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Giant excitonic upconverted emission from two-dimensional semiconductor in doubly resonant plasmonic nanocavity

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Light(Science & Applications) 2022年第7期11卷 1523-1534页

作者： Pengfei Qi Yuchen Dai Yang Luo Guangyi Tao Liheng Zheng Donglin Liu Tianhao Zhang Jiadong Zhou Bo Shen Feng Lin Zheng Liu Zheyu Fang School of Physics State Key Laboratory for Mesoscopic PhysicsAcademy for Advanced Interdisciplinary StudiesCollaborative Innovation Center of Quantum MatterNano-optoelectronics Frontier Center of Ministry of EducationPeking UniversityBeijing 100871China Institute of Modern Optics Nankai UniversityTianjin Key Laboratory of Micro-scale Optical Information Science and TechnologyTianjin 300350China Photonics Research Center School of PhysicsMOE Key Lab of Weak-Light Nonlinear Photonicsand Tianjin Key Lab of Photonics Materials and Technology for Information ScienceNankai UniversityTianjin 300071China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

Phonon-assisted upconverted emission is the heart of energy harvesting,bioimaging,optical cryptography,and optical *** has been demonstrated that emerging two-dimensional(2D)semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D ***,there is little research on the further enhancement of excitonic upconverted emission in 2D ***,we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic *** to the enhanced light collection,enhanced excitation rate,and quantum efficiency enhancement arising from the Purcell effect,an upconverted emission amplification of>1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are *** findings pave the way for the development of excitonic upconversion lasing,nanoscopic thermometry,and sensing,revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.

关键词： converted resonant doubly

Genuinely Multidimensional Physical-Constraints-Preserving FiniteVolume Schemes for the Special Relativistic Hydrodynamics

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Communications in Computational Physics 2023年第9期34卷 955-992页

作者： Dan Ling Huazhong Tang School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an 710049P.R.China Nanchang Hangkong university Jiangxi ProvinceNanchang 330063P.R.China Center for Applied Physics and Technology HEDPS and LMAMSchool of Mathematical SciencesPeking UniversityBeijing 100871P.R.China

This paper develops the genuinely multidimensional HLL Riemann solver for the two-dimensional special relativistic hydrodynamic equations on Cartesian meshes and studies its physical-constraint-preserving(PCP)*** on the resulting HLL solver,the first-and high-order accurate PCP finite volume schemes are *** the high-order scheme,the WENO reconstruction,the third-order accurate strong-stability-preserving time discretizations and the PCP flux limiter are *** numerical results are given to demonstrate the accuracy,performance and resolution of the shock waves and the genuinely multi-dimensional wave structures *** our PCP finite volume schemes.

关键词： Genuinely multidimensional schemes HLL physical-constraint-preserving property high order accuracy special relativistic hydrodynamics

A New Index Developed for Fast Diagnosis of Meteorological Roles in Ground-Level Ozone Variations

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Advances in Atmospheric Sciences 2022年第3期39卷 403-414,558-563页

作者： Weihua CHEN Weiwen WANG Shiguo JIA Jingying MAO Fenghua YAN Lianming ZHENG Yongkang WU Xingteng ZHANG Yutong DONG Lingbin KONG Buqing ZHONG Ming CHANG Min SHAO Xuemei WANG Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Institute for Environmental and Climate ResearchJinan UniversityGuangzhou 510632China School of Atmospheric Sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen UniversityGuangzhou 510275China Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China

China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T_(2)× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O_(2)pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O_(2)concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O_(2)pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O_(2)variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.

关键词： ground-level ozone meteorology synthetic index photochemical reaction condition physical dispersion capacity

Synchronization and temporal nonreciprocity of optical microresonators via spontaneous symmetry breaking

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Advanced Photonics 2019年第4期1卷 15-20页

作者： Da Xu Zi-Zhao Han Yu-Kun Lu Qihuang Gong Cheng-Wei Qiu Gang Chen Yun-Feng Xiao peking university State Key Laboratory for Artificial Microstructures and Mesoscopic PhysicsSchool of PhysicsBeijingChina Nano-optoelectronics Frontier Center of the Ministry of Education Collaborative Innovation Center of Quantum MatterBeijingChina Shanxi university Collaborative Innovation Center of Extreme OpticsTaiyuanChina Beijing Academy of Quantum Information Sciences BeijingChina National university of Singapore Department of Electrical and Computer EngineeringSingaporeSingapore Shanxi university Institute of Laser SpectroscopyState Key Laboratory of Quantum Optics and Quantum Optics DevicesTaiyuanChina

Synchronization is of importance in both fundamental and applied physics,but its demonstration at the micro/nanoscale is mainly limited to low-frequency oscillations such as mechanical *** report the synchronization of two coupled optical microresonators,in which the high-frequency resonances in the optical domain are aligned with reduced *** is found that two types of synchronization regimes emerge with either the first-or second-order transition,both presenting a process of spontaneous symmetry *** the second-order regime,the synchronization happens with an invariant topological character number and a larger detuning than that of the first-order ***,an unconventional hysteresis behavior is revealed for a time-dependent coupling strength,breaking the static limitation and the temporal *** synchronization of optical microresonators offers great potential in reconfigurable simulations of manybody physics and scalable photonic devices on a chip.

关键词： :microcavity synchronization spontaneous symmetry breaking nonreciprocity

Size effect on transverse free vibrations of ultrafine nanothreads

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中国物理B:英文版 2023年第9期32卷 21-27页

作者：郑卓群李晗宿柱丁楠徐旭占海飞王立峰 State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Management Science and Information Engineering Jilin University of Finance and EconomicsChangchun 130117China College of Mathematics Jilin UniversityChangchun 130012China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbane 4001Australia

Due to their unique properties and appealing applications,low dimensional sp^(3)carbon nanostructures have attracted increasing attention *** on the beam theory and atomistic studies,this work carries out a comprehensive investigation on the vibrational properties of the ultrathin carbon nanothreads(NTH).Size effect is observed in transverse free vibrations of *** quantify such effects,the modified couple stress theory(MCST)is utilized to modify the Timoshenko beam *** to the first four order frequencies of NTHs from atomistic simulations,the critical length scale parameter of MCST is calibrated as 0.1 *** is shown that MCST has minor effect on the first four order modal shapes,except for the clamped *** makes the modal shapes at the clamped boundary closer to those observed in atomistic *** study suggests that to some extent the MCST-based Timoshenko beam theory can well describe the transverse vibration characteristics of the ultrafine NTHs,which are helpful for designing and fabricating the NTH-based nanoscale mechanical resonators.

关键词： carbon nanothread size effect natural frequency modal shapes molecular dynamics simulation

Super-strong interactions between multivalent anions and graphene

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Chinese Physics B 2021年第4期30卷 425-431页

作者： Xing Liu Guosheng Shi Shanghai Applied Radiation Institute State Key Laboratory Advanced Special SteelShanghai UniversityShanghai 200444China Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China

Based on the density functional theory(DFT) calculations,we showed that the interactions between different valence anions(PO_(4)^(3-),CH_(3)PO_(4)^(2-),(CH_(3))_(2)PO_(4)^(-)) and graphene significantly increased as the valence of anion increased from negative monovalence to negative *** adsorption energy of(CH_(3))_(2)PO_(4)^(-)on the electron-rich graphene flake(C84H24)is-8.3 kcal/*** adsorption energy of CH_(3)PO_(4)^(2-) on the electron-rich graphene flake(C_(84)H_(24)) is-48.0 kcal/mol,which is about six times that of(CH_(3))_(2)PO_(4) adsorption on electron-rich graphene flake(C_(84)H_(24)) and is even much larger than that of CO_(3)^(2-) adsorption on electron-deficient aromatic ring C_(6)F_(6)(-28.4 kcal/mol).The adsorption energy of PO_(4)^(3-)on the electron-rich graphene flake(C_(84)H_(24)) is-159.2 kcal/mol,which is about 20 times that of(CH_(3))_(2)PO_(4) adsorption on the graphene flake(C_(84)H_(24)).The super-strong adsorption energy is mainly attributed to the orbital interactions between multivalent anions and *** work provides new insights for understanding the interaction between multivalent anions and π-electron-rich carbon-based nanomaterials and is helpful for the design of graphene-based DNA biosensor.

关键词： graphene multivalent anions anion-πinteraction density functional theory

Application of kernel ridge regression in predicting neutron-capture reaction cross-sections

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Communications in Theoretical Physics 2022年第9期74卷 98-104页

作者： T X Huang X H Wu P W Zhao State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

This article provides the first application of the machine-learning approach in the study of the cross-sections for neutron-capture reactions with the kernel ridge regression(KRR)*** is found that the KRR approach can reduce the root-mean-square(rms)deviation of the relative errors between the experimental data of the Maxwellian-averaged(n,γ)cross-sections and the corresponding theoretical predictions from 69.8%to 35.4%.By including the data with different temperatures in the training set,the rms deviation can be further significantly reduced to 2.0%.Moreover,the extrapolation performance of the KRR approach along different temperatures is found to be effective and reliable.

关键词： kernel ridge regression machine learning neutron-capture reaction

Four New Phloroglucinol-Terpene Adducts from the Leaves of Myrciaria cauliflora

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Natural Products and Bioprospecting 2021年第1期11卷 111-118页

作者： Ming Chen Jia-Qing Cao Wen-Jing Wang Ni-Ping Li Yan Wu Lei Wang Wen-Cai Ye Institute of Traditional Chinese Medicine&Natural Products College of PharmacyJinan UniversityGuangzhou 510632People’s Republic of China Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research Jinan UniversityGuangzhou 510632People’s Republic of China

Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria *** structures with absolute configurations were elucidated by combination of spectroscopic analysis,single crystal X-ray diffraction,and electronic circular dichroism(ECD)*** 1 was a rearranged isobutylphloroglucinol-pinene adduct featuring an unusual 2,3,4,4a,10,11-hexahydro-1H-3,11a-methanodibenzo[b,f]oxepin *** 4 showed moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.

关键词： Myrciaria cauliflora Phloroglucinol-terpene adducts Antibacterial activity

Chiral detection of biomolecules based on reinforcement learning

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Opto-Electronic Science 2023年第1期2卷 1-10页

作者： Yuxiang Chen Fengyu Zhang Zhibo Dang Xiao He Chunxiong Luo Zhengchang Liu Pu Peng Yuchen Dai Yijing Huang Yu Li Zheyu Fang School of Physics Peking UniversityBeijing 100871China The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics School of Physics&Center for Quantitative BiologyAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Wenzhou Institute University of Chinese Academy of SciencesWenzhou 325001China

Chirality plays an important role in biological processes,and enantiomers often possess similar physical properties and different physiologic *** recent years,chiral detection of enantiomers become a popular *** metasurfaces enhance weak inherent chiral effects of biomolecules,so they are used in chiral *** intelligence algorithm makes a lot of contribution to many aspects of ***,we propose a nanostructure design method based on reinforcement learning and devise chiral nanostructures to distinguish *** algorithm finds out the metallic nanostructures with a sharp peak in circular dichroism spectra and emphasizes the frequency shifts caused by nearfield interaction of nanostructures and *** work inspires universal and efficient machine-learning methods for nanophotonic design.

关键词： chiral detection metasurface deep learning cathodoluminescence