Search results for "Functions"
showing 10 items of 1066 documents
Six-parameters deformations of fourth order Peregrine breather solutions of the NLS equation.
2013
We construct solutions of the focusing NLS equation as a quotient of two determinants. This formulation gives in the case of the order 4, new deformations of the Peregrine breather with 6 real parameters. We construct families of quasi-rational solutions of the NLS equation and describe the apparition of multi rogue waves. With this method, we construct the analytical expressions of deformations of the Peregrine breather of order 4 with 6 real parameters and plot different types of rogue waves.
Degenerate determinant representation of solutions of the NLS equation, higher Peregrine breathers and multi-rogue waves.
2012
We present a new representation of solutions of the focusing NLS equation as a quotient of two determinants. This work is based on a recent paper in which we have constructed a multi-parametric family of this equation in terms of wronskians. This formulation was written in terms of a limit involving a parameter. Here we give a very compact formulation without presence of a limit. This is a completely new result which gives a very efficient procedure to construct families of quasi-rational solutions of the NLS equation. With this method, we construct Peregrine breathers of orders N=4 to 7 and multi-rogue waves associated by deformation of parameters.
Determinant representation of NLS equation, Ninth Peregrine breather and multi-rogue waves
2012
This article is a continuation of a recent paper on the solutions of the focusing NLS equation. The representation in terms of a quotient of two determinants gives a very efficient method of determination of famous Peregrine breathers and its deformations. Here we construct Peregrine breathers of order $N=9$ and multi-rogue waves associated by deformation of parameters. The analytical expression corresponding to Peregrine breather is completely given.
Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.
2012
We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…
Respiratory proteins in Sipunculus nudus--implications for phylogeny and evolution of the hemerythrin family.
2009
Three major classes of respiratory proteins are known, hemoglobin, molluscan and arthropod hemocyanin, and hemerythrin (Hr). Similar to hemoglobin, respiratory Hr is packed into erythrocytes floating in the coelomic fluid and is only known from sipunculids, brachiopods, and priapulids. Owing to this scattered distribution, the presence of Hr is generally assumed to be the plesiomorphic condition without phylogenetic importance. By sequencing 2000 Expressed Sequence Tags (ESTs) from Sipunculus nudus, we found 75 Hr-coding ESTs assembled to 20 cDNA contigs classified as four distinct Hr isoforms: three polymeric Hrs (subunit A, A', and B) and the monomeric myo-hemerythrin (myoHr). Phylogeneti…
NATURAL SELECTION AND THE ORGAN-SPECIFIC DIFFERENTIATION OF HIV-1 V3 HYPERVARIABLE REGION
2004
The existence of organ-specific HIV-1 populations within infected hosts has been studied for many years; nonetheless results reported by different authors are somewhat discrepant. To tackle this problem, we used a population genetics approach to analyze previously published data from the V3 hypervariable region of the envelope env gene. Our results are compatible with a population subdivision by organs in 95% of individuals analyzed at autopsy. In addition, populations infecting the nervous system and testicles clearly appear as differentiated subsets of the so-called macrophage-tropic variants. Liver and kidney may harbor differentiated populations as well. Although it is widely accepted t…
Comparative Sequence Analysis ofMycobacterium lepraeand the New Leprosy-CausingMycobacterium lepromatosis
2009
ABSTRACTMycobacterium lepromatosisis a newly discovered leprosy-causing organism. Preliminary phylogenetic analysis of its 16S rRNA gene and a few other gene segments revealed significant divergence fromMycobacterium leprae, a well-known cause of leprosy, that justifies the status ofM. lepromatosisas a new species. In this study we analyzed the sequences of 20 genes and pseudogenes (22,814 nucleotides). Overall, the level of matching of these sequences withM. lepraesequences was 90.9%, which substantiated the species-level difference; the levels of matching for the 16S rRNA genes and 14 protein-encoding genes were 98.0% and 93.1%, respectively, but the level of matching for five pseudogenes…
Nucleon and nuclear spin structure functions
1997
Nuclear effects in polarized inelastic electron scattering off polarized $^3He$ and polarized $^2H$ are discussed; in the resonance region, Fermi motion effects are found to be much larger than in deep inelastic scattering. It is shown that improperly describing nuclear dynamics would lead to the extraction of unreliable neutron spin structure functions; on the other hand side, simple and workable equations, relating the Gerasimov -- Drell -- Hearn Integral for the neutron to the corresponding quantity for $^3He$ and $^2H$, are proposed. Nuclear effects in the recent E143 data are estimated by a proper procedure.
The importance of kinematic twists and genuine saturation effects in dijet production at the Electron-Ion Collider
2021
We compute the differential yield for quark anti-quark dijet production in high-energy electron-proton and electron-nucleus collisions at small $x$ as a function of the relative momentum $\boldsymbol{P}_\perp$ and momentum imbalance $\boldsymbol{k}_\perp$ of the dijet system for different photon virtualities $Q^2$, and study the elliptic and quadrangular anisotropies in the relative angle between $\boldsymbol{P}_\perp$ and $\boldsymbol{k}_\perp$. We review and extend the analysis in [1], which compared the results of the Color Glass Condensate (CGC) with those obtained using the transverse momentum dependent (TMD) framework. In particular, we include in our comparison the improved TMD (ITMD…
Model nuclear energy density functionals derived from ab initio calculations
2020
We present the first application of a new approach, proposed in [Journal of Physics G: Nuclear and Particle Physics, 43, 04LT01 (2016)] to derive coupling constants of the Skyrme energy density functional (EDF) from ab initio Hamiltonian. By perturbing the ab initio Hamiltonian with several functional generators defining the Skyrme EDF, we create a set of metadata that is then used to constrain the coupling constants of the functional. We use statistical analysis to obtain such an ab initio-equivalent Skyrme EDF. We find that the resulting functional describes properties of atomic nuclei and infinite nuclear matter quite poorly. This may point out to the necessity of building up the ab init…