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Generation of Laser Light via Ultrasonic Four-wave Mixing

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Chinese Journal of Lasers 2001年第2期 62-69页

作者： ou fa (department of applied physics, south china university of technology, guangzhou 510641, china) wu Fugen HE Minggao (department of applied physics, guangdong university of technology, guangzhou 510090, china)

On the basis of the interaction between phonons in ionic crystals with anharmonic lattice vibration, we present a laser model on acoustic nondegenerate four wave mixing. Two beams of high frequency ultrasound, incident on the acoustic cavity fulfilled with the medium of ionic crystal, play the role of pumping and one of the two side band modes of the pumping frequency as an acoustic signal mode has a strong interaction with the optical cavity mode, the coupling out of which will be the light (far infrared) output of a laser. The problem is treated with quantum mechanics. The theory shows that there is the threshold phenomenon as usual lasers and a so called “phase matching” condition is derived, which should be satisfied for stability of the system.

关键词： acoustic four wave mixing laser anharmonicity of the ionic lattice

Ultrasonic generation via direct interaction between photons and phonons in anharmonic lattice of ionic crystals

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Chinese Journal of Acoustics 2000年第2期19卷 182-191页

作者： ou fa (department of applied physics, south china university of technology guangzhou 510641) wu Fugen HE Minggao (physics department, guangdong university of technology guangzhou 510090) LIU Cuihong (physics department, guangzhou Teachers’College Guangzh

A theory of ultrasonic generation via direct interaction of transverse optic (TO) phonons with photons in anharmonic lattice of ionic crystals is presented. There are two methods of supplying light energy for the excitation of TO lattice wave as a high frequency ultrasound: (A) incident light comes from the source outside the cavity? fulfilled with ionic crystal medium, (B) photon mode of the cavity possesses the gain of amplification by stimulated radiation of active atoms doping in the medium. More attention is drawn to the case (B). The working system of case (B), as a mixture of lasing action and ultrasonic generation, has the threshold phenomena like usual laser. And the linear stability analysis shows that the nonlineax phonon-photon coupling and the interaction among phonons themselves, both of which reflect the anharmonicity of lattice vibration, are necessary to the stable ultrasonic output. So this laser-ultrasonic generation mixture would be also a measure to investigate the lattice-dynamic nonlinearity and correlated electromagnetic properties of ionic crystals.

关键词： Ultrasonic generation via direct interaction between photons and phonons in anharmonic lattice of ionic crystals mode

光子-玻色子元激发耦合激光模型的准周期自脉冲和混沌状态

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中国激光 1998年第6期25卷 533-538页

作者：何明高欧发广东工业大学数理系华南理工大学应用物理系

简化并用计算机求解了经过改进后的光子－玻色子元激发非线性耦合激光模型的动力学方程，并对所得到的包括梯形和矩形准周期自脉冲、尖峰自脉冲、零维和一维吸引子以及阵发性混沌等一系列有趣的现象进行了讨论和研究。

关键词：非线性光学玻色子自脉冲混沌光子激光模型

Bifurcation　of　Dicke　Model　Driven　by　Laser　Field　and　Scaling　Theory　of　Critical　Exponents　far　from　Equilibrium

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Chinese Journal of Lasers 1996年第5期 429-438页

作者： ou fa (CCAST (World Laboratory) P. O. Box 8730, Beijing 100080 and department of applied physics, south china university of technology, guangzhou 510641)wu Fugen (department of basic Course, guangdong university technology,guangzhou 510090)

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关键词： bifurcation of optical dissipative system critical exponent scaling rules

A meteorologically adjusted ensemble Kalman filter approach for inversing daily emissions:A case study in the Pearl River Delta,china

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Journal of Environmental Sciences 2022年第4期34卷 233-248页

作者： Guanglin Jia Zhijiong Huang Xiao Tang Jiamin ou Menghua Lu Yuanqian Xu Zhuangmin Zhong Qing’e Sha Huangjian wu Chuanzeng Zheng Tao Deng Duohong Chen Min He Junyu Zheng School of Environment and Energy South China University of TechnologyUniversity Town CampusGuangzhou 510006China Institute for Environmental and Climate Research Jinan UniversityGuangzhou 511486China Institute of Atmospheric physics Chinese Academy of SciencesBeijing 100029China faculty of Social and Behavioural Sciences Utrecht UniversityUtrechtCH 3584the Netherlands guangzhou Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510640China State Environmental Protection Key Laboratory of Regional Air Quality Monitoring Guangdong Environmental Monitoring CenterGuangzhou 510308China department of Environmental Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China

The conventional Ensemble Kalman filter(EnKF),which is now widely used to calibrate emission inventories and to improve air quality simulations,is susceptible to simulation errors of meteorological inputs,making accurate updates of high temporal-resolution emission inventories *** this study,we developed a novel meteorologically adjusted inversion method(MAEInv)based on the EnKF to improve daily emission *** new method combines sensitivity analysis and bias correction to alleviate the inversion biases caused by errors of meteorological *** demonstration,we used the MAEInv to inverse daily carbon monoxide(CO)emissions in the Pearl River Delta(PRD)region,*** the case study,60%of the total CO simulation biases were associated with sensitive meteorological inputs,which would lead to the overestimation of daily variations of posterior *** the new inversion method,daily variations of emissions shrank dramatically,with the percentage change decreased by 30%.Also,the total amount of posterior CO emissions estimated by the MAEInv decreased by 14%,indicating that posterior CO emissions might be overestimated using the conventional *** evaluations using independent observations revealed that daily CO emissions estimated by MAEInv better reproduce the magnitude and temporal patterns of ambient CO concentration,with a higher correlation coefficient(R,+37.0%)and lower normalized mean bias(NMB,-17.9%).Since errors of meteorological inputs are major sources of simulation biases for both low-reactive and reactive pollutants,the MAEInv is also applicable to improve the daily emission inversions of reactive pollutants.

关键词： Emission inversion Daily emissions Meteorological adjustment Ensemble Kalman filter

Information Entropy Squeezing for a Atom in Mode-Mode Competition System

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Communications in Theoretical physics 2008年第12期50卷 1411-1416页

作者： wu Qin faNG Mao-fa LI Shao-Xin LI Ying HU Yao-Hua School of Basic Medical Science Guangdong Medical College Dongguan 523808 China College of physics and Information Science Hunan Normal University Changsha 410081 China

The entropy squeezing properties for a two-level atom interacting with a two-mode field via two differentcompeting transitions are investigated from a quantum information point of *** influences of the initial state of thesystem and the relative coupling strength between the atom and the field on the atomic information entropy squeezingare *** results show that the squeezed direction and the frequency of the information entropy squeezing canbe controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field,*** find that,under the same condition,no atomic variance squeezing is predicted from the HUR while optimal entropysqueezing is obtained from the EUR,so the quantum information entropy is a remarkable precision measure for theatomic squeezing in the considered system.

关键词： J-C模型非线性动力学性质原子物理学

Mapping the elastic properties of two-dimensional MoS_(2) via bimodal atomic force microscopy and finite element simulation

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npj Computational Materials 2018年第1期4卷 246-253页

作者： Yuhao Li Chuanbin Yu Yingye Gan Peng Jiang Junxi Yu Yun ou Dai-Feng Zou Cheng Huang Jiahong Wang Tingting Jia Qian Luo Xue-Feng Yu Huijuan Zhao Cun-fa Gao Jiangyu Li State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics&AstronauticsNanjing 210016 JiangsuChina Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen518055 GuangdongChina department of Mechanical Engineering Clemson UniversityClemsonSC 29634-0921USA Key Laboratory of Low Dimensional Materials and Application technology of Ministry of Education School of Materials Science and EngineeringXiangtan UniversityXiangtan 411105 HunanChina Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment Hunan University of Science and TechnologyXiangtan 411201 HunanChina School of physics and Electronic Science Hunan University of Science and TechnologyXiangtan 411201 HunanChina Institute of Biomedicine and Biotechnology Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055 GuangdongChina Shenzhen Institutes of Advanced technology Chinese Academy of SciencesShenzhen 518055 GuangdongChina department of Mechanical Engineering University of WashingtonSeattleWA 98195USA

Elasticity is a fundamental mechanical property of two-dimensional(2D)materials,and is critical for their application as well as for strain ***,accurate measurement of the elastic modulus of 2D materials remains a challenge,and the conventional suspension method suffers from a number of *** this work,we demonstrate a method to map the in-plane Young’s modulus of mono-and bi-layer MoS_(2) on a substrate with high spatial *** atomic force microscopy is used to accurately map the effective spring constant between the microscope tip and sample,and a finite element method is developed to quantitatively account for the effect of substrate stiffness on *** these methods,the in-plane Young’s modulus of monolayer MoS_(2) can be decoupled from the substrate and determined as 265±13 GPa,broadly consistent with previous reports though with substantially smaller *** is also found that the elasticity of mono-and bi-layer MoS_(2) cannot be differentiated,which is confirmed by the first principles *** method provides a convenient,robust and accurate means to map the in-plane Young’s modulus of 2D materials on a substrate.

关键词： modulus modal element

小柴胡汤瓦锅煎煮与机器煎煮质量的多维度评价

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中国医院药学杂志 2022年第18期42卷 1882-1885页

作者：吴招娣袁鑫钟燕珠吴俊标施宏彬胡黎龚又明欧阳百发区炳雄王颖彦林华广东省中医院药学部广东广州510120 康美药业股份有限公司广东广州510230

目的:从HPLC指纹图谱、指标性成分含量、出膏率、密度及pH值方面,多维度评价传统瓦锅煎煮与现代机器煎煮所得小柴胡汤的质量。方法:分别采用传统瓦锅煎煮法、机器常压一煎法和机器常压两煎法制备汤液。HPLC色谱柱为Agilent ZORBAX SB-C_... 详细信息

目的:从HPLC指纹图谱、指标性成分含量、出膏率、密度及pH值方面,多维度评价传统瓦锅煎煮与现代机器煎煮所得小柴胡汤的质量。方法:分别采用传统瓦锅煎煮法、机器常压一煎法和机器常压两煎法制备汤液。HPLC色谱柱为Agilent ZORBAX SB-C_(18)(250 mm×4.6 mm, 5μm),检测波长为205 nm,流动相为乙腈-0.1%磷酸水溶液,柱温为30℃,流速为1.0 mL·min^(-1),检测的指标性成分有甘草苷、甘草酸铵、黄芩苷、人参皂苷Rg1、人参皂苷Rb1、柴胡皂苷a和柴胡皂苷d。结果:3种方法制备的小柴胡汤HPLC指纹图谱相似度大于99%;机器两煎法中甘草苷、柴胡皂苷d的含量高于瓦锅煎煮(P0.05);机器一煎法中人参皂苷Rg1、人参皂苷Rb1、柴胡皂苷a的含量低于瓦锅煎煮(P<0.05),其余成分的含量与瓦锅煎煮无统计学差异,机器一煎的出膏率和密度虽低于瓦锅煎煮,但均达到了瓦锅煎煮的90%以上。结论:小柴胡汤现代机器煎煮与传统瓦锅煎煮的质量无明显差异。

关键词：小柴胡汤瓦锅煎煮机器一煎机器两煎质量指标性成分 HPLC指纹图谱

Extension of Noether's theorem in PT-symmetry systems and its experimental demonstration in an optical setup

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Science china(physics,Mechanics & Astronomy) 2023年第4期66卷 13-27页

作者： Qi-Cheng wu Jun-Long Zhao Yu-Liang fang Yu Zhang Dong-Xu Chen Chui-Ping Yang Franco Nori Quantum Information Research Center Shangrao Normal UniversityShangrao 334001China School of physics Nanjing UniversityNanjing 210093China department of physics Hangzhou Normal UniversityHangzhou 311121China Theoretical Quantum physics Laboratory RIKENWako-shiSaitama 351-0198Japan RIKEN Center for Quantum Computing RIKENWako-shiSaitama 351-0198Japan physics department The University of MichiganAnn Arbor 48109-1040USA

Noether’s theorem is one of the fundamental laws in physics,relating the symmetry of a physical system to its constant of motion and conservation *** the other hand,there exist a variety of non-Hermitian parity-time(PT)-symmetric systems,which exhibit novel quantum properties and have attracted increasing *** this work,we extend Noether’s theorem to a class of significant PT-symmetry systems for which the eigenvalues of the PT-symmetry Hamiltonian HPTchange from purely real numbers to purely imaginary numbers,and introduce a generalized expectation value of an operator based on biorthogonal quantum *** find that the generalized expectation value of a time-independent operator is a constant of motion when the operator presents a standard symmetry in the PT-symmetry unbroken regime,or a chiral symmetry in the PT-symmetry broken *** addition,we experimentally investigate the extended Noether’s theorem in PT-symmetry single-qubit and two-qubit systems using an optical *** experiment demonstrates the existence of the constant of motion and reveals how this constant of motion can be used to judge whether the PT-symmetry of a system is ***,a novel phenomenon of masking quantum information is first observed in a PT-symmetry two-qubit *** study not only contributes to full understanding of the relation between symmetry and conservation law in PT-symmetry physics,but also has potential applications in quantum information theory and quantum communication protocols.

关键词： Noether’s theorem PT-symmetry systems chiral symmetry optical setup