• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 503
  • 157
  • 114
  • 86
  • 25
  • 20
  • 15
  • 9
  • 7
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • Tagged with
  • 1180
  • 201
  • 167
  • 109
  • 101
  • 98
  • 94
  • 94
  • 92
  • 91
  • 89
  • 87
  • 87
  • 82
  • 82
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Auto Template Assembly of CaCO3-Chitosan Hybrid Nanoboxes and Nanoframes in Ionic Liquid Medium

Chen, Hsingming Anna 2011 May 1900 (has links)
Recently, there has been increased effort in researching methods for producing hollow nanostructures because of their potential impact in the fields of catalysis, separation processes, drug delivery, and energy storage and conversion devices. The purpose of this thesis is to describe a method for forming hollow inorganic-organic hybrid nanoboxes and nanoframes. This approach relies upon ionic liquid (1-butyl-3-methyl-imidazolium chloride) mediated auto-templating assembly of CaCO3 and chitosan to form nanoframes (two open faces) and nanoboxes (one open face). The average dimension of the nanostructures formed was 339 ± 95 x 299 ± 89 nm. Detailed structure of nanoboxes and nanoframes were obtained by 3-D electron tomography and X-ray diffraction. Chemical bonding was determined by FTIR, and the ratio of organics to inorganics in the nanostructures was determined by thermal gravimetric analysis. The chitosan to CaCO3 weigh ratio, mixing strength, temperature, and dialysis time were varied to further elucidate the method of formation. It was found that increasing the mixing power caused the equilibrium nanostructure dimension to decrease. On the other hand, varying the experimental temperature in the range of 80 to 160˚C did not affect the nanostructure dimension. The dialysis study showed that during dialysis the nanostructure core was increasingly removed. Nanoframes were observed after 72 hours of dialysis. With further dialysis, there was continued erosion of nanoframes. Results indicate that the concentration gradient and the solubility difference between the mixture components were responsible for this transformation.
182

Etude des propriétés structurales et modélisations de poudres nanostructurées de fer obtenues par broyage mécanique

Grafoute, Moussa Greneche, Jean-Marc January 2004 (has links) (PDF)
Reproduction de : Thèse de doctorat : Physique : Le Mans : 2004. / Titre provenant de l'écran-titre. Bibliogr. en fin de chapitres.
183

Etude des propriétés électroniques des états de Shockley dans les surfaces nanostructurées auto-organisées

Didiot, Clément Kierren, Bertrand. Malterre, Daniel January 2007 (has links) (PDF)
Thèse de doctorat : Physique : Nancy 1 : 2007. / Titre provenant de l'écran-titre. Bibliogr.
184

Synthèse de copolymères par greffage radicalaire de méthacrylate de méthyle sur polyoléfine par extrusion réactive, en vue de la nanostructuration

Badel, Thierry Michel, Alain Chaumont, Philippe. January 2005 (has links) (PDF)
Reproduction de : Thèse de doctorat : Chimie macromoléculaire : Lyon 1 : 2005. / Titre provenant de l'écran titre. 173 réf. bibliogr.
185

Transfert de chaleur à échelles de temps et d'espace ultra-courtes simulation numérique pour des nanofils et nanofilms de semiconducteur /

Terris, Damian Joulain, Karl. Lemonnier, Denis January 2008 (has links) (PDF)
Reproduction de : Thèse de doctorat : Energie, Thermique, combustion : Poitiers : 2008. / Titre provenant de l'écran-titre. Bibliogr. 121 réf.
186

Semiclassical theory of spin transport in metallic and semiconductor heterostructures

Qi, Yunong, January 2003 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
187

Light emitting diodes based on ZnO nanorods /

Ng, Man-ching, Alan. January 2010 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references. Also available online.
188

Semiclassical theory of spin transport in metallic and semiconductor heterostructures /

Qi, Yunong, January 2003 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
189

Light emitting diodes based on ZnO nanorods

Ng, Man-ching, Alan. January 2010 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references. Also available in print.
190

Light emitting diodes based on ZnO nanorods

Ng, Man-ching, Alan., 吳文政. January 2010 (has links)
published_or_final_version / Physics / Doctoral / Doctor of Philosophy

Page generated in 0.0401 seconds