30results about How to "To achieve a limiting effect" patented technology

The invention discloses a fastening device for assisting in tightening a three-jaw chuck on a lathe. The fastening device comprises a right-angle hanging plate with a bolt hole, wherein an air cylinder is embedded in the horizontal end surface of the right-angle hanging plate; the lower end of the air cylinder is in power connection with a lifting rod; an arc-shaped track is arranged at the lowerend of the lifting rod; and a swinging assembly is arranged in the arc-shaped track. According to the fastening device disclosed by the invention, a plurality of groups of limiting rods which are clamped on double surfaces and are arrayed along the three-jaw chuck in an annular manner are utilized, and the limiting rods can be movably separated from abutting against an extension rod of the three-jaw chuck, so that synchronous rotation or disconnection transmission of the three-jaw chuck is controlled; the position change of oil liquid difference in a sealed pipeline is changed, so that the limiting capacity of rotation of a double-surface clamping structure part is realized, and the ordered working steps of the clamping structure part clamping-sliding out-releasing-sliding back along a circular rail are realized; and the whole process can be controlled by a program, and manual intervention is not needed, so that the problem that a workpiece is not completely fixed due to insufficient force is avoided, and the probability that workers are accidentally injured by a cutter is reduced.

The invention discloses a light emitting diode epitaxial wafer and a preparation method thereof, which belong to the technical field of semiconductors. The epitaxial wafer comprises a substrate, a buffer layer, an un-doped GaN layer, an N-type GaN layer, multiple quantum well layers, an electron barrier layer and a P-type GaN layer, wherein the multiple quantum well layers comprise multiple firstsub layers; each first sub layer comprises a quantum well layer and a quantum barrier layer; the quantum barrier layer which is the closest to the electron barrier layer comprises multiple second sublayers and a third sub layer; each second sub layer comprises a fourth sub layer, a fifth sub layer and a sixth sub layer; each fourth sub layer is an AlGaN layer; each fifth sub layer is a GaN layerwith Mg and In doped at the same time; the In doping position in each fifth sub layer is close to the sixth sub layer; each sixth sub layer is a GaN layer; the third sub layer is a GaN layer with Mg and In doped at the same time; and the Mg and In doping concentrations in the third sub layer are higher than those in each fifth sub layer. Hole injection can be increased, and the light emitting efficiency of the LED is improved.

The invention relates to an indirectly-heated semiconductor type gas sensor testing device and method, the indirectly-heated semiconductor type gas sensor testing device comprises a base, a fixed frame and a cavity, the two sides of the cavity are rotatably connected with the fixed frame through a horizontal connecting rod, and the fixed frame is rotatably connected with the base through a vertical connecting rod; the problem that the to-be-detected gas cannot be fully mixed due to the density when the to-be-detected gas is more than two kinds of mixed gas is solved, meanwhile, the mixing and shaking-up speed of the gas is increased, and the excessive loss of the gas-sensitive material is reduced. And meanwhile, the jackscrews are respectively arranged on the horizontal connecting rod and the vertical connecting rod, so that the limiting effect of the axial rotation of the cavity and the axial rotation of the fixed frame is realized. A plurality of gas input valves which are uniformly distributed are arranged at the top of the cavity, so that various gases to be detected can be connected; meanwhile, the liquid evaporation pond is arranged on the fixed platform, volatile liquid in the liquid evaporation pond is heated through the heating rod at the bottom of the liquid evaporation pond, gas is formed, and detection is facilitated.

The invention discloses a method for realizing homogenized control of a light beam by utilizing a free-form curved lens, and the method comprises the following steps of step 1, determining a light distribution form of a light source needing the homogenized control; step 2, determining position information of an area realizing the homogenized control; step 3, determining a lens material; step 4, dividing the homogenized controlled area into a plurality of subareas on the basis of energy conversation law; step 5, establishing a one-one correspondence relation between any subarea in step 4 and a light source emergent angle; and step 6, solving a surface shape of the free-form curved lens according to the refraction law and the correspondence relation in steps 4 and 5. Due to the adoption of the method, the light beam homogenized control of any light source is realized, and the light beam presents uniform light spots in any shape after passing through the curved lens.