Search results for "INTERACTION"
showing 10 items of 5710 documents
No-core configuration-interaction model for the isospin- and angular-momentum-projected states
2016
[Background] Single-reference density functional theory is very successful in reproducing bulk nuclear properties like binding energies, radii, or quadrupole moments throughout the entire periodic table. Its extension to the multi-reference level allows for restoring symmetries and, in turn, for calculating transition rates. [Purpose] We propose a new no-core-configuration-interaction (NCCI) model treating properly isospin and rotational symmetries. The model is applicable to any nucleus irrespective of its mass and neutron- and proton-number parity. It properly includes polarization effects caused by an interplay between the long- and short-range forces acting in the atomic nucleus. [Metho…
Solution of the Skyrme-Hartree–Fock–Bogolyubovequations in the Cartesian deformed harmonic-oscillator basis. (VIII) hfodd (v2.73y): A new version of …
2017
We describe the new version (v2.73y) of the code HFODD which solves the nuclear Skyrme Hartree-Fock or Skyrme Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we have implemented the following new features: (i) full proton-neutron mixing in the particle-hole channel for Skyrme functionals, (ii) the Gogny force in both particle-hole and particle-particle channels, (iii) linear multi-constraint method at finite temperature, (iv) fission toolkit including the constraint on the number of particles in the neck between two fragments, calculation of the interaction energy between fragments, and calculation of the nuclear and Coulomb ene…
High‐nuclearity mixed‐valence magnetic clusters : A general solution of the double exchange problem
1996
We report here a general solution of the double‐exchange problem in the high‐nuclearity mixed valence systems containing arbitrary number P of the electrons delocalized over the network of N (P<N) localized spins. The developed approach is based on the successive (chainlike) spin‐coupling scheme and takes full advantage from the quantum angular momentum theory. In the framework of this approach the closed‐form analytical expressions are deduced for the matrix elements of the double exchange interaction, two‐electron transfer, and three‐center interaction that can be referred to as the potential exchange transfer. For the arbitrary nuclearity mixed‐valence systems the matrix elements of all …
Constant, cycling, hot and cold thermal environments: strong effects on mean viability but not on genetic estimates
2012
It has frequently been suggested that trait heritabilities are environmentally sensitive, and there are genetic trade-offs between tolerating different environments such as hot and cold or constant and fluctuating temperatures. Future climate predictions suggest an increase in both temperatures and their fluctuations. How species will respond to these changes is uncertain, particularly as there is a lack of studies which compare genetic performances in constant vs. fluctuating environments. In this study, we used a nested full-sib/half-sib breeding design to examine how the genetic variances and heritabilities of egg-to-adult viability differ at high and low temperatures with and without da…
Surface charge fine tuning of reversed-phase/weak anion-exchange type mixed-mode stationary phases for milder elution conditions.
2015
A series of new mixed-mode reversed-phase/weak anion-exchange (RP/WAX) phases have been synthesized by immobilization of N-undecenyl-3-α-aminotropane onto thiol-modified silica gel by thiol-ene click chemistry and subsequent introduction of acidic thiol-endcapping functionalities of different type and surface densities. Click chemistry allowed to adjust a controlled surface concentration of the RP/WAX ligand in such a way that a sufficient quantity of residual thiols remained unmodified which have been capped by thiol click with either 3-butenoic acid or allylsulfonic acid as co-ligands. In another embodiment, performic acid oxidation of N-undecenyl-3-α-aminotropane-derivatized thiol-modifi…
Nonlinear response of a batch BZ oscillator to the addition of the anionic surfactant sodium dodecyl sulfate.
2007
The response of the Belousov-Zhabotinsy (BZ) system to the addition of increasing amounts of the anionic surfactant sodium dodecyl sulfate (SDS) was monitored at 25.0 degrees C in stirred batch conditions. The presence of SDS in the reaction mixture influences the oscillatory parameters, i.e., induction period and oscillation period, to an extent that depends on the surfactant concentration. The experimental results have shown that the induction period increases slightly on increasing surfactant concentration and, then, a further increase in the [SDS] leads to an enhancement while the oscillation period increases monotonously on increasing SDS concentration. It has been proposed that the re…
CH-Directed Anion-π Interactions in the Crystals of Pentafluorobenzyl-Substituted Ammonium and Pyridinium Salts
2010
Simple pentafluorobenzyl-substituted ammonium and pyridinium salts with different anions can be easily obtained by treatment of the parent amine or pyridine with the respective pentafluorobenzyl halide. Hexafluorophosphate is introduced as the anion by salt metathesis. In the case of the ammonium salt 4, water co-crystallisation seems to suppress effective anion-pi interactions of bromide with the electron-deficient aromatic system, whereas with salts 5 and 6 such interactions are observed despite the presence of water. However, due to asymmetric hydrogen-bonding interactions with ammonium side chains, the anion of 5 is located close to the rim of the pentafluorophenyl group (eta(1) interac…
N-Propyl-N′-2-pyridylurea-modified silica as mixed-mode stationary phase with moderate weak anion exchange capacity and pH-dependent surface charge r…
2018
Herein, we present a novel silica-based stationary phase modified with N-propyl-N'-2-pyridylurea selector. Due to the weakly basic properties of the pyridine selector and the presence of residual silanols after selector immobilization, a zwitterionic surface with a pI observed at approximately pH 5.5 was measured by electrophoretic light scattering in pH-dependent ζ-potential determinations. The capability of the new N-propyl-N'-2-pyridylurea-modified silica to serve as mixed-mode stationary phase was investigated. For this purpose, it was characterized under RP and HILIC conditions using test mixtures. Subsequent classification of this stationary phase in comparison to in-house and commerc…
Stable-bond polymeric reversed-phase/weak anion-exchange mixed-mode stationary phases obtained by simultaneous functionalization and crosslinking of …
2019
Abstract A polymeric reversed-phase/weak anion exchange (Poly-RP/WAX) mixed-mode stationary phase has been prepared by coating of a poly(3-mercaptopropyl)methylsiloxane film on vinyl-modified silica (100 A, 5 μm) and simultaneous in situ functionalization with N-(10-undecenoyl)-3-aminoquinuclidine as well as crosslinking to the vinyl silica surface by solventless thiol-ene double click reaction. Such bonding chemistry showed greatly enhanced stability compared to brush-type analogs with bifunctional siloxane bonding to silica. Solid-state 29Si-CP/MAS NMR confirmed the immobilization of the siloxane layer. pH-Dependent ζ-potential determinations revealed a high anion-exchange capacity over t…
Comparative analysis of the electrostatics of the binding of cationic proteins to vesicles: Asymmetric location of anionic phospholipids
2009
The role of electrostatics is studied in the adsorption of cationic proteins to zwitterionic phosphatidylcholine (PC) and anionic PC/phosphatidylglycerol (PG) mixed small unilamellarvesicles (SUVs). For model proteins the interaction is monitored vs. PG content at low ionic strength. The adsorption of lysozyme and myoglobin (isoelectric point, pl 7-11) is investigated in SUVs, along with changes of the fluorescence emission spectra of the cationic proteins, via their adsorption on SUVs. In the Gouy-Chapman formalism, the activity coefficient goes with the square of charge number. Deviations from the ideal model could indicate the asymmetric location of the anionic phospholipid in the bilaye…