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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 958-970页

作者： Jialiang Wu Zhen wang Ruixu Liu yu Shan Chenxuan wang the College of Electrical Engineering Zhejiang UniversityHangzhou 310027China the Economic Research Institute of State Grid Zhejiang Electric Power Co. Ltd.Hangzhou 310016China

Hybrid multi-terminal direct current(MTDC)transmission technology has been a research focus,and primary frequency regulation(FR)improvement in the receiving-end system is one of the problems to be *** paper presents a decentralized primary FR scheme for hybrid MTDC power systems considering multi-source enhancement to help suppress frequency disturbance in the receiving-end *** the converters only need local frequency or DC voltage signal input to respond to system disturbance without communication or a control center,i.e.,a decentralized control *** proposed scheme can activate appropriate power sources to assist in FR in various system disturbance severities with fine-designed thresholds,ensuring sufficient utilization of each power *** better balance FR performance and FR resource participation,an evaluation index is proposed and the parameter optimization problem is further ***,the validity of the proposed scheme is verified by simulations in MATLAB/Simulink.

关键词： Decentralized control scheme primary frequency regulation(FR) rate of change of frequency(ROCOF) system frequency disturbance

Investigation of Ce/BEA as a passive NO_(x)adsorber:*** occurrences of cerium and adsorption behavior

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Journal of Rare Earths 2024年第7期42卷 1265-1271,I0003页

作者： Minghui yu Yiying Ding Xiaojie yu Siwei Yan Meiqing Shen Jianqiang wang Jun wang Gurong Shen School of Materials Science and Engineering Tianjin UniversityTianjin300350China School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has great potential as a passive NO_(x)absorber(PNA)to reduce the NO_(x)emissions during the cold start phase especially in diesel engine for its high resistance to CO and suitable NO_(x)desorption temperature ***,as a novel material,its physical and chemical properties still remain *** this work,Ce/BEA was synthesized by ion-exchange method to identify the active species in NO_(x)adsorption,compared with aggregated Ce species in Ce/SiAlO_(x) prepared by impregnation method.X-ray diffraction(XRD),high resolution-transmission electron microscopy(HR-TEM)and aberration-corrected-scanning transmission electron microscopy(AC-STEM)were performed to confirm the isolated single atom formation of Ce species in Ce/***-vis diffraction reflection spectra(DRS)and X-ray photoelectron spectroscopy(XPS)were conducted to find the difference of chemical environment between the isolated Ce species and aggregated *** performance evaluation and temperature programmed reduction of hydrogen(H_(2)-TPR)results show the high NO_(x)storage capacity and active oxygen species quantity in Ce/*** is also found that the main NO_(x)adsorption species are Ce^(4+)-O^(∗)rather than Ce^(3+).NO_(x)-diffuse reflectance infrared Fourier transform spectroscopy(NO_(x)-DRIFTS)confirms that the bidentate nitrite species are the critical NO_(x)adsorption intermediates and the conception of NO_(x)adsorption and desorption processes is proposed.

关键词： Passive NO_(x)absorber Ce/BEA Isolated Ce species Rare earths

Study on multi-timescale operation of hydrogen-containing energy coupled with transportation system

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Clean Energy 2024年第3期8卷 79-94页

作者： Xingang wang Zhiyong yu Jiayu Bian Jin yu State Grid Xinjiang Electric Power CO LTD.Urumqi830000China State Grid Xinjiang Electric Power Economic and Technology Research Institute Urumqi830000China

With the widespread attention on hydrogen energy,the operation optimization of the coupling system of hydrogen energy and transportation has become a critical ***,this study develops a hydrogen-containing energy transportation coupling system for the system collaborative operation framework,operation mode and equipment modelling of the ***,a medium-to long-term operation optimization model and a short-term operation optimization model were constructed considering the differences in the operation of coupled systems at different timescales and operating costs as the objective function and power balance and system equipment as *** the medium-and long-term operation optimization model,the planning scenario reduction method is used to reduce the wind power generation *** the short-term operation optimization model,a multivariate uncertainty model is constructed to represent the uncertainty in the coupling ***,the solution method of the model is ***,a coupled system is simulated to verify the effectiveness of the model.(i)When the initial scene set is 600,the typical scene reduction method using Latin hypercube sampling and the Wasserstein distance can reduce operating costs by 7.60%and 9.49%compared with K-means reduction and K-media reduction methods.(ii)The sensitivity coefficients of hydrogen sales price,electricity sales price and maintenance rate to operating costs are-0.031%,-1.009%and 0.0105%,respectively.(iii)Considering multiple uncertainties can help make optimal decisions based on the overall consideration of disadvantage scenarios,thereby reducing system operating costs.

关键词： hydrogen-containing energy system transportation system multi-timescale operation optimization

Quantum Spin Exchange Interactions to Accelerate the Redox Kinetics in Li–S Batteries

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Nano-Micro Letters 2024年第5期16卷 370-383页

作者： yu Du Weijie Chen yu wang yue yu Kai Guo Gan Qu Jianan Zhang Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation of Zhengzhou City College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001People’s Republic of China

Spin-engineering with electrocatalysts have been exploited to suppress the“shuttle effect”in Li–S *** selec-tion,spin-dependent electron mobility and spin potentials in activation barriers can be optimized as quantum spin exchange interactions lead-ing to a significant reduction of the electronic repulsions in the orbitals of ***,we anchor the MgPc molecules on fluorinated carbon nanotubes(MgPc@FCNT),which exhibits the single active Mg sites with axial *** to the density functional theory calculations,the electronic spin polarization in MgPc@FCNT not only increases the adsorption energy toward LiPSs intermediates but also facilitates the tunneling process of electron in Li–S *** a result,the MgPc@FCNT provides an initial capacity of 6.1 mAh cm^(-2) even when the high sulfur loading is 4.5 mg cm^(-2),and still maintains 5.1 mAh cm^(-2) after 100 *** work provides a new perspective to extend the main group single-atom catalysts enabling high-performance Li–S batteries.

关键词： Metal phthalocyanines Spin polarization Electrocatalysis Li–S batteries

HEAT KERNEL ON RICCI SHRINKERS(II)

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Acta Mathematica Scientia 2024年第5期44卷 1639-1695页

作者： yu LI Bing wang Institute of Geometry and Physics University of Science and Technology of ChinaHefei230026China Hefei National Laboratory Hefei230088China

This paper is the sequel to our study of heat kernel on Ricci shrinkers[29].In this paper,we improve many estimates in[29]and extend the recent progress of Bamler[2].In particular,we drop the compactness and curvature boundedness assumptions and show that the theory of F-convergence holds naturally on any Ricci flows induced by Ricci shrinkers.

关键词： Ricci flow Ricci shrinker heat kernel

Spatiotemporal variations of parameters of internal solitary waves in the northern South China Sea

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Journal of Oceanology and Limnology 2024年第2期42卷 421-438页

作者： yu’ang LIU Yifei JIANG Xiaojiang ZHANG Zhiyuan wang yu CAO Huizan wang College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China

The dynamic parameters for internal solitary waves(ISWs)derived from the extended Korteweg-de Vries(eKdV)equation play an important role in the understanding and prediction of *** spatiotemporal variations of the dynamic parameters of the ISWs in the northern South China Sea(SCS)were studied based on the reanalysis of long-term temperature and salinity *** results for spectrum analysis show that there are definite geographical differences for the periodic variation of the parameters:in shallow water,all parameters vary with a wave period of one year,while in deep water wave components of the parameters at other frequencies *** wavelet analysis,the wavelet power spectral densities in deep water exhibited an inter-annual variation *** example,the wave component of the dispersion coefficient with a wave period of about half a year reached its power peak once every two *** on previous work,this inter-annual variation pattern was deduced to be caused by dynamic *** further work on the regulatory mechanisms,empirical orthogonal function(EOF)decomposition was *** was found that the modes of the dispersion coefficient have different geographical distributions,explaining the reason why the wave components in different frequencies appeared in different *** numerical simulation results confirm that the variations in the parameters of the ISWs derived from the eKdV equation could affect the waveforms significantly because of changes in the polarity of the ***,the periodic variations of the dynamic parameters are related to the geographical location because of dynamic processes operating.

关键词： internal solitary waves(ISWs) dynamic parameters eKdV equation spatiotemporal variation polarity empirical orthogonal function(EOF)decomposition

Parallel Light Fields: A Perspective and A Framework

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 542-544页

作者： Fei-yue wang yu Shen IEEE State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of ScienceBeijing 100049

Dear Editor,Light fields give relatively complete description of scenes from perspective of angles and positions of rays. At present time, most of the computer vision algorithms take 2D images as input which are simplified expression of light fields with depth information discarded. In theory, computer vision tasks may achieve better performance as long as complete light fields are acquired.

关键词： computer Framework simplified

Cardiac regeneration: Pre-existing cardiomyocyte as the hub of novel signaling pathway

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Genes & Diseases 2024年第2期11卷 747-759页

作者： Tao wang Xinzhe Chen Kai wang Jie Ju Xue yu Wanpeng yu Cuiyun Liu Yin wang Institute for Translational Medicine The Affiliated Hospital of Qingdao UniversityCollege of MedicineQingdao UniversityQingdaoShandong 266023China College of Medicine Qingdao UniversityQingdaoShandong 266023China

In the mammalian heart,cardiomyocytes are forced to withdraw from the cell cycle shortly after birth,limiting the ability of the heart to regenerate and *** development of multimodal regulation of cardiac proliferation has verified that pre-existing cardiomyocyte proliferation is an essential driver of cardiac *** the continuous development of genetic lineage tracking technology,it has been revealed that cell cycle activity produces polyploid cardiomyocytes during the embryonic,juvenile,and adult stages of cardiogenesis,but newly formed mononucleated diploid cardiomyocytes also elevated sporadically during myocardial *** implied that adult cardiomyocytes have a weak regenerative capacity under the condition of ischemia injury,which offers hope for the clinical treatment of myocardial ***,the regeneration frequency and source of cardiomyocytes are still low,and the mechanism of regulating cardiomyocyte proliferation remains further *** is noteworthy to explore what force triggers endogenous cardiomyocyte proliferation and heart ***,we focused on summarizing the recent research progress of emerging endogenous key modulators and crosstalk with other signaling pathways and furnished valuable insights into the internal mechanism of heart *** addition,myocardial transcription factors,non-coding RNAs,cyclins,and cell cycle-dependent kinases are involved in the multimodal regulation of pre-existing cardiomyocyte ***,awakening the myocardial proliferation endogenous modulator and regeneration pathways may be the final battlefield for the regenerative therapy of cardiovascular diseases.

关键词： Cardiac regeneration Cell cycle re-enter Myocardial infarction Pre-existing cardiomyocyte proliferation Regenerative therapy of cardiovascular diseases

Stochastic Flexibility Evaluation for Virtual Power Plants by Aggregating Distributed Energy Resources

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 988-999页

作者： Siyuan wang Wenchuan Wu Qizhan Chen Junjie yu Peng wang Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Zhongshan Power Supply Bureau of the Guangdong Power Grid Corporation Zhongshan 528400China Beijing Qingda Gaoke System Control Company Beijing 102208China CSEE IEEE

To manage a large amount of flexible distributed energy resources(DERs)in the distribution networks,the virtual power plant(VPP)is introduced into the *** VPP can optimally dispatch these resources in a cluster manner and provide flexibility for the power system operation as a *** existing studies formulate the equivalent power flexibility of the aggregating DERs as deterministic optimization models without considering their *** this paper,we introduce the stochastic power flexibility range(PFR)and timecoupling flexibility(TCF)to describe the power flexibility of *** this model,both operational constraints and the randomness of the DERs’output are incorporated,and a combined model and data-driven solution is proposed to obtain the stochastic PFR,TCF,and cost function of *** aggregating model can be easily incorporated into the optimization model for the power system operator or market bidding,considering ***,a numerical test is *** results show that the proposed model not only has higher computational efficiency than the scenario-based methods but also achieves more economic benefits.

关键词： Chance constrained optimization combined model and data-driven stochastic power flexibility virtual power plant

Ensemble successor representations for task generalization in offline-to-online reinforcement learning

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Science China(Information Sciences) 2024年第7期67卷 240-255页

作者： Changhong wang Xudong yu Chenjia BAI Qiaosheng ZHANG Zhen wang Space Control and Inertial Technology Research Center Harbin Institute of Technology Shanghai Artificial Intelligence Laboratory Shenzhen Research Institute of Northwestern Polytechnical University School of Cybersecurity Northwestern Polytechnical University

In reinforcement learning(RL), training a policy from scratch with online experiences can be inefficient because of the difficulties in exploration. Recently, offline RL provides a promising solution by giving an initialized offline policy, which can be refined through online interactions. However, existing approaches primarily perform offline and online learning in the same task, without considering the task generalization problem in offline-to-online adaptation. In real-world applications, it is common that we only have an offline dataset from a specific task while aiming for fast online-adaptation for several tasks. To address this problem, our work builds upon the investigation of successor representations for task generalization in online RL and extends the framework to incorporate offline-to-online learning. We demonstrate that the conventional paradigm using successor features cannot effectively utilize offline data and improve the performance for the new task by online fine-tuning. To mitigate this, we introduce a novel methodology that leverages offline data to acquire an ensemble of successor representations and subsequently constructs ensemble Q functions. This approach enables robust representation learning from datasets with different coverage and facilitates fast adaption of Q functions towards new tasks during the online fine-tuning *** empirical evaluations provide compelling evidence showcasing the superior performance of our method in generalizing to diverse or even unseen tasks.

关键词： offline reinforcement learning online fine-tuning task generalization successor representations ensembles