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Optimal Configuration of Fault Location Measurement Points in DC Distribution Networks Based on Improved Particle Swarm Optimization Algorithm

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Energy Engineering 2024年第6期121卷 1535-1555页

作者： Huanan Yu Hangyu li He Wang Shiqiang Li Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of EducationNortheast Electric Power UniversityJilin132012China

The escalating deployment of distributed power sources and random loads in DC distribution networks hasamplified the potential consequences of faults if left uncontrolled. To expedite the process of achieving an optimalconfiguration of measurement points, this paper presents an optimal configuration scheme for fault locationmeasurement points in DC distribution networks based on an improved particle swarm optimization algorithm.Initially, a measurement point distribution optimization model is formulated, leveraging compressive sensing.The model aims to achieve the minimum number of measurement points while attaining the best compressivesensing reconstruction effect. It incorporates constraints from the compressive sensing algorithm and networkwide viewability. Subsequently, the traditional particle swarm algorithm is enhanced by utilizing the Haltonsequence for population initialization, generating uniformly distributed individuals. This enhancement reducesindividual search blindness and overlap probability, thereby promoting population diversity. Furthermore, anadaptive t-distribution perturbation strategy is introduced during the particle update process to enhance the globalsearch capability and search speed. The established model for the optimal configuration of measurement points issolved, and the results demonstrate the efficacy and practicality of the proposed method. The optimal configurationreduces the number of measurement points, enhances localization accuracy, and improves the convergence speedof the algorithm. These findings validate the effectiveness and utility of the proposed approach.

关键词： Optimal allocation improved particle swarm algorithm fault location compressed sensing DC distribution network

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Decision Making and Ability： An Explanation of Elitism in China＇s Government

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2017年第4期12卷 635-659页

作者： Shiqiang Li School of Economics University of Chinese Academy of Social Sciences Beijing 100089China

This article tries to explain elitism in China＇s governmental decision making. Our model shows that the governments＇ expected utility increases with a bureaucrat＇s ability to make decisions under the flexible framework of delegation and communication （with separated reporting strategy）. In the early of 1950s, China＇s government choose a flexible decision making framework in order to efficiently manage many affairs in a complex environment. This initial choice started the process of a self-reinforcing demand for ability inside of the flexible decision making framework. With the current reforms of streamlining administrations and retreating from the market, the elitism of China＇s government might reverse.

关键词： elitism decision rule China delegation communication bureaucrat

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[4+1]Cyclization of benzohydrazide and ClCF_(2)COONa towards 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d_(5)

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Chinese Chemical Letters 2022年第3期33卷 1511-1514页

作者： Ya Wang shiqiang Mu Xin li Qiuling Song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d_(5) via[4+1]cyclization of ClCF_(2)COONa with non-amine compounds containing amino groups is developed.Of note,this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds.The current protocol features simple operation,readily accessible raw materials,wide substrate scope and valuable products.

关键词： Transition-metal-free catalyzed [4+1]Cyclization Halofluorinated compounds 1,3,4-Oxadiazoles

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Optimal Bidding Strategy for PV and BESSs in Joint Energy and Frequency Regulation Markets Considering Carbon Reduction Benefits

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JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY 2024年第2期12卷 427-439页

作者： Bian, Jing Song, Yuheng Ding, Chen Cheng, Jianing li, shiqiang li, Guoqing Northeast Elect Power Univ Key Lab Modern Power Syst Simulat & Control & Rene Minist Educ Jilin 132000 Peoples R China Datang Northeast Elect Power Test & Res Inst Co Lt Changchun 130102 Peoples R China

Photovoltaic (PV) and battery energy storage systems (BESSs) are key components in the energy market and crucial contributors to carbon emission reduction targets. These systems can not only provide energy but can also generate considerable revenue by providing frequency regulation services and participating in carbon trading. This study proposes a bidding strategy for PV and BESSs operating in joint energy and frequency regulation markets, with a specific focus on carbon reduction benefits. A two-stage bidding framework that optimizes the profit of PV and BESSs is presented. In the first stage, the day-ahead energy market takes into account potential real-time forecast deviations. In the second stage, the real-time balancing market uses a rolling optimization method to account for multiple uncertainties. Notably, a real-time frequency regulation control method is proposed for the participation of PV and BESSs in automatic generation control (AGC). This is particularly relevant given the uncertainty of grid frequency fluctuations in the optimization model of the real-time balancing market. This control method dynamically assigns the frequency regulation amount undertaken by the PV and BESSs according to the control interval in which the area control error (ACE) occurs. The case study results demonstrate that the proposed bidding strategy not only enables the PV and BESSs to effectively participate in the grid frequency regulation response but also yields considerable carbon emission reduction benefits and effectively improves the system operation economy.

关键词： Real-time systems Frequency control Carbon dioxide Power generation Regulation Optimization Automatic generation control Photovoltaic (PV) battery energy storage system (BESS) energy market carbon market frequency regulation service bidding strategy PHOTOVOLTAIC POWER-PLANTS BATTERY STORAGE WIND FARM SYSTEM OPTIMIZATION FACIliTIES CAPABIliTY

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Dynamic Economic Scheduling with Self-Adaptive Uncertainty in Distribution Network Based on Deep Reinforcement Learning

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Energy Engineering 2024年第6期121卷 1671-1695页

作者： Guanfu Wang Yudie Sun Jinling li Yu Jiang Chunhui li Huanan Yu He Wang Shiqiang Li State Grid liaoning Electric Power Co. Ltd.Liaoyang Power Supply CompanyLiaoyang111000China Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of Education(Northeast Electric Power University)Jilin132012China Jilin Northeast Electric Power University Science and Technology Development Co. Ltd.Jilin132012China

Traditional optimal scheduling methods are limited to accurate physical models and parameter settings, which aredifficult to adapt to the uncertainty of source and load, and there are problems such as the inability to make dynamicdecisions continuously. This paper proposed a dynamic economic scheduling method for distribution networksbased on deep reinforcement learning. Firstly, the economic scheduling model of the new energy distributionnetwork is established considering the action characteristics of micro-gas turbines, and the dynamic schedulingmodel based on deep reinforcement learning is constructed for the new energy distribution network system with ahigh proportion of new energy, and the Markov decision process of the model is defined. Secondly, Second, for thechanging characteristics of source-load uncertainty, agents are trained interactively with the distributed networkin a data-driven manner. Then, through the proximal policy optimization algorithm, agents adaptively learn thescheduling strategy and realize the dynamic scheduling decision of the new energy distribution network system.Finally, the feasibility and superiority of the proposed method are verified by an improved IEEE 33-node simulationsystem.

关键词： Self-adaptive the uncertainty of sources and load deep reinforcement learning dynamic economic scheduling

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Pyridine terminated polyurethane dendrimer/chlorinated butyl rubber nanocomposites with excellent mechanical and damping properties

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Chinese Journal of Chemical Engineering 2023年第1期53卷 211-221页

作者： Jiacheng Chen Jincheng Wang Shuhong li Kailing Xiang shiqiang Song College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceShanghai 201620China

Due to the special viscoelastic property, traditional rubber with high performance has been widely used in human life and production. However, it is challenging to improve the damping property without sacrificing the extensibility. In this work, a novel type of second-generation polyurethane dendrimer terminated with pyridine(G2-Py) was synthesized by using thiolactone chemistry and subsequently complexed with Zn ions. The structure and morphology of G2-Py were characterized. G2-Py-Zn2+was then mixed with chlorinated butyl rubber(CIIR) by a two-roll mill. A series of CIIR/G2-Py-Zn2+elastomers were obtained through vulcanization. CIIR/G2-Py-Zn2+elastomers could achieve high stretchability(a strain of ~1035%), high mechanical strength(a tensile stress of 7.64 MPa). This was benefitted from the friction between G2-Py and CIIR as well as variety of non-covalent bonds provided by G2-Py-Zn2+,which can dissipate energy to further improve the strength and extensibility. The coordination of Zn2+-pyridine was confirmed by Fourier transform infrared spectroscopy, stress relaxation and cycle tensile test. To further investigate the morphology and damping properties of the elastomers, scanning electron microscopy and dynamic mechanical analysis were performed. CIIR-5 showed the best damping performance with higher tan δ_(max) and wider effective damping temperatures. Therefore, this dendrimer modification technology provides wider applications for CIIR elastomers in daily life.

关键词： Coordination bonds Hydrogen bonds Polyurethane dendrimer Nanostructure Polymers Composites

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Feeding citrus flavonoid extracts decreases bacterial endotoxin and systemic inflammation and improves immunometabolic status by modulating hindgut microbiome and metabolome in lactating dairy cows

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Animal Nutrition 2023年第2期13卷 386-400页

作者： Yuchao Zhao shiqiang Yu liuxue li Huiying Zhao Yuqin li linshu Jiang Ming liu Beijing Key Laboratory of Dairy Cow Nutrition Animal Science and Technology CollegeBeijing University of AgricultureBeijing102206China Beijing Beinong Enterprise Management Co. Ltd.Beijing102206China

The objectives of this study were to determine the effects of dietary supplementation with citrus flavonoid extracts(CFE)on milk performance,serum biochemistry parameters,fecal volatile fatty acids,fecal microbial community,and fecal metabolites in dairy cows.Eight multiparous lactating Holstein cows were used in a replicated 4×4 Latin square design(21-day period).Cows were fed a basal diet without addition(CON)or basal diet with added CFE at 50(CFE50),100(CFE10),and 150 g/d(CFE150).Feeding CFE up to 150 g/d increased milk yield and milk lactose percentage.Supplementary CFE linearly decreased milk somatic cell count.Serum cytokines interleukin-1β(IL-1β),IL-2,IL-6,and tumor necrosis factor-α(TNF-α)concentrations decreased linearly as the levels of CFE increased.Cows in CFE150 had lower serum lipopolysaccharide and lipopolysaccharide binding protein compared with CON.These results indicate feeding CFE decreased systemic inflammation and endotoxin levels in dairy cows.Furthermore,feeding CFE linearly increased the concentrations of total volatile fatty acids,acetate,and butyrate in feces.The relative abundances of beneficial bacteria Bifidobacterium spp.,Clostridium coccoides-Eubacterium rectale group,and Faecalibacterium prausnitzii in feces increased linearly with increasing CFE supplementation.The diversity and community structure of fecal microbiota were un-affected by CFE supplementation.However,supplementing CFE reduced the relative abundances of genera Ruminococcus_torques_group,Roseburia,and Lachnospira,but increased genera Bacteroides and Phascolarctobacterium.Metabolomics analysis showed that supplementary CFE resulted in a significant modification in the fecal metabolites profile.Compared with CON,fecal naringenin,hesperetin,hippuric acid,and sphingosine concentrations were greater in CFE150 cows,while fecal GlcCer(d18:1/20:0),Cer(d18:0/24:0),Cer(d18:0/22:0),sphinganine,and deoxycholic acid concentrations were less in CFE150 cows.Predicted pathway analysis suggested that"sphingolipid metabolism"was signif

关键词： Citrus flavonoid Dairy cow Fecal microbiota Systemic inflammation Volatile fatty acid

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Rare variants in novel and known genes associated with primary angle closure glaucoma based on whole exome sequencing of 549 probands

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Journal of Genetics and Genomics 2019年第7期46卷 353-357页

作者： Wenmin Sun Xueshan Xiao Shiqiang Li Jiamin Ouyang Xueqing li Xiaoyun Jia Xing liu Qingjiong Zhang State Key Laboratory of Ophthalmology Zhongshan OphthalmicCenter Sun Yat-sen University

Primary angle closure glaucoma(PACG)is one of the most common causes of irreversible blindness in Asia and about 80%of PACG are present in Asia(Song et al.,2017).Genetics plays an important role in the development of PACG(Gramer et al.,2014).Recently,eight common SNPs were found to be strongly associated with PACG(Vithana et al.,2012;Khor et al.,2016)and mutations in MYRF cause high hyperopia accompanied with PACG(Xiao et al.,2019).

关键词： irreversible blindness hyperopia

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Global warming weakening the inherent stability of glaciers and permafrost

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Science Bulletin 2019年第4期64卷 245-253页

作者： Yongjian Ding shiqiang Zhang lin Zhao Zhongqin li Shichang Kang State Key Laboratory of Cryospheric Science Northwest China Ecological Environment and Resource Research Institute Chinese Academy of Sciences Key Laboratory of Ecohydrology of Inland River Basin Chinese Academy of Sciences University of Chinese Academy Sciences Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity Northwest University College of Urban and Environmental Sciences Northwest University State Cryosphere Monitor and Research Station Northwest China Ecological Environment and Resource Research Institute Chinese Academy of Sciences State Glacier Monitor and Research Station Northwest China Ecological Environment and Resource Research Institute Chinese Academy of Sciences

The Cryosphere has been undergoing a worldwide retreat, as seen in the decrease in the areal extent and volume of glaciers and in the areal extent of permafrost. This paper presents a systematic examination of the inherent stability changes of glaciers and permafrost caused by warming. Various study results suggest that over the past 30 years, the internal temperature of glaciers and permafrost exhibits an overall accelerating warming trend. The warming rate peaked in the mid-2000s and slowed slightly for several years afterward. In recent years, however, the warming rate has seemed to pick up again. The warming of glaciers and permafrost has exerted great impact on their stability, displayed as intensified melting,increased glacier surging, enlargement of supraglacial lakes, and increased permafrost degradation.Even without a future temperature increase, some glaciers will continue to shrink, and the number of surging glaciers will increase. The transition from low-temperature to high-temperature permafrost is a noticeable warning sign of a comprehensive degradation of permafrost. These results indicate that‘‘warming" glaciers and permafrost will exert significant impacts on the hydrology, ecology, and stability of engineering in cold regions.

关键词： Warming Englacial temperature Permafrost Internal thermal state Stability

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何时应该杜绝“搞变通”——一个非正式授权理论解释

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经济学报 2023年第3期10卷 311-333页

作者：李石强中国社会科学院大学经济学院

党的十九届四中全会提出要杜绝制度执行中“搞变通”的现象。本文构建了一个一般化的委托人具有事后私人信息的两期模型对此进行解释。模型表明,中央政府不会允许地方政府在无法观察社会环境冲击的情况下进行灵活变通。但是,如果社会环... 详细信息

党的十九届四中全会提出要杜绝制度执行中“搞变通”的现象。本文构建了一个一般化的委托人具有事后私人信息的两期模型对此进行解释。模型表明,中央政府不会允许地方政府在无法观察社会环境冲击的情况下进行灵活变通。但是,如果社会环境冲击幅度足够大,中央政府会允许有能力观察社会环境冲击的地方政府在第1期进行变通,然后在第2期沿用第1期的实际决策,以实现对冲击最好的应对。反之,如果社会环境较为稳定,中央政府对社会最优政策的认识清楚,那么从一开始就不会允许地方政府灵活变通,而是始终坚持执行最初的既定决策。

关键词：变通授权执行中央政府地方政府

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