C. Cruz, J. Figueirinhas, P. Sebastião, A. C. Ribeiro, F. Noack, H. Nguyen, B. Heinrich, D. Guillon
In this work we present the first study of molecular dynamics in the S c and 4> h mesophases of a liquid crystal of biforked molecules. This study was performed by means of proton N MR relaxation measurements obtained at different temperatures in the studied phases, combining standard and fast field-cycling techniques in order to cover a large domain of Larmor frequencies (100 Hz-300 MHz). The experimental results were analysed considering the potential contributions of different relaxation mechanisms, namely local molecular rotational reorientations, self-diffusion and collective movements. The description of the contributions of the rotational reorientations and self-diffusion mechanisms are not quite different in the two studied phases. The main distinction in the molecular dynamics is found in the low Larmor frequency range dominated by the collective movements. While in the S c phase this contribution can be described by the law characteristic of smectic layer undulations, the contribution of the collective movements in the h phase can be assigned to elastic deformation of the columns.
{"title":"MOLECULAR DYNAMICS IN THE COLUMNAR AND LAMELLAR MESOPHASES OF A LIQUID CRYSTAL OF BIFORKED MOLECULES","authors":"C. Cruz, J. Figueirinhas, P. Sebastião, A. C. Ribeiro, F. Noack, H. Nguyen, B. Heinrich, D. Guillon","doi":"10.1515/zna-1996-0304","DOIUrl":"https://doi.org/10.1515/zna-1996-0304","url":null,"abstract":"In this work we present the first study of molecular dynamics in the S c and 4> h mesophases of a liquid crystal of biforked molecules. This study was performed by means of proton N MR relaxation measurements obtained at different temperatures in the studied phases, combining standard and fast field-cycling techniques in order to cover a large domain of Larmor frequencies (100 Hz-300 MHz). The experimental results were analysed considering the potential contributions of different relaxation mechanisms, namely local molecular rotational reorientations, self-diffusion and collective movements. The description of the contributions of the rotational reorientations and self-diffusion mechanisms are not quite different in the two studied phases. The main distinction in the molecular dynamics is found in the low Larmor frequency range dominated by the collective movements. While in the S c phase this contribution can be described by the law characteristic of smectic layer undulations, the contribution of the collective movements in the </> h phase can be assigned to elastic deformation of the columns.","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"65 1","pages":"155-166"},"PeriodicalIF":1.8,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83956361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. M. Habib, M. Abdel-Kader, M. Salem, S. Abdel-Halim
{"title":"Oxidation of a cyanine dye with o-Cl-dibenzoyle peroxide and peroxydisulphate","authors":"A. M. Habib, M. Abdel-Kader, M. Salem, S. Abdel-Halim","doi":"10.1002/CHIN.198839118","DOIUrl":"https://doi.org/10.1002/CHIN.198839118","url":null,"abstract":"","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"35 1","pages":"614-616"},"PeriodicalIF":1.8,"publicationDate":"1988-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90703579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Der sechzigste Geburtstag von Dr. Gerhard Hildebrandt gibt Anlaß, der Tätigkeit dieses erfolgreichen Forschers und Organisators zu gedenken. H a t doch Hildebrandt es fertig gebracht, entgegen mancherlei Widerständen, im Fritz-Haber-Institut in Dahlem die Tradition seines Vorgängers G. Borrmann fortzusetzen und eine Schule für einen exakten Zweig der Kristallographie zu schaffen, der, sich ausbreitend, allerlei Arten der Röntgeninterferenzen und verwandter Methoden umfaßt. So ist es Hildebrandts Verdienst, daß die auf Laue zurückgehende und durch Borrmann experimentell erforschte K u n d e von der feineren Struktur der Röntgeninterferenzen erweitert und auf verwandte Probleme angewandt wurde. Wir wünschen dem jugendlichen Forscher weitere erfolgreiche Jahre des Schaffens auf seinem ursprünglichen Gebiet und auf den neu in Angriff genommenen Erweiterungen mit schönen neuen Resultaten. P . P . Ewald
{"title":"Gerhard Hildebrandt zum 30.Mai 1982","authors":"P. P. Ewald, G. Borrmann","doi":"10.1515/zna-1982-0501","DOIUrl":"https://doi.org/10.1515/zna-1982-0501","url":null,"abstract":"Der sechzigste Geburtstag von Dr. Gerhard Hildebrandt gibt Anlaß, der Tätigkeit dieses erfolgreichen Forschers und Organisators zu gedenken. H a t doch Hildebrandt es fertig gebracht, entgegen mancherlei Widerständen, im Fritz-Haber-Institut in Dahlem die Tradition seines Vorgängers G. Borrmann fortzusetzen und eine Schule für einen exakten Zweig der Kristallographie zu schaffen, der, sich ausbreitend, allerlei Arten der Röntgeninterferenzen und verwandter Methoden umfaßt. So ist es Hildebrandts Verdienst, daß die auf Laue zurückgehende und durch Borrmann experimentell erforschte K u n d e von der feineren Struktur der Röntgeninterferenzen erweitert und auf verwandte Probleme angewandt wurde. Wir wünschen dem jugendlichen Forscher weitere erfolgreiche Jahre des Schaffens auf seinem ursprünglichen Gebiet und auf den neu in Angriff genommenen Erweiterungen mit schönen neuen Resultaten. P . P . Ewald","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"46 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85462638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Thouless instability conditions in the binuclear iron complex 1 have been investigated by means of a semiempirical INDO approach. The behaviour of the restricted Hartree-Fock (HF) wave function with respect to singlet, non-singlet and complex variations of the orbitals is studied. The existence of a spin decoupled solution near the diamagnetic closed shell groundstate is demonstrated. The nature of the correlation processes (angular vs left-right) for the various orbital fluctuations is discussed.
{"title":"The Validity of the Hartree-fock(HF) Picture in Diamagnetic Binuclear transition Metal compounds:trans[(eta5-C5H5)Fe(CO)2]2","authors":"M. Bohm","doi":"10.1515/zna-1982-0307","DOIUrl":"https://doi.org/10.1515/zna-1982-0307","url":null,"abstract":"The Thouless instability conditions in the binuclear iron complex 1 have been investigated by means of a semiempirical INDO approach. The behaviour of the restricted Hartree-Fock (HF) wave function with respect to singlet, non-singlet and complex variations of the orbitals is studied. The existence of a spin decoupled solution near the diamagnetic closed shell groundstate is demonstrated. The nature of the correlation processes (angular vs left-right) for the various orbital fluctuations is discussed.","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"33 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80907040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phase Diagrams of (NH4, M)X and(ND4, M)X WITH M=TL, Rb or Cs and X= Cl or Br (In German)","authors":"P. Brauer","doi":"10.1002/CHIN.197940015","DOIUrl":"https://doi.org/10.1002/CHIN.197940015","url":null,"abstract":"","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"208 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1979-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76144212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dissociation rates o f H F in electrical discharges have been calculated by solving a system of vibrational master equations, including e-V (electron-vibration), V-V (vibration-vibration) and V-T (vibration-translation) energy exchanges. The results show that large dissociation rates can be obtained by this mechanism only when the e-V pumping rates overcome the V-T deactivating rates. This occurs for electron number densities larger than 1013cm-3 . F inally the close connection o f the present results w ith the corresponding ones obtained by using as vibrational excitation source an IR powerfull laser is shown and discussed.
{"title":"Non Equilibrium Dissociation of HF in Electrical Discharge: The Role of Vibrational Excitation","authors":"M. Capitelli, M. Dilonardo","doi":"10.1515/zna-1978-0916","DOIUrl":"https://doi.org/10.1515/zna-1978-0916","url":null,"abstract":"Dissociation rates o f H F in electrical discharges have been calculated by solving a system of vibrational master equations, including e-V (electron-vibration), V-V (vibration-vibration) and V-T (vibration-translation) energy exchanges. The results show that large dissociation rates can be obtained by this mechanism only when the e-V pumping rates overcome the V-T deactivating rates. This occurs for electron number densities larger than 1013cm-3 . F inally the close connection o f the present results w ith the corresponding ones obtained by using as vibrational excitation source an IR powerfull laser is shown and discussed.","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"56 3 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89394420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namensnennung 4.0 Lizenz. Substituted Derivatives of 10-Phenyl-9-Acetoxyanthracene
{"title":"Substituted Derivatives of 10-PhenyI-9-Acetoxyanthracene","authors":"J. Heldt, J. Hedt, I. Gronowska","doi":"10.1002/chin.197532061","DOIUrl":"https://doi.org/10.1002/chin.197532061","url":null,"abstract":"für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namensnennung 4.0 Lizenz. Substituted Derivatives of 10-Phenyl-9-Acetoxyanthracene","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"56 13 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1975-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79754557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Elektrochemische Unter suchung der Chemischen Diffusion in Wustit mit Hilfe eines oxidischen Festelektrolyten","authors":"H. Rickert, W. Weppner","doi":"10.1002/chin.197507028","DOIUrl":"https://doi.org/10.1002/chin.197507028","url":null,"abstract":"","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"71 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1975-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76925879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular g-Values, Magnetic Susceptibility Anisotropies and Molecular","authors":"W. Czieslik, D. Sutter","doi":"10.1002/CHIN.197507093","DOIUrl":"https://doi.org/10.1002/CHIN.197507093","url":null,"abstract":"","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"2 7","pages":""},"PeriodicalIF":1.8,"publicationDate":"1975-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/CHIN.197507093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72455830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bestimmungder Bildungsenthalpie von Nitroxychlorid (Chlornitrat NO3CI) als Beitrag zur Deutung der Kubetuj des thermischen NO3Cl-Zerfalls in der Gasphase and in der Lösungsphase","authors":"H. Knauth, H. Martin, W. Stockmann","doi":"10.1002/chin.197420014","DOIUrl":"https://doi.org/10.1002/chin.197420014","url":null,"abstract":"","PeriodicalId":54395,"journal":{"name":"Zeitschrift Fur Naturforschung Section A-A Journal of Physical Sciences","volume":"17 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"1974-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81984273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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