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Exponentially Convergent Multiscale Finite Element Method
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作者 Yifan Chen Thomas Y.Hou Yixuan Wang 《Communications on Applied Mathematics and Computation》 EI 2024年第2期862-878,共17页
We provide a concise review of the exponentially convergent multiscale finite element method(ExpMsFEM)for efficient model reduction of PDEs in heterogeneous media without scale separation and in high-frequency wave pr... We provide a concise review of the exponentially convergent multiscale finite element method(ExpMsFEM)for efficient model reduction of PDEs in heterogeneous media without scale separation and in high-frequency wave propagation.The ExpMsFEM is built on the non-overlapped domain decomposition in the classical MsFEM while enriching the approximation space systematically to achieve a nearly exponential convergence rate regarding the number of basis functions.Unlike most generalizations of the MsFEM in the literature,the ExpMsFEM does not rely on any partition of unity functions.In general,it is necessary to use function representations dependent on the right-hand side to break the algebraic Kolmogorov n-width barrier to achieve exponential convergence.Indeed,there are online and offline parts in the function representation provided by the ExpMsFEM.The online part depends on the right-hand side locally and can be computed in parallel efficiently.The offline part contains basis functions that are used in the Galerkin method to assemble the stiffness matrix;they are all independent of the right-hand side,so the stiffness matrix can be used repeatedly in multi-query scenarios. 展开更多
关键词 Multiscale method Exponential convergence Helmholtz's equation Domain decomposition Nonlinear model reduction
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Confirmation of a Sub-Saturn-size Transiting Exoplanet Orbiting a G Dwarf:TOI-1194 b and a Very Low Mass Companion Star: TOI-1251 B from TESS
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作者 Jia-Qi Wang Xiao-Jun Jiang +18 位作者 Jie Zheng Hanna Kellermann Arno Riffeser Liang Wang Karen A.Collins Allyson Bieryla Lars A.Buchhave Steve B.Howell Elise Furlan Eric Girardin Joao Gregorio Eric Jensen Felipe Murgas Mesut Yilmaz Sam Quinn Xing Gao Ruo-Yu Zhou Frank Grupp Hui-Juan Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期129-143,共15页
We report the confirmation of a sub-Saturn-size exoplanet,TOI-1194 b,with a mass of about 0.456+0.055-0.051M_(J),and a very low mass companion star with a mass of about 96.5±1.5 MJ,TOI-1251 B.Exoplanet candidates... We report the confirmation of a sub-Saturn-size exoplanet,TOI-1194 b,with a mass of about 0.456+0.055-0.051M_(J),and a very low mass companion star with a mass of about 96.5±1.5 MJ,TOI-1251 B.Exoplanet candidates provided by the Transiting Exoplanet Survey Satellite(TESS)are suitable for further follow-up observations by ground-based telescopes with small and medium apertures.The analysis is performed based on data from several telescopes worldwide,including telescopes in the Sino-German multiband photometric campaign,which aimed at confirming TESS Objects of Interest(TOIs)using ground-based small-aperture and medium-aperture telescopes,especially for long-period targets.TOI-1194 b is confirmed based on the consistent periodic transit depths from the multiband photometric data.We measure an orbital period of 2.310644±0.000001 days,the radius is 0.767+0.045-0.041RJ and the amplitude of the RV curve is 69.4_(-7.3)^(+7.9)m s^(-1).TOI-1251 B is confirmed based on the multiband photometric and high-resolution spectroscopic data,whose orbital period is 5.963054+0.000002-0.000001days,radius is 0.947+0.035-0.033 R_(J) and amplitude of the RV curve is 9849_(-40)^(+42)ms^(-1). 展开更多
关键词 planets and satellites fundamental parameters-planets and satellites gaseous planets-stars fundamental parameters-stars low-mass-methods data analysis-techniques photometric-techniques spectroscopic
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远震体波有限破裂过程反演敏感性测试及其在汶川地震上的应用
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作者 韦生吉 倪四道 +2 位作者 Ozgun Konca Don Helmberger 陈颙 《地震》 CSCD 北大核心 2010年第3期13-29,共17页
本文利用远震P和SH波反演得到2008年5月12日汶川大地震(MW=7.9)的一系列有限破裂模型。使用一种基于小波变换的模拟退火非线性反演方法,我们将主断层划分成若干个子断层,在反演时同时确定每个子断层上的滑移量、滑动角、上升时间(riseti... 本文利用远震P和SH波反演得到2008年5月12日汶川大地震(MW=7.9)的一系列有限破裂模型。使用一种基于小波变换的模拟退火非线性反演方法,我们将主断层划分成若干个子断层,在反演时同时确定每个子断层上的滑移量、滑动角、上升时间(risetime)以及平均破裂速度。我们首先根据一个假定的破裂模型生成理论地震图,将该理论地震数据作为输入进行反演,对该有限破裂反演方法进行了一系列测试,以验证反演对断层倾角、平均破裂速度、最大破裂深度等参数的敏感性。然后我们采用4个不同倾角的断层面来对汶川地震远震体波记录进行反演。结果表明,若对只在一个断层面上模拟该地震,30°倾角是个较为合适的值。反演的结果还表明,此次地震有两个主要的能量释放区域,并且主断层面存在倾角变化的可能性。在将来的研究中,可以结合GPS,InSAR测地学以及强震等数据,来对强震的破裂过程做更细致的研究。 展开更多
关键词 汶川地震 有限破裂反演 波形反演
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钨酸铅晶体的发光光谱及辐照诱导色心的研究 被引量:2
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作者 曲向东 张立原 +2 位作者 朱人元 廖晶莹 殷之文 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2001年第4期601-608,共8页
概要介绍了纯钨酸铅晶体和不同掺杂钨酸铅晶体发光光谱及辐照性能的研究结果.测量了晶体的光致发光和辐射激发发光光谱,比较了辐照诱导色心的密度和辐射发光光谱之间的关系.详细分析了钨酸铅晶体辐照诱导色心密度的分布,根据辐照诱... 概要介绍了纯钨酸铅晶体和不同掺杂钨酸铅晶体发光光谱及辐照性能的研究结果.测量了晶体的光致发光和辐射激发发光光谱,比较了辐照诱导色心的密度和辐射发光光谱之间的关系.详细分析了钨酸铅晶体辐照诱导色心密度的分布,根据辐照诱导色心模型,计算了色心的能量及分布. 展开更多
关键词 钨酸铅 色心 辐照诱导 发光光谱 闪烁晶体 辐照损伤
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洛杉矶盆地密集地震台网 被引量:1
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作者 Robert W.Clayton Thomas Heaton +5 位作者 Monica Kohler Mani Chandy Richard Guy Julian Bunn 陈会忠(译) 张晁军(校) 《国际地震动态》 2019年第12期14-21,35,共9页
引言位于加州洛杉矶的密集强震区域(社区)地震台网(Community Seismic Network,CSN),目前由500个传感器组成(图1)。地震台网的传感器是低成本微机电(low-cost microelectromechanical,MEM)加速度计传感器,最大可以记录±2g的加速度... 引言位于加州洛杉矶的密集强震区域(社区)地震台网(Community Seismic Network,CSN),目前由500个传感器组成(图1)。地震台网的传感器是低成本微机电(low-cost microelectromechanical,MEM)加速度计传感器,最大可以记录±2g的加速度。台网最初的主要产品是在大地震发生后几秒钟测量地面震动(图2)。 展开更多
关键词 地震台网 地面震动 传感器组成 微机电 加速度 密集
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An Essential Oil Blend Decreases Methane Emissions and Increases Milk Yield in Dairy Cows 被引量:5
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作者 Kenton J. Hart Hefin G. Jones +3 位作者 Kate E. Waddams Hilary J. Worgan Beatrice Zweifel C. Jamie Newbold 《Open Journal of Animal Sciences》 2019年第3期259-267,共9页
This study was conducted to investigate the effect of a commercial essential oil (EO) additive on milk production and methane (CH4) emissions from dairy cows. Early lactation Holstein-Friesian dairy cows were fed gras... This study was conducted to investigate the effect of a commercial essential oil (EO) additive on milk production and methane (CH4) emissions from dairy cows. Early lactation Holstein-Friesian dairy cows were fed grass, whole crop wheat and corn silage total mixed ration. Cows were allocated to one of two experimental treatments: Control (no additive, CON) or 1 g/head/day of EO. Cows were housed in a free stall barn, split into two pens for the duration of the experiment. Two gas data loggers units used to measure CH4 emissions were provided per pen for the duration of the 22 week-long study. Milk yield was determined daily, and milk components were analyzed every two weeks. CH4 was recorded continuously, and daily values were tabulated. Body weight and body condition score were determined at the start and bi-weekly. Results were analyzed as a randomized complete block trial. In total, 149 cows participated in the study (76 CON, 73 EO). Milk yields were greater (P < 0.05) for the test treatment (28.3 CON, 31.2 EO) with no change in milk component concentrations. Milk component concentrations were unaffected (P > 0.05) by treatment. Yields of fat, protein, lactose, and solids were higher for EO fed cows (P 4 output was reduced with the EO compared to the CON treatment (411 g/day vs 438 g/day;13.8 g/L of milk vs 17.2 g/L of milk, P < 0.05) over the duration of the trial. There were no effects of treatment on reproductive performance or the occurrence of mastitis. Feeding EO to dairy cows reduced CH4 emissions whilst also increasing performance. 展开更多
关键词 DAIRY COWS Essential OILS Methane Milk Yield
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Terrain radiometric calibration of airborne UAVSAR for forested area 被引量:2
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作者 CHENG Xiaoguang Naiara PINTO GONG Jianya 《Geo-Spatial Information Science》 SCIE EI 2012年第4期229-240,共12页
In the field of biomass estimation,terrain radiometric calibration of airborne polarimetric SAR data for forested areas is an urgent problem.Illuminated area correction ofσ-naught could not completely remove terrain ... In the field of biomass estimation,terrain radiometric calibration of airborne polarimetric SAR data for forested areas is an urgent problem.Illuminated area correction ofσ-naught could not completely remove terrain features.Inspired by Small and Shimada,this paper tested gamma-naught on one mountainous forested area using airborne Uninhabited Aerial Vehicle Synthetic Aperture Radar data and found it could remove most terrain features.However,a systematic increasing trend from far range to near range is found in airborne SAR cases.This paper made an attempt to use the relationship between distance to SAR sensor andγ-naught to calibrateγ-naught.Two quantitative evaluation methods are proposed.Experimental results demonstrate that variation ofγ-naught can be constrained to a limited extent from near range to far range.Since this method is based on ground range images,it avoids complicated orthorectification. 展开更多
关键词 terrain radiometric calibration UAVSAR sigma-naught γ-naught
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Characterizing microlensing planetary system OGLE-2014-BLG-0676Lb with adaptive optics imaging
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作者 Xiao-Jia Xie Subo Dong +10 位作者 Yossi Shvartzvald Andrew Gould Andrzej Udalski Jean-Philippe Beaulieu Charles Beichman Laird Miller Close Calen BHenderson Jared RMales Jean-Baptiste Marquette Katie MMorzinski Christopher RGelino 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第12期357-364,共8页
We constrain the host-star flux of the microlensing planet OGLE-2014-BLG-0676 Lb using adaptive optics(AO)images taken by the Magellan and Keck telescopes.We measure the flux of the light blended with the microlensed ... We constrain the host-star flux of the microlensing planet OGLE-2014-BLG-0676 Lb using adaptive optics(AO)images taken by the Magellan and Keck telescopes.We measure the flux of the light blended with the microlensed source to be K=16.79±0.04 mag and J=17.76±0.03 mag.Assuming that the blend is the lens star,we find that the host is a 0.73_(-0.29)^(+0.14)M_(⊙)star at a distance of2.67_(-1.41)^(+0.77)kpc,where the relatively large uncertainty in angular Einstein radius measurement is the major source of uncertainty.With mass of M_(p)=3.68_(-1.44)^(+0.69)M_J,the planet is likely a"super Jupiter"at a projected separation of r_(⊥)=4.53_(-2.50)^(+1.49)AU,and a degenerate model yields a similar M_p=3.73_(-1.47)^(+0.73)M_(J)at a closer separation of r_(⊥)=2.56_(-1.41)^(+0.84)AU.Our estimates are consistent with the previous Bayesian analysis based on a Galactic model.OGLE-2014-BLG-0676 Lb belongs to a sample of planets discovered in a"secondgeneration"planetary microlensing survey and we attempt to systematically constrain host properties of this sample with high-resolution imaging to study the distribution of planets. 展开更多
关键词 gravitational lensing:micro instrumentation:adaptive optics instrumentation:high angular resolution (stars:)planetary systems
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Recent Advances in Photoacoustic Tomography
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作者 Lei Li Lihong V.Wang 《Biomedical Engineering Frontiers》 2021年第1期27-43,共17页
Photoacoustic tomography(PAT)that integrates the molecular contrast of optical imaging with the high spatial resolution of ultrasound imaging in deep tissue has widespread applications in basic biological science,prec... Photoacoustic tomography(PAT)that integrates the molecular contrast of optical imaging with the high spatial resolution of ultrasound imaging in deep tissue has widespread applications in basic biological science,preclinical research,and clinical trials.Recently,tremendous progress has been made in PAT regarding technical innovations,preclinical applications,and clinical translations.Here,we selectively review the recent progresses and advances in PAT,including the development of advanced PAT systems for small-animal and human imaging,newly engineered optical probes for molecular imaging,broad-spectrum PAT for label-free imaging of biological tissues,high-throughput snapshot photoacoustic topography,and integration of machine learning for image reconstruction and processing.We envision that PAT will have further technical developments and more impactful applications in biomedicine. 展开更多
关键词 CLINICAL TOPOGRAPHY INTEGRATE
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CMS Requirements for the Grid
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作者 K.Holtman J.Amundson 《International Conference on Computing in High Energy and Nuclear Physics》 2001年第1期754-757,共4页
CMS physicists need to seamlessly access their experimental data and results,independent of location and storage medium,in order to focus on the exploration for the new physics signals arther than the complexities of ... CMS physicists need to seamlessly access their experimental data and results,independent of location and storage medium,in order to focus on the exploration for the new physics signals arther than the complexities of worldwide data management .In order to achieve this goal,CMS has adopted a tiered worldwide computing model which will incorporate emerging Grid technology.CMS has started to use Grid tools for data processing,replication and migration,Important Grid components are expected to be delivered by the Data Grid projects.like projects,CMS has created a set of long-term requirements to the Grid projects.These requirements are presented and discussed. 展开更多
关键词 粒子物理学 实验数据 CMS 网格规格
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The Terabyte Analysis Machine Project The Distance Machine:Performance Report
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作者 JamesAnnis KoenHoltman 《International Conference on Computing in High Energy and Nuclear Physics》 2001年第1期93-94,共2页
The Terabyte Analysis Machine Project is Developing hardware and software to analyze Terabyte scale datasets.The Distance Machine framework provides facilities to flexibly interface application specific indexing and p... The Terabyte Analysis Machine Project is Developing hardware and software to analyze Terabyte scale datasets.The Distance Machine framework provides facilities to flexibly interface application specific indexing and partitioning algorthms to large scientific databases. 展开更多
关键词 软件开发 Terabyte 图象处理
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Simulating the Farm Production System Using the MONARC Simulation Tool
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作者 Y.Wu I.C.Legrand 《International Conference on Computing in High Energy and Nuclear Physics》 2001年第1期514-517,共4页
The simulation program developed by the "Models of Networked Analysis at Regional Centers"(MONARC) project is a powerful and flexible tool for simulating the behavior of large scale distributed computing sys... The simulation program developed by the "Models of Networked Analysis at Regional Centers"(MONARC) project is a powerful and flexible tool for simulating the behavior of large scale distributed computing systems,In this study,we further validate this simulation tool in a large-scale distributed farm computing system.We also report the usage of this simulation tool to identify the bottlenecks and limitations of our farm system. 展开更多
关键词 软件开发 FARM MONARC实验
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Atlas of dynamic spectra of fast radio burst FRB 20201124A
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作者 王铂钧 胥恒 +64 位作者 姜金辰 徐江伟 牛佳瑞 陈平 李柯伽 张冰 朱炜玮 东苏勃 张春风 傅海 周德江 张永坤 王培 冯毅 李晔 李冬子 鲁文宾 杨元培 RNCaballero 蔡策 陈卯蒸 戴子高 艾力·伊沙木丁 甘恒谦 韩金林 郝龙飞 黄玉祥 姜鹏 李承奎 李菂 李辉 李新乔 李志玄 刘志勇 罗睿 门云鹏 牛晨辉 彭文溪 钱磊 宋黎明 孙京海 王发印 汪敏 王娜 王维扬 吴雪峰 肖硕 熊少林 徐永华 徐仁新 杨俊 杨轩 姚蕊 易祁彬 岳友岭 于东俊 余文飞 袁建平 张彬彬 张松波 张双南 赵一 郑伟康 朱岩 邹金航 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期1-4,共4页
Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, ... Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076. 展开更多
关键词 fast radio burst FAST
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Timing of syn-orogenic extension in the Western Alps revealed by calcite U-Pb and hematite(U-Th)/He dating
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作者 Antonin Bilau Yann Rolland +11 位作者 Stéphane Schwartz Cécile Gautheron Thierry Dumont Dorian Bienveignant Benjamin Brigaud Nicolas Godeau Abel Guihou Pierre Deschamps Xavier Mangenot Marianna Corre Rosella Pinna-Jamme Nathaniel Findling 《Geoscience Frontiers》 2025年第2期59-75,共17页
Understanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen,assessing seismological risks and understanding mineralization processes.In the Western Alps,one o... Understanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen,assessing seismological risks and understanding mineralization processes.In the Western Alps,one of the main controversies in existing tectonic models is the understanding of syn-orogenic extension.Seismological evidence shows widespread extensional deformation related to the reactivation of major lithospheric structures,such as the Penninic Frontal Thrust(PFT).However,the onset age and origin of extension are still debated due to the lack of suitable geochronological data.Fault hematite and calcite geochronology as well as clumped isotope data can be used to relate fluid regimes to fault activity.The analysis of calcite brecciae from extensional faults above the PFT shows that two distinct fluid regimes were present.The first regime,occurring before 2 Ma is associated with upwelling of deep fluids and is recorded by fault calcite at a temperature>110°C.The second fluid regime is characterized by a meteoric signature and temperatures around 36°C,representing crystallization since 2 Ma.This study presents a new model for the Miocene tectonic history of the Western Alps that combines(U-Th)/He and U-Pb geochronology on fault hematite(13.3±0.8 to<0.8 Ma)and calcite(5.3±0.6 Ma).Results demonstrate a progression of extensional fault activity from east to west,from the Middle Miocene(ca.13 Ma)to the Quaternary.The onset of extension in the inner part of the belt coincides with the development of the fold and thrust belt in the western Alpine foreland.Our new model proposes that extension occurs in the hanging wall of a large top-to-the-west thrust,known as the Alpine Frontal Thrust.This thrust,located to the west of the External Crystalline Massifs gives rise to their uplifting and extension at the rear. 展开更多
关键词 Western Alps Briançonnais zone Hematite(U-Th) He U-Pb calcite Clumped isotopes Syn-orogenic extension
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Single-pulse ultrafast real-time simultaneous planar imaging of femtosecond laser-nanoparticle dynamics in flames
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作者 Yogeshwar Nath Mishra Peng Wang +2 位作者 Florian J.Bauer Murthy S.Gudipati Lihong V.Wang 《Light(Science & Applications)》 SCIE EI CSCD 2024年第10期2312-2320,共9页
The creation of carbonaceous nanoparticles and their dynamics in hydrocarbon flames are still debated in environmental,combustion,and material sciences.In this study,we introduce single-pulse femtosecond laser sheetco... The creation of carbonaceous nanoparticles and their dynamics in hydrocarbon flames are still debated in environmental,combustion,and material sciences.In this study,we introduce single-pulse femtosecond laser sheetcompressed ultrafast photography(fsLS-CUP),an ultrafast imaging technique specifically designed to shed light on and capture ultrafast dynamics stemming from interactions between femtosecond lasers and nanoparticles in flames in a single-shot.fsLS-CUP enables the first-time real-time billion frames-per-second(Gfps)simultaneous twodimensional(2D)imaging of laser-induced fluorescence(LIF)and laser-induced heating(LIH)that are originated from polycyclic aromatic hydrocarbons(PAHs)and soot particles,respectively.Furthermore,fsLS-CUP provides the real-time spatiotemporal map of femtosecond laser-soot interaction as elastic light scattering(ELS)at an astonishing 250 Gfps.In contrast to existing single-shot ultrafast imaging approaches,which are limited to millions of frames per second only and require multiple laser pulses,our method employs only a single pulse and captures the entire dynamics of laserinduced signals at hundreds of Gfps.Using a single pulse does not change the optical properties of nanoparticles for a following pulse,thus allowing reliable spatiotemporal mapping.Moreover,we found that particle inception and growth are derived from precursors.In essence,as an imaging modality,fsLS-CUP offers ultrafast 2D diagnostics,contributing to the fundamental understanding of nanoparticle’s inception and broader applications across different fields,such as material science and biomedical engineering. 展开更多
关键词 PULSE SCATTERING dynamics
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Focusing light into scattering media with ultrasound-induced field perturbation 被引量:7
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作者 Zhongtao Cheng Lihong V.Wang 《Light(Science & Applications)》 SCIE EI CAS CSCD 2021年第9期1702-1713,共12页
Focusing light into scattering media,although challenging,is highly desirable in many realms.With the invention of time-reversed ultrasonically encoded(TRUE)optical focusing,acousto-optic modulation was demonstrated a... Focusing light into scattering media,although challenging,is highly desirable in many realms.With the invention of time-reversed ultrasonically encoded(TRUE)optical focusing,acousto-optic modulation was demonstrated as a promising guidestar mechanism for achieving noninvasive and addressable optical focusing into scattering media.Here,we report a new ultrasound-assisted technique,ultrasound-induced field perturbation optical focusing,abbreviated as UFP.Unlike in conventional TRUE optical focusing,where only the weak frequency-shifted first-order diffracted photons due to acousto-optic modulation are useful,here UFP leverages the brighter zeroth-order photons diffracted by an ultrasonic guidestar as information carriers to guide optical focusing.We find that the zeroth-order diffracted photons,although not frequency-shifted,do have a field perturbation caused by the existence of the ultrasonic guidestar.By detecting and time-reversing the differential field of the frequency-unshifted photons when the ultrasound is alternately ON and OFF,we can focus light to the position where the field perturbation occurs inside the scattering medium.We demonstrate here that UFP optical focusing has superior performance to conventional TRUE optical focusing,which benefits from the more intense zeroth-order photons.We further show that UFP optical focusing can be easily and flexibly developed into double-shot realization or even single-shot realization,which is desirable for high-speed wavefront shaping.This new method upsets conventional thinking on the utility of an ultrasonic guidestar and broadens the horizon of light control in scattering media.We hope that it provides a more efficient and flexible mechanism for implementing ultrasound-guided wavefront shaping. 展开更多
关键词 PERTURBATION MEDIA REALIZATION
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Physical picture of the optical memory effect 被引量:16
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作者 Honglin Liu Zhentao Liu +2 位作者 Meijun Chen Shensheng Han Lihong V.Wang 《Photonics Research》 SCIE EI CSCD 2019年第11期1323-1330,共8页
The optical memory effect is an interesting phenomenon that has attracted considerable attention in recent decades. Here, we present a new physical picture of the optical memory effect, in which the memory effect and ... The optical memory effect is an interesting phenomenon that has attracted considerable attention in recent decades. Here, we present a new physical picture of the optical memory effect, in which the memory effect and the conventional spatial shift invariance are united. Based on this picture we depict the role of thickness, scattering times, and anisotropy factor and derive equations to calculate the ranges of the angular memory effect(AME) of different scattering components(ballistic light, singly scattered, doubly scattered, etc.), and hence a more accurate equation for the real AME ranges of volumetric turbid media. A conventional random phase mask model is modified according to the new picture. The self-consistency of the simulation model and its agreement with the experiment demonstrate the rationality of the model and the physical picture, which provide powerful tools for more sophisticated studies of the memory-effect-related phenomena and wavefront-sensitive techniques, such as wavefront shaping, optical phase conjugation, and optical trapping in/through scattering media. 展开更多
关键词 EFFECT SCATTERED hence
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Development of Ultra-High Density Silicon Nanowire Arrays for Electronics Applications 被引量:7
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作者 Dunwei Wang Bonnie A.Sheriff +1 位作者 Michael McAlpine James R.Heath 《Nano Research》 SCIE EI CSCD 2008年第1期9-21,共13页
This article reviews our recent progress on ultra-high density nanowires(NWs)array-based electronics.The superlattice nanowire pattern transfer(SNAP)method is utilized to produce aligned,ultra-high density Si NW array... This article reviews our recent progress on ultra-high density nanowires(NWs)array-based electronics.The superlattice nanowire pattern transfer(SNAP)method is utilized to produce aligned,ultra-high density Si NW arrays.We fi rst cover processing and materials issues related to achieving bulk-like conductivity characteristics from 1020 nm wide Si NWs.We then discuss Si NW-based fi eld-effect transistors(FETs).These NWs&NW FETs provide terrifi c building blocks for various electronic circuits with applications to memory,energy conversion,fundamental physics,logic,and others.We focus our discussion on complementary symmetry NW logic circuitry,since that provides the most demanding metrics for guiding nanofabrication.Issues such as controlling the density and spatial distribution of both p-and n-type dopants within NW arrays are discussed,as are general methods for achieving Ohmic contacts to both p-and n-type NWs.These various materials and nanofabrication advances are brought together to demonstrate energy effi cient,complementary symmetry NW logic circuits. 展开更多
关键词 Ultra-high density nanowire superlattice nanowire pattern transfer logic circuit
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Single-shot real-time femtosecond imaging of temporal focusing 被引量:25
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作者 Jinyang Liang Liren Zhu Lihong V.Wang 《Light(Science & Applications)》 SCIE EI CAS CSCD 2018年第1期593-602,共10页
While the concept of focusing usually applies to the spatial domain,it is equally applicable to the time domain.Realtime imaging of temporal focusing of single ultrashort laser pulses is of great significance in explo... While the concept of focusing usually applies to the spatial domain,it is equally applicable to the time domain.Realtime imaging of temporal focusing of single ultrashort laser pulses is of great significance in exploring the physics of the space–time duality and finding diverse applications.The drastic changes in the width and intensity of an ultrashort laser pulse during temporal focusing impose a requirement for femtosecond-level exposure to capture the instantaneous light patterns generated in this exquisite phenomenon.Thus far,established ultrafast imaging techniques either struggle to reach the desired exposure time or require repeatable measurements.We have developed single-shot 10-trillion-frame-per-second compressed ultrafast photography(T-CUP),which passively captures dynamic events with 100-fs frame intervals in a single camera exposure.The synergy between compressed sensing and the Radon transformation empowers T-CUP to significantly reduce the number of projections needed for reconstructing a high-quality three-dimensional spatiotemporal datacube.As the only currently available real-time,passive imaging modality with a femtosecond exposure time,T-CUP was used to record the first-ever movie of nonrepeatable temporal focusing of a single ultrashort laser pulse in a dynamic scattering medium.T-CUP’s unprecedented ability to clearly reveal the complex evolution in the shape,intensity,and width of a temporally focused pulse in a single measurement paves the way for single-shot characterization of ultrashort pulses,experimental investigation of nonlinear light-matter interactions,and real-time wavefront engineering for deep-tissue light focusing. 展开更多
关键词 ULTRASHORT PASSIVE SCATTERING
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Rapid fabrication of microrings with complex cross section using annular vortex beams 被引量:2
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作者 Chenchu Zhang Hanchang Ye +5 位作者 Rui Cao Shengyun Ji Heng Zhang Linhan Zhao Sizhu Wu Hua Zhai 《Chinese Optics Letters》 SCIE EI CAS CSCD 2022年第2期187-191,共5页
A ring-shaped focus, such as a focused vortex beam, has played an important role in microfabrication and optical tweezers.The shape and diameter of the ring-shaped focus can be easily adjusted by the topological charg... A ring-shaped focus, such as a focused vortex beam, has played an important role in microfabrication and optical tweezers.The shape and diameter of the ring-shaped focus can be easily adjusted by the topological charge of the vortex. However,the flow energy is also related to the topological charge, making the individual control of diameter and flow energy of the vortex beam impossible. Meanwhile, the shape of the focus of the vortex beam remains in the hollow ring. Expanding the shape of focus of structural light broadens the applications of the vortex beam in the field of microfabrication. Here, we proposed a ring-shaped focus with controllable gaps by multiplexing the vortex beam and annular beam. The multiplexed beam has several advantages, such as the diameter and flow energy of the focal point can be individually controlled and are not affected by the zero-order beam, and the gap size and position are controllable. 展开更多
关键词 MICROFABRICATION femtosecond laser structural beams MICRORING
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