bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breaking with the authoritarian past in Portugal: continuities and discontinuities of international linkages and their impact on the political system
Authors: Magone José M. 
Published: October 2005

This article<fn id="p1-f1" symbol="*">This article is derived from a paper that was presented to the CPHRC's Second International Conference, The Estado Novo: the final years', Paris, 27–28 September 2002.</fn> seeks to delineate the interactive relationship between the European Union and the establishment of a Portuguese democracy that was itself shaped by processes that had already begun during the 1960s. In the first section we will discuss the relationship between the authoritarian regime and the European Union. The second section discusses how the European Union shaped the outcome of the revolutionary process. The third section explains why it took so long for Portugal to become a member of the European Community. The fourth section discusses Portugal's integration into the European Union and how it gained the self-confidence with which to shape European policy-making.
The NEXUS vision: an alternative to the reference value concept
Authors: Goldschmidt Henk M. J. 
Published: October 2005

AbstractIn Lundberg's brain-to-brain turnaround time loop, the postanalytical phase is undoubtedly one of the most difficult phases. Of course, error prolongation can cause serious problems when quality is not sufficiently assessed and assured in the preanalytical and analytical phases. However, in the postanalytical phase following reporting, interpretation and action are at stake; and with this the wellbeing of the patient. Here exists a grey area of responsibility between the laboratory and physician. The laboratory should correctly report the measurement as data. But to place this in the correct context requires additional information on (specific) reference values, specificity, sensitivity and possible interpretation of the data. Here is where the ultimate interaction between the laboratory and the physician (representing the patient) occurs. What happens when errors occur in this phase? Do errors occurring in the previous phases effect this phase? What types of errors occur in the postanalytical phase? Postanalytical quality is the ultimate check on the coherence of the preanalytical, analytical and postanalytical quality; it is a check on the overall quality. It ties together the quality of the question to be answered, the analytical quality that is achieved and the usefulness of the answer obtained. In addition, it also checks quality in the context of the patient and physician interaction. Can errors be avoided and can a predictable quality level be assessed and be assured? A model, called NEXUS vision is described.
Stoichiometric valence versus structural valence: Conclusions drawn from a study of the influence of polyhedron distortion on bond valence sums
Authors: Liebau Friedrich , Wang Xiqu 
Published: October 2005

Abstract
From studies of the influence of polyhedron distortions on bond valence sums (BVS), it is concluded that larger deviations of the BVS values from corresponding values of their classical valence are due to the fact that so far no distinction has been made between the stoichiometric valence derived from chemical analysis and the structural valence derived from structure data.
The structure of multiple twinned CsMgInF6and its relationship to other pyrochlore derived fluorides
Authors: Friese Karen , Gesland Jean-Yves , Grzechnik Andrzej 
Published: October 2005

AbstractThe pyrochlore derived fluoride structures with general composition AM2+M3+F6crystallize in space groups which are in group-subgroup relationship toFd-3m, the space group of the archetype pyrochlore structure. All orthorhombic representatives investigated so far show an ordered M2+/M3+distribution over two symmetrically independent octahedral sites. CsMgInF6crystallizes in space groupPnmawith lattice parametersa= 7.5285(1),b= 7.5285(1) andc= 10.6459(1) Å. The investigated crystal was a second degree twin, where the independent twin elements are a combination of the three- and fourfold rotation axes of the archetype cubic lattice. The pseudosymmetry of the compound with respect to space groupImmais extremely high and a reliable decision about the correct symmetry was only possible when inspecting partial agreement factors for the weak reflectionsh+k+l= 2n+ 1 only. With respect to the other orthorhombic pyrochlore derived ter nary fluorides, the present compound differs in the fact that the M2+/M3+ions are completely disordered in CsMgInF6.
Structural phase transitions in two-dimensional systems: Pb/Ge(111) and Sn/Ge(111)
Authors: Cano Andrés , Levanyuk Arkadi P. , Michel Enrique G. 
Published: October 2005

Abstract
The adsorption systems Pb/Ge(111) and Sn/Ge(111) exhibit temperature induced structural phase transitions. We report here a phenomenological analysis of these phase transitions starting from Landau theory. On the basis of symmetry arguments, we show that essential differences are expected theoretically for the critical behav ior of the two interfaces. The influence of hopping defects in these systems is treated using a Landau-like approach. This approach gives us a consistent and general manner to interpret the existing experimental data for these interfaces.
Revised prediction of B1 to B2 phase transition pressures in YbN, YbP and YbAs
Authors: Winkler Björn , Milman Victor 
Published: October 2005

Abstract
Quantum mechanical calculations based on density functional theory and a generalized gradient approx imation have been used to study the pressure-induced B1 to B2 structural phase transition in YbN, YbP and YbAs. The phase transitions are predicted to occur at 137 GPa in YbN, at 25 GPa in YbP, and at 20 GPa in YbAs. These values are significantly lower than those predicted by empirical poten tial model calculations. Bulk moduli are predicted to be 136, 70 and 63 GPa for YbN, YbP and YbAs, respectively.
CaZrGeO5 and the triclinic instability of the titanite structure type
Authors: Malcherek Thomas , Elleman-Olesen Rikke 
Published: October 2005

Abstract
CaZrOGeO4 has been synthesized and its structure has been refined from X-ray powder diffraction data as triclinic, A1̅ (P1̅). A displacive structural phase transition to a monoclinic structure of the titanite aristotype with space group symmetry A2/a (C2/c) is observed near 488 K. The non-symmetry breaking spontaneous strain below the phase transition corresponds to a contraction of the structure normal to the octahedral chain direction. The coordination of Ca changes from 7-fold in the high temperature phase to 8-fold in the triclinic low temperature phase. A limiting monoclinic-angle is postulated below which compounds of the titanite topology and general stoichiometry CaMOXO4 distort to triclinic symmetry.
Nanoscale phase transformations in relaxor-ferroelectric lead scandium tantalate and lead scandium niobate
Authors: Mihailova Boriana , Bismayer Ulrich , Güttler Bernd , Gospodinov Marin , Boris Alexander , Berndhard Christian , Aroyo Mois 
Published: October 2005

Abstract
Structural transformations that take place on cooling down in Pb-based relaxor ferroelectrics are investigated on the basis of polarized Raman spectroscopy and far infrared ellipsometry applied on single-crystal samples of PbSc0.5Ta0.5O3 (PST) and PbSc0.5Nb0.5O3 (PSN). The temperature evolution of phonon anomalies reveals different preferred ferroic species in PST and PSN. Near the dielectric constant maximum cooperative shifts of Pb atoms in respect to the oxygen sheets perpendicular to the cubic body diagonal occur in larger spatial regions for PST than for PSN. On cooling down this structural modification becomes preferential for PST, thus giving rise to highly anisotropic ferroelectric domains. In PSN the temperature decrease favours B-cation deviations from the BO6-octahedral centres, which leads to formation of small-sized polar clusters distributed in the isotropic matrix. Near 180 K PST undergoes an additional phase transition that involves reduction of the rotation symmetry. The nanoscale phase transformations in PST are affected by the presence of point defects rather than by the degree of long-range B-site ordering. The spectroscopic data give some evidence that in PSN additional multiplication of the unit cell takes place, besides the common perovskite-structure doubling Pm3̅m – Fm3̅m.
Decomposition of Tertiary Alkoxy Radicals
Authors: Buback Michael , Kling Matthias , Schmatz Stefan 
Published: October 2005

Abstract
Rate coefficients of β-scission reactions in tertiary alkoxy radicals, R(CH3)2CO (R = methyl, ethyl, tert-butyl and neo-pentyl) have been estimated via density functional theory (DFT) calculations in conjunction with statistical unimolecular rate theory. For tert-butoxy, results obtained by employing different basis sets are compared with experimental values, indicating that UB3LYP/6-31G(d,p) excellently predicts kinetic data. Rate coefficients for inter- and intramolecular hydrogen abstraction are also reported. Depending on R, the β-scission rate may vary by orders of magnitude. The predicted temperature dependence of the alcohol-to-ketone product ratios for alkoxy radical decomposition in a hydrocarbon environment is in remarkably close agreement with the corresponding ratios measured on the product mixtures from decomposition of tert-butyl and tert-amyl peroxyacetates in solution of n-heptane.
Solute Diffusion in Supercritical Solvents – Diffusion Coefficients D
12
∞ and Diffusion–Viscosity Relationship for the Aromatic Model Solute Biphenyl in Carbon Dioxide
Authors: Weingärtner Hermann , Klask Ulrich , Schneider Gerhard M. 
Published: October 2005

Abstract
The temperature and density dependence of the mutual diffusion coefficient D
12
∞ of biphenyl at infinite dilution in supercritical carbon dioxide has been measured by the Taylor dispersion method at several temperatures from 309 K to 331 K and at pressures between about 8 MPa and 20 MPa, corresponding to densities from about 500 kg m−3 to 850 kg m−3. The observed diffusion coefficients are of the order of 10−8 m2 s−1. They decrease about linearly with increasing density and increase slightly with increasing temperature. The experimental data show a density and temperature dependence of the quantity D
12
∞η/T, indicating a breakdown of the Stokes–Einstein relation. The use of empirical fractional power laws for describing the self-diffusion–viscosity relationship is discussed.
Closed Solubility Loops in Liquid Mixtures
Authors: Wang Jingtao , Anisimov Mikhail A. , Sengers Jan V. 
Published: October 2005

Abstract
Based on the principle of isomorphic critical behavior of fluid mixtures we derive a simple equation for closed solubility loops in a temperature–concentration diagram at constant pressure. The validity of the simple equation is tested by comparisons with experimental solubility data for liquid mixtures at atmospheric pressure and at elevated pressures. We also elucidate the nature of liquid–liquid phase separation in the vicinity of a double critical point. Specifically, we show how from an expansion around the critical double point one can develop a description of solubility loops as a function of pressure.
Thermodynamic Properties of the Binary Mixture of Methane and Hydrogen Sulfide
Authors: Sakoda Naoya , Uematsu Masahiko 
Published: October 2005

Abstract
From the interest of the thermodynamic properties for natural gas system, we have developed the thermodynamic property model for the binary mixture of methane and hydrogen sulfide system by the Helmholtz free energy function. Our model represents divergence of the critical curve and vapor–liquid–liquid equilibrium of this system as well as thermodynamic properties with high accuracy. The behavior of critical curve and phase equilibrium is discussed in detail with comparison of that for the mixture of methane and ethane system. Thermodynamic properties of methane and hydrogen sulfide system have been calculated using our model and their behavior as a function of composition is also reported.
IR Spectroscopic Investigation of Heteropolymolybdate Catalysts: Acidic Properties and Reactivity towards Propene
Authors: Jentoft Friederike C. , Kröhnert Jutta , Schlögl Robert 
Published: October 2005

Abstract
Compounds of the general type CsxH3+y−xPVyMo12−yO40 (x = 0, 2–4 with y = 1, or x = 0, 2 with y = 0) were investigated by IR spectroscopy. After thermal treatment at 473–773 K in vacuum or N2, the probe molecules CO (at 77 K, in transmission) or CO2 (at 298 K, in diffuse reflectance) were adsorbed. On the surface of Cs2H2PVMo11O40 and Cs2HPMo12O40, Brønsted acid sites were indicated by a CO band at 2162 cm−1. All Cs containing compounds produced CO bands at 2152 cm−1 or CO2 bands at 2341 cm−1. Additional weak Lewis acid sites of Mo or V in at least two oxidation states were detected after treatment at 673 K. The fraction of the reduced species decreased in the order H4PVMo11O40 > Cs2H2PVMo11O40 > Cs3HPVMo11O40. In situ DRIFT spectra of these three compounds taken during interaction with propene at up to 673 K revealed that the pattern of IR bands typical of the Keggin anion was unaffected at x = 3, altered severely for the acid and to an intermediate extent for x = 2. The changes are consistent with a diminishing of the splitting of the P–O frequency. The Keggin structure represents the initial oxidized state of the heteropoly compound catalysts. Reduction affects but does not destroy the local structure as probed by IR spectroscopy. The more easily reducible H4PVMo11O40 is active for propene oxidation at 513 K, Cs2H2PVMo11O40 only at 617 K.
Dry-Gel Synthesis of Mesoporous MCM-41 Materials with Modified Pore Structure
Authors: Xu Mingcan , Wang Wei , Weitkamp Jens , Hunger Michael 
Published: October 2005

Abstract
For the first time, the dry-gel conversion method was applied for the preparation of MCM-41 materials with partially crystalline framework. The X-ray diffraction pattern of the material obtained after a dry-gel conversion time of 36 h consists of reflections of both long-range ordered MCM-41 material and zeolite ZSM-5. The nitrogen adsorption/desorption isotherm confirms the presence of micropores and uniform mesopores with a narrow pore size distribution. By 29Si MAS NMR spectroscopy it was evidenced that a significant portion of the amorphous MCM-41 framework was transformed into a partially crystalline framework. TEM and SEM images indicate the occurrence of mesopores with disturbed arrangements, but no formation of separate zeolite ZSM-5 crystals occurred. By 1H MAS NMR spectroscopy of the above-mentioned material, the formation of hydroxyl groups with a chemical shift of ca. 4 ppm and a concentration of ca. 0.1 mmol/g was observed. The acid strength of these hydroxyl groups, as studied by adsorption of the 13C MAS NMR probe molecule 13C-2-acetone, was found to agree with that of bridging OH groups in zeolite H-ZSM-5. After conversion times of 48 h and 72 h, an extensive to total transformation of the dry gel into zeolite ZSM-5 occurred.
Ti-Oxo Radicals and Product Selectivity in Olefin Oxidations over Titanosilicate Molecular Sieves
Authors: Shetti Vasudev N. , Srinivas D. , Ratnasamy P. 
Published: October 2005

Abstract
The O–O bond of Ti-oxo species (Ti-peroxo, Ti-hydroperoxo or Ti-superoxo) generated on titanosilicate molecular sieves contacted with H2O2 cleaves either heterolytically or homolytically. While the former type of O–O cleavage (generating non-radical reactive oxygen intermediates) leads to selective epoxide products, the latter (generating reactive oxygen radical intermediates, O2
−• and HOO•) results in non-selective, allylic oxidation products in cyclohexene oxidation. These radicals were detected using EPR spin trapping techniques; 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was used as the spin trap. Radical quenchers like hydroquinone suppressed their concentration and enhanced epoxide selectivity.
The Effect of Rh Particle Size on the Catalytic Performance of Porous Silica supported Rhodium Catalysts for CO Hydrogenation
Authors: Zhou Shutian , Zhao Hong , Ma Ding , Miao Shaojun , Cheng Mojie , Bao Xinhe 
Published: October 2005

Abstract
Silica-supported Rh catalysts with different Rh particle dimensions were investigated for CO hydrogenation. The catalysts were characterized by various techniques such as TEM, H2-TPR and N2 adsorption to study the catalyst morphology, the size distributions of Rh particles and the silica pores. It was found that the distribution and the size of Rh particles were affected by the silica pores, and the metal grains were enclosed in the pores of the support, and thereby their growth was limited. The catalytic activity and selectivity to C2-oxygenates for CO hydrogenation were found to be significantly controlled by the Rh particle sizes, and the higher activity and selectivity to C2-oxygenates were obtained over bigger Rh particles, within the range of the reported particle sizes.
Preparation of Co2+/ZSM5 Catalysts by Solid-State Reaction: Influence of the Precursor on Cobalt Speciation
Authors: Mhamdi M. , Marceau E. , Khaddar-Zine S. , Ghorbel A. , Che M. , Taarit Y. Ben , Villain F. 
Published: October 2005

Abstract
Co2+/ZSM5 catalysts (Co/Al = 1, overstoichiometric ratio) have been prepared by solid-state reaction at 500 °C in argon from H-ZSM5 and four Co(II) precursors: formate, nitrate, chloride and acetate. Co3O4 particles supported by the zeolite grains are the only cobalt-containing phases detected when formate is used. When cobalt nitrate is the precursor, Co3O4 particles appear to be independent from the grains. A fraction of cobalt has nevertheless migrated into the zeolite; this is linked with [Co(H2O)6](NO3)2 low melting point and wetting of the zeolite grains by the molten salt at the beginning of the thermal treatment. Catalysts prepared from cobalt chloride contain both nanometric Co3O4 particles on the support grains and cobalt ions inside the zeolitic channels. Ion exchange is possible, at least partly, due to the fact that unlike nitrate and formate, cobalt chloride has not decomposed before reaching the temperature at which the exchange process is activated. This process is chemically driven by the release of HCl in the gas phase. Finally, the major phase detected when cobalt acetate is the precursor is a poorly organized cobalt phyllosilicate surrounding zeolite grains. Acetate ions attack the zeolitic framework from outside during the solid-state reaction; cobalt ions are inserted in the silicate matrix and progressively migrate deeper in the grains upon thermal activation.
Active Sites at Finite Coverages – an STM Investigation of the Dissociation of NO on Ru(0001)
Authors: Wintterlin J. , Zambelli T. 
Published: October 2005

Abstract
We have investigated the role of active sites on a partially adsorbate covered surface. The decomposition of NO molecules on a Ru surface served as model reaction. Experiments were performed in an ultra-high vacuum chamber, by dosing NO on a Ru(0001) single crystal surface at 300 K. The distributions of N and O atoms resulting from the NO decomposition were investigated by scanning tunneling microscopy. We find massive changes compared to the zero-coverage limit that has been studied before. Whereas atomic steps are active sites for the decomposition of the NO molecules at low coverages, the flat terraces also become active at higher coverages. Mobile O atoms on the terraces, formed by the initial dissociation of the NO molecules, are responsible for this effect. Furthermore, narrow terraces fill with N and O atoms at a higher rate than wide terraces, also contrasting the low coverage result. The effect can be understood by the blocked surface diffusion of NO precursors to the steps by N atoms accumulating at the steps. On the approximately half covered surface striking mesoscopic concentration patterns are observed, connected with a demixing of the N and O atoms. Here two effects contribute, the different surface diffusion rates of N and O atoms away from the steps, and the different interactions between the two types of atoms. At saturation NO forms a molecular state, with one NO molecule per unit cell of the (2×2) mixed structure of N and O atoms.
Durability of Marker-Quantitative Trait Loci Haplotypes in Structured Populations
Authors: Miller Judith R , Hawthorne David 
Published: October 2005

AbstractGiven the relative ease of identifying genetic markers linked to QTL (compared to finding the loci themselves), it is natural to ask whether linked markers can be used to address questions concerning the contemporary dynamics and recent history of the QTL. In particular, can a marker allele found associated with a QTL allele in a QTL mapping study be used to track population dynamics or the history of the QTL allele? For this strategy to succeed, the marker-QTL haplotype must persist in the face of recombination over the relevant time frame. Here we investigate the dynamics of marker-QTL haplotype frequencies under recombination, population structure, and divergent selection to assess the potential utility of linked markers for a population genetic study of QTL. For two scenarios, described as “secondary contact” and “novel allele,” we use both deterministic and stochastic methods to describe the influence of gene flow between habitats, the strength of divergent selection, and the genetic distance between a marker and the QTL on the persistence of marker-QTL haplotypes. We find that for most reasonable values of selection on a locus (s ≤ 0.5) and migration (m &gt; 1%) between differentially selected populations, haplotypes of typically spaced markers (5 cM) and QTL do not persist long enough (&gt;100 generations) to provide accurate inference of the allelic state at the QTL.
Global Gene Expression Profile of Human Cord Blood–Derived CD133+ Cells
Authors: Jaatinen Taina , Hemmoranta Heidi , Hautaniemi Sampsa , Niemi Jari , Nicorici Daniel , Laine Jarmo , Yli-Harja Olli , Partanen Jukka 
Published: October 2005

AbstractHuman cord blood (CB)–derived CD133+ cells carry characteristics of primitive hematopoietic cells and proffer an alternative for CD34+ cells in hematopoietic stem cell (HSC) transplantation. To characterize the CD133+ cell population on a genetic level, a global expression analysis of CD133+ cells was performed using oligonucleotide microarrays. CD133+ cells were purified from four fresh CB units by immunomagnetic selection. All four CD133+ samples showed significant similarity in their gene expression pattern, whereas they differed clearly from the CD133+ control samples. In all, 690 transcripts were differentially expressed between CD133+ and CD133+ cells. Of these, 393 were increased and 297 were decreased in CD133+ cells. The highest overexpression was noted in genes associated with metabolism, cellular physiological processes, cell communication, and development. A set of 257 transcripts expressed solely in the CD133+ cell population was identified. Colony-forming unit (CFU) assay was used to detect the clonal progeny of precursors present in the studied cell populations. The results demonstrate that CD133+ cells express primitive markers and possess clonogenic progenitor capacity. This study provides a gene expression profile for human CD133+ cells. It presents a set of genes that may be used to unravel the properties of the CD133+ cell population, assumed to be highly enriched in HSCs.