Abstract: A method for calibrating extrinsic parameters of surround-view cameras on a vehicle includes: determining extrinsic parameters of the first camera and the second camera; determining a first pose initial value, a second pose initial value, a third pose initial value, and a fourth pose initial value; determining extrinsic parameters of the third camera and fourth camera according to the extrinsic parameters of the first camera and second camera, the first pose initial value, the second pose initial value, the third pose initial value, and the fourth pose initial value. According to the visual odometer information of the first camera and the second camera, the extrinsic parameters of the first camera and second camera are first determined, and the extrinsic parameters of the third camera and fourth camera are then determined according to the extrinsic parameter of the first camera and the extrinsic parameter of the second camera.

Abstract: A method for piloting from bypass in a network based on a satellite load platform can unify the influence of distance change and Doppler frequency shift of satellite ground stations in the whole network, and realize accurate quasi synchronization between the clock of the whole network and the clock of the satellite. The method includes transmitting a pilot signal from bypass based on a satellite load platform in a satellite communication system, taking a spaceborne high stability timing clock source as a reference, and transmitting the pilot signal to all downlink beams to provide the pilot signal for all satellite stations covered by the satellite.

Abstract: A method for quasi-synchronous code division multiple access based on synchronization clock by piloting can make CDMA operate in quasi-synchronous conditions, so it is suitable for open wireless channels with relay nodes, such as satellite communication systems, and open wireless channels without relay nodes. The method includes: adopting a mode of CDMA spread spectrum transmission to share power resources to transmit signals at multiple transmitting stations in open wireless channels; adopting an external pilot signal to provide synchronization clock for the CDMA signals transmitted by multiple terminal stations in the open wireless channels, eliminating path delay differences from the multiple terminal stations to a relay node or receiving station, and making multi-channel CDMA signals received at the relay node or receiving station clock synchronized and phase aligned. The method can realize the quasi-synchronous reception of multi-channel CDMA signals.

Abstract: A cover, a fluid end and a plunger pump are provided. The cover includes: a body, the body being cylindrical, and the body including a first end, a second end, and a side surface connecting the first end and the second end; a main flow channel extending along an axis of the body; a plurality of subsidiary flow channels, each of the plurality of subsidiary flow channels being communicated with the main flow channel; a first opening, located at the first end and communicated with the main flow channel; and a plurality of second openings, located at the side surface of the body; each of the plurality of subsidiary flow channels being communicated with at least one of the plurality of second openings.

Abstract: A micro inverter and a modulation method thereof are provided in the present disclosure. The micro inverter includes a filter, a transformer, and a switching circuit. The switching circuit includes one or more first switching circuit and one second switching circuit. Each of the first switching circuits has an input terminal serving as an output terminal of a direct-current power supply, and is configured to convert a direct current into an alternating current and output the alternating current to the second switching circuit. An output terminal of the second switching circuit is connected to a primary side of the transformer. A secondary side of the transformer is connected to an input terminal of the filter.

Abstract: A plunger, a hydraulic end and a plunger pump are disclosed. The plunger includes a plunger body, the plunger body includes a flow channel; a first liquid inlet hole is located in the plunger body and passes through the sidewall of the plunger body; the plunger body includes a first end portion and a second end portion, a flow channel extends from the first end portion to the second end portion, a part of the flow channel close to the first end portion is closed, the flow channel extends to the second end portion and forms a first opening, the first liquid inlet hole is communicated with the flow channel, the first valve assembly is located at the first opening, and is configured to allow fluid to flow out from the flow channel at the first opening and prevent fluid from flowing back to the flow channel from outside.

Abstract: A method for allocating resource and accessing in open wireless channels includes: covering multiple types of user terminal stations in open wireless channels; making dynamic adaptive matching according to comprehensive change factors of a transmitting end and a receiving end in each communication process. The factors of the transmitting end mean that a type and transmitting capacity of a transmitting station are changed, a current state of the wireless channel between the transmitting station and a relay node is changed, a working state of a receiving end of the relay node is changed, and user services to be transmitted are changed; the factors of the receiving end mean that a type and receiving capacity of a receiving station are changed, a current state of the channel from the relay node to the receiving station is changed, and a working state of a transmitting end of the relay node is changed.

Abstract: A puller includes a first claw and a second claw arranged opposite to each other. The first claw includes a first pulling part, a first limiting part and a first connecting part. The first limiting part includes a first body part, a first notch part and a second notch part. The second claw includes a second pulling part, a second limiting part and a second connecting part. The second limiting part includes a second body part, a third notch part and a fourth notch part. A size of the second pulling part is smaller than or equal to a size of the second notch part.

Abstract: A method for piloting from bypass in a network with open wireless channels is disclosed. The method includes: 1) selecting a terminal station as a reference in open wireless channels, and sending a pilot signal, in which all or some frequency bands of open wireless channels occupied by the pilot signal are pilot frequency bands, and the proportion of power of the pilot signal to the total power of the pilot frequency bands is 0.1‰-5%; 2) spreading the pilot signal with a spread spectrum code when it is transmitted, and then superimposing on a communication signal in the pilot frequency bands in a low power spectrum signal mode similar with noise; and 3) providing pilot, carrier wave and clock synchronization, standard timing and indication information for network construction and mutual communication of multiple types of terminal stations in channels by the pilot signal.

Abstract: A fluid splitter, a fluid end, and a plunger pump are provided. The fluid splitter includes: a body having a shape of column and including a first end, a second end, and a side surface connecting the first end and the second end; a first opening, located at the side surface of the body; a first cavity, located at the first end; a first channel, communicated with the first opening and the first cavity, respectively, the first channel extending from the first opening to the first cavity and being configured to allow fluid to flow therethrough; a second opening, located at the side surface of the body; a second cavity, located at the second end; and a second channel, communicated with the second opening and the second cavity, respectively, the second channel extending from the second opening to the second cavity and being configured to allow fluid to flow therethrough.

Abstract: A cover, a fluid end and a plunger pump are provided. The cover includes: a body, the body being cylindrical, and the body including a first end, a second end, and a side surface connecting the first end and the second end; a main flow channel extending along an axis of the body; a plurality of subsidiary flow channels, each of the plurality of subsidiary flow channels being communicated with the main flow channel; a first opening, located at the first end and communicated with the main flow channel; and a plurality of second openings, located at the side surface of the body; each of the plurality of subsidiary flow channels being communicated with at least one of the plurality of second openings.

Abstract: A puller includes a first claw and a second claw arranged opposite to each other. The first claw includes a first pulling part, a first limiting part and a first connecting part. The first limiting part includes a first body part, a first notch part and a second notch part. The second claw includes a second pulling part, a second limiting part and a second connecting part. The second limiting part includes a second body part, a third notch part and a fourth notch part. A size of the second pulling part is smaller than or equal to a size of the second notch part.

Abstract: A plunger, a hydraulic end and a plunger pump are disclosed. The plunger includes a plunger body, the plunger body includes a flow channel; a first liquid inlet hole is located in the plunger body and passes through the sidewall of the plunger body; the plunger body includes a first end portion and a second end portion, a flow channel extends from the first end portion to the second end portion, a part of the flow channel close to the first end portion is closed, the flow channel extends to the second end portion and forms a first opening, the first liquid inlet hole is communicated with the flow channel, the first valve assembly is located at the first opening, and is configured to allow fluid to flow out from the flow channel at the first opening and prevent fluid from flowing back to the flow channel from outside.

Abstract: A method for quasi-synchronous code division multiple access based on synchronization clock by piloting can make CDMA operate in quasi-synchronous conditions, so it is suitable for open wireless channels with relay nodes, such as satellite communication systems, and open wireless channels without relay nodes. The method includes: adopting a mode of CDMA spread spectrum transmission to share power resources to transmit signals at multiple transmitting stations in open wireless channels; adopting an external pilot signal to provide synchronization clock for the CDMA signals transmitted by multiple terminal stations in the open wireless channels, eliminating path delay differences from the multiple terminal stations to a relay node or receiving station, and making multi-channel CDMA signals received at the relay node or receiving station clock synchronized and phase aligned. The method can realize the quasi-synchronous reception of multi-channel CDMA signals.

Abstract: A method for allocating resource and accessing in open wireless channels includes: covering multiple types of user terminal stations in open wireless channels; making dynamic adaptive matching according to comprehensive change factors of a transmitting end and a receiving end in each communication process. The factors of the transmitting end mean that a type and transmitting capacity of a transmitting station are changed, a current state of the wireless channel between the transmitting station and a relay node is changed, a working state of a receiving end of the relay node is changed, and user services to be transmitted are changed; the factors of the receiving end mean that a type and receiving capacity of a receiving station are changed, a current state of the channel from the relay node to the receiving station is changed, and a working state of a transmitting end of the relay node is changed.

Abstract: A method for piloting from bypass in a network with open wireless channels is disclosed. The method includes: 1) selecting a terminal station as a reference in open wireless channels, and sending a pilot signal, in which all or some frequency bands of open wireless channels occupied by the pilot signal are pilot frequency bands, and the proportion of power of the pilot signal to the total power of the pilot frequency bands is 0.1‰-5%; 2) spreading the pilot signal with a spread spectrum code when it is transmitted, and then superimposing on a communication signal in the pilot frequency bands in a low power spectrum signal mode similar with noise; and 3) providing pilot, carrier wave and clock synchronization, standard timing and indication information for network construction and mutual communication of multiple types of terminal stations in channels by the pilot signal.

Abstract: A fluid splitter, a fluid end, and a plunger pump are provided. The fluid splitter includes: a body having a shape of column and including a first end, a second end, and a side surface connecting the first end and the second end; a first opening, located at the side surface of the body; a first cavity, located at the first end; a first channel, communicated with the first opening and the first cavity, respectively, the first channel extending from the first opening to the first cavity and being configured to allow fluid to flow therethrough; a second opening, located at the side surface of the body; a second cavity, located at the second end; and a second channel, communicated with the second opening and the second cavity, respectively, the second channel extending from the second opening to the second cavity and being configured to allow fluid to flow therethrough.

Abstract: A method for piloting from bypass in a network based on a satellite load platform can unify the influence of distance change and Doppler frequency shift of satellite ground stations in the whole network, and realize accurate quasi synchronization between the clock of the whole network and the clock of the satellite. The method includes transmitting a pilot signal from bypass based on a satellite load platform in a satellite communication system, taking a spaceborne high stability timing clock source as a reference, and transmitting the pilot signal to all downlink beams to provide the pilot signal for all satellite stations covered by the satellite.

Abstract: A method for synthesizing high-content NaY molecular sieves with kaolin sprayed microspheres includes adding functional components and deionized water into kaolin so as to be pulped into a mixed slurry. The slurry is sprayed into microspheres. The microspheres are calcined at a temperature between 700 and 1,000° C. and mixed with a directing agent for crystallization. The resultant solid is filtrated and washed with water and then dried to obtain a final in-situ crystallized product with high content of molecular sieves.

Abstract: A method for synthesizing high-content NaY molecular sieves with kaolin sprayed microspheres is provided, comprising that functional components and deionized water are added into the kaolin so as to be pulped mixed slurry, and the slurry is sprayed into microspheres, the sprayed microspheres are calcined at a temperature between 700 and 1,000° C. and the obtained is mixed up with directing agent for crystallization, the resultant solid is filtrated from mother liquid and washed by water. The functional components include structural agents, and the addition of the agents is about 2˜10 percent by mass of the kaolin; the structural agents are one or more of starch, graphite powder, and carboxymenthyl cellulose. Alternatively according to the present invention, one part of the sprayed microspheres with particle sizes of 20˜110 ?m is calcined at high temperature to get high-temperature calcined kaolin microspheres, while the other part is calcined at a low temperature to get meta kaolin microspheres.