bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simple photometric determination of free cyanide ion in aqueous solution with 2,6-dichlorophenolindophenol
Authors: Yari Abdollah , Kargosha Kazem 
Published: June 2006

Abstract
In this work, a simple photometric method with high accuracy and precision for measuring trace amounts of free cyanide ion in aqueous solution is demonstrated. Under the evaluated conditions, we could determine CN− concentration in the range of 5–70 ppm easily. The work is based upon the photometric titration of CN− with Co(II) in the presence of 2,6-dichlorophenolindophenol (DCPIP) at λmax = 602 nm in aqueous solution. The optimal conditions, such as pH, ionic strength, and concentration of chromopher were evaluated. The interence effect of many other cations and anions studied and the results are given here. The optimized titration was successfully used to determine the concentration of free cyanide ion in aqueous solutions.
Partially nanowire-structured TiO2 electrode for dye-sensitized solar cells
Authors: Suzuki Yoshikazu , Ngamsinlapasathian Supachai , Yoshida Ryuhei , Yoshikawa Susumu 
Published: June 2006

AbstractPartially nanowire-structured TiO2 was prepared by a hydrothermal processing followed by calcination in air. The hydrogen titanate powder as-synthesized was calcined at 300 °C for 4 h to obtain the partially nanowire-structured TiO2. A dye-sensitized solar cell (DSC) with a film thickness of 5.6 μm, fabricated using the partially nanowire-structured TiO2 showed better performance than using a fully nanowire-structured TiO2 or a conventional equi-axed TiO2 nanopowder. The short-circuit current density (JSC), the open-circuit voltage (VOC), the fill factor (FF) and the overall efficiency (η) are 11.9 mA/cm2, 0.754 V, 0.673 and 6.01 %, respectively. The effects of one-dimensional nanostructure and electron expressway concept are discussed.
Solid-state IR-LD spectroscopy of codeine and N-norcodeine derivatives
Authors: Bakalska Rumyana , Ivanova Bojidarka , Kolev Tsonko 
Published: June 2006

AbstractLinear-dichroic infrared spectra (IR-LD) of 3-ethoxy-4-(N-norcodeino-)cyclobutene-1,2-dione (1) and codeine dihydrogenphosphate (Codeinum phosphoricum) (2), oriented as solid suspensions in nematic liquid crystals, have been measured. IR characteristic band assignments were made, and used in stereo-structural predictions. The results were compared with crystallographic structures of similar organic systems, and found to be in good agreement.
Changes of thermal, mechanical and magnetic properties of an amorphous Fe80Cr5B15 alloy during magnetic and structural phase transitions
Authors: Kamasa Paweł , Myśliński Piotr 
Published: June 2006

Abstract
Thermal, mechanical and thermomagnetic properties associated with the magnetic and structural transition of an amorphous Fe80Cr5B15 alloy are described. The investigation was carried out in a simultaneous dilatometric and thermomagnetic experiment. An anomaly of the thermal expansion coefficient at the Curie point and a change in mechanical properties just before the onset of crystallization are observed. The results are compared with the thermal behavior obtained by differential scanning calorimetry.
The possibility of time resonance (explosion) phenomena in high-energy nuclear reactions
Authors: Olkhovsky Vladislav , Dolinska Marina , Omelchenko Sergey 
Published: June 2006

Abstract
This study shows that the exponential decrease of the energy spectra, accompanied by slight oscillations, with final-fragment energy in high-energy nuclear reaction, and independent of fragments, targets, projectiles, and projectile energies, can be explained under some conditions in the range of strongly overlapping compound resonances by a new phenomenon of time resonances (explosions). These time resonances (explosions) correspond to the formation of a few highly-excited, non-exponentially decaying nuclear clots (partial compound nuclei consisting of certain small groups of target and projectile nucleons). The proposed approach is an alternative way of analyzing experimental data compared with the majority of known descriptions (for instance, fireball models). This is a new and more general version of the time-evolution approach compared with the Izumo-Araseki time compound-nucleus model.
Rapidly rotating Bose-Einstein condensates in anharmonic confinement
Authors: Lu Li-Hua , Li You-Quan 
Published: June 2006

Abstract
We study a rapidly rotating Bose-Einstein condensate in anharmonic confinement and find that many properties, such as the critical rotating frequency and phase diagram, are different from those in a harmonic trap. We investigate the phase transitions between various vortex lattices and find that a hole emerges in the center of the cloud when the rotating frequency Θ reaches Θh but it becomes invisible when Θ > 1.0842ω
⊥.
Simulating a perpendicular exchange-biased structure with a partially covering nonmagnetic insertion at the FM/AFM interface
Authors: Błlachowicz Tomasz 
Published: June 2006

Abstract
The existence of minority spins, opposite to the perpendicular exchange bias, and majority spins aligned with this bias, and the dependence of the perpendicular exchange-bias field on the imprint effect, caused by the partially covering spacer at the ferromagnetic/antiferromagnetic (FM/AFM) interface, have been studied using Ising-type simulations. The present investigation suggests that the main factors influencing this phenomenon were dependent on the FM/AFM interface morphology, the balance between FM/AFM coupling and the FM-spins coupling, and the numerical balance between minority and majority spins. It was also determined that the imprint phenomenon can be used to enhance the perpendicular exchange-bias for small partial insertions at the FM/AFM interface.
Hydrogels in Biology and Medicine: From Molecular Principles to Bionanotechnology
Authors: Peppas N. A. , Hilt J. Z. , Khademhosseini A. , Langer R. 
Published: May 2006

AbstractHydrophilic polymers are the center of research emphasis in nanotechnology because of their perceived “intelligence”. They can be used as thin films, scaffolds, or nanoparticles in a wide range of biomedical and biological applications. Here we highlight recent developments in engineering uncrosslinked and crosslinked hydrophilic polymers for these applications. Natural, biohybrid, and synthetic hydrophilic polymers and hydrogels are analyzed and their thermodynamic responses are discussed. In addition, examples of the use of hydrogels for various therapeutic applications are given. We show how such systems' intelligent behavior can be used in sensors, microarrays, and imaging. Finally, we outline challenges for the future in integrating hydrogels into biomedical applications.
Cover Picture: Using a Core–Sheath Distribution of Surface Chemistry through 3D Tissue Engineering Scaffolds to Control Cell Ingress (Adv. Mater. 11/2006)
Authors: Barry J. J. A. , Howard D. , Shakesheff K. M. , Howdle S. M. , Alexander M. R. 
Published: May 2006

AbstractThe cover image shows a section through a 3D microcomputed‐tomography reconstruction of a porous polymer tissue‐engineering scaffold. Fibroblast cells (red) are encouraged to populate the interior of the disc by using a core/sheath distribution of plasma polymer (pp) coating. The background shows the cells on a flat surface, where their preference for adhesion to the pp allylamine surface (left) adjacent to a pp hexane (right) surface is readily apparent. This report by Alexander and co‐workers on p. 1406 is the first of cellular guidance within porous scaffolds using plasma polymerization, a coating method readily transferable to other scaffold materials.
A DFT Study of the Molecular Mechanisms of the Nucleophilic Addition of Ester‐Derived Lithium Enolates and Silyl Ketene Acetals to Nitrones: Effects of the Lewis Acid Catalyst
Authors: Domingo Luis R. , Arnó Manuel , Merino Pedro , Tejero Tomás 
Published: May 2006

AbstractThe molecular mechanisms for the nucleophilic addition of lithium enolates and silyl ketene acetals to nitrones in the absence and in the presence of a Lewis acid (LA) catalyst to give isoxazolidin‐5‐ones or hydroxylamines have been investigated by DFT methods at the B3LYP/6‐31G* level. The addition of lithium enolates to nitrones gives the corresponding hydroxylamines, while the addition of silyl ketene acetals affords isoxazolidin‐5‐ones through a concerted 1,3‐dipolar cycloaddition. The addition of the silyl ketene acetals to LA‐coordinated nitrones yields isoxazolidin‐5‐ones by a polar concerted cycloaddition or a stepwise nucleophilic attack via zwitterionic intermediates. A silyl migration on the [3+2] cycloadduct yields the corresponding O‐silylhydroxylamine. An analysis of the global electrophilicity of the reagents accounts for the strong electrophile activation of the LA‐coordinated nitrone, and the analysis of the local indices leads to an explanation for the experimentally observed regioselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Do Serine Octamers Exist in Solution? Relevance of this Question in the Context of the Origin of Homochirality on Earth
Authors: Vandenbussche Sophie , Vandenbussche Guy , Reisse Jacques , Bartik Kristin 
Published: May 2006

AbstractRecent MS studies have suggested that serine clusters could have played a role in the origin of homochirality on Earth. Aqueous serine solutions have been probed in order to see if serine clusters, such as those observed by MS, are present in solution. IR measurements as well as NMR chemical shift and diffusion coefficient measurements, as a function of pH and serine concentration, suggest that these clusters do not exist in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Using size exclusion chromatography‐RPLC and RPLC‐CIEF as two‐dimensional separation strategies for protein profiling
Authors: Simpson David C. , Ahn Seonghee , Pasa‐Tolic Ljiljana , Bogdanov Bogdan , Mottaz Heather M. , Vilkov Andrey N. , Anderson Gordon A. , Lipton Mary S. , Smith Richard D. 
Published: May 2006

AbstractBottom‐up proteomics (analyzing peptides that result from protein digestion) has demonstrated capability for broad proteome coverage and good throughput. However, due to incomplete sequence coverage, this approach is not ideally suited to the study of modified proteins. The modification complement of a protein can best be elucidated by analyzing the intact protein. 2‐DE, typically coupled with the analysis of peptides that result from in‐gel digestion, is the most frequently applied protein separation technique in MS‐based proteomics. As an alternative, numerous column‐based liquid phase techniques, which are generally more amenable to automation, are being investigated. In this work, the combination of size‐exclusion chromatography (SEC) fractionation with RPLC‐Fourier‐transform ion cyclotron resonance (FTICR)‐MS is compared with the combination of RPLC fractionation with CIEF‐FTICR‐MS for the analysis of the Shewanella oneidensis proteome. SEC‐RPLC‐FTICR‐MS allowed the detection of 297 proteins, as opposed to 166 using RPLC‐CIEF‐FTICR‐MS, indicating that approaches based on LC‐MS provide better coverage. However, there were significant differences in the sets of proteins detected and both approaches provide a basis for accurately quantifying changes in protein and modified protein abundances.
Capillary electrophoresis of affinity complexes between subviral 80S particles of human rhinovirus and monoclonal antibody 2G2
Authors: Kremser Leopold , Petsch Martina , Blaas Dieter , Kenndler Ernst 
Published: May 2006

AbstractHuman rhinoviruses (HRVs), the main etiologic agents of the common cold, transform into subviral B‐ or 80S particles (they sediment at 80S upon sucrose density gradient centrifugation) during infection and, in vitro, upon exposure to a temperature between 50 and 56°C. With respect to the native virion they lack the genomic RNA and the viral capsid protein VP4. 80S particles are unstable and easily disintegrate into their components, VP1, VP2, and VP3 in buffers containing SDS. However, this detergent was found to be a necessary constituent of the BGE for the analysis of these viruses and their complexes with receptors and antibodies by CE. We here demonstrate that dodecylpoly(ethyleneglycol ether) (D‐PEG) a nonionic detergent, is suitable for analysis of subviral particles as it preserves their integrity, in contrast to SDS. Electrophoresis of the 80S particles in borate buffer (pH 8.3, 100 mM) containing 10 mM D‐PEG resulted in a well‐defined electrophoretic peak. The identity of the peak was confirmed, among other means, by complexation with mAb 2G2, which recognizes a structural epitope exclusively present on subviral particles but not on native virus. Upon incubation of the 80S particles with mAb 2G2 the peak disappeared, but a new peak, attributed to the antibody complex emerged. The separation system allowed following the time course of the transformation of intact HRV serotype 2 into 80S particles upon incubation at temperatures between 40 and 65°C. We also demonstrate that subviral particles derived from HRV2 labeled with the fluorescence dyes FITC or Cy3.5 were stable in the separation system containing D‐PEG. Dye‐modified particles were still recognized by mAb 2G2, suggesting that the exposed lysines that are derivatized by the reagent do not form part of the epitope of the antibody.
Hexagonally‐closed‐packed micro‐light‐emitting diodes
Authors: Choi H. W. , Chua S. J. 
Published: May 2006

AbstractA micro‐light‐emitting diode array, based on a hexagonal closed‐packed structure is presented. Compared to previous designs such as microdisk and microring, the packing density of individual hexagonal elements can be increased to over 80% to minimize wastage of junction area. The increased sidewall area provides additional light extraction pathways. The hexagonal LED emits twice as much light compared to a conventional broad‐area LED with equal junction area, and 50% more light than a microdisk array LED. The marked improvement in efficiency makes the additional processing step worthwhile. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Doping efficiency and segregation of Si in AlN grown by molecular beam epitaxy
Authors: Lebedev V. , Morales F. M. , Romanus H. , Ecke G. , Cimalla V. , Himmerlich M. , Krischok S. , Schaefer J. A. , Ambacher O. 
Published: May 2006

AbstractThe growth of Si‐doped 2H‐AlN thin films by plasma‐induced molecular‐beam epitaxy is reported. We have found that Si positively affects the epitaxy being an effective surfactant for AlN growth with a remarkable impact on the crystal quality. It was also observed that heavy doping conditions result in the volume segregation of Si at the threading dislocation network and in the formation of an amorphous (AlO)(SiO)N cap layer caused by post‐growth surface oxidation of the accumulated Al and segregated Si. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlGaN films grown on trenched sapphire substrates using a low‐temperature GaNP buffer layer by MOCVD
Authors: Sumiyoshi K. , Tsukihara M. , Kawamichi S. , Yan F. , Sakai S. 
Published: May 2006

AbstractA technique has been developed to grow low‐dislocation‐density AlGaN films in this paper. The AlGaN film is laterally overgrown on a trenched sapphire substrate with a low‐temperature (LT) GaNP buffer layer by metalorganic chemical vapour deposition (MOCVD). The optical charactertics and microstructure of the AlGaN films have been invesigated by means of cathodoluminescence (CL), high‐resolution X‐ray diffraction (HRXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. It is shown that the dislocation densities in the Al0.07Ga0.93N film are reduced to 8.7 x 108 cm–2 (by CL) and 2.7 x 109 cm–2 (by TEM) in the whole trenched sapphire, and 4.0 x 108 cm–2 (by CL) and 1.3 x 109 cm–2 (by TEM) in the trenched area. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonant photoluminescence excitation studies of InGaN/GaN single quantum wells
Authors: Graham D. M. , Dawson P. , Godfrey M. J. , Kappers M. J. , Barnard J. S. , Humphreys C. J. , Thrush E. J. 
Published: May 2006

AbstractThe optical properties of InGaN/GaN single quantum well structures, with indium fractions of 0.15 and 0.25, have been studied under resonant excitation conditions. The low temperature (T = 6 K) photoluminescence spectra show a broad recombination feature that we attribute to acoustic phonon accompanied absorption and emission from a distribution of localized states. Also we observe in the sample with the indium fraction of 0.15 a sharp line that we attribute to LO phonon accompanied recombination of excitons in the resonantly excited localized states. Comparing the form of the spectra with model calculations, where we consider the deformation potential coupling of localized excitons to an effectively continuous distribution of acoustic phonons, enables us to show that the in‐plane localization length scale of the excitons may be as small as 2.5 Å. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance of AlGaN/GaN heterojunction FETs for microwave power applications
Authors: Miyamoto H. 
Published: May 2006

AbstractThis paper describes design and performance of AlGaN/GaN heterojunction FETs for microwave power applications. A recessed‐gate FET with a field‐modulating plate (FP) was developed for high‐voltage power operation at L‐band and C‐band. The developed recessed FP‐FETs exhibited a 230‐W CW output power at 2 GHz and a 156‐W pulsed output power at 4 GHz. A T‐shaped 0.25‐μm‐gate FET was fabricated for high‐frequency power operation at Ka‐band. A 1.0‐mm‐wide FET exhibited a 5.8‐W CW output power at 30 GHz. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of InN/AlInN MQWs by RF‐MBE
Authors: Terashima W. , Che S. B. , Ishitani Y. , Yoshikawa A. 
Published: May 2006

AbstractWe studied on the growth of N‐polarity InN/AlInN MQWs by radio frequency plasma‐assisted MBE. We found that the growth temperature greatly affected the structural properties of InN/AlInN MQWs. The growth temperature for achieving fine periodic MQWs was in the range from 550 to 580 °C. By optimizing the growth conditions, we for the first time successfully fabricated InN‐based MQWs with AlxIn1–xN (∼0.2 < x < ∼0.3) barrier layers. Clear satellite peaks up to the 3rd order in high resolution X‐ray diffraction were observed, indicating that being fine periodic MQWs‐structures with fairly flat and sharp interfaces. Photoluminescence peaks ranging from 0.68 to 0.99 eV were observed depending on the well thickness and they were in good agreement with those estimated by simple theoretical calculation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Band‐to‐band and inner shell excitation VIS‐UV photoluminescence of quaternary InAlGaN alloys
Authors: Fukui K. , Naoe S. , Okada K. , Hamada S. , Hirayama H. 
Published: May 2006

AbstractVisible and ultraviolet photoluminescence and photoluminescence excitation spectra of quaternary InAlGaN alloys were measured. The excitation photon energy covers from band edge to 180 eV, near both nitrogen K (∼400eV) and aluminium K (∼1.5 keV) inner shell energy region. From photoluminescence excitation spectra photoluminescence intensity per incident photon number varies in proportion to incident photon energy. This result implies that many conduction band electron ‐ valence band hole pairs which are responsible for photoluminescence are produced by high energy excitation. Time resolved decay curves were also measured in the same energy region. No effect of high energy excitation on time resolved decay measurements suggests a role of indium on the photoluminescence mechanism in InAlGaN system. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence spectra of GaN films grown at low temperature by compound‐source molecular beam epitaxy
Authors: Honda Tohru , Sawada Masaru , Kobayashi Toshiaki , Egawa Shinichi , Aoki Yohta , Akiyama Miwako , Kawanishi Hideo 
Published: May 2006

AbstractThe photoluminescence spectra of GaN films deposited by compound‐source molecular beam epitaxy (CS‐MBE) at 450 °C are reported. A near band‐edge emission was observed from the GaN layers grown on (0001) 6H‐SiC substartes by CS‐MBE at 18 K. The cathodoluminescence spectra of the deposited films and GaN powders were also observed at 20 K. The emission intensity per film thickness of the deposited films is roughly the same as that of GaN powders. Electroluminescent devices were fabricated using the deposited films, and a UV light emission was observed from these devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthese, Kristallstruktur und magnetisches Verhalten von Gd(CF3CF2COO)3(H2O)3
Authors: Rohde Alexander , Urland Werner 
Published: May 2006

AbstractSynthesis, Crystal Structure and Magnetic Behaviour of Gd(CF3CF2COO)3(H2O)3Single crystals of Gd(CF3CF2COO)3(H2O)3 have been obtained by reaction of Gd2O3 with an aqueous solution of CF3CF2COOH. The compound crystallizes triclinically in the space group $P{\bar 1}$ (No. 2; Z = 2; a = 928.5(1) pm, b = 1037.1(1) pm, c = 1147.3(2) pm, α = 90.44(2)°, β = 108.56(1)°, γ = 106.49(1)°). In the crystal structure the gadolinium ions are bridged by carboxylate groups to dimers and are coordinated eightfold by oxygen atoms. The magnetic behaviour was investigated in the temperature range of 1.77 to 300 K. The magnetic data indicate weak antiferromagnetic interactions within the dimeric unit (Jex = −0.0057 cm−1).
Synthesen, Eigenschaften und Kristallstrukturen der Cluster‐Salze Bi6[PtBi6Cl12] und Bi2/3[PtBi6Cl12]
Authors: Hampel Silke , Ruck Michael 
Published: May 2006

AbstractSyntheses, Properties and Crystal Structures of the Cluster Salts Bi6[PtBi6Cl12] and Bi2/3[PtBi6Cl12]Melting reactions of Bi with Pt and BiCl3 yield shiny black, air insensitive crystals of the subchlorides Bi6[PtBi6Cl12] and Bi2/3[PtBi6Cl12]. Despite the substantial difference in the bismuth content the two compounds have almost the same pseudo‐cubic unit cell and follow the structural principle of a CsCl type cluster salt. Bi6[PtBi6Cl12] consists of cuboctahedral [PtBi6Cl12]2− clusters and Bi62+ polycations (a = 9.052(2) Å, α = 89.88(2)°, space group P 1, multiple twins). In the electron precise cluster anion, the Pt atom (18 electron count) centers an octahedron of Bi atoms whose edges are bridged by chlorine atoms. The Bi62+ cation, a nido cluster with 16 skeletal electrons, has the shape of a distorted octahedron with an opened edge. In Bi2/3[PtBi6Cl12] the anion charge is compensated by weakly coordinating Bi3+ cations which are distributed statistically over two crystallographic positions (a = 9.048(2) Å, α = 90.44(3)°, space group $R{\bar 3}$). Bi6[PtBi6Cl12] is a semiconductor with a band gap of about 0.1 eV. The compound is diamagnetic at room temperature though a small paramagnetic contribution appears towards lower temperature.