Abstract: Provided are a method for maintaining Walker constellation formation and a terminal device. The method comprises: determining a first offset amount of each satellite within a simulation time period according to parameters of a Walker constellation; performing first offset on each satellite according to the first offset amount to obtain a Walker constellation after the first offset; determining a second offset amount of each satellite within the simulation time period according to parameters of the Walker constellation after the first offset; and superimposing the first offset amount and the second offset amount, and performing second offset on each satellite so as to maintain the formation of the Walker constellation.

Abstract: The disclosure describes a low-orbit satellite deorbit control method and system based on a particle swarm algorithm. The method includes: constructing an objective function according to a position parameter and a perturbation acceleration of each of particles in a particle swarm as well as a preset Lagrangian multiplier and a penalty factor; determining an objective fitness of each particle and a population fitness of the particle swarm based on the objective function, updating the position parameter and the velocity of each particle, and obtaining a population optimal fitness at a maximum number of iterations; updating the Lagrangian multiplier and the penalty factor according to the population optimal fitness, comparing the objective deviation value with a preset convergence condition, and determining an objective population fitness and an objective position parameter according to a comparison result to obtain an objective deorbit mode.

Abstract: A superhydrophobic hemispherical array which can realize droplet pancake bouncing phenomenon is provided. The superhydrophobic hemispherical array shows an arc-shape structure which is narrow at the top and wide at the bottom, where a is the angle that substrate-gas interface goes across the gas and reaches substrate-hemisphere interface, d refers to the diameter of the contact area between hemispherical structure and substrate, s represents the space between two adjoining hemispheres, h denotes the vertical height from the top of hemisphere to substrate surface, and 70°?a?90°, 900 ?m?d ?1700 ?m, s?550 ?m, 600 ?m?h?1100 ?m, respectively. The superhydrophobic hemispherical array has a water contact angle larger than 150° and roll-off angle lower than 10°.

Abstract: Provided are a method for maintaining Walker constellation formation and a terminal device. The method comprises: determining a first offset amount of each satellite within a simulation time period according to parameters of a Walker constellation; performing first offset on each satellite according to the first offset amount to obtain a Walker constellation after the first offset; determining a second offset amount of each satellite within the simulation time period according to parameters of the Walker constellation after the first offset; and superimposing the first offset amount and the second offset amount, and performing second offset on each satellite so as to maintain the formation of the Walker constellation.

Abstract: The disclosure describes a low-orbit satellite deorbit control method and system based on a particle swarm algorithm. The method includes: constructing an objective function according to a position parameter and a perturbation acceleration of each of particles in a particle swarm as well as a preset Lagrangian multiplier and a penalty factor; determining an objective fitness of each particle and a population fitness of the particle swarm based on the objective function, updating the position parameter and the velocity of each particle, and obtaining a population optimal fitness at a maximum number of iterations; updating the Lagrangian multiplier and the penalty factor according to the population optimal fitness, comparing the objective deviation value with a preset convergence condition, and determining an objective population fitness and an objective position parameter according to a comparison result to obtain an objective deorbit mode.

Abstract: Provided is a method and system of evaluating a constellation spare strategy based on a stochastic time Petri net, which is applied in the technical field of constellation operation management. The method comprises: constructing a single satellite STPN model and an orbital plane STPN model, and establishing a navigation constellation STPN model that includes multiple spare strategies according to the single satellite STPN model and the orbital plane STPN model; establishing an availability model according to the number of malfunctioning satellites and the constellation value (CV) in the navigation constellation STPN model, and establishing a cost model according to operating costs of the navigation constellation STPN model; and evaluating the navigation constellation STPN model using the availability model and the cost model, and determining a target spare strategy from the multiple spare strategies according to an evaluation result.

Abstract: The present invention belongs to the technical field of high-efficiency, high-precision and high-performance laser bending of metal sheets, and relates to a line-shape spot laser bending method for metal sheets. The present invention uses a multimode laser scanning mirror or a single piezoelectric deformable mirror to convert laser Gaussian distributed point spots to uniformly distributed line-shape spot, and meanwhile, loads the spots in a bending line area and bends metal sheets so that the temperature field in the bending line of the metal sheet is distributed uniformly to achieve the purposes of reducing warpage deformation, enhancing bending angle consistency and increasing the bending efficiency.

Abstract: A superhydrophobic hemispherical array which can realize droplet pancake bouncing phenomenon is provided. The superhydrophobic hemispherical array shows an arc-shape structure which is narrow at the top and wide at the bottom, where a is the angle that substrate-gas interface goes across the gas and reaches substrate-hemisphere interface, d refers to the diameter of the contact area between hemispherical structure and substrate, s represents the space between two adjoining hemispheres, h denotes the vertical height from the top of hemisphere to substrate surface, and 70°?a?90°, 900 ?m?d ?1700 ?m, s?550 ?m, 600 ?m?h?1100 ?m, respectively. The superhydrophobic hemispherical array has a water contact angle larger than 150° and roll-off angle lower than 10°.

Abstract: A PZT transducer-horn integrated ultrasonic driving structure consists of a nut, a bolt, a left PZT circular stack, a flange, a right PZT truncated stack and a horn. The horn, the right PZT truncated stack, the flange and the left PZT circular stack are arranged in sequence and connected via the bolt and then fastened via the nut; the right PZT transducer is a truncated cone-shaped stack formed by PZT circular plates; and the right PZT transducer and the horn are integrated to form the ultrasonic driving structure. Considering the dimension of PZT on two sides of the flange and the horn meet the requirements for ultrasonic vibration node and antinode, the dimension of round contour of the circular PZT stack and flange is reduced to increase the thickness of the truncated PZT stack and flange.

Abstract: A PZT transducer-horn integrated ultrasonic driving structure consists of a nut, a bolt, a left PZT circular stack, a flange, a right PZT truncated stack and a horn. The horn, the right PZT truncated stack, the flange and the left PZT circular stack are arranged in sequence and connected via the bolt and then fastened via the nut; the right PZT transducer is a truncated cone-shaped stack formed by PZT circular plates; and the right PZT transducer and the horn are integrated to form the ultrasonic driving structure. Considering the dimension of PZT on two sides of the flange and the horn meet the requirements for ultrasonic vibration node and antinode, the dimension of round contour of the circular PZT stack and flange is reduced to increase the thickness of the truncated PZT stack and flange.

Abstract: A detection device is described for measuring the vaporization-melt ratio, the device including a light source, a first and second optical lens group, a slit, a first and second steering mirror, a first and second primary mirror, a glass container, a colored blade, and a high-speed recording analyzer. The first primary mirror and the second primary mirror are symmetrically placed at both ends of the glass container. The first optical lens group is located between the light source and the slit. The second optical lens group is located between the colored blade and the high-speed recording analyzer. The first steering mirror is installed behind the slit, passing the light from the slit to the first primary mirror. The light reflected by the second primary mirror is passed to the colored blade from the second steering mirror located between the second primary mirror and the colored blade.

Abstract: A detection device for measuring the vaporization-melt ratio, the device including a light source, a first and second optical lens group, a slit, a first and second steering minor, a first and second primary minor, a glass containers, an object, a colored blade, and a high-speed recording analyzer. The first and second primary mirror is symmetrically placed at both ends of the glass container. The first optical lens group is located between the light source and the slit. The second optical lens group is located between the colored blade and the high-speed recording analyzer. The first steering mirror is installed behind the slit, passing the light through the slit to the first primary mirror. The light reflected by the second primary mirror is passed to the colored blade through the second steering minor located between the second primary minor and the colored blade.