Perhaps you should try some spelling variations:
"particle and nuclear physical" » "particle and nuclear physics", "particle and nonlinear physical"
"particle and nuclear material" » "particle and nuclear materials", "particle and nuclear matrix", "particle and nuclear matter"
"particle and nuclear optical" » "particle and nuclear option", "particle and nonlinear optical"
"particle and nuclear medical" » "particle and nuclear medicine"

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 and nuclear physical") OR ("particle and nuclear optical"))) OR ((("particle and nuclear medical") OR ("particle and nuclear material")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"particle and nuclear physical\") OR (\"particle and nuclear optical\"))) or (((\"particle and nuclear medical\") or (\"particle and nuclear material\"))))".
• Removing quotes may allow a broader search: (((( particle and nuclear physical ) OR ( particle and nuclear optical ))) or ((( particle and nuclear medical ) or ( particle and nuclear material )))).
• Adding a wildcard symbol may retrieve word variants: (((("particle and nuclear physical") OR ("particle and nuclear optical"))) or ((("particle and nuclear medical") or ("particle and nuclear material"))))*.