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密度不同的颗粒在流体中的沉降特性

计算力学学报 2018年第5期35卷 650-655页

作者：刘依聂德明中国计量大学计量测试工程学院杭州310018

采用格子Boltzmann方法(LBM)对雷诺数范围为5≤Re≤12的双颗粒沉降进行了直接数值模拟研究,主要关注颗粒之间的密度差异k对其周期性振动的影响。根据雷诺数颗粒沉降特性可以分成三个阶段,即当Re较小时,颗粒的振动幅度随k的增大而减小,... 详细信息

采用格子Boltzmann方法(LBM)对雷诺数范围为5≤Re≤12的双颗粒沉降进行了直接数值模拟研究,主要关注颗粒之间的密度差异k对其周期性振动的影响。根据雷诺数颗粒沉降特性可以分成三个阶段,即当Re较小时,颗粒的振动幅度随k的增大而减小,当Re较大时则正好相反,介于两者之间存在一个临界雷诺数,在此雷诺数附近,颗粒的沉降同时具有以上两种特征。同时还研究了两个颗粒的稳定沉降结构以及重颗粒摆脱轻颗粒的条件。

关键词：格子Boltzmann方法颗粒沉降颗粒密度直接数值模拟

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双颗粒沉降的动力学分析

计算力学学报 2016年第6期33卷 895-904页

作者：陈荣前聂德明中国计量学院计量测试工程学院杭州310018

采用格子Boltzmann-虚拟区域方法对雷诺数范围为50≤Re≤200的双颗粒自由沉降进行了直接数值模拟。首先,研究发现双颗粒最终沉降的位置分别在通道的1/4和3/4位置附近,且与颗粒的初始间距、雷诺数以及通道宽度无关。其次,重点研究了颗粒... 详细信息

采用格子Boltzmann-虚拟区域方法对雷诺数范围为50≤Re≤200的双颗粒自由沉降进行了直接数值模拟。首先,研究发现双颗粒最终沉降的位置分别在通道的1/4和3/4位置附近,且与颗粒的初始间距、雷诺数以及通道宽度无关。其次,重点研究了颗粒沉降过程中所受的侧向力(与沉降方向垂直),首次揭示了侧向力的振动频率与雷诺数呈二次关系,且单颗粒的结果始终小于双颗粒的结果;研究还发现侧向力的振动频率与通道宽度近似呈幂律函数关系,且幂律指数与雷诺数有关,雷诺数越大,幂律指数的绝对值越小。最后还研究了雷诺数及通道宽度对侧向力振动振幅的影响。

关键词：颗粒沉降动力学分析格子Boltzmann方法虚拟区域方法

并列双椭圆柱绕流的格子Boltzmann-虚拟区域方法的模拟研究

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计算力学学报 2014年第4期31卷 517-525页

作者：聂德明郑梦娇高原林建忠中国计量学院计量测试工程学院杭州310018

采用格子Boltzmann-虚拟区域方法对并列双椭圆柱绕流进行了模拟研究。首先,通过与并列双圆柱的结果进行对比,验证了数值方法的有效性。其次对雷诺数为200时两种间距(g=0.5a和2.0a,g为柱体表面间距,a为椭圆长轴)的情况进行了研究,考察了... 详细信息

采用格子Boltzmann-虚拟区域方法对并列双椭圆柱绕流进行了模拟研究。首先,通过与并列双圆柱的结果进行对比,验证了数值方法的有效性。其次对雷诺数为200时两种间距(g=0.5a和2.0a,g为柱体表面间距,a为椭圆长轴)的情况进行了研究,考察了椭圆长轴与短轴之比,即α值对柱体升阻力系数及涡结构的影响。研究发现,与圆柱相比,对于g=0.5a椭圆柱的升阻力系数可能出现两种变化,一是升阻力随时间演化较规则,接近周期性;二是流场可能长时间偏向于其中一个椭圆柱,这些变化与α的值有关。对于g=2.0a,两个椭圆柱后的某一区域内会出现四列涡街,经过一段时间,四列涡街又会演化成两列向两侧扩张的涡街。

关键词：椭圆柱格子Boltzmann方法虚拟区域方法绕流

消除毛细管电泳槽道中弯道导致的扩散效应的新方法

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应用数学和力学 2005年第6期26卷 631-636页

作者：李志华林建忠聂德明浙江大学力学系流体传动及控制国家重点实验室

　首先分析了毛细管通道中流动的弯道效应及其产生的原因,接着在建立电渗流场数学模型的基础上,用有限差分法对弯道处内外壁面上不同电荷分布时的扩散进行了数值模拟·　根据计算结果,提出了一种基于改变弯道处内外壁面上电荷分布的新方... 详细信息

　首先分析了毛细管通道中流动的弯道效应及其产生的原因,接着在建立电渗流场数学模型的基础上,用有限差分法对弯道处内外壁面上不同电荷分布时的扩散进行了数值模拟·　根据计算结果,提出了一种基于改变弯道处内外壁面上电荷分布的新方法,以此使流场的弯道效应最弱·　同时还建立了分析和确定弯道处最佳电荷分布的优化方法·　结果表明。

关键词：微流动电泳电渗扩散弯道

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研究生德育应遵循的基本原则

高教论坛 2002年第6期 85-86页

作者：谢嘉梁聂德民浙江大学法学院浙江杭州310028

本文就如何科学、有效的开展研究生德育工作提出了十条基本原则 ,即德育的首位原则、方向性原则、主体性原则、“三全”原则、超越性原则、长期性原则、系统性原则、服务性原则、层次性原则和实践性原则。

关键词：研究生教育德育工作教育原则主体性原则

Microbubble-enhanced ultrasound exposure improves gene transfer in vascular endothelial cells

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World Journal of Gastroenterology 2006年第46期12卷 7508-7513页

作者： Fang nie Hui-Xiong Xu Qing Tang ming-de Lu department of Medical Ultrasonics First Affiliated Hospital Sun Yat-Sen UniversityGuangzhou 510080 Guangdong Province China department of Hepatobiliary Surgery First Affiliated Hospital Sun Yat-Sen University Guangzhou 510080Guangdong Province China

AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein （pEGFP） transfer into human umbilical vein endothelial cells （HUVECs）. METHODS： HUVECs with fluorescein isothiocyanatedextran （FD500） and HUVECs with pEGFP were exposed to continuous wave （1.9 MHz, 80.0 mW/cm^2） for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS： The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone （24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001）. Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue （16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001）. No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue （94.1% ± 2.3% vs 91.1% ± 4.1% ）. CONCLUSION： The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.

关键词： Microbubble Ultrasound Gene transfer Human umbilical vein endothelial cell Enhanced green fluorescent protein

SYNTHESIS AND CHARACTERIZATION OF WATER-SOLUBLE CdSe NANOPARTICLES CAPPED BY AOT

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Chinese Journal of Polymer Science 2013年第9期31卷 1284-1289页

作者： Yan-ming Chen Xiao-bo nie School of Petrochemical Engineering Shenyang University of Technology

Water-soluble CdSe nanoparticles were synthesized using AOT （sodium bis（2-ethylehexyl）-sulfosuccinate） as stabilizer, cadmium acetate and NazSeSO3 as precursors in aqueous phase. The influence of some key factors, such as reaction time, temperature, concentration and molar ratio of precursors on the optical properties of CdSe nanoparticles was systematically investigated through UV-Vis and PL spectra. Powder X-ray diffraction （XRD） was used to characterize the crystalline structure of synthesized CdSe nanoparticles. As-prepared CdSe nanoparticles exhibit an apparent quantum confinement effect and typical hexagonal wurtzite structures. Finally, the optimal experimental conditions were obtained.

关键词： AOT CdSe Nanoparticles Aqueous phase.

design and Dynamics Analysis of Anti-skid Braking System for Aircraft with Four-wheel Bogie Landing Gears

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 277-284页

作者： ZHANG ming nie Hong ZHU Rupeng Key Laboratory of Fundamental Science for National defense-Advanced design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics andAstronautics Nanjing 210016 China

In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are *** are few open literatures related to anti-skid braking system for multi-wheels due to technology *** China,the research on multi-channel control and non-equilibrium regulation has just started,and the design of multi-channel control system for anti-skid braking,the simulation of asymmetry taxiing under braking are not *** this paper,a dynamics model of ground movement for aircraft with four-wheel bogie landing gears is established for braking simulation, considering the six-degree-of-freedom aircraft body and the movement of bogies and wheels.A multi-channel anti-skid braking system is designed for the wheels of the main landing gears with four-wheel *** eight wheels on left and right landing gears are divided into four groups,and each group is controlled via one *** cross protection and self-locked protection modules are added between different channels.A multi-channel anti-skid braking system with slip-ratio control or with slip-velocity control is established *** on the aircraft dynamics model,aircraft braking to stop with anti-skid control on dry runway and on wet runway are *** simulation results demonstrate that in asymmetric conditions,added with cross protection and self-locked protection modules,the slip-ratio-controlled braking system can automatically regulate brake torque to avoid deep slipping and correct aircraft *** proposed research has reference value for improving brake control effect on wet runway.

关键词： anti-skid braking system four-wheel bogie landing gear multi-channel control dynamics model

Optimization design containing dimension and buffer parameters of landing legs for reusable landing vehicle

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Chinese Journal of Aeronautics 2022年第3期35卷 234-249页

作者： Bo LEI ming ZHANG Hanyu LIN Hong nie Key Laboratory of Fundamental Science for National defense-Advanced design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structure Nanjing University of Aeronautics and AstronauticsNanjing 210016China

For the landing legs with single air chamber in the buffer structure of the reusable landing vehicle,the geometric topological models and the dynamic model associated with the hard points of the landing legs are *** geometric constraint relationship in the design of the landing legs is also *** whole vehicle dropping test is conducted,and the test results agree well with that of the simulation model,which validates the dynamic *** on the verified model,the effect of hard point positions on the performance of the landing system is *** multidisciplinary collaborative optimization algorithm and archive-based micro genetic algorithm(CO-AMGA)are used to optimize the design parameters that contain the hard points and the *** with artificial iteration,the maximum landing impact acceleration response of the vehicle and the buffer struct maximum force are reduced by 30.70%and 14.51%respectively,and the maximum length of retractable pillar decreases by 8.54%while the design margin increases by 69.11%.The proposed optimization method is efficient and can greatly facilitate the design of landing legs.

关键词： Dynamics Impact test Landing system Optimization design Reusable landing vehicle