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法国高超声速冲压发动机技术研究(英文)

推进技术 2010年第6期31卷 650-659页

作者： francois falempin 法国MBDA公司

法国正在致力于发展高超声速吸气式推进系统和推阻平衡预测能力所需要的技术。通过地面试验研究完成其大部分技术开发,目前正在对燃烧室进行攻关研究,以确保燃烧效率和结构热力强度满足要求。另一方面,为了掌握推阻平衡技术,必须进行飞... 详细信息

法国正在致力于发展高超声速吸气式推进系统和推阻平衡预测能力所需要的技术。通过地面试验研究完成其大部分技术开发,目前正在对燃烧室进行攻关研究,以确保燃烧效率和结构热力强度满足要求。另一方面,为了掌握推阻平衡技术,必须进行飞行试验。因此,MBDA和ONERA正在推进LEA飞行试验计划。此计划始于2003年1月,准备在后续几年内完成马赫数4到8的若干次飞行试验。在2009年中期,通过关键设计评估完成了LEA飞行器推进系统的验证。将确定在2011年春季通过一系列自由射流试验验证飞行器的推阻平衡。此外,系统地开展了可重复使用运载器和高速民用飞行器的可行性和可实现的工作性能研究。

关键词：高超音速飞行器空气喷气发动机推进系统述评

MBDA R&T EFFORT ON PULSED AND CONTINUOUS DETONATION WAVE ENGINES

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Transactions of Nanjing University of Aeronautics and Astronautics 2011年第1期28卷 12-22页

作者： falempin francois Le Naour Bruno MBDA导弹系统公司未来飞行器动力部

The continuous detonation wave engine（CDWE）can be considered to reduce the environmental conditions generated by pulsed detonation engine（PDE）while reducing the importance of initiation issue and simplifying some integration *** experimental programs are performed by MBDA and Lavrentiev Institute to study CDWE operating mode and to address some key points for the feasibility of an operational rotating wave engine for space *** is found that such engine can deliver impressive thrust in a very small package（275 daN for internal diameter of 50 mm and length of 100 mm,kerosene-oxygen engine）and that can be increased with the use of a diverging *** to the geometry of the combustion chamber,a plug or aerospike nozzle seems to be the best design,the thrust vectoring capability of this engine（with the local change of the mass flow rate）being a way to solve the problem of attitude *** heat fluxes are very high but located mostly near the injection *** point will help the gasification of the liquid component injected inside the combustion *** preliminary tests are performed to evaluate the capability of C/SiC composite materials to sustain the very severe mechanical environment generated by the rotating detonation *** these first steps,a large scale ground demonstrator allowing to address all issues for a continuous detonation rocket engine using LH2/LOx mixture is designed by *** the first step toward the development of this large scale engine,a small scale demo is tested in Spring 2010.

关键词： detonation wave engine propulsion performance model

Characterisation of the granular dynamics at the interface between a pipe and a granular flow in a rotating drum

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Particuology 2024年第3期86卷 117-125页

作者： francois Rioual Paule Emmanuelle Eva Gbehe Research Unit FRISE National Research Institute for Agriculture Food and the Environment1 Rue Pierre Gilles De Gennes92160AntonyFrance

A new mobile bed heat exchanger is presented in this work which is composed of a flowing granular material in a rotating drum and a cylindrical pipe with potential interest in different energy applications as cooling,heating or heat recovery *** optimal design of the device requires a characterisation of the phenomena involved at the interface between the granular flow and the *** process is modelled by the discrete element method and a global classification of the flow patterns around the pipe is presented with respect to the three main control parameters of the problem:the Froude number,the diameter ratio and the relative filling height of the *** second part is devoted to the characterisation of the structure of the flow at the interface(velocity field,density field)in particular in a so-called Biflow regime where granular motion occurs above as well as below the pipe which is favourable to transfer by convection.A typical behavior at the interface with the pipe consists of a zone I with high velocities of particles at the top of the pipe,a second zone with quasistatic particles or low velocity particles at the front and at the bottom of the pipe and a last zone ll of depletion of particles at the back of the *** Froude number has a limited effect on the features of this structure on the first layer in the range of Froude numbers considered whereas the relative height is a more determinant parameter to control the relative magnitude of velocities in zone I and zone Il as well as the extent of the depletion *** first hydrodynamical characterisation can shed light on the dynamical regimes with improved transfer between the particles and the pipe boundary.

关键词： Granular flow Transfer Heat exchange Mobile bed Boundary condition

Design and Experimental Testing of a Moving Coil Actuator with Compensation Coil

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 707-716页

作者： Boyuan Yin Xianwu Zeng John Frederick Eastham Emelie Nilsson Jean-francois Rouquette Jean Rivenc Ludovic Ybanez Xiaoze Pei Department of Electronics&Electrical Engineering University of BathBathBA27AYUnited Kingdom Airbus UpNext BlangnacFrance Airbus CRT BlangnacFrance Department of Mechanical Engineering University of BathBathBA27AYUnited Kingdom

Hydrogen-powered electric aircraft have attracted significant interests aiming to achieve decarbonization *** DC electric networks are facing great challenges in DC fault protection *** interrupters are widely used in low voltage and medium voltage power systems due to being environmentally friendly with low *** this paper a moving coil actuator with compensation coils for a vacuum interrupter,as part of a hybrid direct current circuit breaker,is designed and experimentally *** coils are used to improve operating speed compared with original moving coil *** between four possible connections of compensation coils and original moving coil actuator are carried *** results show comparisons between different connections of actuator coils in terms of opening time and coil current with a range of pre-charged capacitor *** performance of each actuator connection is also *** actuator with compensation coils is shown to have a higher current rising rate and achieve faster opening speed,which is a critical requirement for electric aircraft network *** parallel connection actuator achieves the highest opening speed within 3.5 ms with capacitor voltage of 50 V.

关键词： Circuit breaker compensation coil moving coil actuator vacuum interrupter

From Control Theory to Gravitational Waves

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Advances in Pure Mathematics 2024年第2期14卷 49-100页

作者： Jean-francois Pommaret CERMICS Ecole des Ponts Paris Tech Paris France

When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D1:η→ξ such that Dξ = η implies D1η = 0. When D is involutive, the procedure provides successive first-order involutive operators D1,...,Dn when the ground manifold has dimension n. Conversely, when D1 is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D1η = 0. If this is possible, that is when the differential module defined by D1 is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D1 is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D1 is formally surjective, controllability just amounts to the formal injectivity of ad(D1), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4).

关键词： Differential Operator Differential Sequence Killing Operator Riemann Operator Bianchi Operator Cauchy Operator Control Theory Controllability Elasticity General Relativity

Incidental and secondary findings in trio exome sequencing

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Genes & Diseases 2024年第4期11卷 152-154页

作者： Camille Cohen Emeline Bellanger Jeremie Mortreux Laure Raymond francois Vialard Rodolphe Dard Department of Genetics Centre Hospitalier Intercommunal de Poissy-Saint-Germain-en-LayePoissy 78300France RHuMA UMR-BREEDINRA-ENVA-UVSQMontigny le Bretonneux 78180France Service de Genetique Laboratoire Eurofins BiomnisLyon 69007France

Exome sequencing(ES)generates secondary findings(SFs)in 2%of tested individuals if one follows the American College of Medical Genetics and Genomics(ACMG)guide-lines.i,z2 However,the rate of incidental and secondary findings(ISFs)is higher in routine clinical practice because of(i)the use of trio ES instead of solo sequencing and(i)the exclusion of the incidental findings(IFs)of medical value concerning genes in the ACMG ***,it is not clear how sufficient is a restricted list of genes to detect every ISF of major clinical value;and what is the amount of additional workload for the laboratory.

关键词： routine clinical finding

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A Taste of Success

ChinAfrica 2024年第5期16卷 44-45页

作者： francois ESSOMBA Cameroon

Cooperation between China and Cameroon has reached extraordinary heights over the past two decades,which has deepened both the diplomatic and economic *** mutually beneficial partnership has made China the leading buyer of Cameroonian products,with a market share of 25.8 percent in 2021,and the leading supplier,with a market share of 17.5 percent in 2020,according to data from the National Institute of Statistics of Cameroon.

关键词： mutually market partnership

Toward a Malaria-Free Future

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Beijing Review 2024年第23期67卷 30-31页

作者： francois Essomba ChinAfrica magazine

Malaria is a potentially fatal disease transmitted by certain species of *** to the World Health Organization(WHO),globally in 2022,there were an estimated 249 million malaria cases and 608,000 malaria deaths in 85 *** was the location of 94 percent of malaria cases and 95 percent of malaria deaths,with children under 5 there accounting for about 80 percent of all malaria deaths.

关键词： Malaria malaria cases

Geochemical fingerprints and hydrocarbon potential of Paleocene mudrocks in the Tano Basin, Ghana: insights from biomarkers and stable carbon isotopes

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Acta Geochimica 2024年第2期43卷 255-279页

作者： Kojo Amoako Nancy Pearl Osei-Boakye Ningning Zhong N’Guessan francois De Sales Konan Gordon Foli Prince Opoku Appau Clifford Fenyi Ebenezer Apesegah Research Group for Marine Geochemistry(ICBM-MPI Bridging Group) Institute for Chemistry and Biology of the Marine Environment(ICBM)Carl von Ossietzky University OldenburgAmmerlander Heerstr.26129 OldenburgGermany State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing 102249China Department of Geological Engineering Faculty of Civil and Geo-EngineeringKwame Nkrumah University of Science and TechnologyKumasiGhana Ghana National Gas Company 225 Osibisa CloseAirport WestAccraGhana Petroleum Corporation GNPCPMBPetroleum HouseTemaGhana

The Paleocene mudrocks in Ghana’s Tano Basin have received limited attention despite ongoing efforts to explore hydrocarbon resources.A thorough geochemical analysis is imperative to assess these mudrocks’petroleum generation potential and formulate effective exploration *** this study,a comprehensive geochemical analysis was carried out on ten Paleocene rock cuttings extracted from TP-1,a discovery well within the Tano *** analytical techniques,including total organic carbon(TOC)analysis,Rock–Eval pyrolysis,gas chromatography-mass spectrometry,and isotope ratio-mass spectrometry,were employed to elucidate their hydrocar-bon potential and organic ***ﬁndings in this study were subsequently compared to existing geochemical data on Paleocene source rocks in the South Atlantic marginal *** results indicated that the Paleocene samples have TOC content ranging from 0.68 to 2.93 wt%.The prevalent kerogen types identiﬁed in these samples were Type Ⅱ and Type Ⅲ.Molecular and isotope data suggest that the organic matter found in the Paleocene mudrocks can be traced back to land plants and lower aquatic *** mudrocks were deposited in a transi-tional environment withﬂuctuating water salinity,charac-terized by sub-oxic redox *** indices,both bulk and molecular,indicated a spectrum of maturity levels within the Paleocene mudrocks,spanning from immature to marginally mature,with increasing maturity observed with greater *** comparison,the organic composition and depositional environments of Paleocene source rocks in the Tano Basin closely resemble those found in the Niger Delta Basin,Douala,and Kribi-Campo Basins,the Kwanza Formation in Angola,and certain Brazilian marginal ***,it is worth noting that Paleocene source rocks in some of the basins,such as the Niger Delta and Brazilian marginal basins,exhibit rela-tively higher thermal maturity levels compared to those observed in the current Paleocene samp

关键词： Paleocene source rocks Source input Depositional environment Thermal maturity Hydrocarbon potential Tano Basin West Africa