18 results on '"Peiqing Yu"'
Search Results
2. Evolutionary pattern and influencing factors of the aquaculture development in the Guangdong-Hong Kong-Macao Greater Bay area during 1986–2020
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Peiqing Yuan, Xianwei Wang, Yanwu Zhou, Zhixin Qi, Kai Liu, Yongjun Fang, and Yazhou Ning
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Aquaculture ponds ,Remote sensing ,Spatiotemporal variations ,Influencing factors ,Guangdong–Hong Kong–Macao Greater Bay Area ,Ecology ,QH540-549.5 - Abstract
The rapid expansion of aquaculture ponds at the end of the last century raised concerns about their environmental and ecological impacts in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). This study aims to comprehensively investigate the spatiotemporal evolutionary characteristics and explore the influencing factors of aquaculture development in the GBA. An automated approach was established to extract the aquaculture pond areas on the Google Earth Engine (GEE) platform using Landsat images and showed high accuracy. The aquaculture development in the GBA underwent three phases of rapid expansion (1986–1996), constant transformation (1996–2010), and drastic contraction (2010–2020), and was closely related to the important aquaculture policies in China and Guangdong Province. The local aquaculture ponds showed three evolutionary patterns of continuous shrinkage, earlier shrinkage, and later shrinkage, which were mainly influenced by the economic development level and urbanization in each city. Rapid urbanization created great demands for aquaculture products and intense land use competition, which drove the conversion of aquaculture ponds into impervious land and migration from the central GBA towards the surrounding coast and upstream areas. Government policies promoted the initial rapid increase and regulated the aquaculture ponds to develop towards a more environment-friendly and intensive mode, which led to a steady increase of aquaculture products despite the drastic decrease in aquaculture pond areas in the past decade. These evolutionary features are of significance for policymakers and farmers to maintain the sustainable development of aquaculture in the GBA and Guangdong Province.
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- 2024
- Full Text
- View/download PDF
3. Performances Enhancement of a-Si:H Thin Film Photovoltaic Cells by Incorporating Silver Nanoparticles
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Jean-Philippe Blondeau, Christophe Longeaud, Julien Roussel, Timothée Pingault, Alexandre Jaffré, Jacques Meot, Esidor Ntsoenzok, Peiqing Yu, Caroline Andreazza, Pauline Sylvia Pokam Kuisseu, Elyaakoubi Mustapha, Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), Interfaces, Confinement, Matériaux et Nanostructures ( ICMN), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon), Laboratoire pluridisciplinaire de recherche en ingénierie des systèmes, mécanique et énergétique (PRISME), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Solems, Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon), and Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
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010302 applied physics ,Materials science ,business.industry ,Mie scattering ,Photovoltaic system ,02 engineering and technology ,Surfaces and Interfaces ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,7. Clean energy ,01 natural sciences ,Silver nanoparticle ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,0103 physical sciences ,Materials Chemistry ,Optoelectronics ,Electrical and Electronic Engineering ,Thin film ,0210 nano-technology ,business ,Plasmon ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2018
4. An Earthquake Early Warning System in Fujian, China
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Peiqing Yu, Yongxiang Wei, Jun Li, Xing Jin, Hongcai Zhang, Lanchi Kang, Shicheng Wang, and Lingzhu Huang
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ALARM ,Geophysics ,010504 meteorology & atmospheric sciences ,Warning system ,Geochemistry and Petrology ,Computer science ,Magnitude (mathematics) ,Earthquake warning system ,010502 geochemistry & geophysics ,China ,01 natural sciences ,Seismology ,0105 earth and related environmental sciences - Abstract
As one of the most economically developed and seismically active regions of China, Fujian faces a threat from severe earthquakes, particularly those that occur in Taiwan. Following the worldwide construction of an earthquake early warning (EEW) system, we developed an EEW system in Fujian in 2009 and began online testing in November 2012. During this testing, our EEW system successfully processed several earthquakes in both the Fujian region and Taiwan. The results showed that, for inland events (Fujian region), the first alarm was generated 6.4±0.97 s after the first station was triggered, with a location error of 4.6±4.0 km and magnitude estimation error of 0.6±0.5. For offshore events (Taiwan), the first alarm was generated 13.7±2.9 s after the first station was triggered, with a location error of 30.6±31.4 km and magnitude estimation error of −0.2±0.4. Online testing allows us to continuously improve and perfect our system. In 2017, our system will officially begin providing EEW information to the public in the Fujian region. In addition to the preceding, the architecture, key algorithms, software design, and online testing results are included in this article to provide readers with a comprehensive understanding of our EEW system.
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- 2016
5. Tandem Hydration of Diisonitriles Triggered by Isonitrile Hydratase in Streptomyces thioluteus
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Muhammad Ali, Haibo Zhang, Jing He, Lijuan Wang, Yiguang Zhu, Siqi Zhu, Mengyi Zhu, Xiaofei Gu, Peiqing Yu, and Qingbo Zhang
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0301 basic medicine ,Tandem ,Chemistry ,Organic Chemistry ,Endogeny ,010402 general chemistry ,01 natural sciences ,Biochemistry ,In vitro ,0104 chemical sciences ,Enzymatic Assays ,Streptomyces thioluteus ,03 medical and health sciences ,030104 developmental biology ,Heterologous expression ,Physical and Theoretical Chemistry ,Formamides - Abstract
The biosynthetic pathway of diisonitrile chalkophore SF2768 was identified in Streptomyces thioluteus through heterologous expression recently. Isolation and structure elucidation of the N-substituted formamides that coexisted with the diisonitriles implied that a hydration event was involved. In vitro enzymatic assays of an endogenous isonitrile hydratase suggested a rare sequential-hydration of the diisonitriles. Additionally, the results of Cu-CAS assays indicate that both partial and complete hydration led to the loss of the copper-chelating ability of SF2768.
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- 2018
6. Study of traps in P3HT:PCBM based organic solar cells using fractional thermally stimulated current (FTSC) technique
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José Alvarez, Anne Migan-Dubois, Yunfei Zhou, Denis Mencaraglia, Michael Krueger, Arouna Darga, Peiqing Yu, Virginie Vissac, SCM - Equipe Semiconducteurs en Couches Minces, Laboratoire de génie électrique de Paris (LGEP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS)
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Organic solar cell ,Gaussian ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Molecular physics ,Spectral line ,Trap (computing) ,symbols.namesake ,Impurity ,Materials Chemistry ,HOMO/LUMO ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,Chemistry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,Ceramics and Composites ,symbols ,InformationSystems_MISCELLANEOUS ,0210 nano-technology - Abstract
International audience; Thermally Stimulated Current (TSC) measurement, well known technique for trap level detection, was applied to derive the density of occupied states in organic solar cells. The device structure is Glass/ITO/P3HT:PCBM/Al. Analysis of the TSC spectra allows to determine the Fermi level position from the edge of the nearest band (LUMO or HOMO) (~ 0.42 eV). At that time, TSC peaks cannot be evaluated due to multiple traps that contribute to the current signal. In order to achieve a rough picture of the trap structure, Fractional TSC (FTSC) method was applied. The procedure is based on multiple temperature cycles which evaluate activation energies for different ranges of temperatures. The results reveal several plateaus, pointing out the presence of four trap levels (0.12 eV, 0.16 eV, 0.20 eV and 0.35 eV). Additionally, a curve-fitting procedure is done in order to characterize the trap parameters and achieved with five trap levels (0.059 eV, 0.12 eV, 0.14 eV, 0.20 eV and 0.35 eV) in Gaussian or exponential distribution. Four of them are in complete agreement with measured FTSC ones. Those results are very well correlated with our other characterizations by Admittance Spectroscopy (AS). The results presented here show that, in spite of the chemical differences between inorganic materials and conjugated polymers, FTCS technique can still be applied to determine the density of occupied states in these materials, as long as care is taken. Polymers are low-mobility materials with large concentrations of deep impurities.
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- 2012
7. Structural, magnetic and optical properties of vanadium doped zinc oxide: Systematic first-principles investigations
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Pengfei Xing, Ping Wu, Wei Zhou, Peiqing Yu, Qinggong Song, and Junfu Guo
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Materials science ,Condensed matter physics ,Magnetic moment ,Band gap ,Fermi level ,Doping ,Vanadium ,chemistry.chemical_element ,General Chemistry ,Zinc ,Condensed Matter Physics ,Condensed Matter::Materials Science ,symbols.namesake ,chemistry ,Ferromagnetism ,Materials Chemistry ,symbols ,Condensed Matter::Strongly Correlated Electrons ,Density functional theory - Abstract
The electronic structural, magnetic and optical properties of pure and V-doped ZnO are investigated by first-principles calculations based on the density functional theory. With the introduction of V atoms, the spin-splitting near the Fermi level leads to a net magnetic moment of the system. A significant possibility of room temperature ferromagnetism (RTFM) originated from the Ruderman–Kittel–Kassuya–Yosida (RKKY) exchange is predicted. Oxygen vacancy is positive to enhance the ferromagnetism while zinc vacancy is negative. With respect to the optical properties, the presence of V atoms was found to have an obvious influence on the transmittivity, especially in the low energy region. A slight V-doping can keep a high optical transmission and smoothly modulate the optical bandgap.
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- 2012
8. Investigation of electric charge transport in conjugated polymer P3HT: PCBM solar cell with temperature dependent current and capacitance measurements
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Anne Migan, Denis Mencaraglia, Roshanak Rabdbeh, Arouna Darga, Bernard Ratier, Peiqing Yu, André Moliton, Laboratoire de génie électrique de Paris (LGEP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), MINACOM, XLIM (XLIM), and Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)
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Fullerene ,Materials science ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Analytical chemistry ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Thermal conduction ,7. Clean energy ,01 natural sciences ,Capacitance ,Electric charge ,Space charge ,Polymer solar cell ,law.invention ,law ,0103 physical sciences ,Solar cell ,InformationSystems_MISCELLANEOUS ,010306 general physics ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
We investigated quantitatively the electronic transport properties of a bulk heterojunction polymer/fullerene solar cell, based on structure Glass/ITO/P3HT:PCBM/Al. The current-voltage I-V characteristics in the intermediate positive bias and temperature regime (0.2 V ≤ V ≤ 1.5 V, 180 K ≤ T ≤ 250 K) can be well fitted by a modified Poole-Frenkel PF detrapping model. Combining these results with the high frequency capacitance measurements, we could then derive independently the absorber thickness and its dielectric constant. At low temperature (80 K ≤ T ≤ 170 K), the I-V data can be well accounted for with Space Charge Limited Current (SCLC) regimes. At intermediate positive bias (1 V ≤ V ≤ 2.3 V), the current is dominated by the trapped space charges with an exponential traps distribution, while at high positive bias (2.5 V ≤ V ≤ 4 V), the space charges due to injected free carrier play an important role for the conduction. From the fits to the two different SCLC models, we could then extract the electrically active defects parameters controlling the transport. These parameters were confirmed by space charge capacitance spectroscopy (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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- 2010
9. Dissolution Characteristics of Hydrophobically Associating Polyacrylamide in Stirred Tanks
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Guozhong Zhou, Xiangli Long, Minghui Xie, Huaxiao Wu, Peiqing Yu, and Min Liu
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chemistry.chemical_classification ,Environmental Engineering ,Materials science ,Waste management ,General Chemical Engineering ,Polymer flooding ,Polyacrylamide ,General Chemistry ,Polymer ,Biochemistry ,Viscosity ,Impeller ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Enhanced oil recovery ,Solubility ,Dissolution - Abstract
Enhanced oil recovery (EOR) by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China. Hydrophobically associating polyacrylamide (HAPAM) has been recently proposed as a new flooding agent. The solubility of HAPAM is low, which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield. Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving. But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks. In this paper, effects of temperature, salinity, stirring speed, impeller type and stirring method on the dissolution of HAPAM are reported. The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed, but the viscosity of the polymer solution decreases. There is an optimal range of salinity for polymer dissolving. Combining the operation mode of up-pumping with varying stirring speed, hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity.
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- 2010
10. Influence of Gold nanoparticles (Au NPs) for performance improvement of a-Si:H photovoltaic cells
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Esidor Ntsoenzok, Jean-Philippe Blondeau, Jacques Meot, Perrine Dutheil, Amaël Caillard, Peiqing Yu, Anne-Lise Thomann, Elyaakoubi Mustapha, Caroline Andreazza, Julien Roussel, Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Interfaces, Confinement, Matériaux et Nanostructures ( ICMN), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Département Images, Robotique, Automatique et Signal [Orléans] (IRAUS), Laboratoire pluridisciplinaire de recherche en ingénierie des systèmes, mécanique et énergétique (PRISME), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Groupe de recherches sur l'énergétique des milieux ionisés (GREMI), and Solems
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Amorphous silicon ,Materials science ,Annealing (metallurgy) ,Biophysics ,Mie modelization ,Nanotechnology ,02 engineering and technology ,01 natural sciences ,7. Clean energy ,Biochemistry ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,Sputtering ,0103 physical sciences ,Thin solar films efficiency improvement ,Thin film ,Absorption (electromagnetic radiation) ,Plasmon ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,business.industry ,Scattering ,Diffusionmechanisms ,021001 nanoscience & nanotechnology ,chemistry ,Optoelectronics ,Plasmonics ,0210 nano-technology ,business ,Biotechnology ,Localized surface plasmon - Abstract
The efficiency of thin-film solar cells using a-Si:H is limited by the decrease in a-Si:H layer optical path length and its poor light absorption at red and near-infrared (NIR) wavelengths. Metal nanoparticles (NPs) such as Au have been shown to increase the absorption in the active material and the cell performances, by exhibiting localized surface plasmon (LSP) resonances. Our work’s goals are to understand NP influence in such cells and to perform an optimal structure by increasing the amount of light absorbed within the cell using NPs scattering. Modeling based on Mie theory is first carried out using bulk Palik data for Au spheres with various diameters and refractive medium indexes. Using modeling results, Au layers were deposited on glass and SnO2 substrates either by thermal evaporation in vacuum or sputtering, followed by thermal annealing (200~500 °C) in order to promote the NP growth. SEM pictures show quasi-spherical Au NP shape with an average size around 100 nm depending on the deposited layer and the annealing temperature and time. This diameter range switches extinction of NPs in scattering regime. Annealing temperature strongly affects the NP morphology. Surface coverage decreases and sphericity appears to increase with T. UV-visible spectroscopy displays distinct LSP resonances around 672 nm after annealing with a red shift while T increases. Based on these results, the thin films a-Si:H solar cells with Au NPs are realized and studied. Confirmed with the modeling results and the experimental values, the configuration in NIP junction with the Au NPs in back contact can optimize the photovoltaic properties, by the backscattering of incident light.
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- 2014
11. Study of the electronic properties of wide band gap CIGSe solar cells: Influence of copper off-stoichiometry
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Morgane Fruzzetti, H. Marko, Boris Morel, Arouna Darga, John Kessler, Ludovic Arzel, Sébastien Noël, Denis Mencaraglia, Nicolas Barreau, Peiqing Yu, Jean-Paul Kleider, Wilfried Favre, SCM - Equipe Semiconducteurs en Couches Minces, Laboratoire de génie électrique de Paris (LGEP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS)
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Photoluminescence ,Materials science ,Analytical chemistry ,Wide-bandgap semiconductor ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,7. Clean energy ,01 natural sciences ,Space charge ,Copper ,Diffusion capacitance ,Spectral line ,Electronic, Optical and Magnetic Materials ,chemistry ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,010306 general physics ,0210 nano-technology ,Stoichiometry ,Electronic properties - Abstract
The objective of this work is to study the influence of the copper (Cu) content ( y = [Cu]/([In] + [Ga])) on the electronic properties of wide band gap (1.35 eV, x = [Ga]/([In] + [Ga]) ~ 0.55) Cu(In,Ga)Se 2 (CIGSe) thin film solar cells. For this study, solar cells samples with a variation in y from 0.97 to 0.84 have been fabricated. The efficiencies of solar cells have been divided by two for y varying from 0.97 to 0.84. Junction capacitance methods and photoluminescence were used to get information about space charge and defects properties. The increase of the Cu-content y of the absorber, leads to a widening of the space region, due a decrease of the net carriers concentration. The photoluminescence spectra of the solar cells with high absorber Cu-content y , slightly close to stoichiometry 0.95–0.97) have revealed a defect level of about 0.18 eV, which is not present in the solar cells with y less than 0.95. These observations are discussed in terms of a decrease of the defect complex (2V Cu + M Cu with M = In or Ga) stability at higher Ga contents.
- Published
- 2012
12. Optical Modeling of Gold nanoparticles (Au NP) for efficiency improvement of a-Si:H photovoltaic cells
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Elyaakoubi Mustapha, Perrine Dutheil, Jacque Meot, Anne-Lise Thomann, Esidor Ntsoenzok, Caroline Andreazza, Jean-Philippe Blondeau, Peiqing Yu, and Julien Roussel
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Materials science ,Annealing (metallurgy) ,Scattering ,Mie scattering ,Analytical chemistry ,Spectroscopy ,Absorption (electromagnetic radiation) ,Luminescence ,Optical path length ,Localized surface plasmon - Abstract
The efficiency of thin-film solar cells using a-Si:H is limited by the decrease in a-Si:H layer optical path length and its poor light absorption at red and NIR wavelengths. Metal NP such as Au have been shown to increase the absorption in the active material and then cell performances, by exhibiting localized surface plasmon (LSP) resonances. Our work’s goal is to understand NP influence in such cells, to perform an optimal structure by increasing the amount of light absorbed within the cell using NP scattering and luminescence. Modeling based on Mie theory is first carried out using bulk Palik data for Au spheres with various diameters and refractive medium indexes. Using modeling parameters, Au layers were deposited on glass and SnO2 substrates respectively by thermal evaporation in vacuum and sputtering, followed by thermal annealing (200 ∼ 500°C) in order to promote the NP growth. MEB pictures show quasispherical Au NP shape with a mean size of 150nm. This diameter range switches extinction of NP in scattering regime. Annealing temperature (T) strongly affects the NP morphology. Surface coverage decreases and sphericity appears to increase with T. UV-Visible spectroscopy displays distinct LSP resonances around 600nm after annealing with a red shift while T increases.
- Published
- 2014
13. Tandem Hydration of Diisonitriles Triggered by Isonitrile Hydratase in Streptomyces thioluteus.
- Author
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Mengyi Zhu, Lijuan Wang, Qingbo Zhang, Muhammad Ali, Siqi Zhu, Peiqing Yu, Xiaofei Gu, Haibo Zhang, Yiguang Zhu, and Jing He
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- 2018
- Full Text
- View/download PDF
14. Removal of p-Nitrophenol by Adsorption with 2-Phenylimidazole-Modified ZIF-8
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Yu Zhao, Peiqing Yuan, Xinru Xu, and Jingyi Yang
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p-nitrophenol ,zeolitic imidazolate frameworks ,adsorption ,Organic chemistry ,QD241-441 - Abstract
Petrochemical wastewater contains p-nitrophenol, a highly toxic, bioaccumulative and persistent pollutant that can harm ecosystems and environmental sustainability. In this study, ZIF-8-PhIm was prepared for p-nitrophenol removal from petrochemical wastewater using solvent-assisted ligand exchange (SALE) with 2-phenylimidazole(2-PhIm). The ZIF-8-PhIm’s composition and structure were characterised using the XRD, SEM, FT-IR, 1H NMR, XPS and BET methods. The adsorption effect of ZIF-8-PhIm on p-nitrophenol was investigated with the static adsorption method. Compared to the ZIF-8 materials, ZIF-8-PhIm exhibited stronger π-π interactions, produced a multistage pore structure with larger pore capacity and size, and had increased hydrophilicity and exposure of adsorption sites. Under optimised conditions (dose = 0.4 g/L, T = 298 K, C0 = 400 mg/L), ZIF-8-PhIm achieved an adsorption amount of 828.29 mg/g, which had a greater p-nitrophenol adsorption capacity compared to the ZIF-8 material. The Langmuir isotherm and pseudo-second-order kinetic models appropriately described the p-nitrophenol adsorption of ZIF-8-PhIm. Hydrogen bonding and π-π interactions dominated the p-nitrophenol adsorption of ZIF-8-PhIm. It also had relatively good regeneration properties.
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- 2023
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15. Comprehensive Investigation on Spatiotemporal Variations of Tropical Cyclone Activities in the Western North Pacific, 1950–2019
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Qi Yu, Xianwei Wang, Yongjun Fang, Yazhou Ning, Peiqing Yuan, Bingrou Xi, and Runzhi Wang
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tropical cyclones ,Western North Pacific ,genesis frequency ,landfall ,El Niño–Southern Oscillation ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
Tropical Cyclones (TCs) are the most severe natural disasters in the Western North Pacific Ocean (WNP). While previous studies reported evident changes over certain regions or seasons between typical periods, there is a lack of a complete picture of the long-term variations in TC activities in the WNP. This study carried out a comprehensive investigation on the spatiotemporal variations in TC genesis locations and transit pathways in the WNP, based on the TC best-track datasets from the China Meteorological Administration Shanghai Typhoon Institute. The results showed that the TC genesis and occurrence frequencies showed drastic decreases and westward shifts in the WNP from 1950 to 2019. The greatest decrease in TC genesis occurred for Tropical Depressions (TDs: 10.8−17.1 m/s) and Typhoons (TYs: > 32.7 m/s). The number of Tropical Storms (TSs: 17.2−32.6 m/s) and the mean intensity (2 min maximum sustained wind speed) of TCs overall showed no evident change. The decadal average of TC genesis frequency increased by 63% in the near-coast seas (WNPO), but decreased by 46% near the central Pacific Ocean (WNCP), demonstrating a westward shift for TC genesis locations. The TC genesis and occurrence frequencies also showed significant declines in the southern Philippine Sea (SPS) and South China Sea (SCS), while they showed a lower reduction in the Eastern East China Sea (EECS), the northern ocean edge of TC genesis areas, resulting in an increase in the average latitude of TC genesis locations, a spurious northward shift. The La Niña and El Niño years showed contrasting effects on TC genesis frequency and landfall ratios. There were greater instances of TC genesis and greater landfall ratios during the La Niña mature phase, while there were fewer TC formations and lower landfall ratios during the short duration (SD) El Niño developing phase. The TC genesis locations showed a distinct northwestward shift during La Niña years compared to those during El Niño years.
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- 2023
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16. CFD Simulation and Optimal Design of a New Parabolic–Shaped Guided Valve Tray
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Qiliang Ye, Chenyu Wang, Hao Sun, Yu’an Li, and Peiqing Yuan
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parabolic–shaped guided valve tray ,rectangular guided valve tray ,CFD ,clear liquid height ,velocity distribution ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A new parabolic–shaped guided valve tray is proposed. The gas–liquid two–phase flow of parabolic and conventional rectangular guided valve trays is simulated using the computational fluid dynamics (CFD) method. The clear liquid height on the tray was predicted for different combinations of the superficial gas velocity, liquid flow intensity and weir height. The predicted values were in good agreement with the calculated ones. The parabolic–shaped guided valve tray has a more uniform flow form by comparing the gas–liquid two–phase flow behavior of parabolic and rectangular guided valve trays: the liquid level difference is slight, the guiding effect is strong, and the re–mixing phenomenon is improved. Further modeling and simulations were conducted for nine parabolic–shaped guided valve trays of different function expressions. The optimum valve structure is the parabolic–shaped guided valve of the a–value at 0.075 and the t–value at 26.
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- 2023
- Full Text
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17. Heat Integration for Phenols and Ammonia Recovery Process of Coal Gasification Wastewater Considering Optimization of Process Parameters
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Qiliang Ye, Jiang Zeng, Yuan Li, Peiqing Yuan, and Fuchen Wang
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coal gasification wastewater ,heat exchanger network ,heat integration ,genetic algorithm ,Technology - Abstract
A heat integration optimization method that considers the changes in process parameters is proposed to find the global optimal process scheme for a coal chemical company’s phenols and ammonia recovery process. The phenols and ammonia recovery process is simulated by Aspen Plus, and a programming method for heat exchanger networks synthesis that can simultaneously optimize process parameters and heat integration is constructed by Matlab. Taking the total annual cost as the objective function, the following process parameters are optimized: the hot feed temperature and cold/hot feed ratio of sour water stripper, the temperature of three-step partial condensation system, the feed temperature and column pressure of both solvent distillation column and solvent stripper. The result shows that, compared with the heat integration process under original process parameters, the new heat integration process saves 14.3% energy consumption and reduces the total annual cost by about 15.1%. The new heat integration process provides guidance for the optimization of the phenols and ammonia recovery process. The proposed heat integration optimization method based on changing process parameters is an effective and practical tool that offers good application prospects.
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- 2022
- Full Text
- View/download PDF
18. An Earthquake Early Warning System in Fujian, China.
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Hongcai Zhang, Xing Jin, Yongxiang Wei, Jun Li, Lanchi Kang, Shicheng Wang, Lingzhu Huang, and Peiqing Yu
- Subjects
EARTHQUAKE hazard analysis ,EARTHQUAKE magnitude ,SEISMOLOGICAL research ,EARTHQUAKE engineering - Abstract
As one of the most economically developed and seismically active regions of China, Fujian faces a threat from severe earthquakes, particularly those that occur in Taiwan. Following the worldwide construction of an earthquake early warning (EEW) system, we developed an EEW system in Fujian in 2009 and began online testing in November 2012. During this testing, our EEW system successfully processed several earthquakes in both the Fujian region and Taiwan. The results showed that, for inland events (Fujian region), the first alarm was generated 6.4±0.97 s after the first station was triggered, with a location error of 4.6±4.0 km and magnitude estimation error of 0.6±0.5. For offshore events (Taiwan), the first alarm was generated 13.7±2.9 s after the first station was triggered, with a location error of 30.6±31.4 km and magnitude estimation error of -0.2±0.4. Online testing allows us to continuously improve and perfect our system. In 2017, our system will officially begin providing EEW information to the public in the Fujian region. In addition to the preceding, the architecture, key algorithms, software design, and online testing results are included in this article to provide readers with a comprehensive understanding of our EEW system. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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