5,499 research outputs found
The Rogue Wave and breather solution of the Gerdjikov-Ivanov equation
The Gerdjikov-Ivanov (GI) system of and is defined by a quadratic
polynomial spectral problem with matrix coefficients. Each element
of the matrix of n-fold Darboux transformation of this system is expressed by a
ratio of determinant and determinant of
eigenfunctions, which implies the determinant representation of and
generated from known solution and . By choosing some special
eigenvalues and eigenfunctions according to the reduction conditions
, the determinant representation of provides
some new solutions of the GI equation. As examples, the breather solutions and
rogue wave of the GI is given explicitly by two-fold DT from a periodic "seed"
with a constant amplitude.Comment: 8 figures, 17 page
Self-consistent tilted-axis-cranking study of triaxial strongly deformed bands in Er at ultrahigh spin
Stimulated by recent experimental discoveries, triaxial strongly deformed
(TSD) states in Er at ultrahigh spins have been studied by means of the
Skyrme-Hartree-Fock model and the tilted-axis-cranking method. Restricting the
rotational axis to one of the principal axes -- as done in previous cranking
calculations -- two well-defined TSD minima in the total Routhian surface are
found for a given configuration: one with positive and another with negative
triaxial deformation . By allowing the rotational axis to change
direction, the higher-energy minimum is shown to be a saddle point. This
resolves the long-standing question of the physical interpretation of the two
triaxial minima at a very similar quadrupole shape obtained in the principal
axis cranking approach. Several TSD configurations have been predicted,
including a highly deformed band expected to cross lesser elongated TSD bands
at the highest spins. Its transitional quadrupole moment \,eb
is close to the measured value of 11\,eb; hence, it is a candidate for
the structure observed in experiment.Comment: 5 pages, 5 figure
The cosmological origin of Higgs particles
A proposal of the cosmological origin of Higgs particles is given. We show,
that the Higgs field could be created from the vacuum quantum conformal
fluctuation of Anti-de Sitter space-time, the spontaneous breaking of vacuum
symmetry, and the mass of Higgs particle are related to the cosmological
constant of our universe,especially the theoretical estimated mass m of
Higgs particles is m =.Comment: 7 pages,no figure
Litter decomposition in a subtropical plantation in Qianyanzhou, China
A long-term (20 months) bulk litter decomposition experiment was conducted in a subtropical plantation in southern China in order to test the hypothesis that stable isotope discrimination occurs during litter decomposition and that litter decomposition increases concentrations of nutrients and organic matter in soil. This was achieved by a litter bag technique. Carbon (C), nitrogen (N) and phosphorus (P) concentrations in the remaining litter as well as delta(13)C and delta(15)N during the experimental period were measured. Meanwhile, organic C, alkali-soluble N and available P concentrations were determined in the soils beneath litter bags and in the soils at the control plots. The dry mass remaining (as % of the initial mass) during litter decomposition exponentially declined (y = 0.9362 e(-0.0365x) , R (2) = 0.93, P < 0.0001), but total C in the remaining litter did not decrease significantly with decomposition process during a 20-month period. By comparison, total N in the remaining litter significantly increased from 5.8 +/- A 1.7 g kg(-1) dw litter in the first month to 10.1 +/- A 1.4 g kg(-1) dw litter in the 20th month. During the decomposition, delta(13)C values of the remaining litter showed an insignificant enrichment, while delta(15)N signatures exhibited a different pattern. It significantly depleted (15)N (y = -0.66x + 0.82, R (2) = 0.57, P < 0.0001) during the initial 7 months while showing (15)N enrichments in the remaining 13 months (y = 0.10x - 4.23, R (2) = 0.32, P < 0.0001). Statistically, litter decomposition has little impact on concentrations of soil organic C and alkali-soluble N and available P in the top soil. This indicates that nutrient return to the topsoil through litter decomposition is limited and that C cycling decoupled from N cycling during decomposition in this subtropical plantation in southern China
A unified approach to combinatorial key predistribution schemes for sensor networks
There have been numerous recent proposals for key predistribution schemes for wireless sensor networks based on various types of combinatorial structures such as designs and codes. Many of these schemes have very similar properties and are analysed in a similar manner. We seek to provide a unified framework to study these kinds of schemes. To do so, we define a new, general class of designs, termed “partially balanced t-designs”, that is sufficiently general that it encompasses almost all of the designs that have been proposed for combinatorial key predistribution schemes. However, this new class of designs still has sufficient structure that we are able to derive general formulas for the metrics of the resulting key predistribution schemes. These metrics can be evaluated for a particular scheme simply by substituting appropriate parameters of the underlying combinatorial structure into our general formulas. We also compare various classes of schemes based on different designs, and point out that some existing proposed schemes are in fact identical, even though their descriptions may seem different. We believe that our general framework should facilitate the analysis of proposals for combinatorial key predistribution schemes and their comparison with existing schemes, and also allow researchers to easily evaluate which scheme or schemes present the best combination of performance metrics for a given application scenario
CO observations of major merger pairs at z=0: Molecular gas mass and star formation
We present CO observations of 78 spiral galaxies in local merger pairs. These
galaxies representa subsample of a Ks-band selected sample consisting of 88
close major-merger pairs (HKPAIRs), 44 spiral-spiral (S+S) pairs and 44
spiral-elliptical (S+E) pairs, with separation kpc and mass ratio
<2.5. For all objects, the star formation rate (SFR) and dust mass were derived
from HERSCHEL PACS and SPIRE data, and the atomic gas mass, MHI, from the Green
Bank Telescope HI observations. The complete data set allows us to study the
relation between the gas (atomic and molecular) mass, dust mass and SFR in
merger galaxies. We derive the molecular gas fraction (MH2/M*),
molecular-to-atomic gas mass ratio (MH2/MHI), gas-to-dust mass ratio and SFE
(=SFR/MH2) and study their dependences on pair type (S+S compared to S+E),
stellar mass and the presence of morphological interaction signs. We find an
overall moderate enhancements (~2x) in both molecular gas fraction (MH2/M*),
and molecular-to-atomic gas ratio (MH2/MHI) for star-forming galaxies in
major-merger pairs compared to non-interacting comparison samples, whereas no
enhancement was found for the SFE nor for the total gas mass fraction
(MHI+MH2)/M*. When divided into S+S and S+E, low mass and high mass, and with
and without interaction signs, there is a small difference in SFE, moderate
difference in MH2/M*, and strong differences in MH2/MHI between subsamples. For
MH2/MHI, the difference between S+S and S+E subsamples is 0.69+-0.16 dex and
between pairs with and without interaction signs is 0.53+-0.18 dex. Together,
our results suggest (1) star formation enhancement in close major-merger pairs
occurs mainly in S+S pairs after the first close encounter (indicated by
interaction signs) because the HI gas is compressed into star-forming molecular
gas by the tidal torque; (2) this effect is much weakened in the S+E pairs.Comment: Accepted in A&A, 19 page
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