1-H苯并三氮唑乙酸酯的合成、表征及其摩擦学性能

苯并三氮唑具有良好的摩擦学性能, 但在矿物油中的溶解性较差.为提高其在矿物油中的溶解性,采用1-H苯并三氮唑与氯乙酸酯进行取代反应,合成了3种1-H苯并三氮唑乙酸酯新型润滑油添加剂,用IR、UV、1H NMR、13C NMR、MS和元素分析对其结构进行了分析表征,确证了其结构.利用四球试验机考察了其在液体石蜡中的最大无卡咬负荷值.结果表明:合成的3种化合物均能溶于大部分有机溶剂而难溶于水;热失重分析结果表明,第一分解温度均高于218 ℃,能适应一般工况条件的要求;3种化合物在液体石蜡中有良好的极压抗磨作用,最大无卡咬负荷值可达862 N,与二烷基二硫代磷酸锌(ZDDP)相当.     

1,4-双(二硫代甲酸乙酸酯基)哌嗪衍生物的合成与摩擦学性能研究

合成了5种新型无灰无磷环境友好润滑油添加剂1,4-双(二硫代甲酸乙酸酯基)哌嗪衍生物,采用1H NMR、13C NMR、IR、UV-vis、MS和元素分析对其结构进行了表征,在热重分析仪上考察了其热稳定性能,并利用四球摩擦磨损试验机考察了其在液体石蜡中的极压性能和抗磨性能.结果表明,此类添加剂有较高的热稳定性和很好的承载能力,可以明显改善液体石蜡的抗磨性能.     

新型含N杂环化合物的合成及其摩擦学性能研究

合成了一种新型含N杂环化合物添加剂,利用红外光谱仪定性分析了其结构,利用热重试验和油溶性试验考察了其热稳定性及其对液体石蜡基础油的感受性,利用四球和HQ-1环块试验机考察了其摩擦学性能。结果表明其具有较好的热稳定性及其对液体石蜡基础油良好的感受性,能降低长磨磨斑直径和减小摩擦因数,有效提高基础油的摩擦学性能。     

点/线/面接触条件下喹唑啉酮胺润滑油添加剂的摩擦学性能

目前杂环化合物作为润滑油添加剂在机械润滑领域受到重视,但对无硫磷含氮杂环化合物在多种接触方式下的摩擦学性能的研究还不多。合成一种新型无硫磷喹唑啉酮胺润滑油添加剂并利用四球试验机、环块试验机和万能摩擦磨损试验机分别考察了点/线/面接触条件下其在液体石蜡中的摩擦学性能,再用光学显微镜、扫描电子显微镜和X射线光电子能谱仪对其摩擦表面进行分析。试验结果表明:油溶性喹唑啉酮胺在液体石蜡中能显著改善基础油的摩擦磨损状况,明显提高基础油的承载能力,表现出良好的摩擦学性能,其作用机理是其在摩擦过程中与金属表面发生了摩擦化学反应,生成了含氧化亚铁、有机氮化物和含氮金属配合物等的复合膜,有效地提高了液体石蜡的减摩抗磨性能。     

六氢吡啶二硫代氨基甲酸衍生物的合成及其摩擦学性能研究

采用六氢吡啶二硫代氨基甲酸钠与氯乙酸酯进行取代反应,合成了4种新型润滑油添加剂;用IR、UV、^1HNMR、^13C NMR、MS和元素分析对其结构进行表征;对它们的热稳定性和油溶性进行了评价;利用四球摩擦磨损试验机初步考察了它们的摩擦学性能。结果表明,这一类添加剂均具有良好的热稳定性和一定的油溶性,可以明显提高基础油的承载能力。     

羟乙基咪唑啉对矿物润滑油生物降解及摩擦学性能的影响

以液体石蜡模拟矿物润滑油基础油,考察羟乙基咪唑啉作为润滑油生物降解促进剂对液体石蜡生物降解性、抗磨减摩性、热稳定性、抗腐蚀性、防锈性的影响。结果表明：羟乙基咪唑啉可显著提高液体石蜡的生物降解性,其原因是羟乙基咪唑啉降低了油/水界面张力和加速了微生物生长;羟乙基咪唑啉还可在一定程度上改善液体石蜡的抗磨减摩性、抗腐蚀性和防锈性,且对液体石蜡热稳定性影响不大。     

新型潜香化合物2,3-吡嗪二羧酸薄荷醇酯的热裂解分析

为开发高温释放型烟用香料添加剂,本研究以2,3-吡嗪二羧酸和薄荷醇为原料,N,N′-二环己基碳酰亚胺（DCC）为缩合剂,4-二甲氨基吡啶（DMAP）为催化剂,经酯化反应制备了新型潜香目标化合物2,3-吡嗪二羧酸薄荷醇酯。该化合物经X射线单晶衍射、核磁共振波谱（¹H NMR,¹³C NMR）、红外光谱（IR）和高分辨质谱（HRMS）表征后,结合同步热稳定性分析,采用在线热裂解 气相色谱/质谱（Py-GC/MS）法对裂解产物进行定性和半定量分析,并初步推测了其可能的裂解机理。结果表明：在主要热失重区间268.5~334.9 ℃范围内,目标化合物基本分解完全,熔融温度为140.9 ℃,裂解温度为315.9 ℃;共鉴定出目标化合物的46种裂解产物,主要有薄荷烯、薄荷醇和吡嗪等多种对烟草香味有重要作用的致香成分。该方法能够方便、快速地分离鉴定高温食品香料添加剂的热裂解产物,可为该添加剂在烟草中的加香应用提供理论参考。     

表面修饰SiO2纳米微粒作为液体石蜡添加剂抗磨性能的研究

用原位表面修饰法合成了异辛酸修饰SiO2纳米微粒，利用四球摩擦磨损试验机考察了SiO2纳米微粒作为液体石蜡添加剂的摩擦学行为。用扫描电子显微镜（SEM）和X射线光电子能谱仪（XPS）对钢球磨损表面进行了分析。试验结果表明，SiO2纳米微粒作为液体石蜡添加剂具有良好的抗磨损性能，能显著提高液体石蜡的失效载荷；表面修饰SiO2纳米微粒在摩擦过程中发生了摩擦化学反应，形成了含SiO2及有机分解产物等组分的复合边界润滑膜，从而表现出良好的抗磨性和较高的承载能力。     

油酸镁的制备及抗磨性能研究

以油酸和氧化镁为原料在165℃下制得了油酸镁,利用红外光谱对其分子结构进行了表征,将油酸镁加入液体石蜡基础油中,发现其在液体石蜡中可稳定分散。用四球摩擦磨损实验机对油酸镁的摩擦学性能进行了考察,并用SEM和EDS对磨斑表面进行了研究。结果表明,油酸镁质量分数为3%时,可使液体石蜡基础油的磨斑直径降低32%;含油酸镁的液体石蜡润滑时,在摩擦表面发生了复杂的化学反应,生成的反应膜使润滑油具有良好的抗磨性能。     

采用HPLC-MS/MS技术确定当归芍药散中2个新化合物来源

中医经典名方当归芍药散(DSS)在古代用于治疗痛经等妇科疾病,现代广泛用于痛经、老年痴呆、更年期综合征和黄褐斑等40多种疾病的治疗。在筛选该方镇痛活性部位的研究中,发现DSS中的A-N-30部位具有镇痛活性,从中分离得到2个新化合物(1)和(2),并鉴定了它们的化学结构。为进一步对2个新化合物进行活性和结构修饰等研究,需确定2个新化合物的来源,然后大量制备。采用高效液相色谱-串联质谱(HPLC-MS/MS)技术,在电喷雾正离子检测模式下,以一级质谱扫描、子离子扫描和多反应离子监测(MRM)方式,同时检测该方剂的6个组成药材,以2个新化合物为对照品,确定它们均来源于白术。     

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.     

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....     

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。     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.