The General Electric Company formally opened three new laboratories during the last months of 1950. The first of these, its main research center at the Knolls, is located near Schenectady, N.Y., in Niskayuna Township on a high bluff overlooking the Mohawk River. Construction began in 1946 and at this point the plant is virtually completed. Its five major laboratory buildings, however, have been in use for some time.