The field has such a broad scope -- and basic research is still so new in some nanosubspecialties -- that worries have arisen about its ability to deliver on ambitious technology goals that may take 20 years to achieve.

• 此纳米技术的领域是如此广泛以至引起一些人们担心，政府能否实现有关此技术的远大目标月阿能需20年才能实现。