Abstract: Disclosed are a saw blade quick-change structure for electric tools, and a saw blade quick-change method. The saw blade quick-change structure for electric tools comprises a locking mechanism, a head shell, a tool rest and a quick-change buckle. The locking mechanism is installed in the head shell and used for fixing or releasing a saw blade. The tool rest is installed at the bottom of the head shell. The quick-change buckle is hinged to the head shell and used for controlling the locking mechanism to lock or release the saw blade. The locking mechanism comprises a movable rod, a locking rod, a collet chuck, a locking block, a stop collar and a return spring. The collet chuck is located below the movable rod. The locking rod is clamped by the collet chuck. The locking block and the stop collar are used for controlling the collar chuck to open or close. The return device is used for returning the locking block.

Abstract: The present disclosure discloses a maltooligosyl trehalose synthase mutant with improved thermal stability, and belongs to the technical fields of enzyme engineering and protein engineering. The residual enzyme activities of the MTSase mutants S361R, S444E, S361R/S444E, S361K/S444E, G415P/S361R/S444E and G415P consistent with the present disclosure after treatment at 60° C. for 10 min are respectively 70.3%, 50.1%, 83.5%, 65.9%, 100% and 80.7%, which are respectively 1.6, 1.1, 1.9, 1.5, 2.3 and 1.9 times of that of the wild type. The half-lives of the S361R/S444E and G415P/S361R/S444E at 60° C. are respectively 14.9 min and 90.8 min which are respectively 3.2 and 19.7 times of that of the wild type, indicating that the thermal stability of the MTSase mutant consistent with the present disclosure is significantly improved than that of the wild type.

Abstract: A method for forming a changeable mist of an aromatherapy machine and the aromatherapy machine are provided. A mist storage cavity with an upward opening is disposed on the aromatherapy machine, and a mist outlet of the aromatherapy machine communicates with an inner space of the mist storage cavity. When the aromatherapy machine generates an atomized vapor in an atomization chamber, the atomization chamber is provided with an internal air pressure higher than an atmospheric pressure, so that the atomized vapor is ejected outward at a different speed state based on a different internal air pressure, so as to form a different mist retention state. In a first configuration solution, the internal air pressure is controlled to be slightly higher than an external atmospheric pressure, so that the atomized vapor floats out in a slow surge manner, and that the atomized vapor is accumulated as a haze in the inner space.

Abstract: The present disclosure discloses a maltooligosyl trehalose synthase mutant with improved thermal stability, and belongs to the technical fields of enzyme engineering and protein engineering. The residual enzyme activities of the MTSase mutants S361R, S444E, S361R/S444E, S361K/S444E, G415P/S361R/S444E and G415P consistent with the present disclosure after treatment at 60° C. for 10 min are respectively 70.3%, 50.1%, 83.5%, 65.9%, 100% and 80.7%, which are respectively 1.6, 1.1, 1.9, 1.5, 2.3 and 1.9 times of that of the wild type. The half-lives of the S361R/S444E and G415P/S361R/S444E at 60° C. are respectively 14.9 min and 90.8 min which are respectively 3.2 and 19.7 times of that of the wild type, indicating that the thermal stability of the MTSase mutant consistent with the present disclosure is significantly improved than that of the wild type.