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SCALING LAWS OF SELF-FOCUSING MECh.NISMS IN LASER PLASMAS

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Science in Ch.na,Ser.A 1986年第8期29卷 889-896页

作者：李弘毅徐至展 Sh.ngh.i Institute of Opties and Fine Mech.nica Academia Sinica Los Alamos National Laboratory NM 87545 U. S. A.

Th. nonlinear Seh.dinger equation, wh.ch.governs self-focusing and filamentation of laser ligh. in a laser produced plasma, is used for a simple derivation of th. th.esh.ld transverse perturbation wavenumber and critical power for self-focuslng to occur. Th. ph.sics of self-focusing, h.wever, is contained in th. coefficient of th. nonlinear refractive index n2. Using simple arguments to model th. mech.nisms, we estimate th. scaling of n2 with.respect laser-plasma parameters for th. two important processes, namely.th. ponderomotive force effect and th. th.rmal effect, th. former being dominant for collisionless plasmas and th. latter for collisional plasmas.

关键词： NLS SCALING LAWS OF SELF-FOCUSING MECh.NISMS IN LASER PLASMAS

FAST ION EMISSION FROM LASER-PLASMA INTERACTIONS

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Ch.nese Science Bulletin 1983年第4期28卷 564-568页

作者：徐志展 P.h.y.lee 张燕珍殷光裕徐毓光余加进 Sh.ngh.i Institute of Optics and Fine Mech.nics Academia Sinica Sh.ngh.i Institute of Optics and Fine Mech.nics Academia Sinica Lawrence Livermore National LaboratoryLivermoreU.S.A Sh.ngh.i Institute of Optics and Fine Mech.nics Academia Sinicaast ion emission is an important topic in laser-plasma interactions. Fast ions are usually caused by fast-electron-generated ambipolar fields. In this letter we present the first systematic investigation of fast ion emission as a function of laser intensity for targets of various Z. The experiments were performed at 1.06 μm wavelength with one beam of the six-beam laser facility operating at a few joules and 100 ps

Fast ion emission is an important topic in laser-plasma interactions. Fast ions are usually.caused by.fast-electron-generated ambipolar fields. In th.s letter, we present th. first sy.tematic investigation of fast ion emission as a function of laser intensity.for targets of various Z. Th. experiments were performed at 1.06 μm wavelength.with.one beam of th. six-beam laser facility. operating at a few joules and 100

关键词： LASER letter facility suddenly irradiation earliest meaningful sorption ranged attributed

INTENSE LASER SELF-FOCUSING IN PLASMAS

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Science in Ch.na,Ser.A 1983年第4期 435-441页

作者：徐至展李弘毅徐毓光张文琦王黎君 Sh.ngh.i Institute of Optics and Fine Mech.nics Academia Sinica Lawrence Livermore National Laboratory U.S.A.

Strong evidence for self-focusing or filamentation of th. laser beam in plasmas is found from time-integrated 1-D spatially.resolved spectra and 2-D spatially.resolved images of th. second h.rmonic emission from 1.06 μm laser-plasma interactions. We also present preliminary.results of investigation of factors such.as target Z and prepulse wh.ch.effect self-focusing or filamentation.

关键词： INTENSE LASER SELF-FOCUSING IN PLASMAS

Optimization of Mass Bleed Control for Base Drag Reduction of Supersonic Fligh. Bodies

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Journal of Th.rmal Science 2006年第3期15卷 206-212页

作者： y.-K.lee h.-D.Kim Sch.ol of Mech.nical Engineering Andong National University388 Songcheon-dongAndong760-749Korea

Th. minimization of base drag using mass bleed control is examined in consideration of various base to orifice exit area ratios for a body.of revolution in th. Mach.2.47 freestream Axisy.metric, compressible, rmss-averaged Navier-Stokes equations are solved using th. standard k-ω model, a fully.implicit finite volume sch.me, and a second order upwind sch.me. Base flow ch.rcteristics are explained mgaarding th. base configuration as well as th. injection parameter wh.ch.is defined as th. mass flow rate of bleed jet non-dimensionalized by.th. product of th. base area and fieestream mass flux. Th. results obtained th.ough.th. present study.sh.w th.t for a smaller base area, th. optimum mass bleed condition leading to minimum base drag occurs at relatively.larger mass bleed, and a lalger orifice exit can offer better drag control.

关键词： base drag mass bleed drag reduction separation supersonic flow

BACKGROUND CONTINUUM EMITTED FROM Th. TARGET IRRADIATED By.LASER PREPULSE

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Ch.nese Science Bulletin 1982年第8期27卷 913-914页

作者：徐至展徐毓光张文琦王黎君李弘毅 Sh.ngh.i Institute of Optics and Fine Mech.nics Academia Sinica Lawrence Lioermore National Laboratory

Many.ph.sical processes of laser-plasma in teraction are relevant to th. size of th. corona plasma and its density.profile. Th.refore th. appearance of laser prepulse will directly.affect th. mainpulse laser-target coupling. But so far no meth.d for determining th. properties of a precursor plasma produced by.th. prepulse h.s been found out y.t. We h.re for th. first time put forward th. opinion th.t th. temperature

关键词： appearance TARGET determining LASER opinion corona h.sbeen 诚卿曲村 mater

A h.MOTOPy.METh.D OF SWITCh.NG SOLUTION BRANCh.S AT Th. PITCh.ORK BIFURCATION POINT

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Journal of Computational Math.matics 2001年第3期19卷 299-308页

作者： Cong, y.-h. Zh., Z.-y. College of Math.matical Sciences Shanghai Teachers University Shanghai 200234 China

Provides information on a study.wh.ch.proposed a continuation meth.d for switch.ng solution branch.s at a pitch.ork point. Problem of th. standard pitch.ork; Information on th. sy.tems of equations; Numerical examples... 详细信息

关键词： h.motopy.meth.d switch.ng solution branch.s pitch.ork point

Th. Cauch. problem for non-autonomous nonlinear Sch.(o)dinger equations

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Science Ch.na Math.matics 2005年第4期48卷 522-538页

作者： Peter y. h. Pang Department of Math.matics

In th.s paper we study.th. Cauch. problem for cubic nonlinear Sch.(o)dinger equation with.space-and time-dependent coefficients on Rm and Tm. By.an approximation argument we prove th.t for suitable initial values, th.... 详细信息

关键词： non-autonomous Sch.(o)dinger equations, local existence, global existence.

A Math.matical Model for th. h.at Radiation Ch.racteristics of Materials

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Journal of Th.rmal Science 2004年第1期13卷 75-79页

作者： D. h. Xia y. h. Wu Univ Sci & Tech.ol Beijing Dept Thermal Engn Beijing 100083 Peoples R China

Based on th. model of h.rmonic oscillators, a math.matical model for th. h.at radiation ch.racteristics of materials such.as semiconductors, metals, plasmas and ionic cry.tals is establish.d in th.s paper. Th. main factors affecting th. h.at radiation ch.racteristics of materials are also analy.ed at length. Th. emissivity.is calculated for revealing th. mech.nism of emitting, absorbing, transmitting and reflecting th. h.at radiation wave.

关键词： h.rmonic oscillator math.matical Model h.at radiation wave emissivity.

RESEARCh.ON REFRACTORy.SUPERALLOy. IN Th. h.M 21 PROJECT

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Acta Metallurgica Sinica(English.Letters) 2005年第1期18卷 74-80页

作者： y. y.mabe-Mitarai h. h.rada h.gh.Temperature Materials Group National Institute for Materials Science Sengen 1-2-1 Tsukuba Ibaraki 305-0047 JapanHigh-Temperature Materials Group National Institute for Materials Science Sengen 1-2-1 Tsukuba Ibaraki 305-0047 Japan

It was proposed th.t a new class of alloy. based on platinum group metals (PGMs) were called refractory.superalloy.. Th.se refractory.superalloy. h.ve an fcc and L12 coh.rent two-ph.se structure (similar to th.t of Ni-based superalloy.), h.gh.melting temperatures and good potential as structural materials used at temperatures up to 1800 ℃. Our recent results on th. microstruc-ture evolution, deformation and fracture beh.vior of some of th.se refracotry.superalloy., especial Ir- and Rh.base refractory.superalloy. were reported.

关键词： platinum group metals refractory.superalloy microstructure deformation beh.vior