38results about How to "No obvious deformation" patented technology

The invention discloses an eyepiece and a head mounted display device. The eyepiece comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are arrayed in parallel sequentially between an aperture slot and a display screen, wherein the second lens and third lens form a glued lens group, the other lenses are separately arranged. The first lens, third lens and the fourth lens are plus lenses, the second lens is a minus lens, the fifth lens is a plus lens, the sixth lens is a minus lens, or the fifth lens is a minus lens, the sixth lens is a plus lens. The eyepiece can acquire a big rear cut-off distance, and supports Myopia regulation in a wide range. Myopic people can see images clearly without wearing myopia lenses. At the same time, the eyepiece is compact in structure, has a big exit pupil diameter and a big exit pupil distance, permits certain level of wearing deviation, possesses a big viewing angle and small distortion, a high transfer function and a small color difference, and can guarantee the image clarity and color expressiveness.

The invention relates to a high-performance tungsten / steel composite material based on high-temperature application and a preparation method thereof and belongs to the technical field of preparation of composite materials. By adoption of the high-performance tungsten / steel composite material, the problems of large residual joint stress, low strength, poor heat resistance and high connection temperature in an existing tungsten / steel connector are solved. The high-performance tungsten / steel composite material is prepared from a tungsten-based layer, a titanium layer, a niobium layer, a nickle layer and a steel-based layer which are arranged in sequence and prepared by adopting a welding method. The high-performance tungsten / steel composite material is obtained by superposing the tungsten-based layer, the titanium layer, the niobium layer, the nickle layer and the steel-based layer in sequence according to the superposition mode of the tungsten-based layer, the titanium layer, the niobium layer, the nickle layer and the steel-based layer and carrying out vacuum diffusion bonding. The high-performance tungsten / steel composite material has the advantages that the room-temperature tensile strength is larger than or equal to 352MPa, and the tensile strength at the temperature of 650DEG C is larger than or equal to 338MPa; the structure design is reasonable, the process is simple, the large-scale application is convenient, and simultaneously, the high-performance tungsten / steel composite material can be widely applied in diffusion bonding of refractory metal and other dissimilar metal materials.

The invention discloses a forming method of a variable cross section special-shaped single tube of a thrust chamber body of a liquid-propellant rocket engine. The method comprises the following stepsthat (1), bend shaping is conducted, specifically, a single tube workpiece in the annealing state and filled with filling materials is placed in a bend shaping tool for bend shaping machining, so thatthe workpiece can be bent along an inner molding surface curve of a theoretical single tube; (2) preforming is conducted, specifically, the single tube workpiece is placed in a preforming tool of a hinge pressing plate structure, the preforming tool is adopted to press the single tube workpiece in an oblateness shape with plane included angles of two sides being the same as the theoretical singletube; (3), hydraulic bulging is conducted, specifically, an internal high pressure forming mold with a high pressure forming inner cavity being completely attached to the outer surface of the theoretical single tube is adopted to apply high pressure from the interior of the single tube workpiece to the outside to conduct bulging; (4), annealing is conducted and the single tube workpiece is back into the annealing state; and (5), the step (3) and the step (4) are repeated until the single tube workpiece is completely attached to the wall surface of the high pressure forming inner cavity, and asingle tube finished product is obtained. Machining accuracy and yield of single tube products can be obviously improved with the method.

The invention relates to a tungsten / transition layer / steel composite material and a low-temperature and low-pressure active diffusion connection preparation method thereof, and belongs to the technical field of preparation of composite materials. Raw materials used for preparing the tungsten / transition layer / steel composite material comprise a tungsten substrate, an active metal Ti layer, a soft interface layer and a steel substrate. The method comprises the following steps: welding the soft interface layer and the steel substrate through a traditional welding process, sequentially superposing the obtained layer to the active metal Ti layer and the tungsten substrate, and carrying out vacuum diffusion connection to prepare a tungsten substrate / titanium layer / soft interface layer / steel substrate connecting piece which is the high-performance tungsten / steel composite material. The tensile strength of the composite material is greater than or equal to 386MPa. The composite material has a reasonably designed structure, and the problems of large joint residual stress, low strength and high requirements of welding conditions of present tungsten / steel connecting pieces are solved through matching of the structure with the method. The preparation method is simple, and is convenient for industrial application.

The invention discloses a device and a method for preparing wear-resistant and rust-proof coatings on the inner walls of large-diameter pipes. The device comprises a to-be-sprayed matrix tube externally sleeved with an energy absorption tube, a lining tube is arranged in the to-be-sprayed matrix tube, an annular explosive loading layer is wound around the external surface of the lining tube, a tapered slot is carved on the surface of the annular explosive loading layer, to-be-sprayed powder is filled in the annular explosive loading layer, and the to-be-sprayed powder is composed of 70-80 parts by weight of WC-Co composite powder and 20-30 parts by weight of a gas generating agent. After one end of the annular explosive loading layer is detonated by a detonating device, the to-be-sprayed powder is driven by explosion to impact the inner wall of the to-be-sprayed matrix tube at a high speed, so that a wear-resistant and rust-proof coating is formed on the internal surface of the to-be-sprayed matrix tube. Compared with conventional methods, a hard wear-resistant and rust-proof coating prepared according to the device and method disclosed by the invention has the characteristics of good bonding strength, low porosity, high hardness, wear resistance, rust prevention, and the like, and can raise the strength of body materials; and a good hard wear-resistant and rust-proof coating can be obtained on the inner wall of a large-diameter pipe.

A simultaneous monitoring device for femtosecond laser micromachining comprises a femtosecond laser, wherein two parallel holophotes, an attenuation piece, a polarizing film, a beam splitter prism, two diaphragms, a shutter, a focusing lens and a machining object are sequentially arranged along a femtosecond laser light path outputted by the femtosecond laser. The machining object is fixed on a rotating translation device, and the centers of the diaphragms and the vertical central line of the machining object are on the same plane. An L-type support is further fixed on the rotating translation device, and the L-type support is provided with a CCD for monitoring. The rotating translation device, the CCD and the L-type support are all connected with a computer through signal lines. The beam splitter prism divides femtosecond laser into two light beams having completely same energy, one light beam is used for machining along the femtosecond laser light path, and the other light beam enters a power meter along the other light path to measure the energy of the femtosecond laser. Real-time simultaneous monitoring for changes generated on the surface of the machining object is achieved, and errors caused by multimetering are reduced. The two diaphragms are the same in height and collinear, and the light beams are kept fixed.

The invention discloses a photoetching method capable of preventing a silicon wafer from being warped. The photoetching method comprises the following steps of cleaning the silicon wafer, evenly spreading front glue, prebaking, exposing, developing, drying, evenly spreading glue at the edge of the front side of the silicon wafer, evenly spreading glue on the back side of the silicon wafer, hardening and corroding. A circle of photoetching glue is evenly spread on the periphery of a figure face after photoetching procedure developing, so that the position of the circle which is coated by the glue is prevented from being corroded, no small notch is formed at the edge of the silicon wafer, and trouble in operation of blade coating glass slurry is avoided; meanwhile, the edge of the silicon wafer is not corroded, so that the mechanical strength of the silicon wafer is improved to a certain extent; furthermore, the uncorroded surface of the circle can reduce effects of glass shrinkage stress on a shape of the silicon wafer in glass shaping; after the glass is shaped, the silicon wafer has no obvious deformation, the surface of the silicon wafer is flat, and operation of following-up procedures is not prone to generating fragments.

The invention relates to a pressure chamber structure for comprehensive dielectric performance measurement under high pressure and a measurement method thereof. The pressure chamber structure includes a ceramic ring, a mold steel sleeve, a basalt fiber sleeve and an anti-expansion protection steel sleeve. The anti-expansion protection The steel sleeve is set on the outside of the basalt fiber sleeve, and a through hole is arranged inside the basalt fiber sleeve. The side wall of the through hole connects the ceramic ring and the mold steel sleeve, and the lower end of the ceramic ring is supported by the side of the through hole. wall support, the upper end is connected to the mold steel sleeve, and the pressure chamber structure is provided with a low-pressure hole and a high-pressure hole, and the low-pressure hole and the high-pressure hole both penetrate from the outside of the pressure chamber structure to the inside of the basalt fiber sleeve through hole. Compared with the prior art, the invention can withstand higher pressure, can be used to measure various dielectric properties, and has the advantages of convenient measurement, firmness and reliability, and low manufacturing cost.