介电谱技术检测乙醇汽油中乙醇含量

根据乙醇汽油中乙醇含量不同时介电特性也不同的特点,提出一种快速测定乙醇汽油中乙醇含量的介电谱新方法。对配制的22个样品的介电谱进行了分析,对预测乙醇含量的不同数学模型做了比较。结果表明,用偏最小二乘法建立模型能实现对22个样品的准确预测,绝大多数结果能够满足国家标准方法对误差的要求,说明介电谱技术可以应用于现场快速检测乙醇汽油中的乙醇含量。     

红外光谱信息管理系统

本文介绍了光谱数据库系统的程序设计思想和技术关键。数据库系统包含纯化合物红外光谱约9万张,高聚物红外光谱1.2万张,药品红外光谱1千张,以及核磁共振谱10万多张。可以按光谱编号、化学名、商品名、原子数、分子式进行查询,还能根据未知物光谱图的谱峰形状进行检索。结果得到未知化合物的相关信息及其标准谱图。     

采用相关分析解析石油产品近红外光谱

选择一系列结构上具有代表性的烃类化合物,配制不同浓度的溶液,以及它们不同浓度的重整汽油溶液,在中红外,短波近红外和长波近红外光谱仪上,分别测定溶液的中红外光谱、短波近红外光谱和长波近红外光谱。采用相关分析方法对中红外光谱和近红外光谱进行关联,确立重整汽油各结构基团吸收谱带在近红外短波区及长波区的精确位置,并考察化学环境和物理环境对谱带位置的影响。     

用改装的SP-3420A型气相色谱仪测定汽油中含氧化合物含量

对SP-3420A型气相色谱仪进行了改装,采用多维气相色谱分析技术,实现了对汽油中含氧化合物含量的测定,取得了良好效果。     

氧选择性检测器测定汽油中醇醚类含氧化合物的研究

采用氧选择性火焰离子化检测器，用一根非极性毛细管色谱柱作为分析柱，测定无铅汽油中含氧化合物的含量及总氧含量。本文对仪器各种部件的性能进行了考察，选择了最佳分析条件，建立了完善的分析方法。这套系统操作简单，分析时间短，数据准确，原理合理，符合国际上的发展趋势，便于技术推广，也为今后各炼厂及汽车行业控制无铅汽油中含氧化合物的含量创造了技术条件。     

环己烷氧化副产物全组分的质谱分析

本研究建立了利用多种质谱技术分析表征环己烷氧化副产物的方法。将环己烷氧化副产物在减压条件下切割为馏程小于300 ℃的轻组分与馏程大于300 ℃的重组分。利用全二维气相色谱-飞行时间质谱法（GC×GC-TOF MS）对轻组分中的54种含氧有机物进行定性与半定量分析,发现轻组分主要是由酮类、醚类与醇类组成。利用傅立叶变换-离子回旋共振质谱法（FT-ICR MS）对重组分的分子组成进行表征,发现重组分中基本是O.2～O.5类的含氧有机物。重组分中化合物的碳数随O原子个数的增加而增加,但双键相等数（DBE）的分布却基本不变,从而推测重组分中可能同时含有环烷环、C=C、C=O以及醇、醚类C-O键等多种官能团。利用傅里叶变换红外光谱（FTIR）技术验证了质谱分析结果的可靠性。本工作可为含氧有机物混合复杂体系的分析研究提供新的思路。     

基于LabVIEW的温度监控与介电谱测试系统研制

采用有效值测量代替峰值测量的方法,并采用方波的直流分量与方波的高电平峰值之比代替占空比,从而间接测量相位差的方法,对样品的介电谱进行测量.运用虚拟仪器技术,将温度监控系统与介电谱测试系统相结合,设计并实现了温度监控与介电谱测试系统.该系统可以对样品温度变化情况进行实时跟踪记录,对制冷器的制冷情况进行随动控制,对样品的介电温谱及介电频谱进行测试并记录.实验表明,该系统具有良好的性能.     

近红外光谱技术识别车用汽油的应用研究

研究了不同牌号汽油的近红外光谱识别技术。研究结果表明，90号和93号汽油烃族组成的差异在近红外光谱得到充分体现，利用近红外光谱技术对二者进行识别是可行的；但识别比较困难，无法采用传统的马氏距离法进行准确识别。采用WPT-BAYES（小波包变换-贝叶斯）方法，可以大幅度提高识别精度，其正确识别率高达98％以上，满足使用要求。     

一种石油添加剂的红外差谱分析技术研究

应用红外差谱技术和计算机检索技术对一种未知石油添加剂成功地进行了分析,从而确定该添加剂是由甲苯、N,N-二乙基羟胺和壬基酚聚氧乙烯醚（NP 10）3种组分组成的.实验表明,红外差谱分析技术是油品添加剂分析的一种有效方法.     

石油馏分荧光光谱等高线特征谱分析研究

相对色谱或色质联用分析,荧光分析法具有灵敏度高、选择性好、取样量少、分析结果快速等优点。三维荧光光谱是有机物种类鉴别领域的新技术,可应用于石油馏分的分类,且具有准备过程简单、信息量丰富和费用低的优点。分析了柴油、汽油、混合油3类石油馏分的三维荧光光谱特征,应用图像信息统计原理,提出了基于三维荧光等高线特征谱分析技术的一种新方法,研究了同一馏分和不同馏分之间特征谱的相关特性,并给出了利用等高线特征谱相关系数鉴别油品的新方法,对3类馏分的分析结果表明,此方法数据客观,识别结果准确。     

Effect of oxygenates blending with gasoline to improve fuel properties

The purpose of this paper is to study the effect of oxygenate additives into gasoline for the improvement of physicochemical properties of blends.Methyl Tertiary Butyl Ether(MTBE),Methanol,Tertiary butyl alcohol(TBA),and Tertiary amyl alcohol(TAA) blend into unleaded gasoline with various blended rates of 2.5%,5%,7.5%,10%,15%,and 20%.Physicochemical properties of blends are analyzed by the standard American Society of Testing and Materials(ASTM) methods.Methanol,TBA,and TAA increase density of the mixtures,but MTBE decreases density.The addition of oxygenates lead to a distortion of the base gasoline’s distillation curves.The Reid vapor pressure(RVP) of gasoline is found to increase with the addition of the oxygenated compounds.All oxygenates improve both motor and research octane numbers.Among these four additives,TBA shows the best fuel properties.     

Behavioral differences between group I and group II base oils during thermo-oxidative degradation

A simple approach has been adopted to accelerate thermo-oxidative degradation of selected group I and group II base oils by heating each oil in air at specified temperatures. Chromatographic, spectroscopic and thermal techniques are then applied to establish fundamental differences between the oil types by monitoring compositional changes due to their degradation. The oil properties investigated include hydrocarbon type composition, boiling range distribution, the amount of oxygen and types of oxygenated species, molecular weight distribution, and low-temperature fluidity. While most troublesome degradation products from group I oil are insoluble deposits, group II oil yields oil-soluble low as well as high boiling oxygenated species. It is found that the group I oil degradation path reflects preferential reaction of aromatic hydrocarbons to yield polar compounds and insoluble residue. In contrast, the degradation of the group II oil yields high amounts of oxygenated products at the expense of saturates. Since additives are often utilized to protect the base oil from degradation, the above findings are discussed in the context of selection of proper additives for the formulation of engine oil or other lubricants using different oil types.     

Antifriction action of lubricant additives

The influence of antifriction additives for engine oils on fuel economy in gasoline engines has encouraged an interest in research into their action mechanisms. The influence of additives of different types on the antifriction properties of engine oils has now been investigated; additives have been discovered which effectively increase thermal stability of the lubricating layers and decrease friction coefficient, even at high temperatures. The structure and composition of the surface layers of friction pairs have been studied with Auger electron spectroscopy. The inter-relationship between the effectiveness of the antifriction action of the additives and their influence on the thickness and the composition of the surface layers has been ascertained. The most effective antifriction action was obtained where the thickness of the surface layers was reduced within certain limits, and where there was an optimisation of the oxygen and sulphur content. Certain regularities were established, since they were noticed while testing antioxidant, antiwear, antifriction, and detergent additives of different composition.     

The Tribological Performances of Multilayer Graphite-Like Carbon (GLC) Coatings Sliding Against Polymers for Mechanical Seals in Water Environments

Boron-based lubricant additives have recently received significant attention, because of their wear-reducing and frictional properties and low pollution. At the same time, dithiocarbamate complexes with different metals have a long history of being used as multifunctional additives to lubricants. In this study, novel, environmentally friendly additives containing alkylborate and dithiocarbamate groups with alkyl or methylbenzyl substitutes in one molecule were studied. Tribological tests were performed with the additives admixed in a mineral oil using steel-on-steel contacts in a four-ball tribometer. Borate derivatives of different dithiocarbamate ligands were synthesized by several step reactions to investigate tribochemical properties of boron, sulfur, and nitrogen combined in one selected compound. Viscous liquid products were characterized by multinuclear ¹H, ¹³C, and ¹¹B NMR spectroscopy. The surface morphology and the elemental composition of the tribofilms were investigated using an optical profiler and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). It was found that some of these novel compounds provide better antiwear performance and similar frictional properties compared with a commercially available ZnDTP package. Traces of sulfur in the tribofilms formed with both 0.2 and 1.0 wt% of alkylborate–dithiocarbamate compounds in a mineral oil were detected with EDS.     

Tribological,electrochemical, and spectral analysis of zinc dialkyldithiophosphates (ZDDP) of different thermal stabilities

The antiwear properties of five zinc dialkyldithiophosphates, which differed in thermal stability, were evaluated in a 4-ball machine by a preliminary wear track formation method. After testing the additives, the wear resistance of the films formed was measured by the increase in preliminary wear scar diameter over that of the additive-free oil. IR spectroscopy was then used to study the transformation products of additives after thermostatic testing at between 100 and 240°C on steel surfaces, where the interaction products were evaluated by electrode potential method. The interaction of the decomposition products of dithi-ophosphates with metal surfaces was found to be followed by a change in electrode potential. For the tested additives, a relationship is shown between antiwear effectiveness of the film on a friction track during tribological tests and the electrode potential value of the steel sample. Different parts of the relationship between the electrode potential and temperature relate to different stages of dithiophosphate decomposition measured by IR spectroscopy. It can be said that chemical modification of the steel surface which produces an improvement of antiwear properties, starts at the decomposition temperature of the dithiophosphate neutral salt.     

Antifriction action of engine oil additives

The mechanism of the antifriction action of engine oil additives remains unclear. In order to elucidate this, tribological tests of various additives were carried out using friction machines and a multi‐cylinder engine. Investigation of the friction surfaces was carried out using Auger electron spectroscopy. Comparative tests revealed compounds capable of increasing the thermal stability of the lubricating layers and decreasing the friction coefficient over a wide range of temperatures. An interrelation was established between the efficiency of the antifriction action of additives and their influence on the composition and thickness of the surface layers. The most effective antifriction action is due to the localisation of tribochemical processes of formation of secondary structures in thinner surface layers. The results obtained can explain the behaviour of zinc and molybdenum dithiophosphates and dithiocarbamates, and detergents of different composition and basicity, and their influence on the antifriction properties of engine oils.     

A kinetic study of interface reactions for an organic molybdenum compound as a lubricant additive

The kinetics of molybdenum-sulphur compounds as anti-wear and extreme pressure additives are studied on a V-block-pin testing machine. The surface films of pins are analysed by Auger electron spectroscopy (AES). The apparent reaction order in the general kinetic equation can be determined from the experimental data. The results show that the composition of the surface film depends on the relative reaction rates of sulphidation and oxidation and can be found from the AES profile, where k is the reaction rate constant. The surface film of a mixture of iron oxide and sulphide possesses better anti-wear properties than the sulphide film alone.     

Quantification of anhydrous ethanol and detection of adulterants in commercial Brazilian gasoline by Raman spectroscopy

Raman spectroscopy can be used to evaluate the quality of fuels in a remote, rapid, and nondestructive manner without the need for reagents. In this study, Raman was used to quantify anhydrous ethanol in commercial gasoline and to detect peaks due to compounds commonly used for the adulteration of commercial gasoline. Samples of commercial gasoline were collected from fuel stations in the region of Santos, SP, Brazil. Samples of naphtha from the refinery, pure ethanol, and ethanol diluted in distilled water at concentrations close to the range used in the gasoline were also obtained and characterized. Raman spectra were collected using a dispersive Raman spectrometer (830?nm, 2?cm^?1 resolution in the 400–1800?cm^?1 spectral range). As expected, the spectra of commercial gasoline showed pronounced peaks of naphtha and ethanol. By using the peak intensities of the ethanol diluted in water, the ethanol concentration was found to be in the range of 27%?±?1% in most of the samples; some samples presented ethanol concentrations as high as 28.8%, suggesting adulteration. Some samples presented peaks at 766, 798, and 995?cm^?1 with higher intensities, suggesting the presence of an adulterant with organic characteristics, such as solvents with aromatic rings. Raman spectroscopy has been shown to be effective in determining the adulteration of commercial gasoline, which may contribute to rapid quality control of fuels at the point of sale.     

XPS and XANES characteristics of tribofilms and thermal films generated by two P- and/or S-containing additives in water-based lubricant

Two phosphates were synthesized and their tribological properties as water-soluble lubricant additives were evaluated by using four-ball tester. The micro/nano-scale chemical characteristics of tribofilms and thermal films formed from these additives in different conditions were explored by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) spectroscopy. The results show that the additives have better anti-wear and friction reducing properties than the oleate solution at higher load. Surface analysis results indicate that tribofilms are mainly composed of absorbed layer and chemical reactant layer, in which phosphorus exists in the form of adsorbed molecule, phosphate or polyphosphate, and sulfur in the form of alkyldisulfide, sulfide and sulfate. As to the thermal films, phosphate (or polyphosphate) and sulfate are detected as the main components. The anti-wear and friction-reducing performances can be ascribed to the formation of films on the metal surface, and the mechanism of the process of molecules adsorption, new compounds production through tribochemical reactions, film formation and destruction.