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Characteristic Analysis of Power Oscillations Caused by Disharmony Among Voltage-source-controlled Units in Three-terminal Local Power Grid

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1295-1308页

作者： Qiyi Yu yi tang School of Electrical Engineering Southeast UniversityNanjing 210018China

Previous studies have demonstrated that disharmony among voltage-source-controlled units(VSCUs)may occur on an alternating current(AC)transmission or distribution line under steady-state operating conditions(SSOCs)or quasistatic operating conditions(QSSOCs).As the studies on frequency disharmony have been expanded to multiple disharmonized vS-CUs in the local power grid,its adverse effects on AC lines and equivalent load(EL)at the bus without active voltage control ability(non-active bus)need to be investigated *** the locality of disharmony and common topological con-nections among VSCUs,this paper adopts a Y-type three-termi-nal local power grid(LPG)as the research *** disharmony among the three VSCUs is ***,for the load at non-active bus,the formulas for single-phase instantaneous voltage,load current,load power,as well as average power un-der disharmony operating conditions(DOCs)are *** characteristic indicators of the above electrical quantities are defined,which can measure the amplification and reduction de-grees of the above electrical quantities before and after ***,for the line directly connected to VSCUs,the formulas for single-phase instantaneous line current and power and the average power under DOCs are *** characteristic indicators of power flow are defined,which can be used to quantify the peak amplification impact of oscillation before and after ***,the case study on the Y-type three-terminal LPG under the single-disharmony and the multi-dis-harmony switching scenarios indicates that the long-period pow-er oscillation caused by disharmony may occur in the load flow at the non-active bus and the line *** oscillation causes a serious decrease in load capability and a significant amplification of the peak of line power oscillation.

关键词： New power system power oscillation disharmony voltage-source-controlled unit(VSCU) characteristic analysis

EXPANSIONS OF STEP-TRANSITION OPERATORS OF MULTI-STEP METHODS AND ORDER BARRIERS FOR DAHLQUIST PAIRS

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Journal of Computational Mathematics 2006年第1期24卷 45-58页

作者： Quan-dong Feng yi-fa tang LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China Graduate School of the Chinese Academy of Sciences Beijing 100080 China

Using least parameters, we expand the step-transition operator of any linear multi-step method （LMSM） up to O（τ^s＋5） with order s = 1 and rewrite the expansion of the steptransition operator for s = 2 （obtained by the second author in a former paper）. We prove that in the conjugate relation G3^λτ o G1^τ =G2^τ o G3^λτ with G1 being an LMSM,（1） theorder of G2 can not be higher than that of G1; （2） if G3 is also an LMSM and G2 is a symplectic B-series, then the orders of G1, G2 and G3 must be 2, 2 and 1 respectively.

关键词： Linear Multi-Step Method Step-Transition Operator B-series Dahlquist(Conjugate) pair Symplecticity

A novel ice slurry producing system with vacuum freezing

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Journal of Central South University 2017年第3期24卷 736-742页

作者： tang yi-fang School of Energy Science and Engineering Central South University Changsha 410083 China Collaborative Innovation Center of Building Energy Conservation & Environmental Control Zhuzhou 412007 China

A novel vacuum ice slurry producing system with jet-pumps was proposed to deal with the problems of high energy consumption and ice *** this novel system,one steam driven by a jet-pump was used to create vacuum in a hermetic vessel where water was sprayed through a nozzle to produce ice slurry,while the other steam was used to provide enough cold energy to make the left vapor in the hermetic vessel *** models of this novel system were established and theoretical simulation on the performance characteristics was also implemented based on the MATLAB *** show that the novel system is feasible and practicable,and the system performance is affected by many factors,such as the temperature of the generators,condensing temperature,evaporation temperature,and the cooling load of the refrigerator *** findings are helpful to improve the performance of ice slurry producing system.

关键词： ice slurry vacuum freezing ejector solar energy

Computational Bioluminescence

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Chinese Journal of Chemistry 2021年第1期39卷 43-49页

作者： yi-Qi tang Ya-Jun Liu College of Chemistry Beijing Normal UniversityBeijing 100875China

Bioluminescence(BL)is an amazing natural phenomenon whose visible light is pro-duced by living *** to its high sensitivity,high selectivity and high signal-to-noise ratio,BL has been applied broadly in biotechnology and biomedical ***,for centuries,we can only receive some sporadic and static information from experimental observations,the mechanism of most BL is *** the past 14 years,we have been performing theoretical study on all kinds of bioluminescent systems,and have uncovered the mechanism and details of several *** as an example,we qualitatively introduce our theoretical study of firefly BL in this account.

关键词： Bioluminescence Reaction mechanisms Density functional calculations Ab initio calculations Molecular dynamics

Synthesis and Properties of An Aminated hypocrellin B

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Chinese Chemical Letters 2001年第2期12卷 117-118页

作者： yi Jin tang Jing yi AN Institute of photographic chemistry Academi SinicaBeijing 100101

A new aminated-perylenequinone derivative 2 was synthesized by the reaction of 1 (hypocrellin B) with 6-aminohexanoic-acid. The structure of 2 was identified by UV-Vis, MS, IR and H-1-NMR. Thc amphiphility spectrum an... 详细信息

关键词： Hypocrellins amination amphiphility photochemical properties

Global attractivity of asymptotically almost periodic Nicholson＇s blowflies models with a nonlinear density-dependent mortality term

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International Journal of Biomathematics 2018年第6期11卷 77-91页

作者： yi tang Shenglan Xie College of Mathematics and Computational Science Hunan First Normal University Changsha Hunan 410205 P. R. China Nanhu College Jiaxing University Jiaxing Zhejiang 314001 P. R. China

This paper focuses on the study of a class of asymptotically almost periodic Nicholson＇s blowflies models with a nonlinear density-dependent mortality term. By virtue of differ-ential inequality techniques, a set of easily verifiable sufficient conditions are established to show that every solution of the considered model is asymptotically almost periodic, and it also converges to a same almost periodic function as t →＋∞ , which improves and supplements some previously known researches. Moreover, a numerical example is given to test the feasibility and effectiveness of the obtained results.

关键词： Nicholson's blowflies model nonlinear density-dependent mortality asymp-totically almost periodic solution convergence.

Seed-induced synthesis of functional MFI zeolite materials:Method development,crystallization mechanisms,and catalytic properties

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Frontiers of Chemical Science and Engineering 2020年第2期14卷 143-158页

作者： Zhaoqi Ye Hongbin Zhang Yahong Zhang yi tang Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsLaboratory of Advanced Materialsand Collaborative Innovation Center of Chemistry for Energy MaterialsFudan UniversityShanghai 200433China Institute for Preservation of Chinese Ancient Books Fudan University LibraryFudan UniversityShanghai 200433China

As an important zeolite material,MFI zeolites,as well as their controllable synthesis,are of great interest in both basic and applied *** the developed synthetic approaches,the seed-induced method has gradually evolved into a facile,low-cost,and even green alternative to give zeolites the desirable physicochemical *** this review,we briefly summarize the development of seed-induced syntheses of diverse functional MFI zeolites,where the“living”seed crystals not only direct the formation of zeolitic framework but also function as special“templates”or“units”to fine-tune the zeolite materials with diverse sizes,shapes,compositions,morphologies and pore ***,on the basis of their structural features and crystallization behaviors in seed-induced synthesis,we reveal the roles of seeds and discuss the related crystallization mechanisms including both classical and non-classical *** also want to guide readers to investigate the structure-performance relationships between these functional MFI zeolite catalysts and suitable catalytic reactions.

关键词： seed-induced synthesis MFI zeolite synthesis mechanism catalytic property

In-situ reconstruction of catalysts in cathodic electrocatalysis: New insights into active-site structures and working mechanisms

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Journal of Energy Chemistry 2022年第7期31卷 414-436,I0011页

作者： Wenbiao Zhang Yang Yang yi tang Qingsheng Gao College of Chemistry and Materials Science and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou 510632GuangdongChina Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsLaboratory of Advanced Materials and Collaborative Innovation Center of Chemistry for Energy Materials(iCHEM)Fudan UniversityShanghai 200433China

Cathodic electrocatalytic reactions, such as hydrogen evolution and CO_(2)/N_(2) reduction, are the key processes that store intermittent electricity into stable chemical energy. Although a great progress has been made to boost activity and selectivity via elaborative catalyst design, the structure–property relationships have not been sufficiently understood in the context of surface reconfiguration under working conditions. Recent efforts devoted to tracking dynamic evolution of electrocatalysts using in-situ and/or operando techniques gave new insights into the real structure and working mechanism of active sites,and provided principles to design better catalysts. The achievement of cathodic electrocatalysts in this subject is herein summarized, focusing on the correlations between reconstructed surface and electrocatalytic performance. Briefly, the thermodynamics of reconstruction at cathodes is discussed at first, and then the representative progresses in H_(2) evolution and CO_(2)/N_(2) reduction are introduced in sequence to acquire insights into electrochemical processes on in-situ reconfigured surfaces or interfaces. Finally, a perspective is offered to guide future investigations. This review is anticipated to shed some new light on in-depth understanding cathodic electrocatalysis and exploiting prominent electrocatalysts.

关键词： Hydrogen evolution reaction CO_(2)reduction reaction Nitrogen reduction reaction In-situ reconstruction Electronic configurations Valence states Topological changes

Physical-data Fusion Modeling Method for Energy Consumption Analysis of Smart Building

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Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 482-491页

作者： Xiao Han Chaohai Zhang yi tang Yujian Ye the Jiangsu Key Laboratory of New Energy Generation and Power Conversion Nanjing University of Aeronautics and AstronauticsNanjing 211106China the School of Electrical Engineering Southeast UniversityNanjing 210096China the Department of Electrical and Electronic Engineering Imperial College LondonLondonU.K.

The energy consumption of buildings accounts for approximately 40%of total energy *** accurate energy consumption analysis of buildings can not only promise significant energy savings but also help estimate the demand response potential more accurately,and consequently brings benefits to the upstream power *** paper proposes a novel physical-data fusion modeling(PFM)method for modeling smart buildings that can accurately assess energy ***,a thermal process model of buildings and an electrical load model that focus on building heating,ventilation,and air conditioning(HVAC)systems are presented to analyze the thermal-electrical conversion process of energy consumption of ***,the PFM method is used to improve the accuracy of the energy consumption analysis model for buildings by modifying the parameters that are difficult to measure in the physical model(i.e.,it effectively modifies the electrical load model based on the proposed PFM method).Finally,case studies involving a real-world dataset recorded in a high-tech park in Changzhou,China,demonstrate that the proposed method exhibits superior performance with respect to the traditional physical modeling(TPM)method and data-driven modeling(DDM)method in terms of the achieved accuracy.

关键词： Smart building physical-data fusion modeling method energy consumption precision model thermal-electrical conversion.