1,988 research outputs found
Orientation-dependent binding energy of graphene on palladium
Using density functional theory calculations, we show that the binding
strength of a graphene monolayer on Pd(111) can vary between physisorption and
chemisorption depending on its orientation. By studying the interfacial charge
transfer, we have identified a specific four-atom carbon cluster that is
responsible for the local bonding of graphene to Pd(111). The areal density of
such clusters varies with the in-plane orientation of graphene, causing the
binding energy to change accordingly. Similar investigations can also apply to
other metal substrates, and suggests that physical, chemical, and mechanical
properties of graphene may be controlled by changing its orientation.Comment: 5 pages, 6 figure
Recommended from our members
Implicit theories of emotion shape regulation of negative affect
Mental contrasting of a desired future with the present reality strengthens the link between expectations and goal pursuit: The higher expectations of success, the more people engage in goal pursuit; the lower expectations of success, the more people let go or disengage from goal pursuit. In three studies, we tested if mental contrasting increases the link between expectations and goal pursuit by affecting the strength of mental associations between future and reality. We used lexical decision tasks to measure the strength of associations between future and reality for different domains of goal pursuit (i.e., interpersonal relations, achievement), and compared results in the mental contrasting condition to relevant control conditions (i.e., reverse contrasting and content control). In the mental contrasting condition but not in the control conditions emerged a strong link between expectations of success and the strength of associations between future and reality (Study 1, 2). The strength of associations between future and reality in turn mediated the link between expectations and self-reported as well as other-rated goal pursuit in the mental contrasting condition (Study 1, 2). Finally, the link between expectations and the strength of associations between future and reality in the mental contrasting condition vanished when the goal was attained (Study 3). Taken together, these results suggest that strength of future–reality associations are a mechanism specific to mental contrasting effects on goal pursuit
Exchange and correlation energies of ground states of atoms and molecules in strong magnetic fields
Using a Hartree-Fock mesh method and a configuration interaction approach
based on a generalized Gaussian basis set we investigate the behaviour of the
exchange and correlation energies of small atoms and molecules, namely th e
helium and lithium atom as well as the hydrogen molecule, in the presence of a
magnetic field covering the regime B=0-100a.u. In general the importance of the
exchange energy to the binding properties of at oms or molecules increases
strongly with increasing field strength. This is due to the spin-flip
transitions and in particular due to the contributions of the tightly bound
hydrogenic state s which are involved in the corresponding ground states of
different symmetries. In contrast to the exchange energy the correlation energy
becomes less relevant with increasing field strength. This holds for the
individual configurations constituting the ground state and for the crossovers
of the global ground state.Comment: 4 Figures acc.f.publ.in Phys.Rev.
Feeding Practices in South Dakota Cattle Feedlots
During March 1989, a mail survey of South Dakota cattle feedlot managers was undertaken. The purposes of the survey were to characterize the nature of the cattle feeding industry in South Dakota and to determine the relationships between (i) each of size-of-feedlot and geographic location within the state and (ii) management practices followed by cattle feeders. Direct relationships exist between size-of-feedlot and the following: (1) rate of feedlot utilization in each quarter of the year (P\u3c.10); (2) percentage grain relative to roughage in both growing and finishing diets (P\u3c.10); (3) percentage of feedlots feeding high moisture grain, cracked grain, and ground hay (P\u3c.01); (4) percentage of feedlots using rumen stimulants and growth implants (P\u3c.01); and (5) percentages of managers testing feeds for nutrient composition, using feed scales to control feeding rates, maintaining feed records for separate pens of cattle, and hiring consultants to formulate rations (P\u3c.01). On the other hand, inverse relationships exist between size-of-feedlot and the following: (6) days on feed for heifer calves, yearling steers, and yearling heifers (P\u3c.10); (7) slaughter weight of steers (Pc.10); (8) percentage of home-raised hay and dry grain (P\u3c.10); (9) percentage of feedlots feeding ground grain and unprocessed hay (P\u3c.01); and (10) percentage of feedlots not using feed additives (P\u3c.10). Average days on feed for steer and heifer calves are lower (P\u3c.05) in the West than in other areas of the state. More milo is fed in the West; more barley is fed in the North Central region; and less home-raised corn silage and haylage are fed in the West than in other regions (P\u3c.05)
Reconstruction methods for acoustic particle detection in the deep sea using clusters of hydrophones
This article focuses on techniques for acoustic noise reduction, signal
filters and source reconstruction. For noise reduction, bandpass filters and
cross correlations are found to be efficient and fast ways to improve the
signal to noise ratio and identify a possible neutrino-induced acoustic signal.
The reconstruction of the position of an acoustic point source in the sea is
performed by using small-volume clusters of hydrophones (about 1 cubic meter)
for direction reconstruction by a beamforming algorithm. The directional
information from a number of such clusters allows for position reconstruction.
The algorithms for data filtering, direction and position reconstruction are
explained and demonstrated using simulated data.Comment: 7 pages, 13 figure
KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea
High energy neutrinos produced in astrophysical processes will allow for a
new way of studying the universe. In order to detect the expected flux of high
energy neutrinos from specific astrophysical sources, neutrino telescopes of a
scale of a km^3 of water will be needed. A Northern Hemisphere detector is
being proposed to be sited in a deep area of the Mediterranean Sea. This
detector will provide complimentary sky coverage to the IceCube detector being
built at the South Pole. The three neutrino telescope projects in the
Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design,
and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a
3-year Design Study; the status of the Design Study is presented and some
technical issues are discussed.Comment: 4 pages, 3 figures, Prepared for the 10th International Conference on
Astroparticle and Underground Physics (TAUP 2007), Sendai, Japan, 11-15 Sep
200
Measurements and Simulation Studies of Piezoceramics for Acoustic Particle Detection
Calibration sources are an indispensable tool for all detectors. In acoustic
particle detection the goal of a calibration source is to mimic neutrino
signatures as expected from hadronic cascades. A simple and promising method
for the emulation of neutrino signals are piezo ceramics. We will present
results of measruements and simulations on these piezo ceramics.Comment: 5 pages, 5 figure
Feijão comum: características morfo-agronômicas de cultivares.
O presente trabalho objetivou avaliar as características morfoagronômicas de cultivares de feijão comum de diversos grupos comerciais na época de safrinha
Componentes produtivos de cultivares de feijão comum em cultivo safrinha.
O presente trabalho teve por objetivo avaliar os componentes produtivos de cultivares de feijão comum de diversos grupos comerciais na época de safrinha
- …