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Conceptual design of an ex.eriment to study dust destruction by astrophysical shock waves

High Power Laser Science and engineering 2018年第3期6卷 9-14页

作者： M. J.-e. Manuel T. Temim e. Dwek A. M. Angulo e x. belancourt.r. e drake C. C. Kuranz M. J. MacDonald B. A. remington General Atomics 3550 General Atomics Court San Diego CA 92121 USA Space Telescope Science Institute 3700 San Martin Drive Baltimore MD 21218 USA Observational Cosmology Lab Code 665 NASA Goddard Space Flight Center Greenbelt MD 20771 USA Climate and Space Science and engineering University of Michigan Ann Arbor M148109 USA Department of Physics University of California Berkeley CA 94720 USA Lawrence Livermore National Laboratory Livermore CA 94450 USA

A novel laboratory ex.erimental design is described that will investigate the processing of dust grains in astrophysical shocks. Dust is a ubiquitous ingredient in the interstellar medium(ISM) of galax.es; however, its evolutionary cycle is still poorly understood. especially shrouded in mystery is the efficiency of grain destruction by astrophysical shocks generated by ex.anding supernova remnants. While the evolution of these remnants is fairly well understood, the grain destruction efficiency in these shocks is largely unknown. The ex.eriments described herein will fill this knowledge gap by studying the dust destruction efficiencies for shock velocities in the range ～10–30 km/s(μm/ns), at which most of the grain destruction and processing in the ISM takes place. The ex.eriments focus on the study of grain–grain collisions by accelerating small(～1 μm) dust particles into a large(～5–10 μm diameter) population; this simulates the astrophysical system well in that the more numerous, small grains impact and collide with the large population. Facilities that combine the versatility of high-power optical lasers with the diagnostic capabilities of x.ray free-electron lasers, e.g., the Matter in ex.reme Conditions instrument at the SLAC National Accelerator Laboratory, provide an ideal laboratory environment to create and diagnose dust destruction by astrophysically relevant shocks at the micron scale.

关键词： laboratory astrophysics shock waves dust destruction

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ex.erimental platform for the investigation of magnetized-reverse-shock dynamics in the contex. of POLAr

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High Power Laser Science and engineering 2018年第3期6卷 36-49页

作者： B. Albertazzi e. Falize A. Pelka e Brack e Kroll r. Yurchak e. Brambrink e Mabey N. Ozaki S. Pikuz L. Van Box.Som J. M. Bonnet-Bidaud J. e. Cross e. Filippov G. Gregori r. Kodama M. Mouchet T. Morita Y. Sakawa r. e drake C. C. Kuranz M. J.-e. Manuel C. Li e Tzeferacos D. Lamb U. Schramm M. Koenig LULI- CNrS Ecole Polytechnique CEA: Universite Paris-Saclay UPMC Univ Paris 06: Sorbonne Universites- F-91128 Palaiseau cedex France CeA-DAM-DIF F-91297 Arpajon France CeA Saclay DSM/Irfu/Service d'Astrophysique F-91191 Gif-sur- Yvette France Helmholtz-Zentrum Dresden - rossendorf HZDr Bautzner Landstrαβe 400 01328 Dresden Germany Department of Atmospheric Oceanic and Space Sciences University of Michigan Ann Arbor M148109 USA Graduate School of engineering Osaka University Suita Osaka 565-0871 Japan JIHT-rAS 13-2 lzhorskaya st. Moscow 125412 Russia National research Nuclear University MePhl Moscow 115409 Russia Department of Physics University of Oxford Parks Road Oxford OX1 3PU UK Institute of Laser engineering Osaka University Suita Osaka 565-0871 Japan LUTH Observatoire de Paris UMR CNRS 8102 Universite Paris Diderot 92190 Meudon France Department of energy engineering Science Faculty of Engineering Sciences Kyushu University Japan General Atomics San Diego CA 92121 USA Plasma Science and Fusion Center Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA Flash Center for Computational Science University of Chicago IL 60637 USA

The influence of a strong ex.ernal magnetic field on the collimation of a high Mach number plasma flow and its collision with a solid obstacle is investigated ex.erimentally and numerically. The laser irradiation （I - 2 × 10^14 W. cm-2） of a multilayer target generates a shock wave that produces a rear side plasma ex.anding flow. Immersed in a homogeneous 10 T ex.ernal magnetic field, this plasma flow propagates in vacuum and impacts an obstacle located a few mm from the main target. A reverse shock is then formed with typical velocities of the order of 15-20 4- 5 km/s. The ex.erimental results are compared with 2D radiative magnetohydrodynamic simulations using the FLASH code. This platform allows investigating the dynamics of reverse shock, mimicking the processes occurring in a cataclysmic variable of polar type.

关键词： accretion processes high-power laser hydrodynamics laboratory astrophysics polar radiative shocks

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脑电图光刺激的光驱反应频谱研究(英文)

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中国临床康复 2003年第19期7卷 2684-2685页

作者：童晓欣 Miles e.drake Jr 北京大学深圳医院神经内科广东省深圳市518036 epilepsy Center Department of NeurologyThe Ohio State University Medical CenterColumbusOhio USA

目的借助数字化脑电图(DigitaleeG)易于定量分析脑电功率的优势,提高eeG间歇性闪光刺激诱发试验的临床诊断价值。方法本组共60例,男38例,女22例,年龄24～67岁。对60例常规eeG(-)的患者包括:癫痫20例、头痛20例和神经精神障碍20例进行了d... 详细信息

目的借助数字化脑电图(DigitaleeG)易于定量分析脑电功率的优势,提高eeG间歇性闪光刺激诱发试验的临床诊断价值。方法本组共60例,男38例,女22例,年龄24～67岁。对60例常规eeG(-)的患者包括:癫痫20例、头痛20例和神经精神障碍20例进行了digitaleeG检查,在枕部01,0z和02处分别测量10s安静时和间歇性闪光刺激(IPS)5,10以及15Hz的α波绝对和相对功率。结果所有患者的α功率在IPS5,15Hz时减退,IPS10Hz时增高,其中癫痫患者表现最显著,而神经精神障碍患者最不明显。前者安静、IPS5,10,15Hz时枕中Oz所测绝对功率(μV2)、相对功率(%)分别为330±40,39.7±2.8,176±24,30.0±1.9,207±29,32.5±2.0和164±25,26.7±2.0;后者则分别为189±28,22.2±2.7,140±21,21.7±1.3,176±22,22.8±1.6和127±16,17.7±1.6。两者安静时的Oz处相对功率比较,P,t分别为9.85×10-24,22.75;2.42×10-29,32.5,差异有显著性意义(PeeG能够定量测定IPS的脑电功率谱变化,提高IPS的临床诊断价值。

关键词：脑电图光刺激光驱反应频谱诊断癫痫头痛神经精神障碍

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Differential responses of three coastal grassland species to seawater flooding

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Journal of Plant ecology 2017年第2期10卷 322-330页

作者： Mick e.Hanley Tom L.Gove Gregory r.Cawthray Timothy D.Colmer School of Biological Sciences Plymouth UniversityDrake CircusPlymouth PL48AAEngland School of Plant Biology The University of Western Australia35 Stirling HighwayCrawley6009 WAAustralia

Aims Supratidal plant communities fulfil a vital role in coastal protec-tion,but despite an increased likelihood of seawater flooding resulting from anthropogenic climate change,we understand little about how tidal inundation affects these habitats or interactions between their component *** aim was to determine how three common coastal grassland species responded to simulated seawater flooding and how subsequent changes to their ecophysi-ology,growth and survival might affect plant-plant interactions in mix.d *** Seeds of three widely distributed european coastal grassland species(Leontodon autumnalis Asteraceae,Plantago lanceo-lata Plantaginaceae and Trifolium pratense Fabaceae)were collected from a coastal grassland site in South West *** ex.eriment 1,we quantified changes in leaf ion(K^(+),Na^(+),Cl^(−))concentrations as a response to short-duration(0,2,8 or 24 h)immersion in seawater of the root-zone before monitoring longer-term effects on plant survival and *** a second ex.eriment,we ex.mined community-level responses by subjecting mix.d assemblages of all three species to seawater immersion for(0,12,24 or 96 h).Important Findings When grown individually,one species(Trifolium)had markedly reduced survival with increasing soil immersion time,but a con-sistent decline in plant growth for all species with flooding dura-tion was most likely linked to osmotic and ionic stresses caused by salt ion *** mix.d assemblages,all species suffered increased mortality and reduced growth following seawater flood-ing,although the relative contribution of one species(Leontodon)to total biomass increased in flooded *** thus demon-strate a number of species-specific responses to simulated seawater flooding and show that when grown together,interactions between plants are altered as a *** argue that variation in the responses of component plant species will dictate how coastal plant communities respond to,and r

关键词： climate change salinity sea-level rise soil waterlogging storm surge microcosm

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A Numerical Tank through Linear and Quadratic Finite element Methods

A Numerical Tank through Linear and Quadratic Finite Element...

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第七届全国水动力学学术会议暨第十九届全国水动力学研讨会

作者： drake K．r． Department of Mechanical engineering University College LondonTorrington PlaceLondonWC1E 7JE U．K．

＜正＞The hydrodynamic problem of nonlinear wave and body interaction is solved through a linear and quadratic finite element method based numerical tank. The velocity potential theory is used as the effect of the viscosity is usually small on water waves and on bodies that are large relative to the wavelength. The continuity equation and the boundary conditions are satisfied through a Galerkin method over the fluid domain. The integration over each element is performed analytically for the linear shape function and numerically for the quadratic shape function. The global matrix.equations in both cases are solved through an iteration with a pre-conditioner. Various simulations and comparisons are made for single and multiple cylinders in regular and bichromatic waves generated by a piston wave maker in the tank.

关键词： Nonlinear wave-body interactions finite element analysis Gaussian Quadrature tri-tree based hybrid mesh the wave model numerical wave tank

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传热与传质分析

传热与传质分析

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作者： e.r.G.·埃克特(e.r.G. eckert) r.M.·德雷克(r.M. drake)

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Macrophage phenotypes correspond with remodeling outcomes of various acellular dermal matrices

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Open Journal of regenerative Medicine 2012年第3期1卷 51-59页

作者： Hitesh Agrawal Sunil S. Tholpady Anthony e. Capito David B. drake Adam J. Katz Department of Plastic and reconstructive Surgery University of Virginia Health System Charlottesville USA

Macrophages have recently been characterized as having an M1 or M2 phenotype based on receptor ex.ression, mechanism of activation and function. The effects of macrophage phenotype upon tissue remodeling following implantation of an acellular dermal matrix.(ADM) is largely unknown. The purpose of this study was to compare the macrophage phenotype and tissue remodeling elicited by four different ADMs (DermaMatrix. AlloDerm, Integra and Der mACeLL). ADM samples were wrapped around the inferior epigastric vessels of a rat and were harvested on 7, 14, 21 and 42 days post implantation. Immunohistologic methods were used to identify macrophage surface markers CD68 (pan macrophage), CCr7 (M1 profile), and CD206 (M2 profile). All human derived ADMs showed a bell shaped curve for distribution of CD68+ macrophages with peaks for DermaMatrix.occurring at day 14 and peak influx.for AlloDerm occurring on day 21. In contrast, bovine derived Integra showed an increasing trend of macrophages with time. DermACeLL had the highest influx.of macro- phages while Integra had the lowest. A quantitative analysis of phenotype of macrophages in AlloDerm showed that the cells were predominantly M1 at 7, 14, 21 and 42 days post implantation. In contrast, Integra showed a mix.d M1/M2 population of macrophages at all time points. The histopathologic evaluation showed that a predominantly M1 macrophage response was associated with a more inflamematory type tissue remodeling outcome in AlloDerm while a mix.d M1/M2 macrophage response was associated with a more constructive tissue remodeling response seen in the other substrates.

关键词： Acellular Dermal Matrix Derma Matrix AlloDerm Integra Derm Acell

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AUTOMATICALLY OPerATING rADArS FOr MONITOrING INSeCT PeST MIGrATIONS

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entomologia Sinica 2002年第4期9卷 27-29页

作者： V.A.drake 澳大利亚新南威尔士大学物理学院

Over the last three decades, special purpose “entomological” radars have contributed much to the development of our understanding of insect migration, especially of the nocturnal migrations at altitudes of up to ～1 km that are regularly undertaken by many important pest species. One of the limitations of early radar studies, the difficulty of maintaining observations over long periods, has recently been overcome by the development of automated units that operate autonomously and transmit summaries of their observations to a base laboratory over the public telephone network. These relatively low cost Insect Monitoring radars (IMrs) employ a novel “ZLC” configuration that allows high quality data on the migrants' flight parameters and identity to be acquired. Two IMrs are currently operating in the semi arid inland of eastern Australia, in a region where populations of migrant moths (Lepidoptera) and Australian plague locusts Chortoicetes terminifera (Orthoptera) commonly originate, and some ex.mples of outputs from one of these units are presented. IMrs are able to provide the data needed to characterize a migration system, i.e. to estimate the probabilities of migration events occurring in particular directions at particular seasons and in response to particular environmental conditions and cues. They also appear capable of fulfilling a “sentinel” role for pest management organisations, alerting forecasters to major migration events and thus to the likely new locations of potential target populations. Finally, they may be suitable for a more general ecological monitoring role, perhaps especially for quantifying year to year variations in biological productivity.

关键词： insect migration pest forecasting radar monitoring Australia

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Physicochemical Characterization of Sediment in Northwest Arkansas Streams

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Journal of environmental Protection 2011年第5期2卷 629-638页

作者： Chris W. rogers Andrew N. Sharpley Brian e. Haggard J. Thad Scott Bodie M. drake 不详

eutrophication of surface waters is a critical concern in regions around the world facing nutrient surpluses as a result of confined animal feeding operations (CAFOs) and subsequent land application of manures. While large amounts of research ex.st on the transport of nutrient enriched runoff from fields to surface waters less information is available on in-stream processes controlling the transport of P in-stream. Thus, information is needed on the role of stream sediments in regulating transient phosphorus (P) to better understand the relationship between nutrient inputs and water quality. Fine-sized sediments ( 2-mm) consume and store P. From fine-sized sediment a modified P saturation ratio (PSrmod), related to the sediment’s ability to bind P and determined from Mehlich-3 ex.racted nutrients, has been correlated to in-stream dissolved reactive P (DrP) concentrations. The objectives of this study were to determine the relative size distribution of total- and fine-sized sediment (sand, silt clay) fractions among streams, determine the optimum sample number needed to characterize Mehlich-3 P (M3P) and PSrmod, and finally determine the applicability of PSrmod, as an indicator of stream water column DrP concentrations. Stream sediments were sampled from the 0- to 3-cm depth from stream reaches ranging from (25 – 75 m) in August, 2008 for characterization along with water samples collected from the thalweg for DrP concentration determination. Additional water column samples were collected along with fine-sized sedi- ment chemical properties in February, May, and June 2009. The distribution of sediment size classes was statistically similar, with 2- to 20- and 20- to 75-mm sized sediment dominating. Fine-sized sediment (mod, were determined to typically be sufficiently characterized by a sample scheme utilizing three samples points. Modified P saturation ratio of mod, has the potential to be used as an indicator of the ability of stream sediments to enrich stream wate

关键词： Stream Phosphorus Nutrient enrichment Sediment

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癫痫患者P50听觉诱发电位的研究

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华中医学杂志 2000年第4期24卷 175-176页

作者：童晓欣 Miles e. drake Jr 深圳市中心医院神经科美国俄亥俄州州立大学医院神经科

目的　探讨 P5 0在癫痫患者检测中的临床价值。方法　对 2 5例癫痫患者 (其中 7例额叶癫痫 ;18例颞叶癫痫 )进行 P5 0测试 ,分析 P5 0波的潜伏期和波幅 (峰峰值 )以及在不同刺激频率时 P5 0波幅 (峰峰值 )的比率。选择年龄、性别与患者... 详细信息

目的　探讨 P5 0在癫痫患者检测中的临床价值。方法　对 2 5例癫痫患者 (其中 7例额叶癫痫 ;18例颞叶癫痫 )进行 P5 0测试 ,分析 P5 0波的潜伏期和波幅 (峰峰值 )以及在不同刺激频率时 P5 0波幅 (峰峰值 )的比率。选择年龄、性别与患者组相匹配的 2 5名健康受试者对照组。结果　癫痫患者组 P5 0波的潜伏期较长 ,波幅则显著减低 ,其中以 18例颞叶癫痫患者表现显著 ,7例额叶癫痫患者不明显。刺激频率稍加快时 ,患者组 P5 0的波幅比率明显减小。结论　 P5 0波的潜伏期和波幅反应异常与颞叶功能障碍密切相关 ,可帮助临床鉴别额、颞叶癫痫灶 ;其波幅衰减现象似与癫痫发作间期行为和认知改变相关 ,但也可能受药物的影响。

关键词：癫痫 P50听觉诱发电位额叶颞叶 erPS

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