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Experimental investigation and comparative study of inter-turn short-circuits and unbalanced voltage

Fatima BABAA, Abdelmalek KHEZZAR, Mohamed el kamel OUMAAMAR

《能源前沿（英文）》 2013年第7卷第3期页码 271-278 doi: 10.1007/s11708-013-0258-6

摘要： A transient model for an induction machine with stator winding turn faults on a single phase is derived using reference frame transformation theory. The negative sequence component and the 3rd harmonic are often considered as accurate indicators. However, small unbalance in the supply voltage and/or in the machine structure that exists in any real system engenders the same harmonics components. In this case, it is too difficult to distinguish between the current harmonics due to the supply voltage and those originated by inter-turn short-circuit faults. For that, to have the correct diagnosis and to increase the sensitivity and the reliability of the diagnostic system, it is crucial to provide the relationship between the inter-turn short-circuits in the stator winding and the supply voltage imbalance through an accurate mathematical model and via a series of experimental essays.

关键词： induction machines fault indicator inter-turn short-circuit fault unbalance supply voltage

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A new and best approach for early detection of rotor and stator faults in induction motors coupled to variable loads

Abderrahim ALLAL,Boukhemis CHETATE

《能源前沿（英文）》 2016年第10卷第2期页码 176-191 doi: 10.1007/s11708-015-0386-2

摘要： Today, induction machines are playing, thanks to their robustness, an important role in world industries. Although they are quite reliable, they have become the target of various types of defects. Thus, for a long time, many research laboratories have been focusing their works on the theme of diagnosis in order to find the most efficient technique to predict a fault in an early stage and to avoid an unplanned stopping in the chain of production and costs ensuing. In this paper, an approach called Park’s vector product approach (PVPA) was proposed which was endowed with a dominant sensitivity in the case in which there would be rotor or stator faults. To show its high sensitivity, it was compared with the classical methods such as motor current signature analysis (MCSA) and techniques studied in recent publications such as motor square current signature analysis (MSCSA), Park’s vector square modulus (PVSM) and Park-Hilbert (P-H) (PVSM ). The proposed technique was based on three main steps. First, the three-phase currents of the induction motor led to a Park’s vector. Secondly, the proposed PVPA was calculated to show the distinguishing spectral signatures of each default and specific frequencies. Finally, simulation and experimental results were presented to confirm the theoretical assumptions.

关键词： induction motor incipient broken bar extended Park’s vector approach spectral analysis inter-turn short-circuit Hilbert transform

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电力系统中对称和/或不对称故障的限流器阻抗优化新方法 None

Mahmoud MODARESI, Hamid LESANI

《信息与电子工程前沿（英文）》 2018年第19卷第2期页码 297-307 doi: 10.1631/FITEE.1601689

摘要：为给电力网络设计者选择故障限流器（fault current limiters，FCLs）的阻抗类型和阻值，提出一种基于其在网络中的位置计算最佳FCL阻值的新方法。

关键词：故障限流器（FCL）；FCL阻抗；短路电流；故障电流；电力系统

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基于极限学习机的电动汽车锂离子动力电池外部短路热模型研究 Article

杨瑞鑫, 熊瑞, Weixiang Shen, Xinfan Lin

《工程（英文）》 2021年第7卷第3期页码 395-405 doi: 10.1016/j.eng.2020.08.015

摘要：

锂离子动力电池外部短路（ESC）是电动汽车常见且严重的电气故障之一。为此，本文提出了一种新型电池热模型以准确刻画动力电池外部短路发生后的温度行为。主要工作如下：在不同电池荷电状态和环境温度下，设计并系统地开展了动力电池外部短路实验；为保证模型参数的物理意义和模型的精准性，利用集总参数热模型替换经典极限学习机中的激活函数，构建了基于极限学习机的电池热（ELMT）模型，实现了模型无需迭代调节参数和模型参数就可以具备物理属性的双重优势，极大提高了模型计算效率与准确度；为了评估模型改进的必要性，比较了极限学习机热模型与遗传算法参数化的多集总参数热（MLT）模型。结果表明，ELMT模型相比MLT模型具有更优异的计算效率以及拟合、预测精度。其中，ELMT模型拟合和预测电池温度的均方根误差分别为0.65 ℃和3.95 ℃，MLT模型拟合和预测电池温度的均方根误差分别为3.97 ℃和6.11 ℃。

关键词：电动汽车电池安全外部短路温升预测极限学习机

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Investigating the role of exiting vehicles and turn indicator usage in gap acceptance at single-lane

Nathan P. BELZ

《结构与土木工程前沿（英文）》 2017年第11卷第1期页码 8-16 doi: 10.1007/s11709-016-0365-7

摘要： Roundabouts are becoming a preferred form of intersection control type due to their safety and capacity benefits. Yield control at roundabout entries inherently reduces fuel consumption and emissions when compared to other conventional intersection types. However, these benefits can be limited by poor driver behavior and judgment when entering the roundabout. This research addresses the nature of gap distributions and use of turn indicators by exiting vehicles at three single-lane roundabouts in Vermont, New York, and Alaska. Presented here is a comparison of vehicle headways measured at two different locations in each roundabout. Rejected headways are analyzed in the context of priority abstaining events when entering drivers yield to vehicles exiting on the same leg of the roundabout suggesting that “true” critical gaps are being overestimated. Results indicate that exiting vehicles, particularly those that do not use their turn indicators when departing from the major-stream of traffic have an influence on the entry decision of drivers on the same approach. This behavior is of particular concern for intersection efficiency (i.e., delay) and sustainability (i.e., excess fuel consumption and emissions). Results prompt the consideration of more consistent guidance on and enforcement of turn indicator use during roundabout negotiations.

关键词： roundabouts exiting vehicles turn indicator use headways

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一种改进的新型桥式固态限流器的研究

李洪凤,贾贵玺,齐炜,徐伟

《中国工程科学》 2005年第7卷第8期页码 75-79

摘要：

随着电网容量的不断扩大，短路电流限制技术已成为故障保护的一个研究热点。提出的新型桥式电路是在原有桥式拓扑结构上进行了改进，并提出了新的控制策略。详细介绍了新型桥式限流器的基本工作原理及特点，给出了基于Matlab/Simulink软件的仿真分析和基于天津大学动模实验室的实验结果。仿真与实验结果证明了所提出新型拓扑与控制策略的正确性。

关键词：短路限流器新型桥式电路 Matlab/Simulink仿真动模实验

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Machinability of damage-tolerant titanium alloy in orthogonal turn-milling

Tao SUN, Lufang QIN, Junming HOU, Yucan FU

《机械工程前沿（英文）》 2020年第15卷第3期页码 504-515 doi: 10.1007/s11465-020-0586-2

摘要： The damage-tolerant titanium alloy TC21 is used extensively in important parts of advanced aircraft because of its high strength and durability. However, cutting TC21 entails problems, such as high cutting temperature, high tool tip stress, rapid tool wear, and difficulty guaranteeing processing quality. Orthogonal turn-milling can be used to solve these problems. In this study, the machinability of TC21 in orthogonal turn-milling is investigated experimentally to optimize the cutting parameters of orthogonal turn-milling and improve the machining efficiency, tool life, and machining quality of TC21. The mechanism of the effect of turn-milling parameters on tool life is discussed, the relationship between each parameter and tool life is analyzed, and the failure process of a TiAlN-coated tool in turn-milling is explored. Experiments are conducted on the integrity of the machined surface (surface roughness, metallographic structure, and work hardening) by turn-milling, and how the parameters influence such integrity is analyzed. Then, reasonable cutting parameters for TC21 in orthogonal turn-milling are recommended. This study provides strong guidance for exploring the machinability of difficult-to-cut-materials in orthogonal turn-milling and improves the applicability of orthogonal turn-milling for such materials.

关键词： orthogonal turn-milling damage-tolerant titanium alloy tool life and failure machined surface integrity machinability

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京津城际铁路桥梁沉降观测与评估技术

丁愿文

《中国工程科学》 2009年第11卷第1期页码 43-47

摘要：

以京津城际铁路工程为例，系统地介绍了无碴轨道客运专线（高速铁路）桥梁沉降观测的具体要求、方法，并提出了沉降评估的数学模型和判定条件。

关键词：京津城际铁路桥梁沉降观测评估

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Variable eccentric distance-based tool path generation for orthogonal turn-milling

Fangyu PENG,Wei WANG,Rong YAN,Xianyin DUAN,Bin LI

《机械工程前沿（英文）》 2015年第10卷第4期页码 352-366 doi: 10.1007/s11465-015-0361-y

摘要：

This study proposes an algorithm for maximizing strip width in orthogonal turn-milling based on variable eccentric distance. The machining error model is first established based on the local cutting profile at the contact line. The influencing factors of the strip width are then investigated to analyze their features and determine an optimizing strategy. The optimized model for maximum machining strip width is formulated by adopting a variable eccentric distance. Hausdorff distance and Fréchet distance are introduced in this study to implement the constraint function of the machining error in the optimized model. The computing procedure is subsequently provided. Simulations and experiments have been conducted to verify the effectiveness of the proposed algorithm.

关键词： orthogonal turn-milling variable eccentric distance local cutting profile machining strip-width maximization

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A novel flavonol-based colorimetric and turn-on fluorescent probe for rapid determination of hydrazine

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 24-33 doi: 10.1007/s11705-022-2171-1

摘要： Hydrazine is extremely toxic and causes severe harm to human body. Herein, a novel fluorescent probe 4-oxo-2-styryl-4H-chromen-3-yl thiophene-2-carboxylate (FHT) was synthesized for detecting hydrazine by using natural cinnamaldehyde as starting material. This probe exhibited significantly enhanced fluorescence response towards hydrazine over various common metal ions, anions, and amine compounds. The detection limit of probe FHT for hydrazine was as low as 0.14 μmol·L^–1, significantly lower than that of the threshold value of 0.312 μmol·L^–1, imposed by the Environmental Protection Agency. Moreover, the proposed probe was able to detect hydrazine within wide pH (5–10) and linear detection ranges (0–110 μmol·L^–1). This probe was employed for determining trace hydrazine in different environmental water samples. The probe FHT-loaded filter paper strips were able to conveniently detect hydrazine of low concentration through distinct naked-eye and fluorescent color changes. Importantly, the probe FHT with low cytotoxicity was successfully applied to visualize hydrazine in living Hela cells and zebrafish.

关键词： cinnamaldehyde 3-hydroxychromone derivative hydrazine fluorescent probe

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Impact of inter-fuel substitution on energy intensity in Ghana

Boqiang LIN, Hermas ABUDU

《能源前沿（英文）》 2020年第14卷第1期页码 27-41 doi: 10.1007/s11708-019-0656-5

摘要： Energy intensity and elasticity, together with inter-fuel substitution are key issues in the current development stage of Ghana. Translog production and ridge regression are applied for studying these issues with a data range of 2000–2015. The current energy dynamics reveal the expected inverse relationship: higher energy intensity and lower elasticity with economic growth. There are evidences of energy-economic challenges: high energy cost, inefficiency and backfire rebound effect. The implications are higher energy losses in the system, more consumption of lower-quality energy together with low energy technology innovation. Energy is wasted and directly not productive with economic activities. It is observed further that the higher energy intensity invariably increases CO emission because approximately 95% of total energy is derived from hydrocarbons and biomass. An inter-fuel substitution future scenario design was further conducted and the results were positive with growth, lower energy intensity, and improved energy efficiency. Therefore, government and energy policymakers should improve energy efficiency, cost, and productiveness. That is, they should change energy compositions and augment energy technology innovation, thus, increasing renewable share to 15% by 2026, reducing wood and charcoal by about 69%, and increasing natural gas to about 776%. Energy policymakers should enhance the installation of smart energy, cloud energy solution, tokenization of energy system and storage.

关键词： energy intensity energy elasticity inter-fuel substitution prospects energy contribution Translog production approach ridge regression

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Self-catalytic pyrolysis thermodynamics of waste printed circuit boards with co-existing metals

《环境科学与工程前沿（英文）》 2022年第16卷第11期 doi: 10.1007/s11783-022-1581-0

摘要：

● The co-existing metals in WPCBs has positive catalytic influence in pyrolysis.

关键词： Waste printed circuit board Catalyst Pyrolysis Kinetics

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Yuan-zhang Liu: a Short Biography

Anon

《工程管理前沿（英文）》 2014年第1卷第1期页码 113-114 doi: 10.1530/J-FEM-2014016

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Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit

《环境科学与工程前沿（英文）》 2023年第17卷第10期 doi: 10.1007/s11783-023-1723-z

摘要：

● Au, Ag and Pd were recovered from WPCBs with high efficiencies.

关键词： Thiosulfate Printed circuit boards Precious metals Leaching Hydrometallurgy

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Financing Model Decision of Inter-basin Water Transfer Projects

Ji-wei Zhu,Li-nan Zhou,Zhao Zhai,Cong Wang

《工程管理前沿（英文）》 2016年第3卷第4期页码 396-403 doi: 10.15302/J-FEM-2016060

摘要： Inter-basin Water Transfer Projects require the appropriate financing model to attract large amounts of social investment. Therefore, financing model decision becomes the key of engineering construction. In three aspects, such as the subject, the object and the target of the financing model, Grey Target Model is established in this paper. First, the complex financing mode decision problems of Inter-basin Water Transfer Projects are decomposed by using hierarchical decomposition method. Then Analytical Hierarchy Process (AHP) method is used to calculate the comprehensive weight of evaluation index. Experts’ opinions financing model are transformed into the evaluation matrix based on the Dephi method. The Weighted Grey Target Model is used to calculate the approaching degree of financing model and assists financing mode decision. In addition, this paper takes the water diversion project from the Han to the Wei River of Shaanxi Province as a verification example for the model. For other water diversion projects, the evaluation results are also reliable and provide theoretical references for the financing model decision of Inter-basin Water Transfer Projects.

关键词： Inter-basin Water Transfer Projects financing model Weighted Grey Target Model water diversion Han River Wei River