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Effect of doped strontium on catalytic properties of La_(1-x)SrxMnO_(3) for rhodamine B degradation

Journal of Rare Earths 2021年第11期39卷 1362-1369,I0002页

作者： Jiaxiu Guo YueJing Ting Shen Hongdi Luo Juan Liang Shandong Yuan College of Architecture and Environment Sichuan UniversityChengdu 610065China National Engineering Technology Research Center for Flue Gas Desulfurization Chengdu 610065China Institute of New Energy and Low Carbon Technology Sichuan UniversityChengdu 610065China

A series of La_(1-x)Sr_(x)MnO_(3) samples were prepared by sol-gel method and used to degrade rhodamine B(RhB) in *** samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),N_(2) adsorption-desorption,temperature-programmed reduction of H_(2)(H_(2)-TPR) and temperature-programmed desorption of O_(2)(O_(2)-TPD).The results show that the degradation of RhB is highly dependent on the initial pH value of *** doping enhances the degradation ability of LaMnO_(3) for RhB in the time range of 0-40 min under a strong acidic environment,but all samples exhibit similar degradation rate from 40 to 60 *** La_(0.7)Sr_(0.3)MnO_(3)-RhB reaction system,there are two different degradation pathways,including N-de-ethylation,chromophore cleavage,ring-opening and ***_(1-x)Sr_(x)MnO_(3)(x ≤0.3) has the perovskite structure of La-Mn oxides,while La_(0.6)Sr_(0.4)MnO_(3) exhibits a Sr_(0.4)MnLa_(0.6)O_(2).98 perovskite *** doping leads to distortion of rhombohedral crystal structure and increases the relative content of Mn^(4+).The perovskite structure is stable in strong acidic environment during RhB degradation,but the relative content of Mn^(4+)and Mn^(3+) on the material surface *** doped LaMnO_(3) achieves specific surface area of 58.8 m^(2)/g and total pore volume of 0.152 cm^(3)/***,Sr^(2+)doping improves redox properties of La-Mn oxides,and the presence of defects makes oxygen diffusion easier compared with the undoped samples.

关键词： Organic pollutant Degradation Rhodamine B LaMnO_(3) Sr Perovskite

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Characteristics of air flow driven by the free surface of the open channel

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Journal of Hydrodynamics 2022年第1期34卷 69-75页

作者： Jing Gong Jun Deng Wang-ru Wei Wei-wei Li State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China

Spillway tunnels are a key structure in large-scale water conservancies. The high-head water inlet makes the water surface-velocity extremely high, and the air is driven by the free surface of the water to move downstream. This paper studies the air velocity distribution above the water surface through the model tests, under the assumption that the airflow is a turbulent boundary layer with a rough interface, and the influence of the water depth and the water velocity on the air velocity distribution is analyzed. It is shown that the air velocity is in an exponential distribution. As the measured position moves upward, the air velocity gradually decreases, and the gradient decreases. When the water depth increases, the air velocity increases but with the same distribution form. With the increase of the water surface-velocity, the air velocity at the same measuring point increases, the variation range near the water surface is large, the air boundary layer height increases slightly, and the index coefficient of the air velocity distribution function decreases. Through numerical fitting, the calculation formula of the air boundary layer thickness at different water surface velocities is obtained, along with the numerical value of the index coefficient.

关键词： Open channel air velocity distribution air boundary layer height index coefficient

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Spatial resolution and image processing for pinhole camera-based X-ray fluorescence imaging: a simulation study

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Nuclear science and Techniques 2022年第5期33卷 135-153页

作者： Ze He Ning Huang Peng Wang Zi-Han Chen Bo Peng Key Laboratory of Radiation Physics and Technology of the Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China

Spatial resolution and image-processing methods for full-field X-ray fluorescence(FF-XRF)imaging using X-ray pinhole cameras were studied using Geant4simulations with different geometries and algorithms for image *** main objectives were:(1)calculating the quantum efficiency curves of specific cameras,(2)studying the relationships between the spatial resolution and the pinhole diameter,magnification,and camera binning value,and(3)comparing image-processing methods for pinhole camera *** results were obtained using a point and plane source as the X-ray fluorescence emitter and an array of 100×100 silicon pixel detectors as the X-ray *** quantum efficiency of a back-illuminated deep depletion(BI-DD)structure was above 30%for the XRF energies in the 0.8–9 keV range,with the maximum of 93.7%at 4 *** best spatial resolution of the pinhole camera was 24.7μm and 31.3 lp/mm when measured using the profile function of the point source,with the diameter of 20μm,magnification of 3.16,and camera bin of 1.A blind deconvolution algorithm with Gaussian filtering performed better than the Wiener filter and Richardson iterative methods on FF-XRF images,with the signal-to-noise ratio of 7.81 dB and improved signalto-noise ratio of 7.24 dB at the diameter of 120μm,magnification of 1.0,and camera bin of 1.

关键词： Full-field X-ray fluorescence(FF-XRF) X-ray pinhole camera Spatial resolution Image processing

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Study on the catalytic performance of LaMnO3 for the RhB degradation

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JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS 2020年 109卷 15-25页

作者： Luo, Hongdi Guo, Jiaxiu Shen, Ting Zhou, Houren Liang, Juan Yuan, Shandong Sichuan Univ Coll Architecture & Environm Chengdu 610065 Sichuan Peoples R China Natl Engn Technol Res Ctr Flue Gas Desulfurizat Chengdu 610065 Sichuan Peoples R China Sichuan Univ Inst New Energy & Low Carbon Technol Chengdu 610065 Sichuan Peoples R China

LaMnO3 nanoparticles were synthesized by citric acid complex sol-gel method and used to degrade rhodamine B (RhB) in water. The effects of initial pH value, LaMnO3 dosage, RhB concentration and disrupter agents on the degradation of RhB were investigated. We found that LaMnO3 exhibits an excellent degradation ability of RhB in high acidic conditions without additional oxidants or light irradiation and can achieve 99.7% degradation efficiency for RhB and 65.8% for total organic carbon. This result showed that LaMnO3 itself provides an effective oxidative system to degrade RhB. Furthermore, a reasonable degradation pathway of RhB was proposed, including N-de-ethylation, chromophore cleavage, opening-ring, and mineralization. Finally, LaMnO3 samples before and after the reaction were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. It is found that LaMnO3 can maintain perovskite structure in the degradation of RhB. Mn ions in LaMnO3 provides active center and plays a role of electron transfer during RhB degradation. (C) 2020 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Organic pollutants Catalytic oxidation LaMnO3 Rhodamine B Perovskite

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Effect of Si Content on the Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel after a Quenching and Partitioning Process

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JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE 2024年 1-15页

作者： Shi, Tang Wang, Hui Huang, Xuefei Sichuan Univ Coll Mat Sci & Engn Chengdu 610065 Peoples R China Nucl Power Inst China Sci & Technol Reactor Fuel & Mat Lab Chengdu 610041 Sichuan Peoples R China

Ferritic/martensitic (F/M) steel is considered as one of the most promising cladding materials for Lead-cooling fast reactors due to its favorable mechanical properties and radiation resistance. Quenching and partitioning (Q&P) process can further improve the mechanical properties of the F/M steels compared to conventional normalizing and tempering or quenching and tempering process. In this study, the Q&P process was employed to 9Cr F/M steels with different Si content (0, 0.4, 0.7, 1 wt.%), and the effect of Si content on their microstructure and mechanical properties was studied. The microstructure was characterized through SEM, EBSD, and TEM. The mechanical properties at room and elevated temperatures (500, 600, 700 degrees C) were tested. The results indicated that the addition of Si (0 to 1 wt.%) leads to a slight decrease in the ultimate tensile strength (UTS)/yield strength (YS) of the F/M steel at room temperature from 1328.3/986.5 MPa to 1300.7/950.7 MPa, respectively. Meanwhile, the fracture elongation (FE) maintains at about 16%. Additionally, as the Si content increases from 0 to 1 wt.%, the UTS and YS of the samples at elevated temperatures show a similar trend. However, the FE of the samples initially increases at 500 degrees C, noticeably decreases at 600 degrees C, and eventually rises at 700 degrees C. Only the FE at 600 degrees C was lower compared to that at room temperature. Furthermore, the UTS and YS of the samples decrease with increasing temperature. Although Si addition brings a higher solid solution strengthening effect, it is offset by the coarsening of block size and the formation of delta-ferrite. As a result, a little change in the strength of the steel is obtained.

关键词： ferritic/martensitic (F/M) steel mechanical properties Si addition quenching-partitioning

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A novel multi-objective scheduling model for grid-connected hydro-wind-PV-battery complementary system under extreme weather: A case study of sichuan, China

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RENEWABLE ENERGY 2023年第1期212卷 818-833页

作者： Zhou, Siyu Han, Yang Zalhaf, Amr S. Chen, Shuheng Zhou, Te Yang, Ping Elboshy, Bahaa Univ Elect Sci & Technol China Sch Mech & Elect Engn Chengdu 611731 Peoples R China Tanta Univ Fac Engn Elect Power & Machines Engn Dept Tanta 31511 Egypt Tsinghua Univ Sichuan Energy Internet Res Inst Smart City Energy Syst Lab Chengdu 610299 Peoples R China Tanta Univ Fac Engn Dept Architectural Engn Tanta 31511 Egypt

Affected by extreme hot and dry weather events, the power supplied by hydropower is seriously insufficient in sichuan province during the summer of 2022, causing severe power shortage and incalculable economic losses for the society. Therefore, a novel multi-objective scheduling model based on grid-connected hydro-wind-solar-battery energy resources combining flexible reserves is proposed to collaboratively guarantee the power supply reliability of both the contracted long-distance power transmission and the local electricity demand under extreme hot and dry weather. The intermittent nature of water inflow, wind speed, solar irradiance, and load is considered, and the multi-scenarios are produced using Latin Hypercube Sampling method. In this work, thermal plants are regarded as flexible reserves for easing the load shedding level of local load. The McCormick's En-velope method is implemented to linearize the power production model of the hydropower station. A multi-objective model, including minimum penalty cost of load shedding and carbon dioxide emission, is proposed to achieve the economic-environmental equilibrium of the power system. The proposed multi-objective optimal hybrid energy complementary strategy is transformed into a single objective model via epsilon-constraint method, and the fuzzy satisfying method is introduced to select the best compromise solution in the Pareto Front. The meteorological information of the summer of 2022 is collected to verify the effectiveness of this proposed mixed-integer-linear-programming energy complementary model based on a hydropower station on the Jinsha River in sichuan province, China. Numerical experiments demonstrate that the proposed model is efficient and can enhance the reliability of real-world power systems under extreme hot and dry weather. A set of policy sug-gestions have been provided for sichuan province to develop the power grid to face the extreme weather effect.

关键词： Extreme hot and dry weather Power shortage Multi-objective model Hydro-wind-solar-battery Flexible reserve Hybrid energy complementary strategy

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Carbonized Polymer Dots-Promoted Photocatalytic Activation of Molecular Oxygen for Efficient and Selective Oxidation of Thioethers to Sulfoxides

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NANO LETTERS 2024年第44期24卷 13895-13902页

作者： Song, Qiao Li, Wanyong Shan, Feishi Peng, Xue Wang, Leyong Wang, Zhouyu Yu, Xiao-Qi Xihua Univ Dept Chem Chengdu 610039 Peoples R China Asymmetr Synth & Chiral Technol Key Lab Sichuan Pr Yibin 644000 Peoples R China Nanjing Univ Sch Chem & Chem Engn Key Lab Mesoscop Chem MOE Nanjing 210023 Peoples R China

Sulfoxides are essential in pharmaceuticals and chemicals, yet traditional thioether oxidation struggles with selectivity and sustainability. This study introduces carbonized polymer dots (CPDs) as effective photocatalysts for ecofriendly thioether to sulfoxide oxidation, using water and ethanol to enhance reaction selectivity and efficiency under 455 nm blue light. These catalysts not only show remarkable efficacy under mild conditions but also display high selectivity for sulfoxide formation, proving versatile across a broad range of substrates. We further elucidated the catalytic mechanism, confirming the predominant roles of singlet oxygen and superoxide anions through both spectroscopic evidence and quenching experiments. The method extends to the synthesis of pharmaceuticals such as oxfendazole, albendazole sulfoxide, and sulindac, highlighting its practical utility. Overall, our findings present a sustainable and efficient avenue for sulfoxide synthesis, thereby broadening the practical utility of CPDs in photocatalytic transformations.

关键词： carbon dots photocatalysis molecular oxygenactivation selective oxidation sulfoxides

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Machine-learning-accelerated structure prediction of PtSnO nanoclusters under working conditions

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PHYSICAL CHEMISTRY CHEMICAL PHYSICS 2024年第43期26卷 27624-27632页

作者： Zeng, Fanke Cen, Wanglai Sichuan Univ Inst New Energy & Low Carbon Technol Natl Engn Res Ctr Flue Gas Desulfurizat Chengdu 610065 Peoples R China

Credible property exploration or prediction can not be achieved without well-established compositions and structures of catalysts under working conditions. We construct surrogate models via combination of machine learning (ML), genetic algorithm (GA) and ab initio thermodynamics (AITD) to accelerate global optimization of PtSn binary metal oxides, which are typically used for CO2-assisted propane dehydrogenation to propylene. This challenging case illustrates that the subtle oxidized states of PtSnO clusters can be predicted in a large chemical space including a wide range of reaction conditions. The oxidation patterns, phase diagrams and atomic charge distributions of the PtSnO clusters have been discussed. The Sn decorating mechanism to Pt in PtSnO has been explained. These results also indicate that the oxidation of PtSn clusters is more feasible under working conditions, and that previous understanding obtained only with a fully reduced PtSn alloy may be incomplete.

关键词： Genetic algorithms

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Generation of sulfones utilizing β-sulfinyl esters as masked aryl sulfinates under redox-neutral conditions

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ORGANIC & BIOMOLECULAR CHEMISTRY 2024年第17期22卷 3381-3385页

作者： Zhang, Yixin Yang, Zhu Yang, Hongjun Li, Xuefeng Yang, Lu Southwest Minzu Univ Sch Chem & Environm Key Lab Gen Chem Natl Ethn Affairs Commiss Key Lab Key Lab Gen Chem Natl Ethn Affairs CommissKey Lab Chengdu 610041 Peoples R China

A method for generation of SVI sulfones from beta-sulfinyl esters (SIV) under transition-metal-free non-oxidative mild conditions is presented. Various sulfones have been achieved with moderate to excellent yields. The advantage of using beta-sulfinyl esters as masked aryl sulfinates has also been exemplified using brominated substrates. Oxygen isotope-labeling experiments indicated that the oxygen atoms incorporated into the sulfone product come from the sulfoxide of the beta-sulfinyl ester. Successive beta-elimination/O-addition/sulfinate esterification/beta-elimination processes are proposed for the mechanism of generating SVI from SIV. A method for generation of SVI sulfones from beta-sulfinyl esters (SIV) under transition-metal-free non-oxidative mild conditions is presented.

关键词： Esters

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A Trifolium repens flavodoxin-like quinone reductase 1 (TrFQR1) improves plant adaptability to high temperature associated with oxidative homeostasis and lipids remodeling

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PLANT JOURNAL 2023年第2期115卷 369-385页

作者： Cheng, Bizhen Zhou, Min Tang, Tao Hassan, Muhammad Jawad Zhou, Jianzhen Tan, Meng Li, Zhou Peng, Yan Sichuan Agr Univ Coll Grassland Sci & Technol Chengdu 611130 Peoples R China

Maintenance of stable mitochondrial respiratory chains could enhance adaptability to high temperature, but the potential mechanism was not elucidated clearly in plants. In this study, we identified and isolated a TrFQR1 gene encoding the flavodoxin-like quinone reductase 1 (TrFQR1) located in mitochondria of leguminous white clover (Trifolium repens). Phylogenetic analysis indicated that amino acid sequences of FQR1 in various plant species showed a high degree of similarities. Ectopic expression of TrFQR1 protected yeast (Saccharomyces cerevisiae) from heat damage and toxic levels of benzoquinone, phenanthraquinone and hydroquinone. Transgenic Arabidopsis thaliana and white clover overexpressing TrFQR1 exhibited significantly lower oxidative damage and better photosynthetic capacity and growth than wild-type in response to high-temperature stress, whereas AtFQR1-RNAi A. thaliana showed more severe oxidative damage and growth retardation under heat stress. TrFQR1-transgenic white clover also maintained better respiratory electron transport chain than wild-type plants, as manifested by significantly higher mitochondrial complex II and III activities, alternative oxidase activity, NAD(P)H content, and coenzyme Q10 content in response to heat stress. In addition, overexpression of TrFQR1 enhanced the accumulation of lipids including phosphatidylglycerol, monogalactosyl diacylglycerol, sulfoquinovosyl diacylglycerol and cardiolipin as important compositions of bilayers involved in dynamic membrane assembly in mitochondria or chloroplasts positively associated with heat tolerance. TrFQR1-transgenic white clover also exhibited higher lipids saturation level and phosphatidylcholine:phosphatidylethanolamine ratio, which could be beneficial to membrane stability and integrity during a prolonged period of heat stress. The current study proves that TrFQR1 is essential for heat tolerance associated with mitochondrial respiratory chain, cellular reactive oxygen species homeostas

关键词： thermotolerance reactive oxygen species photosynthesis mitochondrial respiration chain lipid metabolism coenzyme Q10 quinone toxicity

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