Integrable open supersymmetric U model with boundary impurity

An integrable version of the supersymmetric U model with open boundary conditions and an impurity situated at one end of the chain is introduced. The model is solved through the algebraic Bethe ansatz method and the Bethe ansatz equations are obtained.Comment: RevTeX, 8 pages, no figures, final version to appear in Phys. Lett.

The carbon dioxide emissions of firms:a spatial analysis

In order to gain a greater understanding of firms' 'environmental behaviour' this paper explores the factors that influence firms' emissions intensities and provides the first analysis of the determinants of firm level carbon dioxide (CO2) emissions. Focussing on Japan, the paper also examines whether firms' CO2 emissions are influenced by the emissions of neighbouring firms and other possible sources of spatial correlation. Results suggest that size, the capital-labour ratio, R&D expenditure, the extent of exports and concern for public profile are the key determinants of CO2 emissions. Local lobbying pressure, as captured by regional community characteristics, does not appear to play a role, however emissions are found to be spatially correlated. This raises implications for the manner in which the environmental performance of firms is modelled in future

Entropy engineering in inorganic non-metallic glass

Advances in developing high entropy alloys and ceramics with improved physical properties have greatly broadened their application field from aerospace industry, public transportation to nuclear plants. In this review, we describe the concept of entropy engineering as applicable to inorganic non-metallic glasses, especially for tailoring and enhancing their mechanical, electrical, and optical properties. We also present opportunities and challenges in calculating entropy of inorganic non-metallic glass systems, correlating entropy to glass formation, and in developing functional inorganic non-metallic glasses via the entropy concept

InAs Photodiodes for 3.43 mu(text)m Radiation Thermometry

We report an evaluation of an epitaxially grown uncooled InAs photodiode for the use in radiation thermometry. Radiation thermometry measurements was taken using the photodiode covered blackbody temperatures of 50 °C-300 °C. By determining the photocurrent and signal-to-noise ratio, the temperature error of the measurements was deduced. It was found that an uncooled InAs photodiode, with the peak and cutoff wavelengths of 3.35 and 3.55 μm, respectively, measured a temperature of 50 °C, with an error of 0.17 °C. Many plastics have C -H molecular bond absorptions at 3.43 μm and hence radiate thermally at this wavelength. Our results suggest that InAs photodiodes are well suited to measure the temperature of plastics above 50 °C. When tested with a narrow bandpass filter at 3.43 μm and blackbody temperatures from 50 °C-300 °C, the InAs photodiode was also found to produce a higher output photocurrent, compared with a commercial PbSe detectors

An InGaAlAs-InGaAs two-color photodetector for ratio thermometry

We report the evaluation of a molecular-beam epitaxy grown two-color photodetector for radiation thermometry. This two-color photodetector consists of two p+in+ diodes, an In0.53Ga0.25Al0.22As (hereafter InGaAlAs) p+in+ diode, which has a cutoff wavelength of 1180 nm, and an In0.53Ga0.47As (hereafter InGaAs) p+in+ diode with a cutoff wavelength of 1700 nm. Our simple monolithic integrated two-color photodetector achieved comparable output signal and signal-to-noise (SNR) ratio to that of a commercial two-color Si-InGaAs photodetector. The InGaAlAs and InGaAs diodes detect blackbody temperature as low as 275°C and 125°C, respectively, with an SNR above 10. The temperature errors extracted from our data are 4°C at 275°C for the InGaAlAs diode and 2.3°C at 125°C for the InGaAs diode. As a ratio thermometer, our two-color photodetector achieves a temperature error of 12.8°C at 275°C, but this improves with temperature to 0.1°C at 450°C. These results demonstrated the potential of InGaAlAs-InGaAs two-color photodetector for the development of high performance two-color array detectors for radiation thermometry and thermal imaging of hot objects

Ground-state properties of tubelike flexible polymers

In this work we investigate structural properties of native states of a simple model for short flexible homopolymers, where the steric influence of monomeric side chains is effectively introduced by a thickness constraint. This geometric constraint is implemented through the concept of the global radius of curvature and affects the conformational topology of ground-state structures. A systematic analysis allows for a thickness-dependent classification of the dominant ground-state topologies. It turns out that helical structures, strands, rings, and coils are natural, intrinsic geometries of such tubelike objects

Generalized Farey trees, transfer Operators and phase transitions

We consider a family of Markov maps on the unit interval, interpolating between the tent map and the Farey map. The latter map is not uniformly expanding. Each map being composed of two fractional linear transformations, the family generalizes many particular properties which for the case of the Farey map have been successfully exploited in number theory. We analyze the dynamics through the spectral analysis of generalized transfer operators. Application of the thermodynamic formalism to the family reveals first and second order phase transitions and unusual properties like positivity of the interaction function.Comment: 39 pages, 10 figure

Skyrmion Excitation in Two-Dimensional Spinor Bose-Einstein Condensate

We study the properties of coreless vortices(skyrmion) in spinor Bose-Einstein condensate. We find that this excitation is always energetically unstable, it always decays to an uniform spin texture. We obtain the skyrmion energy as a function of its size and position, a key quantity in understanding the decay process. We also point out that the decay rate of a skyrmion with high winding number will be slower. The interaction between skyrmions and other excitation modes are also discussed.Comment: 5 pages, 4 figures, final version published in Phys. Rev.