Entrance shape design of spread extrusion die for large-scale aluminum panel
作者：
Liu, Zhiwen* ;Li, Luoxing;Yi, Jie;Wang, Guan
期刊：
International Journal of Advanced Manufacturing Technology ,2019年101(5-8):1725-1740 ISSN：0268-3768
通讯作者：
Liu, Zhiwen
作者机构：
[Liu, Zhiwen] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Yi, Jie; Wang, Guan; Liu, Zhiwen; Li, Luoxing] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Liu, Zhiwen] U;[Liu, Zhiwen] H;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
关键词：
Large-scale aluminum panel;Spread extrusion die;Entrance shape;ALE algorithm;Simulation
摘要：
The entrance shape of spread die plays a crucial role in the quality control of large-scale aluminum panel production. The conventional design of spread die is generally based on the experience and expertise of the die designers or costly plant trials. Thus, it is difficult to guarantee the material flow through subsequent feeder die with the same velocity and ensure the die strength. In this work, the extrusion processes of three spread dies with different entrance shapes used generally in the real extrusion production for large-scale aluminum panel were investigated by FE simulations. Firstly, 3D-FE models for simulating the extrusion processes of the three spread dies were established by using HyperXtrude software based on ALE algorithm. Then, the effects of different die designs on the material flow behavior, extrusion load, temperature, residual stress distribution, and die deflection were synthetically studied by analyzing and comparing the simulated results. Finally, the optimal die was manufactured and corresponding extrusion experiment was carried out on a 2600-t extrusion press. The simulation and experimental results show that the die 2 with fan-shaped entrance was the optimum one among the three spread dies, where the minimum required extrusion load, uniform flow velocity at the die exit, minimum residual stress in extruded profile, and minimum die deflection were obtained. This study could provide effective guidance on the entrance shape design of spread extrusion die for the large-scale aluminum panel.
语种：
英文
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基于AMESim液压挖掘机蓄能器回收系统
作者：
刘洋;李岚;卢青松
期刊：
机械研究与应用 ,2018年31(4):26-28+33 ISSN：1007-4414
作者机构：
南华大学 机械工程学院,湖南 衡阳,421001;[卢青松; 刘洋; 李岚] 南华大学
关键词：
能量回收;回转装置;AMESim仿真
摘要：
传统的液压挖掘机的回转装置在工作过程中存在着较大的能量损失,其原因是在工作的过程中整个回转平台有较多的启动和制动。过程中还存在着转动惯量较大,这些都是导致能量损失的原因。针对这一能量损失,通过加入蓄能装置把损失的能量回收再利用。在回转制动过程中蓄能器回收能量,在反转阶段蓄能器释放能量提供能量,并通过AMESim软件进行仿真试验。试验结果表明蓄能器能量回收系统达到了一定的能量回收,节能效果较为显著,能量损失也得到了降低。
语种：
中文
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Simulation Analysis of Porthole Die Extrusion Process and Die Structure Modifications for an Aluminum Profile with High Length-Width Ratio and Small Cavity
作者：
Liu, Zhiwen* ;Li, Luoxing* ;Li, Shikang;Yi, Jie;Wang, Guan
期刊：
Materials ,2018年11(9) ISSN：1996-1944
通讯作者：
Liu, Zhiwen;Li, Luoxing
作者机构：
[Liu, Zhiwen] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Yi, Jie; Wang, Guan; Liu, Zhiwen; Li, Shikang; Li, Luoxing] Hunan Univ, State Key Lab Adv Design & Manufacture Vehicle Bo, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Liu, Zhiwen] U;[Liu, ZW; Li, LX] H;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;Hunan Univ, State Key Lab Adv Design & Manufacture Vehicle Bo, Changsha 410082, Hunan, Peoples R China.
关键词：
ALE formulation;aluminum profile;die structure modifications;porthole die;simulation;small mandrel
摘要：
The design of a porthole die is one of the key technologies for producing aluminum profiles. For an aluminum profile with high length-width ratio and small cavity, it is difficult to control the metal flow through porthole die with the same velocity to ensure the die's strength. In the present study, the porthole die extrusion process of aluminum profile with small cavity was simulated using HyperXtrude 13.0 software based on ALE formulation. The simulation results show for the traditional design scheme, the metal flow velocity in porthole die at every stage was severely not uniform. The standard deviation of the velocity (SDV) at the die exit was 19.63 mm/s. The maximum displacement in the small mandrel was 0.0925 mm. Then, aiming at achieving a uniform flow velocity and enough die strength, three kinds of die structure modifications for the porthole die were proposed. After optimization, desired optimization results with SDV of 0.448 mm/s at the die exit and small mandrel deflection were obtained. Moreover, the temperature uniformity on the cross-section of die exit, welding pressure, and die strength were improved greatly. Finally, the optimal porthole die was verified by the real extrusion experiment. A design method for porthole die for aluminum with a high length-width ratio and small cavity was proposed, including sunken port bridges to rearrange the welding chamber in upper die, increasing the entrance angle of portholes, introducing the baffle plate, and adjusting the bearing length. © 2018 by the authors.
语种：
英文
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Propagation of in-plane wave in viscoelastic monolayer graphene via nonlocal strain gradient theory
作者：
Xiao, Weiwei* ;Li, Li;Wang, Meng
期刊：
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING ,2017年123(6):1-9 ISSN：0947-8396
通讯作者：
Xiao, Weiwei
作者机构：
[Xiao, Weiwei] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Li, Li] Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.;[Wang, Meng] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Xiao, Weiwei] U;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Phase Velocity;Graphene Sheet;Nonlocal Parameter;Strain Gradient Theory;Nonlocal Elasticity Theory
摘要：
The behaviors of monolayer graphene sheet have attracted increasing attention of many scientists and researchers. In this study, the propagation behaviors of in-plane wave in viscoelastic monolayer graphene are investigated. The constitutive equation and governing equation for in-plane wave propagation is developed by employing Hamilton’s principle and nonlocal strain gradient theory. By solving the governing equation of motion, the closed-form dispersion relation between phase velocity and wave number is derived and an asymptotic phase velocity can be acquired. The effects of wave number, material length scale parameter, nonlocal parameter and damping coefficient on in-plane wave propagation behaviors are discussed in the numerical studies. It is found that, when exciting wavelengths or structural dimensions become comparable to the material length scale parameters and nonlocal parameters, the scaling effects on wave propagation behaviors are significant. For nanoscaled graphene sheet, the effects of nonlocal parameter, material length scale parameter and damping coefficient on phase velocity are tiny at low wave numbers while significant at high wave numbers. The phase velocity would increase with the increase of material length scale parameter or the decrease of nonlocal parameter and damping coefficient. Furthermore, results indicate that the asymptotic phase velocity can be increase by increasing material length scale parameter or decreasing nonlocal parameter. © 2017, Springer-Verlag Berlin Heidelberg.
语种：
英文
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二次调节应用在液压升降机中的仿真与分析
作者：
卢青松;李岚
期刊：
科技风 ,2017年(17):171-172 ISSN：1671-7341
作者机构：
南华大学机械工程学院
关键词：
液压升降机;二次调节;仿真;节能
摘要：
液压系统已经涉猎机械的各个行业,对工程机械的发展有着不可磨灭的作用[1]。尤其最近几年,由于工程的需要,液压升降机被广泛使用,但是由于升降机燃油利用率低,油耗高等缺点,使液压升降机的节能要求凸显出来。本文将二次调节技术应用到液压升降机中进行仿真分析,通过与传统的升降机进行仿真对比发现,基于二次调节的液压升降机在流量利用率上有很大的提高,运动状态也很稳点,在能源节约方面有很大的改进,有很好的节能效果。
语种：
中文
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Accurate modal superposition method for harmonic frequency response sensitivity of non-classically damped systems with lower-higher-modal truncation
作者：
Xiao, Weiwei* ;Li, Li;Lei, Sheng
期刊：
Mechanical Systems and Signal Processing ,2017年85:204-217 ISSN：0888-3270
通讯作者：
Xiao, Weiwei
作者机构：
[Xiao, Weiwei] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Li, Li; Lei, Sheng] Huazhong Univ Sci & Technol, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
通讯机构：
[Xiao, Weiwei] U;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Frequency response sensitivity;Frequency shifting;Non-classical damping;Modal superposition method;Modal truncation error;Harmonic response
摘要：
Frequency response and their sensitivities analysis are of fundamental importance. Due to the fact that the mode truncation errors of frequency response functions (FRFs) are introduced for two times, the errors of frequency response sensitivities may be larger than other dynamic analysis. Many modal correction approaches (such as modal acceleration methods, dynamic correction methods, force derivation methods and accurate modal superposition methods) have been presented to eliminate the modal-truncation error. However, these approaches are just suitable to the case of un-damped or classically damped systems. The state-space equation based approaches can extend these approaches to non-classically damped systems, but it may be not only computationally expensive, but also lack physical insight provided by the superposition of the complex modes of the equation of motion with original space. This paper is aimed at dealing with the lower-higher-modal truncation problem of harmonic frequency response sensitivity of non-classically damped systems. Based on the Neumann expansion and the frequency shifting technique, the contribution of the truncated lower and higher modes to the harmonic frequency response sensitivity is explicitly expressed only by the available middle modes and system matrices. An extended hybrid expansion method (EHEM) is then proposed by expressing harmonic frequency response sensitivity as the explicit expression of the middle modes and system matrices. The EHEM maintains original-space without having to involve the state-space equation of motion such that it is efficient in computational effort and storage capacity. Finally, a rail specimen is used to illustrate the effectiveness of the proposed method. (C) 2016 Elsevier Ltd. All rights reserved.
语种：
英文
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CDIO指导下材料成型及控制工程专业人才培养模式探索
作者：
周娟;郭棣彬;张佳;樊湘芳;陈勇;...
期刊：
教育现代化 ,2016年(15):7-8 ISSN：2095-8420
作者机构：
1. 南华大学机械工程学院;2. 南华大学人力资源处
关键词：
材料成型及控制工程;CDIO教育模式;人才培养模式
摘要：
材料成型及控制工程专业是适应中国工业发展而设置的专业,属于是交叉学科,旨在促进工业领域中成型技术的发展。党的十八大召开,对中国人才培养以新的指导思想,即工科专业要着力于培养应用型人才。材料成型及控制工程专业在人才培养上,就要按照这一指导思想而积极针对创新教育以探索。CDIO是培养学生工程能力的教育模式,有助于对学生的终生学习能力以培养,让学生能够在操作中学习,实现了专业教育与技术教育的融合。本论文针对CDIO指导下材料成型及控制工程专业人才培养模式进行探索。
语种：
中文
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基于AMEsim的双排轴向柱塞泵仿真研究
作者：
梁永富;李岚;贾晓沛
期刊：
机械工程师 ,2016年(1):52-54 ISSN：1002-2333
作者机构：
南华大学 机械工程学院,湖南 衡阳,421001;南车南京浦镇车辆有限公司,南京,210031
关键词：
双排轴向柱塞泵;仿真分析;降低噪声
摘要：
在对双排轴向柱塞泵的工作原理及其运动进行理论分析,利用仿真软件AMEsim对其进行建模仿真,设置合理参数,对其进行相应分析,并与单排轴向柱塞泵的动态仿真分析结果进行比较,得到双排轴向柱塞泵能更好地降低流量脉动,有效地降低噪声。
语种：
中文
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合作学习在《焊接结构》课程中的重要性研究
作者：
周娟;郭棣彬;陈勇;李岚
期刊：
教育现代化 ,2016年(05):157-158 ISSN：2095-8420
作者机构：
1. 南华大学机械工程学院;2. 南华大学人力资源处
关键词：
合作学习;焊接结构课程;应用策略
摘要：
《焊接结构》作为焊接专业教学内容的重要组成部分,在培养学生综合、工程等素质方面发挥着不可比拟的作用。随着教育改革的不断深入,焊接专业教师积极转变了教学方式、目标、任务等。其中,合作学习在《焊接结构》教学中得到了充足的应用。本文结合笔者实际教学经验,首先,研究了合作学习应用于高等院校《焊接结构》教学中的重要性,而后浅析了合作学习应用于高等院校《焊接结构》教学中存在的弊端,最后提出了合作学习应用于高等院校《焊接结构》教学中的有效策略,以期对提高我国焊接专业教学工作有所帮助。
语种：
中文
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压力补偿在高空作业车同步动作上的应用
作者：
彭威旺;李岚
期刊：
机床与液压 ,2014年(4):53-54 ISSN：1001-3881
作者机构：
南华大学机械工程学院,湖南衡阳,421000
关键词：
压力补偿;同步系统;AMESim仿真
摘要：
针对高空作业车双缸同步控制精度不高和多执行器同时动作时出现流量不足的现象，采用压力补偿阀使双缸的负载相同，在多执行器同时动作时充当负荷均衡阀使系统对流量具有抗饱和性能。用电液控制阀调节执行器的速度以达到节能的目的。运用AMESim软件进行仿真，为优化压力补偿在系统中的运用提供了理论依据。
语种：
中文
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蓄能器在挖掘机节能驱动系统中的仿真研究
作者：
王欣;李岚;宋友明;梁永富
期刊：
机械工程师 ,2014年(9):95-97 ISSN：1002-2333
作者机构：
南华大学机械工程学院,湖南衡阳,421001
关键词：
液压挖掘机;蓄能器;能量回收;回转系统
摘要：
液压挖掘机在工作过程中频繁的启动和制动造成很大的能量损失,文中将二次调节技术应用到挖掘机回转液压系统中,利用蓄能器进行能量回收,在必要的时候进行释放,可实现转台能量的回收和再利用.通过AMEsim软件进行仿真试验,判别蓄能器在新的液压系统中的设计是否合理、能否达到节能的目的.
语种：
中文
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基于Solidworks和Ansys齿轮泵齿轮轴的有限元分析
作者：
宋友明;李岚;王欣;梁永富
期刊：
机械工程师 ,2014年(8):134-135 ISSN：1002-2333
作者机构：
南华大学机械工程学院,湖南衡阳,421001
关键词：
齿轮泵;齿轮轴;建模
摘要：
通过对CB-B125型外啮合齿轮泵的三维建模,针对齿轮泵中受力复杂的齿轮轴结合ANSYS软件进行有限元分析.分析结果表明在工况条件下,齿轮轴最容易发生破坏的部位是在键槽附近,这为设计人员在设计齿轮泵的过程中提供了理论依据.
语种：
中文
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Influence of High-Frequency Micro-Forging on Microstructure and Properties of 304 Stainless Steel Fabricated by Laser Rapid Prototyping
作者：
Zhang, Yan* ;Qiu, Chang Jun;Chen, Yong;Yu, Jinshui;Zhou, Ju;...
期刊：
steel research international ,2013年84(9):870-877 ISSN：1611-3683
通讯作者：
Zhang, Yan
作者机构：
[Qiu, Chang Jun; Li, Linsheng; Yu, Jinshui; Zhou, Ju; Zhang, Yan] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Chen, Yong] Chongqing Univ, Coll Mat Sci & Engn, Chongqing 400044, Peoples R China.;[Wang, Zhongchang; Chen, Yong] Tohoku Univ, WPI Res Ctr, Adv Inst Mat Res, Aoba Ku, Sendai, Miyagi 9808577, Japan.
通讯机构：
[Zhang, Yan] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
laser rapid prototyping;high-frequency micro-forging;304 stainless steel;mechanical properties
摘要：
We report the fabrication of the 304 stainless steel by the laser rapid prototyping harmonized with high-frequency micro-forging and demonstrate that both microstructure and properties of the prepared samples can be enhanced significantly. Structurally, we find that the large regular dendritic microstructure can be broken into pieces and that the internal defects are to some extent eliminated. Moreover, grains are refined remarkably. As a consequence of such structural modification, mechanical properties are found to be enhanced considerably by demonstrating a much broader fluctuation in tensile strength, a marked increase in tensile and yielding strength, and a drastic enhancement in surface hardness by 76% after the micro-forging. Further calculations reveal that the defect region is shrunken substantially after micro-forging. Detailed analysis of fractures in the tensile samples provides convincing evidence that plastic properties can be improved as well by the micro-forging.
语种：
英文
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Methane steam reforming: Kinetics and modeling over coating catalyst in micro-channel reactor
作者：
Wang, Feng* ;Qi, Bo;Wang, Guoqiang;Li, Longjian
期刊：
International Journal of Hydrogen Energy ,2013年38(14):5693-5704 ISSN：0360-3199
通讯作者：
Wang, Feng
作者机构：
[Wang, Feng] Chongqing Univ, Minist Educ, Key Lab Low Grade Energy Utilizat Technol & Syst, Chongqing 400030, Peoples R China.;[Qi, Bo] Univ South China, Dept Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Wang, Guoqiang; Li, Longjian] Chongqing Univ, Coll Power Engn, Chongqing 400030, Peoples R China.
通讯机构：
[Wang, Feng] C;Chongqing Univ, Minist Educ, Key Lab Low Grade Energy Utilizat Technol & Syst, Chongqing 400030, Peoples R China.
关键词：
Methane steam reforming;Kinetics;Micro-channel;Hydrogen production;Coating catalyst
摘要：
Kinetics of methane steam reforming for hydrogen production has been studied through experiment in a micro-channel reactor over coating catalyst. The catalyst coating prepared by cold spray on stainless steel substrate is based on a mixture of Ni-Al oxides which is normally employed in industry for methane primary steam reforming. Two kinetic laws namely parallel as well as inverse models have been derived at atmospheric pressure, and power law type kinetics have been established using non-linear least squares optimization. With the above kinetics, simulation study has been carried out to find out temperature distribution in the micro-channel over coating catalyst at two different types of boundary conditions. The results show a quite different "cold spot" character and reactants, products distribution character in the reaction channel due to its own distinct heat and mass transfer features. The kinetics and simulation study results can be applied in aid of micro-channel reactor design, and suggestion has been proposed for catalytic coating preparation and optimization. Copyright ©2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
语种：
英文
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基于CAD系统的协同设计探讨
作者：
吴思燕;李岚
期刊：
科技创新与应用 ,2013年(31):276-276 ISSN：2095-2945
作者机构：
[吴思燕; 李岚] 南华大学机械工程学院
关键词：
协同设计
摘要：
近年来,为了能够有效地缩短产品开发周期,降低产品的设计成本,充分地利用异地资源,融入CSCW技术后的异构CAD系统的研究工作正在不断深入。文章对基于异构CAD平台的协同设计的相关问题进行了阐述和探讨。
语种：
中文
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注塑机液压系统绿色设计的策略与展望
作者：
黎坚;李岚
期刊：
机械研究与应用 ,2013年(5):185-187 ISSN：1007-4414
作者机构：
南华大学 机械工程学院,湖南 衡阳,421001
关键词：
注塑机;液压系统;绿色设计
摘要：
注塑机液压系统的绿色设计包括节能、降噪、防漏和防污染等方面，每一个方面有特定的技术手段来实现。详细地介绍了注塑机液压系统的绿色设计及其优缺点，并提出应根据注射成形制品的工艺、关键设备的研发水平采取相适应的节能技术，以提高整机的性价比的建议。
语种：
中文
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挖掘机回转装置能量回收系统中蓄能器的设计计算
作者：
吴辰;李岚;李林升
期刊：
机械工程与自动化 ,2013年(2):62-63 ISSN：1672-6413
作者机构：
南华大学机械工程学院,湖南 衡阳,421001;[李林升; 吴辰; 李岚] 南华大学
关键词：
挖掘机;能量回收;蓄能器;仿真
摘要：
以某型号挖掘机为研究对象,主要研究液压蓄能器对挖掘机回转装置制动能量回收技术.通过对挖掘机回转装置的制动过程进行动力学分析,建立能量平衡方程.利用仿真软件,对液压蓄能器的容积及工作压力进行计算,通过分析比较,实现能量再生系统中液压蓄能器的参数匹配.
语种：
中文
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《机械工程材料》双语教学的探索与实践
作者：
朱红梅;李岚;李必文
期刊：
教育教学论坛 ,2013年(30):239-240 ISSN：1674-9324
作者机构：
南华大学 机械工程学院,湖南 衡阳,421001
关键词：
机械工程材料;双语教学;复合型人才
摘要：
本文针对目前国内高校《机械工程材料》课程双语教学中存在的问题,结合该课程自身的特点,在教材的选择、课件的设计、教学方法与手段及考核方式等方面进行了探索与实践,提出了对该课程有效进行双语教学的一些建议,以期培养出既懂专业又懂外语的复合型人才。
语种：
中文
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开设《工程材料及应用》课程第二课堂的探索
作者：
朱红梅;李必文;李岚
期刊：
教育教学论坛 ,2013年(32):212-213 ISSN：1674-9324
作者机构：
南华大学 机械工程学院,湖南 衡阳,421001
关键词：
工程材料及应用;第二课堂;创新能力
摘要：
本文在分析了《工程材料及应用》课程自身特点及其第一课堂的教学现状基础上,指出了开设该课程第二课堂的必要性,并对第二课堂活动的开展内容和形式进行了一些探索,为提升机械类专业学生的实践创新能力提供参考。
语种：
中文
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湖南省属高校机械专业学生就业状况与就业意愿抽样调查报告
作者：
叶江;邱长军;李岚;樊湘芳;王源蜜
期刊：
湖南科技学院学报 ,2012年33(4):155-157 ISSN：1673-2219
作者机构：
南华大学机械工程学院,湖南衡阳,421001
关键词：
就业状况;就业意愿;抽样调查;机械专业
摘要：
文章通过对06级、07级958名湖南省地方高等学校机械类本科毕业生和08级、09级950名在校大学生的抽样调查，从就业岗位类型等方面描述了湖南省属高等学校机械专业本科毕业生的就业现状与在校大学生的个人职业发展意愿。调查显示：13％的毕业生考上了研究生继续深造，21％从事设计与研发方面的工作，52％从事制造、安装、维护、产品销售等方面的工作，而创业等其它方面的工作占13％。20％的在校大学生准备考研，30％希望从事设计与研发方面的工作，25％准备从事制造、安装、维护、产品销售等方面的工作，而创业等其它方面占到了25％。结果表明：一半以上的毕业生从事工程技能、工程应用性的工作，只有30％在设计或研发岗位，而在校学生偏向设计与研发的比例明显高于现状。
语种：
中文
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