Abstract: A train braking control method and device supporting multi-stage deceleration, and a storage medium are provided. The method includes the following steps: calculating an initial value of kinetic energy of a train; calculating work of traction force of the train in a process from an initial position to traction removal; calculating work of gravity force of the train in a process from the initial position to a stop; calculating work of braking force of the train in a process from a braking application position to the stop; calculating maximum allowable kinetic energy of the train among all restriction points from the initial position to a stop point; obtaining kinetic energy of the train according to the following formula, determining whether the kinetic energy of the train exceeds the maximum allowable kinetic energy at the restriction point, if so, triggering emergency braking of the train, or else, operating the train normally.

Abstract: A method for preparing large graphene sheets in large scale includes steps of: under a mild condition, processing graphite powders with intercalation through an acid and an oxidant; washing away metal ions and inorganic ions in the graphite powders with dilute hydrochloric acid, then filtering and drying; and, finally processing with a heat treatment. The present invention breaks through a series of bottlenecks restricting an efficient preparation of graphene that result from a traditional method of using large amounts of deionized water to wash graphite oxide to be neutral, and easily realizes a batch production. A radial scale of the prepared graphene sheets is distributed from 20 um to 200 um.

Abstract: A method for preparing large graphene sheets in large scale includes steps of: under a mild condition, processing graphite powders with intercalation through an acid and an oxidant; washing away metal ions and inorganic ions in the graphite powders with dilute hydrochloric acid, then filtering and drying; and, finally processing with a heat treatment. The present invention breaks through a series of bottlenecks restricting an efficient preparation of graphene that result from a traditional method of using large amounts of deionized water to wash graphite oxide to be neutral, and easily realizes a batch production. A radial scale of the prepared graphene sheets is distributed from 20 um to 200 um.