Abstract: Embodiments of the present application provide a prediction method, device and system for rock mass instability stages, and belong to the technical field of rock mass instability prediction. The method includes the steps: acquiring acoustic emission signals of rock mass; extracting feature parameters from the acquired acoustic emission signals; and predicting instability stages of the rock mass in accordance with the feature parameters and a preset back propagation (BP) neural network model, wherein the preset BP neural network model is obtained by training a BP neural network and a genetic algorithm by virtue of the feature parameters of the acoustic emission signals at different rock mass instability stages. According to the technical solution in the present application, the problem in the training process of the BP neural network model that model parameter optimization may be easily trapped in a locally optimal solution is effectively solved.

Abstract: Provided are a display panel, a manufacturing method thereof, and a display device. The display panel includes an alignment mark region arranged within a flat region of a peripheral region of the display panel. The peripheral region is a region of the display panel other than an active area of the display panel. An alignment mark pattern is arranged within the alignment mark region, and/or at least one film layer within the alignment mark region is hollowed out.

Abstract: The present invention discloses a phthalide derivative, the structure of said derivative is represented by Formula (I) or Formula (II). The present invention also discloses the preparation method and use of said derivative. The phthalide compound obtained through structure modifications in the present invention enhances the chemical stability and pharmacological activity of the phthalide compound, facilitating the improvement of the druggability of such compounds.

Abstract: An air conditioner and a control method thereof are provided. The air conditioner includes: a compressor including a coil; an oil pool connected to the compressor through an oil piping; a main control board configured to receive a power-on signal of the air conditioner, obtain an actual temperature of the oil pool after receiving the power-on signal, generate a required heating amount in response to the actual temperature of the oil pool being lower than a preset startup temperature, and generate timing control signals according to the required heating amount; a power device, wherein two sides of the power device are respectively connected to the main control board and the coil, and the power device is configured to drive the coil to heat the oil pool according to the timing control signals generated by the main control board.

Abstract: An air conditioner and a control method thereof are provided. The air conditioner includes: a compressor including a coil; an oil pool connected to the compressor through an oil piping; a main control board configured to receive a power-on signal of the air conditioner, obtain an actual temperature of the oil pool after receiving the power-on signal, generate a required heating amount in response to the actual temperature of the oil pool being lower than a preset startup temperature, and generate timing control signals according to the required heating amount; a power device, wherein two sides of the power device are respectively connected to the main control board and the coil, and the power device is configured to drive the coil to heat the oil pool according to the timing control signals generated by the main control board.