[OAI-implementers] Superscript- and subscript-nodes

Dr. Elmar Haake haake at suub.uni-bremen.de
Wed Sep 21 03:16:26 EDT 2005

Dear Thomas,

thank you for your answer!
Our tangible problem is implementing a chemical summary formular like 
2-(Me_2 NCH_3 )C_6 H_4
What shall we deal with this example?


Thomas G. Habing schrieb:

> Dr. Elmar Haake wrote:
>> Hi,
>> Since we are acting as an OAI-Data- and OAI-Service-Provider we are
>> interested in implementing special characters in our repository.
>> We guess that it must be possible to implement UTF-8-coded numeric
>> entities in the OAI2.0-interface. But how is it with superscripted
>> characters like <sup>2+</sup>?
>> These characters does not have numeric entities, so I would like to ask
>> you about this case.
>> We think, it must be possible to output the node in the way like HTML
>> (e.g. <sup>2%2B</sup>), because the service-provider could parse them
>> via XSLT-processor in an own routine.
>> But the characters "<" and ">" are not URI-encoded, so it would not be
>> possible to transfer them via the OAI-interface in the described way. If
>> we encode them, the XSLT-Processor cannot parse it to the HTML-node
>> (parsing is only possible with nodes beginning with <....>, not with
>> &lt;...&gt;)
>> So we resides in a dilemma. As a possible solution we think about
>> cutting them away. But on this way we would modify the content which is
>> not optimal for exchanging the metadata.
>> Has someone of you any experiences or ideas?
>> Greetings
>> Elmar
> There are Unicode code points for various superscripted and 
> subscripted characters in the ranges U+2070..U+209F plus U+00B2, 
> U+00B3, and U+00B9.  Because of font issues, most systems cannot 
> display more than just the numbers 1-3 as superscripts, but it might 
> be adequate for your needs, for example, <sup>2+</sup> could be 
> encoded as &#xB2;&#x207A;
> If you need to represent more complex math in Unicode you might want 
> to check out the technical report "Unicode Support for Mathematics" at 
> http://www.unicode.org/reports/tr25/index.html and also

Dr. Elmar Haake
Fachreferat Chemie, IT Dienste
Staats- und Universitaetsbibliothek Bremen

D-28359 Bremen

Tel.: 0049 421 218 3612
Fax:  0049 421 218 2614

aktuell: http://suche.suub.uni-bremen.de

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