bluuebunny/crossref_metadata_2025_split huggingface dataset:
The characteristics of the Coulomb gap in the density of states of germanium doped irradiation defects
Authors: El‐Hakim S. A. 
Published: May 2004

AbstractThis work deals with the determination of the characteristics of the Coulomb gap (CG) in the density of states (DOS) in the vicinity of the Fermi level, from the analysis of the temperature dependence of dc conductivity in the temperature range (1.5 K–300 K) in germanium, disordered by large fluences of fast reactor neutrons. From application, the percolation theory of conductivity and the variable range hopping (VRH) under the effect of the Coulomb interaction of localized carriers, the localization radius is found to be 49.2 Å. The dielectric constants of the samples are determined. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence spectra and decay kinetics in ZnWO4 and CdWO4 crystals
Authors: Chernov S. , Grigorjeva L. , Millers D. , Watterich A. 
Published: May 2004

AbstractThe luminescence spectra and luminescence decay kinetics in ZnWO4 (nominal pure and doped with Fe and Mo) under pulsed electron beam and pulsed nitrogen laser excitation have been investigated. It is suggested that the two‐stage intrinsic luminescence decay observed under ionizing radiation excitation in ZnWO4 and CdWO4 was due to two different self‐trapped exciton (STE) configurations in these crystals. The role of Fe and Mo impurities for scintillation efficiency in ZnWO4 and CdWO4 has been discussed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐injection in semiconductors: materials challenges and device aspects
Authors: Van Roy Willem , Van Dorpe Pol , Motsnyi Vasyl , Liu Zhiyu , Borghs Gustaaf , De Boeck Jo 
Published: May 2004

AbstractSuccessful spin‐injection from magnetic contacts into a semiconductor heterostructure (up to room temperature) is seen as one of the key features to realise spintronic applications. In this paper we describe our effort in establishing spin‐injection in the tunneling regime from various different ferromagnetic contacts. The device structure that is used to test the spin‐injection is a III–V light emitting device. This device has good characteristics as a detector of the injected electron spin‐polarisation. We summarise the results on spin‐injection obtained from different magnetic contact strategies: ferromagnetic metal/AlOx, ferromagnetic metal/Schottky tunnel barrier and ferromagnetic semiconductor/Zener diode combination. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of La0.7Ce0.3MnO3 thin film
Authors: Han S. W. , Lee J. D. , Kim K. H. , Mitra C. , Jeong J. I. , Kim K. J. , Kim B. S. , Min B. I. , Kim J. H. , Wi S. C. , Kang J.‐S. 
Published: May 2004

AbstractThe electronic structure of epitaxial thin films of La0.7Ce0.3MnO3 (LCeMO) has been investigated using photoemission spectroscopy (PES) and X‐ray absorption spectroscopy (XAS). The measured valence‐band PES, Ce 3d PES, and Ce 3d XAS spectra for LCeMO consistently indicate that the localized Ce 4f orbitals are almost unoccupied so that the Ce valence is nearly tetravalent. The Mn 2p XAS spectrum suggests Mn2+ and Mn3+ mixed‐valent states of Mn ions in LCeMO. The LSDA + U calculation agrees better with the measured PES/XAS spectra than the LSDA calculation (U: the on‐site Coulomb interaction). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theories for individual excited states
Authors: Nagy Á. 
Published: May 2004

AbstractVariational and nonvariational density functional theories of a single excited state are reviewed. The asymptotic behavior of the exchange correlation potential in these theories is studied. Generalized OPM and KLI approximations are discussed. Cusp relation for the Kohn–Sham and exchange correlation potentials is proved in the KLI approximation. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
The electronic spectrum of linear HC9H+
Authors: Mühlhäuser Max , Haubrich Jan , Peyerimhoff Sigrid D. 
Published: May 2004

AbstractAb initio multi‐reference singles and doubles configuration interaction (MRD–CI) calculations are employed to determine the vertical electronic spectrum of HC9H+. The transition energy for the first dipole‐allowed transition 12Πg ← X2Πu is computed at 2.13 eV, in reasonable agreement with the experimental value of 659 nm (1.88 eV) recently measured in a neon matrix. It is computed with an oscillator strength of f = 0.007. Furthermore, two previously unknown transitions at 2.72 eV (22Πg ← X2Πu) and at 5.47 eV (42Πg ← X2Πu) are calculated with large f‐values. These dominating states show considerable multi‐reference character. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Theoretical studies on the effects of methods and parameterization on the calculated free energy of hydration for small molecules
Authors: Alagona Giuliano , Ghio Caterina , Nagy Peter I. 
Published: May 2004

AbstractFree energies of hydration (FEH) have been computed for 13 neutral and nine ionic species as a difference of theoretically calculated Gibbs free energies in solution and in the gas phase. In‐solution calculations have been performed using both SCIPCM and PCM polarizable continuum models at the density functional theory (DFT)/B3LYP and ab initio Hartree–Fock levels with two basis sets (6‐31G* and 6‐311++G**). Good linear correlation has been obtained for calculated and experimental gas‐phase dipole moments, with an increase by ∼30% upon solvation due to solute polarization. The geometry distortion in solution turns out to be small, whereas solute polarization energies are up to 3 kcal/mol for neutral molecules. Calculation of free energies of hydration with PCM provides a balanced set of values with 6‐31G* and 6‐311++G** basis sets for neutral molecules and ionic species, respectively. Explicit solvent calculations within Monte Carlo simulations applying free energy perturbation methods have been considered for 12 neutral molecules. Four different partial atomic charge sets have been studied, obtained by a fit to the gas‐phase and in‐solution molecular electrostatic potentials at in‐solution optimized geometries. Calculated FEH values depend on the charge set and the atom model used. Results indicate a preference for the all‐atom model and partial charges obtained by a fit to the molecular electrostatic potential of the solute computed at the SCIPCM/B3LYP/6‐31G* level. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Development of regionalized hydrological models in an area with short hydrological observation series
Authors: Hoffmann Lucien , El Idrissi Abdelkhalak , Pfister Laurent , Hingray Benoît , Guex Frédéric , Musy André , Humbert Joël , Drogue Gilles , Leviandier Thierry 
Published: May 2004

AbstractHigh spatio‐temporal resolution monitoring has only been progressively developed in the Rhine–Meuse basins over the last few decades. As a consequence, basic hydrological information can be very scarce in some areas. In regions which are homogeneous from a hydroclimatological and physiogeographical point of view, hydrographs can be reproduced via regionalized hydrological models, provided that climatological observation series are available.The Alzette river basin, monitored since the mid‐1990s by a very dense hydroclimatological observation network, had been chosen in the framework of the IRMA‐SPONGE project FRHYMAP for transposing the conceptual hydrological models HRM and SOCONT and regionalizing their parameters. The regionalized models were to be used both for extending the currently available runoff series and evaluating runoff in neighbouring non‐monitored basins.The 16 monitored sub‐basins of the Alzette, reflecting the physiogeographical diversity of the study area, were divided into two subsets, serving for both the calibration and the validation procedures. Once the transposition of the models to the Alzette basin had been successfully assessed, their parameters were linked to the physiogeographical characteristics of the sub‐basins. The performance of the thus regionalized models was assessed via a validation on a subset of basins that had not been retained for the elaboration of the regional parameter sets.The transposition of the HRM and SOCONT model to the Alzette river basin was completed successfully. Results overall proved to be satisfying, with the HRM model performing equally well for low flows and high flows, while the SOCONT model showed best results for high flows and a systematic overestimation of the mean discharge. Both models proved to be adequate for evaluating daily runoff in non‐monitored basins of the Grand‐Duchy of Luxembourg, helping thus to counterbalance the considerable lack of hydrological observation series in this part of the Rhine basin. Copyright © 2004 John Wiley & Sons, Ltd.
Integration of ecological aspects in flood protection strategies: defining an ecological minimum
Authors: Geilen Noël , Jochems Hans , Krebs Laurence , Muller Serge , Pedroli Bas , Van der Sluis Theo , Van Looy Kris , Van Rooij Sabine 
Published: May 2004

AbstractPolicy makers are confronted with the question of how to combine sustainable flood protection and floodplain rehabilitation in the best possible way. Both topics deal with spatial planning aspects in a range of scales. This question was the starting point for the development of an evaluation method within the IRMA/SPONGE project INTERMEUSE, illustrated on the basis of assumed flood protection strategies in the Meuse river basin (the ‘sponge’ strategy, the ‘retention’ strategy, and the ‘floodplain lowering’ or ‘winter bed’ strategy). The integration of flood protection and floodplain rehabilitation can be performed on two scale levels that are interrelated: on the regional level the focus is on (large parts of) an entire stream basin; on the local level specific site conditions are taken as starting point. Ecological aspects under study are spatial cohesion of habitats as identified by species population persistence modelling (regional, longitudinal level) and required habitat quality for carabid beetles and for meadow vegetation gradients as assessed by correspondence analysis (local, transversal level). The carabid beetles are taken as indicative for the ecological integrity of the river bed, the meadow vegetation for that of the floodplain.A unifying concept in the evaluation of ecological integrity is the ecological minimum: the critical boundary or minimum level of habitat conditions for a potentially good ecological functioning. It is the least acceptable state for a river ecosystem that is still functional to some extent, compared to a natural river ecosystem. The results of this study show clearly that there is a good chance to combine floodplain rehabilitation aims with flood protection activities, both on a local and on an international scale. Although ecological effect assessment and ecological optimizing (referring to a natural reference state) remain basic, additionally the assessment of the ecological minimum helps to define design strategies for integrated flood protection, especially in situations where there is an opportunity for river rehabilitation. Copyright © 2004 John Wiley & Sons, Ltd.
Assessment of the effects of cyclic floodplain rejuvenation on flood levels and biodiversity along the Rhine River
Authors: Baptist Martin J. , Penning W. Ellis , Duel Harm , Smits Antonius J. M. , Geerling Gertjan W. , Van der Lee Guda E. M. , Van Alphen Jos S. L. 
Published: May 2004

AbstractTo reduce flood risks in the Netherlands, measures to increase the flood conveyance capacity of the Rhine River will be implemented. These measures will provide more room for the river and include lowering of the floodplains and excavation of secondary channels. Moreover, these measures provide opportunities for ecological rehabilitation of the floodplains. However, it is expected that floodplain sedimentation and softwood forest development in rehabilitated floodplains will gradually reduce the conveyance capacity and the biodiversity. Therefore, a floodplain management strategy was proposed that would meet both flood protection and nature rehabilitation objectives. This strategy, Cyclic Floodplain Rejuvenation (CFR), aims at mimicking the effects of channel migration by removal of softwood forests, by lowering floodplains or by (re)constructing secondary channels. In this study, the effects of CFR measures on reducing flood levels and enhancing biodiversity along the Waal River were assessed. A one‐dimensional hydraulic modelling system was applied together with rule‐based models for floodplain vegetation succession and floodplain sedimentation. The model simulations demonstrated that the flood management strategy of Cyclic Floodplain Rejuvenation is able to sustain safe flood levels in the Waal River when about 15% of the total floodplain area is rejuvenated with a return period of 25 to 35 years. The rejuvenation strategy led to a diverse floodplain vegetation distribution that largely complies to the historical reference for the Waal River. Cyclic Floodplain Rejuvenation may be the appropriate answer to solve the dilemma between flood protection and nature rehabilitation in highly regulated rivers. Copyright © 2004 John Wiley & Sons, Ltd.
BIO‐SAFE: assessing the impact of physical reconstruction on protected and endangered species
Authors: de Nooij R. J. W. , Lenders H. J. R. , Leuven R. S. E. W. , de Blust G. , Geilen N. , Goldschmidt B. , Muller S. , Poudevigne I. , Nienhuis P. H. 
Published: May 2004

AbstractAssessing actual and potential biodiversity of river–floodplain ecosystems on the basis of policy and legislation concerning endangered and protected species is necessary for consistency between different policy goals. It is thus a prerequisite to sustainable and integrated river management. This paper presents BIO‐SAFE, a transnational model that quantifies the relevance of species and ecotopes, characteristic of the main channels and floodplains of the rivers Rhine and Meuse, on the basis of international treaties and directives and national Red Data Lists. BIO‐SAFE was developed into a tool for biodiversity assessment with regard to design and evaluation of physical planning projects, Environmental Impact Assessments and comparative landscape–ecological studies. It was conceived to be applicable in Germany, France, Belgium and the Netherlands.Taxonomic groups involved are higher plants, birds, herpetofauna, mammals, fish, butterflies, and dragonflies and damselflies. The linkage of habitat requirements of species to ecotopes allows the user to derive information at the level of several ecotope types and scales. The model requires input data on presence of species and/or surface area of ecotopes. BIO‐SAFE has been applied to flood risk reduction projects along the rivers Rhine and Meuse. Results show that BIO‐SAFE yields quantitative information regarding the degree to which actual situations, reconstruction designs and developments of species and ecotope composition meet national and international agreements on biodiversity conservation.Attuning biodiversity conservation and flood risk reduction measures is a major issue in applied ecology and spatial planning. Assessments with BIO‐SAFE can help find an optimal balance. Because of its policy‐based character, BIO‐SAFE yields information that is complementary to ecological biodiversity indices, single‐species habitat models and ecological network analysis. The development of BIO‐SAFE was based on species characteristic of rivers and floodplains, but the method can easily be applied to other ecosystems as well. Copyright © 2004 John Wiley & Sons, Ltd.
Nutrient retention in floodplains of the Rhine distributaries in The Netherlands
Authors: van der Lee G. E. M. , Olde Venterink H. , Asselman N. E. M. 
Published: May 2004

AbstractDenitrification, plant uptake and sedimentation are important mechanisms of nutrient retention in floodplains. Due to nutrient retention, nitrogen (N) and phosphorus (P) loads of the river decrease, which is a primary aim in European water quality management. However, the relative contribution of the various retention mechanisms to nutrient retention is largely unknown, as is the total retention that may be achieved. The aim of this study was the estimation of nutrient retention by the mechanisms of plant uptake, silt sedimentation and denitrification for the Dutch Rhine distributaries over one hydrological year (April 2000–March 2001). N and P retention in these floodplain stretches were estimated by means of measured process rates in the floodplains and one‐dimensional hydrodynamic and sedimentation models.Estimated total retention of N (all mechanisms together) is less than 3% of the annual load, which can be considered as insignificant. The total retention of P was 5 to 18% of the annual P load, which is significant. Floodplain sedimentation was the most important retention mechanism for both N and P. As excavation of the floodplain is expected to increase annual sedimentation rates, floodplain lowering as carried out in river restoration projects, may lead to a considerable increase in retention of P, but will hardly affect retention of N, because N was mainly present as dissolved nitrate in the river water. Copyright © 2004 John Wiley & Sons, Ltd.
Developing views of nature of science in an authentic context: An explicit approach to bridging the gap between nature of science and scientific inquiry
Authors: Schwartz Reneé S. , Lederman Norman G. , Crawford Barbara A. 
Published: May 2004

AbstractReform efforts emphasize teaching science to promote contemporary views of the nature of science (NOS) and scientific inquiry. Within the framework of situated cognition, the assertion is that engagement in inquiry activities similar to those of scientists provides a learning context conducive to developing knowledge about the methods and activities through which science progresses, and, in turn, to developing desired views of NOS. The inclusion of a scientific inquiry context to teach about NOS has intuitive appeal. Yet, whether the learners are students, teachers, or scientists, the empirical research does not generally support the claim that engaging in scientific inquiry alone enhances conceptions of NOS. We studied developments in NOS conceptions during a science research internship course for preservice secondary science teachers. In addition to the research component, the course included seminars and journal assignments. Interns' NOS views were assessed in a pre/post format using the Views of Nature of Science questionnaire, [VNOS‐C] and interviews. Results indicate most interns showed substantial developments in NOS knowledge. Three factors were identified as important for NOS developments during the internship: (1) reflection, (2) context, and (3) perspective. Reflective journal writing and seminars had the greatest impact on NOS views. The science research component provided a context for reflection. The interns' role perspective appeared to impact their abilities to effectively reflect. Interns who assumed a reflective stance were more successful in deepening their NOS conceptions. Those who maintained a scientist's identity were less successful in advancing their NOS views through reflection. In light of these results, we discuss the significance and challenges to teaching about NOS within inquiry contexts. © 2004 Wiley Periodicals, Inc. Sci Ed 88:610–645, 2004
Humanizing science education
Authors: Donnelly James F. 
Published: May 2004

AbstractThis paper argues that the diverse curriculum reform agendas associated with science education are strongly and critically associated with the educational characteristics of the humanities. The article begins with a survey of interpretations of the distinctive contribution which the humanities make to educational purposes. From this survey four general characteristics of the humanities are identified: an appeal to an autonomous self with the right and capacity to make independent judgements and interpretations; indeterminacy in the subject matter of these judgements and interpretations; a focus on meaning, in the context of human responses, actions, and relationships, and especially on the ethical, aesthetic, and purposive; and finally, the possibility of commonality in standards of judgement and interpretation, under conditions of indeterminacy. Inquiry and science technology and society (STS) orientated curriculum development agendas within science education are explored in the light of this analysis. It is argued that the four characteristics identified are central to the educational purposes of these and other less prominent modes of curriculum development in science, though not unproblematically so. In the light of this discussion the prognosis and challenges for science curriculum development are explored. © 2004 Wiley Periodicals, Inc. Sci Ed 88: 762–784, 2004
Brief report: Parents’ life events and substance use among German adolescent girls: testing a family mediation model
Authors: Wiesner Margit , Juang Linda 
Published: May 2004

AbstractIn this cross‐sectional study, data from 202 German adolescent girls (ages 13–17 years) and their parents were utilized to test whether the relationship between parents’ stressful life events and their daughter's substance use was mediated by higher levels of parents’ depressive symptoms, lower quality of the relationship between the parents, and poor parenting behaviour. Structural equation modelling revealed that these family characteristics did not account for the link between parents’ stressful life events and adolescent girl's substance use. Further research is needed to better understand the mechanisms that account for such linkages.
Does past pain influence current pain: biological and psychosocial models of sex differences
Authors: Rollman Gary B. , Abdel‐Shaheed Jennifer , Gillespie Joanne M. , Jones Kevin S. 
Published: May 2004

AbstractPrevious studies have generally indicated sizeable sex differences for both laboratory pain reactivity and clinical pain reports. Numerous biological and psychosocial models have been invoked to account for these findings, but the laboratory and clinical findings have generally been examined in isolation. This paper reviews data which show a relationship between past clinical pain experiences and current responses to experimentally induced pain. Individuals with a greater pain history tend to show lower pain tolerance. Since women often have high pain experience levels and lower pain tolerance, one might ask whether the two factors are related. We review several models, based upon concepts of neonatal differences in pain reactivity, hypervigilance following early pain experiences, and concepts of peripheral and central sensitization or plasticity which might help to bridge the gap between clinical and experimental findings.