2098 results about "Central symmetry" patented technology

An adaptive optical lens device, system and method of using the same is composed of at least two planar substrates and at least one homogeneous nematic liquid crystal (LC) layer. One planar substrate has a spherical or annular ring-shaped Fresnel grooved transparent electrode within it, the other has a transparent electrode coated on its inner surface. The thickness of the LC layer is uniform. When a voltage is applied across the LC layer, a centro-symmetrical gradient distribution of refractive index within LC layer will occur. Therefore, the LC layer causes light to focus. By controlling the applied voltage, the focal length of the lens is continuously tunable.

The present invention is a method for exploring the viewpoint and focal length of a fisheye lens camera (FELC). It employs the characteristic of the central symmetry of the distortion of the fisheye lens (FEL) to set its optic axis by means of a calibration target with a plurality of symmetrically homocentric figures. Once the optic axis is fixed, further disclose the viewpoint (VP) of the FELC along the optic axis through a trail-and-error procedure and calculate its effective focal length and classify it to the primitive projection mode. Because the invention is capable of finding out both the internal and external parameters of the FELC and the calibration method is easy, low-cost, suitable to any projection model, and has greater sensitivity corresponding to an increasing in image distortion, the distortive images can be transformed easily to normal ones which fit in with a central perspective mechanism. Furthermore, the invention is also practicable and excellent in its applications in the fields of quality identification of the FEL and wide-view 3-D metering.

A plate board type MIMO (multiple-input multiple-output) array antenna including a board, a plurality of antenna elements manufactured on the board, and an isolation unit offsetting effects of electromagnetic waves radiated from the plurality of antenna elements on the other antenna elements of the plurality of antenna elements. In a case where two antenna elements are used, the isolation unit may include at least one isolation element positioned within a space between the two antenna elements on the board and symmetric with respect to a center of a distance between the two antenna elements.

A sun tracking system includes a first, and a second photo sensors, separately mounted on a solar panel on two positions apart from one another and symmetrical with respect to a center of the panel. A first sleeve surrounds the first photosensor; a second sleeve surrounds the second photosensor. Each of the sleeves has an inclined opening with reference to the surface of the panel.

The vertical dual-shaft four-cylinder electrohydraulic servo testing machine comprises: a hydraulic pressure drive for dual-direction stress filed, a four-cylinder drive fit to any loading path, a differential close-loop servo system, a function generator fit to different waves, a position transfer device fit to assemble the test piece, a guide plate and linear rail to ensure co-shaft and avoid bending. This invention is very convenient.

The invention discloses a polarized reconfigurable magneto-electric dipole antenna, comprising a square upper PCB board, a square lower PCB board, a feed port and four antenna units. The four antenna units are arranged on the diagonals of the upper PCB board in a central symmetry mode. The lower PCB board comprises a square substrate integrated waveguide resonant cavity and a coupling slot. An inner conductor of the feed port is connected with patches on the upper surface of the lower PCB board. An outer conductor is connected with the patches on the lower surface of the lower PCB board. The polarized reconfigurable magneto-electric dipole antenna provided by the invention has the advantages of simple structure, low loss, wide bandwidth, high gain, high radiation efficiency and convenient switch among three polarized states. The polarized reconfigurable magneto-electric dipole antenna is very applicable to a modern wireless communication system, especially a 5G-band WiFi system.

The invention provides an electric power steering system with an individually adjustable-parameter and curve-type power characteristic. The system is characterized in that: the power characteristic curve is a segmentation curve which is symmetric about the centre of a zero input moment point; an integral curve can be determined by setting 5 key parameter values on the curve, and, when one or more key parameters are regulated, the integrity of the curve and the continuity of the first-order derivative can still be guaranteed without modifying other parameters. The power characteristic of the electric power steering system provided by the invention can change the shape of the curve by adjusting 5 of the key parameter values to achieve different assisting effects, so the electric power steering system has the optimum steering performance which is expected by drivers.

An optical filter is disclosed which adjusts the contours of blurred images and maintains the size of blurred images. The optical filter includes a substrate being substantially transparent and a first layer whose optical density changes continuously, formed on the substrate. A transmission rate of the first layer decreases substantially linearly from a center toward a periphery of the optical filter, and the transmission rate distribution is symmetric with respect to the center.

The invention provides a seamless assembly large screen displayed with multi-unit image and an assembly method thereof, belonging to the field of large-screen assembly technique. The large screen is formed by the assembly of a group of display units and is characterized in that the mainbody surface of the surface glass substrate of the display unit is a planar structure; the edge surface of the surface glass substrate is an arc structure of the same specification; arc surfaces of adjacent sides of all display units are symmetric correspondingly to the joint center; each display unit is matched with an image rectifier which is connected with image input data; the seamless assembly large screen displayed with multi-unit image and assembly method thereof utilize non-uniform image density display, optical principle and image distortion rectification technique to eliminate the assembly seam on the large screen; furthermore, as the display units have the same specification and can be mass-produced, the production cost is reduced, the installation is convenient and the quality is stable.

The invention discloses a multifunctional shearing test fixture used for composite material parameter identification. The multifunctional shearing test fixture comprises an upper fixture body and a lower fixture body, wherein the upper fixture body is connected with a loading part of a testing machine; the lower fixture body is connected with a supporting platform of the testing machine; the upper fixture body is the same as the lower fixture body in structure and in central symmetry with the lower fixture body; each of the upper fixture body and the lower fixture body comprises a connecting piece (1), a clamping piece (5) and a clamping mechanism; the connecting pieces (1) are connected with the testing machine and the clamping pieces (5); each clamping piece (5) is divided into an upper part and a lower part; the upper parts are connected with the connecting pieces (1) and an angle limiting mechanism is arranged at the upper part; the lower parts and the clamping mechanisms are jointly used for clamping a test piece; the clamping mechanisms comprise regulating parts and compressing pieces (6); the compressing pieces (6) are connected with the clamping pieces (5) through an adjusting mechanism; a limiting mechanism is arranged on the clamping piece (5) and used for limiting positions of the compressing pieces to enable the compressing pieces to perform movement along set tracks. The multifunctional shearing test fixture has the advantages of being light in weight, simple in operation and easy to dissemble and capable of realizing pure shear, tension-shear and tension-shear combined loading.

The invention discloses a metal-oxide gas sensor based on MEMS (Micro-Electro-Mechanic System) and a preparation technology thereof. The gas sensor is characterized by comprising an Si substrate, an insulating layer, two thin-film resistor heating elements, a rectangular micro array, a pair of sensitive electrodes and a metallic oxide three-dimensional multi-level nano-structure produced on the rectangular micro array, wherein partial Si at the lower part of the Si base is removed in an anisotropic manner through wet etching; at the front of the gas sensor, the heating elements and the sensitive electrodes are arranged in a central symmetry and spiral manner, the rectangular micro array is arranged in the center, and the heating elements, the sensitive electrodes and the rectangular micro array are positioned on the same layer; the heating elements can also serve as temperature detecting elements. According to the invention, the nano-structure synthetized by adopting a hydrothermal method can realize the bridge type electrical connection through the mutually crossed dendritic structures, and is finally connected with the sensitive electrodes; the arrangement manner of the rectangular micro array is changed, and nano-materials of different types are replaced, so that the metal-oxide nano gas sensor based on different measuring circuits and sensitive materials of different types can be processed.

The invention discloses a variable-rigidity elastic joint of a cam structure. The variable-rigidity elastic joint is composed of a shell, a shaft and an outer ring. The shaft is arranged at the rotation center of the shell and fixed to the shell. The shell and the outer ring are connected through a rotation pair. A plurality of symmetrical leaf springs are arranged on the outer ring in the radial direction. One end of each leaf spring is fixedly connected with the outer ring, and the other end of each leaf spring penetrates through a spring to be fixedly connected with the shaft. One end of each spring is connected to the shaft, and the other end of each spring is connected to a sliding block. The sliding blocks are arranged in the middles of the leaf springs and connected with the leaf springs in a sliding mode. A cam disk is arranged on the shaft, of a central symmetry structure and connected with the shaft through a rotation pair. A cam roller is arranged at the upper end of each sliding block. Cam transmission is achieved through the cam disk and the cam rollers. The variable-rigidity elastic joint solves the problems that an existing structure is relatively complex and the variable-rigidity characteristic is poor, and the variable-rigidity elastic joint which is simple in structure and allows the rigidity to be regulated in real time in the movement process can be obtained.

The invention relates to a circuit-type fishpond breeding system integrating a circulating water treatment process. The circuit-type fishpond breeding system integrating the circulating water treatment process comprises a fishpond shaped like an annular runway, and sewage treatment systems arranged in an inner ring of the fishpond. Each sewage treatment system comprises a vertical flow type solid-liquid separator (1), wherein a sewage discharging groove (5) perpendicular to the water flow direction is formed in the bottom of the fishpond and communicated with an inlet of the vertical flow type solid-liquid separator (1), an outlet of the vertical flow type solid-liquid separator (1) is communicated with a micro-filtration machine (2), outlet water of the micro-filtration machine (2) adopts a water pump (3) and a water lifting pipe (4) for water lifting and is injected into a biological filter (6), the biological filter (6) is separated from an aeration oxygenation pond (8) through a separation plate and is communicated with the aeration oxygenation pond (8) through a through hole in the lower portion of the separation plate, a water falling pipe (7) is arranged on the lateral wall of the aeration oxygenation pond (8) and communicated with the fishpond, and the water outlet direction at the bottom of the water falling pipe (7) is the same as the water flow direction of the fishpond. The number of the sewage treatment systems is two, and the sewage treatment systems are evenly distributed in the inner ring of the annular fishpond in a central symmetry mode.

The invention discloses a polarization maintaining optical fiber with a small bending radius and a manufacture method of the polarization maintaining optical fiber and relates to the field of optical fiber manufacture. The polarization maintaining optical fiber comprises a silica cladding, a core layer, a second silica cladding ring, a third fluorine-doped silica cladding ring and two stress cat eyes are sequentially arranged in the silica cladding from inside to outside, and the two stress cat eyes are in central symmetry with the core layer. By means of the manufacture method, the bending radius of the manufactured polarization maintaining optical fiber is smaller than 5mm, operating wavelength of the polarization maintaining optical fiber is 1550nm, and supplementary deterioration of the polarization maintaining optical fiber is under 0.4dB/km. According to the polarization maintaining optical fiber, under the condition that the bending radius is small, low-loss information transmission of the polarization maintaining optical fiber is achieved, low supplementary deterioration and good crosstalk characteristics of the polarization maintaining optical fiber are guaranteed, fiber optic sensors with small sizes can be manufactured by means of the polarization maintaining optical fiber, and requirements of users are satisfied.

The invention provides a prestressed shear wall and vertical joint combining-connecting structure. The prestressed shear wall and vertical joint combining-connecting structure comprises at least two prestressed shear walls, two pieces of embedded profile steel and one fixing assembly. The embedded profile steel is embedded into the side walls of the prestressed shear walls, and the two pieces of embedded profile steel are arranged between the two prestressed shear walls and are fixed by the fixing assembly. The fixing assembly comprises two clamping plates, multiple hoop bars, multiple bolts and at least four longitudinal bars. The web plates of the two pieces of embedded profile steel are connected through the front clamping plate, the back clamping plate and the bolts. The four longitudinal bars are arranged along the connecting cross sections of the two pieces of embedded profile steel in a central symmetry mode, and the hoop bars are welded on the front clamping plate and the back clamping plate and are in bound connection with the longitudinal bars. The invention further provides a construction method of the prestressed shear wall and vertical joint combining-connecting structure. The prestressed shear wall and vertical joint combining-connecting structure is large in bearing capacity, good in anti-seismic property, superior in integrality, convenient to construct, good in construction quality and good in fireproof performance.

The invention discloses a broadband dual-polarization antenna and a radiating unit thereof. The radiating unit comprises two pairs of symmetrical dipoles with mutually orthogonal polarization, and each pair of symmetrical dipoles comprises a pair of radiation arms and a pair of balens used for being fixed on a metal reflection plate and implementing same side supporting to each radiation arm at the end where the radiation arms are close. Each radiation arm is arranged on a same reference plane, the whole radiating unit and the geometric center of the reference plane are of a symmetrical structure, the reference plane extends towards the bottom directions of the baleens to form a space which is defined as a containing space, each radiation arm is in a shape of closed single line, a main body located on the reference plane exists, the radiation arm is provided with an expanding portion extending to the containing space in a bending mode from the main body of the radiation arm at one end of the radiation arm far away from the corresponding balen. The broadband dual-polarization antenna and the radiating unit lengthen path length of current in the radiation arm by fully using space, thereby being capable of reducing size of the radiation arm based on appointed electrical specifications.

The invention discloses a testing device and testing method for simulating the hydraulic fracture characteristic of a concrete bedrock contact surface. The testing device mainly comprises a mold, a steel sheet, pressure measuring guide pipes, a water seal fixture, a water pressure loading system, strain gauges, a clip gauge, a computer and the like. A pair of discs are cut in the mold in a central symmetry mode, can rotate and are used for allowing the steel sheet to be inserted into preformed initial cracks with different thicknesses, widths, roughness and angles; the water seal fixture clamps a test piece in a screwing mode through a screw to seal the water pressure, a high-pressure-resistant water guide pipe is connected with a fixture thread center hole formed in the center of a water seal device through a thread connector, the strain gauges are arranged in the development direction of the cracks, and a coloring agent is added into a water tank connected with the high-pressure-resistant water guide pipe to track the propagation trajectory of the hydraulic fracture cracks. The testing device can be used for studying the hydraulic fracture characteristic of the concrete bedrock contact surface, is simple and convenient to operate and can truly reflect the crack propagation characteristic among contact surfaces of different materials.