检索结果-南通市图书馆

Cauchy Problems for KdV-type Equations and Higher-Order Conditional Symmetries

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2008年第3期49卷 545-548页

作者： LI Ji-Na ZHANG Shun-Li ZUO Su-Li center for nonlinear Studies Department of Mathematics Northwest University Xi＇an 710069 China center of nonlinear science Ningbo University Ningbo 315211 China

We develop the generalized conditional symmetry （GCS） approach to solve the problem of dimensional reduction of Cauchy problems for the KdV-type equations. We characterize these equations that admit certain higherorder GCSs and show the main reduction procedure by some examples. The obtained reductions cannot be derived within the framework of the standard Lie approach.

关键词： KdV-type equations generalized conditional symmetry Cauchy problem

Determining H0 using a model-independent method

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2017年第1期12卷 133-140页

作者： Pu-Xun Wu Zheng-Xiang Li Hong-Wei Yu center for nonlinear science and department of physics Ningbo University Ningbo 315211 China center for High Energy physics Peking University Beijing 100080 China department of Astronomy Beijing Normal University Beijing 100875 China

By using type Ia supernovae （SNIa） to provide the luminosity distance （LD） directly, which depends on the value of the Hubble constant H0 = 100h km·s^-1· Mpc^-1, and the angular diameter distance from galaxy clusters or baryon acoustic oscillations （BAOs） to give the derived LD according to the distance duality relation, we propose a model-independent method to determine h from the fact that different observations should give the same LD at a given redshift. Combining the Sloan Digital Sky Survey II （SDSS-II） SNIa from the MLCS2k2 light curve fit and galaxy cluster data, we find that at the 1σ confidence level （CL）, h = 0.5867±0.0303 for the sample of the elliptical β model for galaxy clusters, and h = 0.6199± 0.0293 for that of the spherical β model. The former is smaller than the values from other observations, whereas the latter is consistent with the Planck result at the 2σ CL and agrees very well with the value reconstructed directly from the H（z） data. With the SDSS-II SNIa and BAO measurements, a tighter constraint, h = 0.6683 ± 0.0221, is obtained. For comparison, we also consider the Union 2.1 SNIa from the SALT2 light curve fitting. The results from the Union 2.1 SNIa are slightly larger than those from the SDSS-II SNIa, and the Union 2.1 SNIa ＋ BAOs give the tightest value. We find that the values from SNIa ＋ BAOs are quite consistent with those from the Planck and the BAOs, as well as the local measurement from Cepheids and very-low-redshift SNIa.

关键词： Hubble constant luminosity distance angular diameter distance

Variable Coefficient KdV Equation and the Analytical Diagnoses of a Dipole Blocking Life Cycle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics Letters 2006年第4期23卷 887-890页

作者：唐晓艳黄菲楼森岳 department of physics Shanghai Jiao Tong University Shanghai 200030 center of nonlinear science Ningbo University Ningbo 315211 department of Marine Meteorology Ocean University of China Qingdao 266003

A variable coefficient Korteweg de Vries （VCKdV） system is derived by considering the time-dependent basic flow and boundary conditions from the well-known Euler equation with an earth rotation term. The analytical solution obtained from the VCKdV equation can be successfully used to explain fruitful phenomena in fluid and other physical fields, for instance, the atmospheric blocking phenomena. In particular, a diploe blocking case happened during 9 April 1973 to 18 April 1973 read out from the National center for Environmental Prediction/National center for Atmospheric Research （NCEP/NCAR） reanalysis data is well described by the analytical solution.

关键词： ROSSBY SOLITON MODEL ATMOSPHERIC BLOCKING NUMERICAL-SIMULATION COHERENTSTRUCTURES EDDY INTERACTION PLANETARY-WAVES ENVELOPE TOPOGRAPHY CONTEXT

The distance duality relation test from the ACT cluster and type Ia supernova data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2016年第5期16卷 135-144页

作者： Lin-Hai Hu Pu-Xun Wu Hong-Wei Yu center of nonlinear science and department of physics Ningbo University Synergetic Innovation center for Quantum Effects and Applications Hunan Normal University center for High Energy physics Peking University

The validity of the cosmic distance-duality （DD） relation is investigated by using 91 measure- ments of the gas mass fraction of galaxy clusters recently reported by the Atacama Cosmology Telescope （ACT） and the luminosity distance from the Union2.1 type Ia supernova （SNIa） sample independent of any cosmological models and the value of the Hubble constant. We consider four different approaches to derive the gas mass function and two different parameterizations of the DD relation, and find that they have very slight influences on the DD relation test and the relation is valid at the la confidence level. We also discuss the constraints on a andβ, which represent the effects of the shapes and colors of the light curves of SNIa, respectively. Our results on a and β are different from those obtained from the ACDM model and the galaxy cluster plus SNIa data.

关键词： cosmology: theory -- galaxies -- clusters: general-distance scale

Latest cosmological constraints on Cardassian expansion models including the updated gamma-ray bursts

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第9期11卷 1019-1030页

作者： Nan Liang Pu-Xun Wu Zong-Hong Zhu department of Astronomy Beijing Normal University Beijing 100875 China center for High Energy physics Peking University Beijing 100871 China center of nonlinear science and department of physics Ningbo University Ningbo 315211 China

We constrain the Cardassian expansion models from the latest observa- tions, including the updated Gamma-ray bursts （GRBs）, which are calibrated using a cosmology independent method from the Union2 compilation of type Ia supernovae （SNe Ia）. By combining the GRB data with the joint observations from the Union2 SNe Ia set, along with the results from the Cosmic Microwave Background radia- tion observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release. we find significant constraints on the model oarameters of the original Cardassian model ΩM0=0.282-0.014^0.015,n=0.03-0.05^＋0.05 and n=-0.16-3.26^＋0.25,β=0.76-0.58^＋0.34 of the modified polytropic Cardassian model, which are consistent with the ACDM model in a l-or confidence region. From the reconstruction of the deceleration parameter q（z） in Cardassian models, we obtain the transition redshift ZT = 0.73 ± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.

关键词： gamma-rays bursts -- cosmology cosmological parameters

Approximate Symmetry Reduction and Infinite Series Solutions to the nonlinear Wave Equation with Damping

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2009年第10期26卷 1-4页

作者：赵远张顺利楼森岳 center for nonlinear Studies Department of Mathematics Northwest University Xi'an 710069 department of physics Shanghai Jiao Tong University Shanghai 200240 department of physics Ningbo University Ningbo 315211

The approximate symmetry perturbation method is applied to the nonlinear damped wave equation. The approximate symmetry reduction equations of different orders are derived and the corresponding series reduction soluti... 详细信息

关键词： sea surface nonliear interaction numerical method

Gödel-Type Universes in f(R) Gravity with an Arbitrary Coupling between Matter and Geometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics Letters 2011年第12期28卷 39-42页

作者： ZHANG Tao WU Pu-Xun YU Hong-Wei department of physics and Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Hunan Normal UniversityChangsha 410081 center for nonlinear science and department of physics Ningbo UniversityNingbo 315211

By studying the Gödel-type solution,the causality in f(R)gravity with an arbitrary coupling between matter and geometry is *** that the matter source is a perfect fluid and a scalar field,respectively,we find that for the perfect fluid case,noncausal Gödel−type solutions exist and there is a critical radius rc beyond which the causality is *** the scalar field case,the violation of causality is forbidden.

关键词： perfect scalar radius

Research progress in metal-organic frameworks and their derivatives in electrochemistry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China Chemistry 2025年

作者： Lingling Chen Yuxin Liu Yichun Su Wenchen Zhu Guangyu Du Huan Pang School of Chemistry and Chemical Engineering Yangzhou University department of Applied physics The Hong Kong Polytechnic University Interdisciplinary Materials Research center Institute for Advanced Study Chengdu University State Key Laboratory of Coordination Chemistry Nanjing University

Metal-organic frameworks (MOFs) are distinguished by their unique porosity and meticulously ordered framework structures,setting them apart from conventional complexes. These materials are defined by their highly organized crystalline and pore structures, extensive surface areas, robust porosity, and superior adsorption capabilities. Owing to their exceptional structural and functional attributes, MOFs and their derivatives are leveraged across a broad spectrum of applications, demonstrating significant potential across diverse sectors. In recent times, the scientific community has increasingly focused on MOFs, underscoring their growing importance in research. Despite the promising array of applications for MOFs and their derivatives,challenges persist in practical deployments, and the pathway to research advancement remains daunting. This document delves into the synthesis and various applications of MOFs and their derivatives, particularly in the domains of energy storage, catalysis,sensing, and water treatment. It also highlights the ongoing research progress in the field of electrochemistry, including developments in lithium ion batteries (LIBs), lithium-sulfur batteries (LSBs), zinc-ion batteries (ZIBs), aqueous nickel-zinc batteries (NZBs), and supercapacitors. Finally, it provides an outlook on the future prospects and potential hurdles facing the development of MOF materials.

关键词：

Evolutionary snowdrift game on heterogeneous Newman-Watts small-world network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2008年第8期17卷 2759-2763页

作者：杨涵新高坤韩筱璞汪秉宏 department of Modern physics and nonlinear science center University of Science and Technology of China

We study the evolutionary snowdrift game in a heterogeneous Newman-Watts small-world network. The heterogeneity of the network is controlled by the number of hubs. It is found that the moderate heterogeneity of the network can promote the cooperation best. Besides, we study how the hubs affect the evolution of cooperative behaviours of the heterogeneous Newman-Watts small-world network. Simulation results show that both the initial states of hubs and the connections between hubs can play an important role. Our work gives a further insight into the effect of hubs on the heterogeneous networks.

关键词： complex networks snowdrift game cooperation heterogeneous Newman-Watts small-world network