Abstract: Devices and methods are provided for preventing user churn, wherein the methods include: collecting target user data corresponding to one or more target users associated with a target application program (101), the target user data including user basic attribute information, user behavioral indicator information and user active indicator information; determining a target user type of the one or more target users based on at least information associated with the target user data of the one or more target users (102), the target user type including a normal active user, an approximately silent user and a silent user; and in response to the target user type of the one or more target users being an approximately silent user, pushing first data for promoting activeness to the one or more target users associated with the target application program (103).

Abstract: A method and a device for recommendation of media content are described. The method includes: calculating scores of media content labels in a computer media content library; in descending order of the scores, selecting a first threshold media content label as a candidate media content label; for the candidate media content label, finding out a media content corresponding to the candidate media content label from the media content library; for the media content corresponding to the candidate media content label, in descending order of the amount of page views, selecting a second threshold media content as a media content to be recommended corresponding to the candidate media content label; and recommending the media content to be recommended corresponding to the candidate media content label to a user. The method and device can recommend popular media contents to users, and reduce the style difference between the media contents.

Abstract: A sample stacking method using on-line automatic solid phase extraction coupled to nonaqueous capillary electrophoresis, and an interface structure between a solid-phase preconcentration cartridge and a capillary therefor. The sample analysis method using solid phase extraction coupled to nonaqueous capillary electrophoresis by connecting a solid-phase preconcentration cartridge with a capillary includes: extracting a sample on a solid phase; injecting an elution solvent at an outlet terminal of the capillary, the elution solution desorbing analytes adsorbed onto a solid-phase material of a solid-phase preconcentration cartridge; and injecting a nonaqueous buffer solution from the outlet terminal of the capillary to push the elution solvent to the solid-phase material.

Abstract: A sample stacking method using on-line automatic solid phase extraction coupled to nonaqueous capillary electrophoresis, and an interface structure between a solid-phase preconcentration cartridge and a capillary therefor. The sample analysis method using solid phase extraction coupled to nonaqueous capillary electrophoresis by connecting a solid-phase preconcentration cartridge with a capillary includes: extracting a sample on a solid phase; injecting an elution solvent at an outlet terminal of the capillary, the elution solution desorbing analytes adsorbed onto a solid-phase material of a solid-phase preconcentration cartridge; and injecting a nonaqueous buffer solution from the outlet terminal of the capillary to push the elution solvent to the solid-phase material.