检索结果-内蒙古大学图书馆

A Coupled Bioheat Transfer Model for Customized Whole-Eye Modeling in Retinal Laser Surgery

学校读者我要写书评

暂无评论

SSRN 2022年

作者： Zhao, P.H. Li, K. Zhang, H. Li, Dong Chen, B. Zheng, Y.P. Li, W.P. Wang, G.X. Fan, L.H. Yao, L. State Key Laboratory of Multiphase Flow in Power Engineering Xi 'an Jiaotong University Shaanxi Xi'An710049 China Department of Ophthalmology The Second Affiliated Hospital of Xi 'an Jiaotong University Shaanxi Xi'An710004 China The First Affiliated Hospital of Xi'an Joao Tong University Shaanxi Xi'An710061 China Department of Mechanical Engineering The University of Akron Akron United States

The photo-thermal effects of laser on tissue is widely used in ophthalmology to treat retinal diseases. By adjusting the pulse duration from nano to tens of seconds, the multi-scale retinal lesion from micro to millimeter size can be thermally targeted. Large scale difference among the target lesions brought extra challenge for retinal laser surgery modeling. In this study, we developed a coupled whole eye model for retinal laser surgery. In the model, Penens bioheat transfer equation was adapted for the whole eye temperature modeling. Simultaneously, we treat the fundus as a multi-layered porous medium made of a tissue matrix buried with highly-absorbing chromophores (melanin or blood). Two-temperature equations, one for the chromophore and the other for the surrounding tissue, will be developed based on the local thermal non-equilibrium theory of porous media. The Pennes model and the two-temperature model was coupled together to calculated the thermal responses of eye during several laser retinal surgery process with pulse duration from nano to tens of seconds. The simulation results proved our model is capable of modeling laser retinal surgery process in different time scale. Furthermore, the present coupled model was applied in a real fundus anatomy from a patient with diabetic retinopathy to illustrate its feasibility in customized laser protocol planning. © 2022, The Authors. All rights reserved.

关键词： Ophthalmology

Study on Heat and Mass Transfer Distance of Water-Film Evaporation in Limited Space Using Dual-Wavelength Digital Holographic Interference

学校读者我要写书评

暂无评论

SSRN 2022年

作者： Liu, Jing-Nan Zhang, Meng-Meng Zhang, Lin-Xin Di, Jiang-Lei Zhao, Jian-Lin Gao, Ming Sun, Yue-Dong Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions Shaanxi Key Laboratory of Optical Information Technology School of Physical Science and Technology Northwestern Polytechnical University Shaanxi Xi’an710129 China Advanced Institute of Photonics Technology School of Information Engineering Guangdong Provincial Key Laboratory of Information Photonics Technology Guangdong University of Technology Guangzhou51006 China

To study the heat and mass transfer between evaporating water film and air in limited space, the temperature and humidity distributions of air near the flowing water film was measured using dual-wavelength digital holographic interference (DHI). The holograms were recorded by CMOS with two different wavelengths of 532 nm and 671 nm. We derived the relationships between the phase changes reconstructed from the holograms and the air temperature and humidity changes based on the Edlen formulas. A experimental model was built to generate steady water film and demonstrate the heat and mass transfer in air countercurrent to the water film, which flows down on the copper plate. The model has two symmetrical tunnels isolated by a copper plate in the middle, allowing to compare the cases of heat mass transfer with and without evaporation. The relative measurement errors of temperature and humidity are less than x% and y%, respectively, by comparing the reconstructed results with the sensor measured values. Based on the measurement results, the concept, feature transfer distance (FTD), is proposed, which characterizes the intensity of heat and mass transfer. By analyzing FTD, the main influencing factors of heat and mass transfer were obtained. © 2022, The Authors. All rights reserved.

关键词： Evaporation

Effiects of surface roughness on oil-water-solid three-phase contact line

学校读者我要写书评

暂无评论

Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2016年第9期37卷 1901-1905页

作者： Zheng, Wen-Xiu Sun, Cheng-Zhen Xiong, Tao Lü, Xiao-Ming Bai, Bo-Feng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Frist Gas Production Factory PetroChina Xinjiang Oilfield Branch Company Karamay834000 China

We established a dodecane-water-graphite system from molecular dynamics insight. The effiects of surface roughness on the three-phase contact line are studied from the aspects of the microscopic contact angle, adsorption property of water and oil molecules and adsorption energy of water molecules. The results show that adsorption intensity is weaker with the existence of roughness, which causes a larger contact angle when surface in water side has raised structure and a smaller contact angle when surface in oil side has raised structure. Oil molecules near solid surface exhibit a layer-by-layer distribution and roughness has little effiect on it. The existence of roughness weakens the orientation of water molecules, which results in weaker adsorption and stability. © 2016, Science Press. All right reserved.

关键词： Molecular dynamics

Numerical study on the mechanism of drag modulation by dispersed drops in two-phase Taylor-Couette turbulence

学校读者我要写书评

暂无评论

arXiv

arXiv 2023年

作者： Su, Jinghong Yi, Lei Zhao, Bidan Wang, Cheng Xu, Fan Wang, Junwu Sun, Chao New Cornerstone Science Laboratory Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing100084 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences P. O. Box 353 Beijing100190 China Department of Engineering Mechanics School of Aerospace Engineering Tsinghua University Beijing100084 China

The presence of a dispersed phase can significantly modulate the drag in turbulent systems. We derived a conserved quantity that characterizes the radial transport of azimuthal momentum in the fluid-fluid two-phase Taylor-Couette turbulence. This quantity consists of contributions from advection, diffusion, and two-phase interface, which are closely related to density, viscosity, and interfacial tension, respectively. We found from interface-resolved direct numerical simulations that the presence of the two-phase interface consistently produces a positive contribution to the momentum transport and leads to drag enhancement, while decreasing the density and viscosity ratios of the dispersed phase to the continuous phase reduces the contribution of local advection and diffusion terms to the momentum transport, respectively, resulting in drag reduction. Therefore, we concluded that the decreased density ratio and the decreased viscosity ratio work together to compete with the presence of two-phase interface for achieving drag modulation in fluid-fluid two-phase turbulence. Copyright © 2023, The Authors. All rights reserved.

关键词： Drag

Unique Z-Scheme TiO2 Homojunction Enabling Photocatalytic Water Splitting with Unit Quantum Efficiency

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Lu, Kejian Guan, Xiangjiu Liu, Feng Fu, Yiwei Peng, Hao Hu, Anlan Huang, Jie Yu, Fangbo Zhang, Chunyang Xue, Fei Fu, Wenlong Liu, Maochang InternationalResearchCenter for Renewable Energy State Key Laboratory ofMultiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi710049 Xi’an China Suzhou Academy ofXi’an Jiaotong University Jiangsu Suzhou215123 China

TiO2 appears as the most widely investigated semiconductor photocatalyst for solar water splitting, yet with limited success approaching the upper limit of quantum efficiency. Promising performance could be expected from optimizing crystal and electronic structures via modulating Ti-O coordination, with respect to overcoming the obstacles from poor charge transfer behaviour and inferior surface reaction kinetics, while remaining as a significant challenge. Herein, we demonstrate a novel defect-rich Z-scheme TiO2 homojunction photocatalyst by precisely thermodynamically regulated one-step symbiotic phase transition. The Z-scheme TiO2 promises a remarkable H2 evolution rate (2.20 mmol h-1) with a quantum efficiency of 99.24% at 350 nm. Detailed analysis indicates the electronic interactions and redistribution induced by the modification of Ti-O coordination, which contributes to establishing a unique charge transfer via Z-scheme mode and an activated surface to break through the kinetic barrier of water oxidation for achieving overall water splitting. © 2023, The Authors. All rights reserved.

关键词： Titanium dioxide

Numerical Study on the Impact Characteristics of a Single Molten Lead Bismuth Droplet on Water

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Lin, Yue Zhang, Dalin Chen, Yutong Zhang, Xisi Deng, Jian Du, Peng Tian, Wenxi Qiu, Suizheng Su, Guanghui Department of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University No.28 Xianningxilu Beilinqu Shaanxi Xi’an710049 China Institute of Reactor Engineering Technology China Institute of Atomic Energy Beijing102413 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu610213 China

As an important link in the possible occurrence of steam explosions, the interaction between molten materials and coolant is of great significance for safety analysis in severe accidents of nuclear reactors. This study is based on the two-dimensional multiphase and multi-component fluid dynamics code ACENA to model the process of single molten lead bismuth droplet impacting a water tank and obtain the velocity changes of the molten droplet as it moves through the water tank. Furthermore, a sensitivity analysis of relevant factors such as the heat transfer area fraction and drag coefficient of the droplet is carried out. To verify models in ACENA, the computation results are compared to experimental data. It is demonstrated that the overall trend of the velocity curve acquired by the ACENA code during the interaction between a molten lead bismuth droplet and water is consistent with the experimental results. The droplet falling velocity increases with the increase in droplet temperature when the temperature of water is the same, and the droplet falling velocity increases with the increase of water temperature at the same droplet temperature. The simulation results by ACENA code for MFCI are in good agreement with experiments which verifies the accuracy of relevant models in ACENA. It can provide an effective means for safety analysis of nuclear reactors in China. © 2024, The Authors. All rights reserved.

关键词： Drops

Origin of Granular Capillarity Revealed by Particle-Based Simulations

学校读者我要写书评

暂无评论

Physical Review Letters 2017年第21期118卷 218001-218001页

作者： Fengxian Fan Eric J. R. Parteli Thorsten Pöschel Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Jun Gong Road 516 200093 Shanghai China Institute for Multiscale Simulation Friedrich-Alexander-Universität Erlangen-Nürnberg Nägelsbachstraße 49b 91052 Erlangen Germany Department of Geosciences University of Cologne Pohligstraße 3 50969 Cologne Germany

When a thin tube is dipped into water, the water will ascend to a certain height, against the action of gravity. While this effect, termed capillarity, is well known, recent experiments have shown that agitated granular matter reveals a similar behavior. Namely, when a vertical tube is inserted into a container filled with granular material and is then set into vertical vibration, the particles rise up along the tube. In the present Letter, we investigate the effect of granular capillarity by means of numerical simulations and show that the effect is caused by convection of the granular material in the container. Moreover, we identify two regimes of behavior for the capillary height Hc∞ depending on the tube-to-particle-diameter ratio, D/d. For large D/d, a scaling of Hc∞ with the inverse of the tube diameter, which is reminiscent of liquids, is observed. However, when D/d decreases down to values smaller than a few particle sizes, a uniquely granular behavior is observed where Hc∞ increases linearly with the tube diameter.

关键词： Classical mechanics Complex systems Wetting Dry granular materials

Insight into the Interconversions of Three-Phase Products Through the Supercritical Water Gasification of Bark

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Ge, Hui Yi, Lei Huang, Yong Peng, Pai Cao, Wen Chen, Yunan Qi, Xingang Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University No.28 Xianning West Road Xi'An710049 China International Institute for Innovation Jiangxi University of Science and Technology Jiangxi 341000 China Suzhou Academy Xi’an Jiaotong University No.99 Ren’ai Road Jiangsu Suzhou215123 China

The clean and efficient utilization of biomass waste for hydrogen production conforms to social development in the future. In this work, hydrogen production from supercritical water gasification (SCWG) of fir bark (FB) was investigated systematically at various reaction temperatures (500–750 °C), feedstock concentrations (5%–15%), and retention time (0–40 min). The gaseous, liquid, and solid products were analyzed comprehensively to determine the gasification mechanism. The results demonstrated that FB was the alternative feedstock for hydrogen production. The maximum CE and H2 selectivity of 95.34% and 0.99 were obtained at 700 °C-5%-40 min. High reaction temperature and prolonging retention time accelerated the conversions of phenolic compounds in liquid products and functional groups in solid products. High feedstock concentration also resulted in the bond-making between functional groups in solid products. The reaction mechanism was proposed based on the components of gaseous and liquid products and the variations of functional groups in solid products. © 2023, The Authors. All rights reserved.

关键词： Hydrogen production

Sacos-Plate: A New Thermal-Hydraulic Subchannel Analysis Code for Plate Type Fuel Assemblies

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Sun, Ruiyu Wang, Jianjun Wang, Jinshun Chen, Ronghua Jiang, Xing Tian, Wenxi Qiu, Suizheng Su, Guanghui Gui, Minyang Harbin Engineering University China School of Nuclear Science and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University China State Key Lab. of Multiphase Flow in Power Engineering Xi’an Jiaotong University China Shanghai Nuclear Engineering Research Design Institute Shanghai China

Over the past few decades, plate-type fuel elements have been widely used in advanced research reactors, small modular pressurized water reactors, production reactors, etc., with the advantages of compact structure arrangement, good heat transfer characteristics and high fuel consumption. Currently, a thermal-hydraulic subchannel analysis code, namely SACOS-PLATE code, was newly designed to satisfy the calculation of different types of plate fuel elements under various steady-state operating conditions. Based on the original SACOS code, this updated version modifies the flow distribution model, the plate heat conduction model, the heat distribution model as well as the flow heat transfer model, and then realizes the simulation of the special thermal-hydraulic phenomena of the fuel and the rectangular flow channel. In this present study, the RA-6 experimental data was used to validate the code, and the simulation calculation was performed on the JRR-3 research reactor, which proved the good computing capability of SACOS-PLATE code. © 2023, The Authors. All rights reserved.

关键词： Plates (structural components)