44results about How to "Easy to implement and promote" patented technology

The invention relates to a fixing assembly for a mask plate. The fixing assembly comprises a frame with an evaporation area. The frame is used for fixing the mask plate covering the evaporation area, and supporting strips which are detachably arranged on the frame and penetrate through the evaporation area to be used for supporting the mask plate. According to the fixing assembly for the mask plate, the deformation degree of the mask plate can be reduced, and the shape of a solid thin film formed after evaporation is completed is promoted to be nearly consistent with an expected shape.

The invention relates to a powder grinding device which comprises a main body, an abrasive wheel assembly arranged in the main body, a rotary adjusting ring arranged on the abrasive wheel assembly and used for adjusting crudeness and fineness of powder ground by the abrasive wheel assembly, a power source arranged on the main body and used for promoting rotation of the rotary adjusting ring, and an angle controller arranged on the main body and used for controlling the rotation angle of the rotary adjusting ring. According to the powder grinding device, the crudeness and fineness of the ground powder are adjusted by the adoption of an electric control mode, so that the use of the powder grinding device is simple, and the level in people's heart is improved.

The invention relates to a travelling device for an arch bridge. The travelling device comprises a guide rail and a moving unit. The guide rail is fixedly arranged on the bottom surface of the arch bridge. A chain is fixedly arranged at the bottom end of the guide rail. The moving unit is suspended on the guide rail through suspension mechanisms. Chain wheels and power sources are arranged on the moving unit. The power sources can drive the chain wheels to rotate on the chain, and the moving unit is enabled to move on the guide rail. The travelling device is simple in structure, convenient to produce, stable and reliable in operation and convenient to operate, popularize and apply.

The invention relates to a dry type etching machine and a gathering device for gathering magnetic particles in the gas. The dry type etching machine sequentially comprises an etching device, an air draft device and the gathering device in the gas flowing direction, wherein the gathering device is arranged between the etching device and the air draft device. The gathering device comprises a casing and a magnetic filtering unit arranged in the casing. Channels are formed between the magnetic filtering unit and the casing, and/ or in the magnetic filtering unit, wherein the magnetic filtering unit can adsorb the magnetic particles in the gas flowing through the channels to prevent the magnetic particles from being deposited in the air draft device, therefore, the air draft efficiency of the air draft device is increased, and the service life of the air draft device is prolonged.

The invention relates to a multi-stage cyclone dehydration device which comprises a barrel, an air inlet formed in the side wall of the barrel, an air outlet formed in the top of the barrel, a water outlet formed in the bottom of the barrel, a core tube arranged in the barrel and a curved baffle plate surrounding the periphery of the core tube, wherein the curved baffle plate limits a spiral flow channel surrounding the outside of the core tube in an upper area in the barrel, and limits a liquid collecting cavity in a lower area in the barrel; the spiral flow channel is connected with the air inlet; the core tube is connected with the air outlet; the liquid collecting cavity is connected with the water outlet; and when a gas carrying a liquid enters the inside of the spiral flow channel from the air inlet, the gas rotates and enters the liquid collecting cavity under the action of the spiral flow channel, the liquid is separated from the gas under the action of centrifugal force and flows outside through the water outlet, and the gas enters the core tube and flows outside from the air outlet. The multi-stage cyclone dehydration device is capable of carrying out efficient dehydration on the gas carrying the liquid in a wet dust removal system, and is low in resistance and high in dust removal efficiency.

The invention relates to a running device for an arch bridge. The running device comprises guide rails fixedly arranged on the undersurface of the arch bridge and moving units hung on guide rail assemblies through hanging mechanisms, wherein a chain is fixedly arranged at the bottom end of each guide rail; chain wheels and a power source are arranged on each moving unit. Due to the construction of the power sources, the chain wheels can be driven to rotate on the chains, so that the moving units move on the guide rails. The running device for the arch bridge is simple in structure, convenient to produce, stable and reliable in operation and convenient to apply and popularize.

The invention relates to a cleaning brake control method based on a railway vehicle, comprising the following steps: S1: judging that the train enters a braking state, and detecting that the train hasa braking instruction; S2: indexing location library information, performing comparative analysis with the actual running position of the current vehicle, and outputting that the 'position condition'is effective at a position meeting the cleaning brake preset conditions; S3: indexing load library information, performing comparative analysis with the actual load of the current vehicle, and outputting that the 'load condition' is effective at the load meeting the cleaning brake preset conditions; S4: enabling a control module to send a 'cleaning brake flag bit' to an electric brake system under the condition that the conditions are all met; S5: comparing the total cleaning brake energy Ec with preset total cleaning brake energy ES to make a judgement; S6: after cleaning brake is ended, removing the 'cleaning brake flag bit', and recovering the electric brake function of the electric brake system. The cleaning brake control method has the advantages of being simple in principle, easy torealize and popularize, and capable of improving the cleaning effect.

The invention relates to a single-ankle type knee joint prosthesis which comprises components of an ankle base with a sinking hole and/or through hole, wherein the ankle base comprises a chamber outerpart, a boss type chamber inner part and a fin type chamber inner part, wherein the chamber outer part comprises a first bone surface copying surface, a first folding surface, a joint bone top surface and a joint bone side surface, the boss type chamber inner part is arranged on the joint bone top surface, and the fin type chamber inner part is arranged on the joint bone side surface; and an ankle cap which comprises a second bone surface copying surface and a second folding surface, wherein the second folding surface is in matched connection with the first folding surface and the ankle cap packages the bottom end of the ankle base. and the second bone surface copying surface can be independently used as a femur ankle joint surface and is in matched splicing with the first bone surface copying surface. The single-ankle type knee joint prosthesis can match the tibia of a patient, thereby preventing tibia cutting operation of a patient with femur ankle lesion and without tibia lesion inknee joint displacement surgery by a doctor, effectively reducing bone cutting operation difficulty and loss amount of high-quality sclerotin, reducing wound area caused by the surgery, and shortening an after-surgery recovering time length.

The invention relates to cooking equipment. The equipment comprises an equipment main body comprising an open inner container, a door body pivoted with the open inner container, and a cooking space defined by the open inner container and the door body; an air supply mechanism which is connected with the open inner container; and an exhaust mechanism which is connected with the open inner container, wherein the cooking equipment further comprises a releasing assembly and/or an actuating assembly, the releasing assembly is arranged in the cooking space and can release the low-temperature fresh air input by the air supply mechanism into the high-temperature old air in the cooking space in a scattered mode, and the actuating assembly is arranged in the equipment body and can promote the high-temperature old air and the low-temperature fresh air in the cooking space to be mixed with each other. According to the cooking equipment, the defects that after the cooking equipment is used, indoorcooling is uneven, and the cooling rate is difficult to increase can be overcome, and therefore, the risk that exhausted gas scalds users, especially impetuous users, can be further reduced.

The invention relates to a hinge with a locking function. The hinge comprises a first rotary body, a second rotary body, a hinge shaft and an insertion rod, wherein the first rotary body comprises a mounting part and a rotary connecting part; a first insertion hole is formed in the rotary connecting part; the second rotary body comprises another mounting part and another rotary connecting part; a second insertion hole is formed in the rotary connecting part of the second rotary body; the hinge shaft penetrates into both the first rotary part and the second rotary part; when the first rotary body rotates relative to the second rotary body repeatedly, the included angle between the mounting parts of the first rotary body and the second rotary body changes repeatedly in a set range, and the relative state of the first inserting hole and the second insertion hole can switch between a coaxial state and a staggered state; when the first insertion hole and the second insertion hole are coaxial, the insertion rod can be inserted into both the first insertion hole and the second insertion hole under the action of external force, so as to prevent the first rotary body and the second rotary body from rotating relatively. The hinged provided by the invention integrates the functions of a lock and a common hinge into a whole body, so as to reduce the cost and lower the assembly difficulty of the product.

The invention relates to a hinged knee prosthesis comprising: a femoral assembly comprising a femoral condyle and a femoral medullary pin connected to the femoral condyle; a tibial assembly comprisinga tibial tray, a tibial medullary pin and a tibial pad, the tibial pad comprising a pad body and a hollow shaft, and the hollow shaft first passing through the tibial tray and then being coaxially inserted into the tibial medullary pin; and a hinge assembly comprising a hinged member disposed in a intercondylar notch of the femoral condyle and inserted into the hollow shaft and a hinged shaft passing through the femoral condyle and the hinged member. The tibial assembly is rotatable relative to the femoral assembly with the hinged shaft as the axis to allow the hinged knee prosthesis to perform flexion and extension. The tibial tray and the tibial medullary pin are rotatable relative to the tibial pad and the femoral assembly with the hollow shaft of the tibial pad as the axis to allow the hinged knee prosthesis to perform internal and external rotation. The hinged knee prosthesis of the invention can perform flexion and extension well as internal and external rotation, thereby effectively improving the flexibility of use thereof.

The invention relates to a light-emitting device and a backlight module. The light-emitting device comprises a substrate provided with a first electrode pin and a second electrode pin, a reflecting layer arranged on the upper surface of the substrate, a fluorescent layer arranged on the upper surface of the reflecting layer, and an LED chip embedded between the reflecting layer and the fluorescent layer. The LED chip is connected with the first electrode pin and the second electrode pin through two wires penetrating through the reflecting layer respectively. According to the light-emitting device, it can be avoided that light rays of the LED chip are shielded by terminals and the wires, and thus the brightness and the evenness of the light-emitting device can be improved.

The invention relates to a method and device for managing and controlling household equipment and an intelligent robot. The method comprises: 101, judging whether a set user leaves a target residenceor not according to a departure response signal provided by departure response equipment, and if the set user leaves the target residence, executing the step 102; 102, judging whether the gas equipment is turned off or not according to a working state signal provided by gas equipment in the target residence, and if the gas equipment is not turned off, executing the step 103; and step 103, commanding the gas equipment to be automatically turned off. According to the method, the device and the intelligent robot, the gas equipment can be actively turned off after the set user leaves the target room, so that the fire risk of the target residence is effectively reduced, and indoor potential safety hazards are eliminated to a certain extent.

The invention relates to a drop type arrester. The drop type arrester comprises an insulator, a rainproof cap, a drop device and a zinc oxide arrester main body, wherein the left end of the rainproof cap is connected with the upper end of the insulator, and a conducting component with a clamping groove is arranged in the rainproof cap; the left end of the drop device is connected with the insulator; the upper end of the zinc oxide arrester main body is connected with the right end of the rainproof cap, a fixing sleeve and a thermal explosion type disconnector are arranged on a lower end threaded rod of the zinc oxide arrester main body, the fixing sleeve is connected with the right end of the drop device, the internal thread of the thermal explosion type disconnector is matched with a lower end threaded rod of the zinc oxide arrester main body, and the fixing sleeve is fixed onto the lower end threaded rod of the zinc oxide arrester main body. According to the drop type arrester disclosed by the invention, the drop device is connected with the lower end threaded rod of the zinc oxide arrester main body through the fixing sleeve and the thermal explosion type disconnector, the arrester does not exert pressure on piezoresistors therein, and then the zinc oxide arrester main body has a better lightning-protection effect.

The invention relates to a pair of pliers, which comprises a pliers head and a pliers handle, wherein the pliers head is provided with a first pliers element and a second pliers element, a first pliers jaw element and a second pliers jaw element are respectively arranged on the first pliers head element and the second pliers head element, the first pliers jaw element is provided with a first clamping surface, the second pliers jaw element is provided with a second clamping surface, a convex strip is arranged on the first clamping surface, and a groove is formed in the second clamping surface, wherein when the first pliers head element is combined with the second pliers head element, the convex strip can enter the groove, and when the first pliers head element is separated from the second pliers head element, the convex strip can be moved out from the groove. The pliers provided by the invention have the advantages that a metal wiring terminal is flatted through clamping by the convex strip and the groove, and the flattening clamping mode can ensure that the metal wiring terminal can still be effectively flattened through clamping after the pliers are frequently used, so that a conducting wire can be firmly fixed in the metal wiring terminal, and the occurrence of an open circuit phenomenon is prevented.

The invention relates to a carrying clamp and stacking equipment. The carrying clamp comprises a base connected with a carrying device, a first clamping piece and a second clamping piece, wherein thefirst clamping piece and the second clamping piece are arranged on the base and can be used for clamping box-type products, the first clamping piece and the second clamping piece can move relatively,an inserting arm extending in the direction away from the first clamping piece is arranged on the side, away from the second clamping piece, of the first clamping piece, and the inserting arm can bearthe box-type products. According to the carrying clamp and the stacking equipment, the problems that in the prior art, a clamp cannot be suitable for various types of box-type products, and only onebox-type product can be clamped at the same time can be solved, so that the stacking efficiency is improved.

The invention relates to a maintenance base for a display device. The maintenance base comprises a first frame, a second frame, a telescopic bracket, a screw lead assembly and a power mechanism, wherein the second frame is parallel to and spaced from the first frame; the telescopic bracket is arranged between the first frame and the second frame; the screw lead assembly is arranged between the first frame and the second frame; and the power mechanism is arranged on either the first frame or the second frame. The second frame, which is driven by the power mechanism through the screw lead assembly, can move towards or away from the first frame, so that the telescopic bracket can do an expansion or contraction motion along with the second frame. According to the maintenance base for the display device provided by the invention, the second frame provided with the display device can be automatically pushed out when the display device is to be maintained and repaired, so that the display device can be maintained and repaired by the maintenance personnel.

The invention discloses cleaning equipment. The cleaning equipment comprises a liquid storage tank, a sterilizing device and a spray nozzle which are arranged in sequence along the flow direction of cleaning liquid, wherein the sterilizing device comprises an ultraviolet lamp for sterilizing the cleaning liquid. The cleaning equipment according to the invention can be used for sterilizing the internal cleaning liquid in order to prevent objects to be cleaned from being polluted in a cleaning process.

The invention relates to a press-fitting tool for an inverted shoulder joint prosthesis. The press-fitting tool for an inverted shoulder joint prosthesis comprises a bracket capable of holding a mortar cup of the reverse shoulder joint prosthesis; An indenter having a spherical surface of a spherical socket surface that matches a cushion of a top-pressure inverse shoulder prosthesis; A linear pressure apply mechanism is connected with the bracket and the pressure head. When the cup of the reverse shoulder joint prosthesis is held by the bracket, the linear pressing mechanism can be operated todrive the pressing head to move toward the cup, and the cushion placed between the cup and the cup is pressed into the cup by the pressing head, so that the cushion is locked in the cup. The press-fitting tool can help the operator to press the cushion of the reverse shoulder joint prosthesis into the cup safely, and the cushion is locked in the cup. The press-fit tool can help the operator to press the cushion of the reverse shoulder joint prosthesis into the cup safely.

The invention relates to a device for pressing a magnet into a cup cover. The device comprises a base, a restraining member arranged on the base and capable of containing or clamping the cup cover, and a pressing mechanism arranged on the base and capable of pressing a magnetic component into an assembling groove of the cup cover. When the device for pressing the magnetic component into the cup cover is used, the cup cover is first contained or clamped through the restraining member, and then the magnetic component is pressed into the assembling groove of the cup cover through the pressing mechanism, so that the pressing of the magnetic component is completed. Due to the fact that the device carries out the pressing operation of the magnetic component by replacing manual pressing with a mechanical pressing mode, the device not only can reduce the labor intensity paid by an operator in the assembling process and improve the working efficiency of the operator, but also can reduce the risk of accidental injury of the operator in the pressing process.

The invention relates to a falling type lightning arrester. The falling type lightning arrester comprises a ceramic insulator, a rainproof cap, a falling device and a zinc oxide lightning arrester main body, wherein the rainproof cap is provided with an inverted U-shaped part and two sheet-shaped guide parts; the inverted U-shaped part is internally provided with a conductive part; the falling device comprises a first conductive base and a second conductive base; the first conductive base is connected with the lower end of the ceramic insulator; the zinc oxide lightning arrester main body is connected with the second conductive base and is hung in a hook groove of the first conductive base through a hook of the second conductive base, so that the zinc oxide lightning arrester main body can rotate relative to the ceramic insulator. When the zinc oxide lightning arrester main body rotates upward relative to the ceramic insulator, the upper end of the zinc oxide lightning arrester main body enters the rainproof cap under the guide effect of the sheet-shaped guide parts and is in clamping joint with a clamping groove. The rainproof cap of the falling type lightning arrester provided by the invention is used for integrally combining a traditional rainproof cap and a guide fork so as to guarantee that the rainproof cap of the falling type lightning arrester has a guide function, and an assembling process can also be simplified, so that the production efficiency is easily improved.

The invention relates to a riveting connection die and riveting pressure equipment. The riveting connection die comprises an upper die which comprises an upper die base body and a first pressing riveting structure arranged on the upper die base body, a lower die, N first locking mechanisms and a second locking mechanism. The lower die comprises a lower die base body, a rotating disc arranged on the lower die base body and N second pressing riveting structures arranged on the rotating disc, each second pressing riveting structure can receive a set of fasteners, and N is a positive integer larger than or equal to 2; the N first locking mechanisms are arranged on the lower die base body; and the second locking mechanism is arranged on the lower die base body. When the rotating disc rotates on the lower die base body and stops at the position where the ith first locking mechanism and the second locking mechanism can be promoted to be interlocked, the ith second pressing riveting structure is forced to be aligned with the first pressing riveting structure; and the first pressing riveting structure and the ith second pressing riveting structure can rivet a sheet metal part and a group of fasteners between the upper die and the lower die when the upper die and the lower die are combined, and i belongs to [1, N]. The riveting connection die is higher in use efficiency and better in riveting pressure quality.

The invention relates to a sealing tool and a system for sealing detection of a sealed container, and the sealing tool comprises a tool main body which is used for being connected with a driving device and comprises a small-diameter cavity, a large-diameter cavity, and an annular plane formed between the small-diameter cavity and the large-diameter cavity; a gas injection port which is formed in the tool main body in the radial direction, is communicated with the small-diameter cavity and is used for being connected with a gas charging device; a sealing washer which is fixed in the large-diameter cavity of the tool main body and abuts against the annular plane of the tool main body, wherein the tool body is arranged on the connector of the closed container in a sleeving mode, and the large-diameter cavity can be used for containing the connector of the closed container so the sealing washer can abut against the connector of the closed container. The sealing tool and the system for sealing detection of the sealed container can be connected with the sealed container in a sealed mode, the problem that the sealed container with good sealing performance is judged to be a defective product is solved, and therefore the situation that the yield of the sealing tool is reduced due to misjudgment is avoided, and the manufacturing cost of the sealed container is effectively reduced.

The invention relates to the field of assembly type concrete prefabricated component installation, in particular to a Y-shaped supporting device for temporary supporting of prefabricated wall. The Y-shaped supporting device comprises a Y-shaped supporting rod, three fixed supports and three telescopic adjusting rods, wherein the Y-shaped supporting rod comprises a first supporting rod, a second supporting rod and a third supporting rod, the telescopic adjusting rods are respectively fixed on the fixed supports, and the first supporting rod, the second supporting rod and the third supporting rod are respectively connected with one telescopic adjusting rod. The whole supporting device is in a Y shape, the cross coupling is installed, so that an included angle between the support and the building ground can be effectively avoided, an included angle can be formed between the Y-shaped supporting rod and the vertical face of the wall, and therefore, obstacles on the ground of the building or reserved holes are effectively avoided. The length of the Y-shaped supporting rod can be adjusted through the telescopic adjusting rods, the installation of prefabricated walls of different sizes can be adapted, the occupied space is small, use is efficient and convenient, the standardization degree is high, and implementation, popularization and application are convenient.

The invention relates to an overturning and transporting device for a composite air deflector. The overturning and transporting device comprises a support, a storage assembly, a clamping mechanism, adriving mechanism and a conveying mechanism, wherein the storage assembly comprises a bearing component rotationally arranged on the support; the clamping mechanism is arranged on the storage assemblyand can clamp the composite air deflector; the driving mechanism is arranged on the support and used for driving the storage assembly to overturn; and the conveying mechanism is arranged below the bearing component. The driving mechanism can drive the storage assembly, the clamping mechanism and the composite air deflector to overturn and make an inner plate and an outer plate of the composite air deflector separated from each other so that the clamping mechanism can release the overturned composite air deflector onto the conveying mechanism. By means of the overturning and transporting device, the problem that no device can replace manual work to overturn and transport the composite air deflector in the prior art is solved, the composite air deflector can be overturned after the attaching procedure and conveyed to the position in front of a press machine, the labor cost can be effectively reduced, and the production efficiency of the composite air deflector can be greatly improved.

The invention relates to a drop-out fuse. The drop-out fuse comprises an insulator, a rain hat, a dropping device and a fusion tube, wherein the rain hat is provided with an inverted U-shaped part and two sheet-shaped guiding parts, and is of an integral structure; a conductive component is arranged in the inverted U-shaped part; the dropping device comprises a first conductive base and a second conductive base; the first conductive base is connected with a lower end of the insulator; and the fuse tube is connected with the second conductive base, and hung in a hooking groove of the first conductive base through a hanging pole of the second conductive base in order that the fusion tube can rotate relative to the insulator. When the fusion tube rotates upwards relative to the insulator, an upper end of the fusion tube is guided into the rain hat under the guiding actions of the sheet-shaped guiding parts, and clamped with a clamping groove. In the rain hat of the drop-out fuse, a conventional rain hat and a guiding fork are combined, so that the rain hat of the drop-out fuse has a guiding function; an assembly process can be simplified; and the production efficiency can be increased easily.

The invention relates to a smoke exhaust pipe, a smoke exhaust system and a gas water heater. The smoke exhaust pipe comprises a pipe body and a smoke exhaust port. Wherein the pipe body is provided with a first section suitable for being connected with a main body of the gas water heater and a second section connected with the first section, an included angle is formed between the extending direction of the first section and the extending direction of the second section, and at least the inner pipe wall of the lower side of the second section is sunken outwards to form a groove; and the smoke outlet is formed on the groove wall of the groove. Even if an obtuse angle is formed between the second section of the pipe body and the first section of the pipe body due to installation errors or wind blowing and the like, rainwater entering the groove through the smoke exhaust port can flow to the lowest position of the groove under the action of gravity and then flow out through the smoke exhaust port in the groove. And the service life of the smoke exhaust pipe and the service life of the main body of the gas water heater cannot be shortened due to backflow into the main body of the gas water heater. Therefore, the smoke exhaust pipe can overcome the defect that the service life of the water heater is shortened due to the fact that a smoke exhaust pipe in the prior art easily causes rainwater backflow.

The invention relates to a fracturing device used for an oil-gas pipe column. The device comprises a cylindrical assembly connected with the oil-gas pipe column in series and used for defining buffer space for receiving fluid in the oil-gas pipe column, a sliding sleeve fixedly arranged on the inner wall of the cylindrical assembly through a cutting unit and an actuating mechanism capable of pushing the sliding sleeve. When the actuating mechanism pushes the sliding sleeve to force the cutting unit to lose efficiency, the sliding sleeve enters the buffer space and performs buffer motion under the combined effect of the buffer space and the fluid. The fracturing device used for the oil-gas pipe column has following beneficial effects: due to the fact that the e fracturing device used for the oil-gas pipe column can timely buffer movement of the sliding sleeve, friction loss and collision damage to the sliding sleeve, an outer cylinder and related parts can be greatly reduced so that service life of the fracturing device is prolonged.

The invention relates to a motor control device used for an electric automobile. The motor control device used for the electric automobile comprises a base, a top cover and a container cavity, wherein the base and the top cover are detachably connected, and the container cavity is formed in the base and the top cover. A power module and a capacitor are arranged at the bottom in the container cavity. A control board contained in the container cavity is arranged above the power module and the capacitor. A wire holder is arranged on the upper surface of the control board. The power module and the capacitor are connected with the wire holder through a busbar. Compared with the prior art, the motor control device used for the electric automobile is smaller in size and lower in weight. Meanwhile, the motor control device which is small in size and low in weight can reduce the load of the electric automobile and improve the flexibility of the electric automobile.

The invention relates to an air-conditioning system and a control method thereof. The air-conditioning system comprises an outdoor heat exchanger, an indoor heat exchanger, a compressor, an expansion valve, a first valve, a second valve, a first heat release component, a second heat release component, a temperature measuring sensor and a control module, wherein the first heat release component and the second heat release component are used for heating the outdoor heat exchanger, the temperature measuring sensor and the control module are used for measuring the surface temperature of an outdoor sensor, an outlet of the compressor is connected with the first valve and the second valve, the first valve and the second valve are connected with the first heat release component and the second heat release component correspondingly, the first heat release component and the second heat release component are both connected with an inlet of the compressor, and the control module can control the on-off state of the first valve and the second valve according to the testing result of the temperature measuring sensor. According to the air-conditioning system, the problem that the defrosting effect and the heating efficiency of the air-conditioning system are difficult to balance can be solved, the outdoor heat exchanger can be safely defrosted, and the higher heating efficiency of the air-conditioning system can be maintained.