bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifrequency spectroscopy of laser active centers Nd3+ and Yb3+ in nearly stoichiometric LiNbO3
Authors: Malovichko G. , Bratus V. , Munro M. , Kokanyan E. , Okulov S. , Grachev V.
Published: March 2007

Lithium niobate crystals doped with neodymium and ytterbium were studied with the help of the electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR) and optical absorption. Tremendous narrowing of magnetic resonance lines in nearly stoichiometric samples in comparison with congruent ones allowed us to distinguish four non‐equivalent centers (NEC) of Nd3+ and five NEC of Yb3+, as well as line splitting caused by hyperfine interaction of neodymium electrons with nuclear spins of magnetic isotopes 143Nd, 145Nd, 171Yb and 173Yb. It was shown that some of the centers has axial C3 symmetry, whereas all others have lowest C1 symmetry due to presence of intrinsic defects or/and charge compensation defects in the near neighborhood of Nd3+ and Yb3+. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of defect‐trap‐related europium sites in gallium nitride
Authors: Fleischman Z. , Tafon P. S. , Dierolf V. , Munasinghe C. , Steckl A. J.
Published: March 2007

We performed site‐selective combined excitation‐emission spectroscopy (CEES) studies on Eu‐doped GaN layers grown using Interrupted Growth Epitaxy (IGE). We identified numerous Eu3+ incorporation sites, which exhibit different relative emission intensities as the growth conditions are varied. We found defecttrap related Eu sites that can be excited over a wide spectral range and that dominate the photoluminescence spectra for above‐bandgap excitation. Spectra obtained through above‐bandgap excitation, which simulates EL operation, are identical to the emission spectra of these defect‐trap related sites, indicating that these particular Eu ions would be the major contributors to electroluminescent (EL) emission in these samples. In resonant excitation, however, the emission from these sites is rather weak suggesting that these are minority sites. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Site‐selective studies of erbium ion defects in thermally grown silicon oxides
Authors: Fleischman Z. , Dierolf V. , Dong Z. , Zhang Y. , White M. , Pafchek R. , Webster M. , Koch T.
Published: March 2007

Using the site‐selective technique of combined excitation emission spectroscopy (CEES), we have studied a variety of Er‐doped silicon oxide layers and silicon‐rich oxide (SRO) layers which contain silicon nanocrystals. With this technique we identi.ed Er cluster defect sites which are created during thermal annealing and which dominate at high Er concentrations. We investigate the role that Si nanocrystals play in the relative abundance of these cluster sites. In attempts to reduce this clustering effect, we observed mixed results by modifying the growth procedure such that Er is already present in the silicon during oxide growth. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Cu ions on the photo‐transport properties in KTaO3:(Cu,V) single crystals
Authors: Rossella F. , Perucchini L. , Galinetto P. , Samoggia G. , Mozzati M. C. , Azzoni C. B. , Badalyan A. G. , Trepakov V. A. , Syrnikov P. P.
Published: March 2007

Photoconductivity kinetics, temperature dependence and excitation spectra were measured in the intervals 15‐300 K and 2‐4.2 eV in KTaO3:(Cu,V) single crystals processed by oxidation/reduction treatments. The kinetics, excited by band‐gap excitation, present very slow saturation times, while faster time responses were observed using excitation below the band‐gap. The oxidized crystal exhibited higher photoconductivity when Elight > 3 eV. Linear dependence on light intensity was measured, suggesting one center recombination processes. Optical absorption at room temperature was checked as complementary information. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermoluminescence, photoluminescence and optically stimulated luminescence properties of X‐ray irradiated RbMgF3:Mn2+
Authors: Dotzler C. J. , Williams G. V. M. , Edgar A.
Published: March 2007

Optically stimulated luminescence (OSL) is observed after x‐ray irradiation in Mn2+ doped RbMgF3 polycrystalline samples over a wide wavelength range in the near UV and with a stimulation maximum near 350 nm. The OSL emission occurs by relaxation from the first excited state to the ground state of Mn2+. It is possible that one of the electron traps can be attributed to an F ‐center. However, thermoluminescence (TL) measurements show that there are at least 5 defect centers in this compound. Sintered polycrystalline samples have a higher OSL intensity when compared with the as‐made samples. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transient and near‐edge absorption in YVO4 crystals
Authors: Millers D. , Yochum H. M. , Pankratov V. , Potera P. , Grigorjeva L.
Published: March 2007

The process of near‐edge absorption annealing in air was studied up to 1500C in YVO4. In this annealing process, two stages with activation energies of 0.16 eV and 0.38 eV were obtained. (Should combine to make this one paragraph)In addition to the annealing study, the transient absorption induced by pulsed electron beam excitation (270 keV, 8 ns) was completed on a set of YVO4 samples with different near‐edge absorption levels in the spectral region 3.2‐3.5 eV. The spectral range from ∼1.25 eV up to 3.0 eV is covered by strong transient absorption. Transient absorption spectra show at least three broad overlapping bands (∼1.3 eV, ∼2.0 eV and ∼3.0 eV). The 3 eV peak position is close to the near‐edge absorption band and correlation between transient absorption bands and absorption due to stable colour centers was studied. It is suggested that absorption bands at ∼1.3 eV and ∼2.0 eV are due to electron and hole polarons, correspondingly. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigation of tungstate crystals with point defects
Authors: Hizhnyi Yu. A. , Nikolaenko T. N. , Nedilko S. G.
Published: March 2007

The electronic structure of WO66––Zn2+ complex in ZnWO4 crystal is calculated by the configuration interaction method in embedded cluster approach. The dependencies of energies of the electronic states of WO66––Zn2+ centre on displacements of atomic coordinates that model vibrations of WO66– group are calculated. Spectrum of ZnWO4 crystal intrinsic emission is explained on the basis of obtained results. The influence of nearby VO and VZn vacancies on electronic structure of WO66––Zn2+ complex is studied. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal and photo stimulated luminescence of F‐centre aggregates in electron and X‐ray irradiated KCl:Eu2+ polycrystalline films
Authors: Aceves R. , Gracia‐Jiménez J. M. , Silva‐González R. , Tabares‐Muñoz C.
Published: March 2007

The thermoluminescence (TL) and photostimulated luminescence (PSL) of KCl:Eu2+ films irradiated with low energy electrons, β‐ and X‐rays have been investigated. The TL glow curves have been related to irradiation induced defects in both the film and substrate accordingly to the penetration depth of radiation. Measurements of photransferred TL (PTTL) suggested the F, FZ and F‐aggregates formation by X‐ray and low energy electrons. The photostimulation of a previously irradiated sample with 560, 640 and 655 nm have revealed the F2 and F3 defects related infrared (IR) luminescence. An additional PSL band peaked around 1380 nm was observed by photostimulation with 640 nm which could be related to F type defects. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Co‐emission of Tb3+ and Eu3+ ions in LiNbO3:Tb 3+, Eu 3+ single crystals
Authors: Alvarez E. R. , Sosa R. F. , Földvári I. , Polgár K. , Péter Á. , Muñoz A. F.
Published: March 2007

In this paper the optical properties (emission and excitation spectra) of Tb3+ and Eu3+ ions in LiNbO3:Tb3+(LNTb), and LiNbO3:Eu3+(LNEu) single crystals, and of Tb3+ and Eu3+ ions in doubly doped LiNbO3:Tb3+,Eu3+ (LNTbEu) are presented, in the 200‐700 nm range at 12 K. The results are discussed and combined with previous observations on the optical properties of LiNbO3:Tb3+(LNTb), LiNbO3:Eu3+ (LNEu) in order to get a better understanding on the nature of the Tb3+→ Eu3+ energy transfer mechanism, observed in our LNTbEu samples. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Common features of thermoluminescence in NaCl and LiF crystals
Authors: Davidson A. T. , Kozakiewicz A. G. , Derry T. E. , Comins J. D. , Suszynska M. , Valberg L. , Townsend P. D.
Published: March 2007

We review our work on the thermoluminescent properties of LiF and NaCl crystals. The role of impurities and their effect on glow curves is considered. A spectral analysis of light emitted at glow peaks suggests some common processes active in the two materials, including intrinsic emission from self trapped excitons near 360 nm wavelengths and impurity enhanced emission near 417 nm wavelengths. The latter may be related to the presence of impurity‐vacancy dipoles in a form which favors TL emission. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Toward control of point defects in lithium fluoride thin layers
Authors: Montereali R. M. , Bonfigli F. , Marolo T. , Mussi V. , Nichelatti E.
Published: March 2007

Point defect formation and stabilization properties, as well as their peculiar spectroscopic characteristics, locally modify the optical properties of insulating materials. Thin layers containing high concentrations of colour centres, hosted in a LiF single crystal and/or a polycrystalline matrix, offer the opportunity to develop innovative light‐emitting photonic devices. Control of all the critical parameters should be required on spatial dimension comparable with the optical wavelengths. Recent developments in laser technologies, electron and particles beam methods, and novel photon sources, have opened a wide range of opportunities. An overview of the most significant advances in this field is provided, with particular emphasis on colour‐centre LiF‐based innovative miniaturised light sources, optical amplifiers and lasers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopy of Eu:YAG nanopowders
Authors: Georgescu S. , Chinie A. M. , Stefan A. , Toma O.
Published: March 2007

YAG:Eu nanopowders were synthesized by a nitrate‐citrate sol‐gel method. The morphologic modifications produced by thermal treatments at various temperatures were monitored by a series of parameters obtained from the optical fluorescence spectroscopy: intensity ratio of the transitions 5D0 → 7F2 and 5D0 → 7F1, the maximum splitting of the 7F1 level, and the linewidths of some fluorescence transitions. Abrupt changes of the monitored parameters are observed at the amorphous‐crystalline transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ionic mechanisms in the optically stimulated luminescence of quartz
Authors: Martini M. , Galli A.
Published: March 2007

Among the many centres found in crystalline quartz it is well known that Al, substitutional for Si, is always present in different concentrations giving rise at Room Temperature to ionic migration of the associated alkali ions. Many authors evidenced that these alkali ions are involved in trapping and recombination at the basis of Thermally and Optically Stimulated Luminescence, TL and OSL respectively. We have focused our attention on the OSL of quartz that is now widely used in sediment dating, although the trapping‐detrapping mechanisms have not yet been clarified. Bulk synthetic crystalline quartz, with known concentrations of Al and alkali ions has been used. There is evidence that an ionic migration is at the basis of the OSL phenomenon, linking OSL emission with the TL peaks known as “110 °C” and “325 °C”. This result is also supported by Radioluminescence (RL) measurements performed on swept and unswept quartzes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermoluminescence and visible reflectance spectroscopy applied to the study of blue‐green mosaic silica‐glass tesserae
Authors: Galli A. , Poldi G. , Martini M. , Sibilia E.
Published: March 2007

We report the results of a series of measurements of Thermally Stimulated Luminescence (TSL) and visible reflectance spectrometry (vis‐RS) performed on several modern blue‐green silica glass mosaic tesserae. They were produced from the same matrix with different additions of colouring and opacifying oxides to get a wide shadow of blue colorations. This study follows others previously performed on archaeological mosaics, and aims at the understanding of the TSL emission of this class of glasses, particularly suitable for dating. The usefulness of the combined techniques for the identification of the metal ions responsible for the blue coloration in a given sample is confirmed as well as the positive role played by antimony in enhancing the TSL response. In general, however, the TSL characteristics of mosaic glasses depend on the glassy matrix and on its crystallisation degree rather than on the formation of colour centres associated to the introduction of colouring oxides. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and macro defects of ZnO single crystals
Authors: Li Xinhua , Xu Jiayue , Shen Hui , Wu Anhua , Li Xiaomin
Published: March 2007

ZnO single crystal has been grown from 22 mol%ZnO‐78 mol%PbF2 high temperature solution in a homemade vertical Bridgman furnace. The macro growth defects, such as growth striations, boundary, negative crystal, bubbles, and inclusions, were investigated by optical microscopy and an electron probe X‐ray microanalyser (EPMA). The formation mechanisms of these defects were discussed associated with the growth parameters. The approaches to reduce macro defects were proposed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion size effect dependence on the glow peak temperature in europium doped mixed crystals
Authors: Rodríguez‐Mijangos R. , Pérez‐Salas R.
Published: March 2007

The ion size effect on the thermoluminescence (TL) glow curve structure of europium doped binary mixed alkali halide crystals samples was investigated as a function of molar composition. A linear expression, that relates the characteristic glow peak temperature to the ionic size, was found and used to predict the TL temperature shifts associated to the size of Cl– and Br– anions in a binary mixed alkali halide sample at a given composition. In addition the behavior of the mixed binary crystals with components KCl and RbCl doped with divalent Europium is presented. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence in AlN: macro‐size and nano‐powder
Authors: Berzina B. , Trinkler L. , Grabis J. , Steins I.
Published: March 2007

Photoluminescence (PL) properties in AlN are studied when size of polycrystalline grains is reduced from macro‐size (AlN ceramics and macro‐size powder) to nano‐size (nano‐powder). It was found that in all these materials within the UV‐ blue spectral region two PL bands are observed at ∼400 nm (caused by the oxygen‐related defects) and at 480 nm (with unknown defect structure) but the ratio of their intensities depends on the grain size. Reduction of AlN grain size results in decrease of the 400 nm band and increase of the 480 nm band. It allows the following conclusions: i) reduction of AlN grain size results in decrease of oxygen (the native impurity of AlN) content in the crystalline lattice, and ii) the defects responsible for 480 nm PL band could originate from the material surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intrinsic luminescence of YAlO3 perovskites
Authors: Zorenko Yu. , Voloshinovskii A. , Gorbenko V. , Zorenko T. , Nikl M. , Nejezchleb K.
Published: March 2007

Intrinsic emission of complex oxides with perovskite structure was analyzed in the undoped single crystal (SC) and single crystalline films (SCF) of YAlO3 (YAP) using the time‐resolved luminescence spectroscopy under excitation by synchrotron radiation. In contrast to bulk SC the YAP SCF are characterized by much lower concentration of YAl antisite and vacancy‐type defects, which contribute to the intrinsic emission of YAP SC. Such a difference comes mainly from much lower temperature of the film growth using the Liquid Phase Epitaxy. For this reason, comparison of YAP SC and SCF appears very useful to study the nature of the intrinsic emission of perovskites consisting mainly of the exciton and defect‐related luminescence. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy dependence of the electron‐hole in‐plane anisotropy in InAs/GaAs quantum dots
Authors: Testelin C. , Aubry E. , Chaouache M. , Maaref M. , Bernardot F. , Chamarro M. , Gérard J.‐M. , Ferreira R.
Published: March 2007

Due to a regrettable technical error some Greek and special letters in the paper were not reproduced. Please, find here the fully corrected article.

In pump‐probe experiments, we measured the anisotropic exchange energy splitting of the low‐lying electron‐hole pair states in an ensemble of as‐grown InAs/GaAs self‐assembled quantum dots. This splitting shows a monotonic decrease with the energy of interband emission. We discuss this result considering different parameters: shape anisotropy, wavefunction confinement, size of the quantum dots, and piezoelectric effect. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigations on analytical potential energy function and spectroscopic parameters for the state b3Πu of dimer 7Li2
Authors: Shi De‐Heng , Sun Jin‐Feng , Zhu Zun‐Lue , Ma Heng , Liu Yu‐Fang , Zhu Zheng‐He
Published: March 2007

The SAC‐CI (symmetry‐adapted‐cluster configuration‐interaction) method presented in Gaussian 03 program package is applied to investigate the adiabatic potential energy curves (PECs) of 7Li2(b3Πu). These calculations are performed at numbers of basis sets, such as 6‐311++G(3df,3pd), 6‐311++G(2df,2pd), 6‐311++G(df,pd), D95V++, D95(3df,3pd), D95(d,p), cc‐PVTZ, 6‐311++G and 6‐311++G(d,p). All the ab initio calculated points are fitted to the analytic Murrell‐Sorbie functions and then used to compute the spectroscopic parameters. The analytic potential energy function (APEF) for this b3Πu state is reported. By comparison, the spectroscopic parameters reproduced by the APEF attained at 6‐311++G(2df,2pd) are found to be very close to the latest experimental findings. With the APEF obtained at the SAC‐CI/6‐311++G(2df,2pd) level of theory, a total of 62 vibrational states is found when J = 0. The complete vibrational levels, classical turning points, inertial rotation and centrifugal distortion constants for these vibrational states are also reported. The reasonable dissociation limit for this state is deduced using the calculated results at present. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Planar mono‐, di‐ aza‐ and phospha‐naphthalene: Structure and aromaticity
Authors: Wang Lei , Wang Haijun
Published: March 2007

In this article, we used magnetic criteria, magnetic susceptibility isotropic and nucleus‐independent chemical shifts (NICS), calculated with (density functional theory) B3LYP levels at the 6‐31G** basis set, to evaluate aromaticity of a set of 29 planar bicyclic π‐electron systems: naphthalene and its mono‐ and di‐ aza‐ and phospha‐derivatives. The result showed significant collinearity of the above two magnetic criteria when evaluating N‐containing naphthalenes, but did not speak with the same voice when evaluating P‐containing naphthalenes. Thus, we could conclude that magnetic susceptibility is a reliable criterion and NICS is not in our case. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Theoretical study on AlnO2 (n = 1–10) clusters and O2 adsorption on the Al(111) surface
Authors: Sun Jiao , Lu Wen‐Cai , Wang Hong , Zhao Li‐Zhen , Sheng Li Ze‐ , Sun Chia‐Chung
Published: March 2007

The structural properties of neutral and ionic AlnO2 (n = 1–10) clusters have been systematically investigated using the density functional method B3LYP with a standard 6‐311+G(d) basis set. The calculated results show that in the AlnO, AlnO2, and AlnO (n ≥ 3) clusters, O atoms tend to penetrate into the aluminum clusters with some Al atoms moving outward. The binding energies and natural charges populations indicate that the oxygen‐etching is generally stronger in the order Al < Aln < Al for n < 3, and Al > Aln > Al for n ≥ 3. To further understand the mechanism of interaction between Al and O2, the adsorption of O2 on the Al(111) surface was studied using the density functional theory with plane wave pseudopotential method. The calculated results are consistent with the experimental observation that the O2 molecule would dissociate on the Al(111) surface and be adsorbed in adjacent hollow sites, forming a local structure of Al3O–Al3O. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Preparation of a biochip on porous silicon and application for label‐free detection of small molecule‐protein interactions
Authors: Hu Ligang , Xu Songyun , Pan Chensong , Zou Hanfa , Jiang Guibin
Published: March 2007

A new approach for the preparation of a biochip on porous silicon and the application of the biochip for detection of small molecule‐protein interactions with desorption/ionization on porous silicon (DIOS) was demonstrated. The galvanostatically etched porous silicon substrates were chemically modified firstly to yield carboxylic acid terminated surfaces, and then the protein was covalently attached to the surface through amide bonding. By applying a solution of candidate chemicals to the surface and a subsequent wash step, the masses of captured compounds could be analyzed by DIOS. DIOS has advantages of being a direct detection tool compared to the classic florescence or chemiluminescence methods, because the process of labeling molecules employed in the florescence or chemiluminescence methods can sometimes alert the properties of the labeled molecule. The recognition between proteins and their binding partners is efficient and selective. A good tolerance to disturbance and high enrichment factor of the biochip to the analytes was observed. As an on‐chip‐based approach, the demonstrated method has a potential to perform in a high‐throughput format. Copyright © 2007 John Wiley & Sons, Ltd.
Distinction of gaseous soot precursor molecules and soot precursor particles through photoionization mass spectrometry
Authors: Happold Joachim , Grotheer Horst‐Henning , Aigner Manfred
Published: March 2007

Samples were drawn from sooting premixed low‐pressure ethylene oxygen flames and investigated through photoionization mass spectrometry using either KrF or ArF lasers as the radiation source. With the former, mass spectra were obtained as described in the literature and characterized through a series of signal groups, one for each C‐number and extending to aboutm/z1000, assigned as a PAH series. When the ArF laser was used the same series was observed with a somewhat higher sensitivity. In addition, a new series was observed overlaid on the PAH series and starting at aboutm/z680. The new series exhibited abundant ions and it completely dominated the spectrum beyondm/z1000. This series was identified as being the spectrum of soot precursor particles. Through measurement of the ionization order it was concluded that at least two photons are needed for ionization of PAHs whereas the particles need only one photon. Consequently, they can be measured with high sensitivity when an ArF laser is used as the radiation source. Furthermore, the discrimination of soot precursor molecules and soot precursor particles becomes possible through photoionization and this enables an improved understanding of the mass spectra. This should allow a particle growth mechanism to be deduced in the near future. Copyright © 2007 John Wiley & Sons, Ltd.
XPS characterization of the corrosion film formed on the electroless nickel deposit prepared using different stabilizers in NaCl solution
Authors: Cheong Woo‐Jae , Luan Ben L. , McIntyre N. S. , Shoesmith David W.
Published: March 2007

X‐ray photoelectron spectroscopy (XPS) was used to examine the corrosion films formed on electroless nickel (EN) deposits prepared in an EN solution containing two different types and concentrations of bath stabilizers in Ar‐purged and oxygenated neutral 5% NaCl solution. Two distinctive corrosion films were observed after long periods of immersion. An enrichment of elemental phosphorus compared to nickel was observed on the surface of the EN deposit produced with no stabilizer and with maleic acid (MA). By comparison, a high degree of surface oxidation was observed on the EN deposit prepared with thiourea. Trace impurities of sulfur in the EN deposit prepared with thiourea appear to result in enhanced corrosion and, in turn, lead to the build‐up of corrosion products on the EN surface. By contrast, a P‐enriched chemical passivation layer was formed on the EN deposits prepared either without any stabilizer or with MA present. Copyright © 2007 Crown in the right of Canada, and John Wiley & Sons, Ltd.
Memory functioning following terror attack and the suggested immunization by religious faith
Authors: Gigi Ariela , Papirovitz Merav , Hagit Masika
Published: March 2007

Exposure to a terrorist attack is a traumatic experience that may result in elevated anxiety levels (DSM‐IV, 1994). Aspects of religiousness were found to be correlated with better mental health outcomes. This study assessed levels of anxiety and cognitive functioning in subjects who were exposed to terror attacks and correlated it with reported levels of religious faith. Thirty‐seven participants were recruited from religious settlements in the West Bank area in Israel. Fifteen subjects had been exposed to a terrorism event without developing predict post‐traumatic stress disorder and 22 controls had no such exposure. Learning and memory retrieval, for verbal and visual stimuli, were tested and the groups were compared. Half of the stimuli in each modality (verbal and visual) were rated as stressful, and half of them were rated as neutral. Responses and reaction times were recorded. Additionally, participants completed questionnaires to assess current anxiety and anxiety‐proneness and reported religiousness. Memory performance was found to be significantly lower for those exposed to terror attack, in comparison with the controls. The differences were significant for visual stimuli only and in particular for the stress‐related stimuli. The terrorism exposed group reported higher levels of state anxiety that was negatively correlated with levels of their reported religious faith. Although aspects of religiousness were found to be negatively correlated with current anxiety levels in the terrorism exposed group, this study did not show religious beliefs provided immunity against cognitive deterioration. Copyright © 2007 John Wiley & Sons, Ltd.
Influence of rotor structural dynamics representations on the electrical transient performance of FSIG and DFIG wind turbines
Authors: Ramtharan Gnanasambandapillai , Jenkins Nicholas , Anaya‐Lara Olimpo , Bossanyi Ervin
Published: March 2007

An assessment of the impact that the representation of rotor structural dynamics has on the electrical transient performance of fixed‐speed induction generators (FSIGs) and doubly fed induction generators (DFIGs) wind turbines is presented. A three‐mass model that takes into account not only the shaft flexibility but also the blade flexibility in the structural dynamics is developed and used to derive an effective two‐mass model of the drive train dynamics, which represents the dominant natural frequency of vibration of the rotor structure. For the purposes of this investigation, the dynamic performance of both FSIG and DFIG wind turbines is evaluated during electrical transients such as a three‐phase fault in the network. The studies are conducted in the software code Bladed, where a detailed representation of the structural dynamics is used to derive the three‐mass model and the effective two‐mass model. Simulation results which illustrate how these representations of the rotor dynamics affect the response of the wind turbine during the fault are presented and discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Divalent Nickel and Monovalent Copper Pseudohalide Coordination Polymers Incorporating the Kinked Organodiimine 4,4′‐Dipyridylamine: From a (4,4)‐Type Lamellar Motif to an Unprecedented Staircase Morphology
Authors: Knapp Warren R. , Thomas Justin G. , Martin David P. , Braverman Maxwell A. , Trovitch Ryan J. , LaDuca Robert L.
Published: March 2007

The divalent nickel isothiocyanate coordination polymer [Ni(NCS)2(dpa)2] (1) has been prepared in high yield via the hydrothermal combination of Ni(SCN)2 with the kinked tethering ligand 4,4′‐dipyridylamine (dpa), and characterized via single crystal X‐ray diffraction, infrared spectroscopy and elemental and thermal analysis. 1 manifests offset stacked 2‐D (4,4)‐topology layered motifs organized into 3‐D via interlamellar supramolecular N–H···S hydrogen bonding. Hydrothermal reaction of CuCl2·2H2O, NaSCN, and dpa afforded the copper (I) thiocyanate coordination polymer [Cu2(SCN)2(dpa)] (2), whose single crystal structure revealed unprecedented 1‐D [Cu2(SCN)2] zig‐zag staircase motifs constructed via connection of the Cu2S2 “stair steps” at their adjacent sides via μ3‐1,1,3‐SCN anions. The 3‐D structure of 2 is propagated by covalent linkage of each [Cu2(SCN)2] staircase to four others through dipodal dpa tethering ligands, enhanced by N–H···S and C–H···S supramolecular interactions to two other staircases.
Polysulfonylamine. CLXXVIII Onium‐Salze des Benzol‐1,2‐di(sulfonyl)amins (HZ): Eine zweite Kristallform des Ammonium‐Salzes NH4Z·H2O und Kristallstruktur des Bis(triphenylphosphoranyliden)ammonium‐Salzes [Ph3PNPPh3]Z
Authors: Zerbe Eva‐Maria , Wölper Christoph , Roca Piñol Silvia , Jones Peter G. , Blaschette Armand
Published: March 2007

Polysulfonylamines. CLXXVIII. Onium Salts of Benzene‐1,2‐di(sulfonyl)amine (HZ): A Second Crystal Form of the Ammonium Salt NH4Z·H2O and Crystal Structure of the Bis(triphenylphosphoranylidene)ammonium Salt [Ph3PNPPh3]Z

A dimorphic form of NH4Z·H2O, where Z− is N‐deprotonated ortho‐benzenedisulfonimide, has been obtained and structurally characterized (previously known form 1A: monoclinic, P21/c, Z′ = 1; new polymorph 1B: monoclinic, P21/n, Z′ = 1). Both structures are dominated by an abundance of classical hydrogen bonds N+–H/O–H···O=S/OH2, whereby the anionic N− function does not act as an acceptor. The major difference between the dimorphs arises from the topology of the hydrogen bond network, which is two‐dimensional in 1A, leading to a packing of discrete lamellar layers, but three‐dimensional in 1B. Moreover, the latter network is reinforced by a set of weak C–H··O/N hydrogen bonds, whereas the layered structure of 1A displays only one independent C–H···O bond, providing a link between adjacent layers. The compound [Ph3PNPPh3]Z (2, monoclinic, P21/c, Z′ = 1) is the first structurally authenticated example of an ionic Z− derivative in which the cation contains neither metal bonding sites nor strong hydrogen bond donors. This structure exhibits columns of anions, surrounded by four parallel columns of cations, giving a square array. The large cations are associated into a three‐dimensional framework via weak C–H···C(π) interactions and an offset face‐to‐face phenyl interaction, while the anions occupy tunnels in this framework and are extensively bonded to the surrounding cations by C–H···O/N− hydrogen bonds and C–H···C(π) interactions.
Synthese und Kristallstrukturen von α‐ und β‐Ba3(PS4)2 sowie von Ba3(PSe4)2
Authors: Jörgens Stefan , Mewis Albrecht
Published: March 2007

Synthesis and Crystal Structures of α‐, β‐Ba3(PS4)2 and Ba3(PSe4)2

Ba3(PS4)2 and Ba3(PSe4)2 were prepared by heating mixtures of the elements at 800 °C for 25 h. Both compounds were investigated by single crystal X‐ray methods. The thiophosphate is dimorphic and undergoes a displacive phase transition at about 75 °C. Both modifications crystallize in new structure types. In the room temperature phase (α‐Ba3(PS4)2: P21/a; a = 11.649(3), b = 6.610(1), c = 17.299(2) Å, β = 90.26(3)°; Z = 4) three crystallographically independent Ba atoms are surrounded by ten sulfur atoms forming distorted polyhedra. The arrangement of the PS4 tetrahedra, isolated from each other, is comparable with the formation of the SO42− ions of β‐K2SO4. In β‐Ba3(PS4)2 (C2/m; a = 11.597(2), b = 6.727(1), c = 8.704(2) Å; β = 90.00(3)°; Z = 2) the PS4 tetrahedra are no more tilted along [001], but oriented parallel to each other inducing less distorted tetrahedra and polyhedra around the Ba atoms, respectively. Ba3(PSe4)2 (P21/a; a = 12.282(2), b = 6.906(1), c = 18.061(4) Å; β = 90.23(3)°; Z = 4) is isotypic to α‐Ba3(PS4)2 and no phase transition could be detected up to about 550 °C.
Na3F[WO4]: A Sodium Fluoride Ortho‐Oxotungstate(VI) with Strands of Face‐Shared Fluoride‐Centred Sodium Octahedra According to $^{1}_{\infty}\rm \{[FNa_{6/2}]^{2+}\}$
Authors: Hartenbach Ingo , Schleid Thomas
Published: March 2007

During the reaction of Na2[WO4] with YF3 purposed to yield fluoride‐derivatized yttrium oxotungstates(VI), colourless platelet‐shaped single crystals of Na3F[WO4] emerged as main product. The title compound crystallizes orthorhombically in the space group Pnma (a = 559.59(5), b = 751.02(7), c = 1285.98(9) pm) with four formula units per unit cell. Besides isolated ortho‐oxotungstate units [WO4]2− (d(W–O) = 176–178 pm) the crystal structure contains two crystallographically independent Na+ cations which are both octahedrally coordinated by four oxygen atoms and two fluoride anions. The F− anions are surrounded by six sodium cations (d(F–Na) = 224–242 pm) also in an octahedral fashion. These octahedra built up chains along [100] by sharing trans‐oriented faces according to $^{1}_{\infty}\rm \{[FNa_{6/2}]^{2+}\}$, which are stacked according to a hexagonal closest rod‐packing. The cationic strands are surrounded, interconnected and charge‐balanced by isolated [WO4]2− tetrahedra with almost ideal shape and every O2− ligand is terminally coordinated by three Na+ cations.
Alkali Metal and Trimethylsilyl Carbamoselenothioates – Synthesis, Structure, and some Reactions
Authors: Kawai Kohji , Ibi Kazumasa , Ebihara Masahiro , Kato Shinzi
Published: March 2007

This paper describes the synthesis and some reactions of potassium, rubidium, cesium and trimethylsilyl carbamoselenothioates. The potassium salts were synthesized in 70–80 % yields by reacting the corresponding thiocarbamoyl chlorides with potassium selenide in acetonitrile. Furthermore, the rubidium and cesium salts were obtained in good yields by treating the trimethylsilyl esters with the corresponding metal fluorides. The crystal structure of acetonitrile‐solvated potassium N,N‐dimethylcarbamoselenothioate consisted of dimeric units, featuring μ‐carbamoselenothioate anions associated with potassium cations that are located on the upper and lower sides of a plane involving two opposing carbamoselenothioate groups. These heavier alkali metal salts readily reacted with alkyl halides to give both S‐ and Se‐alkyl esters. The reaction of the potassium salts with trimethylsilyl chlorides forms S‐ and Se‐trimethylsilyl carbamoselenothioates which are in equilibrium. The reaction of the salts and silyl esters with organo Group‐14 and ‐15 elements halides gave exclusively the corresponding Se‐substituted products in good yields.
Improved Synthesis of the [Ru(η6‐p‐cymene)Cl3] Anion: Facile Isolation under Mild Conditions
Authors: Vock Carsten A. , Dyson Paul J.
Published: March 2007

Reaction of [Ru(η6‐p‐cymene)Cl2]2 with two equivalents of [Ph4P][Cl] in CH2Cl2 yields [Ph4P][Ru(η6‐p‐cymene)Cl3], containing a trichlororuthenate(II) anion. In solution, an equilibrium between the product and [Ru(η6‐p‐cymene)Cl2]2 is observed, which in CDCl3 is nearly completely shifted to the dimer, whereas in CD2Cl2 essentially a 1:1‐mixture of the two ruthenium species is present. Crystallization from CH2Cl2/pentane yielded two different crystals, which were identified by X‐ray analysis as [Ph4P][Ru(η6‐p‐cymene)Cl3] and [Ph4P][Ru(η6‐p‐cymene)Cl3]·CH2Cl2.
Syntheses and Crystal Structures of New Palladium(II) and Platinum(IV) Trialkylsulfonium Compounds
Authors: Heß David , Gorlov Mikhail , Fischer Andreas , Kloo Lars
Published: March 2007

The reactions of platinum(II) iodide with triethyl‐ or trimethylsulfonium iodide in acetonitrile solution lead to the formation of crystalline products (Et3S)2[PtI6] (1) and [Me3S]2[PtI6]·CH3CN (2), respectively. The formation of Pt(IV) complexes may be explained either by disproportionation of PtI2 or oxidation by oxygen. Palladium(II) iodide reacts with triethylsulfonium iodide to give the palladium(II) complex (Et3S)2[PdI4] (3). The crystal structures of 1–3 were determined by single‐crystal X‐ray diffraction. In the crystal structures, the compounds 2 and 3 exhibit an extensive hydrogen‐bonding network.
Über die Identität eines sogenannten Ammoniumcarbonat‐Präparates
Authors: Kuhn Norbert , Ströbele Markus , Meyer H.‐Jürgen
Published: March 2007

On the Identity of a so‐called Ammonium Carbonate Sample

Commercial samples of so‐called “ammionum carbonate” are shown to contain ammonium carbamate rather than ammonium carbonate. In fact samples may contain varying quantities of α‐ and β‐(NH4)(CO2NH2), of which only the α‐phase is reported in the literature. Mixtures of both phases tend to leak the volatile α‐phase and to react with moisture to form (NH4)(HCO3). The crystal structure of the new β‐(NH4)(CO2NH2) is refined from X‐ray powder data.
Synthesis, Structure and Magnetic Properties of a Novel Nickel(II) Radical Heterospin Complex with Salicylaldoxime
Authors: Ma Yue , Zhang Wei , Xu Gong‐Feng , Yoshimura Kazuyoshi , Liao Dai‐Zheng , Jiang Zong‐Hui , Yan Shi‐Ping
Published: March 2007

A novel heterospin complex containing both NiII and nitroxide radical ligands: [Ni(salox)2(NIT4Py)2] (1) (salox = salicylaldoxime, NIT4Py = 2‐(4′‐pyridyl)‐4,4,5,5‐ tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide) has been synthesized and structurally characterized. The structure consists of neutral Ni(salox)2(NIT4Py)2 moieties bridged by intermolecular hydrogen bonds, forming a one‐dimensional chain structure. Magnetic measurements show intramolecular antiferromagnetic interactions between NIT4Py and Ni2+ ion.
Giant Retroperitoneal Sarcomas: A Single Institution Experience
Authors: Doglietto Giovanni B. , Tortorelli Antonio P. , Papa Valerio , Rosa Fausto , Bossola Maurizio , Prete Francesco P. , Covino Marcello , Pacelli Fabio
Published: March 2007

Background

Retroperitoneal sarcomas (RS) are a rare group of malignant soft‐tissue tumors; due to the flexibility of the retroperitoneum, they generally grow to a large size before becoming symptomatic, often involving surrounding structures. Therefore, the surgeon is frequently compelled to perform large excisions. The aim of this study is to assess clinical and pathological factors affecting prognosis in patients with RS who underwent surgical treatment, comparing giant forms (size ≥ 25 cm) with smaller ones (size < 25 cm).

Methods

The hospital records of 73 consecutive patients who underwent surgical exploration for primary RS at our unit between 1984 and 2003 were reviewed. Statistical analysis of factors influencing overall and disease‐free survival was performed including both the whole group of patients and only those who underwent complete surgical resection.

Results

Giant RS showed a lower resectability rate than smaller forms (54.2% vs. 84.2%, P = 0.005). In the group with complete surgical excision (51 out of 73), patients with giant RS had a higher rate of adjacent organ resection compared with the smaller ones (84.2% vs. 53.1%, P = 0.023). Tumor size did not influence prognosis: after complete resection, 5‐year overall survival was 60.9% and 56.3% for giant RS and smaller forms respectively, while 5‐year disease‐free survival was 54.3% and 48.3% for the two groups respectively. Advanced stage, incomplete gross surgical resection, higher tumor grade, non‐liposarcoma histology and microscopic infiltration of margins were found to be significantly negative prognostic factors.

Conclusions

The present study confirms the importance of aggressive surgical management for RS, in order to offer these patients the best chance of long‐term survival.
Comparison of AngioJet Rheolytic Pharmacomechanical Thrombectomy versus AngioJet Rheolytic Thrombectomy in a Porcine Peripheral Arterial Model
Authors: Lin Peter H. , Mussa Firas F. , Hedayati Nasim , Naoum Joseph J. , Zhou Wei , Yao Qizhi , Kougias Panagiotis , El Sayed Hosam F. , Chen Changyi
Published: March 2007

Introduction

Rheolytic thrombectomy using the AngioJet catheter for arterial thrombosis has been shown to be effective in restoring blood flow. Additional infusion of thrombolytic agents via the AngioJet catheter results in combined rheolytic pharmacomechanical thrombolysis (PMT), which further enhances thrombectomy efficacy. However, the histologic response to rheolytic PMT therapy remains unclear. This study compares the acute and chronic vessel wall response and hemolysis due to conventional AngioJet rheolytic thrombectomy (RT) and AngioJet PMT in the porcine peripheral arterial model.

Methods

A total of 19 juvenile pigs were divided into acute and chronic groups. In the acute group (n = 6), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed 4 days following interventions. In the chronic group (n = 5), bilateral common carotid, femoral, and iliac arteries ranging from 3 to 6 mm in diameter were randomized to the control RT group or to PMT therapy. Vessels were analyzed at 30 days following interventions. Hemolytic evaluation was performed in additional eight pigs, which were randomized to either RT or PMT intervention.

Results

In the acute group, similar histologic injury grades were noted between the RT‐ and PMT‐treated femoral and iliac vessels. Endothelial denudation in the RT and PMT vessels were 43% and 39% (NS), respectively. Vessels with intact internal elastic lamina (IEL) in the RT and PMT groups were 54% and 57% (NS), respectively. In vessels < 4 mm in diameter, fractured IEL in the AT and PMT groups occurred in 23% and 27% (NS), respectively. The degrees of smooth muscle cell (SMC) loss were similar for the RT‐ and PMT‐treated vessels (45% and 40%, respectively; NS). In the chronic group, no differences were seen between the RT and PMT groups with respect to endothelial denudation, IEL fracture rate, or SMC loss. Similar degrees of medial thickening or intimal hyperplasia were noted in the RT and PMT groups (49% and 43%, respectively; NS). No difference in hemolytic effect was noted in the treatment groups.

Conclusions

AngioJet rheolytic pharmacomechanical thrombectomy treatment incurs an equivalent safety profile in medium‐caliber peripheral arteries when compared to rheolytic thrombectomy treatment. No difference in hemolytic reaction occurred in either group. The observed clinical efficacy of rheolytic pharmacomechanical thrombectomy does not result in untoward vessel injury compared to conventional rheolytic thrombectomy therapy.
STRUGGLES UNDER AUTHORITARIANISM: REGIMES, STATES, AND PROFESSIONAL ASSOCIATIONS IN THE ARAB WORLD
Authors: Moore Pete W. , Salloukh Bassel F.
Published: March 2007

The failure of social science expectations that several Arab states would democratize in the 1980s and 1990s forced a reappraisal. The belief that chronic fiscal crisis and waning popular support would lead regimes to loosen authoritarian controls and thus possibly lead to democratization proved disappointingly unfounded. Instead, regimes that launched liberalizations in the 1980s reversed or halted most political-reform components in the following decade. Given that rising oil and commodity prices since 2003 have eased budgetary constraints for many states (especially in the Gulf), the emerging pattern is political change and shifts under authoritarian regimes over time, not democratization. A number of recent works have responded by quantitatively and qualitatively assessing factors that account for regional imperviousness to democratization as well as change in different directions. The purpose of this essay is to contribute to these responses in two ways: one, conceptualizing important change in state–society relations short of democratization; and two, comparatively analyzing the cases of Jordan, Kuwait, and Syria to propose ways of explaining these outcomes.
ALTERNATIVE APPROACHES TO MODERNIZATION IN THE LATE OTTOMAN PERIOD: İZMİRLİ İSMAİ L HAKKI'S RELIGIOUS THOUGHT AGAINST MATERIALIST SCIENTISM
Authors: Özervarli M. Sait
Published: March 2007

The aim of this article is to explore the distinctiveness of İzmirli İsmail Hakki (1869–1946) in the context of late Ottoman intellectual history and to suggest several implications of his thought on our understanding of debates on religion and modernization among Ottomans in the modern period. Studies on modern Islamic thought in the 19th and 20th centuries are mostly limited, especially in Western literature, to works dealing with a few well-known figures in the Arab world, such as Jamal al-Din al-Afghani and Muhammad Abduh. However, a close investigation into several mostly neglected or yet uncovered thinkers of the Ottoman capital, Istanbul, can provide us with more interesting aspects of this period. The earlier interest of Istanbul ulama in modernization, their closer and more direct contact with Europeans, and the long historical experience of central Ottoman intelligentsia in similar reviving attempts are some of these aspects. This article aims to demonstrate that central Ottoman studies can make significant contributions to the current knowledge of the period, not only in political history, as has been the main focus so far, but also in religious and intellectual thought. It will show how a contact was established between modern European and Ottoman religious thought, in which ways the issue of modernization became an important topic in religious circles, and what kind of perceptions took place among them about its content and limits.
REJECTIONIST ISLAMISM IN SAUDI ARABIA: THE STORY OF JUHAYMAN AL-'UTAYBI REVISITED
Authors: Hegghammer Thomas , Lacroix Stéphane
Published: March 2007

This article examines the origin and legacy of the rebel group that stormed the great Mecca mosque in November 1979. Extensive fieldwork and new primary sources show that the rebels represented a radicalized faction of a large pietistic organization established in Medina in the mid–1960s under the name al–Jama a al–Salafiyya al–Muhtasiba (JSM). The rebel faction had broken with the mother organization in 1977 and developed into an apocalyptic sect under the leadership of Juhayman al–Utaybi, who spent two years as a fugitive in the desert before the attack. Although the rebellion was crushed, the early 1990s witnessed a resurgence of Juhayman's ideas in Saudi Arabia. The article argues that the JSM, the Mecca rebels, and their heirs represent a widely ignored undercurrent of Saudi Islamism. Pietistic and isolationist, this so–called rejectionist Islamism is intellectually and sociologically distinct from the two other strains of Saudi Islamism, namely, reformism and jihadism.