64results about How to "Not heavy" patented technology

The invention provides a laser range finder stabilized platform used for a vessel with single degree of freedom and its control method. The laser range finder stabilized platform comprises a machinery support, a navigation attitude sensor, a servo driven controller, a servo motor, a photoelectric encoder and a laser range finder; the machinery support comprises an external support and an internal support, the external support and the internal support are rotationally connected by a transmission shaft; the external support is arranged on the vessel, the navigation attitude sensor is fixed on the external support, the servo motor is arranged on the external support and connected with the internal support through the transmission shaft, the laser range finder is arranged on the internal support, the photoelectric encoder enables coaxial arrangement with the servo motor; the attitude signals from the vessels enable real time acquisition by the navigation attitude sensor and then are input in the servo driven controller, the photoelectric encoder enables real time monitoring of the servo motor rotation angle information and makes a feedback to the servo control driver; a PID regulator is provided in the servo driven controller, the received the signal by the navigation attitude sensor and the feedback signal of the photoelectric encoder can control the rotation of the driving motor through the output signal treated by the PID regulator.

The invention relates to a hyperspectral all-polarization imaging device and method based on a symmetrical wedge-shaped interference cavity. The device comprises a front imaging objective, a symmetrical wedge-shaped interference cavity system, a micro polarization modulation array, a detector and a signal processing system which are sequentially placed in a light path direction. The method comprises steps as follows: Step one, incident light arrives at the symmetrical wedge-shaped cavity via the front imaging objective to form multi-beam interference; Step two, beams pass through the micro polarization modulation array, and a same object point generates four polarization-state interference image points on a target surface of the detector simultaneously after modulated by four polarization pixels of the micro polarization modulation array; Step three, four groups of polarization interference information of a target point under different light path differences are acquired through push-scanning; Step four, the signal processing system acquires two-dimensional light intensity information of a scene, spectral information and all polarization parameters of each spectral segment after spectrum recovery and polarization information reconstruction. The method has the advantages that the spectrum resolution, the light flux and the target resolution are high, the spectrum information and polarization information can be acquired synchronously and the like.

The invention discloses a percussion head of an expectoration instrument, relates to the field of expectoration instruments, and provides the percussion head which achieves percussion through linear motion and is used for the expectoration instrument. The percussion head of the expectoration instrument comprises a shell, an end cover, a motor, a driving disc, a vibration disc, reset springs, a flexible head, an adjusting sleeve and a handle; at least two guide pillars are connected to a lower end plate of the shell; the end cover covers a main shell body; the motor, the driving disc, the vibration disc and the reset springs are coaxially arranged in the main shell body from top to bottom; the motor is connected with the end cover; the driving disc is connected with the motor, bearings arearranged between the driving disc and the main shell body and limit the driving disc to axial movement, an annular driving track is arranged on the driving disc, and the surface of the annular drivingtrack is in a wavy shape; the vibration disc sleeves the guiding pillars, and balls are arranged on the vibration disc; the reset springs make the balls be in contact with the annular driving track;the flexible head is connected with the vibration disc, and the adjusting sleeve is connected with the shell and is adjustable in axial position; the handle is connected with the main shell body.

The invention belongs to the field of bridge reinforcing, and particularly relates to a novel old-arch-bridge reinforcing structure and a construction method thereof. The novel old-arch-bridge reinforcing structure comprises a bridge body 1, an epoxy mortar filling layer 4 is arranged below the bridge body 1, and a transverse stiffening steel frame is arranged on the epoxy mortar filling layer 4.Arc ribs are connected by using prefabricated box-type splicing steel plates 8, and prestress is applied between the arc ribs by using prestressed reinforcements 9. Then concrete is poured at arch feet, the arch rib and steel plate connecting ends and tensioning anchoring anchorage devices to form an integral structure. Finally, H-shaped steel 7, the box type splicing steel plates 8 and weld joints 5 are subjected to painting and other anti-septic treatment. The transverse stiffening steel frame structure comprises an anchor screw rod 2, an anchor bolt 3, a stiffening rib 6 and the H-shaped steel 7. The structure technology of the novel old-arch-bridge reinforcing structure can reinforce arch bridges, construction is simple and convenient, the cost of reinforcement is low, dead weight enhancement is less, and the reinforcement effect is good; and the novel old-arch-bridge reinforcing structure is a relatively economical and safe method to reinforce the arch bridges based on structuralforce analysis.

The invention relates to a calibration device and method for a magnetic probe in a TEM well. The device comprises a Helmholtz coil, a foot stand and a probe in the TEM well, wherein the foot stand is arranged on the top of the Helmholtz coil, and is provided with a central round hole; a calibrated dial with scales of 360 degrees is rotationally arranged on the periphery of the central round hole; during calibration and testing, the probe in the TEM well is inserted into the central round hole of the foot stand, and is connected with the calibrated dial on the foot stand through a hoop. The mounting accuracy (error) of an Hy coil and Hx coil of a horizontal component probe and a posture measuring component can be measured accurately, and the orthogonal deviation values of the Hy and Hx coils can be tested accurately.

The invention discloses a portal frame special for device installation of an urban rail traffic power supply system. The portal frame comprises cross beams. The cross beams are H-shaped I-steel, the two sides of the cross beams are correspondingly connected with first stand columns correspondingly. The bottoms of the first stand columns are correspondingly connected with second stand columns, and the first stand columns vertically stretch out and draw back in the second stand columns. The bottoms of the second stand columns are correspondingly connected with base steel channels, and a plurality of positioning through holes are formed in the second stand columns and correspondingly connected with positioning pins penetrating through the second stand columns. The bottoms of the base steel channels are correspondingly connected with universal trundles, and movable slide wheels are arranged on the cross beams. The portal frame special for device installation of the urban rail traffic power supply system has the advantages that the height can be adjusted, installation, dismantling and moving are convenient, construction is convenient and fast, and destruction and pollution to structural beams or the wall top are reduced.

The invention relates to the technical field of bridge construction, in particular to a bridge pier structure and a construction method thereof. The bridge pier structure comprises a prefabricated bearing platform, a prefabricated bridge pier, a steel plate assembly and a thin-walled circular ring; two groups of first steel rebars and second steel rebars which are arranged in the vertical direction and uniformly distributed in the form of a circumference; the first steel rebars are positioned on the internal sides of the second steel rebars; the top ends of the first steel rebars and the second steel rebars both extend out of the upper surface of the prefabricated bearing platform; a hollow steel tube which runs through the prefabricated bridge pier and is arranged in the vertical direction is embedded in the prefabricated bridge pier; and the prefabricated bridge pier is arranged on the prefabricated bearing platform through the hollow steel tube. The bridge pier structure has the advantages that the structural design is simple; the construction is convenient; as only a small part of later pouring concrete needs to be poured, the construction efficiency is enhanced, and the construction period of the bridge is reduced; the influence of bridge construction on city traffic environment is effectively relieved; and the assembling strength and integrity of the prefabricated bridgepier and the prefabricated bearing platform are also guaranteed.

The invention relates to a lift fan system for an air cushion ship model. An air channel is formed in an air cushion ship model body. The lift fan system is characterized in that a lift fan group is arranged above the air cushion ship model body, and is formed by connecting two fans in series; the two fans are arranged one above the other; an air outlet positioned on the lower fan is connected with a sleeve; the bottom of the sleeve is connected with the air cushion ship model body; the sleeve is communicated with the air channel in the air cushion ship model body.

The invention provides an insulation water retaining aerial cable which comprises a conductor, a shielding layer and an insulation layer. The conductor is composed of an inner core portion formed by 8-12 aluminum alloy leads arranged in the center of a cable and an outer core portion formed by 8-11 pure aluminum leads arranged on the outer layer of the inner core portion. Water retaining yarn fills the space among the leads, an inner shielding layer is wrapped outside the conductor, the insulation layer is wrapped outside the inner shielding layer, the cable can prevent water corrosion completely, a good electric conducting performance is guaranteed, and the weight is not large. The invention further provides a manufacture method of the insulation water retaining aerial cable.

The invention provides a battery cover, a preparation method of the battery cover, and a mobile terminal. The preparation method of the battery cover comprises the following steps: providing a ceramicsubstrate, wherein the ceramic substrate comprises an inner surface and an outer surface which are oppositely arranged; forming a reinforcing layer covering the ceramic substrate on the inner surfaceof the ceramic substrate; processing the outer surface, so that the thickness of the ceramic substrate is reduced to a first preset thickness; and processing the reinforcing layer, so that the thickness of the reinforcing layer is reduced to a second preset thickness. The thickness of the ceramic substrate in the battery cover can be reduced to an expected value under the condition that the ceramic substrate is not broken, and the prepared battery cover has sufficient structural strength on the premise that the weight of the prepared battery cover is close to a glass front cover.

The invention provides a light power transmission line suspension clamp pin mounting device and a using method thereof. The suspension clamp comprises a U-shaped frame, a clamp hull is arranged in theU-shaped frame, a sliding block is installed at the bottom of the clamp hull, a sliding rail is arranged at the bottom of an inner cavity of the U-shaped frame, the sliding rail is in sliding connection with the sliding block through the sliding block in the sliding rail, and a first spring is installed on one side of the sliding block. Second spring, a riveting aluminum pressing plate and a plastic wire pressing plate match one another. A cable penetrates through the hollow inner part of the ship clamping body. The second springs on the two sides are used for telescopic extrusion; the riveting aluminum pressing plates on the two sides and the plastic wire pressing plates on the two sides extrude each other, so that cables and the clamp ship body are clamped, the loosening phenomenon isnot prone to occurring, relative movement between the cables and the clamp ship body can be reduced, abrasion of the cables can be effectively reduced, the overall weight of the clamp is not heavy, and the load of a tower can also be reduced.

The invention provides an invisible reinforcing device for concrete cantilever gallery road and a reinforcing method thereof. The device comprises a concrete cantilever component and a long reinforcing steel bar, wherein stirrups and tensile bars are arranged in the concrete cantilever component; the free end of the concrete cantilever component is provided with a blind hole I which is longitudinally formed; a reinforcing steel bar I is fixedly arranged in the blind hole I; a round ring I is fixedly arranged at the end, extending out of the blind hole I, of the reinforcing steel bar I; a blind hole II is longitudinally formed in the cantilever end of the concrete cantilever component, and a reinforcing steel bar II is fixedly arranged in the blind hole II; a round ring II is arranged at the end, extending out of the blind hole II, of the reinforcing steel bar II, and can rotate around the axis of the reinforcing steel bar II at 360 degrees; one end of the long reinforcing steel bar is fixedly connected with the round ring I, and the other end of the long reinforcing steel bar runs through the round ring II and is fixedly arranged on a rock wall; and a strain gauge is adhered to the long reinforcing steel bar between the rock wall and the round ring II. According to the reinforcing method, prestress is applied to a component to improve the safety of the component; and construction under the component can be avoided, and scaffold construction is not required.

The invention discloses prefabricated pipe joint assembly equipment and a construction method thereof. The prefabricated pipe joint assembly equipment comprises a supporting-connecting mechanism, a positioning mechanism, a tensioning mechanism and a power system, wherein the supporting-connecting mechanism comprises a lifting device and a supporting-connecting frame; the lifting device comprises a lifting oil cylinder and a steel supporting plate; the positioning mechanism comprises a rectangular rear positioning frame, positioning oil cylinders and clamping parts; the positioning oil cylinders are correspondingly arranged on four corners of the rectangular rear positioning frame; the clamping parts are fixedly connected with the front ends of the piston rods of the positioning oil cylinder; the tensioning mechanism comprises telescopic oil cylinders and sliding guide rails; and the power system comprises a hydraulic pump, a control valve group and an oil tank. By adoption of the prefabricated pipe joint assembly equipment and the construction method, a one-step forming and assembly process of a prefabricated assembly-type comprehensive pipe rack can be achieved; the one-step forming and assembly process comprises the steps of pipe joint supporting and connection, adjusting and aligning, tensioning, and the like; and the operation is simple, the working efficiency is high, the working period is short, the degree of mechanization is high, the labor intensity is low, the labor cost is reduced, and the environmental pollution is reduced.

The invention relates to a plate cabinet mounting lifting frame of an urban rail transit power supply system. The plate cabinet mounting lifting frame is wholly of a detachable structure. The plate cabinet mounting lifting frame comprises an I-shaped steel beam and first vertical columns, wherein the first vertical columns are arranged below the I-shaped steel beam, the first stand columns are movably connected with second stand columns, and a plurality of positioning pins used for adjusting the heights are arranged on the second stand columns; a pulley block and an electric hoist are movablyconnected below the I-shaped steel beam, universal wheels are arranged below the second stand columns, base steel channels are arranged between the second stand columns and the universal wheels, inclined supporting steel channels for supporting the second stand columns and the base steel channels are arranged between the second stand columns and the base steel channels; and the universal wheels are provided with brake systems. The plate cabinet mounting lifting frame has the advantages that the electric hoist is directly installed on the movable pulley block on the lifting frame to carrying out hoisting installation on a plate cabinet, so that the damage and pollution to a structural beam or the wall top is reduced; the plate cabinet mounting lifting frame is high in structural strength, and not easy to deform; and the plate cabinet mounting lifting frame greatly improves the installation efficiency of the plate cabinet, saves the labor, and reduces the safety risk of aloft operation.

Circular hood type soft blast tube is composed of fan, soft blast tube and circular hood etc. In time of air blowing, circular hood is plumped up, and blast tube is supported circularly so as to be good for a expedite flue. The soft blast tube is prepared as following: a round of circular hoods are tailored on inner wall of the blast tube in every distance (about 1.5 M); material of circular hood is same to material of the blast tube; being cutting up into a long strip, cloth of circular hood is tailored on inner wall of the blast tube in transverse direction directly; several holes of circular hood prepared when tailoring circular hood. Cloth of circular hood is in use for front circular hood and back circular hood. After being sewed, the back circular hood is closed, no air going through. It is not sewing on the said holes on front circular hood. Thus, entering through the holes, wind plumps up the soft blast tube.

A voltage sensor suitable for field measurement of a transformer substation comprises a grading ring, a primary voltage sensing unit, an acquisition transmission unit and an elevating platform. According to the voltage sensing unit, a high-voltage capacitor and a low-voltage capacitor are composed of parallel-board capacitors; and high-voltage capacitor and the low-voltage capacitor are filled with air, thereby forming a gas capacitor. The high-voltage capacitor is composed of three gas capacitors with polar distances of 1.5m. The low-voltage capacitor is composed of one gas capacitor with polar distance of 0.04m. The high-voltage capacitor and the low-voltage capacitor realize voltage shunting through serial connection. The acquisition transmission unit is arranged below the low-voltage capacitor. Furthermore the acquisition transmission unit is connected with the low-voltage capacitor through an optical fiber. The acquisition transmission unit is obtained through successively connecting a signal processing module, an A / D conversion module and an FPGA. A signal which is output from the acquisition transmission unit is transmitted to a subsequent processing terminal through the optical fiber. The voltage sensor has advantages of realizing live verification to an electronic voltage transformer, shortening verification period, simplifying operation step, preventing loss caused by power failure, and improving accuracy and reliability in online verification of the electronic voltage transformer.

The invention relates to a cutting machine of strip-shaped slice material, which belongs to the field of machinery. The cutting machine comprises a machine body and a disc-shaped cutter blade arranged at the cross section of the machine body; the disc-shaped cutter blade and the upper surface of the machine body form a Beta angle; the cutting machine is characterized in that the upper end of the machine body is provided with a flexible coil and a coil rotating motor device, and a position on the lower end of the machine body which corresponds to the disc-shaped cutter blade is provided with a hanging driving motor; the hanging driving motor and the disc-shaped cutter blade are respectively provided with a hanging driving wheel and a hanging driven wheel which are connected by a convex groove guide rail; the cutting machine adopts the DC motor, is easy to regulate speed and realize reverse and positive rotation, and has the advantages of simple machine structure design, light weight, time and labor saving in automatic control, safety and high efficiency.

A Chinese medicine in the form of coated tablet for treating gynopathy is prepared from the active components extracted from 7 Chinese-medicinal materials including zedoary, microcrystalline cellulose, hydroxypropyl cellulose and SiO2 proportionally. Its preparing process is also disclosed.

The invention discloses a device for measuring a flight trajectory of a flying insect without contact. The device comprises a receiver array, a transparent top cover and a base, the transparent top cover and the base are combined to form an enclosed space for insect activities, the base is provided with an infrared ray emitting source which can emit spherical infrared rays to the outside, and thereceiver array is uniformly and compactly installed at the inner side of the transparent top cover, can receive the infrared rays emitted by the infrared ray emitting source, and is connected with a signal processing device through a signal line; a method for measuring the flight trajectory of the flying insect without contact comprises the steps that in a dark environment, the infrared emitter isturned on, the position of a receiver which does not receive the infrared rays is determined, three-dimensional coordinate parameters of the insect are calculated by using a formula according to theposition of the receiver, and the flight trajectory of the insect is obtained by comparing a large number of coordinate parameters. By means of the device and method for measuring the flight trajectory of the flying insect without contact, the flight trajectory can be measured without causing any harm to the flying insect or by reducing human influence on the flying insect as much as possible.

A cold storage wall is characterized in that the cold storage wall comprises a matrix wall, polyurethane foam layers and vacuum insulation boards, wherein, vacuum insulation boards are inserted in the polyurethane foams of different thickness, and the vacuum insulation boards in each thickness layer are arranged in intervals; the thickness of the polyurethane foam layers is between 8mm and 25mm; material A of the polyurethane foam layer is isocyanate and material B is polyester polyol and auxiliary agent. The construction method of the wall comprises the steps of (1) spraying a polyurethane foam layer; (2) paving the vacuum insulation boards in intervals, and spraying a layer of polyurethane foam; (3) repeating step (1)-(2) to obtain a polyurethane foam layer wall that has the vacuum insulation boards inserted in. The beneficial effects of the present invention are that (1) the heat insulation effect is good; (2) the construction is convenient; and (3) the cold storage wall slit condensed water is prevented from icing and destroying the wall structure.

The invention provides a semi-prefabricated concrete column module and belongs to the technical field of buildings. The semi-prefabricated concrete column module is structurally composed of hollow concrete blocks, longitudinal reinforcing steel bars, spiral stirrups and carbon fiber cloth. The longitudinal reinforcing steel bars and the spiral stirrups are arranged in solid parts of the concrete blocks. The concrete blocks are connected through the carbon fiber cloth. The longitudinal reinforcing steel bars are arranged on the four edges of each block in the length direction of the hollow concrete block. Each spiral stirrup is spirally arranged on the outer side of the corresponding longitudinal reinforcing steel bars. In a construction field, all column modules only need to be vertically stacked together and are connected through pasting the carbon fiber cloth, the longitudinal reinforcing steel bars are inserted in the hollow parts, then the concrete is poured, and therefore a column can be formed.

A diff case (4) is attached to a side face of a ring gear wheel (48) on the opposite side to the side on which the ring gear wheel (48) and a pinion gear wheel (35) mesh with each other. The ring gear wheel (48) integrally has a boss portion (54), in which a driven shaft is fitted, on the meshing side with the pinion gear wheel (35). An annular member (56) slidably movable in an axial direction thereof is provided on the boss portion (54) with a guide portion for guiding the annular member (56). A lock pin (70) is provided on the annular member (56) for inserting into pin holes (71, 72) formed in the ring gear wheel (48) and a left output side cam to place the differential mechanism into a locked state. A sliding region within which the annular member (56) slidably moves is disposed so as to be included in a projection region of the diameter of the pinion gear wheel (35).

The invention discloses a metering type material feeding device comprising a material box, a material distributing device connected with the material box, a limiting device and a hopper fixed to the upper end of the material box. The material distributing device comprises a rotating shaft fixed to the upper end of the inner wall of the material box, and a plurality of material distributing trays fixed to the side wall of the rotating shaft in a mode of an annular array. The section in the vertical direction of each material distributing tray is triangular, and the vertex angle end on one sideof each material distributing tray is fixed to the side wall of the rotating shaft. The limiting device comprises a motor fixed to the material box and a limiting disc connected with the motor. A plurality of grooves are annularly distributed on the side edge of the limiting disc, and the widths of the grooves are the same as the widths in the direction of the medial axis of the rotating shaft ofthe material distributing trays. The hopper is of an inverted tapered structure. The lower end of the hopper is provided with a discharging pipe. The discharging pipe is arranged towards the side, close to the limiting device, of the rotating shaft and located above the distributing trays. The metering type material feeding device is in a pure mechanical structure, can realize quantitative feeding, and is simple in overall structure design.

A display which does not require color filters, has low optical losses, and is not heavy and large, and a method for displaying an image using the display includes a substrate on one side of which sub-pixels are arranged. Each sub-pixel includes two opposite electrodes and an emitter layer which is interposed between the two electrodes. The emitter layer receives the light projected from an excitation light source, and is able to radiate photoluminescence light. The photoluminescence light from the emitter layer may be controllably quenched by an electrical field formed by the electrodes.

The invention relates to a combined mold which comprises a shape follow-up mold and a supporting mold. The shape follow-up mold comprises a main body, a reinforcing layer, a working surface and an assembling surface, the main body is formed by pressing or printing granular materials, a reinforcing layer is arranged on the surface of the main body, or the reinforcing layer permeates into the surface of the main body, the surface, in contact with a sand mold cavity, of the main body is a working surface, the other opposite surface is the assembling surface, and the supporting mold is mounted onone side of the assembling surface of the main body and matched with the assembling surface in shape. A particle material convenient to form is used for printing or pressing to form the shape follow-up mold, the advantage that the particle materials are convenient to form is utilized, the defect that the particle materials are insufficient in hardness is overcome through the reinforcing layer withhigh tensile strength and hardness, the supporting mold serves as a filling material, and therefore the problems of the overall tensile strength and hardness are solved; and meanwhile, the overall mass can be light, and therefore the combined mold which makes up for the defects and integrates all the advantages is obtained.

An electric automobile side wall comprises a side wall inner plate assembly, an outer skin and a door-opening-surrounding reinforcing assembly located between the side wall inner plate assembly and the outer skin. According to the electric automobile side wall, through the three layers of parts from inside to outside, the structure strength of the periphery of an automobile door frame is improved; the electric automobile side wall is of a hollow structure and low in weight; and the electric automobile side wall is low in weight and high in strength, lightweight design of a whole automobile is facilitated, and the endurance mileage of the whole automobile can be increased.

According to the external hanging type microscope and the intelligent terminal, the intelligent terminal comprises the terminal shell and the camera, the microscope comprises the magnifying lens module and the clamping module, the magnifying lens module can be configured to be detachably fixed to the terminal shell, and when the magnifying lens module is fixed to the terminal shell, the clamping module can clamp the magnifying lens module. The camera abuts against the magnifying lens module and is used for collecting optical signals passing through the lens assembly. The clamping module is configured to be detachably fixed to the magnifying lens module and / or the terminal shell, and a clamping space used for clamping or placing a flat observed object is formed between the clamping module and the first side of the magnifying lens module. The flat observed object can be clamped or placed in the clamping space, so that the situation that the flat observed object deviates from the light path observation position and even falls off from the clamping space due to the fact that the intelligent terminal is moved, shaken or inclined in the magnification observation process can be avoided, and the intelligent terminal is moved, shaken or inclined in the magnification observation process; and the flat observed object can still be clearly observed.

The invention provides production equipment and a production process for an edge-turned flange of a large pipe. The production equipment for the edge-turned flange of the large pipe is characterized by comprising the large pipe, a stepped inner shaft stretching into an end part body of the large pipe, and an outer die sleeve clamped at the end part of the large pipe and the periphery of the innershaft, wherein a limit ring used for being fixed into the end part body of the large pipe is arranged on a first end part of the stepped inner shaft in a sleeved manner; the shaft diameter of the first end part of the stepped inner shaft is less than the shaft diameter of an inner pipe wall of the large pipe, so that an annular gap ring is formed; a groove is formed in the inner wall surface of the outer die sleeve; the groove and the annular gap ring form a pouring cavity body used for producing the edge-turned flange; a central pouring flow channel, as well as a pouring-in port and a pouring-out port which communicate with the central pouring flow channel are formed in the stepped inner shaft; and the pouring-out port faces the pouring cavity body. The production equipment for the edge-turned flange of the large pipe is beneficial to facilitating to production for the flange on the end part of the large pipe, and facilitates to the subsequent installation.

The invention relates to a computer reading device. The bottom surface of the computer reading device is a semiellipsoid; one side is provided with a recess of an inverted lingulate groove; the lower part of the inverted lingulate groove is provided with a notch; on the semiellipsoidal bottom, a battery case is arranged below the inverted lingulate groove; and two wires of the positive and negative poles of the battery case are arranged in a metal support sleeve and connected with a bulb. The invention has the advantages of low weight and small volume, and has the functions of a manuscript clamp for type-in and reading, a reading light, a pen holder and a letterweight; and the functions of the invention do not interfere with each other.