Spin control of 12B and 12N and the axial charge from their β-ray spin-alignment correlations

The spin manipulation technique by use of the β-NMR is further refined, based on the recent thorough studies of hyperfine interactions of ¹²B and ¹²N in Mg. By using this technique, the alignment correlation terms in the β-ray angular distribution of the A = 12 system are precisely measured, so that the axial charge is singled out to be y = 4.66 ± 0.06 (stat.) ± 0.13 (syst.) which shows clear mesonic enhancement over the impulse value. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of Quantizing Magnetic Field on Cyclotron Energy and Cyclotron Effective Mass in Size Quantized Films with Non-Parabolic Energy Band

The Fermi energy, cyclotron energy and cyclotron effective mass of degenerate electron gas in a sizeoquantized semiconductor thin film with non-parabolic energy bands are studied. The influences of quantizing magnetic field on these quantities in two-band approximation of the Kane model are investigated. It is shown that the Fermi energy oscillates in a magnetic field. The period and positions of these oscillations are found as a function of film thickness and concentration of electrons. Cyclotron energy and cyclotron effective mass are investigated as a function of film thickness in detail The results obtained here are compared with experimental data on GaAs quantum wells.     

Stability and Chaos of Two Coupled Bose-Einstein Condensates with Three-Body Interaction

We study the dynamics of two Bose-Einstein condensates （BECs） tunnel-coupled by a double-well potential. A real three-body interaction term is considered and a two-mode approximation is used to derive two coupled equations, which describe the relative population and relative phase. By solving the equations and analyzing the stability of the system, we find the stable stationary solutions for a constant atomic scattering length. When a periodically time- varying scattering length is applied, Melnikov analysis and numerical calculation demonstrate the existence of chaotic behavior and the dependence of chaos on the three-body interaction parameters.     

Hydrothermal synthesis of WO3·H2O with different nanostructures from 0D to 3D and their gas sensing properties

In this paper, WO₃·H₂O with different nanostructures from 0D to 3D were successfully synthesized via a simple yet cost-effective hydrothermal method with the assistance of surfactants. The structures and morphologies of products were investigated by XRD and SEM. Besides, we systematically explained the evolution process and formation mechanisms of different WO₃·H₂O morphologies. It is noted that both the kinds and amounts of surfactants strongly affect the formation of WO₃·H₂O crystals, as reflected in the tailoring of WO₃·H₂O morphologies. Furthermore, the gas sensing performance of the as-prepared samples towards methanol was also investigated. 3D flower-like hierarchical architecture displayed outstanding response to target gas among the four samples. We hoped our results could be of great benefit to further investigations of synthesizing different dimensional WO₃·H₂O nanostructures and their gas sensing applications.     

Viscosities and their correlations with structures of Cu–Ag melts

The viscosities of a series of Cu–Ag melts in a temperature range from 1473 K to nearly liquid temperatures are measured by using an oscillating viscometer. At the same temperature, the value of viscosity increases first with silver content increasing, and reaches a maximum value at the eutectic component Cu40Ag60, then decreases. All the temperature dependences of the viscosities of Cu–Ag melts conform with the Arrhenius equation. The parameters of correlation length D of the studied Cu–Ag melts are calculated according to the experimental results of x-ray diffraction. The temperature dependence of correlation length D shows an exponential decay function, which is similar to the Arrhenius equation. Based on the values of viscosities and correlation length D, a direct correlation between viscosity and liquid structure is found for the investigated Cu–Ag melts through comparative analysis.     

Isolation of fe charge states by ion implantation and their study by mössbauer spectroscopy

Matrix isolation of impurity atoms in a frozen rare-gas lattice is a well-known technique for the study of atoms in quasi-free states. The usual procedure consists of co-evaporating these atoms together with the matrix atoms and depositing them simultaneously on a cold substrate. Subsequently, the frozen samples can be studied by optical spectroscopy or, as has been proved more recently, by Mössbauer spectroscopy.

The technical limitations of the co-evaporation procedure narrow the application range of this method. We have therefore tried to develop the ion implantation technique as a suitable alternative to the co-evaporation. Ion implantation does not put any limitation on the species and the concentration of the isolated atoms; moreover, it is particularly suited for the isolation of radioactive impurities, which may be investigated by Mossbauer spectroscopy.

In a first series of experiments, we have implanted ⁵⁷Co into a frozen Xe matrix, hereby producing isolated Fe⁺ and Fe⁰ states by the electron capture decay of the implanted nuclei.¹ A second experiment was devoted to the study of ⁵⁷Fe implanted in solid O₂.² Due to the high reactivity of oxygen, it would have been impossible to produce this sample by co-evaoporation. Mössbauer data show some evidence that in this case Fe⁶⁺ states have been produced. The results of these experiments will be discussed and further perspectives will be sketched.     

Spectral-luminescent properties of γ-pyrilocyanines and their heteroanalogs with modified complex anions

Spectral-luminescent properties of γ-pyrilocyanines and their heteroanalogs with modified complex anions have been studied. It was shown that the fluorescence quantum yield in the series pyrilo-, thiapyrilo-, and selenopyrilocyanine decreased for mono-and trimethinecyanines as well as through substitution of TlCl₄⁻ for ClO₄⁻. This is likely due to the increased probability of singlet-triplet transfers under the influence of heavy atoms. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 666–671, September–October, 2008.     

Interaction of Methane with Single-Walled Carbon Nanotubes： Role of Defects,Curvature and Nanotubes Type

We investigate the interaction of single-walled carbon nanotubes （SWCNTs） and methane molecule from the first principles. Adsorption energies are calculated, and methane affinities for the typical semiconducting and metallic nanotubes are compared. We also discuss role of the structural defects and nanotube curvature on the adsorption capability of the SWCNTs. We could observe larger adsorption energies for the metallic CNTs in comparison with the semiconducting CNTs. The obtained results for the zig zag nanotubes with various diameters reveal that the adsorption energy is higher for nanotubes with larger diameters. For defected tubes the adsorption energies are calculated for various configurations such as methane molecule approaching to the defect sites pentagon, hexagon, and heptagon in the tube surface. The results show that the introduce defects have an important contribution to the adsorption mechanism of the methane on SWNTs.     

Products of distributions and collision of a δ-wave with a δ′-wave in a turbulent model

We study the possibility of collision of a δ-wave with a stationary δ′-wave in a model ruled by equation f (t)u _t+[u²?β(x?γ(t))u]_x = 0, where f, β and γ are given real functions and u = u(x, t) is the state variable. We adopt a solution concept which is a consistent extension of the classical solution concept. This concept is defined in the setting of a distributional product, which is not constructed by approximation processes. By a convenient choice of f, β and γ, we are able to distinguish three distinct dynamics for that collision, to which correspond phenomena of solitonic behaviour, scattering, and merging. Also, as a particular case, taking f = 2 and β = 0 we prove that the referred collision is impossible to arise in the setting of the inviscid Burgers equation. To show how this framework can be applied to other physical models, we included several results already obtained.     

Energy Density and Production Ratios of Baryon from QGP with Diquarks

At a very high temperature, the quark matter is a hot and dense matter under the colour deconfinement condition, and quarks can coalescent diquarks. Energy density of this system is figured out. A way to calculate baryon ratios produced from quark gluon plasma with diquarks in relativistic heavy ion collisions is presented.     

Interaction of binary cuprates with oxygen and water vapor at temperatures of 200–400°C

Interaction of binary cuprates with oxygen and water vapor at T = 200–400°C has been studied. It has been established that only compounds containing oxygen vacancy chains in their structure can absorb oxygen and moisture from annealing atmosphere. Absorption of oxygen brings about decrease in the lattice parameters while embedding of OH^? groups leads to their growth. In contrast to YBa₂Cu₃O _y , binary cuprates do not undergo phase transitions in interaction with the atmosphere. Saturation with water and formation of oxyhydroxides is followed by their hydrolytic decomposition involving formation of simpler oxides and hydroxides.     

Studies on the Interaction of Tricyclazole with β-cyclodextrin and human Serum Albumin by Spectroscopy

The interaction of tricyclazole (TCZ) with β-cyclodextrin (β-CD) and human serum albumin (HSA) were studied by fluorescence spectrum, UV-visible spectrum and second-order scattering technology. It was shown that TCZ has quite a strong ability to quench the fluorescence launching from HSA by reacting with it and forming a certain kind of new compound. The quenching and the energy transfer mechanisms were discussed, respectively. The binding constants and thermodynamic parameters at four different temperatures, the binding locality, and the binding power were obtained. The conformation of HSA was discussed by synchronous and three-dimensional fluorescence techniques. The inclusion reaction between β-CD and TCZ was explored by scattering method, the inclusion constants and the thermodynamic parameters at 297 K and 311 K were figured out, respectively. The mechanism of inclusion reaction was speculated and linkage among the toxicity of TCZ, the exterior environment and its concentration was attempted to explain on molecule level.     

Interaction of pair coherent state with a three-level Λ-type atom and generation of a modified Bessel-Gaussian state with a vortex structure

The evolution of a system state is derived based on the nonresonant interaction of a three-level "Λ" type atom with two cavity modes at a pair coherent state and two classic fields, and a cavity field state is analysed in detail under conditional detecting. It is found that the quantized modified Bessel-Gaussian states as well as the superposition states consisting of the quantized vortex states with different weighted coefficients may be prepared through carefully preparing an initial atomic state and appropriately adjusting the interaction time. The scheme provides an additional choice to realize the two-mode quantized vortex state within the context of cavity quantum electrodynamics (QED).     

Interaction of Anthracycline 3′-azido-epirubicin with Calf Thymus DNA via Spectral and Molecular Modeling Techniques

Anthracycline antibiotics are extensively applied to clinical antitumor therapy. The binding mode and mechanism of a new anthracycline 3′-azido-epirubicin (AEPI) with calf thymus deoxyribonucleic acid (ctDNA) were investigated employing multiple spectroscopy techniques in Tris-HCl buffer solution (pH 7.4). Effect of pH on the interaction was provided to determine the proper environment for whole research. Iodide quenching studies and fluorescence polarization measurement indicated that ctDNA quenched the fluorescence of AEPI significantly via intercalation binding mode. The binding constants and binding sites for the interaction were calculated. From binding constant dependence on the temperature, static quenching mechanism of AEPI by ctDNA was confirmed based on the Stern-Volmer equation. Additionally, the thermodynamic parameters for the reaction revealed that the van der Waals force and hydrogen bonding were the main acting forces in the binding process. Molecular modeling result indicated that the hydrogen bonding played a major role in the binding of AEPI to ctDNA.     

Mutual influence of hydrogen and vacancies in α-zirconium on the energy of their interaction with metal

We presents a first-principles investigation on the interaction energy of hydrogen and vacancies with α-zirconium. It is established that the presence of vacancies in zirconium increases the hydrogen–metal binding energy; the presence of hydrogen in the zirconium lattice reduces the vacancy formation energy. It is shown that hydrogen and vacancies in zirconium form complexes that considerably distort the metal lattice. The increase in the covalency degree of the metal–metal and hydrogen–metal bounds is observed in the vicinity of these complexes.     

Stability and Symmetry-Breaking Bifurcation for the Ground States of a NLS with a δ′ Interaction

We determine and study the ground states of a focusing Schrödinger equation in dimension one with a power nonlinearity |ψ|^2μ ψ and a strong inhomogeneity represented by a singular point perturbation, the so-called (attractive) δ′ interaction, located at the origin. The time-dependent problem turns out to be globally well posed in the subcritical regime, and locally well posed in the supercritical and critical regime in the appropriate energy space. The set of the (nonlinear) ground states is completely determined. For any value of the nonlinearity power, it exhibits a symmetry breaking bifurcation structure as a function of the frequency (i.e., the nonlinear eigenvalue) ω. More precisely, there exists a critical value ω* of the nonlinear eigenvalue ω, such that: if ω₀ <  ω <  ω*, then there is a single ground state and it is an odd function; if ω >  ω* then there exist two non-symmetric ground states. We prove that before bifurcation (i.e., for ω <  ω*) and for any subcritical power, every ground state is orbitally stable. After bifurcation (ω = ω^* + 0), ground states are stable if μ does not exceed a value ${\mu^\star}$ that lies between 2 and 2.5, and become unstable for μ > μ*. Finally, for μ >  2 and ${\omega \gg \omega^*}$ , all ground states are unstable. The branch of odd ground states for ω <  ω* can be continued at any ω >  ω*, obtaining a family of orbitally unstable stationary states. Existence of ground states is proved by variational techniques, and the stability properties of stationary states are investigated by means of the Grillakis-Shatah-Strauss framework, where some non-standard techniques have to be used to establish the needed properties of linearization operators.     

Interaction of a pair coherent state with a three-level Λ-type atom and generation of a modified Bessel-Gaussian state with a vortex structure

The evolution of a system state is derived based on the nonresonant interaction of a three-level "Λ" type atom with two cavity modes at a pair coherent state and two classic fields,and a cavity field state is analyzed in detail under conditional detecting.It is found that the quantized modified Bessel-Gaussian states as well as the superposition states consisting of the quantized vortex states with different weighted coefficients may be prepared through carefully preparing an initial atomic state and appropriately adjusting the interaction time.The scheme provides an additional choice to realize the two-mode quantized vortex state within the context of cavity quantum electrodynamics(QED).