bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural, optical, and electrical properties of n‐ZnO/p‐GaAs heterojunction
Authors: Tekmen Süleyman , Gür Emre , Asıl Hatice , Çınar Kübra , Coşkun Cevdet , Tüzemen Sebahattin 
Published: March 2010

Abstractn‐ZnO film grown by electrodeposition (ECD) on p‐GaAs substrate was characterized by structural, optical, and electrical techniques. X‐ray diffraction (XRD) measurement clearly showed formation of ZnO thin film with a strong c‐axis (0002) preferential orientation. Photoluminescence (PL) measurements showed that the grown film has a strong and narrow ultraviolet (UV) emission indicating high‐quality ZnO thin film. Current–voltage (I–V) measurement of n‐ZnO/p‐GaAs heterojunction shows diode‐like rectifying characteristics with an almost five‐order rectification factor and a turn‐on voltage of 2 V.
Fabrication of novel Ag nanowires/poly(vinylidene fluoride) nanocomposite film with high dielectric constant
Authors: Zheng Wei , Lu Xiaofeng , Wang Wei , Wang Zhaojie , Song Mingxin , Wang Yu , Wang Ce 
Published: March 2010

AbstractA nanocomposite with Ag nanowires embedded into poly(vinylidene fluoride) (PVDF) has been prepared via a simple casting method. The uniform dispersion of Ag nanowires is characterized by scanning electron microscopy and the dielectric properties of composite films on volume fraction of Ag nanowires and frequency are fully investigated. The percolation threshold of the composite is relatively large, 20 vol.%. The dielectric constant of Ag nanowires/PVDF composite film is as high as 800 in the low‐frequency range (100 Hz), and remains at 379 at 1000 Hz with 20 vol.% of Ag nanowires. Meanwhile, the Ag nanowires/PVDF composite film exhibits low dielectric loss of 0.15, which shows potential for applications in advanced electronics.Dependence of the effective dielectric constant of the Ag nanowires/PVDF composites on the Ag nanowires volume fraction at room temperature and 1000 Hz. And the inset is the surface of the composite film (fAg = 20 vol.%).magnified image
Site‐selective anodic etching of InP substrate using self‐organized spheres as mask
Authors: Yokoyama Takayuki , Asoh Hidetaka , Ono Sachiko 
Published: March 2010

AbstractOrdered microstructures were formed on an InP substrate by metal‐assisted chemical etching or anodic etching using a layer of colloidal crystals consisting of polystyrene spheres as a mask. When the metal‐assisted chemical etching of the InP substrate was carried out in a mixed solution of H2SO4/H2O2 using a Pt honeycomb pattern as a catalyst, obtained by ion sputtering through the mask on the substrate, InP column arrays with a close‐packed configuration having an ordered periodicity were formed. Furthermore, by anodic etching at the optimum HCl concentration with a layer of colloidal crystals as a mask, InP disk arrays or pillar arrays were fabricated.
Polycrystalline silicon germanium thin films prepared by aluminum‐induced crystallization
Authors: Iwasa Takehiro , Kaneko Tetsuya , Nakamura Isao , Isomura Masao 
Published: March 2010

AbstractThe aluminum‐induced crystallization (AIC) of amorphous silicon germanium (a‐SiGe) was investigated in bilayer structure of aluminum (Al) and a‐SiGe at the eutectic temperature of Al–Ge system (420 °C) or higher temperature. Due to energy dispersive X‐ray spectroscopy (EDX) measurements after the AIC at 420 °C, crystallized SiGe alloys are formed with island structures and Al locates between the islands. The layer‐exchange is confirmed in the island regions. In the AIC at 450 °C, similar island structures are observed but the Ge is sometimes found with Al probably due to the eutectic. The layer‐exchange of SiGe seems incomplete. On the other hand, Si and Ge are separately localized in the AIC at 500 °C, which is observed by the EDX images and also suggested by the Raman and X‐ray diffraction (XRD) measurements. Probably, the eutectic helps to segregate Ge from SiGe alloys. We confirm that thermal annealing above the eutectic temperature of Al and Ge is not suitable for the AIC of a‐SiGe and the segregation of Si and Ge prevents the complete layer exchange.
Simulation and modelling of photonic and plasmonic crystal back reflectors for efficient light trapping
Authors: Biswas Rana , Zhou Dayu 
Published: March 2010

AbstractWe design photonic crystal back reflectors for thin film a‐Si:H solar cells that maximize the absorption of photons within the absorber layer. Rigorous scattering matrix (S‐matrix) simulation approaches are used where Maxwell's equations are rigorously solved for the layered solar cell structure. Metallic photonic crystals consisting of hole arrays as well as metallic pyramidal arrays are considered. Simulations predict an optimum lattice spacing between 700 and 750 nm and an increase in absorption of ∼10%. The metallic photonic crystals strongly diffract light within the absorber layer, and are very effective in harvesting weakly absorbing photons with energies just above the band edge.
The effect of the film H content on the crystallization of laser processed and thermally annealed HWCVD a‐Si:H
Authors: Mahan A. H. , Dabney M. S. , Parilla P. A. , Ginley D. S. 
Published: March 2010

AbstractWe demonstrate the use of laser processing to affect the nucleation of crystallites in thermally annealed HWCVD a‐Si:H thin films. The influence of film H content is investigated by XRD measurements during in situ 600 °C thermal anneal on both as grown films and on films that have been laser irradiated. All laser irradiated films show a reduced incubation time (τo) for crystallization compared to as‐grown films, with the largest differences exhibited for samples with higher film H. We show that a recently developed model for a nucleation center in a‐Si:H can be used to explain how the film H content affects this change in τo and also predict the magnitude of this change with laser processing (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of hydrogen dilution profiling on the microscopic structure of amorphous and nanocrystalline silicon mixed‐phase solar cells
Authors: Yan Baojie , Jiang Chun‐Sheng , Yan Yanfa , Sivec Laura , Yang Jeffrey , Guha Subhendu , Al‐Jassim M.M. 
Published: March 2010

AbstractMicroscopic structure and solar cell performance in hydrogenated mixed‐phase thin film silicon (Si:H) solar cells are studied. The samples were made with RF glow discharge with different hydrogen dilution profiles. The material properties were measured with Raman, X‐TEM, AFM, and C‐AFM. Several interesting phenomena are observed. First, the cone‐structured nanocrystalline aggregations were formed when a constant hydrogen dilution was used. Second, no uniform block‐like (or cylinder‐like) structured nanocrystalline clusters were observed even when hydrogen dilution profiling was optimized for this purpose. Instead, tree‐like structured nanocrystalline clusters were formed and embedded in the intrinsic layer. Third, the magnitude of light‐induced Voc increase was reduced by hydrogen dilution profiling. When the dilution profiling was sufficiently steep, no light‐induced Voc increase was observed. Instead, the Voc decreased after light‐soaking regardless of the crystalline volume fraction. In addition, AFM and C‐AFM showed that this type of mixed‐phase material has hill‐like surface structure, where the hills correspond to nanocrystalline clusters. The local current density in hill‐like areas was much higher in the samples made with constant hydrogen dilution than those using hydrogen dilution profiling. For the samples with a very steep hydrogen dilution profiling, the local forward current density is very low. Based on our previous model, the light‐induced Voc increase depends on the formation of the current path in the nanocrystalline cluster areas. When a steep hydrogen dilution profiling is used, the tree‐like nanocrystalline clusters are isolated and embedded in the intrinsic layer, therefore, no high current paths are formed and no light‐induced Voc increase is observed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low temperature processed p‐type bottom gate microcrystalline silicon thin film transistors
Authors: Moustapha O. , Abramov A. , Daineka D. , Oudwan M. , Bonnassieux Y. , Roca i Cabarrocas P. 
Published: March 2010

AbstractWe report on processing of p‐type bottom gate microcrystalline silicon thin film transistors (p‐type BG TFT). In particular, we demonstrate that a thermal annealing at 250 °C is required to get ideal contacts, regardless of the drain‐source met al. We found that aluminium is the best suited metal for source and drain contacts, as in the case of n‐type thin film transistors.The TFTs mobility and sub‐threshold slope (V/dec) are improved when a hydrogen plasma treatment was applied to the a‐SiN:H prior to µc‐Si deposition. Our best p‐type BG TFTs exhibit a field effect mobility of ∼ 1.2 cm2/Vs, a sub threshold slope of ∼1V/dec and an ON/OFF ratio of 105 while keeping a stable threshold voltage (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimized‐geometry ARROW waveguides using TiO2 as anti‐resonant layer
Authors: Carvalho Daniel O. , Albertin Katia F. , Alayo Marco I. 
Published: March 2010

AbstractThe simulation, fabrication and characterization of ARROW waveguides using dielectric films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and Sputtering techniques, are presented in this work. Amorphous titanium oxide (TiO2) films were used as first cladding layer and silicon oxynitride (SiOxNy) films, as core layer. Furthermore, homemade routines based in two computational methods were used, for numerical simulations: Transfer Matrix Method (TMM) for the determination of the optimum thickness values of the Fabry‐Perot layers, and the Finite Difference Method (FDM) for 2D design and determination of the maximum width that allows single‐mode operation. The utilization of thermally grown silicon oxide as second anti‐resonant layer, along with improvements in the Reactive Ion Etching conditions for the definition of sidewalls of the optical waveguides were responsible for diminishing optical attenuations. Optimization of the waveguide rib height was done both through FDM simulations and experimentally. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermodynamic limit for large random trees
Authors: Bakhtin Yuri 
Published: March 2010

AbstractWe consider Gibbs distributions on finite random plane trees with bounded branching. We show that as the order of the tree grows to infinity, the distribution of any finite neighborhood of the root of the tree converges to a limit. We compute the limiting distribution explicitly and study its properties. We introduce an infinite random tree consistent with these limiting distributions and show that it satisfies a certain form of the Markov property. We also study the growth of this tree and prove several limit theorems including a diffusion approximation. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
The impact of a project‐based science curriculum on minority student achievement, attitudes, and careers: The effects of teacher content and pedagogical content knowledge and inquiry‐based practices
Authors: Kanter David E. , Konstantopoulos Spyros 
Published: March 2010

AbstractProject‐based science (PBS) curricula have project‐ and inquiry‐based aspects that leverage the strengths of urban students from ethnic and racial groups underrepresented in science careers, potentially impacting positively these students' science achievement and attitudes and thus their college and career plans. We aimed to determine the extent to which a PBS curriculum would show this. We provided professional development to bolster urban teachers' science content knowledge (CK) and science pedagogical content knowledge (PCK) to observe the maximal impact of the PBS curriculum. We found that students' science achievement improved with the PBS curriculum, but that their attitudes toward science and plans to pursue science did not. Increases in teachers' CK and PCK with the professional development correlated with the improvements in student science achievement but did not correlate with improvements in student science attitudes or plans. However, the frequency of teachers' use of specific inquiry‐based activities did correlate with improvements in students' science attitudes and plans. In sum, the extent of the success of a PBS curriculum with students from groups underrepresented in science careers appears to be dependent on elements of both teacher knowledge (CK and PCK) and teachers' frequency of use of inquiry‐based activities that are consistent with culturally relevant pedagogical practices. © 2010 Wiley Periodicals, Inc. Sci Ed 94:855–887, 2010
Cultural processes in science education: Supporting the navigation of multiple epistemologies
Authors: Bang Megan , Medin Douglas 
Published: March 2010

AbstractAlthough there has been considerable focus on the underrepresentation of minorities in science, technology, engineering, and mathematics (STEM) disciplines and the need for science instruction that fosters diversity, much of the associated effort has focused on the goal of diversity and tended to assume that science and science learning are acultural. We describe a conceptual framework employed in our work with both urban and rural Native American communities that focuses on culturally based epistemological orientations and their relation to the cultural practices associated with science instruction. We summarize evidence on the efficacy of community‐based science education to support the proposition for a shift in orientation toward science education from aiming to have students adopt specific epistemologies to supporting students' navigation of multiple epistemologies. © 2010 Wiley Periodicals, Inc. Sci Ed 94:1008–1026, 2010
Sequential Reactions Directed by Core/Shell Catalytic Reactors
Authors: Wei Yanhu , Soh Siowling , Apodaca Mario M. , Kim Jiwon , Grzybowski Bartosz A. 
Published: March 2010

AbstractMillimeter‐sized reactor particles made of permeable polymer doped with catalysts arranged in a core/shell fashion direct sequences of chemical reactions (e.g., alkyne coupling followed by hydrogenation or hydrosilylation followed by hydrogenation). Spatial compartmentalization of catalysts coupled with the diffusion of substrates controls reaction order and avoids formation of byproducts. The experimentally observed yields of reaction sequences are reproduced by a theoretical model, which accounts for the reaction kinetics and the diffusion of the species involved.
Differential effects of serotonin (5‐HT)2receptor‐targeting ligands on locomotor responses to nicotine‐repeated treatment
Authors: Zaniewska Magdalena , Mccreary Andrew C. , Wydra Karolina , Filip Małgorzata 
Published: March 2010

AbstractWe verified the hypothesis that serotonin (5‐HT)2receptors control the locomotor effects of nicotine (0.4 mg kg−1) in rats by using the 5‐HT2Areceptor antagonist M100907, the preferential 5‐HT2Areceptor agonist DOI, the 5‐HT2Creceptor antagonist SB 242084, and the 5‐HT2Creceptor agonists Ro 60‐0175 and WAY 163909. Repeated pairings of a test environment with nicotine for 5 days, on Day 10 significantly augmented the locomotor activity following nicotine administration. Of the investigated 5‐HT2receptor ligands, M100907 (2 mg kg−1) or DOI (1 mg kg−1) administered during the first 5 days in combination with nicotine attenuated or enhanced, respectively, the development of nicotine sensitization. Given acutely on Day 10, M100907 (2 mg kg−1), Ro 60‐0175 (1 mg kg−1), and WAY 163909 (1.5 mg kg−1) decreased the expression of nicotine sensitization. In another set of experiments, where the nicotine challenge test was performed on Day 15 in animals treated repeatedly (Days: 1–5, 10) with nicotine, none of 5‐HT2receptor ligands administered during the second withdrawal period (Days: 11–14) to nicotine‐treated rats altered the sensitizing effect of nicotine given on Day 15. Our data indicate that 5‐HT2Areceptors (but not 5‐HT2Creceptors) play a permissive role in the sensitizing effects of nicotine, while stimulation of 5‐HT2Areceptors enhances the development of nicotine sensitization and activation of 5‐HT2Creceptors is essential for the expression of nicotine sensitization. Repeated treatment with the 5‐HT2receptor ligands within the second nicotine withdrawal does not inhibit previously established sensitization. Synapse 64:511–519, 2010. © 2010 Wiley‐Liss, Inc.
Oxidative modifications of proteins by sodium arsenite in human umbilical vein endothelial cells
Authors: Lii Chong‐Kuei , Lin Ai‐Hsuan , Lee Shu‐Lien , Chen Haw‐Wen , Wang Tsu‐Shing 
Published: March 2010

AbstractEpidemiologic studies have demonstrated that chronic arsenic exposure is associated with the incidence of chronic diseases. This association is partly related to the increase in reactive oxygen species (ROS) overload and protein oxidation that result from arsenic exposure. In this study, we intended to identify proteins susceptible to oxidative carbonylation by sodium arsenite and the impact of carbonylation on the function of these proteins in human umbilical vein endothelial cells (HUVECs). The 2,4‐dinitrophenylhydrazine (DNPH) dot‐blot assay revealed that arsenite (0–50 μM) dose‐dependently increased protein carbonylation. Consistent with these findings, the cellular ROS level as measured by 2′,7′‐dichlorofluorescein diacetate (DCHF‐DA) assay was increased in cells exposed to arsenite. By two‐dimensional gel electrophoresis and matrix assist laser desorption ionization time of flight mass spectrometry (MALDI‐TOF/MS), one glycolytic enzyme, enolase‐α, two cytoskeleton proteins, fascin (F‐actin associated protein) and vimentin, and two protein quality control proteins, HSC70 (heat‐shock cognate protein 70), and PDIA3 (protein disulfide isomerase family A, member 3) were identified to be arsenic‐sensitive carbonlyated proteins. Accompanied by carbonylation, enolase‐α activity was dose‐dependently decreased and the F‐actin filament network was disturbed. Taken together, our results suggest that arsenite exposure results in the generation of carbonylated proteins, and the resultant changes in energy metabolism and in the cytoskeletal network may partly lead to cell damage. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Natural language processing
Authors: Martinez Angel R. 
Published: March 2010

AbstractApproximately 40 years ago, the goal of endowing computers with the capacity to understand natural language began. These efforts were originally callednatural language understanding, which is now more frequently callednatural language processing(NLP). NLP is considered a branch of artificial intelligence (AI), but over the years it has become an interesting area of study in computational statistics and text data mining. NLP encompasses approaches that use computers to analyze, determine semantic similarity, and translate between languages. The area usually deals with written languages, but it could also be applied to speech. In this article, we cover definitions and concepts necessary for the understanding of NLP, methods at the word and sentence level (word sense disambiguation, part‐of‐speech tagging, and parsing), and the vector space model for NLP at the document level. Copyright © 2010 John Wiley & Sons, Inc.This article is categorized under:Statistical Learning and Exploratory Methods of the Data Sciences > Text Mining
Scale space methods
Authors: Holmström Lasse 
Published: March 2010

AbstractWe discuss methods that use multiscale smoothing for explorative data analysis and inference. The problems considered involve nonparametric density estimation and regression, time series analysis, image analysis, and more general spatial data analysis settings. Copyright © 2010 John Wiley & Sons, Inc.This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Statistical Graphics and Visualization
Parental Attitudes, Beliefs, and Perceptions about Genetic Testing for FAP and Colorectal Cancer Surveillance in Minors
Authors: Levine Fallon R. , Coxworth James E. , Stevenson David A. , Tuohy Thérèse , Burt Randall W. , Kinney Anita Y. 
Published: March 2010

AbstractFamilial adenomatous polyposis (FAP) is the second most common hereditary colorectal cancer syndrome and confers a nearly 100% lifetime risk of developing colorectal cancer. Understanding factors that facilitate and inhibit genetic testing and cancer surveillance in children who are members of families affected by FAP will better equip clinicians to clarify misunderstandings and facilitate appropriate care. The aims of this study were to examine parental attitudes and beliefs regarding endoscopic surveillance and genetic testing in minors at risk for developing FAP. This cross‐sectional study includes analyses of qualitative and quantitative interview data collected from parents of children with or at risk for FAP. This report includes data from 28 parents with a total of 51 biological children between 10–17 years of age. The parents had a clinical and/or genetic diagnosis of FAP. Most commonly reported facilitators included provider recommendation (surveillance) and personalized medical management (genetic testing). Most commonly reported barriers included lack of provider recommendation (surveillance) and cost (genetic testing).
Commentary on “Life as a Pregnant Genetic Counselor”
Authors: Sahhar Margaret Alicia 
Published: March 2010

AbstractThe genetic counseling role is complex. There are frequently challenges raised for the genetic counselor both personally with the client and through factors external to the genetic counselor such as the clinical setting. The pregnant genetic counselor working in a prenantal diagnosis center may be confronted by her own countertransference towards the client or by the client's tranference. The processes of transference and countrtransference need to be clearly understood, identified and dealt with in a sensitive self aware manner to facilitate the role of communicating empathically and giving genetic information to facilitate informed client decision making. Regular professional supervision and debriefing for the genetic counselor are essential to develop professional boundaries and to develop self awareness.
Prebiotic effect of fruit and vegetable shots containing Jerusalem artichoke inulin: a human intervention study
Authors: Ramnani P. , Gaudier E. , Bingham M. , van Bruggen P. , Tuohy K. M. , Gibson G. R. 
Published: March 2010

The present study aimed to determine the prebiotic effect of fruit and vegetable shots containing inulin derived from Jerusalem artichoke (JA). A three-arm parallel, placebo-controlled, double-blind study was carried out with sixty-six healthy human volunteers (thirty-three men and thirty-three women, age range: 18–50 years). Subjects were randomised into three groups (n22) assigned to consume either the test shots, pear-carrot-sea buckthorn (PCS) or plum-pear-beetroot (PPB), containing JA inulin (5 g/d) or the placebo. Fluorescentin situhybridisation was used to monitor populations of total bacteria, bacteroides, bifidobacteria,Clostridium perfringens/histolyticumsubgroup,Eubacterium rectale/Clostridium coccoidesgroup, Lactobacillus/Enterococcusspp.,Atopobiumspp.,Faecalibacterium prausnitziiand propionibacteria. Bifidobacteria levels were significantly higher on consumption of both the PCS and PPB shots (10·0 (sd0·24) and 9·8 (sd0·22) log10cells/g faeces, respectively) compared with placebo (9·3 (sd0·42) log10cells/g faeces) (P < 0·0001). A small though significant increase inLactobacillus/Enterococcusgroup was also observed for both the PCS and PPB shots (8·3 (sd0·49) and 8·3 (sd0·36) log10cells/g faeces, respectively) compared with placebo (8·1 (sd0·37) log10cells/g faeces) (P = 0·042). Other bacterial groups and faecal SCFA concentrations remained unaffected. No extremities were seen in the adverse events, medication or bowel habits. A slight significant increase in flatulence was reported in the subjects consuming the PCS and PPB shots compared with placebo, but overall flatulence levels remained mild. A very high level of compliance (>90 %) to the product was observed. The present study confirms the prebiotic efficacy of fruit and vegetable shots containing JA inulin.