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Optimized Auxiliary Frequency Control of Wind Farm Based on Piecewise Reduced-order Frequency Response Model

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 791-802页

作者： Xu Zhang Chen Zhao Junchao Ma Long Zhang dan sun Chenxu Wang Yan Peng Heng Nian the School of Electrical Engineering Zhejiang UniversityHangzhou 310058China Electric Power Research Institute of State Grid Zhejiang Electric Power Corporation Hangzhou 310014China

With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely *** traditional system frequency response(SFR)model is not suitable for the wind power generation system due to its poor accuracy and *** this paper,a piecewise reduced-order frequency response(PROFR)model is proposed,and an optimized auxiliary frequency control(O-AFC)scheme of WF based on the P-ROFR model is ***,a full-order frequency response model considering the change in operating point of wind turbine is established to improve the *** order to simplify the fullorder model,a P-ROFR model with second-order structure and high accuracy at each frequency response stage is *** on the proposed P-ROFR model,the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed ***,an OAFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency ***,the effectiveness of the proposed P-ROFR model and the performance of the proposed OAFC scheme are verified by simulation studies.

关键词： Frequency response piecewise reduced-order wind farm auxiliary frequency control

The life-history trait trade-offs mediated by reproduction and immunity in the brown planthopper,Nilaparvata lugens Stål

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Journal of Integrative Agriculture 2024年第6期23卷 2018-2032页

作者： dan sun Hongfeng Wang Jiahui Zeng Qiuchen Xu Mingyun Wang Xiaoping Yu Xuping Shentu Zhejiang Provincial Key Laboratory of Biometrology and Inspection&Quarantine College of Life ScienceChina Jiliang UniversityHangzhou 310018China

Reproduction and immune defense are costly functions,and they are expected to tradeoff with each other to drive *** brown planthopper(BPH),Nilaparvata lugens Stål(Hemiptera,Delphacidae),is a global superpest that mostly damages rice ***-like symbionts(YLS)exist in the abdominal fat body tissue and are tightly associated with the development,growth,and reproduction of *** previous research demonstrated that mating behavior promotes the release of YLS from the fat body into the hemolymph in the BPH,thereby triggering an immune ***,the fitness costs related to life-history traits of BPH(such as survival rate)have a strong dependence on the relative abundance of ***,the possible relationship between reproduction and the immune response in BPH has not been *** this study,an omics-based approach was used to analyze the transcriptome of fat body tissues in mated and unmated BPH at 72 h post-eclosion,from which two antimicrobial peptide genes,NlDefensin A(NlDfA)and NlDefensin B(NlDfB),were selected since they were highly expressed in mated ***,the full-length cDNA sequences of the NlDfA and NlDfB genes were cloned and *** results showed up-regulation of the NlDfA and NlDfB genes in mated BPH when compared to unmated ***-temporal expression analysis indicated that the NlDfA and NlDfB genes were expressed in all tissues and developmental stages,and they were most highly expressed in the fat body at 24 h ***,the symbionts in BPH were significantly inhibited by the in vitro expression of the NlDfA and NlDfB ***,RNA interference(RNAi)-mediated suppression of NlDfA and NlDfB dramatically increased the relative abundance of YLS in the fat body,while YLS in the hemolymph decreased *** BPHs also displayed some fitness disadvantages in survival,fecundity,hatchability,and possibly the vertical transmission of YLS from hemolymph to *** results

关键词： Nilaparvata lugens reproduction immune defense trade-off

Novel 2D bifunctional layered rare-earth hydroxides@GO catalyst as a functional interlayer for improved liquid-solid conversion of polysulfides in lithium-sulfur batteries

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Chinese Chemical Letters 2024年第5期35卷 434-440页

作者： Haodong Wang Xiaoxu Lai Chi Chen Pei Shi Houzhao Wan Hao Wang Xingguang Chen dan sun CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Fujian Normal UniversityFuzhou 350007China Xiamen Institute of Rare Earth Materials Haixi InstitutesChinese Academy of SciencesXiamen 361021China School of Microelectronics Hubei UniversityWuhan 430062China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen 361021China

The detrimental“shuttle effect”of lithium polysulfides(LiPSs)together with sluggish multi-order reaction kinetics are the main drawbacks hindering lithium-sulfur(Li-S)batteries from commercial ***,we first propose the implementability of layered rare-earth hydroxides(LREHs)in Li-S batteries to optimize electrochemical *** this work,a two-dimensional(2D)rare-earth-based composite constructed by the layered gadolinium hydroxy chloride[Gd_(2)(OH)_(5)(H_(2)O)_(n)]Cl nanoplates(LGdH NPs)and graphene oxide(GO)was designed as a sulfur immobilizer for Li-S *** the experimental results and density functional theory(DFT)calculations,it is revealed that the LGdH@GO composite not only provides a strong anchoring of the intermediates during cycling,but also acts as an effective catalyst to accelerate the liquid-solid conversion of *** Li-S batteries assembled by LGdH@GO modified separators delivered a superior rate performance with a specific capacity of 605.34 mAh/g at 5 C,as well as excellent cycle stability with a decay rate of 0.087%over 500 cycles at 2 *** study provided a deep understanding of the mechanism to suppress the“shuttle effect”by the LREHs,and a guide to design effective functional interlayers for high-performance Li-S batteries with excellent electrocatalytic activity.

关键词： Lithium-sulfur batteries Functional separator Layered rare-earth hydroxides Shuttle effect Adsorption Catalysis

基于CiteSpace软件分析的太赫兹超材料器件研究

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光谱学与光谱分析 2024年第4期44卷 910-917页

作者：戴林林苏晋寇菲菲亓丽梅孙丹丹石丹北京邮电大学电子工程学院北京100876 山东师范大学光操作与应用协同创新中心山东济南250358

超材料具备天然材料没有的电磁性质,基于超材料的太赫兹(THz)功能器件在生物分子检测、医学成像、安全检查等领域都具有广泛的应用前景。采用CiteSpace软件对2016年—2023年web of science网站上有关太赫兹超材料功能器件的参考文献进... 详细信息

超材料具备天然材料没有的电磁性质,基于超材料的太赫兹(THz)功能器件在生物分子检测、医学成像、安全检查等领域都具有广泛的应用前景。采用CiteSpace软件对2016年—2023年web of science网站上有关太赫兹超材料功能器件的参考文献进行了可视化分析,综述了THz超材料功能器件的研究进展、热点领域,并对其发展前景进行了预测,从而为从事相关研究的工作人员提供借鉴。此次分析共检索到紧密相关文献2159篇。论文从发表文献的国家、机构和作者贡献、被引次数和关键词聚类等多方面分别进行了分析和讨论。得到了最近几年THz超材料功能器件的研究领域,主要包括吸波器、滤波器、电磁诱导透明、调制器、非对称传输、波前调控、编码超表面、机器学习、生物传感和量子纠缠超表面等。研究发现在THz超材料功能器件领域,中国发文量占所有文章总数的50%以上,英国、中国、美国这三个国家的影响力最高。通过对科研机构的合作网络分析,发现发文量排名前十位的科研机构均是中国单位,其中天津大学发文量占据第一位。通过对论文作者的共现分析和共被引分析,可以分别统计出作者的发文数量和影响力。为进一步研究THz超材料功能器件的研究热点,对关键词进行了聚类分析,得到了11个集群,总结了5个关键研究领域。最后给出了研究领域的分布图,以知识树的形式分析了各个领域的发展现状。其中吸波器、滤波器、调制器、电磁诱导透明等领域已经研究成熟。生物传感、非对称传输、天线等领域处于发展阶段,并逐渐成熟。机器学习、量子纠缠超表面成为未来的研究热点。

关键词：超材料太赫兹功能器件 CiteSpace

动态制度变迁中的学习行为——理论发展回顾与探讨

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经济社会体制比较 2024年第1期 182-193页

作者：孙丹丰雷西北农林科技大学经济管理学院中国人民大学公共管理学院

动态制度变迁中的学习行为是新制度经济学的重要议题。目前学界对学习理论如何服务于制度研究的机制尚不明确,难以揭示学习行为对制度变迁的影响路径。文章基于文献综述的研究发现:学习理论通过促使制度变迁的微过程实例化和辅助进化思... 详细信息

动态制度变迁中的学习行为是新制度经济学的重要议题。目前学界对学习理论如何服务于制度研究的机制尚不明确,难以揭示学习行为对制度变迁的影响路径。文章基于文献综述的研究发现:学习理论通过促使制度变迁的微过程实例化和辅助进化思想描绘动态特征两种机制,补充制度理论。学习行为通过三种路径影响制度变迁:学习类型的一些概念能够解释制度内生性,引入学习行为的制度研究有助于分析多层次互动,以及可以将行为与制度的协同演化特征具体化。诺斯、斯泰因、葛拉克、钱德勒等人的动态模型对学习行为的引入由浅入深,一致肯定了学习行为对主体认知的塑造作用及对制度变迁的决定性作用。一个完整的包含学习行为的制度分析框架应该既包括多层次互动又蕴含协同演化思想,前者可以整合自下而上和自上而下两个方向的制度变迁,后者能够实现微观行为与宏观制度之间的交织与相融。

关键词：制度理论学习理论学习行为多层次互动协同演化

Physiological Analysis of Drought Resistance of Seven Cultivars Spring Wheat in Northern Regions of China

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Journal of Northeast Agricultural University(English Edition) 2024年第2期31卷 1-12页

作者： Gao Fengmei Zhang Fuzhi Zhao Yuanling Li Tie Li Dongmei sun Minglong Zhang Qichang Liu Ningtao sun dan Tian Chao sun Lianfa Institute of Crop Resources Heilongjiang Academy of Agricultural SciencesHarbin 150086China College of Art and Design Harbin Institute of Information EngineeringHarbin 150431China

In order to determine the physiological mechanism of drought resistance of northern wheat in China,six drought resistant wheat and one sensitivity to drought wheat were planted in *** were subjected to drought treatment and normal water when the plants grew to the 3-leaf *** were collected at 10,20,30,and 40 days after the drought treatment,*** electrical conductivity,photosynthetic parameters,chlorophyll fluorescence parameters,sugar content,proline content,protein content,and active oxygen scavenging enzyme activity of the plants were detected,and the agronomic traits of the wheat varieties were investigated at *** results indicated that the phenotype and yield-related factors of Darkhan 144 changed little under the drought *** relative electrical conductivity of Kefeng 6 and Darkhan 166 was lower under the drought stress,and their cell membrane was less *** Darkhan 144 and Darkhan 166 had higher drought resistance coefficients,and were the wheat varieties with stronger drought ***,the physiological mechanisms of drought resistance of these three wheat were different:Darkhan 144 maintained a higher photosynthetic activity under the drought stress;Darkhan 166 maintained a higher protein content,photosynthetic activity and active oxygen scavenging enzyme *** addition,other drought-resistant varieties Kefeng 6,Kefeng 10 and Longmai 26 had a higher content of osmoregulatory substances under the drought stress.

关键词： wheat tolerance drought physiological mechanism

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计及工作点偏移的减载风电系统频率响应模型

电力系统自动化 2024年第16期48卷 79-87页

作者：张龙孙丹张旭年珩浙江大学电气工程学院浙江省杭州市310027

随着风电并网容量不断升高,利用减载风电机组参与一次调频对保障系统频率稳定性具有重要意义。然而,风机的工作点会随其转速变化而发生偏移,使得风机的实际一次调频贡献小于期望值。为此,文中首先分析了频率故障后风电机组减载功率跟踪... 详细信息

随着风电并网容量不断升高,利用减载风电机组参与一次调频对保障系统频率稳定性具有重要意义。然而,风机的工作点会随其转速变化而发生偏移,使得风机的实际一次调频贡献小于期望值。为此,文中首先分析了频率故障后风电机组减载功率跟踪控制与综合惯量控制的交互影响,指出了风机工作点偏移导致其调频效果削弱的基本原理。其次,基于风机的转子运动方程推导了风电功频传递函数,建立了计及减载风电机组工作点偏移的系统频率响应模型,并利用最小二乘法对其进行降阶,推导了系统频率最低点的解析式。然后,针对虚拟惯量控制的频率恢复期间引起功率倒流、微分环节放大噪声等缺点,提出利用下垂控制替代综合惯量控制。同时,为使减载风电机组获得期望的调频效果,基于频率最低点和稳态频率指标对风机控制参数进行了修正,提出了两种等效下垂系数的计算方法。最后,在MATLAB/Simulink平台建立了四机两区域模型,验证了所提降阶方法及修正方法的有效性。

关键词：风电机组系统频率响应模型降阶惯量控制等效下垂系数

计及调频能力和经济效益的储能集群多状态区间优化策略

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电力系统自动化 2024年第5期48卷 58-67页

作者：段潇涵孙丹赵琛年珩浙江大学电气工程学院浙江省杭州市310027

可再生能源发电系统的快速增长使得电力系统的频率安全面临着挑战。针对分布式储能集群二次调频过程中所面临的问题,提出一种计及调频能力和经济效益的储能集群多状态区间优化策略。该策略依据荷电状态将所有储能单元划分为多个状态区间... 详细信息

可再生能源发电系统的快速增长使得电力系统的频率安全面临着挑战。针对分布式储能集群二次调频过程中所面临的问题,提出一种计及调频能力和经济效益的储能集群多状态区间优化策略。该策略依据荷电状态将所有储能单元划分为多个状态区间,再结合自动发电控制指令及各区间的极限功率确定优化区间。针对非优化区间内的单元,输出功率直接由出力优先级确定;针对优化区间内的单元,利用反映调频成本和整体荷电状态的目标函数及约束条件完成最优求解,从而确定输出功率。仿真结果表明,所提策略能大大减小控制中心的运算量,功率分配结果能有效提升储能集群的二次调频能力,同时提升储能集群的经济效益。

关键词：分布式储能集群自动发电控制调频经济效益多状态区间功率分配

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刷式密封刷丝浮升效应流固耦合数值研究

航空动力学报 2024年第9期39卷 95-105页

作者：孙基生孙丹赵欢慕伟张杰一温帅方沈阳航空航天大学航空发动机学院、辽宁省航空宇航推进系统先进测试技术重点实验室沈阳110136 中国航发沈阳发动机研究所沈阳110015 中国航发动力传输航空科技重点实验室沈阳110015

基于简化悬臂梁模型分析了刷式密封刷丝浮升效应理论,采用ALE(arbitrary Lagrange-Euler)流固耦合方法建立了刷式密封刷丝浮升效应三维瞬态数值求解模型,在验证了数值模型准确性基础上,研究了刷丝总体变形特性,量化分析了刷丝自由端轴... 详细信息

基于简化悬臂梁模型分析了刷式密封刷丝浮升效应理论,采用ALE(arbitrary Lagrange-Euler)流固耦合方法建立了刷式密封刷丝浮升效应三维瞬态数值求解模型,在验证了数值模型准确性基础上,研究了刷丝总体变形特性,量化分析了刷丝自由端轴向、径向和总体变形量,研究了结构参数与工况参数对刷式密封刷丝浮升效应的影响规律,揭示了刷式密封刷丝浮升效应诱发机理。研究结果表明:刷式密封刷丝浮升效应是前排刷丝受非定常径向气流作用产生的刷丝扰动现象,刷丝浮升效应会使前排刷丝向来流方向发生较大变形,并使前排刷丝与转子面产生径向间隙,泄漏量增加。当进出口压比从2提高至4,刷丝自由端平均变形量增加了47%,将前挡板保护高度从1.5 mm提高至2.5 mm,刷丝自由端平均变形量增加了36%,均使刷丝浮升效应增强。刷式密封前挡板与刷丝束间隙提供的径向气流通道,进出口压差在前挡板与刷丝束间隙内产生的径向压力梯度是刷丝浮升效应的诱发条件,提高刷丝直径和降低前挡板与刷丝束间隙均可降低刷丝浮升效应。

关键词：刷式密封刷丝浮升效应 ALE(arbitrary Lagrange-Euler)方法流固耦合变形特性

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