检索结果-南通市图书馆

Numerical study on waste polyethylene pyrolysis driven by self-sustaining smoldering

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第2期67卷 627-638页

作者： PAN RuMing WU YiBo GUENE LOUGOU Bachirou SHUAI Yong DEBENEST Gérald School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institut de Mecanique des Fluides de Toulouse(IMFT)-Universite de Toulouse CNRS-INPT-UPSToulouse 31400France

Polyethylene is the type of waste plastic that accounts for the most significant proportion of municipal solid waste.Waste polyethylene can be valorized via pyrolysis and produce value-added oil,gas,and char.On the other hand,self-sustaining smoldering is an emerging technical means to deal with sand/soil contaminated by organic matter.The high-temperature heat generated by smoldering can be used as a heat source for pyrolyzing waste polyethylene.Therefore,this study investigates numerically the pyrolysis of waste polyethylene driven by self-sustaining smoldering.A novel 4-step lumped kinetic model is proposed for simulating the pyrolysis of waste polyethylene.The results indicate that the operating parameters can determine the pyrolysis product yields by regulating the pyrolysis temperature and the volatile residence time.Note that higher temperatures and longer residence times favor the generation of shorter-chain pyrolysis products because of the intensified volatiles’secondary cracking.It can be concluded that a high interface-wall heat transfer coefficient(400 W m^(-2)K^(-1)),a low PE content(0.20),a high char concentration(2.4%),and a moderate air velocity(0.040 m s^(-1))are beneficial to oil yield.To some extent,this study may broaden the boundaries for the application of self-sustained smoldering-driven pyrolysis.

关键词： self-sustained smoldering waste polyethylene thermal decomposition oil production waste valorization

A level line of the Gaussian free field with measure-valued boundary conditions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第2期67卷 367-404页

作者： Titus Lupu Hao Wu Laboratoire de Probabilités Statistique et ModélisationSorbonne Universitéand UniversitéParis CitéCNRSParis F-75005France Yau Mathematical Sciences Center Tsinghua UniversityBeijing 100084China

In this article, we construct samples of Schramm-Loewner-evolution-like curves out of samples ofthe conformal loop ensemble and Poisson point processes of Brownian excursions. We show that the laws of thesecurves depend continuously on the intensity measure of the Brownian excursions. Using such a construction ofcurves, we extend the notion of level lines of the Gaussian free field to the case where the boundary conditionis measure-valued.

关键词： Schramm-Loewner evolution conformal loop ensemble Brownian excursion Gaussian free field

Genome-resolved metagenomics of Venice Lagoon surface sediment bacteria reveals high biosynthetic potential and metabolic plasticity as successful strategies in an impacted environment

在线全文

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第1期6卷 126-142页

作者： Elisa Banchi Erwan Corre Paola Del Negro Mauro Celussi Francesca Malfatti National Institute of Oceanography and Applied Geophysics OGS TriesteItaly FR2424 Station Biologique de RoscoffPlateforme ABiMS(Analysis and Bioinformatics for Marine Science)Sorbonne Universite CNRS29680 RoscoffFrance Department of Life Sciences University of TriesteTriesteItaly

Bacteria living in sediments play essential roles in marine ecosystems and deeper insights into the ecology and biogeochemistry of these largely unexplored organisms can be obtained from‘omics’approaches.Here,we characterized metagenome-assembled-genomes(MAGs)from the surface sediment microbes of the Venice Lagoon(northern Adriatic Sea)in distinct sub-basins exposed to various natural and anthropogenic pressures.MAGs were explored for biodiversity,major marine metabolic processes,anthropogenic activity-related functions,adaptations at the microscale,and biosynthetic gene clusters.Starting from 126 MAGs,a non-redundant dataset of 58 was compiled,the majority of which(35)belonged to(Alpha-and Gamma-)Proteobacteria.Within the broad microbial metabolic repertoire(including C,N,and S metabolisms)the potential to live without oxygen emerged as one of the most important features.Mixotrophy was also found as a successful lifestyle.Cluster analysis showed that different MAGs encoded the same metabolic patterns(e.g.,C fixation,sulfate oxidation)thus suggesting metabolic redundancy.Antibiotic and toxic compounds resistance genes were coupled,a condition that could promote the spreading of these genetic traits.MAGs showed a high biosynthetic potential related to antimicrobial and biotechnological classes and to organism defense and interactions as well as adaptive strategies for micronutrient uptake and cellular detoxification.Our results highlighted that bacteria living in an impacted environment,such as the surface sediments of the Venice Lagoon,may benefit from metabolic plasticity as well as from the synthesis of a wide array of secondary metabolites,promoting ecosystem resilience and stability toward environmental pressures.

关键词： Antibiotic resistance PAHs Biosynthetic gene clusters Microscale Mobilome Resistome

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 climate.In 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 satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant 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 quality.Emission 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 studies.Changes 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 discussed.Moreover,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 inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For 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 overestimation.Considering 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

Almost primes in short intervals

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2010年第9期53卷 2511-2524页

作者： WU Jie Institut Elie Cartan Nancy,cnrs,Nancy-Université,INRIA,Boulevard des Aiguillettes,B.P.239,54506 Vand CEuvre-lès-Nancy,France Institut Elie Cartan Nancy CNRS Nancy-Université INRIA VandŒuvre-lès-Nancy France

In this paper,we prove that the short interval(x-x101/232,x] contains at least an almost prime P2 for sufficiently large x,where P2 denotes an integer having at most two prime factors counted with multiplicity.

关键词： estimates on exponential sums distribution of integers with specified multiplicative constraints applications of sieve methods

Active MoS_(2)-based electrode for green ammonia synthesis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第1期65卷 268-275页

作者： Xin Liu Lei Yang Tao Wei Shanping Liu Beibei Xiao School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Institute Charles Gerhardt Montpellier UMR-5253Universite de MontpellierCNRSENSCMPlace E.Bataillon34095 Montpellier Cedex 05France

Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.

关键词： Nitrogen reduction reaction Density functional theory calculations Molybdenum disulfide Electrochemistry Catalyst Thermodynamics

Diatom and Diatomite: Different Focus on Natural Media to Material Science Path

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

American Journal of Analytical Chemistry 2024年第1期15卷 1-29页

作者： Secou Sall Vasiliki Papaefthimiou Thierry Dintzer Fabrice Vigneron Eric Brendlé Pierre Petit Tom Ferte Saliha Haddoum Sana Labidi Corinne Petit ICPEES UMR-CNRS 7515 Strasbourg University Strasbourg France Adscientis Wittelsheim France ICS CNRS UPR 22 Strasbourg France IPCMS UMR CNRS 7504 Strasbourg University Strasbourg France Ecole Nationale Polytechnique El-Harrach Algeria

Bio-silica issued from diatom, a microalgae, is attracted increasing attention in material science thanks to its peculiar nanoarchitecture and related properties with versatile applications. The present work is a deep analysis on morphological and chemical properties of bio-silica issued from fossil origin (diatomaceous earth) and living one (algal paste). An optimization in purification protocol was performed to obtain multiparous bio-silica from its raw media with keeping its original shape entirely. Multiple characterization methods as scanning electronic microscopy (SEM), infrared spectroscopy, x-ray diffraction (DRX), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and inverse gas chromatography (IGC), were used to check the purification protocol efficiency as well as to gather accurate information on morphology and chemical composition of diatom material obtained in large amount.

关键词： Diatom Diatomite Bio-Silica Purification Frustule

Blockage and distortion effects on a vane-island type diffuser performance of centrifugal pumps for various flow rates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

排灌机械工程学报 2016年第12期34卷 1013-1021页

作者： SI Qiaorui DAZIN Antoine DUPONT Patrick ROUSSETTE Olivier BOIS Gérard National Research Center of Pumps Jiangsu University Laboratoire de Mécanique de Lille (UMR cnrs 8107) Arts et Métiers ParisTech Laboratoire de Mécanique de Lille(UMR cnrs 8107) Ecole Centrale de Lille

Experimental investigation of mean flow velocity and pressure inside the vane-island type diffuser passage of a test centrifugal pump model is presented.A directional three-hole probe was used to investigate hub-to-shroud flow properties at diffuser leading and trailing edge planes.In addition,the mid-section between suction and pressure sides along the diffuser passage was also studied.All these measurements were performed at five different flow conditions.The flow structures at the inlet section of the diffuser and along with the passage were analyzed in detail,with a focus on the flow distribution and the pressure recovery evolution of different diffuser parts.Blockage and distortion effects were analyzed by using existing published particle image velocimetry(PIV)measurements in the outer part of the impeller and around the diffuser throat in order to get a better understanding of the overall performances and local flow structures of such a diffuser design.The results show that back flows occur on the shroud region from impeller exit plane up to the semi-vaneless part of the diffuser at low flow rates.Aerodynamic blockage effects combining with blade thickness geometrical blockage tend to diminish the effects of theoretical high positive incidence.For high flow rates,negative incidence effects induce high local velocity on the pressure side of the diffuser just after the throat.Existing aerodynamic blockage associated with low flow distortions are found to have a beneficial effect on pressure recovery for low flow rates.On the contrary,high flow distortions are found for increased flow rates,resulting in a low pressure recovery inside the semi-vane less part of the diffuser and after the throat.

关键词： vane island diffuser flow structure pressure recovery three-hole probe particle image velocimetry

Constant charge method or constant potential method:Which is better for molecular modeling of electrical double layers?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 54-60页

作者： Liang Zeng Xi Tan Xiangyu Ji Shiqi Li Jinkai Zhang Jiaxing Peng Sheng Bi Guang Feng State Key Laboratory of Coal Combustion Schoolof Energy and PowerEngineeringHuazhong Universityof Science and Technology(HUST)Wuhan 430074HubeiChina Sorbonne Universite CNRSPhysico-chimie des Electrolytes et Nanosystemes InterfaciauxPHENIXF-75005 ParisFrance

In molecular modeling of electrical double layers(EDLs),the constant charge method(CCM)is prized for its computational efficiency but cannot maintain electrode equipotentiality like the more resourceintensive constant potential method(CPM),potentially leading to inaccuracies.In certain scenarios,CCM can yield results identical to CPM.However,there are no clear guidelines to determine when CCM is sufficient and when CPM is required.Here,we conduct a series of molecular simulations across various electrodes and electrolytes to present a comprehensive comparison between CCM and CPM under different charging modes.Results reveal that CCM approximates CPM effectively in capturing equilibrium EDL and current-driven dynamics in open electrode systems featuring ionic liquids or regular concentration aqueous electrolytes,while CPM is indispensable in scenarios involving organic and highly concentrated aqueous electrolytes,nanoconfinement effects,and voltage-driven dynamics.This work helps to select appropriate methods for modeling EDL systems,prioritizing accuracy while considering computationalefficiency.

关键词： Electrochemical interface Molecular dynamics Electrode polarization modeling Nanoconfinement effect