bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality of life before and one year following stem cell transplantation using an individualized and a standardized instrument
Authors: Wettergren L. , Sprangers M. , Björkholm M. , Langius‐Eklöf A. 
Published: July 2007

AbstractObjective: The aim was to prospectively measure quality of life in patients with malignant blood disorders following stem cell transplantation (SCT) using an individualized and a standardized measure.Methods: Twenty‐two consecutive patients were assessed before and one year following SCT, using a generic and disease‐related version of the Schedule for the Evaluation of Individual Quality of Life‐Direct Weighting (SEIQoL‐DW) and the EORTC QLQ‐C30. Results of the QLQ‐C30 were compared with Swedish norm values.Results: A majority of the patients reported concerns related to health before as well as one year after SCT, recorded by both instruments. Mean scores produced by the SEIQoL‐DW, and four scales of the EORTC QLQ‐C30, showed a change over time, indicating improved quality of life one year after SCT. In comparison with Swedish norm values for the EORTC QLQ‐C30, SCT recipients reported a worse functioning.Conclusions: In addition to well‐known disease and treatment‐related problems, areas not typically included in standardized instruments were nominated in the disease‐related SEIQoL‐DW. Such areas included positive aspects, e.g. a changed view of life and oneself. The results support the use of the generic and disease‐related SEIQoL‐DW to achieve a comprehensive picture of patient's clinical situation under treatment or when recovering from illness. Copyright © 2007 John Wiley & Sons, Ltd.
Nanostructured cobalt on porous silicon substrate: Structure and magnetic behaviour
Authors: Belkacem W. , Mliki N. , Belhi R. , Saikaly W. , Yangui B. 
Published: July 2007

AbstractDuring an anodization process, porous silicon (PS) consisting of pores with a diameter of about 40 nm and a depth from 5 µm to 40 µm has been produced. To achieve oriented channels in this mesoporous range, a p+‐type Si wafer was electrochemically etched in an aqueous electrolyte of HF. We report the formation, after the anodization step, of a cobalt nanostructure in a porous silicon matrix. Co nanocrystals on and in a porous silicon layer have been prepared by the UHV evaporation technique and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). This technique was performed to show the chemical element distribution within the channels. It is found that the deposition condition is an important factor for obtaining nano‐structures. Initial deposition leads to Co particle penetration in silicon pores whereas subsequent deposition results only in an increase of the thickness at the surface with no further penetration. Additional experiments were carried out by using the magneto‐optical Kerr effect to obtain information about the magnetic properties. The first results show that the magnetic response for layers <5 nm presents an important perpendicular component of magnetization whereas for thicker deposited layers (8 nm < t < 20 nm) the magnetic response seems to act as that of a thin film in which the squareness of the hysteresis loop decreases with increasing film thickness. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Insignificant mixed‐alkali effect in Li2O–Na2O–Fe2O3–P2O5 glasses
Authors: Tashtoush N. M. , El‐Desoky M. M. 
Published: July 2007

AbstractConductivity spectra of mixed‐alkali ions in iron phosphate glasses have been studied in the frequency range from 400 Hz to 200 kHz, and over a temperature range from 333 K to 493 K. The ac conductivity as a function of temperature was divided into two domains; one where the absolute of ac conductivity is close to the dc conductivity, and one where the absolute magnitude of the ac conductivity is larger than the dc conductivity. The concentration of charge carriers was found to be almost independent of temperature, but was weakly dependent on composition. It seems that the conductivity was essentially determined by the hopping frequency. The activation energy for the hopping frequency is close to that of the dc conductivity and the glasses behave as strong electrolytes. The frequency exponent appears to be independent of temperature, but depends very weakly on composition. The glasses show weak pronounced mixed‐alkali effect in the mixed lithium and sodium iron phosphate glasses. The small minimum and maximum in dc conductivity and activation energy, respectively, are further evidence of the low mobility of the lithium and sodium ions in these iron phosphate glasses. We have also presented a scaling of the conductivity spectra, which implies that the relaxation dynamics of charge carriers in the present glasses is weakly dependent on temperature and composition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of nano‐ and microstructured GaN in bulk powder and on substrate
Authors: Ghosh R. , Basak D. 
Published: July 2007

AbstractA detailed investigation has been carried out to study the effects of growth temperature, NH3 flow rate, grinding‐mediated annealing of the as‐synthesized GaN powder, different substrates and Au catalyst on the products grown by a direct reaction of Ga with NH3. Nanowires of diameter in the range 15–40 nm are grown around a narrow temperature zone, 1000 °C < t < 1100 °C, with a 150 sccm NH3 gas flow rate. Beyond this temperature zone, GaN platelets are formed in a large scale. Annealing of the as‐synthesized GaN powder at 800 °C after a grinding process results in the growth of dendrite‐like GaN nanostructures and above 800 °C, only hillocks of GaN platelets are grown. The layers formed on sapphire and ZnO/quartz substrates consist of GaN nano‐ and microrods of diameter 40–100 nm and 1–1.5 μm respectively that show ultraviolet (UV) emission peaks below 400 nm. Large‐scale synthesis of GaN nanorods of diameter 60–100 nm has been achieved on Au/quartz substrate at 1050 °C with a 150 sccm of NH3 gas flow rate. The nanorods exhibit a strong UV emission peak indicating a better optical quality. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydride electronics
Authors: Karazhanov Smagul Zh. , Ravindran P. , Vajeeston P. , Ulyashin Alexander G. 
Published: July 2007

AbstractWith the help of first‐principles density functional calculations, using AlH3 as a model system, we have shown that some of the hydrides possess the features of transparent conducting oxides (TCO). Based on this observation we discuss here the possible novel applications of hydrides in electronic device technology as electrical conducting materials, which can have both n‐ and p‐type conductivity and at the same time transparent in the infrared (IR), near IR, or visible regions. Moreover, some advantages concerning properties of interfaces in case of using hydrides in modern multilayer based device structures are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoemission from the potassium halides in the photon energy range 7 to 30 eV
Authors: Blechschmidt D. , Skibowski M. , Steinmann W. 
Published: July 2007

AbstractThe spectral distribution of the photocurrent at different retarding potentials as well as the energy distribution of the photoelectrons at a fixed photon energy have been measured for all potassium halides. The synchrotron radiation of DESY was used as a light source. The samples were thin films evaporated under ultra‐high vacuum. The threshold energy, the distance between the valence band and the K+3p core level, and the position of the Fermi level have been determined. The onset of electron–electron scattering and the appearence of inelastically scattered electrons in the photoemission has been demonstrated. The decay of the core excitons has been investigated. The core exciton structure in the spectra of the photoyield is due to direct recombination. There is some evidence that an Auger process occurs as additional decay mechanism.
Transport Phenomena in Thin Films of Semi‐Metals with Non‐Spherical Energy Surfaces at Low Temperatures
Authors: Kamal J. , Tewari D. P. 
Published: July 2007

AbstractThe size dependence of the transport coefficients of semi‐metals has been studied assuming nonspherical energy surfaces and taking into account the energy dependence of the relaxation time. Detailed calculations have been performed for thin bismuth films at low temperatures considering the anisotropy in the mass tensor. Cartesian tensor expansion technique has been used to solve the Boltzmann transfer equation in the presence of a static electric field applied along the surface of the film and a magnetic field in the transverse direction. Results obtained are in good qualitative agreement with the experimental results of Colombani and Huet.
Identification of Three Trapping Centers in Calcium Tungstate
Authors: Koehler H. A. , Kikuchi C. 
Published: July 2007

AbstractPartial thermal annealing of nominally pure calcium tungstate, after gamma irradiation at 78 °K, provided evidence for identifying three major 4900 Å thermoluminescence peaks at 0.36, 0.55, and 0.72 eV with three groups of electron spin resonance lines of paramagnetic tungsten at g001 = 2.009 and 1.843 and niobium at g001 = 2.021, respectively. The impurity center identified with the paramagnetic Nb+4 ion is assigned to a tungsten site and a NbO complex. Arguments are presented for the assignment of two lattice defect models, a WO complex with nearby WO3 and NbO complexes, and a WO complex with a nearby calcium deficiency, to the paramagnetic (W+5)A and (W+5)B ions, respectively.
On the canonical transformation in the theory of exciton–phonon interaction
Authors: Davydov A. S. , Pestryakov G. M. 
Published: July 2007

AbstractA canonical transformation which eliminates the trilinear exciton–phonon interaction and introduces new elementary excitations — “dressed” excitons — is proposed; it holds true both for the narrow and for broad exciton bands. The energy spectrum of the dressed excitons is investigated in detail for a one‐dimensional model of Frenkel excitons interacting with optical phonons.
On Certain Peculiarities of Electrical and Optical Properties of Many‐Valley Semiconductors
Authors: Dneprovskaya T. S. 
Published: July 2007

AbstractA theoretical study of the effects of the light pumping on the conductivity of the multi‐valley n‐type semiconductors is presented. It is shown that the existence of the resonant impurity states associated with the secondary minima cause the peculiarities in the conductivity dependence on the pumping intensity. Under certain conditions this dependence should contain a hysteresis loop.
The Specific Heat of Terbium Arsenate
Authors: Berkhahn W. , Kahle H. G. , Klein L. , Schopper H. C. 
Published: July 2007

AbstractSpecific heat measurements on TbAsO4 were carried out in the temperature region between 0.8 and 30 K. They show that this compound undergoes two phase transitions; one at TD = (27.7 ± 0.5) K, which is caused by a crystallographic phase transition from tetragonal to orthorhombic symmetry and another, at TN = (1.50 ± 0.02) K, which has to be attributed to a magnetic phase transition from the paramagnetic to the anti ferromagnetic state. An effective exchange integral and critical parameters were determined and compared with theory. The contribution to the heat capacity associated with the crystallographic phase transition shows a typical molecular field behaviour; the experimental values and the data derived from a modified molecular field theory are in very good agreement.
Raman Spectrum of Polaritons in the Presence of Mass Defects
Authors: Ohtaka K. 
Published: July 2007

AbstractIn the low concentration limit of mass defects, the Raman spectrum is examined in the polariton region, i.e., in the small momentum transfer region. Expressions for the lifetime broadening and the frequency shift of the polariton peak are derived and the impurity‐induced continuous spectrum is also discussed. Calculations made so far for the localized mode polariton are improved in several respects. It is also shown that the electro‐optical coefficient derived from the PA type of the electron‐polariton interaction has only a apparent ω‐dependence to be eliminated in getting the proper Raman intensity.
Electron Paramagnetic Resonance (EPR) of Phosphorus in Silicon‐Rich Silicon–Germanium Alloys
Authors: Vollmer H. , Geist D. 
Published: July 2007

Abstractg‐values, hyperfine splittings, and line widths of the EPR‐spectra of phosphorus substituted into Si1−xGex alloys were investigated at 9.3 GHz and 1.8 K in the range 1 ≧ (1 — x) ≧ 0.84 with phosphorus concentrations between 5 × 1015 and 1019 cm−3. The peculiar variation of the measured quantities with the silicon concentration is discussed with regard to band structure investigations and to the individual surroundings of each phosphorus atom.
Surface and Bulk Magnetic Exciton Resonance in a Thin Film of an Induced Ferromsgnet
Authors: Kowalewski L. , Popielewicz A. 
Published: July 2007

AbstractSurface and bulk longitudinal magnetic exciton resonance is investigated in a thin film of an induced ferromagnet. Infrared absorption intensities in the low temperature range are calculated for a thin film with f.c.c. structure and for the singlet‐singlet molecular field level model. The calculations are made in the approximation of the pure 4fn configuration.
EPR and Spin–Lattice Relaxation of Mo3+ Ions in Corundum
Authors: Sharoyan E. G. , Torosyan O. S. , Markosyan E. A. , Gabrielyan V. T. 
Published: July 2007

AbstractThe EPR spectra of Mo3+ ions in corundum at v = 9.25 GHz and T = 77 °K were investigated. It is shown, that Mo3+ ions isomorphously replace Al3+ ions in the octahedral coordination. Due to the large zero‐field splitting, only the −1/2 ↔ +1/2 transition is observed. The zero‐field splitting constant 2D = (−49 ± 18) GHz, the spectroscopic splitting factor g⊥ = 1.968 ± 0.001, g ⊥ = 1.98 ± 0.01, and the hyperfine splitting constant A‖ = (119 ± 1) MHz, A⊥ = (121 ± 2) MHz are determined. It is shown that in the case of large zero‐field splitting 2D ≫ v the magnitude of 2D can be determined by measurements at a single frequency, using the value of geff at 35°2′ (cos2 θ = 2/3). The angular dependence of the hyperfine structure splitting due to the large zero‐field splitting is observed and good agreement with values calculated in first order of perturbation theory is obtained. The spin‐lattice relaxation times of Mo3+ ions in corundum are estimated from the magnitude of the broadening of the absorption curves with increasing temperature. In the temperature range of 77 to 500 °K the spin–lattice relaxation rate is τ1−1 ∼ T2.5.
Properties of type‐II superconductors with arbitrary impurity concentration near Hc2
Authors: Ovchinnikov Yu. N. , Brandt E. H. 
Published: July 2007

AbstractThe magnetic field distribution H and the magnetization 4πM are calculated by the method of energy‐integrated Green's functions near the upper critical field HC2 as a function of temperature, electron mean free path, and of the concentration of paramagnetic impurities. The field distribution of Delrieu and of one of the authors is thereby reproduced. The non‐linearity of the magnetization curve is investigated. At low temperatures and long mean free paths this non‐linearity becomes pronounced and leads to a logarithmically vanishing slope of the magnetization curve as the applied field approaches Hc2.
The dielectric function of GeS single crystals determined by electron energy loss spectroscopy
Authors: Venghaus H. , Büchner U. 
Published: July 2007

AbstractElectron energy loss spectra were taken with 50 keV electrons on GeS single crystals for 0 < E < 40 eV and with different orientations of transferred momentum. No anisotropy of the energy loss functions Im (–1/ϵii) (i = x, y, z) could be observed indicating ϵxx ≈ ϵyy ≈ ϵzz for E 3 eV. ϵxx is calculated from Im (–1/ϵxx) by Kramers‐Kronig analysis. Our results indicate that the dielectric function of GeS is, to a good approximation, isotropic for E > 3 eV despite the layer type structure of the compound.
Group Theoretical Analysis and Phonon Modes of V3Si
Authors: Achar B. N. N. , Barsch G. R. 
Published: July 2007

AbstractThe group theoretical analysis of the dynamical matrix has been carried out for the A15 structure by using the irreducible multiplier representations of the point group of the wave vector. Numerical results are presented for the complete set of phonon dispersion relations in V3Si along the principal symmetry directions calculated from a microscopic model given earlier.
A simple phenomenological model for the lattice dynamics of B. C. C. metals
Authors: Raiand R. C. , Hemkar M. P. 
Published: July 2007

AbstractA simple phenomenological model is developed for b.c.c. metals which considers ion‐ion interaction up to second neighbours and electron‐ion interaction on the lines of Bhatia theory using an appropriate value for the screening parameter. The volume force is averaged over the whole Wigner‐Seitz sphere. In the present model the ionic lattice is in equilibrium in a medium of electrons. The theory is satisfactorily applied to the computation of phonon dispersion curves and Debye characteristic temperatures for four alkali metals, lithium, sodium, potassium, and rubidium.
Theory of axial dechanneling
Authors: Ōmura T. , Kitagawa M. , Ohtsuki Y. H. 
Published: July 2007

AbstractMaking use of the generalized Fokker‐Planck equation, and the diffusion coefficients for the many‐phonon excitations and the single electron excitation, the dechanneled fractions for 1.6 MeV H+ in the Si [110] axis are calculated numerically. The temperature dependence of the calculated results is stronger than that of the Lindhard model. Comparison between the present results and the experiments is also made.
Quadratic electronic polarizability of the interacting electron gas
Authors: Paasch G. , Rennert P. 
Published: July 2007

AbstractThe quadratic electronic polarizability of the interacting electron gas is calculated with a self‐consistent method. It can be expressed by the dielectric function and by the quadratic response function of non‐interacting electrons. It is shown that this result is correct in the sense of many‐body perturbation theory within the RPA. As the simplest application the asymptotic behaviour of the total potential is considered which is caused by an additional point charge in the electron gas.
Biexciton resonant two‐photon absorption in CuCl
Authors: Phach Vu Duy , Bivas A. , Hönerlage B. , Grun J. B. 
Published: July 2007

AbstractIn studying the two‐photon absorption (TPA) of the biexciton in CuCl by using two different light sources, interesting information is obtained. The biexciton ground‐state energy is determined accurately; its symmetry is experimentally verified; a value for the TPA coefficient is deduced and compared with a theoretical evaluation; a lineshape analysis enables us to discuss the damping constants of the exciton and biexciton states involved.
Resistivity and thermoelectric power of liquid lithium and sodium from Harrison's first principle
Authors: Mitra N. R. , Thakur J. , Srivastava P. L. 
Published: July 2007

AbstractThe nonlocal pseudopotential formalism of Harrison is applied to the problem of resistivity and thermoelectric power of liquid metals, lithium and sodium. Slater's recent value of α in the Xα‐exchange is used. Exchange and correlation between the conduction electrons are taken into account using the modified dielectric function proposed by Vashishta and Singwi. The results agree well with the experimental values.
Exciton emission of ytterbium‐implanted cadmium telluride
Authors: Nahum J. , Bryant F. J. 
Published: July 2007

AbstractLuminescence measurements show that implantation of cadmium telluride with ytterbium (followed by a suitable annealing treatment) produces an ytterbium defect capable of binding an exciton. Annihilation of the exciton bound to this defect produces a sharp emission at 1.5850 eV. Preliminary studies show that the emission does not split if the crystal is subjected to uniaxial stress. The temperature dependences of these and other excitons are studied and compared with the temperature dependences obtained for Yb3+ emissions in ytterbium‐implanted cadmium telluride.
Theory of the thermomagnetic effects in thin films in a magnetic field of arbitrary magnitude
Authors: Askerov B. M. , Kuliev B. I. , Figarova S. R. , Ya. Shteinshraiber V. 
Published: July 2007

AbstractThermomagnetic effects of a thin film in a magnetic field normal to the film surface are studied for an arbitrary value of specularity parameter p. Using the solution of the Boltzmann equation for an arbitrary film thickness and magnetic field strength the basic thermomagnetic coefficients are calculated, the Nernst‐Ettingshausen coefficient (N‐E) Q, the thermopower in a magnetic field α(H), and the thermal conductivity in a magnetic field χ. A detailed analysis is given of their dependences on the thickness, magnetic field strength, and the parameter p. It follows from the analysis that in a weak magnetic field the thermopower α and the N‐E coefficient Q are practically p‐independent. The computer calculations show that α and Q oscillate as functions of the magnetic field strength, the oscillations of Q being more pronounced than those of the electronic thermal conductivity. χ varies monotonically with the magnetic field.
H2O Related Centers in Potassium Chloride
Authors: Kuczynski G. C. , Dietz P. E. , Hamill W. H. , Jischke J. H. 
Published: July 2007

AbstractVacuum annealing of crystals of KCl at 600 °C produces stable defect centers which trap electrons during uv or γ irradiation as well as during additive coloration. When vacuum annealed crystals are exposed to 2 atm H2O at 200 °C prior to γ irradiation, coloration is suppressed, including the F band. This may be due to displacement of an electron from F by interstitial H2O which occupies V. When previously untreated crystals are exposed to 0.25 atm of HCl at 200 °C and γ‐irradiated, only one of the color centers previously mentioned is observed. The same center is produced in crystals grown from aqueous KCl containing HCl. The center is attributed to H3O+F. Precursor H3O+ (and OH−) is produced by heating in vacuum at 600 °C. Additional chemical reactions are required to account for the other bands.
Electron Paramagnetic Resonance of Mn2+ in Guanidinium Aluminium Sulfate Hexahydrate
Authors: Milsch B. , Windsch W. 
Published: July 2007

AbstractThe electron paramagnetic resonance (EPR) spectrum of Mn2+ ions in ferroelectric guanidinium aluminium sulfate hexahydrate is analyzed. It turned out that these impurity ions enter into regular Al3+ lattice sites forming two non‐equivalent magnetic hexaquo‐manganese (II) complexes of axial symmetry. The hyperfine lines of several fine‐structure transitions exhibit a hidden “spin‐flip” satellite structure. It results from the proton ligand hyperfine interaction in the magnetic hexaquocomplexes. A strong dependence on temperature and uniaxial stress is found for the zero‐field splitting parameter D. Its variation with temperature is discussed in terms of thermal lattice expansion and local lattice vibration effects.
IR Absorption of OH and OD Centres and OH/OH, OD/OD, and OH/OD Complexes in Cu‐Doped ZnO Single Crystals
Authors: Gärtner F. G. , Mollwo E. 
Published: July 2007

AbstractWith ZnO:Cu:H, ZnO:Cu:D, and ZnO:Cu:H:D IR‐active absorption line spectra composed of 20 absorption bands are observed. Regarding the values of the absorption coefficients one of the 20 absorption bands is prominent (“main peak”), 18 absorption bands lie on the high energy side of the main peak (“side bands”). Measurements with the main peaks and the side bands are represented.