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Experimental Study on Momentum Transfer of Surface Texture in Taylor-Couette Flow

Chinese Journal of Mechanical Engineering 2017年第3期30卷 754-761页

作者： yabo xue Zhenqiang YAO De CHENG state key laboratory of mechanical system and vibration shanghai jiao tong universityShanghai 200240China school of mechanical engineering shanghai jiao tong universityShanghai 200240China

The behavior of Taylor-Couette （TC） flow has been extensively studied. However, no suitable torque prediction models exist for high-capacity fluid machinery. The Eckhardt-Grossmann-Lohse （EGL） theory, derived based on the Navier-Stokes equations, is proposed to model torque behavior. This are the significant energy theory suggests that surfaces transfer interfaces between cylinders and annular flow. This study mainly focuses on the effects of surface texture on momentum transfer behavior through global torque measurement. First, a power-law torque behavior model is built to reveal the relationship between dimensionless torque and the Taylor number based on the EGL theory. Second, TC flow appa- ratus is designed and built based on the CNC machine tool to verify the torque behavior model. Third, four surface texture films are tested to check the effects of surface texture on momentum transfer. A stereo microscope and three-dimensional topography instrument are employed to analyze surface morphology. Global torque behavior is measured by rotating a multi component dynamometer, and the effects of surface texture on the annular flow behavior are observed via images obtained using a high-speed camera. Finally, torque behaviors under four differentsurface conditions are fitted and compared. The experi- mental results indicate that surface textures have a remarkable influence on torque behavior, and that the peak roughness of surface texture enhances the momentum transfer by strengthening the fluctuation in the TC flow.

关键词： Torque behavior - Momentum transferbehavior Surface texture Experimental study TaylorCouette flow (TC flow)

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间隙环流作用下的泰勒涡演化及环流速度分布特性研究

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力学季刊 2023年第2期44卷 343-352页

作者：陈明明薛亚波潍坊学院建筑工程学院山东潍坊261061 上海交通大学船舶海洋与建筑工程学院上海200240 上海交通大学机械与动力工程学院上海200240

屏蔽电机运转过程中由于粘性旋转流体所受到的离心力作用,间隙内部出现泰勒涡结构,使得间隙环流有着复杂的速度分布特性.这种速度分布特性不仅对屏蔽电机水力损耗及散热特性具有重要影响,而且也是屏蔽电机转子动力学所关注的基础科学问... 详细信息

屏蔽电机运转过程中由于粘性旋转流体所受到的离心力作用,间隙内部出现泰勒涡结构,使得间隙环流有着复杂的速度分布特性.这种速度分布特性不仅对屏蔽电机水力损耗及散热特性具有重要影响,而且也是屏蔽电机转子动力学所关注的基础科学问题.本文借助间隙环流流动性能实验平台,采用高速摄像机拍摄观测了湍流核心区泰勒涡的演化过程,面向工程应用阐明了间隙环流湍流核心区流动对边界层速度的影响规律,可为设计屏蔽电机间隙流道的尺度提供理论依据.采用计算流体动力学软件建立间隙环流仿真模型,研究了定间隙条件下泰勒涡的演化过程与环流速度分布特性,初步探讨了变间隙比对间隙环流速度结构的影响规律.研究结果表明,泰勒涡随间隙比及转子转速演化的仿真计算结果与实验测试结果的变化趋势较吻合.泰勒涡在径向与轴向方向上的速度分布具有显着差异,间隙环流涡的流动方向会改变流动边界的速度结构.当转速增大时,间隙环流由层流转变为湍流,速度形状不再沿间隙径向线性分布,而是产生畸变,呈现出壁面周围速度快速减小,中间速度渐趋平稳的轮廓.

关键词：屏蔽电机间隙环流间隙比流动状态泰勒涡

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环形流道内周向流对摩擦因子的修正公式

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上海交通大学学报 2017年第1期51卷 46-50页

作者：张磊华姚振强沈洪成德薛亚波上海交通大学机械与动力工程学院上海200240 上海交通大学机械系统与振动国家重点实验室上海200240

针对屏蔽电动机定转子环形流道内转子转动对其摩擦因子的影响作定量分析.搭建缩尺实验台,实验分析了不同转子转速下定转子间的压力分布规律.实验结果表明:转速的升高会引起压降增大,间隙环流的摩擦因子需要在经验公式上进行修正,分析拟... 详细信息

针对屏蔽电动机定转子环形流道内转子转动对其摩擦因子的影响作定量分析.搭建缩尺实验台,实验分析了不同转子转速下定转子间的压力分布规律.实验结果表明:转速的升高会引起压降增大,间隙环流的摩擦因子需要在经验公式上进行修正,分析拟合数据得到了修正系数与切向、轴向雷诺数比值的映射关系,从而推导出了环形流道内考虑周向流动下摩擦因子的修正公式.为了验证该公式的准确性与普遍性,利用计算流体动力学(CFD)软件对缩尺实验台与主泵屏蔽电动机定转子间的流场分别进行仿真,对比数值仿真与该修正公式所求得的摩擦因子,结果表明偏差在合理范围内.

关键词：环形流道摩擦因子修正公式周向流屏蔽泵计算流体动力学

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Mechanisms behind the surprising observation of supra-thermal ions in NIF’s fusion burning plasmas

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Science Bulletin 2025年第3期70卷 359-364页

作者： Yuhan xue Dong Wu Jie Zhang Key Laboratory for Laser Plasmas and Department of Physics and Astronomy Collaborative Innovation Center of IFSA(CICIFSA)Shanghai Jiao Tong UniversityShanghai 200240China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Although ignition had been achieved at the National Ignition Facility(NIF),recent observations of the experiments indicate novel physics that beyond theoretical predictions emerge,e.g.,the neutron analysis of experiments has revealed deviations from the Maxwellian distributions in ion relative kinetic energies of burning plasmas,with the surprising emergence of supra-thermal deuterium and tritium(DT)ions that fall outside the predictions of macroscopic statistical hydrodynamic *** our newly developed hybrid-particle-in-cell code,incorporating the newly-proposed model of large-angle collisions,we infer that that this could be attributed to the increased significance of large-angle collisions among DT ions andα-particles in the burning *** and unprecedented kinetic investigations into the implications of large-angle collisions in the burning plasma have yielded several key findings,including an ignition moment promotion by~10 ps,the presence of supra-thermal ions below an energy threshold,and approximately twice the expected deposition ofα-particles *** rationality of our findings is confirmed through the congruency between the neutron spectral moment analyses conducted by the NIF and our kinetic simulations,both highlighting progressively widening disparities between neutron spectral moment analyses and hydrodynamics predictions,which becomes more pronounced as the yield *** kinetic simulations with large-angle collisions not only provide novel insights for experiment interpretation but also open new research opportunities for the largely unexplored regime of the nuclear burning plasmas,which are distinguished by their exceptionally high energy densities and hold immense potential for illuminating the intricate physics that underpins the evolution of the early universe.

关键词： lon kinetics Supra-thermal ions Large-angle collisions Non-equilibrium ignition Inertial confinement fusion Burning plasmas

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Targeting cholesterol trafficking to mitigate axonal degeneration in hereditary spastic paraplegia

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Neural Regeneration Research 2025年第5期20卷 1397-1398页

作者： Zhenyu Chen xue-Jun Li Department of Biomedical Sciences University of Illinois College of Medicine RockfordRockfordILUSA Department of Bioengineering University of Illinois at ChicagoChicagoILUSA

Axonal degeneration underlies many debilitating diseases including hereditary spastic paraplegia(HSP),a genetically and clinically diverse group of disorders characterized by spasticity and weakness of the lower *** is one significant cause of chronic neurodisability due to the lack of effective treatments and a wide range of onset ages from early childhood to 70 years.

关键词： degeneration diseases hereditary

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PbrMYB4,a R2R3-MYB protein,regulates pear stone cell lignification through activation of lignin biosynthesis genes

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Horticultural Plant Journal 2025年第1期11卷 105-122页

作者： Dongliang Liu Yongsong xue Runze Wang Bobo Song Cheng xue Yanfei Shan Zhaolong xue Jun Wu College of Horticulture State Key Laboratory of Crop Genetics&Germplasm Enhancement and UtilizationNanjing Agricultural UniversityNanjingJiangsu 210095China Anhui Provincial Key Laboratoryof Horticultural Crop Quality Biology Schoolof HorticultureAnhui Agricultural UniversityHefeiAnhui 230036 China State Key Laboratory of Crop Biology College of Horticulture Science and EngineeringShandong Agricultural UniversityTai'anShandong 271018China

Pear(Pyrus bretschneideri)fruit stone cells are primarily composed of lignin and have strongly lignified cell *** presence of stone cells has a negative influence on fruit texture and taste,and thus the reduction of stone cell content in pear fruit is a key goal of breeding ***,research into the key transcription factors and regulatory networks associated with pear fruit stone cell formation have been *** here used a combination of co-expression network and expression quantitative trait locus(eQTL)analyses in 206 pear cultivars with different stone cell contents to identify relevant genes;these analyses uncovered the gene PbrMYB4,a R2R3 MYB transcription factor *** was a strong positive correlation between relative PbrMYB4 expression levels in the fruit flesh and stone cell/lignin *** of PbrMYB4 significantly increased the lignin contents,whereas silencing of PbrMYB4 had the opposite effect,decreasing the contents of ***4 overexpression in pear calli significantly promoted lignin *** Arabidopsis thaliana,PbrMYB4 overexpression resulted in increasing lignin deposition,cell wall thickness of vessels and xylary fiber,and accelerating expression level of lignin biosynthetic ***4 was found to activate 4-Coumarate:Coenzyme A Ligase(Pbr4CL1)by binding to AC-I elements in the promoter regions,as demonstrated with dual-luciferase reporter assays and a yeast one-hybrid *** results demonstrated that PbrMYB4 positively regulated lignin biosynthesis in pear fruit stone cells by activating lignin biosynthesis *** study improves our understanding of the gene regulatory networks associated with stone cell formation in pear fruit,providing guidance for molecular breeding of pear varieties with low stone cell content.

关键词： Pear Stone cell R2R3-MYBs Lignin

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青海涉藏地区经济合作社嵌入社会治理的路径研究--以班玛经验为例

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山东农业工程学院学报 2021年第11期38卷 53-58页

作者：羊中太薛亚博青海民族大学青海西宁810000

在国家乡村振兴战略实施的背景下,发展壮大乡村集体经济以推进国家治理体系与治理能力现代化的进程中,经济合作社作为乡村振兴战略的中坚力量嵌入到社会治理的进程中是社会治理体系发展的必要趋势。本文通过对班玛县的实地调查,分析了... 详细信息

在国家乡村振兴战略实施的背景下,发展壮大乡村集体经济以推进国家治理体系与治理能力现代化的进程中,经济合作社作为乡村振兴战略的中坚力量嵌入到社会治理的进程中是社会治理体系发展的必要趋势。本文通过对班玛县的实地调查,分析了青海涉藏地区县域经济合作社内在驱动力不足和社会资本吸引力不足的问题,运用多中心治理理论和利益相关者理论对所产生问题进行了解释、分析,提出了完善经济合作社嵌入社会治理的对策建议。

关键词：经济合作社社会治理利益相关者多中心治理班玛经验

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Perspectives on additive manufacturing for warhead applications

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Defence Technology(防务技术) 2025年第1期43卷 225-251页

作者： Hao xue Qiang Zhou Chuan Xiao Guangyan Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Ordnance Science and Research Academy of China Beijing 100089China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

According to different damage modes,warheads are roughly divided into three types:fragmentation warheads,shaped charge warheads,and penetrating *** to limitations in material and structural manufacturing,traditional manufacturing methods make it difficult to fully utilize the damage ability of the *** manufacturing(AM)technology can fabricate complex structures,with classified materials composition and customized components,while achieving low cost,high accuracy,and rapid production of the *** maturity of AM technology has brought about a new round of revolution in the field of *** this paper,we first review the principles,classifications,and characteristics of different AM *** development trends of AM technologies are pointed out,including multi-material AM technology,hybrid AM technology,and smart AM *** our survey,PBF,DED,and EBM technologies are mainly used to manufacture warhead damage *** and DIW technologies are mainly used to manufacture warhead ***,the research on the application of AM technology in three types of warhead and warhead charges was reviewed and the existing problems and progress of AM technologies in each warhead were ***,we summarized the typical applications and look forward to the application prospects of AM technology in the field of warheads.

关键词： Additive manufacturing Fragmentation warhead Shaped charge warhead Penetrating warhead Warhead charge

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Oxygen atmosphere enhances ball milling remediation of petroleum-contaminated soil and reuse as adsorptive/catalytic materials for wastewater treatment

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Journal of Environmental Sciences 2025年第1期147卷 652-664页

作者： Pingting Gao Simin Song Mingxin Wang Meng Yao Jinjuan xue School of Environmental Science and Engineering Changzhou UniversityChangzhou 213164China Jiangsu Petrochemical Safety and Environmental Protection Engineering Research Center Changzhou 213164China

Ball milling is an environmentally friendly technology for the remediation of petroleumcontaminated soil(PCS),but the cleanup of organic pollutants requires a long time,and the post-remediation soil needs an economically viable disposal/reuse strategy due to its vast *** present paper develops a ball milling process under oxygen atmosphere to enhance PCS remediation and reuse the obtained carbonized soil(BCS-O)as wastewater treatment *** total petroleum hydrocarbon removal rates by ball milling under vacuum,air,and oxygen atmospheres are 39.83%,55.21%,and 93.84%,*** Langmuir and pseudo second-order models satisfactorily describe the adsorption capacity and behavior of BCS-O for transition *** Cu^(2+),Ni^(2+),and Mn^(2+)adsorbed onto BCS-O were mainly bound to metal carbonates and metal ***,BCS-O can effectively activate persulfate(PDS)oxidation to degrade aniline,while BCS-O loaded with transition metal(BCS-O-Me)shows better activation efficiency and ***-O and BCS-O-Me activated PDS oxidation systems are dominated by^(1)O_(2)oxidation and electron *** main active sites are oxygen-containing functional groups,vacancy defects,and graphitized *** oxygen-containing functional groups and vacancy defects primarily activate PDS to generate^(1)O_(2)and attack *** carbon promotes aniline degradation by accelerating electron *** paper develops an innovative strategy to simultaneously realize efficient remediation of PCS and sequential reuse of the postremediation soil.

关键词： Petroleum-contaminated soil Ball milling Oxygen atmosphere Pyrolysis Resource utilization

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Turbulent Agglomeration of Microparticles in a Cylinder Wake Flow Using LES-DEM:Focusing on the Effect of the Reynolds Number

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Journal of Thermal Science 2025年第1期34卷 34-49页

作者： WANG Shuang MU Lin LI xue XIE Jun DONG Ming School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China School of Optical Information and Energy Engineering Wuhan Institute of TechnologyWuhan 430205China School of Energy and Environment Shenyang Aerospace UniversityShenyang 110136China

Turbulent agglomeration is viewed as a promising technology for enhancing fine particle removal *** better understand particle transport,agglomeration behaviors,and fluid-particle interactions,we numerically explored these phenomena under cylindrical vortex wake influence using a coupled large eddy simulation and discrete element method(LES-DEM)*** validity of the LES approach was verified by comparison with available direct numerical simulation(DNS)*** adopted the Johnson-Kendall-Roberts(JKR)contact model for particle-particle *** particle dispersion and agglomeration characteristics of particles with different diameters(d_(p)=2-20μm)in the laminar and transition of shear layer(TrSL)flow regimes were *** particles were concentrated at the vortex centers,while larger particles accumulated around the *** agglomeration efficiency exhibited an M-shaped profile spanwise(y-direction).With increasing Reynolds number,the agglomeration efficiency and turbulence intensity *** particle agglomeration efficiency peaks at a certain Reynolds ***,at higher Reynolds numbers,reducing the residence time of particles in the flow field decreases the agglomeration efficiency.

关键词： microparticle particle agglomeration discrete element method large eddy simulation

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