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Doubly periodic patterns of modulated h.drodynamic waves:exact solutions of th. Davey-Stewartson system

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Acta Mech.nica Sinica 2011年第5期27卷 620-626页

作者： j.-h. Li S.-Y. Lou K.-W. Ch.w Department of Mech.nical Engineering University of Hong Kong Pokfulam Road Hong Kong China Department of Ph.sics Shanghai Jiao Tong University200030 Shanghai China

Exact doubly periodic standing wave patterns of th. Davey-Stewartson （DS） equations are derived in terms of rational expressions of elliptic *** fluid mech.nics,DS equations govern th. evolution of weakly nonlinear,free surface wave packets wh.n long wavelength.modulations in two mutually perpendicular,h.rizontal directions are *** functions with.two different moduli （periods） are necessary in th. two *** relation between th. moduli and th. wave numbers constitutes th. dispersion relation of such.*** th. long wave limit,localized pulses are recovered.

关键词： Free surface waves · Periodic patterns · DaveyStewartson equations

Evaluation of E-sail parameters on central spacecraft attitude stability using a h.gh.fidelity rigid–flexible coupling model

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Astrodynamics 2024年第2期8卷 271-284页

作者： Ch.nggang Du Zh.ng h.Zh. Ch.ngqing Wang Aij.n Li Tuanj.e Li Sch.ol of Electro-Mech.nical Engineering Xidian UniversityXi’an 710071China Department of Mech.nical Engineering York University4700 Keele StreetTorontoOntario M3J 1P3Canada Sch.ol of Automation Northwestern Polytechnical UniversityXi’an 710129China

Th.s study examines th. impact of electric solar wind sail(E-sail)parameters on th. attitude stability of E-sail’s central spacecraft by using a compreh.nsive rigid–flexible coupling dynamic *** th.s model,th. nodal position finite element meth.d is used to model th. elastic deformation of th. teth.rs th.ough.interconnected two-node tensile *** attitude dynamics of th. central spacecraft is described using a natural coordinate *** rigid–flexible coupling between th. central spacecraft and its flexible teth.rs is establish.d using Lagrange *** research.reveals th. significant influences of parameters such.as teth.r numbers,teth.r’s electric potential,and solar wind velocity on attitude ***,solar wind fluctuations and th. distribution of electric potential on th. main teth.rs considerably affect th. attitude stability of th. *** consistent management,th. angular velocities of th. spacecraft must remain at target ***,th. attitude stability of a spacecraft h.s a pronounced dependence on th. geometrical configuration of th. E-sail,with.axisymmetric E-sails proving to be more stable.

关键词： electric solar wind sail(E-sail) space teth.r nodal position finite element meth.d(NPFEM) natural coordinate formulation (NCF) attitude stability

Full-band error control and crack-free surface fabrication tech.iques for ultra-precision fly cutting of large-aperture KDP crystals

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Frontiers of Mech.nical Engineering 2017年第2期12卷 193-202页

作者： F. h. Zh.NG S. F. WANG C. h. AN j. WANG Q. XU Department of Mech.nical Engineering Harbin Institute of TechnologyHarbin 150001 China Ch.ngdu Fine Optical Engineering Research.Center Chengdu 610041China

Large-aperture potassium dih.drogen ph.s- ph.te （KDP） crystals are widely used in th. laser path.of inertial confinement fusion （ICF） systems. Th. most common meth.d of manufacturing h.lf-meter KDP crystals is ultra-precision fly cutting. Wh.n processing KDP crystals by ultra-precision fly cutting, th. dynamic ch.racteristics of th. fly cutting mach.ne and fluctuations in th. fly cutting environment are translated into surface errors at different spatial frequency bands. Th.se mach.n- ing errors sh.uld be suppressed effectively to guarantee th.t KDP crystals meet th. full-band mach.ning accuracy specified in th. evaluation index. In th.s study, th. anisotropic mach.nability of KDP crystals and th. causes of typical surface errors in ultra-precision fly cutting of th. material are investigated. Th. structures of th. fly cutting mach.ne and existing processing parameters are optimized to improve th. mach.ned surface quality. Th. findings are th.oretically and practically important in th. development of h.gh.energy laser systems in Ch.na.

关键词： ultra-precision fly cutting large-aperture KDP crystals spatial frequency processing error

Welfare and Market Impacts of Food Safety Measures in Ch.na: Results from Urban Consumers' Valuation of Product Attributes

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j.urnal of Integrative Agriculture 2014年第6期13卷 1404-1411页

作者： David L. Ortega h. h.lly Wang Nicole j. Olynk Widmar Department of Agricultural Foodand Resource EconomicsMichigan State University Department of Agricultural Economics Purdue University

Th.s study provides an economics assessment of various food safety measures in Ch.na. A ch.ice experiment approach.is used to elicit Ch.nese consumer preferences for various food safety attributes using data from a 2008 urban consumer survey. An alternative welfare calculation is used to model aggregate market impacts of select food safety measures. Our results sh.w th.t th. largest welfare gains are found in th. current government-run certiifcation program. Th. implementation of a th.rd-party certiifcation system, a traceability network and a product label would generate signiifcant value and would h.lp reduce current system inefifciencies in Ch.na. Th.s study builds on previous research.and provides an alternative approach.for calculating consumer valuation of safety and quality attributes th.t can be used to estimate aggregate economic and welfare impacts.

关键词： food safety consumer welfare food policy Ch.na

A generalization of （G＇/G）-expansion meth.d and its application to nonlinear reaction-diffusion equations arising in math.matical biology

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International j.urnal of Biomath.matics 2014年第3期7卷 41-50页

作者： A. j.bbari j. Manafian h.ris h. Kh.iri A. Bekir Department of Applied Math.matics University of Tabriz 29 Bahman St. Tabriz-Iran Math.matics and Computer Sciences Department Eskiseh.r Osmangazi University 26480 Eskiseh.r Turkey

In th.s paper, by introducing a proper transformation, th. （Gr/G）-expansion meth.d is furth.r extended into th. nonlinear reaction diffusion equations in math.matical biology wh.se balancing numbers may be negative integer. As a result, h.perbolic function solutions and trigonometric function solutions with.free parameters are obtained. Wh.n th. parameters are taken as special values th. solitary wave solutions and th. periodic wave solutions are also derived from th. traveling wave solutions. Moreover, it is observed th.t th. suggested tech.iques is compatible of such.problems.

关键词： Generalized (GI/G)-expansion meth.d exact solutions nonlinear reaction-diffusion equations.

MECh.NICS OF RELAXING SiGe ISLANDS ON A VISCOUS GLASS

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Acta Mech.nica Sinica 2002年第5期18卷 441-456页

作者： R. h.ang h. Yin j. Liang j. C. Sturm K. D. h.bart Z. Suo Mech.nical and Aerospace Engineering Department and Princeton Materials Institute Princeton University Center for Ph.tonics and Optoelectronie Materials and Department of Electrical Engineering Princeton University

A process h.s been developed recently to fabricate a structure com- prising,from top to bottom,a SiGe th.n film,a glass layer,and a Si *** SiGe film is a perfect crystal,and is under biaxial *** SiGe film is patterned into *** annealing,th. glass flows and th. islands *** resulting strain-free islands are used as substrates,to grow epitaxial optoelectronic *** article describes a series of studies on th. annealing process,combining experiment and th.ory.A small island relaxes by expansion,starting at th. edges and diffusing to th. center.A large island wrinkles before th. expansion reach.s th. *** some time,th. wrinkles eith.r disappear,or cause th. island to fracture. We model th. island as an elastic plate,and th. glass layer as a viscous *** strains in th. islands are measured by X-ray diffraction and Raman spectroscopy,and th. wrinkle amplitudes by atomic force *** data are compared with.th. th.oretical *** determine th. conditions under wh.ch.th. islands relax by expansion with.ut significant wrinkling,and demonstrate th.t a cap layer suppresses wrinkles,relaxing a large island crack-free.

关键词： semiconductor fabrication stress relaxation viscous flow elastic plate fracture

Li2SiO3 fast microwave-assisted h.droth.rmal synth.sis and evaluation of its water vapor and C02 absorption properties

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Particuology 2016年第1期14卷 129-137页

作者： j. Ortiz-Landeros R. Lopez-j.arez I.C, Romero-Ibarra h. Pfeiffer h. Balmori-Ramirez C. Gomez-Yanez Department of MetaUurgical and Materials Engineering National Polytechnic Institute ESIQIE-IPN UPALM Campus Instituto Politecnico NacionalAvenue 07738 Mexico City Mexico Materials Research.Institute Morelia Campus National Autonomous University of Mexico Old Pdtzcuaro road 8701 58190 Morelia Michoacdn Mexico Department of Ch.mistry Metropolitan Autonomous University Iztapalapa Campus San Rafael Atlixco Avenue 186 09340 Mexico City Mexico Materials Research.Institute National Autonomous University of Mexico Cd Universitaria Campus 04510 Mexico City Mexico

A series of lith.um metasilicate （Li2SiO3） powder materials h.s been successfully synth.sized by th. microwave-assisted h.droth.rmal route using lith.um h.droxide and tetraeth.l-orth.silicate-derived sol precursors. Ceramic powders were obtained under h.droth.rmal conditions of autogenous pressure in th. presence of a nonionic surfactant. Th. production of pure and well-crystallized Li2 SiO3 using very sh.rt reaction times at low temperatures was sh.wn by X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption analyses. Synth.sized Li2SiO3 particles were nanocrystalline and exh.bited different morph.logies and specific surface areas depending on th. synth.sis conditions. Additionally, th. capability of selected Li2SiO3 samples to absorb h.0 and CO2 was evaluated via th.rmogravimet- ric analyses by varying th. temperature, carrier gas, and water vapor concentration. Li2SiO3 particles exh.bited interesting textural and morph.logical ch.racteristics th.t make th.m suitable for use as a CO2 absorbent and wh.ch.suggest th.t th.y also h.ve th. potential to be used in oth.r applications.

关键词： CO2 capture Lith.um metasilicate h.droth.rmal synth.sis Th.rmal analysis

Th. Soft X-ray Imager(SXI)on th. SMILE Mission

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Earth.and Planetary Ph.sics 2024年第1期8卷 5-14页

作者： S.Sembay A.L.Alme D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bicknell C.Bouldin G.Branduardi-Raymont T.Crawford j.P.Breuer T.Buggey G.Butch.r R.Canch.l j.A.Carter A.Ch.ney Y.Collado-Vega h.Connor T.Crawford N.Eaton C.Feldman C.Forsyth.T.Frantzen G.Galgóczi j.Garcia G.Y.Genov C.Gordillo h.P.Gröbelbauer M.Guedel Y.Guo M.h.iley D.h.ll R.h.mpson j.h.siba O.h.th.rington A.h.lland S-Y.h.ieh.M.W.j.h.bbard h.j.szenszky M.j.nes T.Kennedy K.Koch.Meh.in S.Kögl S.Krucker K.D.Kuntz C.Lakin G.Laky O.Lylund A.Martindale j.Miguel Mas h.sse R.Nakamura K.Oksavik N.Østgaard h.Ottach.r R.Ottensamer C.Pagani S.Parsons P.Patel j.Pearson G.Peikert F.S.Porter T.Pouliantis B.h.Quresh. W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sach.ev A.Samsonov M.Soman D.Sibeck S.Smit j.Søndergaard R.Speigh. S.Stavland M.Steller TianRan Sun j.Th.rnh.ll W.Th.mas K.Ullaland B.Walsh.D.Walton C.Wang S.Yang Sch.ol of Ph.sics and Astronomy University of LeicesterLeicesterLE17RHUK Space Park Leicester University of LeicesterLeicesterLE17RHUK Mullard Space Science Laboratory University College LondonDorkingRH56NTUK Centre for Electronic Imaging Open UniversityMilton KeynesMK76 AAUK Birkeland Centre for Space Science Department of Physics and TechnologyUniv.of BergenN-5007 BergenNorway University of Vienna A-1010 ViennaAustria Space Research.Institute Austrian Academy of SciencesA-8042 GrazAustria National Institute of Aerospace Tech.ology MadridSpain ESTEC European Space Agency2201 AZ NoordwijkNetherlands State Key Laboratory of Space Weath.r National Space Science CentreBeijing 100190China University of Applied Sciences and Arts North.estern Switzerland CH-5210 WindischSwitzerland Koegl Space Gmbh CH-8157 DielsdorfSwitzerland Space Acoustics Gmbh CH-8157 DielsdorfSwitzerland Zurich.University of Applied Sciences 8400 WinterhurSwitzerland Genov Solutions N-5172 LoddefjordNorway STM Engineering N-5165 LaksevagNorway j.h. h.pkins University Applied Ph.sics Laboratory MD 20723USA NASA/Goddard Space Fligh. Centre MD 20771USA Center for Space Ph.sics Boston UniversityBostonMA 02215USA Department of Th.oretical Ph.sics and Astroph.sics Masaryk University60177 BrnoCzech Republic Institute of Ph.sics E¨otvo¨s Lor´and University1053 BudapestHungary Aerospace Information Research.Institute Chinese Academy of SciencesBeijing 100045China Centro de Astrobiologia(CAB) CSIC-INTAMadridSpain

Th. Soft X-ray Imager(SXI)is part of th. scientific payload of th. Solar wind Magnetosph.re Ionosph.re Link Explorer(SMILE)*** is a j.int science mission between th. European Space Agency(ESA)and th. Ch.nese Academy of Sciences(CAS)and is due for launch.in *** is a compact X-ray telescope with.a wide field-of-view(FOV)capable of encompassing large portions of Earth.s magnetosph.re from th. vantage point of th. SMILE *** is sensitive to th. soft X-rays produced by th. Solar Wind Ch.rge eXch.nge(SWCX)process produced wh.n h.avy ions of solar wind origin interact with.neutral particles in Earth.s *** provides a mech.nism for boundary detection with.n th. magnetosph.re,such.as th. position of Earth.s magnetopause,because th. solar wind h.avy ions h.ve a very low density in regions of closed magnetic field *** sensitivity of th. SXI is such.th.t it can potentially track movements of th. magnetopause on timescales of a few minutes and th. orbit of SMILE will enable such.movements to be tracked for segments lasting many *** is led by th. University of Leicester in th. United Kingdom(UK)with.collaborating organisations on h.rdware,software and science support with.n th. UK,Europe,Ch.na and th. United States.

关键词： Soft X-ray Imaging micropore optics large area CCD

Recent Ventures in Interdisciplinary Arctic Research.Th. ARCPATh.Proj.ct

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Advances in Atmosph.ric Sciences 2024年第8期41卷 1559-1568页

作者： Astrid E.j.OGILVIE Leslie A.KING Noel KEENLYSIDE François COUNILLON Brynh.ldur DAVIÐSDÓTTIR Níels EINARSSON Sergey GULEV Ke FAN Torben KOENIGK j.mes R.MCGOODWIN Marianne h.RASMUSSON Sh.ting YANG Institute of Arctic and Alpine Research.INSTAAR) University of ColoradoBoulder CO 80303USA Stefansson Arctic Institute AkureyriÍS-600Iceland Royal Roads University BC V9B 5Y2Canada University of Bergen Bergen N-5007Norway Nansen Environmental and Remote Sensing Centre Bergen N-5007Norway University of Iceland Reykjavík 102Iceland Sh.rsh.v Institute of Oceanology Moscow 117218Russia Moscow State University Moscow 11991Russia Ch.nese Academy of Sciences Beijing 100045China Swedish.Meteorological and h.drological Institute SE-60176 NorrköpingSweden Danish.Meteorological Institute CopenhagenØ2100Denmark Obukh.v Institute of Atmosph.ric Ph.sics RAS119017MoscowRussia

Th.s paper celebrates Professor Yongqi GAO's significant ach.evement in th. field of interdisciplinary studies with.n th. context of h.s final research.proj.ct Arctic Climate Predictions: Path.ays to Resilient Sustainable Societies-ARCPATh.h.tps://***/en/proj.cts/finish.d-proj.cts/arcpath.. Th. disciplines represented in th. proj.ct are related to climatology, anth.opology, marine biology, economics, and th. broad spectrum of social-ecological studies. Team members were drawn from th. Nordic countries, Russia, Ch.na, th. United States, and Canada. Th. proj.ct was transdisciplinary as well as interdisciplinary as it included collaboration with.local knowledge h.lders. ARCPATh.made significant contributions to Arctic research.th.ough.an improved understanding of th. mech.nisms th.t drive climate variability in th. Arctic. In tandem with.th.s research. a combination of h.storical investigations and social, economic, and marine biological fieldwork was carried out for th. proj.ct study areas of Iceland, Greenland, Norway, and th. surrounding seas, with.a focus on th. j.int use of ocean and sea-ice data as well as social-ecological drivers. ARCPATh.was able to provide an improved framework for predicting th. near-term variation of Arctic climate on spatial scales relevant to society, as well as evaluating possible related ch.nges in socioeconomic realms. In summary, th.ough.th. integration of information from several different disciplines and research.approach.s, ARCPATh.served to create new and valuable knowledge on crucial issues, th.s providing new path.ays to action for Arctic communities.

关键词： Recent Ventures in Interdisciplinary Arctic Research.Th. ARCPATh.Proj.ct