Class F fly ash-based geopolymers formed by pressure were prepared, and the preparation factors effecting on properties especially mechanical strength were discussed and optimized. The geopolymer specimens show excellent integrated properties such as mechanical strength, acid-resistance and water absorption and can be potentially applied to acid-resisting bricks except for acid-resistance left to be improved. The elevated curing temperature and the prolonged curing time are both beneficial to develop the mechanical strength as well as the moderately increased forming pressure and quartz sand/fly ash ratio. Being pretreated at elevated temperature for proper time before press forming improves the mechanical strength and reduces the water absorption greatly.
Abstract. In the development of today's human science and technology, course content and curriculum system are constantly changing; new concepts put forward frequently; subject border gradually becoming blurred, Course cross and fusion becoming more and more intense in the "Internet+" Environment. Thus, it is urgent to set the rules for researching the historical and current learning resources by Category. This paper based on the existing technology of search engine and automatic text classification makes an attempt to put forward a new heuristic intelligent search technology.
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