Are there hacks or smaller scientific search engines offering you context-sensitive/semantic search?
I know it's disappointing, but here goes: I am not aware of features allowing context-sensitive search in scientific search engines, with two exceptions:


Web of Science has a SAME operator, which matches “records where the terms separated by the operator appear in the same sentence”. Given that Web of Science supports a whooping number of 4 search operators (AND, OR, NOT and SAME), it is pretty safe to say this is sadly the full extent of its context-sensitive search features.
SciFinder attributes some meaning to prepositions, which have a role in restricting results to “closely associated” matches of operands. This basically means “same sentence” (details in the linked page).


Yes, these features are poor and we should hope for better search capabilities. At the same time, it's a start and it can be useful.