期刊文献+
共找到1,530篇文章
< 1 2 77 >
每页显示 20 50 100
Research trends in methods for controlling macro-micro motion platforms 被引量:6
1
作者 Lufan Zhang Pengqi Zhang +1 位作者 Boshi Jiang Heng Yan 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2023年第3期64-78,共15页
With ongoing economic,scientific,and technological developments,the electronic devices used in daily lives are developing toward precision and miniaturization,and so the demand for high-precision manufacturing machine... With ongoing economic,scientific,and technological developments,the electronic devices used in daily lives are developing toward precision and miniaturization,and so the demand for high-precision manufacturing machinery is expanding.The most important piece of equipment in modern high-precision manufacturing is the macro-micro motion platform(M3P),which offers high speed,precision,and efficiency and has macro-micro motion coupling characteristics due to its mechanical design and composition of its driving components.Therefore,the design of the control system is crucial for the overall precision of the platform;conventional proportional–integral–derivative control cannot meet the system requirements,and so M3Ps are the subject of a growing range of modern control strategies.This paper begins by describing the development history of M3Ps,followed by their platform structure and motion control system components,and then in-depth assessments of the macro,micro,and macro-micro control systems.In addition to examining the advantages and disadvantages of current macro-micro motion control,recent technological breakthroughs are noted.Finally,based on existing problems,future directions for M3P control systems are given,and the present conclusions offer guidelines for future work on M3Ps. 展开更多
关键词 macro-micro motion platform Precision positioning Control method Piezoelectric driver Voice coil motor
在线阅读 下载PDF
Design of a Novel Macro-Micro Integrated Brain Surgery Robot Based on Modular Parallel Mechanisms 被引量:1
2
作者 Hao Zheng Chenbo Liang +4 位作者 Feng Gao Chenkun Qi Bingze He Renqiang Liu Longhai Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第5期349-364,共16页
The advancement and development of medical surgical robots have provided new technological support for brain surgery and neurosurgical procedures,improving the reliability of highly complex and precise surgeries.In tu... The advancement and development of medical surgical robots have provided new technological support for brain surgery and neurosurgical procedures,improving the reliability of highly complex and precise surgeries.In turn,this urges the design and development of novel surgical robots to possess higher precision,stability,and enhanced motion capabilities.In response to this practical demand,this paper introduces a macro-micro integrated medical brain surgery robot system based on the concept of modular PMs(parallel mechanisms),which have a total of 13 active DOFs(degrees of freedom).This system divides the motion process of brain surgery into a large-scale macro-motion space and a small-scale high-precision motion space for design and planning control.The introduction of the design concept that combines multiple modular parallel sub-mechanisms has brought a significant level of decoupling characteristics to the mechanism itself.A comprehensive introduction and analysis of the surgical robot are provided,covering aspects such as design,kinematics,motion planning,and performance indicators.To address the pose allocation and coordination of motion between the macro platform and the micro platform,a pose allocation algorithm based on the decoupling and non-decoupling characteristics in various dimensions of the macro-micro platform is proposed.The designed measurement experiments have demonstrated that the repeatability in positioning accuracy of the macro and micro platform reaches the level of micron and submicron respectively.Practical experiments of motion control and simulated brain electrode implantation validate the excellent performance and stability of the entire surgical robot system.This research contributes innovative insights to the development of medical surgical robot systems,particularly in the domain of mechanism design. 展开更多
关键词 Medical surgical robot macro-micro integrated system Modular parallel mechanism High-precision robot
在线阅读 下载PDF
Power Supply of Macro-Micro Driven Linear Piezoelectric Motor
3
作者 Zhang Tiemin Liao Yiyong +2 位作者 Xu Zhilin Liang Li Cao Fei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2017年第1期22-29,共8页
To investigate a novel macro and micro driven linear piezoelectric motor composed of an ultrasonic motor with macro movement and a piezoelectric actuator with micro movement,a digital signal processing(DSP)based macro... To investigate a novel macro and micro driven linear piezoelectric motor composed of an ultrasonic motor with macro movement and a piezoelectric actuator with micro movement,a digital signal processing(DSP)based macro and micro power supply is designed,which fits the new linear piezoelectric motor.The power supply comprises a control circuit,a voltage conversion circuit,an amplifier circuit,a half-bridge module,an optical isolatorsdrive circuit,etc,where the DSP of TMS320F28335 is used as the controller.When the linear piezoelectric motor working in a macro driven state,the power supply outputs alternating currents with high frequency and high voltage,which drives the linear piezoelectric motor dynamically at an ultrasonic frequency;while working in the micro driven state,the power supply outputs direct currents with high voltage,which drives the linear piezoelectric motor in micro driven statically.Here a prototype of the macro-micro power supply is designed.After a series of experiments on the power supply with and without loads,the results show that the power supply can drive and control the macro micro driven linear piezoelectric motor,and realizes quick and seamless switch between macro and micro drive.In addition,the power supply can drive and control the ultrasonic motor or piezoelectric ceramic micro actuator individually.The power supply achieves the multiple parameters of output signals adjustable simultaneously and exhibits good control characteristics. 展开更多
关键词 LINEAR piezoelectric motor macro-micro drive DSP half-bridge module
在线阅读 下载PDF
Cross-scale Correlation of Macro-micro Evaluation Indexes for Asphalt Binder
4
作者 YU Tengjiang ZHANG Haitao +2 位作者 SUN Xiaowen LI Ming WANG Haomin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第5期892-899,共8页
In order to further study the reliability of macro evaluation indexes,molecular dynamics (MD) was applied to the evaluation of asphalt binder.Micro evaluation indexes (potential energy,surface free energy,solubility p... In order to further study the reliability of macro evaluation indexes,molecular dynamics (MD) was applied to the evaluation of asphalt binder.Micro evaluation indexes (potential energy,surface free energy,solubility parameter and diffusion coefficient) of asphalt binder in different service phases (virgin,modified,aged and rejuvenated) were simulated.Combined with the variation characteristics of asphalt binder macro evaluation indexes (permeability,ductility,viscosity and softening point) in different service phases,the cross-scale correlation of macro-micro evaluation indexes was explored.The results show that the macro and micro evaluation indexes of asphalt binder have different characteristics in different service phases.The essence of the variation in the properties of asphalt binders is the difference in micro composition.In addition,there is a certain correlation between macro and micro evaluation indexes,which can be described by the gray relation theory.The cross-scale correlation of macro-micro evaluation indexes can provide a certain theoretical basis for the development of asphalt binder. 展开更多
关键词 asphalt binder macro-micro indexes cross-scale correlation different service phases molecular dynamics
原文传递
Macro-Micro-Anatomy of the Lingual Artery
5
作者 吴海燕 何光篪 陈尔瑜 《Journal of Medical Colleges of PLA(China)》 CAS 1990年第3期300-305,共6页
The macro-micro-anatomy of the lingual artery of 25 adult cadavers wasstudied.The origin of the artery is rather concentrated and the greater cornu of thehyoid bone can be used as the indicator.The entrance of the art... The macro-micro-anatomy of the lingual artery of 25 adult cadavers wasstudied.The origin of the artery is rather concentrated and the greater cornu of thehyoid bone can be used as the indicator.The entrance of the artery into the hyoglossusmuscle is almost constantly along the posterior border of the muscle,where the artery issuperficially located and easily to be exposed,and has a constant relationship with thevein and hypoglossal nerve.Thus the lingual artery can be used as the artery of a recipientarea in case of tongue reconstruction.The deep lingual artery has two types ofbranches;the short ones mainly supply the muscles of tongue while the long ones mainlysupply the mucosa by forming a submucosal network.In the muscles of tongue,minutearterioles run tortuously along the muscular fibers with abundant anastomoses betweeneach other,but no anastomosis is found to cross over the rnidline of the tongue.Be-neath the mucosa,there is an arterial network spreading all over the whole tongue notlimited to one side.The relationship of the arterial architecture to the structure and thefunctions of the tongue and its clinical significance were discussed. 展开更多
关键词 LINGUAL ARTERY deep LINGUAL ARTERY sublinguat ARTERY ARTERIAL architecture macro-micro-anatomy
暂未订购
Adaptive fixed-time prescribed performance control for macro-micro composite positioning stage with input saturation
6
作者 Guohuai LIN Xun CHEN +3 位作者 Jiecai LONG Yun CHEN Lanyu ZHANG Renquan LU 《Science China(Technological Sciences)》 2026年第1期332-343,共12页
In this paper,the adaptive tracking control problem for macro-micro composite positioning stage(MMCPS)with error constraints and input saturation is considered.The MMCPS has important applications in realizing high-sp... In this paper,the adaptive tracking control problem for macro-micro composite positioning stage(MMCPS)with error constraints and input saturation is considered.The MMCPS has important applications in realizing high-speed macromotion and high-precision micromotion,which can be regarded as a non-strict feedback interconnected nonlinear system.A fixed-time prescribed performance(FTPP)function is proposed to restrict the tracking error and virtual errors.Based on the designed barrier Lyapunov function,the transform errors can also be constrainted in the prescribed constant bounds.Furthermore,an auxiliary system is constructed to compensate adverse effect of the saturation nonlinearity.By integrating the nonlinear filtering technique into the backstepping control framework,the problem of computational complexity explosion can be effectively avoided.For the purpose of achieving better transient performance and improving control precision,an adaptive FTPP tracking control method is presented.According to the Lyapunov stability theory,the proposed control method guarantees that all dynamic errors can converge to the prescribed bounds within fixed time.Finally,a simulation example is given to indicate the effectiveness of the designed controller. 展开更多
关键词 adaptive control fixed-time prescribed performance function input saturation macro-micro composite positioning stage(MMCPS) nonlinear system
原文传递
Iso-scalar liquid drop model fitting experimental binding energies within the macro-micro approach
7
作者 Krzysztof Pomorski Zhigang Xiao 《Chinese Physics C》 2025年第6期187-193,共7页
A new liquid drop model with iso-scalar volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with a number of protons and neutrons larger or equal to twenty. The ground-state m... A new liquid drop model with iso-scalar volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with a number of protons and neutrons larger or equal to twenty. The ground-state microscopic energy corrections are considered. Although the model contains only six adjustable parameters in its macroscopic part, the quality of mass reproduction is high and comparable with other contemporary mass estimates.Additionally, the fission barrier heights of actinide nuclei evaluated using the topographical theorem of Myers and?wia tecki are close to the data. 展开更多
关键词 macro-micro model nuclear masses fission barrier heights scission point properties
原文传递
基于定位误差补偿的亚微米级宏微驱动系统设计与试验
8
作者 杨满芝 刘嘉豪 +3 位作者 张传伟 桂皓晨 李林岳 冯斌 《农业机械学报》 北大核心 2026年第1期404-412,共9页
为解决传统机械系统在大范围运动中高精度定位问题,本文设计了一种精密宏微驱动系统,通过微驱动系统补偿宏驱动系统定位误差,实现亚微米级精密定位。基于柔性铰链杠杆原理和平衡附加力原理,设计了一种微动放大机构,可将输入位移按设计... 为解决传统机械系统在大范围运动中高精度定位问题,本文设计了一种精密宏微驱动系统,通过微驱动系统补偿宏驱动系统定位误差,实现亚微米级精密定位。基于柔性铰链杠杆原理和平衡附加力原理,设计了一种微动放大机构,可将输入位移按设计放大比1.5精密放大且无附加位移。在宏微驱动系统中,伺服电机和滚珠丝杠结合作为宏驱动系统,采用压电陶瓷制动器驱动微动放大机构作为微驱动系统,并用以补偿宏驱动系统的定位误差,实现大行程高精度运动。在完成宏微驱动系统工作原理设计的基础上,分析系统定位误差并提出误差补偿方案,开展宏微驱动系统定位误差补偿试验。试验结果显示:在运动行程2 mm范围内,经过定位误差补偿后,宏微驱动系统的平均定位误差由14.49μm降低至0.34μm,平均定位误差降低97.65%。定位误差补偿试验验证了宏微驱动系统设计及误差补偿方案的有效性与精确性。 展开更多
关键词 宏微驱动系统 定位误差补偿 微动机构 柔性铰链
在线阅读 下载PDF
基于宏微观摩擦接触模型的湿式摩擦元件温度场失效概率分析
9
作者 吴健鹏 丁奥 +3 位作者 马彪 李和言 王立勇 杨成冰 《中国机械工程》 北大核心 2026年第1期40-50,59,共12页
为精确量化湿式摩擦元件的温度场失效概率问题,先建立热-机械耦合仿真与单对粗糙峰接触模型实时交互的宏微观摩擦模型获取温度,再构建温度场失效概率统计模型。利用核密度估计建立失效参数的概率密度函数,采用蒙特卡罗模拟进行了概率计... 为精确量化湿式摩擦元件的温度场失效概率问题,先建立热-机械耦合仿真与单对粗糙峰接触模型实时交互的宏微观摩擦模型获取温度,再构建温度场失效概率统计模型。利用核密度估计建立失效参数的概率密度函数,采用蒙特卡罗模拟进行了概率计算。试验结果表明,仿真与试验的数据高度吻合,所建立的统计模型能有效且精确计算湿式摩擦元件的失效概率。 展开更多
关键词 湿式摩擦副 失效概率分析 宏微观交互 核密度函数 蒙特卡罗模拟
在线阅读 下载PDF
黏土基泡沫聚合土路基材料的保温性能及力学特性
10
作者 赵阳 卢正 +4 位作者 刘杰 张荣 颜廷舟 唐楚轩 李剑 《中国科学院大学学报(中英文)》 北大核心 2026年第1期51-60,共10页
以乌鲁木齐绕城高速沿线的挖方弃土为基础,结合水泥和泡沫,共同研发具有多孔保温特性的泡沫聚合土。系统探讨湿密度、土壤掺量和水料比对泡沫聚合土导热性能、无侧限抗压强度和刚度的影响,建立孔隙结构与宏观性能之间的内在联系。研究... 以乌鲁木齐绕城高速沿线的挖方弃土为基础,结合水泥和泡沫,共同研发具有多孔保温特性的泡沫聚合土。系统探讨湿密度、土壤掺量和水料比对泡沫聚合土导热性能、无侧限抗压强度和刚度的影响,建立孔隙结构与宏观性能之间的内在联系。研究结果表明,当泡沫聚合土的密度从600 kg/m^(3)提升至1200 kg/m^(3)时,其导热系数增长约1倍,强度增强约3.95倍,模量更是增长约10.5倍。相较于传统的路基土,泡沫聚合土的导热系数显著降低52%~96.4%。进一步对孔隙结构进行分析,发现随着单位体积内泡沫聚合土孔径的减小,骨架占比相应增加,气孔体积则有所减少。这种细观结构的变化在宏观性能上表现为保温性能的提升(即导热系数的降低)以及力学性能的显著增强(包括强度和刚度的提升)。泡沫聚合土不仅展现出较好的保温性能,还具备较强的力学特性,为季冻区路基的防寒保温层提供了合适的解决方案。 展开更多
关键词 泡沫聚合土 导热系数 力学性能 宏细观相关性
在线阅读 下载PDF
Design of a control system for a macro-micro dual-drive high acceleration high precision positioning stage for IC packaging 被引量:11
11
作者 LIU YanJie LI Teng SUN LiNing 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第7期1858-1865,共8页
A macro-micro dual-drive positioning system showing good potential for high acceleration and high precision positioning required in IC packaging applications is devised in this paper. The dual-drive positioning stage ... A macro-micro dual-drive positioning system showing good potential for high acceleration and high precision positioning required in IC packaging applications is devised in this paper. The dual-drive positioning stage uses a VCM (voice coil motor) driven macro positioning stage and a PZT piezo-electric driven micro positioning stage. The coupling characteristics of the system are analyzed to produce a control structure with a micro positioning stage that can dynamically compensate for the positioning error produced by the macro positioning stage. Models of the two positioning stages are described. The models cover both the mechanism and the actuator. For the macro positioning stage, friction characteristics are taken into account, and a controller with an LQG (linear-quadratic-Gaussian) control algorithm combining a feed-forward compensation algorithm is derived. A PID controller is used to control the micro positioning stage. Detailed designs are derived for the proposed approach, and the performance is validated by simulation. 展开更多
关键词 macro-micro dual-drive POSITIONING stage control system friction LQG
原文传递
基于临界慢化原理探讨胃“炎-癌转化”中西医防治思路
12
作者 欧阳冀琪 张润顺 +2 位作者 王懿 沈垚村 吕文良 《世界科学技术-中医药现代化》 北大核心 2026年第1期86-96,共11页
本文将临界慢化原理引入胃“炎-癌转化”这一复杂、非线性的动态演化规律,探究可干预关键节点。从宏观和微观层面,探索胃“炎-癌转化”过程中失稳态的早期识别体系构建思路:基于人工智能技术将宏观的中医四诊辨证及内镜检查与微观的血... 本文将临界慢化原理引入胃“炎-癌转化”这一复杂、非线性的动态演化规律,探究可干预关键节点。从宏观和微观层面,探索胃“炎-癌转化”过程中失稳态的早期识别体系构建思路:基于人工智能技术将宏观的中医四诊辨证及内镜检查与微观的血清分子标志物及微生物检测相结合。从中医整体恒动视角,探讨失稳态阶段有效的中医药干预策略:在邪毒入侵的起始阶段,重在减少外界干扰因素;在胃腑气乱之渐进期,重在增强人体自身恢复力;在胃络形变的后期,重在把握病势以释顽疾,以重塑胃的内环境平衡及自我调节功能。本文以期在胃“炎-癌转化”的关键时期阻断或逆转疾病进程,为中西医防治胃癌前病变提供新思路。 展开更多
关键词 临界慢化 炎-癌转化 胃癌前病变 宏微结合 中医防治
暂未订购
同轴集成式宏微复合驱动器的驱动力和微动位移优化研究
13
作者 喻曹丰 王宁 +2 位作者 张奇龙 杨坤 魏益军 《机电工程》 北大核心 2026年第1期149-158,共10页
精密定位与驱动技术是实现高精度加工的关键基础。通过优化同轴集成式宏微复合驱动器的结构,提高其宏微复合驱动器(MMCA)驱动力与微动位移的工作性能,可以实现高速大行程运动与纳米级定位精度的协同输出目的。为了解决同轴集成式宏微复... 精密定位与驱动技术是实现高精度加工的关键基础。通过优化同轴集成式宏微复合驱动器的结构,提高其宏微复合驱动器(MMCA)驱动力与微动位移的工作性能,可以实现高速大行程运动与纳米级定位精度的协同输出目的。为了解决同轴集成式宏微复合驱动器(MMCA)工作性能低下的问题,对MMCA的永磁体和微动线圈结构进行了优化研究。首先,以MMCA的驱动力为目标函数,以提高宏动线圈上产生的磁通密度模和波动幅度为评判标准,优化了永磁体结构;然后,提出了六段变半径的微动线圈的设计方法,以超磁致伸缩材料(GMM)的伸长量为目标函数,以微动线圈在GMM棒上产生的磁通密度模为评价指标,优化了微动线圈各段的最佳半径;最后,基于仿真优化参数搭建了实验平台,对MMCA驱动力与微动位移的性能提升进行了验证。研究结果表明:将永磁体梯度优化为1.5 mm、弧度半径为1350 mm,在6 A宏动线圈电流下实现了191.2 N的优化驱动力目标,驱动力性能提高了36.6%;同时,采用六段变半径分别为15 mm、13 mm、10 mm、9 mm、9 mm、10 mm的微动线圈设计,将微动位移从57.5μm提升至74.4μm,微动位移性能提高了29.4%。宏微驱动性能的显著提升,表明了该优化方法的有效性,可以为宏微复合驱动器设计优化提供一种方案。 展开更多
关键词 超精密加工 超精密定位与驱动技术 磁通密度模 宏微复合驱动器 微动线圈 宏动结构和微动结构 超磁致伸缩材料
在线阅读 下载PDF
Task Space Division and Trajectory Planning for a Flexible Macro-Micro Manipulator System 被引量:1
14
作者 罗凌智 张宇 孙增圻 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第5期607-613,共7页
This paper deals with a flexible macro-micro manipulator system, which includes a long flexible manipulator and a relatively short rigid manipulator attached to the tip of the macro manipulator. A flexible macro manip... This paper deals with a flexible macro-micro manipulator system, which includes a long flexible manipulator and a relatively short rigid manipulator attached to the tip of the macro manipulator. A flexible macro manipulator possesses the advantages of wide operating range, high speed, and low energy consumption, but the disadvantage of a low tracking precision. The macro-micro manipulator system improves tracking performance by compensating for the endpoint tracking error while maintaining the advantages of the flexible macro manipulator. A trajectory planning scheme was built utilizing the task space division method. The division point is chosen to optimize the error compensation and energy consumption for the whole system. Then movements of the macro-micro manipulator can be determined using separate inverse kinematic models. Simulation results for a planar 4-DOF macro-micro manipulator system are presented to show the effectiveness of the control system. 展开更多
关键词 macro-micro manipulator trajectory planning trajectory tracking control task space division flexible manipulator
原文传递
The study on systemic risk of rural finance based on macro-micro big data and machine learning 被引量:1
15
作者 Wanling Zhou Sulin Pang Zhiliang He 《Statistical Theory and Related Fields》 CSCD 2023年第4期261-275,共15页
It’s the basic premise of promoting the healthy development of rural finance and strengthen-ing macro-prudential supervision to measure the systemic risk of rural finance accurately.We establish the dynamic factor CA... It’s the basic premise of promoting the healthy development of rural finance and strengthen-ing macro-prudential supervision to measure the systemic risk of rural finance accurately.We establish the dynamic factor CAPM and make an all-round and multi-angle quantitative study on the systemic risk of rural finance in China by constructing macro-micro index system and using machine learning to reduce the dimension of high-dimensional data.Our results show that the dynamic factor CAPM of using macro-micro big data can evaluate systemic risk of rural finance more comprehensively and systematically,and machine learning performs well in processing high-dimensional data.In addition,China’s rural financial systemic risk is stable compared with the Shanghai and Shenzhen main markets,but it is also susceptible to macro and micro influ-enced factors.Finally,it is pointed out that the early warning system of rural financial systemic risk could be constructed at macro and micro level,respectively. 展开更多
关键词 macro-micro big data machine learning systemic risk dynamic CAPM
原文传递
非线性载荷作用下岩石高效破碎的研究进展
16
作者 赵环帅 潘永泰 +3 位作者 曹行健 赵英嘉 余超 乔鑫 《北京大学学报(自然科学版)》 北大核心 2026年第1期198-208,共11页
结合国内外发展现状,分析开展岩石高效破碎理论与技术研究的必要性,介绍非线性载荷在岩石破碎中的主要优势,从非线性压缩加载(单轴压缩、巴西劈裂和点载荷)、冲击加载(应力波、机械冲击和高压电脉冲)和振动加载3个方面,系统分析非线性... 结合国内外发展现状,分析开展岩石高效破碎理论与技术研究的必要性,介绍非线性载荷在岩石破碎中的主要优势,从非线性压缩加载(单轴压缩、巴西劈裂和点载荷)、冲击加载(应力波、机械冲击和高压电脉冲)和振动加载3个方面,系统分析非线性载荷下岩石破碎方面的研究进展,阐述不同加载方式下破岩的优缺点。针对目前非线性载荷下岩石破碎研究中存在的问题,提出岩石力学模型构建、宏-细-微观多尺度探索、加载方式复合、能量测试与计算以及智能技术应用等未来的重点研究方向。 展开更多
关键词 岩石破碎 非线性载荷 力学模型 宏-细-微观多尺度 加载方式复合 能量计算 智能技术
在线阅读 下载PDF
宏微运动平台导轨架模态分析及优化设计
17
作者 张璐凡 姜薄士 +1 位作者 张鹏启 张相锋 《机械设计与制造》 北大核心 2026年第2期97-100,106,共5页
导轨架作为超高加速度宏微运动平台的关键机构,导轨架的共振会严重影响平台的定位精度。这里通过SolidWorks和ANSYS Workbench联合仿真,对导轨架进行研究分析,首先在SolidWorks中建立模型并使模型参数化,导入到ANSYS Workbench中进行模... 导轨架作为超高加速度宏微运动平台的关键机构,导轨架的共振会严重影响平台的定位精度。这里通过SolidWorks和ANSYS Workbench联合仿真,对导轨架进行研究分析,首先在SolidWorks中建立模型并使模型参数化,导入到ANSYS Workbench中进行模态分析,获得导轨架的前六阶固有频率和振型,然后利用ANSYS Workbench的DM模块,设计质量最轻和一阶固有频率最大的优化目标,对模型进行直接优化和响应面优化。最后,将得到的优化方案进行对比分析,结果表明,导轨架一阶固有频率增加了4.0%,质量减少了4.55%。通过对导轨架进行优化设计,达到了指定优化目标,研究结果对宏微运动平台超精密定位实现具有重要意义。 展开更多
关键词 宏微运动平台 导轨架 模态分析 优化设计
在线阅读 下载PDF
基于Romax的双齿轮消隙机构优化设计
18
作者 孙艺勐 万林林 +1 位作者 陈泽郡 高明铭 《机械工程师》 2026年第2期14-19,22,共7页
为了在保证传动精度的前提下减小消隙预紧力对传动系统产生的影响,以企业需求所设计的双齿轮消隙机构为优化对象,在施加消隙预紧力的工况下通过Romax软件对机构的齿轮进行了优化设计。以端面重合度、弯曲应力、接触应力、齿顶高修正系... 为了在保证传动精度的前提下减小消隙预紧力对传动系统产生的影响,以企业需求所设计的双齿轮消隙机构为优化对象,在施加消隙预紧力的工况下通过Romax软件对机构的齿轮进行了优化设计。以端面重合度、弯曲应力、接触应力、齿顶高修正系数、安全系数和使用寿命为优化目的,改变直齿轮的模数和压力角及斜齿轮的模数、压力角和螺旋角进行优化;以传递误差、单位长度载荷与接触斑点为优化目的,对斜齿轮进行了齿轮齿向鼓形和斜度修形,渐开线鼓形和斜度修形,优化后的齿轮更符合双齿轮消隙机构的设计需求。 展开更多
关键词 双齿轮消隙 Romax软件 优化设计 宏观参数优化 微观齿廓修形
在线阅读 下载PDF
短期氧污染对二氧化碳管道内壁顶部腐蚀的影响研究
19
作者 侯禹岑 梁沛楠 +3 位作者 冯兆缘 齐亮 徐云泽 王明昱 《装备环境工程》 2026年第1期97-105,共9页
目的 针对管道内壁顶部腐蚀问题,系统探究CO_(2)与O_(2)交互作用下冷凝液滴环境中碳钢腐蚀的动态演变过程。方法 采用丝束电极(WBE)技术持续监测表面宏电池电流的动态演变,同时借助电化学阻抗谱(EIS)解析典型位置的局部微电池腐蚀差异... 目的 针对管道内壁顶部腐蚀问题,系统探究CO_(2)与O_(2)交互作用下冷凝液滴环境中碳钢腐蚀的动态演变过程。方法 采用丝束电极(WBE)技术持续监测表面宏电池电流的动态演变,同时借助电化学阻抗谱(EIS)解析典型位置的局部微电池腐蚀差异。结果 当环境由CO_(2)转为O_(2)时,WBE表面宏电池电流急剧升高,阴阳极分布重构,局部阳极电流显著集中。EIS分析进一步揭示,微电池腐蚀行为受腐蚀产物膜特性与氧扩散过程协同调控。结论 短期氧污染会显著加剧二氧化碳管道内壁顶部的宏电池电流腐蚀过程,增加液滴边缘局部未成膜区域的点蚀风险。 展开更多
关键词 顶部腐蚀 氧污染 二氧化碳腐蚀 丝束电极 局部腐蚀 宏电池电流 微电池电流
在线阅读 下载PDF
用于肺部给药的微纳米递送系统研究进展
20
作者 田芝玉 邓晓栖 +1 位作者 乌兰 杨明世 《沈阳药科大学学报》 2026年第1期1-14,共14页
肺部给药作为一种快速、有效、非侵入性且可兼顾肺局部疾病和全身性疾病的给药方式,近年来备受关注。由于肺泡部血管密集,比表面积较大且肺泡细胞较薄,经肺部途径递送至肺泡部的药物可被迅速吸收入血,进入全身循环,避免肝脏首过效应,进... 肺部给药作为一种快速、有效、非侵入性且可兼顾肺局部疾病和全身性疾病的给药方式,近年来备受关注。由于肺泡部血管密集,比表面积较大且肺泡细胞较薄,经肺部途径递送至肺泡部的药物可被迅速吸收入血,进入全身循环,避免肝脏首过效应,进而提高药物的生物利用度。此外,肺部给药更是肺局部疾病治疗的理想途径。其首要优势为可以使药物直接到达病变部位,提高肺局部药物浓度,减少全身药物暴露,与系统性给药相比,能够实现以更低的给药剂量达到同等或更佳的治疗效果。然而肺部复杂的生理结构,对药物递送系统提出了严苛的要求。在肺部药物递送系统的研发过程中,小分子化学药物与蛋白质、多肽、mRNA及siRNA类等大分子药物的递送研究均取得较大进展。肺部给药有望在未来医学领域中实现更高效、安全的药物递送及疾病干预,发挥更为关键的作用。本文将对肺部的解剖结构、肺部递送的屏障以及用于肺部递送的微纳米递送系统进行综述。 展开更多
关键词 肺部递送 吸入制剂 微纳米递送系统 小分子药物 大分子药物
原文传递
上一页 1 2 77 下一页 到第
使用帮助 返回顶部