Abstract: The present disclosure relates to the technical field of oxygen carrier, discloses a medium-entropy perovskite oxygen carrier and its preparation method and application thereof, the synthesis procedure includes preparing an aqueous solution from metallic nitrate serving as a raw material, performing a coprecipitation reaction with at least one of aqueous ammonia solution, a sodium hydroxide aqueous solution or a sodium carbonate aqueous solution as a precipitant at a pH value of 9.5 to 10.5; obtaining the La3CoMnAlO9 powers after stirring, standing, washing, drying and calcining. The preparation method is simple, synthetic conditions are easy to control, and batch production could be achieved.

Abstract: The present disclosure relates to multiband antenna apparatuses. An example multiband antenna apparatus includes a first dipole radiating element, a second radiating element, and a metasurface superstrate (MSS) structure. The first dipole radiating element may be configured to operate at a first frequency band and arranged on an upper plane of a support structure in a first distance to a reflector plate. The second radiating element may be configured to operate at a second frequency band and arranged on a lower plane of the support structure in a second distance to the reflector plate. The second distance is smaller than the first distance. The second frequency band is higher than the first frequency band. The MSS structure is arranged in an area inside arms of the first dipole radiating element and enhances a performance of the second radiating element.

Abstract: An antenna element for a multi-band antenna device includes a dielectric body provided with one or more metal layers. The dielectric body includes a base plate and one or more wall elements arranged on the base plate. One or more first radiating elements and one or more second radiating elements are arranged on the base plate, and are configured to radiate in a first and a second frequency band, respectively. A first feeding network is connected to the first radiating elements and a second feeding network is connected to the second radiating elements, for operating the first and second radiating elements as a first and second antenna array, respectively. The first feeding network is provided, at least partly, as a metal layer of the one or more metal layers on the one or more wall elements.

Abstract: The present disclosure relates to two-dimensional antennas and network devices. One example antenna includes a reflection panel, at least two antenna arrays, at least one common feeding network, and at least two array feeding networks. The at least two antenna arrays are on the reflection panel. Each antenna array comprises at least one independent radiation unit and at least one common radiation unit. Each antenna array corresponds to an array feeding network of the at least two array feeding networks. Each independent radiation unit in each antenna array is connected to a particular array feeding network corresponding to the particular antenna array. Each common radiation unit in each antenna array is connected to the at least one common feeding network. The at least one common feeding network is connected to the at least two array feeding networks corresponding to the at least two antenna arrays.

Abstract: The present disclosure relates to two-dimensional antennas and network devices. One example antenna includes a reflection panel, at least two antenna arrays, at least one common feeding network, and at least two array feeding networks. The at least two antenna arrays are on the reflection panel. Each antenna array comprises at least one independent radiation unit and at least one common radiation unit. Each antenna array corresponds to an array feeding network of the at least two array feeding networks. Each independent radiation unit in each antenna array is connected to a particular array feeding network corresponding to the particular antenna array. Each common radiation unit in each antenna array is connected to the at least one common feeding network. The at least one common feeding network is connected to the at least two array feeding networks corresponding to the at least two antenna arrays.

Abstract: A method and a device for checking health of a link are disclosed in the present disclosure. The method includes: receiving and saving control information generated by a keep-alive program; performing a matching on a message received according to the control information, processing the message if the matching is successful, and sending a processed message to the server to be checked; and determining that the link is healthy if a response message is received from the server to be checked, and determining that the link is unhealthy if no response message r is received from the server to be checked.

Abstract: A method and a device for checking health of a link are disclosed in the present disclosure. The method includes: receiving and saving control information generated by a keep-alive program; performing a matching on a message received according to the control information, processing the message if the matching is successful, and sending a processed message to the server to be checked; and determining that the link is healthy if a response message is received from the server to be checked, and determining that the link is unhealthy if no response message r is received from the server to be checked.

Abstract: A backplane connector has a housing, a first insulative base, a second insulative base, multiple first terminals, multiple second terminals and multiple third terminals. Each of the insulative bases is mounted in the housing and is formed into one-piece. The first terminals are mounted on the first insulative base. The second terminals are mounted on the second insulative base. The third terminals are mounted on the insulative bases. The one-piece insulative bases excellently reduce their tolerances and raise the structurally strength of the backplane connector. Therefore, the production rate of the backplane connector increases.

Abstract: An exemplary polishing brush includes a mounting member, a plurality of polishing bristles and a latching member. The mounting member defines a plurality of through holes. Each of the polishing bristles is partially inserted into one of the plurality of through holes respectively. The latching member connects with all of the polishing bristles at a side of the through holes of the mounting member, and fixed in the mounting member. When the latching member is disconnected from the mounting member, the polishing bristles are detached from the mounting member.