Abstract: Disclosed are a method and system for evaluating sonar self-noise at a ship design stage. The method includes: building a ship structure full-scale geometric simulation model; acquiring loss factors and sonar transducer space outfitting acoustic absorption coefficient material parameters; acquiring mechanical excitation, hydrodynamic excitation, and propeller excitation; inputting the loss factors and the sonar transducer space outfitting acoustic absorption coefficient material parameters into an established statistical energy evaluation model, and applying a mechanical excitation to a face plate of foundation of the built ship structure full-scale geometric simulation model, applying a hydrodynamic excitation to the surface of a ship hull, and applying a propeller excitation to a stern shaft to perform calculation of sonar self-noise of a ship to obtain total spectral density level of the sonar self-noise; and evaluating spectral density level calculation results by index requirements.

Abstract: A water environment temperature measurement tool includes measurement boxes and a counterweight box; a plurality of groups of the measurement boxes are provided; the counterweight box is movably connected with a group of measurement boxes; and each measurement box is provided with a temperature measurement instrument inside. The water environment temperature measurement tool further comprises: control mechanisms, each comprising a water inlet pipe, a water retaining member, an elastic member, a control assembly, a rotating seat, a rotating shaft, a second screw rod, a control seat and a rotary assembly. In the water environment temperature measurement tool of the present invention, the control mechanisms can achieve extraction and temperature measurement of water at different water body depths by cooperating with the measurement boxes and the temperature measurement instruments.

Abstract: A structural temperature self-monitoring system based on a chiral structured shape memory polymer microporous plate, comprising a fixing apparatus, a chiral structured microporous plate, and a triboelectric nanogenerators set. Each chiral element of microporous plate is provided with a hexagonal cell and six chiral legs, and the microporous plate may occur specific deformation under certain conditions. The microporous plate is fixed on the fixed apparatus, and the triboelectric nanogenerators set comprises two lateral sliding mode triboelectric nanogenerators that are symmetrically distributed; the data of deformation of chiral structured microporous plate in converse directions is collected; and a voltage is emerged for measurement. The system can monitor the temperature of any portion of structure without an external power supply, and obtain the temperature data possessing both timeliness and accuracy under the condition of ensuring the integrity and representativeness of temperature data.

Abstract: Disclosed are a method and system for evaluating sonar self-noise at a ship design stage. The method includes: building a ship structure full-scale geometric simulation model; acquiring loss factors and sonar transducer space outfitting acoustic absorption coefficient material parameters; acquiring mechanical excitation, hydrodynamic excitation, and propeller excitation; inputting the loss factors and the sonar transducer space outfitting acoustic absorption coefficient material parameters into an established statistical energy evaluation model, and applying a mechanical excitation to a face plate of foundation of the built ship structure full-scale geometric simulation model, applying a hydrodynamic excitation to the surface of a ship hull, and applying a propeller excitation to a stern shaft to perform calculation of sonar self-noise of a ship to obtain total spectral density level of the sonar self-noise; and evaluating spectral density level calculation results by index requirements.

Abstract: Aspects of the subject technology relate to systems and methods for identifying the quality of cement bonding of an exterior surface of a wellbore casing to an Earth formation. Methods of the present disclosure may allow for bond indexes to be identified in real-time as a cementing operation is performed even when tools that perform the cementing operation generate acoustic noise that interfere with measurements used to evaluate cement bonding quality. These methods may include transmitting acoustic signals, receiving acoustic signals, filtering the received acoustic signals, identifying magnitude and attenuation values to associate with the received acoustic signals, and comparing trends in the magnitudes with the identified attenuation values. These methods may also include correcting attenuation values associated with measured data based on a set of correction rules such that bond indexes can be identified. Such correction rules may be associated with data generated by a computer model.

Abstract: The present invention discloses compounds of Formula (I), and pharmaceutically acceptable salts, thereof: which inhibit coronavirus replication activity. The invention further relates to pharmaceutical compositions comprising a compound of Formula (I) or a pharmaceutically acceptable salt thereof, and methods of treating or preventing a coronavirus infection in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of Formula (I) or a pharmaceutically acceptable salt thereof.

Abstract: A common control channel-free communication method and system featuring integrated autonomous link establishment and frequency conversion, belonging to the technical field of wireless communication is provided. The method comprises: autonomously establishing, by a caller communication node a two-way communication link with a responder communication node through a calling and responding mechanism; and monitoring, by the caller communication node, operating frequency points through a real-time interference detection mechanism, and autonomously updating transmitted signal feature parameters of the caller communication node at certain frequency conversion slots, so that the responder communication node can update transmitted signal feature parameters in the responder communication node after receiving the updated transmitted signal feature parameters.

Abstract: A method for detecting contact of a swinging leg of a robot with ground includes: obtaining a torque on each joint of the swinging leg when the robot is in a swing phase; estimating a force on a foot of the swinging leg by using a force Jacobian matrix based on the torque on each joint of the swinging leg, and calculating a rate of change of force of the foot in a vertical direction according to the force on the foot; and determining that the swinging leg has contacted the ground in response to a preset consecutive number of values of the rate of change of force being greater than a preset threshold.

Abstract: A method for controlling a robot includes: obtaining current motion state information of the robot and desired motion trajectory information corresponding to a target task; determining task execution coefficient matrices corresponding to the robot performing the target task according to the desired motion trajectory information and the motion state information; constructing matching dynamic constraints for task-driven parameters of the robot according to the desired motion trajectory information and the motion state information; constructing matching parameter distribution constraints for the task-driven parameters according to the motion state information and body action safety constraints corresponding to the target task; solving a pre-stored task execution loss function by using the task execution coefficient matrices to obtain the target-driven parameters satisfying the dynamic constraints and the parameter distribution constraints; and controlling operation state of each joint end effector of the robot a

Abstract: A casing includes a body for accommodating a battery management system and a mounting member fixed on the body. The mounting member includes a first end and a second end at opposite locations. The first end is provided with an elastic member. The second end is provided with a clamping portion. The clamping portion is configured to be clamped to an assembly bracket. The elastic member is configured to generate a rebound force under limitation of the assembly bracket, so as to fix the mounting member at a location on the assembly bracket.

Abstract: The present invention discloses a reconstruction method and system of fluorescence molecular tomography based on wavelet and Schur decomposition, the method including the steps of: transforming the inverse problem of fluorescence molecular tomography into a linear matrix equation; solving the linear matrix equation and updating reconstruction parameters iteratively using the obtained solution to obtain a final reconstruction result; in which, in the process of solution of the linear matrix equation, wavelet transform is performed on the linear matrix equation to obtain an overview matrix equation, Schur decomposition is performed on the overview matrix equation to obtain a subsystem with a reduced number of conditions, and the linear matrix equation is calculated using the solution of the subsystem. The present invention reduces the amount of calculation in the process of reconstruction, speedups the process of reconstruction, improves the imaging efficiency and further improves the imaging quality.

Abstract: An opening and closing device includes a door cover including a vent and an opening and closing member configured to be inserted into the door cover through an opening of the vent along an extension direction of the vent. The opening and closing member includes an air door and is movable between an open position at which the air door does not close the vent and a closed position at which the air door closes the vent.

Abstract: The present disclosure provides a secondary battery which comprises: a cap plate provided with a first electrode terminal; an electrode assembly comprising a main body and a first electrode tab; a first connecting piece connected between the first electrode tab and the first electrode terminal. The first connecting piece includes a first electrode terminal connecting portion, a first electrode tab connecting portion and a first fusing portion. The secondary battery further comprises an insulating piece arranged on the first connecting piece to prevent direct physical contact between the first electrode tab and the first electrode terminal connecting portion by covering at least an edge of the first electrode terminal connecting portion.

Abstract: The present disclosure provides a secondary battery and an assembly therefor. The secondary battery includes: a cap plate provided with a first electrode terminal; electrode assemblies, each electrode assembly comprising a first electrode tab; a first connecting piece connected between the first electrode tab and the first electrode terminal. The first connecting piece includes a first electrode terminal connecting portion, a first electrode tab connecting portion and a first fusing portion. The secondary battery further includes an insulating holding block connected with the first electrode terminal connecting portion and the first electrode tab connecting portion respectively, and the insulating holding block is configured to maintain the first electrode terminal connecting portion and the first electrode tab connecting portion in position relative to each other when the first fusing portion is fused.

Abstract: Systems, methods, and non-transitory computer-readable media can determine a first ephemeral message to be shared through a first unified message thread corresponding to a group of recipients, the first ephemeral message being created by a user operating the computing device. The first ephemeral message can be provided to a social networking system for distribution to the group of recipients through the first unified message thread, wherein both ephemeral messages and non-ephemeral messages are exchanged between the group of recipients through the same first unified message thread.

Abstract: The present invention relates to a loosening mechanism and an aerial fog generating device, wherein the loosening mechanism comprises a rotating portion; the rotating portion comprises an outer housing and an inner housing, the outer housing is sleeved onto the inner housing, and the inner housing is used for placing an aerial fog forming substrate; a pressing mechanism is provided on the inner housing, the outer housing is capable of moving along a circumferential direction, and the circumferential movement is converted into axial movement to drive the pressing mechanism to apply a radial pressing force to the aerial fog forming substrate; the inner housing is capable of being rotatably connected to the aerial fog generating device between a first position and a second position, and the aerial fog forming substrate and a heating element are capable of generating relative movement in the circumferential direction in the process from the first position to the second position; and the aerial fog forming substra

Abstract: An opening and closing device includes a door cover including a vent and an opening and closing member configured to be inserted into the door cover through an opening of the vent along an extension direction of the vent. The opening and closing member includes an air door and is movable between an open position at which the air door does not close the vent and a closed position at which the air door closes the vent.

Abstract: Systems, methods, and non-transitory computer-readable media can provide a messaging interface, the messaging interface including one or more options for accessing at least one unified message thread, wherein both ephemeral messages and non-ephemeral messages are exchanged between a group of users through the unified message thread. A determination can be made that a user operating the computing device has created a message to be sent through the unified message thread. The message can be provided for distribution to the group of users through the unified message thread.

Abstract: The present disclosure provides a secondary battery which comprises: a cap plate provided with a first electrode terminal; an electrode assembly comprising a main body and a first electrode tab; a first connecting piece connected between the first electrode tab and the first electrode terminal. The first connecting piece includes a first electrode terminal connecting portion, a first electrode tab connecting portion and a first fusing portion. The secondary battery further comprises an insulating piece arranged on the first connecting piece to prevent direct physical contact between the first electrode tab and the first electrode terminal connecting portion by covering at least an edge of the first electrode terminal connecting portion.