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991.
李凤林  刘德福 《分析化学》1992,20(3):325-328
本文研究了我国37种原油、机油和柴油的荧光激发光谱和发射光谱特征。提出用比值法或发射波长法将矿物油分组,尔后选择相应的标准油。该法克服了统一方法制取标准油烦琐、费时的缺点。  相似文献   
992.
High pressure thermogravimetric analysis (HPTG) was used in order to study the oxidation of crude oil in a porous medium under pressurised conditions for simulation of in-situ combustion during oil recovery. Three distinct reaction regions were observed from the HPTG curves in an oxidising environment subjected to a constant heating rate. These were low temperature oxidation, fuel deposition and high temperature oxidation. The method of Coats and Redfern was used to obtain kinetic parameters and the results are discussed.The authors would like to express their appreciation for the financial support of TUBITAK (The Scientific and Technical Research Council of Turkey) and the Royal Society.  相似文献   
993.
MCM-22和ITQ-2分子筛负载型催化剂加氢裂化性能的对比研究   总被引:5,自引:0,他引:5  
 以MCM-22和ITQ-2分子筛为载体, WNi为活性组分,制得两种负载型催化剂,考察了两种催化剂的加氢裂化性能,并通过N2吸附、氨程序升温脱附和原位红外光谱对催化剂进行了表征. 减压瓦斯油加氢裂化反应结果表明, WNi/ITQ-2的加氢裂化活性高于WNi/MCM-22, 并且前者的反应温度相对较低. WNi/ITQ-2具有高催化活性是因为ITQ-2分子筛具有空旷的次级结构和较多的可接近的酸性位; 中油选择性高是因为空旷的次级结构使裂化产物快速离开酸性位而避免了二次裂化.  相似文献   
994.
含氟硅油合成研究及其应用   总被引:7,自引:0,他引:7  
综述了具有不同含氟取代基的氟硅单体合成方法,以及由这些单体制备氟硅油的研究成果。介绍了氟硅油不同的分子结构与其丰富多彩的性能之间的关系。  相似文献   
995.
The quality of grains is influenced by storage pests, which are not only spoilers of stored grain, but also vectors of human and animal diseases. Chemical pesticides play an essential role in the cultivation and storage of cereals, however, due to the low degradability and residual toxicity of synthetic pesticides on the environment and non-target organisms, as well as the increasing resistance of target organisms to them, consideration should be given to the development of alternative pest control agents. Compounds isolated from natural sources have emerged as preferred targets for the development of novel insecticidal agents because of their eco-friendliness, safety, and effectiveness. In this review, we primarily focus on the natural product (NPs) control of storage pests. The effective monomer components of NPs and their anti-insect mechanisms were discussed, and natural sources of inspiration and models for insect repellents are described. This review aimed to provide guidelines for the exploitation and utilization of green and efficient natural insecticides.  相似文献   
996.
The essential oil of Nepeta satureioides Boiss. from Iran was isolated by hydrodistillation in yield of 0.06% (w/w). The chemical composition of the essential oil was analyzed by GC and GC-MS. Forty-five compounds accounting for 97.4% of the total oil were identified. The major components were linalool (23.8%), (Z,E)-farnesol (14.7%), linalyl acetate (11.1%), β-caryophyllene (6.6%), lavandulol acetate (6.6%), caryophyllene oxide (6.4%), and (Z)-β-farnesene (3.4%). Oxygenated terpenoids were the main group of compounds. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 144–145, March–April, 2006.  相似文献   
997.
Charles Pedersen's career is reviewed from the time of his early life in Korea and Japan and scientific training in the United States to the present. His 42-year research career was practically and scientifically productive, leading finally to a share of the Nobel prize in chemistry for 1987. Commercially significant accomplishments included a large improvement in the yield of tetraethylead antiknock and discovery of the first oil soluble agents for inhibiting catalytic effects of copper in degradation of petroleum products and rubber. This led to a study of the interactions of metals with chelating agents and the resultant effects on oxidation reactions, thence to the behavior of peroxides and their reactions with substrates. He also discovered the antiknock activity of ferrocene. While studying the effects of ligands on the catalytic behavior of vanadium he discovered the crown compounds and their ability to include alkali metal ions. He devoted the last years of his career to elaborating their chemistry.Taken in part with permission fromCurrent Topics in Macrocyclic Chemistry in Japan, E. Kimura (ed.), Hiroshima University School of Medicine, Hiroshima, 1987.  相似文献   
998.
本法将数字化的溢油和可疑溢油源样品的红外光谱视为N—维空间的两个矢量,它们间的角距离即作为定量比较两油品相似程度的依据。计算时选用表征油品组成特征的四个关键谱带:1600、1375、810和720cm~(-1)作为分析谱带。为了降低实验误差和风化影响,附加了一种新的数学处理过程,研究规划出N行M列(N>M)的线性矛盾方程组,用最小二乘解法处理原始数据求得问题的最可信赖解,从而用计算分析取得令人满意结果,并在现场执法服务中得到证实。  相似文献   
999.
建立在线式红外分光测油仪的校准方法。在线式红外分光测油仪的校准主要包括绝缘电阻、示值误差、重复性、漂移和最小检出浓度等项目。通过分析实验数据,测量范围不大于10 mg/L时,示值误差不超过±0.8 mg/L;测量范围大于10 mg/L时,示值相对误差不超过±8%;重复性不大于2%;零点漂移不超过±0.5 mg/L,示值漂移不超过±5%;最小检出浓度不大于0.5 mg/L,仪器的计量性能正常。据此对影响仪器性能的各个参数进行全面评价,确认各项指标控制在合理范围内。该校准方法切实可行,可用于在线式红外分光测油仪的校准。  相似文献   
1000.
The measurement of water in lubricating oils is important because water accelerates the corrosion of metal parts and bearings in motors. Some of the additives added to lubricating oils to improve their performance react with the Karl Fischer reagent (KFR) causing a positive bias in the water measurement. A new oven evaporation technique for measuring water in oils has been developed that is automated, requires less sample handling, is easily calibrated, and is capable of measuring relatively small mass fractions of water (50 mg/kg sample). A series of motor oils was analyzed with the standard KFR, a reagent that detects interfering substances that reduce iodine, and the aldehyde–ketone reagent that does not detect substances that react with methanol and form water. The oil samples were heated to 107°C and then reheated to 160°C. At both temperatures, material was measured by both KFRs, but only zinc dithiophosphate released sulfur compounds that would react with the reagent that detects interfering substances. Mass fractions of between 20 and 70% of the volatile material released at either temperature were measured with the standard KFR but not with the aldehyde–ketone reagent. These results demonstrate that there are a number of sources of positive bias in the measurement of water in motor oils and that the standard KFR cannot be used to measure water in motor oils and motor oil additives. These results also indicate that some of the material reacts with methanol to form water. Finally, these results suggest that some of the material that is volatile at 160°C and not at 107°C may be water that is physically occluded or may be substances that react with diethyleneglycol monomethylether to produce water.  相似文献   
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