检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2002年第2期10卷 142-148页

作者：周力行杨玟廉春英 l.s.fan D.J.lee Department of Engineering Mechanics Tsinghua University Beijing 100084 China Department of Chemical Engineering The Ohio State University USA

A full second-order moment (FsM) model and an algebraic stress (AsM) two-phase turbulence modelare proposed and applied to predict turbulent bubble-liquid flows in a 2D rectangular bubble column. Predictiongives the bubble and liquid velocities, bubble volume fraction, bubble and liquid Reynolds stresses and bubble-liquidvelocity correlation. For predicted two-phase velocities and bubble volume fraction there is only slight differencebetween these two models, and the simulation results using both two models are in good agreement with the particleimage velocimetry (PIV) measurements. Although the predicted two-phase Reynolds stresses using the FsM are insomewhat better agreement with the PIV measurements than those predicted using the AsM, the Reynolds stressespredicted using both two models are in general agreement with the experiments. Therefore, it is suggested to usethe AsM two-phase turbulence model in engineering application for saving the computation time.

关键词： second-order moment model two-phase turbulence bubble-liquid flow bubble column

large-eddy simulation of Bubble-liquid Confined Jets

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2002年第4期10卷 381-384页

作者：杨玟周力行 l.s.fan Department of Engineering Mechanics Tsinghua University 北京 100084

The large-eddy simulation (lEs) with two-way coupling is used to study bubble-liquid two-phase confined multiple jets discharged into a 2D *** lEs results reveal the large-eddy vortex structures of both liquid flow and bubble motion,the shear-generated and bubble-induced liquid turbulence,and indicate much stronger bubble fluctuation than that of the liquid,the enhancement of liquid turbulence by *** shear and bubble-liquid interaction are important for the liquid turbulence generation in the case studied.

关键词： large-eddy simulation bubble-liquid flow two-phase jet

鼓泡床内气泡-液体两相湍流代数应力模型的数值模拟

在线全文

学校读者我要写书评

暂无评论

化工学报 2002年第8期53卷 780-786页

作者：周力行杨玟廉春英 l.s.fan D.J.lEE 清华大学工程力学系北京100084 俄亥俄州立大学化学工程系

现有的气泡 -液体两相流动的数值模拟中 ,或者不考虑湍流 ,或者仅仅考虑液体湍流 ,但是直接模拟和PIV测量结果都表明气泡由于尾迹的作用有强烈的湍流脉动 .本文首次推导和封闭了同时模拟气泡湍流脉动和液体湍流脉动的二阶矩输运方程两... 详细信息

现有的气泡 -液体两相流动的数值模拟中 ,或者不考虑湍流 ,或者仅仅考虑液体湍流 ,但是直接模拟和PIV测量结果都表明气泡由于尾迹的作用有强烈的湍流脉动 .本文首次推导和封闭了同时模拟气泡湍流脉动和液体湍流脉动的二阶矩输运方程两相湍流模型 ,并在此基础上建立了代数应力气泡 -液体两相湍流模型 .用代数应力模型模拟了二维矩形断面鼓泡床内气泡 -液体两相流动 .预报结果给出了气泡和液体两相速度场、两相Reynolds应力及湍动能分布和气泡体积分数分布 .模拟结果与PIV测量结果符合很好 ,表明了模型的合理性 .研究结果表明 ,原先静止的液体在气泡因浮力而产生的上升运动的作用下产生回流流动 ,而气泡则只有上升运动 .气泡速度始终大于液体速度 .在床内气泡湍流脉动确实始终很强烈 .液体则由于气泡的作用以及自身速度梯度产生的双重作用而发生湍流脉动 .气泡的脉动显著地大于液体的脉动 .两相湍流脉动都是各向异性的。

关键词：数值模拟鼓泡床气液两相湍流代数应力模型单汽泡动力学

气泡-液体多股射流二阶矩两相湍流模型的模拟

在线全文

学校读者我要写书评

暂无评论

工程热物理学报 2002年第2期23卷 231-234页

作者：杨玟周力行李荣先 l.s.fan 清华大学工程力学系北京100084 Department of Chemical Engineering The Ohio state University

本文采用二阶矩两相湍流模型模拟了气泡－液体闭式多股射流。研究结果显示出预报的两相速度、雷诺应力和气泡体积分数分布的合理性，以及在速度较高和剪切较强的情况下，气泡湍流脉动仍然大于液体湍流脉动，气泡增强液体湍流，气液两相... 详细信息

本文采用二阶矩两相湍流模型模拟了气泡－液体闭式多股射流。研究结果显示出预报的两相速度、雷诺应力和气泡体积分数分布的合理性，以及在速度较高和剪切较强的情况下，气泡湍流脉动仍然大于液体湍流脉动，气泡增强液体湍流，气液两相湍流脉动均存在各向异性，而且气泡脉动的各向异性比液体脉动的大等规律。

关键词：两相湍流二阶矩模型数值模拟气泡-液体多股射流速度应力体积脉动

在线全文

学校读者我要写书评

暂无评论

气泡-液体闭式多股射流的大涡模拟研究

工程热物理学报 2003年第1期24卷 127-130页

作者：杨玟周力行李荣先 l.s.fan 清华大学工程力学系北京100084 Department of Chemical Engineering The Ohio State UniversityColumbusUSA

采用气泡-液体两相流动的欧拉-拉氏大涡模拟,研究了矩形通道内多股射流形成的气泡-液体两相湍流流动,得到了气液两相湍流瞬态结构,产生和发展过程。研究结果发现气泡和液体都有瞬态大涡结构,气泡脉动比液体的强。大涡模拟统计结果给出... 详细信息

采用气泡-液体两相流动的欧拉-拉氏大涡模拟,研究了矩形通道内多股射流形成的气泡-液体两相湍流流动,得到了气液两相湍流瞬态结构,产生和发展过程。研究结果发现气泡和液体都有瞬态大涡结构,气泡脉动比液体的强。大涡模拟统计结果给出了有无气泡两种情况下的液体湍流脉动速度均方根值分布。瞬态和统计结果都表明,气泡增大了液体湍流,液体湍流来源于其自身的剪切产生和气泡的作用。这与二阶矩模型模拟结果定性一致。

关键词：气泡-液体闭式多股射流气液两相射流两相湍流大涡模拟

Tackling the microlensing wave effects of strong lensing gravitational waves with TAAH

在线全文

学校读者我要写书评

暂无评论

science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 257-258页

作者： Zuhui fan south-Western Institute for Astronomy Research Yunnan University

The rapid development of gravitational wave（GW） observations since their first detection in 2015 [1] has opened a completely new window for exploring the Universe. Consequently, astronomical research has entered the multimessenger era, allowing us to use different tracers to view the cosmos from various perspectives. Among others, the appealing application of gravitational wave events from compact binary mergers is that they can act as standard sirens to determine absolute cosmic distances entirely independent of standard candles. This approach is one of the most promising means to solve the current H0tension problem.

关键词：

soluble epoxide hydrolase:a next-generation drug target for Alzheimer's disease and related dementias

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2585-2586页

作者： Andrew Gregory Chengyun Tang fan fan Department of Physiology Medical College of GeorgiaAugusta UniversityAugustaGAUSA

Alzheimer's disease(AD)and Alzheimer's diseaserelated dementias(ADRD)represent a significant public health challenge,with projections indicating a substantial increase in affected individuals due to the aging global *** the World Health Organization,AD/ADRD has affected more than 55 million individuals worldwide,with an additional 10 million cases diagnosed each year.

关键词： Alzheimer population drug

Effect of a Carbon Fibre-steel Fibre-graphite Conductive Filler on the Electrothermal Properties of Cementitious Materials

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials science) 2025年第1期40卷 141-151页

作者： fan Yanan WEI Hong ZHENG Hongyong DU Hongxiu Department of Architecture and Environmental Engineering Taiyuan UniversityTaiyuan 030032China College of Civil Engineering Taiyuan University of TechnologyTaiyuan 030032China

Carbon fibre,steel fibre and graphite were used as conductive fillers to prepare cementitious materials with excellent electrothermal *** electrically conductive cementitious materials with different volume dosages were analysed through compressive and flexural strength,electrochemical impedance spectroscopy and temperature rise *** equivalent circuit model was established to study the electrically conductive heat generation mechanism in the electrically conductive cementitious *** results indicate that the mechanical properties of cementitious composite materials with a ternary conductive phase are better than those of pristine cementitious materials because the fibrous filler improves their mechanical ***,the incorporation of graphite in the material reduces its *** fibrous and point-like conductive phase materials into the cementitious material enhances the overall conductive pathway and considerably reduces the electrical resistance of the cementitious material,enhancing its conductive *** volume ratios of carbon fibre,steel fibre and graphite that achieve an optimal complex doping in the cementitious material were 0.35%,0.6%and 6%,*** was determined using the mutation point of each circuit element parameter as the percolation *** addition,at a certain safety voltage,there is a uniform change between the internal and surface temperatures of the conductive cementitious material,and the heating effect in this materialis is considerably better than that in the pristine cementitious material.

关键词： cementitious composites conductive fillers electrothermal properties electrochemical impedance spectroscopy

Endoscopy-assisted lightweight diagnosis system based on transformers for colon polyp detection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics letters 2025年第1期21卷 57-64页

作者： fan Weiming YU Jiahui JU Zhaojie school of Automation and Electrical Engineering Shenyang Ligong University Department of Biomedical Engineering Zhejiang University school of Computing University of Portsmouth

The integration of endoscopy has significantly propelled the diagnosis and treatment of gastrointestinal diseases, with colonoscopy establishing itself as the primary method for early diagnosis and preventive care in colorectal cancer(CRC). Although deep learning holds promise in mitigating missed polyp rates, modern endoscopy examinations pose additional challenges, such as image blurring and atomizing. This study explores lightweight yet powerful attention mechanisms, introducing the spatial-channel transformer(sCT), an innovative approach that leverages spatial channel relationships for attention weight calculation. The method utilizes rotation operations for inter-dimensional dependencies, followed by residual transformation, encoding inter-channel and spatial information with minimal computational overhead. Extensive experiments on the CVC-Clinic DB polyp detection dataset, addressing endoscopy pitfalls, underscore the superiority of our sCT over other state-of-the-art methods. The proposed model maintains high performance, even in challenging scenarios.

关键词： Endoscopy

Macro-mechanics and Microstructure of Nanomaterial-modified Geopolymer Concrete: A Comprehensive Review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials science) 2025年第1期40卷 204-214页

作者： WANG Tao fan Xiangqian GAO Changsheng QU Chiyu The National Key laboratory of Water Disaster Prevention Nanjing Hydraulic Research InstituteNanjing 210024China southern Marine science and Engineering Guangdong laboratory(Guangzhou) Guangzhou 511458China school of Water Conservancy and Transportation Zhengzhou UniversityZhengzhou 450001China

We have described in detail the effects of nano-siO_(2),nano-CaCO_(3),carbon nanotubes,and nano-Al_(2)O_(3) on geopolymer concrete from the perspectives of macro mechanics and *** existing research results show that the mechanism of nano-materials on geopolymer concrete mainly includes the filling effect,nucleation effect,and bridging effect,the appropriate amount of nano-materials can be used as fillers to reduce the porosity of geopolymer concrete,and can also react with Ca(OH)2 to produce C-s-H gel,thereby improving the mechanical properties of geopolymer *** optimum content of nano-siO_(2) is between 1.0%and 2.0%.The optimum content of nano-CaCO_(3) is between 2.0%and 3.0%.The optimum content of carbon nanotubes is between 0.1%and 0.2%.The optimum content of nano-Al_(2)O_(3) is between 1.0%and 2.0%.The main problems existing in the research and application of nanomaterial-modified geopolymer concrete are summarized,which lays a foundation for the further application of nanomaterial in geopolymer concrete.

关键词： nanomaterials low carbon geopolymer concrete macro-mechanics microstructure