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Improvement of the Lewis-Abegg-Octet Rule Using an “Even-Odd” Rule in Chemical Structural formulas: Application to Hypo and Hyper-Valences of Stable Uncharged Gaseous Single-Bonded Molecules with Main Group Elements

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Open Journal of Physical Chemistry 2014年第2期4卷 60-66页

作者： Geoffroy Auvert cea-leti 17 avenue des martyrs f38000 Grenoble France

As Lewis proposed his octet rule, itself inspired by Abegg’s rule, that a molecule is stable when all its composing atoms have eight electrons in their valence shell, it perfectly applied to the vast majority of known stable molecules. Only a few stable molecules were known that didn’t fall under this rule, such as PCl5 and Sf6, and Lewis chose to leave them aside at the time of his research. With further advances in chemistry, more exceptions to this rule of eight have been found, usually with the central atom of the structure having more or less than eight electrons in its valence shell. Theories have been developed in order to modify the octet rule to suit these molecules, defining these as hyper- or hypo-valent molecules and using other configurations for the electrons. The present paper aims to propose a representation rule for gaseous single-bonded molecules that makes it possible to reconcile both;molecules following the octet theory and those which do not. In this representation rule, each element of the molecule is subscripted with two numbers that follow a set of simple criteria. The first represents the number of valence electrons of the element;while the second is calculated by adding the first number to the number of the element’s covalent bonds within the molecule. The latter is equal to eight for organic molecules following the octet rule. Molecules being exceptions to the octet rule are now encompassed by this new even-odd rule: they have a valid chemical structural formula in which the second number is even but not always equal to eight. Both rules—octet and even-odd—are discussed and compared, using several well-known gaseous molecules having one or several single-bonded elements. A future paper will discuss the application of the even-odd rule to charged molecules.

关键词： Octet Rule Hypervalence Hypovalence Even-Odd Rule Electron-Pair Single Bond Molecule Chemistry

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Getting in phase: DNA damage repair mechanisms and liquid-liquid phase separation of the plant-specific histone methyltransferase MtSUVR2

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Molecular Plant 2022年第8期15卷 1266-1267页

作者： Stephanie Hutin Chloe Zubieta Laboratoire de Physiologie Cellulaire et Végétale Univ.Grenoble AlpesCNRSCEAINRAEIRIG-DBSCI-LPCV17 Avenue des Martyrs38054 GrenobleFrance

Liquid-liquid phase separation(LLPS)has become a widely accepted mechanism forthedynamic compartmentalization of different cellular components into membraneless organelles or other cellular *** occurs when the concentration of a protein,nucleic acid,or other molecule reaches a saturation concentration and its partition into high-and low-concentration phases is energetically favorable.

关键词： separation liquid phase

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Magnetic and specific heat studies of the frustrated Er_2Mn_2O_7 compound

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Journal of Rare Earths 2013年第1期31卷 54-59页

作者： N.Ben Amor M.Bejar E.Dhahri M.A.Valente P.Lachkar E.K.Hlil Laboratory of Applied Physics Faculty of Sciences of SfaxBP 1171University of Sfax I3N and Physics Department University of Aveiro MCMf Néel InstitutCNRS25 avenue des MartyrsBuilding FBP 16638042 Grenoble cedex 9France MCBT Institut NéelCNRS25 avenue des MartyrsBuilding EBP 16638042 Grenoble cedex 9France

A new ErzMn207 compound was synthesized by the ceramic method and its crystal structure was characterized LJsing powder X-ray diffraction （XRD） and observed by scanning electron microscopy （SEM）. The magnetic properties were investigated using a BS2 magnetometer and the heat capacity was studied using a quantum design （PPMS）. The structural study revealed that this compound was monophasic and crystallized in the monoclinic system with the P2/M space group. Magnetization measurements were carried out in the temperature range of 1.8-200 K under an applied magnetic field of 0.05 T. A crossover from a room temperature para- magnetic phase to an antiferromagnetic one at low temperature was detected from the magnetic study. The magnetic susceptibility, in the paramagnetic region above 40 K, was found to present a simple Curie-Weiss type behavior. from the specific heat （G,） measurements in magnetic fields up to 5 T, we noted the presence of a wide peak characteristic of a second order magneto-structural transition.

关键词： magnetic frustration magnetic phase transition specific heat rare earths

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Dynamics of the phase-change material GeTe across the structural phase transition

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frontiers of physics 2019年第2期14卷 65-71页

作者： T. Chatterji S. Rols U. D. Wdowik Institut Laue-Langevin 71 avenue des Martyres38000 GrenobleFrance Institut of Technology Pedagogical UniversityPodchorazych 2PL-30-084 KrakowPoland

Results of inelastic neutron scattering experinients and ab initio molecular dynamics simulations for GeTe 一 the parent compound of phase-change materials are reported. The inelastic neutron spectra of GeTe powder samples have been determined in the temperature range extending from 300 to 700 K. The phonon peaks undergo thermal shifts resulting from anharmonic effects being weaker for acoustic than optic modes. A small concentration of free charge carries arising from the presence of Ge-vacancies was found not to affect significantly the neutron weighted phonon densities of states of GeTe. The spectral pattern changes qualitatively across the structural phase transition, but the local structure of GeTe remains hardly affected, as confirmed by the analysis of temperature dependence of the pairdistribution function obtained from ab initio molecular dynamics investigations. The present theoretical studies support in a wide extent our experimental observations and also those provided by local probe methods.

关键词： phase-change mat erials inelastic neutron scattering ab initio molecular dynamics

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Ultra-long-working-distance spectroscopy of single nanostructures with aspherical solid immersion microlenses

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Light(Science & Applications) 2020年第1期9卷 1561-1571页

作者： Aleksander Bogucki Lukasz Zinkiewicz Magdalena Grzeszczyk Wojciech Pacuski Karol Nogajewski Tomasz Kazimierczuk Aleksander Rodek Jan Suffczynski Kenji Watanabe Takashi Taniguchi Piotr Wasylczyk Marek Potemski Piotr Kossacki faculty of Physics University of Warsawul.Pasteura 502-093 WarsawPoland National Institute for Materials Science TsukubaIbaraki 305-0044Japan Laboratoire National des Champs Magnetiques Intenses CNRS-UJF-UPS-INSAavenue des Martyrs 2538042 GrenobleFrance

In light science and applications,equally important roles are played by efficient light emitters/detectors and by the optical elements responsible for light extraction and *** latter should be simple,cost effective,broadband,versatile and compatible with other components of widely desired micro-optical ***,they should also operate without high-numerical-aperture ***,we demonstrate that all these requirements can be met with elliptical microlenses 3D printed on top of light ***,the microlenses we propose readily form the collected light into an ultra-low divergence beam(half-angle divergence below 1°)perfectly suited for ultra-longworking-distance optical measurements(600mm with a 1-inch collection lens),which are not accessible to date with other spectroscopic *** microlenses can be fabricated on a wide variety of samples,including semiconductor quantum dots and fragile van der Waals heterostructures made of novel two-dimensional materials,such as monolayer and few-layer transition metal dichalcogenides.

关键词： versatile latter optics

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fault Current Limitation with Superconducting YBCO Thin films

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Tsinghua Science and Technology 2003年第3期8卷 334-341页

作者： C.Villard C.Peroz Consortium of Research for the Emergence of Advanced Technologies(CRETA)and Center of Research on Very Low Temperatures(CRTBT) National Center for Scientific Research(CNRS)25 Avenue des MartyrsBP 166X GrenobleFrance-European CommunityConsortium of Research for the Emergence of Advanced Technologies(CRETA)and Center of Research on Very Low Temperatures(CRTBT)National Center for Scientific Research(CNRS)25 Avenue des MartyrsBP 166X GrenobleFrance-European Community

The behavior of YBCO/metal bilayers under transport currents was explored in the framework of fault current limitation (fCL). Properties of the superconducting-normal transition were first studied phenomenologically during sweep current experiments. for current rates higher than 500 A/s, the transition into the normal state was based on non-thermal phenomena and was characterized by a flux creep regime ended by a jump into the normal state. At lower sweep rates, a total diversion of the current in the metallic shunt was observed for temperatures higher than 85K. In this regime, a partial recovery of the superconducting state took place due to a finite thermal resistance between the superconducting and the metallic films. These two properties of partial diversion into the shunt and of fast switching for a quick rise of the current during a default were exploited for current limitation at 77 K. fCL experiments at 50 Hz show that YBCO/Au bilayers limit the current in about 1ms at a value of 2. 5/c by developing electrical fields as high as 3kV/m. Moreover, a recovery of the zero resistance state could occur under rated mode. A straightforward application of this property would be the transformer connection. finally, results on DC current limitation and recovery under nominal mode were presented for the first time.

关键词： fault current limiters thin films YBCO dissipation superconductors

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Contribution of different granulometric populations to powder reactivity

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Particuology 2009年第1期7卷 39-44页

作者： Jean-Charles Benezet Ali Benhassaine Ecole des Mines d’Alès 6 Avenue de Clavieres 30319 ALES CedexFrance Ecole des Mines d’Alès 6 Avenue de Clavieres 30319 ALES CedexFrance

In this article, different population contributions of quartz powders to chemical reactivity in pozzolanic reaction were studied. Deconvolution software was used to show the different particle populations of each product. Reaction of quartz powder with lime in the pozzolanic reaction at 20 ℃ shows that reactivity of each powder population depends on its particle size. Adsorbed fine particles on coarse particle surfaces have a significant role in the first term of the reaction. In a second term, the micropowders react. The mesopowders react only in the last reaction terms. Until now, the reactivity of adsorbed powder has been attributed to amorphization of the particle surface.

关键词： Quartz population Reaction rate Curve deconvolution Powder granulometry Specific surface area

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A Nominally Second-Order Cell-Centered finite Volume Scheme for Simulating Three-Dimensional Anisotropic Diffusion Equations on Unstructured Grids

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Communications in Computational Physics 2014年第9期16卷 841-891页

作者： Pascal Jacq Pierre-Henri Maire Remi Abgrall cea/CESTA 15 Avenue des Sablieres CS 6000133116 Le Barp cedexFrance. Institut fur Mathematik Universitat ZurichCH-8057 ZurichSwitzerland.

We present a finite volume based cell-centered method for solving diffusion equations on three-dimensional unstructured grids with general tensor *** main motivation concerns the numerical simulation of the coupling between fluid flows and heat *** corresponding numerical scheme is characterized by cell-centered unknowns and a local ***,the scheme results in a global sparse diffusion matrix,which couples only the cell-centered *** space discretization relies on the partition of polyhedral cells into sub-cells and on the partition of cell faces into *** is characterized by the introduction of sub-face normal fluxes and sub-face temperatures,which are auxiliary unknowns.A sub-cellbased variational formulation of the constitutive fourier law allows to construct an explicit approximation of the sub-face normal heat fluxes in terms of the cell-centered temperature and the adjacent sub-face *** elimination of the sub-face temperatures with respect to the cell-centered temperatures is achieved locally at each node by solving a small and sparse linear *** system is obtained by enforcing the continuity condition of the normal heat flux across each sub-cell interface impinging at the node under *** parallel implementation of the numerical algorithm and its efficiency are described and *** accuracy and the robustness of the proposed finite volume method are assessed by means of various numerical test cases.

关键词： finite volume methods unstructured grids anisotropic diffusion parallel computing

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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

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The effect of ozone on pine forests in South-Eastern france from 2017 to 2019

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Journal of forestry Research 2023年第2期34卷 301-315页

作者： Anumol Shashikumar Svetlana Bičárová Dalstein-Richier Laurence Groupe International d′Etudes des forêts Sud-Européennes(G.I.E.f.S) 69Avenue des Hespérides06300 NiceFrance Institute of Earth Science of the Slovak Academy of Sciences 05960 StaráLesnáTatranskáLomnicaSlovakia

In South-Eastern forests of france,risks linked to the effects of tropospheric ozone(O_(3))are real;its annual impact has been observed specifically near the coastline and in high altitude mountains during the period *** this study,the risk assessment of O_(3)pollutant was carried out using two approaches based on forest response indicators such as O_(3)specific foliar visible injury and by stomatal O_(3)*** O_(3)dose values(POD_(0))were obtained by the DO_(3)SE *** model requires hourly O_(3)concentration for POD_(0)calculation.A modified approach that uses measurements from passive samplers(monthly average O_(3)concentration)was tested for the calculation of POD_(0)and test results showed good agreement with the POD_(0)calculated using hourly O_(3)*** the model input file,the average O_(3)concentration is used for POD_(0),and this could be useful for POD_(0)calculation when the active monitor is *** this study,a flux-based assessment provided better correlation with O_(3)specific leaf injury,which is also *** visible injury in response to O_(3)indicates that Pinus cembra and Pinus halepensis are more affected and therefore more sensitive than Pinus *** POD_(0)and stomatal conductance(Gsto)seem to be induced by environmental factors,primarily rainfall and the soil water potential(fSWP).The correlation between the O_(3)flux metric and environmental variables with forest response indicators by Spearman rank test confirms *** as one of the most sensitive species to O_(3).

关键词： Ozone foliar visible injury Phytotoxic ozone dose Stomatal conductance DO_(3)SE

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