31results about How to "Improve axial uniformity" patented technology

The invention relates to a device and method for preparing an optical fiber preform base material by VAD, comprising a reaction chamber for deposition and a rotating lifting boom extending into the inner chamber of the reaction chamber, and the lower part of the inner chamber of the deposition chamber corresponds to the glass target rod to be deposited The core layer blowtorch and the cladding layer blowtorch are arranged at intervals below, and the core layer blowtorch and the cladding layer blowtorch are respectively connected with the core layer raw material control system and the cladding layer raw material control system. The transmitting end and the laser receiving end form a core layer laser detection system, which is characterized in that the core layer material control system is connected with the core layer laser detection system and PLC to form a PID between the core layer blowtorch material flow rate and the laser detection receiving value Closed-loop regulation system forms real-time feedback regulation. The invention has the advantages of simple structure, clear control logic, direct and rapid feedback, stable and reliable deposition performance, stable powder stick profile, uniform core diameter and outer diameter, thereby improving production stability and product quality.

A polarization maintaining fibre with high birefringence is composed of fibre core and cladding layer in which there are the triangular stress element arranged symmetrically at both sides of fibre core and the optional stress holes. Its preparing process includes combining core rod with stress rods by OVD technology, spraying the cladding layer, and drawing. Its advantages are simple preparing process, and high axial uniforming, strength and performance.

The invention discloses a variable crucible ratio monocrystal silicon growth method which comprises the following steps of: growing monocrystal silicon in a crucible; and after the monocrystal silicon enters constant-diameter growth, regulating variable crucible ratio to continuously increase so as to carry out variable crucible ratio monocrystal silicon growth. According to the variable crucible ratio monocrystal silicon growth method disclosed by the invention, the liquid level of monocrystal interface growth can be slowly increased, the natural thermal convection of a molten mass can be effectively accelerated, the oxygen content concentration of the molten mass can be kept and the axial oxygen content consistency of monocrystal silicon can be effectively improved; and the variable crucible ratio monocrystal silicon growth method is convenient to operate and suitable for the industrialized production.

The invention discloses a device loaded with a structured catalyst with radial wall flow. According to the invention, a plurality of structural units are loaded in a reaction tube. Each structural unit comprises a reactant stream wall flow guide panel, a structured carrier loaded with a catalyst, and an expansion ring with a thermal expansion and contraction effect. The reactant stream wall flow guide panel is arranged at the top end of the structured carrier loaded with the catalyst. The bottom end of the structured carrier loaded with the catalyst is embedded in the expansion ring with thermal expansion and contraction effect. The reactant stream wall flow guide panel is a solid cylindrical body coaxial with the structured carrier loaded with the catalyst. The expansion ring with thermal expansion and contraction effect is a hollow cylindrical body coaxial with the structured carrier loaded with the catalyst. The cross-sections of two hollow parts are overlapped. The device provided by the invention has the advantages of simple structure, low pressure drop, and uniform fluid distribution. With the device, advantages of the structured catalyst in the aspects of heat transfer and mass transfer can be fully performed. Material stream radial wall flow can be realized. The device can be used in industrialized production for producing propylene from methanol.

The invention relates to a manufacturing device and a manufacturing method for a polarization maintaining optical fiber preform. The device comprises a disk with scaled calibration, four claws forming a cross shape and screws in one-to-one correspondence and meshing connection with the claws; and the rotating screw can control relative movement of the four claws. Two claws in the horizontal direction are respectively provided with a groove with adjustable diameter.

The invention discloses a linear transmission device, and belongs to the field of medical imaging. The device comprises a motor, a speed reduction device, a clutch and a transmission assembly which are coaxially connected, wherein the transmission assembly comprises a ball screw connected with the clutch and a ball nut, the ball nut is adaptive to the ball screw, the ratio between the lead of theball screw and the diameter of the ball screw is 1.0-2.0, the ball nut can be driven to do linear motion by the ball screw, and when the clutch is powered off, the ball nut can be manually pulled anda scanning bed arranged on the ball nut and loaded with a patient can be driven. With the linear transmission device provided by the invention, low-speed linear motion can be achieved, an end effect of a linear motor having the same function can be effectively prevented on the premise that the scanning bed loaded with the patient can be pulled out of a scanning region, the scanning bed can be enabled to be in a uniform low-speed motion state within the whole scanning range, and the axial uniformity of a scanning image is improved.

The invention discloses a high-stability force generator with compensation, which comprises a shell, a compensation sheet, a positioning ring, a magnetic steel, a magnetic conducting ring, a moving frame, and a magnetizing ring. The shell, the magnetic conducting ring and the magnetic increasing ring are all made of magnetic conducting materials, and together with the magnetic steel, a closed-loop magnetic circuit is established, and the moving frame is a coil wound on the skeleton. When the coil is fed with direct current, the coil generates an electromagnetic force in the magnetic field that is consistent with the axial direction of the product. The force generators of the present invention should be used symmetrically in pairs in a mechanical unit. The invention adopts permanent magnet steel with low temperature coefficient and high magnetic performance to improve the force output capability, and the compensating sheet adopts soft magnetic sheet to compensate the influence of working temperature change on air gap magnetic density. The invention has the advantages of high force output capability, high force stability, convenient processing and manufacturing, etc., and can be used as a force feedback element in inertial instrumentation, servo control, and force or moment measurement.

This invention relates to a self-restructing plasma antenna including a column container, inert gases, a RF excitation antenna, a RF excitation source, a signal coupler, a feeding port and an earth plate characterizing that the column container is filled with inert gases, the source and the antenna are used in exciting and maintaining the plasma, in which, the excitation antenna is set in the inside or outside of the column container, its lead out wire is connected with the RF excitation source, the signal coupler is used to couple the signal to the plasma antenna set out of the container, the lead out wire is connected with the internal conductor of the feeding port and the outer conductor is connected with the earth plate.

The invention provides a novel doping gas path for a zone-melting gas-doped single crystal. The pipeline structure of the doping gas path is shaped like a Greek letter Pi, the middle part of the Pi-shaped doping gas path is an L-shaped section pipeline with an enough length, one end of the L-shaped section pipeline is communicated with a protective gas inlet and a doping gas inlet, the other end of the L-shaped section pipeline is communicated with a gas outlet and a gas exhaust outlet, the gas outlet enters a hearth, a flow meter is arranged at each of the protective gas inlet, the doping gas inlet and the gas outlet, and a pressure valve is arranged at the gas exhaust outlet. By the novel doping gas path provided by the invention, the doping gas can be fully and uniformly mixed with the protective gas in a limited space inside a zone-melting furnace before entering the furnace and thus the uniformity of the gas-doped single crystal is improved and the doping efficiency is increased.