You need to bring those. You will most likely take off your down jacket in a classroom, and I don't think wearing a T-shirt in a classroom is enough in the winter even though there are heaters in the classroom.
Boston's weather is very similiar to Dalian except I think Boston has more rain during the cold season. Bring lots of sweaters and positive attitude hehe because you are going to need them during the long dark, and rainny winter.