内齿行星减速器的结构参数优化

内齿行星减速器是一种新型传动系统。以SHQ4 0型减速器为例 ,对该传动系统中的内齿行星齿板、高速偏心轴、低速输出轴的受力情况进行研究 ,并补充建立各轴之间相互约束应满足的位移协调方程 ,分析得出 ,各轴承承载情况比较恶劣。对减速器的有关结构参数优化后 ,可以明显改善减速器各轴及轴承的承载情况     

聚合物多元醇改善普通聚氨酯软泡压陷的性能研究

为了改善普通聚氨酯软泡的压陷性能，采用添加聚合物多元醇，并对照其添加前后的物性。研究结果表明：聚合物多元醇能有效地提高聚氨酯软泡的压陷性能。     

Misalignment analysis of journal bearing influenced by asymmetric deflection, based on a simple stepped shaft model

The effects of journal misalignment on a journal bearing caused by an asymmetric rotor structure are presented in this study.A new model considering the asymmetric deflection is applied.Also,the thermo-hydrodynamic of the oil film in the journal bearing and straightforward elasticity theory are considered in the analysis.Based on the structure stiffness equivalent characteristic,a simple stepped shaft can reflect the entire complex structure model.The existing lubrication model,which does not consider this angle component,is not very precise for journal bearings.Film pressure,misalignment angle,velocity field,oil leakage,and temperature field were calculated and compared in the journal bearing analysis.The results indicate that bearing performances are greatly affected by misalignment caused by the asymmetric structure.A simple stepped shaft can effectively represent a misaligned journal bearing in a rotor-bearing system.     

Mg6B14笼状团簇的密度泛函理论研究

从第一性原理出发,采用密度泛函理论（DFF）的杂化密度泛函B3LYP方法,在6—31G（d）全电子基组水平上对Mg6B14笼状结构团簇进行了结构优化和频率分析,同时对团簇的能隙、结合能等电子性质进行了分析,用自然键轨道（NaturalBondOrbital,NBO）方法分析了团簇的电荷布局特性和成键性质。结果表明,电荷从Mg原子上转移到B原子上,主要是位于环上的B原子之间成键。B原子主要是sp杂化形成的π键、大π键,Mg原子主要是S轨道参与成键。     

汽车传动轴减振器静动刚度测试分析

论述了在用MTS810材料试验机进行静动态性能测试的原理及方法,并对三种汽车传动轴减振器试件分别进行静刚度、动刚度特性测试。测试结果表明,这种方法简单、有效。试验结果为汽车传动轴减振器的改进提供了参考依据。     

基于Solid Edge齿轮轴参数化设计系统研究

将参数化设计技术应用于齿轮轴的零件设计,通过设计参数来驱动齿轮与轴颈的尺寸,简化齿轮轴模型的设计与修改操作,并提高成组产品的设计效率。该系统基于Solid Edge软件,利用VB进行了二次开发研究,实现了齿轮轴的参数化设计,提高了齿轮轴的设计效率及质量。     

手性离子Co(en)_3~(3+)前线轨道的理论解析

本文用含时密度泛函理论,在B3LYP和6-311G的水平上计算了Co(en)33+的激发态性质,指出了长波区第一个d-d跃迁类型和离子手性间的关系,阐述了轨道解析的重要性。     

Transient Responses of Flexible Non—uniform Spinning Shaft with Nonlinear and Asymmetric Supports

In this paper ,a hybrid approach was developed to investigate the transient responses of a multi-span non-uniform flexble spinning shaft with nonlinear and asymmetric supports.The non-uniform spinning shaft with variable parmeters was modeled as a Bernoulli-Euler beam column with sectional constant cross-section properties by the finite element method.The supporting stiffness behavior of the nonlinear supports was described as a piecewise-linear and asymmetric model.The equations of motion in the matrix form of a multi-span non-uniform spinning shaft with nonlinear and asymmetric supports were formulated using Hamilton‘s principle and the assumed mode method.As an example,a spinning rocket with many variable stiffness supports was numerically simulated by the direct integration method.The transient response and dynamic behavior of this rotate-dynamic system are analyzed.     

防热涂料剪切性能试验影响因素研究

研究结果表明:防热涂料的剪切强度分散性较大,这主要是由于溢胶现象使得搭接长度的准确测量比较困难,同时造成了试件的对中性较差。另外,胶层厚度的不均匀也是造成了数据分散的原因之一。     

储氢合金粉表面电化学修饰镍磷合金的研究

作为镍氢电池负极活性物质,储氢合金是影响电极电化学性能的主要因素,对储氢合金进行表面处理可有效提高镍氢电池电极的电化学性能。实验采用电化学方法对储氢合金表面进行镍磷合金修饰处理,通过扫描电镜(SEM)及EDX能谱对电极表面进行了表征分析,测定了处理前后镍氢电池在1.5C和2C下的大电流放电性能,通过交流阻抗和循环伏安曲线对处理后电极进行了评价。测试结果表明,通过电化学修饰镍磷合金,储氢合金电极的大电流放电性能有所提高,电化学阻抗减小,循环寿命增长,有效提高了镍氢电池的性能。     

PP/MMT复合材料的制备及性能研究

采用甲基丙烯酸甲酯(MMA)与PP接枝共聚物(PP-g-MMA)为界面相容剂,在熔融共混的条件下;利用螺杆挤出机制备PP/MMT复合材料,对其流动性能及力学性能进行了研究.结果表明:PP-g-MMA的加入提高了PP与O-MMT的相客性,当PP-g-MMA用量为20wt%,O-MMT的用量为3wt%时,力学性能最佳:拉伸强度提高了17.46%;常温下冲击强度提高了91.05%;低温(-20℃)条件下的冲击性能比常温下提高了40.29%,比低温下的纯PP提高了246.78%.     

Sedimentation of a single particle between two parallel walls

The sedimentation of a single circular particle between two parallel walls was studied by means of direct numerical simulation (DNS) and experiment. The improved implementation of distributed Lagrange multiplier/fictitious domain method used in our DNS is a promising new way for simulation of particulate flows. The settling behaviors of the particle are presented ranging in Reynolds number from 0 to about 700, which showed that our results for low Reynolds numbers agreed well with that reported before. Nevertheless, for higher Reynolds numbers our results were different from theirs. The long-term mean equilibrium positions in our results were all on the centerline, but not at off-center position as reported before. In order to validate our simulation, experiments were also conducted. The results showed that the sedimenting behavior simulated in this paper agreed well with our experiment result.     

基于20GM定位模块的人字齿轴辊自动堆焊机控制系统

针对原始轴辊堆焊设备定位精度差、加工质量不稳定、堆焊效率低等缺陷,提出利用FX2N-20GM定位模块、FX2N系列PLC和步进电机组合的控制系统方案。实践表明,该控制系统能实现焊枪与轴辊联动控制,保证轴辊获得准确堆焊齿形,大大改善工作环境,提高加工效率。     

CAD/CAE system for the ring planetary reducer with small tooth number difference

A CAD／CAE system of the ring-type planetary reducer with small tooth number difference is presented.It is a parameterized CAD/CAE system adopting the object-oriented technique and comprising in itself the geometric feature database(including the modules of ring-plates with ineer te4eth,eccentric shaft modules and output shaft modules),standard componentdatabase and material database.In cdomparison with design by handwork,this computer aided design and analysis system has the advantages of improved quality,shortened design period and reduced cost.The reliability of the system has been verified by a illustrative example.     

Sedimentation of a single particle between two parallel walls

INTRODUCTIONThecenteringofaparticlewhichsettlesatsmallReynoldsnumbershadbeenstudiedbyseveralresearchers.ChristophersonandDowson(1959)foundthattheoretically,whentheeffectofinertiaisnegligible ,aballachieveseccentricequilibriuninaverticaltubehavingadiameteronlyslightlyexceedingthediameteroftheball.Theyverifiedtheiranalysiswithexperiments.VaseurandCox (1977)didexperimentsonthesedimentationofasmallsphereinaverticalductofarectangularcross section .Theyobservedthatthespherealwaysmigratedtothec…     

浮动环加工夹具的改进设计

浮动轴承中的浮动环是一种薄壁轴套类零件.通过浮动环加工夹具的改进设计,保证了该零件的加工精度要求,不仅提高了该零件的使用性能,而且也相应地提高了浮动轴承的使用寿命.     

论虞集颂盛忠君的馆阁心态

元代著名诗人虞集仕宦生涯的复杂心态在诗歌中有较多流露。一方面,出于对盛世文明的认同,他很多诗歌流露了颂盛忠君的思想;另一方面,在朝屡受排挤和迫害,他也有一些诗歌流露孤独、无奈甚至愤懑的消极情绪。但颂盛忠君一直是他思想的主线,他的归隐之念从未超出过他的仕宦期待,他的仕元立场显然比赵孟頫和袁桷更热忱和积极,他诗歌的情感基调也一直是颂美盛世、感念君恩。把握虞集,离开这条主线所得出的结论都是偏颇和有失公允的。     

基于AutoLisp轴类图样参数化绘图命令的开发

采用Autolisp语言编程对AutoCAD进行二次开发,实现不同轴径、槽宽和槽深的轴剖面图的自动绘制及尺寸标注,提高了轴类零件的绘图效率。     

轨道交通深通风竖井围岩变形应力特征研究

依托重庆轨道交通某通风竖井施工过程,建立竖井开挖支护的过程的三维有限元分析模型,分析竖井开挖支护过程中围岩变形及应力特征.研究结果表明,竖井长边跨中水平位移、地表沉降明显大于短边跨中,围压最大、最小主应力皆在容许范围之内,且为压应力,最大剪应力出现在竖井底部边缘位置,大于围压的抗剪强度,施工过程中应加强支护.受竖井围岩...     

加磁场退火对铁基薄膜巨磁阻抗效应的影响

用射频溅射法制备了(Fe88zr7B5)0.97CU0.03软磁合金薄膜,研究了不同磁场退火方式对(Fe88Zr7B5)0.97 Cu0.03薄膜软磁性能和巨磁阻抗(GMI)效应的影响。结果表明,纵向和横向磁场退火方式都能有效地提高薄膜样品的巨磁阻抗效应,在13 MHz频率下纵向最大GMI比分别为18％和17％;纵向磁场退火能有效消除薄膜样品的磁各向异性,优化薄膜样品的软磁性能;横向磁场退火则能有效感应横向磁各向异性并提高巨磁阻抗效应的磁场响应灵敏度。