Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Liu, Min" wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 20
Tytuł:
Understanding the difficult selective separation characteristics of high-ash fine coal
Autorzy:
Yang, Zili
Liu, Min
Chang, Guohui
Xia, Yangchao
Li, Ming
Xing, Yaowen
Gui, Xiahui
Powiązania:
https://bibliotekanauki.pl/articles/1845210.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high-ash fine coal
flotation
rod grinding
floatability
slime coating
Opis:
As the supply of high-quality coals decreases and mechanical coal mining becomes more widespread, the high selective recovery of high-ash fine coal has become a prominent problem in the flotation process. Herein, we discuss the main reasons why the selective separation of high-ash fine coal is difficult. The analysis of high-ash fine coal properties shows that coarse particles (0.25-0.5 mm) account for 22.53% of the total size fraction and that 57.90% of the coal is moderate- or high-density (+1.4 g/cm3) intergrowth. Grinding experiments show that the traditional rod mill has little impact on the liberation of the intergrowth. Instead, its main function is to adjust the particle size composition to ensure that the particle sizes of high-ash fine coal are within the particle size range suitable for flotation. The flotation results show that a clean coal yield of 30.42%, with a 12.46% ash content, is obtained with the optimal flotation parameters through the roughing and cleaning flotation process. However, the flotation results also show that in the separation of high-ash fine coal, it is difficult to obtain clean coal with a high yield and low ash content at the same time. This is mainly due to the similar floatability of moderate-density and low-density coal particles, which allows a large number of moderate-density coal particles to be recovered, and a significant slime coating of clay on the coal’s surface that is generated during the flotation process. The results of this work provide valuable guidance for high-ash fine coal industrial flotation applications.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 874-883
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pore structure and surface properties of diatomite with mechanical grinding and its influence on humidity control
Autorzy:
Hu, Zhibo
Zheng, Shuilin
Li, Jinyu
Zhang, Shuaiqian
Liu, Min
Wang, Zhicheng
Li, Jiaxin
Sun, Hongjuan
Powiązania:
https://bibliotekanauki.pl/articles/2175445.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
diatomite
mechanical grinding
pore structure
surface properties
humidity control performance
Opis:
Mechanical grinding (MG) is an effective method to regulate the pore structure and surface properties of mineral material. Grinding diatomite samples were prepared by horizontal sander under different grinding time. The pore structure and surface properties of grinding samples were characterized systematically by the particle size analysis, low temperature nitrogen adsorption, MIP, fractal theory, XRD, SEM, TEM, FTIR and surface hydroxyl density analysis. The humidity control performance (HCP) of grinding diatomite was tested under different temperature and relative humidity. The relationship among pore structure, surface properties and HCP was analyzed. The results show that macroporous is more easily damaged by mechanical force than mesoporous, and the internal blind holes structure can be opened. The HCP of diatomite is positively correlated with the specific surface area, mesoporous volume, the inhomogeneity of macroporous structure and the number of hydroxyl groups, while negatively correlated with the proportion of macroporous volume.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 153509
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Curve skeleton extraction via k-nearest-neighbors based contraction
Autorzy:
Zhou, Jianling
Liu, Ji
Zhang, Min
Powiązania:
https://bibliotekanauki.pl/articles/331332.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
curve skeleton
points contraction
point cloud
k nearest neighbors
szkieletyzacja
chmura punktów
metoda k najbliższych sąsiadów
Opis:
We propose a skeletonization algorithm that is based on an iterative points contraction. We make an observation that the local center that is obtained via optimizing the sum of the distance to k nearest neighbors possesses good properties of robustness to noise and incomplete data. Based on such an observation, we devise a skeletonization algorithm that mainly consists of two stages: points contraction and skeleton nodes connection. Extensive experiments show that our method can work on raw scans of real-world objects and exhibits better robustness than the previous results in terms of extracting topology-preserving curve skeletons.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 1; 123-132
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on electrokinetic of kaolinite particles in aqueous suspensions
Autorzy:
Min, F.
Zhao, Q.
Liu, L.
Powiązania:
https://bibliotekanauki.pl/articles/110918.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kaolinite
zeta potential
pH
immersion time
electrophoresis
Opis:
Influence of aqueous phase properties and process parameters on kaolinite particle zeta potential was quantified by electrophoresis experiments. The results indicated that pH strongly altered the zeta potential of kaolinite and it decreases at the beginning and then increases in the range of pH = 2–13. The activity of different cations changes the zeta potential and has the following tendency of Al3+ > Ca2+ > Mg2+ > Na+ and the zeta potential increases due to heterocoagulation of different mineral particles in suspension. It was found that the zeta potential of kaolinite particles increases after the suspension was stirred and decreases at the beginning, and then increases with soaking time. The FTIR results showed that the zeta potential takes into account ion adsorption and the change of Si–O, Al–O and Al–OH groups on the surface of the kaolinite particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 659-672
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influences of process water chemistry on reverse flotation selectivity of iron oxides
Autorzy:
Tang, Min
Wang, Dong
Wu, Yan
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/2175429.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
water chemistry
ion distribution
iron oxides
reverse flotation
Opis:
It is critical for water quality in flotation as it dramatically influences the chemical/electrochemical properties of mineral surfaces and their interactions with reagents. Many potential variations could alter the water chemistry: water recirculation, mineral dissolutions, reagent additions, etc. This study aimed to identify the key elements from the recycled water sources affecting the separation efficiency in a typical industrial flotation circuit of iron oxides through a series of bench/micro flotation tests, zeta potential measurement, etc. The built-up and distribution of the dominant cations/anions in the process water from the roughers in the flotation system was also analyzed and recorded by Inductively Coupled Plasma-Optical Emission (ICP-OES) for a period of about three months when the operations were stable. The flotation results pointed out that a concentrate with a sharp increase of 6.0% Fe recovery and 2.5% SiO2 content was obtained by using the recycled tailing water only in comparison by using fresh water. In contrast, a slight uptrend in the grade of Fe but a substantial loss of near 6.5% Fe recovery occurs by using the treated sewage water alone instead. This could attribute to the ion distributions in these water sources, in which Ca2+, Fen+, Mg2+ or SO42ions were determined as the key ions influencing the flotation behaviors of the iron ore. But the competitive effects of Fe3+ ions were more significant than the ones of Ca2+ or Mg2+ ions. And the occurrence of starch could deteriorate the dilution of silicates in concentration induced by Fe3+/Fe2+ ions. It can be explained by zeta potential measurement or solution chemistry of those ions, indicating that at 8.5-9.0, the coating of the precipitates of Fe(OH)3(s) induced by iron ions alters a reverse on the zeta potentials of quartz. The presence of SO42-ions, however, has a positive role in reducing the possibility of slime coating on silicates due to acting as a chelating agent of iron ions.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 151839
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of coal slime: Coal and kaolinite separation by classification, forward and reverse flotation method
Autorzy:
Shen, Liang
Qiao, Erle
Liu, Lingyun
Xue, Changguo
Liu, Binghe
Min, Fanfei
Powiązania:
https://bibliotekanauki.pl/articles/2146883.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal slime
classification
forward flotation
reverse flotation
Opis:
Coal slime is not only a solid waste, but also a source of energy. With the improvement of environmental protection requirements, the comprehensive utilization of slime has become an urgent problem for coal preparation plants. In this paper, we put forward a promising way of coal slime resource utilization. X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF) and laser particle sizer was used to analyze the properties of coal slime. Obtained results showed that the slime was mainly composed of the coal, kaolinite and quartz with a particle size of -100 μm. Most kaolinite minerals can be enriched in overflow when the feed pressure is 0.2 MPa by using hydrocyclone. 21.3% clean coal with ash content of 12.3% and 33.46% kaolinite with particle size of -5 μm can be recovered by forward flotation and reverse flotation respectively. Coal water slurry with 61% concentration can be prepared from reject of forward flotation and concentrate of reverse flotation at shear rate of 100 s-1. This study has an important practical application value in clean and efficient utilization of coal.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 3; art. no. 147742
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hospitalization patient forecasting based on multi-task deep learning
Autorzy:
Zhou, Min
Huang, Xiaoxiao
Liu, Haipeng
Zheng, Dingchang
Powiązania:
https://bibliotekanauki.pl/articles/2201025.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
hospitalization patient
neural network
multitask learning
pacjent hospitalizowany
sieć neuronowa
nauka wielozadaniowa
Opis:
Forecasting the number of hospitalization patients is important for hospital management. The number of hospitalization patients depends on three types of patients, namely, admission patients, discharged patients, and inpatients. However, previous works focused on one type of patients rather than the three types of patients together. In this paper, we propose a multi-task forecasting model to forecast the three types of patients simultaneously. We integrate three neural network modules into a unified model for forecasting. Besides, we extract date features of admission and discharged patient flows to improve forecasting accuracy. The algorithm is trained and evaluated on a real-world data set of a one-year daily observation of patient numbers in a hospital. We compare the performance of our model with eight baselines over two real-word data sets. The experimental results show that our approach outperforms other baseline algorithms significantly.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2023, 33, 1; 151--162
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on the effect of ions on the surface hydration characteristics of fine quartz
Autorzy:
Liu, Chunfu
Min, Fanfei
Liu, Lingyun
Chen, Jun
Ren, Bao
Lv, Kai
Tan, Yujiao
Powiązania:
https://bibliotekanauki.pl/articles/2146921.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
hydration cation
particle sphericity
hydration factor
viscosity
Opis:
The fine quartz particle hydration and effects of metal ions on the hydration characteristics of fine quartz surface are investigated using the rheological experiment. Several important factors affecting hydration factors, such as particle sphericity, solution pH, ion species, ion concentration were investigated. The results show that viscosity and hydration factor of fine quartz suspension increase with the increase of solution pH. wherein quartz particles have more negative charges on the surface in alkaline environment and strong hydration repulsion; The introduction of metal ions enhances the hydration strength of fine quartz surface to a certain extent. In contrast, high valence and high concentration will increase the viscosity of fine quartz suspension, and the hydration factors of particle surface also increase. At the same ion concentration, the order of influence on the hydration factors of fine quartz particles is Mg2+ > Ca2+ > Na+ > K+. This finding has been attributed to the combination of metal ion hydration and its adsorption on the mineral surface. This study will provide the theoretical guiding significance for the refractory coal slime water and other mineral processing wastewater containing quartz particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 150280
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of ultrasonic pre-treatment on coal slime flotation
Autorzy:
Lv, Wenbao
Chen, Jun
Min, Fanfei
Hou, Baohong
Liu, Chunfu
Powiązania:
https://bibliotekanauki.pl/articles/1450106.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultrasonic pretreatment
surface property
high-ash fine mud
flotation
Opis:
Combined with the characteristics of flotation feed originating from China’s Panyidong Coal Preparation Plant, the ash, zeta potential, X-ray fluorescence spectroscopy and contact angle test were used to study changes in the surface properties of flotation feed under ultrasonic pre-treatment, and its effect on flotation of coal slime. Results show that Preferred pre-treatment process is ultrasonic secondary treatment, ultrasonic secondary pre-treatment can remove most of the high-ash fine mud for instance kaolinite, montmorillonite and quartz in the coal slurry, reduce the surface electronegativity of coal particles, and increase the contact angle of coal particles. Thus, the concentrate ash content decreases to 13%, the recovery rate, yield of flotation concentrate and combustible matter recovery reach 92.6%, 90.9% and 97.6%, respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 173-183
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tuning The Crystallographic Structure And Morphology Of Nanocrystalline CaB6 Films Deposited By DC Magnetron Sputtering
Optymalizacja struktury krystalograficznej i morfologii nanokrystalicznych warstw CaB6 naniesionych metodą napylania magnetronowego
Autorzy:
Zhang, L.
Zhao, G.
Liu, H.
Min, G.
Yu, H.
Powiązania:
https://bibliotekanauki.pl/articles/356295.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CaB6 films
crystallographic structure
morphology
argon pressure
warstwy CaB6
struktura krystalograficzna
morfologia
ciśnienie argonu
Opis:
Through changing the argon pressure, CaB6 films with different crystallographic orientation and morphology on glass substrates were prepared by direct current (DC) magnetron sputtering method. The film textures, crystallite sizes, composition and morphology were investigated by a spectrum of characterizing techniques in terms of X-ray diffraction (XRD), field emission scanning electron microscopy with energy dispersive spectrometer (FESEM-EDS), atomic force microscopy (AFM), Raman shift spectroscopy. The influence of argon pressure on microstructure was studied. The average grain size increased with the argon pressure increasing from 0.8 Pa to 1.5 Pa. Meanwhile, the dominant crystal face changed from (110) to (100). Then the grain size decreased when the argon pressure increased to 2.0 Pa. The surface morphology evolved from typical cauliflower-like nanocrystalline clusters to faceted rectangular pyramids. It was found that considerable amount of argon atoms were trapped in the films. The formation process of CaB6 films was also analyzed in this paper.
Warstwy CaB6 naniesiono na podłoża szkliste metodą magnetronowego rozpylania stałoprądowego (DC). Poprzez kontrolę ciśnienia argonu otrzymano warstwy o różnej morfologii i orientacji krystalograficznej. Strukturę, wielkość krystalitów oraz skład chemiczny warstw badano przy zastosowaniu następujących technik: dyfrakcji rentgenowskiej (XRD), skaningowej mikroskopii elektronowej w połączeniu ze spektroskopią dyspersji energii promieniowania rentgenowskiego (SEM-EDS), mikroskopii sił atomowych (AFM) oraz spektroskopii Ramana. Badano wpływ ciśnienia argonu na mikrostrukturę warstwy. Wraz ze wzrostem ciśnienia argonu z 0,8 Pa do 1,5 Pa zwiększyła się średnia wielkość ziaren przy jednoczesnej zmianie głównych kierunków krystalograficznych – z (110) w (100). Natomiast w wyniku dalszego wzrostu ciśnienia do 2,0 Pa, wielkość ziaren zmniejszyła się. Zaobserwowano także zmiany w morfologii powierzchni. Stwierdzono, że znaczna ilość atomów argonu została uwięziona w warstwach. W niniejszej pracy poddano także analizie proces powstawania warstw CaB6.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 897-901
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption of methylamine cations on kaolinite basal surfaces : A DFT study
Autorzy:
Chen, Jun
Min, Fan-fei
Liu, Ling-yun
Jia, Fei-fei
Powiązania:
https://bibliotekanauki.pl/articles/949692.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kaolinite
methylamine cations
density functional theory
competitive adsorption
adsorption mechanism
Opis:
To explore the interaction of alkylamine surfactants with kaolinite, the density functional theory (DFT) method was used to calculate the single adsorption of different methylamine cation on kaolinite basal surfaces and the competitive adsorption of methylamine cation and water molecule on kaolinite basal surfaces, respectively. Different methylamine cations can adsorb on kaolinite basal surfaces by electrostatic interaction and hydrogen bonds, and the methylamine cations more easily adsorbed on kaolinite Si-O surface. In the case of competitive adsorption with water molecule, the methylamine cation is capable of flushing out the surrounding water molecule to get rid of its steric effect and stably adsorbing on kaolinite basal surfaces, and the adsorption state of the competitive adsorption system is more stable. The adsorption mechanism of methylamine cation on kaolinite basal surface should be the result of electrostatic interaction and hydrogen bonds, and the electrostatic interaction plays the main role.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 2; 338-349
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preconcentration of a low-grade betafite ore by dense medium cyclone
Autorzy:
Lv, Zihu
Wei, Min
Zhao, Dengkui
Wu, Dongyin
Liu, Changmiao
Cheng, Hongwei
Powiązania:
https://bibliotekanauki.pl/articles/2146943.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
preconcentration
betafite
dense medium cyclone
uranium
niobium
Opis:
In order to find an economical and feasible short process for betafite preconcentrating and to provide a reference for the development of similar low-grade uranium deposits, preconcentration of the betafite ore was investigated based on mineralogical characterization study, float-sink tests, and dense medium cyclone (DMC) separation experiments. The float-sink test results revealed that the gravity separation of the betafite ore was feasible, and the expected particle size range was chosen to be 3~0.3 mm. The effect of important parameters of the DMC experiment such as particle size, grade of the feed, separation density, and inlet pressure on the separation performance of betafite ore was studied. Under the optimal experimental conditions, the expanded experiments were performed and the heavy minerals contained 4557 ppm U and 5200 ppm Nb2O5 with a recovery of 88.86% and 79.73%, respectively, were obtained. Besides, the enrichment ratio (E) values of U and Nb2O5 were 14.24 and 12.78 severally, and the tailings discarding ratio (R) value was 93.76%. The results demonstrate that the preconcentration of low-grade betafite by DMC can remove a large number of tailings and obtain a high-grade uranium concentrate.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 1; 1--14
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SCREENING THE SPECIFIC SUBSTRATES OF ADENYLATION DOMAIN FROM MARINE ACTINOMYCETES BY FLUORESCENCE QUENCHING AND ISOTHERMAL TITRATION CALORIMETRY
Autorzy:
LEI, MING
ZHAO, ZHIJUAN
LIU, KE
LIU, YANLI
ZHANG, HUI
WU, XUE
GONG, SIYING
MA, YANLING
ZHAO, HAOBIN
LIU, JINLIN
MIN, JINRONG
QI, CHAO
Powiązania:
https://bibliotekanauki.pl/articles/895432.pdf
Data publikacji:
2018-12-31
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
A domain
Aspartic acid
Fluorescence quenching (FQ)
Isothermal titration calorimetry (ITC)
Marine actinomycetes
static quenching
Opis:
Adenylation domain (A domain) is a model of non-ribosomal peptide synthetases (NRPs), responsible for binding and activating the substrates-amino acids. In this study, a pGEX-2T-sare0718 recombinant plasmid (the gene sare0718 was cloned from Salinispora arenicola CNS-205, S.arenicola CNS-205) was transformed and expressed as a protein GST-Sare0718. Fluorescence quenching (FQ) was conducted to investigate the binding of 20 common amino acids to GST-Sare0718, then isothermal titration calorimetry (ITC) also be used[changed]. The results of FQ revealed that intrinsic fluorescence of GST-Sare0718 is quenched steadily by addition of aspartic acid (Asp) and glutamine (Gln) through static quenching mechanism. The binding constants Ka are Asp (1.504×106 L/mol) ≥ Gln (1.468×105 L/mol). And there is one binding site on the protein GST-Sare0718. We confirmed Asp preference of GST-Sare0718 by ITC. Therefore, Asp is the specific substrate. In addition, the experimental data indicates that the prediction system, “the specificity-conferring code”, is not suitable for marine actinomycetes. So it is urgent to set up a special predictive system for marine actinomycetes.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2018, 75, 6; 1287-1292
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model predictive direct power control of energy storage quasi-Z-source grid-connected inverter
Autorzy:
Tang, Min'an
Yang, Shangmei
Zhang, Kaiyue
Wang, Qianqian
Liu, Chenggang
Dong, Xuewang
Powiązania:
https://bibliotekanauki.pl/articles/2042769.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quasi Z-Source
inverter
energy storage
power control
model predictive
space vector
Opis:
In order to overcome the shortcoming of large switching losses caused by variable switching frequency appears in the conventional finite control set model predictive control (FCS-MPC) algorithm, a model predictive direct power control (MP-DPC) for an energy storage quasi-Z-source inverter (ES-qZSI) is proposed. Firstly, the power prediction model of the ES-qZSI is established based on the instantaneous power theory. Then the average voltage vector in the coordinate system is optimized by the power cost function. Finally, the average voltage vector is used as the modulation signal, and the corresponding switching signal with fixed frequency is generated by the shoot-through segment space vector pulse width modulation (SVPWM) technology. The simulation results show that the ES-qZSI realizes six shoot-through actions per control cycle and achieves the constant frequency control of the system, which verifies the correctness of the proposed control strategy.
Źródło:
Archives of Electrical Engineering; 2022, 71, 1; 21-35
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved dynamic surface sliding mode method for autonomous cooperative formation control of underactuated USVS with complex marine environment disturbances
Autorzy:
Dong, Zaopeng
Qi, Shijie
Yu, Min
Zhang, Zhengqi
Zhang, Haisheng
Li, Jiakang
Liu, Yang
Powiązania:
https://bibliotekanauki.pl/articles/32909478.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underactuated USV
dynamic surface sliding mode control
lateral velocity tracking differentiator
nonlinear disturbance observer
Opis:
In this paper, a novel dynamic surface sliding mode control (DSSMC) method, combined with a lateral velocity tracking differentiator (LVTD), is proposed for the cooperative formation control of underactuated unmanned surface vehicles (USVs) exposed to complex marine environment disturbances. Firstly, in view of the kinematic and dynamic models of USVs and the design idea of a virtual control law in a backstepping approach, the trajectory tracking control problem of USVs’ cooperative formation is transformed into a stabilisation problem of the virtual control law of longitudinal and lateral velocities. Then, aiming at the problem of differential explosion caused by repeated derivation in the process of backstepping design, the first-order low-pass filter about the virtual longitudinal velocity and intermediate state quantity of position is constructed to replace differential calculations during the design of the control law, respectively. In order to reduce the steady-state error when stabilising the virtual lateral velocity control law, the integral term is introduced into the design of the sliding mode surface with a lateral velocity error, and then the second-order sliding mode surface with an integral is structured. In addition, due to the problem of controller oscillation and the role of the tracking differentiator (TD) in active disturbance rejection control (ADRC), the LVTD is designed to smooth the state quantity of lateral velocity. Subsequently, based on the dynamic model of USV under complex marine environment disturbances, the nonlinear disturbance observer is designed to observe the disturbances and compensate the control law. Finally, the whole cooperative formation system is proved to be uniformly and ultimately bounded, according to the Lyapunov stability theory, and the stability and validity of the method is also verified by the simulation results.
Źródło:
Polish Maritime Research; 2022, 3; 47-60
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 20

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies