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Burst mode enabled ultrafast laser inscription inside gallium arsenide

International Journal of Extreme Manufacturing 2022年第4期4卷 179-187页

作者： andong wang Pol Sopeña David Grojo Aix-Marseille University CNRSLP3UMR734113009 MarseilleFrance

Ultrafast laser inscription(ULI)inside semiconductors offers new perspectives for 3D monolithic structures to be fabricated and new functionalities to be added in electronic and photonic microdevices.However,important challenges remain because of nonlinear effects such as strong plasma generation that distort the energy delivery at the focal point when exposing these materials to intense infrared light.Up to now,the successful technological demonstrations have primarily concentrated on silicon(Si).In this paper,we target at another important semiconductor:gallium arsenide(GaAs).With nonlinearities higher than those of Si,3D-machining of GaAs with femtosecond pulses becomes even harder.However,we show that the difficulty can be circumvented by burst-mode irradiation.We generate and apply trains of pulses at terahertz repetition rates for efficient pulse-to-pulse accumulation of laser-induced free carriers in the focal region,while avoiding an overdose of prefocal excitations.The superior performance of burst-mode irradiation is confirmed by a comparative study conducted with infrared luminescence microscopy.The results indicate a successful reduction of the plasma density in the prefocal region so that higher pulse energy reaches the focal spot.The same method is applied to identify optimum irradiation conditions considering particular cases such as asymmetric pulse trains and aberrated beams.With 64-pulse trains,we successfully manage to cross the writing threshold providing a solution for ULI inside GaAs.The application potential is finally illustrated with a stealth dicing demonstration by taking benefit of the burst mode.The irradiation method opens wide possibilities for 3D structuring inside GaAs by ULI.

关键词： laser processing ultrafast laser inscription THz-repetition-rate burst semiconductors gallium arsenide

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Initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments

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Chinese Journal of Aeronautics 2022年第1期35卷 277-289页

作者： Yangguang ZHANG Yueliang CHEN Yong ZHANG Guixue BIAN Chenguang wang andong wang Naval Aviation University Qingdao Campus Qingdao 266041China

The initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments(pH=3.5)are studied by Scanning Electron Microscope(SEM),optical microscope,Fourier Transform Infrared Spectroscopy(FT-IR),X-Ray Diffraction(XRD),potentiodynamic polarization,Electrochemical Impedance Spectroscopy(EIS),and Scanning Kelvin Probe(SKP).The results show that pitting corrosion occurs at the initial corrosion stage,and the potential difference between the second phase particles is the main cause of pitting.Pitting pits on different locations gradually expand and coalesce with the proceeding of corrosion.The main components of corrosion products are Al_(2)O_(3),Al(OH)_(3),and AlCl_(3),and the generation rate of the corrosion product layer under the salt spray environment is larger than that under acid immersion environment.Under both environments,the Volta potential distribution first disperses and then concentrates,while the charge transfer resistance first decreases and then increases with the corrosion time.The Volta potential gradually shifts in a positive direction,indicating that corrosion products have an inhibitory effect on corrosion.After the same corrosion time,the corrosion product layer resistance and the expectation of the Volta potential of the salt spray sample are higher than those of the immersion sample.Comparatively,the corrosion current density for the salt spray sample is significantly lower than the immersion sample,which indicates that the thicker the corrosion product layer,the stronger the inhibition of corrosion reaction.

关键词： 7B04 aluminum alloy Acid salt spray Corrosion mechanism Corrosion products Electrochemistry Scanning Kelvin probe

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Distribution and invasion of Spartina alterniflora within the Jiaozhou Bay monitored by remote sensing image

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Acta Oceanologica Sinica 2022年第6期41卷 31-40页

作者： Jianbu wang Zhaoyang Lin Yuanqing Ma Guangbo Ren Zijun Xu Xiukai Song Yi Ma andong wang Yajie Zhao Laboratory of Marine Physics and Remote Sensing First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China School of Information and Electrics Beijing Institute of TechnologyBeijing 100081China Shandong Marine Resources and Environment Research Institute Shandong Provincial Key Laboratory of Restoration for Marine EcologyYantai 264006China North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China Shandong Yellow River Delta National Nature Reserve Administration Committee Dongying 257091China

Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has reached more than 500 hm^(2).For this reason,combined with field surveys,remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out.To accurately identify S.alterniflora within the Jiaozhou Bay coastal wetland,we used a new method which is an implement of deep convolutional neural network,and by which we got a higher accuracy than the traditional method.Based on distribution of S.alterniflora extracted by the proposed method,the temporal and spatial distribution characteristics of S.alterniflora were analyzed.And then combined with environmental factors,the invasion mechanism of S.alterniflora in the Jiaozhou Bay was analyzed in detail.From the monitoring results,it can be seen that S.alterniflora in Jiaozhou Bay is mainly distributed in the beaches near the Yanghe River Estuary and its southern side,the Dagu River Estuary and the Nügukou.Spartina alterniflora first broke out near the Yanghe River Estuary and gradually spread to the tidal flats near the Nügukou.The Dagu River Estuary is dominated by S.anglica,whose area has not changed much over the years,and a small amount of S.alterniflora has invaded later.

关键词： Spartina alterniflora remote sensing coastal wetland deep residual network

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Ultrafast Laser Writing Deep inside Silicon with THz-Repetition-Rate Trains of Pulses

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Research 2020年第1期2020卷 1478-1488页

作者： andong wang Amlan Das David Grojo Aix-Marseille Univ. CNRSLP3 UMR 734113009 MarseilleFrance

Three-dimensional laser writing inside silicon remains today inaccessible with the shortest infrared light pulses unless complex schemes are used to circumvent screening propagation nonlinearities.Here,we explore a new approach irradiating silicon with trains of femtosecond laser pulses at repetition rates up to 5.6 THz that is order of magnitude higher than any source used for laser processing so far.This extremely high repetition rate is faster than laser energy dissipation from microvolume inside silicon,thus enabling unique capabilities for pulse-to-pulse accumulation of free carriers generated by nonlinear ionization,as well as progressive thermal bandgap closure before any diffusion process comes into play.By space-resolved measurements of energy delivery inside silicon,we evidence changes in the interplay between detrimental nonlinearities and accumulation-based effects.This leads to a net increase on the level of space-time energy localization.The improvement is also supported by experiments demonstrating high performance for 3D laser writing inside silicon.In comparison to repeated single pulses,irradiation with trains of only four-picosecond pulses with the same total energy leads to an apparent decrease of the energy threshold for modification and drastic improvements on the repeatability,uniformity,and symmetricity of the produced features.The unique benefits of THz bursts can provide a new route to meet the challenge of 3D inscription inside narrow bandgap materials.

关键词： repetition Deep shortest

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Dynamic model and response characteristics of liquid desiccant air-conditioning system driven by heat pump

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Building Simulation 2021年第6期14卷 1773-1784页

作者： Bowen Guan Xiaohua Liu Tao Zhang andong wang Department of Building Science and Technology Tsinghua UniversityBeijing 100084China Deportment of Electrical and Electronic Engineering University of Hong KongHong Kong 999077China

The liquid desiccant air-conditioning system is considered as an energy-efficient alternative to the vapor compression system.The dynamic response characteristics of the system under variable cooling load play an important role in the air temperature and humidity control performance of the system.However,the dynamic response characteristics have not been fully revealed in previous studies.Thus,a dynamic model for a heat pump driven liquid desiccant air-conditioning(HPLDAC)system is established to investigate the dynamic response characteristics of the system in this study.Subsequently,experiments were conducted to validate the accuracy of the dynamic model.The simulation results show a good agreement with the experimental data.The simulation results reveal that evaporating water from the solution is a time-consuming process,compared to adding water to the solution.It spends a long time for the HPLDAC system to decrease the high relative humidity of supply air to a low value,which limits the air temperature and humidity control performance of the system.The upper band for the water replenishing value opening(△φup)is a crucial parameter to improve the limitation.When△φup decreases from 1.0%产to 0.25%,the time consumed to reduce the supply air relative humidity to the new lower set value can be saved by 30.6%.

关键词： dynamic model response characteristics liquid desiccant-temperature and humidity independent control air conditioning system

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Amplifying Orbital Angular Momentum Modes in Ring-Core Erbium-Doped Fiber

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Research 2020年第1期2020卷 1342-1353页

作者： Jun Liu Shi Chen Hongya wang Shuang Zheng Long Zhu andong wang Lulu wang Cheng Du Jian wang Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan430074 HubeiChina Fiberhome Telecommunication Technologies Co.Ltd. Wuhan 430074China

Lots of research efforts have been devoted to increase the transmission capacity in optical communications using orbital angular momentum(OAM)multiplexing.To enable long-haul OAM mode transmission,an in-line OAM fiber amplifier is desired.A ring-core fiber(RCF)is considered to be a preferable design for stable OAM mode propagation in the fiber.Here,we demonstrate an OAM fiber amplifier based on a fabricated ring-core erbium-doped fiber(RC-EDF).We characterize the performance of the RC-EDF-assisted OAM fiber amplifier and demonstrate its use in OAM multiplexing communications with OAM modes carrying quadrature phase-shift keying(QPSK)and quadrature amplitude modulation(QAM)signals.The amplification of two OAM modes over four wavelengths is demonstrated in a data-carrying OAM-division multiplexing and wavelength-division multiplexing system.The obtained results show favorable performance of the RC-EDF-assisted OAM fiber amplifier.These demonstrations may open up new perspectives for long-haul transmission in capacity scaling fiber-optic communications employing OAM modes.

关键词： amplifier fiber Erbium

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Zircon U-Pb geochronology,geochemistry and Sr-Nd-Pb isotopes from the metamorphic basement in the Wuhe Complex:Implications for Neoarchean active continental margin along the southeastern North China Craton and constraints on the petrogenesis of Mesozoic granitoids

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Geoscience Frontiers 2013年第1期4卷 57-71页

作者： andong wang Yican Liu M.Santosh Xiaofeng Gu CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of China Division of Interdisciplinary Science Faculty of ScienceKochi UniversityAkebono-cho 2-5-1Kochi 780-8520Japan China University of Geosciences(Beijing)

We report zircon U-Pb geochronology, geochemistry and Sr-Nd-Pb isotope data from mafic granulites and garnet amphibolites of the Wuhe Complex in the southeastern margin of the North China Craton （NCC）. In combination with previous data, our results demonstrate that these rocks represent fragments of the ancient lower crust, and have features similar to those of the granulite basement in the northern margin of the NCC. A detailed evaluation of the Pb isotope data shows that Pb isotopes cannot effectively distinguish the role of the Yangtze Craton basement from that of the NCC basement with regard to the source and generation of magmas, at least for southeastern NCC. The age data suggest that the protoliths of the granulites or amphibolites in the Wuhe Complex were most Likely generated in Neoarchean and that these rocks were subjected to Paleoproterozoic （1.8-1.9 Ga） high-pressure granulite facies meta- morphism. This study also shows that the Precambrian metamorphic basement in the southeastern margin of the NCC might have formed in a tectonic setting characterized by a late Neoarchean active continental margin.

关键词： Precambrian metamorphic basement North China Craton Sr-Nd-Pb isotope Active continental margin

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黄河口西南侧小岛河河口天然牡蛎礁的牡蛎种群结构

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生态学报 2024年第7期44卷 3086-3097页

作者：左涛张贝叶王俊左明王安东中国水产科学研究院黄海水产研究所青岛266071 青岛市海洋科学与技术试点国家实验室海洋生态与环境科学功能实验室青岛266237 上海海洋大学水产与生命学院上海201306 东营市海洋发展研究院东营257091 山东黄河三角洲国家级自然保护区管理委员会东营257091

牡蛎礁是生态系统服务价值高、但退化最严重及受关注度最高的海洋生境之一,牡蛎礁修复亦成为国际海洋生态修复的热点。掌握牡蛎自然种群状况及动态变化是评估牡蛎礁修复效果的基础。目前,我国天然牡蛎礁的牡蛎种群状况相关的背景资料较... 详细信息

牡蛎礁是生态系统服务价值高、但退化最严重及受关注度最高的海洋生境之一,牡蛎礁修复亦成为国际海洋生态修复的热点。掌握牡蛎自然种群状况及动态变化是评估牡蛎礁修复效果的基础。目前,我国天然牡蛎礁的牡蛎种群状况相关的背景资料较为缺乏。在黄河口西南侧的小岛河河口新发现天然活体牡蛎礁,但该牡蛎礁曾被大规模的商业采捕,亟需推进针对性的保护和修复研究工作。基于2021年11月对该牡蛎礁开展的牡蛎种群生态调查,分析其种类组成、年龄结构及生长特征。结果显示:该牡蛎礁分布有近江牡蛎(Crassostrea ariakensis)和长牡蛎(Crassostrea gigas)。牡蛎礁上以活体牡蛎为主,死亡牡蛎壳体数仅占6.1%—6.7%。活体牡蛎的密度和生物量分别为(2811±778)个/m^(2)和(21.97±30.43)kg/m^(2),近江牡蛎较多,其密度和生物量分别占比55.7%和76.4%。近江牡蛎和长牡蛎的年龄分别介于0+—4+龄和0+—2+龄,它们都以壳高介于30—40 mm及壳质量80%)。近江牡蛎的壳体形态参数均值都高于同龄组长牡蛎的相应值。两种牡蛎壳体均呈负异速增长,不同龄级的壳体延展方向不同。拟合von Bertalanffy生长方程得到,近江牡蛎和长牡蛎的渐近壳高分别为286 mm和173 mm,估算的拐点年龄分别为5.47龄和2.56龄,两种牡蛎的生长曲线分布存在极显著差异(P3年的原位保护、修复和连续监测计划。

关键词：近江牡蛎长牡蛎种群结构牡蛎礁黄河口

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Episodic crustal growth and reworking at the southeastern margin of the North China Craton: evidence from zircon U–Pb and Lu–Hf isotopes of Archean tonalite–trondhjemite–granodiorite gneisses in the Bengbu-Wuhe area

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Acta Geochimica 2021年第3期40卷 366-389页

作者： Jianjun Wan andong wang Jiayong Pan Chengdong Liu Yan Zhao Zhengbing Zhou Xiandong Luo State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China College of Earth Sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Continental Dynamics Northwest UniversityXi'an 710069China Geological Exploration Technology Institute of Anhui Province Hefei 230041China

The cratonization history of the North China Craton(NCC)and the nature of tectonothermal events are still highly controversial.Tonalite-trondhjemite-granodiorite(TTG)gneisses,as the dominant lithological assemblages in Archean metamorphic terranes,can provide significant clues to the magmatic and metamorphic evolution of Precambrian crust.This study presents zircon laser-ablation inductively-coupled-plasma mass spectrometry U–Pb ages,trace-element,and in-situ LA-MC-ICPMS zircon Hf isotope data for the TTG gneisses from the Bengbu-Wuhe area on the southeastern margin of the NCC.Cathodoluminescence images and trace elements indicated that magmatic zircons display the characteristics of euhedral-subhedral crystals with oscillatory growth zoning structures,high RREE contents,marked Ce positive anomalies,and Pr–Eu negative anomalies.The metamorphic zircons display the spherical-oval crystals with distinct core-rim structures,high and homogeneous luminescent intensity,lower RREE,Nb,Ta,Hf contents,relative flat REE patterns,weak Ce positive anomalies,and Pr-Eu negative anomalies.The Ti–in–zircon geothermometer data indicate that the crystallization temperature of the TTG gneiss ranged from 754 to 868℃.Zircon U–Pb ages indicate that the TTG gneisses formed at 2.79–2.77 Ga and 2.50 Ga and underwent metamorphism at 2.57–2.52 Ga.The Hf isotopic data indicate that the magmatic zircons exhibit high,positive eHf(t)values close to those of the coeval depleted mantle,whereas the metamorphic zircons exhibit negative or nil eHf(t)values.This implies that the TTG gneisses were derived from the partial melting of the~2.9–2.6 Ga juvenile crustal sources mixed with~3.0–2.8 Ga ancient crustal materials.Combined with the regional tectonic evolution,we propose that the metamorphic basement at the southeastern margin of the NCC underwent episodic crustal growth at~2.7 and~2.5 Ga and subsequently underwent crustal reworking or re-melting of the ancient crust during the Neoarchean.The Neoarchean TTG gneisses might have been derived from the

关键词： In-situ zircon Hf isotope Neoarchean North China Craton TTG gneiss Zircon U–Pb dating

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OBH-RSI:Object-Based Hierarchical Classification Using Remote Sensing Indices for Coastal Wetland

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Journal of Beijing Institute of Technology 2021年第2期30卷 159-171页

作者： Zhaoyang Lin Jianbu wang Wei Li Xiangyang Jiang Wenbo Zhu Yuanqing Ma andong wang Beijing Key Laboratory of Fractional Signals and Systems Beijing Institute of TechnologyBeijing 100081China Laboratory of Marine Physics and Remote Sensing First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Shandong Provincial Key Laboratory of Restoration for Marine Ecology Shandong Marine Resources and Environment Research InstituteYantai 264006China Shandong Yellow River Delta National Nature Reserve Administration Committee Dongying 257091China

With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset.

关键词： Yellow River Delta vegetation index object-based hierarchical classification wetland multi-source remote sensing

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