11,285 research outputs found
Tropical variability simulated in ICON-A with a spectral cumulus parameterization
We implemented a spectral cumulus parameterization based on a cloud-resolving model (SC scheme) in the icosahedral nonhydrostatic atmospheric model (ICON-A). We compared the resulting simulated climatology and tropical variability with results from the standard version of ICON-A using a variant of the Tiedtke-Nordeng scheme (TK scheme) using observational and reanalysis data. The climatological errors of the SC scheme were similar to those of the TK scheme, but several biases, such as properties of meridional winds and precipitation pattern in the western Pacific, were much improved. For tropical variability, we found that the SC scheme improved the interannual response of the precipitation in the western Pacific and was able to simulate Madden-Julian oscillation (MJO) features much better than the TK scheme. We investigated the reason for the better simulation of the MJO using composite analysis and column process analysis for moisture. Our results suggest that the entrainment parameterization of the SC scheme is necessary to reproduce the MJO; however, spectral representation and improved convective closure are also found to contribute for better MJO simulation. These parameterizations improved moisture supply from low-level clouds and cloud mass flux which were needed to sustain the MJO. Ā© 2019. The Authors
Structure and decay pattern of linear-chain state in 14C
The linear-chain states of C are theoretically investigated by using
the antisymmetrized molecular dynamics. The calculated excitation energies and
the decay widths of the linear-chain states were compared with the
observed data reported by the recent experiments. The properties of the
positive-parity linear-chain states reasonably agree with the observation, that
convinces us of the linear-chain formation in the positive-parity states. On
the other hand, in the negative-parity states, it is found that the
linear-chain configuration is fragmented into many states and do not form a
single rotational band. As a further evidence of the linear-chain formation, we
focus on the decay pattern. It is shown that the linear-chain states
decay to the excited states of daughter nucleus as well as to
the ground state, while other cluster states dominantly decay into the ground
state. Hence, we regard that this characteristic decay pattern is a strong
signature of the linear-chain formation
Solar cells of metal-free phthalocyanine dispersed in polyvinyl carbazole. 1: Effects of the recrystallization of H2PC on cell characteristics
The development of an organic semiconductor solar cell and the effects of the recrystallization of metal free phthalocyanine (H2PC) on the characteristics of NESA/H2PC-PVK/Au sandwich cells were investigated. Alfa-H2PC sandwich cells showed photovoltage and photocurrent in a two direction opposite to that shown y as supplied H2PC cells, which consists mainly of beta-H2PC. Some difference was observed in the response times of the two cells. It is suggested that photocharacteristics change with the specific resistance of the H2PC, which is related to its crystal forms. In the cells with low resistance H2PC carriers are generated in H2PC by illumination, while in high resistance H2PC cells, carriers are generated in PVK which is sensitized with H2PC
3alpha clustering in the excited states of 16C
The alpha cluster states of 16C are investigated by using the antisymmetrized
molecular dynamics. It is shown that two different types of alpha cluster
states exist: triangular and linear-chain states. The former has an approximate
isosceles triangular configuration of alpha particles surrounded by four
valence neutrons occupying sd-shell, while the latter has the linearly aligned
alpha particles with two sd-shell neutrons and two pf-shell neutrons. It is
found that the structure of the linear-chain state is qualitatively understood
in terms of the 3/2 pi- and 1/2 sigma- molecular orbit as predicted by
molecular-orbital model, but there exists non-negligible Be+alpha+2n
correlation. The band-head energies of the triangular and linear-chain
rotational bands are 8.0 and 15.5 MeV, and the latter is close to the He+Be
threshold energy. It is also shown that the linear-chain state becomes the
yrast sstate at J=10 with excitation energy 27.8 MeV owing to its very large
moment-of-inertia comparable with hyperdeformation.Comment: 7 pages, 5 figure
Spacetime Fermions in Light-cone Gauge Superstring Field Theory and Dimensional Regularization
We consider the dimensional regularization of the light-cone gauge type II
superstring field theories in the NSR formalism. In the previous work, we have
calculated the tree-level amplitudes with external lines in the (NS,NS) sector
using the regularization and shown that the desired results are obtained
without introducing contact term interactions. In this work, we study the
tree-level amplitudes with external lines in the Ramond sector. In order to
deal with them, we propose a worldsheet theory to be used instead of that for
the naive dimensional regularization. With the worldsheet theory, we regularize
and define the tree-level amplitudes by analytic continuation. We show that the
results coincide with those of the first quantized formulation.Comment: 28 pages, 5 figures; v2: more details of our manipulations in
subsection 3.2 added, figures and references added; v3: clarifications adde
Quality Management of the Accounting Services
Often, the accounting services are vital for the success of a business, and their quality is very important, both for the users of accounting information, as well as for the providers of services.The present paper highlights the role of the accounting services in the processes of planning, coordination and development of the management policies of the economic entities. There a re identified a series of factors which are responsible for the quality of the accounting process and for the efficiency of the activity undertaken by the accountants
Compact Claude cycle refrigerator for laboratory use
A Claude cycle refrigerator with a three stage reciprocating expansion engine is described. Instead of a cam mechanism, valves are driven directly by magnetic solenoids operated by means of a micro processor control system. A swash plate mechanism is used to convert reciprocating motion of the expander pistons to rotary motion. A refrigeration capacity of 8 watts was achieved at 4.5 K with the operating pressure of 1.1 MPa and flow rate of 2.4 g/sec.. An effect of overintake operation was studied. Experimental results show that the efficiency of the expander has a peak point in the region of overintake operation with constant cycle speed, which agrees with theoretical results. The electrically controlled valve system is useful to vary the valve timing to achieve an optimum condition of operation
Light-cone Gauge NSR Strings in Noncritical Dimensions II -- Ramond Sector
Light-cone gauge superstring theory in noncritical dimensions corresponds to
a worldsheet theory with nonstandard longitudinal part in the conformal gauge.
The longitudinal part of the worldsheet theory is a superconformal field theory
called X^{\pm} CFT. We show that the X^{\pm} CFT combined with the
super-reparametrization ghost system can be described by free variables. It is
possible to express the correlation functions in terms of these free variables.
Bosonizing the free variables, we construct the spin fields and BRST invariant
vertex operators for the Ramond sector in the conformal gauge formulation. By
using these vertex operators, we can rewrite the tree amplitudes of the
noncritical light-cone gauge string field theory, with external lines in the
(R,R) sector as well as those in the (NS,NS) sector, in a BRST invariant way.Comment: 33 pages; v2: minor modification
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