Search | Engineering

订阅投稿

首页学术期刊学术焦点学术视频工程成就工程前沿联系我们 English

资源类型

期刊论文 107

会议视频 1

年份

2023 1

2022 7

2021 4

2020 5

2019 5

2018 5

2017 2

2016 4

2015 6

2014 13

2013 3

2012 4

2011 3

2010 8

2009 8

2008 6

2007 10

2005 2

2002 2

2001 3

展开︾

关键词

客运专线 3

故障诊断 2

检测 2

管线钢 2

20 kt级重载组合列车 1

32 m箱梁 1

BPA 1

IFOC 1

IF钢 1

Q值监测 1

SARS危机 1

SUF钢板 1

TNT装药爆炸 1

Z源逆变器 1

三峡工程 1

三端单片开关电源 1

三维扫描振镜 1

三维测量 1

三重盈余 1

展开︾

检索范围：

排序：展示方式：

unified power electronic controller for wind driven grid connected wound rotor induction generator using linecommutated inverter

D. R. BINU BEN JOSE, N. AMMASAI GOUNDEN, Raavi SRI NAGA RAMESH

《能源前沿（英文）》 2013年第7卷第1期页码 39-48 doi: 10.1007/s11708-012-0229-3

摘要： The implementation of a simple power converter for a wound rotor induction generator employing a three phase diode bridge rectifier and a line commutated inverter in the rotor circuit for super synchronous speeds has been proposed. The detailed working of the system in power smoothing mode and maximum power point tracking mode is presented. The current flow in the rotor circuit is controlled (by controlling the firing angle of the line commutated inverter) for controlling the stator power in both the modes. An 8 bit PIC microcontroller has been programmed to vary the firing angle of the line commutated inverter. Experiments have been carried out on a 3-phase, 3.73 kW, 400 V, 50 Hz, 4-pole, 1500 r/min wound rotor induction generator and the results obtained with the generator supplying power in both the modes are furnished. The complete scheme has been modeled using MATLAB/SIMULINK blocks and a simulation study has been conducted. The experimental waveforms are compared with the simulation results and a very close agreement between them is observed.

关键词： line commutated inverter MPPT power smoothing wound rotor induction generator

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

Z源逆变器在异步电动机中的应用

朱红,祝龙记,夏若飞

《中国工程科学》 2014年第16卷第3期页码 86-91

摘要：

近年来，间接磁场定向控制（IFOC）的异步电机驱动由于其效率高、稳定性能强及功率因数高，被广泛应用在高性能驱动系统中。本文采用IFOC技术来控制异步电机的速度大小，并使用Z源逆变器，即在逆变器主电路前加上一对阻抗（LC）网络，通过控制直通占空比，可以实现升/降压功能、提高异步电机的效率。

关键词： IFOC 异步电机 Z源逆变器

HTML PDF 收藏

Unified power quality conditioner based on a three-level NPC inverter using fuzzy control techniques

Salim CHENNAI,M-T BENCHOUIA

《能源前沿（英文）》 2014年第8卷第2期页码 221-239 doi: 10.1007/s11708-014-0317-7

摘要： This paper presents a novel and efficient control scheme for unified power quality conditioner (UPQC) based on three-level neutral point clamped (NPC) inverter using fuzzy logic techniques. The proposed UPQC is capable of mitigating source current harmonics and compensate all voltage disturbances such as voltage sags, swells, unbalances and harmonics. It is designed by the integration of series and shunt active filters (AFs) sharing a common DC bus capacitor. The DC voltage is maintained constant using proportional integral voltage controller. The synchronous reference frame (SRF) theory is used to get the reference signals for shunt active power filters (APFs) and the power reactive theory (p-q theory) for series APFs. The shunt and series APF reference signals derived from the control algorithm and sensed signals are injected in two controllers to generate switching signals. To improve the UPQC capability, fuzzy logic techniques are introduced to control the series APF. The performances of the proposed UPQC system are evaluated in terms of power factor correction, mitigation of voltage or current harmonics and all other voltage disturbances compensation using Matlab-Simulink software and SimPowerSystem toolbox. The simulation results illustrate the performance of the proposed UPQC at the common connection point of the nonlinear load to improve the power energy quality.

关键词： three-level neutral point clamped (NPC) inverter unified power quality conditioner (UPQC) current harmonics mitigation fuzzy logic controller voltage disturbance compensation shunt active filter series active filter power quality energy improvement

HTML PDF 收藏

Acoustic fault signal extraction via the line-defect phononic crystals

《机械工程前沿（英文）》 2022年第17卷第1期页码 10-10 doi: 10.1007/s11465-021-0666-y

摘要： Rotating machine fault signal extraction becomes increasingly important in practical engineering applications. However, fault signals with low signal-to-noise ratios (SNRs) are difficult to extract, especially at the early stage of fault diagnosis. In this paper, 2D line-defect phononic crystals (PCs) consisting of periodic acrylic tubes with slit are proposed for weak signal detection. The defect band, namely, the formed resonance band of line-defect PCs enables the incident acoustic wave at the resonance frequency to be trapped and enhanced at the resonance cavity. The noise can be filtered by the band gap. As a result, fault signals with high SNRs can be obtained for fault feature extraction. The effectiveness of weak harmonic and periodic impulse signal detection via line-defect PCs are investigated in numerical and experimental studies. All the numerical and experimental results indicate that line-defect PCs can be well used for extracting weak harmonic and periodic impulse signals. This work will provide potential for extracting weak signals in many practical engineering applications.

关键词： phononic crystals line-defect fault signal extraction acoustic enhancement

HTML PDF 收藏

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases using line-by-line

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年第8卷第1期页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity HITEMP HITRAN Planck mean absorption coefficients

HTML PDF 收藏

Pareto lexicographic α-robust approach and its application in robust multi objective assembly line balancing

null

《机械工程前沿（英文）》 2014年第9卷第3期页码 257-264 doi: 10.1007/s11465-014-0294-x

摘要：

Robustness in most of the literature is associated with min-max or min-max regret criteria. However, these criteria of robustness are conservative and therefore recently new criteria called, lexicographic α-robust method has been introduced in literature which defines the robust solution as a set of solutions whose quality or jth largest cost is not worse than the best possible jth largest cost in all scenarios. These criteria might be significant for robust optimization of single objective optimization problems. However, in real optimization problems, two or more than two conflicting objectives are desired to optimize concurrently and solution of multi objective optimization problems exists in the form of a set of solutions called Pareto solutions and from these solutions it might be difficult to decide which Pareto solution can satisfy min-max, min-max regret or lexicographic α-robust criteria by considering multiple objectives simultaneously. Therefore, lexicographic α-robust method which is a recently introduced method in literature is extended in the current research for Pareto solutions. The proposed method called Pareto lexicographic α-robust approach can define Pareto lexicographic α-robust solutions from different scenarios by considering multiple objectives simultaneously. A simple example and an application of the proposed method on a simple problem of multi objective optimization of simple assembly line balancing problem with task time uncertainty is presented to get their robust solutions. The presented method can be significant to implement on different multi objective robust optimization problems containing uncertainty.

关键词： Pareto lexicographic α-robust assembly line balancing

HTML PDF 收藏

Hybrid intelligent water drop bundled wavelet neural network to solve the islanding detection by inverter-based

Mehrdad TARAFDAR HAGH,Homayoun EBRAHIMIAN,Noradin GHADIMI

《能源前沿（英文）》 2015年第9卷第1期页码 75-90 doi: 10.1007/s11708-014-0337-3

摘要： In this paper, a passive neuro-wavelet based islanding detection technique for grid-connected inverter-based distributed generation was developed. The weight parameters of the neural network were optimized by intelligent water drop (IWD) to improve the capability of the proposed technique in the proposed problem. The proposed method utilizes and combines wavelet analysis and artificial neural network (ANN) to detect islanding. Connecting distributed generator to the distribution network has many benefits such as increasing the capacity of the grid and enhancing the power quality. However, it gives rise to many problems. This is mainly due to the fact that distribution networks are designed without any generation units at that level. Hence, integrating distributed generators into the existing distribution network is not problem-free. Unintentional islanding is one of the encountered problems. Discrete wavelet transform (DWT) is capable of decomposing the signals into different frequency bands. It can be utilized in extracting discriminative features from the acquired voltage signals. In passive schemes with a large non-detection zone (NDZ), concern has been raised on active method due to its degrading power quality effect. The main emphasis of the proposed scheme is to reduce the NDZ to as close as possible and to keep the output power quality unchanged. The simulation results from Matlab/Simulink shows that the proposed method has a small non-detection zone, and is capable of detecting islanding accurately within the minimum standard time.

关键词： islanding detection neuro-wavelet intelligent water drop (IWD) non-detection zone (NDZ) distributed generation (DG)

HTML PDF 收藏

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿（英文）》 2016年第10卷第2期页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要： There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词： grounding transmission line tower back flashover probability FDTD method

HTML PDF 收藏

低调制度下二极管箝位型多电平逆变器新型PWM控制方法

辛想,张庆范,胡顺全,李瑞来

《中国工程科学》 2007年第9卷第10期页码 91-96

摘要：

二极管箝位型多电平逆变器作为一种应用于高压大功率变换场合的变换器，其PWM控制技术是研究的核心内容之一。本文针对已有载波PWM方法中低调制度下电平退化的问题，提出了一种新颖的载波PWM方法，既便是在低调制度下，所有的电平都能够得到应用。仿真结果表明，这种方法可以提高二极管箝位型逆变器在低调制度下的器件利用率，使得逆变器在低调制度下工作于较高频率。

关键词：二极管箝位型逆变器载波PWM 低调制度冗余状态

HTML PDF 收藏

A fast compound direct iterative algorithm for solving transient line contact elastohydrodynamic lubrication

null

《机械工程前沿（英文）》 2014年第9卷第2期页码 156-167 doi: 10.1007/s11465-014-0297-7

摘要：

A fast compound direct iterative algorithm for solving transient line contact elastohydrodynamic lubrication (EHL) problems is presented. First, by introducing a special matrix splitting iteration method into the traditional compound direct iterative method, the full matrices for the linear systems of equations are transformed into sparse banded ones with any half-bandwidth; then, an extended Thomas method which can solve banded linear systems with any half-bandwidth is derived to accelerate the computing speed. Through the above two steps, the computational complexity of each iteration is reduced approximately from O(N3/3) to O(β2N), where N is the total number of nodes, and β is the half-bandwidth. Two kinds of numerical results of transient EHL line contact problems under sinusoidal excitation or pure normal approach process are obtained. The results demonstrate that the new algorithm increases computing speed several times more than the traditional compound direct iterative method with the same numerical precision. Also the results show that the new algorithm can get the best computing speed and robustness when the ratio, half-bandwidth to total number of nodes, is about 7.5%–10.0% in moderate load cases.

关键词： elastohydrodynamic lubrication transient line contact matrix splitting iteration method the Thomas method

HTML PDF 收藏

FUNCTIONAL GAIN OF FRUIT NETTED-CRACKING IN AN INTROGRESSION LINE OF TOMATO WITH HIGHER EXPRESSION OF

《农业科学与工程前沿（英文）》 2021年第8卷第2期

摘要：

Fruit cracking is a major disorder that affects the integrity of fruit and reduces the commercial value of tomato and other fleshy fruit. Here, we have found a novel fruit ‘netted-cracking’ (FNC) phenotype in tomato introgression line IL4-4 which is present in neither the donor parent (LA0716) nor the receptor parent (M82). An F₂ population was generated by crossing IL4-4 with M82 to genetically characterize the FNC gene and this showed that a single dominant gene determined fruit netted-cracking. Further map-based cloning narrowed down the FNC locus to a 230 kb region on chromosome 4. Sequencing and annotation analysis show that FNC(Solyc04 g082540) was the most likely candidate gene. Functional characterization of FNC by overexpressing FNC^AC and FNC^IL4-4resulted in the fruit netted-cracking phenotype, suggesting that the FNC transcript level results in the functional gain of fruit netted-cracking. These findings were further confirmed by FNC ortholog in netted-cracking pepper and melon, indicating a common regulatory mechanism in different plant species. Furthermore, cytoplasm and nucleus-localized FNC indicates increased expression of genes involved in suberin, lignin, lipid transport and cell wall metabolism. These findings provide novel genetic insights into fruit netted-cracking and offer a way to promote molecular improvement toward cracking resistant cultivars.

关键词： fine mapping / fruit netted-cracking / introgression line / transcript level

HTML 收藏

A novel light fluctuation spectrum method for in-line particle sizing

Shouxuan QIN, Xiaoshu CAI, Li MA

《能源前沿（英文）》 2012年第6卷第1期页码 89-97 doi: 10.1007/s11708-012-0176-z

摘要： This paper discusses two problems in in-line particle sizing when using light fluctuation method. First, by retrieving the ratio of particle concentrations at different time, the intensity of incident light is obtained. There exists narrow error between the calculated and pre-detected value of the intensity of incident light. Secondly, by combining spectrum analysis with Gregory’s theory, a multi-sub-size zone model is proposed, with which the relationship between the distribution of turbidity and the particle size distribution (PSD) can be established, and an algorithm developed to determine the distribution of turbidity. Experiments conducted in the laboratory indicate that the measured size distribution of pulverized coal conforms well with the imaging result.

关键词： in-line measurement particle size distribution (PSD) incident light intensity particle concentration light fluctuation

HTML PDF 收藏

A naive optimization method for multi-line systems with alternative machines

Weichang KONG, Fei QIAO, Qidi WU

《机械工程前沿（英文）》 2019年第14卷第4期页码 377-392 doi: 10.1007/s11465-019-0544-z

摘要： The scheduling of parallel machines and the optimization of multi-line systems are two hotspots in the field of complex manufacturing systems. When the two problems are considered simultaneously, the resulting problem is much more complex than either of them. Obtaining sufficient training data for conventional data-based optimization approaches is difficult because of the high diversity of system structures. Consequently, optimization of multi-line systems with alternative machines requires a simple mechanism and must be minimally dependent on historical data. To define a general multi-line system with alternative machines, this study introduces the capability vector and matrix and the distribution vector and matrix. A naive optimization method is proposed in accordance with classic feedback control theory, and its key approaches are introduced. When a reasonable target value is provided, the proposed method can realize closed-loop optimization to the selected objective performance. Case studies are performed on a real 5/6-inch semiconductor wafer manufacturing facility and a simulated multi-line system constructed on the basis of the MiniFAB model. Results show that the proposed method can effectively and efficiently optimize various objective performance. The method demonstrates a potential for utilization in multi-objective optimization.

关键词： multi-line systems alternative machines feedback control closed-loop optimization

HTML PDF 收藏

Establishment and drug sensitivity evaluation of murine ascites hepatocarcinoma cell line with high lymphatic

Hongying ZHANG, Jianwu TANG, Wenting ZHU, Chunxiu HU, Guowang XU

《医学前沿（英文）》 2009年第3卷第2期页码 119-129 doi: 10.1007/s11684-009-0022-9

摘要： In order to provide a sensitive cell line model for investigating the mechanisms underlying the lymphatic metastasis of tumors and the effect of medicine against cells, a new murine ascites hepatocarcinoma cell line with high lymphatic metastatic potential (Hca-P/L ) was established and the effect of curcumin on biological behavior of Hca-P/L was observed. Murine ascites hepatocarcinoma cell strain with low lymphatic metastatic potential (Hca-P) was subcutaneously inoculated into the medioventral line of a mouse 615 and the first generation of metastatic tumor cells of inguinal lymph node (Hca-P/L ) was obtained. Then, Hca-P/L was screened by the route of mouse foot pad subcutaneously → lymph node → scale-up culture → mouse foot pad subcutaneously for five times consecutively. The sensitivity of two murine ascites hepatocarcinoma cell lines (Hca-P and Hca-P/L ) and two anchorage-dependent human hepatocarcinoma cell lines (SMC7721 and HepG ) to curcumin were studied by use of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after these cells had been pretreated by curcumin at the concentration of 15-240 μmol/L for 48 h. After pretreatment by curcumin at the maximum non-cytotoxic dose of 15 μmol/L , the effect of curcumin against cell proliferation of Hca-P and Hca-P/L was observed by inverted microscope, cell growth curve and cell population doubling time; the effects of curcumin on cell cycles of Hca-P/L and Hca-P were studied by flow cytometry (FCM). The results showed Hca-P/L spreading to the lymph nodes at multiple sites in mice was screened from Hca-P. The lymph node metastatic rate was 100%. Curcumin had significant growth inhibiting effect on both murine ascites and human hepatocarcinoma cell lines in a dose-dependent manner ( <0. 05). At concentrations of 30-120 μmol/L, curcumin had more inhibition on murine ascites hepatocarcinoma cell lines than on human anchorage-dependent hepatocarcinoma cell lines. At concentrations of 60-240 μmol/L, curcumin had more inhibition on Hca-P/L with (the 50% inhibitory concentration) IC of 51.48 μmol/L than on Hca-P with IC of 90.87 μmol/L. After pretreatment by curcumin at the maximum non-cytotoxic dose of 15 mol/L for 7 days, the proliferations of Hca-P/L and Hca-P were inhibited ( <0.05) in a time-dependent manner ( <0.01) and the population doubling time of Hca-P/L and Hca-P was prolonged ( <0.01), and curcumin had more inhibition on Hca-P/L than on Hca-P ( <0.05). After pretreatment by 15 μmol/L curcumin for 48 h, the morphous of Hca-P/L was influenced more seriously than that of Hca-P and the cell cycle was redistributed with Hca-P/L being blocked in the S phase and Hca-P in the S and G /M phases. Hca-P/L was validated to be more sensitive to curcumin than Hca-P. Hca-P/L is a novel sensitive cell line model for investigating the mechanisms underlying tumor lymphatic metastasis and the effect of the medicine against cells.

关键词： murine ascites hepatocarcinoma cell line metastasis curcumin drug sensitivity

HTML PDF 收藏

标题作者时间类型操作

unified power electronic controller for wind driven grid connected wound rotor induction generator using linecommutated inverter

D. R. BINU BEN JOSE, N. AMMASAI GOUNDEN, Raavi SRI NAGA RAMESH

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

Z源逆变器在异步电动机中的应用

朱红,祝龙记,夏若飞

期刊论文

Unified power quality conditioner based on a three-level NPC inverter using fuzzy control techniques

Salim CHENNAI,M-T BENCHOUIA

期刊论文

Acoustic fault signal extraction via the line-defect phononic crystals

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases using line-by-line

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

Pareto lexicographic α-robust approach and its application in robust multi objective assembly line balancing

null

期刊论文

Hybrid intelligent water drop bundled wavelet neural network to solve the islanding detection by inverter-based

Mehrdad TARAFDAR HAGH,Homayoun EBRAHIMIAN,Noradin GHADIMI

期刊论文

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

期刊论文

低调制度下二极管箝位型多电平逆变器新型PWM控制方法

辛想,张庆范,胡顺全,李瑞来

期刊论文

A fast compound direct iterative algorithm for solving transient line contact elastohydrodynamic lubrication

null

期刊论文

FUNCTIONAL GAIN OF FRUIT NETTED-CRACKING IN AN INTROGRESSION LINE OF TOMATO WITH HIGHER EXPRESSION OF

期刊论文

A novel light fluctuation spectrum method for in-line particle sizing

Shouxuan QIN, Xiaoshu CAI, Li MA

期刊论文

A naive optimization method for multi-line systems with alternative machines

Weichang KONG, Fei QIAO, Qidi WU

期刊论文

Establishment and drug sensitivity evaluation of murine ascites hepatocarcinoma cell line with high lymphatic

Hongying ZHANG, Jianwu TANG, Wenting ZHU, Chunxiu HU, Guowang XU

期刊论文

关注我们