Abstract: Magnetic resonance imaging (MRI) systems and compositions thereof are provided. The MRI systems may include a main magnet configured to generate a primary magnetic field, the primary magnet forming a bore. The MRI system may include a gradient coil arranged in the bore and configured to generate a gradient magnetic field that provides a magnetic field environment with the main magnetic field. The gradient coil may include a shielding gradient coil including two or more coil units. One of the two or more coil units may be wound along a first coil path. Another one of the two or more coil units may be wound along a second coil path. The MRI system may also include a shimming structure arranged between the gradient coil and the primary magnet and configured to homogenize the main magnetic field.

Abstract: Embodiments of the present application provide a dental robot and an oral navigation method. The dental robot comprises a tandem positioning arm, wherein the tandem positioning arm comprises a pedestal, several positioning arms and a jacket, and the jacket is configured to clamp surgical instruments; the pedestal, the several positioning arms and the jacket are connected in series in sequence by rotary joints; a joint angle measuring device is mounted at each of the rotary joints. According to the dental robot and the oral navigation method provided by the present application, by the lightweight of the tandem positioning arm, the volume and weight of the dental robot system are reduced, which improves the practicality of the dental robot in surgical operations.

Abstract: This application provides a screw compressor and a slide valve thereof. The slide valve includes: a valve body having a cylindrical shape extending in an axial direction, with a side surface having a pressure discharge surface that matches an outer peripheral contour of a rotor of the screw compressor; a discharge chamber provided at an end of the pressure discharge surface along the axial direction; a slider provided in the discharge chamber, and configured to slide along a radial direction of the valve body, a shape of an outer edge of the slider matching a shape of the pressure discharge surface; and a spring connected to the slider and configured to drive the slider to slide to a position where the outer edge of the slider is flush with the pressure discharge surface.

Abstract: Aspects of this disclosure are directed to an artificial intelligence (AI)-based named entity recognition (NER) method and apparatus, an electronic device, and a non-transitory computer-readable storage medium. The method can include performing, by an electronic device, vector transformation processing on text elements in a to-be-recognized text to obtain text representations of the text elements, and constructing a candidate entity phrase according to text elements that are in the to-be-recognized text and whose total quantity does not exceed an element quantity threshold.

Abstract: A gradient coil assembly and a magnetic resonance imaging system comprising a Z-axis gradient coil are provided. The gradient coil assembly comprises a Z-axis gradient coil. The Z-axis gradient coil comprising a first coil and a second coil, the first coil and the second coil being arranged along an axial direction of the Z-axis gradient coil. The first coil comprises a first subcoil and a second subcoil. The first subcoil and the second subcoil extend alongside each other. The second coil comprises a third subcoil and a fourth subcoil. The third subcoil and the fourth subcoil extend alongside each other.

Abstract: Embodiments of the present application provides a method and a system for evaluating implanting precision of an implant. The method includes: obtaining a second surface model of an oral cavity containing a target implant; obtaining an actual position of the target implant in a first three-dimensional model based on the second surface model, the first three-dimensional model and a first surface model; and obtaining an evaluation result of the implanting precision of the target implant based on the actual position of the target implant in the first three-dimensional model and an predicted position of the target implant in the first three-dimensional model. By means of the method and system according to the embodiments of the present application, the second surface model of the oral cavity containing the target implant is obtained after implantation is completed using an oral digital scanning device to obtain the evaluation result of the implanting precision of an implant of the target implant.

Abstract: A fuel injector in a fuel system having a first fuel supply of a first fuel and a second fuel supply of a second fuel includes a multifunctional control valve movable in the fuel injector to control admission of the first fuel to a combined-fuel outlet passage, and to control a timing and an injection pressure of a fuel charge containing the first fuel. In an embodiment the first fuel includes a compression-ignition fuel such as diesel and the second fuel includes an alcohol fuel such as methanol. Related apparatus and methodology is disclosed.

Abstract: A novel vehicle-mounted wireless charging system is disclosed, which includes a transmitter. The transmitter includes a full-bridge unit, a compensating unit, a transmitting unit and a selecting unit. The full-bridge unit consists of one or two full-bridge modules, the compensating unit consists of two or more compensating network modules, the transmitting unit consists of multiple transmitting coils, and the selecting unit is used for switching different coils. Two full-bridge modules, two compensating network modules and multiple transmitting coils form a first mode, different full-bridge modules are selected to charge different models of mobile phones by switching through the selecting unit; one full-bridge modules, two groups of compensating network modules and multiple transmitting coils form a second mode, different compensating network modules are selected to charge different models of mobile phones by switching through the selecting unit.

Abstract: Operating an engine system includes cold starting an engine, closing spill valves to pressurize fuel in a plurality of plunger cavities, opening injection valves in some of a plurality of fuel injectors to inject fuel into firing cylinders in an engine cycle, and opening spill valves in some of the plurality of fuel injectors while injection valves therein remain closed to bleed fuel to a lower pressure space in the engine cycle. The pressurization of fuel in the fuel injectors remaining closed parasitically loads the engine to increase a fuel burned amount hastening warm up and limiting misfire. Related apparatus and control logic is also disclosed.

Abstract: A dual fuel engine system includes an engine, and a fuel system including a pressurized fuel reservoir, a first fuel pump, and a plurality of second fuel pumps each having an actuating fluid inlet fluidly connected to at least one of the first fuel pump or the pressurized fuel reservoir. The plurality of second fuel pumps may intensify or de-intensify a pressure of a second fuel relative to a pressure of the first fuel used to actuate the second fuel pumps so as to obtain an increased flow rate of the second fuel. Related apparatus and methodology is also disclosed.

Abstract: Disclosed is a personal flying machine using compressed air as power source, and an operation method thereof, the flying machine including a stationary rotor lift device in a cyclone duct, a seat frame and a compressed air supply device; wherein the stationary rotor lift device in a cyclone duct includes a cyclone duct, in-duct stationary rotors and in-duct compressed air artificial wind blowing ports; wherein the in-duct stationary rotor includes a stationary propeller hub and a plurality of stationary blades fixed connected around the stationary propeller hub and arranged radially; wherein the stationary blade is shaped as an airplane's wing having an airfoil, an angle of attack, a leading edge and a trailing edge; wherein the compressed-air supply device supplies compressed air to the in-duct compressed-air artificial wind blowing ports to eject airflows towards the leading edges of the stationary blades and form a cyclone to generate lift.

Abstract: An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

Abstract: An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

Abstract: A fully variable electro-hydraulic valve system, comprising a sliding sleeve (A103, B103), a spiral shaft (A102, B102), a piston (A105, B105), and a reset spring (A104, B104). The sliding sleeve (A103, B103) is fixed relative to an engine; the piston (A105, B105) abuts against a valve assembly (106); the spiral shaft (A102, B102) is axially controlled by a cam surface of a camshaft (101); and the spiral shaft (A102, B102) is provided with a spiral groove (A102D, B102D) and a blockage part (A102G, B102G). When the spiral groove (A102D, B102D) communicates with a limiting oil hole (A118, B118), a sliding sleeve cavity (Q) communicates with a low-pressure oil path of the engine for pressure relief.

Abstract: A screw compressor comprises: a rotor set comprising male rotor and female rotor meshing with each other; a rotor housing; and a partition plate, fixed on the rotor housing and having a first annular section and a second annular section. The annular outer surface diameter of the first annular section is the same or substantially the same as the diameter of the circle formed by the male rotor teeth tips. The annular inner surface diameter of the first annular section is the same or substantially the same as the male rotor main shaft diameter. The annular outer surface diameter of the second annular section is the same or substantially the same as the diameter of the circle formed by the female rotor teeth tips. The annular inner surface diameter of the second annular section is the same or substantially the same as the female rotor main shaft diameter.

Abstract: Magnetic resonance imaging (MRI) systems and compositions thereof are provided. The MRI systems may include a main magnet configured to generate a primary magnetic field, the primary magnet forming a bore. The MRI system may include a gradient coil arranged in the bore and configured to generate a gradient magnetic field that provides a magnetic field environment with the main magnetic field. The gradient coil may include a shielding gradient coil including two or more coil units. One of the two or more coil units may be wound along a first coil path. Another one of the two or more coil units may be wound along a second coil path. The MRI system may also include a shimming structure arranged between the gradient coil and the primary magnet and configured to homogenize the main magnetic field.

Abstract: Embodiments of the present application provide a calibration method and device for dental implant navigation surgery, and a tracking method and device for dental implant navigation surgery. The calibration method comprises: (110) obtaining a position of a scanning area (304) relative to a second visual marker (306) based on a spatial position of a first visual marker (305) disposed on a scanning device (302), a spatial position of the second visual marker (306) disposed on a surgical area (303), and a scanning position of the scanning area (304) obtained by scanning with the scanning device (302); and (120) registering the position of the scanning area (304) relative to the second visual marker (306) with a three-dimensional scene to obtain a transformation matrix, and applying the transformation matrix to the tracking of a surgical instrument.

Abstract: A registration method and an electronic device for visual navigation in dental implant surgery, comprising obtaining a three-dimensional model of a target tooth to be registered, an entity model of the target tooth and a second model of the target tooth, obtaining a position and attitude matrix of the three-dimensional model in a virtual coordinate system according to the coordinates of at least three points on a three-dimensional model of a substrate after the registration of the three-dimensional model in the virtual coordinate system, mounting the entity model of the target tooth onto a registration standard board, obtaining a position and attitude matrix of the entity model in the visual coordinate system according to three optical marks and the points on the entity model corresponding to the three points, and obtaining a correspondence between the virtual coordinate system and the visual coordinate system according to two position and attitude matrices.