Abstract: The invention, belonging to the field of membrane technology, presents a method for the direct growth of ultrathin porous graphene separation membranes. Etching agent, organic solvent and polymer are coated on metal foil, and then they are calcined at high temperature in absence of oxygen; after removal of metal substrate and reaction products, single-layered or multi-layered porous graphene membranes are obtained. Alternatively, the dispersion or solution of etching agent is coated on metal foil, on which a polymer film is then overlaid. The obtained sample is subsequently calcined at high temperature in absence of oxygen; after removal of metal substrate and reaction products, single-layered or multi-layered porous graphene membranes are obtained. The method involved in this invention is simple and highly efficient, and allows direct growth of ultrathin porous graphene separation membranes, without needing expensive apparatuses, chemicals and graphene raw material.

Abstract: A separation and purification coupled process with a high helium yield and diversified products is provided. The process is as follows. Firstly, a low-concentration helium-containing gas after being pressurized and pre-treated enters a two-stage and two-section membrane separation unit to produce a helium product with a medium concentration by concentrating stage by stage through the membrane separation unit. A part of the helium with medium concentration enters an adsorption unit for further concentration to produce a helium product above grade A.

Abstract: A toolholder matched with the internal jet cooling spindle for cryogenic coolant is mainly composed of a hollow toolholder body, a high-performance thermal insulation structure and a bidirectional sealing structure. They can guide the cryogenic coolant from the spindle to the internal cooling channel of cutting tool and realize the cryogenic thermal insulation and dynamic sealing. The high-performance thermal insulation structure inside the toolholder employs the material with a low thermal conductivity and a low linear expansion coefficient to restrain the low temperature impact of cryogenic coolant on the toolholder and spindle, to ensure the dimensional accuracy and assembly accuracy of the toolholder. The bidirectional sealing structure in the toolholder uses the ultra-low temperature resistant seal rings to prevent the cryogenic coolant from leaking towards the spindle and the cutting tool, to ensure the stability of the coolant transport.

Abstract: The present invention belongs to the technical field of petroleum exploitation engineering, and discloses a 3D modeling method for cementing hydrate sediment based on a CT image. Indoor remolding rock cores or in situ site rock cores without hydrate can be scanned by CT; a sediment matrix image stack and a pore image stack are obtained by gray threshold segmentation; then, a series of cementing hydrate image stacks with different saturations are constructed through image morphological processing of the sediment matrix image stack such as dilation, erosion and image subtraction operation; and a series of digital rock core image stacks of the cementing hydrate sediment with different saturations are formed through image subtraction operation and splicing operation to provide a relatively real 3D model for the numerical simulation work of the basic physical properties of a reservoir of natural gas hydrate.

Abstract: A white light interferometric fiber-optic gyroscope based on a rhombic optical path difference bias structure includes a laser, a rhombic optical path difference bias structure, a fiber coil and a photodetector. The white light interferometric fiber-optic gyroscope adopts an all-fiber structure to simplify the complexity of a gyroscope system and reduce the overall cost. A white light interferometric demodulation algorithm is used to realize linear output of rotation rate signals.

Abstract: A speed control method for a permanent magnet synchronous motor considering current saturation and disturbance suppression aims to effectively ensure that a current of the motor is always within a given range to avoid the problem of control performance reduction caused by the fact that the current gets into a saturation state, ensure the safety of a system, do not need to use unavailable state variables such as motor acceleration and the like, effectively estimate and compensate disturbances including parameters uncertainty and unknown load torque disturbance existing in a permanent magnet synchronous motor system, and rapidly and accurately control a speed of the motor finally. There is no need to configure a plurality of sensors in practical industrial application, so system building costs can be reduced on the one hand, and the stability of the system can be improved on the other hand.

Abstract: A pressure measuring device for a scale model for elastic similar structure of a wing in a large transport plane adopts a bracket for pressure measuring steel pipes formed by 3D printing, shapes of an upper surface and an lower surface of the bracket are completely the same as local airfoile profiles of a skin at required pressure measuring positions, and the upper surface and the lower surface of the bracket are bonded to the skin and wing beams; a pressure measuring hose is connected with the pressure measuring steel pipe, and the pressure measuring steel pipe is embedded into the bracket and fixed to it; the upper surface and the lower surface of the bracket are provided with semi-cylindrical convex structures; and the pressure measuring steel pipe extends out of the pressure measuring hole in the surface of the skin for pressure measuring steel pipe in the bracket.

Abstract: The present disclosure provides a method for preparing a self-floating transparent nano ultrathin film. According to the present disclosure, the MXene film layer and the nano ultrathin film layer are sequentially subjected to suction filtration on the substrate material by utilizing a vacuum suction filtration technology, and thus a double-film structure is loaded on the substrate material; then an oxidant is subjected to oxidizing and bubbling on the MXene film layer in a permeation way, and thus the substrate material and the nano ultrathin film layer can be separated in a physical isolating manner. Finally, the nano ultrathin film is completely separated in a liquid phase floating separation manner. The nano ultrathin film prepared by the method provided by the present disclosure has a specific thickness and light transmittance through different loading capacities, and the substrate material can be repeatedly utilized.

Abstract: An overlapping and progressive forming method for a high-performance multi-element NiAl-based alloy tubular part, including: winding continuously flexible substrates of Ni and Al, and alloying coating continuously or selectively along a width direction or a rolling direction to obtain coated flexible substrates; winding continuously the coated flexible substrates on an outer surface of a core roller according to a sequence of Ni above and Al below to form a Ni/Al laminated structure having a plurality of layers with an outermost layer being a Ni layer, and consolidating with ultrasonic with assistance of a pulse current to combine the continuously wound flexible substrates into a laminated tube blank; and placing the laminated tube blank into a mold, applying a pulse current to both ends of the laminated tube blank for hot fluid high-pressure forming, and synthesizing in-situ to prepare the tubular part with assistance of the pulse current.

Abstract: A two-dimensionality detection method for industrial control system attacks: collecting data; transmitting the data to a PLC and an embedded attack detection system; uploading, by the PLC, received data to an SCADA system; transmitting, by the SCADA system, the data to the embedded attack detection system after classifying and counting the data; before starting detection, directly reading, by the embedded attack detection system, the data measured by sensors; refining data association relationships and probability distribution characteristics of the sensors of normal operation to complete storage of health data model; after starting detection, in first dimensionality, comparing the data collected directly by the sensors with statistical data of the SCADA system to judge the attacked condition of the SCADA system, and in second dimensionality, comparing the characteristics of the data collected directly by the sensors and counted online with the health data model to judge the attacked condition of the sensors.

Abstract: A 3D measurement model and the spatial calibration method based on a 1D displacement sensor are proposed. A 3D measurement system based on a fixed 1D displacement sensor is established; then a spatial measurement model based on the 1D displacement sensor is established; and then based on the high precision pose data of the measurement plane and sensor measurement data, spatial calibration constraint equation are established; a weighted iterative algorithms is employed to calculate the extrinsic parameters of the 1D sensor that meet the precision requirements, then the calibration process is completed. A high precision 3D measurement model is established; a 3D measurement model based on a 1D displacement sensor is established, and the calibration method of the measurement model is proposed, which will improve the precision of the 3D measurement model and solve the problem of inaccurate spatial measurement caused by the errors of the sensor extrinsic parameters.

Abstract: A variable acceleration curved surface spiral gear transmission mechanism for accelerated oscillator damper damping systems is disclosed. Through the orthogonal orbit planetary gear set moving along the parallel circular arc line guide rail, the concave surface spiral gear and the convex surface spiral gear are meshed at different radii, so as to realize the continuous changing of the speed ratio and changing of the acceleration of the additional mass block. The spiral curve limit guide groove is set on the surface of concave surface spiral gear and convex surface spiral gear, and the changing rate of speed changing ratio is adjusted by designing different spiral curves, and then the acceleration changing rate of additional mass block is controlled.

Abstract: Disclosed are an oxazine compound and an application thereof. The oxazine compound has a structure of a general formula F. The oxazine compound described in the disclosure is a photo/acoustic dynamic active organic molecule with near-infrared absorption-emission function as well as photosensitivity and acoustic sensitivity. Maximum absorption and emission wavelengths of the compound are both greater than 660 nanometers, and a triplet-state conversion rate of the compound is high; and under illumination or ultrasound, the compound can produce reactive oxygen species with high efficiency, which has a good killing effect on cancer cells and cancer tissues, and almost has no toxic or side effects on normal tissues while achieving photo/acoustic dynamic therapy on tumors.

Abstract: The present invention provides an interval error observer-based aircraft engine active fault tolerant control method, and belongs to the technical field of aircraft control. The method comprises: tracking the state and the output of a reference model of an aircraft engine through an error feedback controller; compensating a control system of the aircraft engine having a disturbance signal and actuator and sensor faults through a virtual sensor and a virtual actuator; observing an error between a system with fault of the aircraft engine and the reference model through an interval error observer, and feeding back the error to the error feedback controller; and finally, using a difference between the output of the reference model of the system with fault and the output of the virtual actuator as a control signal to realize active fault tolerant control of the aircraft engine.

Abstract: A multi-material inspection system and velocity measurement method of critically refracted longitudinal wave based on single-angle wedges belong to the field of nondestructive testing of high-end equipment. The method includes the following steps: designing a transmitting wedge and a receiving wedge with the same inclination angle, and building phased array ultrasonic-based inspection systems of critically refracted longitudinal wave; estimating a longitudinal wave velocity range of a material to be tested, calculating and optimizing a phased array ultrasonic delay law, and building a relation between a longitudinal wave velocity and an amplitude of critically refracted longitudinal wave; reading and interpolating the arrival time of a received signal, and calculating a longitudinal wave velocity of the material to be tested; determining an optimal delay law, and exciting and receiving a critically refracted longitudinal wave.

Abstract: A series of 8-(bisphenylethynyl)-ester flexible multiple ring-containing fluoroboron pyrrole liquid crystal dyes are synthesized by introducing a diphenylethynyl rigid structure at position 8 of a boron-dipyrromethene core via a Sonogashira coupling reaction, and a flexible multiple ring such as bicyclohexane, or cholesterol is connected to the biphenylethynyl via an esterification reaction. The dye compounds all have maximum emission wavelengths in methylene chloride concentrated around 525 nm, present green fluorescence, and show good dichroic colour ratios and ordered parameters in E7 liquid crystal. The liquid crystal compounds are in a liquid crystal intermediate phase within the range of 100-280° C., and may be used for manufacturing liquid crystal display products, especially as guest dyes for guest-host mode liquid crystal displays. The response time can be improved and a rapid response effect achieved when the compounds are added to E7 liquid crystal and used for a guest-host display mode.

Abstract: The present invention provides a string-type mooring system. A support frame is provided on a dock. Two free guide rollers are provided at vertical corresponding positions that are respectively below a cross arm of the support frame and above the dock. The two free guide rollers are respectively wound with a cable. One end of each cable is connected to a platform arm fixed on a platform, and the other end thereof is horizontally connected with one end of a spring. The other ends of the two springs are respectively connected with a hydraulic device. The present invention provides an omnidirectional restoring force for the moored platform through the elastic deformation of the springs to control the movement response of the platform within a certain range. The present invention can adjust the slow change of the vertical position of the platform caused by tidal fluctuation.

Abstract: An electric controlled bi-directional bending actuator with deformability and stiffness tunable capacity is disclosed. The electric controlled bi-directional bending actuator with deformability and stiffness tunable capacity comprises three kinds of functional layers that are electro-deformable layers, electro-variable stiffness layers and flexible electrodes. From up to bottom, they are the first flexible electrodes layer, the first electro-deformable layer, the second flexible electrodes layer, the electro-variable stiffness layer, the third flexible electrode layer, the second electro-deformable layer and the fourth flexible electrode layer. The adjacent layers are glued together. The electro-deformable layer is made from dielectric elastomers. The electro-variable stiffness layer is made from electro-rheological materials, including electro-rheological fluids, electro-rheological gels or electro-rheological elastomers.

Abstract: A supporting device and method for a large thin-walled part is disclosed. The supporting device comprises a processing device and a supporting device. A workpiece is positioned between the processing device and the supporting device and is clamped at a periphery in a flexible clamping mode. A cutter in the processing device is connected with an iron core. A coil is wound on the iron core. When the coil is energized, a magnetic field is generated around the coil. A blade part of the cutter is in contact with a processing side of the workpiece. The supporting method combines the magnetorheological fluid technology with the jet supporting technology, and uses a jet impact force to offset part of a milling force. The current magnitude and winding mode of the coil are changed to control magnetic field intensity. The magnetorheological fluid is cured instantly to support the workpiece.

Abstract: A freezing support device and method for a large thin-walled part, which belongs to the technical field of machining support. The present invention realizes freezing support for a large thin-walled part by a freezing system and an auxiliary system, wherein the freezing system comprises a heating source, a freezing source, flexible films, support plates, etc., and the auxiliary system comprises a rotating device, a moving plate and guide rails. The present invention utilizes ice with a certain thickness formed on a support side of a machining area and supports a workpiece through the ice, and the ice is always used as a support along with the progress of machining to have an effect of follow-up support. The present invention simplifies a support structure, and has the advantages of low cost, no contamination to a machine tool, and convenient use; plays a function of clamping the workpiece.