{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:60272"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:60272","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Bau einer heizbaren Ultraschalldüse zur mikrowellenspektroskopischen Untersuchung schwerflüchtiger Substanzen im Molekularstrahl","abstract":"Within the scope of this work a new heatable molecular beam nozzle has been developed which is able to evaporate substances with low vapor pressure. With this nozzle low vapor pressure substances can be measured with the high resolution and high sensitivity of the molecular beam Fouriertransform microwave spectroscopy. Following molecules of the thiazole type have been studied: 4,5-dimethylthiazole, benzo[b]thiophene, benzothiazole and 2-methylbenzothiazole. For all these molecules the rotational spectra has been assigned for the first time. Apart from the rotational constants and the quartic centrifugal distortion constants for those molecules with internal rotors barrier to internal rotation could be determined. In the case of nitrogen containing molecules, the diagonal quadrupole coupling constants, in some cases also the off-diagonal elements, have been obtained.","abstract_html":"Within the scope of this work a new heatable molecular beam nozzle has been developed which is able to evaporate substances with low vapor pressure. With this nozzle low vapor pressure substances can be measured with the high resolution and high sensitivity of the molecular beam Fouriertransform microwave spectroscopy. Following molecules of the thiazole type have been studied: 4,5-dimethylthiazole, benzo[b]thiophene, benzothiazole and 2-methylbenzothiazole. For all these molecules the rotational spectra has been assigned for the first time. Apart from the rotational constants and the quartic centrifugal distortion constants for those molecules with internal rotors barrier to internal rotation could be determined. In the case of nitrogen containing molecules, the diagonal quadrupole coupling constants, in some cases also the off-diagonal elements, have been obtained.","abstract_has_math":false,"creators":["Welzel, Alexandra"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Stahl, Wolfgang"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2000,"date_issued":"2000","date_published":"2000","updated_at":"2026-07-30T19:42:56Z","subjects":["info:eu-repo/classification/ddc/530","Physik","Strahldüse","Molekularstrahl","Thiazole","Mikrowellenspektroskopie","Fourier-Spektroskopie"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121993%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121993%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121993%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/60272","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Stahl, Wolfgang"]},{"key":"dc:creator","label":"Author","values":["Welzel, Alexandra"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2000"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-280"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/530","Physik","Strahldüse","Molekularstrahl","Thiazole","Mikrowellenspektroskopie","Fourier-Spektroskopie"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/60272","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121993%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Within the scope of this work a new heatable molecular beam nozzle has been developed which is able to evaporate substances with low vapor pressure. With this nozzle low vapor pressure substances can be measured with the high resolution and high sensitivity of the molecular beam Fouriertransform microwave spectroscopy. Following molecules of the thiazole type have been studied: 4,5-dimethylthiazole, benzo[b]thiophene, benzothiazole and 2-methylbenzothiazole. For all these molecules the rotational spectra has been assigned for the first time. Apart from the rotational constants and the quartic centrifugal distortion constants for those molecules with internal rotors barrier to internal rotation could be determined. In the case of nitrogen containing molecules, the diagonal quadrupole coupling constants, in some cases also the off-diagonal elements, have been obtained."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University III, 204 S. : graph. Darst. (2000). = Aachen, Techn. Hochsch., Diss., 2000"]},{"key":"dc:title","label":"Title","values":["Bau einer heizbaren Ultraschalldüse zur mikrowellenspektroskopischen Untersuchung schwerflüchtiger Substanzen im Molekularstrahl"]}]}],"canonical_facts":{"dc:contributor":["Stahl, Wolfgang"],"dc:coverage":["DE"],"dc:creator":["Welzel, Alexandra"],"dc:date":["2000"],"dc:description":["Within the scope of this work a new heatable molecular beam nozzle has been developed which is able to evaporate substances with low vapor pressure. With this nozzle low vapor pressure substances can be measured with the high resolution and high sensitivity of the molecular beam Fouriertransform microwave spectroscopy. Following molecules of the thiazole type have been studied: 4,5-dimethylthiazole, benzo[b]thiophene, benzothiazole and 2-methylbenzothiazole. For all these molecules the rotational spectra has been assigned for the first time. Apart from the rotational constants and the quartic centrifugal distortion constants for those molecules with internal rotors barrier to internal rotation could be determined. In the case of nitrogen containing molecules, the diagonal quadrupole coupling constants, in some cases also the off-diagonal elements, have been obtained."],"dc:identifier":["https://publications.rwth-aachen.de/record/60272","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121993%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-280"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University III, 204 S. : graph. Darst. (2000). = Aachen, Techn. Hochsch., Diss., 2000"],"dc:subject":["info:eu-repo/classification/ddc/530","Physik","Strahldüse","Molekularstrahl","Thiazole","Mikrowellenspektroskopie","Fourier-Spektroskopie"],"dc:title":["Bau einer heizbaren Ultraschalldüse zur mikrowellenspektroskopischen Untersuchung schwerflüchtiger Substanzen im Molekularstrahl"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:42:56Z"}