资源类型

期刊论文 346

年份

2024 2

2023 20

2022 19

2021 23

2020 14

2019 14

2018 22

2017 15

2016 15

2015 13

2014 14

2013 18

2012 14

2011 16

2010 19

2009 22

2008 31

2007 24

2006 5

2005 3

展开 ︾

关键词

城市河流 2

微反应器 2

数值模拟 2

ADV 1

CCUS 1

CFD 1

CO2利用 1

Cas12a 1

Chebyshev多项式 1

Colebrook隐式方程 1

HY-2 卫星 1

Matlab 1

PIV 1

Preissmann格式 1

S 特性 1

SIMPLEC算法 1

SO3 1

k-ε模型 1

三氣氢硅法 1

展开 ︾

检索范围：

排序： 展示方式：

Cylindrical particulate internal flows: A review

Lizhong HUANG, Xiang GAO, Jianzhong LIN

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 385-393 doi: 10.1007/s11465-012-0354-z

摘要：

The study of cylindrical particulate internal flows has wide industrial applicability hence received much attention. This article reviews the cylindrical particulate internal flows over the past twenty years. The research is related to the cylindrical particulate flows in the straight channel, curved channel and rotational channel. Finally, several open research issues have been identified.

关键词： cylindrical particulate flow     internal flow    

HTML PDF 收藏

Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

Dawei ZHANG, Fan LI, Shuaipeng LI, Shengdun ZHAO

《机械工程前沿（英文）》 2019年 第14卷 第3期   页码 351-357 doi: 10.1007/s11465-019-0528-z

摘要： Counter-roller spinning (CRS), where the mandrel is replaced by rollers, is an effective means of manufacturing large-sized, thin-walled, cylindrical parts with more than 2500 mm diameter. CRS is very complex because of multi-axis rotation, multi-local loading along the circumference, and radial-axial compound deformation. Analytical or experimental methods cannot fully understand CRS. Meanwhile, numerical simulation is an adequate approach to investigate CRS with comprehensive understanding and a low cost. Thus, a finite element (FE) model of CRS was developed with the FORGE code via meshing technology, material modeling, determining the friction condition, and so on. The local fine mesh moving with the roller is one of highlights of the model. The developed 3D-FE model was validated through a CRS experiment by using a tubular blank with a 720 mm outer diameter. The developed 3D-FE model of CRS can provide a basis for parameter optimization, process control, die design, and so on. The data on force and energy predicted by the 3D-FE model can offer reasonable suggestions for determining the main mechanical parameters of CRS machines and selecting the motors. With the predicted data, an all-electric servo-drive system/machine with distributed power was designed in this work for CRS with four pairs of rollers to manufacture a large-sized, thin-walled, cylindrical part with 6000 mm diameter.

关键词： large-sized cylindrical part     counter-roller spinning     aluminum alloy     finite element method     distributed power    

HTML PDF 收藏

Design of a piezoelectric transducer cylindrical phase modulator for simulating acoustic emission signals

HE Cunfu, HANG Lijun, WU Bin

《机械工程前沿（英文）》 2007年 第2卷 第3期   页码 370-373 doi: 10.1007/s11465-007-0065-z

摘要： To conveniently carry out the pipeline leak experiment in a laboratory, leak acoustic signals are simulated by using the converse piezoelectric effect of a piezoelectric transducer (PZT) cylindrical phase modulator. On the basis of the piezoelectric equations and electromechanical equivalence principle, the transfer function of a PZT cylindrical phase modulator is delivered. A PZT cylindrical phase modulator is designed, and the numerical simulation is conducted. Results prove that the PZT cylindrical phase modulator can effectively simulate leak acoustic emission signals when the frequency is lower than 25 KHz.

关键词： KHz     numerical simulation     modulator     cylindrical     PZT    

HTML PDF 收藏

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0006-x

摘要： A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions. By analyzing the discrete isogeometric equations with the aid of harmonic wave assumption, the frequency error measures are rationally derived for the quadratic and cubic formulations for Kirchhoff–Love cylindrical shells. In particular, the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shells is naturally embedded into the frequency error measures without the need of explicit frequency expressions, which usually are not trivial for the shell problems. In accordance with these theoretical findings, the 2nd and 4th orders of frequency accuracy are attained for the isogeometric schemes using quadratic and cubic basis functions, respectively. Numerical results not only thoroughly verify the theoretical convergence rates of frequency solutions, but also manifest an excellent magnitude match between numerical and theoretical frequency errors for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells.

关键词： isogeometric analysis     Kirchhoff–Love cylindrical shell     free vibration     frequency error     convergence    

HTML PDF 收藏

Investigation on a cylindrical ultrasonic micromotor

ZHU Hua, CHEN Chao, ZHAO Chunsheng

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 394-398 doi: 10.1007/s11465-007-0068-9

摘要： The relationship between the arrangement of ceramics and the force coefficient shows that the maximum excitation efficiency will be obtained when the ceramics are placed at the trough of the first bending mode of the stator. Therefore, a cylindrical ultrasonic micromotor with a novel stator is proposed. The prototype motor is 5 mm in diameter, 30 mm in length and 4.2 g in weight. The micromotor operates with the first bending mode at 53 kHz. Its maximum speed is 350 r/min when the drive voltage is 200 V and the stall torque reaches 2.5 mN · m. As this motor is suitable for miniaturization because of its simple structure, another cylindrical ultrasonic micromotor is developed. Piezoelectric ceramic tube is used as its stator. This micromtor is 2 mm in diameter, 7 mm in length and 0.258 g in weight. Its speed reaches 813 r/min when the drive voltage is 60 V at 75 kHz. The operation mechanism, structure and design method of these two motors are introduced.

关键词： coefficient     bending     kHz     suitable     weight    

HTML PDF 收藏

Multifractal characteristics of cylindrical sludge drying

Weiyun WANG, Aimin LI,

《环境科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 464-469 doi: 10.1007/s11783-009-0040-5

摘要： This paper analyzes dewatered sludge drying using the multifractal theory. The drying rates of cylindrical sludge with equal masses but different cross-sectional diameters was studied, from which multifractal parameters such as partition function and quality exponent were obtained. The parameters acquired were used to calculate the multifractal singularity spectrum and indicate the presence of multifractal characteristics. The smaller cross-sectional diameters of the sludge were found to be non-homogeneous, and required quantitative methods to analyze.

关键词： multifractal characteristic     multifractal singularity spectrum     sewage sludge drying    

HTML PDF 收藏

Predication of discharge coefficient of cylindrical weir-gate using adaptive neuro fuzzy inference systems

Abbas PARSAIE,Amir Hamzeh HAGHIABI,Mojtaba SANEIE,Hasan TORABI

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 111-122 doi: 10.1007/s11709-016-0354-x

摘要： Settlement of sediments behind weirs and accumulation of materials floating on water behind gates decreases the performance of these structures. Weir-gate is a combination of weir and gate structures which solves them Infirmities. Proposing a circular shape for crest of weirs to improve their performance, investigators have proposed cylindrical shape to improve the performance of weir-gate structure and call it cylindrical weir-gate. In this research, discharge coefficient of weir-gate was predicated using adaptive neuro fuzzy inference systems (ANFIS). To compare the performance of ANFIS with other types of soft computing techniques, multilayer perceptron neural network (MLP) was prepared as well. Results of MLP and ANFIS showed that both models have high ability for modeling and predicting discharge coefficient; however, ANFIS is a bit more accurate. The sensitivity analysis of MLP and ANFIS showed that Froude number of flow at upstream of weir and ratio of gate opening height to the diameter of weir are the most effective parameters on discharge coefficient.

关键词： weir-gate     soft computing     crest geometry     circular crest weir     cylindrical shape    

HTML PDF 收藏

A method for quantifying bias in modeled concentrations and source impacts for secondary particulate

Cesunica E. Ivey, Heather A. Holmes, Yongtao Hu, James A. Mulholland, Armistead G. Russell

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0866-6

摘要： A method for quantifying source impacts for secondary PM species is derived. The method provides estimates of bias in modeled concentrations. Adjusted concentrations match corresponding observations at monitored locations. Sources impacts on secondary species are estimated over the US for 20 sources. Community Multi-Scale Air Quality (CMAQ) estimates of sulfates, nitrates, ammonium, and organic carbon are highly influenced by uncertainties in modeled secondary formation processes, such as chemical mechanisms, volatilization, and condensation rates. These compounds constitute the majority of PM mass, and reducing bias in estimated concentrations has benefits for policy measures and epidemiological studies. In this work, a method for adjusting source impacts on secondary species is developed that provides estimates of source contributions and reduces bias in modeled concentrations compared to observations. The bias correction adjusts concentrations and source impacts based on the difference between modeled concentrations and observations while taking into account uncertainties at the location of interest; and it is applied both spatially and temporally. We apply the method over the US for 2006. The mean bias for initial CMAQ concentrations compared to observations is −0.28 (OC), 0.11 (NO ), 0.05 (NH ), and −0.08 (SO ). The normalized mean bias in modeled concentrations compared to observations was effectively zero for OC, NO , NH , and SO after applying the secondary bias correction. 10-fold cross-validation was conducted to determine the performance of the spatial application of the bias correction. Cross-validation performance was favorable; correlation coefficients were greater than 0.69 for all species when comparing observations and concentrations based on kriged correction factors. The methods presented here address model uncertainties by improving simulated concentrations and source impacts of secondary particulate matter through data assimilation. Secondary-adjusted concentrations and source impacts from 20 emissions sources are generated for 2006 over continental US.

关键词： Particulate matter     Source apportionment     Secondary particulate matter     Chemical transport modeling     Receptor modeling    

HTML PDF 收藏

Vibratory behaviors of Jeffcott system on cylindrical roller bearings

Hao WU, Jianwen WANG, Qi AN

《机械工程前沿（英文）》 2009年 第4卷 第3期   页码 305-309 doi: 10.1007/s11465-009-0036-7

摘要： A Jeffcott rotor system of cylindrical roller bearings is studied in detail. Its critical speed is calculated by a new calculation method with roller bearing stiffness and damping. The influences of bearing parameters, such as the roller length, rotor mass, distance between the bearings and the kinematics viscosity of oil on the system critical speed are numerically studied, and the influences of an oil film and damping on the critical speed are also studied. Regular curves of the relationship between the geometric parameters and the system critical speed are obtained. The results show that with increasing roller length and radial load, the critical speed increases; and with increasing rotor mass and the distance between the bearings and the kinematics viscosity, the critical speed decreases. This means that an oil film will decrease the critical rotational speed of the rotor system.

关键词： roller bearing     bearing-rotor system     design value     critical rotational speed    

HTML PDF 收藏

Torsional vibrations of a cylindrical foundation embedded in a saturated poroelastic half-space

Dazhi WU,Lu YU

《结构与土木工程前沿（英文）》 2015年 第9卷 第2期   页码 194-202 doi: 10.1007/s11709-015-0292-z

摘要： Considering the interactions between an embedded foundation and saturated soil, the torsional vibrations of a cylindrical foundation embedded in a saturated poroelastic medium are analyzed in this paper. Both a rigid foundation and an elastic foundation are considered. Assuming both the side surface and the bottom surface of the foundation are perfectly bonded to soil, the reaction torques that the side soil and bottom soil acting on the foundation can be gained from basic dynamic equations of the poroelastic medium. According to the dynamic equilibrium equations of a foundation under harmonic torque, the torsional vibrations of an embedded cylindrical foundation are presented. Besides, the angular amplitude of the foundation, the equivalent stiffness and damping coefficients of the soil are expressed explicitly. Selected examples are presented to investigate the influence of relevant parameters on the torsional vibrations.

关键词： embedded foundation     saturated soil     rigid foundation     elastic foundation     torsional vibration    

HTML PDF 收藏

Vanadium and molybdenum concentrations in particulate from Palermo (Italy): analytical methods using

Diana AMORELLO,Santino ORECCHIO

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 605-614 doi: 10.1007/s11783-014-0703-8

摘要： The main purpose of this work was to develop a reliable method for the determination of vanadium (V) and molybdenum (Mo) in atmosphere particles or aerosols because they can not be readily measured using conventional techniques. For this research, 30 particulate samples were collected from five different stations located at Palermo, Italy. We used the catalytic adsorptive stripping voltammetry and differential pulsed voltammetry to measure V and Mo in atmospheric particulate, respectively. The represented method includes advantages of high sensitivity, high selectivity, simplicity, reproducibility, speed and low costs. The quantification limits for V and Mo are, respectively, 0.57 and 0.80 ng·m . The precision, expressed as relative standard deviation (RSD %), was about 2% for both metals. The mean recoveries of added V and Mo were about 99.5% and ranged from 97% to 101%. Vanadium concentrations in particulate samples collected in Palermo area ranged from 0.57 to 7.7 ng·m , while Mo concentrations were in the range 0.8–51 ng·m . In many cases the concentrations of two elements in the particulate samples fall below the detection limits. The mean concentrations for V and Mo in particulate samples, collected in Palermo area, were respectively 3.1 and 5.9 ng·m .

关键词： vanadium     molybdenum     particulate     voltammetry     Palermo    

HTML PDF 收藏

Recent advances of hydrogen production through particulate semiconductor photocatalytic overall water

《能源前沿（英文）》 2022年 第16卷 第1期   页码 49-63 doi: 10.1007/s11708-022-0817-9

摘要： Solar energy-driven photocatalytic water splitting has been investigated for decades to produce clean and renewable green hydrogen. In this paper, the cutting-edge research within the overall water splitting system is summarized from the one-step photocatalytic overall water splitting (POWS) system to the two-step system and the cocatalysts research in this field. In addition, the photocatalytic reaction engineering study is also reviewed which is crucial for future scale-up. This mini-review provides a picture of survey of recent progress of relevant overall water splitting system, with particular attention paid to material system and mechanistic breakthroughs, and highlights the challenge and opportunity of the current system.

关键词： photocatalysis     overall water splitting     hydrogen    

HTML PDF 收藏

Seasonal variations in leaf capturing of particulate matter, surface wettability and micromorphology

Huixia WANG, Hui SHI, Yangyang LI, Ya YU, Jun ZHANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 579-588 doi: 10.1007/s11783-013-0524-1

摘要： The seasonal changes in leaf particulate matter (PM) accumulation, surface wettability and micromorphology in urban tree species, including ( . ), ( . ) and ( . ), were studied during a single growing season. The three species showed distinct seasonal trends in PM accumulation, increasing from spring to autumn (or winter) even during the rainy season, but at different rates. During the study, the leaf PM retention amount of , a species with ridged leaf surfaces, was significantly higher than that of and , species with waxy leaf surfaces. The contact angles of water droplets on leaves decreased with leaf age except on the abaxial surface of , which remained non-wettable or highly non-wettable throughout the growing season; the decrease in the contact angle on adaxial surface of was greater when compared with and . A significant and negative relationship existed between leaf PM retention amounts and contact angles on adaxial surface of leaves of all three species. The increase in wettability, probably caused when epicuticular wax was destroyed by mechanical and chemical abrasion, seemed to be the main factor leading to seasonal variations in leaf PM accumulation.

关键词： contact angle     particulate matter     retention amount    

HTML PDF 收藏

Pollution characteristics of particulate matters emitted from outdoor barbecue cooking in urban Jinan

Yifei Song, Lei Sun, Xinfeng Wang, Yating Zhang, Hui Wang, Rui Li, Likun Xue, Jianmin Chen, Wenxing Wang

《环境科学与工程前沿（英文）》 2018年 第12卷 第2期 doi: 10.1007/s11783-018-1024-0

摘要： To understand the pollution characteristics of particulate matter emitted from outdoor barbecue cooking in eastern China, measurements of the PM mass concentration, the number concentration of particles with a diameter of 0.01 to 1.0 m, and the particle size distribution from 0.3 to 25 m were carried out at seven barbecue restaurants in urban Jinan. The average PM mass concentration and sub-micron particle number concentrations at a distance of 1 m from the grills were 250 to 1083 g/m and 0.90 × 10 to 2.23 × 10 cm , respectively, which were much higher than those in the ambient air of the urban area. Compared to the ambient atmosphere, barbecue cooking emitted very high levels of particles with a larger increase in the concentrations of super-micron particles than that of sub-micron particles. The super-micron particle number concentrations at the barbecue restaurants were 10 to 100 times higher than those observed in the ambient urban atmosphere. The barbecue smoke had a significant effect on the particle concentrations in the surrounding region. Both mass and number concentrations of particles exhibited maximum values immediately near the barbecue grills and often reached a peak at a distance of 10 to 15 m. The removal efficiency of a range hood for the cooking particles was tested in an indoor kitchen. The range hood effectively cleaned the particulate matter pollution caused by cooking with a removal efficiency larger than 80%. Therefore, the use of a range hood is recommended for outdoor barbecue restaurants coupled with a smoke purifier to clean the emitted high concentrations of particles.To understand the pollution characteristics of particulate matter emitted from outdoor barbecue cooking in eastern China, measurements of the PM mass concentration, the number concentration of particles with a diameter of 0.01 to 1.0 m, and the particle size distribution from 0.3 to 25 m were carried out at seven barbecue restaurants in urban Jinan. The average PM mass concentration and sub-micron particle number concentrations at a distance of 1 m from the grills were 250 to 1083 g/m and 0.90 × 10 to 2.23 × 10 cm , respectively, which were much higher than those in the ambient air of the urban area. Compared to the ambient atmosphere, barbecue cooking emitted very high levels of particles with a larger increase in the concentrations of super-micron particles than that of sub-micron particles. The super-micron particle number concentrations at the barbecue restaurants were 10 to 100 times higher than those observed in the ambient urban atmosphere. The barbecue smoke had a significant effect on the particle concentrations in the surrounding region. Both mass and number concentrations of particles exhibited maximum values immediately near the barbecue grills and often reached a peak at a distance of 10 to 15 m. The removal efficiency of a range hood for the cooking particles was tested in an indoor kitchen. The range hood effectively cleaned the particulate matter pollution caused by cooking with a removal efficiency larger than 80%. Therefore, the use of a range hood is recommended for outdoor barbecue restaurants coupled with a smoke purifier to clean the emitted high concentrations of particles.

关键词： Barbecue smoke     Particulate matters     Pollution characteristics     Emissions     Removal    

HTML PDF 收藏

Determination of polyfluoroalkyl compounds in water and suspended particulate matter in the river Elbe

Lutz AHRENS, Merle PLASSMANN, Zhiyong XIE, Ralf EBINGHAUS

《环境科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 152-170 doi: 10.1007/s11783-009-0021-8

摘要： The distribution of polyfluoroalkyl compounds (PFCs) in the dissolved and particulate phase and their discharge from the river Elbe into the North Sea were studied. The PFCs quantified included C -C perfluorinated sulfonates (PFSAs), 6∶2 fluorotelomer sulfonate (6∶2 FTS), C and C perfluorinated sulfinates (PFSiAs), C -C perfluorinated carboxylic acids (PFCAs), perfluoro-3,7-dimethyl-octanoic acid (3,7m -PFOA), perfluorooctane sulfonamide (FOSA), and n-ethyl perfluroctane sulfonamidoethanol (EtFOSE). PFCs were mostly distributed in the dissolved phase, where perfluorooctanoic acid (PFOA) dominated with 2.9-12.5 ng/L. In the suspended particulate matter FOSA and perfluorooctane sulfonate (PFOS) showed the highest concentrations (4.0 ng/L and 2.3 ng/L, respectively). The total flux of ∑PFCs from the river Elbe was estimated to be 802 kg/year for the dissolved phase and 152 kg/year for the particulate phase. This indicates that the river Elbe acts as a source of PFCs into the North Sea. However, the concentrations of perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) in the North Sea were higher than that in the river Elbe, thus an alternative source must exist for these compounds.

关键词： polyfluoroalkyl compounds (PFCs)     perfluorooctane sulfonate (PFOS)     perfluorooctanoic acid (PFOA)     surface water     water-particulate partitioning    

HTML PDF 收藏

标题 作者 时间 类型 操作

Cylindrical particulate internal flows: A review

Lizhong HUANG, Xiang GAO, Jianzhong LIN

期刊论文

Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

Dawei ZHANG, Fan LI, Shuaipeng LI, Shengdun ZHAO

期刊论文

Design of a piezoelectric transducer cylindrical phase modulator for simulating acoustic emission signals

HE Cunfu, HANG Lijun, WU Bin

期刊论文

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

期刊论文

Investigation on a cylindrical ultrasonic micromotor

ZHU Hua, CHEN Chao, ZHAO Chunsheng

期刊论文

Multifractal characteristics of cylindrical sludge drying

Weiyun WANG, Aimin LI,

期刊论文

Predication of discharge coefficient of cylindrical weir-gate using adaptive neuro fuzzy inference systems

Abbas PARSAIE,Amir Hamzeh HAGHIABI,Mojtaba SANEIE,Hasan TORABI

期刊论文

A method for quantifying bias in modeled concentrations and source impacts for secondary particulate

Cesunica E. Ivey, Heather A. Holmes, Yongtao Hu, James A. Mulholland, Armistead G. Russell

期刊论文

Vibratory behaviors of Jeffcott system on cylindrical roller bearings

Hao WU, Jianwen WANG, Qi AN

期刊论文

Torsional vibrations of a cylindrical foundation embedded in a saturated poroelastic half-space

Dazhi WU,Lu YU

期刊论文

Vanadium and molybdenum concentrations in particulate from Palermo (Italy): analytical methods using

Diana AMORELLO,Santino ORECCHIO

期刊论文

Recent advances of hydrogen production through particulate semiconductor photocatalytic overall water

期刊论文

Seasonal variations in leaf capturing of particulate matter, surface wettability and micromorphology

Huixia WANG, Hui SHI, Yangyang LI, Ya YU, Jun ZHANG

期刊论文

Pollution characteristics of particulate matters emitted from outdoor barbecue cooking in urban Jinan

Yifei Song, Lei Sun, Xinfeng Wang, Yating Zhang, Hui Wang, Rui Li, Likun Xue, Jianmin Chen, Wenxing Wang

期刊论文

Determination of polyfluoroalkyl compounds in water and suspended particulate matter in the river Elbe

Lutz AHRENS, Merle PLASSMANN, Zhiyong XIE, Ralf EBINGHAUS

期刊论文