inconvertibility
  不能交換,不能兌換
  In·con·vert·i·bil·i·ty n.  The quality or state of being inconvertible; not capable of being exchanged for, or converted into, something else; as, the inconvertibility of an irredeemable currency, or of lead, into gold.
  ◄ ►
  inconvertibility
       n : the quality of not being exchangeable; "the inconvertibility
           of their currency made international trade impossible"
           [ant: convertibility]