bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of gamma irradiation and air annealing on Yb‐doped YAlO3 single crystals
Authors: Zeng Xionghui , Zhao Guangjun , Xu Jun , Li Hongjun , He Xiaoming 
Published: April 2005

AbstractThe effects of gamma irradiation on as‐grown 5 at% Yb:YAlO3 (YAP) and air annealing on gamma‐irradiated 5 at% Yb:YAP have been studied by the difference in the absorption spectra before and after treatment. The gamma irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAP crystal. After air annealing, the gamma‐irradiation effects were totally removed over the wavelength range 390–800 nm and the concentrations of Fe3+ and Yb3+ were slightly increased. For the first time, the gamma‐irradiation‐induced valence changes between Yb3+ and Yb2+ ions in Yb:YAP crystals have been observed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport properties of double‐gate SiO2–Si–SiO2 quantum well
Authors: Prunnila Mika , Ahopelto Jouni , Sakaki Hiroyuki 
Published: April 2005

AbstractWe report on fabrication and low temperature transport properties of double‐gate SiO2–Si–SiO2 quantum well with a 16.5 nm thick Si layer. The device is fabricated on a silicon‐on‐insulator substrate utilizing wafer bonding, which enables us to use heavily doped back gate. Transport properties of the device are characterized by low field Hall and high field magnetotransport measurements at 4.2 K and at 0.38 K, respectively. Top (back) Si–SiO2 interface peak mobility of 1.9 m2/Vs (1.0 m2/Vs) is measured at 4.2 K. When both gates have a (large) positive bias the Hall carrier density is observed to fall below the value of the expected total carrier density, which is interpreted to arise from the occupancy of the second sub‐band in the Si well. This is confirmed by the high field magnetotransport measurements. In quantizing magnetic fields the longitudinal resistivity minima show Landau level filling factor behavior which is typical for weakly coupled bi‐layers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High power second‐order distributed feedback quantum cascade lasers
Authors: Pflügl C. , Austerer M. , Schrenk W. , Golka S. , Andrews A. M. , Strasser G. 
Published: April 2005

AbstractWe present high power mid‐infrared surface‐emitting single mode GaAs‐based quantum cascade lasers (QCLs). By using an air‐AlGaAs waveguide combined with second‐order distributed feedback processing, we obtained optical output, via the surface, above 3W. Surface‐normal dual‐lobe light emission exceeds the emission from one as‐cleaved facet by a factor of six. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarisation‐sensitive switch: An integrated intensity‐independent solution for 1.3 µm based on the polarisation anisotropy of ordered InGaAsP
Authors: Krämer S. , Neumann S. , Prost W. , Tegude F. J. , Malzer S. , Döhler G. H. 
Published: April 2005

AbstractOrdered materials provide new possibilities for optical device applications. Through a strong polarisation anisotropy of absorption a high functional polarisation‐sensitive switch can be fabricated which in addition is nearly independent on the optical power. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of electric field on the probability of optical transitions in InGaAs/GaAs quantum wells observed by photo‐ and electroreflectance methods
Authors: Pikhtin A. N. , Komkov O. S. , Bugge F. 
Published: April 2005

AbstractThe influence of an electric field on the energy spectrum and the probability of optical transitions in InGaAs/GaAs single quantum wells (QWs) of different widths has been investigated with photo‐ and electroreflectance techniques. The electric field in the area of a QW is varied in a wide range and controlled by well‐defined Franz–Keldysh oscillations. A quadratic red shift of electroreflectance features concerned with interband excitonic transitions in QWs is observed. The electric field dependence of the intensity of these features and calculated data for the probability of optical transitions are compared. There are some field values when transitions that are symmetry‐forbidden in zero field are much stronger than symmetry‐allowed transitions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of site preference and lattice vibrations in Sm2Fe17–xMnx
Authors: Qian Ping , Chen Nan‐Xian , Shen Jiang 
Published: April 2005

AbstractThe ternary Sm2Fe17–xMnx systems in which Fe is replaced by Mn have been studied to ascertain the effect of substitution on their phase stability, site preference and lattice vibration. Calculation is based on a series of interatomic pair potentials related to the rare earth and transition metals, which are obtained by a strict lattice inversion method. Substitution of Mn for Fe make cohesive energy of Sm2Fe17–xMnx decreased markedly, indicating ternary element Mn can stabilize the Sm2Fe17–xMnx compound. And Mn atom preferentially substitutes for Fe in the 6c site and randomly substitutes in the 18h and 18f site. Besides, the phonon density of states of Sm2Fe15Mn2, the according specific heat, vibrational entropy and Debye temperature are calculated first, and a qualitative analysis with pair potentials is also carried out. The method utilized in the present investigation offers a rather easy and direct way to study the structural and vibrational properties of Sm2Fe17–xMnx. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational CI techniques for computing dispersion constants
Authors: Bendazzoli Gian Luigi 
Published: April 2005

AbstractWe describe the computation of dispersion constants using variational subspace methods to solve the perturbation theory equations in the tensor product space of the interacting molecules, treated separately at a (full) configuration interaction (CI) level. These new techniques are more accurate than the numerical quadrature of the Casimir Polder integral at the expense of a small additional computational cost. We also show how to compute the norm of the residual of the perturbative solution in the tensor product space to check convergence. The methods are tested on LiH and BH. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Distributed Gaussian discrete variable representation
Authors: Karabulut Hasan , Kalay Mestan 
Published: April 2005

AbstractA discrete variable representation (DVR) made from distributed Gaussians gn(x) = e, (n = −∞, …, ∞) and its infinite grid limit is described. The infinite grid limit of the distributed Gaussian DVR (DGDVR) reduces to the sinc function DVR of Colbert and Miller in the limit c → 0. The numerical performance of both finite and infinite grid DGDVRs and the sinc function DVR is compared. If a small number of quadrature points are taken, the finite grid DGDVR performs much better than both infinite grid DGDVR and sinc function DVR. The infinite grid DVRs lose accuracy due to the truncation error. In contrast, the sinc function DVR is found to be superior to both finite and infinite grid DGDVRs if enough grid points are taken to eliminate the truncation error. In particular, the accuracy of DGDVRs does not get better than some limit when the distance between Gaussians d goes to zero with fixed c, whereas the accuracy of the sinc function DVR improves very quickly as d becomes smaller, and the results are exact in the limit d → 0. An analysis of the performance of distributed basis functions to represent a given function is presented in a recent publication. With this analysis, we explain why the sinc function DVR performs better than the infinite grid DGDVR. The analysis also traces the inability of Gaussians to yield exact results in the limit d → 0 to the incompleteness of this basis in this limit. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Local HSAB principle in the conjugate addition of p‐substituted thiophenols to cyclohexenone
Authors: Meza Rocío , Gordillo Bárbara , Galván Marcelo 
Published: April 2005

AbstractIn the formation of new bonds through the Michel‐type addition of thiolates to a α,β‐conjugate system, it is observed that the reaction takes place faster if the thio donor compound contains an electron‐rich group or the enone acceptor is highly electron deficient. In contrast, the hard–soft acid–base (HSAB) principle predicts that this reaction is favored when a soft–soft interaction between the reactants takes place. Taking into account that softness is related to a barely electronegative atom of high polarizability, we consider it of interest to analyze the effect of charge transfer of a p‐substituent on the softness of sulfur in thiophenols, as well as its impact in the conjugate addition to 2‐cyclohexen‐1‐one. Experiments‐in‐competition, net charge of X‐groups at the p‐position of the aromatic ring, the global and local softness at sulfur, and the electrophilicity, obtained by density functional theory (DFT), led to the observation that the reaction is faster for electron attractor thiophenols. The softness at sulfur increases by delocalization of charge through the aromatic ring. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Formation and physical characteristics of van der Waals molecules, cations, and anions: Estimates of complete basis set values
Authors: Zahradník Rudolf , S̆roubková Libus̆e 
Published: April 2005

AbstractComplete basis set (CBS) values are sought either for highly accurate molecular characteristics of small species (e.g., pairs of rare gas atoms or the HF dimer) or for medium‐size molecules or ions (e.g., bases of nucleic acids, the benzene dimer). In the latter case, only the Møller–Plesset type 2 (MP2) procedure with DZ and TZ basis sets is feasible. In the present work, both aspects are relevant. Altogether 23 species and 7 reactions are treated, including van der Waals (vdW) molecules ((H2)2, rare gas dimers), cations (H … Rg, Rg = He, Ne, Ar, Kr), and anions associated with the CH potential energy surface (CH4 … H−, CH … H2, and the CH (D3h) Eyring activated complex). Use has been made of various extrapolation formulas. An exponential‐type formula is also reliable in instances when only small basis set data are available. By means of a formula used in our previous work (FX = F∞ + a n−1, where FX is a physical characteristics obtained with a cc‐pVXZ basis set and X is the cardinal number, F∞ a CBS value searched for, and n the total number of atomic functions in the basis set), it is possible to show that CBS ΔE values of association processes (e.g., A + B ⇋ A − B, where A and B are held together by a bond of variable strength) are essentially the same, regardless of whether simple or augmented basis sets are used when considering or neglecting corrections for the basis set superposition error (BSSE). © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Electronic structure, chemical binding, and elastic properties of M–H interactions as calculated by the Xα–DV method
Authors: Yuryeva E. I. , Pletney R. N. , Skripov A. V. 
Published: April 2005

AbstractThe nonempirical Xα‐discrete‐variation cluster method was used for a quantum chemistry investigation of interactions between a hydrogen atom and other atoms in systems of practical interest: M–H (MTi, V, Cr, Fe, Ni) and TaV2:H. We have calculated the parameters of chemical binding between M and H atoms: degree of ionicity (α), covalency (β), metallicity (γ), coefficient of bond elasticity (k), and reduced binding energy $\bar{E}$bin. On the basis of the results obtained for M–H (MTi, V, Cr, Fe, Ni), we have formulated the main trends of chemical binding and used these conclusions for the system TaV2:H. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A new conceptual framework integrating environment into corporate performance evaluation
Authors: Sheu Her‐Jiun , Lo Shih‐Fang 
Published: April 2005

AbstractBusinesses aim to make profit, but very often they fail to take environmental protection into consideration in the drive to please stakeholders. In this article, a new conceptual framework for evaluating corporate integrated development through the perspective of efficiency (looking at the company's work value created in terms of input–output) is introduced. Under the proposed framework, businesses, investors and society can conveniently understand and evaluate corporate holistic performance including its operational competence, financial health and environmental friendliness. Therefore, decisions of different levels and groups could be made with programmed consideration on this purely analytical ground. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Ireland in the new century: an opportunity to foster an ethic of sustainable enterprise
Authors: Kennelly James J. , Bradley Finbarr 
Published: April 2005

AbstractIreland's economy has undergone enormous change over the past decade, with rapid development accompanied by increasing pressures upon the natural environment. One element of this process has been the development of an ‘enterprise culture’ within Ireland. In this paper, we argue that Ireland is uniquely advantaged to build upon this enterprise culture, and to develop a ‘sustainable enterprise culture’ that is more consistent with the principles of sustainable development. Indeed, we see this as a unique opportunity to further the development of Ireland in an economically, ecologically and socially sustainable manner. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Assessing forest cover sustainability and deforestation risk from socioeconomic and biophysical indicators – a case study from Rampa Forests, south India
Authors: Prasad V. Krishna , Badarinath K. V. S. 
Published: April 2005

AbstractAssessing socio‐economic and biophysical constraints on the deforestation process gains importance in the context of increasing pressure on tropical forests. In this study, we quantify forest change ‘hotspots’, defined as the areas where land cover changes are likely to occur in the near future, by utilizing land use/cover data, in conjunction with socio‐economic and biophysical indicators, from one of the tropical forests of south India. We assessed deforestation risk as a function of density of shifting cultivation, density of agricultural area to total area, land availability for agricultural purposes, demand of endosomatic energy and the applied power to forest ecosystem. Results suggested that, due to relatively high demand for resources and high percentage of agricultural labourers, one of the provinces had high risk of forest loss. The indicators selected were useful in addressing deforestation in the study area and have potential to establish sustainable forest management models elsewhere. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Coping with chronic and extreme risks in contemporary Athens: confrontation or resilience?
Authors: Sapountzaki Kalliopi , Chalkias Christos 
Published: April 2005

AbstractThe present work attempts to address the main aspects of chronic and extreme risks in contemporary Athens. It focuses on two cases of acute chronic risk bedevilling the capital region, namely road accidents and noise pollution, and one case of extreme risk, namely seismic disasters. In all cases social vulnerability, seen as the attribute of social and economic entities that can serve to increase damage from given danger, is a basic determinant of risk level. This social vulnerability might be defined in terms of three constituent elements: exposure to, resistance against and resilience to danger impacts.The whole analysis seeks the generating causes of the relevant high risk levels; their distribution across the geographical and social space of the capital region; their impacts on citizens' lifestyle and awareness of unsustainability; the public policy actions to abate or mitigate them and the individuals' adaptive reactions or efforts to escape risks and finally the repercussions of individualized and governmental responses on future risk and vulnerability levels. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Prenatal ultrasonography and neonatal imaging of complete cleft sternum: a case report
Authors: Twomey E. L. , Moore A. M. , Ein S. , McAuliffe F. , Seaward G. , Yoo S.‐J. 
Published: April 2005

AbstractThe prenatal diagnosis of a complete cleft sternum was established in a fetus of a twin pregnancy at 22 weeks' gestation. We present the prenatal imaging and correlation with postnatal magnetic resonance imaging and high‐resolution ultrasonography. Thinned and depressed midline anterior chest wall transmitting the cardiac pulsation was the clue to the diagnosis, and the defective sternum could be identified on close sonographic observation. Successful surgical correction was undertaken at 2 months of age. There were no major associated abnormalities such as ectopia cordis or midline abdominal wall defects. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
The sensitivity of antenatal ultrasound for predicting renal tract surgery in early childhood
Authors: Bhide A. , Sairam S. , Farrugia M.‐K. , Boddy S.‐A. , Thilaganathan B. 
Published: April 2005

AbstractObjectiveTo establish the sensitivity of antenatal ultrasound for identifying the need for renal tract surgery in infancy and early childhood.MethodsA retrospective analysis of the surgical records in children under 5 years of age undergoing renal tract surgery in a regional pediatric urological surgery referral unit was carried out. All records between May 1997 and July 2002 were examined to assess the relationship between prenatal ultrasound findings and postnatal surgical pathology.ResultsA total of 106 operations had been performed. The detection rate of multicystic renal dysplasia was 100% (17/17). The equivalent detection rates for pelviureteral junction obstruction, duplex renal system and vesicoureteral reflux were 82.8, 67 and 26.1%, respectively. None of the babies with renal tumors had abnormal antenatal ultrasound findings. The diagnosis of postnatal renal surgical pathology was made on the basis of prenatal scan findings in 59.6% of cases, while recurrent urinary tract infection led to the diagnosis in 26.0%.ConclusionsApproximately 40% of children requiring surgery for renal tract pathology will have a normal antenatal ultrasound examination. The prevalence of abnormal antenatal ultrasound findings varies depending on the type of renal tract pathology. Despite these findings, the commonest indicator for surgery remains abnormal prenatal scan findings, followed by recurrent urinary tract infections. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Zur Klassifizierung sowie zur Existenz, Eindeutigkeit und Stabilität der Lösungen klassischer kontinuumsmechanischer Dämpfungsmodelle
Authors: Nolte B. , Müller zum Hagen H. 
Published: April 2005

AbstractHinsichtlich ihres physikalischen und mathematischen Verhaltens werden partielle Differentialgleichungen untersucht, welche die folgenden vier Dämpfungsmodelle beschreiben: Das Maxwell‐Modell, das Jeffreys‐Modell, das Kelvin‐Voigt‐Modell sowie das Poynting‐Thomson‐Modell. Insgesamt handelt sich um sogenannte rheologische Dämpfungsmodelle, die ohne Kenntniss der mikroskopischen Gegebenheiten auskommen und im integralen Mittel die tatsächlichen Phänomene hinreichend gut beschreiben. Zwei der partiellen Differentialgleichungen (Dämpfungsmodell nach Maxwell und Poynting‐Thomson) sind rein hyperbolisch (nach Transformation) und die zwei anderen partiellen Differentialgleichungen sind parabolisch‐hyperbolisch. Für das parabolisch‐hyperbolische partielle Differentialgleichungssystem, welches (nach Transformation) die Dämpfungsmodelle nach Jeffreys und Kelvin‐Voigt beschreibt, wird eine Energieungleichung (a priori Abschätzung) hergeleitet. Aus dieser folgt die Eindeutigkeit und die Stabilität der Lösung. Die Existenz der Lösung lässt sich mit Hilfe der Energieungleichung beweisen. Ferner mußten die Verträglichkeitbedingungen zwischen den Randwertvorgaben (vom parabolischen Anteil) mit den Anfangswertvorgaben berücksichtigt werden. Die Vorgabelinien der Randwerte sind Charakteristiken (bzgl. des hyperbolischen Anteils). Insgesamt stellt diese Arbeit eine Kurzfassung zweier institutsinternen Arbeiten dar ([6,11]).
Second‐order effects in the torsion of elastic materials with voids
Authors: Ieşan D. 
Published: April 2005

AbstractThis paper applies the technique of successive approximation to the nonlinear theory of elastic materials with voids, as developed by Nunziato and Cowin [2]. The complete set of equations for the first and second order approximation is derived. The torsion problem within the second‐order theory is studied. It is shown that the solution can be expressed in terms of solutions of some two‐dimensional problems. The theory is applied to study the torsion of a circular cylinder. It is shown that an infinitesimal twist produces a second‐order volume fraction field which is proportional to the square of the amount of torsion.
On numerical stability in large scale linear algebraic computations
Authors: Strakoš Z. , Liesen J. 
Published: April 2005

AbstractNumerical solving of real‐world problems typically consists of several stages. After a mathematical description of the problem and its proper reformulation and discretisation, the resulting linear algebraic problem has to be solved. We focus on this last stage, and specifically consider numerical stability of iterative methods in matrix computations. In iterative methods, rounding errors have two main effects: They can delay convergence and they can limit the maximal attainable accuracy. It is important to realize that numerical stability analysis is not about derivation of error bounds or estimates. Rather the goal is to find algorithms and their parts that are safe (numerically stable), and to identify algorithms and their parts that are not. Numerical stability analysis demonstrates this important idea, which also guides this contribution. In our survey we first recall the concept of backward stability and discuss its use in numerical stability analysis of iterative methods. Using the backward error approach we then examine the surprising fact that the accuracy of a (final) computed result may be much higher than the accuracy of intermediate computed quantities. We present some examples of rounding error analysis that are fundamental to justify numerically computed results. Our points are illustrated on the Lanczos method, the conjugate gradient (CG) method and the generalised minimal residual (GMRES) method.