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Wyszukujesz frazę "Li, Zhao" wg kryterium: Autor


Tytuł:
ENDOGENOUS INSTITUTIONS AND ECONOMIC GROWTH: EVIDENCE FROM CHINA
Instytucje endogeniczne a wzrost gospodarczy na przykładzie Chin
Autorzy:
Li, Zhao
Chu, Yujing
Powiązania:
https://bibliotekanauki.pl/articles/947423.pdf
Data publikacji:
2020
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
economic institutions
ownership discrimination
capital allocation
economic growth
instytucje gospodarcze
dyskryminacja własności
alokacja kapitału
wzrost gospodarczy
Opis:
W artykule zbadano wpływ instytucji gospodarczych na akumulację kapitału w sektorze prywatnym przez sektor finansowy, a także cele działalności gospodarczej firm o zróżnicowanej strukturze własności w ramach socjalistycznej gospodarki rynkowej na przykładzie Chin w odniesieniu do neoklasycznej metody wzrostu gospodarczego. Autor stwierdził, że instytucje gospodarcze były głównym czynnikiem wpływającym na efektywność alokacji kapitału pomiędzy sektorem prywatnym a państwowym. Badania sugerują, że prywatne firmy starają się zatrudniać specjalistyczną kadrę w celu ulepszenia instytucji gospodarczych, aby zastąpić kapitał polityczny. Biorąc pod uwagę, że strategia reformy chińskich instytucji gospodarczych miała skalę ogólnokrajową po przeprowadzonym regionalnym projekcie pilotażowym, autor stwierdza, że reforma instytucji gospodarczych w regionach miała istotny wpływ na wzrost gospodarczy.
Źródło:
Financial Sciences. Nauki o Finansach; 2020, 25, 1; 54-77
2080-5993
2449-9811
Pojawia się w:
Financial Sciences. Nauki o Finansach
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic interactions stability analysis of hybrid renewable energy system with SSSC
Autorzy:
He, Ping
Qi, Pan
Ji, Yuqi
Li, Zhao
Powiązania:
https://bibliotekanauki.pl/articles/1841302.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
damping characteristics
dynamic interaction analysis
eigenvalue analysis
hybrid renewable energy system
SSSC
charakterystyka tłumienia
dynamiczna analiza interakcji
analiza wartości własnej
hybrydowy system energii odnawialnej
Opis:
The static series synchronous compensator (SSSC) has demonstrated its capability in providing voltage support and improving power system stability. The objective of this paper is to analyze the dynamic interaction stability mechanism of a hybrid renewable energy system connected with doubly-fed induction generators (DFIGs) and solid oxide fuel cell (SOFC) energy with the SSSC. For this purpose, a linearized mathematical model of this modified hybrid single-machine infinite-bus (SMIB) power system is developed to analyze the physical mechanism of the SSSC in suppressing oscillations and the influence on the dynamic stability characteristics of synchronization. Typical impacting factors such as the series compensation level, the SOFC penetration and tie-line power are considered in the SMIB and two-area systems. The impact of dynamic interactions on enhancing damping characteristics and improving transient performance of the studied systems is demonstrated using eigenvalue analysis and dynamic time-domain simulations, which validates the validity of the proposed physical mechanism simultaneously.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 445-462
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of damping characteristics and index evaluation of a wind-PV-thermal-bundled power transmission system by combining PSS and SSSC
Autorzy:
He, Ping
Wu, Xinxin
Li, Congshan
Zheng, Mingming
Li, Zhao
Powiązania:
https://bibliotekanauki.pl/articles/140453.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
damping characteristics
eigenvalue analysis
power system stabilizer
wind-PV-thermal-bundled power system
Opis:
The grid integration of large-scale wind and solar energy affects the power flow of wind-PV-thermal-bundled power transmission systems and may introduce an unpredicted threat to the power system’s small signal stability. Meanwhile, a power system stabilizer (PSS) and static synchronous series compensator (SSSC) play an important role in improving the static and dynamic stability of the system. Based on this scenario and in view of the actual engineering requirements, the framework of wind-PV-thermal-bundled power transmitted by an AC/DC system with the PSS and SSSC is established considering the fluctuation of wind and photovoltaic power output and the characteristics of the PSS and SSSC. Afterwards, the situation model is constructed in the IEEE 2-area 4-unit system, and the influence of the PSS and SSSC on the system stability under different operating conditions is analyzed in detail through eigenvalue analysis and time-domain simulation. Finally, an index named the gain rate is defined to describe the improvement of the stability limitations of various wind-PV-thermal operating conditions with the PSS and SSSC. The results indicate (K) that the damping characteristics, dynamic stability and stability limitations for various wind-PV-thermal operating conditions of the wind-PV-thermal-bundled power transmission system can be significantly improved by the interaction of the PSS and SSSC.
Źródło:
Archives of Electrical Engineering; 2020, 69, 3; 705-721
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromechanical transient modeling of energy storage based on virtual synchronous machine technology
Autorzy:
Cui, Juntao
Li, Zhao
He, Ping
Gong, Zhijie
Dong, Jie
Powiązania:
https://bibliotekanauki.pl/articles/2135738.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
battery energy storage system
electromechanical transient model
virtual synchronous machine
Opis:
This paper proposes an electromechanical transient method to build a battery energy storage system-based virtual synchronous generator model, suitable for a large-scale grid. This model consists of virtual synchronous generator control, system limitation and the model interface. The equations of a second-order synchronous machine, the characteristics of charging/discharging power, state of charge, operating efficiency, dead band and inverter limits are also considered. By equipping the energy storage converter into an approximate synchronous voltage source with an excitation system and speed regulation system, the necessary inertia and damping characteristics are provided for the renewable energy power system with low inertia and weak damping. Based on the node current injection method by the power system analysis software package (PSASP), the control model is built to study the influence of different energy storage systems. A study on the impact of renewable energy unit fluctuation on frequency and the active power of the IEEE 4-machine 2-area system is selected for simulation verification. Through reasonable control and flexible allocation of energy storage plants, a stable and friendly frequency environment can be created for power systems with high-penetration renewable energy.
Źródło:
Archives of Electrical Engineering; 2022, 71, 3; 581--599
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the mechanism of a mixed collector onto magnesite surface to improve the flotation separation of magnesite from hornblende
Autorzy:
Wang, Enlei
Li, Xiaoan
Dai, Shujuan
Li, Zhao
Zhao, Tonglin
Song, Baoxu
Han, Baisui
Powiązania:
https://bibliotekanauki.pl/articles/1445774.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnesite
hornblende
mixed collector
flotation separation
Opis:
Low-grade magnesite is not effectively used mainly due to high silicon content, especially the separation of magnesite and hornblende. In this research, a novel mixture of sodium oleate and dodecyl phosphate collector was used to increase the flotation difference between magnesite and hornblende. Artificially mixed mineral concentrates grade 47.10% (MgO content) concentrate recovery of 84.45% was obtained by micro flotation test, the results showed that the mixed collector of sodium oleate and dodecyl phosphate played a better selective promotion role in the flotation of magnesite. The interaction mechanism of this mixed collector with hornblende and magnesite surfaces was investigated using Fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS), which showed that the mixed collector in terms of magnesium selection was mainly adsorbed on these magnesium sites of magnesite, and the surface of magnesite thus became hydrophobic, allowing magnesite to float and separate from hornblende.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 4; 125-138
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nature Cellulose Fibre Extracted from Different Cotton Stalk Sections by Degumming
Naturalne włókna celulozowe ekstrahowane z różnych części łodyg bawełny za pomocą odgumowywania
Autorzy:
Li, L.
Zhao, L.
Powiązania:
https://bibliotekanauki.pl/articles/233460.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
fibre extraction
cotton stalk
residue gum content
morphology
ekstrakcja włókna
bawełniana łodyga
odgumowanie
włókna łykowe
morfologia
Opis:
Bast fibres are important because they have biodegradable and eco-friendly characteristics. In this paper, natural cellulose fibre extracted from cotton stalk by degumming was investigated. On the basis on the chemical propertiess of cotton stalk bark, a cotton stalk was divided into three sections before fibres were extracted. Through an orthogonal experiment, the extracting conditions of fibres from different sections were obtained. The flexibility and linear density of the fibres extracted were then tested, and the morphology of the fibres was observed by SEM. It was shown that the flexibility and fineness of fibres from the different sections were various. The singular unit fibrel morphology of fibres from different sections had a visible difference.
Włókna łykowe odgrywają istotną rolę ponieważ są biodegradowalne i przyjazne środowisku. Badano naturalne celulozowe włókna ekstrahowane z łodyg bawełny poprzez odgumowywanie. Na podstawie właściwości chemicznych łodygę bawełny dzielono na trzy części przed przeprowadzeniem ekstrakcji. Doświadczalnie określono warunki ekstrakcji dla poszczególnych wyodrębnionych sekcji. Badano elastyczność i masę liniową, oraz za pomocą SEM morfologię. Stwierdzono, że zarówno elastyczność jak i masa liniowa włókien jest różna dla różnych sekcji łodygi. Morfologia jednostkowych włókien wyekstrahowanych różniła się widocznie dla wszystkich trzech części łodygi.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 6 (114); 37-40
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation influenced by the rheological properties of diaspore-pyrite mixed pulp
Autorzy:
Zhao, Yongqing
Li, Xianhai
Powiązania:
https://bibliotekanauki.pl/articles/27323666.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bauxite
diaspore
pyrite
flotation
rheological property
viscosity
Opis:
The effects of pyrite and diaspore with different particle sizes on the rheological properties of pulp with butyl xanthate added as a collector were studied, and the mechanism for rheological pyrite separation from diaspore by flotation was probed. The apparent viscosity of the diaspore pulp with different particle sizes was higher than that of pyrite, especially for -30 μm diaspore. Microfine diaspore was an important component affecting the apparent viscosity and yield stress of the diaspore-pyrite mixed pulp, and the pulp became a non-Newtonian fluid when the mass fraction of fine-grained diaspore in the mixed pulp was high. In this study, sodium hexametaphosphate (SHMP) was used to control the rheology of the mixed pulp and improve the pyrite flotation, and the S (sulfur) recovery rate first increased and then decreased with increasing SHMP concentration. The apparent viscosity of the pulp decreased by 3.01% and the S recovery rate increased by 34.83% when the amount of added SHMP was 0.05 mg/kg. The apparent viscosity with 0.50 mg/kg SHMP was 21.76% lower than that seen with the addition of 0.05 mg/kg SHMP, but the S recovery rate was also reduced by 14.94%. Further research showed that the increased SHMP concentration led to increases in the electronegativities of the particle surface and the repulsive force between particles, which prevented agglomeration of the particles, reduced the apparent viscosity and yield stress of the mixed pulp, promoted collisions between the pyrite particles and the bubbles, and reduced the resistance of the air bubbles to flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 174305
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Influencing Factors of the Acoustic Performance of the Muffler Considering Acoustic-structural Coupling
Autorzy:
Zhao, Bo
Li, He
Powiązania:
https://bibliotekanauki.pl/articles/31339942.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic performance
muffler
acoustic-structural coupling
transmission loss
mode
optimisation
Opis:
In the calculation of the acoustic performance of mufflers, the walls of mufflers are usually treated rigidly without considering the acoustic-structural coupling, but the results so calculated differ significantly from the actual situation. Based on the basic equations, the article derives the finite element equations of the muffler system while considering the acoustic-structural coupling effect and theoretically analyses the connection between the acoustic-structural coupling system and the structural and acoustic modes. The structural and acoustic modes of the muffler are calculated and the reasons for the mutation of the transmission loss curve of the muffler when the acoustic-structural coupling is considered are analysed. The results show that the acoustic-structural coupling is the result of the interaction between the structure and the air inside the expansion chamber under acoustic excitation, which manifests mutations in the sound pressure inside the muffler in some frequency bands. Then, using a single-chamber muffler as an example, the transmission loss is used to characterise the performance of the muffler. The effects of different factors such as shell thickness, structure, porous media material lining, and restraint method on the acoustic-structural coupling effect of the muffler are analysed, and the structure of a double-chamber muffler is successfully optimised according to the conclusions.
Źródło:
Archives of Acoustics; 2022, 47, 4; 479-490
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal conductivity of a Brown Earth soil as affected by biochars derived at different temperatures: Experiment and prediction with the Campbell model
Autorzy:
Zhao, B.
Li, L.
Zhao, Y.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/2082959.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
biochar
bulk density
thermal conductivity
Brown Earth soil
Campbell model
Opis:
Thermal conductivity is a significant heat transfer property of soil. However, the influence of biochar on this property is not well known. In this research, the influence of corn straw biochars prepared at 300, 500 and 700oC on the thermal conductivity of a Brown Earth (Hapli-Udic Cambisol, FAO) soil and its prediction using a Campbell model was examined. The outcomes revealed that the bulk densities of the soil markedly decreased with increases in the biochar amendment rates of 1, 3, and 5% in linear patterns. The reduction in bulk density was mainly attributed to an increase in soil porosity and organic carbon content. With increasing volumetric water contents (10, 20, 30 and 40%), the thermal conductivity of the soils significantly increased, whereas those of soils with biochar amendment were obviously less than that of the CK and the differences increased with the biochar application rates. The pyrolysis temperature of biochar exhibited a negligible effect on the bulk density and thermal conductivity of soils at large. Combining the linear reduction of bulk density with the biochar amendment rate into the Campbell model, well-fitting results for the variation inthermal conductivity versus volumetric water content were obtained and accurate values could be predicted.
Źródło:
International Agrophysics; 2020, 34, 4; 433-439
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of Fe and V via selective reduction–magnetic separation of vanadium-titanium magnetite concentrate
Autorzy:
Liu, Liwei
Li, Guofeng
Zhao, Libing
Li, Jinpeng
Li, Yanfeng
Powiązania:
https://bibliotekanauki.pl/articles/2146847.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
vanadium-titanium magnetite concentrate
selective reduction
magnetic separation
Fe separation
V separation
Opis:
With the aim of separating Fe and V, a vanadium-titanium magnetite concentrate was selectively reduced, followed by magnetic separation. The processes accompanying reduction of the vanadium-titanium magnetite concentrate were investigated using thermodynamic simulation, experiments, scanning electron microscopy, and electron probe microanalysis. Appropriate reduction conditions and controlling the amount of CaCO3 promoted the reduction of Fe-containing minerals to metallic Fe. V was released from magnetite, ilmenite, and titanomagnetite, and was inhibited to reduce to metallic V, leading to V enrichment in the non-magnetic products in the form of oxides. Moreover, the Fe particles wrapped the slag phase when the amount of CaCO3 exceeded 8%, which is unfavourable for the magnetic separation of Fe and V. Magnetic products with an Fe content of 87.19%, Fe recovery of 82.62%, V content of 0.09% and non-magnetic products with a V content of 1.00% and a V recovery of 85.49% were obtained when the vanadium-titanium magnetite concentrate was reduced for 100 min at 1623 K with a C/O molar ratio of 2.5 and 8% CaCO3, followed by separating at a magnetic field strength of 85 mT.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 1; 50--62
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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