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基于幅值特征和Hausdorff距离的配电网故障定位方法

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电力系统自动化 2020年第7期44卷 169-177页

作者：李振兴王朋飞王新翁汉琍龚旸三峡大学电气与新能源学院湖北省宜昌市443002 梯级水电站运行与控制湖北省重点实验室(三峡大学) 湖北省宜昌市443002

为了消除单相接地故障下配电网区段定位受系统中性点接地方式、不同过渡电阻以及线性相关法定位盲区等因素对定位准确性的影响,提出一种幅值特征下基于Hausdorff距离算法的故障区段定位方法。首先,分析了零序电流暂态分量故障特征,明确... 详细信息

为了消除单相接地故障下配电网区段定位受系统中性点接地方式、不同过渡电阻以及线性相关法定位盲区等因素对定位准确性的影响,提出一种幅值特征下基于Hausdorff距离算法的故障区段定位方法。首先,分析了零序电流暂态分量故障特征,明确健全区段、故障区段两端零序电流暂态分量幅值特征的关系。其次,引入Hausdorff距离算法,测算馈线区段两端零序电流暂态分量幅值特征匹配度,进一步通过与设定阈值的比较,可以有效区分出故障区段。仿真验证结果表明,所提方法无定位盲区,在不同系统接地方式、不同接地过渡电阻下均能够准确定位故障区段。

关键词：配电网小波分解 Hausdorff距离算法故障定位

π-Pimer,π-Dimer,π-Trimer,and 1Dπ-Stacks in a Series of Benzene Triimide Radical Anions:Substituent-Modulated π Interactions and Physical Properties in Crystalline State

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CCS Chemistry 2023年第6期5卷 1343-1352页

作者： De-Hui Tuo Shuxuan Tang pengfei Jin Jikun Li Xinping Wang Chuang Zhang Yu-Fei Ao Qi-Qiang Wang De-Xian Wang BeijingNational Laboratory for Molecular Sciences CASKey Laboratory of MolecularRecognition andFunctionInstitute of ChemistryChinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049 State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023 Beijing National Laboratory for Molecular Sciences Key Laboratory of PhotochemistryInstitute of ChemistryChinese Academy of SciencesBeijing 100190

We herein present the efficient syntheses,crystal structures,and physical properties of a series of novel benzene triimide(BTI)radical anions,emphasizing the relationship between molecular structure with spin–spin intermolecular interactions and physical properties in the crystalline *** radical crystals were preparedby reducingvarious substitutedBTIs(1)with cobaltocene(CoCp2),followed by sequential crystallization *** isolable radical species,that is,neutral molecule-radical anion pair(2)and monoradical species(3),were obtained from BTIs bearing small substituents(ethyl and propyl),while for those bearing larger substituents(butyl,hexyl,and benzyl)sole monoradicals(3)were *** radical species showed diverse intermolecular stackings in the crystalline state referred to asπ-pimer,π-dimer,alternatingπ-trimer,and one-dimensional(1D)slippedπ-stacks depending on the length and size of the *** spin–spin interactions arising from the substituent-tuned radical packings were demonstrated by electron spin resonance(ESR)*** structure–property relationshipwas studied in terms of magnetism and *** radicalπ-pimers andπ-stacks with effective charge transport exhibited paramagnetic property and conductivity feasibly at room temperature,whileπ-dimers andπ-trimers featuring thermally populated spin-triplet stateswere antiferromagnetic and nonconductive due to their strong radical–radical pairing effect.

关键词： radical pimer radical dimer anion radical benzene triimide π-πstacking

Flexible control strategy for HVDC transmission system adapted to intermittent new energy delivery

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Global Energy Interconnection 2021年第4期4卷 425-433页

作者： Chenhao Li Kuan Li Changhui Ma pengfei Zhang Qi Tao Yingtao Sun Xin Wang State Grid Shandong Electric Power Research Institute JinanP.R.China State Grid International Development Limited BeijingP.R.China State Grid Jinan Power Supply Company JinanP.R.China Independent Power Transmission Operator S.A. 89 Dyrrachiou Str.&Kifisou 10443AthensGreece

Intermittent new energy delivery requires increasing the flexibility of ultra-high voltage direct current(DC)power *** on a converter steady-state model and a DC power model,the control angle constraints of a converter valve are relaxed for power *** this paper,a flexible DC power control method based on a fixed tap changer position is *** initial ratio of the converter transformer is *** effects of the fixed-tap changer position control on the control angle,reactive power compensation,and commutation failure are *** new control method allows a DC system to operate at a large angle and increase the additional reactive power loss while improving the commutation security ***-state and electromagnetic transient simulations in the CIGRE test system verify the validity of the method proposed in this paper and the correctness of the analysis conclusions.

关键词： Tap changer DC power Firing angle Reactive power compensation Extinction angle Commutation failure

Overreliance on Net Export and Investment Impedes China's Structural Transformation: Estimation and Analysis Based on a Multi-Sector Growth Model

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China Economist 2019年第3期14卷 44-65页

作者： Qu Shenning Li pengfei Lyu Tie Institute of Industrial Economics (IIE) Chinese Academy of Social Sciences (CASS)

Since reform and opening-up in 1978, changes in China's industrial structure have generally followed the pattern of "Kuznets facts" but still exhibits some unique characteristics, which led us to raise the following three questions regarding China's structural transformation:(1) Why did the share of China's agricultural and manufacturing employment reduce/increase intermittently rather than continuously?(2) Why did the share of China's agricultural employment increase during certain periods? When the share of manufacturing employment reduced, why did the workforce reversely flow into agriculture rather than move to the service sector?(3) Why did growth in the share of China's service sector employment decelerate before reaching its peak? Why did the share of employment in the industrial sector suddenly increase after an abrupt decline? This paper creates a multisector economic growth model that contains non-homothetic preferences and differentiated productivity, and incorporates the "two drivers" therein for a demand-side estimation and analysis. The result shows that China's economic growth model driven by net export and investment is a critical factor for explaining the three questions regarding its structural transformation. This paper believes that only by implementing supply-side structural reforms, reducing the dependence on net export and investment, and achieving sustainable endogenous economic growth will China be able to expedite its industrial restructuring.

关键词： structural transformation net export and investment multi-sector economic growth model supply-side structural reforms

基于QPSO-HMM的滚动轴承故障程度辨识

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振动．测试与诊断 2021年第6期41卷 1138-1142,1238页

作者：杨铮鑫王明罡龚博党鹏飞沈阳化工大学机械与动力工程学院沈阳110142 采油六厂第二油矿地质队大庆163400

综合量子粒子群优化算法(quantum particle swarm optimization,简称QPSO)的全局搜索能力与隐马尔科夫模型(hidden Markov model,简称HMM)良好的时间序列分类能力,提出一种基于QPSO-HMM的滚动轴承故障程度辨识方法,并利用实测振动信号... 详细信息

综合量子粒子群优化算法(quantum particle swarm optimization,简称QPSO)的全局搜索能力与隐马尔科夫模型(hidden Markov model,简称HMM)良好的时间序列分类能力,提出一种基于QPSO-HMM的滚动轴承故障程度辨识方法,并利用实测振动信号对该方法的性能进行验证。首先,采用变分模态分解对实测振动信号进行分解,并用奇异值分解进行信号特征提取;其次,利用QPSO算法和样本信号对HMM进行训练;最后,将测试信号输入训练得到的HMM中进行滚动轴承故障程度辨识。结果表明,该算法解决了HMM的参数估计局部最优化问题,对滚动轴承不同故障程度的辨识准确率较高。

关键词：故障程度辨识隐马尔科夫模型量子粒子群优化滚动轴承

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基于鲁棒主成分分析的运动目标检测优化算法

电子与信息学报 2018年第6期40卷 1309-1315页

作者：杨依忠汪鹏飞胡雄楼伍能举合肥工业大学电子科学与应用物理学院合肥230009

针对鲁棒主成分分析(Robust Principal Component Analysis,RPCA)算法中将动态背景误检为运动目标的问题,该文提出一种运动目标检测优化算法。在RPCA算法初步检测出运动目标后,利用动态背景在时间域上满足高斯分布的特性,以及动态背景... 详细信息

针对鲁棒主成分分析(Robust Principal Component Analysis,RPCA)算法中将动态背景误检为运动目标的问题,该文提出一种运动目标检测优化算法。在RPCA算法初步检测出运动目标后,利用动态背景在时间域上满足高斯分布的特性,以及动态背景和运动目标在整个视频流上检出点均值和方差的差异特性,进一步将动态背景和运动目标分离开来。实验结果表明,所提算法能够有效地处理动态背景的问题,并在一定程度上完整检测出运动目标。

关键词：运动目标检测鲁棒主成分分析动态背景时间域

Study on the Cap Rock Deformation of Hutubi Underground Gas Storage by GPS Observations

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Earthquake Research in China 2016年第3期30卷 439-450页

作者： Wang Dijin Li Yu Nie Zhaosheng Wang Tan Qiao Xuejun Li Jie Yu pengfei Cheng Ruizhong Institute of Seismology China Earthquake Administration Wuhan 430071 China National Earthquake Infrastructure Service Beijing 100045 China Earthquake Administration of Xinjiang Uygur Autonomous Region Urumqi 830011 China

The deformation responses of surface cap rocks of Underground Gas Storage( UGS) in Hutubi,Xinjiang during gas injection and production were investigated with the GPS data recorded by the deformation monitoring network,which includes 13 observation sites. The time series of three-dimensional deformation of the surface cap rocks was obtained in the UGS operation process,and the deformation signals in different phases were identified by combining the GPS data with wellhead pressure data. The results show that the respiration response of surface cap rock deformation is obvious during gas injection and production of UGS,and the surface deformation due to a 1MPa change of wellhead pressure is 1. 02 mm in gas injection and 1. 24 mm in gas production horizontally, and- 1. 11 mm in gas injection and 0. 86 mm in gas production vertically.

关键词： Underground gas storage GPS observations Three-dimensional time series Deformation response

基于粒子群算法的宽带真延时平面阵列方向图综合

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国防科技大学学报 2020年第5期42卷 31-36页

作者：丛雯珊余岚杜鹏飞罗雄杨海达空军预警学院预警技术系湖北武汉430019

针对大阵元间距平面阵列方向图综合问题,提出基于粒子群算法的宽带真延时平面阵列方向图综合方法。该方法根据真延时条件下阵列方向图主瓣和栅瓣指向的特点,采用宽带真延时抑制阵列方向图的栅瓣;利用粒子群优化算法优化阵列结构,得到具... 详细信息

针对大阵元间距平面阵列方向图综合问题,提出基于粒子群算法的宽带真延时平面阵列方向图综合方法。该方法根据真延时条件下阵列方向图主瓣和栅瓣指向的特点,采用宽带真延时抑制阵列方向图的栅瓣;利用粒子群优化算法优化阵列结构,得到具有较高主副瓣比的平面阵列方向图。通过对8×8的矩形平面阵进行仿真,验证了所提方法的有效性,在此基础上,还仿真研究了该方法对栅瓣的抑制性能与信号带宽之间的关系。

关键词：粒子群算法宽带真延时平面阵列栅瓣抑制信号带宽

改良与传统股方肌骨瓣治疗青壮年股骨头坏死的临床疗效比较

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中华老年骨科与康复电子杂志 2024年第3期10卷 165-170页

作者：浦路桥李川齐宝闯卜鹏飞蔡兴博白艳罗欢徐永清中国人民解放军联勤保障部队第九二〇医院骨科昆明650032

目的回顾性分析比较改良股方肌骨瓣与传统股方肌骨瓣治疗青壮年股骨头坏死的临床疗效。方法按照纳入及排除标准收集联勤保障部队第九二〇医院2019年1月至2020年7月因股骨头坏死接受保髋手术治疗的78例患者资料,分为改良股方肌骨瓣组和... 详细信息

目的回顾性分析比较改良股方肌骨瓣与传统股方肌骨瓣治疗青壮年股骨头坏死的临床疗效。方法按照纳入及排除标准收集联勤保障部队第九二〇医院2019年1月至2020年7月因股骨头坏死接受保髋手术治疗的78例患者资料,分为改良股方肌骨瓣组和传统股方肌骨瓣组,各组38例,对比分析两组手术时间,切口长度,Hb下降量,术后36个月VAS评分,髋关节Harris评,及髋关节活动度及并发症情况,股骨头生存率等指标,评价两种手术方式的临床效果。结果所有患者均顺利完成手术并获得随访,随访时间为(39.5±3.2)月,无伤口感染及深静脉血栓等并发症发生。改良组切口平均长度(10.7±0.9)cm,血红蛋白(hemoglobin,Hb)下降量(10.6±1.1)g/L,较传统组(13.5±0.7)cm,(12.1±1.1)g/L均减小,P<0.05,差异有统计学意义;术后36个月改良组髋关节Harris评分(86.7±4.5)、ROM(311.5±15.0)较传统组(82.7±5.4)、(294.4±20.8)改善明显,P<0.05,差异有统计学意义,两组患者在手术时间及VAS评分方面无显著差异,改良组优良率94.7%与传统组优良率89.5%无显著性差异,改良组股骨头生存率高于传统组。结论改良股方肌骨瓣可有效保留股骨头后上支持带动脉,治疗青壮年股骨头坏死的临床疗效较传统股方肌骨瓣效果好,是保留髋关节手术的一种选择。

关键词：股骨头坏死股方肌骨瓣髋关节数字减影血管造影