bluuebunny/crossref_metadata_2025_split huggingface dataset:
A detailed analysis of the Raman spectra in superconducting boron doped nanocrystalline diamond
Authors: Szirmai Péter , Pichler Thomas , Williams Oliver A. , Mandal Soumen , Bäuerle Christopher , Simon Ferenc 
Published: November 2012

AbstractThe light scattering properties of superconducting (Tc ≈ 3.8 K) heavily boron doped nanocrystalline diamond has been investigated by Raman spectroscopy using visible excitations. Fano type interference of the zone‐center phonon line and the electronic continuum was identified. Lineshape analysis reveals Fano lineshapes with a significant asymmetry (q ≈ −2). An anomalous wavelength dependence and small value of the Raman scattering amplitude is observed in agreement with previous studies.
Raman investigation of few‐layer graphene on different substrate structures
Authors: Lee Jong‐Kwon , Yamazaki Shiro , Kim Do‐Hyun , Kim Gyu‐Tae , Dettlaff‐Weglikowska Urszula , Roth Siegmar 
Published: November 2012

AbstractWe report Raman analysis of few‐layer graphene (FLG) transferred on flat and patterned substrate structures. These different surface structures created by patterning an area of a Si‐substrate produce differences in the interaction between FLG and the substrate surface. The topography measurement performed by scanning tunneling potentiometry shows that the FLG on the patterned substrate was deformed periodically with 3–4 nm depth variation. Raman spectroscopy reveals that two important features related to the G‐ and 2D‐modes in graphitic structures show different sensitivity to the interaction with the substrate for single‐layer graphene (SLG), FLG, and graphite. Whereas SLG and FLG placed on the patterned substrate demonstrate a strong shift of both 2D‐ and G‐peaks to lower frequencies with respect to the flat part, the multilayer graphene in a graphite flake shows almost no difference between patterned and non‐patterned substrates. We identified the origin of the observed changes in the Raman spectra of SLG and FLG as effects created by the underlying substrate. Especially, substrate induced periodic strain and surface interaction were taken into account to interpret the results.
Hybrid InGaN/CdZnO quantum well structures for optoelectronic applications in the short wavelength spectral region
Authors: Park Seoung‐Hwan , Ahn Doyeol 
Published: November 2012

AbstractSpontaneous emission characteristics of hybrid InxGa1 − xN/Cd0.05Zn0.95O quantum well (QW) structures were theoretically investigated by using multi‐band effective mass theory. The transition wavelength of the InGaN/CdZnO QW structure is shown to be changed from 415 to 580 nm when the In content x is varied from 0.1 to 0.3. The conventional InGaN/GaN QW structure shows that its peak intensity linearly decreases with increasing peak wavelength. On the other hand, the InGaN/CdZnO QW structure shows that the spontaneous emission coefficient reaches a maximum at around the peak wavelength of 0.484 µm, which corresponds to x = 0.2. This can be explained by the fact that, in a range of the short peak wavelengths, the InGaN/CdZnO QW structure has a very shallow potential well. In a range of the longer peak wavelengths above 0.47 µm, the InGaN/CdZnO QW structure is expected to have a larger spontaneous emission peak than the InGaN/GaN QW structure. This can be explained by the fact that the former has a reduced internal field compared to the latter.
Compensation effect and magnetostriction in CoCr2−xFexO4
Authors: Zhang Hong‐guo , Wang Weng‐hong , Liu En‐ke , Tang Xiao‐dan , Li Gui‐jiang , Zhang Hong‐wei , Wu Guang‐heng 
Published: November 2012

AbstractThe magnetic compensation and magnetostriction properties in Fe‐doped CoCr2O4 samples have been investigated. Structural and magnetic measurements imply that the doped Fe3+ ions initially occupy the B1 (Cr) sites when x < 0.1, and then mainly take the A (Co) sites. This behaviour results in a role conversion of magnetic contributors and a composition compensation between two competitively magnetic sublattices at x = 0.1. Temperature‐dependent compensation has also been found in the samples with x = 0.1–0.22, with the compensation temperature in the range of 40–104 K. The Fe3+ doping also modulates the exchange interaction of the system and prevents the formation of long‐range conical order of spins. The magnetoelectric transition temperature at 23 K in CoCr2O4 is shifted to lower temperature by increasing the dopants. The magnetostriction effect in this system has been observed for the first time. The strain has a maximum value of about 280 ppm at x = 0.4. The magnetostriction is consistent with the behaviour of the two magnetic compensations.
Carrier transport and charge transfer properties in coumarin‐doped bulk‐heterojunction materials
Authors: Watanabe T. , Maeda T. , Yamashita K. , Yanagi H. 
Published: November 2012

AbstractWe have investigated photovoltaic properties of organic solar cells using polymer‐fullerene bulk‐heterojunction films doped with coumarin dyes. Whereas the coumarin molecules used in this study had similar absorption bands, evident difference was observed in the open‐circuit voltage as well as in the short‐circuit current. In particular, the doping of coumarin 307 was found to cause a distinct enhancement in the open‐circuit voltage. On the other hand, the doping of coumarin 30 gave a serious degradation in the device performance. These results were strongly associated with calculated molecular energies of the doped dyes, especially with the highest occupied molecular orbital energy. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells
Authors: Narayan Monishka Rita , Singh Jai 
Published: November 2012

AbstractThe influence of binding energy and diffusion length on the dissociation of excitons in organic solids is studied. The binding energy and excitonic Bohr radius of singlet and triplet excitons are calculated and compared using the dissociation energy of 0.3 eV, which is provided by the lowest unoccupied molecular orbital offset in heterojunction organic solar cells. A relation between the diffusion coefficient and diffusion length of singlet and triplet excitons is derived using the Förster and Dexter transfer processes and are plotted as a function of the donor‐acceptor separation. The diffusion length reduces nearly to a zero if the distance between donor and acceptor is increased to more than 1.5 nm. It is found that the donor‐acceptor separation needs to be ≤ 1.5 nm for easy dissociation on singlet excitons leading to better conversion efficiency in heterojunction organic solar cells. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Relaxation time distribution of distant‐pair recombination: Application to QFRS of PL in a‐Si:H
Authors: Aoki Takeshi , Ikeda Kosuke 
Published: November 2012

AbstractThe distribution function of relaxation time of distant‐pair (DP), or nongeminate recombination is derived in an analytic form from the existing theories of DP recombination to analyse the data of quadrature frequency resolved spectroscopy (QFRS) of photoluminescence (PL) in a‐Si:H with the competing recombination model. The distribution function has a single parameter of metastable carrier density n and yields too narrow QFRS spectrum to fit the experimental data. This is improved with introducing the fluctuation Δ of the electron localisation radius ae. The devised formula is demonstrated to predict the dependence of the DP recombination on the photogeneration rate and the defect density in the QFRS data of the high‐quality and defective a‐Si:H. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optoelectronic and thermal properties of solution‐based graphene thin films
Authors: Bauld Reg , Shafiq Ahmed M. , Fanchini Giovanni 
Published: November 2012

AbstractIn this paper we review some of the relationships existing between the optical properties, electrical conductivity, and thermal conductivity in graphene based transparent and conducting thin films. We provide a set of tools that are useful to identify the optimal trade‐off between transmittance and electrical conductivity in these films. In addition we present a set of thermal conductivity measurements of graphene thin films and relate them to the electrical properties in order to build a comprehensive picture of the electrical, thermal, and optical properties of graphene based thin films (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
White polymer light‐emitting diodes co‐doped with phosphorescent iridium complexes bearing the same cyclometalated ligand
Authors: Ikawa Shigeru , Yagi Shigeyuki , Maeda Takeshi , Nakazumi Hiroyuki 
Published: November 2012

AbstractIn order to develop white organic light‐emitting devices, we fabricated poly(9‐vinylcarbazole)‐based polymer light‐emitting diodes (PLEDs) using blue‐ and orange‐phosphorescent bis‐cyclometalated iridium(III) complexes Ir‐1a and Ir‐1b as emitting co‐dopants, both of which possess the same cyclometalated ligand. The PLED co‐doped with Ir‐1a and Ir‐1b in a single emitting layer (WPLED‐1) yielded the optimized white electroluminescence with a Commission Internationale de L'Eclairage (CIE) chromaticity coordinate of (0.33, 0.46), although the value of the color rendering index (CRI) was very poor (CRI = 58). Thus, in order to improve the color rendering properties of WPLED‐1, the deep red‐phosphorescent iridium(III) complex Ir‐2 was employed as an additional co‐dopant. In the PLED co‐doped with Ir‐1a, Ir‐1b and Ir‐2 (WPLED‐2), tuning the ratio of the three emitting co‐dopants allowed us to obtain white electroluminescence with high color rendering properties (CRI = 82), where the CIE chromaticity coordinate of (0.38, 0.44) was obtained. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mg‐doped InXGa1‐XN films deposited by reactive rf‐magnetron sputtering
Authors: Itoh Takashi , Kato Yoshinori , Hibino Syun , Katayama Ryuichi , Ohashi Fumitaka , Nonomura Shuichi 
Published: November 2012

AbstractIn order to use as p‐layer material of top cell, Mg‐doped amorphous indium gallium nitride (a‐InXGa1‐XN) films were deposited at room temperature by simultaneous reactive rf‐magnetron sputtering. Mg composition ratio increased from 0 to 0.039 with increasing rf‐power inputted into Mg target from 0 to 10 W. Large change in the In and N composition ratios were not observed by the Mg doping. Dark conductivity increased from 5.57 × 10–7 to 1.26 × 10–3 S/cm with increasing the Mg composition ratio from 0 to 0.039. The activation energy decreased from 0.51 to 0.041 eV with increasing the Mg composition ratio from 0 to 0.039. Based on these results, Mg‐doping in a‐InXGa1‐XN films deposited at room temperature by simultaneous reactive rf‐magnetron sputtering was discussed (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eu‐concentration dependence of optical and scintillation properties for Eu‐doped SrF2 single crystals
Authors: Kurosawa Shunsuke , Yokota Yuui , Yanagida Takayuki , Yoshikawa Akira 
Published: November 2012

AbstractSome Eu‐doped scintillators, such as Eu:SrI2, emit around 400‐nm wavelength that originates from 5d‐4f transition of Eu2+, while some Eu‐doped crystals have emissions from Eu3+ (f‐f emission). In this report, effect of Eu‐doping on optical and scintillation properties of SrF2 crystals with Core‐valence luminescence is discussed. The samples had 0.1, 0.2, 0.5, 1.0, and 2.0 mol% of Eu and were grown by an annealing method. As a result, 5D0‐7Fi (i =1, 2) transition (Eu3+) was detected in the SrF2, containing over 0.5 mol% of Eu, while emission from 0.1 and 0.2‐mol% Eu:SrF2 originated from 5d‐4f transition of Eu2+ and Core‐valence luminescence. The light output of SrF2 doped with 0.1, 0.2, 0.5, 1.0 and 2.0 mol% Eu was estimated to be 13,000 ± 1,000, 12,000 ± 1,000, 13,000 ± 2,000, 8,000 ± 1,000 and 7,000 ± 1,000 photons/MeV, respectively. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On downlink power allocation for multiuser variable‐bit‐rate video streaming
Authors: Huang Yingsong , Mao Shiwen , Li Yihan 
Published: November 2012

ABSTRACTIn this paper, we study the problem of power allocation for streaming multiple variable‐bit‐rate (VBR) videos in the downlink of a cellular network. We consider a deterministic model for VBR video traffic and finite playout buffer at the mobile users. The objective is to derive the optimal downlink power allocation for the VBR video sessions, such that the video data can be delivered in a timely fashion without causing playout buffer overflow and underflow. The formulated problem is a nonlinear nonconvex optimization problem. We analyze the convexity conditions for the formulated problem and propose a two‐step greedy approach to solve the problem. We also develop a distributed algorithm based on the dual decomposition technique, which can be incorporated into the two‐step solution procedure. The performance of the proposed algorithms is validated with simulations using VBR video traces under realistic scenarios. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Elliptical Snorkel on the Decarburization Rate in Single Snorkel Refining Furnace
Authors: Rui Qixuan , Jiang Fang , Ma Zhuang , You Zhimin , Cheng Guoguang , Zhang Jian 
Published: November 2012

AbstractIn the present work, physical model experiments were performed to investigate the effect of elliptical snorkel on the decarburization in single snorkel refining furnace. A round snorkel with the same cross‐section area as the elliptical snorkel was also made for comparison. Bubble behavior was recorded by a high speed video camera in this study. A volumetric mass transfer coefficient kA/V was used to evaluate the decarburization rate. Measurement of the volumetric mass transfer coefficient kA/V was made by means of the carbon dioxide desorption from a NaOH solution. It is found when the plug location is close to the center of the ladle bottom, almost all the bubbles get into the snorkels. However, when the plug location is too far away from the center of ladle bottom, bubbles will escape from the outside of the snorkel. kA/V generally rises with increasing gas flow rate. Moreover, kA/V is increased when the plug is moved from the center to the half radius of the ladle bottom. However, kA/V is decreased when the plug is moved from the half radius of ladle bottom to the ladle sidewall. It is indicated that kA/V for the elliptical snorkel is larger than that for the round one when the plug is located between the center and half radius of ladle bottom. Nevertheless, when the plug is located between the half radius and the ladle sidewall, the kA/V for the elliptical snorkel is smaller than that for the round one.
Numerical and analytical investigations on plain channels in coupled instabilities
Authors: Ungermann Dieter , Brune Bettina , Lübke Sebastian 
Published: November 2012

AbstractThis paper presents numerical and analytical investigations of thin‐walled steel C‐section members subjected to both local and global buckling. The results presented here are based on experimental tests which are dealt with in a previous publication [1]. Numerical calculations using the finite element method are performed to recalculate test results from stub column tests with local buckling and long column tests with coupled local and global buckling failure. These results are analysed using different design procedures based on Eurocode 3. Using modified buckling factors and an approach considering effective stiffness by approximation, it is possible to determine the ultimate buckling loads from tests and numerical investigations efficiently.
The Design of Langqi Min River Bridge, Fuzhou, China
Authors: Zhang Min , Wan Tianbao , Wang Yingliang 
Published: November 2012

AbstractOne key project in the Chinese city of Fuzhou is Langqi Min River Bridge, which connects the business and technology district with downtown Fuzhou. The main bridge is a twin‐pylon cable‐stayed structure with a main span of 680 m and a steel box girder. This paper presents the detailed design features of the bridge, including foundations, anti‐ship collision devices, pylons, steel box girder and stay cables.
The art of major bridge‐building – Hellmut Homberg and his contribution to multiple cable‐stayed spans
Authors: Pelke Eberhard , Kurrer Karl‐Eugen 
Published: November 2012

AbstractBased on findings from Büchenauer Bridge (1956), the North Elbe Bridge in Hamburg (1963) and the bridge over the Rhine at Leverkusen (1965), Homberg designed and engineered the Friedrich Ebert Bridge across the River Rhine. This was the first bridge in the world with cables that distribute instead of concentrate the load transfer, and thus define the bridge deck as a continuous, elastically supported element and not as a beam on point supports.After the building of major bridges declined in Germany, Homberg became active in France, and later rounded off his work with multi‐cable‐stayed bridges in the UK. That work resulted in the Queen Elizabeth II Bridge (1991), Homberg’s late magnum opus.This article contains a complete catalogue of Homberg’s multi‐cable‐stayed bridges and discusses for the first time previously unpublished designs by Homberg. These prove that he had already moved on from the classic cable‐stayed bridge to the general multi‐span cable‐stayed bridge as early as 1963.
Box traps for feral swine capture: A comparison of gate styles in Texas
Authors: Long David B. , Campbell Tyler A. 
Published: November 2012

AbstractMany different types of traps have been developed to increase feral swine (Sus scrofa) capture efficiency. Though not previously compared, gate styles may influence capture success. Our objectives were to report feral swine capture data from 31 trapping campaigns conducted in 17 counties from 2005 to 2011 in Texas, USA, compare capture rates by demographic category between side‐swing and rooter gates, and evaluate influences of moisture, using the Palmer Drought Severity Index (PDSI), on juvenile capture rates. We trapped feral swine during all months of the year. Our trap configurations were identical with the exception of gate style. Traps had either side‐swing or rooter gates. We captured 1,310 feral swine during 2,424 trap‐nights. We found no differences in capture rates between gate styles for adults, adult males, or adult females. However, we found juvenile capture rates and total capture rates to differ between gate styles. Box traps with rooter gates captured more juveniles, resulting in more total captures than in box traps with side‐swing gates. Partitioned rooter gates are constructed to allow for continual entry after the gate has been tripped; whereas with single‐panel side‐swine gates, continual entry may be more challenging for juvenile animals that lack the size and strength to push through the spring tension. Rooter gates should be considered over side‐swing gates in management programs aimed at overall damage reduction. However, in management or research programs that seek to capture adult feral swine, side‐swing gates may be more appropriate because fewer non‐target juvenile feral swine are captured. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Distribution of Candida in the oral cavity and its differentiation based on the internally transcribed spacer (ITS) regions of rDNA
Authors: Zahir R. A. , Himratul‐Aznita W. H. 
Published: November 2012

AbstractThis study aimed to determine the distribution of Candida species in the oral cavity and differentiate the species based on PCR amplification, including HinfI and MspI digestion, in order to assess the effectiveness of using the rDNA region for species identification. Samples from saliva as well as palate, tongue and cheek mucosa surfaces were collected from 45 individuals, consisting of three groups: periodontal disease patients; denture‐wearers; and the control group. The samples were serially diluted, spread on BHI and YPD agar plates and scored for colony‐forming units (CFUs). Fifteen random candidal colonies were isolated and subjected to genomic DNA extraction, based on glass beads disruption. Four primers were used to amplify regions in the rDNA, and the ITSI‐5.8S‐ITSII PCR product was digested by HinfI and MspI restriction enzymes. The microbial loads on all sites of the denture‐wearers were found to be significantly higher than control, while in the periodontal disease group only the microbial loads on the tongue were significantly higher than control. Meanwhile, there was no significant difference at other sites. The restriction fragment lengths of the clinical samples were compared to those of seven control species, allowing the differentiation of all seven species and the identification of 14 species from the clinical samples. The MspI restriction digest was not able to distinguish between C. albicans and C. dubliniensis, whereas the HinfI digest could not distinguish between C. tropicalis and C. parapsilosis. It was concluded that PCR–RFLP of the candidal rDNA region has potential for species identification. This study demonstrates the potential use of candidal rDNA as a means for identifying Candida species, based on genotype. The results also indicate the possibility of constructing genetic probes that target specific restriction fragments in the ITSI‐5.8S‐ITSII region, enabling swift and precise identification of Candida species. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis, Characterization, and Properties of Few‐layer Metal Dichalcogenides and their Nanocomposites with Noble Metal Particles, Polyaniline, and Reduced Graphene Oxide
Authors: Matte H. S. S. Ramakrishna , Maitra Urmimala , Kumar Prashant , Govinda Rao Bolla , Pramoda K. , Rao C. N. R. 
Published: November 2012

AbstractFew‐layer graphene‐like sheets of MoS2, WS2, MoSe2 and WSe2 were prepared by employing two methods. The first method uses microwave synthesis in ethylene glycol or water medium and the second method involves laser irradiation of the bulk samples dispersed in dimethylformamide. The few‐layer dichalcogenide samples were characterized by various microscopic and spectroscopic techniques. These graphene mimics show room‐temperature ferromagnetism and exchange bias besides magnetoresistance at room temperature. We have deposited nanoparticles of gold, silver, and platinum on few‐layer WS2 and characterized the nanocomposites. Nanocomposites of MoS2 with reduced graphene oxide show increase in resistivity with increasing amount of MoS2. The polyaniline MoS2 composite prepared by in situ polymerization of aniline in the presence of few‐layer MoS2 shows evidence of polaronic character.
Virtual Fossils: a New Resource for Science Communication in Paleontology
Authors: Rahman Imran A. , Adcock Keith , Garwood Russell J. 
Published: November 2012

Abstract
Computer-aided 3-D reconstruction of fossils, or virtual paleontology, is an increasingly common and powerful technique. It is now regularly used for research in paleontology, yet to date has impacted little on public outreach and science communication; however, it is ideally suited for these purposes, being increasingly cheap and available, dynamic and exciting, and applicable to a range of topics. Here, we provide an introduction to the field, and a case study of its use for a public engagement event. The steps involved in creating such an educational resource are outlined, and include computed tomography scanning, digital visualization, and 3-D printing of fossils. We emphasize the value of virtual fossils for science communication; they allow for diverse learning styles in a variety of topics. In the future, we hope that virtual paleontology will become a mainstay of communicating the history of life, thereby promoting accurate understanding of evolution.