柴油中不同组分的摩擦特性及表征

采用蒸馏法对国产柴油进行分离并对不同馏分段柴油的摩擦性能进行了考察,同时采用色谱柱分离法将分离出不同的柴油极性组分并对其润滑性进行了考察;通过SEM扫描电镜对不同含量的极性组分润滑下的磨斑形貌进行了表征,应用高频往复试验机分析了摩擦力及电阻曲线。试验结果表明,随着柴油馏出温度的逐渐升高,其抗磨性能逐渐增加;随着柴油极性的增大,柴油组分的润滑性能越好。柴油的摩擦特性与氮含量和多环芳烃之间有较好相关性,柴油的润滑性关键取决于其中的极性有机物及其数量。     

直馏柴油的润滑性和抗磨损性能

柴油是柴油发动机燃料供给系统的润滑剂,其润滑性影响发动机动力性和经济性.采用高频往复试验,研究了国产直馏柴油的润滑性,采用SRV模拟试验和柴油发动机喷射系统台架试验, 研究了国产直馏柴油的抗磨性能.结果表明,低硫低润滑性的柴油会导致发动机柱塞偶件严重磨损,而高硫低润滑性也可能导致柴油发动机高压喷射系统出现严重的磨损,应根据柴油发动机抗磨损需求, 研究提出柴油润滑性指标.     

柴油润滑性的机制研究

利用作者从事柴油润滑性研究与检测工作十年来积累的大量数据,将柴油的常规理化分析指标以及质谱分析结果与柴油润滑性的相关性进行归纳总结,探讨柴油润滑性的机制。结果表明:脱硫工艺过程与柴油的润滑性有很好的相关性;磨损对某些含硫物质的多少并不敏感;柴油中氮含量越高,润滑性越好;柴油的黏度和密度越大,润滑性越好;馏出点温度越高,馏分的润滑性越好;饱和烃中的链烷烃和环烷烃对润滑性起负作用,而非饱和烃对润滑性有贡献,在芳烃组分中,多环芳烃比单环芳烃对提高润滑性的贡献大。     

基于SRV磨损试验机评定柴油润滑性能评定

采用SRV线摩擦磨损试验机考察柴油的润滑性与柱塞偶件磨损的相关性。结果表明,低硫（S含量wS≤500 μg/g）低润滑柴油润滑时柱塞偶件磨损比较严重,其润滑性与柱塞偶件磨损没有相关性;高硫低润滑柴油的承载能力较高,其润滑时柱塞偶件磨损相对较轻,且润滑性与柱塞偶件磨损相关性较好;适量的酸性组分有助于提高柴油的润滑性和承载能力。部分直馏工艺生产的高硫含量柴油虽经HFRR测试润滑性较差,但在适量酸性组分、较高运动黏度共同作用下,实际SRV测试时并未出现严重的磨损。     

基于SRV磨损试验机的柴油润滑性能评定

采用SRV线摩擦磨损试验机考察柴油的润滑性与柱塞偶件磨损的相关性。结果表明,低硫(S含量wS≤500μg/g)低润滑柴油润滑时柱塞偶件磨损比较严重,其润滑性与柱塞偶件磨损没有相关性;高硫低润滑柴油的承载能力较高,其润滑时柱塞偶件磨损相对较轻,且润滑性与柱塞偶件磨损相关性较好;适量的酸性组分有助于提高柴油的润滑性和承载能力。部分直馏工艺生产的高硫含量柴油虽经HFRR测试润滑性较差,但在适量酸性组分、较高运动黏度共同作用下,实际SRV测试时并未出现严重的磨损。     

常压塔三线柴油凝点的软测量

常减压装置是炼化企业加工的第一道工序．加工目的是在不同温度、压力下将原油中轻重组分分馏出来，主要产品有汽油、溶剂油、煤油、柴油、蜡油等，其中努力提高柴油收率具有非常重要意义。柴油凝点是反映柴油质量的一个重要指标．柴油牌号是根据柴油凝点来划分，如0#柴油标准中柴油凝点指标应不大于0℃。实际生产中，平稳控制柴油凝点具有重要意义。如馏出口柴油凝点偏高，会影响出厂质量：而如果控制馏出口柴油凝点偏低，则会使质量过剩，失去部分直馏柴油收率。     

生物柴油调合燃料润滑性能的研究

对不同来源的生物柴油、车用柴油及其生物柴油调合燃料的润滑性能及影响因素采用高频往复试验机法(HFRR)进行研究,认为不同原料的生物柴油其调合柴油燃料的润滑性能存在差异;生物柴油的精制深度会减弱调合柴油燃料的润滑性能;生物柴油体积分数大于20%的调合燃料其润滑性基本与纯生物柴油达到一致;生物柴油体积分数为5%的调合燃料中超标的水含量会降低其润滑性能,但幅度不大,其润滑性主要由5%的生物柴油决定,抗氧、防锈剂、流动改进剂不影响润滑性能;与车用柴油不同,生物柴油调合燃料的运动黏度与磨斑直径没有很好的对应关系。     

低硫柴油润滑性的研究

探讨了低硫柴油燃料的润滑性和活性抗磨添加剂。低硫柴油抗磨性能既取决于含氧、含氮极性物质，又随粘度增加线性提高。醇、醚、酯、羧酸以及酰胺等化合物均具有一定的抗磨性能，脂肪酸和酯性能比较突出，且与结构类型有关，其中长链脂肪酸单脂抗磨性能最为优越。     

柴油中含硫化合物类型分布及变化规律

采用气相色谱法-硫化学发光检测器研究了几种不同直馏柴油中含硫化合物的类型分布,和直馏柴油加氢脱硫过程中各种含硫化合物类型的变化规律,为加氢脱硫催化剂和工艺研究提供了依据。     

生物柴油对内燃机油抗磨性能的影响研究

在内燃机油中分别加入不同比例的生物柴油和矿物柴油,采用四球摩擦磨损试验机考察了生物柴油和矿物柴油对内燃机油抗磨性能的影响.结果表明,内燃机油中加入生物柴油和矿物柴油后,抗磨性能变差,不同原料制备的生物柴油对内燃机油抗磨性能的影响无明显差异;此外,加有生物柴油和矿物柴油的内燃机油在高温氧化后抗磨性能进一步降低,其中加有生物柴油的内燃机油氧化后抗磨性能降低更为明显.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.