Abstract: A heat-assisted magnetic recording head includes a first feature, a second feature, and a bilayer adhesion structure. The first feature includes a first primary metal. The second feature includes an oxide region, and a mixed metal oxide adhesion layer that is adhered to the oxide region and provided on a surface of the second feature. The bilayer adhesion structure includes the mixed metal oxide adhesion layer of the second feature, and a metal adhesion layer. The metal adhesion layer is disposed between and adhered to the first feature and the mixed metal oxide adhesion layer of the second feature. The metal adhesion layer includes a second primary metal that is different than the first primary metal.

Abstract: An online system maintains a plurality of content items. The online system selects and provides content items to users of the online system in response to impression opportunities to provide content items to users. A plurality of segments of the impression opportunities are determined. Each segment categorizes the impression opportunities. A relationship between a value metric and computing resources used in the selection process are determined for each segment. Each relationship provides a rate of increase of the value metric given an increase in computing resources used. An allocation of computing resources used per impression opportunity for each of segment is determined based on the rates. A plurality of impression opportunities are identified. In response, one or more content items are selected for each impression opportunity using computing resources according to the determined allocation for the segment to which each impression opportunity belongs.