Thermal entanglement and teleportation in a two-qubit Heisenberg chain with Dzyaloshinski-Moriya anisotropic antisymmetric interaction

Thermal entanglement of a two-qubit Heisenberg chain in presence of the Dzyaloshinski-Moriya (DM) anisotropic antisymmetric interaction and entanglement teleportation when using two independent Heisenberg chains as quantum channel are investigated. It is found that the DM interaction can excite the entanglement and teleportation fidelity. The output entanglement increases linearly with increasing value of input one, its dependences on the temperature, DM interaction and spin coupling constant are given in detail. Entanglement teleportation will be better realized via antiferromagnetic spin chain when the DM interaction is turned off and the temperature is low. However, the introduction of DM interaction can cause the ferromagnetic spin chain to be a better quantum channel for teleportation. A minimal entanglement of the thermal state in the model is needed to realize the entanglement teleportation regardless of antiferromagnetic or ferromagnetic spin chains.Comment: 1 tex;5eps. accepted by Physical Review

Round-Tube and Microchannel Heat Exchanger Modeling at Wet Air Condition

This paper discusses the modeling of round tube plate fin heat exchanger (RTPF) and microchannel heat exchanger (MCHX) under wet air conditions. Â The heat exchanger models are based on finite volume method. In each control volume, the empirical heat transfer and pressure drop correlations for refrigerant and air are adopted and the effectiveness-NTU method is applied for heat transfer calculation. For the round tube heat exchanger, the tube circuiting is considered. For microchannel heat exchanger, both uniform distribution and maldistribution among parallel microchannel tubes are investigated and compared. When the air dew point temperature is higher than the tube wall temperature, dehumidification occurs. Two methods are compared to simulate the wet air condition: (1) the air side is simulated based on the total enthalpy method; (2) the air side is simulated based on simultaneous heat and mass transfer method. The heat exchanger models are validated against the experimental results of a 2.5 ton residential air-conditioning system in Air-Conditioning and Refrigeration Center at University of Illinois. The experiment was conducted based on AHSI/AHRI standard 210/240 at Conditions A, B (wet coil) and C (dry coil). The baseline system contains round-tube evaporator, while the round-tube evaporator is later replaced with a microchannel evaporator. The microchannel heat exchanger is tested at both direct expansion and flash gas bypass conditions. The models show good accuracy compared to the experimental results. The capacities are within 2% while the saturation temperatures are within 2oC

The private capacity of quantum channels is not additive

Recently there has been considerable activity on the subject of additivity of various quantum channel capacities. Here, we construct a family of channels with sharply bounded classical, hence private capacity. On the other hand, their quantum capacity when combined with a zero private (and zero quantum) capacity erasure channel, becomes larger than the previous classical capacity. As a consequence, we can conclude for the first time that the classical private capacity is non-additive. In fact, in our construction even the quantum capacity of the tensor product of two channels can be greater than the sum of their individual classical private capacities. We show that this violation occurs quite generically: every channel can be embedded into our construction, and a violation occurs whenever the given channel has larger entanglement assisted quantum capacity than (unassisted) classical capacity.Comment: 4+4 pages, 2 eps figures. V2 has title and abstract changed; its new structure reflects the final version of a main paper plus appendices containing mathematical detail

(meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetra­azacyclo­tetra­deca­ne)copper(II) bis­(O,S-dibenzyl dithio­phosphate)

In the crystal structure of the title compound, [Cu(C16H36N4)](C14H14O2PS2)2, the CuII atom is located on an inversion center and is chelated by four N atoms of the macrocyclic meso-5,5,7,12,12,14- hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­decane ligand in a square-planar geometry, with Cu—N distances of 2.013 (3) and 2.014 (3) Å. In the crystal structure, one O,S-dibenzyl dithio­phosphate counter-anion links with the CuII complex cation through N—H⋯O and N—H⋯S hydrogen bonding. During the synthesis, the structure of the anion re-arranged from O,O′-dibenzyl dithio­phosphate in the starting material to O,S-dibenzyl dithio­phosphate in the title compound

(5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene)nickel(II) bis­[O,O′-bis­(4-tert-butyl­phen­yl) dithio­phosphate]

The title salt, [Ni(C16H32N4)](C20H26O2PS2)2, comprises a centrosymmetric [Ni(Me6[14]dieneN4)]2+ dication (Me6[14]dieneN4 is 5,7,7,12,14,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene) and two O,O′-bis­(4-tert-butyl­phen­yl) dithio­phosphate anions. The NiII ion lies on an inversion centre and displays a slightly distorted NiN4 square-planar chelation arrangement with four N atoms from the Me6[14]dieneN4 macrocycle. Two S atoms from symmetry-related anions are located in pseudo-axial positions with respect to the NiII ion, with Ni⋯S distances of 3.2991 (7) Å. Inter­molecular N—H⋯S and C—H⋯S hydrogen bonds link the complex cation and pair of anions into a 1:2 type salt

(meso-5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetra­azacyclo­tetra­deca-4,11-diene)nickel(II) bis­[O,O′-bis(4-methyl­phen­yl) dithio­phosphate]

In the title compound, [Ni(C16H32N4)](C14H14O2PS2)2 or [Ni(trans[14]dien)][S2P(OC6H4Me-4)2]2, where trans[14]dien is meso-5,7,7,12,14,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­deca-4,11-diene, the NiII ion lies across a centre of inversion and is four-coordinated in a relatively undistorted square-planar arrangement by the four N atoms of the macrocyclic ligand trans[14]dien. The two O,O′-di(4-methyl­phen­yl)dithio­phos­phates act as counter-ions to balance the charge. Important geometric data include Ni—N = 1.9135 (16) and 1.9364 (15) Å

Improved Farmer\u27s Capasity Model of Private Forest Management: Studies in Ranggang Village, South Kalimantan

Farmer\u27s capacity is one of the important factors that determine the success of private forest management. However, the farmer\u27s capacity level in several places is still low so that potentially to inhibiting successful of private forests management practices. This study aims to analyze the factors that affect farmer\u27s capacity level of private forests management practices, and to formulate improved farmer\u27s capacity model of private forests management in Ranggang Village, South Kalimantan. The data was analyzed by Structural Equation Model (SEM) with the help of SmartPls 2.0 M3. Results showed (1) learning experience level directly affect to farmer\u27s capacity while farmer\u27s characteristics, external support, social and cultural environment supporting, the role of extension, and information availability indirectly affect to farmer\u27s capacity of private forests management in Ranggang Village, and (2) improved farmer\u27s capacity model can be done by improving the farmer\u27s learning experience through intensive, scheduled, and suistainable education, training and extension with stakeholders support