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Quality Control of 1-Alkyl-3-methylimidazolium Ionic Liquid Precursors with HPLC

过程工程学报 2007年第6期7卷 1094-1098页

作者：张延强张建敏陈玉涣张锁江 State Key Laboratory of Multi-phase Complex System Institute of Process EngineeringChinese Academy of Sciences

A high performance liquid chromatography(HPLC) method was proposed to monitor the synthesis and purification of the 1-alkyl-3-methylimidazolium ionic liquid precursors from alkylation of 1-methylimidazole with alkyl halides and determine the purity of final *** results showed that separation of 1-methylimidazole from the precursors could be obtained under the HPLC performance conditions such as cation exchange column,acetonitrile/KH2PO4 aqueous solution and 209 nm *** content of unreacted 1-methylimidazole in the precursors could be easily calculated from their corresponding HPLC peak areas with the calibration curve of *** retention times of the 1-alkyl-3-methylimidazolium ionic liquid precursors decreased with their increasing alkyls,and the ionic liquids with the same cation and different anions had almost the same retention times.

关键词：质量控制 1-烃基-3-甲基咪唑液相色谱离子性液体前体纯度 1-甲基咪唑

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Simplified equivalent models of large-scale wind power and their application on small-signal stability

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Journal of Modern Power systems and Clean Energy 2013年第1期1卷 58-64页

作者： Nan DING Zongxiang LU Ying QIAO Yong MIN State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua UniversityBeijing 100084China

With the rapid growth of grid-connected wind power penetration level,it is necessary to study the impacts of wind power on power system *** small-signal stability of power systems with large-scale wind power is explored using the eigenvalue analysis method.A prototype sample system,the two-synchronous-generator system with a wind farm,is proposed for theoretical ***,simplified models of wind turbines(WTs)and the corresponding equivalent models of wind farms are *** kinds of typical WT models,i.e.,squirrel cage induction generator,doubly-fed induction generator,and permanent magnet synchronous generator are ***,based on the simplified equivalent models,effects of large-scale wind farms on the electromechanical oscillation modes(EOMs)of synchronous systems are *** results indicate that wind farms of the three kinds of WTs have positive effects on ***,long transmission lines connecting wind farmto the systemmay produce negative effects on the small-signal stability of the system.

关键词： Wind turbine(WT) Small-signal stability Electromechanical oscillation mode(EOM) Simplified model Equivalent model

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Source enumeration method by combining diagonal loading and constructing second-order statistics

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The Journal of China Universities of Posts and Telecommunications 2023年第1期30卷 47-55页

作者： Wang Chuanchuan Zeng Yonghu Wang Liandong Li Zhipeng State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Luoyang 471003China

A source enumeration method based on diagonal loading of eigenvalues and constructing second-order statistics is proposed,for the case that the antenna array observed signals are overlapped with spatial colored noise,and the number of antennas compared with the number of snapshots meet the requirement of general asymptotic ***,the sample covariance matrix of the observed signals is obtained,the eigenvalues of the sample covariance matrix can be acquired by eigenvalue decomposition,and the eigenvalues are diagonally loaded,and a new formula for calculating the diagonal loading is *** on the diagonal loaded eigenvalues,the difference values are calculated for the adjacent eigenvalues after diagonal loading,and the statistical variance of the difference values is *** this basis,the second-order statistics of the difference values are constructed,and when the second-order statistics are minimized,the corresponding number of sources is *** proposed method has wide applicability,which is suitable for both general asymptotic regime and classical asymptotic system,and is suitable for both white Gaussian noise environment and colored noise *** method makes up for the lack of source enumeration methods in the case of general asymptotic system and colored noise.

关键词： source enumeration general asymptotic regime colored noise diagonal loading second-order statistics

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Numerical Solution of Lock-Release Gravity Current with Viscous Self-Similar Regime

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海洋工程：英文版 2004年第1期18卷 157-162页

作者：张立柱李行伟陈国谦 Department of Mechanics and Engineering Science/State Key Laboratory for Turbulence and Complex System Department of Civil Engineering

Lock-release gravity currents with a viscous self-similar regime are simulated by use of the renormalization group (RNG) k-ε model for Reynolds-stress closure. Besides the turbulent regime with initially a slumping phase of a constant current front speed and later an inviscid self-similar phase of front speed decreasing as t -1/3 (where t is the time measured from release), the viscous self-similar regime is satisfactorily reproduced with front speed decreasing as t -4/5, consistent with well known experimental observations.

关键词： gravity current self-similarity turbulence modeling environmental fluid mechanics

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New evidential reasoning approach based on multiple attribute decision making 3

New evidential reasoning approach based on multiple attribut...

引用

3rd IEEE International Conference on Electronic Information Technology and Computer Engineering, EITCE 2019

作者： Hu, Lifang Bai, Rong Yang, Zhengyi Key Laboratory of Complex Ship System Simulation Beijing100161 China

ISBN: (纸本)9781728135847

A new approach is developed for dealing with seriously conflicting evidence especially when the information quality is relatively low resulting from sensors' poor identification performance. The approach combines MADA and the Dempster-Shafer theory of evidence (DST) to deal with the interval uncertainties or local ignorance. A belief interval matrix is firstly constructed, and then an objective programming model is established to obtain the attribute weights. Thus the alternatives can be ranked by using the weighted correlation projection of alternative onto optimum solution. Our proposed method can sufficiently utilize the objective information of alternatives, and at the same time meet the subjective requirements of the decision makers as much as possible. A typical example is given to test the proposed method against some existing methods, and the result shows its superior and practicality, as well its effectiveness of making the decision problem much simpler especially in the case of combining evidence with high conflict information given by 'bad' evidences. © 2019 IEEE.

关键词： Decision making

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Underdetermined mixing matrix estimation by comprehensive application of cluster validity indexes

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The Journal of China Universities of Posts and Telecommunications 2020年第6期27卷 73-86页

作者： Wang Chuanchuan Jiang Lin Zeng Yonghu Wang Liandong State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Luoyang 471003China

To solve the problem of mixing matrix estimation for underdetermined blind source separation(UBSS)when the number of sources is unknown,this paper proposed a novel mixing matrix estimation method based on average information entropy and cluster validity index(CVI).Firstly,the initial cluster center is selected by using fuzzy C-means(FCM)algorithm and the corresponding membership matrix is obtained,and then the number of clusters is obtained by using the joint decision of CVI and average information entropy index of membership matrix,then multiple cluster number estimation results can be obtained by using multiple ***,according to the results of the number of multiple clusters estimation,the number of radiation sources is determined according to the principle of the subordination of the minority to the *** cluster center vectors obtained from the clustering operation of the estimated number of radiation sources are fused,that is the mixing matrix is estimated based on the degree of similarity of the cluster center *** the source signal is not sufficiently sparse,the time-frequency single source detection processing can be combined with the proposed method to estimate the mixing *** effectiveness of the proposed method is validated by experiments.

关键词： UBSS estimation of the number of radiation sources mixing matrix FCM clustering CVI

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An Optimal Competitive Bidding and Pricing Strategy for Electric Vehicle Aggregator Considering the Bounded Rationality of Users

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IEEE Transactions on Industry Applications 2025年

作者： Wang, Qi Huang, Chunyi Wang, Chengmin Xie, Ning Li, Kangping Qiu, Peng Shanghai Jiao Tong University School of Electronic Information and Electrical Engineering Shanghai200240 China Northeast Electric Power University Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Jilin132012 China Shanghai Jiao Tong University College of Smart Energy Shanghai200240 China State Grid Zhejiang Electric Power Company Electric Power Research Institute Hangzhou310014 China

Accurate estimation of the charging demand of electric vehicle (EV) users has a profound impact on the profitability of the EV aggregator (EVA). Existing studies concerning the market strategy of EVA normally assume the EV users are equipped with complete rationality and simplify the real interactive process among EVAs and EV users, making the derived strategy unable to adapt to the practical situations. To address this bottleneck, a novel competitive bidding and pricing strategy for EVA considering both the bounded rationality of EV users and various game relationships between multiple agents is proposed. Firstly, the evolutionary game theory is utilized to simulate the bounded rational charging behaviors of EV users under differentiated charging prices, while their demand elasticity and uncertainty of driving pattern is also taken into account. Secondly, the complex interactions among EVAs and EV users are modeled, where the competition between EVAs is constructed by a non-cooperative game with incomplete information and the interplay between EVAs and EV users is built as a Stackelberg game. Finally, numerical results validate the effectiveness of the proposed method and demonstrate the pricing strategy preferences of EVAs based on the diverse price elastic coefficients of EV users. © 2025 IEEE. All rights reserved

关键词： Game theory

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Viscous Rayleigh-Taylor instability with and without diffusion effect

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Applied Mathematics and Mechanics(English Edition) 2017年第2期38卷 263-270页

作者： Chenyue XIE Jianjun TAO Ji LI Center for Applied Physics and Technology (CAPT)-MOE Key Laboratory of High Energy Density Physics Simulation (HEDPS) State Key Laboratory for Turbulence and Complex System (SKLTCS) Department of Mechanics and Engineering ScienceCollege of Engineering Peking University Department of Engineering University of Cambridge

The approximate but analytical solution of the viscous Rayleigh-Taylor insta- bility （RTI） has been widely used recently in theoretical and numerical investigations due to its clarity. In this paper, a modified analytical solution of the growth rate for the viscous RTI of incompressible fluids is obtained based on an approximate method. Its accuracy is verified numerically to be significantly improved in comparison with the previous one in the whole wave number range for different viscosity ratios and Atwood numbers. Fur- thermore, this solution is expanded for viscous RTI including the concentration-diffusion effect.

关键词： viscous Rayleigh-Taylor instability (RTI) dispersion relation diffusioneffect

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A coevolutionary framework of business-IT alignment via the lens of enterprise architecture

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Journal of systems Engineering and Electronics 2020年第5期31卷 983-995页

作者： LIN Menglong YI Shuanghui ZHANG Mengmeng CHEN Tao CHEN Honghui ZHANG Xiaoxue Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410072China National Key Laboratory for Complex System Simulation Academy of Military SciencesBeijing 100000China

Due to the turbulent external business environment, the complexity of internal relations of the organization and the emergence of subversive IT roles, the business-IT alignment(BITA)has become increasingly difficult. The unsuccessful realization of BITA will lead to the waste of organizational resources, the reduction of return on investment and eventually the loss of competitive advantage. In recent years, coevolution has received widespread attention due to its ability to describe the dynamic relationship between IT and business. Multiple principles such as quickening learning action loops and adopt suitable organizing principles for achieving business and IT coevolution(BITC) are obtained. However, the continuous BITC is still hard to be achieved because of the lack of complete BITC management. This paper focuses on the management process of the BITC and how to perform it gradually. A coevolution framework combines the enterprise architecture(EA) approach with the coevolution analysis is proposed, which contains the design of EA, the sensing and governance of the misalignment and the procedure of the EA misalignment *** steps for the governance and prevention of misalignment are discussed in particular. Through comparison with the principles,characteristics and methods of coevolution in the literature, the proposed framework is evaluated. The results show that the proposed framework is effective for BITC implementation.

关键词： business-IT alignment(BITA) coevolution misalignment governance misalignment prevention enterprise architecture

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On the Fourier approximation method for steady water waves

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Acta Oceanologica Sinica 2014年第5期33卷 37-47页

作者： ZHAO Hongjun SONG Zhiyao LI Ling KONG Jun State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering College of HarborCoastal and Offshore Engineering Hohai University Key Laboratory of Virtual Geographic Environment Key Laboratory for Numerical Simulation of Largescale Complex System Nanjing Normal University School of Engineering The University of Queensland

A computational method for steady water waves is presented on the basis of potential theory in the physical plane with spatial variables as independent quantities. The finite Fourier series are applied to approximating the free surface and potential function. A set of nonlinear algebraic equations for the Fourier coefficients are derived from the free surface kinetic and dynamic boundary conditions. These algebraic equations are numerically solved through Newton＇s iterative method, and the iterative stability is further improved by a relaxation technology. The integral properties of steady water waves are numerically analyzed, showing that （1） the set-up and the set-down are both non-monotonic quantities with the wave steepness, and （2） the Fourier spectrum of the free surface is broader than that of the potential function. The latter further leads us to explore a modification for the present method by approximating the free surface and potential function through different Fourier series, with the truncation of the former higher than that of the latter. Numerical tests show that this modification is effective, and can notably reduce the errors of the free surface boundary conditions.

关键词： steady water waves Fourier series Newton's method relaxation technology wave properties

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