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A novel symmetrical 3-DOF PKM and its performance comparison with 3-PRS PKM

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High Technology Letters 2017年第2期23卷 131-140页

作者：刘宇哲 Wu Jun Wang Liping zhao jingshan Wang Jinsong Yu Guang State Key Laboratory of Tribology and Institute of Manufacturing Engineering Department of Mechanical Engineering Tsinghua University Beijing 100084 P. R. China Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control Beijing 100084 P. R. China

A novel symmetrical 3-degree-of-freedom(DOF) parallel kinematic manipulator(PKM) is firstly presented,which is named 3-P(Qu) *** to the structure feature,a double closed loop vector method is proposed to investigate this *** on this method,kinematic,velocity and error models of this manipulator are established ***3-PRS PKM has been applied successfully in practice and its structure is similar to the 3-P(Qu) RU PKM,corresponding models of a 3-PRS PKM are given and a performance comparison study between them is investigated on workspace,manipulator dexterity,position error and error *** comparison results reveal that the 3-P(Qu) RU PKM has the advantage on velocity performance and the disadvantage on accuracy *** novel 3-P(Qu) RU PKM is an available selection for a tool head of a hybrid machine tool and the analysis is greatly helpful for the further applications of this manipulator.

关键词： comparison study parallel kinematic manipulator(PKM) kinematics velocity error

Microstructure and performance of dissimilar joint QCr0.8/TC4 welded by uncentered electron beam

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Rare Metals 2007年第S1期26卷 344-348页

作者： LIU Wei,ZHANG Binggang,HE jingshan and zhao Haisheng State Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol State Key Lab Adv Welding Prod Technol Harbin 150001 Peoples R China

The mechanical property of dissimilar metal joint between QCr0.8 and TC4 alloy made with centered electron beam is bad and the highest tensile strength of the joint is only about 82.1 *** bad mechanical property is mainly caused by the asymmetric fusion of the two base metals and the generation of the brittle Ti-Cu intermetallic *** finite element analysis shows that the amount of the melted QCr0.8 copper alloy can be added to reduce the amount of the brittle intermetallic *** bias distance to the copper alloy hc has obvious effect on the tensile *** hc=0.8 mm,the tensile strength of the joint can reach 270.5 *** reaction layer near the fusion line on the TC4 side consists of the intermetallic compound and the melted base metal which does not *** joint fractures at the reaction layer and presents quasi-cleavage or transcrystalline rupture in tensile tests.

关键词： QCr0.8 copper alloy TC4 alloy uncentered electron beam welding

Kinematics and K&C Experiment of a Rectilinear Rear Independent Suspension

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Kinematics and K&C Experiment of a Rectilinear Rear Independ...

直线导引型前独立悬架及转向杆系的设计与动力学仿真

2015中国汽车工程学会年会

作者： Xiang Liu Jie Zhang jingshan zhao Xianyong Zhou Tsinghua University Department of Mechanical Engineering Department of Development and Research Wanxiang Group Technical Center

A rectilinear rear independent suspension(RRIS)which has the ability to remain the wheel alignment parameters(WAPs)invariable in theory is presented in this *** kinematic analysis of the RRIS indicates that the WAPs are not sensitive to the hardpoints and the compensation length is much less than the suspension *** order to investigate the actual WAPs,the K&C experiment of the RRIS and twin-trapezoidal link suspension(TTLS)were carned *** comparison results indicate that the RRIS has better WAPs and smaller forces along both lateral and longitudinal directions,which could reduce the tire wear and enhance the handling ability in application.

关键词： rectilinear suspension kinematics wheel alignment parameters K&C experiment

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汽车工程 2010年第7期32卷 611-616页

作者：朱浩贾晓红赵景山清华大学精密仪器与机械学系北京100084

研究了一种理论上能做直线导引运动的新型空间机构,基于这一空间机构和相匹配的转向杆系,建立了汽车前独立悬架系统动力学模型。考虑悬架导向机构的结构参数、转向杆系对车轮运动的影响以及橡胶衬套的变形,通过仿真分析,得出了该新型前... 详细信息

研究了一种理论上能做直线导引运动的新型空间机构,基于这一空间机构和相匹配的转向杆系,建立了汽车前独立悬架系统动力学模型。考虑悬架导向机构的结构参数、转向杆系对车轮运动的影响以及橡胶衬套的变形,通过仿真分析,得出了该新型前独立悬架的主要运动学特性参数的变化规律,验证了理论分析结果。与麦弗逊和双叉臂式前悬架主要运动学特性参数进行对比表明,该新型前独立悬架具有优异的运动学性能,与其匹配的转向杆系能最大限度地减小转向干涉。

关键词：独立悬架空间机构转向杆系运动学动力学仿真

The Effect of Fifth Wheel Location on Handling Stability of Articulated Vehicles

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The Effect of Fifth Wheel Location on Handling Stability of ...

无胶筛分毛细管电泳法检测微量蛋白质骨桥蛋白

2016中国汽车工程学会年会暨展览会

作者： Liu Xiang Chen Wei zhao jingshan Chang Tao Xu Xian Dongfeng Commercial Vehicle Technical Center Department of Mechanical Engineering Tsinghua University

The fifth wheel location has a directly effect on the vehicle performance,including the ride comfort,handling stability and fuel *** paper aims at studying the effect of fifth wheel location on handling stability by combining the theory analysis and simulation.A simplified model to calculate axle loads was established in first and verified by *** analysis results have shown that the axle loads of 1st,4th,5th and 6th are increasing along with the front offset of fifth wheel while the axle loads of 2nd and 3rd are ***,the handling stability is evaluated by considering the on center handling,stable steer,steer returnability and steer *** the results denote that increasing the front offset will improve the handling stability on the whole.

关键词： fifth wheel location axle load handling stability articulated vehicle dynamics

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色谱 2005年第5期23卷 520-523页

作者：赵京山温进坤韩梅河北医科大学基础医学研究所河北省医学生物技术重点实验室河北石家庄050017

采用非涂层毛细管,以150mm o l/L硼酸盐缓冲液为电泳缓冲液,30g/L聚乙二醇(PEG)20000为筛分介质,经对分离条件进行优化,成功地建立了用无胶筛分毛细管电泳检测微量蛋白质的方法。用所建立的方法测定骨桥蛋白,其批内、批间迁移时间的相... 详细信息

采用非涂层毛细管,以150mm o l/L硼酸盐缓冲液为电泳缓冲液,30g/L聚乙二醇(PEG)20000为筛分介质,经对分离条件进行优化,成功地建立了用无胶筛分毛细管电泳检测微量蛋白质的方法。用所建立的方法测定骨桥蛋白,其批内、批间迁移时间的相对标准偏差均小于5%,回收率大于95%,被检测样品中骨桥蛋白的含量与其峰面积呈良好的线性关系(相关系数为0.996),最低检测限为0.079g/L。考察了无血清饥饿培养对血管平滑肌细胞分泌骨桥蛋白的影响,结果表明无血清饥饿培养24h骨桥蛋白的合成与分泌达到高峰,此后随时间延长含量随之降低,此结果与采用W estern b lo t方法检测的结果一致。该方法具有进样量小(nL级)、检测速度快、可自动化等优点,是一种简便、快捷的检测微量蛋白质的好方法。

关键词：毛细管电泳聚乙二醇20000 无胶筛分骨桥蛋白血管平滑肌细胞

在线推扫富集-胶束电动毛细管色谱检测旋覆花素中和大鼠血浆中的旋覆花内酯

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色谱 2006年第5期24卷 508-512页

作者：赵京山温进坤韩梅河北医科大学基础医学研究所河北省医学生物技术重点实验室河北石家庄050017

采用熔融石英毛细管,以含有50mm o l/L十二烷基硫酸钠的50mm o l/L硼酸盐缓冲液为电极缓冲液,以10mm o l/L硼酸盐缓冲液为上样缓冲液,经过对分离条件的优化,成功地建立了胶束电动毛细管色谱结合在线sw eep ing(推扫)富集技术检测中性脂... 详细信息

采用熔融石英毛细管,以含有50mm o l/L十二烷基硫酸钠的50mm o l/L硼酸盐缓冲液为电极缓冲液,以10mm o l/L硼酸盐缓冲液为上样缓冲液,经过对分离条件的优化,成功地建立了胶束电动毛细管色谱结合在线sw eep ing(推扫)富集技术检测中性脂溶性物质旋覆花内酯(acety lb ritann ilac tone,ABL)的实验方法。所建方法的批内、批间测定值的相对标准偏差均小于5%,灵敏度为0.005g/L,回收率大于92%;被检测样品的含量与峰面积呈良好的线性关系,相关系数为0.997 5。用所建立的方法检测了旋覆花素中ABL的含量及其在体内的动态变化,结果表明胶束电动毛细管色谱结合在线sw eep ing样品富集技术可显著提高检测的灵敏度。该方法具有操作简单、进样量小(nL级)、检测速度快等特点,弥补了毛细管电泳在测定痕量组分方面的不足。

关键词：胶束电动毛细管色谱 sweeping在线富集技术旋覆花内酯旋覆花素大鼠血浆

原位聚合制备聚氨酯/氧化石墨烯纳米复合材料的力学性能和热稳定性能研究

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材料研究学报 2014年第12期28卷 901-908页

作者：李国兴赵景珊孙科王强王明西南大学化学化工学院重庆400715 西南大学材料与能源学部重庆400715

采用两步投料法,将氧化石墨烯(GO)与4,4′-二苯基甲烷二异氰酸酯(MDI)充分反应后、再加入聚醚多元醇和三羟甲基丙烷原位聚合制备聚氨酯(PU)/GO纳米复合材料。用广角x衍射、拉伸仪、热失重分析仪和扫描电子显微镜等研究了GO含量对PU/GO... 详细信息

采用两步投料法,将氧化石墨烯(GO)与4,4′-二苯基甲烷二异氰酸酯(MDI)充分反应后、再加入聚醚多元醇和三羟甲基丙烷原位聚合制备聚氨酯(PU)/GO纳米复合材料。用广角x衍射、拉伸仪、热失重分析仪和扫描电子显微镜等研究了GO含量对PU/GO复合材料弹性模量、拉伸强度、断裂伸长率和热稳定性能的影响。研究发现当GO含量为0.2%时,GO在PU基体内分散均匀未出现团聚现象;当GO含量增加时,出现GO团聚体,且随着GO含量增加而增加。GO团聚现象对PU/GO复合材料的力学性能和热稳定性提高具有不利的影响。未出现GO团聚体的PU/0.2%GO复合材料具有最佳力学性能和热稳定性。用连二亚硫酸钠、氢氧化钠水溶液就地还原制备还原PU/GO纳米复合材料(PU/rGO),研究GO还原对复合材料力学性能和热稳定性的影响。结果发现,GO在PU基体内可以实现一定程度的就地还原,还原后复合材料的力学性能有所下降,但热稳定性能有所提高。

关键词：有机高分子材料氧化石墨烯原位聚合聚氨酯力学性能

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车轮摆振影响因素与工程解决方法综述

汽车技术 2017年第1期 20-25页

作者：刘向陈伟赵景山东风商用车有限公司技术中心武汉430056 清华大学北京100081

首先阐述了车轮摆振的现象特征和分类;然后分别从结构组成和系统参数两个方面,对车轮摆振的影响因素和影响规律进行了论述;进一步结合案例对车轮摆振的工程解决方法进行了整理和归纳。对车轮摆振影响因素与工程解决方法进行的系统化和... 详细信息

首先阐述了车轮摆振的现象特征和分类;然后分别从结构组成和系统参数两个方面,对车轮摆振的影响因素和影响规律进行了论述;进一步结合案例对车轮摆振的工程解决方法进行了整理和归纳。对车轮摆振影响因素与工程解决方法进行的系统化和规范化梳理为其理论研究和工程问题解决提供了有价值的参考和指导。

关键词：车轮摆振强迫摆振自激摆振影响因素工程解决方法