156results about How to "Reduced service life impact" patented technology

The invention relates to a low-temperature rapid self-heating method for a lithium-ion battery. The method comprises the following steps: (S1) determining a polarization voltage amplitude range which does not have influence on the service lifetime of the lithium-ion battery and is safely used, and selecting a sine AC voltage amplitude according to the range; (S2) calculating the relationship between heat production power and frequency and obtaining a frequency point, namely the optimal heat production frequency point, with the maximum heat production power according to the relationship between battery impedance and frequency under the selected sine AC voltage amplitude; and (S3) carrying out heating free of lifetime loss on the battery by a sine AC signal according to the amplitude determined in the step (S1) and the frequency determined in the step (S2). The low-temperature rapid self-heating method for the lithium-ion battery has the effects of being high in heating rate, obvious in low-temperature performance improvement, free of an influence on the service lifetime of the lithium-ion battery, good in heating temperature uniformity and the like; and the target of reducing the influence on the service lifetime of the lithium-ion battery to the maximal extent is achieved.

The invention discloses a low-temperature self-heating method of a lithium ion battery pack. The low-temperature self-heating method comprises the steps of determining an optimal heating frequency range compatible with a battery aging state and state-on-charge (SOC) according to a principle of minimum influence on lifetime of a battery; designing a series resonant inversion circuit, and exploring an optimal control strategy so that the inversion circuit outputs a sine AC current of a target frequency and target amplitude at a battery side; and performing low-temperature self-heating on the battery pack by the sine AC current output from the resonant inversion circuit, wherein the internal resistance of the battery is gradually reduced with the temperature rising of the battery, the output current amplitude of the resonant inversion circuit is adaptively increased, the heating rate of the battery pack is improved, and the battery pack is rapidly raised to a target temperature. The low-temperature self-heating method has the effects of fast self-heating rate on the lithium ion battery pack under a low temperature, obvious improvement on low-temperature performance, high self-heating efficiency, no influence on service lifetime of the lithium ion battery, good heating temperature uniformity and the like, and the promotion and the application of an electric vehicle in a cold place are facilitated.

The invention provides a method for reducing time limit combination step progression of distribution network relaying protection, comprising the following steps: 1, realizing differential protection (DP) between all incoming switches and all outgoing switches in a distribution switching station or a distribution firewall; and 2.1,, if the DP meets action conditions, tripping off all the incoming switches without time delay; 2.2, if the DP does not meet the action conditions, executing overcurrent criterion on all the outgoing switches: judging whether the overcurrent I is more than set current Iset, namely I is more than Iset; and if the outgoing switches meet the overcurrent criterion at some time, tripping off the outgoing switches. The method is utilized to realize selective actions without time delay for the relaying protection between two-stage panel switches in the distribution switching station (or a distribution firewall), thus reducing the time limit combination step progression of the distribution network relaying protection, and greatly decreasing maintenance workload of relaying protection personnel. The invention also discloses a device for reducing time limit combination step progression of distribution network relaying protection.

The invention provides a wind farm active power optimal control method based on power prediction information. The method is based on prediction of ultra-short-term wind power, various limitations on operation of a wind farm are taken into consideration, output of various turbines is smoothened, the action frequency of a turbine control system is reduced, an optimal algorithm is adopted, and accordingly variation of output power of each turbine is optimized. Compared with a current common variable-proportion allocation algorithm, the method has the advantages that the frequency of violent fluctuation of the output of the wind turbines can be reduced and can be reduced completely at most, accordingly, total adjustment frequency of the wind farm is reduced, and the method is favorable for reducing maintenance cost of the wind farm and is also beneficial to reducing influences of power adjustment to the service lives of the wind turbines.

The invention discloses an error checking and correcting (ECC) verification module and a data reading-writing method of the module, so as to solve the technical defect of low flexibility in present ECC verification modules. The verification module comprises: an ECC circuit used for ECC treatment of an ECC code word so as to obtain an error checked and corrected data set; a latch used for storing the error checked and corrected data set and updating the received input data to corresponding data positions in the checked and corrected data set, thus forming a data set to be written in; a verification circuit used for real-time verification of the data set to be written in and for generation of a verification bit corresponding to the data set to be written in; a write buffer used for writing the data set to be written in and a corresponding verification bit thereof into a storage medium. The embodiment of the invention realizes reading data from a main array or writing data into the main array in ECC code words, so that the control is easier and the data writing operation is speeded up.

The invention relates to a surface-aluminum-evaporated peep-proof film with anti-reflection performance and a preparation method thereof. The peep-proof film comprises a PET layer and a peep-proof structure layer arranged on the surface of one side of the PET layer, wherein the peep-proof structure layer comprises a UV light-cured resin layer and an evaporated film layer evaporated on the surface of the resin layer; and the surface-aluminum-evaporated peep-proof film further comprises a moth-eye anti-reflection structure layer arranged on the surface of the other side of the PET layer. The preparation method comprises an adhesive dripping process, a filling process, a UV illumination process and a demolding process. Compared with the prior art, the surface-aluminum-evaporated peep-proof film disclosed by the invention has the advantages that different surfaces can be imprinted on both side surfaces of the PET layer; and the preparation method is simple, and commercial requirements on high speed, large area, high resolution and high flux can be met.

The invention relates to the communication technology field and particularly relates to a handset loss prevention method and system based on wearable equipment. The method specifically comprises steps that 1, a handset is in wireless matching connection with the wearable equipment; 2, a safety distance between the wearable equipment and the handset is set by a user, and a distance monitoring program starts; 3, an actual distance is measured and acquired; and 4, the actual distance is compared with the safety distance, if the actual distance is smaller than the safety distance, the process returns to the step 3 to continue measurement, if the actual distance is greater than the safety distance, an alarm strategy starts. The method has advantages of high stability, high accuracy, timely alarming and convenient and rapid use.

An embodiment of the invention discloses an oil mass measuring method, an oil mass measuring device and an oil pressure calibration method, relates to the technical field of automatic transmissions, and aims at solving the technical problem that in the prior art, an oil level is greatly influenced by temperature and shape variation of an oil pan so that the real oil mass of transmission oil cannot be measured accurately. The oil mass measuring method comprises measuring an oil level corresponding to current volume V of oil pan oil, and obtaining a measurement oil level H; correcting the measurement oil level H to a first correction oil level h corresponding to the oil pan in a regular shape; establishing a changing curve h-T of the first correction oil level h along with the oil temperature T and a changing curve rho-T of the oil density rho along with the oil temperature T; obtaining a pressure P value corresponding to the oil temperature T according to the curve h-T and the curve rho-T; and obtaining the oil mass of oil according to the pressure P value. The oil mass measuring method, the oil mass measuring device and the oil pressure calibration method are used for measuring the oil mass of a gearbox of the automatic transmissions.

The disclosure, which belongs to the technical field of the computer, relates to a method and apparatus for playing audio data. The method comprises the following steps that: when audio data sent by a sound source device are started to be received, a starting time point of the audio data receiving is determined; according to a corresponding relation between a pre-stored time period and a playing volume, the playing volume corresponding to the time period where the starting time point is located is determined to be a current playing volume; and the audio data are played by the current playing volume. According to the technical scheme, the influence on the service life of the audio output device can be reduced.

The present invention relates to one kind of heat resistant reinforced polyethylene pipe and its making process. The materials for the polyethylene pipe includes ultralow density polyethylene 100 weight portions, nanometer silica 20 weight portions and antioxidant 0.1 weight portion. The polyethylene pipe is made through the steps of stoving the materials, feeding, extruding, molding, vacuum sizing, cooling, drawing, ink jetting printing, winding and product packing. It is made in an automatically controlled production line in high production speed and high product quality.

The invention discloses a non-volatile memory with an error checking / correcting (ECC) circuit and methods thereof for reading and writing data. Read-write operations are carried inside the memory, with ECC code words as the unit. The method for writing the data comprises the following steps: acquiring the head address and the end address of external input data and buffering the external input data; acquiring the bytes which are unnecessary to be replaced, namely write-back data, from a memory array of the non-volatile memory if part of the bytes in an ECC data set in which the external input data are included is unnecessary to be replaced; forming a new ECC data set with the external input data or the external input data and the write-back data and buffering the new ECC data set; generating a corresponding check bit for the new ECC data set; and writing the new ECC data set and the corresponding check bit into the memory array. The invention only erases the corresponding ECC code words during writing data and improves the memory flexibility and the utilization efficiency of the memory space.

The invention discloses a low-temprature flue gas denitration and poisoning-prevention system. In an SCR (Selective Catalytic Reduction) denitration facility, a modified active carbon layer and a multilayered denitration catalyst are arranged along a flowing direction of flue gas in sequence; the modified active carbon layer is used for adsorbing water vapor, SO2, heavy metal and dust in flue gas through physical adsorption and chemical adsorption; the multilayered denitration catalyst is used for removing NOx in the flue gas; the denitration efficiency of a denitration catalyst is guaranteed so that the denitration rate of the denitration catalyst can be stabilized to be a relatively high numerical value; and the problem that a low-temperature catalyst is likely to cause poisoning is solved, active carbon can be cyclically used, byproducts can be utilized and the production cost is reduced.

The invention discloses a display substrate. The display structure comprises a display region and a hollow slot arranged at the periphery of the display region; the display substrate comprises a basestructure layer, a light-emitting unit arranged on the base structure layer and located at the display region; the base structure layer comprises a first organic base layer, the light-emitting unit isarranged on the first organic base layer, a groove structure located between the hollow slot and the display region is formed on the first organic base layer; the display substrate further comprisesa first inorganic package layer for covering the light-emitting unit and the groove structure. Through the display substrate disclosed by the invention, the first inorganic package layer enables the vertical section of the first organic base layer to be reduced in a groove structure location, thereby preventing a part of water oxygen from intruding into the first organic base layer close to the display region, and then preventing the water oxygen from intruding into the light-emitting unit, and improving the service life of the display substrate.

The invention discloses a data writing method and device of block equipment and a medium. The method comprises the steps of acquiring data to be written and the total data amount of the data; applyinga storage space the capacity of which is in accordance with the total data amount in the block equipment, and writing data sub-blocks to the storage space; generating address offsets of the data in the storage space and the attribute information of the data to write the address offsets and the attribute information into a key value database, and writing the address offsets and the attribute information into the block equipment through a MiniFS file system. According to the method, a data writing mechanism is further improved on the basis of the MiniFS file system only with the basic functionsof a film system, the data does not need to be written into logs again before stored to the block equipment, and therefore the influence on the service life of the block equipment is reduced. The method reduces the overall system expense caused during data writing and ensures the overall performance of the system. In addition, the data writing device of the block equipment and the medium have theadvantages above.

The invention discloses a wide-area over-current protection method and system for power distribution networks. A wide-area protection main station collects information whether over-current protection devices monitor over-currents through a high-speed signal channel, which are separately mounted at the sites of individual power distribution switches in a power distribution network to be protected; if the wide-area protection main station collects the over-current information, whether an inter-phase short-circuit fault occurs inside a generalized node is judged; if the inter-phase short-circuit fault occurs inside the generalized node, the wide-area protection main station remotely controls the most upstream power distribution switch in the generalized node to trip out to clear the fault. The method and system disclosed by the invention achieve selective protection against over-currents due to inter-phase short-circuit in power distribution networks without needing time-limit cooperation, can be used for solving the difficulty of time-limit cooperation in power distribution networks and isolating inter-phase faults in power distribution networks with minimal switch on-off operation frequency, and are suitable for different types of open-loop power distribution networks.

The invention discloses a nonvolatile memory with an ECC circuit and a reading and writing method thereof. An external interface of the memory performs data transmission by taking a byte as a unit; and the reading and writing is performed in the memory by taking an ECC code word as a unit. The method for writing data comprises the following steps of: acquiring a starting address and an end address of external input data and caching the external input data; if partial bytes of an ECC data set in which the external input data is positioned are not needed to be replaced, acquiring the bytes not needed to be replaced, namely write back data from a storage array of the nonvolatile memory and caching the write back data; forming a new ECC data set by the external input data, or the external input data and the write back data, and generating a corresponding check bit for the new ECC data set; and writing the new ECC data set and the corresponding check bit into the storage array. When the data is written, the corresponding ECC code word is only erased. The invention has the advantages of improving storage flexibility and the utilization rate of the storage space.

The invention provides a multi-agent based ordered charging method of an electric automobile. The method is characterized in that a home agent and a transformer substation agent coordinately work to service a power grid agent to handle with a large amount of complex charging requests in a distribution manner; and the charging behavior of the electric automobile is scheduled through a real-time greedy algorithm. According to the method, the current real-time energy demand information and the charging time arrangement of the electric automobile, rather than the information of the electric automobile to be connected to a power grid in future and a complex prediction method and the optimizing technology, are needed, so that the expansion is high; and the method is applied to the high permeability condition of the electric automobile. The charging process of the electric automobile is a constant-power continuous charging process through which a battery of the electric automobile is prevented from being frequently switched among the charging modes, and the influence of the charging schedule on the service life of the battery of the electric automobile can be reduced to the maximum. With the adoption of the method, the real-time charging optimizing effect of the electric automobile is effectively improved; the peak shaving and load shifting can be performed well while the user demand is met and the user charging cost is decreased, and the power grid stability is ensured.

The invention discloses a straight-line tool magazine. The straight-line tool magazine comprises a tool rest, multiple tool guide rods used for installing tools and slidably arranged on the tool rest, driving parts and a moving mechanism. The tool guide rods are distributed orderly along the length direction of the tool rest. The sliding directions of the tool guide rods are vertical to the length direction of the tool rest. The driving parts are used for driving the tool guide rods to slide in a reciprocating manner. The number of the driving parts is smaller than that of the tool guide rods. The moving mechanism is used for driving one driving part to move in a reciprocating manner along the length direction of the tool rest. The straight-line tool magazine has the following beneficial effects: by additionally arranging the movable mechanism, one driving part used for driving the tool guide rods to move in a reciprocating manner can move along the length direction of the tool rest; therefore, the driving parts can drive at least two tool guide rods to move in a reciprocating manner so that the number of the driving parts is effectively reduced; and driving cost of the straight-line tool magazine is lowered.

The invention discloses a range hood, relates to the technical field of range hoods, and aims to solve the problem of easy shortening of the service life of a fan due to need of an outdoor unit to exchange heat and direct contact of sucked lampblack and steam with the fan in a traditional range hood. The range hood comprises a shell; a smoke inlet and a smoke outlet are formed in the shell; the smoke inlet is communicated indoors; the smoke outlet is communicated outdoors through a smoke discharge pipe; a flue is formed in the shell; and a fan is arranged in the flue. The range hood further comprises a lampblack condensation module; the lampblack condensation module includes a condenser shell connected to the external of the shell; a condenser is arranged in the condenser shell, and is connected with an evaporator; the evaporator is arranged in the smoke inlet; an intake port and an exhaust port are formed in the condenser shell; the intake port is communicated indoors; the exhaust port is connected with a heat exchange pipe; and the heat exchange pipe and a smoke discharge pipe are both communicated with a venturi pipe. The range hood can be used for treating kitchen lampblack.

The invention discloses an automatic spraying cooling device for a power transformer and a spraying cooling method. The automatic spraying cooling device comprises a mounting rack, a tap water pipe, a plurality of spraying pipes, a flow sensor, an electronic valve, a controller, a plurality of draught fans, a plurality of frequency converters, and a plurality of temperature sensors. The automatic spraying cooling device for the power transformer and the spraying cooling method regulate the air speed and the flow of the spraying pipes according to the temperature of the transformer, the cooling mode is further changed, and spraying and air blowing are mainly conducted. The water is only directly sprayed to the surface of the transformer when the temperature is relatively high, spraying water to a gap of the transformer and blowing air are mainly used to cool the transformer indirectly by cooling the air when the temperature is relatively low, spraying on the transformer for a long period of time is reduced, and the influence on the service life of the transformer is reduced.

The invention belongs to the field of washing machines, and particularly discloses a washing machine eccentricity detection method, including starting a dehydration spinning program, judging whether the eccentricity of an outer tub rotating at the current rotation speed is greater than or smaller than the impact eccentricity value when an acceleration sensor detects that the eccentricity value ofthe outer tub rotating at the current rotation speed is greater than the limit eccentricity value; if the eccentricity of the outer tub running at the current rotation speed is greater than the impacteccentricity, then determining whether to perform eccentricity correction or not; if the eccentricity of the outer tub running at the current rotation speed is smaller than the impact eccentricity, then judging whether to continue to spin or not. By the eccentricity detection method, regulation of the eccentricity not enough to cause tub impact or the accidental eccentricity can be reduced, spinning time for dehydration can be shortened, and washing efficiency can be improved.

The invention relates to a dynamic gap type screw press comprising a spiral auger driven by a speed reducer and front and rear flange sleeves for supporting the spiral auger, wherein moving and static sheet groups matched with the spiral auger are arranged between the front flange sleeve and the rear flange sleeve; the front flange sleeve is provided with a feed opening; the rear flange sleeve is provided with a discharge opening; the spiral auger consists of a tapered shaft and blades; the outside diameters of the blades are equal; the screw pitches of the blades are equal; the inside diameters of the moving and the static sheet groups are greater than the outside diameter of the blades of the spiral auger; and the inside diameters of moving blades of the moving and the static sheet groups are smaller than the outside diameter of the blades of the spiral auger. According to the invention, sludge is propelled and extruded in the moving and the static sheet groups by the spiral auger consisting of the tapered shaft and the equidistant blades so as to realize the solid-liquid separation. The dynamic gap type screw press has simple structure and is convenient to process and stable for dehydration and has long service life; the equidistant blades have high rigidity; and the moving and the static sheet groups have the functions of draining, automatically cleaning, preventing blockage and the like.

The invention discloses a construction waste crushing device with a dust collection function and a method. The crushing device comprises a supporting base plate, a supporting frame, a crushing box, astanding box and a dust collector. A crushing assembly is movably connected with the interior of the crushing box, a driving motor is arranged on the outer wall of the crushing box and connected withthe crushing assembly, a material guiding slope plate and oscillation mechanisms are arranged inside the crushing box separately, the material guiding slope plate is located below the crushing assembly, a material separating sieve plate is arranged between the oscillation mechanisms, and the material separating sieve plate is located below the material guiding slope plate; the crushing method comprises the following steps of 1 material mixing and crushing, 2 oscillating and separating, 3 standing and dust removal and 4 maintaining. The crushing device is simple in structure, high in crushing efficiency and good in crushing effect, collected building waste granules are uniform, and follow-up utilization is convenient; the crushing method is reasonable and orderly, easy to control, automaticand efficient, the labor intensity of workers is lowered, and the service life of the device is prolonged.

The invention belongs to the field of cables, and particularly relates to a high temperature and high voltage resistant cable. The cable comprises a conductor and a sheath layer externally wrapping the conductor, the sheath layer is orderly composed of an insulating layer, a mica belting layer, a low-smoke halogen-free flame retardant polyolefin inner jacket, a woven shielding layer, a low-smoke halogen-free flame retardant polyolefin outer jacket and an outer sheath from inside to outside; material of the insulating layer and material of the outer sheath both are modified fluoroplastic for cables, and the modified fluoroplastic for cables comprises the following constituents in parts by weight: 60-80 parts of polytetrafluoroethylene, 10-20 parts of wear-resistant agent, 5-10 parts of fire retardant, 7-16 parts of plasticizer, 5-9 parts of filler, 1-3 parts of antioxidant, 1-3 parts of paraffin oil, 0.1-0.2 parts of ratproof master batch and 0.1-0.2 parts of temite preventing master batch. The structure above can perform multi-angle protection for the cable, and can effectively reduce influence of high temperature and high voltage generated when conducting the conductor or outside severe environment on service life of the cable.

The invention provides a colorful explosion-proof membrane which comprises a PET or TPU layer optical membrane, and the upper surface and the lower surface of the PET or TPU layer optical membrane arecoated with a liquid crystal colorful layer and a PS reflective coating layer which are arranged in a self-orientation mode respectively. An OCA optical film, a hot melt film or a UV tackifier layeris coated between a PET release film and a colorful layer, meanwhile, transfer printing textures are arranged between the optical film and a reflection coating layer, the PS reflection coating layer is a high-reflection sheet-shaped silver or nanometer reflection coating, and roll-to-roll silk-screen printing ink is arranged on the lower surface of the reflection layer. According to the scheme, the use effect of the explosion-proof membrane is effectively improved, the service life of the explosion-proof membrane is effectively prolonged, meanwhile, the production process of the explosion-proof membrane is simplified, an electroplated metal layer is prevented from being adopted, environmental protection is improved, meanwhile, the production quality of the explosion-proof membrane is effectively guaranteed, and the reflection effect on different colors and the blocking effect on infrared rays and ultraviolet rays are improved and stripping of an adhesive layer is avoided.

The invention relates to an oil-electric-hydraulic hybrid power system with a self-powered front shaft and a self-powered rear shaft and a conversion method of different working patterns, and belongsto the field of vehicle hybrid power. The oil-electric-hydraulic hybrid power system comprises a front shaft oil-electric hybrid power and a rear shaft electric-hydraulic hybrid power; on the front shaft of the vehicle, an engine is in parallel connection with a front shaft motor through a front shaft clutch, and is connected with a front shaft differential through a gearbox; and on the rear shaftof the vehicle, a hydraulic pump / a motor is in parallel connection with a rear shaft motor through a rear shaft clutch, and is connected with the rear shaft main decelerator / differential assembly. According to the oil-electric-hydraulic hybrid power system disclosed by the invention, a hydraulic unit is introduced, so that in the braking process of the vehicle, the energy recovery rate of the vehicle can be increased, the consumption of the electric current of the front shaft motor and the rear shaft motor can be reduced, and the impact of discharging / charging current to a battery in the process of driving / energy recovering can be reduced, so that in the driving process, the dynamic performance of the vehicle can be strengthened; and the front shaft and the rear shaft are self-powered, sothat the passability of the vehicle is also strengthened.

The invention relates to an omnibearing peep-proof film with an antireflection function and a manufacturing process thereof. The omnibearing peep-proof film comprises a PET layer, a peep-proof structural layer arranged on one side surface of the PET layer and a moth-eye antireflection structural layer arranged on the other side surface of the PET layer, wherein the peep-proof structural layer comprises a resin bottom layer and a UV light-cured resin layer; parameters can be changed according to the actual requirement, so that a visual angle can be freely selected, the security of a display screen in any direction is guaranteed, and the light transmittance in a visual range is high; by virtue of the bionics principle, the moth-eye antireflection structural layer adopts a moth-eye-like micro-nano structure as the antireflection layer, so that the loss of reflected light can be effectively inhibited in a relatively wide wave spectrum range; a reel-to-reel UV double-side rolling process comprises an adhesive dripping step, a filling step, a UV illuminating step and a demolding step, and different structures can be separately press-printed on two side surfaces of the PET layer, so that the manufacturing process is simple, and the commercialization requirement on rapidness, large area, high resolution and high flux can be met.

The invention relates to the technical field of battery management of electric vehicles, and provides a battery management system for intelligent driving. The battery management system for the intelligent driving aims to solve the problem that a thermorunaway phenomenon occurred by an uni-monomer cell cannot be detected in time in an existing battery management system, the battery management system for the intelligent driving comprises a temperature detection module, a temperature detection module used for detecting the temperature of the monomer cell and generating monomer temperature information, a processing module used for sending control information, and an alarming module used for sending the pre-alarming information after receiving the control information; the temperature detectionmodule further comprises a battery pack temperature detection unit which is used for detecting the battery pack temperature and generating battery pack temperature information, the processing module is further used for processing the monomer temperature information and the battery pack temperature information to obtain the monomer temperature change rate and the battery pack temperature change rate; and the battery management system for the intelligent driving further comprises a comparison module used for comparing the monomer temperature change rate and the battery pack temperature change rate, and when the comparison result is inconsistent, the processing module sends the control information.

The invention relates to a hydraulic power-assisted steering system, in particular to a cam type assistance-adjustable hydraulic power-assisted steering system, which comprises a steering pump, a liquid storage tank, a hydraulic power-assisted steering gear, a vehicle speed sensor, a control unit, a pressure sensor, an assistance adjustor and a stepping motor for driving the assistance adjustor. An outlet of the hydraulic power-assisted steering gear is communicated with the liquid storage tank, and the assistance adjustor further comprises a cylinder block, a piston and a cam which is used for converting rotation of the stepping motor into linear motion, and the control unit is used for controlling the steeping motor according to input signals of the vehicle speed sensor and the pressuresensor. The cam type assistance-adjustable hydraulic power-assisted steering system and the control method thereof have the advantages that assistance can be adjusted according to needs, energy consumption is low, and the problems that existing hydraulic power-assisted steering systems are unstable in high-speed steering and insufficient in portability in low-speed steering and the problem of high load of vehicular accumulators in electronic hydraulic power-assisted steering systems are solved.

The invention provides a focusing ring for the aluminum etching process. The inner diameter lateral wall and the inner diameter bottom edge of the focusing ring are respectively provided with a material layer capable of absorbing a small amount of etching gas, and the concentration of plasmas at the edges of wafers is accordingly reduced; furthermore, the size of the inner diameter of the focusing ring is reduced, so that the distances between the edges of the wafers and the inner diameters of the focusing ring in the aluminum etching process are decreased, the concentration of the plasmas at the edges of the wafers is reduced, deposition of polymer at the edges, in particular to the back faces of the edges, of the wafers is accordingly and greatly reduced, peeling of the polymer at the edges of the wafers is reduced, and the quality and the yield of a device are improved.