Погугли термин "углеводное окно", http://www.google.ch/search?q=%D1%83%D0%B3%D0%BB%D0%B5%D0%B2%D0%BE%D0%B4%D0%BD%D0%BE%D0%B5+%D0%BE%D0%BA%D0%BD%D0%BE&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:de:official&client=firefox-a