bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behaviour of chemical solutes during a storm in a rainforested headwater catchment
Authors: Grimaldi Catherine , Grimaldi Michel , Millet Antoine , Bariac Thierry , Boulègue Jacques 
Published: January 2004

AbstractThe aim of this study is to identify, in a small catchment area located within a tropical forest, the pedological compartments in which the export of nutrients and chemical erosion of solutes occur during a stormflow event. The catchment area displays two types of lateral flow: (i) overland flow at the surface of the soil in the litter and root mat and (ii) groundwater flow in a macroporous subsurface horizon. We interpret the variations of stream‐water chemistry during a storm‐flow event using the separation of storm‐flow hydrograph data between overland and groundwater flow, and (Cl−) as a chemical parameter characterizing the residence time of water in the soil. It appears that K+ especially was released into the throughfall, whereas Ca++, Mg++ and Na+ were clearly released from the litter. K+ disappeared rapidly from soil solution, whereas Ca++ and Mg++ were more progressively absorbed by the vegetation. The Ca++ and Mg++ contents in groundwater increased with increasing residence time owing to the transpiration of trees. The export of H4SiO4 in the overland flow was moderate, i.e. 24% of total H4SiO4 export in the stream flow, as overland flow represented 39% of total runoff. The subsurface horizon—where active groundwater flow occurs—was successively affected by chemical erosion during the storm‐flow peak, and then by neoformation of kaolinite favoured by increasing water residence time. Copyright © 2003 John Wiley & Sons, Ltd.
Correlation between El Niño–Southern Oscillation (ENSO) and precipitation in South‐east Asia and the Pacific region
Authors: Xu Z. X. , Takeuchi K. , Ishidaira H. 
Published: January 2004

AbstractThe relationship between El Niño–Southern Oscillation (ENSO) events versus precipitation anomalies, and the response of seasonal precipitation to El Niño and La Niña events were investigated for 30 basins that represent a range of climatic types throughout South‐east Asia and the Pacific region. The teleconnection between ENSO and the hydroclimate is tested using both parametric and non‐parametric approaches, and the lag correlations between precipitation anomalies versus the Southern Oscillation Index (SOI) several months earlier, as well as the coherence between SOI and precipitation anomalies are estimated. The analysis shows that dry conditions tend to be associated with El Niño in the southern zone, and part of the middle zone in the study area. The link between precipitation anomalies and ENSO is statistically significant in the southern zone and part of the middle zone of the study area, but significant correlation was not observed in the northern zone. Patterns of precipitation response may differ widely among basins, and even the response of a given river basin to individual ENSO events also may be changeable. Copyright © 2003 John Wiley & Sons, Ltd.
The importance of oxygen isotope provenance in relation to solute content of bulk meltwaters at Imersuaq Glacier, West Greenland
Authors: Yde Jacob C. , Tvis Knudsen N. 
Published: January 2004

AbstractStable oxygen isotope analysis and measurement of several dissolved cations and anions of bulk meltwater samples have provided information about the hydrochemical environment of the glacial hydrological system at Imersuaq Glacier, an outlet tongue from the Greenland ice‐sheet, West Greenland. The samples were collected at frequent intervals during the period 20–28 July 2000 in a small (<20 L s−1) englacial meltwater outlet at the glacier margin. The results document the following findings: (i) a marked diurnal variation of δ18O is related to the composition of oxygen isotope provenances, mainly near‐marginal local superimposed ice and basal up‐sheared ice further up‐glacier; (ii) a relationship is seen between all base cations (Na+, K+, Ca2+, Mg2+), SO42−and δ18O, indicating that solute acquisition is provided by solid–solution contact with the up‐sheared ice—as the relationship with Cl−is weak the influence of seasalt‐derived solutes is small in the area; (iii) when the melt rate is high, two diurnal maxima of δ18O values and solute concentrations are measured, and it is suggested that a snow meltwater component is responsible for the second maximum of δ18O—a short residence time leads to a delayed decrease in ion concentrations. Copyright © 2003 John Wiley & Sons, Ltd.
Plot‐scale measurement of soil erosion at the experimental area of Sparacia (southern Italy)
Authors: Bagarello V. , Ferro V. 
Published: January 2004

AbstractObtaining good quality soil loss data from plots requires knowledge of the factors that affect natural and measurement data variability and of the erosion processes that occur on plots of different sizes. Data variability was investigated in southern Italy by collecting runoff and soil loss from four universal soil‐loss equation (USLE) plots of 176 m2, 20 ‘large’ microplots (0·16 m2) and 40 ‘small’ microplots (0·04 m2). For the four most erosive events (event erosivity index, Re ≥ 139 MJ mm ha−1 h−1), mean soil loss from the USLE plots was significantly correlated with Re. Variability of soil loss measurements from microplots was five to ten times greater than that of runoff measurements. Doubling the linear size of the microplots reduced mean runoff and soil loss measurements by a factor of 2·6–2·8 and increased data variability. Using sieved soil instead of natural soil increased runoff and soil loss by a factor of 1·3–1·5. Interrill erosion was a minor part (0·1–7·1%) of rill plus interrill erosion. The developed analysis showed that the USLE scheme was usable to predict mean soil loss at plot scale in Mediterranean areas. A microplot of 0·04 m2 could be used in practice to obtain field measurements of interrill soil erodibility in areas having steep slopes. Copyright © 2003 John Wiley & Sons, Ltd.
A network‐index‐based version of TOPMODEL for use with high‐resolution digital topographic data
Authors: Lane S. N. , Brookes C. J. , Kirkby M. J. , Holden J. 
Published: January 2004

AbstractThis paper describes the preliminary development of a network‐index approach to modify and to extend the classic TOPMODEL. Application of the basic Beven and Kirkby form of TOPMODEL to high‐resolution (2·0 m) laser altimetric data (based upon the UK Environment Agency's light detection and ranging (LIDAR) system) to a 13·8 km2 catchment in an upland environment identified many saturated areas that remained unconnected from the drainage network even during an extreme flood event. This is shown to be a particular problem with using high‐resolution topographic data, especially over large appreciable areas. To deal with the hydrological consequences of disconnected areas, we present a simple network index modification in which saturated areas are only considered to contribute when the topographic index indicates continuous saturation through the length of a flow path to the point where the path becomes a stream. This is combined with an enhanced method for dealing with the problem of pits and hollows, which is shown to become more acute with higher resolution topographic data. The paper concludes by noting the implications of the research as presented for both methodological and substantive research that is currently under way. Copyright © 2004 John Wiley & Sons, Ltd.
Reference distributions for complement proteins C3 and C4: A comparison of a large cohort to the world's literature
Authors: Ritchie Robert F. , Palomaki Glenn E. , Neveux Louis M. , Navolotskaia Olga 
Published: January 2004

AbstractThe lack of credible reference materials and satisfactory methods for quantifying serum levels has limited the bedside use of complement protein (C3 and C4) measurements. However, great technological strides have been made in the last few years. The remaining barrier to a more relevant and cost‐effective use of serum protein data for diagnosis and prognosis is the availability of reliable reference intervals from birth to old age for both males and females. Fifty‐one publications reporting reference intervals were identified that meet the criteria used in our prior four studies, and these were analyzed statistically. Previous small studies with constrained age ranges agree, on average, with our larger series of life‐long reference ranges. This meta‐analysis provides support for our reference ranges and places them in the context of previous publications. J. Clin. Lab. Anal. 18:9–13, 2004. © 2004 Wiley‐Liss, Inc.
Zone center wavenumbers of tetragonal AGa2X4 (A = Cd, Zn; X = S, Se)
Authors: Gupta H. C. , Singh M. K. , Tiwari L. M. 
Published: January 2004

AbstractA short‐range force constant model (SRFCM) was applied to investigate the phonons in AGa2X4 (A = Cd, Zn; X = S, Se) defect chalcopyrite compounds in the tetragonal phase. The calculation with six stretching and one bending force constants in the SRFCM agrees well with the observed Raman and infrared wavenumbers. In CdGa2X4, the nearest Ga—X interatomic force constants of its bonds were found to be stronger than the nearest Cd—X interatomic force constants, whereas in ZnGa2X4, the nearest Zn—X interatomic force constants of its bonds were found to be weaker than the nearest Zn—X interatomic force constants. The variation of interatomic force constants is discussed. The dominant force constants have nearly the same ratio when Se replaces S. Copyright © 2003 John Wiley & Sons, Ltd.
Resonance Raman spectroscopic studies of [Ru(phen)2qdppz]2+ and its interactions with calf thymus DNA
Authors: Abraham B. , Sastri C. V. , Maiya B. G. , Umapathy S. 
Published: January 2004

AbstractResonance Raman (RR) spectroscopy was employed to study the metal to ligand charge transfer (MLCT) and intraligand transition (IL) state of the [Ru(phen)2qdppz]2+ complex, where phen = 1, 10‐phenanthroline and qdppz = naphtho[2,3‐a]dipyrido[3,2‐h:2′,3′‐f]phenazine‐5,18‐dione. The vibrational bands were assigned based on the data available for [Ru(phen)2dppz]2+ (dppz = dipyrido[3,2‐a:2′,3′‐c]phenazine), [Ru(dppz)3]2+ and [Ru(phen)3]2+. The tail end of the MLCT band is inferred to be the Ru → qdppz localized transition based on vibrational intensity analysis. On intercalation with DNA, the modes assigned to qdppz decrease in intensity owing to ππ stacking interactions with the DNA bases. RR data show that the above complex binds to DNA through intercalation via the qdppz moiety. Copyright © 2003 John Wiley & Sons, Ltd.
Fourier transform Raman spectra (in aqueous solution) of serine and tetraaqua serine aluminium(III) cation complex: [Al(Ser)(H2O)4]2+. DFT: B3LYP/3–21G structural and vibrational calculations
Authors: Téllez S. Claudio A. , de Moraes Silva Andrea , Felcman Judith 
Published: January 2004

AbstractThe tetraaquaserine aluminium(III) cation complex was prepared from a mixture of solutions 5 mol l−1 of Al(NO3)3·9H2O and serine (Ser) at pH 0.5. Raman spectra of serine and of serine with Al(NO3)3·9H2O, both in aqueous solution, show that four water molecules participate in the coordination sphere of Al(III). Density functional theory calculations, DFT: B3LYP/3–21G, were performed for serine and for the [Al(Ser)(H2O)4]2+ cation complex. The vibrational results agree well with the experimental fourier transform (FT) Raman spectra in the higher and low‐energy regions. For serine, the observed FT‐Raman spectrum matches the DFT‐calculated spectrum. Approximate assignments of the vibrational modes were made for both compounds. DFT‐calculated geometric parameters are also given for serine and [Al(Ser)(H2O)4]2+. Copyright © 2004 John Wiley & Sons, Ltd.
Raman spectroscopy of the arsenates and sulphates of the tsumcorite mineral group
Authors: Frost Ray L. , Kloprogge J. Theo , Martens Wayde N. 
Published: January 2004

AbstractThe structure of a selection of arsenate‐and sulphate‐based minerals of the tsumcorite group was studied by the combination of Raman and infrared spectroscopy. A comparison is made with the sulphate‐bearing mineral natrochalcite. Isomorphic substitution of sulphate for arsenate is observed for gartrellite and thometzekite. The positions of the hydroxyl and water stretching vibrations are related to the strength of the hydrogen bond formed between the OH unit and the AsO4 anion. Estimates of the hydrogen bond distances are calculated using a Libowitzky‐type function. Characteristic Raman spectra of the minerals allow the assignment of the bands to specific vibrational modes. Copyright © 2004 John Wiley & Sons, Ltd.
Vibrational spectra of arsenic triiodide: a lattice dynamics study
Authors: Zeng W. Y. , Anderson A. 
Published: January 2004

AbstractA simple force constant model is described and applied to the vibrations of the layered molecular crystal of arsenic triiodide. The model uses nine adjustable parameters (three intramolecular and six intermolecular) to calculate the wavenumbers of 14 optical normal modes, and good agreement with observed Raman and infrared data in both the lattice and internal mode regions was obtained. Estimates of the magnitudes of the various types of interatomic forces were derived. The most important is that between As and I atoms in adjacent layers and the next is that between As atoms in the same layer. The forces between I—As—I ‘sandwiches’ are primarily of the weaker van der Waals type, which accounts for the cleavage properties of this crystal. The principal intramolecular forces show appreciable decreases in magnitude, compared with those applicable to isolated molecules, interpreted as a charge‐transfer effect from intra‐ to intermolecular bonds. Copyright © 2003 John Wiley & Sons, Ltd.
Structure and vibrational spectra of a new trihydrate diphosphate, MnNH4NaP2O7·3H2O
Authors: Brouzi K. , Ennaciri A. , Harcharras M. , Capitelli F. 
Published: January 2004

AbstractThe new trihydrate diphosphate, MnNH4NaP2O7·3H2O, were synthesized and investigated by X‐ray diffraction and vibrational spectroscopy. Single crystal structure has been obtained using 1361 reflections with a final R value of 0.0564. This salt crystallizes in the monoclinic system, space group Cc, with Z = 4 and the following unit‐cell parameters: a = 10.1125(12), b = 16.4370(3), c = 5.5987(7) Å, β = 104.314° (9), V = 901.7 Å3. The atomic arrangement is a three‐dimensional framework built from P2O74− diphosphate anions linked by MnO6, NaO6 and NH4O6 octahedra. The P2O74− anion shows bent eclipsed configuration with bridge angle P‐O‐P of 125.9(4)°. The infrared and Raman spectra of this salt have been recorded and interpreted using factor group analysis. Most of the bands are observed in both infrared and Raman spectra, which confirms a non‐centrosymmetric space group. The apparence of υas POP and υs POP in infrared and Raman spectra point to a bent POP bridge in MnNH4NaP2O7·3H2O. Copyright © 2003 John Wiley & Sons, Ltd.
Redox and conformational equilibria of cytochrome c552 from Thermus thermophilus adsorbed on a chemically modified silver electrode probed by surface‐enhanced resonance Raman spectroscopy
Authors: Bernad Sophie , Soulimane Tewfik , Lecomte Sophie 
Published: January 2004

AbstractSurface‐enhanced resonance Raman spectroscopy (SERRS) was employed to study the potential‐dependent processes of the electron transferring heme protein cytochrome c552 (Cyt‐c522) from Thermus thermophilus. Cyt‐c552 was adsorbed on Ag electrodes coated with functionalized self‐assembled monolayers (SAMs) of alkanethiols, regarded as a model of its redox partner ba3‐oxidase. By a quantitative analysis of the SERR spectra recorded at different potentials, the redox potential of Cyt‐c552 and the number of transferred electrons were determined. On pure hydrophobic alkanethiols, the Cyt‐c552 heme structure is greatly modified in a non‐electroactive way with the appearance of a 5cHS species. When Cyt‐c552 is adsorbed on mixed surfaces of hydroxyl‐ and methyl‐terminated alkanethiols, the electron transfer is effective (n = 1) and the structure of the heme is not modified, as is assumed when Cyt‐c552 interacts with its natural redox partner ba3‐oxidase. When the chain length of the mixed SAMs is increased, the defects on the surface are decreased and the electron transfer becomes less efficient. The presence of defects in the organization of the short chain of five carbons seems to be relevant for having a good surface model of the redox partner. Copyright © 2003 John Wiley & Sons, Ltd.
Anharmonic line shift and linewidth of the Raman modes in TlInS2 layered crystals
Authors: Yuksek N. S. , Gasanly N. M. , Aydinli A. 
Published: January 2004

AbstractThe temperature dependence of the unpolarized Raman spectra from TlInS2 layered crystal was measured between 10 and 300 K. The analysis of the experimental data showed that the temperature dependences of wavenumbers and linewidths are well described by considering the contributions from thermal expansion and lattice anharmonicity. The purely anharmonic contribution (phonon–phonon coupling) was found to be due to three‐phonon processes. This work demonstrates that the two Raman modes at 280.9 and 292.3 cm−1 exhibit changes toward high wavenumbers as the temperature is raised from 10 to 300 K. Copyright © 2003 John Wiley & Sons, Ltd.
Spectroscopic investigation of yellow majolica glazes
Authors: Sakellariou K. , Miliani C. , Morresi A. , Ombelli M. 
Published: January 2004

AbstractThe yellow decorations of some ceramic art objects were examined through different spectroscopic techniques and optical and electronic microscopy. The yellow pigment was identified as lead antimonate, the well‐known Naples Yellow. Its use in the course of history seems to be strongly discontinuous, but the diagnostic techniques used to date may not have been adequate. Samples from original masterpieces have been compared with a yellow pigment synthesized in our laboratory, following a Renaissance ancient recipe for Naples Yellow. Concordant results were obtained with Fourier transform IR and UV–visible reflectance spectroscopy, Raman microscopy, optical microscopy and scanning electron microscopy. It is demonstrated that the micro‐Raman technique is very effective for the unambiguous identification of the pigment and its firing temperature. Copyright © 2003 John Wiley & Sons, Ltd.
On‐site Raman analysis of Medici porcelain
Authors: Colomban Ph. , Milande V. , Lucas H. 
Published: January 2004

AbstractOn‐site Raman analyses were performed at the Musée National de Céramique, Sèvres, France, on the rare, first‐known European porcelain dishes, produced from 1575 to 1587 in Florence, under the patronage of Grand Duke Francesco I de Medici. The results are discussed in the light of previous chemical analyses. The different identified phases are α‐quartz, feldspar, calcium phosphate and β‐(and α‐) wollastonite, i.e. the fingerprints of both hard‐ and soft‐paste porcelains. The presence of feldspar is consistent with the high potassium and aluminium content, evident from previous composition analysis. The good dissolution of quartz grains and the signature of β‐wollastonite (CaSiO3) are consistent with a frit‐ware technology. Calcium phosphate in the enamel indicates that the Islamic technique of opacification with calcined bone was used. Copyright © 2003 John Wiley & Sons, Ltd.
The correct form of the Raman scattering tensor
Authors: Hassing S. , Svendsen E. Nørby 
Published: January 2004

AbstractIn the literature about Raman scattering, an unsatisfactory ambiguity exists in the basic Kramers–Heisenberg formula. The sign in front of the damping constant Γℓ appears to be arbitrary. In the present paper we show that the correct form is the one where Γℓ has the same sign as the excitation frequency ω. The argument is based on the causality principle, leading to the requirement that the real and imaginary parts of the scattering tensor constitute a pair of Hilbert transforms. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of different silver substrate on the SERS signal of sulfide adsorbent
Authors: Li Fengting , Zhang Bingru , Li Xia , Qiao Junlian , Li Guangtao 
Published: January 2004

AbstractThe chemisorption of dodecyl disulfide and phenyl disulfide on chemically deposited silver film and HNO3‐etched silver foils was investigated by Fourier‐transform surface‐enhanced Raman scattering spectroscopy (FT‐SERS). These disulfides can cleave and are chemisorbed on silver surfaces. We found these two kinds of substrates showed different activation to the sulfides and there is some fine distinction of SERS signals of the same chemical on the substrates. The enhancing effect of the adsorbent signal and adsorption depend on the substrate state. Chemically deposited silver substrate shows better activation and SERS enhancing effect than the HNO3‐etched silver foils. Copyright © 2004 John Wiley & Sons, Ltd.
Micro‐Raman spectroscopy of Si‐, C‐, Mg‐ and Be‐implanted GaN layers
Authors: Wang L. S. , Tripathy S. , Sun W. H. , Chua S. J. 
Published: January 2004

AbstractWe have carried out a systematic Raman study on Si‐, C‐, Mg‐ and Be‐implanted GaN layers. In the as‐implanted GaN layers, new Raman bands around 293–300, 360 and 666–671 cm−1 have appeared. From the phonon‐dispersion curves for hexagonal GaN, the 293–300 cm−1 and 666–671 cm−1 bands are assigned to the highest acoustic‐phonon branch and the optical‐phonon branch at the Brillouin zone boundaries, respectively. Several new modes at 168, 199, 320 and 346 cm−1 are also observed in the Raman spectra of Be‐implanted GaN after post‐implantation annealing and could be associated with Be‐related local vibrational modes in GaN. In the Si‐implanted GaN, we have also observed a new local vibrational mode at 612 cm−1 after thermal annealing. Copyright © 2004 John Wiley & Sons, Ltd.
The Lindisfarne Gospels and two other 8th century Anglo‐Saxon/Insular manuscripts: pigment identification by Raman microscopy
Authors: Brown Katherine L. , Clark Robin J. H. 
Published: January 2004

AbstractThe Lindisfarne Gospels (Cotton MS Nero D iv, ca. 715 AD) and two nearly contemporary manuscripts (Royal MS 1B vii and Add. MS 40618) held in the British Library have been analysed in detail by Raman microscopy in order to establish the palette of each. The blue pigment used on the Lindisfarne Gospels is shown not to be lazurite, as concluded in 1960 by visual examination of known pigments and those on the Gospels, but exclusively indigo. Of the Anglo‐Saxon and Insular manuscripts studied so far by Raman microscopy, the earliest found to include lazurite in its palette is Add. MS 40618, not on its still extant original miniature of ca. 756 AD, but on later additions of ca. 920 AD. The Insular triumvirate palette, which had been assumed to consist of orpiment, red lead and verdigris, was found also to include red ochre and vergaut (indigo admixed with orpiment) but not necessarily verdigris. The palettes of the manuscripts studied, as specified in existing literary sources, are not reliable, and careful in situ scientific analysis of the pigments present is essential to establish the identity of the latter and of any decomposition products present. Copyright © 2004 John Wiley & Sons, Ltd.