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Wyszukujesz frazę "Li, S" wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
Measurement and analysis of coastal waves along the north sea area of China
Autorzy:
Sun, S.
Li, H.
Sun, H.
Powiązania:
https://bibliotekanauki.pl/articles/259794.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
coastal wave
measurement
buoy
spectral analysis
Opis:
Taking advantage of coastal wave environment to carry out scaled ship model test is an effective testing technology for ship performance. In this paper, the method of spectral analysis is adopted to calculate the significant wave height, period, wave spectrum and some other parameters of some places along the North Sea area of China. The measured wave spectrum and the ocean spectrum are handled into non-dimensional form to evaluate their similarity. The influence of wind direction and tide on coastal waves was analyzed. And the results indicate that the coastal wave spectrum is similar to the ocean spectrum under some specific conditions.
Źródło:
Polish Maritime Research; 2016, 3; 72-78
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on green water of tumblehome hull using dam-break flow and RANSE models
Autorzy:
Sun, S.
Du, W.
Li, H.
Powiązania:
https://bibliotekanauki.pl/articles/259806.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
tumblehome hull
Green water
Dam-break flow
RANSE
Opis:
The tumblehome hull adopts some novelty designs such as low-tumblehome freeboard and wave-piercing bow. The new form design makes the ship have many special hydrodynamic performances. Especially the green water of tumblehome hull is different from that of hulls with flare free board. Green water is a strong nonlinear phenomenon of ship-wave interaction, the variation of free surface of liquid is complicated, and there are still some difficulties to solve green water problems well with numerical simulation method. In this paper firstly the motion responses of the tumblehome hull was calculated based on 3D potential theory, and then the dam-break flow model was used to calculate green water height and pressure distribution. According to the result of numerical simulation, some typical working conditions are chosen for 3D CFD simulation using RANS method. The results of numerical simulation methods are compared with the experimental results measured in towing tank. The influence of different ship form parameters and wave parameters to the green water of tumblehome hull is analyzed, and some regularities of green water on tumblehome hull in regular waves are summarized.
Źródło:
Polish Maritime Research; 2017, S 2; 172-180
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for phase wraps reduction in profilometry
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173793.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
zero-padding
Fourier transform
carrier-frequency
profilometry
Opis:
In order to completely eliminate, or greatly reduce the number of phase wraps in 2D wrapped phase map, Gdeisat and co-workers proposed an algorithm, which uses shifting the spectrum towards the origin. But the spectrum can be shifted only by an integer number, meaning that the phase wraps reduction is often not optimal. In addition, Gdeisat’s method will take much time to make the Fourier transform, inverse Fourier transform, select and shift the spectral components. In view of the above problems, we proposed an improved method for phase wraps elimination or reduction. First, the wrapped phase map is padded with zeros, the carrier frequency of the projected fringe is determined by high resolution, which can be used as the moving distance of the spectrum. And then realize frequency shift in spatial domain. So it not only can enable the spectrum to be shifted by a rational number when the carrier frequency is not an integer number, but also reduce the execution time. Finally, the experimental results demonstrated that the proposed method is feasible.
Źródło:
Optica Applicata; 2017, 47, 2; 295-306
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of colloidal montmorillonite particles on froth flotation of graphite, galena and fluorite
Autorzy:
Chen, T.
Zhao, Y.
Li, H.
Song, S.
Powiązania:
https://bibliotekanauki.pl/articles/110589.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
montmorillonite
graphite
galena
fluorite
slime coating
entrainment
Opis:
The effect of colloidal montmorillonite (MMT) on froth flotation of graphite, galena and fluorite was investigated in this work. The results showed that the presence of sufficient amount of colloidal MMT particles in the mineral slurry would be detrimental of flotation by reducing the recovery of minerals. This observation was attributed to slime coating of MMT on the coarse valuable mineral particles and entrainment of MMT particles in the froth product together with water in the triangle froth zones. The former would reduce the recovery of the valuable minerals because of hydrophilic MMT coating. The latter would decrease the concentrate grade. The degree of slime coating depended on slurry pH, while the degree of entrainment was closely related to water recovery. It was also found that slime coating was a dominant factor in mineral flotation in acidic pH regions in the presence of colloidal MMT particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 699-713
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal vibration control of conical shells with collocated helical sensor/actuator pairs
Optymalne sterowanie drganiami powłok stożkowych za pomocą spiralnego skolokowanego układu czujnika i elementu wykonawczego
Autorzy:
Li, H.
Hu, S. D.
Tzou, H. S.
Chen, Z. B.
Powiązania:
https://bibliotekanauki.pl/articles/280352.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
smart structure
conical shell
diagonal sensor/actuator
optimal vibration control
Opis:
This paper focuses on the optimal vibration control of clamped-free conical shells using distributed helical piezoelectric sensor/actuator (S/A) pairs. Based on the independent modal space control, the response of conical shell to external excitations is represented by the summation of all participating natural modes and their respective modal participation factors, and each mode can be controlled independently. The modal equation is transformed into the linear state space form. The linear quadratic (LQ) controllers are designed for each independent mode. The optimal gain matrix is related to the ratio G∗ between the control voltage and sensing signal by the modal control force per unit voltage B2 and the sensing signal per unit displacement C1. Because B2 and C1 change with locations of the S/A pair, the optimal control effects, modal control forces and corresponding optimal control voltages are evaluated using two S/A pairs at different locations. The results indicate that the optimal control method is effective in vibration control of the shell. The optimal control effect also depends on the location of the S/A pair and modal shapes as well as the modal control force and input voltage.
W pracy skoncentrowano się na problemie optymalnego sterowania drganiami jednostronnie zamocowanych powłok stożkowych za pomocą spiralnie ułożonego układu piezoelektrycznego czujnika skolokowanego z elementem wykonawczym (S/A). W oparciu o wyniki płynące z rozwiązania przestrzennego zagadnienia sterowania modalnego, dynamiczną odpowiedź powłoki na wymuszenie zewnętrzne wyrażono sumą postaci własnych, jednocześnie stwierdzając, że można niezależnie ingerować w poszczególne postaci własne układu. Równanie modalne przetransformowano do liniowej formuły stanu. Zaprojektowano sterowniki liniowo-kwadratowe (LQ) niezależnie dla każdej postaci własnej. Optymalną macierz współczynników wzmocnienia skorelowano z transmitancją G∗ pomiędzy napięciem sterowania i sygnału czujnika poprzez jednostkową siłę sterującą odniesioną do napięcia B2 oraz sygnału czujnika w stosunku do przemieszczenia C1. Ponieważ B2 i C1 zmieniają się wraz ze zmianą położenia skolokowanych par S/A, przeprowadzono ewaluację modalnych sił sterujących i odpowiadających im napięć dla różnych położeń układu sterowania. Wyniki badań potwierdziły efektywność optymalnego sterowania drganiami powłoki stożkowej. Zauważono także wrażliwość uzyskanego stopnia sterowania na położenie pary czujnika i elementu wykonawczego oraz wartości modalnej siły sterującej, jak i napięcia.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 3; 769-784
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One shot profilometry using iterative two-step temporal phase-unwrapping
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173912.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
composite fringe pattern
Fourier transform
two-step temporal phase-unwrapping
Opis:
This paper reviews two techniques that have been recently published for three-dimensional profilometry and proposes one shot profilometry using iterative two-step temporal phase-unwrapping by combining the composite fringe projection and the iterative two-step temporal phase unwrapping algorithm. In temporal phase unwrapping, many images with different frequency fringe pattern are needed to project, which would take much time. In order to solve this problem, Ochoa proposed a phase unwrapping algorithm based on phase partitions using a composite fringe. However, we found that the fringe order determined through the construction of phase partitions tended to be imprecise. Recently, we proposed an iterative two-step temporal phase unwrapping algorithm, which can achieve high sensitivity and high precision shape measurement. But it needs multiple frames of fringe images which would take much time. In order to take into account both the speed and accuracy of three-dimensional shape measurement, we get a new, and more accurate unwrapping method based on a composite fringe pattern by combining these two techniques. This method not only retains the speed advantage of Ochoa’s algorithm, but also greatly improves its measurement accuracy. Finally, the experimental evaluation is conducted to prove the validity of the proposed method.
Źródło:
Optica Applicata; 2017, 47, 1; 97-110
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of energy-size reduction to the control of circulating load in vertical spindle pulverizer
Autorzy:
Li, H.
He, Y.
Zhang, Y.
Ge, Z.
Xie, W.
Wang, S.
Li, K.
Powiązania:
https://bibliotekanauki.pl/articles/110803.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
circulating load control
response of energy-size reduction
mixture grinding
energy efficiency
Opis:
In the vertical spindle pulverizer (VSP), the large circulation ratio and high ash and sulfur contents in circulating load would result in intensive energy consumption and low grinding efficiency. Although the control of circulating load would help increase the energy efficiency, no quantitative study has been conducted due to the high temperature and pressure in the closed VSP. In this study, response of energy-size reduction to the control of circulating load was studied by the experimental simulation method. Coal mixtures with fine/coarse ratio of 11:1, 8:1 and 6:1 were ground by a lab-scale roller mill. Energy-size reductions of the coarse coal were compared to evaluate the influence of circulating load control. Results showed that the product with the coarse coal increased by 30% when the specific breakage energy was 1.0 kWht–1 as the circulation ratio decreased from 11 to 6. Meanwhile, a breakage characteristic index of the coarse coal was two times higher due to the cushioning effect of fines. Besides, decrease of circulation ratio led to increase of the breakage rate of coarse coal, and the energy saving improved by 57%. With the same energy input of 2.0 kWht-1, the yield of –0.09 mm pulverized fuel (PF) increased from 22 to 43%. Therefore, controlling the circulating load is an effective method to improve the breakage rate of coarse coal and energy efficiency for PF generation.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 793-801
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Reinforcement of the TNT System by a Newly-designed GAP-based Polyurethane-Urea: a Molecular Simulation Investigation
Autorzy:
Qian, W.
Shu, Y.
Ma, Q.
Li, H.
Wang, S.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/358512.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
TNT
GAP
polyurethane-urea
inter-molecular interaction
mechanical properties
Opis:
A glycidyl azide (GAP)-based polyurethane-urea (PUU) modifier used in the 1,3,5-trinitrotoluene (TNT)-based composite explosive was investigated by molecular simulation. Inter-molecular interactions were investigated using quantum chemistry calculation on the dimer of TNT and GAP-PUU, and attractive forces were found between the two molecules. The cohesive energy densities and the solubility parameters were obtained through molecular dynamics simulations combined with thermodynamic calculations on the TNT and GAP-PUU amorphous cell models, and the miscibility of the modifier in molten TNT was predicted to be good. The interaction energies and the mechanical properties were then obtained by molecular simulations and mechanical calculations on the solid-phase models of the GAP-PUU with TNT along three crystalline directions, and an improvement in the mechanical properties was predicted.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 411-426
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Responses of plant species to different aboveground removal treatments with implications for vegetation restoration in the Mu Us Sandland (Inner Mongolia)
Autorzy:
Li, H.
Yi, S.
Lai, L.
Zhou, J.
Sun, Q.
Jiang, L.
Gao, Y.
An, P.
Shimizu, H.
Zheng, Y.
Powiązania:
https://bibliotekanauki.pl/articles/57151.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
It is generally assumed that plants can respond to varying degrees of physical damage by growth compensation via resprouting, and resprouting is a key functional trait in many species. Few studies have investigated how grass and shrub species distributed in moving dunes and semifixed dunes in semiarid areas respond to the combined effects of temperature and shoot removal. Medicago sativa, Artemisia ordosica, and Artemisia sphaerocephala plants were grown in a glasshouse for 8 weeks at air temperatures of 10/20°C, 12.5/22.5°C, 15/25°C, and 17.5/27.5°C (night/day) and were subjected to treatments of removing all leaves (LR), removing all leaves followed by cutting at half the plant height (HC), and removing all aboveground tissue (WC). The species, temperature, and damage extent had significant effects on the shoot number, leaf mass ratio, leaf area ratio and ratio of belowground to aboveground dry matter, and the species had a significant effect on the net assimilation rate, specific leaf area, and total biomass. The three species grew well under the HC and LR treatments, and high temperatures (15/25°C and 17.5/27.5°C) significantly promoted the regrowth of the three species. Medicago sativa grew faster than the two Artemisia species. Medicago sativa can be used for fertilizing or vegetation restoration in unimportant conservation areas, and the two Artemisia species can be effectively used for vegetation restoration in the Mu Us Sandland. Due to the low labor costs and the local climate conditions, plants should be clipped before the beginning of the main growing season (end of May or early June) to ensure rapid growth.
Źródło:
Acta Societatis Botanicorum Poloniae; 2019, 88, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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