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Flocculation and magnetically-assisted sedimentation of size-sorted beidellite platelets mixed with maghemite nanoparticles

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Nano Research 2020年第11期13卷 3001-3011页

作者： sofia Housni sébastien Abramson jean-Michel Guigner pierre Levitz Laurent Michot Laboratoire de PHysico-chimie des Electrolytes et Nanosystèmes InterfaciauX(PHENIX UMR 8234 Sorbonne Université-CNRS)Sorbonne UniversitéParis75252France Institut de Minéralogie de Physique des Matériaux et de Cosmochimie(IMPMC UMR 7590Sorbonne Université-IRD-CNRS-MNHN)Sorbonne UniversitéParis75252France

In this study,the flocculation and the subsequent decantation step of mixed suspensions of 10 nm-sizedγ-Fe_(2)O_(3) magnetic nanoparticles and 500 nm-sized beidellite clay platelets was *** work may find application in the field of water treatment,specifically the flocculation processes with magnetically assisted *** a short description of the preparation and characterization of the raw materials(nanoparticles and clays),the influence of several parameters(pH,concentrations of nanoparticles and clays etc.)on the amount of flocculated materials was examined,which gave information on the concentration ranges allowing a complete flocculation,together with a better understanding on the interactions between nanoparticles and clays responsible for *** optimal conditions for magnetically assisted settling were then determined by comparing for each sample sedimentation velocities under gravity and in the presence of a Nd-Fe-B ***,the complex multiscale structure of the flocs in water was explored,through the measurement of several bulk properties(zeta-potential and volume measurements,laser granulometry),while the organization of the materials at a microscopic scale was investigated by cryo-transmission electron microscopy(cryo-TEM)and small-angle X-ray scattering(sAXs).

关键词： magnetic separation nanoparticles clay flocculation decantation characterization

Migration of bone marrow progenitor cells in the adult brain of rats and rabbits

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World Journal of stem Cells 2016年第4期8卷 136-157页

作者： Donnahue Dennie jean-pierre Louboutin David s strayer section of Anatomy Department of Basic Medical SciencesUniversity of the West IndiesMona Campus Department of Cell Biology Anatomy and PathologyThomas Jefferson University

Neurogenesis takes place in the adult mammalian brain in three areas:subgranular zone of the dentate gyrus(DG);subventricular zone of the lateral ventricle;olfactory *** molecular markers can be used to characterizethe cells involved in adult *** has been recently suggested that a population of bone marrow(BM)progenitor cells may migrate to the brain and differentiate into neuronal *** explore this hypothesis,we injected recombinant sV40-derived vectors into the BM and followed the potential migration of the transduced ***-term BM-directed gene transfer using recombinant sV40-derived vectors leads to expression of the genes delivered to the BM firstly in circulating cells,then after several months in mature neurons and microglial cells,and thus without central nervous system(CNs)*** of transgene-expressing cells expressed NeuN,a marker of mature ***,BM-derived cells may function as progenitors of CNs cells in adult *** mechanism by which the cells from the BM come to be neurons remains to be *** the observed gradual increase in transgene-expressing neurons over 16mo suggests that the pathway involved differentiation of BM-resident cells into neurons,cell fusion as the principal route cannot be totally ruled *** studies using similar viral vectors showed that BM-derived progenitor cells migrating in the CNs express markers of neuronal precursors or immature ***-positive cells were found in the subgranular zone of the DG of the hippocampus 16 mo after intramarrow injection of the *** addition to cells expressing markers of mature neurons,transgene-positive cells were also positive for nestin and doublecortin,molecules expressed by developing neuronal *** cells were actively proliferating,as shown by short term BrdU incorporation *** seizures by using kainic acid increased the number of BM progenitor cells transduced by sV40vectors migrating

关键词： stem cells Bone marrow Hippocampus Cell therapy sV40 Brain Nestin Doublecortin Neurons Development Epilepsy seizures

Evidence of a Light-sensing Role for Folate in Arabidopsis Cryptochrome Blue-Light Receptors

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Molecular Plant 2008年第1期1卷 68-74页

作者： Nathalie Hoang jean-pierre Bouly Margaret Ahmad Universite Paris Vl Casier 156 4 Place Jussieu 75005 Paris France Penn state University 25 Yearsley Mill Road Media PA 19063 USA

Arabidopsis cryptochromes cry1 and cry2 are blue-light signalling molecules with significant structural similarity to photolyases-a class of blue-light-sensing DNA repair enzymes. Like photolyases, purified plant cryptochromes have been shown to bind both flavin and pterin chromophores. The flavin functions as a light sensor and undergoes reduction in response to blue light that initiates the signalling cascade. However, the role of the pterin in plant cryptochromes has until now been unknown. Here, we show that the action spectrum for light-dependent degradation of cry2 has a significant peak of activity at 380 nm, consistent with absorption by a pterin cofactor. We further show that cry1 protein expressed in living insect ceils responds with greater sensitivity to 380 nm light than to 450 nm, consistent with a light-harvesting antenna pigment that transfers excitation energy to the oxidized flavin of cry1. The pterin biosynthesis inhibitor DHAP selectively reduces cryptochrome responsivity at 380 nm but not 450 nm blue light in these cell cultures, indicating that the antenna pigment is a folate cofactor similar to that of photolyases.

关键词： ARABIDOPsIs thaliana CRYPTOCHROMEs PLANT growth sEEDLINGs BLUE light

Useful zero friction simulations for assessing MBs codes Pascal’s formula giving wheelsets frequency for zero wheel-rail friction

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Theoretical & Applied Mechanics Letters 2022年第3期12卷 145-155页

作者： jean pierre Pascal Pascal Coding Rue d’ErquyPleneuf-Val-Andre F-22370France

Present study provides a simple analytical formula,the“Klingel-like formula”or“Pascal’s Formula”that can be used as a reference to test some results of existing railway codes and specifically those using rigid *** develops properly the 3D Newton-Euler equations governing the 6 degrees of freedom(DoF)of unsuspended loaded wheelsets in case of zero wheel-rail friction and constant ***,by solving numerically these equations,we got pendulum like harmonic oscillations of which the calculated angular frequency is used for assessing the accuracy of the proposed formula so that it can in turn be used as a fast practical target for testing multi-body system(MBs)railway *** to the harmonic property of these pendulum-like oscillations,the squareω2 of their angular frequency can be made in the form of a ratio K/M where K depends on the wheelset geometry and load and M on its *** on K and M are useful to understand wheelsets *** analytical formula is derived from the first order writing of full trigonometric Newton-Euler equations by setting zero elastic wheel-rail penetration and by assuming small *** trigonometric equations are numerically solved to assess that the formula providesω2 inside a 1%accuracy for usual wheelsets *** decreasing the conicity down to 1×10^(−4) rad,the relative formula accuracy is under 3×10^(−5).In order to test the formula reliability for rigid contact formulations,the stiffness of elastic contacts can be increased up to practical rigidity(Hertz stiffness×1000).

关键词： Unsuspended wheelsets Klingel formula Rigid contact Harmonic oscillation Multi body system railway codes Code validation

Relation between silico-aluminous fly ash and its coal of origin

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Particuology 2008年第2期6卷 85-92页

作者： jean-Charles Benezet pierre Adamiec Ali Benhassaine Ecole des Mines d'Alès 6 Avenue de Clavieres30319 ALES CedexFrance

Fly ashes are typical complex solids which incorporate at the same time intrinsic properties derived from the layers （various mineralogical and dimensional spectra） and major transformations generated during prior processing. To use fly ashes in various applications, it is necessary to characterise them completely. The first research to date carried out on silico-aluminous fly ashes in order to characterise them physically, morphologically, chemically and mineralogically, resulted in the recognition that they are relatively simple materials. In the present study, a silico-aluminous fly ash coming from the power station of Albi （France） was selected. Heat treatment at 450 and 1200℃ together with coal simulated the treatment undergone by coal in the power station in order to mimic real coal residue. In conclusion, the diversity of the particles contained in fly ash could only be exolained by the relation existing between the fly ash and its coal of origin.

关键词： Fly ash selection Thermal treatment

Pozzolanic reactivity of silico-aluminous fly ash

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Particuology 2008年第2期6卷 93-98页

作者： pierre Adamiec jean-Charles Benezet Ali Benhassaine Ecole des Mines d'Alès 6 Avenue de Clavières30319 ALES CedexFrance

For some years it has been possible to control the particle size of fly ashes, by-products of thermal power stations. Incorporating these very fine particles （obtained by grinding and/or pneumatic selection） improves the physical-mechanical characteristics of mortars and concretes. In this study, we measured the lime consumption of the various fractions （granulometric and densimetric） and identified by X-ray diffraction the neoformed phases by the pozzolanic reaction, to show that it is not sufficient to simply define the pozzolanicity of products based on lime consumption since it does not take into account the nature of the phases formed. The size of the particles used in the test samples also has a determining effect on the quantity of lime consumed. Before comparing results, it is necessary to ensure that the size of the particles （of the global ash and its constituents） be the same. Two distinct neoformed ohases appear： CsH in the largest granular fractions （d〉 40 μm） and C3AH6 in the smaller fractions.

关键词： Fly ash Pozzolanic reaction Particle size

Ocean-based climate actions recommended by academicians from Europe and China

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science China Earth sciences 2022年第8期65卷 1612-1614页

作者： jean-pierre GATTUsO Nianzhi JIAO Laboratoire d’Océanographie de Villefranche CNRS-Sorbonne University-IddriParis75006France Carbon Neutral Innovation Reaserch Center Xiamen UniversityXiamen361005China

Ocean acidification,deoxygenation and sea level Rise impacted by global warming intertwined with anthropogenic activities have resulted in tremendous ecological losses at species,diversity and ecosystem levels,leading... 详细信息

关键词： warming climate consequences

Reconstructing the cruise-phase trajectory of deep-space probes in a general relativistic framework:An application to the Cassini gravitational wave experiment

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Astrodynamics 2023年第3期7卷 301-314页

作者： Joseph O’Leary jean-pierre Barriot school of Physics University of MelbourneParkvilleVIC3010Australia Australian Research Council Centre of Excellence for Gravitational Wave Discovery(OzGrav) ParkvilleVIC3010Australia Observatoire Géodésique de Tahiti University of French PolynesiaBP 657098702Faa’aTahitiFrench Polynesia

Einstein’s theory of general relativity is playing an increasingly important role in fields such as interplanetary navigation,astrometry,and *** spacecraft and interplanetary probe prediction and estimation platforms employ a perturbed Newtonian framework,supplemented with the Einstein-Infeld-Hoffmann n-body equations of *** time in Newtonian mechanics is formally universal,the accuracy of modern radiometric tracking systems necessitate linear corrections via increasingly complex and error-prone post-Newtonian techniques—to account for light deflection due to the solar system *** flagship projects such as the EsA/JAXA BepiColombo mission now operating at unprecedented levels of accuracy,we believe the standard corrected Newtonian paradigm is approaching its limits in terms of *** this paper,we employ a novel prototype software,General Relativistic Accelerometer-based Propagation Environment,to reconstruct the Cassini cruise-phase trajectory during its first gravitational wave experiment in a fully relativistic *** results presented herein agree with post-processed trajectory information obtained from NAsA’s sPICE kernels at the order of centimetres.

关键词： general relativity planetary orbitography orbit prediction and determination

Combination of Tsoft and ET34-ANA-V80 software for the preprocessing and analysis of tide gauge data in French Polynesia

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Geodesy and Geodynamics 2023年第1期14卷 26-34页

作者： Bernard Ducarme jean-pierre Barriot Fangzhao Zhang Catholic University of Louvain Georges Lemaître Centre for Earth and Climate Research(ELI)1348 Louvain-la-NeuveBelgium Geodesy Observatory of Tahiti University of French Polynesia(UPF)PunaauiaFrench Polynesia College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China

since 2008 a network of five sea-level monitoring stations was progressively installed in French *** stations are autonomous and data,collected at a sampling rate of 1 or 2 min,are not only recorded locally,but also transferred in real time by a radio-link to the NOAA through the GOEs *** new ET34-ANA-V80 version of ETERNA,initially developed for Earth Tides analysis,is now able to analyze ocean tides *** a two-step validation scheme,we took advantage of the flexibility of this new version,operated in conjunction with the preprocessing facilities of the Tsoft software,to recover co rrected data series able to model sea-level variations after elimination of the ocean tides *** performed the tidal analysis of the tide gauge data with the highest possible selectivity(optimal wave grouping)and a maximum of additional terms(shallow water constituents).Our goal was to provide corrected data series and modelled ocean tides signal to compute tide-free sea-level variations as well as tidal prediction models with centimeter *** also present in this study the characteristics of the ocean tides in French Polynesia and preliminary results concerning the non-tidal variations of the sea level concerning the tide gauge setting.

关键词： Tide gauges Tidal data processing Mean sea level