酯类油对PAO基础油黏温性能的影响

为提高PAO(聚α-烯烃)对极性添加剂的感受性,改善PAO对橡胶密封件的相容性,通常在PAO基础油中加入少量的酯类油。研究PAO 2c与少量酯类油(邻苯二甲酸二丁酯(DBP)和癸二酸二异辛酯(DIOS))的混合油样的高低温黏度变化规律。结果表明,高温条件下,PAO 2c与酯类混合油样稳定,没有出现相分离;低温条件下,DBP与PAO 2c混合油样出现分层现象,为确保混合基础油的低温性能,邻苯二甲酸二丁酯的质量分数宜分别控制在20%以内。这对调制低温性能优良、橡胶相容性好的润滑油有指导意义。     

某型国产与进口航空发动机润滑油泡沫特性对比研究

针对某型国产航空润滑油代替进口航空发动机润滑油50-1-4Ф后,存在的滑油系统压力下降明显并存在明显波动的问题,采用滚子轴承模拟试验装置对该型国产与进口航空发动机润滑油的高温抗泡性能进行对比研究,同时考察2种润滑油基础油聚α-烯烃(PAO)与癸二酸二异辛酯(DOS)之间高温抗泡性能的差异。结果表明:同一氧化温度下国产航空润滑油及其基础油PAO高温抗泡性能明显差于进口50-1-4Φ航空润滑油及其基础油DOS;不同氧化温度下2种成品油与其基础油的抗泡性能变化趋势基本一致,表明润滑油的抗泡性能主要取决于其润滑基础油。因此国产航空润滑油存在的油压不稳的问题,极有可能是其采用的非极性基础油聚α-烯烃(PAO)抗泡性能明显差于进口油品使用的是极性基础油DOS导致的。     

PAO油和硅油调和基础油的特殊黏度变化规律

通过测定不同黏度的聚α-烯烃(PAOs)、硅油及其不同调和比例混合基础油在-50~50℃时的运动黏度,研究调和基础油的黏度随调和组分和温度的变化规律。结果表明,调和基础油的实测黏度远小于按国际通用黏度模型计算得到的黏度值;黏度相差较大的PAO油与硅油调和时,调和基础油的高低温运动黏度均在两调和组分的黏度之间变化;而黏度接近的PAO油与硅油调和时,在一定成分范围内,调和基础油的低温运动黏度低于两调和组分的黏度,其低温流动性更加优异。特定的PAO油与硅油能够相互用作低温降黏剂进一步改善润滑油的低温性能。通过引入分子间相互作用对这一现象进行了解释。     

两种合成航空润滑基础油高温氧化衰变机理研究

为研究航空润滑油的热氧化安定性,模拟聚α-烯烃(PAO)和酯类油(DE)两种合成航空润滑基础油在发动机内的高温工况,借助傅里叶红外光谱(FTIR)、气相色谱/质谱(GC/MS)联用等仪器对反应油样的黏度和结构组成进行测试与分析.结果表明,PAO具有较差的热氧化安定性能,在200℃时就发生分解,而DE的分解温度可达到300℃.在两种航空润滑基础油的高温衰变中,均有不同的产物生成.PAO衰变产物主要包括烷烃和烯烃,而DE的衰变产物主要是含氧化合物.最后,根据实验结果分析了航空润滑基础油的高温衰变机理.     

两种合成航空润滑基础油高温氧化衰变机理研究（英文）

为研究航空润滑油的热氧化安定性,模拟聚α-烯烃(PAO)和酯类油(DE)两种合成航空润滑基础油在发动机内的高温工况,借助傅里叶红外光谱(FTIR)、气相色谱/质谱(GC/MS)联用等仪器对反应油样的黏度和结构组成进行测试与分析。结果表明,PAO具有较差的热氧化安定性能,在200℃时就发生分解,而DE的分解温度可达到300℃。在两种航空润滑基础油的高温衰变中,均有不同的产物生成。PAO衰变产物主要包括烷烃和烯烃,而DE的衰变产物主要是含氧化合物。最后,根据实验结果分析了航空润滑基础油的高温衰变机理。     

润滑油橡胶相容性的研究

润滑油与橡胶密封材料相容性差而导致的泄漏问题越来越得到大家的重视,越来越多的润滑油产品对橡胶相容性提出了要求.利用CEC-L-39-96方法研究常用基础油、黏度指数改进剂、清净剂、分散剂、抗氧剂等对润滑油相容性的影响.研究结果表明:基础油类型对橡胶相容性影响很大,酯类油使丙烯酸酯橡胶溶解,1203使硅橡胶变质;黏度指数改进剂对各种橡胶影响很小;部分单剂对橡胶相容性有正面作用.     

硅油与酯类油混合基础油黏温性能的研究

研究3种硅油与癸二酸二异辛酯混合基础油的黏温性能,发现在一定比例范围内硅油与酯类油的混合基础油,其低温运动黏度比硅油与酯类油的低温运动黏度都要小.因此,硅油与酯类油能够相互作为低温降黏剂使用.这对调制低温性能优异的润滑油具有指导作用.     

PDSC法研究煤转化基础油的氧化安定性

用加压差示扫描量热法(PDSC)研究了煤转化的基础油(CTL)和Ⅲ类油以及Ⅳ类油(PAO)的氧化安定性,并考察了3种基础油对抗氧剂的感受性.结果表明CTL基础油的氧化安定性和Ⅲ类油接近,但是比Ⅳ类差.3种基础油对胺类抗氧剂(AO)的感受性相近,但Ⅳ类油的感受性最好.由煤转化而成的CTL基础油有可能成为Ⅲ类基础油的替代品.     

某型航空发动机润滑油性能结构热衰变机制研究

某型航空润滑油主要由基础油聚α-烯烃（PAO）和抗氧剂N-苯基-α-萘胺（T531）组成。借助高温高压反应釜模拟航空发动机温度,研究不同温度下抗氧剂T531对PAO理化性能的影响,并利用气相色谱/质谱联用（GC/MS）技术从分子水平上分析反应产物的结构组分变化,探究PAO和T531的高温衰变机制。结果表明,高温促使PAO基础油发生分子链断裂反应并产生了含氧化合物,致使PAO黏度降低和酸值升高;在一定温度范围内T531较好地延缓了PAO分子链的断裂;T531长时间在高温环境中也会发生衰变,产生大量链状酮类化合物,加深了润滑油颜色。     

氧化石墨烯添加剂对基础油成膜特性的影响

为了探究氧化石墨烯(GO)添加剂在不同润滑状态下对基础油成膜特性的影响,利用原子力显微镜(AFM)和傅里叶变换红外光谱仪(FTIR)分别对GO的厚度、层数和表面官能团进行表征,选用聚α-烯烃(PAO10)和聚醚(PAG)为基础油,利用球-盘点接触光干涉油膜厚度测量试验台,研究GO添加剂在弹流润滑和混合润滑状态下对不同基础油润滑成膜性能的影响。结果表明：在全膜润滑状态下,GO对PAO10和PAG基础油的成膜能力影响很小,添加GO前后基础油的最小膜厚相差并不大;在混合润滑状态下,GO可有效地提高PAO10基础油的最小膜厚,减缓接触区内的乏油状况,而对PAG基础油成膜性能的影响很小。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.