Autor: Zhao, Feng - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Grid-side current harmonic suppression based on Butterworth filter and quasi-proportional resonance controller
Autorzy:: Zhao, Feng
Zhang, Jianing
Chen, Xiaoqiang
Wang, Ying
Tematy:: Butterworth filter
current harmonic suppression
high-speed electric multiple units
quasi-PR controller
traction drive system; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2172801.pdf Link otwiera się w nowym oknie
Opis:: In order to meet the lightweight requirements of high-speed trains, the inductancecapacitance (LC) resonance circuits are cancelled in the traction drive system of some high-speed electric multiple units (EMUs) in China, which will lead to large low-order current harmonics on the grid side in the traction drive system of EMUs, seriously affecting the power quality. Therefore, the low-order harmonic current of the traction drive system of an EMU is studied in this paper. Firstly, the working principle of a four-quadrant pulse rectifier in a traction drive system is analyzed, and then the generation mechanism of loworder current harmonics on the grid side is studied deeply. Secondly, the voltage outer loop and current inner loop control of a four-quadrant pulse rectifier are optimized respectively. In the voltage outer loop control, a Butterworth filter is designed to suppress the beat frequency voltage of the DC side voltage, so as to indirectly suppress the low-order current harmonics. In the current inner loop, a quasi-proportional resonance (PR) controller with harmonic compensation is used to suppress low-order current harmonics, and a novel loworder current harmonics suppression strategy based on the Butterworth filter and quasi-PR controller is proposed. Finally, the results of the simulated validation of the proposed control strategy show that compared with the existing method of the notch filter ₊ PR controller, the proposed optimal control strategy has a better effect on low-order current harmonic suppression, and improves the dynamic performance of the control system, further showing the correctness and effectiveness of the optimal control strategy.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Electrical neutralization ability of polyaluminum chloride (PACl) coagulants with different OH–/Al3+ ratios by fluorescence quenching effect
Autorzy:: Chi, Fung Hwa
Cheng, Wen Po
Yu, Ruey Fang
Chen, Zhao Feng
Tematy:: stała Sterna-Volmera
polichlorek glinu
kwas humusowy
fluorescencja
Stern-Volmer constant
polyaluminum chloride
humic acid
fluorescence; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/207968.pdf Link otwiera się w nowym oknie
Opis:: The electrical neutralization ability of polyaluminum chlorides (PACls) with respect to humic acid was investigated by the fluorescence quenching method. The Stern–Volmer constant (K_q) at various pH and coagulation doses was determined for polyaluminum chlorides (PACl-B) of various basicities (B, B = [OH^–]/[Al]). The experimental results show that under acidic conditions, the order of K_qvalues of PACl-B is PACl-2.5 > PACl-2.3 > PACl-1.5 > AlCl₃. In solutions of pH = 7, the order of K_qvalues is PACl-1.5 > PACl-2.3 > PACl-2.5 > AlCl3. When pH > 7, aluminum ions are rapidly hydrolyzed, thus PACls of various basicities generally do not show capacity for electrical neutralization with humic acid. At pH = 6, all PACls-B obtain the maximum K_q values, indicating that humic acid and PACl-Bcoagulation process is less affected by H⁺ or OH^– ions, and produces the best electrical neutralization ability. Compared to the past method of using surface potential as a means of determining the ability of neutralization of coagulation, the results of this study show that the K_q value of the quenching effect can reduce the experiment complexity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Topology analysis and parameter design of three-level multi-input DC/DC converter based on multi-source access
Autorzy:: Tian, Jingjing
Qu, Jiaoping
Zhao, Feng
Chen, Xiaoqiang
Wang, Ying
Gan, Yang
Tematy:: multi-input converter
parameter design
power sharing
three-level
topology analysis; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2202547.pdf Link otwiera się w nowym oknie
Opis:: A three-level multi-input DC/DC converter is proposed to solve the problems of complex interface circuit structure and high economic cost for multi-source access to the joint power supply distribution system. In this structure, multiple dc sources are integrated into a three-level DC/DC converter. In comparison with the two-stage counterpart, two active switches and boost diodes are eliminated, while two blocking diodes are added to block the reverse current from the dc-link capacitors. In addition, when the input inductors work in the discontinuous conduction mode, power sharing among different input sources can be achieved by properly selecting the inductance value. The working principle of the converter is analyzed by introducing nine working modes in detail and deriving the steady-state relationship expressions. The parameter range of the element is determined and the design process of a group of dynamic parameter values is shown. Finally, the power electronics real-time simulation platform is built based on StarSim HIL and the corresponding experimental waveforms are given to verify the topology and analysis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Energy-saving optimal scheduling under multi-mode “source-network-load-storage” combined system in metro station based on modified Gray Wolf Algorithm
Autorzy:: Tian, Jingjing
Qian, Yu
Zhao, Feng
Mo, Shenglin
Xiao, Huaxuan
Zhu, Xiaotong
Liu, Guangdi
Tematy:: bilevel optimization
grey wolf optimization algorithm
multi-mode
peak shaving
valley-filling
source-network-load-storage; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59111824.pdf Link otwiera się w nowym oknie
Opis:: Aiming to address power consumption issues of various equipment in metro stations and the inefficiency of peak shaving and valley filling in the power supply system, this study presents an economic optimization scheduling method for the multi-modal “source-network-load-storage” system in metro stations. The proposed method, called the Improved Gray Wolf Optimization Algorithm (IGWO), utilizes objective evaluation criteria to achieve economic optimization. First, construct a mathematical model of the “source network-load-storage” joint system with the metro station at its core. This model should consider the electricity consumption within the station. Secondly, a two-layer optimal scheduling model is established, with the upper model aiming to optimize peak elimination and valley filling, and the lower model aiming to minimize electricity consumption costs within a scheduling cycle. Finally, this paper introduces the IGWO optimization approach, which utilizes meta-models and the Improved Gray Wolf Optimization Algorithm to address the nonlinearity and computational complexity of the two-layer model. The analysis shows that the proposed model and algorithm can improve the solution speed and minimize the cost of electricity used by about 5.5% to 8.7% on the one hand, and on the other hand, it improves the solution accuracy, and at the same time effectively realizes the peak shaving and valley filling, which provides a proof of the effectiveness and feasibility of the new method.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Status taksonomiczny ośmiu gatunków dzierzb występujących w Chinach
Taxonomic status of some shrike species
Taxonomic Status of Eight Asian Shrike Species (Lanius): Phylogenetic Analysis Based on Cyt b and CoI Gene Sequences
Autorzy:: Krištín, Anton
Liang, Gang
Lei, Fu-Min
Zhao, Hong-Feng
Yin, Zuo-Hua
Wang, Hong-Jian
Zhang, Wei
Współwytwórcy:: Museum and Institute of Zoology, Polish Academy of Sciences
Wydawca:: Natura Optima Dux Foundation
Museum and Institute of Zoology, Polish Academy of Sciences
Powiązania:: Acta Ornithologica
Opis:: pg(s) 173–180
Complete Cyt b gene sequences (1143bp), partial CoI gene sequences (1176bp) and Cyt b gene sequences combined with CoI gene sequences (2319bp) from 22 samples of 8 Lanius species were analysed using the phylogenetic method. Molecular phylogenetic trees were reconstructed using the Maximum Parsimony (MP), Maximum Likelihood (ML), Neighbour-joining (NJ) and MrBayesV3.1 (BI) methods. 228 and 216 nucleotide sites were found to be substituted in the Cyt b gene and CoI gene sequences respectively, accounting for 19.5% and 18.4% of the total nucleotide sites in the Cyt b gene and CoI gene sequences. In the phylogenetic trees, L. minor and L. tigrinus were the first to diverge. Then, a parallel clade diverged: one was clustered with L. isabellinus and L. collurio, which formed a sister group; the other was clustered with L. schach and L. cristatus, which was parallel to the cluster of L. tephronotus and L. bucephalus. Shrikes L. isabellinus, L. collurio, L. schach and L. tephronotus were independent species. The melanistic form of L. schach is a variation group of L. schach.
Dostawca treści:: RCIN - Repozytorium Cyfrowe Instytutów Naukowych

Książka

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Skocz do pozycji: 6.

Tytuł:: Construction of a reduced mechanism for diesel-natural gas -hydrogen using HCCI model with Direct Relation Graph and Sensitivity Analysis
Autorzy:: Rui, Zhao
Leping, Xu
Shiquan, Feng
Tematy:: diesel
natural gas
hydrogen
reduced mechanism
DRG
SA; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/779831.pdf Link otwiera się w nowym oknie
Opis:: Based on the theory of direct relation graph (DRG) and sensitivity analysis (SA), a reduced mechanism for diesel CH₄-H₂ tri-fuel is constructed. The detailed mechanism of Lawrence Livermore National Laboratory, which has 654 elements and 2827 elementary reactions, is used for mechanism reduction with DRG. Some small thresholds are used in the process of simplifying the detailed mechanism via DRG, and a skeletal mechanism of 266 elements is obtained. Based on the framework of the skeletal mechanism, the time-consuming approach of sensitivity analysis is used for further simplification, and the skeletal mechanism is reduced to 262 elements. Validation of the reduced mechanism is done via a comparison of ignition delay time and laminar flame speed from the calculation using the reduced mechanism and the detailed mechanism or experiment. The reduced mechanism shows good agreement with the detailed mechanism and with related experimental data.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Phylogenetic Analyses on the Tintinnid Ciliates (Protozoa, Ciliophora) Based on Multigene Sequence Data
Autorzy:: Zhao, Yan
Gao, Feng
Li, Jiqiu
Yi, Zhenzhen
Tematy:: Phylogeny, Ciliophora, choreotrichs, Tintinnida, SSU rDNA, ITS1-5.8S-ITS2 region, ITS2 secondary structure; Pokaż więcej
Wydawca:: Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Powiązania:: https://bibliotekanauki.pl/articles/763453.pdf Link otwiera się w nowym oknie
Opis:: In order to better understand phylogenetic relationships among tintinnid ciliated protozoa, we sequenced and analyzed the SSU rDNA and ITS1-5.8S-ITS2 regions of 10 species belonging to five genera in the order Tintinnida. The secondary structures of the ITS2 region were compared among 8 closely related genera, revealing two stable helices of the palm. In addition, we identified a bulge absence in position II of the ITS2 putative secondary structures of species in basal positions in phylogenetic trees, suggesting the absence bulge might be an ancestral character in the order Tintinnida. Phylogenetic analyses based on SSU rDNA and ITS1-5.8S-ITS2 regions sequence show 1) divergences within the family Tintinnidae are higher than that among other four families (Codonellidae, Ptychocylididae, Metacylididae and Codonellopsidae), suggesting the subdivision of the this family; 2) the family Ptychocylididae is polyphyletic; 3) the subdivision of Tintinnopsis are suggested, because the Tintinnopsis spp. scatter into different clades; 4) species with agglutinated loricae are not clearly separated from that with hyaline ones.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Study on flotation behavior and mechanism of separating chalcopyrite and Molybdenite with ethyl mercaptoglycolate as inhibitor
Autorzy:: Yang, Xiao-Feng
Xu-Zhao
Liu, Yao-Yao
Tematy:: ethyl thioglycolate
chalcopyrite
molybdenite
inhibitor
separation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/24085868.pdf Link otwiera się w nowym oknie
Opis:: The effect of ethyl thioglycolate organic small molecule inhibitors on chalcopyrite molybdenite flotation behaviour is investigated via single mineral micro-flotation tests, zeta potential tests, and X-ray photoelectron spectroscopy (XPS) analysis. Results of the flotation test indicate that ethyl thioglycolate organic small-molecule inhibitors can effectively separate Cu and Mo and selectively inhibit chalcopyrite under weak alkaline conditions. Infrared spectroscopy and XPS analysis show that hydrophilic functional groups C=O and -COOH in the ethyl thioglycolate organic small molecules can chemically adsorb onto the chalcopyrite surface. Moreover, ethyl thioglycolate has no obvious effect on zeta potential of molybdenite. Therefore, ethyl thioglycolate can effectively separate chalcopyrite and molybdenite.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Theoretical Studies of ESR Parameters and Local Lattice Structure of the Vanadate-Lithium-Borate Glasses
Autorzy:: Feng, W.
Zhao, M.
Li, T.
Zhang, X.
Xue, J.
Tematy:: 71.70.Ch
75.10.Dg
61.72.Bb
76.30.Fc; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1419845.pdf Link otwiera się w nowym oknie
Opis:: Electron spin resonance spectral parameters of $V^{4+}$ ions in vanadate-lithium-borate glasses have been calculated by the crystal-field theory. The theoretical results are $g_{∥ }$ = 1.940, $g_{⊥}$ = 1.983 and $A_{∥ } = -175 \times 10^{-4} cm^{-1},$ $A_{⊥} = -65 \times 10^{-4} cm^{-1}$ which are good agreement with the experimental values ($g_{∥ }$ = 1.939(3), $g_{⊥}$ = 1.998(3) and $A_{∥ } = (170.6-176.4) \times 10^{-4} cm^{-1},$ $A_{⊥} = (61.3-71.4) \times 10^{-4} cm^{-1}$). In addition, the bond lengths of the local lattice structure are, respectively, $R_{∥ }$ = 1.5 Å and $R_{⊥}$ = 1.95 Å which have been shown to have a compressed tetrahedral geometry along the $C_4$ axis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Study on the floc-bubble adhesion behavior of hematite in static flow field
Autorzy:: Zhang, Jinxia
Feng, Hongjun
Niu, Fusheng
Sun, Weiguang
Zhao, Yawei
Tematy:: bubble
floc
adhesion
charge-coupled device (CCD) camera
Derjaguin-Landau-Verwey-Overbeek (DLVO) theory; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1449769.pdf Link otwiera się w nowym oknie
Opis:: To investigate the adhesion of hematite flocs to gas bubbles in floc floatation, this paper develops an observation system for floc-bubble collision and adhesion with two charge-coupled device (CCD) cameras. The sizes of flocs and bubble were 45.36μm and 0.90mm, respectively, and the distance between a floc and the bubble center (sedimentation distance) was set to 0.25cm. Three surfactants, namely, sodium oleate, lauryl amine and sodium dodecyl sulfate (SDS), were selected for our research. Several experiments were conducted to disclose how surfactant concentration and pH affect the surface adhesion between hematite flocs and bubbles. Then, the adhesion mechanism was discussed in details based on the experimental results. The results show that the highest adhesion probability was achieved for the said floc and bubble at the lauryl amine concentration of 8mg/L, the sedimentation distance of 0.25cm and the pH of 9. After touching the bubble, the hermamite floc slid on the bubble surface, forming a stable three-phase interface after 67ms. Then, the radial position of the floc no longer changed, despite the floc motion on the bubble surface. According to the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the potential energy of the van der Waals force, there was a repulsive force between the floc and the bubble in the absence of surfactant and an attractive force in the presence of the surfactant of lauryl amine. In addition, a thin solvation shell is conducive to the adhesion between the floc and the bubble.
Dostawca treści:: Biblioteka Nauki

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