• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 149
  • 24
  • 17
  • 11
  • 8
  • 5
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 264
  • 73
  • 46
  • 39
  • 38
  • 34
  • 24
  • 23
  • 21
  • 19
  • 17
  • 17
  • 17
  • 16
  • 14
  • 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.
91

Aspects of the environmental chemistry of technetium

Gawenis, James Allen, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
92

Adsorbate-induced nanoscale faceting of rhenium surfaces

Wang, Hao, January 2008 (has links)
Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 130-135).
93

Technetium and rhenium labeled cyclic melanotropin analogues as imaging and therepeutic [sic] agents for melanoma

Wang, Nannan, January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 153-156). Also available on the Internet.
94

Aspects of the environmental chemistry of technetium /

Gawenis, James Allen, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
95

Feasibility study of the chemical vapor infiltration of rhenium

Ellzey, Karen Elizabeth 05 1900 (has links)
No description available.
96

Equipment and process development for fabrication of rhenium-based composites by chemical vapor infiltration

Renier, Mark C. 08 1900 (has links)
No description available.
97

NMR spectroscopic studies of binding and exchange in rhenium alkane complexes

Lawes, Douglas John, Chemistry, Faculty of Science, UNSW January 2008 (has links)
The transition metal complexes cyclopentadienylrhenium tricarbonyl [CpRe(CO)3, Cp = cyclopentadienyl] and (isopropylcyclopentadienyl)rhenium tricarbonyl [(i-PrCp)Re(CO)3, i-Pr = isopropyl] were photolysed in alkanes at low temperature and the resulting alkane complexes, of the general formula Cp'Re(CO)2(alkane) (Cp' = Cp or (i-PrCp)), were studied using NMR spectroscopy. Characteristic proton chemical shifts (δ) and couplings (3JHH) were observed for alkane complexes of several linear, branched and cyclic alkanes of up to eight carbons. Alkanes with chemically distinct methyl (CH3) and/or methylene (CH2) units were observed alternatively binding through each unit to rhenium. No bound methine unit was observed. Large C-H coupling constants (1JCH) were observed for protons of several bound CH3 and CH2 units, indicating the bound C-H is intact. These species are, thus, alkane sigma (σ) complexes, wherein the alkane has an agostic (M-H-C, 3 centre 2 electron) interaction with the rhenium centre. The CH3 binding mode of (i-PrCp)Re(CO)2(1-pentane) was elucidated; sequential deuteration in the bound CH3 revealed an equilibrium isotope effect (EIE) in the remaining proton/s, confirming that only one C-H has an agostic interaction with rhenium at any instant . NMR parameters δ(1H) (-8.22), δ(13C) ( 42.4) and 1JCH (85 Hz) for the complexed C-H reveal it is unequivocally intact and yet strongly interacting with the rhenium centre, hallmarks for the agostic interaction. Intramolecular exchange was identified between pentane complex isomers Cp'Re(CO)2(1-pentane), Cp'Re(CO)2(2-pentane) and Cp'Re(CO)2(3-pentane). Equilibrium constants were determined, revealing a preference for CH2 binding over CH3. The inequivalent hydrogens found in methylene groups of cyclohexane at low temperature permitted simultaneous observation of axial and equatorial C-H protons of a bound CH2 in CpRe(CO)2(cyclohexane); an EIE, upon deuteration, indicated rapid exchange between complexed C-H bonds in the bound CH2 unit. The rhenium centre was found to prefer complexation of the axial C-H bond, over the equatorial, with K ~2.9. Intermolecular exchange of alkane ligands with free solvent was directly observed, in the competitive complexation of the [CpRe(CO)2] fragment to different alkanes in binary mixtures. The preference cyclohexane > cyclopentane > pentane > isobutane was established and equilibrium constants determined. The kinetics were followed by NMR and modelled, revealing rate constants; decay rates were also determined.
98

Synthetic, structural and spatial studies of rhenium compounds.

Wei, Yi. Lock, C.J.L. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1995. / Source: Dissertation Abstracts International, Volume: 56-12, Section: B, page: 6741. Adviser: C. J. L. Lock.
99

Development and optimization of W-188/Re-188 and Mo-99/Tc-99m gel radioisotope generators /

Liang, Qixue, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / "m in ⁹⁹mTc on short title page is supercript." Typescript. Vita. Includes bibliographical references (leaves 131-136). Also available on the Internet.
100

Development and optimization of W-188/Re-188 and Mo-99/Tc-99m gel radioisotope generators

Liang, Qixue, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / "M in ⁹⁹mTc on short title page is supercript." Typescript. Vita. Includes bibliographical references (leaves 131-136). Also available on the Internet.

Page generated in 0.0452 seconds