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Wyszukujesz frazę "Liu, Qi" wg kryterium: Autor


Tytuł:
Laser Welding of TA15 Titanium Alloy and Inconel 718 Dissimilar Metals
Autorzy:
An, Qi
Wu, Dongting
Liu, Peng
Zou, Yong
Powiązania:
https://bibliotekanauki.pl/articles/2174556.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
TA15 titanium alloy
Inconel 718 nickel-based alloy
laser welding
microstructure
tensile strength and fracture characteristic
Opis:
This paper studied the effect of laser welding technology on dissimilar metal welding joints of TA15 titanium alloy and Inconel 718 nickel-based alloy. The research results indicate that the laser welding of TA15 titanium alloy and Inconel 718 nickel-based alloy directly was difficult to form well, which due to the intermetallic compounds caused the joint brittle. When the pure Cu foil was used as the filling layer, the quality of the welding joints can be improved effectively. The experimental results also indicate that there were brittle intermetallic-compounds in the laser welding seam, and the laser power had an important influence on the performance and mechanical properties of the dissimilar metal joint. The maximum average tensile strength of the welding joint of 2300 W was increased to 252.32 MPa. Scanning electron microscope(SEM) results show that the fracture morphology was river pattern, a typical morphological of cleavage fracture, and the mode was brittle fracture.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1267--1276
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adptive heading control of underactuated unmanned surface vehicle based on improved backpropagation neural network
Autorzy:
Dong, Zaopeng
Li, Jiakang
Liu, Wei
Zhang, Haisheng
Qi, Shijie
Zhang, Zhengqi
Powiązania:
https://bibliotekanauki.pl/articles/32917278.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underactuated unmanned surface vehicle
backpropagation neural network controller
heading control
hyperbolic tangent function
Opis:
Aiming at the challenges to the accurate and stable heading control of underactuated unmanned surface vehicles arising from the nonlinear interference caused by the overlay and the interaction of multi interference, and also the uncertainties of model parameters, a heading control algorithm for an underactuated unmanned surface vehicle based on an improved backpropagation neural network is proposed. Based on applying optimization theory to realize that the underactuated unmanned surface vehicle tracks the desired yaw angle and maintains it, the improved momentum of weight is combined with an improved tracking differentiator to improve the robustness of the system and the dynamic property of the control. A hyperbolic tangent function is used to establish the nonlinear mappings an approximate method is adopted to summarize the general mathematical expressions, and the gradient descent method is applied to ensure the convergence. The simulation results show that the proposed algorithm has the advantages of strong robustness, strong anti-interference and high control accuracy. Compared with two commonly used heading control algorithms, the accuracy of the heading control in the complex environment of the proposed algorithm is improved by more than 50%.
Źródło:
Polish Maritime Research; 2023, 1; 54-64
1233-2585
Pojawia się w:
Polish Maritime Research
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
Tytuł:
In vitro co-stimulation of anti-tumor activity by soluble B7 molecules
Autorzy:
He, Wei
Hu, Zhong-Bo
Liu, Fang
Feng, Xian-Qi
Zou, Ping
Powiązania:
https://bibliotekanauki.pl/articles/1041178.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
immunotherapy
tumor escape
gene fusion
recombinant fusion proteins
Opis:
In order to investigate the anti-tumor activity of a soluble B7-1/immunoglobulin G fusion protein and explore an effective method to eliminate immune escape of tumor cells, a recombinant vector encoding this fusion protein was constructed and constitutively expressed in Chinese hamster ovary cells. After purification with protein G affinity chromatography, the soluble fusion protein was tested for bioactivity. Results showed that the fusion protein could significantly increase the density of B7-1 molecules on WEHI-3 cells, a mouse leukemia cell line. Through allogeneic mixed lymphocyte tumor cultures, it was demonstrated that, with the presence of the first signal, it could also significantly enhance T cell activation and killing activity against WEHI-3 cells and interleukin-2 secretion by activated mouse T lymphocytes. The conclusion can be drawn that the soluble B7-IgG fusion protein has a potent capacity to generate or enhance anti-tumor immune response in vitro, and its clinical value deserves further investigation.
Źródło:
Acta Biochimica Polonica; 2006, 53, 4; 807-813
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green Fabrication of Nanoscale Energetic Molecular Perovskite (H2dabco)[Na(ClO4)3] with Reduced Mechanical Sensitivity
Autorzy:
Hu, Li-shuang
Du, Zelin
Liu, Yang
Gong, Shida
Guang, Chunyu
Li, Xin
Yang, Zhi
Jia, Qi
Liang, Kaili
Powiązania:
https://bibliotekanauki.pl/articles/27787996.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
molecular perovskite
(H2dabco)[Na(ClO4)3]
ball milling
thermal decomposition
mechanical sensitivity
Opis:
High-energy-density molecular perovskite energetic materials with high detonation performance have attracted much attention, but poor safety performance has limited their potential applications. In this paper, nano sodium perchlorate-based molecular perovskite (H2dabco)[Na(ClO4)3] (nano DAP-1) was fabricated by green ball-milling technology. The structure and morphology of the samples were characterized and the results showed that nano DAP-1 with nearly spherical morphology has a narrow particle size distribution, < 1 μm. The thermal decomposition properties were investigated by differential scanning calorimetry (DSC). The exothermic peak of nano DAP-1 thermal decomposition was 330.0 °C, a decrease of 51.7 °C compared with that of raw DAP (381.7 °C). The apparent activation energy (Ea) of nano DAP-1 was calculated to be 160.9 kJ·mol–1, which is lower than that of raw DAP-1 (168.6 kJ·mol–1). Mechanical sensitivity studies showed that nano DAP-1 (H50: 64 cm) exhibited a lower impact sensitivity than that of the raw DAP-1 (H50: 51 cm). This work provides a simple and effective way for improving the thermal decomposition properties and safety performance of molecular perovskite energetic materials.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 369--384
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Metal Oxides on the Thermal Decomposition Kinetics and Mechanisms of HAN/PVA Based Propellants
Autorzy:
Hu, Song-qi
Liu, Xue-li
Liu, Lin-Lin
Kang, Bo
Zhang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/27787991.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HAN/PVA-based propellant
metal oxides
catalytic behaviour
kinetic parameters
Opis:
The thermal decomposition processes of HAN/PVA-based propellants have been investigated using a simultaneous thermogravimetric analysis (TGA) – differential scanning calorimetry (DSC), coupled with Fourier-Transform Infrared Spectroscopy (FTIR) and Mass Spectrometry (MS) system. The activation energy (Ea), pre-exponential factor A and reaction mechanism function f(α) of the decomposition processes have been determined by non-isothermal and Malek methods. The results showed that the decomposition process of an HAN/PVA sample occurs mainly in the temperature range 202.2~220.1 °C, with a mass loss, heat release and Ea of about 84.8%, 1474.18 and 88.76 kJ·mol–1, respectively. Of the seven metal oxides studied as catalysts, Al2O3, V2O5 and Fe2O3 have significant catalytic effects on an HAN/PVA-based propellant, in lowering the decomposition temperature, with Ea changing from 88.8 to 83.7, 85.6 and 113.6 kJ·mol–1, respectively. The f(α) of both HAN/PVA and HAN/PVA/Al2O3 samples can be expressed as f(α) = (1 – α)2, whereas f(α) = α or f(α) = α/2 fit well for the HAN/PVA/V2O5 and HAN/PVA/Fe2O3 samples.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 322-338
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Camouflage Assessments with Digital Pattern Painting Based on the Multi-Scale Pattern-in-Picture Evaluation Model
Autorzy:
Jia, Qi
Xu, Weidong
Yi, Yang
Liu, Jun
Hu, Jianghua
Zhu, Liyan
Yang, Xin
Powiązania:
https://bibliotekanauki.pl/articles/24200962.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
computer-aided
camouflage assessment
pattern painting
evaluation
simulation
military camouflage
Opis:
In general, traditional evaluations of target camouflage effects are usually conducted based on observational data and general results of statistical analysis. This widely applied methodology quantifies the detection and identification probabilities of camouflage objects but has considerable shortcomings. This data evaluation process is laborious and time-consuming and very low in reproducibility, which sheds light on the necessity of developing a more efficient method in this study field. The growth of computeraided image processing technology provides technical support for camouflage effect evaluation based on digital image processing. Digital pattern painting, which has been previously applied to combat utility uniforms, is a new methodology full of potential due to its broad geographical adaptability. This study proposes a multi-scale pattern-in-picture method to evaluate camouflage effects at different distances. We also established a computer-aided background image library and camouflage assessments with digital simulation and created an evaluation system that could be effectively applied to combat utility uniforms. More than 40 testers participated in this study, who were asked to score the designed camouflage schemes using the evaluation system proposed. The data from simulation assessments and individual evaluations show that the computer-aided simulation assessments conducted as part of this research can efficiently and objectively evaluate the camouflage effect on military objects.
Źródło:
Fibres & Textiles in Eastern Europe; 2023, 31, 2; 39--50
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
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:
Looped-chain-based active current sharing strategy in DC microgrids
Autorzy:
Li, D.
Liu, Y.
Gu, Y.
Qi, H.
Powiązania:
https://bibliotekanauki.pl/articles/141109.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active current sharing
DC microgrids
looped control diagram
Opis:
The integration of renewable energy sources in modern electric grids have drawn increasing attention nowadays. In order to effectively manage large-scale renewable energy sources and achieve flexible and efficient operation, the concept of microgrids have been proposed. Considering the nature of DC outputs in many distributed energy resources (DERs), DC microgrids have been extensively studied in the past years. Among the operational issues in DC microgrids, current sharing issues have become an important topic since it is highly relevant to the operation of DC microgrids. By adopting a proper design of current sharing strategy in DC microgrids, the current rating violations in each interface converter can be successfully avoided. In this paper, a looped-chainbased active current sharing strategy is proposed to realize high accuracy current sharing in DC microgrids. In particular, the output current is shared between the neighboring interface converters. Hence, following a clockwise or counter-clockwise order, a loopedchain- based control diagram can be established to share the reference value of the output current. A final status in the whole DC microgrid is that the output current of every interface converter is equalized. Hence, the desired current sharing objective can be satisfied. A MATLAB simulation model is established to verify the proposed loopedchain- based active current sharing strategy in DC microgrids.
Źródło:
Archives of Electrical Engineering; 2017, 66, 3; 559-569
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the co-processing technology of crude oil and coal and its deployment
Autorzy:
Li, Suan
Liu, Qi
Deng, Qingyu
Ye, Hang
Zhou, Xuejie
Qiao, Aijun
Powiązania:
https://bibliotekanauki.pl/articles/2174828.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
crude oil
coal
the co-processing technology
process development
industrial application
Opis:
The effect of process conditions on the co-processing technology of crude oil and coal was investigated. Crude oil/coal matching performance, swelling degree, crude oil/coal slurry viscosity-temperature characteristics and process parameters were obtained via the laboratory scale and pilot scale studies. The optimum reaction temperature of the co-processing was 445~450 °C, the pressure was 19 MPa, the catalyst addition was 3 wt.%, the reaction time was 2 h, and the ratio of hydrogen to crude oil was 1500 (V/V). Furthermore, the co-processing technology including catalyst and corresponding equipment based on the slurry bed hydrogenation were developed. By using this co-processing technology, the feed ratio of crude oil and coal can be 1:1, the coal conversion rate can be over 99%, the light oil (oil and aromatics) yield was over 70%, and the end products were gasoline, diesel, jet fuel, aromatics and LPG. The product quality meets the Euro V standard, whilst aromatics accounted for 48% of the light oil. So it was proved to be feasible to co-refine crude oil and coal at a ratio of 1:1. What’s more, the slurry bed hydrogenation plant and its equipment were tested for long-term operation, and it has been proved that this co-processing technology could be deployed as large-scale industrial application.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 4; 39--50
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Self-catalysed hydrogenation of heavy oil and coal mixtures
Autorzy:
Li, Suan
Sun, Zhenguang
Liu, Qi
Ye, Hang
Wang, Kunpeng
Powiązania:
https://bibliotekanauki.pl/articles/27315628.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
self-catalysed
heavy oil
hydrogenation
coal liquefaction
co-processing technology
Opis:
Coal liquefaction and heavy oil processing have become the urgent need for national energy strategic technology reserves in China. However, the inactivation of solid catalysts in these processes is an inevitable problem. Therefore,a self-catalysed method was proposed. The properties of raw oil could be changed by adding a modifier, as it has the function of self-catalysis, and the additional catalyst is no longer needed. The effect of 200 ppm modifier onthe hydrogenation of heavy oil and 500 ppm on the hydrogenation of coal and oil were investigated. The results showed that modifiers could be miscible with heavy oil at 50~100 °C and could change the properties of oil. When the temperature exceeded 250 °C, the sulfur element in the heavy oil combined with the metal element broughtin by the modifier to form a particle with the size of 2–8 nm, which could interact with the hydrogen molecule toactivate the hydrogen molecule. Activated hydrogen atoms further formed the complexes with nickel, vanadium,calcium, iron, and other elements in heavy oil to achieve the purpose of purifying and lightening the oil phase.Therefore, the self-catalysed method could be widely used in oil re fining and would greatly promote the development of the oil refining and catalysis industry.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 2; 8--14
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Crystal Structure, and Properties of a Novel, Highly Sensitive Energetic, Coordination Compound: Iron (II) Carbohydrazide Perchlorate
Autorzy:
Liu, R.
Zhou, Z.
Qi, S.
Yang, L.
Wu, B.
Huang, H.
Zhang, T.
Powiązania:
https://bibliotekanauki.pl/articles/358343.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
iron (II) carbohydrazide perchlorate
energetic material
high
sensitivity
DFT
energy gap
Opis:
A single crystal of iron (II) carbohydrazide perchlorate [FeII (CHZ)3](ClO4)2 (FeCP), a novel, lead-free, energetic coordination compound, was synthesized and its structure determined by X-ray single crystal diffraction for the frst time. The crystal belongs to the monoclinic system P2(1)/n space group, with a = 1.0066(2) nm, b = 0.8458(2) nm, c = 2.1194(4) nm, β = 100.693(3)° and Z = 4. The central Fe(II) ion is coordinated to three bidentate carbohydrazide units through the carbonyl oxygen atom and an amino nitrogen atom, forming a six-coordinated, non-centrosymmetric complex cation. The thermal analyses by differential scanning calorimetry and thermogravimetry show that the onset temperature of thermal decomposition (152.7 °C) and the critical temperature of thermal explosion of FeCP (161.2 °C) are both much lower than those of other transition metal carbohydrazide perchlorate compounds, and also those of some other primary explosives in service. FeCP has a high enthalpy of combustion, as measured by oxygen bomb calorimetry. The impact, friction and fame sensitivity tests indicate that FeCP is extremely sensitive and hazardous. Unexpected explosions occurred even during the operational processes. In order to explore the intrinsic cause of these explosions, theoretical calculations of the orbital energies were performed based on DTF. These results reveal that the impact sensitivity is positively correlated with the energy gap between HOMO and LUMO: the smaller energy gap results in the higher impact sensitivity.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 1; 17-36
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular cloning and expression analysis of a new gene for short-chain dehydrogenase/reductase 9
Autorzy:
Liu, Shen
Huang, Chaoqun
Li, Dawei
Ren, Weihua
Zhang, Haoxing
Qi, Meiyan
Li, Xin
Yu, Long
Powiązania:
https://bibliotekanauki.pl/articles/1041143.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
liver
clone
short-chain dehydrogenase/reductase
Opis:
We report here the cloning and characterization of a novel human short-chain dehydrogenases/reductase gene SCDR9, isolated from a human liver cDNA library, and mapped to 4q22.1 by browsing the UCSC genomic database. SCDR9 containing an ORF with a length of 900 bp, encoding a protein with a signal peptide sequence and an adh_short domain. GFP localization shows SCDR9 protein concentrated in some site of the cytoplasm, but not in the ER. Expression pattern in eighteen tissues revealed that SCDR9 is expressed highly in liver. Soluble recombinant protein was successfully purified from Escherichia coli using pET28A(+) expression vector. Our data provides important information for further study of the function of the SCDR9 gene and its products.
Źródło:
Acta Biochimica Polonica; 2007, 54, 1; 213-218
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model for the heat transfer behavior of a cooling system
Autorzy:
Liu, Wen
Zhang, Chi
Hu, Xiao-Xiong
Cao, Jian-Bo
Liu, Li-Jiao
Ye, Xin-Y
Lin, Li
Qi, Xun-Ji
Powiązania:
https://bibliotekanauki.pl/articles/2050060.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adsorption system
refrigerating system
desorption
simulation
Opis:
For purposes of studying the heat transfer behavior of various fluids in a refrigeration system, a dynamic model is established, obtained on the basis of analysis concerning the effects of adsorption velocity, adsorbent bed temperature, condensing temperature, and heat transfer fluids, as well as changes of external conditions. It is demonstrated that adsorption velocity increases sharply in the initial phase of adsorption process and gradually declines after reaching a peak value, whereas condensing temperature increases sharply in the initial phase of desorption process and decreases after reaching a peak value with the desorption quantity decreasing. Furthermore, the increase of heat source temperature and the decrease of cooling water temperature can advance the adsorption process. The present study therefore suggests some ways of improving the performance of such a refrigeration system by increasing heat source temperature, decreasing ambient air temperature, increasing return air temperature and decreasing cooling water temperature.
Źródło:
Control and Cybernetics; 2020, 49, 3; 315--332
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Activation of quartz flotation by Cu2+, Ni2+ in the sodium ethylxanthogenate (EX) system
Autorzy:
Liu, Yang
Tong, Xiong
Xie, Rui-Qi
Xie, Xian
Song, Qiang
Fan, Pei-Qiang
Powiązania:
https://bibliotekanauki.pl/articles/24085981.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
flotation
ions activation
sodium ethylxanthogenate
adsorption mechanism
Opis:
During the flotation of metal sulfide minerals, due to the interference of unavoidable ions, the quartz also partially floats in some cases. The studies on the mechanism of quartz being activated and floating up are still insufficient. In this study, the influence of the Cu2+ and Ni2+ unavoidable ions on the floatation of quartz was studied by micro-flotation experiments, adsorption detection, zeta potential measurement, solution composition calculation, infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses, and atomic force microscopy (AFM) observation. This provides a theoretical reference for further understanding the mechanism of sodium ethylxanthogenate and quartz surface, as well as the development of a new quartz depressant. The results of flotation showed that after activation by Cu2+ (1×10-4 mol/dm3) and Ni2+ (5×10-5 mol/dm3), the quartz was captured by sodium ethylxanthogenate (EX: 1.4×10-4 mol/dm3) under alkaline conditions (pH=10), while the best recoveries were obtained as 80% and 43%, respectively. The results of adsorption and zeta potential measurements showed that the precipitation rate of Cu2+ was greater than that of Ni2+ under alkaline conditions. Additionally, both Cu2+ and Ni2+ electrostatically adsorbed on the quartz surface and changed the zeta potential of quartz. The solution composition calculation further showed that Cu(OH)+, Cu(OH)2(s), and Ni(OH)+, Ni(OH)2(s) were the main components in the solution under alkaline conditions. The FT-IR and XPS analyses and AFM observations demonstrated that Cu and Ni species adsorbed on O atoms on the quartz surface, providing active sites for EX adsorption, and EX combines with Cu and Ni species on the quartz surface to generate -O-Cu-EX and -O-Ni-EX complexes. Finally, the quartz floated up due to the formation of hydrophobic products and firm adsorption.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 166368
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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