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Nanorocks, volatiles and plate tectonics

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Geoscience Frontiers 2021年第5期12卷 202-214页

作者： gautier Nicoli Silvio Ferrero Institut für Geowissenschaften Universität Potsdam14476 Potsdam-GolmGermany Museum für Naturkunde(MfN) Leibniz-Institut für Evolutions-und Biodiversitätsforschung10115 BerlinGermany

The global geological volatile cycle(H,C,N)plays an important role in the long term self-regulation of the Earth ***,the complex interaction between its deep,solid Earth components(*** and mantle),Earth’s fluid envelopes(*** and hydrosphere)and plate tectonic processes is a subject of ongoing *** this study we want to draw attention to how the presence of primary melt(MI)and fluid(FI)inclusions in high-grade metamorphic minerals could help constrain the crustal component of the volatile *** that end,we review the distribution of MI and FI throughout Earth’s history,from ca.3.0 Ga ago up to the present *** argue that the lower crust might constitute an important,longterm,volatile storage unit,capable to influence the composition of the surface envelopes through the mean of weathering,crustal thickening,partial melting and crustal assimilation during volcanic *** with thermodynamic modelling,our compilation indicates that periods of well-established plate tectonic regimes at<0.85 Ga and 1.7-2.1 Ga,might be more prone to the reworking of supracrustal lithologies and the storage of volatiles in the lower *** hypothesis has implication beyond the scope of metamorphic petrology as it potentially links geodynamic mechanisms to habitable surface *** and FI in metamorphic crustal rocks then represent an invaluable archive to assess and quantify the co-joint evolution of plate tectonics and Earth’s external processes.

关键词： Nanorocks Plate tectonics Volatiles Lower crust

Exploring the metamorphic consequences of secular change in the siliciclastic compositions of continental margins

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Geoscience Frontiers 2018年第4期9卷 967-975页

作者： gautier Nicoli Brendan Dyck Department of Earth Sciences University of Cambridge Department of Earth Sciences Simon Fraser University

Shale and greywacke compositions from the Archean to Phanerozoic record a secular change in the siliciclastic material that comprises much of Earth＇s continental margins, past and present. This study explores the metamorphic consequence of these compositional changes, by comparing phase equilibrium models constructed for average Archean, Proterozoic, and Phanerozoic shale and greywacke compositions equilibrated along two Barrovian-type geotherms： 1330℃/GPa（A） and 800 ℃/GPa（B）. Our models show that Archean siliciclastic rocks can retain up to 4 vol.% water at middle to lower crustal conditions, nearly twice that of Proterozoic and Phanerozoic compositions. The increased ferromagnesium content of Archean siliciclastic rocks stabilizes chlorite to higher temperatures and results in a biotite-rich assemblage at solidus temperatures. Accordingly, water-absent biotite dehydration melting is predicted to play a greater role in the generation of melt in the metamorphism of Archean aged units,and water-absent muscovite dehydration melting is of increasing importance through the Proterozoic and Phanerozoic. This secular variation in predicted mineral assemblages demonstrates the care with which metamorphic facies diagrams should be applied to Archean compositions. Moreover, secular changes in the composition of shale and greywacke is reflected in the evolution of anatectic melt towards an increasingly less viscous, Ca-rich, and Mg-poor monzogranite.

关键词： Secular change Shale Greywacke Dehydration melting Thermodynamic modelling Perple_X

End-of-Life Decision making in circular economy using generalized colored stochastic Petri nets

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Autonomous Intelligent Systems 2022年第1期2卷 32-49页

作者： gautier Vanson Pascale Marangé Eric Levrat Universitéde Lorraine CRANUMR 7039Campus SciencesBP 70239Vandoeuvre-lès-Nancy54506France

Circular economy enables to restore product value at the end of life *** no longer used or ***,the product life cycle is extended and this economy permits to reduce waste increase and resources *** are several revaluation options(reuse,remanufacturing,recycling,...).So,decisionmakers need to assess these options to determine which is the best ***,we will present a study about an End-Of-Life(EoL)decision making which aims to facilitate the industrialization of circular *** this,it is essential to consider all variables and parameters impacting the decision of the product trajectory.A first part of the work proposes to identify the variables and parameters impacting the decision making.A second part proposes an assessment approach based on a modeling by Generalized Colored Stochastic Petri Net(GCSPN)and on a Monte-Carlo *** approach developed is tested on an industrial example from the literature to analyze the efficiency and effectiveness of the *** first application showed the feasibility of the approach,and also the limits of the GCSPN modelling.

关键词： Circular economy Sustainability Decision making Generalized colored stochastic Petri net Monte-Carlo simulation

Effects of meteorological conditions and topography on the bioaccumulation of PAHs and metal elements by native lichen(Xanthoria parietina)

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Journal of Environmental Sciences 2021年第11期33卷 193-205页

作者： Julien Dron Aude Ratier Annabelle Austruy gautier Revenko Florence Chaspoul Emmanuel Wafo Institutécocitoyen pour la Connaissance des Pollutions Fos-sur-MerFrance Aix Marseille Université Avignon UniversitéCNRS UMR-7263IRD-237IMBEMarseilleFrance Aix Marseille Université INSERM U-1261SSAIRBAMCTMarseilleFrance Universitéde Lyon UniversitéLyon 1CNRS UMR-5558LBBEVilleurbanneFrance

The bioaccumulation of PAHs and metal elements in the indigenous lichens Xanthoria parietina was monitored during two years at a quarterly frequency,in 3 sites of contrasted anthropic *** impact of the meteorological factors(temperature,relative humidity,rainfall,wind speed)was first estimated through principal component analysis,and then by stepwise multilinear regressions to include wind *** pollutants levels reflected the proximity of atmospheric emissions,in particular from a large industrial *** humidity and mild temperatures,and in a lower extent low wind speed and rainfall,also favored higher concentration *** contributions of these meteorological aspects became minor when including wind direction,especially when approaching major emission *** bioaccumulation integration time towards meteorological variations was on a seasonal basis(1–2 months)but the wind direction and thus local emissions also relied on a longer time scale(12 months).This showed that the contribution of meteorological conditions may be prevalent in remote places,while secondary in polluted areas,and should be definitely taken into account regarding long-term lichen biomonitoring and inter-annual *** the same time,a quadruple sampling in each site revealed a high homogeneity among supporting tree species and *** resulting uncertainty,including sampling,preparation and analysis was below 30%when comfortable analytical conditions were ***,the occurrence of unexpected events such as a major forest fire,permitted to evaluate that this type of short,although intense,events did not have a strong influence on PAH and metals bioaccumulation by lichen.

关键词： Indigenous lichen Biomonitoring Climate Seasonal impacts Sampling uncertainties Integration time

Empirical rock physics relationships on carbonate dry-frame elastic properties

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Petroleum Science 2021年第3期18卷 783-806页

作者： Zi-Zhen Wang gautier Njiekak Douglas RSchmitt Rui-He Wang Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao 266555China School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266555China Department of Physics University of AlbertaEdmontonCanada Department of Earth Atmosphericand Planetary SciencePurdue UniversityWest LafayetteUSA

Laboratory tests were conducted to analyze the ultrasonic velocity response to the pressure change in dry carbonate rocks from the Weyburn oilfield,***-four samples are from seven wells with helium porosities ranging from 1%to 29%.Thin-section images,SEM and mercury intrusion porosimetry were performed to show their inner structures and pore throat size distributions.P-and S-wave velocities(V_(p) and V_(s))measurements were first done under hydrostatic loading and then while unloading,with confining pressures varying between 3 and 35 *** results indicate that V_(p) and V_(s) in these samples follow a linear relation independent of the pressure *** ratio V_(p)/V_(s) is more responsive to pressure change irrespective of the pore ***-third of the carbonate samples show abnormal V_(p)/V_(s) reduction with the increase in the effective *** pressure dependence of velocities(PDV)of Weyburn carbonate rocks varies widely even for samples from the same formation with similar sedimentary *** with loosely packed crystals and/or relatively large dominant pore diameter have higher *** exponential empirical model V=A−Ce^(DPe) was tested;therein,V is the elastic wave velocity,Pe is the effective confining pressure,and A,C and D are the best fitting coefficients determined by curve *** model gives good fits for most of the Weyburn carbonate *** a statistical point of view,there is no difference between the V_(p)-and V_(s)-derived exponential coefficient D.

关键词： Velocity Carbonate rocks Pressure dependence Pore structure

Effects of External Stresses on the Carbide Precipitation in Bainite Transformation

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Journal of Beijing Institute of Technology 2005年第2期14卷 192-195页

作者：苏铁健 DENIS S gautier E School of Materials Science and Engineering Beijing Institute of Technology Beijing100081 China Laboratory of Metal Materials Science and Technology Ecole des Mines de Nancy Nancy Cedex F-54042 France Laboratory

TEM observation of carbide precipitates in bainite has been carried out for steel 40CMD8. Specimens transformed at 350 ℃ and 450 ℃ without external stress contain respectively the lower and the upper bainite. No fundamental change in carbide precipitation is observed in specimen transformed at 350 ℃ under stress of 128 MPa. The very fine cementite is found precipitated within the upper bainite plates in specimen transformed at 450 ℃ under stress of 144 MPa, which can be explained as the result of the difficulty of carbon diffusing out of the massive ferrite plate within a much shortened transformation time due to the external stress. For all the specimens examined, Bagaryatskii orientation relationship is found existing between the carbides and ferrite matrix.

关键词： bainite transmission electron microscopy carbide phase transformation

Woody plant assemblage and the structure of miombo woodland along a disturbance gradient in Hurungwe, Zambezi Valley, Zimbabwe

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Journal of Forestry Research 2021年第5期32卷 1867-1877页

作者： Tatenda Gotore Hilton GTNdagurwa Shakkie Kativu Denis gautier Laurent Gazull Forest Research Centre P.O.Box HG595HighlandsHarareZimbabwe Department of Forest Resources and Wildlife Management Faculty of Applied ScienceNational University of Science and TechnologyP.O.Box AC 939 AscotBulawayoZimbabwe School of Animal Plant and Environmental SciencesUniversity of the WitwatersrandPrivate Bag 3Wits 2050South Africa Department of Biological Sciences Faculty of ScienceUniversity of ZimbabweP.O.Box MP167 Mount PleasantHarareZimbabwe Forêt et Sociétés Univ MontpellierCIRADTA C-105/DCampus international de Baillarguet34398 Montpellier Cedex 5France

Miombo woodlands near human settlements are under significant pressures from human activities,with negative consequences on their structure and *** studies are limited,we assessed the structure and species composition of a portion of miombo woodland along an increasing disturbance gradient from a national park,through a buffer zone to communal lands in northeast *** concentric plots of 2 and 11 m radii were established in each area to record woody species composition,diameter,height,basal area,density and volume as well as evidence of *** of site,growth stage and their interaction on vegetation diversity and structural parameters were tested using a general linear model(GLM).Principal component analysis(PCA) tested the association between species and site and ANOVA the differences in the level of disturbance across *** diversity did not differ between sites except for evenness,which increased with *** and richness were greater in seedlings and saplings than mature trees across sites,*** and mature tree diameters differed significantly between *** and density of mature trees declined with increasing disturbance while seedling densities peaked at intermediate disturbance levels(buffer zone).Tree harvesting,was more evident in the buffer zone and in the communal area relative to the national *** contrast,fire frequency was greater in the national park and in the buffer zone relative to the communal *** results of this study identify a true miombo woodland dominated by Brachystegia boehmii with a stable population,as illustrated by an inverse-J shape in diameter class distribution on all sites,and that these woodlands are generally resilient to disturbances,maintaining similar species composition and structure at various levels of ***,continued monitoring of disturbance levels and miombo woodland response is recommended to ensure sustainable utilisation of

关键词： Miombo woodlands cComposition Diversity Structure Anthropogenic disturbances

Health financing policies in Sub-Saharan Africa:government ownership or donors’influence?A scoping review of policymaking processes

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Global Health Research and Policy 2017年第1期2卷 116-132页

作者： Lara gautier Valéry Ridde Department of social and preventive medicine School of Public HealthUniversitéde MontréalMontréalQuébecCanada Public Health Research Institute(IRSPUM) Universitéde MontréalMontréalQuébecCanada Centre d’Etudes en Sciences Sociales sur les Mondes Africains Américains et AsiatiquesUniversitéParis Diderot-Paris VIISorbonne Paris CitéParisFrance

Background:The rise on the international scene of advocacy for universal health coverage(UHC)was accompanied by the promotion of a variety of health financing *** donors presented health insurance,user fee exemption,and results-based financing policies as relevant instruments for achieving UHC in Sub-Saharan ***“donor-driven”push for policies aiming at UHC raises concerns about governments’effective buy-in of such *** the latter has implications on the success of such policies,we searched for evidence of government ownership of the policymaking ***:We conducted a scoping review of the English and French literature from January 2001 to December 2015 on government ownership of decision-making on policies aiming at UHC in Sub-Saharan ***-five(35)results were *** extracted,synthesized and analyzed data in order to provide insights on ownership at five stages of the policymaking process:emergence,formulation,funding,implementation,and ***:The majority of articles(24/35)showed mixed results(*** was identified at one or more levels of policymaking process but not all)in terms of government *** of only five papers provided evidence of ownership at all reviewed policymaking *** results demonstrated some lack of government ownership at any of the five stages,we noticed that donors did not necessarily play a role:other actors’involvement was contributing to undermining government-owned decision-making,such as the private *** also found evidence that both government ownership and donors’influence can successfully ***:Future research should look beyond indicators of government ownership,by analyzing historical factors behind the imbalance of power between the different actors during policy *** is a need to investigate how some national actors become policy champions and thereby influence policy *** order to effectively achiev

关键词： owned policy formulation

Refinement of Bouguer anomalies derived from the EGM2008 model,impact on gravimetric signatures in mountainous region:Case of Cameroon Volcanic Line,Central Africa

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Earth and Planetary Physics 2020年第6期4卷 639-650页

作者： Paul gautier Kamto Cyrille Mezoue Adiang Severin Nguiya Joseph Kamguia Loudi Yap Geodesy Research Laboratory National Institute of Cartography(NIC)YaoundeCameroon Department of Physics Faculty of ScienceUniversity of Yaounde ICameroon Laboratory E3M Faculty of Industrial EngineeringUniversity of DoualaCameroon Department of Physics Faculty of ScienceUniversity of DoualaCameroon

Global geopotential models have not included the very high frequencies of the Earth’s external gravity *** is called omission *** omission error becomes more important in mountainous areas(areas with highly variable topography).The work reported here consists in reducing the omission error in measurements of Bouguer gravity anomalies,by refining the global geopotential model EGM2008 using the spectral enhancement *** method consists in computing the residual terrain effects and then coupling them to the gravimetric signal of the global geopotential *** compute the residual terrain effects,we used the Residual Terrain Model(RTM)*** refine it required a reference surface(ETOPO1)developed up to degree 2190(the maximum degree of the EGM2008 model)and a detailed elevation model(AW3D30).Computation was performed with the TC program of the GRAVSOFT *** topography of the study area was assumed to have a constant density of 2670 kg/*** the inner and outer zones,the respective integration radii of 10 km and 200 km have been *** obtained very important RTM values ranging from−53.59 to 34.79 *** values were added to the gravity anomalies grid of the EGM2008 model to improve accuracy at high *** a part of the Cameroon Volcanic Line and its surroundings(mountainous area),we made a comparison between the residual Bouguer anomalies before and after *** report differences ranging from−37.40 to 26.40 *** conclude that the impact of omission error on gravimetric signatures is observed especially in areas with high variable topography,such as on the Cameroon Volcanic Line and around the localities of Takamanda,Essu,Dumbo,and *** finding illustrates the great influence that topography has on accurate measurement of these gravity anomalies,and thus why topography must be taken into *** can conclude that in preparing a global geopotential model,a high resolution DTM must be used to decrease

关键词： residual Terrain Model EGM2008 Omission error refined Bouguer anomalies mountainous area