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Wyszukujesz frazę "Li, Y.J." wg kryterium: Autor


Tytuł:
Galvanic contacting effect of pyrite on xanthate adsorption on galena surface: DFT simulation and cyclic voltammetric measurements
Autorzy:
Ke, B.
Chen, J.
Li, Y.
Chen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110904.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
DFT
galvanic interaction
pyrite surface
galena surface
cyclic voltammetric measurements
Opis:
The effect of galvanic interaction between pyrite and galena on xanthate adsorbing on the galena surface has been investigated by means of density functional theory (DFT) and cyclic voltammetric measurements. The calculated results show that differences in the contact site and contact distance between galena and pyrite can affect the intensity of the galvanic interaction, and the relationship between the intensity of galvanic interaction and the adsorption ability of xanthate on galena surface has been studied in detail. In general, the galvanic interaction between pyrite and galena surface can enhance the adsorption of xanthate on the galena surface. The adsorption energies of xanthate on the galena surface decrease with the decrease of contact distance, and when the contact distance is lower than 4 Å, the adsorption energies decrease significantly at Pb-Pb, Pb-S and S-S sites. In particular, at the contact distance of 3 Å, a sharp decrease of adsorption energy is observed at the Pb-Pb contact site; in this case, the negative shift of the Pb-S bonding range and DOS non-locality at Pb-Pb contact site are significantly greater than that of the S-S or Pb-S contact sites. The cyclic voltammetric measurements reveal that the galvanic interaction between galena and pyrite improves the adsorption of xanthate on galena surface, which is in good agreement with the DFT results.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 826-836
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in the states of polarization of random electromagnetic beams in atmospheric turbulence
Autorzy:
Li, J.
Zhao, K.
Lai, Y.
Powiązania:
https://bibliotekanauki.pl/articles/174110.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
non-Kolmogorov atmospheric turbulence
random electromagnetic beams
degree of polarization
orientation angle
degree of ellipticity
Opis:
Taking the random electromagnetic cosh-Gaussian beam as a typical example of random electromagnetic beams, the analytical expressions for the cross-spectral density matrix element of random electromagnetic cosh-Gaussian beams propagating through non-Kolmogorov atmospheric turbulence are derived, and used to study the changes in the states of polarization (degree of polarization, orientation angle and degree of ellipticity) of random electromagnetic cosh-Gaussian beams in non-Kolmogorov atmospheric turbulence. It is shown that the states of polarization of random electromagnetic cosh-Gaussian beams in non-Kolmogorov atmospheric turbulence are different from those in free space. The degree of polarization decreases, and the orientation angle and degree of ellipticity increase with increasing structure constant. The on-axis degree of polarization and the degree of ellipticity appear to have an oscillatory behavior and the orientation angle has a rapid transition for the larger cosh-part parameter of random electromagnetic cosh-Gaussian beams in atmospheric turbulence.
Źródło:
Optica Applicata; 2017, 47, 1; 51-62
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative methodology for recycling iron from magnetic preconcentrate of an iron ore tailing
Autorzy:
Yu, J.
Han, Y.
Gao, P.
Li, Y.
Yuan, S.
Li, W.
Powiązania:
https://bibliotekanauki.pl/articles/110888.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetic preconcentrate
iron ore tailing
iron recycling
fluidized magnetization roasting
magnetic separation
Opis:
Iron ore tailing is a kind of hazardous solid waste produced by iron and steel industry. In order to separate and recycle iron from the magnetic preconcentrate of an iron ore tailing, an innovative technological route of fluidized magnetization roasting followed by low-intensity magnetic separation was proposed in this paper. The effects of roasting temperature, dosages of reducing gas CO and fluidizing gas N2 on recovery rate of iron were carried out and optimized. The results showed that the hematite was almost reduced to magnetite by a gas mixture of 4 m3/h CO and 1 m3/h N2 at roasting temperature of 540 °C. Under the optimized conditions, a magnetic concentrate assaying 61.4 wt% Fe with a recovery rate of 81.8% was obtained from the magnetic preconcentrate of an iron ore tailing. The iron chemical phase, X-ray diffraction (XRD), and optical metallographic microscope analyses revealed that siderite was converted to magnetite successfully after roasting, and some coarse magnetite-hematite interlocking particles were formed due to insufficient reaction time, which could also be recovered by magnetic separation after liberating from gangue minerals.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 668-676
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The kurtosis parameter of partially coherent controllable dark hollow beams in free space
Autorzy:
Li, J.
Wang, W W
Lai, Y
Powiązania:
https://bibliotekanauki.pl/articles/173815.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kurtosis parameter
partially coherent controllable dark hollow beams
free space
Opis:
Based on the extended Huygens–Fresnel principle and the definition of second-order moments of the Wigner distribution function, the analytical expression for the kurtosis parameter of partially coherent controllable dark hollow beams in free space is derived, and used to study the influence of beam parameters on the kurtosis parameter. It is shown that the kurtosis parameter increases with increasing the wavelength and the waist width, or decreasing the scaling factor, however, the effect of the beam order and the spatial correlation length on the kurtosis parameter depends on the propagation distance. The results can be interpreted physically.
Źródło:
Optica Applicata; 2014, 44, 4; 533-543
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitive detection of acetylene by second derivative spectra with tunable diode laser absorption spectroscopy
Autorzy:
Deng, H.
Sun, J.
Li, P.
Liu, Y.
Yu, B.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/174963.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tunable diode laser absorption spectroscopy
TDLAS
signal processing
Savitzky–Golay filter
trace gas detection
Opis:
A tunable diode laser absorption spectrometer was developed for trace acetylene gas analysis, the system performance was evaluated by combing an appropriate digital signal processing methods, i.e., Savitzky–Golay smoothing and differentiation algorithm. The calculation of the derivative spectra by this method is accompanied by simultaneous data smoothing. Based on the 2nd deriv- ative spectra detection method, the Allan variance technique indicates a C2H2 detection limit of 1.7ppm for 1-s averaging time, and a minimum noise level of 62ppb (parts per billion), at the optimum integration time of ~60s. The calculated 2nd derivative spectra with better resolution, lower detection limits, save signal processing time, and improve the ability to distinguish unresolved spectral signals.
Źródło:
Optica Applicata; 2016, 46, 3; 353-363
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of calcination temperature on activation behaviors of coal-series kaolin by fluidized bed calcination
Autorzy:
Yuan, S.
Han, Y.
Li, Y.
Gao, P.
Yu, J.
Powiązania:
https://bibliotekanauki.pl/articles/109800.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal-series kaolin
fluidized bed calcination
calcination temperature
activation behaviors
Opis:
This paper is aimed at investigating activation behaviors for coal-series kaolin using fluidized bed calcination as a novel method. The properties of calcined products at different temperature by fluidized bed calcination were evaluated by determination of weight loss rate, whiteness, chemical oxygen demand (COD), aluminum dissolution degree. The thermal behaviors and reaction mechanism were characterized by thermo gravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), particle size distribution (PSD) and scanning electron microscopy (SEM). The results showed that calcination temperature was essential factor determining the properties and crystallinity of calcined products using fluidized bed calcination. Coal-series kaolin transformed into irregular and amorphous metakaolin with excellent properties as calcined at 600-900 °C, which attributed to the dehydroxylation of kaolinite and combustion of carbon/organic matter. Calcined kaolin eliminated activity ascribed to the recrystallization into mullite when calcination temperature was over 1000 °C. It was believed that fluidized bed calcination was an efficient thermal activation technology for coal-series kaolin and the calcination temperature should be controlled accurately.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 590-600
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of accuracy of simple methods for design and analysis of a blazed phase grating microstructure
Autorzy:
Wang, W.
Jing, X.
Zhao, J.
Li, Y.
Tian, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173533.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
grating
effective medium theory
scalar diffraction theory
Opis:
In order to precisely analyze and design the transmittance characteristics of a blazed grating, the validity of both the scalar diffraction theory and the effective medium theory is quantitatively demonstrated. By making a comparison of diffraction efficiencies calculated by the two simplified methods and Fourier modal method, the accuracy can be obtained. It is found that when the normalized period is more than three wavelengths of the incident light, the scalar diffraction theory is useful to calculate the transmittance of the blazed grating within the error of less than 3%. The validity of the scalar diffraction theory increases when the normalized period increases. Importantly, by considering the Fresnel reflection effect, the validity of scalar diffraction theory can be significantly enhanced. Furthermore, when no higher-order diffraction waves appear and only zeroth order diffraction wave propagates, the effective medium theory is accurate to compute the diffraction efficiency within the difference of less than 1% between the zeroth order effective medium theory and Fourier modal method. The polarization characteristics of the validity of effective medium theory are also quantitatively demonstrated. The validity of the two simplified theories is dependent on not only the normalized period of surface microstructure but also the normalized groove depth.
Źródło:
Optica Applicata; 2017, 47, 2; 183-198
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behavior of hard-to-separate and high-ash fine coal
Autorzy:
Xing, Y.
Gui, X.
Liu, J.
Cao, Y.
Zhang, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/110585.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation behavior
fine coal
Fuerstenau upgrading curve
energy input
selectivity
Opis:
The flotation behavior of hard-to-separate and high-ash fine coal was investigated using conventional flotation with constant power input. A new flotation process, based on energy input and distribution, was designed to lower the ash content of concentrate. The results obtained using Fourier transform infrared (FTIR) analysis show that the coal samples have good floatability because of many hydrophobic and few hydrophilic functional groups. Under a constant power input, a large number of ash-forming materials floated into a froth product at the start of flotation. Based on the Fuerstenau upgrading curves, it was determined that the 0.25-0.074 mm size fraction range showed the worst selectivity when compared with 0.50-0.25 mm and -0.074 mm size fractions. The desired concentrate with an ash content of 13.98%, 27.59% of ash recovery, and 80.01% combustible matter recovery could be obtained by transferring the excess energy of the flotation-conditioning stage to the pre-conditioning stage and increasing the power input step-by-step in the flotation-conditioning stage at equal total energy consumption.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 703-717
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of intergrown particle liberation on difficult-to-separate coking coal flotation
Autorzy:
Gui, X.
Liu, J.
Cao, Y.
Xing, Y.
Deng, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/109875.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
liberation
particle size
coking coal
hydrophobicity
Opis:
Flotation tests with intergrown particle liberation were conducted to explore a separation method of difficult-to-separate coking coal from the Tangshan Kailuan mine in China. The particle size distribution, density and coal petrography were investigated. The difficult-to-separate coking coal sample resulted in intergrown particles, such as non-liberated coal and rocks. Thus, intergrown coal particle liberation and re-separation tests were conducted. The results showed that grinding time had a great effect on the flotation performance. Grinding prompted coal to dissociate and improve the surface hydrophobic properties of minerals. However, heterogeneous fine silt covered the surface of coal particles when coal was ground too long. The inorganic mineral particles were over-ground and reduced the contact angle of coal. The results of coal rock dissociation and laboratory re-separation tests showed that clean coal combustible recovery increased through intergrown particle liberation and re-separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 279-294
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of root canal irrigation adopting innovative needles with dimple and protrusion
Autorzy:
Li, P.
Zhang, D.
Xie, Y.
Lan, J.
Powiązania:
https://bibliotekanauki.pl/articles/307257.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dimple
protrusion
innovative needles
numerical simulation
passive flow control methods
root canal irrigation
wychylenie zębów
symulacja komputerowa
kanał zębowy
Opis:
As important passive flow control methods, dimples and protrusions have been successfully implemented via geometric modifications to manipulate flow fields to get a desired flow parameters enhancement. In this research, two novel needles were proposed based on a prototype by means of the dimple and protrusion, and flow patterns within a root canal during final irrigation with these needles were numerically investigated. The calculation cases consistent with the clinically realistic irrigant flow rates, which are 0.02, 0.16 and 0.26 mL s–1 are marked as case A, B and C, respectively. The characteristic parameters to estimate irrigation efficiency, such as shearing effect, mean apical pressure, irrigation replacement and fluid agitation, were compared and the optimal geometry in every calculation case was obtained. As shown from the results, flow rates and needle geometries were the causes of irrigation parameters variations. The sum of shear stress, irrigation replacement and fluid agitation were equal in the low flow rate case A, however, the needle with a protrusion on its tip had advantages in the three irrigation characteristic parameters above in calculation case B, and the needle with a dimple on its tip had advantages in calculation case C. Furthermore, the needles proposed did not give rise to the risk of irrigant extrusion. These needles can be better choices at larger flow rates. Therefore, needle geometry optimizations utilizing passive flow control methods are worthy to be investigated in the root canal irrigation enhancement.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 1; 43-50
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral degrees of cross-polarization of stochastic anisotropic electromagnetic beams in modified non-Kolmogorov atmospheric turbulence
Autorzy:
Chen, F.
Chen, J.
Zhao, Q.
Chen, Y
Xin, Y.
Li, J.
Pan, H.
Powiązania:
https://bibliotekanauki.pl/articles/174614.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quasi-homogenous source
modified non-Kolmogorov turbulence
generalized Stokes parameters
Opis:
Based on the extended Huygens–Fresnel principle, variations in generalized Stokes parameters of stochastic anisotropic electromagnetic beams propagating through modified non-Kolmogorov atmospheric turbulence have been analyzed. The changes in generalized Stokes parameters with different turbulence parameters and source parameters were analyzed first. After that, the distributions of the spectral degrees of cross-polarization (SDCP) of isotropic beams and anisotropic beams were simulated. The results show that the profiles of distribution of SDCP of these two kinds of beams are very different in the near field, and will fluctuate through the propagation in atmospheric turbulence, but at last, when the propagation distance is long enough, the difference in the source makes a slight difference in the final profiles of SDCP in the output plane. They mainly depended on the turbulence perturbation, and in the weak turbulence, the profiles of final distribution show more flatter features.
Źródło:
Optica Applicata; 2013, 43, 4; 773-783
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption algorithm by using the logistic map and discrete fractional angular transform
Autorzy:
Yu, J.
Li, Y.
Xie, X.
Zhou, N.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/173813.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
logistic map
discrete fractional angular transform
Opis:
A new image encryption scheme based on logistic map and discrete fractional angular transform has been proposed. In the proposed scheme, the original image is encrypted with the random sequence generated by the logistic map, and the encrypted image is subsequently processed by the discrete fractional angular transform, which produces the ciphertext after double encryptions. The parameters of the logistic map and the order of the discrete fractional angular transform serve as the main keys of the image encryption algorithm. Simulation results show that the proposed image encryption algorithm can effectively resist the attacks of statistical analysis, and has acceptable encryption effect and security.
Źródło:
Optica Applicata; 2017, 47, 1; 141-155
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrashort pulse propagation recording by using the transmission-type light in flight holography
Autorzy:
Fan, Y.
Li, J.
Zheng, S.
Lu, X.
Zhong, X.
Powiązania:
https://bibliotekanauki.pl/articles/174016.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
light in flight
visualization of pulse propagation
holography
Opis:
In this paper, the distortion of the reconstructed images of the propagating light pulse in transmission light-in-flight holography recording was analyzed. Based on the analysis model, for recording the wavefront more accurately, the optimized selection of relevant parameters was made. Furthermore, a cylindrical lens was introduced to correct the image distortion. Additionally, the light-in-flight recording of the wavefront changing during propagation was simulated.
Źródło:
Optica Applicata; 2017, 47, 2; 283-294
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feature extraction of molten pool for laser welding quality real-time inspection
Autorzy:
Zhang, J
Yin, H
Huang, H
Yang, R
Yang, J
Li, Y
Powiązania:
https://bibliotekanauki.pl/articles/173597.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
laser materials processing
process monitoring and control
image analysis
Opis:
This paper proposed an image feature extraction method for laser welding molten pool inspection based on cellular neural network. TC4 titanium alloy thin plates were welded by Nd:YAG pulsed laser. A coaxial machine vision system was designed to acquire molten pool images. An auxiliary lighting source was employed to improve the molten pool image quality. By analyzing molten pool images, the welding defects such as fenestration or insufficient depth were identified. These results can be used as a feedback signal for laser power control. Experimental results showed that the proposed method can be used to improve laser welding quality.
Źródło:
Optica Applicata; 2015, 45, 4; 523-533
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
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

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