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This article reviews various oxidants and catalysts commonly used in catalytic oxidation desulfurization processes,evaluates them,and prospects for the future. The production of green fuel oil is of great significance for reducing environmental pollution and protecting the ecological environment. In order to fully meet the new requirements of sulfur content standards, sulfur-containing compounds ( such as thio-phene and its derivatives) must be effectively removed from fuel oil. Compared with high investment costs and harsh reaction conditions, hydrodesulfurization (HDS) and oxidative desulfurization (ODS) have the advantages of mild reaction conditions, mild operating conditions, and high desulfurization efficiency. [ABSTRACT FROM AUTHOR]

For satellite navigation and positioning receiver is easy to be interferenced by the multipath, this paper presented an accurate tracking method which was based on maximum likelihood estimation and Kalman filtering for multipath BOC (n,n) signal. Firstly, the method made coherent integral accumulation for the receiving signal, and then estimated amplitude and delay of the signal by the method of maximum likelihood, next estimated the estimated result again by Kalman filtering, so got the more accurate multipath amplitude and delay under the low carrier-to-noise ratio. Finally, it used multipath estimation delay lock loop to analyze the phase curves and showed its validity by a simulation experiment. Theory and simulation results show that the method can track multipath BOC (n,n) signal accurately under the low carrier-to-noise ratio. [ABSTRACT FROM AUTHOR]

As a new industry, donkey industry plays an important role in rural economic development. Scholars at home and abroad have conducted relevant research on the nutritional requirements and feed of donkeys, but there are still some data on nutritional requirements that are vacant. The article mainly reviews the current status of donkey breeding and the needs of donkeys for water, energy, protein, amino acids, fats, fatty acids, minerals and vitamins, as well as functional feed additives, and coarse and refined grain applications, to provide reference for efficient donkey feeding, compound feed development and healthy development of donkey breeding industry. [ABSTRACT FROM AUTHOR]