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Machine learning in laser-induced breakdown spectroscopy:A review

Frontiers of physics 2024年第6期19卷 225-252页

作者： Zhongqi Hao Ke Liu Qianlin Lian Weiran Song Zongyu Hou Rui Zhang Qianqian Wang Chen Sun Xiangyou Li Zhe Wang Key Laboratory of Nondestructive Testing(Ministry of Education) Nanchang Hangkong UniversityNanchang 330063China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan 430074China State Key Lab of Power System Department of Energy and Power EngineeringTsinghua-BP Clean Energy CentreTsinghua UniversityBeijing100084China School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China School of Public Health Xinjiang Medical UniversityUrumqi 830054China The Second Medical College of Binzhou Medical University Yantai Affiliated Hospital of Binzhou Medical UniversityYantai264100China School of Electronic Engineering Naval University of EngineeringWuhan 430014China

Laser-induced breakdown spectroscopy(LIBS)is a spectroscopic analytic technique with great application potential because of its unique advantages for online/in-situ ***,due to the spatially inhomogeneity and drastically temporal varying nature of its emission source,the laser-induced plasma,it is difficult to find or hard to generate an appropriate spatiotemporal window for high repeatable signal collection with lower matrix *** quantification results of traditional physical principle based calibration model are unsatisfactory since these models were not able to compensate for complicate matrix effects as well as signal *** learning is an emerging approach,which can intelligently correlated the complex LIBS spectral data with its qualitative or/and quantitative composition by establishing multivariate regression models with greater potential to reduce the impacts of signal fluctuation and matrix effects,therefore achieving rela-tively better qualitative and quantitative *** this review,the progress of machine learning application in LIBS is summarized from two main aspects:(i)Pre-processing data for machine learning model,including spectral selection,variable reconstruction,and denoising to improve qualitative/quantitative performance;(ii)Machine learning methods for better quantification performance with reduction of the impact of matrix effect as well as LIBS spectra *** review also points out the issues that researchers need to address in their future research on improving the performance of LIBS analysis using machine learning algorithms,such as restrictions on training data,the disconnect between physical principles and algorithms,the low generalization ability and massive data processing ability of the model.

关键词： laser-induced breakdown spectroscopy machine learning repeatability matrix effects qualitative and quantitativeanalysis

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The Lithosphere Structure and its Implication for Different Metallogenic Belts beneath the Eastern South China Block

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Acta Geologica Sinica(English Edition) 2024年第S1期98卷 2-5页

作者： CHEN Changxin LÜQingtian CHEN Ling SHI Danian YAN Jiayong AI Yinshuang Chinese Academy of Geological Sciences Beijing 100037China SinoProbe Center Chinese Academy of Geological Sciences and China Geological SurveyBeijing 100037China China MNR Lab of Deep Earth Science and Technology Beijing 100094China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China CAS Center for Excellence in Deep Earth Science Guangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The South China Block(SCB)was formed through the Neoproterozoic amalgamation of the Yangtze Block(YB),the Cathaysia Block(CB),and the accreted components of the Jiangnan orogenic belt(JNO),it is bounded by the Jiangshan–Shaoxing–Pingxiang fault(JSPF)and the Jiujiang–Shitai–Jishou fault(JSJF)(Yao et al.,2019).The SCB has undergone a series of complex geological events,including Paleozoic orogeny,Mesozoic collisions with the North China Craton(NCC)and the Indochina Block,as well as the intracontinental orogeny,leading to extensive lithospheric modifications and magmatic activities(Zhang H J et al.,2023;Fig.1).

关键词： lithosphere structure receiver function mineral system South China Block

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Polar and layered wide-bandgap semiconductors WO2Cl2 and MoO2Br2 with giant birefringence, large second harmonic and ferroelectric photovoltaic effects

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Physical Review B 2024年第15期109卷 155421-155421页

作者： Hao Huo Xiao Jiang Lei Kang Functional Crystals Lab Key Laboratory of Functional Crystals and Laser Technology Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Beijing Computational Science Research Center Beijing 100193 China

van der Waals (vdW) layered semiconductors exhibiting large nonlinear-optical (NLO) effects have substantial potential for developing nanoscale quantum optical devices. NbOCl2, an ultrathin quantum light source, has recently displayed a large second harmonic effect. However, its small bandgap (∼1.8 eV) impedes transparent light conversion across wide spectral regions, especially when utilizing practical 1-µm lasers. In this paper, we found that MO2X2 (M=W, Mo; X=Cl, Br) effectively widens the bandgap by using W6+ or Mo6+ instead of Nb4+ to eliminate in-gap nonbonding orbitals. Meanwhile, the octahedral [MO4X2] motifs display polar Jahn-Teller distortions as large as [NbO2X4] to demonstrate comparable NLO polarization effects. Based on first-principles calculations, WO2Cl2 and MoO2Br2 are predicted to possess wider bandgaps (2.9 and 2.2 eV), giant birefringence (0.5–0.7), and significant second harmonic and ferroelectric photovoltaic effects competitive with NbOX2. These findings provide strong incentives to explore new vdW materials with superior NLO properties.

关键词： Jahn-Teller effect Nonlinear optics Optoelectronics

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The 600 keV electron injections in the Earth's outer radiation belt:A statistical study

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Earth and Planetary physics 2022年第2期6卷 149-160页

作者： ChaoLing Tang Xu Wang BinBin Ni ZhengPeng Su JiChun Zhang Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai Shandong 264209China School of Space Science and Physics Shandong UniversityWeihai Shandong 264209China Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China CAS Center for Excellence in Comparative Planetology Hefei 230026China CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity of Science and Technology of ChinaHefei 230026China Staunch Data Analytics Lab DurhamNew HampshireUSA

Relativistic electron injections are one of the mechanisms of relativistic(≥0.5 MeV) electron enhancements in the Earth’s outer radiation belt. In this study, we present a statistical observation of 600 keV electron injections in the outer radiation belt by using data from the Van Allen Probes. On the basis of the characteristics of different injections, 600 keV electron injections in the outer radiation belt were divided into pulsed electron injections and nonpulsed electron injections. The 600 keV electron injections were observed at 4.5 < L <6.4 under the geomagnetic conditions of 450 nT < AE < 1,450 nT. An L of ~4.5 is an inward limit for 600 keV electron injections. Before the electron injections, a flux negative L shell gradient for ≤0.6 MeV electrons or low electron fluxes in the injected region were observed. For600 keV electron injections at different L shells, the source populations from the Earth’s plasma sheet were different. For 600 keV electron injections at higher L shells, the source populations were higher energy electrons(~200 keV at X ~–9 R_(E)), whereas the source populations for 600 keV electron injections at lower L shells were lower energy electrons(~80 keV at X ~–9 R_(E)). These results are important to further our understanding of electron injections and rapid enhancements of 600 keV electrons in the Earth’s outer radiation belt.

关键词： electron injections relativistic electrons the Earth’s outer radiation belt plasma sheet Van Allen Probes

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Characterizing Kerr Optical Frequency Combs Using Quantum Interference

Characterizing Kerr Optical Frequency Combs Using Quantum In...

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Asia Communications and Photonics Conference and Exhibition (ACP)

作者： Jin Guo Yun-Ru Fan Yong Geng Guang-Wei Deng Hai-Zhi Song You Wang Li-Xing You Zhen Wang Heng Zhou Kun Qiu Guang-Can Guo Qiang Zhou Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu China Key Lab of Optical Fiber Sensing and Communication Networks University of Electronic Science and Technology of China Chengdu China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Southwest Institute of Technical Physics Chengdu China Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei China

For the first time, we characterize the properties of Kerr optical frequency combs using quantum optics. The temporal FWHM of single soliton state is obtained as $\boldsymbol{109.8\pm 6.5}$ fs within the Fourier tra...

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Structured air lasing of N2+

arXiv

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arXiv 2023年

作者： Gao, Jingsong Zhang, Xiang Wang, Yang Fang, Yiqi Lu, Qi Li, Zheng Liu, Yi Wu, Chengyin Gong, Qihuang Liu, Yunquan Jiang, Hongbing State Key Laboratory for Mesoscopic Physics School of Physics Peking University Beijing100871 China Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai200093 China

Structured light has attracted great interest in scientific and technical fields. Here, we demonstrate the first generation of structured air lasing in N2+ driven by 800 nm femtosecond laser pulses. By focusing a vortex pump beam at 800 nm in N2 gas, we generate a vortex superfluorescent radiation of N2+ at 391 nm, which carries the same photon orbital angular momentum as the pump beam. With the injection of a Gaussian seed beam at 391 nm, the coherent radiation is amplified, but the vorticity is unchanged. A new physical mechanism is revealed in the vortex N2+ superfluorescent radiation: the vortex pump beam transfers the spatial spiral phase into the N2+ gain medium, and the Gaussian seed beam picks up the spatial spiral phase and is then amplified into a vortex beam. Moreover, when we employ a pump beam with a cylindrical vector mode, the Gaussian seed beam is correspondingly amplified into a cylindrical vector beam. Surprisingly, the spatial polarization state of the amplified radiation is identical to that of the vector pump beam regardless of whether the Gaussian seed beam is linearly, elliptically, or circularly polarized. Solving three-dimensional coupled wave equations, we show how a Gaussian beam becomes a cylindrical vector beam in a cylindrically symmetric gain medium. This study provides a novel approach to generating structured light via N2+ air lasing. Copyright © 2023, The Authors. All rights reserved.

关键词： Vectors

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通过调控范霍夫奇点在外延单层VSe_(2)中诱导出巡游铁磁性

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science Bulletin 2023年第10期68卷 990-997,M0003页

作者：宗君宇董召阳黄俊伟王开礼汪琪玮孟庆豪田启超邱小东牟浴洋王利任伟谢学栋陈望张永衡王灿李坊森李绍春李建新袁洪涛张翼 National Laboratory of Solid-State Microstructures School of PhysicsNanjing UniversityNanjing 210093China Department of Applied Physics Nanjing University of Science and TechnologyNanjing 210094China College of Engineering and Applied Sciences and National Laboratory of Solid-State Microstructures Nanjing UniversityNanjing 210093China Vacuum Interconnected NanoTech Workstation(Nano-X) Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO)Chinese Academy of SciencesSuzhou 215123China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

处在费米能级处的范霍夫奇点(van Hove singularity)由于具有发散的态密度特征可以诱导出巡游铁磁性.本文在SrTiO_(3)(111)衬底上外延生长单层VSe_(2)薄膜,并通过调控范霍夫奇点诱导出巡游铁磁性.作者通过角分辨光电子能谱技术直接观测... 详细信息

处在费米能级处的范霍夫奇点(van Hove singularity)由于具有发散的态密度特征可以诱导出巡游铁磁性.本文在SrTiO_(3)(111)衬底上外延生长单层VSe_(2)薄膜,并通过调控范霍夫奇点诱导出巡游铁磁性.作者通过角分辨光电子能谱技术直接观测到了单层VSe_(2)中的范霍夫奇点能带结构.理论计算表明,当该范霍夫奇异点靠近费米能级时,可通过斯通纳(Stoner)不稳定性产生巡游铁磁性.实验上,作者利用SrTiO_(3)(111)在低温下极大增强的介电常数εr,通过界面电荷转移效应调控范霍夫奇点向费米能级处移动,并通过电输运测量观测到了3.3 K的巡游铁磁性转变.此外,通过改变薄膜层厚和更换衬底的方式,作者可以进一步调控界面电荷转移效果和范霍夫奇点的能量位置,并对巡游铁磁性进行调控.这项研究证明了范霍夫奇点可以成为巡游铁磁性的调控自由度,并拓展了二维磁体在未来电子信息技术的应用潜力.

关键词： 2D itinerant ferromagnetism Monolayer1T-VSe_(2)Van Hove singularity Molecularbeam epitaxy Angle-resolved photoemission spectroscopy Electronictransport

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Charge-two Weyl phonons with type-III dispersion

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Physical Review B 2022年第13期105卷 134303-134303页

作者： Guangqian Ding Feng Zhou Zeying Zhang Zhi-Ming Yu Xiaotian Wang School of Science Chongqing University of Posts and Telecommunications Chongqing 400065 China School of Physical Science and Technology Southwest University Chongqing 400715 China College of Science Beijing University of Chemical Technology Beijing 100029 China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems and School of Physics Beijing Institute of Technology Beijing 100081 China

In recent years, charge-two Weyl point phonons (WPPs) have attracted increasing attention. Charge-two WPPs not only provide a new platform for realizing phonon-based unconventional Weyl points (WPs) but also help in realizing specific phonon-based transport behaviors. Herein, based on the first-principles calculations and symmetry analysis, we propose a realistic material with the P3121 space group, BaZnO2, which has a charge-two WPP and two charge-one WPPs at high-symmetry points. These three unpaired WPPs form a unique triangular Weyl complex. Unlike previously reported material candidates with type-I or type-II charge-two WPPs, the proposed BaZnO2 has a type-III charge-two WPP, which has a constant frequency surface that contains two electronlike or holelike states connected at the charge-two WP. BaZnO2 can support double-helicoid phonon surface states that cover the entire (001) surface Brillouin zone. The clean type-III WPP, unique triangular Weyl complex, and clear and long surface states in BaZnO2 suggest that it is an excellent platform for further research into the physics and applications of type-III charge-two WPPs. Furthermore, we pointed out that charge-two WPPs with type-III band dispersion may appear at high-symmetry points in space groups 75–80, 89–98, 143–146, 149–155, 168–173, 177–182, 196, 207–210. Besides trigonal BaZnO2, some material candidates, including tetragonal MgTiO4, trigonal Li2GeF6, hexagonal CaSO4, and cubic Li10B14Cl2O25, are also shown to be the hosts of type-III charge-two WPPs.

关键词： Fermi surface First-principles calculations Topological materials k dot p method

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Evaluating the Degradation of Silicon Heterojunction Devices Through Interface Modeling Changes and Chemical Analysis

Evaluating the Degradation of Silicon Heterojunction Devices...

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IEEE Conference Photovoltaic Specialists (PVSC)

作者： Nicholas Moser-Mancewicz Jorge Ochoa Julia Medvedeva Dirk Jordan Steve Johnston Mariana Bertoni Arizona State University Tempe AZ United States Physics Department Missouri University of Science and Technology Rolla MO United States National Renewable Energy Lab Golden CO United States

ISBN: (数字)9781665464260

ISBN: (纸本)9781665475822

As silicon heterojunction (SHJ) solar cells continue to work towards improving their market adoption with record efficiencies, issues surrounding degrading device performance under fielded conditions still remain at the forefront of the community's mind. Therefore, the detailed analysis of fielded module data offers a priceless opportunity to understand this technology. Within this paper we examine changes within the elemental composition and electrical performance of fielded commercial SHJ modules and film stacks of a-Si on high quality c-si. We can determine the loss of passivating hydrogen using electrical performance characterization through IV, characterization of the material structure through glow discharge optical emissions spectroscopy and modeling that represents the interface defect density.

关键词： Performance evaluation Photovoltaic systems Optical losses Degradation Chemical analysis Photovoltaic cells Hydrogen Heterojunctions Silicon Glow discharges

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Perovskite bridging PbS quantum dot/polymer interface enables efficient solar cells

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Nano Research 2022年第7期15卷 6121-6127页

作者： Xing Meng Yifan Chen Fan Yang Jieqi Zhang Guozheng Shi Yannan Zhang Haodong Tang Wei Chen Yang Liu Lin Yuan Shaojuan Li Kai Wang Qi Chen Zeke Liu Wanli Ma Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and PhysicsChangchun 130033China i-Lab CAS Center for Excellence in NanoscienceSuzhou Institute of Nano-Tech and Nano-BionicsSuzhou 215123China Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhen 518055China

Conjugated polymers have been explored as promising hole-transporting layer(HTL)in lead sulfide(PbS)quantum dot(QD)solar *** fine regulation of the inorganic/organic interface is pivotal to realize high device *** this work,we propose using CsPbI_(3) QDs as the interfacial layer between PbS QD active layer and organic polymer *** relative soft perovskite can mediate the interface and form favorable energy level alignment,improving charge extraction and reducing interfacial charge *** a result,the photovoltaic performance can be efficiently improved from 10.50%to 12.32%.This work may provide new guidelines to the device structural design of QD optoelectronics by integrating different solutionprocessed semiconductors.

关键词： lead sulfide quantum dot solar cells perovskite energy level alignment

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