Disclosed are embodiments of systems and methods for prioritizing mobile media player files by providing for the automated addition andor deletion of media items for a mobile media player. The all-road updating data is a difference of all roads extracted from an all-road map data, and the main-road updating map data is a difference of specified roads extracted from the all-road map data. The widget moving module drags and drops a widget from the list to an idle area of the home screen. Therefore, under the nonresonance condition, the influence of the microsphere resonator is small, and light propagation through the multimode optical waveguide is not influenced. Retained attribute-value pairs are stored and used to respond to search queries and facilitate comparison of products. The field device has at least one field device face facing the process and at least one field device face facing away from the process, and is equipped with a thermoelectric transducer which has a transducer face facing the process and a transducer face facing away from the process.