511 research outputs found
Magnetic Properties of the low dimensional spin system (VO)PO: ESR and susceptibility
Experimental results on magnetic resonance (ESR) and magnetic susceptibility
are given for single crystalline (VO)PO. The crystal growth
procedure is briefly discussed. The susceptibility is interpreted numerically
using a model with alternating spin chains. We determine =51 K and
=0.2. Furthermore we find a spin gap of meV from our ESR
measurements. Using elastic constants no indication of a phase transition
forcing the dimerization is seen below 300 K.Comment: 7 pages, REVTEX, 7 figure
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Transplantation of progenitor cells and regeneration enhancement in acute myocardial infarction - (TOPCARE-AMI)
Background - Experimental studies suggest that transplantation of blood-derived or bone marrow–derived progenitor cells beneficially affects postinfarction remodeling. The safety and feasibility of autologous progenitor cell transplantation in patients with ischemic heart disease is unknown
Spin correlations and Dzyaloshinskii-Moriya interaction in CsCuCl
We report on electron spin resonance (ESR) studies of the spin relaxation in
CsCuCl. The main source of the ESR linewidth at temperatures K is attributed to the uniform Dzyaloshinskii-Moriya interaction. The
vector components of the Dzyaloshinskii-Moriya interaction are determined from
the angular dependence of the ESR spectra using a high-temperature
approximation. Both the angular and temperature dependence of the ESR linewidth
have been analyzed using a self-consistent quantum-mechanical approach. In
addition analytical expressions based on a quasi-classical picture for spin
fluctuations are derived, which show good agreement with the quantum-approach
for temperatures K. A small modulation of the
ESR linewidth observed in the -plane is attributed to the anisotropic
Zeeman interaction, which reflects the two magnetically nonequivalent Cu
positions
Modern technologies of adaptation young specialists in the organization
In this article the main directions and technologies of adaptation of young specialists are considered. The author has revealed new technology of adaptation of young specialists which will allow new employees to feel more comfortably on a new workplace, to join collective, and also will lead to reduction of a dissatisfaction and turnover of staff at an initial stage of adaptation
Codes and finite geometries
We explore the connections between finite geometry and algebraic coding theory, giving a rather full account of the Reed-Muller and generalized Reed-Muller codes. Some of the results and many of the proofs are new but this is largely an expository effort that relies heavily on the work of Delsarte et al. and of Charpin. The necessary geometric background is sketched before we begin the discussion of the Reed-Muller codes and their p-ary analogues. We prove all the classical results concerning these codes and include a discussion of the group-algebra approach and prove Berman's theorem characterizing the codes as powers of the radical. Included also is a discussion of the characterization of affine-invariant cyclic codes given by Kasami, Lin and Peterson and its generalization by Delsarte. our theme throughout this work is the relationship between these codes and the codes coming from both affine and projective geometries. The final section develops the theory in the more difficult case in which the field is not of prime order, here must look at subfield subcodes - which complicates the connection with the geometric codes, which are codesover the prime subfield of the field of the geometry
The stable phases of the Cs2CuCl4-xBrx mixed systems
Starting from Cs2CuCl4 and Cs2CuBr4 our project focuses on the growth of the
Cs2CuCl4-xBrx mixed crystals from aqueous solution and the investigation of the
occurring structural variations. The well known orthorhombic structure (space
group Pnma) of the end members of this system is interrupted within the
intermediate composition range Cs2CuCl3Br1 - Cs2CuCl2Br2, if the growth takes
place at room temperature. Within this range a new tetragonal phase is found
(space group I4/mmm). However, in case the growth temperature will be increased
to 50 {\deg}C, the existence of the orthorhombic structure can be extended over
the whole Cs2CuCl4-xBrx mixed system. A detailed analysis of the composition
dependence of the lattice parameters is used to draw conclusions on the
incorporation of Cl- and Br-ions at different sites which is important for the
magnetic interactions between the Cu-ions.Comment: 16 pages,8 figure
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