1.On the base of keeping the same law of motion of original thread-taking-up pole of computerized embroidery machine and relevant sizes, the disc cam with pushing bar of roller of linear motion along the axis with the spring force closure is used to design a new thread-taking-up mechanism.
2.Let T be an associative algebra over the complex filed, and the commutator [T, T]of T be the linear span of the set {[a, b] : a,b∈T}. We describe theσ- wot closure of the commutator of a nest algebra and the norm closure of the commutator of an TAF algebra .
