oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 110 )

2018 ( 2055 )

2017 ( 2044 )

2016 ( 2070 )

Custom range...

Search Results: 1 - 10 of 84747 matches for " 田光宇 "
All listed articles are free for downloading (OA Articles)
Page 1 /84747
Display every page Item
电机-变速器直连系统换挡过程建模及仿真
Modeling and simulation of gear shifting in clutchless coupled motor-transmission system

陈红旭,
- , 2016, DOI: 10.16511/j.cnki.qhdxxb.2015.22.022
Abstract: 相比于有离合器的电机-变速器耦合系统, 电机-变速器直连系统的特性发生了变化, 需要对其换挡过程的特性作深入分析, 并与有离合器系统进行比较。该文运用多体动力学和混杂系统理论建立了电机-变速器直连系统换挡过程的混杂自动机模型, 分析了在不同换挡力、接合套和接合齿圈相对角度和相对转速下, 直连系统换挡品质的变化。通过与有离合器系统进行对比发现, 通过电机的主动同步和对换挡力的控制, 直连系统的换挡品质可以优于有离合器系统。
Abstract:Clutchless coupled motor-transmission system characteristics often change, so models are needed to predict their gear shifting characteristics. This study uses multi-body dynamics and hybrid system theories to build a hybrid automaton model of the gear shifting process in the clutchless coupled system. The shifting quality of the clutchless coupled system is then analyzed for various shifting forces and relative rotational positions and speeds of sleeve and the clutch gear. The clutchless coupled system can provide better shifting quality than systems with clutches by actively controlling the motor torque and shifting force.
自蔓延高温合成技术及应用
SHS Technology and Application
 [PDF]

罗传红,, 毛艳, 何乐,
Material Sciences (MS) , 2012, DOI: 10.12677/ms.2012.21002
Abstract: 本文在概述自蔓延高温合成理论研究成果的基础上,结合自蔓延高温合成技术的特点,分析了该技术在新材料的制备、加工方面的技术优势,并介绍了该方法在工业制造各领域与传统技术相结合的应用现状,以及特殊条件下新型自蔓延高温合成技术的发展趋势,为自蔓延高温合成技术的研究与应用提供参考。
The new theoretical research in self-propagating high-temperature synthesis (SHS) is firstly summed up in this paper, and the features and strengths of SHS are analyzed in detail in the preparing and processing of new materials. The application status and technology trends in the industrial manufacturing are outlined and highlighted while SHS is combined with the traditional manufacturing field as well as the special conditions. These researches can provide a pro- fit reference to applying SHS technology.
从生态批评视角解读《五号屠场》
A Study of Slaughterhouse Five from the Perspective of Ecocriticism
 [PDF]


World Literature Studies (WLS) , 2014, DOI: 10.12677/WLS.2014.22006
Abstract:

《五号屠场》出版于1969年,是根据冯内古特自己在德勒斯顿大轰炸时的真实经历而写成的一部半自传体小说。该小说不仅是冯内古特的代表作品之一,同时也是后现代小说中的经典作品,其研究价值可想而知。以往对冯内库特《五号屠场》的研究,多数是着重于小说的主题研究、黑色幽默、后现代特征与文化研究等方面。本文将在生态批评理论的指导下,着重从自然生态、社会生态和精神生态三个方面对小说《五号屠场》进行详细的文本分析,挖掘冯内古特在小说中所想表达的生态意识,并对小说中所出现的生态关系进行一定的探讨,希望能唤起人们的生态意识。
Slaughterhouse-Five is a semi-autobiographical novel based on Kurt Vonnegut’s experience in firebombing of Dresden and was published in 1969. It is recognized as Kurt Vonnegut’s most influential and highest achievement. Meanwhile, it is widely recognized as a classic fiction of the postmodern literature. Most of the studies of Kurt Vonnegut’s Slaughterhouse Five focus on the aspects of theme, black humor, postmodernism and culture. The present thesis, under the guidance of Ecocriticism as the theoretic framework, focuses on Kurt Vonnegut’s classic novel Slaughterhouse Five and tries to explore Kurt Vonnegut’s ecological consciousness from the ecological, social and ideological perspective by the way of the textual analysis.

混合动力电动汽车(HEV)动力系统试验台的模块化设计研究
谢起成,王冬,
交通运输工程学报 , 2001,
Abstract: 试验台是混合动力电动汽车开发的基础设施。介绍了基于模块化设计方法的混合动力电动汽车动力系统试验台设计,重点阐述了试验台数据采集系统和工况模拟控制系统模块化设计的步骤、方案以及模块整合的方法。该设计成功解决了试验台的通用性问题,为当前的混合动力电动汽车开发提供了良好的柔性试验平台。
车用永磁同步电动机电流环偏差解耦控制系统
吴志红,王双全,朱元,
农业机械学报 , 2011,
Abstract: 以永磁同步电动机矢量控制为基础,分析了转子谐波磁通和电动机参数变化对电流控制器性能的影响。并通过复矢量模型,指出高速下耦合电压使得电流控制性能恶化。针对励磁电流分量和转矩电流分量之间的交叉耦合问题,提出了一种偏差解耦控制方法,并与传统的反馈解耦控制进行了仿真和实验对比。结果表明,所提偏差解耦控制方法实现了宽调速范围内的电流解耦控制,具有很好的参数鲁棒性和扰动抑制能力。
纳米石墨片-羧基丁腈橡胶复合材料结构形态与电性能
Structure morphology and electrical performance of graphite nanoplatelets-carboxylated acrylonitrile butadiene rubber composites

张玉宝,,,董伟
- , 2017, DOI: 10.13801/j.cnki.fhclxb.20160907.002
Abstract: 利用电子束辐照法制备纳米石墨片(GnPs)-羧基丁腈橡胶(XNBR)复合材料,研究辐射剂量对胶乳共混体系稳定性的影响,并对GnPs-XNBR复合材料的交联度、热稳定性、电性能及其形貌予以表征。结果表明:辐照后GnPs-XNBR复合材料的交联度、热稳定性和体积电阻率提高,而共混乳液的稳定性显著降低。辐照强化了乳胶粒子与石墨片之间的界面结合,形成胶乳粒子包覆石墨片的核-壳结构,进而提高石墨片在基体中分散均匀性,并使GnPs-XNBR复合材料的热稳定性和介电常数提高,导电性和介电损耗降低。 The graphite nanoplatelets(GnPs)-carboxylated acrylo nitrile butadiene rubber(XNBR) composites were prepared via emulsion blending by the electron beam irradiation. The effects of the irradiation dose on the emulsion stability, crosslinking degree, thermal stability, electrical performance and the morphology of GnPs-XNBR were characterized. The results show that crosslinking degree, the thermal stability and the volume resistance rate of GnPs-XNBR increase after irradiation, while the stability of the emulsion decrease obviously. The interface interaction between the rubber particles and graphite nanoplatelets and the distribution of graphite nanoplatelets in the rubber matrix are enhanced through the core-shell structure formation attributed to the irradiation, which resulte in the increment of thermal stability and dielectric constant, and also the decrement of the conductivity and dielectric loss of the GnPs-XNBR.
机械变速器换档的接合过程建模及特性分析
Modeling and characteristic analysis of engaging process during gear shifting of mechanical transmissions

陈红旭,卢紫旺,王立军,
- , 2018,
Abstract: 接合套和接合齿圈的接合过程是影响机械变速器换档品质的关键阶段。针对在接合过程中,当接合套和接合齿圈在齿端倒角处接触时碰撞发生,其相对速度会发生突变,相应的耦合关系及动力学方程也会发生改变的现象,为了得到机械变速器整个接合过程的精确数学模型和特性,运用多体动力学理论和混杂系统方法建立了描述接合过程的混杂自动机模型。在该模型中,用3个微分方程组描述接合过程中接合套和接合齿圈在不同耦合关系下的动力学特性;引入泊松恢复系数,建立了4个差分方程组描述碰撞过程接合齿圈转速、接合套轴向运动速度和转速产生的突变。基于该混杂自动机模型,在MATLAB环境下进行了仿真分析,得到了接合过程中接合套和接合齿圈的轨迹、接合时间和最大冲击,分析了换档力、接合套相对接合齿圈的初始转速和位置对接合性能(时间和最大冲击)的影响。研究结果表明:接合套和接合齿圈的相对位置对接合时间和冲击有显著影响;当接合套和接合齿圈的转速差在一定范围内时,接合时间较短,过大的转速差则会使接合时间呈指数上升;接合套和接合齿圈的转速差越大,冲击越大;增大换档力可缩短接合时间,但会增大冲击。在设计机械式自动变速器的控制系统时,应根据机械变速器换档过程的特性,选取最佳的换档力、相对转速、相对位置作为控制参数,进而缩短动力中断时间,减小换档冲击。
The engaging process of engaging sleeve and clutch gear is the key phase influencing the gear shifting performance of mechanical transmissions. During an engaging process, collision occurred when engaging sleeve and clutch gear contacted at the end of the tooth chamfer, their relative speed suddenly changed, and their coupling relationship and dynamic equations also changed. In order to obtain an accurate mathematical model and characteristics of the engaging process of mechanical transmission, a hybrid automaton model was built to describe the engaging process through multi-body dynamics theory and hybrid system methodology. In this model, three sets of differential equations were built to describe the dynamic characteristics of engaging sleeve and clutch gear under different coupling relationships during an engaging process. Poisson recovery coefficient was introduced to build four sets of difference equations to describe the rotational speed of clutch gear, the axial movement speed of engaging sleeve and the sudden change of rotational speed during the collision process. Based on the hybrid automaton model, simulation analysis was carried out in the MATLAB environment. The trajectories, the engaging duration and the maximum impact of engaging sleeve and clutch gear during their engaging process were obtained. The effects of the shifting force and the initial rotational speed and position of engaging sleeve relative to clutch gear on engaging performance were analyzed. The results show that the relative position of engaging sleeve and clutch gear has significant effect on the engaging duration and the maximum impact. If the rotational speed difference of engaging sleeve and clutch gear is within limit, the engaging duration is relatively short, and a big rotational speed difference will cause an exponential rise of engaging duration, a bigger rotational speed difference of engaging sleeve and clutch gear will cause a bigger engaging impact. When increasing the shifting force, the engaging duration will
ACA基因启动子的克隆及功能初探
刘召华,郭洪年,,颖川
生物工程学报 , 2005,
Abstract: 根据已知的ACA基因的 5 '端序列设计三个基因特异的反向引物 (GSP-1,GSP-2 ,GSP-3)分别与 11个简并引物 (AD1-AD11)配对 ,进行热不对称嵌套PCR(ThermalasymmetricinterlacedPCR ,TAIL-PCR)扩增 ,获得了ACA基因起始密码子上游约700bp的片段。为检测其表达特性 ,构建了该片段与Gus嵌合基因的表达载体pBpAG ,在真空条件下通过农杆菌介导 ,转化了植物的叶、果实、种子三种不同组织 ,Gus瞬时表达染色结果显示 ,该DNA片段具有种子特异的启动子活性。对该启动子的一些顺式元件进行了讨论。
燃料电池城市客车动力驱动系统的合理匹配研究
陈树勇,陈全世,仇斌,
公路交通科技 , 2008,
Abstract: 为实现国家"十一五"863重大科研项目——燃料电池城市客车专项的燃料电池城市客车动力性能指标,建立了燃料电池城市客车的整车动力系统结构形式,进而完成新样车的概念设计。对实际目标样车动力驱动系统不同部件(包括电机、变速器、燃料电池、蓄电池)性能参数的合理匹配理论和过程进行了详尽的研究。建立了基于电压控制策略的动力驱动系统仿真模型。仿真结果达到目标样车的动力性能指标,同时建立的仿真模型对进一步深入研究整车控制策略的优化具有重要指导意义。匹配理论和仿真模型对其他类型的电动汽车研究具有一定的参考价值。
逆K型管节点应力集中系数研究
,张士华,海庆,蒙占彬
力学与实践 , 2013, DOI: 10.6052/1000-0879-13-199
Abstract: 逆K型管节点广泛应用于海洋平台,其强度是平台结构安全评估的重要课题.基于ANSYS软件,应用分区域网格划分法,建立含焊缝的逆K型管节点有限元模型,分别计算了在轴向载荷、平面内弯矩和平面外弯矩作用下焊缝周围热点应力的分布情况.通过对105组逆K型管节点模型进行分析,获得了其在3种基本载荷作用下沿焊缝的应力集中系数(stressconcentrationfctor,SCF),并对主管和支管的SCF分别进行研究,得出了几何参数对主管和支管的SCF及极值位置的影响规律.
Page 1 /84747
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.