11,558 research outputs found
Effects of rotation in the energy spectrum of
In this paper, motivated by the experimental evidence of rapidly rotating
molecules in fullerite, we study the low-energy electronic states of
rotating fullerene within a continuum model. In this model, the low-energy
spectrum is obtained from an effective Dirac equation including non-Abelian
gauge fields that simulate the pentagonal rings of the molecule. Rotation is
incorporated into the model by solving the effective Dirac equation in the
rotating referential frame. The exact analytical solution for the
eigenfunctions and energy spectrum is obtained, yielding the previously known
static results in the no rotation limit. Due to the coupling between rotation
and total angular momentum, that appears naturally in the rotating frame, the
zero modes of static are shifted and also suffer a Zeeman splitting
whithout the presence of a magnetic field
A Nonclassical Dihydrogen Adduct of S = Ā½ Fe(I)
We have exploited the capacity of the ā(SiP^(iPr)_3)Fe(I)ā scaffold to accommodate additional axial ligands and characterized the mononuclear S = 1/2 H_2 adduct complex (SiP^(iPr)_3)Fe^I(H_2). EPR and ENDOR data, in the context of X-ray structural results, revealed that this complex provides a highly unusual example of an open-shell metal complex that binds dihydrogen as a ligand. The H2 ligand at 2 K dynamically reorients within the ligand-binding pocket, tunneling among the energy minima created by strong interactions with the three FeāP bonds
Inertial-Hall effect: the influence of rotation on the Hall conductivity
Inertial effects play an important role in classical mechanics but have been
largely overlooked in quantum mechanics. Nevertheless, the analogy between
inertial forces on mass particles and electromagnetic forces on charged
particles is not new. In this paper, we consider a rotating non-interacting
planar two-dimensional electron gas with a perpendicular uniform magnetic field
and investigate the effects of the rotation in the Hall conductiv
Mathematical modeling and uncertainty analysis of greenhouse gas emissions during extraction and refining oil in Poland
A homoleptic phosphine adduct of Tl(I)
A homoleptic phosphine adduct of thallium(I) supported by a tris(phosphino)borate ligand has been isolated and structurally characterized
A multiscale view on inverse statistics and gain/loss asymmetry in financial time series
Researchers have studied the first passage time of financial time series and
observed that the smallest time interval needed for a stock index to move a
given distance is typically shorter for negative than for positive price
movements. The same is not observed for the index constituents, the individual
stocks. We use the discrete wavelet transform to illustrate that this is a long
rather than short time scale phenomenon -- if enough low frequency content of
the price process is removed, the asymmetry disappears. We also propose a new
model, which explain the asymmetry by prolonged, correlated down movements of
individual stocks
Determining smallholder farmersā preferences for Push-Pull technology dissemination pathways in western Kenya
The push-pull technology (PPT) has widely been disseminated to control stemborer (Chilo partellus and Busseola fusca) and Striga weeds (Striga hermonthica and Striga asiatica) in maize fields in Kenya. This study examined farmersā preferences for various dissemination pathways in order to proffer better targeting of resources in an optimal dissemination strategy. The pathways considered were public meetings (barazas), radio, farmer field schools (FFS), field days (FD), farmer teachers (FT), the fellow farmers (FF) and print materials. Using a weighted score index and ordered probit regression, the different pathways were sequentially ranked as FD, FT, FFS, FF, print materials, Radio, and barazas. Marginal effects from ordered probit showed that farmers had the least preferences for baraza and radio pathways. The farmer categories with the highest preference for particular pathways were: less educated farmers for FD, farmers with small land sizes for FT, farmers belonging to groups for FFS, and young educated farmers for the print materials. This information is extremely important for targeting the different segments of farmers.Push-pull technology, Stemborer, Striga, Dissemination pathways, preference, Research and Development/Tech Change/Emerging Technologies,
A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7
Circinus X-1 is a bright and highly variable X-ray binary which displays
strong and rapid evolution in all wavebands. Radio flaring, associated with the
production of a relativistic jet, occurs periodically on a ~17-day timescale. A
longer-term envelope modulates the peak radio fluxes in flares, ranging from
peaks in excess of a Jansky in the 1970s to an historic low of milliJanskys
during the years 1994 to 2007. Here we report first observations of this source
with the MeerKAT test array, KAT-7, part of the pathfinder development for the
African dish component of the Square Kilometre Array (SKA), demonstrating
successful scientific operation for variable and transient sources with the
test array. The KAT-7 observations at 1.9 GHz during the period 13 December
2011 to 16 January 2012 reveal in temporal detail the return to the
Jansky-level events observed in the 1970s. We compare these data to
contemporaneous single-dish measurements at 4.8 and 8.5 GHz with the HartRAO
26-m telescope and X-ray monitoring from MAXI. We discuss whether the overall
modulation and recent dramatic brightening is likely to be due to an increase
in the power of the jet due to changes in accretion rate or changing Doppler
boosting associated with a varying angle to the line of sight.Comment: 7 pages, 5 figures, accepted for publication in MNRAS 14 May 201
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