1,725,321 research outputs found
Accretion column eclipses in the X-ray pulsars GX 1+4 and RX J0812.4-3114
No full textSharp dips observed in the pulse profiles of three X-ray pulsars (GX 1+4, RX J0812.4-3114 and A 0535+26) have previously been suggested to arise from partial eclipses of the emission region by the accretion column occurring once each rotation period. We present pulse-phase spectroscopy from Rossi X-ray Timing Explorer satellite observations of GX 1+4 and RX J0812.4-3114, which for the first time confirms this interpretation. The dip phase corresponds to the closest approach of the column axis to the line of sight, and the additional optical depth of photons escaping from the column in this direction gives rise to both the decrease in flux and increase in the fitted optical depth measured at this phase. Analysis of the arrival time of individual dips in GX 1+4 provides the first measurement of azimuthal wandering of a neutron star accretion column. The column longitude varies stochastically with a standard deviation ranging between 2° and 6° depending on the source luminosity. Measurements of the phase width of the dip both from mean pulse profiles and from the individual eclipses demonstrate that the dip width is proportional to the flux. The variation is consistent with that expected if the azimuthal extent of the accretion column depends only upon the Keplerian velocity at the inner disc radius, which varies as a consequence of the accretion rate M
Electronics 111: EEL 3114 / ETRA 3/0
No full textExamination on Electronics 111: EEL 3114 /ETRA 3/0, Supp Jan 201
Electronics 111: EEL 3114 / ETRA 3/0
No full textExamination on Electronics: 111: EEL 3114 / ETRA 3/0, Supp Jan 201
Thermodynamics 111: MTH 3114 / MTHA3/0
No full textExamination on Thermodynamics 111: MTH 3114 / MTHA 3/0, June 201
Block Card 3114 Muirfield Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: 3114 Muirfield Avenue (Toledo, Ohio) | Dwelling | Heather Downs Addition (Toledo, Ohio) | South Toledo Area (Toledo, Ohio) | Folk House Styl
Mechanistic Investigations into the Palladium-Catalyzed Decarboxylative Allylic Alkylation of Ketone Enolates Using the PHOX Ligand Architecture
Get PDFPalladium-catalyzed asymmetric allylic alkylation has become a large and important field for chemical synthesis. Many methodologies in this field offer mild conditions under which challenging and important molecular features can be reliably synthesized, including chiral all-carbon quaternary stereocenters. As a result, palladium- catalyzed asymmetric allylic alkylation has found significant use in total synthesis, and growing use in industry. While the general process of palladium-catalyzed asymmetric allylic alkylation has been studied for decades, there have been a number of recent modifications and developments, such as asymmetric versions of decarboxylative allylic alkylation procedures that are not yet well understood. The development of future implementations and improvements to palladium-catalyzed asymmetric allylic alkylation and related methodologies is expected to be facilitated by a better understanding of these more recent developments, and thus further mechanistic investigation is warranted.
Reported herein is a set of investigations into the palladium-catalyzed decarboxylative asymmetric allylic alkylation of ketone enolates using the PHOX ligand architecture. By monitoring the reaction via 31P NMR, a series of previously unidentified key intermediates is discovered. Two representatives of these key intermediates are isolated and characterized. The solution behavior of these species under reaction-like conditions is studied along with a few novel and related complexes. The role of these intermediates and their impact on the behavior of the reaction and product formation is discussed. Previously confounding experimentally observed behavior for this methodology is rationalized via the properties elucidated for these discovered intermediates.</p
Block Card 3114 Strathmoor Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Cape Cod Style | 3114 Strathmoor Avenue (Toledo, Ohio) | Dwelling | Heather Downs Addition (Toledo, Ohio) | South Toledo Area (Toledo, Ohio
Block Card 3114 Elmview Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch Style | Dwelling | 3114 Elmvieew Avenue (Toledo, Ohio) | Elmhurst Park Addition (Toledo, Ohio) | Deveaux Area (Toledo, Ohio) | West Toledo (Toledo, Ohio
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