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Microbial Activity Indices: Sensitive Soil Quality Indicators for Trace Metal Stress

Pedosphere 2005年第4期15卷 409-416页

作者： LI Yong-Tao T. BECQUER2 C. QUANTIN M. BENEDetTI P. LAVELLE DAI Jun College of Natural Resources and Environment South China Agricutrual University Guangzhou 510642 （China） umr 137 biodiversité et fonctionnement des sols Institut de Recherche Pour le Déueloppement （France） Université Paris Sud XI FRE Orsay Terre 2566 Bat 504 91405 Cedex （France） umr-CNRS 7047 Lab. de Géochimie et Métallogénie/Université Pierre et Marie Curie （France）

Physicochemical properties, total and DTPA （diethylenetriaminepentaacetic acid）-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon （C） content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg^-1 respectively. DTPA-extractable metals were correlated positively and significantly with total metals, CEC, and organic C （except for DTPA-extractable Cd）, while they were negatively and highly significantly correlated with pH, totall Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C mineralization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some “linked” microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incubation, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone.

关键词： availability indication microbial characteristics trace metals

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Influences of graphene nanoplatelet aspect ratio and thermal treatment on dielectric performances of poly(methyl methacrylate)composites

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High Voltage 2016年第4期1卷 146-150页

作者： Benhui Fan Yu Liu Delong He Jinbo Bai Laboratoire Mécanique des sols Structures et Matériaux(MSSMat)CNRS UMR 8579Ecole CentraleSupelecUniversitéParis SaclayGrande Voie des Vignes92290 Chatenay-MalabryFrance

The dielectric property and percolated behaviour of polymer matrix composites largely depend on the morphology of conductive fillers and external stimulations especially when the composites are processed by melting blending and extrusion-injection *** this study,the poly(methyl methacrylate)(PMMA)matrix composites incorporated by two kinds of graphene nanoplatelets(GNP),G5 and G150 with different aspect ratios(the ratio of diameter and thickness)are prepared to study the influence of GNP morphology on the dielectric performances close to percolation threshold(f_(c)).After annealing at glass transition temperature(T_(g))for 1 h,the dielectric permittivities of PMMA/G5 and PMMA/G150 near fc increase 43 and 38%,respectively,while the dielectric loss change *** improvement on the dielectric property is possibly attributed to the slight change of the distance between adjacent GNPs after annealing at T_(g)which enables to arouse stronger polarisation by tunnelling effect.

关键词： composites dielectric property

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Are Small Grazers and/or Viruses a Structuring Factor of the Free-Living Bacterial Community in Lake Geneva?

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Advances in Microbiology 2013年第3期3卷 233-248页

作者： Stéphan Jacquet Isabelle Domaizon Cécile Chardon Sébastien Personnic INRA UMR CARRTEL Station d’Hydrobiologie Lacustre Equipe Biodiversité Fonctionnement et Evolution des Ecosystèmes Lacustres Thonon-les-Bains Cedex France

Two experiments were conducted to test whether viruses, small auto- and heterotrophic nanoflagellates were key factors regulating at relatively short-term (4 days) and nearby periods (April vs. May) the bacterial community in surface waters of Lake Geneva. 2.5 L containing polycarbonate bottles were incubated in situ with either μm filtered water with additions of either virus-free water or a viral concentrate. Abundances of viruses, prokaryotes and small autotrophs were obtained each day using flow cytometry, while bacterial richness was assessed using 16S rDNA PCR-DGGE and auto- and heterotrophic flagellates counted with epifluorescence microscopy at t0 and t96. Transmission electron microscopy was also used to assess virus-induced bacterial mortality at the start and the end of the experiments. Cloning-sequencing was applied on PCR products obtained after excision of selected DGGE bands to highlight more specifically the identity of bacteria of interest in the context of the experiment. The autotrophs and grazer presence and/or the virus enrichment resulted in different effects on the structure of the bacterial community and the impact was also different with the period. In May, bacterial structure changes seemed to be related to the impact or influence of the eukaryotes (including nanoflagellate grazers), while viruses might have a higher impact on the bacterial community structure the month before. This study provides new persuasive evidence that the presence of viruses and small eukaryotes are likely to drive bacterial community composition and shifts on the short-term in lacustrine ecosystems. More interestingly, such effects seem to be different between viruses and grazers, the ones sustaining, the others reducing bacterial community composition.

关键词： Viruses Bacteria Flagellates PCR-DGGE Richness Regulation Lake

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On the origin of the high tensile strength and ductility of additively manufactured 316L stainless steel: Multiscale investigation

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Journal of Materials Science & Technology 2020年第6期41卷 209-218页

作者： Bassem Barkia Pascal Aubry Paul Haghi-Ashtiani Thierry Auger Lionel Gosmain Frédéric Schuster Hicham Maskrot DEN-Service d’etudes Analytiques et de Réactivitédes Surfaces CEAUniversitéParis-Saclay91191France Laboratoire de Mécanique des sols Structures et MatériauxCentralesupélecUMR CNRS 8579UniversitéParis-Saclay92295France Arts et Métiers ParisTech PIMMUMR CNRS 800675013 ParisFrance CEA Cross-Cutting Program on Materials and Processes Skills 91191Gif-sur-YvetteFrance

We report that 316L austenitic stainless steel fabricated by direct laser deposition(DLD),an additive manufacturing(AM)process,have a higher yield strength than that of conventional 316L while keeping high *** interestingly,no clear anisotropy in tensile properties was observed between the building and the scanning direction of the 3D printed *** examination of the as-built parts shows a heterogeneous solidification cellular *** electron microscopy observations coupled with Energy Dispersive X-ray Spectrometry(EDS)reveal the presence of chemical micro-segregation correlated with high dislocation density at cell boundaries as well as the in-situ formation of well-dispersed oxides and transition-metal-rich *** hierarchical heterogeneous microstructure in the AM parts induces excellent strength of the 316L stainless steel while the low staking fault energy of the as-built 316L promotes the occurrence of abundant deformation twinning,in the origin of the high ductility of the AM *** additional post-process treatments,the AM 316L proves that it can be used as a structural material or component for repair in mechanical construction.

关键词： Additive manufacturing Austenitic stainless steel Dislocation structure Twinning Mechanical behavior Anisotropy

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Genotypic,size and morphological diversity of virioplankton in a deep oligomesotrophic freshwater lake(Lac Pavin,France)

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Journal of Environmental Sciences 2017年第3期29卷 48-59页

作者： Jonathan Colombet Agnès Robin Télesphore Sime-Ngando Laboratory Microorganisms:Oenome and Environment Clermont University Blaise PascalUMR CNRS 602324 avenue des LandaisBP 80026F-63171 AubiereFrance CIRAD UMR Eco&Sols2 place Viala34060 Montpellier Cedex 1France

We examined changes in morphological and genomic diversities of viruses by means of transmission electronic microscopy and pulsed field gel electrophoresis （PFGE） over a nine-month period （April-December 2005） at four different depths in the oligomesotrophic Lac Pavin. We found that the majority of viruses in this lake belonged to the family of Siphouiridae or were untailed, with capsid sizes ranging from 30 to 60 nm, and exhibited genome sizes ranging from 15 to 45 kb. On average, 12 different genotypes dominated each of the PFGE fingerprints. The highest genomic viral richness was recorded in summer （mean = 14 bands per PFGE fingerprint） and in the epilimnion （mean = 13 bands per PFGE fingerprint）. Among the physico-chemical and biological variables considered, the availability of the hosts appeared to be the main factor regulating the variations in the viral diversity.

关键词： VirusLac PavinDynamicMorphological diversity Genomic diversity

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Typical synergistic effect of graphite nanoplatelets and carbon nanotubes and its influence on polymer-based dielectric composites

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High Voltage 2016年第4期1卷 140-145页

作者： Hang Zhao Minhao Yang Delong He Yu Liu Jintao Bai Hui Wang Haowei Chen Jinbo Bai Laboratoire Mécanique des sols Structures et MatériauxCNRS UMR 8579Ecole CentraleSupelecUniversitéParis SaclayGrande Voie des Vignes92290Chatenay-MalabryFrance State Key Lab Incubation Base of Photoelectric Technology and Functional Materials International Collaborative Center on Photoelectric Technology and Nano Functional MaterialsNorthwest UniversityXi’an 710069People’s Republic of China

Graphite nanoplatelets(GNPs)with their intrinsic two-dimensional structure make an excellent compromise of advantages of both graphite and *** to their outstanding inherent properties,GNPs have been widely used as the functional fillers to improve certain performances of polymer-based ***,the multi-layer stacked construction of GNPs could form aggregations easily,which limits their application in polymer-based dielectric ***,the authors exhibit a polydimethylsilicone(PDMS)-based nanocomposite which loading equivalent carbon nanotubes(CNTs)and GNPs as co-loading fillers,whose dielectric properties are improved *** composites were fabricated through a highly-shearing mechanical mixing *** the mixing process,both intrinsic CNTs entanglements and GNPs stacked aggregation could be ameliorated due to the interaction between these two types of *** with the GNPs solely loaded composites,a small quantity of CNTs addition endows GNPs/CNTs/PDMS ternary composites with a significantly decreased percolation threshold(f_(c)∼1.7 vol.%).Both GNPs and CNTs,these two representative conductive carbon constructions with high aspect ratios are able to effectively enhance the establishing efficiency of internal conductive network inner *** results indicate that the development of internal conductive network and dielectric performance of nanocomposites are able to be optimised through the strategy of taking advantage of the synergistic effect of multi-type fillers reasonably.

关键词： composites dielectric carbon

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粤北大宝山高含硫多金属矿污染的水稻土壤污染元素的多元分析

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华南农业大学学报 2005年第2期26卷 22-25,34页

作者：李永涛张池刘科学 Thierry BECQUE Cécile QUANTIN Marc BENEDetTI Patrick LAVELLE 戴军华南农业大学资源环境学院广东广州510642 biodiversité et fonctionnement des sols IRD France Université Paris Sud XI FRE OrsayTerre 2566 France Lab de Géochimie et Métallogénie/Université Pierre et Marie Curie France

调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、... 详细信息

调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、铅和镉的积累.上述污染元素与pH及矿质元素铁、钙之间高度相关,而与锰和铬的相关性差.

关键词：重金属污染水稻土主成分分析大宝山土壤污染

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Using fluorescence-based microplate assay to assess DOM-metal binding in reactive materials for treatment of acid mine drainage

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Journal of Environmental Sciences 2011年第6期23卷 891-896页

作者： Carmen Mihaela Neculita Yves Dudal Gerald J Zagury Department of Civil and Environmental Engineering KAIST335 GwahangnoYuseong-guDaejeon 305-701Korea Institut National de la Recherche Agronomique UMR Eco&Sols-Ecologie Fonctionnelle et Biogéochimie des SolsMontpellier SupAgro-INRA-IRD2Place Pierre VialaBatiment 1234060 Montpellier Cedex 2France Department of Civil Geologicaland Mining EngineeringE'cole Polytechnique de Montre'alC.P.6079 Station Centre-villeMontrealQCH3C 3A7Canada

One potential drawback of compost-based passive bioreactors,which is a promising biotechnology for acid mine drainage（AMD） treatment,is the transport of dissolved organic matter（DOM）-metal complexes in surface *** address this problem,the objective of this study was to assess the maximum capacity of organic substrates to release soluble DOM-metal complexes in treated water. The reactivities of DOM in maple wood chips and sawdust,composted poultry manure,and leaf compost were quantified toward Cd2＋,Ni2＋,Fe2＋,and Cu2＋ using fluorescence *** DOM showed the highest reactivity toward Fe,but a limited number of available sites for sorption,whereas DOM-Cd complexes exhibited the lowest fluorescence ***,the DOM from a mixture of wastes formed higher concentrations of DOM-metal complexes relative to sole *** DOM-metal complexes, the concentrations of DOM-Ni complexes were the *** reaching steady-state,low concentrations of DOM-metal complexes were released in treated water,which is in agreement with theoretical predictions based on geochemical ***,in addition to physicochemical characterization,fluorescence quenching technique is recommended for the substrate selection of bioreactors.

关键词： passive bioreactors acid mine drainage DOM reactivity fluorescence quenching metal complexation

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Effect of Geogenic Lead on Fungal and Collembolan Communities in Garden Topsoil

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土壤圈：英文版 2018年第2期28卷 215-226页

作者： Sophie JOIMEL Hervé CAPIAUX Christophe SCHWARTZ Mickael HEDDE Thierry LEBEAU Cécile LE GUERN Johanne NAHMANI Céline PERNIN Sandrine SALMON Lucia SANTORUFO Béatrice BECHet Jérome CORTet Université de Lorraine Laboratoire Sols et Environnement UMR 1120 Vandceuvre-lès-Nancy 54500 (France) INRA Laboratoire Sols et Environnement UMR 1120 Vandceuvre-lès-Naney 54500 (France) umr ECOSYS INRA AgroParisTech Universitè Paris-Saclay Thiverval-Grignon 78850 (France) Plateforme d'Analyse Moléculaire biodiversitg-Environnement IUT Ggnie Biologique La Roche sur Yon 85035 (France) Institut de Recherche sur les Sciences et Techniques de la Ville (IRSTV) CNRff 2488 Ecole Centrale de Nantes 1 rue de la Noē Nantes 44321 (France) Laboratoire Plandtologie & Gdodynamique Nantes Faculté des Sciences et des Techniques 2 rue de la Houssinière Nantes 44322 (Franee) Bureau de Reeherches Gdologiques et Minières (BRGM) Regional Geological Survey Direction Régionale des Pays de la Loire 1 rue des Saumonières Nantes 44000 (France) umr CEFE 5175 Universitd de Montpellier EPHE Université Paul-Valdry Montpellier Montpellier 34199 (France) Université Lille 1 EA 4515 Laboratoire Gdnie Civil & Géo Environnement Villeneuve D'Ascq 59655 (France) Musdum National d'Histoire Naturelle CNRS UMR 7179 4 Avenue du Petit-Chateau Brunoy 91800 (France) Department of Biology University of Naples Federico Ⅱ Via Cinthia Naples 80126 (Italy) French Institut of Science and Technology for Transport Development and Networks Water and Environment Laboratory Route de Bouaye Bouguenais 44344 (France)

Geogenic lead (Pb) is considered to be less bioavailable than anthropogenic Pb and exerts less effect on the soil fauna. However,Pb contamination in vegetables has been reported in the case of geogenic anomalies, even at moderate concentrations (around 170 mgkg^(-1)). In this study, we investigated collembolan communities using both taxonomic- and trait-based approaches and observed fungal communities to assess the effects of a moderate geogenic Pb anomaly on collembolans and fungi in an urban vegetable garden *** indicated that geogenic Pb indeed modified fungi communities and altered the functional structure of collembolan communities in garden soils. Although geogenic Pb presented low bioavailability, it affected soil fauna and vegetables similar to anthropogenic Pb.

关键词： functional diversity functional trait soil fauna soil food web vegetable garden urban soil

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Wave Propagation in Orthotropic Elastic Shells: Theoretical and Numerical Modeling

Wave Propagation in Orthotropic Elastic Shells: Theoretical ...

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The 10th EPMESC

作者： D. Aubry Laboratoire de Mécanique des sols Structures et Matériaux （CNRS UMR 8579） Ecole Centrale Paris Grande Voie des Vignes 92295 Chatenay-Malabry Cedex France

Shell type structures are used in a wide variety of industrial components, especially in automotive or aeronautic industries. A full understanding and predictive modeling of elastic waves propagation

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