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Energy Spectrum of a Degenerate Fermi Gas at the BEC-BCS Crossover

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Communications in Theoretical Physics 2007年第5X期48卷 855-858页

作者： fang yuan Beijing National Laboratory for Condensed Matter Physics Institute of Physics the Chinese Academy of Sciences Beijing 100080 China

A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green＇s function method are adopted. The result shows that we can end up with a BCS-type theory but with a composite order parameter. Calculation shows that the Bose condensate of BCS Cooper pairs is proportional to the molecular BEC of Bose molecules. The resonance superfluid phase is indicated by the energy spectrum with an obvious interpretation of the transition mechanism.

关键词： degenerate Fermi gas BEC-BCS crossover Feshbach resonance

A solution to parabolic system with the fractional Laplacian

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Applied Mathematics(A Journal of Chinese Universities) 2009年第2期24卷 184-190页

作者： fang Lin fang Dao-yuan Dept. of Math. Zhejiang Univ. Hangzhou 310027 China

The existence of a solution to the parabolic system with the fractional Laplacian （-△） α/2, α 〉 0 is proven, this solution decays at different rates along different time sequences going to infinity. As an application, the existence of a solution to the generalized Navier-Stokes equations is proven, which decays at different rates along different time sequences going to infinity. The generalized Navier-Stokes equations are the equations resulting from replacing -△ in the Navier-Stokes equations by （-△）^m, m〉 0. At last, a similar result for 3-D incompressible anisotropic Navier-Stokes system is obtained.

关键词： parabolic system fractional Laplacian decay rate

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采用小波变换的空间外差干涉图误差分析方法

光谱学与光谱分析 2025年第1期45卷 8-14页

作者：王方原李晓静叶松李树王新强桂林电子科技大学光电工程学院广西桂林541004 广西光电信息处理重点实验室广西桂林541004

空间外差光谱技术(SHS)是一种应用于微弱物质探测、行星勘探以及大气遥感等领域的超光谱分析技术。受实验环境复杂及被测目标信号微弱等因素的影响,空间外差光谱仪的测量结果易出现干涉条纹倾斜、干涉图有斑点噪声等情况,从而最终影响... 详细信息

空间外差光谱技术(SHS)是一种应用于微弱物质探测、行星勘探以及大气遥感等领域的超光谱分析技术。受实验环境复杂及被测目标信号微弱等因素的影响,空间外差光谱仪的测量结果易出现干涉条纹倾斜、干涉图有斑点噪声等情况,从而最终影响测量光谱的精度。为了尝试解决这些问题,提出了基于小波变换的干涉图误差分析方法,对干涉图的斑点噪声水平和条纹倾斜误差进行有效的评价,从而为后续误差校正提供理论基础。首先对无误差的钾灯仿真干涉图加入不同标准差的高斯噪声,利用小波分解提取复小波系数,采用三种噪声估计法对干涉图数据进行计算,结果表明空域相关小波变换法噪声估计结果与真实值偏差最小,而Donoho估计法在修正截距后与真实值具有更好的吻合度。随后采用Db2小波对噪声水平不同的仿真钾灯干涉图进行一层小波分解并提取水平、对角及垂直三个方向的细节系数,采用Donoho估计法对干涉图进行二维噪声分析,有效表征了三幅干涉图各方向上的噪声水平特征。最后对仿真连续光干涉图进行小波分解并提取系数分析,研究了干涉条纹倾斜角度与小波分解系数的关系。研究结果表明,三个方向的小波细节系数估值变化分别在分解到不同层数时具有相似的变化规律:小波细节系数估值与条纹倾斜方向和小波细节系数的所属方向的夹角成反比,条纹倾斜方向与该小波细节系数的方向夹角越小,估值越大,反之则越小,且水平方向分解到第一层、对角方向分解到第二层、垂直方向分解到第三层符合变化规律。该研究是利用小波分解进行空间外差光谱误差分析的有益尝试,也为后续干涉图条纹倾斜误差的校正提供了一种新途径。

关键词：空间外差光谱技术噪声标准差估计干涉图小波变换

Non-formation of vacuum states for Navier-Stokes equations with density-dependent viscosity

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1681-1690页

作者： ZHANG Ting fang Dao-yuan Department of Mathematics Zhejiang University Hangzhou 310027 China

We consider the Cauchy problem, free boundary problem and piston problem for one-dimensional compressible Navier-Stokes equations with density-dependent viscosity. Using the reduction to absurdity method, we prove that the weak solutions to these systems do not exhibit vacuum states, provided that no vacuum states are present initially. The essential re- quirements on the solutions are that the mass and energy of the fluid are locally integrable at each time, and the Lloc1-norm of the velocity gradient is locally integrable in time.

关键词： Compressible Navier-Stokes equations Vacuum states Density-dependent viscosity

Airline Alliance Revenue Distribution Considering Horizontal and Vertical Competition

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第S1期35卷 20-26页

作者： Le Meilong fang yuan College of Civil Aviation Nanjing University of Aeronautics and Astronautics

Considering the existence of multi-level fares in the alliance,and the existence of horizontal competition and vertical competition at the same time,this paper intends to maximize the revenue of airline alliance and fairly distribute the revenue to member ***,a model is built under the centralized mechanism,in which all airlines in the alliance are regarded as a *** solving the model,the shadow price of each flight leg on the code-sharing route is *** is used to calculate the proportion of the revenue ***,the centralized model is decomposed into the single airline model by the *** seat allocation among airlines and distributed revenue can be gotten by solving the *** typical examples are designed to test *** results show that,the model can effectively reflect the managerial principal of the airline alliance,that is maximizing total revenue and fairly distributing the revenue among member airlines.

关键词： airline alliance revenue management proportion of revenue distribution vertical competition horizontal competition

Modified min-sum SCAN decoding algorithm for polar codes

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The Journal of China Universities of Posts and Telecommunications 2018年第6期25卷 90-96页

作者： yuan fang Tian Bin State Key Laboratory of Integrated Services Networks Xidian UniversityXi'an 710071China Collaborative Innovation Center of Information Sensing and Understanding at Xidian University Xi'an 710071China China Electronics Technology Croup Corporation Key Laboratory of Aerospace Information Applications Shijiazhuang 050081China

The state-of-the-art soft-output decoder of polar codes is the soft cancellation(SCAN) decoding algorithm, which performs well at the cost of plentiful computations. Based on the SCAN decoding algorithm, a modified method with revised iterative formula is proposed, marked modified min-sum SCAN(MMS-SCAN). The proposed algorithm simplifies the update formula of nodes and reduces the complexity of iterative decoding process by the piecewise approximation function. Meanwhile, the bit error rate(BER) of the proposed method can approach the performance of original SCAN decoding method without performance loss. The simulation reveals that the MMS-SCAN decoding algorithm can achieve the effect that the BER curve almost coincides with the original SCAN decoding curve.

关键词： polar codes MMS-SCAN iterative formula the piecewise approximation function

Effects of creep characteristics of natural gas hydrate-bearing sediments on wellbore stability

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Petroleum Science 2022年第1期19卷 220-233页

作者： Yang Li yuan-fang Cheng Chuan-Liang Yan Zhi-yuan Wang Li-fang Song School of Petroleum Engineering China University of Petroleum(East China)66 West Changjiang RoadHuangdao DistrictQingdao 266000China

Natural gas hydrate(NGH)reservoirs consist of the types of sediments with weak cementation,low strength,high plasticity,and high *** on the kinetics and thermodynamic characteristics of NGH decomposition,herein a heat-fluid-solid coupling model was established for studying the wellbore stability in an NGH-bearing formation to analyze the effects of the creep characteristics of NGH-bearing sediments during long-term *** results demonstrated that the creep characteristics of sediments resulted in larger plastic yield range,thus aggravating the plastic strain accumulation around the ***,the creep characteristics of NGH-bearing sediments could enhance the effects induced by the difference in horizontal in situ stress,as a result,the plastic strain in the formation around the wellbore increased nonlinearly with increasing difference in in situ *** lower the pore pressure,the greater the stress concentration effects and the higher the plastic strain at the ***,the lower the initial NGH saturation,the greater the initial plastic strain and yield range and the higher the equivalent creep *** plastic strain at the wellbore increased nonlinearly with decreasing initial saturation.

关键词： Natural gas hydrates Wellbore stability Creep Plastic yield

“第二个结合”导向下的高中语文古诗词群文阅读教学探究

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科教文汇 2025年第1期 160-163页

作者：杜爱国袁昉中共武汉市委党校湖北武汉430024 华中师范大学第一附属中学湖北武汉430223

高中语文古诗词群文阅读教学在高中语文教育改革中扮演着重要角色,是实践文化建设“第二个结合”要求的重要方式,有助于培育学生的综合素质和文化认同感。在教学中,教师可以利用精选的课内外古诗词,按照群文阅读要求,以核心素养培育、... 详细信息

高中语文古诗词群文阅读教学在高中语文教育改革中扮演着重要角色,是实践文化建设“第二个结合”要求的重要方式,有助于培育学生的综合素质和文化认同感。在教学中,教师可以利用精选的课内外古诗词,按照群文阅读要求,以核心素养培育、合作探究学习、情景教学营造、批判性思考解读为策略,引导学生感悟语文的精髓与魅力。在实际案例中,可以进一步体会本教学方式的具体应用措施。

关键词：第二个结合古诗词群文阅读

Controlled Self-assembly of Thermo-responsive Amphiphilic H-shaped Polymer for Adjustable Drug Release

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Chinese Journal of Polymer Science 2018年第3期36卷 406-416页

作者： Yang Bai fang-yuan Xie Wei Tian College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi'an 710021China Ministry of Education Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Macromolecular Science and Technology School of ScienceNorthwestern Polytechnical UniversityXi’an 710072China Department of Pharmacy Eastern Hepatobiliary Surgery HospitalThe Second Military Medical UniversityShanghai 200438 China

Despite the fact that some progress has been made in the self-assembly of H-shaped polymers, the corresponding self-assemblies that respond to external stimulus and are further utilized to adjust the release of drugs are still deficient. The stimuli-responsive segments with amphiphilic H-shaped structure are generally expected to enhance the controllability of self-assembly process. The synthesis and self-assembly behavior of thermo-responsive amphiphilic H-shaped polymers with poly（ethylene glycol）（PEG）, polytetrahydrofuran （PTHF） and poly（N-isopropyl acrylamide）（PNIPAM） as building blocks are reported in this paper. The inner architecture structure and size of complex micelles formed by H-shaped self-assemblies were effectively adjusted when the solution temperature was increased above the lower critical solution temperature of PNIPAM segments. Furthermore, it was found that the architecture of self-assemblies underwent a transition from the complex micelles based on primary micelles with hybrid PEG/PNIPAM shells to large complex micelles based on primary micelles with hybrid PTHF/PNIPAM cores and PEG shells during the thermal-induced self-assembly process. The adjustable release rate ofdoxorubicin （DOX） from the DOX-loaded complex micelles and basic cell experiments further proved the feasibility of these self-assemblies as the thermal-responsive drug delivery system.

关键词： H-shaped polymer Thermo-responsive polymer Amphiphilic polymer Self-assembly Drug release