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Moisture-Induced Non-Equilibrium Phase Segregation in Triple Cation Mixed Halide Perovskite Monitored by In Situ Characterization Techniques and Solid-State NMR

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Energy & Environmental Materials 2023年第2期6卷 185-194页

作者： Mohammad Ali Akhavan Kazemi Nicolas Folastre Parth Raval michel Sliwa jean Marie Vianney Nsanzimana Sema Golonu Arnaud Demortiere jean Rousset Olivier Lafon Laurent Delevoye G.N.Manjunatha Reddy Frédéric Sauvage Laboratoire de Réactivité et Chimie des Solides(LRCS) UMR CNRS 7314-Institut de Chimie de Picardie FR 3085Université de Picardie Jules Verne33 rue Saint LeuAmiens Cedex FR-80039France CNRS Centrale LilleUMR 8181UCCSUnitéde Catalyse et Chimie du SolideUniversité de LilleUniversitéd’ArtoisLille F-59000France UMR 8516-LASIRE-Laboratoire de Spectroscopie pour les Interactions la Réactivité et l’EnvironnementCNRSUniversitéde LilleLille F-59000France EDF R&D EDF LabBoulevard Gaspard MongePalaiseau 91120France

Environmental stability is a major bottleneck of perovskite solar *** a handful of studies are investigating the effect of moisture on the structural degradation of the *** mostly rely on ex situ experiments and on completely degraded samples,which restrict the assessment on initial and final *** combining in situ X-ray diffraction under controlled 85%relative humidity,and live observations of the water-induced degradation using liquid-cell transmission electron microscopy,we reveal two competitive degradation paths leading on one hand to the decomposition of state-of-theart mixed cation/anion(Cs_(0.05)(MA_(0.17)FA_(0.83))_(0.95)Pb(Br_(0.17)I_(0.83))_(3)(CsMAFA)into PbI_(2) through a dissolution/recrystallization mechanism and,on the other hand,to a non-equilibrium phase segregation leading to CsPb_(2)Br_(5) and a Cesium-poor/iodide-rich Cs_(0.05)-x(MA_(0.17)FA_(0.83))_(0.95)Pb(Br_(0.17-2y)I_(0.83)+2y)_(3) *** degradation mechanism is corroborated at atomic-scale resolution through solid-state ^(1)H and ^(133)Cs NMR *** to moisture leads to a film containing important heterogeneities in terms of morphology,photoluminescence intensities,and *** results provide new insights and consensus that complex perovskite compositions,though very performant as champion devices,are comparatively metastable,a trait that limits the chances to achieve long-term stability.

关键词： liquid-cell transmission electron microscopy moisture degradation perovskite stability phase segregation solid-state NMR

Removing harvest residues from hardwood stands affects tree growth, wood density and stem wood nutrient concentration in European beech (Fagus sylvatica) and oak (Quercus spp.)

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Forest Ecosystems 2022年第2期9卷 147-159页

作者： Sanjoy Roy jean-michel Leban Bernhard Zeller Gregory van der Heijden Arnaud Reichard Marie-Christine Gehin Philippe Santenoise Laurent Saint-Andre INRAE BEFF-54000 NancyFrance IGN Laboratoire de l’Inventaire ForestierNancyF-54000France Universite de Lorraine AgroParisTechINRAESILVAF-54000 NancyFrance

Background:Higher exportation of harvest residues from forests due to increased demand for woody biomass,has reportedly diminished soil mineral resources and may lead to degraded tree nutrition as well as ***,as nutrients become less available in the soil,the remobilization of nutrients in biomass tissues(plant internal cycling)helps sustain tree *** study aims to quantify the impact of Removing Harvest Residues and Litter(RHRL)during five years on tree growth,wood density,and stem wood nutrient concentrations in young beech and oak forest ***:Our study found that,RHRL significantly decreased tree growth ring width by 14%,and wood density by 3%,in beech trees,in near bark *** also significantly reduced nutrient concentration in near bark and near pith areas of both studied ***,Na and S were found lower by 44%,76%,and 56%,respectively,in near bark area of beech *** near bark area of oak trees,K,Ca,Mg,Na,S,and Fe were lower by 20%,25%,41%,48%,41%,and 16%,respectively.K and Mg concentrations decreased more strongly in near pith area compared to near bark area suggesting internal translocation of these two ***:In beech trees,wood density proved to be an important factor while quantifying the effect of removing harvest residuals on tree growth and *** nutrient loss intensified the remobilization of nutrients con-tained in older tree rings(close to the pith)towards newly formed rings(close to bark).In our study,in beech trees,K was found to be the most recycled major *** results demonstrate the potential of such analysis for providing valuable insight into the effect of RHRL in premature stands on the physiological adaptive strategies of trees and an indication of soil fertility status.

关键词： Harvest residues Fagus sylvatica Quercus petraea Dendroecology Dendrochemistry Radial growth Wood density Tree growth Ring width Translocation

利用重力卫星GRACE监测亚马逊流域2002-2010年的陆地水变化

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地球物理学报 2012年第3期55卷 814-821页

作者：冯伟 jean-michel LEMOINE 钟敏许厚泽中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室武汉430077 中国科学院研究生院北京100049 CNES/GRGS ToulouseFrance 31401 华中科技大学地球物理研究所武汉430074

本文利用GRACE(Gravity Recovery and Climate Experiment)卫星重力资料研究了亚马逊流域2002—2010年的陆地水变化,并与水文模式和降雨资料进行了比较分析.在年际尺度上,GRACE结果表明:2002—2003年和2005年,亚马逊流域发生明显的干旱... 详细信息

本文利用GRACE(Gravity Recovery and Climate Experiment)卫星重力资料研究了亚马逊流域2002—2010年的陆地水变化,并与水文模式和降雨资料进行了比较分析.在年际尺度上,GRACE结果表明:2002—2003年和2005年,亚马逊流域发生明显的干旱现象;2007年至2009年,陆地水呈逐年增加的趋势,并在2009年6月变化值达到最大,为772±181km3;自2009年6月至2010年12月,陆地水总量又急剧减少了1139±262km3,这相当于全球海平面上升3.2±0.7mm所需的水量.水文模式得到的亚马逊流域陆地水在2010年也表现出明显的减少.降雨资料与GRACE观测资料有很好的一致性.在2005年和2010年的干旱期,亚马逊流域的降雨显著减少,说明降雨是亚马逊流域陆地水变化的重要因素.此外,本文采用的尺度因子的方法有效地降低了GRACE后处理误差的影响.

关键词： GRACE 亚马逊流域陆地水

Variation of Stable Isotopes in Surface Snow along a Traverse from Coast to Plateau's interior in East Antarctica and Its Climatic Significance

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Research in Cold and Arid Regions 2009年第1期1卷 14-24页

作者： jean Jouzel michel Stievenard Institut Pierre Simon Laplace/Laboratoire des Sciences du Climat et de l'Environnement CEA-CNRS-University Versailles-Saint Quentin

The variations of stable water isotopes of surface snow in east Antarctic Ice Sheet, are discussed by a total of 251 samples, which were taken along a 330 km traverse from Zhongshan Station to the outer edge of the Antarctic plateau and from four snow pits excavated along the route. Analyzing results of the samples showed the expected linear relationship between the parameters ?D and ?18O with slope S1 and intercept d1. When the data set was examined using a sliding window with a width of 5 samples, it was found that there were two areas with different ratios of S1 and d1. The boundary between these two areas occurred at an elevation of about 2,000 m, suggesting two different sources of water vapour. Nearly half (47%) of the fresh-snow samples had negative deuterium excess (d=?D? 8?18O) values, but few of the snow pit samples did, suggesting that variations of ? are quickly smoothed by isotopic diffusion in the near-surface firn. Analysis of the phase relationship between ?D and deuterium excess in the snow pit stratigraphies showed that they were mostly in phase from Jan. 1994 to Sept. 1995, but mostly out of phase from Sept. 1995 to Jan. 1997.

关键词： east Antarctica ice sheet stable isotopes snow

Topological to trivial insulating phase transition in stanene

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Nano Research 2016年第3期9卷 774-778页

作者： michel Houssa Bas van den Broek Konstantina Iordanidou Anh Khoa Augustin Lu Geoffrey Pourtois jean-Pierre Locquet Valery Afanas'ev Andre Stesmans Department of Physics and Astronomy University of Leuven Celestijnenlaan 200D B-3001 Leuven Belgium imec 75 Kapeldreef B-3001 Leuven Belgium

Electronic properties of stanene, the Sn counterpart of graphene are theoretically studied using first-principles simulations. The topological to trivial insulating phase transition induced by an out-of-plane electric field or by quantum confinement effects is predicted. The results highlight the potential to use stanene nanoribbons in gate-voltage controlled dissipationless spin-based devices and are used to set the minimal nanoribbon width for such devices, which is typically approximately 5 nm.

关键词： two-dimensional (2D)materials topological insulators density functional theory(DFT) simulations electronic structure

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稀释燃烧的火焰稳定性

燃烧科学与技术 2009年第2期15卷 103-108页

作者：刘玉英 MOST jean-michel BAUER Philippe 杨茂林北京航空航天大学能源与动力工程学院北京100083 法国国家科学研究中心燃烧与爆炸实验室普瓦捷86961法国

采用实验研究的方法探讨了反应物预热温度与稀释率两个因素对稀释燃烧火焰稳定性的影响.实验以氮气稀释的甲烷-空气对冲扩散火焰为研究对象,确定了不同反应物预热温度与氧化剂稀释率(氧气体积分数)时火焰的熄火极限,结果表明,增大反应... 详细信息

采用实验研究的方法探讨了反应物预热温度与稀释率两个因素对稀释燃烧火焰稳定性的影响.实验以氮气稀释的甲烷-空气对冲扩散火焰为研究对象,确定了不同反应物预热温度与氧化剂稀释率(氧气体积分数)时火焰的熄火极限,结果表明,增大反应物预热温度拓宽了火焰稳定燃烧区域,而增加氧化剂稀释率(降低氧气体积分数)会降低稀释火焰的稳定性,二者对火焰稳定性的影响作用相反.为了进一步分析反应物预热温度与稀释率对火焰稳定性的影响程度,引入了估算的Damk hler数,分析表明,在实验研究范围内,反应物预热温度对火焰稳定性的影响比稀释率的影响显著,是火焰稳定性的主要影响因素.

关键词：对冲火焰稀释燃烧稳定性熄火极限

Is There an Earthquake Weather?

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Open Journal of Earthquake Research 2020年第2期9卷 69-82页

作者： michel Parrot jean-Louis Pincon LPC2E CNRSOrleansFrance University of Orleans OrleansFrance

The aim of this study is to check if there is a relationship between the seismic activity and the whistlers observed by the micro-satellite DEMETER. Whistlers are the waves emitted by lightning strokes during thunderstorm activity. They use to propagate in the Earth-ionosphere waveguide but also in the ionosphere and the magnetosphere mainly along the magnetic field lines. Due to this reason we have checked the whistler occurrence not close to earthquake epicenters but close to the magnetically conjugate point of these epicenters at the satellite altitude. The number of whistlers is given by a neural network in operation onboard the satellite. It appears that the whistler amplitude is attenuated at the satellite altitude around the magnetic equator. It is why we have removed the earthquakes occurring at low geomagnetic latitudes in the statistic. The whistler rate is normalized with a background value to take into account the seasons and the epicenter locations. A superposed epoch method is used to display the results between -15 and +5 days around the earthquake day and up to 1000 km from the conjugate point of the epicenters. It is shown that the whistler rate is higher the day before the earthquake at a distance less than 200 km. It would be unrealistic to believe in the possibility to use this study for earthquake prediction because everyday thunderstorm activity reliably masks seismic effects. But it is further evidence that there is a lithosphere-atmosphere-ionosphere coupling at the time of the seismic activity.

关键词： Data Processing Earthquake Whistler Ionosphere

Two-and Three-Dimensional Urban Core Determinants of the Urban Heat Island： A Statistical Approach

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Journal of Environmental Science and Engineering(B) 2012年第3期1卷 363-378页

作者： Bumseok Chun jean-michel Guldmann Department of City and Regional Planning The Ohio State University Columbus Ohio 43210 USA

There is no doubt that the UHI （urban heat island） is a mounting problem in built-up environments, due to the energy retention by surface dense building materials, leading to increased temperatures, air pollution, and energy consumption. Much of the earlier research on the UHI has used two-dimensional （2-D） information, such as land uses and the distribution of vegetation. In the case of homogeneous land uses, it is possible to predict surface temperatures with reasonable accuracy with 2-D information. However, three-dimensional （3-D） information is necessary to analyze more complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with 2-D urban surface information to examine the relationship between urban characteristics and temperature. The research includes the following stages：（1） estimating urban temperature; （2） developing a 3-D city model; （3） generating geometric parameters; and （4） conducting statistical analyses using both linear and non-linear regression models. The implications of the results are discussed, providing guidelines for policies aiming to reduce the UHI.

关键词： Urban heat island urban morphology three-dimensional city model geographic information system.

Tailoring the properties of quantum dot-micropillars by ultrafast optical injection of free charge carriers

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Light(Science & Applications) 2021年第11期10卷 2083-2097页

作者： Emanuel Peinke Tobias Sattler Guilherme M.Torelly Patricia L.Souza Sylvain Perret Joel Bleuse Julien Claudon Willem L.Vos jean-michel Gerard UniversitéGrenoble Alpes CEAIRIG-PHELIQS“Nanophysique et Semiconducteurs”groupF-38000GrenobleFrance LabSem-CETUC Pontificia Universidade Catolica do Rio de JaneiroRio de Janeiro22451-900Brazil Complex Photonic Systems(COPS) MESA+Institute for NanotechnologyUniversity of TwenteP.O.Box 2177500 AEEnschedethe Netherlands

We review recent studies of cavity switching induced by the optical injection of free carriers in micropillar cavities containing quantum *** the quantum dots as a broadband internal light source and a streak camera as detector,we track the resonance frequencies for a large set of modes with picosecond time *** report a record-fast switch-on time constant(1.5 ps)and observe major transient modifications of the modal structure of the micropillar on the 10 ps time scale:mode crossings are induced by a focused symmetric injection of free carriers,while a lifting of several mode degeneracies is observed when off-axis injection breaks the rotational symmetry of the *** show theoretically and experimentally that cavity switching can be used to tailor the dynamic properties of the coupled QD-cavity *** report the generation of ultrashort spontaneous emission pulses(as short as 6 ps duration)by a collection of frequency-selected QDs in a switched pillar *** pulses display a very small coherence length,attractive for ultrafast speckle-free ***,the control of QD-mode coupling on the 10 ps time scale establishes cavity switching as an appealing resource for quantum photonics.

关键词： lifting injection cavity