检索结果-南通市图书馆

The Explicit Periodic Wave Solutions and Their Limit Forms for a Generalized b-equation

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2016年第2期32卷 513-528页

作者： Yi-ren CHEN Wei-bo YE Rui LIU School of Mathematics South China University of Technology

In this paper, for b ∈ （-∞,∞） and b ≠ -1, -2, we investigate the explicit periodic wave solutions for the generalized b-equation ut ＋ 2kux - uxxt ＋（1 ＋ b）u2ux =buxuxx ＋ uuxxx, which contains the generalized Camassa-Holm equation and the generalized Degasperis-Procesi equation. Firstly, via the methods of dynamical system and elliptic integral we obtain two types of explicit periodic wave solutions with a parametric variable a. One of them is made of two elliptic smooth periodic wave solutions. The other is composed of four elliptic periodic blow-up solutions. Secondly we show that there exist four special values for a. When a tends to these special values, these above solutions have limits. From the limit forms we get other three types of nonlinear wave solutions, hyperbolic smooth solitary wave solution, hyperbolic single blow-up solution, trigonometric periodic blow-up solution. Some previous results are extended. For b = -1 or b = -2, we guess that the equation does not have any one of above solutions.

关键词： generalized b-equation elliptic integral method explicit periodic wave solutions limit formes

A power fluctuation evaluation method of PV plants based on Rankboost ranking

在线全文

学校读者我要写书评

暂无评论

Protection and Control of Modern Power Systems 2021年第1期6卷 347-356页

作者： Weiyi Xia Zhouyang ren Hui Li bo Hu The State Key Laboratory of Power Transmission Equipment&System Security and New Technology School of Electrical EngineeringChongqing UniversityChongqing400044PR China

Fluctuation evaluation is an important task in promoting the accommodation of photovoltaic (PV) power generation. This paper proposes an evaluation method to quantify the power fluctuation of PV plants. This consists of an index system and a ranking method based on the Rankboost algorithm. Eleven indices are devised and included in the index system to fully cover diverse fluctuation features. By handling missing and invalid data effectively, the ranking method fuses multiple indices automatically and provides a systematic and comprehensive comparison of power fluctuation. Simulation results based on power data from six PV plants indicate that the evaluation list obtained by the Rankboost ranking method is better represented and more comprehensive than that derived by the equal weight method.

关键词： Fluctuation evaluation Photovoltaic power Rankboost ranking algorithm

Microstructure evolution and mechanical properties of a large-sized ingot of Mg–9Gd–3Y–1.5Zn–0.5Zr(wt%) alloy after a lower-temperature homogenization treatment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 271-279页

作者： Zhi-yong Xue Yue-juan ren Wen-bo Luo Yu ren Ping Xu Chao Xu School of Energy Power and Mechanical EngineeringNorth China Electric Power University School of Materials Science and Engineering University of Science and Technology Beijing College of Science Rocket Force University of Engineering

In this paper,a large-sized ingot of Mg–9Gd–3Y–1.5Zn–0.5Zr(wt%) alloy with a diameter of 600 mm was successfully prepared by the semi-continuous casting *** alloy was subsequently annealed at a relatively low temperature of 430°C for 12 h as a homogenization *** microstructure and room-temperature mechanical properties of the alloy were investigated *** results show that the as-cast alloy contained a mass of discontinuous lamellar-shaped 18 R long-period stacking ordered(LPSO) phases with a composition of Mg10 Zn Y and an α-Mg matrix,along with net-shaped Mg5(Y,Gd) eutectic compounds at the grain *** of the eutectic compounds dissolved after the homogenization ***,the amount and dimensions of the lamellar-shaped LPSO phase obviously increased after the homogenization *** structure of the phase transformed into 14H-type LPSO with composition Mg12Zn(Y,Gd).The mechanical properties of the heat-treated large-sized alloy ingot are *** ultimate tensile strength(UTS) and tensile yield strength(TYS) of the alloy reached 207.2 MPa and 134.8 MPa,respectively,and the elongation was 3.4%.The high performances of the large-sized alloy ingot after the homogenization treatment is attributed to the strengthening of the α-Mg solid solution and to the plentiful LPSO phase distributed over the α-Mg matrix.

关键词： magnesium alloys ingots homogenization microstructural evolution mechanical properties

Numerical Modelling of Electroosmotic Driven Flow in Nanoporous Media by Lattice boltzmann Method

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2013年第1期10卷 90-99页

作者： bo Li Wenning Zhou Yuying Yan Zhiwu Han Luquan ren Energy and Sustainability Research Division Faculty of Engineering University of Nottingham Nottingham NG7 2RD UK Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 P. R. China

The lattice boltzmann method was employed to simulate electroosmotic driven flow and Debye layer screening in con- ducting electrolyte around a porous structure with average size of 40 nm. The charge screening around the nanopores was investigated by solving the vector-superpositioned potential equilibrium distribution function and adding electro-kinetic force term to the evolution equation. In this intermediate case of moderate Debye length, the electrophoresis problem becomes complicated. The motion of the particles distorts the screening cloud, which becomes asymmetric, resulting in very complex interactions between the electrolyte, the screening cloud and the particle; but the Electroosmotic Flow （EOF） behaviour was still considered based on the Helmoholtz-Smoluchowski model with adaptation to fit nanoporous flow in the porous structure. In the present approach, the flow in the nanopores is directly modelled; the detailed flow information can be obtained by simplifying the repeated macrostructure. Due to the symmetry of the domain, the size of computational domain can be largely reduced by less repeated spherical nanoparticles. Each pore of the medium contains several lattice nodes on the simplified curved edges and potential gradients are produced by adjusting the zeta potential value. The velocity results for pressure-driven and EOF flows agree well with the analytical solutions and recent experimental results. In particular, the interface between solid particles and fluids, the influences of porosity, solid particle diameter, yield stress and electric parameters in EOF were investigated. The anti-adhesion effect of electroosmotic pumping effect was evaluated, and the pulsed DC was applied in order to enhance the performance of the electroosmotic pumping. The results demonstrate that the present lattice boltzmann model is capable of modelling flow through nanoporous media at certain restrictions while some results deviate from the predictions based on the macr

关键词： electroosmotic flow electroosmotic pumping nanoporous media lattice boltzmann method numerical modelling,anti-adhesion

Synthesis and near infrared electrochromic properties of metallodithiolene complexes

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 2017年第1期60卷 77-83页

作者： Xiuhong Chen Wenqiang Qiao bo Liu Juntao ren Zhiyuan Wang State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China University of Chinese Academy of Sciences Beijing 100049 China Department of Chemistry Carleton University Ottawa Ontario K1S 5B6 Canada

Four metallodithiolene complexes[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?di[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)](3),[4,8-bis(octyloxy)-1,3,5,7-tetrathia]di[1,3-bis(diphenylphosphino)propane?nickel(II)](4),[4,8-bis(octyloxy)-1,3,5,7-tetra-thia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?[1,3-bis(diphenylphosphino)propane·nickel(II)](5)and di[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?nickel(II)(6)were synthesized and the near-infrared(NIR)electrochromic properties were *** spectroelectrochemical spectra and the electrochromic parameters such as optical contrast,switching time,optical density change,electrochromic efficiency and optical attenuation of complexes 3–6 were investigated in *** symmetric binuclear complex 4 showed relatively high electrochromic efficiency of63.0 and 75.4 cm^2/C both in the two oxidation *** complexes exhibited excellent electroactive/electrochromic stability characterized by chronoamperometry(>4000 cyclic switches).

关键词： near-infrared electrochromism metallodithiolene complex spectroelectrochemistry electrochromic switching

Dance2MIDI:Dance-driven multi-instrument music generation

在线全文

学校读者我要写书评

暂无评论

Computational Visual Media 2024年第4期10卷 791-802页

作者： bo Han Yuheng Li Yixuan Shen Yi ren Feilin Han College of Computer Science and Technology Zhejiang UniversityHangzhou 310058China National University of Singapore Singapore 119077Singapore Speech&Audio Team Bytedance AI LabSingapore 048583Singapore Department of Film and TV Technology Beijing Film AcademyBeijing 100088China

Dance-driven music generation aims to generate musical pieces conditioned on dance *** works focus on monophonic or raw audio generation,while the multi-instrument scenario is *** challenges associated with dancedriven multi-instrument music(MIDI)generation are twofold:(i)lack of a publicly available multi-instrument MIDI and video paired dataset and(ii)the weak correlation between music and *** tackle these challenges,we have built the first multi-instrument MIDI and dance paired dataset(D2MIDI).Based on this dataset,we introduce a multi-instrument MIDI generation framework(Dance2MIDI)conditioned on dance ***,to capture the relationship between dance and music,we employ a graph convolutional network to encode the dance *** allows us to extract features related to dance movement and dance ***,to generate a harmonious rhythm,we utilize a transformer model to decode the drum track sequence,leveraging a cross-attention ***,we model the task of generating the remaining tracks based on the drum track as a sequence understanding and completion task.A BERTlike model is employed to comprehend the context of the entire music piece through self-supervised *** evaluate the music generated by our framework trained on the D2MIDI dataset and demonstrate that our method achieves state-of-the-art performance.

关键词： video understanding music generation symbolic music cross-modal learning self-supervision

Spin Polarization Properties of Na Doped Meridianal Tris（8-Hydroxyquinoline） Aluminum Studied by First Principles Calculations

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 2014年第4期31卷 193-196页

作者： ren Jun-Feng YUAN Xiao-bo HU Gui-Chao College of Physics and Electronics Shandong Normal University Jinan 250014

We theoretically investigate the electronic structure and spin polarization properties of Na-doped meridianal tris（S-hydroxyquinoline） aluminum （Alq3） by first principles calculations. It is found that the spin density is distributed mainly in the Alq3 part in the Alq3：Na complex. Electron charge transfer takes place from the Na atom to the Alq3 molecule, which induces asymmetric changing of the molecule bond lengths, thus the spin density distribution becomes asymmetric. Spin polarization of the complex originates from the preferable filling of the spin-split nitrogen and carbon p-orbitals because of the different bond length changes of the Aiq3 molecule upon Na doping.

关键词： Calculations Spin Polarization electronic

OBLIQUE TOWING TEST AND MANEUVER SIMULATION AT LOW SPEED AND LARGE DRIFT ANGLE FOR DEEP SEA OPEN-FRAMED REMOTELY OPERATED VEHICLE

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2012年第2期24卷 280-286页

作者： FAN Shi-bo LIAN Lian ren Ping HUANG Guo-liang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China Chinese Underwater Technology Institute Shanghai Jiao Tong University Shanghai 200231 China

This article presents the newly designed oblique towing test in the horizontal plane for the scaled model of 4 500 m deep sea open-framed Remotely Operated Vehicle （ROV）,which is being researched and developed by Shanghai Jiao Tong *** hydrodynamics coefficients measurement is significant for the maneuverability and control system *** scaled model of ROV was constructed by 1：*** tests of large drift angle were conducted through Large Amplitude Horizontal Planar Motion Mechanism （LAHPMM） under low *** regression method is adopted to process the test data and obtain the related hydrodynamic *** were designed for the horizontal plane motion of large drift angle to verify the coefficients *** the results show that the data can satisfy with the design requirements of the ROV developed.

关键词： Remotely Operated Vehicle (ROV) scaled model large drift angle multiple regression Large Amplitude Horizontal Planar Motion Mechanism (LAHPMM)

An Inverse Power Generation Mechanism Based Fruit Fly Algorithm for Function Optimization

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2019年第2期32卷 634-656页

作者： LIU Ao DENG Xudong ren Liang LIU Ying LIU bo School of Management Wuhan University of Science and Technology Center for Service Science and Engineering Wuhan University of Science and Technology Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System School of Economics and Management Beihang University Academy of Mathematics and Systems Science Chinese Academy of Sciences

As a novel population-based optimization algorithm, fruit fly optimization(FFO) algorithm is inspired by the foraging behavior of fruit flies and possesses the advantages of simple search operations and easy implementation. Just like most population-based evolutionary algorithms, the basic FFO also suffers from being trapped in local optima for function optimization due to premature *** this paper, an improved FFO, named IPGS-FFO, is proposed in which two novel strategies are incorporated into the conventional FFO. Specifically, a smell sensitivity parameter together with an inverse power generation mechanism(IPGS) is introduced to enhance local exploitation. Moreover,a dynamic shrinking search radius strategy is incorporated so as to enhance the global exploration over search space by adaptively adjusting the searching area in the problem domain. The statistical performance of FFO, the proposed IPGS-FFO, three state-of-the-art FFO variants, and six metaheuristics are tested on twenty-six well-known unimodal and multimodal benchmark functions with dimension 30, respectively. Experimental results and comparisons show that the proposed IPGS-FFO achieves better performance than three FFO variants and competitive performance against six other meta-heuristics in terms of the solution accuracy and convergence rate.

关键词： Evolutionary algorithms fruit fly optimization function optimization meta-heuristics