133results about How to "Increase delay" patented technology

The invention belongs to the technical field of decoding algorithms, and particularly relates to a normalized minimum sum decoding and post-processing decoding algorithm of a BCH code, which comprises the following steps of: for the BCH code, optimizing a check matrix in a standard form of the BCH code to obtain an optimal check matrix; inputting the receiving sequence into an improved normalized minimum sum (NMS) decoding algorithm based on the optimal check matrix for decoding; if the decoding is successful, outputting the optimal decoding estimation; and if the decoding fails, inputting a sequence iteration track after the NMS decoding fails into the DIA neural network model, analyzing and outputting the reliability measurement of each bit, and then decoding again through an ordered statistical decoder OSD to obtain the optimal decoding estimation. Through an innovative check matrix optimization algorithm, low density of the check matrix, reduction of the number of short rings and uniform distribution of column weights are successfully realized, and a BCH code decoding scheme which is more efficient and better in performance is provided.

The invention belongs to the technical field of network self-adaption, and particularly relates to a weak network self-adaption algorithm system based on dynamic network monitoring, which comprises the following steps of: deploying a monitoring agent on a network node; extracting network bandwidth, delay and packet loss rate from the network state report, preprocessing the extracted data, and extracting feature vectors from the preprocessed data; adjusting the size of a buffer area for data transmission according to the network bandwidth and delay; and controlling the sending and receiving of data according to the adjusted algorithm and parameter, monitoring the data transmission state in real time in the data transmission process, feeding back the data transmission state information, and adjusting the algorithm and parameter in time according to the feedback information. The problem of how to improve the efficiency and reliability of data transmission under the conditions of complex and changeable network environment, low bandwidth, high delay, serious packet loss and the like in the prior art is solved.

The invention provides a low-energy-consumption three-dimensional point cloud single-target tracking method based on a spiking neural network, and the method comprises the steps: obtaining the three-dimensional point cloud data of a previous frame and a current frame of a target, designing a voxel grid module, and dividing the point cloud into 3D voxels; a feature extraction module is designed, a three-stage pulse convolution block is used as a feature extractor, voxelization point cloud features are extracted, a Transform encoder layer is added, and global context information of the point cloud is captured through a self-attention mechanism; a part-to-part motion modeling module is designed, continuous point cloud features on a time sequence are modeled and coded part by part through a two-dimensional pulse convolution block, and feature information changes of a previous frame and a current frame in corresponding space parts are obtained; and designing a regression prediction module, and inferring the relative motion of the target through a pulse regression prediction module. According to the method, energy consumption is reduced, efficiency is improved, and meanwhile it is guaranteed that the network accurately tracks the target in diversified scenes and motion states.

The invention discloses a 4G FDD stock terminal direct connection satellite-oriented time synchronization method, which comprises the following steps: firstly, a base station delays a starting point of a preamble sequence detection window and enlarges the window size, the base station receives a preamble sequence in the enlarged window and detects the size of time delay by decoding the preamble sequence, and after the base station determines the size of the time delay, the base station delays the starting point of the preamble sequence detection window; according to the method, time delay is divided into an integer part tau i and a decimal part tau f by taking milliseconds as a unit, terminals are divided into two types according to whether the decimal time delay is greater than 0.66 ms or not, so that an uplink frame structure of a base station is modified, the base station determines an uplink subframe scheduling strategy according to the uplink frame structure, the decimal part tau f of the time delay is used for determining a TA value, and the TA value is used for scheduling the uplink subframe. The integer part tau i is used for delaying receiving of uplink information, and the scheduling strategy is applied to subsequent receiving and transmitting of Msg3, downlink HARQ and other uplink information; the stock 4G terminal is directly connected with the satellite under the condition that only the base station side protocol is modified and the terminal side protocol is not changed, so that the 4G communication system supports larger time delay, and meanwhile, the upgrading cost of an operator and a user is reduced.

The invention relates to the technical field of optical communication, and provides a moving target-oriented LiFi communication system two-dimensional beam scanning and lighting source integrated design method, which comprises the following steps: S1, generating initial information; s2, digital signal processing is carried out; s3, carrying out digital-to-analog conversion; s4, converting the electric signal into an infrared light signal; s5, amplifying the signal by an amplifier and outputting the signal from an optical fiber; s6, transmitting the signal to the AWGR; s7, connecting the AWGR to the two-dimensional optical fiber array through an optical fiber; s8, carrying out model selection, driving and modulation on the LED; s9, the LED and the insertion core are interwoven in the two-dimensional optical fiber array; s10, performing energy management; s11, arranging a lens to increase the size of an image surface light spot; s12, transmitting the optical signal to a corresponding receiver; s13, converging and coupling; s14, amplifying the signal by using an amplifier; s15, photoelectric conversion and amplification are carried out through PIN-TIA; s16, performing analog-to-digital conversion on the signal; and S17, restoring the initial information. According to the invention, wavelength control with high capacity and high precision can be provided.

The embodiment of the invention provides a data transmission method and device, equipment and a storage medium. A receiving end receives target data sent by a sending end; verifying a plurality of to-be-verified data packets in the target data, and determining the to-be-verified data packets passing the verification as first data packets; combining the plurality of first data packets into verification data; and comparing the verification data with the target data, determining whether the verification data is consistent with the target data, and further judging whether the target data is successfully transmitted. The receiving end in the embodiment of the invention ensures data consistency, reduces data loss or damage and improves transmission reliability by verifying the data packets to be verified, timely finds errors by comparing the verification data with the target data, avoids further processing of error data, improves transmission accuracy, and improves the transmission efficiency by subpackage verification and combination and parallel processing of a plurality of data packets. The verification time is reduced, and the transmission efficiency is improved.

The invention discloses a write optimization Hash index construction method and system based on a separated memory, and the method comprises the steps: building a Hash index structure comprising a directory, a segment and a bucket in a memory node based on the design of the separated memory, building a directory tree structure comprising a leaf item and a non-leaf item, and caching a corresponding directory in a computing node; maintaining a corresponding predictor for each slot in the barrel, and indicating the position where the slot should be placed during splitting by reading a corresponding bit in the predictor during splitting; when the Hash index is introduced and split, starting a single-thread memory crawler in a memory node to regularly search an unupdated predictor; multiple round-trip times are compressed into one by merging multiple RDMA operations into one RDAM request through passive acknowledgement and batch processing. According to the method, the multi-level catalog is combined with the extensible Hash, the Hash index is expanded and synchronized in a fine-grained mode, meanwhile, the splitting overhead is reduced through a predictor component and optimization splitting, and finally the writing performance is improved.

The embodiment of the invention discloses an SPDIF data stream decoding method and device, a storage medium and decoding equipment, and relates to the field of audio processing. According to the method and the device, the received SPDIF data stream can be directly decoded, and complicated data stream synchronization operation does not need to be executed in advance. According to a traditional decoding method, when digital signals are processed, it is usually needed to firstly ensure that all parts in data streams are strictly aligned in time, that is, data stream synchronization is achieved, the process may involve a complex algorithm and long processing time, the complexity and delay of a system are increased, and decoding failure may be caused by synchronization failure. By directly analyzing the waveform proportion characteristics of the data stream and utilizing a sliding window and waveform proportion matching method, the rapid identification and decoding of the frame header and the frame body are realized. The method does not depend on the absolute time position of each part in the data stream, but decodes based on the physical characteristics of the waveform signal, so that explicit data stream synchronization does not need to be carried out.

The invention discloses a multi-sensor edge system and method based on cross-modal dynamic attention. The method comprises the following steps: S1, acquiring environment data based on multiple sensors and multi-modal input data based on an interaction module; s2, preprocessing the acquired environment data and the multi-modal input data, and performing feature extraction to obtain multi-modal feature data after feature extraction; s3, carrying out space-time dimension enhancement on the multi-modal feature data; s4, dynamically optimizing the configuration of each modal resource based on the enhanced multi-modal characteristic data obtained in the step S3; and S5, inputting the dynamically optimized modal resource information into the generative model to generate an output result. According to the method provided by the invention, the data processing flow is optimized, the data transmission delay is reduced, efficient integration and utilization of information are realized through a cross-modal dynamic attention mechanism, and the accuracy and robustness of decision making are enhanced.

The invention relates to the technical field of computer data, in particular to a floating point data processing method and device, computer equipment and a storage medium. The floating point data processing method is applied to a main processor, a coprocessor composed of an anti-trigonometric function module is embedded in the main processor, and the method comprises the steps that a to-be-processed floating point variable of an anti-trigonometric function and corresponding data processing information are obtained from the coprocessor according to a preset floating point instruction; the method comprises the following steps: converting a to-be-processed floating point variable into a to-be-processed fixed point variable, carrying out shift processing according to an index part and a mantissa part of the to-be-processed floating point variable, mapping a shifted target fixed point variable to a preset coordinate space, carrying out vector iteration on the mapped fixed point variable, obtaining an initial output result after iteration, and carrying out reflection mapping to obtain a target fixed point variable; and obtaining a target output result after reflection and carrying out floating point conversion to obtain a target floating point quantity. The invention provides an anti-trigonometric function floating point data processing method with higher efficiency.

The invention discloses a Q-learning-based high-energy-efficiency task-driven dynamic on-chip interconnection communication method, and belongs to the field of on-chip interconnection of computer systems. According to the method, a self-adaptive topological structure is adopted to map tasks, and different areas are divided according to different features of the tasks for task processing. According to the method, specific on-chip resources and topological structure types can be allocated to each task, so that the consumption of the on-chip resources is reduced. Through the self-adaptive topological structure, the system can flexibly adjust the connection relation and the routing mode in the network-on-chip according to the requirements and characteristics of tasks. Meanwhile, by dividing different areas, the processing processes of different tasks can be isolated, and interference and conflicts are reduced to the maximum extent. The Q-learning reinforcement learning algorithm is used for dynamically changing the transmission direction of the routing algorithm and the number of virtual channels by taking low delay and low power consumption as targets during task operation, so that the balance between the performance and the power consumption in the network-on-chip can be effectively realized.

The invention provides an aviation kerosene catalyst and a preparation method and application thereof. The preparation method of the aviation kerosene catalyst comprises the following steps: dissolving a triblock copolymer P123 in an inorganic acid aqueous solution, stirring for a period of time to fully dissolve the triblock copolymer P123, and uniformly mixing; adding an aluminum source, and stirring for a period of time; adding a cerium source and / or a lanthanum source, and stirring for a period of time; adding a cobalt source, and stirring for a period of time; dropwise adding a silicon source, and stirring for a period of time to obtain a mixture; after the mixture is subjected to crystallization reaction, the obtained product is at least subjected to cooling, washing, solid-liquid separation, drying and roasting, and the aviation kerosene catalyst is obtained. The aviation kerosene catalyst provided by the invention is prepared by the preparation method. The invention also provides application of the aviation kerosene catalyst in preparation of aviation kerosene from synthesis gas. The catalyst can improve the selectivity of C8-C16 aviation kerosene components.

The invention relates to the technical field of computers, in particular to a data security exchange system and method based on self-learning, and the method comprises the steps: periodically monitoring the flow of each port, and analyzing whether the security of a data exchange process is qualified or not according to the flow; when the traffic is relatively large, secondary judgment is performed on whether the data exchange process is qualified or not based on the number of data packets received by the data receiving module, or the reason for disqualification is analyzed based on the time domain change degree of the traffic of the port; when the time domain change degree of the flow is large, data with large transmission flow caused by unqualified data cleaning is considered, and when the time domain change degree of the flow is small, network signals in a spanned area in a data transmission process are considered to be unstable and network switching is frequent, so that the flow of the data of a receiving point is large, and the transmission efficiency of the data is improved. The control precision of the data exchange process is improved, and the safety of the data exchange process is improved.

The invention discloses a remote sensing small target detection method and device, and relates to the field of remote sensing image target detection, and the method comprises the steps: replacing a CIoU loss function in a baseline algorithm with a FocalWIoU loss function, and determining an improved baseline algorithm; the FocalWIoU loss function comprises a FocalWIoU loss function and a WIoU loss function; a modulation factor is introduced into the Focal loss function, and the weight of the sample is adjusted; the WIoU loss function measures the similarity between the target frames; training an improved YOLOv8 model by using the improved baseline algorithm; a GAM module is added behind a second context sensing cross-layer fusion module of a neck network in the improved YOLOv8 model; the GAM module comprises a channel attention sub-module and a space attention sub-module; the channel attention sub-module is used for retaining cross-latitude information; the space attention sub-module is used for fusing space information; and the remote sensing small target in the remote sensing image is detected by using the improved YOLOv8 model. The target detection precision and the detection performance of the remote sensing small target are improved.

The invention discloses a load-oriented dynamic self-adaptive semi-structured JSON (JavaScript Object Notation) data relation mode representation method, which is characterized in that a system architecture comprising a storage layer and a query layer and a load-aware dynamic self-adaptive multi-granularity analysis method are adopted to realize JSON data access with low online analysis overhead; the storage layer comprises data storage and analysis, metadata storage, a mode analyzer, a column counter and a trigger; the query layer comprises a data initialization loading module, a mode checking module and a query execution module; the load-aware dynamic self-adaptive multi-granularity analysis comprises the steps of determining analysis granularity, counting the frequency of query access content, dynamically expanding the analysis granularity, analyzing the granularity and a dynamic self-adaptive strategy of schema. Compared with the prior art, the method has the advantages that the analysis granularity of the JSON data is dynamically adjusted, the overhead of data analysis and access in the query process is reduced, the query delay and the overall throughput of the system are improved, and efficient access of the JSON data is realized.

The utility model belongs to the technical field of heat exchangers, and discloses a vertical heat exchanger which comprises a tube pass box body, a box body sealing head, a tube plate, a cross-shaped partition plate, a shell pass box body, a U-shaped heat exchange tube, a cooling medium I inlet, a cooling medium II inlet, a cooling medium II inlet, a cooling medium II outlet, a thermal medium outlet and a baffle plate. When the vertical heat exchanger is used for condensing or cooling a heat medium, different cooling media can be switched to be used for preheating according to heat exchange requirements, and two different cooling media can be preheated at the same time; and the pollution of two cooling media is avoided, the addition of other condensing equipment is reduced, the occupation of production space is reduced, and the investment cost is reduced while the stable operation of the condensing system is ensured.

The invention discloses a water jet assisted millisecond laser-femtosecond laser secondary composite hole making method. The method comprises the steps that S1, an iron-based high-temperature alloy material is pretreated; s2, preliminarily processing the iron-based high-temperature alloy material through millisecond laser assisted by water jet, and punching for the first time; s3, the transferred iron-based high-temperature alloy material is subjected to finish machining under femtosecond laser, and second-time punching is conducted in combination with ultrasonic vibration; and S4, after punching is completed, the iron-based high-temperature alloy material is cooled, and the quality and precision of machined holes are checked. According to the method, water jet is used for assisting millisecond laser to conduct preliminary punching, heat affected zones are reduced, a good hole shape foundation is laid, fine machining is conducted in combination with ultrasonic vibration assisted femtosecond laser, the roundness and surface quality of holes are further improved, and the machining precision is improved. The problems of poor hole roundness and low machining precision caused by high thermal conductivity of the iron-based high-temperature alloy in femtosecond laser drilling are effectively solved, and the machining quality and precision are remarkably improved.

The application discloses a kind of detection methods of automatically replacing photoresist.The prior art is overcome by the present application, which has the problems of complex process flow, tedious steps and easy to cause abnormal coating due to errors in manual replacement of photoresist bottles.The application comprises the following steps:S1: simultaneously monitor the presence or absence of photoresist in the glue discharge pipe and buffer, determine whether to replace the photoresist bottle alarm prompt, and automatically replace the photoresist bottle operation;S2: simultaneously open the air inlet valve and exhaust bubble valve, when the pressure gauge detects that the air pressure in the photoresist bottle is greater than a certain threshold, start automatic glue supplement;S3: simultaneously monitor the presence or absence of photoresist below the glue discharge pipe, buffer and exhaust bubble valve in real time, to determine whether the buffer is filled with photoresist, close the air inlet valve and exhaust bubble valve, and complete the automatic glue supplement.By simultaneous linkage monitoring of multiple sensors in multiple positions, the replacement of photoresist bottles is automatically completed, reducing labor costs, avoiding human errors, and ensuring the quality of the process flow.

The invention discloses an intelligent computing-oriented deep learning model deployment and task unloading method and system. The method comprises the following steps of: initializing information; model deployment and unloading decision determination are carried out; carrying out transmission compression ratio design; judging whether a preset iteration convergence limit or a maximum number of iterations is reached; if a preset convergence condition or the maximum number of iterations is reached, outputting model deployment, an unloading decision and a transmission compression ratio scheme; and if the preset convergence condition is not met or the maximum number of iterations is reached, adding 1 to the number of iterations, and returning to carry out model deployment and unloading decision determination. The application focuses on the multi-base-station multi-terminal MEC system oriented to intelligent computing, fully considers new characteristics presented by intelligent computing during deep learning model deployment and task unloading of the MEC system, and proposes a comprehensive joint design scheme of model deployment, unloading decision and transmission compression ratio of the MEC system oriented to intelligent computing.

The present invention discloses an automatic compensating balancing component for preventing the cracking of the tank body, comprising a hydraulic oil tank, a cavity for accommodating hydraulic oil in the hydraulic oil tank, an automatic compensating balancing component for cooperating with the hydraulic oil tank, and two automatic compensating balancing units, the two automatic compensating balancing units being divided into an oil inlet end balancing unit and an oil outlet end balancing unit, the oil inlet end balancing unit being used to dock with an oil inlet pipe and complete the input of the hydraulic oil in the hydraulic oil tank, and the oil outlet end balancing unit being used to dock with an oil outlet pipe and complete the output of the hydraulic oil in the hydraulic oil tank. The present invention utilizes the automatic compensating balancing component to realize real-time air pressure regulation during the circulation of hydraulic oil in the hydraulic oil tank, thereby avoiding the expansion and contraction movement of the hydraulic oil tank, prolonging the service life of the hydraulic oil tank, and reducing fatigue wear.

The invention discloses a memory access method and device, a storage medium and an electronic device, a storage system comprises a controller and a memory, space allocation information of the memory is maintained in the controller, and the method comprises the following steps: writing data into the memory in a process of executing a target write request; a current to-be-executed target read request of the storage system is detected, and the target read request is used for requesting to read target data from a memory; converting a target storage position of the target data in a memory according to the space distribution information; matching the target storage position with a reference storage position corresponding to the target write request to obtain a matching result; and under the condition that the matching result is used for indicating that the target storage position and the reference storage position do not belong to the same storage position, the target data is read from the memory in response to the target read request, and by adopting the technical scheme, the problems of poor predictability of time delay of access to the memory and the like in related technologies are solved.

The invention provides a low-delay wave beam direction finding technology realized based on an FPGA. The low-delay wave beam direction finding technology comprises the following steps: establishing a wave beam direction finding simulation mathematical model according to a wave beam direction finding algorithm in combination with specific hardware parameters and indexes and feature information of a to-be-detected flight target; converting the established wave beam direction finding simulation mathematical model into an FPGA program; the method comprises the following steps: establishing a hardware test platform, and programming an FPGA (Field Programmable Gate Array) program into an FPGA baseband board; and performing operation according to the direction testing process to complete direction testing. Compared with the prior art, the delay caused by direction finding is greatly reduced by virtue of the strong parallel processing capability of the FPGA chip and the high-speed clock, and meanwhile, the resolution of direction discrimination is improved. Through application of the FPGA and accurate mathematical modeling, the method has significant advantages in the aspects of direction finding precision, real-time performance, system expansibility, anti-interference capability and the like, and can effectively cope with complex flight target direction finding tasks. Therefore, the technology has wide application prospects in the fields of aerospace, military reconnaissance, unmanned aerial vehicles and the like.

A polyester resin contains a polymer of an acid component (A) and an alcohol component (B). The component (A) contains 80 mol% or more of a 2,6-naphthalenedicarboxylic acid component with respect to a total amount of the component (A). The component (B) contains at least two types selected from the group consisting of 1,4-butanediol, 1,4-cyclohexanedimethanol, and ethylene glycol. The content of the at least one type of the component (B) is 80 mol% or more with respect to a total amount of the component (B).

The present invention discloses a strain of malic acid-enriched strictly anaerobic Faecalibacterium rodentium RFM0224 for preventing obesity and its application, belonging to the technical field of intestinal microorganism-host interaction and its application. The present invention isolates a strain of Faecalibacterium rodentium RFM0224 for the first time, which is a Gram-positive bacterium and an endogenous strain in the intestine of mammals. It can reduce the accumulation of white adipose tissue in the body under a high-fat diet, reduce the levels of total cholesterol (TC) and triglycerides (TG) in serum, and can significantly downregulate the expression of colon inflammatory cytokines IL-6, IL-1β and TNF-αmRNA. This lays a foundation for the use of this strain and the bacterial agent developed based on this strain in the preparation of products related to the prevention and treatment of intestinal inflammation, obesity and hyperlipidemia.

The invention discloses a simulation test system and method for a vehicle control HIL rack, and relates to the technical field of vehicle simulation test. The simulation test system for the vehicle control HIL rack comprises a scene dynamics simulation module, the scene dynamics simulation module is in communication connection with a cluster control module and a scene display module, the cluster control module is in communication connection with a vehicle control HIL rack module, and the scene display module is in communication connection with the scene display module. The scene display module is in communication connection with the graphic workstation module and the vehicle control HIL rack module, and the graphic workstation module is in communication connection with the vehicle control HIL rack module. According to the invention, the problems that in an actual test, a complex driving environment and an emergency need a higher simulation capability, which proposes a higher requirement for the real-time performance and the processing capability of the system, and the data synchronization and transmission mode in the system is not described in detail are solved.

The embodiment of the invention discloses an equipment control method and device and an ad hoc network system, and the method comprises the steps: setting a plurality of semantic tags for node equipment of an ad hoc network from a plurality of different dimensions, embedding a target node equipment tag group in equipment control information when scene control or group control is carried out, and carrying out the scene control or group control. And positioning the target node equipment needing to be controlled by using the target node equipment label group, and sending the equipment control information in the ad hoc network in a broadcast mode. And meanwhile, each node device matches and judges whether a target node device exists or not based on a semantic tag of the node device and a target node device tag group by broadcasting the received device control information, and executes an action instruction in the device control information when judging that the node device is the target node device. Thus, scene control or group control can be realized in a low-latency manner without controlling a command or address translation of the gateway device.

The invention relates to the technical field of network security and cryptography, and discloses a hybrid encryption and decryption method and device based on a trusted video, and the method comprises the steps: carrying out the encryption and decryption of the trusted video based on a secret key and a chip; determining capability parameters of the chip according to the type of the secret key; and when it is detected that the capability parameter of the chip reaches a preset threshold value, performing encryption and decryption processing on the trusted video based on the universal library to obtain target data. According to the method and the device, when the capability parameter of the encryption and decryption chip reaches the upper limit, the universal library is switched to perform encryption and decryption processing, so that a part of pressure of the encryption and decryption chip is effectively released, the multi-channel video playing capability is improved, the multi-channel video playing capability is not limited by the capability of the encryption and decryption chip, and relatively high video delay and jamming are avoided.

The embodiment of the invention relates to a preparation method of a constant current driving light-emitting device and the constant current driving light-emitting device, and the preparation method comprises the steps: providing a semiconductor growth substrate which comprises a first surface and a second surface which are opposite to each other; a semiconductor epitaxial layer is epitaxially grown on the second surface side, the semiconductor epitaxial layer comprises a third surface connected with the semiconductor growth substrate, and the semiconductor epitaxial layer comprises a first semiconductor epitaxial layer, a light-emitting layer and a second semiconductor epitaxial layer which are sequentially stacked in the direction away from the semiconductor growth substrate, the first semiconductor epitaxial layer, the light-emitting layer and the second semiconductor epitaxial layer are used for forming a light-emitting unit; removing a part of the semiconductor growth substrate from the first surface side to expose a part of the third surface, the third surface being a light emitting surface of the light emitting unit; and carrying out ion doping in the residual semiconductor growth substrate to form a plurality of ion doped regions so as to form a constant current unit. Therefore, the stability of the light-emitting device is improved.

The embodiment of the invention provides a permission authentication management method, system and device for a logistics robot and a storage medium. The method comprises the following steps: acquiring an integrated permission authentication package; decomposing the obtained permission authentication packet, and sending the decomposed permission authentication packet to a permission verification facility; receiving an authority authentication result fed back by the authority verification facility; and according to the authority authentication result, the logistics robot carries out logistics distribution operation. According to the embodiment of the invention, the communication and authority authentication mechanism is unified, the compatibility requirement is low, the interactive communication between the logistics robot and the authority verification facility can be realized, the security vulnerability is avoided, and the problems that the time delay is increased and the efficiency is relatively low due to the frequent and repeated authority authentication of the logistics robot in the process of executing the logistics distribution operation can be avoided.

The utility model provides an air filter and a motorcycle. The air filter comprises an air filter shell cover, an air filter shell fixedly connected with the air filter shell cover, and an air filter element combination installed between the combination faces of the air filter shell and the air filter shell cover, and the air filter element combination is fixed to the air filter shell through screws. A concave receding part is arranged on the inner side of the end face of the air filter shell cover and located over the screw, and the distance between the concave receding part and the screw is smaller than the depth of the portion, screwed into a threaded hole in the air filter shell, of the screw. According to the structure, the possibility that the screw falls off and enters an engine cylinder after the screw is loosened in the running process of a vehicle can be effectively prevented, normal running of an engine is guaranteed, an existing structure on the air filter shell cover is reasonably utilized, the number of added new structures is reduced, the complexity of manufacturing and machining is reduced, and the cost is reduced. And meanwhile, the die processing difficulty is reduced, so that the production and manufacturing cost is reduced.