资源类型

期刊论文 1100

会议视频 57

年份

2024 1

2023 95

2022 141

2021 112

2020 66

2019 64

2018 69

2017 48

2016 45

2015 57

2014 50

2013 41

2012 55

2011 39

2010 53

2009 40

2008 29

2007 35

2006 18

2005 11

展开 ︾

关键词

智能制造 32

水资源 16

细水雾 14

农业科学 12

人工智能 11

新一代智能制造 10

可持续发展 6

泥水盾构 6

反渗透 5

水环境 4

环境 4

砂卵石地层 4

绿色化工 4

能源 4

超滤 4

三峡工程 3

农业节水 3

半旱地农业 3

城镇建设 3

展开 ︾

检索范围:

排序: 展示方式:

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)    

Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determinationof trace amounts of copper in water samples

Qingyun CHANG, Jingwen ZHANG, Xin DU, Jingjun MA, Jingci LI,

《环境科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 187-195 doi: 10.1007/s11783-010-0030-7

摘要: A simple and efficient liquid-phase microextraction (LPME) technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry, for the extraction and determination of trace copper in water samples. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. Microextraction efficiency factors (including extraction solvent type, extraction volume, time, temperature, and pH), the amount of the chelating agent, and salt effect were investigated and optimized. Under the optimum extraction conditions, figures of merit of the proposed method were evaluated. The calibration graph was linear in the range of 20–600 g·L with a detection limit of 0.76 g·L. The relative standard deviation (R.S.D) for ten replicate measurements of 20 and 400 g·L of copper was 3.83% and 2.65%, respectively. Finally, the proposed method was applied to tap water, river water, and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

关键词: ultrasound-assisted emulsification     solidified floating organic drop microextraction     flame atomic absorption spectrometry     preconcentration     copper    

CFD evaluation of pressure drop across a 3-D filter housing for industrial gas turbine plants

Fidelis I. ABAM,Samuel O. EFFIOM,Olayinka S. OHUNAKIN

《能源前沿(英文)》 2016年 第10卷 第2期   页码 192-202 doi: 10.1007/s11708-016-0406-x

摘要: This paper investigated the flow distribution and total pressure drop across a designed 3-D filter housing integrated with a 3-stage filtration system using computational fluid dynamics (CFD). The filter housing model was proposed for a heavy-duty industrial gas turbine plant operating at an average ambient temperature of 20°C.The pressure drops across the classes of filters were 652.8 Pa, 2692.2 Pa, 887.8 Pa, 776.2 Pa and 2304.2 Pa for I-GB, GB-GA, GA-FA, FA-HA, and HA-O, respectively. The results obtained indicated an acceptable total pressure drop of 7.2% for the entire filter housing before filter clean-up. Although the CFD simulation result shows that small outlet flow velocity and transonic flows exist at the outlet of the filter housing, the designed filter housing was proved compatible with the studied GT, for inlet flow conditions between 600≤ ≤610 kg/s and 60≤ ≤70 m/s for the air flow rate and velocity, respectively. Furthermore, the designed filter housing could be adopted for the studied GT and locations of Usan and Maiduguri in Nigeria, and other locations with similar environmental conditions.

关键词: computational fluid dynamics (CFD)     pressure drop     flow distribution     filter housing     gas turbine    

A biofilter model for simultaneous simulation of toluene removal and bed pressure drop under varied inlet

Jinying XI,Insun KANG,Hongying HU,Xian ZHANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 554-562 doi: 10.1007/s11783-014-0671-z

摘要: In this study, a biofiltration model including the effect of biomass accumulation and inert biomass growth is developed to simultaneously predict the Volatile Organic Compounds (VOCs) removal and filter bed pressure drop under varied inlet loadings. A laboratory-scale experimental biofilter for gaseous toluene removal was set up and operated for 100 days with inlet toluene concentration ranging from 250 to 2500 mg?m . According to sensitivity analysis based on the model, the VOCs removal efficiency of the biofilter is more sensitive to Henry’s constant, the specific surface area of the filter bed and the thickness of water layer, while the filter bed pressure drop is more sensitive to biomass yield coefficient and original void fraction. The calculated toluene removal efficiency and bed pressure drop satisfactorily fit the experimental data under varied inlet toluene loadings, which indicates the model in this study can be used to predict VOCs removal and bed pressure drop simultaneously. Based on the model, the effect of mass-transfer parameters on VOCs removal and the stable-run time of a biofilter are analyzed. The results demonstrate that the model can function as a good tool to evaluate the effect of biomass accumulation and optimize the design and operation of biofilters.

关键词: Volatile Organic Compounds (VOCs)     biofilters     modelling     biomass accumulation     pressure drop    

The investigation of pressure drop in moving-beds

CHEN Yunhua, ZHU Xuedong, WU Yongqiang, ZHU Zibin

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 184-189 doi: 10.1007/s11705-007-0034-4

摘要: The pressure drop of a cross-flow moving-bed was investigated in a two-dimensional rectangular apparatus. The effects of the particle velocity, the superficial gas velocity, the formation and development of cavity/raceway and voidage of particles on the pressure drop were investigated experimentally under the operational conditions of 0.09 1.35 m/s of the superficial gas velocity and 0.95 9.68 cm/min of the particle velocity. The experimental results show that the particle velocity has little influence on the pressure drop, while the phenomena of cavity and pinning occur when the cross-flow velocity is high enough. The development of a cavity or a raceway can result in three types of variations of pressure drop with time: stabilization, slight fluctuation and severe fluctuation. A cavity appears in a process cycle of formation-growing up-collapsing-fluidization at a high gas velocity. On the basis of experimental results, a model for calculating the pressure drop after a cavity occurs and a dimensionless relationship of cavity size is developed, which gives a good qualitative account of the experimental data.

关键词: development     cross-flow velocity     superficial     qualitative account     stabilization    

产品跌落冲击耐撞性能稳健设计研究进展

杨书仪,刘德顺,赵继云,文泽军

《中国工程科学》 2010年 第12卷 第1期   页码 61-66

摘要:

跌落冲击是物体在短时间内受到强大冲击力而运动状态发生急剧变化的现象,是导致产品特别是小型机电产品外表破损、功能失效的主要原因。近年来,国内外研究学者针对如何提高产品抗跌落冲击的本质耐撞性能进行了大量研究。笔者从研究对象、研究方法等角度,系统总结了产品跌落冲击耐撞性和产品耐撞性能稳健设计的研究现状,归纳了有待进一步研究的问题。

关键词: 跌落冲击     耐撞性     稳健设计    

Self-healing polyamide reverse osmosis membranes with temperature-responsive intelligent nanocontainers

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1183-1195 doi: 10.1007/s11705-022-2287-3

摘要: Improving the performance of reverse osmosis membranes remains great challenge to ensure excellent NaCl rejection while maintaining high water permeability and chlorine resistance. Herein, temperature-responsive intelligent nanocontainers are designed and constructed to improve water permeability and chlorine resistance of polyamide membranes. The nanocontainer is synthesized by layer-by-layer self-assembly with silver nanoparticles as the core, sodium alginate and chitosan as the repair materials, and polyvinyl alcohol as the shell. When the polyamide layer is damaged by chlorine attack, the polyvinyl alcohol shell layer dissolves under temperature stimulation of 37 °C, releasing inner sodium alginate and chitosan to repair broken amide bonds. The polyvinyl alcohol shell responds to temperature in line with actual operating environment, which can effectively synchronize the chlorination of membranes with temperature response and release inner materials to achieve self-healing properties. With adding temperature-responsive intelligent nanocontainers, the NaCl rejection of thin film composite membrane decreased by 15.64%, while that of thin film nanocomposite membrane decreased by only 8.35% after 9 chlorination cycles. Effective repair treatment and outstanding chlorine resistance as well as satisfactory stability suggest that temperature-responsive intelligent nanocontainer has great potential as membrane-doping material for the targeted repair of polyamide reverse osmosis membranes.

关键词: reverse osmosis     nanocontainer     self-healing     chlorine resistance     water permeability    

节水灌溉管理智能决策支持系统研究

汪志农,吕宏兴,王密侠,熊运章,马孝义

《中国工程科学》 2001年 第3卷 第7期   页码 48-53

摘要:

应用人工智能中的专家系统技术,开发并集成了3个不同层次的节水灌溉管理决策支持系统:灌溉预报与节水灌溉决策子系统、灌区计划用水与水量调配管理系统、灌区管理体制改革子系统;介绍了节水灌溉管理智能决策支持系统的理论基础,系统结构,实际应用以及陕西省旱情决策子系统等。

关键词: 灌溉预报     节水灌溉     灌溉管理     智能决策支持系    

Pressure drop analysis on the positive half-cell of a cerium redox flow battery using computational fluid

Fernando F. Rivera, Berenice Miranda-Alcántara, Germán Orozco, Carlos Ponce de León, Luis F. Arenas

《化学科学与工程前沿(英文)》 2021年 第15卷 第2期   页码 399-409 doi: 10.1007/s11705-020-1934-9

摘要: Description of electrolyte fluid dynamics in the electrode compartments by mathematical models can be a powerful tool in the development of redox flow batteries (RFBs) and other electrochemical reactors. In order to determine their predictive capability, turbulent Reynolds-averaged Navier-Stokes (RANS) and free flow plus porous media (Brinkman) models were applied to compute local fluid velocities taking place in a rectangular channel electrochemical flow cell used as the positive half-cell of a cerium-based RFB for laboratory studies. Two different platinized titanium electrodes were considered, a plate plus a turbulence promoter and an expanded metal mesh. Calculated pressure drop was validated against experimental data obtained with typical cerium electrolytes. It was found that the pressure drop values were better described by the RANS approach, whereas the validity of Brinkman equations was strongly dependent on porosity and permeability values of the porous media.

关键词: CFD simulation     porous media     porous electrode     pressure drop     redox flow battery    

低高宽比矩形微通道中流动沸腾的压降特性

张炳雷,徐进良,肖泽军

《中国工程科学》 2007年 第9卷 第12期   页码 86-93

摘要: 以甲醇为工质,在不同进口温度、质量流率、热流密度和倾角下,对低高宽比矩形微通道中流动沸腾压降特性进行了研究,并分别采用均相模型和分相模型对通道压降进行了计算。通过对比实验结果与计算结果发现,均相模型中两相平均粘度的计算应当采用Dukler公式,用其他计算式时误差较大;利用LockhartMartinelli关系式进行的分相模型计算发现,现有C值计算公式,如Chisholm,Lee and Lee,Mishima及Qu and Mudawar等,都不能用于预测该实验中低高宽比微通道的两相压降。实验发现当通

关键词: 压降特性;均相模型;分相模型;微通道;流动沸腾    

闸墩混凝土结构温控防裂措施智能优选研究

黄耀英,丁月梅,吕晓曼,徐佰林

《中国工程科学》 2014年 第16卷 第3期   页码 59-63

摘要:

闸墩混凝土温控防裂是一个与温控措施和材料参数相关的复杂多因素系统优选问题,本文尝试已知混凝土热力学材料参数情况下的温控措施优选,将闸墩混凝土结构内部和表面主拉应力历时曲线和抗拉强度增长曲线关系的最小值作为输入,闸墩表面保温效果、浇筑温度、通水水温、通水时间作为输出,建立了温控措施优选的神经网络模型,采用均匀设计原理进行温控参数组合,并采用水管冷却有限元法仿真分析含冷却水管的闸墩混凝土结构温度场和徐变应力场,获得样本进行学习,以此训练好的网络描述结构主拉应力历时曲线和抗拉强度增长曲线关系的最小值与不同温控措施的非线性关系。将合适的结构主拉应力历时曲线和抗拉强度增长曲线关系的最小值输入训练好的网络,可自动优选出温控防裂措施。算例分析表明,本文建立的温控措施优选神经网络模型是可行的。

关键词: 闸墩     表面保温     通水冷却     浇筑温度     智能优选    

Heat transfer and fluid flow analysis of an artificially roughened solar air heater: a CFD based investigation

Anil Singh YADAV,J. L. BHAGORIA

《能源前沿(英文)》 2014年 第8卷 第2期   页码 201-211 doi: 10.1007/s11708-014-0297-7

摘要: In this paper, the effect of rib (circular sectioned) spacing on average Nusselt number and friction factor in an artificially roughened solar air heater (duct aspect ratio, AR= 5:1) is studied by adopting the computational fluid dynamics (CFD) approach. Numerical solutions are obtained using commercial software ANSYS FLUENT v12.1. The computations based on the finite volume method with the semi-implicit method for pressure-linked equations (SIMPLE) algorithm have been conducted. Circular sectioned transverse ribs are applied at the underside of the top of the duct, i.e., on the absorber plate. The rib-height-to-hydraulic diameter ratio ( ) is 0.042. The rib-pitch-to-rib-height ( ) ratios studied are 7.14, 10.71, 14.29 and 17.86. For each rib spacing simulations are executed at six different relevant Reynolds numbers from 3800 to 18000. The thermo-hydraulic performance parameter for = 10.71 is found to be the best for the investigated range of parameters at a Reynolds number of 15000.

关键词: heat transfer     pressure drop     thermo-hydraulic performance parameter    

基于机器学习的多目标优化设计在按需喷墨生物打印中的应用 Article

时佳, 宋锦春, Bin Song, Wen F. Lu

《工程(英文)》 2019年 第5卷 第3期   页码 586-593 doi: 10.1016/j.eng.2018.12.009

摘要:

按需滴化微喷射(DOD)生物打印技术以其高通量效率和高成本效益在组织工程中得到了广泛的应用。然而,这种类型的生物打印技术面临诸如星形液滴产生、过大的液滴生成和过低的液滴速度等问题。这些问题降低了DOD打印技术的稳定性和精度,打乱了细胞排列,进一步产生结构误差。为了解决这些问题,本文提出了一种基于全连接神经网络(FCNN)的DOD打印参数多目标优化(MOO)设计方法。该MOO问题包括两个目标函数:利用FCNN开发星形液滴产生模型;减小液滴直径,提高液滴速度。为了寻找MOO 问题的帕累托最优解集,本文提出了结合采用Adam算法的混合子梯度下降束法(MSGDB),并采用基于自适应学习速率算法的混合子梯度下降束法(HMSGDBA)。通过与MSGDB的比较研究,证明了HMSGDBA 的优越性。实验结果表明,使用该方法优化可得到稳定的单滴打印过程,液滴速度由0.88 m·s–1 提高到2.08 m·s–1。该方法能提高打印精度和稳定性,对实现精密细胞阵列和复杂的生物功能具有重要意义。此外,对细胞打印实验平台的搭建具有指导意义。

关键词: 按需滴化微喷射生物打印     喷墨打印     按需滴化微喷射生物打印     全连接神经网络    

CFD simulation on shell-and-tube heat exchangers with small-angle helical baffles

Minhua ZHANG,Fang MENG,Zhongfeng GENG

《化学科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 183-193 doi: 10.1007/s11705-015-1510-x

摘要: Shell-and-tube heat exchanger with helical baffles is superior to that with segmental baffles in reducing pressure drop, eliminating dead zone and lowering the risks of vibration of tube bundle. This paper focused on the small-angle helical baffles that have been merely reported in open literature. These baffles are noncontinuous helical baffles with a helix angle of 10° to 30°, and their shapes are 1/4 ellipse, 1/4 sector and 1/3 sector. To assess the integrative performance, /? is employed, and the calculated results show that among the three baffle shapes the heat exchangers with a 1/4 sector helical baffle have the lowest pressure drop. At = 10° and 20°, 1/4 sector helical baffle heat exchangers show the best integrative performance; at = 30°, 1/4 ellipse and 1/4 sector helical baffle heat exchangers perform almost the same. For the study of helix angles, we found that 30° has the best integrative performance at low mass flow rate, almost the same as 20° at high mass flow rate.

关键词: heat transfer     pressure drop     helical baffle     CFD    

智能船舶工程科技发展战略研究

郎舒妍,曾晓光,张民

《中国工程科学》 2019年 第21卷 第6期   页码 27-32 doi: 10.15302/J-SSCAE-2019.06.005

摘要:

随着新兴技术的快速发展,智能船舶逐渐成为船舶工业发展热点。本文介绍了智能船舶技术分类,梳理现阶段国内外智能船舶技术发展现状,研究国外智能船舶技术发展特点,分析我国智能船舶技术发展存在的问题,建议我国在智能船舶技术发展中采取研发与应用并重,分步实施的发展模式,同时加大产学研合作力度,建立船岸一体综合服务模式,并进一步加强人才队伍建设。

关键词: 船舶智能化,智能船舶技术,智能船舶    

标题 作者 时间 类型 操作

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

Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determinationof trace amounts of copper in water samples

Qingyun CHANG, Jingwen ZHANG, Xin DU, Jingjun MA, Jingci LI,

期刊论文

CFD evaluation of pressure drop across a 3-D filter housing for industrial gas turbine plants

Fidelis I. ABAM,Samuel O. EFFIOM,Olayinka S. OHUNAKIN

期刊论文

A biofilter model for simultaneous simulation of toluene removal and bed pressure drop under varied inlet

Jinying XI,Insun KANG,Hongying HU,Xian ZHANG

期刊论文

The investigation of pressure drop in moving-beds

CHEN Yunhua, ZHU Xuedong, WU Yongqiang, ZHU Zibin

期刊论文

产品跌落冲击耐撞性能稳健设计研究进展

杨书仪,刘德顺,赵继云,文泽军

期刊论文

Self-healing polyamide reverse osmosis membranes with temperature-responsive intelligent nanocontainers

期刊论文

节水灌溉管理智能决策支持系统研究

汪志农,吕宏兴,王密侠,熊运章,马孝义

期刊论文

Pressure drop analysis on the positive half-cell of a cerium redox flow battery using computational fluid

Fernando F. Rivera, Berenice Miranda-Alcántara, Germán Orozco, Carlos Ponce de León, Luis F. Arenas

期刊论文

低高宽比矩形微通道中流动沸腾的压降特性

张炳雷,徐进良,肖泽军

期刊论文

闸墩混凝土结构温控防裂措施智能优选研究

黄耀英,丁月梅,吕晓曼,徐佰林

期刊论文

Heat transfer and fluid flow analysis of an artificially roughened solar air heater: a CFD based investigation

Anil Singh YADAV,J. L. BHAGORIA

期刊论文

基于机器学习的多目标优化设计在按需喷墨生物打印中的应用

时佳, 宋锦春, Bin Song, Wen F. Lu

期刊论文

CFD simulation on shell-and-tube heat exchangers with small-angle helical baffles

Minhua ZHANG,Fang MENG,Zhongfeng GENG

期刊论文

智能船舶工程科技发展战略研究

郎舒妍,曾晓光,张民

期刊论文