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A New Method for the Aging Evaluation of Oil-Paper Insulation Using η-Butanol and Methanol

CSEE Journal of Power and Energy Systems 2024年第2期10卷 717-726页

作者： Jianyi wang Yuanxiang Zhou Jun Liu zhaowei wang Song Bai Jiayu Lu Department of High Voltage China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Grid Environmental Protection Beijing 100192China Electrical Engineering Department Tsinghua UniversityBeijing 100084China Solar Storage Division of State Key Lab of Power System and Generation Equipment School of Electrical EngineeringXinjiang UniversityUrumqi 830047China State Grid Wuwei Electric Power Supply Company Wuwei 733000China

To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxide,and carbon dioxide,a method for the simultaneous determination of methanol,ethanol,n−propanol,and η-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry.The measured results show that the determination limits of the four alcohol characterizers can be controlled to 10μg/kg level.Based on this method,the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research.Ethanol,η-propanol,and η-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization,similar to that of methanol.By analyzing 52 sets of measured data of 500 kV EHV transformers in operation,η-butanol is found to have excellent performance,and a new method to evaluate the aging state of oil-paper insulation employing η-butanol and methanol is proposed along with the aging attention value model.The measured data of 500 kV EHV transformers in operation indicate that the combination of η-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging,and the feasibility of the method is verified.Two possible pathways for the generation of η-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.

关键词： Aging characterization determination method methanol η-butanol oil-paper insulation 500 kV transformers

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The Influence of Sea Sprays on Drag Coefficient at High Wind Speed

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Journal of Ocean University of China 2023年第1期22卷 21-27页

作者： SHI Hongyuan LI Qingjie wang zhaowei ZHANG Xuri LI Huaqing XING Hao ZHANG Kuncheng Centre for Ports and Coastal Disaster Mitigation Ludong UniversityYantai 264025China The Center for Ports and Maritime Safety(CPMS) Dalian Maritime UniversityDalian 1160263China Marine Environmental Monitoring Central Station State Oceanic AdministrationYantai 264025China Guangxi Key Laboratory of Marine Environmental Science Guangxi Academy of SciencesNanning 530025China

Field and laboratory observations indicate that the variation of drag coefficient with wind speed at high winds is different from that under low-to-moderate winds.By taking the effects of wave development and sea spray into account,a new parameterization of drag coefficient applicable from low to extreme winds is proposed.It is shown that,under low-to-moderate wind conditions so that the sea spray effects could be neglected,the nondimensional aerodynamic roughness first increases and then decreases with the increasing wave age;whereas under high wind conditions,the drag coefficient decreases with the increasing wind speed due to the modification of the logarithmic wind profile by the effect of sea spray droplets produced by bursting bubbles or wind tearing breaking wave crests.The drag coefficients and sea surface aerodynamic roughnesses reach their maximum values vary under different wave developments.Correspondingly,the reduction of drag coefficient under high winds reduces the increasing rate of friction velocity with increasing wind speed.

关键词： sea spray wave age drag coefficient high wind speed

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A Novel Hybrid Vortex Search and Artificial Bee Colony Algorithm for Numerical Optimization Problems

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Wuhan University Journal of Natural Sciences 2017年第4期22卷 295-306页

作者： wang zhaowei WU Guomin WAN Zhongping School of Mathematics and Statistics Wuhan University Department of Mathematics and Physics Beijing Institute of Petrochemical Technology

Though vortex search（VS） algorithm has good performance in solving global numerical optimization problems, it cannot fully search the whole space occasionally. Combining the vortex search algorithm and the artificial bee colony algorithm（ABC） which has good performance in exploration, we present a HVS（hybrid vortex search） algorithm to solve the numerical optimization problems. We first use the employed bees and onlooker bees of ABC algorithm to find a solution, and then adopt the VS algorithm to find the best solution. In the meantime, we cannot treat the best solution so far as the center of the algorithm all the time. The algorithm is tested by 50 benchmark functions. The numerical results show the HVS algorithm has superior performance over the ABC and the VS algorithms.

关键词： numerical optimization problems vortex searchalgorithm artificial bee colony algorithm hybrid algorithm

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An Improved Cuckoo Search Algorithm for Multi-Objective Optimization

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Wuhan University Journal of Natural Sciences 2017年第4期22卷 289-294页

作者： TIAN Mingzheng HOU Kuolin wang zhaowei WAN Zhongping School of Mathematics and Statistics Wuhan University Faculty of Foundational Education Liming Vocational University

The recently proposed Cuckoo search algorithm is an evolutionary algorithm based on probability. It surpasses other algorithms in solving the multi-modal discontinuous and nonlinear problems. Searches made by it are very efficient because it adopts Levy flight to carry out random walks. This paper proposes an improved version of cuckoo search for multi-objective problems（IMOCS）. Combined with nondominated sorting, crowding distance and Levy flights, elitism strategy is applied to improve the algorithm. Then numerical studies are conducted to compare the algorithm with DEMO and NSGA-II against some benchmark test functions. Result shows that our improved cuckoo search algorithm convergences rapidly and performs efficienly.

关键词： multi-objective optimization evolutionary algorithm Cuckoo search Levy flight

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深度子领域自适应网络电机滚动轴承跨工况故障诊断

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电工技术学报 2024年第1期39卷 182-193页

作者：宋向金孙文举刘国海赵文祥王照伟江苏大学电气信息工程学院镇江212013

针对实际生产中旋转机械工况变化引起状态监测数据分布差异及获取待诊断样本标签困难问题,提出多尺度子领域自适应模型(MSDAM)的跨工况下滚动轴承故障诊断方法。首先,以原始振动信号作为输入,无需信号预处理及人工特征参数提取;其次,搭... 详细信息

针对实际生产中旋转机械工况变化引起状态监测数据分布差异及获取待诊断样本标签困难问题,提出多尺度子领域自适应模型(MSDAM)的跨工况下滚动轴承故障诊断方法。首先,以原始振动信号作为输入,无需信号预处理及人工特征参数提取;其次,搭建多尺度卷积神经网络将已知标签样本和待诊断样本特征迁移到同一子空间,捕获具有细粒度信息的多尺度公共特征;然后,以不同的故障类型来划分相关子域,并通过局部最大均值距离(LMMD)来完成子域的适配,有效削弱不同工况同类故障特征的分布差异;最后,在三个数据集的多个迁移任务上进行试验验证。结果证明,所提MSDAM的跨工况故障诊断性能优于关注全局领域适配的迁移学习方法。

关键词：轴承故障诊断子领域自适应迁移学习软标签学习

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青藏高原农牧民的家庭发展与生活满意度——基于问卷调查数据的分析

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楚雄师范学院学报 2024年第2期39卷 2-10页

作者：杨帆王昭维陈洁西南财经大学社会发展研究院四川成都611130

本文基于一项在四川省甘孜州开展的调查数据,以此为例讨论青藏高原农牧民的家庭发展与生活满意度之间的关系。研究发现:青藏高原农牧民生活满意度整体上较高。农牧民家庭在物质基础、人口素质和社会资本三个方面都处于较高水平,且仍然... 详细信息

本文基于一项在四川省甘孜州开展的调查数据,以此为例讨论青藏高原农牧民的家庭发展与生活满意度之间的关系。研究发现:青藏高原农牧民生活满意度整体上较高。农牧民家庭在物质基础、人口素质和社会资本三个方面都处于较高水平,且仍然保持着传统较大的家庭规模。青藏高原农牧民的家庭发展与生活满意度存在紧密联系,家庭物质基础越好,家庭成员健康状况越好,个体获得的直接家庭支持越多、家庭与社区邻居的互动支持越多,个体生活满意度就越高。促进家庭发展对于提高农牧民生活满意度具有积极意义,在实现共同富裕和乡村振兴的大背景下,不仅应持续推动青藏高原农牧区民生改善,也应协同推进家庭发展,让家庭在促进农牧民美好生活需要不断得到满足的过程中发挥应有且重要的作用。

关键词：青藏高原农牧民家庭发展生活满意度

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Newly discovered insect RNA viruses in China

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Science China(Life Sciences) 2013年第8期56卷 711-714页

作者： QIU Yang wang zhaowei LIU YongXiang QI Nan SI Jie XIANG Xue XIA XiaoLing HU YuanYang ZHOU Xi State Key Laboratory of Virology College of Life SciencesWuhan University

Insects are a group of arthropods and the largest group of animals on Earth,with over one million species described to date.Like other life forms,insects suffer from viruses that cause disease and death.Viruses that are pathogenic to beneficial insects cause dramatic economic losses on agriculture.In contrast,viruses that are pathogenic to insect pests can be exploited as attractive biological control agents.All of these factors have led to an explosion in the amount of research into insect viruses in recent years,generating impressive quantities of information on the molecular and cellular biology of these viruses.Due to the wide variety of insect viruses,a better understanding of these viruses will expand our overall knowledge of their virology.Here,we review studies of several newly discovered RNA insect viruses in China.

关键词： RNA病毒昆虫病毒中国节肢动物生物控制剂细胞生物学生命形式经济损失

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融合TKEO和Goerztel算法的感应电机转子断条故障诊断

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电工技术学报 2024年第12期39卷 3679-3690页

作者：王照伟郭雯君宋向金赵文祥江苏大学电气信息工程学院镇江212013 南京工程学院电力工程学院南京211167

针对电机电流信号特征分析进行转子断条故障诊断时,在低负载工况或早期,转子断条故障存在故障特征微弱以及难以分离等问题,同时需借助速度传感器获取转速信息,增加了硬件成本,该文提出了融合Teager-Kaiser能量算子(TKEO)和Goertzel算法... 详细信息

针对电机电流信号特征分析进行转子断条故障诊断时,在低负载工况或早期,转子断条故障存在故障特征微弱以及难以分离等问题,同时需借助速度传感器获取转速信息,增加了硬件成本,该文提出了融合Teager-Kaiser能量算子(TKEO)和Goertzel算法的感应电机转子断条故障诊断方法。首先,采用Teager-Kaiser能量算子对定子电流进行解调处理,将基频分量转化为直流分量并去除,实现边带故障特征分量到转子断条故障特征分量以及固有偏心谐波分量到转子速度谐波分量的转变,抑制基频频谱泄露对故障诊断和转速估计造成的干扰;其次,利用Goertzel算法对归一化解调信号进行频谱分析,完成转子断条故障特征分量和转子速度谐波分量的快速提取,进而实现不同负载和不同严重程度工况下转子断条的故障诊断。此外,与归一化频域能量算子进行比较,分析其计算效率和稳定性。实验结果表明,所提方法在不同负载和不同严重程度工况下均能够有效地识别转子断条故障特征分量,并且计算量少、可靠性高、实时性强以及硬件成本低。

关键词：转子断条 Goertzel算法固有偏心 Teager-Kaiser能量算子归一化频域能量算子

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考虑深井井下动力钻具影响的钻柱粘滑振动规律

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天然气工业 2024年第6期44卷 87-97页

作者：石祥超焦烨刘景涛王兆巍陈帅油气藏地质及开发工程全国重点实验室•西南石油大学中国石化西北油田分公司

油气勘探开发统计数据显示,深井钻井过程中粘滑振动频发,占钻进时长的50%以上,严重影响了钻井井下安全,延长了钻井周期,增加了钻井成本。由于深井钻柱结构较为复杂,井下动力钻具应用普遍,但动力钻具对井底钻头粘滑振动的影响规律缺乏深... 详细信息

油气勘探开发统计数据显示,深井钻井过程中粘滑振动频发,占钻进时长的50%以上,严重影响了钻井井下安全,延长了钻井周期,增加了钻井成本。由于深井钻柱结构较为复杂,井下动力钻具应用普遍,但动力钻具对井底钻头粘滑振动的影响规律缺乏深入研究,目前尚未有学者提出深井动力钻具下的钻柱全尺寸动力学模型。为此,基于弹簧集中质量原理,建立了包含井下动力钻具的粘滑振动仿真模型和螺杆钻具输出参数的计算模型,研究了螺杆钻具、扭力冲击器及两种工具复合使用对钻头粘滑振动的影响,并基于模型分析了现场实钻案例。研究结果表明:(1)使用螺杆钻具复合钻进时,转盘转速与螺杆转速对粘滑振动影响较大,复合转速越大,越有利于消除粘滑振动;(2)钻压和钻头尺寸越大,需要消除粘滑振动的转速就越大;(3)在保证水力参数的情况下,螺杆输出较高的扭矩和转速,能够有效地抑制钻头粘滑;(4)扭力冲击器和螺杆钻具复合使用情况下,当螺杆钻具的输出参数不足以抑制粘滑振动时,提高扭力冲击器的冲击扭矩和冲击频率,可降低螺杆钻具的临界转速,抑制井底粘滑振动。结论认为,该动力学模型可以为深井合理使用动力钻具、避免粘滑振动和提高机械钻速提供有效的技术支撑,该理论新认识在指导钻井现场钻进,提高钻井效率和降低钻井成本等方面具有重要的现实意义。

关键词：深井钻柱振动粘滑振动动力学井下动力钻具顺北区块螺杆钻具扭力冲击器

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A fluid flow model in the lacunar-canalicular system under the pressure gradient and electrical field driven loads

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Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 899-916页

作者： Xiaogang WU Xiyu wang Chaoxin LI zhaowei wang Yuqin SUN Yang YAN Yixian QIN Pengcui LI Yanqin wang Xiaochun WEI Weiyi CHEN College of Biomedical Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Provincial Key Laboratory for Repair of Bone and Soft Tissue Injury Taiyuan 030001China

The lacunar-canalicular system(LCS)is acknowledged to directly participate in bone tissue remodeling.The fluid flow in the LCS is synergic driven by the pressure gradient and electric field loads due to the electro-mechanical properties of bone.In this paper,an idealized annulus Maxwell fluid flow model in bone canaliculus is established,and the analytical solutions of the fluid velocity,the fluid shear stress,and the fluid flow rate are obtained.The results of the fluid flow under pressure gradient driven(PGD),electric field driven(EFD),and pressure-electricity synergic driven(P-ESD)patterns are compared and discussed.The effects of the diameter of canaliculi and osteocyte processes are evaluated.The results show that the P-ESD pattern can combine the regulatory advantages of single PGD and EFD patterns,and the osteocyte process surface can feel a relatively uniform shear stress distribution.As the bone canalicular inner radius increases,the produced shear stress under the PGD or P-ESD pattern increases slightly but changes little under the EFD pattern.The increase in the viscosity makes the flow slow down but does not affect the fluid shear stress(FSS)on the canalicular inner wall and osteocyte process surface.The increase in the high-valent ions does not affect the flow velocity and the flow rate,but the FSS on the canalicular inner wall and osteocyte process surface increases linearly.In this study,the results show that the shear stress sensed by the osteocyte process under the P-ESD pattern can be regulated by changing the pressure gradient and the intensity of electric field,as well as the parameters of the annulus fluid and the canaliculus size,which is helpful for the osteocyte mechanical responses.The established model provides a basis for the study of the mechanisms of electro-mechanical signals stimulating bone tissue(cells)growth.

关键词： bone canaliculi osteocyte process pressure gradient electricity fluid shear stress(FSS)

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