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A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,France

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Journal of environmental sciences 2024年第1期135卷 521-533页

作者： Chaoyang Xue Gisèle Krysztofiak Yangang ren Min Cai Patrick Mercier Frédéric Le Fur Corinne Robin Benoit Grosselin Véronique Daele Max RMcGillen Yujing Mu Valéry Catoire Abdelwahid Mellouki Laboratoire de Physique et Chimie de l’environnement et de l’Espace(LPC2E) CNRS–UniversitéOrléans–CNES(UMR 7328)Orléans Cedex 245071France Institut de Combustion AérothermiqueRéactivitéEnvironnement(ICARE)CNRSOrléans Cedex 245071France Research Centre for Eco-environmental sciences Chinese Academy of SciencesBeijing 100085China Lig’Air-Association de surveillance de la qualitéde l’air en région Centre-Val de Loire Saint-Cyr-en-Val 45590France Mohammed V University RabatMorocco

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global *** September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS *** on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were *** increases in gaseous pollutants(CO,CH_(4),n_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air *** factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous *** in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and ***,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),n_(2)O,and BC)emissions and compared them with fire emission *** biomass burning emission inventories have uncertainties in estimating small fire burned areas and *** instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FInn)showed significant *** that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

关键词： Wildfire Air quality Emission factor Emission inventory VOLTAIRE supersite

normalized Solution for p-Kirchhoff Equation with a L2-supercritical Growth

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 414-429页

作者： Zhi-min ren Yong-yi LAn school of sciences Jimei UniversityXiamen 361005China

In this paper,we investigate the following p-Kirchhoff equation{∫R^(n)|u|^(2)dx=ρ,(a+b)∫Rn(|Δu}^(p)+|u|^(p))dx)(-Δpu+|u|^(p-2u)=|u|^(s-2)u+μu,x∈R^(n),where a>0,b≥0,p>0 are constants,constants,p*=n-P/np is the critical Sobolev exponent,μis a Lagrange multiplier,-Δpu=-div(|Δu|_(p-2)u),2n2p,μ∈R,and s∈(2n/n+2p-2,p*).We demonstratethat he p-Kirchhoff equation has a normalized solution using the mountain pass lemma and some analysis techniques.

关键词： p-Kirchhoff equation normalized solution mountain-pass lemma

Effects of Co-Firing Biomass and Pulverized Coal on nO Reduction in Cement Precalciner

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Journal of Thermal science 2024年第2期33卷 751-760页

作者： LI Pengpeng ren Qiangqiang LYU Qinggang WAnG Mingyue school of energy Power and Mechanical engineering North China Electric Power UniversityBeijing102206China Institute of engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of sciences Beijing100049China

With increased awareness of the large-scale CO_(2) emissions from the cement industry,there has been growing focus on greenhouse gas reduction *** all these strategies,fuel substitution using biomass fuel is extensively used to achieve CO_(2) zero-emission in cement *** to the avoidable high-temperature-generated thermal nitrogen oxides during cement production,research on the impact of biomass application on nitrogen oxide emissions shall be carried *** types of biomass fuel and bituminous coal were used to investigate the nO reduction characteristics under different O_(2) concentrations on experimental *** was found that the change in oxygen concentration from 9% to 1% increased the reaction time in the reactor from 555 s to 1425 s,which means the increase in oxygen concentration can lead to shorter reaction time,and correspondingly,the existing time of nitric oxide in the flue gas is also shortened,but the peak value of nitric oxide rises,during the process of O_(2) concentration changing from 1% to 9%,the peak nO concentration in the flue gas increased from 5.4×10^(-5) to 1.05×10^(-4).An increase in O_(2) concentration greatly reduces the total reduction of nO and the minimum change in nO *** peak nO concentration during the combustion process of corn stalk is 4.56×10^(-4),which is approximately 7 times higher than that of coal,and it is caused by the high amount of n in corn *** addition of raw meal has an inhibitory effect on the reduction of nO:after adding raw meal,the effective reduction time of nO by fuel decreased by about 20%,but adding raw meal raises CO_(2) concentration of fuel gas in the early stage of reaction.

关键词： cement precalciner biomass fuel coal nO reduction co-firing

Preparation of Kω-g-C_(3)n_(4) composite loaded on magnetic attapulgite and its degradation performance for malachite green

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Chinese Journal of Chemical engineering 2024年第7期71卷 110-121页

作者： Aishun Ma Hanlin Qian Hongxia Liu Sili ren Jiangxi Key Laboratory of Mining&Metallurgy environmental Pollution Control Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Provincial Key Laboratory of Low-Carbon Processing and Utilization of Strategic Metal Mineral Resources Jiangxi University of Science and TechnologyGanzhou 341000China

Visible-light-driven photocatalysis is a promising technology for the treatment of dye *** this work,a novel photocatalyst of Kω-g-C_(3)n_(4) loaded on magnetic attapulgite(ATP)(K-g-C_(3)n_(4)@ATP-Fe_(3)O_(4))with excellent visible light photocatalytic properties and stability were successfully prepared and *** removal efficiency of K-g-C_(3)n_(4)@ATP-Fe_(3)O_(4) for malachite green(MG)was studied,and the degradation mechanism was analyzed and *** was found that the K_(5)-g-C_(3)n_(4)@ATP-Fe_(3)O_(4) photocatalyst possessed excellent degradation efficiency of over 98.0%for the MG dye wastewater under optimal ***,the K_(5)-g-C_(3)n_(4)@ATP-Fe_(3)O_(4) materials possessed good recyclability with a removal rate over 82%after 4 *** visible light condition,the K_(5)-g-C_(3)n_(4)@ATP-Fe_(3)O_(4) photocatalyst produce radicals of·OH and O_(2)^(-)to degrade the MG dyes,which was supported by electron paramagnetic resonance(EPR)and radical trapping *** addition,the LC-MS analysis interpreted the degradation pathways and intermediates of MG in the *** findings in this work indicate that the prepared photocatalytic material has excellent degradation efficiency for MG and can be applied in dye wastewater treatment.

关键词： Photocatalyst Malachite green Kω-g-C_(3)n_(4) Degradation

Predictive value of preoperative routine examination for the prognosis of patients with pT2n0M0 or pT3n0M0 colorectal cancer

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2429-2438页

作者： Peng-Fei Jing Jin Chen en-Da Yu Chao-Yu Miao Department of Colorectal Surgery Changhai HospitalSecond Military Medical University/Naval Medical UniversityShanghai 200433China Department of endocrinology and Metabolism Changhai HospitalSecond Military Medical University/Naval Medical UniversityShanghai 200433China Department of Pharmacology Second Military Medical University/Naval Medical UniversityShanghai 200433China

BACKGROUnD In recent years,the incidence of colorectal cancer(CRC)has been *** the popularization of endoscopic technology,a number of early CRC has been ***,despite current treatment methods,some patients with early CRC still experience postoperative recurrence and *** To search for indicators associated with early CRC recurrence and metastasis to identify high-risk *** A total of 513 patients with pT2n0M0 or pT3n0M0 CRC were retrospectively enrolled in this *** of blood routine test,liver and kidney function tests and tumor markers were collected before *** were followed up through disease-specific database and telephone *** recurrence,metastasis or death were used as the end point of study to find the risk factors and predictive value related to early CRC recurrence and *** We comprehensively compared the predictive value of preoperative blood routine,blood biochemistry and tumor markers for disease-free survival(DFS)and overall survival(OS)of *** multivariate analysis demonstrated that low platelet count was significantly associated with poor DFS[hazard ratio(HR)=0.995,95% confidence interval(CI):0.991-0.999,P=0.015],while serum carcinoembryonic antigen(CEA)level(HR=1.008,95%CI:1.001-1.016,P=0.027)and serum total cholesterol level(HR=1.538,95%CI:1.026-2.305,P=0.037)were independent risk factors for *** cutoff value of serum CEA level for predicting OS was 2.74 ng/*** the OS of CRC patients with serum CEA higher than the cutoff value was worse than those with lower CEA level,the difference between the two groups was not statistically significant(P=0.075).COnCLUSIOn For patients with T2n0M0 or T3n0M0 CRC,preoperative platelet count was a protective factor for DFS,while serum CEA level was an independent risk factor for *** that these measures are easier to detect and more acceptable to patients,they may have broader applications.

关键词： Colorectal cancer Platelet count Serum carcinoembryonic antigen Total cholesterol level Overall survival Disease-free survival

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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nuclear science and Techniques 2024年第6期35卷 130-144页

作者： Zi-Yi Yuan Dong Bai Zhen Wang Zhong-Zhou ren school of Physics science and engineering Tongji UniversityShanghai 200092China College of science Hohai UniversityNanjing 211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and n > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： nuclear binding energies decay Machine learning Gaussian process

Transfer relation between subgrade frost heave and slab track deformation and vehicle dynamic response in seasonally frozen ground

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Journal of Zhejiang University-science A(Applied Physics & engineering) 2024年第2期25卷 130-146页

作者： Juanjuan ren Junhong DU Kaiyao ZHAnG Bin YAn Jincheng TIAn MOE Key Laboratory of High-speed Railway engineering Southwest Jiaotong UniversityChengdu610031China school of Civil engineering Southwest Jiaotong UniversityChengdu610031China school of Civil engineering Central South UniversityChangsha410075China Airport Planning and Design Institute POWERCHINA Kunming Engineering Corporation LimitedKunming650051China

Subgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track-subgrade frost heave and develop a dynamic model of vehicle-track-subgrade frost heave;(2)explore the transfer relation between subgrade frost heave and track structure deformation;(3)examine the characteristics of interlayer debonding;(4)study the influence of subgrade frost heave on the dynamic response of vehicles in high-speed railways in seasonally frozen regions.A Fourier series was used to fit the frost heave waveform and simulate the behavior of subgrade uneven frost heave using data collected *** results show:(i)The position of frost heave significantly affects the transfer of deformation to a slab *** largest deformation of the track slab,with the amplitude transfer ratio reaching 20%,was recorded when the frost heave occurred near the joint of the base plate.(ii)At the same frost heave amplitude,long-wave frost heave causes smaller deformation and debonding of the track structure than short-wave frost *** the wavelength range of 10-30 m,the main frequency of the acceleration spectral density was concentrated between 3.5 and 3.7 Hz,with larger frost heave wavelengths producing smaller superposition on the vertical acceleration of the vehicle.(ii)The maximum wheel-rail force occurs when the front bogie passes the frost heave peak,with greater frost heave amplitudes producing greater wheel-rail *** these results,we conclude there is a clear need to control the frost heave deformation of the track to reduce the dynamic response of the vehicle and in turn improve train operatSubgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track`-subgr

关键词： Slab track Subgrade frost heave Transfer relation Vehicle-track-subgrade coupling Dynamic response

Copper-Free Resin-Based Braking Materials:A new Approach for Substituting Copper with Fly-Ash Cenospheres in Composites

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Chinese Journal of Mechanical engineering 2024年第2期37卷 401-412页

作者： Kaikui Zheng Youxi Lin Shanmin You Zhiying ren Jianmeng Huang school of Mechanical engineering and Automation Fuzhou UniversityFuzhou 350108China national United engineering Laboratory for Advanced Bearing Tribology Henan University of Science and TechnologyLuoyang 471023China

Copper particles emitted from braking have become a significant source of environmental ***,copper plays a crucial role in resin-based braking *** high-performance braking materials without copper has become a significant *** this paper,the resin-based braking materials were filled with flyash cenospheres to develop copper-free braking *** effects of fly-ash cenospheres on the physical properties,mechanical and friction and wear properties of braking materials were ***,the wear mechanism of copper-free resin-based braking materials filled with fly-ash cenospheres was *** results indicate that the inclusion of fly-ash cenospheres in the braking materials improved their thermal stability,hardness and impact strength,reduced their density,effectively increased the friction coefficient at medium and high temperatures,and enhanced the heat-fade resistance of the braking *** inclusion of fly-ash cenospheres contributed to the formation of surface friction film during the friction process of the braking materials,and facilitated the transition of form from abrasive wear to adhesive *** 100-350℃,the friction coefficient of the optimal formulation is in the range of 0.57-0.61,and the wear rate is in the range(0.29-0.65)×10^(-7) cm^(3)·n^(-1)·m^(-1),demonstrating excellent resistance to heat-fade and stability in friction *** research proposes the use of fly-ash cenospheres as a substitute for environmentally harmful and expensive copper in brake materials,which not only improves the performance of braking materials but also reduces their costs.

关键词： Fly-ash cenospheres Braking materials Friction and wear Heat-fade resistance Wear form

Primitive functional groups directed distinct photocatalytic performance of imine-linked donor-acceptor covalent organic frameworks

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nano Research 2024年第6期17卷 4994-5001页

作者： Xitong ren Jiajie Sun Yusen Li Feng Bai Key Laboratory for Special Functional Materials of Ministry of Education National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting TechnologySchool of Materials Science and Engineeringand Collaborative Innovation Center of Nano Functional Materials and ApplicationsHenan UniversityKaifeng 475004China school of Physics and Electronics Henan UniversityKaifeng 475004China

The combination of donor-acceptor(D-A)structures presents a viable strategy for fabricating covalent organic frameworks(COFs)with exceptional photocatalytic ***,the selection of functional groups on donor or acceptor building blocks and their effect on the macroscopic properties of COFs are *** this study,we tactfully synthesized a pair of Py-DBT-COFs from the same pyrene(Py)donor and 4,7-diphenylbenzo[c][1,2,5]thiadiazole(DBT)acceptor cores with distinct primitive functional *** primitive functional groups of building units determine the photocatalytic properties of corresponding ***,Py-C-DBT-COF synthesized from Py-4CHO and DBT-2nH_(2)showcases a splendid H_(2)evolution rate as high as 21,377.7μmol/(g·h)(with 5 wt.%Pt)originating from better charge transfer capacity,which is significantly superior to that of Py-n-DBT-COF constructed from Py-4nH_(2)and *** distinct photocatalytic performances of the two COFs are demonstrated to originate from the different charge separation and transfer *** work supplies a new avenue for optimizing the photocatalytic performance of D-A COFs from the perspective of primitive functional group selections.

关键词： covalent organic frameworks functional group donor-acceptor photocatalysis