Perhaps you should try some spelling variations:
"particle concentrations" » "particle concentration", "particle correlations", "particle penetration"
"particle accelerations" » "particle accelerators", "particle accelerator", "particelle acceleratori", "particle acceleratorss"
"particles acceleration" » "particle accelerator", "particle accelerators", "parallel acceleration"
"particle acceleration" » "particle accelerators"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("particle acceleration") OR ((((("particle accelerations") OR ("particle concentrations"))) OR ("particles acceleration")))).
• Removing quotes may allow a broader search: (( particle acceleration ) or ((((( particle accelerations ) or ( particle concentrations ))) or ( particles acceleration )))).
• Adding a wildcard symbol may retrieve word variants: (("particle acceleration") or ((((("particle accelerations") or ("particle concentrations"))) or ("particles acceleration"))))*.