Abstract: Optimization of a multi-index database access at runtime. A processor receives a query. A processor determines a plan and an RID results threshold for the plan, wherein the plan includes an access to the index. A processor determines a static risk threshold, a static risk for the access, and whether the static risk exceeds the static risk threshold. Responsive to the static risk exceeding the static risk threshold, a processor determines a risk bound for the access, and links the access to the risk bound. A processor accesses the index with the key. Responsive to the access being linked to a risk bound, a processor determines a dynamic risk for the access. A processor receives one or more RID results during the execution of the plan. A processor aborts the execution of the plan if a quantity of the RID results is less than the RID results threshold.

Abstract: A modified lubricant includes lubricant grease and nano-graphite plates dispersed thoroughly in the lubricant grease. The content of the nano-graphite plates is 0.0001 wt % to 10 wt %. Each nano-graphite plate has a length or a width between 1 and 100 ?m, a thickness within 10 nm and 100 nm, and N graphene layers stacked together and a surface modifying layer disposed on the top or bottom of the nano-graphite plates, wherein N is 30 to 300. The surface modifying layer has a surface modifying agent which includes at least two functional groups located at two ends of the surface modifying agent, one of the two functional groups is chemically bonded with certain organic functional group remaining on the surface of the nano-graphite plate, and the other of the two functional groups forms the functional surface of the nano-graphite plate.

Abstract: A modified lubricant includes lubricant grease and nano-graphite plates dispersed thoroughly in the lubricant grease. The content of the nano-graphite plates is 0.0001 wt % to 10 wt %. Each nano-graphite plate has a length or a width between 1 and 100 ?m, a thickness within 10 nm and 100 nm, and N graphene layers stacked together and a surface modifying layer disposed on the top or bottom of the nano-graphite plates, wherein N is 30 to 300. The surface modifying layer has a surface modifying agent which includes at least two functional groups located at two ends of the surface modifying agent, one of the two functional groups is chemically bonded with certain organic functional group remaining on the surface of the nano-graphite plate, and the other of the two functional groups forms the functional surface of the nano-graphite plate.