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Investigation of dynamics of discrete framed structures by a numerical wave-based method and an analytical homogenization approach

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Chinese Journal of Aeronautics 2017年第1期30卷 66-74页

作者： Zhou Changwei Sun Xiangkun Mohamed Ichchou Abdel-Malek Zine jean-Pierre Lainé Stephane Hans claude Boutin Laboratory of Tribology and Systems Dynamics Ecole Centrale de Lyon Ecully 69134 France Institut Camille Jordan Ecole Centrale de Lyon Ecully 69134 France Laboratory of Tribology and Systems Dynamics Ecole Nationale des Travaux Publics de l'Etat Vaulx-en-Velinx 69518 France

In this article, the analytical homogenization method of periodic discrete media（HPDM）and the numerical condensed wave finite element method（CWFEM） are employed to study the longitudinal and transverse vibrations of framed structures. The valid frequency range of the HPDM is re-evaluated using the wave propagation feature identified by the CWFEM. The relative error of the wavenumber by the HPDM compared to that by the CWFEM is illustrated in functions of frequency and scale ratio. A parametric study on the thickness of the structure is carried out where the dispersion relation and the relative error are given for three different thicknesses. The dynamics of a finite structure such as natural frequency and forced response are also investigated using the HPDM and the CWFEM.

关键词： Framed structures Homogenization method Periodic structures Wave finite element method Wave propagation

Amniotic Band Syndrome at the Van Norman Clinic in Burundi: A Case Series

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Surgical Science（外科学） 2024年第3期 118页

作者： Alice Ndayishimiye HélèneBukuru Déogratias Niyungeko Anne Marie Nikuze Sylvestre Bazikamwe jean claude Mbonicura Gilbert Ndayizeye

A quantum cascade laser infrared spectrometer for CO_2 stable isotope analysis：Field implementation at a hydrocarbon contaminated site under bio-remediation

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Journal of Environmental Sciences 2016年第2期28卷 60-74页

作者： Christophe Guimbaud Cécile Noel Michel Chartier Valéry Catoire Michaela Blessing jean Christophe Gourry claude Robert Laboratoire de Physique et de Chimie de l'Environnement et de l'Espace (LPC2E) CNRS et Universite d'Orleans (UMR 7328)45071 Orleans cedex 2 France Bureau de Recherches Geologiques et Minieres (BRGM) 45060 Orleans cedex 2 France

Real-time methods to monitor stable isotope ratios of CO_2 are needed to identify biogeochemical origins of CO_2 emissions from the soil–air interface. An isotope ratio infra-red spectrometer（IRIS） has been developed to measure CO_2 mixing ratio with δ~13C isotopic signature, in addition to mixing ratios of other greenhouse gases（CH_4, N2_O）. The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ~13C of CO_2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO_2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ~13C of the CO_2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO_2 emissions have been measured with an isotopic signature δ~13C suggesting that CO_2 comes from petroleum hydrocarbon *** first field implementation shows that rapid and accurate measurement of isotopic signature of CO_2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO_2 efflux and is promising as a monitoring tool for aerobic bio-treatment.

关键词： Isotope ratio infrared spectrometry Isotopic signature δ^(13)C of CO_2 Biodegradation monitoring Hydrocarbons BTEX

New Opportunities for Lanthanide Luminescence

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Journal of Rare Earths 2007年第3期25卷 257-274页

作者： jean-claude G. Bünzli Steve Comby Anne-Sophie Chauvin Caroline D. B. Vandevyver Laboratory of Lanthanide Supramolecular Chemistry Ecole Polytechnique Fédérale de Lausanne BCH 1402 CH-1015 Lausanne Switzerland

Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence： materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris（8-hydroxyquinolinate） displayed a bright green emission suitable for organic light emitting diodes （OLEDs） was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibili

关键词： lanthanide luminescence sensitization near infrared telecommunications organic light emitting diode (OLED) time-resolved luminescence in cellulo sensing cell imaging rare earths

Origami-Based Design for 4D Printing of 3D Support-Free Hollow Structures

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Engineering 2022年第5期8卷 70-82页

作者： Bingcong Jian Frederic Demoly Yicha Zhang H.Jerry Qi jean-claude Andre Samuel Gomes Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 Centre National de la Recherche Scientifique&Universitede Technologie de Belfort-MontbeliardUniversite Bourgogne Franche-ComteBelfort 90400France George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA 30332USA Laboratoire Reactions et Genie des Procedes UMR 7274 Centre National de la Recherche Scientifique-Universitede LorraineNancy 54001France

The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired organic structures,and multiscale structures,to name a ***,except for obvious cases,very little attention has been given to the design and printing of more complex three-dimensional(3D)hollow structures or folded/creased *** of the main reasons is that such complex open or closed 3D cavities and regular/freeform folds generally lead to printing difficulties from support-structure-related *** address this barrier,this paper aims to investigate four-dimensional(4D)printing as well as origami-based design as an original research direction to design and build 3D support-free hollow *** work consists of describing the rough 3D hollow structures in terms of two-dimensional(2D)printed origami precursor layouts without any support *** origami-based definitions are then embodied with folding functions that can be actuated and fulfilled by 3D printed smart *** desired 3D shape is then built once an external stimulus is applied to the active materials,therefore ensuring the transformation of the 2D origami layout to 3D *** demonstrate the relevance of the proposal,some illustrative cases are introduced.

关键词： Origami-based design 4D printing Smart material Hollow 3D structures Additive manufacturing

Decomposition and decoupling analysis of carbon dioxide emissions in African countries during 1984–2014

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Journal of Environmental Sciences 2021年第4期33卷 85-98页

作者： Claudien Habimana Simbi Jianyi Lin Dewei Yang jean claude Ndayishimiye Yang Liu Huimei Li Lingxing Xu Weijing Ma Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China School of Geographical Sciences Southwest UniversityChongqing 400715China Faculty of Geography University of MarburgMarburg 35032Germany

The potential for mitigating climate change is growing worldwide,with an increasing emphasis on reducing CO_(2)emissions and minimising the impact on the *** continent is faced with the unique challenge of climate change whilst coping with extreme poverty,explosive population growth and economic ***_(2)emission patterns in Africa are analysed in this study to understand primary CO_(2)sources and underlying driving forces *** are examined using gravity model,logarithmic mean divisia index and Tapio's decoupling indicator of CO_(2)emissions from economic development in 20 selected African countries during *** reveal that CO_(2)emissions increased by 2.11%(453.73 million ton)over the research *** centre for African CO_(2)emissions had shifted towards the northeast *** and economic growth were primary driving forces of CO_(2)*** structure and emission efficiency effects partially offset the growth of CO_(2)*** economic growth effect was an offset factor in central African countries and Zimbabwe due to political instability and economic *** structure and emission efficiency were insufficient to decouple economic development from CO_(2)emissions and relieve the pressure of population explosion on CO_(2)emissions in ***,future efforts in reducing CO_(2)emissions should focus on scaleup energy-efficient technologies,renewable energy update,emission pricing and long-term green development towards sustainable development goals by 2030.

关键词： CO_(2)emissions Decoupling Driving forces Logarithmic mean divisia index method Patterns Africa

National Soil Organic Carbon Stocks Inventories under Different Mangrove Forest Types in Gabon

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Open Journal of Forestry（林学期刊） 2024年第2期 127页

作者： Rolf Gaël Mabicka Obame Neil-Yohan Musadji jean Hervé Mve Beh Lydie-Stella Koutika jean Aubin Ondo Farrel Nzigou Boucka Michel Mbina Mounguengui claude Geffroy

The Evolutionary Profile of Patients Operated for Peptic Ulcer Perforation in Bujumbura

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Surgical Science（外科学） 2024年第1期

作者： jean claude Mbonicura Prudence Bukuru Stanislas Harakandi Frank Ijeneza Révérien Ndayirorere François Nduwimana Astère Mbonicura

Influence of Continental Atmospheric Forcing on the Decadal Variabilityof the West African Monsoon

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Atmospheric and Climate Sciences（大气和气候科学） 2024年第1期

作者： Adjoua Moïse Landry Famien Sandrine Djakouré Bi Tra jean claude Youan Serge Janicot Abé Delfin Ochou Arona Diedhiou