Quantum dense coding over Bloch channels

Dynamics of coded information over Bloch channels is investigated for different values of the channel's parameters. We show that, the suppressing of the travelling coded information over Bloch channel can be increased by decreasing the equilibrium absolute value of information carrier and consequently decreasing the distilled information by eavesdropper. The amount of decoded information can be improved by increasing the equilibrium values of the two qubits and decreasing the ratio between longitudinal and transverse relaxation times. The robustness of coded information in maximum and partial entangled states is discussed. It is shown that the maximum entangled states are more robust than the partial entangled state over this type of channels

The Study of the Interac tion between Uranium Monosulphide and Nitrogen

The study of the process of interaction between nitrogen and nearly stoichiometric uranium monosulphide reveals at least three distinct stages. The first one (200-580° C) is characterized by limited interstitial dissolution of nitrogen in th e lattice. At approximately 580° C , US starts to react with N 2 yielding uranium sulphonitride of the composition U 2S 2Ny. Above 1200° C U2S 2N y decomposes into US and U 2S2 _ xNy. The X-ray powder diffraction m ethod was used in order to derive the most probable atomic positions in the crystal structure of U2S2N

The Crystal Structure of TiCuHg2

X-Ray studies in the ternary system Ti-Cu-Hg revealed the existence of a new phase of the composition TiCuHg2. The cubic unit cell has a lattice parameter a = 6.155 A and conta ins appr. 3 formula units. The crystal structure was determined from x-ray powder diffraction data and found to belong to the ordered B 32 structure type. The density measurements indicate that the structure is only 710/o filled

The Crystal Structure of TiCuHg2

X-Ray studies in the ternary system Ti-Cu-Hg revealed the existence of a new phase of the composition TiCuHg2. The cubic unit cell has a lattice parameter a = 6.155 A and conta ins appr. 3 formula units. The crystal structure was determined from x-ray powder diffraction data and found to belong to the ordered B 32 structure type. The density measurements indicate that the structure is only 710/o filled

The Homogeneity Range in the System UP(O)

A large number of samples of uranium monorphosphide were prepared by direct reaction between uranium filings and red phosphor us, followed by homogenization in a high temperature furnace (Degussa) at 1200-1300 °c and a pres,sure of 10-4 Torr (1 Torr = 101.325/760 kPa). Samples were analyzed for uranium, phosphorus and nitrogen, assuming that the difference is oxygen. The oxygen content wa.s found to vary from sample to sample, ranging from 0.54 (min.) up to 7.10 wt. O/o (max.). X-ray analysis did not indicate the presence of U02• The amount of oxygen or nitrogen was not controled in advance, but final results ensured the working hypothesis, since the analytical data were in acordance with the X-ray powder diagrams

On the Existence of the FCC Uranium

Diffusion studies in the system U - S, employing the couples U - US, U - US2 and U -- U3S5 revealed the existence of new FCC phase with the composition ranging from approx. U20S to U8S. The lattice parameter of the phase as obta ~ned in the diffusion couple is 4.95 ± 0.01 A. The same phase can be also obtained by the arc melting of the mixtures of U and US or U and S in the appropriate proportions, if followed by the heat treatment at 1900 °c during at least four hours. It is believed that this is a crystal structure modification of uranium stabilized by the addition of a small quantity of nonmetal atoms, where S and N play a mayor role. The same phase has been obtained through the addition of approximately 9 a/o of Se, Te, P, As, Sb, Bi, C and Si. Although the effect of the stabilization is not yet completely understood all samples contain a FCC phase and posess virtually the same lattice parameter as the phase containing sulphur. The experimental density amounts 14.21 g cm·:i. The calculated density is 13.21 g cm-3

Magnetic structures of Mn3-xFexSn2: an experimental and theoretical study

We investigate the magnetic structure of Mn3-xFexSn2 using neutron powder diffraction experiments and electronic structure calculations. These alloys crystallize in the orthorhombic Ni3Sn2 type of structure (Pnma) and comprise two inequivalent sites for the transition metal atoms (4c and 8d) and two Sn sites (4c and 4c). The neutron data show that the substituting Fe atoms predominantly occupy the 4c transition metal site and carry a lower magnetic moment than Mn atoms. Four kinds of magnetic structures are encountered as a function of temperature and composition: two simple ferromagnetic structures (with the magnetic moments pointing along the b or c axis) and two canted ferromagnetic arrangements (with the ferromagnetic component pointing along the b or c axis). Electronic structure calculations results agree well with the low-temperature experimental magnetic moments and canting angles throughout the series. Comparisons between collinear and non-collinear computations show that the canted state is stabilized by a band mechanism through the opening of a hybridization gap. Synchrotron powder diffraction experiments on Mn3Sn2 reveal a weak monoclinic distortion at low temperature (90.08 deg at 175 K). This lowering of symmetry could explain the stabilization of the c-axis canted ferromagnetic structure, which mixes two orthorhombic magnetic space groups, a circumstance that would otherwise require unusually large high-order terms in the spin Hamiltonian.Comment: 11 pages, 13 figure

A Simulation Model Outline for the Hungarian Forest Sector

The model presented in this paper describes the structure of the Hungarian forest sector. The planning of the sector at a national and company level as well as the mechanism of regulation concerning production, investments, and consumption are also investigated and the exports and imports linked. One of the most important objectives is to create this model in order to study the behavior of the system so as to aid the decision making both in strategic and tactical areas. Apart from forestry the model also includes the wood processing activities