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Focuses on a study of the roles of microorganisms in the metallogeny of weathering crust rare-earth element (REE) deposits in south China. Cultivation and indentification of microorganisms; Effects of microorganisms on dissolution of REE from an original granite; Effects of microorganisms on migration and accumulation of REE in weathering conditions; Conclusion.

Steady-state and dynamic simulations of a hydrocracking fractionator are carried out using the process simulator ASPEN PLUS with industrial process data. The main products of fractionation include naphtha, diesel, and tail oil. To obtain more economic benefits, more naphtha must be produced in a refinery because naphtha is more profitable than other products. Thus, optimizing the hydrocracking process is important. Optimization is often challenging to implement because the product quality of naphtha (dry point) is difficult to measure online by sensors. The product quality of naphtha is sampled and analyzed by experimental ASTM D86 curves in the laboratory, so the measured value will be delayed. To solve this problem, a model of naphtha dry point (NDP) is established by artificial neural networks using simulation results. This NDP model is then used as a soft sensor and applied in an optimal quality control strategy. The online soft sensor and optimal quality control strategy are integrated by MATLAB CAPE-OPEN and ASPEN PLUS with an OLE for Process Control server. The increase of naphtha yield is obvious with the use of the proposed method. Several key factors influencing naphtha yield are investigated using the optimal quality control strategy by dynamic simulation, and the results show excellent system robustness. [ABSTRACT FROM AUTHOR]

A CO2 expanded carbonation technique is proposed for direct synthesis of alumina powders that does not require structure directing substances or templates. Mesoporous amorphous flower-like alumina was synthesized at relatively low volume expansions (lower ethanol to water volume ratio), whereas mesoporous crystalline honey-comb-like alumina was synthesized at high volume expansions. The alumina powders exhibited high surface area and pore size with small crystallite sizes. The alumina structures were stable from 400 to 800 °C. Experimental tests showed that the alumina powders could catalytically convert cyclohexanone to ɛ-caprolactone efficiently. The use of the calcined catalysts (at 400 and 800 °C; flower-like alumina) at equal ethanol to water volume ratio avoids the usual and inevitable hydrolysis of ɛ-caprolactone to ɛ-hydroxyhexanoic acid. The catalyst was recyclable and stable for up to five reaction cycles. [ABSTRACT FROM AUTHOR]