Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 210

年份

2024 2

2023 16

2022 8

2021 16

2020 10

2019 7

2018 10

2017 10

2016 14

2015 10

2014 11

2013 17

2012 10

2011 3

2010 11

2009 8

2008 11

2007 13

2006 2

2005 5

展开︾

关键词

光伏发电 2

建议 2

放大 2

管理 2

管理活动 2

管理科学 2

12相整流 1

CMOS；跨导提升技术；低噪声放大器；变压器；共栅级 1

CO 1

CO₂捕集 1

FLTD型脉冲加速器 1

Fuzzy几何规划 1

HEMTs）；栅槽；数字湿法腐蚀；选择性湿法腐蚀 1

LM331型电压-频率转换器 1

MIMO雷达；波形设计；谱分解；分式二次约束二次规划 1

Matlab 1

Matlab仿真 1

PWM 1

Reed-Solomon码；步进式译码算法；超宽带；流水线架构 1

展开︾

检索范围：

排序：展示方式：

Well-being analysis of GSU transformer insulation incorporating the impact on power generation using

Alagarsamy KRISHNAVEL, Dusmata Kumar MOHANTA, M. Jaya Bharata REDDY

《能源前沿（英文）》 2013年第7卷第3期页码 288-299 doi: 10.1007/s11708-013-0265-7

摘要： With the prevailing power scenario, every watt-second of electrical energy has its own merit in satisfying the consumer demand. At the state of such a stringent energy demanding era, failure of a power generation equipment compounds the energy constraints which will not only result in a huge loss of generation but also have an impact on capital revenue. The unexpected failure of generator step-up (GSU) transformer is especially a major disturbance in the power system operation and leads to unscheduled outages with power delivery problems. The time lag in bringing back the equipment in service after rectification or replacement may increase the criticality as the process involves mobilization of spares and maintenance professionals. Hot atmosphere existing in the vicinity of thermal power stations running round-the-clock with more than 100% plant load factor (PLF) increases the thermal stress of the electrical insulation which leads to premature failure of windings, bushings, core laminations, etc. The healthy state of the GSU transformer has to be ensured to minimize the loss of power generation. As the predication related to failure of a GSU transformer is associated with some uncertainties, a fuzzy approach is employed in this paper along with actual field data and case studies for the well-being analysis of GSU transformer.

关键词： generator step-up (GSU) transformer well-being analysis dissolved gases in oil analysis (DGA) tan delta (TD) sweep frequency response analysis (SFRA) fuzzy inference system (FIS)

HTML PDF 收藏

一种汽油变频发电机组中的辅助直流电源设计

万健如,牛亮,刘建华,牟江峰,余小红

《中国工程科学》 2007年第9卷第4期页码 31-34

摘要：

针对汽油变频发电机组中逆变器所需多组低压直流电源问题，设计了一种多路输出的开关辅助电源，结构简单紧凑、输出电压纹波小、体积小、成本低；通过分析高频变压器的设计原理，设计了一台功率为15W 的四路直流输出的开关辅助电源；实验证明了该辅助电源的可行性。

关键词：汽油变频发电机组直流辅助电源三端单片开关电源高频变压器

HTML PDF 收藏

基于transformer和自适应嵌入策略的可逆信息隐藏 Research Article

周琳娜1,陆智高2,尤玮珂1,房笑妃2

《信息与电子工程前沿（英文）》 2023年第24卷第8期页码 1143-1155 doi: 10.1631/FITEE.2300041

摘要：本文提出一种新的RDH方法，包括基于transformer的预测器和具有多个嵌入规则的新嵌入策略。在预测器部分，我们首先设计了一个基于transformer的预测器。

关键词：可逆信息隐藏；Transformer；自适应嵌入策略

HTML PDF 收藏

脉冲水射流水力共振设计

蒲家宁,陈明

《中国工程科学》 2009年第11卷第2期页码 36-42

摘要：

在导管首端设置正弦脉冲流发生器，下游某处设置空气室，精心构建系统条件造成水力共振，使喷嘴处脉冲射流的压力振幅大大提高。系统的数学物理模型用水力瞬变特征线有限差分方程建立，变时步方法解算。最优水力共振条件用Matlab直接搜索算法搜寻。正弦脉冲流发生器由恒流泵和正弦容积变化活塞缸构成，电动活塞泵用凸轮传动给出恒定流量，活塞缸活塞用凸轮或曲轴连杆传动使缸容正弦变化。

关键词：脉冲水射流水力共振特征线解法变时步法 Matlab 直接搜寻算法正弦脉冲流发生器

HTML PDF 收藏

Structure controlling and process scale-up in the fabrication of nanomaterials

Chunzhong LI,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 18-25 doi: 10.1007/s11705-009-0305-3

摘要： Nanotechnology is already having a significant commercial impact, and will very certainly have a much greater impact in the future. The research on process engineering and scale-up will be very important for the commercial production and application of nanomaterials, because the properties and structure of nanomaterials are not only determined by the nucleation and growth process, but also strongly affected by the engineering properties, such as the mixing, the heat and mass transfer, and also the distribution of temperature, concentration, etc. This paper will present some research work in our laboratory on the fabrication of nanomaterials. Based on the chemical engineering principle and methods, many kinds of novel nanomaterials can be synthesized and their structure can be easily controlled through adjusting the parameters of the fluid mixing, and the distribution of temperature, residence time and concentration, etc. By using the micro-mixing, heat and mass transfer and reaction control methods, the host-guest nanocomposites have been assembled and assumed as the novel electroanalytical sensing nanobiocomposite materials. Based on the principles of chemical engineering, the manufacturing technologies for magnetic powders, calcium carbonate, and titanium dioxide have been developed for commercial-scale production, and the largest production scale has reached 15 kt/year.

关键词： scale-up significant commercial electroanalytical engineering laboratory

HTML PDF 收藏

Analysis of flow over backward facing step with transition

Dwarikanath RATHA,Arindam SARKAR

《结构与土木工程前沿（英文）》 2015年第9卷第1期页码 71-81 doi: 10.1007/s11709-014-0270-x

摘要： The present study deals with the study of the velocity distribution and the separation phenomenon of flow of air over a two dimensional backward facing step. The flow of air over a backward facing step has been investigated numerically using FLUENT. Flow simulation has been carried out in a backward facing step having an expansion ratio (ratio of the height before and after the step) of 1:1.94 and the results obtained are compared with the published experimental results. Comparison of flow characteristics between steps with three different transitions is made. The variation of reattachment length for all the three cases are analyzed for wide range of Reynolds number ranging from 100 to 7000 which covers the laminar, transition and turbulent flow of air. Simulation of the flow over steps with expansion ratios of 1:1.24, 1:1.38, 1:1.47, 1:1.53, 1:1.94, 1:2.20 are also carried out to examine the effect of different expansion ratios on the reattachment length. It is found that the primary reattachment length increases with increase in the expansion ratio. The primary reattachment length at the bottom wall downstream of the step is minimum for the step with round edged transition and maximum for the step with a vertical drop transition.

关键词： Reattachment length backward facing step transition flow separation k-? model

HTML PDF 收藏

有定子径向通风孔的大型永磁同步发电机的转矩特性 Article

He HAO,Wei-zhong FEI,Dong-min MIAO,Meng-jia JIN,Jian-xin SHEN

《信息与电子工程前沿（英文）》 2016年第17卷第8期页码 814-824 doi: 10.1631/FITEE.1500238

摘要：在此文章中，我们研究了应用于海上风电且定子具有径向通风孔的大型低速直驱型永磁同步发电机的转矩特性。首先在二维有限元分析（FEA）下保持相同的定子结构，通过对磁体形状优化设计改善永磁同步发电机的转矩特性。转子分段斜极技术用于抑制机械容差和缺陷的影响，并进一步提高了电机的转矩特性。全面的三维有限元分析是用来准确地评估定子径向通风孔和转子分段斜极对电机转矩特性的总体影响。通过综合的三维有限元分析，我们发现定子具有径向通风孔对转矩特性的影响，例如电机在转子采用和不采用分段斜极技术在转矩脉动和平均扭矩的特性。结果表明，定子具有径向通风孔时不仅会降低电机的平均转矩也会增加转矩脉动。此外，当电机在某些负载情况下，具有分段斜极转子的电机尽管齿槽转矩会减少但是转矩脉动反而可能增加。

关键词：永磁同步发电机；径向通风孔；转矩脉动；分段斜极；磁体形状优化；有限元分析；风电

HTML PDF 收藏

Series transformer based diode-bridge-type solid state fault current limiter

Amir HEIDARY,Hamid RADMANESH,Seyed Hamid FATHI,G. B. GHAREHPETIAN

《信息与电子工程前沿（英文）》 2015年第16卷第9期页码 769-784 doi: 10.1631/FITEE.1400428

摘要： We propose a novel series transformer based diode-bridge-type solid state fault current limiter (SSFCL). To control the fault current, a series RLC branch is connected to the secondary side of an isolation series transformer. Based on this RLC branch, two current limiting modes are created. In the first mode, R and C are bypassed via a paralleled power electronic switch (insulated-gate bipolar transistor, IGBT) and L remains connected to the secondary side of the transformer as a DC reactor. In the second mode, the series reactor impedance is not enough to limit the fault current. In this case, the fault current can be controlled by selecting a proper on-off duration of the parallel IGBT, across the series damping resistor ( ) and capacitor, which inserts high impedance into the line to limit the fault current. Then, by controlling the magnitude of the DC reactor current, the fault current is reduced and the voltage of the point of common coupling (PCC) is kept at an acceptable level. In addition, in the new SSFCL, the series RC branch, connected in parallel with the IGBT, serves as a snubber circuit for decreasing the transient recovery voltage (TRV) of the IGBT during on-off states. Therefore, the power quality indices can be improved. The measurement results of a built prototype are presented to support the simulation and theoretical studies. The proposed SSFCL can limit the fault current without any delay and successfully smooth the fault current waveform.

关键词： Solid state fault current limiter (SSFCL) Power quality Voltage sag Point of common coupling (PCC) Isolation transformer

HTML PDF 收藏

BUEES: a bottom-up event extraction system

Xiao DING,Bing QIN,Ting LIU

《信息与电子工程前沿（英文）》 2015年第16卷第7期页码 541-552 doi: 10.1631/FITEE.1400405

摘要： Traditional event extraction systems focus mainly on event type identification and event participant extraction based on pre-specified event type paradigms and manually annotated corpora. However, different domains have different event type paradigms. When transferring to a new domain, we have to build a new event type paradigm and annotate a new corpus from scratch. This kind of conventional event extraction system requires massive human effort, and hence prevents event extraction from being widely applicable. In this paper, we present BUEES, a bottom-up event extraction system, which extracts events from the web in a completely unsupervised way. The system automatically builds an event type paradigm in the input corpus, and then proceeds to extract a large number of instance patterns of these events. Subsequently, the system extracts event arguments according to these patterns. By conducting a series of experiments, we demonstrate the good performance of BUEES and compare it to a state-of-the-art Chinese event extraction system, i.e., a supervised event extraction system. Experimental results show that BUEES performs comparably (5% higher -measure in event type identification and 3% higher -measure in event argument extraction), but without any human effort.

关键词： Event extraction Unsupervised learning Bottom-up

HTML PDF 收藏

One-step synthesis of recoverable CuCo

Tongzhou Lu, Yongzheng Zhang, Chun Cheng, Yanbin Wang, Yongming Zhu

《化学科学与工程前沿（英文）》 2020年第14卷第4期页码 595-604 doi: 10.1007/s11705-019-1818-z

摘要： A facile one-step hydrothermal method has been adopted to directly synthesize the CuCo S material on the surface of Ni foam. Due to the relatively large specific surface area and wide pore size distribution, the CuCo S material not only effectively increases the reactive area, but also accommodates more side reaction products to avoid the difficulty of mass transfer. When evaluated as anode for Li-ion batteries, the CuCo S material exhibits excellent electrochemical performance including high discharge capacity, outstanding cyclic stability and good rate performance. At the current density of 200 mA·g , the CuCo S material shows an extremely high initial discharge capacity of 2510 mAh·g , and the cycle numbers of the material even reach 83 times when the discharge capacity is reduced to 500 mAh·g . Furthermore, the discharge capacity can reach 269 mAh·g at a current of 2000 mA·g . More importantly, when the current density comes back to 200 mA·g , the discharge capacity could be recovered to 1436 mAh·g , suggesting an excellent capacity recovery characteristics.

关键词： copper cobalt sulfide recoverability one-step hydrothermal method anode material Li-ion battery

HTML PDF 收藏

Noise control technology for generator sets in enclosures

ZHANG Nailong, YANG Wentong, FEI Renyuan

《机械工程前沿（英文）》 2008年第3卷第4期页码 377-384 doi: 10.1007/s11465-008-0051-0

摘要： Currently, noise pollution is an environmental problem all over the world. The health and life of human beings are affected by loud noise from high power generator sets. To reduce such noise, a sound-attenuated enclosure is widely used for its high performance and convenient usage. By installing equipment in an enclosure, noise is controlled and prevented from radiating. In this paper, noise control techniques for enclosures are presented. Enclosure development trends are predicted.

关键词： equipment generator sound-attenuated enclosure convenient Enclosure development

HTML PDF 收藏

Solid-state transformer-based new traction drive system and control

Jianghua FENG, Jing SHANG, Zhixue ZHANG, Huadong LIU, Zihao HUANG

《机械工程前沿（英文）》 2018年第13卷第3期页码 411-426 doi: 10.1007/s11465-018-0467-0

摘要：

A new type of traction drive system consisting of solid-state traction transformer (SSTT), inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining high-voltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The carrier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.

关键词： solid-state traction transformer high-voltage cascaded rectifier LLC resonant converter synchronous rotating reference frame carrier-interleaving phase shift control secondary pulsating voltage beat frequency

HTML PDF 收藏

论航空发动机发展的“渐改法”

温俊峰

《中国工程科学》 2000年第2卷第3期页码 23-26

摘要：

文章简要论述了航空发动机发展的两种途径及其特点，从国内外航空发动机改进发展广泛采用的作法和成功的经验事例，论证了“渐改”发展模式的规律性和重要性，提出了对发动机改进发展应加强组织领导和计划落实的建议。

关键词：航空发动机发动机发展途径渐改法

HTML PDF 收藏

Working Up Green, and Living Up Green

Ji-shan He

《工程管理前沿（英文）》 2014年第1卷第1期页码 2-2 doi: 10.15302/J-FEM-2014002

HTML PDF 收藏

一款基于改进的步进式译码算法实现的流水线架构RS码译码器 Article

Xing-ru PENG,Wei ZHANG,Yan-yan LIU

《信息与电子工程前沿（英文）》 2016年第17卷第9期页码 954-961 doi: 10.1631/FITEE.1500303

摘要：概要：基于改进的步进式译码算法，我们为超宽带系统设计了一款流水线架构的Reed-Solomon（RS）码译码器。为了减小复杂度，改进的步进式译码算法将传统步进式译码算法中冗余的两部分进行了结合。此外，采用流水线架构，使得所设计的译码器以最小时延获得最大吞吐率。因此，对于RS（23,17）码，我们所设计的译码器面积比ME（modified Euclidean）架构和pDCME（pipelined degree-computationless modified Euclidean）架构分别减少了42.5%和24.4%。此外，与传统步进式译码器相比，我们设计的译码器能减少11.3%的面积，且关键路径延迟更低。

关键词： Reed-Solomon码；步进式译码算法；超宽带；流水线架构

HTML PDF 收藏

标题作者时间类型操作

Well-being analysis of GSU transformer insulation incorporating the impact on power generation using

Alagarsamy KRISHNAVEL, Dusmata Kumar MOHANTA, M. Jaya Bharata REDDY

期刊论文

一种汽油变频发电机组中的辅助直流电源设计

万健如,牛亮,刘建华,牟江峰,余小红

期刊论文

基于transformer和自适应嵌入策略的可逆信息隐藏

周琳娜1,陆智高2,尤玮珂1,房笑妃2

期刊论文