• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 85
  • 18
  • 14
  • 12
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 195
  • 34
  • 24
  • 20
  • 18
  • 17
  • 17
  • 17
  • 17
  • 17
  • 17
  • 17
  • 15
  • 14
  • 13
  • 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.
21

Farbveränderungen von zahnärztlichen Kunststoffen durch Bestrahlung mit Xenon-Lampen

Raecke, Hedda, January 1979 (has links)
Thesis (doctoral)--Freie Universität Berlin, 1979.
22

Erzeugung sekundärer Exzitonen in festem Xenon untersucht mit Hilfe der Lumineszenzspektroskopie

Steeg, Barbara. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2000--Hamburg.
23

Xenon and krypton adsorption on the Si(111) 7x7 surface

Conrad, Edward H. January 1983 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 95-97).
24

A laboratory study of strong shock waves in xenon /

Golobic, Robert A. January 1971 (has links)
No description available.
25

OXIDE AND OXIDE FLUORIDES OF XENON(IV) AND NEW DEVELOPMENTS IN XENON(II), AND KRYPTON(II) CHEMISTRY

Brock, David January 2011 (has links)
<p> This Thesis extends the fundamental chemistry of the noble-gas elements, namely, xenon and krypton. More specifically, the chemistry of Xe(IV) has been extended by the synthesis and characterization of Xe(IV) oxide and oxide fluoride derivatives. The syntheses ofXeOF2, F20XeN=CCH3, and XeOF2·nHF and their structural characterizations are described. All three compounds are endothermic and explosive at temperatures approaching 0 °C. Although Xe0F2had been previously reported, it had not been isolated as a pure compound. Xenon oxide difluoride has now been characterized in CH3CN solution by 19F, 170, and 129Xe NMR spectroscopy and XeOF2, F20XeN=CCH3, and XeOF2·nHF have been characterized in the solid-state by Raman spectroscopy. The low temperature X-ray crystal structure ofF20XeN=CCH3 reveals a long Xe-N bond trans to the Xe-0 bond and a geometrical arrangement about xenon in which the atoms directly bonded to xenon are coplanar and CH3C=N acts as a fourth ligand in the equatorial plane. The geometry about xenon is consistent with an AX2YZE2 VSEPR arrangement of bond pairs and electron lone pairs and represents a rare example of a Xe(IV)-N bond. </p> <p> The missing Xe(IV) oxide, Xe02, has been synthesized at 0 °C by hydrolysis of XeF4 in water and 2.00 M H2S04(aq) and characterized by low-temperature Raman Spectroscopy. The Raman spectra ofXe02 amend prior vibrational assignments of xenon doped Si02 and are in accordance with prior speculation that xenon depletion from the Earth's atmosphere could occur by xenon insertion at high temperatures and high pressures into Si02 in the Earth's crust. </p> <p> The XeOF3-anion has been synthesized as its Cs + and N(CH3)/ salts, and structurally characterized in the solid state bylow-temperature Raman spectroscopy. The calculated anion geometry is based on a square planar AX3YE2VSEPR arrangement with the longest Xe-F bond trans to the oxygen atom. The F-Xe-F angle is bent away from the oxygen atom to accommodate the greater spatial requirement of the oxygen double bond domain. The XeOF3-anion of the Cs + salt is fluorine-bridged in the solid-state, whereas the anion ofthe N(CH3)/ salt approximates the gas-phase anion. </p> <p> The [H(OXeF2)n][AsF6] and [FXerr(OXe1vF2)n][AsF6] (n = 1, 2) salts have been synthesized and structurally characterized in the solid state by low-temperature Raman spectroscopy. The chain length of each cation is limited to one or two OXeF2 subunits, which are oxygen-bridged and are strongly ion-paired with the AsF 6-anion. The reaction of XeOF2·xHF in superacidic HF/SbFs solvent mixtures resulted in a mixture of ([XeF3·HF][Sb2Fu])2-[HsF4][SbF6], [XeF3·HF][Sb2Fu], and [XeF3][SbF6]. The XeF/ cations in each structure are very similar, displaying T -shaped coordination of three fluorine atoms, and a short contact to the fluorine atom of HF, m ([XeF3·HF][Sb2F u])2-[H5F4][SbF6] and [XeF3·HF][Sb2Fu], or to a fluorine atom of SbF6in [XeF3][SbF6]. </p> <p> Vibrational frequency assignments for the aforementioned compounds were aided by comparison with frequencies derived from quantum-chemical calculations, by ^(18)O enrichment, and, where appropriate, by 2H enrichment. </p> <p> The syntheses and structural characterizations of [XOF2][AsF6] (X = Cl, Br), the XeF2 adduct-salts, [BrOF2][AsF6}nXeF2 (n = 1, 2), and the KrF2 adduct-salt, [BrOF2][AsF6]'2KrFz, are also described. The crystal structure of [BrOF2][AsF6] shows a positional disorder among the oxygen atom and the fluorine atoms. The low-temperature Raman spectra of [XOFz][AsF6], the complex cation salts, [BrOF2][AsF6]'nXeFz (n = 1, 2), and [BrOF2][AsF6]·2KrF2 have been assigned on the basis ofthe crystal structures and with the aid of quantum-chemical calculations. The low-temperature ( -173 °C) X -ray crystal structure of [Br0Fz][AsF6]'2KrF2 consists of isolated molecular units and represents an example of KrF2 coordinated to a main-group atom. The contact distances between bromine and fluorine atom of NgFz (Ng = Kr, Xe) is shorter in [BrOFz][AsF6]·2XeFz than in the KrFz analogue, which is attributed to the more polar nature of the Xe-F bonds. The ELF and QTAIM analyses of [BrOFz][AsF6h2-and [BrOFz][AsF6]'2XeFz were carried out and are compared with those of free BrOF/ and [BrOFz][AsF6]'2KrFz to better understand the effect of Br(V) coordination number on the localization domain of the Br(V) valence electron lone pair. </p> <p> The syntheses of FXeON160 2 and FXeoNe800) has shed light on the mechanism leading to the formation of FXeON02• Raman spectroscopy indicated the absence of 161180 isotopic scrambling among the oxygen sites of FXeON02 which was confirmed by factor-group analyses ofthe 16 isotopomeric crystallographic unit cells that result from syn-/anti-isomerization, FXe160Ne6oA180s)/FXe160Ne6os180A), among the four FXeON02 molecules of the unit cell. The intermediate oxide fluoride, O(XeF)2, was observed in the synthesis of FXeON02, providing valuable insight into the reaction pathway. A reinterpretation of the solid-state 160-and 180-enriched Raman spectra of O(XeF)z was also carried out. </p> / Thesis / Doctor of Philosophy (PhD)
26

Production of [beta-gamma] coincidence spectra of individual radioxenon isotopes for improved analysis of nuclear explosion monitoring data

Haas, Derek Anderson, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
27

Studies of new oxidative rearrangements of imines and esters

Nongkunsarn, Pakawan January 1996 (has links)
No description available.
28

International Symposium XeMAT2015 September 13-17, 2015 in Dresden, Germany

14 January 2016 (has links) (PDF)
The present Book of Abstracts includes most of the contributions to the International Symposium XeMAT 2015, Xenon/hyperpolarized noble gases in magnetic resonance. This symposium took place from September 13-17, 2015 in Dresden in the new chemistry building of TU Dresden and covered all aspects of the use of xenon and hyperpolarized gases in magnetic resonance. This included for example materials science, biosensing, imaging, and molecular bioimaging as well as all aspects of gas hyperpolarization. The conference program included 15 invited lectures, 14 contributed talks as well as more than 20 posters.
29

Transmission electron diffraction studies of xenon adsorbed on graphite

Faisal, A. Q. D. January 1987 (has links)
No description available.
30

Plasmaless automated xenon difluoride MEMS etching system development and application

Xuan, Guangchi. January 2006 (has links)
Thesis (M.E.E.)--University of Delaware, 2006. / Principal faculty advisor: James Kolodzey, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Page generated in 0.0313 seconds