Abstract: A positive electrode active material and a preparation method therefor, a positive electrode plate, a battery, and an electrical apparatus. The positive electrode active material includes a transition metal oxide and a coating layer. The coating layer is coated on at least part of the surface of the transition metal oxide. The coating layer includes a silicon-containing polymer. The silicon-containing polymer is formed by polymerizing a silane monomer derivative containing a first group and polysiloxane containing a second group. The first group is reactive with the second group. The molecular weight of the silane monomer derivative is less than that of the polysiloxane.

Abstract: Disclosed is a method for supporting online services in providing content items to users of an online system. A request for loading a webpage of an online system is received from a client device. A plurality of content items eligible for being presented to the user is received. For each of the received content items, a trained model is identified based on characteristics of the content item, and a score is determined using the identified trained model and based on characteristics of the user. One or more content items is selected based on the determined scores. The selected one or more content items are sent to the client device for presentation to the user.