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51.
Analogy teaching of calculation of packing absorption column and plate tower of distillation was studied in this paper. Firstly, a detailed analogy of the above calculation problems was studied according to the frame of calculation type, calculation basis, quantitative calculation and qualitative analysis. Secondly, the qualitative analysis of the above calculations was used as examples to illustrate the analysis methodology. Students could master very well the sameness and difference of the calculation of absorption and distillation through analogy teaching. 相似文献
52.
TANG Sufang WEI Na 《偏微分方程(英文版)》2010,(1):1-15
In this paper, by establishing the boundedness of singular integral operators with variable kernels and their commutators with BMO functions on Morrey spaces of homogeneous groups, we prove a local a prior estimate in Sobolev-Morrey space for solutions to the nondivergence parabolic equation with discontinuous coefficients. 相似文献
53.
一类随机利率下的变额寿险模型研究 总被引:2,自引:0,他引:2
本文对随机利率采用在原点反射的布朗运动以及负二项分布建模,具体以即时给付的综合人寿保险模型为研究对象,对寿险理论中的保费,年金以及责任准备金进行研究,并给出相应的表达式。 相似文献
54.
Novel cobalt Fischer-Tropsch synthesis(FTS) catalysts were prepared from natural halloysite nanotubes(HNT) by double-solvent and wetimpregnation methods,and characterized by TEM,XRD,TPR and N2 adsorption-desorption.Comparing with the catalyst prepared by wetimpregnation method,the catalyst prepared by double-solvent method reduces Co3O4 particle migration and agglomeration due to size-induced effect,thus showing higher catalytic activity for Fischer-Tropsch synthesis. 相似文献
55.
溴酸钾—次甲基绿—钒催化体系的研究及在测定抗坏血酸方面的应用 总被引:1,自引:0,他引:1
丁素芳 《理化检验(化学分册)》1999,35(8):346-347
研究了在酸性介质中,抗坏血酸对溴酸钾、次甲基绿、钒催化体系具有显著的活化作用建立了测定抗坏血酸的新方法。线性范围为0.002~0.06μg.ml^-1,方法检出限为1.25×10^-9g.ml^-1,用于药品、尿液中抗坏血酸的测定,结果满意。 相似文献
56.
本文运用主方程等方法给出随机和择优混合演化网络模型稳态度分布存在性的严格证明,并推导度分布的表达式,进而得知该混合演化网络为无标度网络. 相似文献
57.
当系数矩阵满足一定的VMO条件时,利用Campanato凝固系数方法,证明一类退化抛物方程弱解的Morrey正则性.并且,利用H?lder连续函数的积分特征,对方程弱解建立局部最优H?lder连续性. 相似文献
58.
Pengyue Zhao Sufang Fan Chuanshan Yu Junyan Zhang Canping Pan 《Journal of separation science》2013,36(20):3379-3386
A novel design for a rapid clean‐up method was developed for the analysis of pesticide residues in fruit and vegetables followed by LC–ESI‐MS/MS. The acetonitrile‐based sample extraction technique was used to obtain the extracts, and further clean‐up was carried out by applying the streamlined procedure on a multiplug filtration clean‐up column coupled with a syringe. The sorbent used for clean‐up in this research is multiwalled carbon nanotubes, which was mixed with anhydrous magnesium sulfate to remove water from the extracts. This method was validated on 40 representative pesticides and apple, cabbage, and potato sample matrices spiked at two concentration levels of 10 and 100 μg/kg. It exhibited recoveries between 71 and 117% for most pesticides with RSDs < 15%. Matrix‐matched calibrations were performed with the coefficients of determination >0.995 for most studied pesticides between concentration levels of 10–500 μg/L. The LOQs for 40 pesticides ranged from 2 to 50 μg/kg. The developed method was successfully applied to the determination of pesticide residues in market fruit and vegetable samples. 相似文献
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