ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-darwin10.8.0]

I want to parse a page like

http://www.unicode.org/cgi-bin/GetUnihanData.pl?codepoint=ѹ
the url contains non-ascii character as a query.  In this particular
case, it's Chinese.

If I try to open this page like

doc = Nokogiri::HTML(open(query)).read

it gives an error

/Users/soichi/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/uri/common.rb:176:in
`split': bad URI(is not URI?):
http://www.unicode.org/cgi-bin/GetUnihanData.pl?codepoint=
(URI::InvalidURIError)
  from
/Users/soichi/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/uri/common.rb:211:in
`parse'
  from
/Users/soichi/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/uri/common.rb:747:in
`parse'
  from
/Users/soichi/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/open-uri.rb:32:in
`open'
  from split_words_and_search_using_api.rb:23:in `<main>'

Somehow, I need to convert the character (UTF-8) into some valid form
for URL.

Could anybody suggest how to do that?

soichi