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The calcium carbide slag and boron mud were used as raw materials to react with acetic acid to prepare acetate snow melting agent. The microstructure of the snow-melting agent was analyzed by XRD, TG and other methods. The pH, dissolution rate and relative snow-melting ability of the prepared snow-melting agent were tested to evaluate the snow-melting performance of the snow-melting agent. The results show that the acetate phase is mainly calcium acetate when calcium carbide slag is used as the raw material. The product is mixed acetate of calcium acetate and magnesium acetate after adding boron mud. The extraction rate decreased significantly, and the snow melting performance of the acetate product also decreased. When the calcium carbide slagu boron mud is 8u 2,the acetate snow melting agent prepared has high output efficiency, and the three technical indicators of disolution rate, pH and relative snow melting and ice melting ability conform to GB/T 23851-2017 Snow Melting Agents standard. [ABSTRACT FROM AUTHOR]

The experiment studied the screening of α -galactosidase producing strain of Aspergillus niger variants and optimization of fermentation conditions. After UV mutagenesis and subculture of Aspergillus niger strain MX-H, a strain MX-H1 with stable α-galactosidase production was obtained, and its medium for enzyme production was optimized. The 18S rDNA identification showed that strain MX-H1 was identified as Aspergillus niger. The results showed that the optimal conditions were carbon source 15 g/L sucrose, nitrogen source 10 g/L beef extract, the production inducer 0.5 g/L raffinose, the initial pH 6.0, the culture temperature 30 °C, the sample size 30 mL/250 mL and the shaking table 180 r/min for 96 h. Under the optimal conditions, the activity of α-galactosidase was 4.95 U/mL. The experiment provides a reference for industrial production of α-galactosidase. [ABSTRACT FROM AUTHOR]