Abstract: A reasonable millisecond time control method for excavation blasting of a tunnel is provided, and includes: acquiring physical mechanical parameters to establish a millisecond blasting model, and designing four dimensions blasting parameters of explosive quantity, hole number, inter-hole millisecond and inter-row millisecond; simulating, based on the millisecond blasting model, a blasting process of an explosive package using blasting parameters to obtain a blasting vibration curve; obtaining single-hole blasting vibration waveforms, solving a vibration synthesis curve through a vibration synthesis theory; comparing the vibration synthesis curve with the blasting vibration curve to obtain a coupling relationship of blasting parameters; determining a target group of explosive quantity and hole numbers, determining a target millisecond through the coupling relationship of blasting parameters, and relating a millisecond blasting control strategy to control, and it is used for tunneling project to reduce cut blas

Abstract: An earmuff module of a headphone includes a back cover, a sound-receiving hole, a microphone assembly, and an earmuff. The back cover includes a peripheral side wall. The sound-receiving hole is formed on the peripheral side wall of the back cover and penetrates through the peripheral side wall. The microphone assembly is disposed on an inner surface of the peripheral side wall and corresponds to the sound-receiving hole, and is acoustically connected with the sound-receiving hole. The earmuff is detachably assembled on the back cover, and the earmuff includes a foam and a wrapping cover. The wrapping cover includes an extension part and a covering part. The covering part covers the foam. The extension part extends from one end of the covering part to an outer surface of the peripheral side wall and covers the sound-receiving hole. The microphone assembly is located within a range covered by the extension part.

Abstract: A heat exchanger, a manufacturing method thereof and a thermal management system are provided. The heat exchanger includes a metal substrate having a fluid channel for circulating a heat exchange medium, and a coating layer coated on at least part of a surface of the metal substrate. The coating layer includes a rare earth conversion film containing a rare earth element-containing compound, and a hydrophobic film. The rare earth conversion coating film is arranged to directly cover at least part of a surface of the metal substrate of the heat exchanger, and at least part of the hydrophobic coating layer is further away from the metal substrate than the rare earth conversion film. The heat exchanger is provided with hydrophobicity by the coating layer, which facilitates the discharge of condensed water, and improves the corrosion resistance and prolongs the service life of the heat exchanger.

Abstract: The present application provides a heat exchanger and a manufacturing method of a heat exchanger. The heat exchange includes a metal substrate having a fluid channel for circulating a heat exchange medium. The heat exchanger includes a coating having a rare earth conversion coating and a hydrophilic coating. The rare earth conversion coating is arranged to cover at least part of a surface of the metal substrate, and the rare earth conversion coating includes a rare earth element-containing compound. At least part of the hydrophilic coating is further away from the metal substrate than the rare earth conversion coating. A surface of the heat exchanger is hydrophilic, which is conducive to the discharge of condensate water, and can improve corrosion resistance and prolong a service life of the heat exchanger.

Abstract: An earmuff module of a headphone includes a back cover, a sound-receiving hole, a microphone assembly, and an earmuff. The back cover includes a peripheral side wall. The sound-receiving hole is formed on the peripheral side wall of the back cover and penetrates through the peripheral side wall. The microphone assembly is disposed on an inner surface of the peripheral side wall and corresponds to the sound-receiving hole, and is acoustically connected with the sound-receiving hole. The earmuff is detachably assembled on the back cover, and the earmuff includes a foam and a wrapping cover. The wrapping cover includes an extension part and a covering part. The covering part covers the foam. The extension part extends from one end of the covering part to an outer surface of the peripheral side wall and covers the sound-receiving hole. The microphone assembly is located within a range covered by the extension part.

Abstract: A processing method of a heat exchanger and a heat exchanger are provided. The processing method includes following steps. A heat exchanger and a composite material is provided, where the heat exchanger includes a collecting pipe, a fin and a heat exchange tubes. The heat exchange tube is fixed to the collecting pipe. An inner cavity of the heat exchange tube is communicated with an inner cavity of the collecting pipe. At least part of the fin is retained between two adjacent heat exchange tubes. The composite material includes a solvent and an organosilane-based modified material with low surface energy. The composite material is coated on at least part of an outer surface of at least one of the collecting pipe, the heat exchange tube and the fin, and the composite material is cured. The heat exchanger obtained according to the present disclosure shows better hydrophobic performance.

Abstract: A heat exchanger, a processing method of a heat exchanger and a composite material, wherein the heat exchanger includes a collecting pipe, a fin and a numnber of heat exchange tubes. Each of the heat exchange tubes is fixed to the collecting pipe, and an inner cavity of the heat exchange tube is communicated with an inner cavity of the collecting pipe. The fin is retained between two adjacent heat exchange tubes. The heat exchanger further includes a coating layer which is coated on an outer surface of at least one of the collecting pipe, the heat exchange tube and the fin. The coating layer includes micro-nano particles and a polymer obtained by polymerizing monomers including allylic monomers with hydrophilic groups. The micro-nano particles include silicon dioxide and/or titanium dioxide. The coating layer of the heat exchanger has excellent hydrophilic durability.

Abstract: A heat exchanger and a processing method of heat exchanger. The heat exchanger includes a collecting pipe, a fin and a number of heat exchange tubes. The heat exchange tubes are fixed with the collecting pipe. At least part of the fin is fixed between two adjacent heat exchange tubes. The heat exchanger includes a coating with a first matching coating which is in direct contact with at least one of the collecting pipe, the heat exchange tubes and the fin; or, at least one functional films is further spaced between the first matching coating and at least one of the collecting pipe, the heat exchange tubes and the fin. The first matching coating includes a hydrophobic material and a filler of nanoparticle type.

Abstract: Various embodiments include a testing apparatus capable of testing gas flowing in a duct. The apparatus may include: a housing; a sampling tube extending from the housing to be inserted into the duct, the sampling tube including a gas entry channel and a gas exit channel isolated from each other, with a gas inlet of the gas entry channel and a gas outlet of the gas exit channel disposed in a part of the sampling tube leading into the duct and disposed at the same side of the sampling tube, wherein the gas inlet and the gas outlet have matching gas through-flow areas; and a sensor module disposed in the housing and in gas communication with the gas entry channel to test gas sampled from the gas entry channel.

Abstract: A downhole power generation includes a power generation module for providing power to a load. A turbine is driven by flow of a downhole fluid to rotate. A generator is coupled with the turbine for converting rotational energy from the turbine to electrical energy, and an AC-DC rectifier is coupled with the generator for converting an alternating voltage from the generator to a direct voltage. A power conversion circuit couples the AC-DC rectifier with the load. The power conversion circuit is configured for providing a first power to the load when the load is in a working mode and providing a second power to the load when the load is in a non-working mode. The second power is less than the first power. A downhole power generation method is also disclosed.

Abstract: A heat exchanger includes a metal base defining a heat exchange channel for flowing at least one of a refrigerant and a coolant therein, and a coating layer coated at least a part of an outer surface of the metal base. The coating layer includes sol particles and an antibacterial material, where the sol particles include silica. The antibacterial material includes a rare earth element oxide. By combining the antibacterial agent containing the rare earth element oxide with sol, the advantages of each component can be fully utilized. On the one hand, it is easier to attach the antibacterial material via the sol, and on the other hand a surface of the metal base of the heat exchanger can have a good antibacterial and mold-inhibiting effects, which is beneficial to cost reduction.

Abstract: A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.

Abstract: The present application provides a heat exchanger and a manufacturing method of a heat exchanger. The heat exchanger includes a metal substrate, the metal substrate has a fluid channel for circulating a heat exchange medium; and the heat exchanger further includes a coating, the coating includes resin, silica and titanium dioxide, and the coating is arranged to cover at least part of a surface of the metal substrate. Silica particles and titanium dioxide particles are conducive to the formation of a complex micro-nano structure, and leveling and stability of hydrophilic resin contribute to long-term maintenance of the micro-nano structure. The coating of the heat exchanger according to the present application has excellent hydrophilic durability.

Abstract: The present application provides a heat exchanger and a manufacturing method of a heat exchanger. The heat exchange includes a metal substrate having a fluid channel for circulating a heat exchange medium. The heat exchanger includes a coating having a rare earth conversion coating and a hydrophilic coating. The rare earth conversion coating is arranged to cover at least part of a surface of the metal substrate, and the rare earth conversion coating includes a rare earth element-containing compound. At least part of the hydrophilic coating is further away from the metal substrate than the rare earth conversion coating. A surface of the heat exchanger is hydrophilic, which is conducive to the discharge of condensate water, and can improve corrosion resistance and prolong a service life of the heat exchanger.

Abstract: The present disclosure relates to the technical field of material and heat exchange and in particular, to a coating material applied to a heat exchanger, a method of preparing the coating material, a heat exchanger, and a method of treating the heat exchanger. The coating material of the present disclosure applied to a heat exchanger includes a hydrophobic material and a light-to-heat conversion material. Under irradiation of visible light, the light-to-heat conversion material can effectively increase the surface temperature of a coated object, which is beneficial to increasing the surface temperature of the coated object while exerting the hydrophobic performance of the hydrophobic material, thus further improving the effect in slowing down frosting.

Abstract: A head phone structure includes an earmuff casing and a speaker. The earmuff casing includes a first casing and a second casing. A first accommodating space and a first chamber are formed between the first casing and the second casing, and the first chamber is formed outside the first accommodating space. The speaker is disposed in the first accommodating space of the earmuff casing and at least includes a frame and a vibration system. A second chamber is defined and formed by the frame and the vibration system. An airflow is generated in the second chamber when the vibration system vibrates. The second chamber communicates with the first chamber of the earmuff casing.

Abstract: The disclosure relates to a method and device for displaying logistics information, and computer readable storage medium. The method includes acquiring a logistics waybill identifier of at least one item from at least one e-commerce client that is installed on an operating system of a terminal and is configured to display a logistics page; acquiring logistics information corresponding to the logistics waybill identifier, wherein the logistics information indicates a logistics progress of the at least one item; aggregating the acquired logistics information of the at least one item; and displaying the aggregated logistics information in a preset display area provided by the operating system.

Abstract: A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.

Abstract: A head phone structure includes an earmuff casing and a speaker. The earmuff casing includes a first casing and a second casing. A first accommodating space and a first chamber are formed between the first casing and the second casing, and the first chamber is formed outside the first accommodating space. The speaker is disposed in the first accommodating space of the earmuff casing and at least includes a frame and a vibration system. A second chamber is defined and formed by the frame and the vibration system. An airflow is generated in the second chamber when the vibration system vibrates. The second chamber communicates with the first chamber of the earmuff casing.