Abstract: The application discloses a lens and its button adjustment structure. The button adjustment structure includes a connecting seat, a guidepost, a base and an elastic member. The connecting seat is fixedly connected to the lens or may be part of the lens. The connecting seat includes a first gear structure. The guidepost is fixed on a fixed member on one side of the connecting seat. The base is movably sleeved on the guidepost along an axial direction of the guidepost. The base includes a second gear structure. The elastic member is sleeved on an outer periphery of the guidepost and is located between the base and the fixed member. An elastic force of the elastic member drives the second gear structure on the base to engage the first gear structure of the connecting seat.

Abstract: A paramyxovirus vaccine strain for novel coronavirus pneumonia and a construction method thereof are provided. The method includes performing a recombination of N and F genes of Newcastle disease virus type VII of Paramyxoviridae with P, M, H, L genes of Canine distemper virus of Paramyxoviridae to obtain a recombinant virus, inserting S1 gene of the novel coronavirus between the P and M genes of the recombinant virus to obtain a recombinant vector. The vaccine strain constructed can stably and efficiently express the novel coronavirus S1 protein, and induce the body to produce antibodies; and the recombined virus vaccine strain can stimulate the human body to produce mucosal immunity, and the prepared vaccine can be vaccinated through a nasal spray. Moreover, the vaccine strain can be tested in poultry and dogs, saving time, reducing costs, and being more conducive to actual production due to large output.

Abstract: A paramyxovirus vaccine strain for novel coronavirus pneumonia and a construction method thereof are provided. The method includes performing a recombination of N and F genes of Newcastle disease virus type VII of Paramyxoviridae with P, M, H, L genes of Canine distemper virus of Paramyxoviridae to obtain a recombinant virus, inserting S1 gene of the novel coronavirus between the P and M genes of the recombinant virus to obtain a recombinant vector. The vaccine strain constructed can stably and efficiently express the novel coronavirus S1 protein, and induce the body to produce antibodies; and the recombined virus vaccine strain can stimulate the human body to produce mucosal immunity, and the prepared vaccine can be vaccinated through a nasal spray. Moreover, the vaccine strain can be tested in poultry and dogs, saving time, reducing costs, and being more conducive to actual production due to large output.

Abstract: An apparatus for pipeline construction comprises a constructing means located on the lower part of the apparatus, which includes a chest and a unit for completing the operation of construction; a feeding means located on the upper part of the apparatus, which drives the constructing means to rotate and to approach to the constructed pipe, and which includes a main shaft having a central hole, a rod placed in the central hole, a drive means as well as a rod feeding means; a base of the apparatus, the bottom of the base and the top face of the base are detachably connected with the feeding means and the constructing means respectively.