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51.
Summary In the determination of several perhalogenated compounds after gas chromatographic separation on an Apiezon L column, using
a flame ionization detector, all the compounds tested gave linear area-mass plots although the coefficients observed do not
lead to extrapolations which would permit quantitation of perhalogenated compounds for which no standard is available. Of
the compounds tested, dibromodichloromethane, tetrachloroethene and tetrabromoethene gave good linear correlations of area
ratio-mass ratio (using n-decane as the internal standard). Bromotrichloromethane and tetrabromomethane gave continuously
curving area ratio-mass ratio plots which were very reproducible and could be used for graphical interpolation. 相似文献
52.
A History of Fischer-Tropsch Wax Upgrading at BP—— from Catalyst Screening Studies to Full Scale Demonstration in Alaska
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John P. Collins Joep J. H. M. Font Freidet Barry Nay 《天然气化学杂志》2006,15(1):1-10
Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within BP. Catalyst screening and selection was carried out in dedicated micro-reactors and pilot plants, whose designs are critical to the performance selection. Variation in catalyst composition and defining the gas to oil feed ratios with the operating temperature are a few of the parameters studied. Product selection and maximizing diesel yield combined with stability (catalyst life) were the ultimate drivers. The selected catalyst was then tested under commercial conditions in a dedicated 300 barrel per day demonstration plant. The products were also tested in engines to assess their combustion characteristics. 相似文献
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W. Harvey Newsome Peter Collins 《International journal of environmental analytical chemistry》2013,93(4):489-494
Abstract A method was developed for the determination of three fungicides in foods based on alkaline degradation to 3,5-dichloroaniline, isolation of the latter by steam distillation and measurement of the heptafluorobutyrate by gas chromatography. Recoveries averaged 91% from several commodities spiked at from 10–80ppb. The minimum detectable limit of 2.6ppb was attainable in grape, with similar limits found in strawberry, tomato and beans. The method was capable of determining degradation products formed as a result of cooking. 相似文献
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The effect on thermal oxidation of implantation of the alkali species Li, Na, K, Rb and Cs has been studied. A correlation is found with the atomic and ionic radii and atomic masses of the implanted species, the larger ions leading to greater oxidation. We propose that the implanted species may affect the oxide plasticity and that this may be the controlling factor which determines the degree of oxidation. 相似文献
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Debanjan Chakraborty Shyamapada Nandi Rahul Maity Dr. Radha Kishan Motkuri Dr. Kee Sung Han Sean Collins Dr. Paul Humble Dr. James C. Hayes Prof. Tom K. Woo Dr. Ramanathan Vaidhyanathan Dr. Praveen K. Thallapally 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(55):12544-12548
Molecular confinement plays a significant effect on trapped gas and solvent molecules. A fundamental understanding of gas adsorption within the porous confinement provides information necessary to design a material with improved selectivity. In this regard, metal–organic framework (MOF) adsorbents are ideal candidate materials to study confinement effects for weakly interacting gas molecules, such as noble gases. Among the noble gases, xenon (Xe) has practical applications in the medical, automotive and aerospace industries. In this Communication, we report an ultra-microporous nickel-isonicotinate MOF with exceptional Xe uptake and selectivity compared to all benchmark MOF and porous organic cage materials. The selectivity arises because of the near perfect fit of the atomic Xe inside the porous confinement. Notably, at low partial pressure, the Ni–MOF interacts very strongly with Xe compared to the closely related Krypton gas (Kr) and more polarizable CO2. Further 129Xe NMR suggests a broad isotropic chemical shift due to the reduced motion as a result of confinement. 相似文献
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膜的动电特性研究中,往往采用流动电位方法。该方法中,Ag-Ag Cl测试电极的质量是影响测试准确性的关键要素。本文采用正交试验设计和方差分析,着重考察电解法制备Ag-Ag Cl电极过程中,电流强度(I)、氯化时间(t)、电解质溶液浓度(CHCl)、电极来源(n)、烘烤温度(T)、活化电极溶液浓度(CKCl)等因素对Ag-Ag Cl电极稳定性的影响。得到Ag-Ag Cl电极的最优制备参数为:电流密度3.0m A/cm2,氯化时间50min,盐酸浓度0.1mol·L-1,烘烤温度120℃,活化电极溶液(KCl)浓度0.001mol·L-1;最显著影响因素为电极来源,显著影响因素为氯化时间和烘烤温度。对最优条件组合下制备的AgAg Cl电极,进行了稳定性实验,结果表明:制备的电极具有较好的稳定性,24h内电极电位漂移量小于0.10mv,7天内电极电位漂移量小于0.2mv;在聚偏氟乙烯中空纤维超滤膜流动电位测试中,流动电位与流动压差具有良好的线性和可重复性,回归曲线R20.99,变化规律符合Helmholtz-Smoluehowski公式,可以较好满足膜的流动电位测试要求。 相似文献