资源类型

期刊论文 107

年份

2023 5

2022 9

2021 12

2020 5

2019 6

2018 6

2017 8

2016 4

2015 7

2014 6

2013 5

2012 1

2011 9

2010 10

2007 5

2006 2

2005 2

2004 1

2001 1

2000 2

展开 ︾

关键词

内禀尺度 2

微流控 2

液滴 2

生物材料 2

表面效应 2

3D打印 1

ACP1000 1

Cu(In 1

Fe、Co、Ru 碳化物 1

GC-Q-TOFMS 1

Ga)Se2 1

LC-Q-TOFMS 1

三维有限元模型 1

三维细观模拟 1

主支式厨房排烟道 1

主缆索股 1

人工智能 1

位错增殖 1

低温 1

展开 ︾

检索范围：

排序： 展示方式：

Droplet spectra and high-speed wind tunnel evaluation of air induction nozzles

Qing TANG, Liping CHEN, Ruirui ZHANG, Min XU, Gang XU, Tongchuan YI, Bin ZHANG

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 442-454 doi: 10.15302/J-FASE-2017169

摘要：

A series of air induction nozzles were tested in a high-speed wind tunnel. Droplet size spectra were measured for four air induction nozzles (IDK-120-01, IDK-120-02, IDK-120-03 and IDK-120-04) each at three spray pressures (0.3, 0.4 and 0.5 MPa) and seven different air velocities (121.7, 153.4, 185.5, 218.4, 253.5, 277.5 and 305.5 km·h ). The measurement distance (0.15, 0.25 and 0.35 m) from the nozzle orifice was found to be important for the atomization of the droplets. The response surface method was used to analyze the experimental data. The results indicated that v and v of the droplets decreased quasi-linearly with increased wind speed, while v was affected by the quadratic of wind speed. v , v and v of the droplets were all proportional to the orifice size, and were not markedly influenced by the spray pressure. The percentage of the spray volume consisting of droplets with a diameter below 100 mm (%<100 mm) was found to be quadratically related to wind speed, and was not markedly influenced by the spray pressure and orifice size. However, the effect of the orifice size on the %<200 mm could not be ignored.

关键词： air induction nozzle     wind tunnel     aerial spray     droplet size spectra    

HTML PDF 收藏

Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

《农业科学与工程前沿（英文）》 2015年 第2卷 第1期   页码 53-59 doi: 10.15302/J-FASE-2015049

摘要： To adapt to the trend toward low-energy precision irrigation, the droplet distributions for two new prototype sprinklers, outside signal sprinkler (OS) and fluidic sprinkler (FS), were compared with impact sprinkler (IS). A laser precipitation monitor was used to measure the droplet distributions. Droplet size and velocity distributions were tested under four operating pressures for nozzles 1.5 m above the ground. For the operating pressures tested, the mean OS, FS and IS droplet diameters ranged from 0 to 3.4, 0 to 3.5, 0 to 4.0 mm, respectively. The mean OS and FS droplet velocities ranged from 0 to 6.3 m·s , whereas IS ranged from 0 to 6.3 m·s . Being gas-liquid fluidic sprinklers, droplet distributions of the OS and FS were similar, although not identical. IS mostly produced a 0.5 mm larger droplet diameter and a 0.5 m·s greater velocity than OS and FS. A new empirical equation is proposed for determination of droplet size for OS and FS, which is sufficiently accurate and simple to use. Basic statistics for droplet size and velocity were performed on data obtained by the photographic methods. The mean droplet diameter (arithmetic, volumetric and median) decreased and the mean velocity increased in operating pressure for the three types of sprinkler.

关键词： outside signal sprinkler     fluidic sprinkler     impact sprinkler     sprinkler irrigation     droplet size     droplet velocity    

HTML PDF 收藏

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1430-6

摘要：

• UV-vis absorption analyzer was applied in drainage type online recognition.

关键词： Drainage online recognition     UV-vis spectra     Derivative spectrum     Convolutional neural network    

HTML PDF 收藏

A CFD study of the transport and fate of airborne droplets in a ventilated office: The role of droplet−droplet interactions

《环境科学与工程前沿（英文）》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1465-8

摘要：

• Coulomb and Lennard−Jones forces were considered for droplet interactions.

关键词： Droplet interactions     Aerosols     Colloids     CFD     Transport     Fate    

HTML PDF 收藏

Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 129-141 doi: 10.1007/s11709-007-0014-2

摘要： The assumption and problem of the mode-superposition response spectrum method in seismic design code is discussed based on a brief review of the development of the seismic design method for building structures. The scope of application for the classical damping theory is analyzed and the necessity of the research on mode-superposition method for non-classical damping is presented. The progresses on the mode superposition response spectrum theory are discussed. This includes: 1) the complex mode superposition method (in real form) for the non-classically damped linear system and the general calculation formula for the application of code; 2) the complex complete quadratic combination (CCQC) method for the non-classically damped linear system, which is based on the same assumptions as in deducing the complete quadratic combination (CQC) method which is popularly used in seismic design codes of many countries; 3) the complex complete quadratic combination with three components (CCQC3) method, which is a generalization of the CCQC method to the case of multi-components and multiple-support seismic excitations and deducing corresponding method; 4) the approach for calculation of seismic response of the non-classically damped system with overcritical damping and the calculation method of seismic response for the linear system with multiple eigenvalues; 5) the time-dependent CCQC (t) algorithm considering nonstationary earthquake ground motion; 6) an applied and effective method to solve the low order complex vector basis for the large linear non-classically damped system, which can be expediently used in practice to avoid the unknown errors coming from the forced uncoupling method; 7) bringing forward the concept of partial quadratic combination in order to reduce the calculation amount of CQC and CCQC methods, and studying the primary estimation-criterion. The reasonability and applicable scope of these methods are also briefly discussed in this paper.

关键词： generalization     classical damping     mode-superposition response     calculation formula     damping theory    

HTML PDF 收藏

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

《能源前沿（英文）》 2011年 第5卷 第2期   页码 166-173 doi: 10.1007/s11708-010-0105-y

摘要： The optimization of a space power system is greatly affected by the radiation heat transfer in a liquid droplet radiator (LDR). Radiation heat transfer in a two-dimensional bed of phase-change particle is modeled by solving the radiative transfer equation using the discrete ordinates method and the energy equation using the implicit finite difference method. The Mie theory is used to calculate the radiative properties of the droplet bed, whereas the effective medium theory is used to obtain the optical constants of partial solidification droplets. Multiple factors affect heat flux in the LDR, such as size distribution, flow velocity, phase change of droplets, layer thickness, droplet concentration in the layer, and material type of the work fluid; each of these must be analyzed. Calculations show that once size distribution is neglected, the relative error increases significantly. Size distribution has a remarkably strong effect on heat flux when the flow velocity of the working fluid is above 100 m/s. An increase in flow velocity leads to an increase in the total heat flux for the layer with a fixed volume fraction of droplets. The solidification zone occupies nearly half of the layer, and droplets of different sizes exhibit temperature differences to some extent due to local thermal non-equilibrium among them. Droplet concentration in the layer and the material type of the working fluid have strong effects on heat flux, whereas the thickness of the layer has a mild influence on heat flux.

关键词： radiation heat transfer     particle polydispersion     liquid droplet radiator     phase change    

HTML PDF 收藏

Modeling and simulation of droplet translocation and fission by electrowetting-on-dielectrics (EWOD)

Nathan HOWELL, Weihua LI

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 376-388 doi: 10.1007/s11465-010-0104-z

摘要： This paper discusses methods of microfluidic droplet actuation by means of electrowetting-on-dielectrics (EWOD) and provides a technique for modeling and simulating a microfluidic device by using the computational fluid dynamics (CFD) program, Flow3D. Digital or droplet microfluidics implies the manipulation of droplets on a scale of nanoliters (10 L) to femtoliters (10 L), as opposed to continuous microfluidics that involve the control of continuous fluid within a channel. The two operations in focus here are droplet translocation (moving) and droplet fission (splitting), in which the pressures and velocities within the droplet are analyzed and compared to existing works, both theoretical and experimental. The variation in the pressure of the leading and trailing faces of a droplet indicates the variation in surface energy—an important parameter that explains how a droplet will move toward a region of higher electric potential. The higher voltage on one side of a droplet reduces surface energy, which leads to an induced pressure drop, thus resulting in fluid motion. Flow3D simulations are for both water and blood droplets at voltages between 50 V and 200 V, and the droplet size, surface properties (Teflon coated), and geometry of the system are kept constant for each operation. Some peculiarities of the simulation are brought to light, such as instabilities of the system to higher voltages and fluids with higher dielectric constants, as well as the creation of a tertiary droplet when the applied voltage causes a large enough force during fission. The force distribution across the droplet provides a general understanding of the electrowetting effect and more specifically allows for a comparison between the effects that different voltages have on the forces at the droplet surface. The droplet position and mean kinetic energy of the droplet are also investigated and compared to other works, proving the dynamics of a droplet motion found here.

关键词： electrowetting-on-dielectrics (EWOD)     electrowetting     microfluidics     droplet translocation     droplet fission     Flow3D     dielectric constant    

HTML PDF 收藏

Dynamical analysis of droplet impact spreading on solid substrate

Zhaomiao LIU, Huamin LIU, Xin LIU,

《机械工程前沿（英文）》 2010年 第5卷 第3期   页码 308-315 doi: 10.1007/s11465-010-0020-2

摘要： This paper investigates the impact spreading of a droplet on a solid substrate using numerical simulation on the basis of a volume-of-fluid (VOF) model. The process of droplet spreading is described, the analysis of low speed and high speed droplet spreading, and more than one droplet spreading simultaneously is performed. The pressure, velocity, and spreading factor during the droplet spreading are reported. According to the spreading factor’s evolvement, the process of droplet spreading can be classified into spreading phase and recoiling phase. The spreading factors are almost the same at the low speed droplet spreading; however, the pressures on the substrate are quite different and air entrainment may be found as the impact speeds in a certain range. The impact speed impacts on the spreading factors in high speed droplet spreading. The spreading factor obviously increases with increasing impact speed; however, splashing will appear in the status when the speed is high enough in the high speed droplet spreading. The distance between the neighbor droplets affects the film’s quality, and only the distance between the static diameter and the maximum diameter can ensure the film’s quality. The results could help in understanding the process of droplet spreading and provide advice on the operation of a spray coating process.

关键词： droplet     impact spreading     numerical simulation    

HTML PDF 收藏

Synthesis of crystals and particles by crystallization and polymerization in droplet-based microfluidic

Jingtao WANG, Jin ZHANG, Junjie HAN,

《化学科学与工程前沿（英文）》 2010年 第4卷 第1期   页码 26-36 doi: 10.1007/s11705-009-0292-4

摘要： The recent advances in crystallization and polymerization assisted by droplet-based microfluidics to synthesize micro-particles and micro-crystals are reviewed in this paper. Droplet-based microfluidic devices are powerful tools to execute some precise controls and operations on the flow inside microchannels by adjusting fluid dynamics parameters to produce monodisperse emulsions or multiple-emulsions of various materials. Major features of this technique are producing particles of monodispersity to control the shape of particles in a new level, and to generate droplets of diverse materials including aqueous solutions, gels and polymers. Numerous microfluidic devices have been employed to generate monodisperse droplets of range from nm to μm, such as T junctions, flow-focusing devices and co-flow or cross-flow capillaries. These discrete, independently controllable droplets are ideal microreactors to be manipulated in the channels to synthesize the nanocrystals, protein crystals, polymer particles and microcapsules. The generated monodisperse particles or crystals are to meet different technical demands in many fields, such as crystal engineering, encapsulation and drug delivery systems. Microfluidic devices are promising tools in the synthesis of micron polymer particles that have diverse applications such as the photonic materials, ion-exchange and chromatography columns, and field-responsive rheological fluids. Processes assisted by microfluidic devices are able to produce the polymer particles (including Janus particles) with precise control over their sizes, size distribution, morphology and compositions. The technology of microfluidics has also been employed to generate core-shell microcapsules and solid microgels with precise controlled sizes and inner structures. The chosen “smart” materials are sensitive to an external stimulus such as the change of the pH, electric field and temperature. These complex particles are also able to be functionalized by encapsulating nanoparticles of special functions and by attaching some special groups like targeting ligands. The nucleation kinetics of some crystals like KNO was investigated in different microfluidic devices. Because of the elimination of the interactions among crystallites in bulk systems, using independent droplets may help to measure the nucleation rate more accurately. In structural biology, the droplets produced in microfluidic devices provide ideal platforms for protein crystallization on the nanoliter scale. Therefore, they become one of the promising tools to screen the optimal conditions of protein crystallization.

关键词： core-shell     monodisperse     nucleation     Microfluidic     different technical    

HTML PDF 收藏

Numerical study of droplet dynamics impinging onto steel plate covered with scale layer

Jan BOHá?EK, Ale? HORáK

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 389-398 doi: 10.1007/s11465-010-0108-8

摘要： The steel hot rolling process is inseparably connected to an oxide layer called “scale” at high temperatures. Hydraulic descaling of rolled material is a part of all rolling trains. Surface quality after descaling is fundamental for the final surface quality of a rolled product. The process itself is not theoretically well described; various different approaches have been used to clarify the descaling problem. This paper describes the dynamics of high-speed impact between the compressible water droplet and the steel scale layer. The phenomenon is known as water hammer effect. The purpose of this study is to numerically verify the fact that impact stress can be a significant factor during the descaling process. Considering a high droplet impact speed (100–300 ms ), inferential extremely short time interval (0.1–5 μs) peaks in impact pressure reaching 300 MPa can be found. Droplet dynamics was simulated with the help of LS-Dyna solver, whereas the stress analysis was performed in ANSYS interface. The extreme pressure peaks of very short duration in an impact area are a new phenomenon in the descaling theory.

关键词： hydraulic descaling     scale     rolling     water-hammer     descaling theory    

HTML PDF 收藏

A fast antibiotic detection method for simplified pretreatment through spectra-based machine learning

《环境科学与工程前沿（英文）》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1472-9

摘要：

• A spectral machine learning approach is proposed for predicting mixed antibiotic.

关键词： Antibiotic contamination     Spectral detection     Machine learning    

HTML PDF 收藏

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 455-461 doi: 10.15302/J-FASE-2018232

摘要：

Prewetting process can reduce the contact angle between the droplet and the leaf blade, so that the droplet can more easily wet and spread, thereby increasing the quantity of deposition. To improve the effectiveness of pesticides on cotton leaves, prewetting by single-rotor electric unmanned aerial vehicles (UAV) was studied, focusing on the effects of pesticide deposition on cotton leaves during the flowering period. Cotton leaves in 0°–30°, 30°–60°, 60°–90° leaf blade angle ranges (angle between the leaf blade and the horizontal plane) were examined. In the first experiment, four different prewetting volumes (0, 1.6, 3.2 and 4.8 L) were sprayed by a single-rotor electric UAV on four cotton plots (plots A to D) each with an area of 120 m , and then each area was sprayed with a 0.8% (w/v) ponceau 2R solution by another single-rotor electric UAV. The results revealed that with no prewetting, droplet deposition quantity decreased with increasing leaf blade inclination. After prewetting, the mean droplet deposition quantity on plots B, C and D increased by 39.8%, 9.7% and 24.9%, respectively. The prewetting rate of 1.6 L per 120 m had the most significant effect on improving the deposition of droplets. It was also found that the mean droplet deposition quantity in each leaf blade angle range increased after prewetting. For the leaf blade angle range 60° to 90°, this increase was the most pronounced, with 0.043, 0.062, 0.057 and 0.048 L·cm in plots A–D, respectively. Also, droplet deposition uniformity in the leaf blade angle range 60°–90° was better after prewetting. These results should provide a valuable reference for future research and practice to improve the effectiveness of pesticides applied to cotton by aerial applications.

关键词： aerial spray     cotton     deposition     flowering period     leaf angle     prewetting     UAV    

HTML PDF 收藏

The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1356-4

摘要：

•Bacterial concentrations from eight stages were 104–105copies/m3.

关键词： Size distribution     Airborne bacteria     Biological diversity     Human pathogenic bacteria     Composting plants    

HTML PDF 收藏

Influence of sprinkler irrigation droplet diameter, application intensity and specific power on flower

Yisheng ZHANG, Delan ZHU

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 165-171 doi: 10.15302/J-FASE-2017145

摘要： To determine the main parameters of droplet strike damage and avoid flower injury due to the unsuitable practices during sprinkler irrigation, an indoor experiment of irrigation droplet impact on cyclamen was conducted. The influences of different parameters such as droplet diameter, application intensity, specific power on flower strike damage was analyzed using Image Pro-Plus software to compute strike damage area and define damage level by sense-analysis. The results showed that a damage area of <1% represents a safe irrigation level, 1%–3% slight damage level, 3%–6% moderate damage level, and>6% heavy damage level. Equations of application intensity, specific power with sprinkler irrigation time and flower injury ratio were regressed against parameters which cause impact damages. The results indicated that specific power has a significant correlation with injury, and flower damage area increased as the increasing of the value of specific power for the same irrigation time. Application intensity was also correlated with injury when the droplet diameter was larger than 1 mm. When the duration of sprinkler irrigation was 1, 5 and 10 min, the threshold of impinging damage of application intensity was 25.30, 5.01 and 1.64 mm·h and the specific power was 0.467×10 , 9.340×10 and 3.110×10 W·m . These results provide a reference for determining the suitable values of sprinkler properties in operation design.

关键词： application intensity     damage     floriculture     flowers     specific power     sprinkler irrigation    

HTML PDF 收藏

Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 60-64 doi: 10.1007/s11705-013-1313-x

摘要： Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with suitable quality for the gene supporting media. Reduction crystallization experiments were performed in aqueous solution in order to clarify the effect of feeding conditions such as feeding profile, feeding rate, and feeding amount on PSD and shape of Au nanoparticles. Ascorbic acid (AsA) was selected as a reducing agent because it is safe for plants. Au particles of 50 nm, 50–200 nm, and 150–400 nm were obtained in batch operation, single-jet, and double-jet, respectively. Moreover, in single-jet and double-jet, the mean size of the obtained Au particles increases with the decrease of feeding rate or the increase of feeding amount. It is concluded that PSD of Au nanoparticles can be controlled in the range of 50–400 nm by changing feeding conditions of AsA and HAuCl aqueous solution.

关键词： reduction crystallization     particle size distribution     gene transferring media    

HTML PDF 收藏

标题 作者 时间 类型 操作

Droplet spectra and high-speed wind tunnel evaluation of air induction nozzles

Qing TANG, Liping CHEN, Ruirui ZHANG, Min XU, Gang XU, Tongchuan YI, Bin ZHANG

期刊论文

Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

期刊论文

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

期刊论文

A CFD study of the transport and fate of airborne droplets in a ventilated office: The role of droplet−droplet interactions

期刊论文

Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

期刊论文

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

期刊论文

Modeling and simulation of droplet translocation and fission by electrowetting-on-dielectrics (EWOD)

Nathan HOWELL, Weihua LI

期刊论文

Dynamical analysis of droplet impact spreading on solid substrate

Zhaomiao LIU, Huamin LIU, Xin LIU,

期刊论文

Synthesis of crystals and particles by crystallization and polymerization in droplet-based microfluidic

Jingtao WANG, Jin ZHANG, Junjie HAN,

期刊论文

Numerical study of droplet dynamics impinging onto steel plate covered with scale layer

Jan BOHá?EK, Ale? HORáK

期刊论文

A fast antibiotic detection method for simplified pretreatment through spectra-based machine learning

期刊论文

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

期刊论文

The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

期刊论文

Influence of sprinkler irrigation droplet diameter, application intensity and specific power on flower

Yisheng ZHANG, Delan ZHU

期刊论文

Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

期刊论文