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Generation of sustained optimal entropy squeezing of a two-level atom via non-Hermitian operation

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Chinese Physics B 2018年第11期27卷 506-511页

作者： Yan-yi Wang mao-Fa Fang Synergetic Innovation Center for Quantum Effects and Application and Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education School of Physics and Electronics Hunan Normal University Changsha 410081 China

We investigate the entropy squeezing of a two-level atom in the Jaynes–Cummings model, and provide a scheme to generate the sustained optimal entropy squeezing of the atom via non-Hermitian operation. Our results show that the squeezing degree and the persistence time of entropy squeezing of atomic polarization components greatly depend on the non-Hermiticity intensity in non-Hermitian operation. Especially, under a proper choice of non-Hermiticity parameters, the sustained optimal entropy squeezing of the atom can be generated even though the atom is initially prepared in a no entropy squeezing state.

关键词： entropy squeezing non-Hermitian dynamics quantum optics Jaynes-Cummings model

On the governing equations for the compressing process and its coupling with other processes

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Science China(Physics,Mechanics & Astronomy) 2011年第6期54卷 1154-1167页

作者： mao Feng SHI yiPeng xuan LiJun SU WeiDong WU JieZhi State Key Laboratory for Turbulence and Complex Systems College of EngineeringPeking UniversityBeijing 100871China University of Tennessee Space Institute TullahomaTN 37388USA

As a continuation of a recent linear analysis by mao et al.(Acta Mech Sin,2010,26:355),in this paper we propose a general theoretical formulation for the compressing process in complex Newtonian fluid flows,which covers gas dynamics,aeroacoustics,nonlinear thermoviscous acoustics,viscous shock layer,etc.,as its special *** principle on which our formulation is based is the maximally natural and dynamic Helmholtz decomposition of the Navier-Stokes equation,along with the kinematic Helmholtz decomposition of the velocity *** central results are the new dilatation equation and velocity-potential equation,which are the counterparts of vorticity transport equation and vector stream-function equation for the shearing process,*** couplings of the compressing process with shearing and thermal processes,including its physical sources,are carefully *** the possible applications and influences of the new formulation are yet to be explored,our preliminary discussion on the pros and cons of previous formulations pertain to acoustic analogy and that on the process splitting and coupling in highly compressible turbulence indicates that at least the formulation can serve as a new frame of reference by which one may gain some additional insight and thereby develop new approaches to the multi-process complex flow problems.

关键词： longitudinal (compressing) process transversal (shearing) process Helmholtz decomposition aeroacoustics compressible turbulence

Quantum speed limit time of a non-Hermitian two-level system

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Chinese Physics B 2020年第3期29卷 89-94页

作者： Yan-yi Wang mao-Fa Fang Synergetic Innovation Center for Quantum Effects and Application and Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of EducationSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China

We investigated the quantum speed limit time of a non-Hermitian two-level system for which gain and loss of energy or amplitude are present. Our results show that, with respect to two distinguishable states of the non-Hermitian system, the evolutionary time does not have a nonzero lower bound. The quantum evolution of the system can be effectively accelerated by adjusting the non-Hermitian parameter, as well as the quantum speed limit time can be arbitrarily small even be zero.

关键词： quantum speed limit time non-Hermitian dynamics quantum optics

Translating Solutions of the Nonparametric Mean Curvature Flow with Nonzero Neumann Boundary Data in Product Manifold M^(n)×R^(*)

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Chinese Annals of Mathematics,Series B 2022年第4期43卷 601-620页

作者： Ya GAO yi-Juan GONG Jing mao Faculty of Mathematics and Statistics Key Laboratory of Applied Mathematics of Hubei ProvinceHubei UniversityWuhan 430062China

In this paper,the authors can prove the existence of translating solutions to the nonparametric mean curvature flow with nonzero Neumann boundary data in a prescribed product manifold M^(n)×R,where M^(n) is an n-dime... 详细信息

关键词： Translating solutions Singularity Nonparametric mean curvature flow Convexity Ricci curvature

Supramolecular Vesicles Based on Water-Soluble 2,6-Helic[6]arene:High Affinity Binding,Stimuli Responsiveness and Delivery of Doxorubicin to Cancer Cells

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Chinese Journal of Chemistry 2019年第6期37卷 575-580页

作者： xuan Yang Weipeng mao Yamin Liu Libai Li Da Ma Department of Chemistry Fudan University220 Handan RoadShanghai 200433China

Water-soluble 2,6-helic[6]arene was used to construct supramolecular vesicles via host-guest interaction. Water-soluble 2,6-helic[6]arene was discovered to be high affinity host for suitable biomarkers. Supramolecular vesicles were responsive to multiple stimuli types, including temperature, pH, Ca^2+, CO2 bubbling and biomarker displacement. Supramolecular vesicles were used to load and deliver anti-tumor drug doxorubicin to HeLa cells in vitro.

关键词： host-guest systems nanostructures molecular recognitions self-assembly supramolecular vesicles

TIDAL EFFECTS ON GROUNDWATER DYNAMICS IN COASTAL AQUI-FER UNDER DIFFERENT BEACH SLOPES

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Journal of Hydrodynamics 2012年第1期24卷 97-106页

作者： LIU yi SHANG Song-hao mao Xiao-min College of Water Conservancy and Civil EngineeringChina Agricultural UniversityBeijing 100083China State Key Laboratory of Hydroscicncc and Engineering Department of Hydraulic EngineeringTsinghuaUniversityBeijing 100084China College of Water Conservancy and Civil Engineering China Agricultural UniversityBeijing 100083China

The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal *** previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater *** this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping *** simulation results are validated by laboratory experimental data in *** numerical scenarios are designed in a practical scale with different beach *** show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm *** for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance（）in the form of a logarithm *** beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the *** beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length（）,the relative enhancement of the tide induced seawater intrusion（）and the beach angle（）.It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions *** tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.

关键词： tidal effects salt wedges saline intrusion beach slope finite element method

Experimental research on dual polarized laser optical feedback microscope

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光学精密工程 2005年第5期13卷 613-619页

作者： mao Wei ZHANG Shu-lian TAN yi-dong State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments Tsinghua University Beijing 100084 China

The principle of laser optical feedback microscope was presented and demonstrated. Three methods to advance the vertical resolution of laser optical feedback microscope were experimentally studied. The first one is to detect the two polarized lights’ intensities separately with a Wollaston prism instead of to detect the whole light’s intensity. The second is that both of the two orthogonally polarized lights of a birefringent dual frequency laser are fed back. The third one is that only one of the orthogonally polarized lights is fed back. The experimental results show that the modes competition between orthogonally polarized lights can be used to improve the vertical resolution of laser optical feedback microscope effectively.

关键词：激光光纤显微镜光学分析

Polymer translocation through nanopore under external electric field:dissipative particle dynamics study

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Applied Mathematics and Mechanics(English Edition) 2015年第12期36卷 1581-1592页

作者： Jinglin mao yi YAO Zhewei ZHOU Guohui HU Shanghai Institute of Applied Mathematics and Mechanics College of Sciences Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering

The DNA sequencing technology has achieved a leapfrog development in recent years. As a new generation of the DNA sequencing technology, nanopore sequenc- ing has shown a broad application prospect and attracted vast research interests since it was proposed. In the present study, the dynamics of the electric-driven translocation of a homopolymer through a nanopore is investigated by the dissipative particle dynam- ics （DPD）, in which the homopolymer is modeled as a worm-like chain （WLC）. The DPD simulations show that the polymer chain undergoes conformation changes during the translocation process. The different structures of the polymer in the translocation process, i.e., single-file, double folded, and partially folded, and the induced current block- ades are analyzed. It is found that the current blockades have different magnitudes due to the polymer molecules traversing the pore with different folding conformations. The nanoscale vortices caused by the concentration polarization layers （CPLs） in the vicinity of the sheet are also studied. The results indicate that the translocation of the polymer has the effect of eliminating the vortices in the polyelectrolyte solution. These findings are expected to provide the theoretical guide for improving the nanopore sequencing tech- nique.

关键词： nanopore sequencing technology electric-driven translocation dissipative particle dynamics (DPD)

Preparation of Agarose Sulfate and Its Antithrombogenicity

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Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 110-114页

作者： JIE Youping ZHANG Lingmin CHEN Peng mao xuan TANG Shunqing Biomedical Engineering Institute Jinan UniversityGuangzhou 510632China

As one of the seaweed polysaccharide, agarose has received much attention because of its biocompatibility. However, its application in biomedical field was limited with its biological inertia. Modification with some functional groups is needed to obtain agarose derivatives with biological activity and expand its applications. Consequently, agarose was sulfated with chlorosulfonic acid-pyridine with formamide as dispersing agent. The orthogonal test result showed that the optimal reaction condition was the reaction time being 4 h, the reaction temperature 65 ℃ and the ratio of chlorosulfonic acid to agarose 1-4（mL/g）. Two kinds of the insoluble agarose sulfate （below 37 ℃） were synthesized with degree of substitution （DS） being 0.17 and 0.43 respectively. Infrared spectroscopy （IR） and tac nuclear magnetic resonance （13C-NMR） spectroscopy results proved that C3_6 in agarose was sulfated. Their hydrophobic property and BSA adsorption capacity rose with increasing DS, while the adsorption of lib was reduced. The anti-clotting properties of agarose sulfate were significantly improved, and agarose sulfate could protect red blood cells from deformation after adsorption of BSA. These findings demonstrate that the cold-water insoluble agarose sulfate has a promise for applications as heoarin-like material in anticoagulation or endothelial re^enera＇Lion scaffold.

关键词： coal gangue copper tailings XRD oxygen-rich minerals