Abstract: A method for embedding the spread spectrum watermark into images with the self-adaptive embedding strength includes the following steps: designing a spread spectrum watermark capable of completely shielding a host signal interference by using prior knowledge of the host signal interference, self-adaptively adjusting a value of an embedding strength in the spread spectrum watermark with different host images, ensuring imperceptibility of each image while simultaneously maximizing robustness of the watermark, and finally embedding the spread spectrum watermark in the host image. The present disclosure can not only completely shield the host signal interference but also effectively withstand various common image processing attacks and geometric attacks, and at the same time, all the watermarked images can obtain consistent imperceptibility. The present disclosure can be applied to various watermarking techniques based on discrete cosine transform.

Abstract: The present invention discloses a device and a method for monitoring two-stage faults of a TDM-PON with high precision. A two-stage TDM-PON system includes an OLT I, a feeder fiber II, a stage-1 1:n optical splitter III, a stage-1 branch fiber IV, a stage-2 1:n optical splitter V, a stage-2 branch fiber VI, and an optical network unit (ONU) VII. A two-stage optical network monitoring system includes a monitoring part on the OLT I side and a monitoring part on the ONU VII side, where the monitoring part on the OLT I side includes a control-end isolator-free semiconductor laser, a control-end coupler, a control-end optical coupling device, a control-end photodetector, an integrated signal acquisition and processing device, and an optical coupling device; and the monitoring part on the ONU VII side is similar to the monitoring part of the OLT I side.

Abstract: The present invention discloses a multi-channel impact-resistant intelligent-constant-deceleration hydraulic braking system, and relates to the field of safety braking control for mine hoist systems. A technical point of the braking system is that the braking system includes a braking circuit formed by a constant-deceleration hydraulic system, a constant-deceleration electrical closed-loop control system, and a detection and feedback apparatus. The constant-deceleration hydraulic system is provided with N+1 independent complete oil return channels, where N is a positive integer greater than or equal to 3. The oil return channels are disposed in parallel to form parallel independent braking circuits, that is, are “multi-channel” and do not have a “common output point”. The oil return channel includes a backup oil source, an electro-hydraulic signal conversion and amplification component, an operating mode switching apparatus, and an execution component that are sequentially connected.

Abstract: A giant six-legged polar research vehicle with tracked feet, including a platform, six legs arranged at six ends of the platform and six tracked feet arranged below the six legs. A monitoring device is arranged on a top cover. Six power compartments each having a steering device are arranged at six ends of a chassis in the platform. Each leg includes a main traveling device with an upper end and a lower end respectively connected to the steering device and a tracked foot, an auxiliary traveling device with an upper end and a lower end respectively connected to the chassis and the main traveling device, and a connecting device arranged on the main traveling device. The tracked foot includes a main flipping mechanism, an auxiliary flipping mechanism, a tracked foot slewing device, a crawler, a sliding plate and a suspension.

Abstract: Processes for macroscopically separating a maceral concentrate from raw coal are disclosed. In some embodiments, a process includes the following steps: crushing and sieving the raw coal to obtain a first coal sample and a second coal sample; subjecting the first coal sample to a heavy medium cyclone separation process; and subjecting the second coal sample to a froth flotation process. The first coal sample has a particle size within a first particle size range, and the second coal sample has a particle size within a second particle size range. In other embodiments, the froth flotation process uses a froth flotation agent including a foaming agent and a collector. The foaming agent includes at least one item selected from the group consisting of 2-octanol, terpenic oil, and polyethylene glycol (PEG). The collector includes at least one item selected from the group consisting of kerosene, diethyl phthalate (BET), and diesel.

Abstract: Processes for macroscopically separating a maceral concentrate from raw coal are disclosed. In some embodiments, a process includes the following steps: crushing and sieving the raw coal to obtain a first coal sample and a second coal sample; subjecting the first coal sample to a heavy medium cyclone separation process; and subjecting the second coal sample to a froth flotation process. The first coal sample has a particle size within a first particle size range, and the second coal sample has a particle size within a second particle size range. In other embodiments, the froth flotation process uses a froth flotation agent including a foaming agent and a collector. The foaming agent includes at least one item selected from the group consisting of 2-octanol, terpenic oil, and polyethylene glycol (PEG). The collector includes at least one item selected from the group consisting of kerosene, diethyl phthalate (BET), and diesel.

Abstract: The present invention discloses a method for preparing surface-active onion-like carbon nanospheres based on vapor deposition, comprising: directly preparing high-surface-activity onion-like carbon nanospheres formed by coating ferroferric oxide nano-particles on an onion-like graphitized shell by taking liquid small organic molecule alkane n-dodecane as a carbon source to perform chemical vapor deposition at high temperature of 650˜700° C. in an inert carrier gas environment with existence of a ferrocene catalyst. An onion-like carbon nanosphere product prepared according to the present invention has good surface activity and thermal stability, is wide in practicability, and can be widely applied to the fields of adsorbing materials, energy storage materials, catalytic materials, medical materials and the like.

Abstract: An InP-based monolithic integrated chaotic semiconductor laser chip capable of feeding back randomly diffused light, being composed of six regions: a left DFB semiconductor laser, a bidirectional SOA, a left passive optical waveguide region, a doped passive optical waveguide region, a right passive optical waveguide region, and a right DFB semiconductor laser, specifically including: an N+ electrode layer, an N-type substrate, an InGaAsP lower confinement layer, an undoped InGaAsP multiple quantum well active region layer, doped particles, distributed feedback Bragg gratings, an InGaAsP upper confinement layer, a P-type heavily doped InP cover layer, a P-type heavily doped InGaAs contact layer, a P+ electrode layer, a light-emitting region, and isolation grooves. It effectively solves problems of bulky volume of the existing chaotic laser source, the time-delay signature of chaotic laser, narrow bandwidth, and low coupling efficiency of the light and the optical waveguide.

Abstract: This invention discloses a hoisting sheave shaft, a hoisting sheave and a lubricating device thereof, where the hoisting sheave shaft is provided with a first oil injection channel extending axially; an oil inlet of the first oil injection channel is arranged on an end surface of the hoisting sheave shaft; the hoisting sheave shaft is also radially provided with at least one second oil injection channel; the second oil injection channel intersects with the first oil injection channel; and an oil outlet of the second oil injection channel is arranged on an outer circular surface of the hoisting sheave shaft.

Abstract: A three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

Abstract: A rubber belt retracting and deploying device for a belt conveyor includes a base, mounting frames, an upper caterpillar disk, a middle caterpillar disk and a lower caterpillar disk, wherein the lower caterpillar disk is fixedly connected between the symmetric mounting frames, and the middle caterpillar disk is movably connected between the symmetric mounting frames, and may longitudinally slide along the symmetric mounting, frames, such that the lower caterpillar disk and the middle caterpillar disk form a first clamping device; the upper caterpillar disk is movably connected between the symmetric mounting frames, and may longitudinally slide along the symmetric mounting frames, such that the upper caterpillar disk and the middle caterpillar disk form a second clamping device; each of the upper caterpillar disk, the middle caterpillar disk and the lower caterpillar disk is provided with a driving part.

Abstract: A monolithic integrated semiconductor random laser composed of a gain region and random feedback region, comprising: a substrate, a lower confinement layer on the substrate, an active layer on the lower confinement layer, an upper confinement layer on the active layer, a strip-shaped waveguide layer longitudinally made in middle of the upper confinement layer, a P+ electrode layer divided into two segments by an isolation groove and made on the waveguide layer, and an N+ electrode layer on a back face of the lower confinement layer. The two segments of the P+ electrode layer correspond respectively to the gain region and the random feedback region. The random feedback region uses a doped waveguide to randomly feed back light emitted and amplified by the gain region. As a result, random laser is emitted.

Abstract: An experiment device for aiding in measuring abrasion of a conveyer, and a method for detecting abrasion of a conveyer, are provided. The device includes a rack, a reciprocation sliding mechanism, a speed adjusting mechanism and a crankshaft. The reciprocation sliding mechanism can include scrapers and scraper chains, and the scraper chains can be arranged between an upper-layer scraper and a lower-layer scraper. The speed adjusting mechanism can include a motor, a friction driving wheel and a friction driven wheel, and the motor is connected with the friction driving wheel through a motor shaft. The friction driving wheel slides on a shaft in an axial direction, and speed adjustment can be achieved by changing the distance between the centers of the friction driving wheel and the friction driven wheel.

Abstract: A supercritical CO2 reactor and a test system of creepage, diffusion and erosion of rock mass. The supercritical CO2 reactor includes a reactor body having a test chamber, a heating layer arranged in a side wall of the reactor body, a temperature sensor and a pressure sensor arranged in the test chamber, a sealing cover configured to seal an opening of the reactor body, a fixing component arranged on the sealing cover, a hydraulic loading component configured to apply an axial load on the specimen. The reactor body is provided with an air inlet/outlet pipe configured to communicate the test chamber with external environment. The air inlet/outlet pipe is provided with a air valve, and the fixing component includes vertical guide bars, an upper pad and a lower pad slideably arranged on the vertical guide bars. The hydraulic loading component includes a oil-loading tank and an axial loading rod.

Abstract: A method for implementing a centralized control platform of a hydraulic support on a fully mechanized mining working face in underground coal mines, which is used for safety production in the underground coal mines.

Abstract: The present disclosure provides a two-stage blade adjusting device for a counter-rotating axial flow fan. A blade adjusting operation shaft is adjusted to drive a pair of bevel gears to transfer power to a threaded pair coaxial with a transmission shaft, the threaded pair transforms rotary motion of the bevel gears into linear motion to push thrust discs in hubs, the blade installation angle of a first impeller is thus adjusted, and a spacer bush transfers the power to adjust the blade installation angle of a second impeller, so that synchronous adjustment of two-stage blade installation angles is realized. The device is simple and compact in structure and low in manufacturing and maintenance cost, and can be widely applied to large, medium and small counter-rotating axial flow fans.

Abstract: The present invention relates to a wire rope suspension device, control method and multi-rope friction lift system, the device comprising: a first beam (6) and a second beam (9) which are passed by a wire rope (1) and fixed to the wire rope (1); a suspension joint (15), for connecting a lifting container (30); a suspension cylinder (14), having two ends respectively connected to the second beam (9) and the suspension joint (15); a wedge joint (8), being disposed in an accommodating chamber provided inside the second beam (9); and a wire rope bias limiting mechanism, being disposed between the wedge joint (8) and the second beam (9), for driving the wedge joint (8) to lock a wire rope section on one side of the wedge joint (8) itself and releasing movement restriction of a wire rope section on the other side of the wedge joint (8), when the second beam (9) has a displacement with respect to the first beam (6) in a predetermined direction. The present invention allows a convenient rope adjustment operation.

Abstract: There is provided a ventilation apparatus with counter-rotating impellers driven by long shaft, wherein an electric motor and a gearbox are placed outside the air duct by using a long shaft with an internally disposed slim shaft extending therefrom, and are connected with the first stage impeller and second stage impeller inside the air duct by using the long shaft and slim shaft extending therefrom. In this ventilation apparatus with counter-rotating impellers, the components of the ventilation apparatus are placed inside and outside the air duct respectively by using the transmission shaft, which is convenient for maintenance and operation. By remotely arranging the impellers at an axial distance, the hub of the impellers will no longer be affected by an internally disposed electric motor, so as to reduce the ventilation resistance to ventilation. The impellers can be switched between the single impeller rotation and the counter rotation of two impellers.

Abstract: A method for embedding the spread spectrum watermark into images with the self-adaptive embedding strength includes the following steps: designing a spread spectrum watermark capable of completely shielding a host signal interference by using prior knowledge of the host signal interference, self-adaptively adjusting a value of an embedding strength in the spread spectrum watermark with different host images, ensuring imperceptibility of each image while simultaneously maximizing robustness of the watermark, and finally embedding the spread spectrum watermark in the host image. The present disclosure can not only completely shield the host signal interference but also effectively withstand various common image processing attacks and geometric attacks, and at the same time, all the watermarked images can obtain consistent imperceptibility. The present disclosure can be applied to various watermarking techniques based on discrete cosine transform.

Abstract: A 3D bio-printer capable of detecting cell activity is provided. The 3D bio-printer includes an upper PC and a lower 3D printer. A conveying hose is connected to a printhead base of the printer, and a temperature controller is connected to the conveying hose. A printhead controller is connected to the other end of the conveying hose, a printhead is connected to the bottom of the printhead controller, and a main control cabinet controls the printhead to work via a signal generator. A prototyping table is provided under the printhead and is connected with a cell activity detecting device for detecting activity of a printed product. Cell activity can be detected in the process of printing, which ensures that the printed biological tissues maintain biological activity. It can supply multi-biological raw materials and realize multi-biological material printing, which ensures an environment suitable for biological material printing.