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The Drought of Amazonia in 2023-2024

American Journal of Climate Change 2024年第3期13卷 567-597页

作者： Jose A. Marengo Ana P. Cunha Jhan-Carlo Espinoza Rong Fu Jochen Schöngart Juan C. Jimenez Mabel C. Costa Joao M. Ribeiro Sly Wongchuig Siyu Zhao National Center for Monitoring and Early Warning of Natural Disasters/CEMAdeN So Jos dos Campos Brazil UNESP/CEMAdeN So Jos dos Campos Brazil Graduate School of International Studies Korea University Seoul South Korea Institut des Gosciences de lenvironnement (IGE) Institut de Recherche pour le Dvelopement (IRD) Saint Martin dHeres France Instituto de Investigacin sobre la enseanza de las Matemticas (IREM PUCP) Pontificia Universidad Catlica del Per Lima Peru department of Atmospheric and Oceanic Sciences University of California Los Angeles Los Angeles CA USA departament of environmental Dynamics Instituto Nacional de Pesquisas da Amaznia (INPA) Manaus Brazil Global Change Unit (GCU) of the Image Processing Laboratory (IPL) Universitat de Valncia Estudi General (UVEG) Paterna Spain laboratoire detudes en Gophysique et Ocanographie Spatiales (LEGOS) Universit de Toulouse CNES/CNRS/IRD/UT3 Toulouse France

The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to december 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.

关键词： El Niño SST in the Tropical Atlantic Amazon Drought River Levels Heatwave Dry Season Length

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Accumulation of Flavonoids in an ntra ntrb Mutant Leads to Tolerance to UV-C

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Molecular Plant 2009年第2期2卷 249-258页

作者： Talaat Bashandy Ludivine Taconnat Jean-Pierre Renou Yves Meyer Jean-Philippe Reichheld laboratoire Genome et developpement des Plantes Universite de Perpignan UMR CNRS 5096 52 avenue Paul Alduy 66860 Perpignan France Unite de recherche en Genomique Vegetale 91057 Evry cedex France

NADPH-dependent thioredoxin reductases （NTRs） are key regulatory enzymes determining the redox state of thioredoxins. There are two genes encoding NTRs （NTRA and NTRB） in the Arabidopsis genome, each encoding a cytosolic and a mitochondrial isoform. A double ntra ntrb mutant has recently been characterized and shows slower plant growth, slightly wrinkled seeds and a remarkable hypersensitivity to buthionine sulfoximine （BSO）, a specific inhibitor of gluta- thione biosynthesis. In this paper, we demonstrate that this mutant also accumulates higher level of flavonoids. Analysis of transcriptome data showed that several genes of the flavonoid pathway are overexpressed in the ntra ntrb mutant. Accumulation of flavonoids is generally considered a hallmark of plant stress. Nevertheless, no elevation of the expression of genes encoding ROS-detoxification enzymes was observed, suggesting that the ntra ntrb plants do not suffer from oxidative disease. Another hypothesis suggests that flavonoids are specifically synthesized in the ntra ntrb mutant in order to rescue the inactivation of NTR. To test this, the ntra ntrb mutant was crossed with transparent testa 4 （tt4） plants with a mutation in the gene encoding the first enzyme in flavonoid biosynthesis. As ntra ntrb plants are more resistant to UV-C treatment than wild-type plants, this higher resistance was abolished in the ntra ntrb tt4 mutant, suggesting that accumulation of flavonoids in the ntra ntrb mutant protects plants against UV-light.

关键词： abiotic/environmental stress oxidative and photo-oxidative stress secondary metabolism - phenylpropanoidsand phenolics gene expression Arabidopsis.

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X-ray microscopic investigation of molecular orientation in a hole carrier thin film for organic solar cells

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Nano Research 2018年第5期11卷 2771-2782页

作者： Quentin Arnoux Benjamin Watts Sufal Swaraj Francois Rochet Ludovic Tortech laboratoire de chimie Physique Matiere et Rayonnement (LCPMR) UMR 7614 Sorbonne Universites UPMC Univ Paris 06 Paris F-75005 France Institut Parisien de chimie Moleculaire (IPCM) UMR 8232 Sorbonne Universites UPMC Univ Paris 06 Paris F-75005 France laboratoire d'Innovation en chimie des surfaces et Nanosciences (LICSen) NIMBE UMR 3685 CEA Saday Gif-sur-Yvette F-91191 France Paul Scherrer Institute Villigen Psi 5232 Switzerland Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin BP 48 Gif-sur-Yvette F-91192 France

As dipyranylidenes are excellent hole carriers, applications in organic solar cells or organic light emitting diode are envisaged. In the present study, we investigate the morphology of 2,2＇,6,6＇-tetraphenyl-4,4＇-dipyranylidene （DIPO-Ph4） deposited under vacuum on a silicon nitride （Si3N4） substrate, a paradigmatic system for the study of molecular crystal/inorganic substrate interfaces. Samples with various coating ratios and different thermal treatments were prepared. The films were characterized by atomic force microscopy and scanning transmission X-ray microscopy to gain insight into material growth. The results show a change in orientation at a molecular level depending upon the evaporation conditions. We are now able to tailor an organic layer with a specific molecular orientation and a specific electronic behavior.

关键词： organic solar cells scanning transmission X-ray microscopy molecular orientation inorganic/organic interface

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High Temperature Stability of Platinum Nanoparticles on Few-Layer Graphene Investigated by In Situ High Resolution Transmission Electron Microscopy

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Nano Research 2011年第5期4卷 511-521页

作者： Izabela Janowska Maria-Simona Moldovan Ovidiu Ersen Herve Bulou Kambiz Chizari Marc J. Ledoux Cuong Pham-Huu laboratoire des MatEriaux Surfaces et ProcEdEs pour la Catalyse （LMSPC UMR 7515 CNRS） 25 rue Becquerel F-67087 Strasbourg Cedex 02 France Institut de Physique et chimie des Materiaux de Strasbourg （IPCMS UMR 7504 CNRS） 23 rue du Loess F-67037 Strasbourg Cedex 08 France

Heterogeneous catalytic reactions involve the use of highly dispersed active phases such as metal, metal oxide, or metal sulphide nanoparticIes on thermally stable supports. Fluctuations of the reaction temperature during the reactions can induce sintering of the particles. The stability of such small particles represents a crucial parameter in the development of new families of catalysts with high activity in many fields. Here we report the stability of platinum nanoparticles （2-3 nm） on a few-layer graphene （FLG） surface as studied by in situ high temperature transmission electron microscopy.

关键词： Graphene platinium nanoparticles diffusion catalysis TEM annealing

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Effects of nano-voids and nano-cracks on the elastic properties of a host medium: xfem modeling with level-set function and free surface energy

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Acta Mechanica Sinica 2019年第4期35卷 799-811页

作者： B.E. Hachi D. Hachi M. Haboussi laboratoire de Développement en Mécanique et Matériaux (LDMM) Université de Djelfa PB 3117 Djelfa Algérie laboratoire d’Automatique Appliquée et Diagnostics Industriels (LAADI) Université de Djelfa PB 3117 Djelfa Algérie laboratoire des Sciences des Procédés et des Matériaux (LSPM) Université Paris 13 UPR 3407 CNRS Paris France

This work deals with the influences of nano-heterogeneities in the form of voids/cavities or cracks on the elastic (please confirm which word is correct. effective or elastic? According to the title of paper, I choose elastic.) properties of a host medium. With a relatively large ratio of apparent-surface to volume and particularly strong physical interactions with the surrounding medium at nano-scale, nano-heterogeneities can potentially affect the elastic(effective or elastic?) properties of the parent medium (matrix) containing them in a significant manner. This has been reported by various theoretical and experimental studies, some of them are discussed in the present paper. To describe the positive (reinforcement) or negative (degradation) effect of the nano-heterogeneities from the modeling perspective, it is necessary to take into account the energy of interfaces/surfaces between nano-heterogeneities and the matrix which, by the fact of the relatively large extent of their apparent surface and their strong physical interaction with their neighborhood, can no longer be neglected compared to those of the volume energy. Thus, to account for the effects of interfaces/surfaces in a nanostructured heterogeneous medium, the coherent interface model is considered in the present investigation within a periodic homogenization procedure. In this interface/surface model, the displacement vector is assumed to be continuous across the interface while the stress vector is considered to be discontinuous and satisfying the Laplace-Young equations. To solve these equations coupled to the classical mechanical equilibrium problem, a numerical simulation tool is developed in a two-dimensional (2D) context using the eXtended Finite Element Method (XFEM) and the Level-Set functions. The developed numerical tool is then used to carry out a detailed analysis about the effect of nano-heterogeneities on the overall mechanical properties of a medium. The nano-heterogeneities are present

关键词： Interface/Surface energy XFEM Level-Set function Periodic homogenization Nano-voids/Nano-cavities Nano-cracks Nano-inclusions/Nano-heterogeneities

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Oxidation of propane over ammonium-transition metal mixed keggin phosphomolybdate salts

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Journal of Natural Gas Chemistry 2010年第1期19卷 54-60页

作者： T. Mazari C. Roch. Marchal S. Hocine N. Salhi C. Rabia laboratoire de chimie du Gaz Naturel Faculte' de Chimie Universite' des Sciences et de la Technologie Houari Boumedie`ne USTHB BP32 El-Alia Bab-Ezzouar Alger Alge'rie ILV-UMR 8180 CNRS Universite' de Versailles -St Quentin-en-Yvelines Ba?timent Lavoisier 45 avenue des Etats-Unis 78035 Versailles Cedex France

Mixed ammonium-transition metal salts with formula of （NH4）xMyHzPMo12O40 （M = Ni^2＋, Co^2＋ or Fe ^3＋） denoted as MPMo12 have been investigated for the oxidation of propane, with molecular oxygen, at temperature range between 380 ℃ and 420 ℃ after in-situ pre-treatment performed at two heating rate of 5 or 9℃/min. They were characterized by Bet method, XRD, UV-Vis and IR techniques. The catalysts were found to be active in the propane oxidation and selective to propene or acrolein, in particular for samples pre-treated with the heating rate of 9℃/min. FePMo12 was found to be a more active catalyst for propene （17.2% yield） with minimal over deep oxidation （0.3% yield in COx）.

关键词： phosphomolybdate ammonium keggin propane oxidation propene acrolein

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Li(2p←2s)+Na(3s)pressure broadening in the far-wing and line-core profiles

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Chinese Physics B 2022年第7期31卷 247-254页

作者： F Talbi N Lamoudi L Reggami M T Bouazza K Alioua M Bouledroua Physics department Badji Mokhtar UniversityB.P.12Annaba 23000Algeria laboratoire de Physique des Rayonnements Badji Mokhtar UniversityB.P.12Annaba 23000Algeria laboratoire d’etude des surfaces et interfaces de la Matiere Solide(LESIMS) Badji Mokhtar UniversityB.P.12 Annaba 23000Algeria laboratoire LAMA Laboratoire des Materiaux Avances(LAMA)Badji Mokhtar UniversityB.P.12 Annaba 23000Algeria laboratoire de Physique de la Matiere et du Rayonnement LPMR Universite Cherif MessaidiaB.P.1553Souk-Ahras 41000Algeria

This work reports pressure-broadening line-wing and line-core of the lithium Li(2p←2s)resonance line perturbed by ground sodium Na(3s)*** far-wing regions,the calculations are performed quantum-mechanically and are intended to examine the photoabsorption coefficients at diverse *** results show the existence of three satellites,in the blue wing near the wavelengths 470 nm and in the red wing around 862 nm and 1070 *** the line-core region,by adopting the simplified Baranger model,the line-width and line-shift rates are determined,and their variation law with temperature is *** published data were found to compare these results with.

关键词： pressure broadening line-core broadening far-wing spectra photoabsorption

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Climate Services Elaboration for Cocoa Cultivation in Côte d’Ivoire: Contribution of CORdeX Climate Projections

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Agricultural Sciences 2024年第3期15卷 358-375页

作者： Adama Bamba Fidèle Yoroba N’Datchoh Evelyne Toure Kouakou Kouadio Mory Ouattara Kakou M’bo Mamadou Cherif Daouda Kone Arona Diedhiou laboratoire des sciences de la Matière de l’Environnement et de l’Energie Solaire (LASMES) Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire Centre d’Excellence Africain en Changement Climatique Biodiversité et Agriculture Durable (CCBAD) Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire laboratoire Mixte International Climat-Eau-Energy-Agriculture Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire Station Géophysique de LAMTO N’Douci C&#244te d’Ivoire UFR Bioscience Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire Université Grenoble Alpes IRD CNRS Grenoble-INP IGE Grenoble France

This study assessed the contribution of climate projections to improving rainfall information for cocoa crops in the central and southern regions of Côte d’Ivoire. Particular attention was paid to fourteen localities in these two climatic zones. Simulation data were obtained from the CORdeX ensemble and observation data from CHIRPS. They cover the period 1991-2005 for the reference period and the future period from 2021 to 2050 for the RCP4.5 and RCP8.5 scenarios. In addition, the study was based on the water requirements necessary during the critical phase of the cocoa tree (the flowering phase) for a good yield from the cocoa production chain on the one hand, and on a selection of three climate indices CDD, CWD and r95PTOT to study their spatio-temporal changes over two future periods 2021-2035 (near future) and 2036-2050 (medium-term) on the other. These climatic indices influence cocoa cultivation and their use in studies of climatic impacts on agriculture is of prime importance. The analysis of their spatio-temporal changes in this work also contributes to providing climate services based on rainfall, to which cocoa crops are highly sensitive. Our results show that the CDD and CWD indices vary from one region to another depending on latitude. For the fourteen localities studied, the number of consecutive dry days (CDD) could increase between now and 2050, while the number of consecutive wet days (CWD) could decrease over the period 2021-2035 and then increase over the period 2036-2050. The localities of Tabou, Aboisso and San-Pedro record high numbers of CDD index and CWD index for both projection scenarios. In comparison with the RCP4.5 and RCP8.5 scenarios, these results show that the RCP8.5 scenarios are having an impact on cocoa growing in Côte d’Ivoire.

关键词： Cocoa RCP4.5 RCP8.5 Climate Indices Côte D’ivoire

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Sharp large deviation results for sums of independent random variables

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Science China Mathematics 2015年第9期58卷 1939-1958页

作者： FAN XieQuan GRAMA Ion LIU QuanSheng Regularity Team Institut National de Recherche en Informatique et en Automatique laboratoire de Mathmatiques Appliques aux Systèmes Ecole Centrale Paris-Grande Voie des Vignes laboratoire de Mathmatiques de Bretagne Atlantique UMR 6205 University Bretagne-Sud School of Mathematics and Computing Science Changsha University of Science and Technology

We show sharp bounds for probabilities of large deviations for sums of independent random variables satisfying Bernstein's condition. One such bound is very close to the tail of the standard Gaussian law in certain case; other bounds improve the inequalities of Bennett and Hoeffding by adding missing factors in the spirit of Talagrand(1995). We also complete Talagrand's inequality by giving a lower bound of the same form, leading to an equality. As a consequence, we obtain large deviation expansions similar to those of Cram′er(1938),Bahadur-Rao(1960) and Sakhanenko(1991). We also show that our bound can be used to improve a recent inequality of Pinelis(2014).

关键词： Bernstein’s inequality sharp large deviations Cramér large deviations expansion of BahadurRao sums of independent random variabl

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Multichannel imaging for monitoring chemical composition and germination capacity of cowpea(Vigna unguiculata) seeds during development and maturation

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The Crop Journal 2022年第5期10卷 1399-1411页

作者： Gamal ElMasry Nasser Mandour Yahya Ejeez Didier demilly Salim Al-Rejaie Jerome Verdier etienne Belin David Rousseau Agricultural engineering department Faculty of AgricultureSuez Canal UniversityIsmailiaEgypt Groupe d’etude et de Controle des Variétés et des Semences(GEVES) Station Nationale d’Essais de Semences(SNES)Beaucouze49071AngersFrance department of Pharmacology&Toxicology College of PharmacyKing Saud UniversitySaudi Arabia laboratoire Angevin de recherche en Ingenierie des Systemes(LARIS) Universited’AngersAngersFrance Institut National de la recherche Agronomique(INRA) UMR1345 Institut de Recherche en Horticulture et SemencesBeaucouzéF-49071AngersFrance

This study aimed to set a computer-integrated multichannel spectral imaging system as a high-throughput phenotyping tool for the analysis of individual cowpea seeds harvested at different developmental stages. The changes in germination capacity and variations in moisture, protein and different sugars during twelve stages of seed development from 10 to 32 days after anthesis were nondestructively monitored. Multispectral data at 20 discrete wavelengths in the ultraviolet, visible and near infrared regions were extracted from individual seeds and then modelled using partial least squares regression and linear discriminant analysis(LDA) models. The developed multivariate models were accurate enough for monitoring all possible changes occurred in moisture, protein and sugar contents with coefficients of determination in prediction R^(2) of 0.93, 0.80 and 0.78 and root mean square errors in prediction(RMSEP) of 6.045%, 2.236% and 0.890%, respectively. The accuracy of PLS models in predicting individual sugars such as verbascose and stachyose was reasonable with R~2 of 0.87 and 0.87 and RMSEP of 0.071%and 0.485%, respectively;but for the prediction of sucrose and raffinose the accuracy was relatively limited with R^(2) of 0.24 and 0.66 and RMSEP of 0.567% and 0.045%, respectively. The developed LDA model was robust in classifying the seeds based on their germination capacity with overall correct classification of96.33% and 95.67% in the training and validation datasets, respectively. With these levels of accuracy,the proposed multichannel spectral imaging system designed for single seeds could be an effective choice as a rapid screening and non-destructive technique for identifying the ideal harvesting time of cowpea seeds based on their chemical composition and germination capacity. Moreover, the development of chemical images of the major constituents along with classification images confirmed the usefulness of the proposed technique as a non-destructive tool for estim

关键词： Multispectral imaging Multichannel imaging Chemical imaging Spectral analysis Seeds Cowpea

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