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Detection of CO2 and O2 by iron loaded LTL zeolite films

Frontiers of Chemical Science and Engineering 2018年第1期12卷 94-102页

作者： Veselina Georgieva Richard Retoux Valerie Ruaux Valentin Valtchev Svetlana Mintova Laboratoire Catalyse et Spectrochimie (LCS) ENSICAEN CNRS Normandy University 14000 Caen France Laboratoire de Cristallographie et Sciences des Matériaux (CRISMAT) ENSICAEN CNRS Normandy University 14000 Caen France

Detection of oxygen and carbon dioxide is important in the field of chemical and biosensors for atmosphere and biosystem monitoring and fermentation processes. The present study reports on the preparation of zeolite films doped with iron nanoparticles for detection of CO2 and O2 in gas phase. Pure nanosized LTL type zeolite with monomodal particle size distribution loaded with iron （Fe-LTL） was prepared under hydrothermal condition from colloidal precursor suspensions. The zeolite was loaded with iron to different levels by ion exchange. The Fe-LTL suspensions were used for preparation of thin films on silicon wafers via spin coating method. The reduction of the iron in the zeolite films was carried out under H2 flow （50% H2 in Ar） at 300 ℃. The presence of iron nanoparticles is proved by in situ ultra-violet-visible spectroscopy. The properties of the films including surface roughness, thickness, porosity, and mechanical stability were studied. In addition, the loading and distribution of iron in the zeolite films were investigated. The Fe-LTL zeolite films were used to detect O2 and CO2 in a concentration dependent mode, followed by IR spectroscopy. The changes in the IR bands at 855 and 642 cm^-1 （Fe O-H and Fe-O bending vibrations） and at 2363 and 2333 cm^-1 （CO2 asymmetric stretching） corresponding to the presence of O2 and CO2, respectively, were evaluated. The response to O2 and CO2 was instant, which was attributed to great accessibility of the iron in the nanosized zeolite crystals. The saturation of the Fe-LTL films with CO2 and O2 at each concentration was reached within less than a minute. The Fe-LTL films detected both oxygen and carbon dioxide in contrast, to the pure LTL zeolite film.

关键词： zeolite films detection of CO2 and O2 adsorption

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Site dependence of surface dislocation nucleation in ceramic nanoparticles

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npj Computational Materials 2021年第1期7卷 564-570页

作者： Jonathan Amodeo Emile Maras David Rodney Univ Lyon CNRSINSA LyonUCBLMATEISUMR5510VilleurbanneFrance Universitéde Lyon UniversitéClaude Bernard Lyon 1CNRSInstitut Lumière MatièreVilleurbanneFrance

The extremely elevated strength of nanoceramics under compression arises from the necessity to nucleate highly energetic dislocations from the surface,in samples that are too small to contain pre-existing ***,we investigate the site dependence of surface dislocation nucleation in MgO nanocubes using a combination of molecular dynamics simulations,nudgedelastic-band method calculations and rate theory *** an original simulation setup,we obtain a complete mapping of the potential dislocation nucleation sites on the surface of the nanoparticle and find that,already at intermediate temperature,not only nanoparticle corners are favorable nucleation sites,but also the edges and even regions on the side surfaces,while other locations are intrinsically *** are discussed in the context of recent in situ TEM experiments,sheding new lights on the deformation mechanisms happening during ceramic nanopowder compaction and sintering processes.

关键词： deformation dislocation ceramic

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Characterization of Particle Emissions of Turbocharged Direct Injection Gasoline Engine in Transients and Hot Start Conditions

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Journal of Thermal Science 2021年第6期30卷 2056-2070页

作者： Vincent BERTHOME David CHALET Jean-François HETET Ecole Centrale de Nantes LHEEA Lab.(ECN/CNRS)Nantes 44300France

Reducing pollutant emissions,particularly soot particles emitted by internal combustion engines,is a major challenge for car *** this paper,the experimental setup is a turbocharged three-cylinders gasoline direct injection engine installed on a HORIBA dynamic test driven by a HORIBA STARS *** particle-measuring device is a Pegasor Particles Sensor that measures the current carried by previously electrically charged *** hot engine stabilized tests,with lambda parameter lower or equal to one,have very low emission levels,unlike dynamic *** a consequence,the present paper deals with experiments in transient *** diesel engine,cycle tests show that particulate emissions vary *** understand the phenomenon,a simple transient was created and reproduced a hundred times in order to obtain enough data to analyze and compare these different *** transient starts from idle to reach the speed of 2000 r/min and 60 N·m in 5 *** reach this point,it is necessary to stay in full load for about 3 *** maximum deviations of particles reaches 85%with the standard deviationσ=18%.The cylinder pressure sensor shows significant variations at the very beginning of each transient,i.e.,during the first 500 *** kind of result was observed for Worldwide harmonized Light vehicles Test Cycles(WLTC)with a maximum deviations of particles reaching 75%withσ=30%,on Real Drive Emissions Cycle(RDE)with a maximum deviations of particles reaching 45%withσ=22%and for a 300 s Mini-Cycle with a maximum deviations of particles reaching 70%withσ=17%.The Mini-cycle is made up of the five largest accelerations of the WLTP cycle.A complete analysis highlights the importance of filling the first engine *** depends on the opening speed of the throttle,the position of the crankshaft at the beginning of the transient,and the acceleration of the first ***,the NO_(x) sensor shows very slight variations between each *** a consequence,i

关键词： particles gasoline engine cycle-to-cycle variations transients oil consumption

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First ovules integument: what roles?

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National Science Review 2022年第4期9卷 21-22页

作者： Brigitte Meyer-Berthaud AMAP Universit ?e de MontpellierCNRSCIRADINRAEIRD

The Famennian is a period of increased taxonomic diversity for the first representatives of the major plant groups,especially the spermatophytes (*** seed plants) that,today,represent the most abundant and diversified plant group on Earth [1,2].Early spermatophytes evolved a unique ovule-centered reproductive syndrome that allowed them to germinate and grow rapidly in disturbed habitats and,secondarily,to colonize dry habitats unfavorable to the reproduction of their free-sporing predecessors [3,4](Fig.1).In these ovulate organisms,the female gametophyte grows and produces gametes inside the indehiscent megasporangium (nucellus) that differentiates a pollen chamber retaining the pollen grains in its apical *** integument encloses the *** the Runcaria protovule that preceded them by 20 million years,Famennian ovules were all surrounded by a cupule,except perhaps Spermolithus and Warsteinia [5-7].

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Organic photodetectors based on supramolecular nanostructures

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SmartMat 2020年第1期1卷 56-71页

作者： Yifan Yao Yusheng Chen Hanlin Wang Paolo Samorì ISIS UMR 7006 CNRSUniversity of StrasbourgStrasbourgFrance

Self‐assembly of semiconducting(macro)molecules enables the development of materials with tailored‐made properties which could be used as active components for optoelectronics *** nanostructures combine the merits of soft matter and crystalline materials:They are flexible yet highly crystalline,and they can be processed with low‐cost solution *** are devices capable to convert a light input into an electrical *** achieve high photoresponse,the photogenerated charge carriers should be transported efficiently through the self‐assembled nanostructures to reach the electrodes;this can be guaranteed via optimalπ–electron overlapping between adjacent conjugated ***,because of the high surface‐to‐bulk ratio,supramolecular nanostructures are prone to enhance exciton *** qualities make supramolecular nanostructures perfect platforms for photoelectric *** review highlights the most enlightening recent strategies developed for the fabrication of high‐performance photodetectors based on supramolecular *** introduce the key figure‐of‐merit parameters and working mechanisms of organic photodetectors based on single components and p–n *** particular,we describe new methods to devise unprecedented planar and vertical devices to ultimately realize highly integrated and flexible *** incorporation of ordered mesoscopic supramolecular nanostructures into macroscopic optoelectronic devices will offer great promise for the next generation of multifunctional and multiresponsive devices.

关键词： organic crystalline photodetector phototransistor self‐assembly supramolecular electronics

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Seasonal characteristics of biomass burning contribution to Beijing aerosol

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Science China Chemistry 2005年第5期48卷 481-488页

作者： Cachier H. Laboratory of Climate and Environmental Sciences CNRS-CEA Gif sur Yvette France

110 atmospheric aerosol samples collected from November 1997 to October 1998 at two monitoring sites (Ming Tomb and Temple Heaven) in Beijing were analyzed for the con-centration of organic carbon (OC) and water-soluble potassium (K+). Four biomass burning epi-sodes, namely spring farming, summer harvesting, autumn harvesting and leaf falling were iden-tified using the tracer of K+. Biomass burning contribution to the urban aerosol OC concentration in Beijing was estimated by regression analysis of OC and K+ concentration data. The slopes of regression analysis are similar at the two monitoring sites, presenting regional characteristics. Severe air pollution event occurred during autumn harvesting period in 1998 with substantial secondary OC formed, in which biomass burning was one of the major emission sources. Bio-mass burning is a prominent source of aerosol OC in Beijing and is featured by its seasonality and periodicity. It may contribute as much as 30 to 60 percent of the total OC in typical cases.

关键词： biomass burning, water-soluble potassium, OC, atmospheric aerosol, regression analysis.

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Formal verification of synchronous data-flow program transformations toward certified compilers

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Frontiers of Computer Science 2013年第5期7卷 598-616页

作者： Van Chan NGO Jean-Pierre TALPIN Thierry GAUTIER Paul Le GUERNIC Loic BESNARD INRIA Rennes-Bretagne Atlantique Rennes 35042 France IRISA/cnrs Rennes 35042 France

Translation validation was invented in the 90＇s by Pnueli et al. as a technique to formally verify the correctness of code generators. Rather than certifying the code generator or exhaustively qualifying it, translation validators attempt to verify that program transformations preserve semantics. In this work, we adopt this approach to formally verify that the clock semantics and data dependence are preserved during the compilation of the Signal compiler. Translation valida- tion is implemented for every compilation phase from the initial phase until the latest phase where the executable code is generated, by proving the transformation in each phase of the compiler preserves the semantics. We represent the clock semantics, the data dependence of a program and its trans- formed counterpart as first-order formulas which are called clock models and synchronous dependence graphs （SDGs）, respectively. We then introduce clock refinement and depen- dence refinement relations which express the preservations of clock semantics and dependence, as a relation on clock mod- els and SDGs, respectively. Our validator does not require any instrumentation or modification of the compiler, nor any rewriting of the source program.

关键词： formal verification translation validation certi-fied compiler multi-clocked synchronous programs embed-ded systems.

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Biomechanics of transendothelial migration by cancer cells

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BIOCELL 2022年第11期46卷 2381-2386页

作者： CLAUDE VERDIER UniversitéGrenoble Alpes CNRSLIPhyGrenoble38000France

Cancer metastasis is still a major social issue with limited knowledge of the formation of tumors and their *** addition the formation of metastases is very difficult to understand,since it involves very complex physical mechanisms such as cellular interactions and cell rheology,which are *** studies investigated transendothelial migration using sophisticated techniques such as microfluidics,traction force microscopy(TFM)or Atomic Force Microscopy(AFM),combined with physical *** we summarize recent results and suggest new ways to investigate the precise mechanisms used by cancer cells to undergo transendothelial migration.

关键词： Rheology Deformation Forces Adhesion Biophysics

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Validation of a conductometric bienzyme biosensor for the detection of proteins as marker of organic matter in river samples

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Journal of Environmental Sciences 2009年第4期21卷 545-551页

作者： KHADRO Basma NAMOUR Philippe BESSUEILLE Franois LEONARD Didier JAFFREZIC-RENAULT Nicole University of Lyon Laboratory of AnalyticalCNRS UMR 5180 69622 Villeurbanne France Cemagref of Lyon

This article describes a conductometric bi-layer based bienzyme biosensor for the detection of proteins as a marker of organic matter in rivers. Proteins were chosen to be used as indicators of urban pollution. The working mechanism of the bienzyme biosensor is based on the enzymatic hydrolysis of proteins into several fractions （peptides and amino acids）, which results in a local conductivity change depending of the concentration of proteins. In this work, we began with the optimization of biosensor response using bovine serum albumin （BSA） as standard protein. For this objective seven enzymatic biosensors were prepared： four enzymatic sensors with only one layer of enzyme （proteinase K, trypsin, pronase or protease X） and three other enzymatic sensors with two layers （first layer： membrane containing proteinase K; second layer： one of the three other enzymes： trypsin, pronase or protease X）. The biosensors were obtained through the deposition of enzymatic layers and the cross-linking process between enzymes and BSA in saturated glutaraldehyde vapour. The response of the various biosensors, described previously, were compared with the values of total organic carbon （TOC）, and those of organic nitrogen （No~）, as determined by the laboratory accredits （CEMAGREF of Lyon） using the traditional method of analysis （NF EN 1484, infrared spectroscopy） and （NF EN 25663, mineralization/colorimetry assay） respectively for each water sample obtained from different sites in Lyon （France）. The linear correlations obtained with the response of the seven biosensors showed the most important indices of correlations for the biosensor with two enzymatic layers： proteinase K ＋ pronase （pkp）. The optimum conditions for the preparation of the pkp biosensor increased the sensitivity and gave a limit of quantification of 0.583 μg/L for TOC and 0.218 μg/L for Norg in water samples. This sensor shows good reproducibility （2.28%）, a capacity to be used at temperatures range 10-- 30℃ （dependi

关键词： conductometric biosensor proteins enzyme natural water analyses total organic carbon organic nitrogen

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ON THE ASYMPTOTIC SPECTRUM OF A TRANSPORT OPERATOR WITH ELASTIC AND INELASTIC COLLISION OPERATORS

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Acta Mathematica Scientia 2020年第3期40卷 805-823页

作者： Abdul-Majeed AL-IZERI Khalid LATRACH UniversitéClermont Auvergne CNRSLMBPF-63000 Clermont-FerrandFrance

In this article,we investigate the spectral properties of a class of neutron transport operators involving elastic and inelastic collision operators introduced by Larsen and Zweifel[1].Our analysis is manly focused on the description of the asymptotic spectrum which is very useful in the study of the properties of the solution to Cauchy problem governed by such operators(when it exists).The last section of this work is devoted to the properties of the leading eigenvalue(when it exists).So,we discuss the irreducibility of the semigroups generated by these *** close this section by discussing the strict monotonicity of the leading eigenvalue with respect to the parameters of the operator.

关键词： Compactness properties transport operator abstract boundary conditions asymptotic spectrum irreducibility leading eigenvalue

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