检索结果-南通市图书馆

Functionalized monodisperse microbubble production:microfluidic method for fast,controlled,and automated removal of excess coating material

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第4期10卷 391-401页

作者： M.R.P.van den Broek M.Versluis A.van den Berg T.Segers BIOS/lab on a Chip Group Max Planck Center Twente for Complex Fluid DynamicsUniversity of TwenteEnschedeThe Netherlands Physics of fluids Group University of TwenteEnschedeThe Netherlands

Functionalized monodisperse microbubbles have the potential to boost the sensitivity and efficacy of molecular ultrasound imaging and targeted drug delivery using bubbles and *** bubbles can be produced in a microfluidic flow focusing ***,their functionalization and sequential use require removal of the excess lipids from the bubble suspension to minimize the use of expensive ligands and to avoid competitive binding and blocking of the receptor *** date,excess lipid removal is performed by centrifugation,which is labor intensive and challenging to *** importantly,as we show,the increased hydrostatic pressure during centrifugation can reduce bubble ***,we introduce a novel automated microfluidic’washing’***,bubbles are injected in a microfluidic chamber 1mm in height where they are left to float against the top ***,lipid-free medium is pumped through the chamber to remove excess lipids while the bubbles remain located at the top ***,the washed bubbles are resuspended and removed from the device into a collection *** demonstrate that the present method can(i)reduce the excess lipid concentration by 4 orders of magnitude,(ii)be fully automated,and(iii)be performed in minutes while the size distribution,functionality,and acoustic response of the bubbles remain ***,the presented method is a gateway to the fully automated production of functionalized monodisperse microbubbles.

关键词： bubble fluid method

Detection of wheat seedling lines in the complex environment via deep learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2024年第5期17卷 255-265页

作者： Haibo Lin Yuandong Lu Rongcheng Ding Yufeng Xiu Fazhan Yang Key lab of Industrial fluids Energy Conservation and Pollution Control(Ministry of Education) Qingdao 266520ShandongChina School of Mechanical&Automotive Engineering Qingdao University of TechnologyQingdao 266520ShandongChina

Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines based on deep learning was proposed in this study. Firstly, a rotated bounding box was created to improve the YOLOv3 model to predict the approximate position of the wheat seedling line;Then, according to the rotated bounding region obtained by the model, the wheat seedling line was detected by fitting the extracted center points. Finally, a comprehensive evaluation method combining angle error and distance error was proposed to evaluate the accuracy of the extracted crop line. By testing images of wheat seedlings in different environments, the results showed that the mean angle error and distance error respectively reached 0.75° and 10.84 pixels while the mean running time was 63.83 ms for a 1920×1080 pixels image. And compared to the original model the improved algorithm model improved the mAP value by 13.2%. The angle error and the distance error of the improved algorithm model were reduced by 51.4% and 39.7%, respectively. The method proposed in this study can accurately detect the wheat seedling lines at different stages and it is also suitable for the environments with weeds, shadow, bright light, and dark light. At the same time, it has a certain adaptability to wheat seedling images with a yaw angle in the shooting process. The research results could provide a reference for the automatic guidance of early wheat field machinery.

关键词： wheat seedling lines automatic guidance deep learning rotated bounding box evaluation method

Fluid flow driven along microchannel by its upper stretching wall with electrokinetic effects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2018年第3期39卷 395-408页

作者： Hang XU I.POP Q.SUN Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration State Key Lab of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong University Department of Mathematics Babe§-Bolyai University Particulate fluids Processing Centre Department of Chemical EngineeringThe University of Melbourne

We develop a mathematical model to describe the flow in a microchannel driven by the upper stretching wall of the channel in the presence of electrokinetic effects. In this model, we avoid imposing any unphysical boundary condition, for instance, the zero electrostatic potential in the middle of the channel. Using the similarity transformation, we employ the homotopy analysis method （HAM） to get the analytical solution of the model. In our approach, the unknown pressure constant and the integral constant related to the electric potential are solved spontaneously by using the proper boundary conditions on the channel walls, which makes our model consistent with the commonly accepted models in the field of fluid mechanics. It is expected that our model can offer a general and proper way to study the flow phenomena in microchannels.

关键词： microchannel electrokinetic effect stretching wall electro-viscous flowmodel

Untrained neural network for linear tomographic absorption spectroscopy

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第9期67卷 2787-2796页

作者： Chen JingRuo Xu ShiJie Liu HeCong Huang JianQing Liu YingZheng Cai WeiWei Key lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China EMPI Institute for Energy and Materials Processes Reactive FluidsUniversity of Duisburg-EssenDuisburg 47048Germany Department of Electrical and Electronic Engineering The University of Hong KongHong Kong SARChina

Linear tomographic absorption spectroscopy(LTAS) is a non-destructive diagnostic technique widely employed for gas *** inverse problem of LTAS represents a classic example of an ill-posed problem. Linear iterative algorithms are commonly employed to address such problems, yielding generally poor reconstruction results due to the incapability to incorporate suitable prior conditions within the reconstruction process. Data-driven deep neural networks(DNN) have shown the potential to yield superior reconstruction results;however, they demand a substantial amount of measurement data that is challenging to *** surmount this limitation, we proposed an untrained neural network(UNN) to tackle the inverse problem of LTAS. In conjunction with an early-stopping method based on running variance, UNN achieves improved reconstruction accuracy without supplementary training data. Numerical studies are conducted to explore the optimal network architecture of UNN and to assess the reliability of the early-stopping method. A comparison between UNN and superiorized ART(SUP-ART) substantiates the exceptional performance of UNN.

关键词： absorption spectroscopy linear tomography untrained neural networks combustion diagnostics

Computational fluid dynamics simulations of aerosol behavior in a high-speed (Heubach) rotating drum dustiness tester

在线全文

学校读者我要写书评

暂无评论

Particuology 2023年第1期72卷 68-80页

作者： Hongyu Chen Milind A.Jog Leonid A.Turkevich Thermal-fluids and Thermal Processing lab Mechanical&Materials EngineeringUniversity of CincinnatiCincinnatiOH 45221-0072USA Division of Field Studies and Engineering(DFSE) National Institute for Occupational Safety&Health(NIOSH)The Centers for Disease Control&Prevention(CDC)Alice Hamilton Laboratory1090 Tusculum AvenueCincinnatiOH 45226USA

Potential exposure from hazardous dust may be assessed by evaluating the dustiness of the powders being *** is the tendency of a powder to aerosolize with a given input of *** we used computational fluid dynamics(CFD)to numerically investigate the flow inside the European Standard(EN15051)rotating drum dustiness tester during its *** present work extends those CFD studies to the widely used Heubach rotating *** flow characteristics are investigated within the Abe-Kondoh-Nagano k-epsilon turbulence model;the aerosol is incorporated via a Euler-Lagrangian multiphase *** air flow inside these drums consists of a well-defined axial jet penetrating relatively quiescent *** spreading of the Heubach jet results in a fraction of the jet recirculating as back-flow along the drum walls;at high rotation rates,the axial jet becomes *** flow behavior qualitatively differs from the stable EN15051 flow *** aerodynamic instability promotes efficient mixing within the Heubach drum,resulting in higher particle capture efficiencies for particle sizes d<80μm.

关键词： Rotating drum Dustiness Euler-Lagrangian multiphase AKN k-epsilon turbulence

Fabrication of freestanding Pt nanowires for use as thermal anemometry probes in turbulence measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2021年第2期7卷 155-165页

作者： Hai Le-The Christian Küchler Albert van den Berg Eberhard Bodenschatz Detlef Lohse Dominik Krug Physics of fluids Group MESA+InstituteUniversity of Twente7522 NBEnschedeThe Netherlands BIOS lab-on-a-Chip Group MESA+InstituteUniversity of Twente7522 NBEnschedeThe Netherlands Max Planck-University of Twente Center for Complex Fluid Dynamics GöttingenGermany Max Planck Institute for Dynamics and Self-Organization 37077GöttingenGermany

We report a robust fabrication method for patterning freestanding Pt nanowires for use as thermal anemometry probes for small-scale turbulence *** e-beam lithography,high aspect ratio Pt nanowires(~300 nm width,~70µm length,~100 nm thickness)were patterned on the surface of oxidized silicon(Si)*** wet etching processes with dry etching processes,these Pt nanowires were successfully released,rendering them freestanding between two silicon dioxide(SiO2)beams supported on Si ***,the unique design of the bridge holding the device allowed gentle release of the device without damaging the Pt *** total fabrication time was minimized by restricting the use of e-beam lithography to the patterning of the Pt nanowires,while standard photolithography was employed for other parts of the *** demonstrate that the fabricated sensors are suitable for turbulence measurements when operated in constant-current mode.A robust calibration between the output voltage and the fluid velocity was established over the velocity range from 0.5 to 5 m s−1 in a SF6 atmosphere at a pressure of 2 bar and a temperature of 21°*** sensing signal from the nanowires showed negligible drift over a period of several ***,we confirmed that the nanowires can withstand high dynamic pressures by testing them in air at room temperature for velocities up to 55 m s−1.

关键词： nanowires turbulence thermal

Self-healing,Stretchable,Temperature-Sensitive and Strain-Sensitive Hydrogel-based Flexible Sensors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第3期41卷 334-344,I0005页

作者： Chun-Xia Zhao Min Guo Jie Mao Yun-Tao Li Yuan-Peng Wu Hua Guo Dong Xiang Hui Li School of Materials Science and Engineering Southwest Petroleum UniversityChengdu 610500China The Center of Functional Materials for Working fluids of Oil and Gas Field Sichuan Engineering Technology Research Center of Basalt Fiber Composites Development and ApplicationSouthwest Petroleum UniversityChengdu 610500China State Key lab of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

Flexible hydrogels have shown promise as strain sensors in medical monitoring,human motion detection and intelligent *** a hydrogel strain sensor,certain challenges need to be urgently addressed for practical applications,such as the damage caused by external effects,leading to equipment failure,and the inability to perceive ambient temperature,resulting in single ***,a stretchable,self-healing and dual temperature-strain sensitive hydrogel,with a physically-crosslinked network,is designed by constructing multiple dynamic reversible *** oxide(GO)and iron ions(Fe^(3+))act as dynamic bridges in the cross-linked network and are mediated by the covalent and hydrogen bonding,rendering excellent stretchability to the *** reversible features of coordination interactions and hydrogen interactions endow excellent recoverability and self-healing ***,the incorporated N-isopropyl acrylamide(NIPAM)provides excellent temperature responsiveness to the hydrogel,facilitating the detection of external temperature ***,the hydrogels exhibited strain-sensitivity,with a wide working range of 1%-300%,fast response and electrical stability,which can be used as flexible sensors to monitor body motions,e.g.,speaking and the bending of finger,wrist,elbow and ***,the hydrogel possesses dual sensory capabilities,combining external temperature and strain,for potential applications in wearable multifunctional sensing devices.

关键词： Hydrogel sensor Self-healing Dual temperature-strain sensitive Monitor body motions

Experimental Study of Jet Nanofluids Impingement System for Cooling Computer Processing Unit

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics Cooling and Thermal Control 2011年第3期1卷 38-44页

作者： Paisarn Naphon Somchai Wongwises Thermo-fluids and Heat Transfer Enhancement lab Department of Mechanical Engineering Faculty of Engineering Srinakharinwirot University Fluid Mechanics Thermal Engineering and Multiphase Flow Research Lab Department of Mechanical Engineering King M

An experimental investigation of the jet nanofluids impingement heat transfer characteristics of mini-channel heat sink for cooling computer processing unit of personal computer is performed. The experiments are tested under the real personal computer operating conditions: no load and full load conditions. The experiments are performed for the following ranges of the parameters: coolant flow rate varies from 0.008 to 0.020 kg/s, the nozzle diameter is set to 1.00, 1.40, 1.80 mm, the distance nozzle-to-fins tip is 2.00 mm, the channel width of the mini-channel heat sink is 1.00 mm. The nanofluids with suspending of TiO2 particles in base fluid are used as a working fluids. It was observed that the average CPU temperatures obtained from the jet nanofluids impingement cooling system are 3.0%, 6.25% lower than those from the jet liquid impingement and from the conventional liquid cooling systems, respectively. However, this cooling system requires higher energy consumption.

关键词： Jet Impingement Nanofluids Cooling Cooling CPU Mini-Rectangular Fin Heat Sink

Wafer-scale 3D shaping of high aspect ratio structures by multistep plasma etching and corner lithography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2020年第1期6卷 1176-1186页

作者： Shu Ni Erwin J.W.Berenschot Pieter J.Westerik Meint Jde Boer Rene Wolf Hai Le-The Han J.G.E.Gardeniers Niels R.Tas Mesoscale Chemical System Group MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands Inorganic Materials Science Group MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands Nanolab Cleanroom MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands Physics of fluids Group MESA+Institute&Max Planck Center for Complex Fluid DynamicsUniversity of Twente7522 NB EnschedeThe Netherlands BIOS lab-on-a-Chip Group MESA+Institute&Max Planck Center for Complex Fluid DynamicsUniversity of Twente7522 NB EnschedeThe Netherlands

The current progress of system miniaturization relies extensively on the development of 3D machining techniques to increase the areal structure *** this work,a wafer-scale out-of-plane 3D silicon(Si)shaping technology is reported,which combines a multistep plasma etching process with corner *** multistep plasma etching procedure results in high aspect ratio structures with stacked semicircles etched deep into the sidewall and thereby introduces corners with a proper geometry for the subsequent corner *** to the geometrical contrast between the gaps and sidewall,residues are left only inside the gaps and form an inversion mask inside the *** this mask,octahedra and donuts can be etched in a repeated manner into Si over the full wafer area,which demonstrates the potential of this technology for constructing high-density 3D structures with good dimensional control in the bulk of Si wafers.

关键词： lithography high structures