Abstract: The present invention provides a huperzine B crystal and a preparation thereof. Specifically, the present invention provides a crystal form A of the huperzine B crystal. An X-ray diffraction pattern of the crystal form A has the following 2? angular characteristic absorption peak: 9.56±0.2, 13.90±0.2, 14.88±0.2, 16.00±0.2, 25.39±0.2, and 28.78±0.2.

Abstract: Provided is a method for shale gas production prediction, including: acquiring real shale gas production data, and determining a target production decline curve model according to the real shale gas production data; setting a time step for production prediction, and obtaining a linear production decline curve by performing production prediction by using the target production decline curve model based on the time step; determining target shale gas production residuals according to the linear production decline curve and the real shale gas production data, inputting the target shale gas production residuals to a long short-term memory, and obtaining a residual prediction result by performing production prediction according to the long short-term memory and the time step; and determining a target production prediction result of shale gas well to be subjected to production prediction based on the linear production decline curve and the residual prediction result.