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Tytuł:
Experimental study on the effect of micro-cracks on Brazilian tensile strength
Eksperymentalne badanie wpływu mikrospękań na wyniki badań wytrzymałości na rozciąganie według metody brazylijskiej
Autorzy:
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/219114.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Brazilian split test
dry and water saturation
bedding fissure
strength coefficient
coal mine ground control
badania na rozciąganie metodą brazylijską
próbki suche i nasycone wodą
płaszczyzny spękań
współczynnik wytrzymałości
ochrona powierzchni w kopalniach węgla
Opis:
For coal mine ground control issues, it is necessary to propose a failure criteria accounting for the transversely isotropic behaviors of rocks. Hence, it is very helpful to provide experimental data for the validation of the failure criteria. In this paper, the method for preparing transversely isotropic specimens and the scheme of the Brazilian tensile strength test are presented. Results obtained from Brazilian split tests under dry and water-saturated conditions reflect the effect of the development direction β of the structural plane, such as the bedding fissure, on the tensile strength, ultimate displacement, failure mode, and the whole splitting process. The results show that the tensile strength decreases linearly with increasing β. The softening coefficient of the tensile strength shows a sinusoidal function. The values of the slope and inflection point for the curve vary at the different stages of the Brazilian test. The failure mode of the rock specimen presented in this paper generally coincides with the standard Brazilian splitting failure mode. Based on the test results, the major influencing factors for the Brazilian splitting strength are analyzed and a mathematical model for solving the Brazilian splitting strength is proposed. The findings in this paper would greatly benefit the coal mine ground control studies when the surrounding rocks of interest show severe transversely isotropic behaviors.
W związku z zagadnieniami ochrony powierzchni w kopalniach węgla, konieczne jest opracowanie odpowiednich kryteriów klasyfikacji uszkodzeń skał uwzględniających ich poprzeczną izotropowość. Pomocnym jest także dostarczenie danych eksperymentalnych niezbędnych do walidacji kryteriów uszkodzeń. W pracy tej zaproponowano metodę przygotowywania próbek wykazujących izotropowość poprzeczną, omówiono także sposób przeprowadzania testu na rozciąganie metodą brazylijską. Wyniki testu uzyskane na sucho oraz w warunkach nasycenia próbki wodą wskazują wpływ kierunku rozwoju β płaszczyzny strukturalnej (np. płaszczyzn spękań) na wytrzymałość próbki na rozciąganie, maksymalne przemieszczenia, rodzaj uszkodzenia oraz przebieg procesu pękania. Wyniki testu wskazują, że wytrzymałość na rozciąganie maleje liniowo wraz ze wzrostem wartości β. Współczynnik mięknienia próbki w trakcie próby wytrzymałościowej na rozciąganie ma przebieg krzywej sinusoidalnej. Wartości kąta nachylenia oraz punkt przegięcia krzywej różnią się dla poszczególnych etapów próby wytrzymałościowej. Tryb uszkodzeń próbek skalnych przedstawiony w artykule zasadniczo pozostaje w zgodzie z typowymi odkształceniami rejestrowanymi w trakcie testu metodą brazylijską. W oparciu o wyniki eksperymentu, przeanalizowano główne czynniki wpływające na wytrzymałość próbek na rozciąganie i zaproponowano odpowiedni model matematyczny do obliczania wytrzymałości. Wyniki przedstawione w artykule stanowią poważny przyczynek do badań stabilności gruntu i ochrony powierzchni w rejonach górniczych w przypadku gdy sąsiadujące z kopalnią skały wykazują izotropowość poprzeczną.
Źródło:
Archives of Mining Sciences; 2015, 60, 4; 985-996
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved dolphin swarm optimization algorithm based on information entropy
Autorzy:
Li, Y.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/200085.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dolphin swarm optimization
information entropy
convergence
self-adaptive
combinational optimization
Opis:
In order to overcome the shortcomings of the dolphin algorithm, which is prone to falling into local optimum and premature conver-gence, an improved dolphin swarm algorithm, based on the standard dolphin algorithm, was proposed. As a measure of uncertainty, information entropy was used to measure the search stage in the dolphin swarm algorithm. Adaptive step size parameters and dynamic balance factors were introduced to correlate the search step size with the number of iterations and fitness, and to perform adaptive adjustment of the algorithm. Simulation experiments show that, comparing with the basic algorithm and other algorithms, the improved dolphin swarm algorithm is feasible and effective.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 4; 679-685
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A screw dislocation located outside, inside or on the interface of a parabolic elastic inhomogeneity
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38627364.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
screw dislocation
parabolic elastic inhomogeneity
superposition
conformal mapping
analytic continuation
Opis:
Using conformal mapping techniques, superposition and analytic continuation, we derive analytic solutions to the problem of a screw dislocation interacting with a parabolic elastic inhomogeneity. The screw dislocation can be located anywhere either in the surrounding matrix or in the parabolic inhomogeneity or simply on the parabolic interface itself. We obtain explicit expressions for the two analytic functions in the image plane characterizing the elastic fields describing displacement and stresses in the two-phase composite. Using the Peach-Koehler formula, we also obtain the image force acting on the screw dislocation. The analytic function defined in the parabolic inhomogeneity in the physical plane can be interpreted in terms of real and image screw dislocations for any location of the real screw dislocation.
Źródło:
Archives of Mechanics; 2021, 73, 3; 219-235
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniformity of electroelastic field within a three-phase anisotropic piezoelectric elliptical inhomogeneity in anti-plane shear
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38694715.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
three-phase elliptical inhomogeneity
confocal ellipses
monoclinic piezoelectric material
transversely isotropic piezoelectric material
Stroh quartic formalism
real-form solution
Opis:
Using the Stroh quartic formalism, we prove that the internal electroelastic field is unconditionally uniform inside a three-phase anisotropic piezoelectric elliptical inhomogeneity with two confocal elliptical interfaces when the surrounding matrix is subjected to uniform remote anti-plane mechanical and in-plane electrical loading. The inhomogeneity and the matrix comprise monoclinic piezoelectric materials with symmetry plane at x3 = 0 and with poling in the x3-direction; the intermediate interphase layer is a transversely isotropic piezoelectric material with poling in the x3-direction. Moreover, we obtain the internal uniform electroelastic field inside the elliptical inhomogeneity and the non-uniform electroelastic field in the interphase layer in real-form in terms of the fundamental piezoelectricity matrices for both the inhomogeneity and the matrix and the generalized Barnett–Lothe tensors for both the interphase layer and the matrix.
Źródło:
Archives of Mechanics; 2022, 74, 2-3; 143-156
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SO(3) matrix transformation for rapid polarization search and coding in a three-plate polarizer
Autorzy:
Huang, C
Wang, X
Powiązania:
https://bibliotekanauki.pl/articles/174349.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
SO(3) transformer
tabu search
polarization coding
Opis:
A SO(3) transformer of a three-plate polarizer is adopted to rapidly achieve the transformation of the polarized state. The polarization coding based on Stokes components S2 and S3 is analyzed and demonstrated. Tabu search algorithm is used to accelerate the transformation of the polarized state by utilizing Mueller matrix roots decomposition to decompose the SO(3) matrix, and substituting first order Taylor series approximations for the trigonometric functions in the SO(3) matrix. The results show that bias voltage is less than 120 V in the coding zone. The search speed of our algorithm is faster than the one without first order Taylor series approximations by 4 times.
Źródło:
Optica Applicata; 2015, 45, 1; 101-112
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NH4+ adsorption and adsorption kinetics by sediments in a drinking water reservoir
Autorzy:
Sun, H.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/204766.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reservoir
sediment
sorption
sorption isotherm
sorption kinetics
Opis:
The sorption isotherm and sorption kinetics of NH4+by the Fen River reservoir sediment were investigated for a better understanding of the NH4+ sorption characteristics and parameters. The results showed that Q (adsorption content) increased with the increase of Ceq (equilibrium concentration), sorption isotherms could be described by Freundlich equation (R2 from 0.97 to 0.99). Cation exchange capacity (CEC) had a significant correlation with the parameters K and n (R2 was 0.85 and 0.95, respectively). The ENC0 (Ceq as Q was zero) of S1, S2, S3 and S4 was 1.25, 0.57, 1.15 and 1.14 mg L-1, respectively, and they were less than the NH4+ concentrations in reservoir water. The sediments released NH4+ to the Fen River reservoir water and acted as a pollution source, in the form of complex and heterogeneous adsorbents. The NH4+ adsorption kinetic process was composed of ‘fast’ and ‘slow’ reaction patterns and could be fitted using both Elovich equation and Pseudo second-equation. More than one-step may be involved in the NH4+ sorption processes, and interior diffusion was not dominant ion action.
Źródło:
Archives of Environmental Protection; 2016, 42, 4; 90-95
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mode-III crack with variable surface effects
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/282009.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
surface elasticity
variable surface moduli
mode-III crack
Cauchy singular integro-differential equation
Opis:
We study the contribution of variable surface effects to the antiplane deformation of a linearly elastic material with a mode-III crack. The surface elasticity is incorporated using a modified version of the continuum based surface/interface model of Gurtin and Murdoch. In our discussion, the surface moduli are not constant but vary along the crack surfaces. Using Green’s function method, the problem is reduced to a single first-order Cauchy singular integro-differential equation, which is solved numerically using Chebyshev polynomials and a collocation method. Our results indicate that the gradient of the surface shear modulus exerts a significant influence on the crack opening displacement and on the singular stress field at the crack tips.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1319-1327
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-phase parabolic inhomogeneities with internal uniform stresses in plane and anti-plane elasticity
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38442156.pdf
Data publikacji:
2020
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
three-phase parabolic inhomogeneity
coating
internal uniform stresses
plane elasticity
anti-plane elasticity
Opis:
We examine the in-plane and anti-plane stress states inside a parabolic inhomogeneity which is bonded to an infinite matrix through an intermediate coating. The interfaces of the three-phase parabolic inhomogeneity are two confocal parabolas. The corresponding boundary value problems are studied in the physical plane rather than in the image plane. A simple condition is found that ensures that the internal stress state inside the parabolic inhomogeneity is uniform and hydrostatic. Furthermore, this condition is independent of the elastic properties of the coating and the two geometric parameters of the composite: in fact, the condition depends only on the elastic constants of the inhomogeneity and the matrix and the ratio between the two remote principal stresses. Once this condition is met, the mean stress in the coating is constant and the hoop stress on the coating side is also uniform along the entire inhomogeneity-coating interface. The unconditional uniformity of stresses inside a three-phase parabolic inhomogeneity is achieved when the matrix is subjected to uniform remote anti-plane shear stresses. The internal uniform anti-plane shear stresses inside the inhomogeneity are independent of the shear modulus of the coating and the two geometric parameters of the composite.
Źródło:
Archives of Mechanics; 2020, 72, 1; 27-38
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniform stress field inside a non-parabolic open inhomogeneity interacting with a mode III crack
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38612202.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
non-parabolic inhomogeneity
mode III crack
uniform stress field
antiplane elasticity
conformal mapping
singular integral equation
Opis:
Using conformal mapping techniques, analytic continuation and the theory of Cauchy singular integral equations, we prove that a non-parabolic open inhomogeneity embedded in an elastic matrix subjected to a uniform remote anti-plane stress nevertheless admits an internal uniform stress field despite the presence of a finite mode III crack in its vicinity. Our analysis indicates that: (i) the internal uniform stress field is independent of the specific shape of the inhomogeneity and the presence of the finite crack; (ii) the existence of the finite crack plays a key role in the non-parabolic open shape of the inhomogeneity and in the non-uniform stresses in the surrounding matrix; (iii) the two-term asymptotic expansion at infinity of the stress field in the matrix is independent of the presence of the finite crack. Detailed numerical results are presented to demonstrate the proposed theory.
Źródło:
Archives of Mechanics; 2021, 73, 1; 67-81
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniform field within a non-elliptical inhomogeneity in the vicinity of a nearby non-circular Eshelby inclusion
Autorzy:
Wang, X.
Schiavone, P.
Powiązania:
https://bibliotekanauki.pl/articles/38629511.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
non-elliptical inhomogeneity
Booth’s lemniscate inclusion
uniform field
conformal mapping
anti-plane elasticity
inverse problem
Opis:
We rigorously prove that a non-elliptical inhomogeneity continues to permit an internal uniform stress field despite the presence of a nearby non-circular Eshelby inclusion undergoing uniform anti-plane eigenstrains when the surrounding matrix is subjected to uniform remote anti-plane stresses. Here, we adopt a specific representation of the non-circular Eshelby inclusion as a Booth’s lemniscate inclusion. Our analysis indicates that the internal uniform stress field inside the non-elliptical inhomogeneity is independent of the existence of the Booth’s lemniscate inclusion whereas the non-elliptical shape of the inhomogeneity is attributed entirely to its presence. Representative numerical examples are presented to demonstrate the feasibility of the proposed method of general solution.
Źródło:
Archives of Mechanics; 2021, 73, 5-6; 541-555
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positive solutions for the one-dimensional p-Laplacian with nonlinear boundary conditions
Autorzy:
Hai, D. D.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/255386.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
p-Laplacian
semipositone
nonlinear boundary conditions positive solutions
Opis:
We prove the existence of positive solutions for the p-Laplacian problem [formula] where [formula] can be nonlinear, i=1,2 , f:(0,∞)→R is p-superlinear or p-sublinear at ∞ and is allowed be singular (±∞) at 0, and λ is a positive parameter.
Źródło:
Opuscula Mathematica; 2019, 39, 5; 675-689
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dodecyl amine adsorption at different interfaces during bubble attachment/detachment at a silica surface
Autorzy:
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/110684.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
VSFS
air bubble attachment
amine adsorption density
Opis:
The reverse flotation of quartz and other gangue silicate minerals with alkyl amines is an important and well known strategy for the processing of iron ore, low grade bauxite ore, and phosphate rock. Some details of amine adsorption by quartz have been described in the literature, but little is known about the disposition of amine during bubble attachment. Now, a new experimental procedure involving vibrational sum frequency spectroscopy (VSFS) has been developed to provide, for the first time, a more detailed analysis of the state of dodecyl amine (DDA) adsorption at different interfaces during bubble attachment/detachment at a silica surface. The results show that the hydrophobic surface state at the silica surface is created by the transfer of a well-organized monolayer of DDA from the bubble surface to the silica surface during bubble contact and attachment.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 81-88
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Temperature Field, Heat and Fluid Flow of Two-Phase Zone Continuous Casting Cu–Sn Alloy Wire
Autorzy:
Luo, J.
Liu, X.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/380230.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting
two-phase zone continuous casting
alloy Cu-Sn
numerical simulation
temperature field
heat flow
fluid flow
odlewanie ciągłe
strefa odlewania dwufazowego
stop Cu-Sn
symulacja numeryczna
pole temperatury
przepływ ciepła
przepływ płynu
Opis:
Cu–4.7 wt. % Sn alloy wire with Ø10 mm was prepared by two-phase zone continuous casting technology, and the temperature field, heat and fluid flow were investigated by the numerical simulated method. As the melting temperature, mold temperature, continuous casting speed and cooling water temperature is 1200°C, 1040°C, 20 mm/min and 18°C, respectively, the alloy temperature in the mold is in the range of 720°C–1081°C, and the solid/liquid interface is in the mold. In the center of the mold, the heat flow direction is vertically downward. At the upper wall of the mold, the heat flow direction is obliquely downward and deflects toward the mold, and at the lower wall of the mold, the heat flow deflects toward the alloy. There is a complex circular flow in the mold. Liquid alloy flows downward along the wall of the mold and flows upward in the center.
Źródło:
Archives of Foundry Engineering; 2016, 16, 1; 33-40
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climatic response of Betula ermanii along an altitudinal gradient in the northern slope of Changbai Mountain, China
Autorzy:
Wang, X.
Zhao, X.
Gao, L.
Powiązania:
https://bibliotekanauki.pl/articles/41735.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Opis:
The sensitivity of Betula ermanii tree-ring growth to climate variation over an altitudinal gradient was assessed. Betula ermanii forest grows in the northern slope of Changbai Mountain from approximately 1,700mabove sea level (a.s.l.), andforms the upper tree line at nearly 2,100ma.s.l.. Six study sites were constructed along the altitudinal gradient (1,670 to 2,010 m a.s.l.) and ring-width chronologies of Betula ermanii were built. The mean tree-ring series intercorrelation (RBAR) increasedwith elevation. In principal component analysis, the first unrotatedprinciple component explained77.1% of the total variance, indicating the tree-ring growth of Beutla ermanii over the altitudinal gradient was governed by regional climate. Correlation function analysis revealedthat the radial growth of Betula ermanii was significantly similar in response to climatic conditions. Overall, the low temperatures during previous June, July and during the dormant period (previous October to current May) andthe high temperatures during current June, July andAugust would benefit the radial growth of Betula ermanii. Abundant precipitation during growing season (previous June, July, September andcurrent August), previous November andcurrent May, wouldalso facilitate the tree-ring growth. The reason for this uniform growth behavior in Betula ermanii remainedunclear. Betula ermanii in Changbai Mountain formedrelatively pure stands with an open canopy, which might be partly contributing to the common growth response to climatic signals along the altitudinal gradient, but further work was required for testing this assumption.
Źródło:
Dendrobiology; 2013, 70
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Machine Learning Method of PIDVCA
Autorzy:
Li, L.
Wang, X.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/1841618.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
learning methods
personified intelligence
collision avoidance
dynamic collision avoidance
static collision avoidance
Opis:
Building a dynamic collision knowledge base of self-learning is one of the core contents of implementing "personified intelligence" in Personifying Intelligent Decision-making for Vessel Collision Avoidance (short for PIDVCA). In the paper, the machine learning method of PIDVCA combined with offline artificial learning and online machine learning is proposed. The static collision avoidance knowledge is acquired through offline artificial learning, and the isomeric knowledge representation integration method with process knowledge as the carrier is established, and the Dynamic collision avoidance knowledge is acquired through online machine learning guided by inference engine. A large number of simulation results show that the dynamic collision avoidance knowledge base constructed by machine learning can achieve the effect of anthropomorphic intelligent collision avoidance. It is verified by examples that the machine learning method of PIDVCA can realize target perception, target cognition and finally obtain an effective collision avoidance decision-making.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 3; 533-540
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stimulate economic growth by improving transport infrastructure – a lesson from China
Stimuliertes wirtschaftliches Wachstum durch verbesserung der Transportinfrastrukutr - ein lektor aus China
Autorzy:
Wang, X.
Deng, D.
Wu, X.
Powiązania:
https://bibliotekanauki.pl/articles/374982.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
transport infrastructure
economic growth
spillover effects
infrastruktura transportu
wzrost gospodarczy
efekty zewnętrzne
Opis:
This paper uses Feder model to test impacts of transport infrastructure on economic growth. With China provincial data from 1990-2010 the empirical models, including Basic model, Time-Lag model and Spatial model, demonstrate that transport infrastructure does have a positive Spillover Effect on economic growth. However, Direct Effect on economic growth is negative possibly due to Crowding-Out Effect and productivity difference between sectors. The research also proves the Spillover Effects are becoming weaker as time passed. Finally, Spatial Spillover Effect or Network Effects are confirmed.
Diese Thesis benutzt Feder-Model, um die Auswirkung der Transportinfrastruktur, die auf das wirtschaftliche Wachstum zu untersuchen. Mit den Daten aus chinesischen Provinzen zwischen 1990 und 2010 durch das empirische Modell, in dem das Basic-Model, Time-Lag-Model und Spatial-Model beinhaltet, kann man dadurch demonstrieren, dass die Transportinfrastruktur eine positive Spillover-Effekt auf das wirtschaftliche Wachstum auswirkt. Direkte Effekt auf das wirtschaftliche Wachstum ist jedoch möglich negativ, durch die Crowding-Out Effekt und Unausgeglichenheit der Produktivität zwischen Sektoren. Diese Studie beweist auch, dass die Spillover-Effekte mit vergangener Zeit schwächt wird. Außerdem werden die Spatial-Spillover-Effekt oder Network-Effekt nachgewiesen.
Źródło:
Transport Problems; 2014, 9, 4; 63-72
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of a small gas-puff Z-pinch device
Autorzy:
Luo, C.
Wang, X.
Zou, X.
Powiązania:
https://bibliotekanauki.pl/articles/147416.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Z-pinch plasma
plasma diagnostics
multi-frame interferometry
electron density
energy spectra of ion beams
Opis:
A small gas puff Z-pinch device has been constructed and operated. The device has the parameters: the capacitance of energy storage capacitors 16 mi F, charging voltage 22 kV, peak current 210 kA and a quarter of current period 2.4 mi s. A three-frame Mach-Zehnder interferometer and a compact Thomson ion energy analyzer were developed for Z-pinch plasma experiment. According to the results of diagnostics, the electron density ne of the plasma right before pinch instant is larger than 5.4 × 1019/cm3, the corresponding pinch velocity v of the plasma sheath is 9.0 cm/ěs. Clear parabolas produced by neon ions Ne+, Ne2+, Ne3+ and Ne4+ on CR-39 target have been observed. The energy spectra dN/dTdů for Ne+, Ne2+, Ne3+ and Ne4+ ions were determined. The highest energies of Ne+, Ne2+, Ne3+ and Ne4+ ions emitted from our Z-pinch plasma are below 1.3 MeV.
Źródło:
Nukleonika; 2006, 51, 1; 43-46
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Degradation mechanism study of amine collectors in Fenton process by quantitative structure-activity relationship analysis
Autorzy:
Wang, X.
Liu, W.
Duan, H.
Powiązania:
https://bibliotekanauki.pl/articles/110363.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
amine collectors
Fenton process
QSAR
degradation mechanism
quantum chemistry
Opis:
In this study, advanced oxidation processes (AOPs), Fenton process, was applied to degrade ten amine collectors. The experimental results indicated that most of the tested amines could be removed rapidly and effectively at pH=4, while the degradation of quaternary ammonium compounds was less than others. To research the Fenton oxidation process, the degradation-rate constants of amine collectors were calculated by the pseudo-second order kinetic model, then which was used as the dependent variable to establish a quantitative structure activity relationship (QSAR) model. Meanwhile, 16 molecular structure descriptors and quantum mechanical parameters for amine collectors were simulated and analyzed by using Materials Studio software. The optimum QSAR model was established based on the partial least squares regression (PLS) method and confirmed by the statistics analysis. The model revealed that hydrogen bond acceptor (HBA) and the maximum values of electrophilic attack in C atom sites (f(-)c) were the major effect factors for the degradation-rate constants of amine collector.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 713-721
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of high ship speed ratio on collision avoidance behavior of COLREGS
Autorzy:
Wang, X. H.
Li, L.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/116490.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
colregs
Personifying Intelligent Decision-making for Vessel Collision Avoidance (PIDVCA)
Vessel Collision Avoidance
collision avoidance
decision making
relative motion
geometricdiagram of relative motion
anti-collision
Opis:
The speed ratio is an important factor that must be considered when two vessels will course change to avoid collision. In the process of the research on Personifying Intelligent Decision-making for Vessel Collision Avoidance (short for PIDVCA), it is found that the effect of collision avoidance based on the existing “International Regulations for Prevention Collision at sea” (short for COLREGS) is greatly affected by the high speed ratio (k=Vt/V0≥1.5). Through the analysis on the geometric change law of two vessels’ relative motion in Open waters, the effects of the responsibility for the ship collision avoidance under the COLREGS and special case for high-speed ratio is discussed. According to the collision avoidance measures taken for two vessels encounter situation, some reasonable suggestions are put forward and the simulation experiments that based on ship's intelligent collision avoidance simulation platform are given to support the idea.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 2; 319-323
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated approach to classification of mine-like objects using multiple-aspect sonar images
Autorzy:
Wang, X.
Liu, X.
Japkowicz, N.
Matwin, S.
Powiązania:
https://bibliotekanauki.pl/articles/91790.pdf
Data publikacji:
2014
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
object
sea bed
multiple side-scan sonar
Dempster-Shafer theory
DS concept
classifier
imbalance
imbalanced problem
multi-instance class
Opis:
In this paper, the detection of mines or other objects on the seabed from multiple side-scan sonar views is considered. Two frameworks are provided for this kind of classification. The first framework is based upon the Dempster–Shafer (DS) concept of fusion from a single-view kernel-based classifier and the second framework is based upon the concepts of multi-instance classifiers. Moreover, we consider the class imbalance problem which is always presents in sonar image recognition. Our experimental results show that both of the presented frameworks can be used in mine-like object classification and the presented methods for multi-instance class imbalanced problem are also effective in such classification.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2014, 4, 2; 133-148
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of processing parameters on the properties of amphiphilic block copolymer micelles prepared by supercritical carbon dioxide evaporation method
Autorzy:
Jiao, Z.
Wang, Z.
Wang, X.
Fan, W.
Powiązania:
https://bibliotekanauki.pl/articles/778902.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
supercritical carbon dioxide
amphiphilic block copolymer
drug-loaded micelles
processing parameters
optimization
Opis:
The operation parameters for the supercritical carbon dioxide (ScCO2 ) evaporation method greatly affect the properties of the prepared drug-loaded micelles. In this study, the effects of those key parameters on the drug-loading content (LC) and drug entrapment efficiency (EE) are discussed. It is observed that EE and LC of the micelles are slightly increased with the enhancing temperature and the copolymer molecular ratio of hydrophilic/hydrophobic segment, while decreased with the enhancing ScCO2  evaporation rate. The pressure and volume ratio of ScCO2  to H2 O are observed the optimum condition. In addition, the verification experiment is carried out under the obtained optimizing parameters. The prepared micelles exhibit relatively regular spherical shape and narrow size distribution with the EE and LC value of 70.7% and 14.1%, respectively.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 1; 81-86
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech emotion recognition based on sparse representation
Autorzy:
Yan, J.
Wang, X.
Gu, W.
Ma, L.
Powiązania:
https://bibliotekanauki.pl/articles/177778.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech emotion recognition
sparse partial least squares regression SPLSR
SPLSR
feature selection and dimensionality reduction
Opis:
Speech emotion recognition is deemed to be a meaningful and intractable issue among a number of do- mains comprising sentiment analysis, computer science, pedagogy, and so on. In this study, we investigate speech emotion recognition based on sparse partial least squares regression (SPLSR) approach in depth. We make use of the sparse partial least squares regression method to implement the feature selection and dimensionality reduction on the whole acquired speech emotion features. By the means of exploiting the SPLSR method, the component parts of those redundant and meaningless speech emotion features are lessened to zero while those serviceable and informative speech emotion features are maintained and selected to the following classification step. A number of tests on Berlin database reveal that the recogni- tion rate of the SPLSR method can reach up to 79.23% and is superior to other compared dimensionality reduction methods.
Źródło:
Archives of Acoustics; 2013, 38, 4; 465-470
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of ship’s trajectory planning in collision situations by hybrid genetic algorithm
Autorzy:
Ni, S.
Liu, Z.
Cai, Y.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/259640.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
trajectory planning
Multiple Genetic Algorithm
ship collision avoidance
nonlinear programming
COLREGs
Opis:
Ship collision-avoidance trajectory planning aims at searching for a theoretical safe-critical trajectory in accordance with COLREGs and good seamanship. In this paper, a novel optimal trajectory planning based on hybrid genetic algorithm is presented for ship collision avoidance in the open sea. The proposed formulation is established based on the theory of the Multiple Genetic Algorithm (MPGA) and Nonlinear Programming, which not only overcomes the inherent deficiency of the Genetic Algorithm (GA) for premature convergence, but also guarantees the practicality and consistency of the optimal trajectory. Meanwhile, the encounter type as well as the obligation of collision avoidance is determined according to COLREGs, which is then considered as the restricted condition for the operation of population initialization. Finally, this trajectory planning model is evaluated with a set of test cases simulating various traffic scenarios to demonstrate the feasibility and superiority of the optimal trajectory.
Źródło:
Polish Maritime Research; 2018, 3; 14-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peridynamic analysis of 2-dimensional deformation and fracture based on an improved technique of exerting traction on boundary surface
Autorzy:
Zhou, Z.
Yu, M.
Wang, X.
Huang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/38695705.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
peridynamics
peridynamic motion equation
adaptive dynamic relaxation
traction boundary conditions
Opis:
For 2-dimensional problems in peridynamics, the transfer functions of boundary traction are constructed. The peridynamic motion equation introducing the boundary traction is improved and used to solve some typical 2-dimensional deformation and fracture problems, including the uniaxial tension and pure bending of plate, and fracture of a plate with the small circular hole or central crack. The acquired numerical solutions are close to the analytical solutions of elasticity and numerical solutions given by the finite element method. The results show that the improved technique of exerting traction on a boundary surface is valid for calculating the deformation and failure of solid. It provides a new method and path for the analysis of traction boundary value problems in peridynamics.
Źródło:
Archives of Mechanics; 2022, 74, 6; 441-461
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transition and Plasticity Enhancement of Ti-Cu-Based Bulk Metallic Glasses
Autorzy:
Wang, L.
Wang, X.
Zhang, G.
Sun, X.
Powiązania:
https://bibliotekanauki.pl/articles/356824.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bulk metallic glasses
phase transition
annealing
stability
plasticity
Opis:
In this paper, we report the complex crystallization kinetics of phase transition happening in Ti-Cu-based bulk metallic glasses (BMGs), which play significant roles in the glass formation with respect to their low reduced glass transition temperatures, Trg. The first exothermic event just occurs when annealing the BMG samples in the supercooled liquid region, leading to the Avrami exponent deviating from conventional modes affected by the residual amorphous phase. For Ti43Cu43Ni7Zr7 BMG, the plasticity can be improved by pre-annealing at a sub-Tg temperature of 623K (≈50K below Tg) for 0.5 hour, however, deteriorated by 1 hour annealing, which could be related to the change in stability of this BMG against crystallization with different pre-annealing times.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 387-391
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Metal Fibre Content of Blended Electromagnetic Shielding Fabric on Shielding Effectiveness Considering Fabric Weave
Wpływ zawartości włókien metalowych w tkaninach z przędz mieszankowych tworzących barierę elektromagnetyczną na wydajność ekranowania w zależności od splotu tkaniny
Autorzy:
Liu, Z.
Zhang, Y.
Rong, X.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/233107.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
fabric blended electromagnetic shielding
fabric structure
metal fibre content
shielding effectiveness
metal fibre influence
tkaniny barierowe
mieszankowe tkaniny ekranujące
struktura tkaniny
zawartość włókien metalowych
gęstość wątku i osnowy
masa liniowa przędzy
wpływ włókien metalowych
Opis:
There are few researches reported about the influence of the metal fibre content of blended electromagnetic shielding (EMS) fabric on shielding effectiveness (SE) under different fabric parameters. In order to scientifically describe the metal fibre content of blended EMS fabric considering the fabric structure, in this paper two new indicators of structure metal fibre content (SMFC) and structure equivalent thickness (SET) were constructed according to fabric structure parameters of weft and warp density, yarn density and yarn metal content. A number of experiments were designed and sixteen groups of samples prepared to explore the influence of the two indicators on the SE. Firstly the SMFC and SET of the samples were calculated by the equations of the new indicators. SE values of the samples were then tested by the waveguide method. Finally the relations between the new indicators and the SE were analysed according to experimental results and electromagnetic wave theory. Results show that the SMFC and SET can scientifically describe the metal fibre content of the blended EMS fabric. The SMFC and SET show positive growth along with the SE while other parameters remain unchanged. For the basic weave, SE values are an approximate equivalence as long as the total densities are the same as the yarn density and fibre content of the yarns is the same. As the SMFC is consistent, the more floats, the lower the SE. The research in this paper can provide an important reference for the design, testing and production of blended EMS fabric.
Niewiele publikacji opisuje wpływ zawartości włókien metalowych w mieszankowych tkaninach ekranujących przed wpływem promieniowania elektromagnetycznego na wydajność ekranowania w zależności od parametrów tkaniny. W celu naukowego opisu wpływu zawartości włókien metalowych na zdolność ekranowania w zależności od struktury tkaniny zaproponowano dwa nowe współczynniki SMFC (zależny od struktury) i SET (strukturalny ekwiwalent grubości). Współczynniki oblicza się uwzględniając parametry strukturalne m. in. takie jak gęstość wątku i osnowy, masę liniową przędzy i ilość włókien metalowych. Zaprojektowano serię eksperymentów i zaproponowano 16 grup próbek tak zaprojektowanych, aby można było zbadać wpływ parametrów na dwa nowo zaproponowane współczynniki. Wartości współczynników zostały obliczone, a zdolność ekranowania próbek pomierzona w specjalnym urządzeniu badawczym. Analiza wyników pokazała, że nowo zaproponowane współczynniki mogą charakteryzować wielkość tłumienia w zależności od zastosowanej ilości włókien metalowych. Stwierdzono wyraźne zależności tłumienia od stosowanych częstotliwości. Uzyskane wyniki mogą stanowić podstawę dla projektowania, sprawdzania i produkcji tkanin barierowych dla promieniowania elektromagnetycznego.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 4 (112); 83-87
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetohydrodynamic Calculation on Double-Loop Channel Induction Tundish
Autorzy:
Yue, Q.
Pei, X.
Zhang, C.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/350969.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induction heating
electromagnetic field
channel
tundish
Opis:
A mathematical model is developed to investigate the electromagnetic induction heating in a continuous casting tundish with the double-loop inductor. Maxwell’s equations are solved using finite element method to obtain the magnetic flux density, electromagnetic force, and Joule heating. Results show that the induced current through the two channels generates a current loop. The electromagnetic force points to the center of the channel, thus generating a pinch effect on the molten steel. With the skin effect and proximity effect, Joule heating rate reaches its maximum and minimum values at the corners and the center of the crosssection area respectively. Power ampere-turn has a significant influence on the electromagnetic force and Joule heating density. As ampere-turns vary from 3.6×104 to 2.16×105, Joule heating rate increases from 2.4 MW m-3 to 85 MW m-3. Electromagnetic force also increases from 8×104 N m-3 to 3×106 N m-3 in the center axis line of the channel. The present work reveals the relationship between magnetic flux density and electromagnetic force. The results will be helpful in adjusting the electromagnetic field in channel-induction furnaces and modifying the design of channel parameters.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 329-336
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel in-phase disposition SPWM pulse allocation strategy for cascaded H-bridge inverter
Autorzy:
Zhang, Y.
Xiong, J.
Kong, L.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/141155.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
in-phase disposition SPWM
Inverter
CHB
THD
Opis:
A novel in-phase disposition (IPD) SPWM pulse allocation strategy applied to a cascaded H-bridge (CHB) converter is presented in this paper. The reason causing the power of the CHB converter imbalance is analyzed according to the traditional structure, the conception of power imbalance degree is introduced and the principle of the novel in-phase disposition SPWM allocation strategy is deduced in detail. The new pulse allocation scheme can ensure the power balance in 3/4 cycles through interchanging the PWM pulse sequence of the different CHB cell, meanwhile it makes the full advantage of the IPD control strategy, lower the total harmonic distortion (THD) of line voltage compared to a carrier phase shifted (CPS) control strategy, which is verified by theoretical derivation. A seven-level cascaded inverter composed by three H-bridge cells is taken as the example. The simulation and experiment is performed. The results indicate the validity of the analysis and verify the effectiveness of the proposed SPWM allocation strategy.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 361--375
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A polarization filter at 1550 nm based on photonic crystal fiber with symmetry around gold-coated holes
Autorzy:
Zha, F.
Li, J.
Sun, P.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/173897.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal fiber
polarization filter
finite element method
surface plasmon resonance
Opis:
A polarization photonic crystal fiber based on surface plasmon resonance is proposed in this paper. The photonic crystal fiber with gold coated holes is studied through using the finite element method. The impacts of structural parameters on the resonance characteristics are discussed. Numerical simulations show that the resonance wavelength can be modulated by changing the parameters of the air holes and thickness of gold layer. At the resonance wavelength 1550 nm, the loss is 3.8045 dB/m in x-polarization and the loss is 28464 dB/m in y-polarization by adjusting the size of the gold-coated holes and the place of air holes. Results show that the loss of y-polarized mode is much larger than the loss of x-polarized mode. The y-polarized mode is suppressed, and only x-polarized mode can be guided at the resonance wavelength of y-polarized mode. The results indicate that the mode polarized in one direction can be filtered out selectively by adjusting the diameter of air holes, and the filtering effect in a communication band is achieved.
Źródło:
Optica Applicata; 2018, 48, 4; 609-620
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gradient flow optimization for reducing blocking effects of transform coding
Autorzy:
Gao, F.
Li, X.
Wang, X.
Wee, W. G.
Powiązania:
https://bibliotekanauki.pl/articles/907251.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ gradientu
efekt blokowania
kodowanie transformatowe
gradient flow
blocking effects
optimization
transform coding
Opis:
This paper addresses the problem of reducing blocking effects in transform coding. A novel optimization approach using the gradient flow is proposed. Using some properties of the gradient flow on a manifold, an optimized filter design method for reducing the blocking effects is presented. Based on this method, an image reconstruction algorithm is derived. The algorithm maintains the fidelity of images while reducing the blocking effects. Experimental tests demonstrate that the presented algorithm is effective.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2004, 14, 1; 105-111
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tight focusing of radially polarized beams by a devil’s vortex lens
Autorzy:
Chen, Z.
Hu, X.
Chen, X.
Wang, X.
Pu, J.
Powiązania:
https://bibliotekanauki.pl/articles/173576.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
devil’s vortex lens
radially polarized beam
tight focusing
high numerical aperture
Opis:
Tight focusing of radially polarized beams with a devil’s vortex lens is numerically investigated. Multiple focal spots can be generated in the geometric focus when a radially polarized beam is focused by a high numerical aperture objective in the presence of a devil’s vortex lens. The position of the major focal spot shifts from the geometric focus when a devil’s vortex lens with S = 1 is employed, and the position of the focal spot can be controlled by the numerical aperture of the objective. The intensity components of the major focal spot are influenced by the vortex phase of the devil’s vortex lens. A strong longitudinal component near the optical axis is produced by a devil’s vortex lens without vortex phase, and a nearly pure transversal field is produced by a devil’s vortex lens with vortex phase.
Źródło:
Optica Applicata; 2018, 48, 3; 389-398
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterisation of PSA/CNT Composites and Fibres
Wytwarzanie i charakteryzacja kompozytów polisulfonamidowych z udziałem nanorurek węglowych oraz wytworzonych z nich włókien
Autorzy:
Chen, Z.
Xin, B.
Wu, X.
Wang, X.
Du, W.
Powiązania:
https://bibliotekanauki.pl/articles/232490.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
polysulfonamide
nanorurki węglowe
nanokompozyty
własności termiczne
przewodność elektryczna
carbon nanotube
nanocomposites
thermal property
electrical conductivity
Opis:
In this paper, polysulfonamide/carbon nanotube (PSA/CNT) composite solutions with different CNT contents were prepared using the physical blending method. Corresponding composite fibers were extruded and fabricated through a set of wet spinning units, and composite membranes were prepared by the spin-coating method. The PSA/CNT composite fibers and membranes were characterised by means of SEM, FTIR and XRD among others. The mechanical, thermal and electrical properties were also analysed in this study. The experimental results show that CNT at low contents can be distributed homogeneously in the PSA matrix. Furthermore the molecular structure and chemical composition of PSA does not undergo an obvious change. Crystallisation in the PSA can be promoted at low CNT contents because the nano-particles can act as a nucleation agent. Moreover the electrical conductivity of PSA can be improved significantly by the blending of CNT.
Przygotowano szereg zestawów polisulfonamidu i różnej ilości nanorurek węglowych. Z przygotowanego kompozytu wyprodukowano włókna i folie, które zostały scharakteryzowane przez skaningową mikroskopię elektronową, spektroskopię w podczerwieni i dyfrakcję rentgenowską. Analizowano również właściwości mechaniczne, przewodność cieplną i elektryczną otrzymanych próbek. Wyniki wskazują, że przy małym stężeniu nanorurek węglowych mogą one być rozprowadzone jednorodnie w całej matrycy; struktura molekularna i właściwości matrycy PSA nie ulegają zmianie; krystalizacja w matrycy PSA inicjowana jest przez nanorurki; przewodność elektryczna kompozytu zależy w dużym stopniu od ilości dodanych nanorurek.
Źródło:
Fibres & Textiles in Eastern Europe; 2012, 5 (94); 21-25
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of PolyNIMMO-HTPB-polyNIMMO Triblock Copolymer as a Potential Energetic Binder
Autorzy:
Wang, X.
Shu, Y.
Lu, X.
Mo, H.
Xu, M.
Powiązania:
https://bibliotekanauki.pl/articles/358529.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
triblock copolymer
cationic ring opening polymerization
polymer
DSC
Opis:
Triblock copolymer polyNIMMO-HTPB-polyNIMMO was synthesized by cationic ring opening polymerization of NIMMO (3-nitratomethyl-3-methyloxetane) in the presence of hydroxyl-terminated polybutadiene catalyzed by BF3·OEt2. The polymer was characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, and GPC. DSC was used to investigate the thermal behaviour of the triblock copolymer and its exothermic decomposition peak was found to be at 215 °C. All of the results indicated that the triblock copolymer polyNIMMO-HTPB-polyNIMMO might serve as a potential energetic propellant binder.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 456-467
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Autorzy:
Ning, J.
Du, F.
Wang, X.
Wang, L.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/47613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
intertidal zonation
offshore zone
food web
different habitat
trophic interaction
stable isotope
carbon isotope composition
Mirs Bay
China
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution and role of the genus Oithona (Copepoda: Cyclopoida) in the South China Sea
Autorzy:
Wang, L.
Du, F.
Wang, X.
Li, Y.
Ning, J.
Powiązania:
https://bibliotekanauki.pl/articles/47786.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Oithona
Copepoda
Cyclopoida
temperature
hydrological factor
phytoplankton
ichthyoplankton
South China Sea
Oithona plumifera
Oithona similis
Opis:
The relationships between the small cyclopoid copepod Oithona and hydrological factors, phytoplankton and ichthyoplankton were evaluated using the data obtained in the central South China Sea (SCS) in summer 2014. The genus abundance ranged from 6.00 ind. m3 to 93.75 ind. m3 with high abundance band occurring in the branch of SCS Monsoon Jet. The lower temperature and higher salinity in the surface water of the band than other zones indicated that deep water intrusion was a positive factor for aggregation of the genus. The community structure of the genus was dominated by Oithona plumifera and Oithona similis made up 97% of the genus abundance associated with Oithona tenuis. The result of db-RDA analysis showed that the community structure of the genus was affected by temperature, Chl a, larval fishes and fish spawns, and temperature was the most important limiting factor. The result of GAMs analysis showed that abundance of O. tenuis, and copepodites were affected by Chl a, larval fishes and fish spawns; abundance of O. similis was affected by Chl a and fish spawns; and abundance of O. plumifera was affected by Chl a and larval fishes. Therefore, we suggest that the branch of SCS Monsoon Jet and deep water intrusion favor aggregation of plankton in the central SCS in summer. We confirm that the temperature is the limiting factor to the reproduction of the genus Oithona in tropic seas and the genus Oithona is a food-web linker between primary production and larval fishes in the central SCS.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for probing the refractive index change in photorefractive crystals
Autorzy:
Fu, M.
Gao, C.
Wang, X.
Cui, Y.
Dai, S
Powiązania:
https://bibliotekanauki.pl/articles/174913.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Fourier transform profilometry
refractive index change
photorefractive effect
Opis:
A method for probing refractive index changes in photorefractive crystals using an interferometric technique and digital image processing was proposed. Based on equal thickness interference in LiNbO3 crystal and Fourier transform profilometry, we obtained phase value changes in interferograms induced by a photorefractive effect, and further calculated refractive index changes. The maximal values for extraordinary light (e-light) and ordinary light (o-light) are 6.6×10–4 and 1.2×10–4, respectively.
Źródło:
Optica Applicata; 2013, 43, 4; 731-737
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The endomycorrhizal fungal species and their effects on the growth and nutrient characteristics of Eucalyptus maidenii seedlings in China
Autorzy:
Wang, X.
Kong, X.
Zhao, Y.
Cao, Y.
Cao, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2077654.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Eucalyptus maidenii
endomycorrhizal fungi
major species
Opis:
Eucalyptus maidenii plantations are typically fertilized to increase the yields of eucalyptus oil and timber. However, the application of chemical fertilizers is costly and can cause environmental pollution and soil erosion. Mycorrhiza fungi can facilitate the cultivation of optimal seedlings while promoting the growth of trees. To date, investigations into the inoculation of endomycorrhizal fungi to enhance the productivity of E. maidenii in Yunnan, China have not been undertaken. The species/dominant species of endomycorrhizal fungi on E. maidenii in Yunnan were isolated and iden- tified. The effect of endomycorrhizal fungi on E. maidenii was elucidated. The major species of endomycor- rhizal fungi that affect E. maidenii were ascertained. Bulk soil was collected from an E. maidenii plantation, and the species of endomycorrhizal fungi were inves- tigated. The effect of the endomycorrhizal fungi on E. maidenii were analyzed via a single factor experimental design, where the number of spores of endomycorrhizal fungi in the seedling substrate were controlled. The major endomycorrhizal fungi species that affected E. maidenii were ascertained via stepwise regression analysis. Five endomycorrhizal fungal species were isolated from the bulk soil, with the dominant being Glomus ag- gregatum and Glomus mosseae. With higher counts of endomycorrhizal fungal spores in the seedling substrate, the infection rate and intensity of seedlings were observed to increase, as well as the NPK concentrations of the bulk soil. With the increased nitrogen concentration in the bulk soil, the nitrogen concentration of the aerial components of the seedlings also increased. The NPK concentrations in the bulk soil and seedlings, the second order lateral roots, the root activity, and the seedling height were significantly promoted by the presence of endomycorrhizal fungi (the third experimental treatment). The NPK concentrations of the bulk soil and seedlings, as well as the growth indices of seedlings increased through endomycorrhizal fungi inoculation. The major species of the endomycorrhizal fungi on E. maidenii were G. aggregatum, Glomus multicaule, and Claroideoglomus etunicatum.
Źródło:
Dendrobiology; 2020, 83; 68-74
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AE test of calcareous sands with particle rushing
Autorzy:
Tan, F.
Wang, X.
Hu, M.
Wang, R.
Zhu, C.
Powiązania:
https://bibliotekanauki.pl/articles/259886.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
calcareous sands
accoustic emission
conventional triaxial
consolidated undrained
AE signal
particle crushing
Opis:
The particle of calcareous sands was forced to crush, then the energy from the crushing was released by the form of sound waves. Therefore the AE technique was used to detect the calcareous sands AE signal when it crushed. by to study the AE characteristics, the mechanics of calcareous sands was studied. Study showed that: (1) there was the AE activities on the low confining pressure condition at the beginnig of test, (2) there was more and more AE activities with the continuing of test until to the end, (3) the calcareous sands’ AE activities was on the whole testing, (4) the calcareous sands’ particle crushing and mutual friction played different roles for its AE activities. Then the AE model based on the calcarous sands’ particle crushing was discussed.
Źródło:
Polish Maritime Research; 2017, S 2; 118-124
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of air nucleus in liquid water and cavitation inception on marine engineering
Autorzy:
Fu, Q.
Chen, M.
Wang, X.
Zhu, R.
Zhang, G.
Powiązania:
https://bibliotekanauki.pl/articles/260137.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
air nuclei
water
molecular dynamics
stability
surface tension
Opis:
The micro air nucleus widely distributed in the ocean is a necessary condition for the cavitation of hydraulic machinery in seawater. In order to study the stability of air nucleus in seawater and cavitation inception, the computational domain of water molecules with air nucleus was studied using the method of molecular dynamics simulation, and the transient characteristics of air nucleus in liquid water were obtained. The key factors influencing nuclei stability were analyzed. The results showed that air nucleus with a certain mass could maintain the dynamic equilibrium in liquid water. The internal density of air nuclei had a critical value that allowed the nuclei to stably exist in water. The air nuclei mass was the decisive factor in its equilibrium volume in water, and the two were positively correlated. The internal density of air nuclei was negatively correlated with the nuclei radius when the nuclei was stable in water. Liquid surface tension was an important factor affecting the stability of the air nuclei. The larger the initial radius of nuclei, the smaller the water pressure, and the more likely the cavitation occurs.
Źródło:
Polish Maritime Research; 2018, S 3; 111-119
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Descriptions of Dynamic Softening Mechanisms for Ti-13Nb-13Zr Biomedical Alloy in Single Phase and Two Phase Regions
Autorzy:
Quan, G.-Z.
Wang, X.
Li, Y.-L.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/353917.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biomedical titanium alloy
flow stress
dynamic recovery
dynamic recrystallization
dynamic softening
Opis:
Dynamic softening behaviors of a promising biomedical Ti-13Nb-13Zr alloy under hot deformation conditions across dual phase α + β and single phase β regions were quantitatively characterized by establishing corresponding dynamic recovery (DRV) and dynamic recrystallization (DRX) kinetic models. A series of wide range hot compression tests on a Gleeble-3500 thermo-mechanical physical simulator were implemented under the strain rate range of 0.01-10 s−1 and the temperature range of 923-1173 K. The apparent differences of flow stress curves obtained in dual phase α + β and single phase β regions were analyzed in term of different dependence of flow stress to temperature and strain rate and different microstructural evolutions. Two typical softening mechanisms about DRV and DRX were identified through the variations of a series of stress-strain curves acquired from these compression tests. DRX is the dominant softening mechanism in dual phase α + β range, while DRV is the main softening mechanism in single phase β range. The DRV kinetic model for single phase β region and the DRX kinetic model for dual phase α + β region were established respectively. In addition, the microstructures of the compressed specimens were observed validating the softening mechanisms accordingly.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2029-2043
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical Spectroscopy of Equal-Channel Angular Pressed Fe-Cr Alloys and Tungsten
Spektroskopia mechaniczna stopów Fe-Cr i wolframu wyciskanych przez kanał kątowy
Autorzy:
Hao, T.
Tang, H.
Jiang, W.
Wang, X.
Fang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/352822.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical spectroscopy
internal friction technique
Fe-18wt.%Cr alloy and pure W
equal-channel angular
spektroskopia mechaniczna
technika tarcia wewnętrznego
stop Fe-18wt%Cr i czystego W
kanał kątowy
Opis:
nternal friction technique was used to investigate the microstructural stability of equal-channel angular pressed (ECAP) 9Cr1Mo steel (T91), Fe-18wt.%Cr alloy, and pure W. Several non-relaxation internal friction peaks are observed in three ECAP-strained specimens, which are related to the microstructural transition from a severely deformed state to a static recovery state of dislocations, and to recrystallized state. Along with the disappearance of the P1 peak, another relaxation internal friction peak P2 is observed during the second heating run only in Fe-18wt.%Cr alloy, and it does not disappear even during subsequent third heating run. This peak is not observed in T91 steel and W. The P2 peak is likely associated with a process of grain boundary (GB) sliding. Unlike T91, no abundant carbide precipitates distribute on GBs to pin GB and repulse GB sliding, thus, the P2 peak only occurs in Fe-18wt.%Cr alloy. It is concluded that high-temperature internal friction measurements are required to detect the grain boundary peak in pure W.
Technika tarcia wewnętrznego została użyta do zbadania stabilności mikrostruktury poddanych wyciskaniu przez kanał kątowy stali 9Cr1Mo (T91), stopu Fe-18wt%Cr, i czystego W. Zaobserwowano wiele nie-relaksacyjnych pików tarcia wewnętrznego w trzech próbkach odkształconych przez ECAP, które są związane z przejściem ze stanu silnie odkształconego do statycznego stanu zdrowienia dyslokacji, i do stanu zrekrystalizowanego. Wraz z zanikiem piku P1, tylko w przypadku stopu Fe-18wt%Cr obserwowany jest inny pik P2 relaksacji tarcia wewnętrznego podczas drugiego ogrzewania, i nie znika nawet w kolejnym trzecim etapie ogrzewania. Pik ten nie jest obserwowany w stali T91 i W. Pik P2 prawdopodobnie związany jest procesem poślizgu granicy ziaren. W przeciwieństwie do stali T91, brak bogatych w węglik wydzieleń na granicach ziaren, które by unieruchomiły granice i uniemożliwiły poślizg, stąd pik P2 występuje tylko w przypadku stopu Fe-18wt.%Cr. Stwierdzono, że pomiary tarcia wewnętrznego w wysokiej temperaturze są potrzebne, aby wykryć pik granicy ziarna w czystym W.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 3A; 2101-2106
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of fenugreek-gum and particle size on performance of talc flotation
Autorzy:
Gu, G.
Mo, C.
Zhao, K.
Chen, Z.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/109940.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
particle size
fenugreek-gum
depression
flocculation
Opis:
Talc usually exists as a gangue mineral in copper-nickel sulfide, molybdenite etc. In order to separate precious metals, naturally hydrophobic talc should be depressed effectively in flotation process. The effect of fenugreek-gum (FG) on the flotation performance of talc with different particle sizes was studied. The depression mechanism was investigated extensively through tests of flotation, adsorption and zeta potential, as well as infrared spectroscopy and laser particle size analysis. Flotation results indicated that the FG had a strong depression ability for talc with the particle size of -0.074 + 0.037 mm, -0.037 mm and -0.010 mm when proper dosage of FG was added. The coarse talc was completely depressed by 2.5 mg/ dm3 FG. When the particle size decreased, more FG was required to obtain the maximum depressing effect, which was verified by adsorption tests. FG reduced the electronegativity on the talc surface by chemical adsorption, and flocculation of talc powders caused a high efficient depressing effect.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1026-1033
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of oxidation on the wetting of coal surfaces by water: experimental and molecular dynamics simulation studies
Autorzy:
Li, E.
Lu, Y.
Cheng, F.
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/109792.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wettability
oxidation
molecular dynamics simulation
hydrogen bonding
contact angles
coal surfaces
Opis:
The wettability of coal surfaces by water continues to be one of the key factors which determines the success of coal flotation. Consequently, oxidation of coal surfaces is a fundamental issue of interest. In this work, the effect of oxidation on the wetting of coal surfaces and the interaction between water molecules and oxygen-containing sites at the coal surface was investigated based on advancing/receding contact angle measurements and molecular dynamics simulations. For the simulation studies, a flat coal surface was constructed with the assistance of the molecular repulsion between graphite surfaces and the assembly of Wiser coal molecules. Our results indicated that the simulated advancing and receding contact angles were very similar, and both of them decreased, as expected, with an increase of hydroxyl sites at the coal surface. The good agreement between the simulated advancing/receding contact angles and the experimental receding contact angle values suggested that the configuration of the systems and the set of parameters for the simulation were appropriate. The spreading of water is mainly due to the hydrogen bonds formed between the interfacial water molecules and the hydroxyl sites at the coal surface. The hydroxyl groups show stronger hydration capacity than other oxygen-containing groups according to the calculated hydrogen bonds and interaction energies.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1039-1051
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A euenantiornithine bird from the Late Cretaceous Hateg Basin of Romania
Autorzy:
Wang, X.
Dyke, G.J.
Codrea, V.
Godefroit, P.
Smith, T.
Powiązania:
https://bibliotekanauki.pl/articles/21454.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
We present the first record of a euenantiornithine bird from Romania. A small collection of fossil remains from the Maastrichtian add to the known distribution of large euenantiornithines and descriptions of birds from the Haţeg Basin augment the known vertebrate fauna from this famous region of Transylvania. The new specimens referred here to an indeterminate taxon of euenantiornithine further demonstrate that the larger members of this diverse Cretaceous lineage were globally distributed, as many birds are today.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piezoelectric effect on thermoelastic Lamb waves in functionally graded plates
Autorzy:
Wang, X.
Ren, X.
Yu, J.
Zhou, H.
Zhang, X.
Leng, J
Powiązania:
https://bibliotekanauki.pl/articles/38695708.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
thermoelastic wave
attenuation
FGM
piezoelectric effect
physical field distributions
Opis:
Based on the Lord–Shulman thermoelectric elasticity theory, the piezoelectric effect on the thermoelastic Lamb wave propagation in the functionally graded material (FGM) plate is investigated. The coupled wave equations are solved by employing the Legendre polynomial series approach (LSPA), which poses the advantages of small scale of eigenvalues matrix and a convenient solution. It can directly obtain the complex wave number solutions without iteration. The obtained complex solutions, which represent the wave propagation and attenuation, are compared with those available data. Numerical examples show that the influence of gradient is profound. Results indicate that the piezoelectric effects on attenuation with the open and closed circuit condition are consistent for the S0 and S1 modes, but are inconsistent for the A0 and A1 modes. Although the piezoelectric effect is weak on the dispersion and attenuation of thermal waves, it is notable for their physical field distributions. In addition, the relaxation time is critical to electric displacements of a thermal wave mode, but is not essential for those of Lamb-like modes. The results can be used for the optimization of thermo-electric-elastic coupling structures.
Źródło:
Archives of Mechanics; 2023, 75, 1-2; 3-26
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution Growth of Well-Aligned ZnO Nanorods on Sapphire Substrate
Autorzy:
Jia, G.
Hao, B.
Lu, X.
Wang, X.
Li, Y.
Yao, J.
Powiązania:
https://bibliotekanauki.pl/articles/1399510.pdf
Data publikacji:
2013-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Yz
78.40.Fy
68.55.J-
Opis:
Vertically well-aligned ZnO nanorods arrays were synthesized on sapphire substrates by chemical bath deposition. Those sapphire substrates were seeded to control the density and orientation of ZnO nanorods using sol-gel method. Well-aligned and uniformly distributed ZnO nanorods in a large scale were obtained with strongly (002) preferential orientation. The structural properties were characterized by X-ray diffraction spectrometer and morphological characteristics were analyzed by scanning electron microscopy, respectively. The ZnO nanorods are obvious hexangular wurtzite structure and preferentially oriented along the c-axis (002) and growth vertically to the substrates. The optical properties were further thoroughly studied. What is more, the influences of the strain between substrate and ZnO nanorods due to thickness of the ZnO seed-layer on the characteristics and optical properties of ZnO were also analyzed.
Źródło:
Acta Physica Polonica A; 2013, 124, 1; 74-77
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption efficiency of pentafluorobenzene on ionic liquids-based silicas
Autorzy:
Wang, X.
Lin, L.
Xie, J.
Yan, X.
Xiao, W.
Tian, P.
Powiązania:
https://bibliotekanauki.pl/articles/778559.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ionic liquids based silica
pentafl uorobenzene
adsorption
solid-phase extraction
Opis:
The adsorption of pentafl uorobenzene on nine ionic liquid-based silicas was investigated using solid phase extraction. The effects of several variables such as the type of ionic liquid groups, adsorption time, temperatures and water ratio in the solution system were experimentally evaluated. The imidazole-chloride ionic liquid group based silica exhibited the highest adsorption efficiency under the optimized conditions of 5 min adsorption at 30°C in water/methanol (30:70, vol%) solution. In addition, the effects of pH, as well as type and concentrations of chloride salts were investigated. At pH values other than neutral and high salt concentration, the adsorption efficiency was reduced. Finally, the relative standard deviation of less than 5.8% over a 5-day period showed a high precision for the nine tested sorbents.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 3; 47-52
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan Modified Corn Starch and Its Application as a Glass Fibre Sizing Agent
Skrobia kukurydziana modyfikowana chitozanem i jej zastosowanie jako środka klejącego włókien szklanych
Autorzy:
Wang, Y.
Li, J.
Li, H.
Wang, X.
Lei, H.
Huo, J.
Powiązania:
https://bibliotekanauki.pl/articles/232005.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
glass fiber
sizing agent
corn starch
chitosan
modification
włókno szklane
środki klejące
skrobia kukurydziana
chitozan
modyfikacja
Opis:
Chitosan-modified corn starch was prepared and then applied as a glass fiber sizing agent. The effect of the chitosan on starch-based emulsion, film and sized glass fiber was studied. When 5 % of the chitosan was added, the overall performance of the modified film-forming agent was optimal. The viscosity, surface tension and zeta potential of the sizing agent were 44.99 mPa·s, 51.29 mN·m-1 and 4.5 mV, respectively. The modified sizing agent could easily spread over the surface of glass fibre, and conglutinated to the glass surface firmly. The tensile strength and stiffness of modified-starch glass fiber reached 0.43 N·tex-1 and 4.96 cm. Glass fiber with good overall performance was obtained.
W pracy przygotowano skrobię kukurydzianą modyfikowaną chitozanem, a następnie zastosowano ją jako środek klejący włókien szklanych. Określono lepkość, napięcie powierzchniowe i potencjał zeta środka klejącego. Zmierzono wytrzymałość na rozciąganie i sztywność zmodyfikowanego włókna szklanego. Stwierdzono, że modyfikacja skrobi chitozanem powoduje poprawienie jej właściwości jako środka klejącego. Modyfikacja zwiększyła przyczepność skrobi do włókien i poprawiła ich właściwości mechaniczne.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 3 (123); 112-120
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fiber-optic accelerometer based on a modal interferometer using a thin-core fiber
Autorzy:
Wang, X
Wu, X
Li, S
Ge, Q
He, T
Yu, B
Powiązania:
https://bibliotekanauki.pl/articles/174927.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fiber-optic accelerometer
modal interferometer
thin-core fiber
Opis:
A compact fiber-optic accelerometer based on a modal interferometer, which is fabricated by misaligned splicing of a short section of a thin-core fiber between two sections of a standard single-mode fiber, is demonstrated experimentally. A spectrum analysis method is used to detect an acceleration signal rapidly. The experimental results show that the thin-core fiber-based fiber-optic accelerometer has a minimum detectable acceleration of 3.3×10–3g (g – gravitational acceleration), and a wide frequency response range from 10 to 1200 Hz. Moreover, the proposed accelerometer exhibits the advantages of low cost, simple structure and easy fabrication.
Źródło:
Optica Applicata; 2015, 45, 3; 317-325
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unidirectional Torsion Properties of Single Silk Fibre
Właściwości monowłókien jedwabnych przy jednokierunkowym skręcaniu
Autorzy:
Jiang, S.
Cao, G.
Cai, G.
Xu, W.
Li, W.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/232187.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
unidirectional torsion
silk fibre
fracture angle
breaking cycle
SEM
XRD
skręcanie jednokierunkowe
włókno jedwabne
badania
Opis:
The unidirectional torsion properties of silk fibre were investigated on a purpose-built single fibre torsion tester. The torsional fracture angle and the number of cycles of torsion at breaking were recorded, and the effect of the gauge length and pretension together with the torsion speed on the torsion properties of single silk fibre was investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and a tensile tester were used to understand the morphology, structure and tensile properties of silk fibre after torsion deformation. SME photos show that silk fibre exhibits a ribbon-like profile after torsion, and fracture tends to occur at both ends of the silk fibre, where a larger number of twists can be observed. The crystallinity calculated from XRD spectra of silk fibre increases from 26.11% to 34.10% after torsion. The breaking stress and strain decreases slightly with an increase in the gauge length. The breaking cycle increases linearly with an increase in the gauge length, while the actual torsional fracture angle decreases gradually at the same time. The torsional fracture angle together with the breaking cycle decreases gradually as the pretension increases. The fracture angle together with the breaking cycle increases with an increase in the torsion speed. Understanding the unidirectional torsion properties of single silk fibre will benefit its further application in specific areas where the fibre will be subject to frequent torsion and deformation.
Badania przeprowadzono za pomocą specjalnie zbudowanego urządzenia do badania skrętu włókien. Badano kąt przełomu oraz ilość cykli doprowadzających do zerwania. Sprawdzano również wpływ długości próbki oraz wstępnego naprężenia. Oceniono wpływ długości próbki wstępnego naprężenia, szybkości skrętu na właściwości wytrzymałościowe włókien jedwabnych. Stosowano SEM, XRD dla określenia morfologii i struktury włókien. Stwierdzono, że włókna jedwabne po badaniu wykazują formę podobną do taśmy. Na podstawie XRD stwierdzono, że krystaliczność wzrasta od ok. 26% do 34% po skręceniu. Naprężenie zrywające i odkształcenia zmniejszają się lekko przy wzroście długości próbki.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 3 (117); 26-30
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł

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