Can you please help identify this chinese sword?

[Blade]

I have this Dao sword,

It measures about 110 cm, it pretty heavy.
The blade looks pattern welded (damescus steel), and it is sharp.

since the pictures are a little big, i uploaded them to this address:

http://www.geocities.com/blade234k/Dao.html

1) I would like to hear your opinions about this sword, is it original, does it look antique, from what period, where it was probably produced, etc'.

2) how can i tell whether it is really pattern welded or it is ordinary steel with pattern etched upon it?

thanks

Yaniv