The aim of this work is to deproteinize crude polysaccharide from the Stigma maydis by sevag method. According to deproteinization rate and polysaccharide residual rate, the optimized process was deproteinization number (4 times), time of oscillating (11min), the volume ratio of sample to sevag reagent (2:1), the volume ratio of chloroform to n-butyl alcohol (5:1), deproteinization rate was 64.2%, the polysaccharide loss rate was 34.3%, and the purity of polysaccharide was increased from 11.5% to 32.3%.
In view of the characteristics of the blasting tunneling roadway, the paper has analyzed the distribution law and the movement rule of dust in roadway. Combined with the practical problems existing in the field, a series of methods were conducted to investigate and analyze the the dust source of tunneling, the authors propose the following optimal comprehensive directional measures: At first, using the wet shotcrete technology as more as possible to improving the shotcrete. Taking use of the corresponding measures of spraying and watering, and the use of water stemming is mandatory. The amount of wind in the exit of the ventilation duct should be controlled and the quality of water should be improved, enhancing the atomization effect. The settled dust on the walls of the tunnel should be moistened with sticking agent and the individual safeguard should be done better. Adopting the above dustproof measures should effectively solve the problems of a large amount of dust and the working environment of high dust concentration in the heading face by blasting. The working environment can be improved by the effective control for the dust concentration in the heading face .The work of dust comprehensive prevention in the heading face is of significance.
Aim to study the teaching contents, methods, means, and practice of pharmaceutical analysis course in engineering colleges in order to improve teaching efficiency and quality.
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