theory, which explains well the experimental phenomenon that EXBIFS of Cu and Pd is strikingly similar to the p partial density of states, although the s- and d-symmetry contributions are not negligible. The single-scattering model of EXBIFS has been successfully applied for explanation of temperature effects resulting in a smearing of oscillations for big k values. It is established here that interatomic distances can be evaluated from EXBIFS by means of the single-scattering theory and the Fourier analysis.
Źródło:
Acta Physica Polonica A; 1993, 83, 2; 135-155
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended X-Ray Absorption Fine Structure in Catalysis
Autorzy:
Renouprez, A.
Powiązania:
https://bibliotekanauki.pl/articles/1920892.pdf
Data publikacji:
1992-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.Lx
82.65.Jv
Opis:
Applications of extended X-ray absorption fine structure and X-ray edge structure to catalysis are described. Special attention is paid to the study of supported mono- and bimetallic catalysts. The method used to collect in situ data, under reaction conditions are also considered.
Źródło:
Acta Physica Polonica A; 1992, 82, 2; 295-308
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Σ* approach to the fine structure of L
Autorzy:
Friedman, Sy
Powiązania:
https://bibliotekanauki.pl/articles/1205416.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
We present a reformulation of the fine structure theory from Jensen [72] based on his Σ* theory for K and introduce the Fine Structure Principle, which captures its essential content. We use this theory to prove the Square and Fine Scale Principles, and to construct Morasses.
Źródło:
Fundamenta Mathematicae; 1997, 154, 2; 133-158
0016-2736
Pojawia się w:
Fundamenta Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of Exciton Fine Structure Splitting in Quantum Dots
Autorzy:
Stevenson, R. M.
Young, R. J.
Atkinson, P.
Cooper, K.
Ritchie, D. A.
Shields, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/2046985.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
03.67.Mn
78.67.Hc
78.55.Cr
Opis:
Quantum dots have been identified as potential sources of entangled photon pairs, essential for many applications in quantum information. However, in practice structural properties of the dots result in polarisation splitting of the emission lines, which has prevented the realisation of such a source. Here, we present two techniques developed to control the polarisation splitting in a quantum dot both irreversibly and reversibly. We find that the splitting is strongly dependent upon the emission energy, or lateral confinement, of the quantum dot. Thus by precise control of the InAs deposition thickness, it is possible to produce ensembles from which dots with zero polarisation splitting can be easily selected. Additionally, we demonstrate that by using modest in-plane magnetic fields to partially mix the bright and dark exciton states, the polarisation splitting can be reversibly tuned to zero for most dots of a certain type. Finally, we demonstrate the emission of triggered entangled photon pairs from a quantum dot with approximately zero splitting with fidelity >70%.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 311-318
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine Structure of Neutral Excitons in Single GaAlAs Quantum Dots
Autorzy:
Molas, M.
Gołasa, K.
Piętka, B.
Potemski, M.
Babiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/1403612.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
78.67.Hc
Opis:
Optical anisotropy of neutral excitons in GaAlAs/AlAs quantum dots is investigated. Low-temperature polarization-sensitive photoluminescence measurements of single quantum dots are performed. It is found that neutral excitons (X) in the quantum dots exhibit a fine structure splitting. The fine structure splitting ranges from 10 μeV to 100 μeV and correlates with the X energy. The polarization axis of the fine structure splitting is well oriented along [110] crystallographic direction of a substrate. The orientation is attributed to the elongation of GaAlAs/AlAs quantum dots in the [110] direction of the substrate.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 988-990
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some characteristics of fine structure and microstructure of Baltic Sea waters
Autorzy:
Golenko, N.
Powiązania:
https://bibliotekanauki.pl/articles/972856.pdf
Data publikacji:
2001
Wydawca:
Instytut Morski w Gdańsku
Tematy:
Baltic Sea
intrusions
salinity
Opis:
It is generally agreed that fine structure and microstructure are usually beyond the resolution of numerical models. Nevertheless, corresponding processes have a considerable influence on water dynamics and exchanges in the Baltic Sea. Measurements of fine structure were carried out with the scanning CTD probe. Microstructure measurements were performed by towing a system with fast-response velocity, conductivity, and temperature sensors. Bottom turbulence was investigated with the Acoustic Doppler Velocimeter. Domains of high mixing and stining activity were revealed by means of high-resolution profiling on temperature and salinity transects. These domains were found near inhomogeneities of bottom relief such as the Słupsk Sill, the bottom elevation on eastern boundary of the Słupsk Furrow and in areas of ray concentration of quasi-inertial internal waves. Data on transects with manifestations of convection provide an evidence of the non-uniform distribution of turbulence in the upper layer. A bottom turbulence patch with duration of about 2 hours was registered over the slope of the Gotland Deep. The rate of turbulent energy dissipation is about ]105cm2/s3. In the area of Hamrarne and Słupsk Sill, horizontal scales of turbulent patches are between O(10m) and 0(100 m). All obtained data testify the high level of turbulent intermittency, so probability of detecting turbulent patches is high.
Źródło:
Biuletyn Instytutu Morskiego w Gdańsku; 2001, 28, 2; 23-33
1230-7424
2450-5536
Pojawia się w:
Biuletyn Instytutu Morskiego w Gdańsku
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some characteristics of fine structure and microstructure of Baltic Sea waters
Autorzy:
Golenko, N.
Powiązania:
https://bibliotekanauki.pl/articles/1920571.pdf
Data publikacji:
2000
Wydawca:
Instytut Morski w Gdańsku
Tematy:
Baltic Sea
intrusions
salinity
Opis:
It is generally agreed that fine structure and microstructure are usually beyond the resolution of numerical models. Nevertheless, corresponding processes have a considerable influence on water dynamics and exchanges in the Baltic Sea. Measurements of fine structure were carried out with the scanning CTD probe. Microstructure measurements were performed by towing a system with fast-response velocity, conductivity, and temperature sensors. Bottom turbulence was investigated with the Acoustic Doppler Velocimeter. Domains of high mixing and stining activity were revealed by means of high-resolution profiling on temperature and salinity transects. These domains were found near inhomogeneities of bottom relief such as the Słupsk Sill, the bottom elevation on eastern boundary of the Słupsk Furrow and in areas of ray concentration of quasi-inertial internal waves. Data on transects with manifestations of convection provide an evidence of the non-uniform distribution of turbulence in the upper layer. A bottom turbulence patch with duration of about 2 hours was registered over the slope of the Gotland Deep. The rate of turbulent energy dissipation is about ]105cm2/s3. In the area of Hamrarne and Słupsk Sill, horizontal scales of turbulent patches are between O(10m) and 0(100 m). All obtained data testify the high level of turbulent intermittency, so probability of detecting turbulent patches is high.
Źródło:
Biuletyn Instytutu Morskiego w Gdańsku; 2001, 28, 2; 23-33
1230-7424
2450-5536
Pojawia się w:
Biuletyn Instytutu Morskiego w Gdańsku
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended X-ray Bremsstrahlung Isochromat Fine Structure of SiO$\text{}_{2}$
Autorzy:
Sobczak, E.
Nietubyć, R.
Powiązania:
https://bibliotekanauki.pl/articles/1932134.pdf
Data publikacji:
1995-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.25.Tn
79.20.Kz
Opis:
X-ray bremsstrahlung isochromat of amorphous SiO$\text{}_{2}$ deposited on Si crystal was measured in an energy range up to 250 eV above the threshold. Extended X-ray bremsstrahlung isochromat he structure (EXBIFS) was observed up to 150 eV for SiO$\text{}_{2}$ studied. The Fourier transform of EXBIFS showed two peaks originated from first and second neighbors around silicon and oxygen ions. Model calculations of EXBIFS of amorphous SiO$\text{}_{2}$ were performed in terms of single scattering of spherical waves and compared with experimental results.
Źródło:
Acta Physica Polonica A; 1995, 87, 3; 649-656
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine Structure Signatures in Ground Flashes as a Source for HF Radiation
Autorzy:
Edirisinghe, M.
Cooray, V.
Powiązania:
https://bibliotekanauki.pl/articles/412624.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
HF radiation
lightning
Return stroke
Ground flash
Opis:
Lighting radiation fields below 10 MHz are of considerable interest since these frequencies correspond to the natural resonance of structures with dimensions of a few meters to tens of meters. In this paper we present the fine structure signatures of sub-microsecond range pulses appeared at the leader phase and after the return stroke in negative ground flashes which act as a source for HF radiations at 10 MHz, 5 MHz and 3 MHz observed in Sri Lanka, in the tropics. Of the total sub-microsecond range pulses analyzed, 298 were due to positive field changes and 228 were due to negative field changes. The average rise time of those pulses for both polarities is 127 ns and it was found to be varying from 110-160 ns. The peak amplitude is in the range of 0.65-2.19 V/m. For the total 526 pulses analyzed for this study, the FWHM was between 190-310 ns with an arithmetic mean of 238 ns. Signatures of these pulses are similar to the leader like electric field pulses which acted as a strong source for HF radiations at 10 MHz, 5 MHz and 3 MHz. The initiation process of pulses reported in this study could be similar to the initiation process of leader like pulses.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 1; 91-104
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The morphology and fine structure of the Ordovician Cephalodiscus-like genus Melanostrophus
Autorzy:
Mierzejewski, P
Urbanek, A.
Powiązania:
https://bibliotekanauki.pl/articles/23048.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Hemichordata
Ordovician
Pterobranchia
ultrastructure
Cephalodiscus
paleontology
Estonia
Melanostrophus
Opis:
The holotype and a new specimen from the type locality, as well as a few new specimens of Melanostrophus fokini Öpik, 1930, an enigmatic invertebrate from the Ordovician of the Baltic region, have been examined using combined LM, SEM and TEM techniques. This form is reinterpreted as a ?cephalodiscid hemichordate. Its skeleton or coenecium is an encrusting assemblage of uniform zooidal tubes, forming a circular or subcircular palisade−like structure.The zooidal tubes are long (up to 50 mm) and slender, similar to zooidal tubes of the extant pterobranch hemichordate Cephalodiscus (Orthoecus). The fine structure of the skeleton wall is similar to that in graptolites and four components have been recognized within periderm: (i) thick, outer cortical layer, (ii) very thin fusellar layer, constructed of annular growth bands, with their oblique sutures arranged randomly, resembling the fusellar layer of some pterobranchs and primitive graptolites, (iii) inner cortical layer, and (iv) thin, enamel−like inner lining. The periderm is abundantly perforated by pits and holes of different diameters; some of them were probably caused by saprophytic or parasitic borers, but the largest ones (up to 100 µm) are probably primary and mark a tube bifurcation. It is concluded that cortex formation is not a synapomorphy for graptolites.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Type-I and Type-II Confinement in Quantum Dots: Excitonic Fine Structure
Autorzy:
Křápek, V.
Klenovský, P.
Šikola, T.
Powiązania:
https://bibliotekanauki.pl/articles/1398562.pdf
Data publikacji:
2016-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
73.21.La
81.05.Ea
Opis:
We have theoretically studied type-I and type-II confinement in InAs quantum dots with GaAs_{1-y}Sb_y capping layer. The character of the confinement can be adjusted by the Sb content. We have found that upon the transition from type-I to type-II confinement the hole wave functions change the topology from a compact shape to a two-segment shape, resulting in the complex changes in the exciton fine structure splitting with zero values at narticular compositions. Additionally, a high exciton radiative recombination probability is preserved even in type-II. This allows to design strongly luminescent quantum dots with naturally low fine structure splitting, which could serve as sources of entangled photon pairs for quantum communication.
Źródło:
Acta Physica Polonica A; 2016, 129, 1a; A-66-A-69
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Fine Structure of a Triexciton in Single InAs/GaAs Quantum Dots
Autorzy:
Molas, M.
Gołasa, K.
Furman, M.
Lapointe, J.
Wasilewski, Z.
Potemski, M.
Babiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/1403615.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
78.67.Hc
Opis:
Results of experimental study of multiexcitonic emission related to the p-shell of single self-assembled InAs/GaAs quantum dots are presented. Optical properties of a first emission line to appear from the p-shell of a strongly excited quantum dots are investigated using low-temperature polarization-sensitive micro-photoluminescence measurements. The emission line is attributed to the recombination of a complex of three electrons and holes confined in a dot (neutral triexciton), 3X. It is found that the emission consists of two linearly polarized components and the fine structure splitting is larger than the respective splitting of a neutral exciton. The optical anisotropy of the 3X emission is related to the anisotropy of the quantum dot localizing potential. The axis of the 3X optical anisotropy changes from dot to dot covering broad range within ± 50 degrees with respect to the axis defined by the optical anisotropy of a neutral exciton (X). Possible origin of the deviation is discussed.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 991-993
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine Structure of Resonant-Tunneling Peak in GaAs/AlAs Double-Barrier Heterostructure
Autorzy:
Vitusevich, S. A.
Figielski, T.
Mąkosa, A.
Wosiński, T.
Belyaev, A. E.
Konakova, R. V.
Kravchenko, L. N.
Powiązania:
https://bibliotekanauki.pl/articles/1872937.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Gk
85.30.Mn
Opis:
For the first time we observed a fine oscillatory structure, with the period of 36 mV, of the resonant tunneling peak in the current-voltage characteristic of a double-barrier heterostructure. We attribute it to a sequential single-phonon emission of ballistic electrons which tunneled out from the quantum well through the collector barrier.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 377-380
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Remarks and Calculations Concerning Collisional Fine Structure Mixing in Alkali Metal Atoms
Autorzy:
Rosiński, K.
Sirko, L.
Powiązania:
https://bibliotekanauki.pl/articles/1887421.pdf
Data publikacji:
1991-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.50.-s
Opis:
The analysis of all existing theoretical and experimental results concerning collisional fine structure (FS) mixing, suggesting that their agreement depends on FS separation and FS components intensity anomaly, showed that the test of the theoretical model should be made on sodium atoms. Therefore, the mixing cross sections for the nP (n = 6 ÷ 24) states of sodium atoms colliding with noble gas atoms, N2 and sodium atoms in the ground state have been calculated theoretically. Cross sections also for the lowest nP states of Na and Rb atoms have been estimated.
Źródło:
Acta Physica Polonica A; 1991, 79, 4; 543-548
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fine structure of uterin, prostate and Mehlis glands of Caryophyllidea and Cyathocephalata
Autorzy:
Poddubnaya, L.G.
Powiązania:
https://bibliotekanauki.pl/articles/839824.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
Diplocotyle olrikii
Caryophyllaeus laticeps
Mehlis' gland
structure
prostate
Khawia armeniaca
Caryophyllidea
Archigetes sieboldi
Cyathocephalata
Źródło:
Annals of Parasitology; 1998, 44, 3
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine Structure of the Localized Emission from GaInNAs Layers Studied by Micro-Photoluminescence
Autorzy:
Kudrawiec, R.
Latkowska, M.
Sęk, G.
Misiewicz, J.
Ibáñez, J.
Henini, M.
Hopkinson, M.
Powiązania:
https://bibliotekanauki.pl/articles/1791353.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
78.66.Fd
Opis:
GaInNAs bulk-like layers ( ≈ 20% In and ≈ 3% N) grown on GaAs substrate with various crystallographic orientations have been studied by micro-photoluminescence at low temperatures for a broad range of excitation conditions. In addition to photoluminescence peaks, which are associated with heavy- and light-hole free exciton recombination, a band of sharp lines was observed below the fundamental free exciton transition at low excitation. It shows that the localized emission which is typical of this alloy at low temperatures is composed of individual narrow photoluminescence lines which are associated with the recombination of single excitons. They can be localized on various local potential minima including those originating from the alloy content fluctuations and/or deep acceptor(donor)-like complexes.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 930-932
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray Absorption Fine Structure Investigation of the Low Temperature Grown ZnCoO Films
Autorzy:
Wolska, A.
Klepka, M.
Witkowski, B.
Witkowski, M.
Guziewicz, E.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1431568.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.Dm
75.50.Pp
68.55.-a
Opis:
ZnO based diluted magnetic semiconductors are intensively investigated for possible spintronic applications. In the present work we investigate the ZnCoO layers grown at low temperature by atomic layer deposition. The local atomic structure of a series of layers with different Co concentration is investigated by the X-ray absorption fine structure measurements. Two groups of ZnCoO layers are investigated - the ones with an uniform Co distribution and highly nonuniform films. For uniform samples we observe that a majority of Co atoms is built into the ZnO matrix substituting the Zn atoms. In contrast, for the nonuniform samples, metallic Co inclusions are also observed. These results are in strong correlation with the magnetic properties of the films studied separately. Samples with the uniform Co distribution (Co substitutes Zn in ZnO) are paramagnetic, whereas the nonuniform ones show a ferromagnetic response.
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 883-887
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparative Study of the Methods of Speciation Using X-ray Absorption Fine Structure
Autorzy:
Gaur, A.
Shrivastava, B.
Powiązania:
https://bibliotekanauki.pl/articles/1489872.pdf
Data publikacji:
2012-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.Dm
Opis:
Determination of the chemical forms along with the relative quantity of the different species in a given sample, termed as speciation, can be done by analyzing X-ray absorption fine structure spectra. The different methods that can be used for speciation are: principal component analysis, target transformation, methods based on derivative spectra, method based on the relative position of the absorption edge, residual phase analysis, normalized difference absorption edge spectra analysis and linear combination fitting. An attempt has been made to make a comparative study of these different methods of speciation by recording the X-ray absorption fine structure at the copper K-edge in a mixture having cuprous oxide and cupric oxide in a specific ratio. The X-ray absorption fine structure spectra of the two oxides have also been recorded separately and the different characteristic X-ray absorption near edge structure features have been identified and their origins have been discussed. Speciation of the mixture has been done using these different methods and the results obtained have been compared and discussed.
Źródło:
Acta Physica Polonica A; 2012, 121, 3; 647-652
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D metal halide perovskites: a new fascinating playground for exciton fine structure investigations
Autorzy:
Baranowski, Michał
Dyksik, Mateusz
Płochocka, Paulina
Powiązania:
https://bibliotekanauki.pl/articles/35108251.pdf
Data publikacji:
2022
Wydawca:
Radomskie Towarzystwo Naukowe
Tematy:
2D perovskites
exciton
fine structure
dark exciton states
perowskity 2D
ekscyton
struktura subtelna
stany ciemne ekscytonu
Opis:
Two-dimensional (2D) metal halide perovskites are natural quantum wells which consist of low bandgap metal-halide slabs, surrounded by organic spacers barriers. The quantum and dielectric confinements provided by the organic part lead to the extreme exciton binding energy which results in a huge enhancement of exciton fine structure in this material system. This makes 2D perovskites a fascinating playground for fundamental excitonic physics studies. In this review, we summarize the current understanding and quantification of the exciton fine structure in 2D perovskites. We discuss what is the role of exciton fine structure in the optical response of 2D perovskites and how it challenges our understanding of this fundamental excitation. Finally, we highlight some controversy related to particularly large bright-dark exciton states splitting and high efficiency of light emission from these materials. This can result from the unique synergy of excitonic and mechanical properties of 2D perovskites crystals.
Źródło:
Scientiae Radices; 2022, 1, 1; 3-25
2956-4808
Pojawia się w:
Scientiae Radices
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended X-Ray Absorption Fine Structure Studies of Co Doped ZnS and ZnSe Alloys
Autorzy:
Ławniczak-Jabłońska, K.
Gołacki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1931712.pdf
Data publikacji:
1994-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.Lx
78.70.Dm
87.64.Fb
Opis:
X-ray absorption experiments were performed at the Kedge of Co and Zn in Zn$\text{}_{1-x}$Co$\text{}_{x}$S and Zn$\text{}_{1-n}$Co$\text{}_{x}$Se compounds with x = 0.25, 0.16, 0.10, 0.05, 0.00 in the sulphides samples and x = 0.07, 0.02, 0.00 in the selenide ones. Analysis of the extended X-ray absorption fine structure oscillations using phase and amplitudes either from McKale code or from standard samples, gave the distance, number of atoms and the Debye-Waller factors for nearest neighbours. We found that the cation-anion distances Zn-S(Se) or Co-S(Se) are systematically shorter in ZnS than in ZnSe matrix, the Zn-anion distance is always larger than the Co-anion one without any significant Co content dependence. This allowed us to estimate the covalent radius of Co in the studied matrices to be 0.025 Å smaller than the Zn covalent radius and stated that covalent radius of Co is independent of the type of surrounding atoms. In addition the Debye-Waller factors indicated a better ordering in ternary compounds than in the binary standard ones in agreement with rocking curve measurements.
Źródło:
Acta Physica Polonica A; 1994, 86, 5; 727-735
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex trapezoid grating for light trapping in thin-film solar cells: super-fine structure
Autorzy:
Fang, Junfei
Gou, Yuchun
Deng, Jianping
Powiązania:
https://bibliotekanauki.pl/articles/1835802.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
light trapping
complex trapezoid grating
rigorous coupled-wave analysis
solar cell
Opis:
The research of the optimal surface structure has attracted considerable interest because of its potential application in light trapping in thin-film solar cells (TFSCs). In this paper, a super-fine structure named complex trapezoid grating is proposed to improve the optical absorption comparing to the conventional simple trapezoid grating in a-Si:H TFSCs. The numerical calculation by utilizing rigorous coupled-wave analysis (RCWA) is conducted to obtain the optical absorption of the structured surface. The results demonstrate that, compared to a planar slab, the optimized-simple trapezoid grating shows 97% enhancement of power conversion efficiency η while the complex trapezoid grating shows 131% enhancement. Obviously, the complex trapezoid grating exhibits a better performance than the simple grating, which is due to the perfect antireflective effect and microcavity resonance effect. The angular response of the optical absorption in a-Si:H TFSCs was also investigated. The results further indicate that it is a better way to select the complex trapezoid grating in improving the optical absorption of silicon-based TFSCs.
Źródło:
Optica Applicata; 2020, 50, 3; 391-400
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local Structure Around Te in Heavily Doped GaAs:Te using X-Ray Absorption Fine Structure
Autorzy:
Pietnoczka, A.
Bacewicz, R.
Slupinski, T.
Antonowicz, J.
Wei, Su-Huai
Powiązania:
https://bibliotekanauki.pl/articles/1431547.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cj
61.72.uj
Opis:
The annealing of heavily doped GaAs:Te can significantly change the free electron concentration in a reversible manner. These changes of electrical properties are accompanied by the structural changes of GaAs:Te solid solution. We used X-ray Absorption Fine Structure at K-edge of tellurium to determine local changes around Te atoms for different states of the GaAs:Te crystals caused by the annealing corresponding to different electron concentrations. The best EXAFS fit for the samples with high electron concentration was obtained for the substitutional $Te_{As}$ model with elongated Te-Ga bonds (as compared to the As-Ga distance). For the samples in the low concentration state the best fit was for the pairs of Te atoms forming a rhombohedral symmetry double-DX centre, with the proportional admixture of the substitutional tellurium
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 879-882
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Magnetic Field on Fine Structure of Tunnel Current in Double-Barrier Resonant-Tunneling Devices
Autorzy:
Belyaev, A. E.
Vitusevich, S. A.
Glavin, B. A.
Mąkosa, A.
Dobrowolski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1933716.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Gk
85.30.Mn
Opis:
An effect of magnetic field on a fine oscillatory structure revealed in the resonant current flowing through double-barrier resonant-tunneling devices is examined. It is found that the observed variation of the fine structure in a magnetic field parallel to the current direction differs considerably from that appearing in tunnel current flowing through single-barrier structures. Experimental results are explained in terms of the quantum interference effect arising in structures having wide spacer layers.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 675-678
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended X-Ray Absorption Fine Structure Evidence for Homopolar Bonding in Amorphous Cd-As and Zn-P
Autorzy:
Burian, A.
Powiązania:
https://bibliotekanauki.pl/articles/1920901.pdf
Data publikacji:
1992-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.Lx
61.55.Hg
78.30.Fs
Opis:
Local atomic arrangement in evaporated amorphous Cd-As and Zn-P films was investigated by extended X-ray absorption fine structure. Results of modelling indicate that bonds between atoms of the same kind occur for both (Cd,Zn)-rich and (As,P)-rich compositional regions. This specific chemical ordering, much alike to that in the corresponding crystalline polymorphs, appears to play a predominant role in determining of the local structures in these materials.
Źródło:
Acta Physica Polonica A; 1992, 82, 2; 309-313
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine structure of the infective eggs of the dilepidid cestode Hepatocestus hepaticus [Baer, 1932], a parasite of shrew
Autorzy:
Swiderski, Z.
Tkach, V.V.
Powiązania:
https://bibliotekanauki.pl/articles/837575.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
parasite
structure
shrew
Hepatocestus hepaticus
cestode
egg
Źródło:
Annals of Parasitology; 1998, 44, 3
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fine structure of marine hydrophysical fields and its influence on the behaviour of plankton: an overview of some experimental and theoretical investigations
Autorzy:
Druet, C.
Powiązania:
https://bibliotekanauki.pl/articles/48011.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
turbulence
zooplankton
behaviour
temperature
euphotic zone
hydrophysical property
plankton
marine plankton
phytoplankton
hydrophysical field
Opis:
This article is an overview which presents in brief some of the results of research done in the last 20 years on the structure and dynamics of intermittent fine structure in the euphotic zone of the sea and its effect on the behaviour of marine plankton. The introduction provides a general characterisation of this structure and its relations with the plankton concentration field. Chapter 2 covers turbulent mixing processes in layers of homogeneous fine structure,and discusses the dynamic interactions of these layers and how these affect the behaviour of marine phyto- and zooplankton. The principal conclusions,in brief, are that the current state of knowledge,no t only of intermittent fine structure itself and its dynamic transformations,but also of the influence of these processes on the behaviour of marine plankton,i s today still a long way from permitting an accurate description of reality. Moreover,b oth empirical investigations (in situ and in the laboratory) and mathematical modelling,despite the quite advanced stage that the latter has reached,need to be continued. For this reason the prime aim of this article is to show up the gaps in our knowledge which future research in this complex,in terdisciplinary area of oceanography should attempt to fill.
Źródło:
Oceanologia; 2003, 45, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local Structure of Mn in $(La_{1-x}Ho_{x})_{2//3}Ca_{1//3}MnO_{3}$ Studied by X-ray Absorption Fine Structure
Autorzy:
Pietnoczka, A.
Pękała, M.
Bacewicz, R.
Drozd, V.
Fagnard, J.
Vanderbemden, P.
Antonowicz, J.
Zalewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1538864.pdf
Data publikacji:
2010-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cj
75.47.Lx
87.64.kd
Opis:
Results of X-ray absorption fine structure measurements in manganites $(La_{1-x}Ho_{x})_{2//3}Ca_{1//3}MnO_{3}$ with 0.15 < x < 0.50 are presented. When $LaMnO_{3}$ is doped with a divalent element such as $Ca^{2+}$, substituting for $La^{3+}$, holes are induced in the filled Mn d orbitals. This leads to a strong ferromagnetic coupling between Mn sites. Ca ions in $La_{1-x}Ca_{x}MnO_{3}$ introduce a distortion of the crystal lattice and mixed valence Mn ions ($Mn^{3+}$ and $Mn^{4+}$). On the other hand, in manganites $(La_{1-x}Ho_{x})_{2//3}Ca_{1//3}MnO_{3}$ the substitution of La for Ho causes a lattice distortion and induces a disorder, which reduces a magnetic interaction. The ferromagnetic transition temperature and conductivity decrease very quickly with increasing x. The magnetic and transport properties of compounds depend on the local atomic structure around Mn ions. The information on the bond lengths and Debye-Waller factor are obtained from the extended X-ray absorption fine structure (EXAFS) data analysis. The charge state of Mn is determined from the position of the absorption edge in X-ray absorption near edge structure (XANES) data. XAFS results are in good agreement with magnetic characteristics of the studied materials.
Źródło:
Acta Physica Polonica A; 2010, 117, 2; 281-285
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Description of Cochliopodium megatetrastylus n. sp. Isolated from a Freshwater Habitat
Autorzy:
Anderson, O. Roger
Tekle, Yonas I.
Powiązania:
https://bibliotekanauki.pl/articles/763483.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Amoebozoa, comparative morphology, fine structure, molecular genetics, taxonomy
Opis:
Cochliopodium megatetrastylus n. sp. is described based on light microscopy, fine structure and molecular genetic evidence. Amoebae are broadly oval to somewhat triangular during locomotion with average length of 37 μm and breadth of 50 μm, and surrounded by a hyaloplasm margin, somewhat narrow when at rest but more expanded during locomotion (~ 5–10 μm at the anterior). Sparsely occurring subpseudopodia, barely emergent from the hyaloplasm, are blunt and finger-like, occasionally becoming adhesive laterally or at the posterior. Cysts develop after 2–3 weeks in culture and are round with a distinct margin, decreasing in size from 20 to 5 μm during maturation. The granuloplasm contains refractile crystals. A vesicular nucleus (~ 6 μm), containing a nucleolus (2–3 μm), is variable in shape from somewhat lenticular in section to irregularly rounded with undulating or lobed margins. Surface scales (~ 0.3 μm in height) have an apical deeply concave funnel-like collar (~ 0.15 μm deep), without a spine, composed of radial fine rays and concentric filaments forming a finemesh, supported on four non-cross-linked styles (~ 0.2 μm apart) attached to a round to broadly angular base plate (0.6–1 μm) with a fine gridtexture. Cysts are rounded and enclosed by an organic wall bearing remnants of the scales on its outer surface. Both concatenated analysis of SSU-rDNA and COI genes and comparative morphologies support the designation of Cochliopodium megatetrastylus n. sp. as a new species.
Źródło:
Acta Protozoologica; 2013, 52, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrastructure of Diplophrys parva, a New Small Freshwater Species, and a Revised Analysis of Labyrinthulea (Heterokonta)
Autorzy:
Anderson, O. Roger
Cavalier-Smith, Thomas
Powiązania:
https://bibliotekanauki.pl/articles/763447.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Diplophryidae, fine structure, molecular genetics, Labyrinthomyxa, labyrinthulean taxonomy
Opis:
We describe Diplophrys parva n. sp., a freshwater heterotroph, using fine structural and sequence evidence. Cells are small (L = 6.5 ± 0.08, W = 5.5 ± 0.06 µm; mean ± SE) enclosed by an envelope/theca of overlapping scales, slightly oval to elongated-oval with rounded ends, (1.0 × 0.5–0.7 µm), one to several intracellular refractive granules (~ 1.0–2.0 µm), smaller hyaline peripheral vacuoles, a nucleus with central nucleolus, tubulo-cristate mitochondria, and a prominent Golgi apparatus with multiple stacked saccules (~ 10). It is smaller than published sizes of Diplophrys archeri (~ 10–20 µm), modestly less than Diplophrys marina (~ 5–9 µm), and differs in scale size and morphology from D. marina. No cysts were observed. We transfer D. marina to a new genus Amphifila as it falls within a mo-lecular phylogenetic clade extremely distant from that including D. parva. Based on morphological and molecular phylogenetic evidence, Labyrinthulea are revised to include six new families, including Diplophryidae for Diplophrys and Amphifilidae containing Amphifila. The other new families have distinctive morphology: Oblongichytriidae and Aplanochytriidae are distinct clades on the rDNA tree, but Sorodiplophryidae and Althorniidae lack sequence data. Aplanochytriidae is in Labyrinthulida; the rest are in Thraustochytrida; Laby-rinthomyxa is excluded.
Źródło:
Acta Protozoologica; 2012, 51, 4
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proposal of Method of Removal of Mould Material from the Fine Structure of Metallic Foams used as Filters
Metoda usuwania materiału formierskiego z delikatnej struktury piany metalowej stosowanej jako filtr
Autorzy:
Kroupová, I.
Bednářová, V.
Elbel, T.
Radkovský, F.
Powiązania:
https://bibliotekanauki.pl/articles/353533.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallic foam
aluminum foam
manufacturing of metal foam
cast metal filter
piana metalowa
piana aluminiowa
produkcja pian metalicznych
filtr z piany metalowej
Opis:
Metallic foams are materials that are subject of an ongoing research with the broad applicability in many different areas (e.g. automotive industry, building industry, medicine, etc.). These metal materials contain in their structure artificially created pores. These pores give them specific properties, such as: large rigidity at low density, high thermal conductivity, capability to absorb energy, etc. Since the discovery of porous metallic materials numerous methods of production have been developed. The aim of the paper is to introduce effective casting methods of manufacturing of metallic foams, namely cast metal filters from the aluminum alloy. Research deals with investment casting with use of pattern made of polymeric foam, which is used for production of metallic foam with open pores. The main disadvantage of this procedure consists in removing the mould material without damaging the fine structure of the cast filter. Plaster is used as the mould material and the most important result of this paper is the presentation of the effective procedure of plaster removal from the porous structure of cast filters.
Piany metalowe są przedmiotem wielu badań gdyż znajdują szerokie zastosowanie w wielu dziedzinach np. produkcji samochodów. budownictwie czy w medycynie. W swojej strukturze zawierają sztucznie wytworzone pory, zapewniające uzyskanie specyficznych właściwości jak duża wytrzymałość, niewielka gęstość, wysokie przewodnictwo cieplne zdolność do absorpcji energii itp. Od czasu wynalezienia porowatych materiałów metalowych opracowano wiele metod ich wytwarzania. Celem opracowania jest wprowadzenie efektywnych metod odlewniczych produkcji pian metalowych, szczególnie ze stopów glinu. Studium zajmuje się precyzyjną metodą odlewania przy zastosowaniu modelu wykonanego z piany polimerowej stosowanej w produkcji piany z otwartymi porami. Główna niedogodność metody polega na trudności usuwania materiału formierskiego, bez naruszenia delikatnej struktury odlewanego filtra. Jako materiał formierski stosuje się gips i najważniejszym wynikiem pracy jest przedstawienie efektywnej procedury usuwania gipsu z porowatej struktury odlanego filtra.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 2; 727-730
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine-Scale Structure Investigation of Nimonic 263 Superalloy Surface Damaged by Femtosecond Laser Beam
Autorzy:
Milosavljevic, A.
Petronic, S.
Sreckovic, M.
Kovacevic, A.
Krmpot, A.
Kovacevic, K.
Powiązania:
https://bibliotekanauki.pl/articles/1791236.pdf
Data publikacji:
2009-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
01.55.+b
42.62.-b
81.05.Bx
81.20.Vj
Opis:
Due to the specific conditions of manufacturing, processing and utilization of nickel-base superalloys, the implementation of contemporary precision techniques is necessary in the research of the alloys features. Multi-component nickel-base superalloys, with about of 50% of nickel content, are commonly exploited in the conditions of high temperatures and pressures as well as in various aggressive operating environments. For successful quality control, which includes the monitoring of the changes in the alloy microstructure, fine-scale structure investigations are necessary. In this work, the samples of nickel-base superalloys have been exposed to 800 nm femtosecond laser in various operating regimes. Surface damages and dents caused by femtosecond laser pulses have been observed by optical and scanning microscopy.
Źródło:
Acta Physica Polonica A; 2009, 116, 4; 553-556
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid callogenesis and plant regeneration of fine and coarse varieties of rice
Autorzy:
Khokhar, M.I.
Iqbal, M.Z.
Teixeira da Silva, J.A.
Powiązania:
https://bibliotekanauki.pl/articles/80293.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rice
coarse structure
fine structure
plant regeneration
callogenesis
6-benzyladenine
callus induction
root formation
kinetin
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2017, 98, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fine structure of zooidal tubes in Sabelliditida and Pogonophora with reference to their affinity
Ultrastruktura szkieletu Sabelliditida i Pogonophora oraz problem ich związków filogenetycznych
Ul’trastruktura trubok Sabelliditida i Pogonophora i problema ikh filogeneticheskikh svjazejj
Autorzy:
Urbanek, A.
Mierzejewska, G.
Powiązania:
https://bibliotekanauki.pl/articles/21125.pdf
Data publikacji:
1977
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ultrastructure
zooidal tube
tube wall
Sabelliditida
Pogonophora
morphology
fauna
paleontology
Lower Cambrian
Cambrian
Źródło:
Acta Palaeontologica Polonica; 1977, 22, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wytwarzanie struktury ultradrobnoziarnistej z wykorzystaniem koncepcji metody wyciskania bocznego wspomaganego tarciem
Achievement of an ultra-fine-grained structure using the concept of the friction-assisted lateral extrusion method
Autorzy:
Szkudelski, S.
Ziółkiewicz, S.
Pachutko, B.
Powiązania:
https://bibliotekanauki.pl/articles/211450.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Obróbki Plastycznej
Tematy:
wyciskanie boczne
tarcie
SPD
struktura ultradrobnoziarnista
lateral extrusion
friction
ultra fine grained structure
Opis:
W artykule przedstawiono wyniki badań profili wytworzonych metodą wyciskania bocznego wspomaganego tarciem na urządzeniu znajdującym się w Instytucie Obróbki Plastycznej w Poznaniu. Metoda kształtowania polega na wyciskaniu bocznym materiału umieszczonego wewnątrz podgrzewanego pojemnika, na skutek połączenia siły osiowo działającej na próbkę oraz siły tarcia generowanej przez obrotową tarczę. Cykl badań prowadzony był przy trzech prędkościach obrotowych: 8, 18 i 28 obr/min oraz przy trzech wartościach siły wciskającej 30, 55 oraz 80 kN. Wsad wyciskany ze stali gat. 15 grzano do 600° C i poddano stopniu przerobu λ=8. Struktury, uzyskanych w ten sposób profili, obserwowano na mikroskopie świetlnym. Profil o największym rozdrobnieniu ziarna (8 obr/min, 80 kN) poddano obserwacjom EBSD, które pozwoliły określić średnią wielkość ziaren na poziomie 0,53 μm. Tak duże rozdrobnienie jest efektem nałożenia się silnego odkształcenia materiału i przypuszczalnie dynamicznej rekrystalizacji zachodzącej podczas procesu kształtowania. Najlepsza powierzchnia zewnętrzna profili została uzyskana przy małych prędkościach obrotowych i maksymalnej sile wciskającej wsad w obrotową tarczę. Przy prędkości obrotowej 18, 28 obr/min powierzchnia profili charakteryzowała się dużą nieregularnością śladów powstałych na powierzchni będącej w styku z obrotową tarczą. Dla profili o najlepszym stanie powierzchni zewnętrznej wykonano badanie rozkładu mikrotwardości HV0,3 na przekroju poprzecznym – badanie to wykazało najwyższą twardość dla profili uzyskiwanych przy 8 obr/min oraz 80 kN.
This article presents the results of studies on sections manufactured by friction-assisted lateral extrusion on a machine found at the Metal Forming Institute in Poznań. The forming method is based on lateral extrusion of material placed inside of a heated container as a result of the combination of axial forces acting on the specimen and friction generated by the rotating disk. The test cycle was performed at three rotational speeds: 8, 18, and 28 rpm and at three values of extruding force 30, 55, and 80 kN. The extruded grade 15 steel stock was heated to 600° C and subjected to degree of processing λ=8. The structures of sections obtained in this manner were observed under a light microscope. The section with the finest grains (8 rpm, 80 kN) was examined by EBSD, which made it possible to determine a 0.53 μm average grain size. This fine-grained structure is the effect of the combination of strong deformation of a layer of the material and the presumably dynamic recrystallization taking place during the forming process. The best exterior surface of sections was achieved at low rotational speeds and maximum force punching the stock into the rotating disk. At rotational speeds 18, 28 rpm, the surface of sections was characterized by high irregularity of traces formed on the surface in contact with the rotating disk. Testing of HV0.3 microhardness distribution on the cross-section was conducted for sections with the best exterior surface condition – the greatest hardness was obtained for sections produced at 8 rpm and 80 kN.
Źródło:
Obróbka Plastyczna Metali; 2015, 26, 3; 191-202
0867-2628
Pojawia się w:
Obróbka Plastyczna Metali
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure ability of fine textured red soils in north Libya
Autorzy:
Drzymala, S.
Kaczmarek, Z.
Spychalski, W.
Powiązania:
https://bibliotekanauki.pl/articles/24415.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
physical property
chemical property
water resistance
red soil
structure ability
Libya
soil aggregate
soil texture
Źródło:
International Agrophysics; 1995, 09, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ drobnoziarnistości struktury pierwotnej staliwa na prędkość fali ultradźwiękowej
Effect of Fine-Grain Primary Structure of the Cast Steel on the Velocity of Ultrasonic Wave Propagation
Autorzy:
Bartocha, D.
Suchoń, J.
Baron, C.
Szajnar, J.
Powiązania:
https://bibliotekanauki.pl/articles/380807.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
staliwo
struktura pierwotna
fala ultradźwiękowa
propagacja fali
cast steel
primary structure
ultrasonic wave
wave propagation
Opis:
W artykule przedstawiono próbę określenia zależności między stopniem rozdrobnienia struktury pierwotnej staliwa, który jest wynikiem modyfikacji, i prędkością propagacji fali ultradźwiękowej w materiale. Znalezienie takiej zależności umożliwiałoby oszacowanie wielkości ziarna pierwotnej struktury wybranych fragmentów odlewów staliwnych metodą nieniszczącą. Co w efekcie może doprowadzić do opracowania metod szacowania wartości właściwości mechanicznych przez pomiar prędkości rozchodzenia się fal ultradźwiękowych w odlewaniu. W pracy przedstawiono wyniki pomiarów prędkości fal ultradźwiękowych w próbkach pobranych z niskostopowego staliwa konstrukcyjnego. Stopień rozdrobnienia struktury porównywano z pomiarów prędkości fal ultradźwiękowych, a wyniki zostały przeanalizowane i omówione.
The work presents an attempt to determine the relationship between the refinement of the cast steel primary structure which is a result of modifying and the parameter of ultrasonic wave propagation in the material. Finding such a relationship would allow to on estimation of the grain size of the primary structure of selected fragments of cast steel castings with non-destructive methods. What in the long term can lead to the development of methods for estimating the value of the mechanical properties by measuring the velocity of ultrasonic wave propagation in the casting. This paper presents the results of ultrasonic wave velocity measurements in samples taken from low-alloy structural cast steel. Cast steel was modified using different modifiers to obtain diversity refinement of the primary structure. The degree of refinement of the structure was compared with the ultrasonic wave velocity measurements and the results have been analyzed and discussed.
Źródło:
Archives of Foundry Engineering; 2013, 13, 2 spec.; 5-9
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The complementary structural studies of the double metal cyanide type catalysts for the ring opening polymerization of the oxiranes
Komplementarne badania strukturalne dimetalocyjankowych katalizatorów polimeryzacji z otwarciem pierścienia oksiranowego
Autorzy:
Chruściel, A.
Hreczuch, W.
Czaja, K.
Ławniczak-Jabłońska, K.
Janik, J.
Powiązania:
https://bibliotekanauki.pl/articles/947469.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
double metal cyanide catalysts (DMC)
thermal analysis
thermogravimetric analysis (TG)
differential scanning calorimetry (DSC)
evolved gas analysis (EGA)
X-ray absorption spectroscopy (XAS)
X-ray absorption near edge structure (XANES)
extended X-ray absorption fine structure (EXAFS)
katalizatory dimetalocyjankowe (DMC)
analiza termiczna
analiza termograwimetryczna (TGA)
różnicowa kalorymetria skaningowa (DSC)
analiza wydzielanych gazów (EGA)
rentgenowska absorpcyjna spektroskopia struktury przykrawędziowej (XANES)
synchrotronowa absorpcyjna spektroskopia rentgenowska (EXAFS)
Opis:
The extensive complementary experimental studies of the double metal catalysts (DMC) with two kinds of the organic ligands were performed. The chemical justification of the observed TG/DSC (thermogravimetric analysis/differential scanning calorimetry) steps was proposed. Several organic ligand complexing states were found in both types of catalysts. X-ray absorption spectroscopy (XAS) analysis established that only Zn atoms are the active metallic centers in DMC catalyst regardless the used ligand. Cl atoms were detected near some of Zn atoms. Contrary to the common suppositions no significant amount of oxygen atoms was detected in the closest coordination spheres of Zn.
Przeprowadzono badania strukturalne katalizatorów dimetalocyjankowych (DMC) z dwoma rodzajami ligandów organicznych. Zaproponowano wyjaśnienie etapów przebiegu krzywych otrzymanych metodą analizy termograwimetrycznej i różnicowej kalorymetrii skaningowej (TG/DSC) badanych katalizatorów. Wykazano obecność kilku stopni związania ligandów w kompleksach DMC. Na podstawie wyników badań z wykorzystaniem absorpcji rentgenowskiej (XAS) stwierdzono, że centrum aktywne katalizatora stanowi atom cynku. W bezpośrednim sąsiedztwie atomów Zn wykryto obecność atomów Cl, natomiast w najbliższych sferach koordynacyjnych atomu Zn nie wykryto atomów tlenu.
Źródło:
Polimery; 2016, 61, 6; 421-432
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abrasive Wear of Fine-grained Ni3Al Intermetallic Alloys
Autorzy:
Zasada, D.
Jasionowski, R.
Bałdyga, K.
Powiązania:
https://bibliotekanauki.pl/articles/381521.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
abrasion
wear
intermetallic
geometric structure of surface
abrazja
zużycie
faza międzymetaliczna
struktura geometryczna powierzchni
Opis:
Influence of chemical composition and material structure on the abrasive wear of Ni3Al intermetallic alloy in loose abrasive was investigated in details. Boron, zirconium and chromium were used as the alloying elements. The alloys are made up of &gamma' or &gamma'+&gamma phases (single-phase, ordered matrix + disordered area). Grain size of the alloys was varied: 5, 20 and 45 &mi m. Abrasive were experiments were performed with T-07 tester (Norma company) in accordance to the GOST 23.2008-79 standard. Mechanism of surface layer damaging exposed to the loose abrasive was described on the basis of the obtained structural and topographical experiments. The results revealed that relative abrasive wear in loose abrasive is approximately same for all the investigated alloys with varied grain size.
Źródło:
Archives of Foundry Engineering; 2014, 14, 1 spec.; 187-192
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precipitation Processes during Non-Isothermal Ageing of Fine-Grained 2024 Alloy
Autorzy:
Kozieł, J.
Błaż, L.
Włoch, G.
Sobota, J.
Lobry, P.
Powiązania:
https://bibliotekanauki.pl/articles/352499.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AA2024 alloy
scrap metal milling
structure refining
powder metallurgy
precipitation hardening
Opis:
Mechanical alloying and powder metallurgy procedures were used to manufacture very fine-grained bulk material made from chips of the 2024 aluminum alloy. Studies of solution treatment and precipitation hardening of as-received material were based on differential scanning calorimetry (DSC) tests and TEM/STEM/EDX structural observations. Structural observations complemented by literature data lead to the conclusion that in the case of highly refined structure of commercial 2024 alloys prepared by severe plastic deformation, typical multi-step G-P-B →θ” →θ’ →θ precipitation mechanism accompanied with G-P-B →S” →S’ →S precipitation sequences result in skipping the formation of metastable phases and direct growth of the stable phases. Exothermic effects on DSC characteristics, which are reported for precipitation sequences in commercial materials, were found to be reduced with increased milling time. Moreover, prolonged milling of 2024 chips was found to shift the exothermic peak to lower temperature with respect to the material produced by means of common metallurgy methods. This effect was concluded to result from preferred heterogeneous nucleation of particles at subboundaries and grain boundaries, enhanced by the boundary diffusion in highly refined structures. Transmission electron microscopy and diffraction pattern analysis revealed the development of very fine Al4C3 particles that grow due to the chemical reaction between the Al matrix and graphite flakes introduced as a process control agent during the preliminary milling of chips. Al4C3 nano-particles are formed at high temperatures, i.e. during hot extrusion and the subsequent solution treatment of the samples. Highly refined insoluble particles such as aluminum carbide particles and aluminum oxides were found to retard recrystallization and reduce recovery processes during solution treatment of preliminarily milled materials. Therefore, the as-extruded material composed of a milled part and chip residuals retained its initial bimodal structure in spite of solution heat treatment procedures. This points to a high structural stability of the investigated materials, which is commonly required for new technologies of high-strength Al-based materials production.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 1; 169-176
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie komputerowej analizy obrazu do badań struktury brykietów z materiałów drobnoziarnistych
Application of computer image analysis to the study of the briquettes structure made on a fine-grained materials
Autorzy:
Borowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/395226.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
komputerowa analiza obrazu
materiały drobnoziarniste
brykiety
Opis:
Przedstawiono przykład zastosowania komputerowej analizy obrazu celem sprawdzenia i porównania struktury brykietów uzyskanych z metalowych materiałów drobnoziarnistych. Badano brykiety z prasy stemplowej i walcowej zawierające różne dodatki pełniące rolę lepiszcza. Brykiety wykonano z odpadów powstających w procesie obróbki wykańczającej kulkowych łożysk tocznych. Odpady te zawierają znaczne ilości żelaza, które po odpowiednim przetworzeniu mogą nadawać się do utylizacji w przemyśle hutniczym. Na podstawie przeprowadzonych analiz potwierdzono dobór odpowiedniego środka wiążącego w procesie przygotowania mieszanki do brykietowania. Sprawdzono także poprawność sposobu mieszania składników oraz słuszność doboru urządzenia do brykietowania. Stwierdzono, że brykiety z melasą scalane w prasie walcowej posiadają najbardziej jednorodną i zwartą strukturę.
The sample case of computer image analysis to compare the briquettes structure made on a fine-grained metal materials was presented. The tested briquettes, made on the stamp press and the roll press, contained different additional substances as a binder. The briquettes were made of wastes from the finishing process of bearing balls. The wastes contain considerable quantity of iron which can be utilized in metallurgical industry after certain performing. Based on carried out analysis a proper selection of the binder to prepare the mixture for briquetting was confirmed. The correct way of mixing the components and the appropriate selection of briquetting machine were also verified as essential. Therefore, it was concluded that briquettes with molasses made in a roll press have the most homogeneous and compact structure.
Źródło:
Postępy Nauki i Techniki; 2007, 1; 17-24
2080-4075
Pojawia się w:
Postępy Nauki i Techniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of High-Temperature Treatment of Melt on the Composition and Structure of Aluminum Alloy
Autorzy:
Grachev, V. A.
Turakhodjaev, N. D.
Powiązania:
https://bibliotekanauki.pl/articles/382645.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innovative foundry technology
innovative foundry material
heat treatment
aluminum alloy structure
fine-grained microstructure
gasfired arc furnace
electric arc furnace
innowacyjna technologia odlewnicza
innowacyjny materiał odlewniczy
obróbka cieplna
stop aluminium
mikrostruktura drobnoziarnista
piec łukowy elektryczny
piec łukowy gazowy
Opis:
The aim of the current study was to examine the structure of an alloy treated at various temperatures up to 2,000–2,100 °C. Among research techniques for studying alloy structure there were the electron and optical microstructure, X-ray structure, and spectral analysis, and for studying the developed furnace geometric parameters the authors employed mathematical modeling method. The research was performed using aluminum smelting gas-fired furnaces and electric arc furnaces. The objects of the study were aluminum alloys of the brand AK7p and AK6, as well as hydrogen and aluminum oxide in the melt. For determining the hydrogen content in the aluminum alloy, the vacuum extraction method was selected. Authors have established that treatment of molten aluminum alloy in contact with carbon melt at high temperatures of 2,000–2,100 °C has resulted in facilitating reduction of hydrogen and aluminum oxide content in the melt by 40-43% and 50-58%, respectively, which is important because hydrogen and aluminum oxide adversely affect the structure and properties of the alloy. Such treatment contributes to the formation of the extremely fine-grained microstructure of aluminum alloy.
Źródło:
Archives of Foundry Engineering; 2017, 17, 4; 61-66
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Політичні династії Лівану: «тонке налаштування»
The Lebanese Political Dynasties: “the fine-tuning”
Autorzy:
Зелінський, А.Л.
Powiązania:
https://bibliotekanauki.pl/articles/22676743.pdf
Data publikacji:
2022-01-27
Wydawca:
National Academy of Sciences of Ukraine. Institute of World History
Tematy:
Ліванська республіка
кланова структура
політичні династії
заїми (зуама)
нова еліта
«мафіозна демократія»
Lebanese Republic
a clan structure
the political dynasties
zaims (zuama)
a new elite
“a mafia democracy”
Opis:
Невелика за розміром Ліванська республіка вирізняється конфесійною сегментованістю, клановою орієнтованістю й переважною спадковістю місцевої політичної еліти. Олігархічний характер політичного режиму країни кедрів обумовлено традиційною клановою структурою ліванського суспільства. Протягом століть провідну роль у Лівані відігравали територіально-конфесійні клани на чолі з шейхами–заїмами (зуама). Ця система перекочувала у сучасний ліванський політикум. До того ж, вона знаходить підтримку як серед старої, так і серед нової еліти. Тому, чітке уявлення про причетність керівників владних структур Ліванської республіки до тієї чи іншої політичної династії є необхідним для розуміння сучасного стану речей у країні, а також для прогнозування характеру її подальшого політичного розвитку. Найважливішим критерієм послідовності висвітлення діяльності політичних династій країни кедрів виступає ступінь впливу того чи іншого з нинішніх «Заїмів» на нинішні ліванські реалії. З огляду на це, мова піде про родинно-клановий контекст перших трьох осіб держави: Прем’єр-міністра, президента (спікера) національної асамблеї і президента Ліванської республіки, а також про низку неохоплених вище лідерів впливових чи бодай знакових політичних сил, представлених у парламенті, обраному у 2018 році (за винятком Х. Насралли і С. Джааджі). Зокрема, стаття містить аналіз можливостей створення політичних династій діючим прем’єр-міністром Н. Мікаті та спікером парламенту Н. Беррі, перспектив для подальшого існування нещодавно заснованих політичних династій Аунів і аль-Харірі, а також причин політичного виживання родин спадкових ліванських заїмів Джумблатів і Франж’є. Головний висновок публікації полягає у констатації перспективи тотального збереження принципу сімейності у ліванській політиці бодай на найближчі десятиліття.
A small in size, Lebanese Republic is known for it’s a confessional segmentation, a clan orientation and a predominant heredity of the local political elite. A oligarchic nature of a political regime of the country of cedars is due to a traditional clan structure of a lebanese society. For centuries, a leading role in Lebanon was played by the territorial-confessional clans, that wereheaded by the sheikhs–zaims (zuama). This system has migrated to a modern lebanese politics. At the same time, it has the support among both a old one and a new one elite. Therefore, a clear understanding of the involvement of the leaders of the power structures of the Lebanese Republic in a certain political dynasty is necessary for understanding a current state of affairs in the country, as well as to predict the nature of its further political development. So, the primary criterion, which was determines the sequence of the coverage of the activity of the political dynasties of the country of cedars is the degree of the influence on a today’s Lebanese realities of one or another of the current “zaims”. Based on this principle, we will talk about a a family-clan context of the first three persons of the state: the Prime Minister, the President (Speaker) of the National Assembly and the President of Lebanese Republic, as well as a few of the other leaders of the influential or at least the appreciable political forces, that are represented in parliament, which was elected in 2018 (except of H. Nasrallah and S. Geagea). In particular, the article contains an analysis of the possibilities of the creating the political dynasties by the current Prime Minister N. Mikati and Speaker of Parliament N. Berri, the prospects for a further existence of the newly founded political dynasties of the families of Aoun and al-Hariri, as well as the reasons for a political survival of the hereditary Lebanese zaim families Jumblatt and Frangieh. The main conclusion of this publication is the statement about a prospect of a total preservation of the principle of the nepotism in a lebanese politics for at least the coming decades.
Źródło:
Проблеми всесвітньої історії; 2022, 17; 122-157
2707-6776
Pojawia się w:
Проблеми всесвітньої історії
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
4D gas geological research on coal seam with gas hazard potential in mining panel
Autorzy:
Cui, Hongqing
He, Xin
Wang, Zehua
Powiązania:
https://bibliotekanauki.pl/articles/2201387.pdf
Data publikacji:
2022
Wydawca:
Główny Instytut Górnictwa
Tematy:
gas geology
gas hazard prevention
small geological structure
fine geological survey
4D analysis
geologia gazowa
zapobieganie zagrożeniom gazowym
mała struktura geologiczna
szczegółowe badania geologiczne
analiza 4D
Opis:
According to regulations of the mining industry in China, it is necessary to carry out gas hazard prevention projects in advance when mining coal seams with gas hazard potential, and gas geological research should be taken as the basic work for optimal design and effective construction of gas hazard prevention projects. Research on coal seam with gas hazard potential have shown that anomalous geological area could be the gas hazard potential area as well, where superimposed tectonic and mining stress field usually results in tectonically disturbed coal and pressured gas. A 4D gas geological research method is used to find out the anomalous geological area and assess its gas hazard potential. The method covers two ranges of gas geological research: fine geological survey and 4D analysis. The former includes a comprehensive prospect of concealed small geological anomalies (such as small fault, small fold and coal thickness variation) by use of gas extraction projects; The latter includes a dynamic forecast of gas hazard potential from space-time perspective based on numerical simulation analysis on additional stress fields around small geological structures beyond coal mining face. Its research benefit the optimal design and effective implementation of gas hazard prevention measures in coal mining panel with high coal and gas outburst potential.
Źródło:
Journal of Sustainable Mining; 2022, 21, 2; 112--119
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Plastic Properties of Fine-Grained WMD After Micro-Jet Cooling
Własności plastyczne drobnoziarnistego stopiwa schłodzonego mikro-jetowo
Autorzy:
Hadryś, D.
Węgrzyn, T.
Piwnik, J.
Powiązania:
https://bibliotekanauki.pl/articles/355305.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro-jet cooling in welding
coefficient of restitution
plastic strain
dynamic conditions
metallographic structure
acicular ferrite
spawanie z chłodzeniem mikrojetowym
współczynnik restytucji
odkształcenia plastyczne
warunki dynamiczne
struktura metalograficzna
ferryt iglasty
Opis:
Micro-jet welding is an innovative method of weld forced cooling immediately after welding. It allows to obtain weld with superior properties in comparison to conventional welding. The reason for this is to obtain a more favorable structure of the weld metal deposit (WMD) with much higher amount of acicular ferrite (AF). Different structures and mechanical properties of weld metal deposit were obtained by using various gases for cooling. The paper shows the relationship between the type of gas for micro-jet cooling and plastic properties of the weld joint. Coefficient of restitution and plastic strain were selected to describe changes of weld plastic properties for different micro-jet cooling gases. The tests were performed in dynamic conditions (impact).
Spawanie z chłodzeniem mikrojetowym to nowatorska metoda spawania z wymuszonym chłodzeniem spoiny bezpośrednio po spawaniu. Pozwala ona na uzyskanie połączeń spawanych o właściwościach lepszych w porównaniu do spawania tradycyjnego. Przyczyną tego jest uzyskiwania korzystniejszej struktury stopiwa z większą zawartością drobnoziarnistego ferrytu (acicular ferrite – AF). Dzięki zastosowaniu różnych gazów do chłodzenia spoiny, można uzyskiwać różne struktury stopiwa i właściwości mechaniczne. W artykule przedstawiono zależność pomiędzy rodzajem gazu do chłodzenia mikrojetowego, a własnościami plastycznymi połączenia spawanego. Jako wielkości opisujące własności plastyczne wybrano współczynnik restytucji i odkształcenie trwałe. Testy przeprowadzono w warunkach dynamicznych.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 919-923
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola roślin motylkowych drobnonasiennych w gospodarstwie rolnym
The role of fine-grained legume plants in a farm
Autorzy:
Gaweł, E.
Powiązania:
https://bibliotekanauki.pl/articles/339504.pdf
Data publikacji:
2011
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
masa resztek roślinnych
motylkowate w produkcji pasz
PX
rola strukturotwórcza bobowatych
rośliny miododajne
rośliny motylkowate w rekultywacji
symbiotyczne wiązanie azotu
legumes in fodder production
legumes in land reclamation
melliferous plants
plant residue mass
role of legumes in soil structure improvement
symbiotic N fixation
Opis:
W opracowaniu przeglądowym przedstawiono znaczenie roślin motylkowatych (w obecnej systematyce – bobowate) w produkcji wartościowych pasz objętościowych na gruntach ornych w systemie zrównoważonym i ekologicznym. Omówiono ich wpływ na środowisko, działanie strukturotwórcze, wzbogacanie gleby w substancję organiczną i składniki pokarmowe, zwiększenie produkcyjności gleby oraz poprawianie jej właściwości fizykochemicznych. Podkreślono szczególną rolę roślin motylkowatych w obiegu azotu w przyrodzie, związaną z procesem symbiozy z bakteriami brodawkowymi asymilującymi znaczne ilości azotu atmosferycznego i transferem azotu roślinom współrzędnym oraz następczym. Przedstawiono wartość pasz: zielonki, siana, kiszonki i sianokiszonki oraz PX z lucerny i ich wpływ na produkcyjność zwierząt. Omówiono również znaczenie roślin motylkowatych w pszczelnictwie, jako pożytku dla pszczół miodnych, trzmieli i dzikich zapylaczy. Opisano również zastosowanie tych roślin w ochronie środowiska i rekultywacji terenów zniszczonych przez przemysł.
This compiled review of literature data highlights the importance of fine-grained papilionaceous plants in the production of valuable bulk fodder on arable lands in the sustainable and organic systems. The impact of legumes on the environment was discussed and such benefits as improved soil structure, increased soil organic matter and nutrient content, increased soil productivity and improved soil chemical and physical properties were underlined. Emphasis was given to the particular role of legumes in nitrogen recycling in nature through the symbiotic processes which involve nodule-forming bacteria that fix substantial amounts of atmospheric nitrogen and transfer it to co-cultivated and to subsequent crops. The value of particular feeds - fresh herbage, hay, silage and hay ensilage as well as PX concentrate from lucerne - and their effect on animal productivity were presented. In addition, the importance of legumes in apiculture as the honey crops for honeybees, bumble bees and for wild pollinators was discussed. Some attention was also given to the use of these crops in environmental protection and in the reclamation of lands devastated by industry.
Źródło:
Woda-Środowisko-Obszary Wiejskie; 2011, 11, 3; 73-91
1642-8145
Pojawia się w:
Woda-Środowisko-Obszary Wiejskie
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-45 z 45

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