A study of the cross-linking of beta-galactosidase on magnetic beads is reported here. The magnetic beads were prepared from artemisia seed gum, chitosan, and magnetic fluid in the presence of a cross-linking regent (i.e., glutaraldehyde). The reactive aldehyde groups of the magnetic beads allowed the reaction of the amino groups of the enzymes. The animated magnetic beads were used for the covalent immobilization of beta-galactosidase. The effect of various preparation conditions on the activity of the immobilized beta-galactosidase, such as immobilizing time, amount of enzyme, and the concentration of glutaraldehyde, were investigated. The influence of pH and temperature on the activity and the stability of the enzyme, both free and immobilized, have been studied. And o-nitrophenyl-beta-D: -galactopyranoside (ONPG) was chosen as a substrate. The beta-galactosidase immobilized on the magnetic beads resulted in an increase in enzyme stability. Optimum operational temperature for immobilized enzyme was 10 degrees Celsius higher than that of free enzyme and was significantly broader.

Vegetation is a vital part of the natural environment. Variations in vegetation morphology produce changes in the mechanical and fluid characteristics of overland flow. Determining the effects of vegetation lodging on the overland runoff flow regime and resistance is a prerequisite for accurately simulating overland runoff and convergence, revealing the mechanism of overland flow propagation, and the design and management of vegetation protection, soil consolidation, and ecological slope engineering. To systematically study the effects of vegetation lodging on overland runoff, four planting vegetation lodging angles (α) and 10 test water depths were used to simulate experimental research with a 1.0% slope ratio. Experimental results show that the depth and state of vegetation inundation and the degree of lodging significantly influence the flow regime and resistance. Under the same water depth, higher values of α are associated with higher values of the flow velocity, Reynolds number, Froude number, and Darcy–Weisbach resistance coefficient (f), and lower values of the drag coefficient (CD). The overall result is enhanced turbulence in the flow field and weaker flow resistance. Numerical statistics and difference analysis indicate that, when the vegetation is non-submerged, a 10° increase in α produces a 9.30% decrease in f. In the submerged state, a 10° increase in α causes a 26.70% decrease in f. CD is greatly affected by the boundary water depth. Below some critical water depths, an increase of 10° in α reduces CD by 8.48%. Above the critical depth, a 10° increase in α decreases CD by 41.10%.

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