Abstract: A method for accurately positioning a navigation target point includes: selecting a navigation reference with a fixed position, acquiring positions of the navigation reference and the navigation target point in a navigation coordinate system respectively, and calculating a position of the navigation target point relative to the navigation reference, so as to further obtain a position of the navigation target point in a coordinate system of the navigation reference. As long as the navigation reference does not move, the coordinate system of the navigation reference will not change during the entire navigation process, and spatial position coordinates of the navigation target point in the coordinate system of the navigation reference will not be interfered by the navigation coordinate system.

Abstract: The present disclosure relates to a wide-range perpendicular sensitive magnetic sensor and the method for manufacturing the same, the magnetic sensor includes a substrate, a plurality of magnetic tunnel junctions, a plurality of magnetic flux regulators, a first output port and a second output port.

Abstract: The present disclosure relates to a wide-range perpendicular sensitive magnetic sensor and the method for manufacturing the same, the magnetic sensor includes a substrate, a plurality of magnetic tunnel junctions, a plurality of magnetic flux regulators, a first output port and a second output port.

Abstract: The present disclosure relates to an AC/DC closed-loop current sensor, including a magnetism gathering iron core, a TMR chip, a signal processing circuit, a signal generator, and a feedback coil. The TMR chip is arranged at an air gap of the magnetism gathering iron core and connected to the signal processing circuit. The signal processing circuit is connected to the signal generator. The feedback coil is wound around the magnetism gathering iron core and connected to the signal generator. The signal processing circuit is configured to select from the induced signal of the TMR chip and make an amplification to obtain a current signal component and send the current signal component to the signal generator. The signal generator is configured to adjust a current output to the feedback coil based on the current signal component, and output a measurement result of the selected current signal component.

Abstract: A method for preparing Portland cement includes: respectively weighing iron slag, copper slag, vanadium slag, and nickel slag and grinding, to yield prefabricated iron slag, prefabricated copper slag, prefabricated vanadium slag, and prefabricated nickel slag; weighing mica and kaolinite, mixing, and grinding to obtain aluminous raw materials; evenly mixing the prefabricated iron slag and the aluminous raw materials, and calcining, to yield an iron-aluminum eutectic mineral; weighing the marble, fluorite, dolomite, and quartz, evenly mixing the marble, fluorite, dolomite, and quartz with the prefabricated copper slag, prefabricated vanadium slag, and prefabricated nickel slag to yield a first mixture; grinding the iron-aluminum eutectic mineral to yield powders, and calcining a second mixture of the first mixture and the powders, to yield the cement clinker; and cooling the cement clinker, and grinding a third mixture of the cooled cement clinker and the gypsum, to yield the Portland cement.

Abstract: Provided are an interface expanding method and device. It is detected whether there is a voltage input at a power supply pin of the interface, an impedance between a signal indication pin of the interface and a ground pin of the interface is detected when no voltage input is detected, and a type of a cable inserted into the interface is determined according to the detected impedance; it is detected whether there is a short circuit or an open circuit between a data signal positive pin of the interface and a data signal minus pin of the interface when the voltage input is detected, and the type of the cable inserted into the interface is determined according to the detected result; and a relevant component in the tablet computer is controlled, according to the determined type of the calle inserted into the interface, to operate correspondingly.

Abstract: Provided are an interface expanding method and device. It is detected whether there is a voltage input at a power supply pin of the interface, an impedance between a signal indication pin of the interface and a ground pin of the interface is detected when no voltage input is detected, and a type of a cable inserted into the interface is determined according to the detected impedance; it is detected whether there is a short circuit or an open circuit between a data signal positive pin of the interface and a data signal minus pin of the interface when the voltage input is detected, and the type of the cable inserted into the interface is determined according to the detected result; and a relevant component in the tablet computer is controlled, according to the determined type of the calle inserted into the interface, to operate correspondingly.