Abstract: A multi-antenna module system includes a substrate, a plurality of first antenna modules, a plurality of second antenna modules, and a plurality of third antenna modules. The substrate has an opening. The first antenna modules are respectively disposed on the substrate and located on two opposite first sides and two opposite second sides for transmitting and receiving a first frequency band signal. The second antenna modules are respectively disposed on the substrate and located on two opposite third sides for transmitting and receiving a second frequency band signal. The third antenna modules are respectively disposed on the substrate and located on two opposite third sides and two opposite fourth sides for transmitting and receiving a third frequency band signal. The second antenna modules and the third antenna modules are respectively located between the first antenna modules.

Abstract: Provided are a response receiving and sending method, a retransmission method, a communication device, and a storage medium. The method includes: sending a transport block to a first communication device through a pre-configured period resource, and receiving a correct response corresponding to the transport block on a pre-configured correct response resource.

Abstract: A bit may include a matrix portion, the matrix portion exposed at a cone region and a nose region of the bit. A bit may include a steel portion, the steel portion including a bit connection, the steel portion exposed at a gauge region of the bit. A bit may include a plurality of cutting elements secured to the matrix portion at the cone region and the nose region.

Abstract: A blade on a downhole drilling tool includes a blade body and a blade cover. The blade cover is pre-sintered and conforming to the blade outer shape. The blade cover is attached to the blade body. The blade cover includes a seamless connection between a cover leading face and a cover outer face to reduce wear on the outer face of the blade.

Abstract: A tri-band antenna module includes a substrate, a first radiator, a second radiator, and a short-circuit structure. The substrate has a signal feed-in terminal and a ground terminal. The signal feed-in terminal is connected to the first radiator, and the ground terminal is connected to the second radiator. The first radiator includes a first extension block and a second extension block, and the second radiator includes a third extension block and a fourth extension block. The first extension block and the second extension block are separated by a first interval, and the third extension block and the fourth extension block are separated by a second interval. The short-circuit structure is connected between the first extension block and the third extension block, and the short-circuit structure is respectively separated from the first extension block and the third extension block by a first slot and a second slot.

Abstract: The disclosed drill tools have metal matrix composite (MMC) or steel alloy bodies that are formed around one or more pre-fabricated components using either a casting or infiltration process. The pre-fabricated components are made of sintered, infiltrated, and/or cemented particles of an ultrahard material, and may form any suitable portion of the bit blades. The pre-fabricated components may be loaded into a machined mold, and the mold cavity is subsequently filled with powder, such as tungsten carbide powder, filler metal powder, binder metal powder, or combinations thereof. During a casting or infiltration process, the mold and pre-fabricated components are heated to a sufficient temperature to melt the binder metal and/or filler metal, wherein the molten metal superficially interacts with the inner surfaces of the pre-fabricated components to form a metallurgical bond to secure the pre-fabricated components to the bit body.

Abstract: A visual notification device in a fire-fighting system may include an input end, a booster circuit, an energy storage element, at least one flash element, and a flash control circuit, for causing energy in the energy storage element to be applied to the at least one flash element to make it flash. At least one of the booster circuit, the at least one flash element, and the flash control circuit is designed such that a residual voltage across the energy storage element in each flash operation is greater than or equal to the input voltage. The visual notification device may enable the occurrence of a repetitive inrush current to be suppressed effectively without the addition of a current-limiting circuit.

Abstract: A visual notification device in a fire-fighting system may include an input end, a booster circuit, an energy storage element, at least one flash element, and a flash control circuit, for causing energy in the energy storage element to be applied to the at least one flash element to make it flash. At least one of the booster circuit, the at least one flash element, and the flash control circuit is designed such that a residual voltage across the energy storage element in each flash operation is greater than or equal to the input voltage. The visual notification device may enable the occurrence of a repetitive inrush current to be suppressed effectively without the addition of a current-limiting circuit.

Abstract: A method for reducing stress in a downhole tool. The method includes varying a temperature of the downhole tool by at least 5° C. Vibrational energy may be transferred to the downhole tool with a vibration device coupled to the downhole tool. The vibrational energy may cause the downhole tool to move with a frequency from about 10 Hz to about 5 kHz.