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Numerical Investigation of Flutter Stability in Subsonic Space Turbine Blisk with Emphasis on Cut-on/Cut-off Modes and Interblade Phase Angles

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Journal of Thermal Science 2012年第6期21卷 492-499页

作者： Hakim Ferria pascal Ferrand Franois Pacull Stéphane Aubert Laboratoire de Mécanique des Fluides et d'Acoustique CNRS UMR 5509 Université de LyonUniversité Claude Bernard Lyon 1INSA Lyon 36avenue Guy de Collongue69134 EcullyFrance Fluorem 64 chemin des Mouilles69134 EcullyFrance

The so-called blisks,*** bladed disks,are characterized by very low viscous material damping and make the flutter prediction much more *** that framework,a two-dimensional numerical study of a space turbine blisk featuring complex deformation of blades and high eigenfrequency(>40kHz)is *** simulations are based on unsteady Reynolds Averaged Navier Stokes computations linearized in the frequency domain and consist in the superposition of an unsteady linear(in time)pressure field,generated by a harmonic perturbation,upon a steady nonlinear(in space)*** aerodynamic damping coefficient is calculated over a range of nodal diameters,and the blades are predicted aeroelastically ***,violent changes occur and are rather critical since sudden and large deviations in stability *** that context,the nature of the waves propagating from the cascade are *** an approach provides fundamental knowledge about the perturbations which can either propagate to the far-field(cut-on mode)or decay(cut-off mode).It is expected that the ability of the flow to damp or to amplify the blade motion is strongly affected by the way unsteady perturbations are transferred from the cascade to the *** nature of the waves are first assessed from the aforementioned linearized results,then they are evaluated analytically and finally compared.A good agreement is found despite the strong assumptions of the analytical *** results show a clear correlation between the cut-on/cut-off conditions and *** least stable configuration corresponds to cut-off mode at the inlet and no wave at the *** outgoing waves from the cascade,the blade is prone to be less stable:the energy from the blades vibration is necessarily dissipated or sent out by the cascade.

关键词： subsonic flutter LRANS blisk cut-on/cut-off mode interblade phase angle nodal diameter.

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Updating digital elevation models via change detection and fusion of human and remote sensor data in urban environments

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International Journal of Digital Earth 2015年第2期8卷 153-171页

作者： Carolin Klonner Christopher Barron pascal Neis Bernhard Hofle Department of Geography University of HeidelbergHeidelbergGermany

OpenStreetMap(OSM)currently represents the most popular project of Volunteered Geographic Information(VGI):geodata are collected by common people and made available for public *** Laser Scanning(ALS)enables the acquisition of high-resolution digital elevation models that are used for many *** study combines the advantages of both ALS and OSM,offering a promising new approach that enhances data quality and allows change detection:the mainly up-to-date 2D data of OSM can be combined with the high-resolution–but rarely updated–elevation information provided by *** case study investigates building objects of OSM and ALS data of the city of Bregenz,*** quality of OSM is discerned by the comparison of building footprints using different true positive definitions(*** area).High quality of OSM data is revealed,yet also limitations of each method with respect to heterogeneous regions and building outlines are *** the first time,an up-to-date Digital Surface Model(DSM)combining 2D OSM and ALS data is achieved.A multitude of applications such as flood simulations and solar potential assessments can directly benefit from this data combination,since their value and reliability strongly depend on an up-to-date DSM.

关键词： OpenStreetMap airborne laser scanning change detection 3D modelling up-to-date digital surface models

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Roadside vehicle particulate matter concentration estimation using artificial neural network model in Addis Ababa,Ethiopia

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Journal of Environmental Sciences 2021年第3期33卷 428-439页

作者： Solomon Neway Jida Jean-François Hetet pascal Chesse Awoke Guadie Research Laboratory in Hydrodynamics Energetics&Atmospheric Environment(LHEEA)École Centrale de NantesNantes 44300France Department of Mechanical Engineering Faculty of Mechanical&Production EngineeringInstitute of TechnologyArba Minch UniversityArba Minch 21Ethiopia Key Laboratory of Environmental Biotechnology Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Department of Biology College of Natural SciencesArba Minch UniversityArba Minch 21Ethiopia

Currently,vehicle-related particulate matter is the main determinant air pollution in the urban *** study was designed to investigate the level of fine(PM_(2.5))and coarse particle(PM_(10))concentration of roadside vehicles in Addis Ababa,the capital city of Ethiopia using artificial neural network *** train,test and validate the model,the traffic volume,weather data and particulate matter concentrations were collected from 15 different sites in the *** experimental results showed that the city average 24-hr PM_(2.5)concentration is 13%-144%and 58%-241%higher than air quality index(AQI)and world health organization(WHO)standards,*** PM_(10)results also exceeded the AQI(54%-65%)and WHO(8%-395%)*** model runs using the Levenberg-Marquardt(Trainlm)and the Scaled Conjugate Gradient(Trainscg)and comparison were performed,to identify the minimum fractional error between the observed and the predicted *** two models were determined using the correlation coefficient and other statistical *** Trainscg model,the average concentration of PM_(2.5)and PM_(10)exhaust emission correlation coefficient were predicted to be(R^(2)=0.775)and(R^(2)=0.92),*** Trainlm model has also well predicted the exhaust emission of PM_(2.5)(R~2=0.943)and PM_(10)(R^(2)=0.959).The overall results showed that a better correlation coefficient obtained in the Trainlm model,could be considered as optional methods to predict transport-related particulate matter concentration emission using traffic volume and weather data for Ethiopia cities and other countries that have similar geographical and development settings.

关键词： Addis Ababa Artificial neural network PM prediction Roadside emission

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Molecular heterostructure by fusing graphene nanoribbons of different lengths through a pentagon ring junction

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Nano Research 2022年第9期15卷 8465-8469页

作者： Qiang Sun Hao Jiang Yuyi Yan Roman Fasel pascal Ruffieux Materials Genome Institute Shanghai UniversityShanghai 200444China Empa Swiss Federal Laboratories for Materials Science and TechnologyDübendorf 8600Switzerland Department of Chemistry Biochemistry and Pharmaceutical SciencesUniversity of BernBern 3012Switzerland

Graphene nanoribbons(GNRs)have attracted great research interest because of their widely tunable and unique electronic *** required atomic precision of GNRs can be realized via on-surface synthesis *** this work,through a surface assisted reaction we have longitudinally fused the pyrene-based graphene nanoribbons(pGNR)of different lengths by a pentagon ring junction,and built a molecular junction structure on Au(111).The electronic properties of the structure are studied by scanning tunneling spectroscopy(STS)combined with tight binding(TB)*** pentagon ring junction shows a weak electronic coupling effect on graphene nanoribbons,which makes the electronic properties of the two different graphene nanoribbons connected by a pentagon ring junction analogous to type I semiconductor heterojunctions.

关键词： graphene nanoribbons(GNRs) scanning tunneling spectroscopy(STS) non-contact atomic force microscopy(nc-AFM) tight-binding(TB)calculations junction structure

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“To measure is to know”: how advances in image analysis are supporting neural repair strategies

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Neural Regeneration Research 2015年第7期10卷 1040-1042页

作者： pascal Vallotton Robert Michail Ivan Kapsa Digital Productivity Flagship CSIRO Locked Bag 17 North Ryde NSW Australia ARC Centre for Electromaterials Science University of Wollongong (IPRI) Fairy Meadow NSW Australia

Neuronal regeneration in the peripheral nervous system arises via a synergistic interplay of neurotrophic factors,integrins,cytoskeletal proteins,mechanical cues,cytokines,stem cells,glial cells and astrocytes.

关键词： To measure is to know how advances in image analysis are supporting neural repair strategies

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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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Influence of genes,sex,age and environment on the onset of autoimmune hepatitis

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World Journal of Gastroenterology 2009年第9期15卷 1025-1034页

作者： Kathie Béland pascal Lapierre Fernando Alvarez Division of Gastroenterology Hepatology and NutritionCHU Sainte-Justine3175 Cte Ste-CatherineMontreal (Quebec) Canada H3T 1C5Canada

The pathogenesis of autoimmune hepatitis (AIH) is complex. However,it is believed that a susceptible individual,owing to his genetic background,sex and age,can develop the disease following exposure to an environmental trigger. Autoimmune hepatitis does not follow a Mendelian pattern of inheritance; hence no single causative genetic locus has been identified. However,several genes,inside and outside the HLA locus,have been linked to an increased susceptibility to AIH. Epidemiological evidence also suggests that the sex and age of the patient plays a role in AIH pathogenesis as the disease onset occurs mainly in the two first decades of life and a higher disease incidence is observed in females. No environmental trigger has been identified,but several have been proposed,mainly viruses and xenobiotics. This article aims at reviewing the current knowledge on susceptibility factors leading to AIH and putative triggers,emphasizing fundamental mechanisms responsible for the break of liver immunological tolerance.

关键词： Autoimmune hepatitis Genetic Environment Sex Virus

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The USCACA hosted symposiums at the 7th CACA annual meeting and the 15th CSCO annual meeting in Beijing

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Chinese Journal of Cancer 2012年第11期31卷 505-506页

作者： Michael Shi Wancai Yang pascal Qian Li Yan Novartis Oncology One Health PlazaEast HanoverNJ 07936USA Department of Pathology Xinxiang Medical UniversityXinxiangHenan 453003P.R.China Department of Pathology University of Illinois at ChicagoIL 60612USA CDMA Pfizer OncologyShanghai 200041P.R.China USCACA 939 S Highland AveLos AngelesCA 90036USA.

In September 2012,the US Chinese Anti-Cancer Association(USCACA) hosted two symposiums in *** USCACA hosted the first joint session at the 7th annual meetings of the Chinese Anti-Cancer Association(CACA),themed on "Collaboration between the US and China in Cancer Research." Six experts from the United States and China presented their latest work on basic and translational cancer *** this symposium,5 young Chinese scholars,returnees after their training in the United States,were honored the"AFCR-USCACA Scholarships Award." The USCACA hosted a second symposium during the 15th annual meeting of the Chinese Society of Clinical Oncology(CSCO),focused on the "US-China Collaboration in Cancer Drug Clinical Development." An international delegation of oncology experts presented the innovative clinical trial strategies and discussed the biomarkers for cancer early detection and clinical trials,targeted therapy,and new drug *** Oncology Drug Clinical Development and Safety Evaluation Committee was also launched to promote an innovative environment and to provide a collaborative platform for anti-cancer drug development in China.

关键词：协会北京年会中国学者临床试验抗癌药物邪教开发过程

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Modelling of Electrical Conductivity of a Silver Plasma at Low Temperature

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Plasma Science and Technology 2016年第8期18卷 812-820页

作者： pascal ANDRE William BUSSIERE Alain COULBOIS Jean-Louis GELET David ROCHETTE Université Clermont Auvergne LAEPT MERSEN 15 rue Jacques de Vaucanson

During the working of electrical fuses, inside the fuse element the silver ribbon first begins to melt, to vaporize and then a fuse arc appears between the two separated parts of the element. Second, the electrodes are struck and the burn-back phenomenon takes place. Usually, the silver ribbon is enclosed inside a cavity filled with silica sand. During the vaporization of the fuse element, one can consider that the volume is fixed so that the pressure increase appears to reach pressures higher than atmospheric pressure. Thus, in this paper two pressures, 1 atm and 10 atm, are considered. The electrical field inside the plasma can reach high values since the distance between the cathode surface and the anode surface varies with time. That is to say from zero cm to one cm order. So we consider various electrical fields： 102 V/m, 103 V/m, 5×103 V/m, 104 V/m at atmospheric pressure and 105 V/m at a pressure of 10 atm. This study is made in heavy species temperature range from 2,400 K to 10,000 K. To study the plasma created inside the electric fuse, we first need to determine some characteristics in order to justify some hypotheses. That is to say： are the classical approximations of the thermal plasmas physics justified？ In other words： plasma frequency, the ideality of the plasma, the Debye-Hückel approximation and the drift velocity versus thermal velocity. These characteristics and assumptions are discussed and commented on in this paper. Then, an evaluation of non-thermal equilibrium versus considered electrical fields is given. Finally, considering the high mobility of electrons, we evaluate the electrical conductivities.

关键词： electrical conductivity silver fuses non-ideal plasma Debye-Hiickelapproximation drift velocity thermal velocity thermal non-equilibrium electrical fields

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ARISTOTLE SAID ＂HAPPINESS IS A STATE OF ACTIVITY＂ - PREDICTING MOOD THROUGH BODY SENSING WITH SMARTWATCHES

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Journal of Systems Science and Systems Engineering 2018年第5期27卷 586-612页

作者： Peter A Gloor Andrea Fronzetti Colladon Francesca Grippa pascal Budner Joscha Eirich MIT Center for Collective Intelligence 245 First Street 02142 Cambridge MA USA Department of Enterprise Engineering University of Rome Tor Vergata Via del Politecnico n°1 00133 Rome Italy Northeastern University 360 Huntington Avenue 02115 Boston MA USA University of Cologne Albertus-Magnus-PIatz 50923 Koln Germany University of Bamberg Kapuzinerstraβe1696047 Bamberg Germany

We measure and predict states of Activation and Happiness using a body sensing applicationconnected to smartwatches. Through the sensors of commercially available smartwatches we collectindividual mood states and correlate them with body sensing data such as acceleration, heart rate, lightlevel data, and location, through the GPS sensor built into the smartphone connected to the smartwatchWe polled users on the smartwatch for seven weeks four times per day asking for their mood state. Wefound that both Happiness and Activation are negatively correlated with heart beats and with the levelsof light. People tend to be happier when they are moving more intensely and are feeling less activatedduring weekends. We also found that people with a lower Conscientiousness and Neuroticism andhigher Agreeableness tend to be happy more frequently. In addition, more Activation can be predictedby lower Openness to experience and higher Agreeableness and Conscientiousness. Lastly, we find thattracking people＇s geographical coordinates might play an important role in predicting Happiness andActivation. The methodology we propose is a first step towards building an automated mood trackingsystem, to be used for better teamwork and in combination with social network analysis studies.

关键词： Body sensing systems mood tracking smartwatch experience sampling happiness activation

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