Search

This is an article in the field of mineral materials. The utilization of desulfurized gypsum (FGD) to prepare more widely used hemihydrate gypsum plays a very important role in the resource utilization of industrial by-product gypsum. It can not only avoid the large-scale exploitation of natural gypsum, but also realize the resource utilization of desulfurized gypsum. In the process of converting FGD gypsum into hemihydrate gypsum, appropriate concentration of additive and sodium chloride were used as the reaction solution, and the process was heated and stirred under normal pressure. The effects of sodium chloride concentration, additive concentration, solid-liquid ratio, rotation speed and reaction temperature on the phase conversion time and crystal size of dihydrate to hemihydrate gypsum were studied. The increase of additive and sodium chloride concentration not only sped up the phase conversion process but also had a certain inhibitory effect on the average length and average aspect ratio of hemihydrate gypsum crystals. Higher or lower rotation speed hindered the nucleation and growth of hemihydrate gypsum crystals and affected the collision frequency of Ca2+ and SO42- in the NaCl added solution, thus delaying the formation of hemihydrate gypsum. Decreasing the solid-liquid ratio and increasing the temperature had a certain promoting effect on the phase conversion process. At a lower temperature, due to the insufficient driving force of the phase conversion process, it was difficult to transform FGD gypsum into hemihydrate gypsum. The optimal process conditions for preparing hemihydrate gypsum from FGD gypsum were determined as follows: sodium chloride concentration 10%, additive concentration 10%, solid-liquid ratio 1∶5, rotating speed 300 r/min, reaction temperature 100 ℃. Under the best process conditions, the reaction could be completed in 60 min. The average length of the prepared hemihydrate gypsum crystals was as high as 127 μm, and the average aspect ratio was as high as 19. At the same time, the relationship between the activity of water molecules in the solution, the degree of supersaturation and the reaction temperature was studied, and it was determined that the phase conversion process was determined by the temperature and the degree of supersaturation.

To reveal the role of gut microbiota (GM) in the occurrence and development of idiopathic central precocious puberty (ICPP) using 16S rDNA sequencing and bioinformatics analysis. The Danazol-induced ICPP model was successfully constructed in this study. ZBDH and GnRHa treatments could effectively inhibit ICPP in rats, as manifested by the delayed vaginal opening time, reduced weight, decreased uterine organ coefficient, and decreased uterine wall thickness and corpus luteum number, as well as remarkably reduced serum hormone (LH, FSH, and E2) levels. According to 16S rDNA sequencing analysis results, there was no significant difference in the GM community diversity across different groups; however, the composition of the microbial community and the abundance of the dominant microbial community were dramatically different among groups. ZBDH and GnRHa treatments could effectively reduce the abundance of Muribaculateae and Lactobacillus and promote Prevotella abundance. ZBDH and GnRHa were effective in treating Danazol-induced ICPP model rats. The therapeutic effects of ZBDH and GnRHa could be related to the changes in GM in rats.