纳米蛇纹石粉末与柴油机油抗磨减摩剂协同润滑性能研究*

为提升高强化柴油机润滑油的润滑性能,将纳米蛇纹石粉末与极压抗磨剂ZDDP和有机钼减摩剂MoDTC相互复配,采用环块式摩擦试验机研究不同添加剂之间的协同润滑性能,分析摩擦因数、磨损量以及摩擦产物组成等受添加剂组成的影响规律。结果表明:蛇纹石粉末与MoDTC和ZDDP复配能够降低润滑油的摩擦因数与磨损量,并减少摩擦表面划痕;蛇纹石粉末在摩擦副表面形成摩擦自修复涂层,提高摩擦表面硬度和抗磨性能;蛇纹石粉末与MoDTC和ZDDP复配时,蛇纹石粉末促进了MoS_2在摩擦表面的生成,进一步降低了摩擦因数,表明蛇纹石粉末与MoDTC和ZDDP起到协同减摩的作用。     

非硫磷有机钼添加剂的制备及其摩擦学研究

采用二羟乙基十八胺与钼酸铵作为原材料,合成一种新型非硫磷有机钼添加剂N-十八烷基亚胺二乙醇钼酸二酯(HOAM),并利用红外光谱仪(IR)及电感耦合等离子光谱发生仪(ICP)和元素分析(EA)对其进行结构表征,通过热重分析(TGA)研究其热稳定性。以锂基脂为基础脂,应用四球摩擦磨损试验机考察HOAM与市售的Molyvan 855添加剂在锂基脂中的抗磨减摩性能及极压承载能力;应用扫描电子显微镜(SEM)和X射线近边结构吸收光谱(XANES)分析其磨斑形貌及摩擦膜的钼元素的化学组成。试验结果表明：HOAM具有较好的热稳定性,减摩性能和极压性能良好,其作为添加剂添加在锂基脂中可使钢球磨斑直径减小、磨斑形状变规则、犁沟变浅;非硫磷有机钼添加剂HOAM在摩擦过程中在摩擦副表面发生化学反应,生成了含MoO-42的润滑膜,相比Molyvan 855具有更好的抗磨减摩性能。     

润滑油添加剂—有机钼化合物的摩擦磨损性能研究

本文在四球摩擦损试验机上测试了作者合成的一种油溶性有机钼化合物添加剂的摩擦磨损性能。研究了添加剂浓度、时间等对该添加剂作用效果的影响。对其抗极压和时效特性进行了研究。结果表明：该有机钼添加剂是一种具有优良的减摩，抗磨、抗极压性能的油溶性添加剂。特别是对放置一年后的油样测试结果表明该添加抗氧化稳定性也较好，具有推广应用的价值。     

非硫磷有机钼添加剂的制备及其摩擦学性能研究

采用二羟乙基十八胺与钼酸铵作为原材料,合成一种新型非硫磷有机钼添加剂N-十八烷基亚胺二乙醇钼酸二酯(HOAM),并利用红外光谱仪(IR)及电感耦合等离子光谱发生仪(ICP)和元素分析(EA)对其进行结构表征,通过热重分析(TGA)研究其热稳定性。以锂基脂为基础脂,应用四球摩擦磨损试验机考察HOAM与市售的Molyvan 855添加剂在锂基脂中的抗磨减摩性能及极压承载能力;应用扫描电子显微镜(SEM)和X射线近边结构吸收光谱(XANES)分析其磨斑形貌及摩擦膜的钼元素的化学组成。试验结果表明:HOAM具有较好的热稳定性,减摩性能和极压性能良好,其作为添加剂添加在锂基脂中可使钢球磨斑直径减小、磨斑形状变规则、犁沟变浅;非硫磷有机钼添加剂HOAM在摩擦过程中在摩擦副表面发生化学反应,生成了含Mo O-42的润滑膜,相比Molyvan 855具有更好的抗磨减摩性能。     

动车组齿轮箱油中含硫添加剂损失的试验研究

针对高铁动车组牵引系统中齿轮箱润滑油中硫元素损失较快的问题,通过极压作用下含硫添加剂损失试验和高温状态下含硫添加剂损失试验,得到不同负载和温度作用下润滑油添加剂的作用情况,分析润滑油添添加剂的损失原因。结果表明:齿轮油中的含硫极压剂主要成分为多硫化物,且以二硫化物和三硫化物为主,随着压力的增大,多硫化物会附着在摩擦副表面形成滑动层从而降低摩擦因数,多硫化物形成的滑动层比较稳定,不容易损耗;润滑油使用过程中,极压剂中硫被消耗,一部分附着在齿轮表面,一部分生成气体排出,当齿轮箱内温度升高到90℃以上时,硫的消耗会更快。     

全合成切削液的制备及极压剂与防锈剂的协同效应研究

制备一种水基全合成切削液,考察新型有机钼、有机硼极压剂与三乙醇胺硼酸酯防锈剂的协同作用。利用四球摩擦磨损试验机研究切削液的摩擦学性能;采用一级灰口铸铁进行单片、叠片防锈试验,考察全合成切削液的防锈性能;用激光共聚焦显微镜观察试件表面形貌并测量工件的表面粗糙度,研究极压剂对工件表面质量的影响。结果表明:2种极压剂有协同增效的作用,使用复合极压剂后,极压润滑系数(最大无卡咬载荷与摩擦因数的比值)增大,改善加工工件的表面质量;有机硼极压剂和三乙醇胺硼酸酯防锈剂共同作用可增强切削液的防锈作用;当切削液中添加复合极压剂与防锈剂时,与含有单一添加剂的切削液相比,其极压性能与防锈性能均有提高,表明防锈剂和极压剂在切削液中具有协同作用。     

水溶性噻二唑衍生物的合成及其摩擦学性能研究

合成一种新型水溶性噻二唑衍生物,采用红外光谱仪对其结构进行表征,采用SRV摩擦磨损试验机考察其在三乙醇胺水溶液中的摩擦学性能,采用表面轮廓仪及扫描电子显微镜观察磨斑表面形貌。SRV摩擦实验结果表明,该添加剂能显著改善三乙醇胺基础液的抗磨减摩性能,并能有效避免疲劳磨损;XPS结果显示,添加剂通过与摩擦副表面的摩擦反应生成FeS及Fe2O3等反应膜,起到极压抗磨的效果;同时该添加剂还具有很好的抑制铜片腐蚀的性能,是一种环境友好的多功能润滑添加剂。     

摩擦化学膜的成因与结构:矿物质化学和有机质化学观点

减摩剂、抗磨剂、极压剂与修复剂共同构成在摩擦学意义上更完善的摩擦学添加剂系列。摩擦化学膜是摩擦学添加剂在摩擦表面热／应力场中参与生成的无机物种和有机物种的共生体，无机物种构成润滑膜骨架，有机物种或简单无机质点以吸附状态或以间隙化合物形式依附于或弥散于骨架构造中，共同提供摩擦化学膜的全部润滑功效——减摩、抗磨、极压效应和修复功能。应用矿物质化学和有机质化学观点诠释摩擦化学膜的成因与结构特性，特别是基于应力化学原理比较分析岩石物理和地球化学过程中的成岩和生油现象与摩擦化学过程中的润滑效应，提出摩擦成岩与生油化学研究，摩擦化学场中的成岩和生油效应及其摩擦学意义，以及开发基于自然物质和过程的工业摩擦学应用技术。     

新型含氮磷酸酯添加剂的合成及摩擦学性能研究

以脂肪酸甲酯为原料合成一种新型含氮磷酸酯添加剂,通过红外对其结构进行表征,采用四球摩擦试验机考察其在不同基础油中的摩擦学性能,并用扫描电子显微镜和能谱仪观察分析磨痕表面的形貌及元素分布。结果表明:含氮磷酸酯添加剂具有良好的热分解性能和极压抗磨性能;实验后在钢球表面发现了磷元素,表明在摩擦过程中,含氮磷酸酯添加剂通过化学反应在摩擦表面生成了磷酸铁等化合物,从而起到了极压抗磨的作用。     

二次包络蜗轮副润滑油极压抗磨剂的选用研究

二次包络蜗轮副是一种新型的蜗轮蜗杆传动副，目前仍没有适用的润滑油．为研制其润滑油，本文选用传统的硫型抗磨添加剂、自制的有机铜抗磨剂和有机硼抗磨剂，在ＨＱ－１型摩擦磨损试验机上与蜗轮副材料进行配伍性研究，测出Ｐ—Ｖ曲线；在滚滑两用摩擦磨损试验机上测出与蜗轮副材料配合时的胶合温度；在ＭＱ—８００型四球机上测出磨损系数，结果表明：有机铜抗磨添加剂和有机硼抗磨添加剂对蜗轮副显示出较好的减摩、抗磨和抗胶合性能，传统的硫型抗磨添加剂不适合蜗轮副．本文还应用Ｘ射线光电子能谱仪和俄歇电子能谱仪对试件表面膜进了化学结构分析，为二次包络蜗轮副润滑油极压抗磨剂的正确选用提供科学依据．     

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。     

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.     

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.     

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.     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.     

5083H111轧制铝合金的低周疲劳行为

在室温下对5083H111轧制铝合金板三个典型方向——轧制方向(RD方向)、与轧制方向成45°角方向(MD方向)、垂直于轧制方向(TD方向)的试样进行了单轴对称应变控制的低调疲劳试验,研究了不同方向试样的循环变形行为和疲劳寿命差异。结果表明:铝合金板在三个方向上都表现出了明显的循环硬化特性,即在恒定的应变幅下,三个方向的响应应力幅均随着循环次数的增加而增大,并且外加应变幅越大,响应应力幅也越大;三个方向的低周疲劳ε-Nf曲线差别不明显;三参数幂函数寿命模型可以很好地预测5083H111铝合金的低周疲劳寿命。