20,694 research outputs found
Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
We generalized the recently introduced new impurity solver based on the
diagrammatic expansion around the atomic limit and Quantum Monte Carlo
summation of the diagrams. We present generalization to the cluster of
impurities, which is at the heart of the cluster Dynamical Mean-Field methods,
and to realistic multiplet structure of a correlated atom, which will allow a
high precision study of actinide and lanthanide based compounds with the
combination of the Dynamical Mean-Field theory and band structure methods. The
approach is applied to both, the two dimensional Hubbard and t-J model within
Cellular Dynamical Mean Field method. The efficient implementation of the new
algorithm, which we describe in detail, allows us to study coherence of the
system at low temperature from the underdoped to overdoped regime. We show that
the point of maximal superconducting transition temperature coincides with the
point of maximum scattering rate although this optimal doped point appears at
different electron densities in the two models. The power of the method is
further demonstrated on the example of the Kondo volume collapse transition in
Cerium. The valence histogram of the DMFT solution is presented showing the
importance of the multiplet splitting of the atomic states.Comment: 12 pages, 4 figure
X-ray absorption spectra at the Ca-L-edge calculated within multi-channel multiple scattering theory
We report a new theoretical method for X-ray absorption spectroscopy (XAS) in
condensed matter which is based on the multi-channel multiple scattering theory
of Natoli et al. and the eigen-channel R-matrix method. While the highly
flexible real-space multiple scattering (RSMS) method guarantees a precise
description of the single-electron part of the problem, multiplet-like electron
correlation effects between the photo-electron and localized electrons can be
taken account for in a configuration interaction scheme. For the case where
correlation effects are limited to the absorber atom, a technique for the
solution of the equations is devised, which requires only little more
computation time than the normal RSMS method for XAS. The new method is
described and an application to XAS at the Ca -edge in bulk Ca, CaO
and CaF is presented.Comment: 10 pages, 4 figures, submitted to Phys. Rev.
The integrity of serial data highway systems
The Admiralty Surface Weapons Establishment (ASWE) have developed a Local Area Network System. This thesis describes the development of a replacement for this LAN system, based around 16 bit microprocessor hosts, as opposed to the minicomputers currently used. This change gave a substantial reduction in size, and allowed the new system to be installed on a ship and tested under operational conditions. Analysis of the data collected during the tests gave performance information on the ASWE system. The performance of this LAN is compared to that of other leading types of LAN. The design of a portable network controller/ monitor unit is presented, which may be manufactured as a standard controller for the ASWE Serial Highway
Charged particle multiplicity and momenta in -pair decays at 189 GeV
The charged particle multiplicity of W-pair decays is measured with the ALEPH detector at LEP at a cms energy of 189GeV. This is motivated by the study of possible colour reconnection effects in W-pairs where both decay hadronically. The average charged multiplicity of WW>qqqq is compared with predictions of fragmentation models tuned to measurements performed at the Z peak and with measured multiplicities in WW>qqlv events. It is compatible, both with models without implementation of colour reconnection, and with the models including colour reconnection that are studied here
THOUGHT AND MIND AS THE PROJECTION OF MENTAHOLOMORPHIC FIELDS BY THE BRAIN: A PROPOSED MECHANISM
This paper proposes a new understanding of the relationship between brain, mind and other biofields based on the emergent properties of the brain's parallel structure, which create a brain "laser." Several thalamocortical rhythms, including a 40 cycle per second oscillation associated with event scanning and a faster EEG rhythm found in healers and others. are hypothesized to give rise to coherent electromagnetic radiation, as well as multifaceted coherent radiation in the additional dimensions posited by string theory. These rhythms cause repetitive excitation of the sugar/protein coatings of the parallel axons of the thalamocortical columns. The synchronous excitation of these glycocalyxes of the parallel columns will cause similar chemical bonds to resonate and entrain one another, giving rise to coherent radiation. This electromagnetic/multifaceted radiation forms highly complex interference patterns (termed "mentaholomorphic fields~) when they interact with each other and the elecuomagnetic/multifaceted activity in the cortical layers. The resulting mentaholomorphic fields may be related to thought, mind and particular states of consciousness
Studies in the chemistry of the nitrogen-halogen bond
The reactions of diraethylchloramine with a variety of different substrates has been studied. With basic substrates such as hydrazine and the alkyl substituted hydrazines, dimethylchloramine acts as an oxidising agent, but with ammonia and the methylamines contrast was found with the corresponding NH(_2)Cl reactions. Simple nucleophillic attack of the amine on the diraethylchloramine nitrogen explains the products found in the reactions with CH(_3)NH(_2) and NH(_3), whilst dehydrohalegonation reaction accounts for the observed products. With dimethylamine a complex reaction occurs which is most probably intimately associated with the decomposition of (CH(_3))(_2)NCl itself. Dimethylchloramine reacts in two different ways with methyl esters of certain acids. On the one hand, esters typified by CH(_3)0S0(_2)F, and including CH(_3)0Cl0(_3), yielding a cationic species identified as (CH(_3))(_3)(^+)NCl. In this cation, the nitrogen chlorine bond possesses a slight dipole, the positive end of which is directed towards the chlorine atom, in accord with the (^36)Cl NQR absorption frequency of 56.09 MHz, found in the Cl0(^-)(_4), (CH(_3))(_3)(^+)3NCl Cl0(^-)(_4), being in excess of that found for Cl2 . The application of standard approximate methods to the observed coupling constants for the CIO4 and BP4 indicate that the bonding between the nitrogen and chlorine atoms in the cation involves an almost pure chlorine p orbital. The ion, (CH(_3))(_3)(^+)NCl, is precipitable from aqueous solutions of the chlorine trimethylaraine complex, (CH(_3))(_3)NCl(_2), by Cl0(^-)(_4) and BF(^-)(_4) ions. With the methyl halides, dimethylchloramme reacts to yield, with methyl bromide, the addition complex of trimethylaraine, (CH3)3NBrCl, the infra red spectrum of which fits well with the trends observed for other (CH3)3N (Halogen)2 addition complexes, whilst with methyl iodide, a novel tetramethylammonium pseudopolyhalide, (CH(_3))(_4)(^+)N[(CH(_3))(_2)N(ICl)(_2)](^-), forms. Dimethyl bromamine, (CH(_3))(_2)NBr, reacts in a similar way to (CH(_3))(_2)NCl, with alkylating agents, the unstable (CH(_3))(_3)(^+)NBr 0S02(_)F(^-) forms with CH(_3)0S0(_2)F and (CH(_3))(_2)NBr Cl0(^-)(_4) can be precipitated from aqueous solutions of the fluorosulphate by Cl0(^-)(_4) ions. With CH(_3)I, (CH(_3))(_2)NBr yields, in a similar way to (CH(_3))(_2)NCl, (CH(_3))(_4)(^4)N[(CH(_3))(_2)N(IBr(_2))](^-)
Educational television in Bophutatswana: Documentation and social assessment of the 'Edutel' project
Alien Registration- Cowan, Lee D. (Blaine, Aroostook County)
https://digitalmaine.com/alien_docs/27365/thumbnail.jp
- …