Abstract: An electromagnetic ultrasonic double-wave transducer includes a shell (1), and a permanent magnet assembly, a coil (4), a shielding layer (5), and a wire (6) which are provided in said shell (1); said coil (4) is fixed on the bottom of said shell (1) and is located below said permanent magnet assembly; said shielding layer (5) is arranged between said permanent magnet assembly and said coil (4); one end of said wire (6) is connected to said coil (4) while the other end thereof is connected to the power supply and signal plug (7); said permanent magnet assembly includes a third permanent magnet (12) and a fourth permanent magnet (13); the upper end faces of said third permanent magnet (12) and said fourth permanent magnet (13) realize magnetic circuit closing by means of a magnetic circuit closing element (8).

Abstract: An electromagnetic ultrasonic double wave transducer, comprising a shell (1), and a permanent magnet assembly, a coil (4), a shielding layer (5), and a wire (6) which are provided in the shell (1). The permanent magnet assembly comprises a first permanent magnet (2) and a second permanent magnet (3) sleeved on the first permanent magnet (2). The magnetizing directions of the first permanent magnet (2) and the second permanent magnet (3) are perpendicular to the bottom of the shell (1), and the magnetic field directions of the first permanent magnet (2) and the second permanent magnet (3) are opposite. A non-conducting non-magnetic bushing material (9) is provided between the first permanent magnet (2) and the second permanent magnet (3), and upper end faces of the first permanent magnet (2) and the second permanent magnet (3) realize magnetic circuit closing by means of a magnetic circuit closing element (8).

Abstract: An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2? by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

Abstract: An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2? by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

Abstract: An electromagnetic ultrasonic double wave transducer, comprising a shell (1), and a permanent magnet assembly, a coil (4), a shielding layer (5), and a wire (6) which are provided in the shell (1). The permanent magnet assembly comprises a first permanent magnet (2) and a second permanent magnet (3) sleeved on the first permanent magnet (2). The magnetizing directions of the first permanent magnet (2) and the second permanent magnet (3) are perpendicular to the bottom of the shell (1), and the magnetic field directions of the first permanent magnet (2) and the second permanent magnet (3) are opposite. A non-conducting non-magnetic bushing material (9) is provided between the first permanent magnet (2) and the second permanent magnet (3), and upper end faces of the first permanent magnet (2) and the second permanent magnet (3) realize magnetic circuit closing by means of a magnetic circuit closing element (8).

Abstract: Methods and systems for power management include determining a voltage level of a grid; if the voltage level is below a lower voltage threshold, setting power outputs for one or more distributed generators on the grid to maximum; and if the voltage level is above the lower voltage threshold and below an upper voltage threshold, determining power outputs for one or more distributed generators on the grid using sensitivity-based distributed Q compensation.

Abstract: Embodiments of the present invention disclose a method for indicating a physical resource block PRB, including: receiving indication information that is sent by a multi-cell multicast coordination entity MCE and used for indicating usage of a physical resource block PRB in a multimedia broadcast multicast service single frequency network MBSFN subframe; and sending the indication information for indicating the usage of the PRB in the MBSFN subframe to a served user terminal.

Abstract: The present invention discloses a method and system for reselecting or handing over to a broadcast multicast cell. The method includes the following steps: broadcasting, by an MBMS cell, a service area identity list of a service area to which the MBMS cell belongs; determining, by a UE, whether the service area identity list includes a service area identity corresponding to a service; if the service area identity list includes service area identity corresponding to the service, setting, by the UE, a cell reselection priority of a frequency of an MBMS cell to the highest. According to the present invention, a UE can identify whether a cell capable of providing services that the UE is receiving or is interested in around the UE, so that the cell can learn which neighboring cells are MBMS cells and what services are being broadcast in MBMS cells if such MBMS cells are available.

Abstract: The present invention discloses a migration method and an apparatus, which relate to the field of communications technologies and are invented for implementation of proper configuration of different network resources. The method includes: sending, by a base station of a first network, information to a user equipment, where the information is used for: migrating, by the user equipment, from a second network to the first network, where the user equipment is in an idle state relative to the first network; or determining, by the user equipment, whether to migrate from the first network to the second network, where the first network is a 3GPP network, and the second network is a non-3GPP network. The present invention is mainly applied to a process of network migration of the user equipment.

Abstract: Embodiments of the present invention provide a service indication processing method and an apparatus, where the method includes: receiving, by user equipment UE, a system message sent by a base station corresponding to a legacy carrier type LCT cell, where the system message includes information about a new carrier type NCT frequency and information that is about a service area identity of a multimedia broadcast multicast service MBMS SAI and corresponds to the information about the NCT frequency; and performing, by the UE according to the system message, indication processing on an MBMS service that is being received or of interest. The technical solutions of the present invention can ensure continuity of receiving, by the UE, an MBMS service of an NCT cell.

Abstract: Embodiments of the present invention provide a service processing method for a new carrier type cell, an apparatus, and a communications system. The method includes: receiving, by user equipment UE, a system message sent by a base station corresponding to a legacy carrier type LCT cell, where the system message includes multimedia broadcast multicast service MBMS configuration information of a new carrier type NCT cell; and performing, by the UE, service configuration processing on an MBMS of the NCT cell according to the MBMS configuration information of the NCT cell.

Abstract: The present invention discloses a data transmission method, base station and terminal. The method comprises: transmitting, in every subframe used for transmitting multimedia broadcast multicast service (MBMS), n transport blocks (TBs) to terminals, and transmitting to the terminals the correspondence between the MBMS corresponding to each TB in the subframe and the TB serial number of each TB in the subframe; wherein n is an integer greater than one, a period of time occupies in every subframe by the TBs corresponding to same MBMS is same, and each TB in the subframe corresponds to a unique TB serial number. The present invention can transmit two or more TBs to terminals in every subframe, and the TBs transmitted in the subframe can correspond to different MBMSs, thereby realizing the transmission of TBs corresponding to a plurality of MBMSs in a subframe and improving the spectrum effectiveness of the data transmission.

Abstract: A communication method includes: receiving, by a user equipment, measurement configuration information sent by a base station, where the measurement configuration information is used to instruct the user equipment to perform measurement on a WiFi AP, and the measurement configuration information includes a WiFi measurement object and a WiFi measurement quantity; performing, by the user equipment, measurement on the WiFi measurement object according to the WiFi measurement quantity, to obtain a measurement report; and sending, by the user equipment, the measurement report to the base station, so that the base station determines, according to the measurement report, to offload the user equipment to the WiFi AP or stop communication between the user equipment and the WiFi AP.

Abstract: The present invention discloses a migration method and an apparatus, which relate to the field of communications technologies and are invented for implementation of proper configuration of different network resources. The method includes: sending, by a base station of a first network, information to a user equipment, where the information is used for: migrating, by the user equipment, from a second network to the first network, where the user equipment is in an idle state relative to the first network; or determining, by the user equipment, whether to migrate from the first network to the second network, where the first network is a 3GPP network, and the second network is a non-3GPP network. The present invention is mainly applied to a process of network migration of the user equipment.

Abstract: Embodiments of the present invention disclose a method for indicating a physical resource block PRB, including: receiving indication information that is sent by a multi-cell multicast coordination entity MCE and used for indicating usage of a physical resource block PRB in a multimedia broadcast multicast service single frequency network MBSFN subframe; and sending the indication information for indicating the usage of the PRB in the MBSFN subframe to a served user terminal.

Abstract: Methods and systems for power management include determining a voltage level of a grid; if the voltage level is below a lower voltage threshold, setting power outputs for one or more distributed generators on the grid to maximum; and if the voltage level is above the lower voltage threshold and below an upper voltage threshold, determining power outputs for one or more distributed generators on the grid using sensitivity-based distributed Q compensation.

Abstract: A method, a device, and a system for sending and receiving messages are provided. The method for sending messages includes: receiving, by a Mobility Management Entity (MME), an Earthquake and Tsunami Warning System (ETWS) message; setting an information change identifier if the received ETWS message is different from the ETWS message stored by the MME; and sending the received ETWS message and the information change identifier. In the embodiments of the present disclosure, the MME decides whether to send the ETWS message to the eNB. Therefore, the eNB needs only to transmit the received message to the UE transparently, and does not need to judge the content of the ETWS message, thus simplifying the process of the eNB sending the ETWS message and reducing the load of the access network device.

Abstract: A method, a device, and a system for sending and receiving messages are provided. The method for sending messages includes: receiving, by a Mobility Management Entity (MME), an Earthquake and Tsunami Warning System (ETWS) message; setting an information change identifier if the received ETWS message is different from the ETWS message stored by the MME; and sending the received ETWS message and the information change identifier. In the embodiments of the present disclosure, the MME decides whether to send the ETWS message to the eNB. Therefore, the eNB needs only to transmit the received message to the UE transparently, and does not need to judge the content of the ETWS message, thus simplifying the process of the eNB sending the ETWS message and reducing the load of the access network device.

Abstract: The present invention discloses a method and system for reselecting or handing over to a broadcast multicast cell. The method includes the following steps: broadcasting, by an MBMS cell, a service area identity list of a service area to which the MBMS cell belongs; determining, by a UE, whether the service area identity list includes a service area identity corresponding to a service; if the service area identity list includes service area identity corresponding to the service, setting, by the UE, a cell reselection priority of a frequency of an MBMS cell to the highest. According to the present invention, a UE can identify whether a cell capable of providing services that the UE is receiving or is interested in around the UE, so that the cell can learn which neighboring cells are MBMS cells and what services are being broadcast in MBMS cells if such MBMS cells are available.

Abstract: A method, a device, and a system for sending and receiving messages are provided. The method for sending messages includes: receiving, by a Mobility Management Entity (MME), an Earthquake and Tsunami Warning System (ETWS) message; setting an information change identifier if the received ETWS message is different from the ETWS message stored by the MME; and sending the received ETWS message and the information change identifier. In the embodiments of the present disclosure, the MME decides whether to send the ETWS message to the eNB. Therefore, the eNB needs only to transmit the received message to the UE transparently, and does not need to judge the content of the ETWS message, thus simplifying the process of the eNB sending the ETWS message and reducing the load of the access network device.