检索结果-南通市图书馆

A Generalized Method and Exact Solutions in Bose-Einstein Condensates in an Expulsive Parabolic Potential

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第3X期48卷 391-398页

作者： li biao Nonlinear Science Center and Department of Mathematics Ningbo University Ningbo 315211 China Institute of Theoretical Computing East China Normal University Shanghai 200062 China MM Key Lab the Chinese Academy of Sciences Beijing 100080 China

In the paper, a generalized sub-equation method is presented to construct some exact analytical solutions of nonlinear partial differential equations. Making use of the method, we present rich exact analytical solutions of the onedimensional nonlinear Schrfdinger equation which describes the dynamics of solitons in Bose-Einstein condensates with time-dependent atomic scattering length in an expulsive parabolic potential. The solutions obtained include not only non-traveling wave and coefficient function＇s soliton solutions, but also Jacobi elliptic function solutions and *** elliptic function solutions. Some plots are given to demonstrate the properties of some exact solutions under the Feshbachmanaged nonlinear coefficient and the hyperbolic secant function coefficient.

关键词： nonlinear Schrodinger equation symbolic computation soliton

Solving forward and inverse problems of the nonlinear Schrodinger equation with the generalized PT-symmetric Scarf-Ⅱpotential via PINN deep learning

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2021年第12期73卷 1-13页

作者： Jiaheng li biao li School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

In this paper,based on physics-informed neural networks(PINNs),a good deep learning neural network framework that can be used to effectively solve the nonlinear evolution partial differential equations(PDEs)and other types of nonlinear physical models,we study the nonlinear Schrodinger equation(NLSE)with the generalized PT-symmetric Scarf-Ⅱpotential,which is an important physical model in many fields of nonlinear ***,we choose three different initial values and the same Dinchlet boundaiy conditions to solve the NLSE with the generalized PT-symmetric Scarf-Ⅱpotential via the PINN deep learning method,and the obtained results are compared with ttose denved by the toditional numencal ***,we mvestigate effect of two factors(optimization steps and activation functions)on the performance of the PINN deep learning method in the NLSE with the generalized PT-symmetric Scarf-Ⅱ***,the data-driven coefficient discovery of the generalized PT-symmetric Scarf-Ⅱpotential or the dispersion and nonlinear items of the NLSE with the generalized PT-symmetric Scarf-Ⅱpotential can be approximately ascertained by using the PINN deep learning *** results may be meaningful for further investigation of the nonlinear Schrodmger equation with the generalized PT-symmetric Scarf-Ⅱpotential in the deep learning.

关键词： nonlinear Schrodinger equation generalized PT-symmetric scarf-Ⅱpotential physics-informed neural networks deep learning initial value and dirichlet boundary conditions data-driven coefficient discovery

Spectral cutoffs of Fermi-LAT GRBs 080916C and 090926A

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2012年第11期12卷 1519-1525页

作者： biao li Zhuo li Department of Astronomy/Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy ofSciencesKunming 650011China

It is expected that there should be a spectral cutoff at the high energy end of emission from a prompt gamma-ray burst （GRB）, due to, e.g. γγ absorption and/or a high energy cutoff in the electron distribution. We analyze the spectral data of Fermi- LAT detected GRBs 080916C and 090926A, aiming at locating the spectral cutoff. By assuming that the prompt GRB spectrum at the high energy end is a power law with an exponential cutoff, our analysis finds that the cutoff energy Ecutoff depends on the photon index/3 and the cutoff occurs at very high energy, Ecutoff = 161＋533 GeV in GRB 080916C and Ecutoff ≥ 100 GeV （forβ ≈-2.3） in GRB 090926A. Such high energy photons, if they exist, may disfavor the synchrotron origin and need alternative generation mechanisms.

关键词： gamma-rays: bursts -- acceleration of particles

A thermodynamic-based model for modeling thermo-elastoplastic behaviors of saturated clayey soils considering bound water dehydration

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1535-1546页

作者： Mohammadhossein Sojoudi biao li Department of Building Civil and Environmental EngineeringConcordia UniversityMontrealQuebecCanada

The non-isothermal deformation of soft mudrocks or clay soils is one of the most critical issues in energy and environmental related ***-related geomaterials hold complex microstructure and mineral composition,which brings difficulty in investigating their thermo-mechanical *** studies pay little attention to the difference between a thermal plastic strain and the strain from clay *** this study,a new constitutive model is proposed for describing the thermoelastoplastic behaviors of clayey soils under water-saturated *** effect of temperature variation and mechanical loading on elastoplastic strains and dehydration are *** thermodynamics laws and the unconventional plasticity are applied to quantify the thermo-mechanical *** irreversible strain is captured by using Cam-Clay plasticity and subloading yield surface *** dehydration strain is described by utilizing a novel method based on generalized thermodynamics approach and Helmholtz free energy *** internal variables,and the first and second laws of thermodynamics are applied in the *** hardening rule is established by implementing the laws of physical conservation,energy dissipation,and plastic *** proposed model is validated using specially designed thermal consolidation tests on laboratory prepared heavily consolidated clayey soils and some published data of clayey soils with different geological origins.

关键词： Thermo-mechanical process Subloading yield surface Energy methods Clay-bound water Dehydration

The Dbar-dressing method for the(2+1)-dimensional Date–Jimbo–Kashiwara–Miwa equation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第1期76卷 17-23页

作者： Shifei Sun biao li School of Mathematics and Statistics Ningbo UniversityNingbo315211China

In this work,the(2+1)-dimensional Date–Jimbo–Kashiwara–Miwa(DJKM)equation is studied by means of the ■-dressing method.A new ■ problem has been constructed by analyzing the characteristic function and the Green’s function of its Lax *** on solving the ■ equation and choosing the proper spectral transformation,the solution of the DJKM equation is ***,the more general solution of the DJKM equation can be also obtained by ensuring the evolution of the time spectral data.

关键词： (2+1)-dimensional DJKM equation inverse spectral problem Green's function characteristic function ■-dressing method

Strategic Peer-to-peer Energy Trading Framework Considering Distribution Network Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 770-780页

作者： Yanbo Jia Can Wan biao li College of Electrical Engineering Zhejiang UniversityHangzhou 310027China

With the development of smart home energy management technology,prosumers are endowed with increased initiative in peer-to-peer(P2P)transactions,bringing new potential for cost *** this study,a novel strategic P2P energy trading framework is proposed considering the impact of network constraints on personal transaction *** can estimate the allowed power injection before engaging in the P2P energy trading,which is solved in a distributed manner based on the sharing form alternating direction method of multipliers(ADMM)*** quantify the network usage cost for each prosumer and promote local transactions among prosumers at the same bus,a modified continuous double auction(CDA)matching algorithm is proposed including a transaction *** adaptive aggressiveness-based bidding strategy is generated considering the risk of uncertainty in real-time energy delivery amount under the limitations of the distribution *** proposed strategic P2P energy trading framework is tested with the IEEE 37-bus distribution network and it is effective in creating profits for prosumers and supporting distribution network operations.

关键词： Bidding strategy continuous double auction(CDA) distribution network distributed algorithm peer-topeer(P2P)transaction

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第6期51卷 1083-1090页

作者： WANG Jia li biao Nonlinear Science Center and Department of Mathematics Ningbo University Ningbo 315211 China MM Key Lab Chinese Academy of Sciences Beijing 100080 China

Basing on the direct method developed by Clarkson and Kruskal, the nearly concentric Korteweg-de Vries （ncKdV） equation can be reduced to three types of （1＋1）-dimensional variable coefficients partial differential equations （PDEs） and three types of variable coefficients ordinary differential equation. Furthermore, three types of （1＋1）-dimensional variable coefficients PDEs are all reduced to constant coefficients PDEs by some transformations.

关键词： nearly concentric KdV equation CK direct method similarity reductions

Higher-order smooth positons and breather positons of Sine-Gordon equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2022年第8期74卷 51-55页

作者： lin Jiang biao li School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

According to the N-soliton solution derived from Hirota's bilinear method,higher-order smooth positons and breather positons are obtained efficiently through an ingenious limit *** paper takes the Sine-Gordon equation as an example to introduce how to utilize this technique to generate these higher-order smooth positons and breather positons in *** dynamical behaviors of smooth positons and breather positons are presented by some *** the procedure of deduction,the approach mentioned has the strengths of concision and *** terms of feasibility and practicability,this approach can be exploited widely to study higherorder smooth positons and breather positons of other integrable systems.

关键词： Hirota's bilinear method smooth positons breather positons

Riemann-Hilbert approach and soliton solutions for the Lakshmanan-Porsezian-Daniel equation with nonzero boundary conditions

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第11期76卷 20-32页

作者： Yilin Wang biao li School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

We construct the Riemann-Hilbert problem of the Lakshmanan-Porsezian-Daniel equation with nonzero boundary conditions,and use the Laurent expansion and Taylor series expansion to obtain the exact formulas of the soliton solutions in the case of a higher-order pole and multiple higher-order *** dynamic behaviors of a simple pole,a second-order pole and a simple pole plus a second-order pole are demonstrated.

关键词： Lakshmanan-Porsezian-Daniel equation Riemann-Hilbert problem nonzero boundary conditions multiple higher-order poles