Abstract: The present disclosure relates to the technical field of a rehabilitation protective gear, in particular to a telescopic adjusting structure of a support arm and a knee brace. The telescopic adjusting structure of the support arm comprises an adjusting arm and a support arm guard movably connected along the length direction, and further comprises a telescopic adjusting mechanism. The telescopic adjusting mechanism comprises a pushing component, which is movably provided on the support arm guard; a locking component, one end of which is connected with the pushing component, and the other end of which is clamped with the adjusting arm, wherein when the pushing component moves, the locking component is disengaged from or locked with the adjusting arm. The telescopic adjusting mechanism is provided, so that the extension length matching between the adjusting arm and the support arm guard is adjusted.

Abstract: The present invention relates to the field of nonlinear optical crystal materials and provided herein a Li4Sr(BO3)2 compound, a Li4Sr(BO3)2 nonlinear optical crystal as well as preparation method and use thereof. The Li4Sr(BO3)2 nonlinear optical crystal has a second harmonic conversion efficiency at 1064 nm of about two times that of a KH2PO4 (KDP) crystal, and an UV absorption cut-off edge less than 190 nm. Furthermore, the crystal did not disintegrate. By flux method with Li2O, Li2O—B2O and Li2O—B2O3—LiF used as flux agent, large-size and transparent Li4Sr(BO3)2 nonlinear optical crystal can grow. The Li4Sr(BO3)2 crystal had stable physicochemical properties, moderate hardness, and was easy to cut, processing, preserve and use. Therefore it can be used for preparing nonlinear optical devices and thus for developing nonlinear optical applications in the ultraviolet and deep-ultraviolet band.

Abstract: The present invention relates to the field of nonlinear optical crystal materials and provided herein a Li4Sr(BO3)2 compound, a Li4Sr(BO3)2 nonlinear optical crystal as well as preparation method and use thereof. The Li4Sr(BO3)2 nonlinear optical crystal has a second harmonic conversion efficiency at 1064 nm of about two times that of a KH2PO4 (KDP) crystal, and an UV absorption cut-off edge less than 190 nm. Furthermore, the crystal did not disintegrate. By flux method with Li2O, Li2O-B2O and Li2O-B2O3-LiF used as flux agent, large-size and transparent Li4Sr(BO3)2 nonlinear optical crystal can grow. The Li4Sr(BO3)2 crystal had stable physicochemical properties, moderate hardness, and was easy to cut, processing, preserve and use. Therefore it can be used for preparing nonlinear optical devices and thus for developing nonlinear optical applications in the ultraviolet and deep-ultraviolet band.