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Showing 1 to 20 of 66 for “"Halogens"”.
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Interactions of halogens with amines
… stages of the interaction of amines with halogens - in particular, iodine - have been studied. 'In the course of this investigation, it has been shown that amines and iodine interact initially via the nitrogen lone pair to form molecular complexes (CHARGE-TRANSFER COMPLEXES). Several of …
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Halogens and trace elements in subduction zones
… on solubilities and incorporation mechanisms of halogens and trace elements in minerals and aqueous fluids at high temperatures and pressures. The solubility of fluorine and chlorine in upper mantle minerals (forsterite, enstatite and pyrope) and halogen partitioning between aqueous fluids and …
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Toward the photo-induced reductive elimination of halogens
Light-driven energy conversion schemes have been proposed as alternative energy to fossil fuels. The target fuel of these schemes is hydrogen. For photocatalytic hydrogen production to be feasible, it must be performed on energy-poor substrates and must possess high quantum efficiency. The …
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Etching, Roughening, and Patterning of Silicon(100) With Halogens
With variable temperature STM, the surface modification dynamics of Cl- and Br-Si(100)-(2 x 1) were studied. Chlorine (Bromine) caused surface roughening that created pits and regrowth islands with minimal desorption of SiCl 2 (SiBr2). The roughening and equilibrium morphologies at 700--750 K for …
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Anion exchange study of the oxidation states of the halogens, including astatine
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 1960
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Surface reflectance core spectroscopy of halogens, rare gases, alkalis and CO on metal surfaces
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-28T15:03:36Z No. of bitstreams: 1 1980_cunningham.pdf: 5039429 bytes, checksum: 6a907df332d48a6816d0e9530d260918 (MD5)
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Tides, Winds, and Reactive Halogens A Study of Multiphase Chemistry in the Marine Boundary Layer
Reactive halogens in the atmosphere (inorganic compounds containing chlorine, bromine, and/or iodine)have the ability to catalytically destroy ozone (O3) as well as react with NOx (= NO + NO2) , influencing concentrations and ratios of important tropospheric pollutants. They can also react with and …
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Fluid-mobile element cycling (halogens, boron, lithium) and sourcing through the Costa Rican convergent margin
The source of fluids in convergent margins can be traced using fluid-mobile elements such as Cl, Br, I, B, and Li. However, previous studies have often overlooked the forearc. Describing fluid loss from subducting oceanic crust to the forearc is difficult for several reasons including differences …
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Surface Reflectance Core Spectroscopy of Halogens, Rare Gases, Alkalis and Carbon-Monoxide on Metal Surfaces
Reflectivity spectra for the halogens, rare gases, alkalis and the CO molecule adsorbed on metal and insulating surfaces are described. This research employed synchrotron radiation in the energy range from 4 to 20 eV, using both s and p polarized light. Results for adsorbates in three neighboring …
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Evaluating the effects of hydrogeologic processes on the fate of salinity and halogens in headwater catchments
… change) may affect water resources. </p> <p>Halogens (specifically, chloride (Cl), bromide (Br), and iodine (I)) occur naturally at low levels in terrestrial aquatic ecosystems, and may also originate from a suite of anthropogenic sources. Due to their largely conservative behavior, and …
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The impact of volcanic halogens, climate change, and sulfate aerosol geo-engineering on the atmospheric effects of volcanic eruptions
… However, how the co-emission of volcanic halogens, climate change, and concurrent sulfate aerosol geo-engineering would alter the atmospheric effects of sulfur-only explosive volcanic eruptions has, previously, been under-researched. In this thesis, aerosol-chemistry-climate model …
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Studies of some reactions between electrophilic halogens and various conjugated systems in which intermediates or products having rearranged double-bond systems are concerned
PART I A STUDY OF MECHANISTIC VARIATIONS IN THE BROMINATION AND CHLORINATION OF SOME ALKYL PHENOLS, PHENYL ETHERS AND PNENYL ESTERS. The brominations of some 2,6-dialkylphenyl acetates in nitro-methane and in acetic acid have been shown to give (a) products of substitution at both the C-3 and C-4 …
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Formation of secondary organic aerosol and its processing by atmospheric halogen species – A spectroscopic study
… processed with atmospheric trace gases like halogens released through sea-salt activation or from other sources. Based on aerosol smog-chamber experiments, the formation of secondary organic aerosols (SOA) from predominantly aliphatic (α-pinene) or aromatic (catechol and guaiacol) precursors …
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Studies of Arctic Tropospheric Ozone Depletion Events Through Buoy-Borne Observations and Laboratory Studies
… cause the production and release of molecular halogens from frozen, salty surfaces, though this mechanism is not yet well understood. The subsequent photolysis of molecular halogens produces reactive halogen atoms that remove ozone from the atmosphere in these so-called “Ozone Depletion Events” …
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Synthetic Chiral Stationary Phases in Enantioselective Liquid Chromatography
… polarizable aromatic substituents, such as halogens, have been found to enhance $\pi - \pi$ face to face interactions and can be used in the designs of new CSPs so as to improve their enantioselectivity. The structural elements required for successful enantioseparations of hydantoins and …
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Synthesis of Well-Defined N-Heterocyclic Carbene (NHC) Complexes of Late Transition Metals
… the carbene, undergoes oxidative addition with halogens to afford gold(III) NHC complexes, or dehalogenation in presence of inorganic silver salts to afford cationic gold(I) mono-NHC complexes in coordinating solvent. The coordinating solvent can be replaced by a neutral or anionic group to …
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A Regional Chemical Characterization and Analysis of Groundwater in Eastern Ontario
… Ontario, Canada, where elevated TDS, Na and halogens occur in shallow groundwater. Water-types, PCA and mapping are used to investigate the processes and features controlling the chemistry. The chemical patterns are associated with glaciomarine deposits (extent, thickness) and bedrock …
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Exchange reactions of organic halides and organo-silicon compounds with boron tribromide and boron triiodide
… been investigated. The results show exchange of halogens between the BX3 (X = Br# 1) and the organic halidef exchange of the halogen of the C-X bond being proved. The rates of halogen exchange vary. Reaction of the heavier halides with organo-silicon compounds indicated that the silicon-carbon …
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Understanding the origin of the recovery of superconductivity in halogenated YBCO single crystal : atomic structure study
… The key question concerns the role of these halogens in the lattice. In order to shed light to this problem, we have performed multiple-edge x-ray absorption fine structure (XAFS) measurements about the Y K, Ba L_3, I L_3, Cu K and Br K-edges at room temperature on brominated (non-brominated) …
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