bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of defects at the interface between 3C‐SiC quantum dots and a SiO2 embedding matrix
Authors: Vörös Márton , Gali Adam , Kaxiras Efthimios , Frauenheim Thomas , Knaup Jan M. 
Published: December 2011

AbstractDue to the favorable band offsets, SiC nanoparticles embedded in silica form a very interesting quantum dot (QD) system. It is possible to produce such QDs in a simple oxidation–carbonization–reoxidation process on Si wafers. This could thus enable production of Si based LED integrated into Si logic devices. However, the luminescence of these QDs, is quenched. This is attributed to defect‐mediated recombination of electron–hole pairs, most probably at the SiC/SiO2 interface. We present tight‐binding simulated annealing calculations, in order to construct models of SiC QDs in SiO2, with the aim of obtaining an overview of the possible defects at the SiC/SiO2 interface. We identify a number of recurring interface defects which can be attributed to C or Si rich conditions or general lattice mismatch relaxation. Similar to defects have been shown to be electrically active at the SiC/SiO2 interface in MOS structures. We find evidence for strained Si–Si bonds, which can act as recombination centers in isolated SiC QDs. The defect classes identified in this work can serve as the basis for future, high precision simulations of their electronic structure.magnified imageA 66‐atom spherical SiC nanocrystal with a shell of SiO2 including –OH termination (66‐sph‐1 cluster, only QM zone shown; cf. Fig. 2 for key).
First‐principles Liouville–von Neumann equation for open systems and its applications
Authors: Koo Siu Kong , Yam Chi Yung , Zheng Xiao , Chen GuanHua 
Published: December 2011

AbstractWe present a first‐principles Liouville–von Neumann equation for open systems. The time‐dependent holographic electron density theorem which is the foundation for our formalism is introduced. Approximation schemes for practical simulations are given. In order to demonstrate the applicability of our formalism, a realistic simulation of a simple molecular device system is presented and discussed. magnified image
A comparative study of density functional and density functional tight binding calculations of defects in graphene
Authors: Zobelli Alberto , Ivanovskaya Viktoria , Wagner Philipp , Suarez‐Martinez Irene , Yaya Abu , Ewels Chris P. 
Published: December 2011

AbstractThe density functional tight binding approach (DFTB) is well adapted for the study of point and line defects in graphene based systems. After briefly reviewing the use of DFTB in this area, we present a comparative study of defect structures, energies, and dynamics between DFTB results obtained using the dftb+ code, and density functional results using the localized Gaussian orbital code, AIMPRO. DFTB accurately reproduces structures and energies for a range of point defect structures such as vacancies and Stone–Wales defects in graphene, as well as various unfunctionalized and hydroxylated graphene sheet edges. Migration barriers for the vacancy and Stone–Wales defect formation barriers are accurately reproduced using a nudged elastic band approach. Finally we explore the potential for dynamic defect simulations using DFTB, taking as an example electron irradiation damage in graphene.magnified image
DFTB‐MD derived sputtering energy threshold map for a carbon atom in a graphene plane.
Coherent manipulation of quadrupole biexcitons in cuprous oxide by 2D femtosecond spectroscopy
Authors: Roslyak Oleksiy , Aparajita Upali , Birman Joseph L. , Mukamel Shaul 
Published: December 2011

AbstractWe propose using coherent optical spectroscopy to study and control optically‐forbidden (dark) biexciton states in crystals of cuprous oxide. These states are revealed in the correlation spectra cross resonances due to coherence with the quadrupole allowed 1Sexciton manifold. The signal is obtained by means of sum‐over‐state formalism and comparing equations of motion for the weakly interacting quadrupole excitons with their analogue of non‐interacting quasiparticles. The dephasing mechanisms include rapid Auger relaxation of biexcitons which allegedly impedes the Bose–Einstein condensation of quadrupole excitons. An interesting effect attributed to the deviation of the quadrupole excitons from theortho–paraexcitons picture is that the positions of the biexciton resonances are defined by the energy splitting between$\Gamma _{5;yz}^{ + } $and$\Gamma _{5;xz}^{ + } $excitons and can be tuned by an external perturbation. Possible quantum computing and lasing applications of the quadrupole induced chirality effects of the excitons and biexcitons, and coherence between exciton/biexciton manifolds are discussed.
Chemical synthesis of ZnO hexagonal thin nanodisks and dye‐sensitized solar cell performance
Authors: Navaneethan M. , Archana J. , Arivanandhan M. , Hayakawa Y. 
Published: December 2011

AbstractWell defined highly monodispersed single crystalline ZnO hexagonal thin nanodisks have been synthesized by a wet chemical route. Ethylenediaminetetraacetic acid is used as an organic ligand in the chemical synthesis. Ultraviolet near band edge emission is predominant over the defect level emission in these ZnO nanodisks. The ZnO nanodisks have an average diameter of 150 nm and thickness of 40 nm. A dye‐sensitized solar cell is fabricated using ZnO nanodisks by spray pyrolysis deposition and it exhibits an efficiency of 2.63% with the ruthenium sensitizer N719 dye. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Depth Properties of scaled attachment random recursive trees
Authors: Devroye Luc , Fawzi Omar , Fraiman Nicolas 
Published: December 2011

AbstractWe study depth properties of a general class of random recursive trees where each node i attaches to the random node \documentclass{article} \usepackage{mathrsfs, amsmath, amssymb}\pagestyle{empty} \begin{document} \begin{align*}\left\lfloor iX_i\right\rfloor\end{align*} \end{document}
and X0,…,Xn is a sequence of i.i.d. random variables taking values in [0,1). We call such trees scaled attachment random recursive trees (sarrt). We prove that the typical depth Dn, the maximum depth (or height) Hn and the minimum depth Mn of a sarrt are asymptotically given by Dn ∼μ‐1 log n, Hn ∼ αmax log n and Mn ∼ αmin log n where μ,αmax and αmin are constants depending only on the distribution of X0 whenever X0 has a density. In particular, this gives a new elementary proof for the height of uniform random recursive trees Hn ∼ elog n that does not use branching random walks.© 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2011
Fifty Years of Mössbauer Spectroscopy in Solid State Research – Remarkable Achievements, Future Perspectives
Authors: Gütlich Philipp 
Published: December 2011

AbstractMössbauer spectroscopy was founded more than fifty years ago based on an outstanding discovery by the young German physicist Rudolf Ludwig Mössbauer while working on his Ph.D. thesis. He discovered the recoilless nuclear resonance fluorescence of gamma radiation and was awarded the Nobel Prize in Physics in 1961 as one of the youngest recipients of this most prestigious award. His discovery led to the development of a new technique for measurements of hyperfine interactions between nuclear moments and electromagnetic fields. This method, with highest sharpness of tuning of 10–13, yields information on valence state, symmetry, magnetic behavior, phase transition, lattice dynamics and other solid state properties.
A Further Extension of Pnictide Oxide Chemistry – Synthesis and Structure of La2AuP2O
Authors: Eul Matthias , Möller Manfred H. , Hoffmann Rolf‐Dieter , Jeitschko Wolfgang , Pöttgen Rainer 
Published: December 2011

AbstractThe phosphide oxide La2AuP2O was synthesized from lanthanum filings, dried La2O3, gold pieces, and ground red phosphorus in the ideal 1.33:0.33:1:2 ratio in an evacuated silica tube at 1473 K. Small single crystals were obtained by recrystallization in a NaCl/KCl flux. The structure was determined on the basis of single‐crystal X‐ray diffractometer data: new type, C2/m, a = 1537.3(3), b = 427.39(8), c = 1009.2(2) pm, β = 131.02(1) °, wR2 = 0.046, 1102 F2 values, 38 variables. La2AuP2O contains two striking structural motifs: The oxygen atoms are located in La4 tetrahedra. The latter are cis‐edge‐shared forming polymeric cationic [La2O]4+ chains. These cationic units are separated and charge‐balanced by [AuP2]4– polyanions which have monovalent gold in distorted trigonal planar phosphorus coordination. Two crystallographically independent phosphorus sites occur in the polyanion, i.e. isolated P3– besides dumb‐bells P24– (P2–P2 223 pm). La2AuP2O, which crystallizes in the form of ruby red transparent crystals, is an electron precise phosphide oxide (4La3+)(2Au+)(2P3–)(P24–)(2O2–).
Stability and bifurcation in a gene regulatory network model with delay
Authors: Wang Z. , Liu Z. , Yuan R. 
Published: December 2011

AbstractA delayed gene regulatory network model with positive and negative feedbacks is considered. We investigate the stability of the positive equilibrium and the existence of Hopf bifurcation of the model by analyzing the associated characteristic transcendental equation. Applying the normal form theory and center manifold theorem, we consider the direction of the Hopf bifurcation and stability of the bifurcating periodic solutions. An example is given and numerical simulations are performed to illustrate the obtained results.
Comma N' cents in pricing: The effects of auditory representation encoding on price magnitude perceptions
Authors: Coulter Keith S. , Choi Pilsik , Monroe Kent B. 
Published: December 2011

AbstractNumbers and prices can be processed and encoded in three different forms: 1) visual [based on their written form in Arabic numerals (e.g., 72)], 2) verbal [based on spoken word‐sounds (e.g., “seventy” and “two”), and 3) analog (based on judgments of relative “size” or amount (e.g., more than 70 but less than 80)]. In this paper, we demonstrate that including commas (e.g., $1599 vs. $1599) and cents (e.g., $1599.85 vs. $1599) in a price's Arabic written form (i.e., how it is perceived visually) can change how the price is encoded and represented verbally in a consumer's memory. In turn, the verbal encoding of a written price can influence assessments of the numerical magnitude of the price. These effects occur because consumers non‐consciously perceive that there is a positive relationship between syllabic length and numerical magnitude. Three experiments are presented demonstrating this important effect.
In silico comparative analysis of conserved genes expressed in solanaceous plants under abiotic stresses
Authors: gupta sanchita , dhawan sunita singh , sharma ashok 
Published: December 2011

AbstractThe gene expression data was studied in order to analyze genes involved in different abiotic stresses in solanaceous plants. Salt, temperature (heat & cold) and drought are the main abiotic stresses to the plants. Abiotic stress responses are important for sessile organisms like plants because they have to cope with environmental changes to survive. The idea was to analyze those differentially expressed genes, which show common expression in response to different abiotic stress conditions in each plant. Mitogen activated protein kinases (MAPK) are important mediators in signal transmission, connecting the perception of external stimuli to cellular responses. In plants, MAPKs plays a major role in the signaling of abiotic stresses. The expression data were retrieved from gene expression omnibus (GEO) database at NCBI. The set of genes were selected showing up or down regulation in at least two abiotic stresses. These genes were used for searching their involvement in different steps of MAP kinase pathway. Our findings suggest that a common set of genes are the key players in signaling pathway responsible for initiation of cascade of reaction in response to stress. The study will help to understand how the conserved genes are expressing differentially in response to various abiotic stresses. The common genes affecting the MAP kinase pathway might be highly conserved. These genes may be used to study the response of different abiotic stresses in other plant species.
Lack of Generalization of Auditory Learning in Typically Developing Children
Authors: Halliday Lorna F. , Taylor Jenny L. , Millward Kerri E. , Moore David R. 
Published: December 2011

PurposeTo understand the components of auditory learning in typically developing children by assessing generalization across stimuli, across modalities (i.e., hearing, vision), and to higher level language tasks.MethodEighty-six 8- to 10-year-old typically developing children were quasi-randomly assigned to 4 groups. Three of the groups received twelve 30-min training sessions on multiple standards using either an auditory frequency discrimination task (AFD group), auditory phonetic discrimination task (PD group), or visual frequency discrimination task (VFD group) over 4 weeks. The 4th group, which was the no-intervention control (NI) group, did not receive any training. Thresholds on all tasks (AFD, PD, and VFD) were assessed immediately before and after training, along with performance on a battery of language assessments.ResultsRelative to the other groups, both the AFD group and the PD group, but not the VFD group, showed significant learning on the stimuli upon which they were trained. However, in those instances where learning was observed, it did not generalize to the nontrained stimuli or to the language assessments.ConclusionsNonspeech (AFD) or speech (PD) discrimination training can lead to auditory learning in typically developing children of this age range. However, this learning does not always generalize across stimuli or tasks, across modalities, or to higher level measures of language ability.
Dialect Variation and Reading: Is Change in Nonmainstream American English Use Related to Reading Achievement in First and Second Grades?
Authors: Terry Nicole Patton , Connor Carol McDonald , Petscher Yaacov , Conlin Catherine Ross 
Published: December 2011

Purpose
In this study, we examined (a) whether children who spoke Nonmainstream American English (NMAE) frequently in school at the beginning of 1st grade increased their use of Mainstream American English (MAE) through the end of 2nd grade, and whether increasing MAE use was associated with (b) language and reading skills and school context and (c) greater gains in reading skills.

Method
A longitudinal design was implemented with 49 children who spoke NMAE moderately to strongly. Spoken production of NMAE forms, word reading, and reading comprehension were measured at the beginning, middle, and end of 1st and 2nd grades. Various oral language skills were also measured at the beginning of 1st grade.

Results
Results indicate that most children increased their MAE production during 1st grade and maintained these levels in 2nd grade. Increasing MAE use was predicted by children’s expressive vocabulary and nonword repetition skills at the beginning of 1st grade. Finally, the more children increased their MAE production, the greater were their reading gains from 1st grade through 2nd grade.

Conclusions
The findings extend previous reports of a significant association between NMAE use and specific reading skills among young children and have implications for theory, educational practice, and future research.
General and Specific Effects of Lexicon in Grammar: Determiner and Object Pronoun Omissions in Child Spanish
Authors: Pérez-Leroux Ana Teresa , Castilla-Earls Anny Patricia , Brunner Jerry 
Published: December 2011

PurposeThis study explores the hypothesis that vocabulary growth can have 2 types of effects in morphosyntactic development. One is a general effect, where vocabulary growth globally determines utterance complexity, defined in terms of sentence length and rates of subordination. There are also specific effects, where vocabulary size has a selective impact on the acquisition of grammatical markers and where lexicon is a prerequisite for typological convergence. The study compares the differential effects of vocabulary in 2 measures of morphosyntactic development: omissions of object clitic pronouns and definite articles.MethodCorrelation analysis and structural equation models were used to analyze the statistical effects of measures of vocabulary and grammatical development in 110 Spanish-speaking monolingual children ages 3–5 years.ResultsThe data revealed general effects of vocabulary growth on utterance length and subordination rates and on the use of definite determiners and object pronouns. Specific effects of vocabulary growth were identified for object pronouns but not for determiners.ConclusionsThe study found support for a 2-dimensional model separating lexicon and syntax and for 2 types of relationships. Vocabulary development generally determines sentence complexity and further evidence for specific effects in object pronoun use.
Selective Auditory Attention in Adults: Effects of Rhythmic Structure of the Competing Language
Authors: Reel Leigh Ann , Hicks Candace Bourland 
Published: December 2011

Purpose
The authors assessed adult selective auditory attention to determine effects of (a) differences between the vocal/speaking characteristics of different mixed-gender pairs of masking talkers and (b) the rhythmic structure of the language of the competing speech.

Method
Reception thresholds for English sentences were measured for 50 monolingual English-speaking adults in conditions with 2-talker (male–female) competing speech spoken in a stress-based (English, German), syllable-based (Spanish, French), or mora-based (Japanese) language. Two different masking signals were created for each language (i.e., 2 different 2-talker pairs). All subjects were tested in 10 competing conditions (2 conditions for each of the 5 languages).

Results
A significant difference was noted between the 2 masking signals within each language. Across languages, significantly greater listening difficulty was observed in conditions where competing speech was spoken in English, German, or Japanese, as compared with Spanish or French.

Conclusions
Results suggest that (a) for a particular language, masking effectiveness can vary between different male–female 2-talker maskers and (b) for stress-based vs. syllable-based languages, competing speech is more difficult to ignore when spoken in a language from the native rhythmic class as compared with a nonnative rhythmic class, regardless of whether the language is familiar or unfamiliar to the listener.
Effect of Onset and Rhyme Primes in Preschoolers With Typical Development and Specific Language Impairment
Authors: Gray Shelley , Reiser Mark , Brinkley Shara 
Published: December 2011

Purpose
In this study, the authors used cued shadowing to examine children’s phonological word-form representations by studying the effects of onset and rhyme primes on lexical access.

Method
Twenty-five preschoolers with specific language impairment (SLI; hereafter known as the SLI group), 24 age- and gender-matched children (AM group), and 20 vocabulary- and gender-matched children (VM group) participated. Children listened to pairs of words and repeated the second word as quickly as they could. Primes included words with overlapping onsets, words with overlapping rimes, and identical or unrelated words.

Results
As expected, unrelated words inhibited production in the AM and VM groups. Overlapping rimes primed production in the AM group. No inhibitory or priming effects were found for the SLI group.

Conclusion
Phonological priming may be used to study the phonological representations of preschool-age children. Results suggest that none of the groups accessed words incrementally. Priming for overlapping rimes by the AM but not the VM or SLI groups may indicate that the AM group benefited from lexical organization favoring nucleus + rime organization that has not yet developed for the VM or SLI groups. The lack of inhibition in the SLI group suggests that their phonological representations were not detailed enough to prime words in their lexicon or that they did not process the prime or target words.
Examining Success of Communication Strategies Used by Formal Caregivers Assisting Individuals With Alzheimer’s Disease During an Activity of Daily Living
Authors: Wilson Rozanne , Rochon Elizabeth , Mihailidis Alex , Leonard Carol 
Published: December 2011

Purpose
To examine how formal (i.e., employed) caregivers' use verbal and nonverbal communication strategies while assisting individuals with moderate to severe Alzheimer’s disease (AD) during the successful completion of an activity of daily living (ADL). Based on the literature, the authors hypothesized that caregivers' use of 1 proposition, closed-ended questions, and repetition would be of most benefit.

Method
Twelve caregiver–AD dyads participated in this observational study. Each dyad was videorecorded on 6 separate occasions while completing handwashing. Handwashing sessions were transcribed and systematically coded for the use of communication strategies during completion of the ADL.

Results
Caregiver–AD dyads successfully completed 90% of all handwashing sessions, and caregivers employed a variety of communication strategies. Consistent with our hypotheses, during successful task completion, caregivers most frequently provided individuals with AD with 1 direction or idea (i.e., proposition) at a time, closed-ended questions, and paraphrased repetition. Caregivers also frequently used encouraging comments and the resident’s name during the task; however, use of these strategies was not correlated to task success rate.

Conclusion
This study adds to the limited body of evidence supporting the use of specific communication strategies by caregivers assisting individuals with moderate to severe AD during successful completion of ADLs.
Contribution of Linguistic Variables to Bilingual Listeners' Perception of Degraded English Sentences
Authors: Shi Lu-Feng 
Published: December 2011

Purpose
The present study was designed to investigate what linguistic variables best predict bilingual recognition of acoustically degraded sentences and how to identify bilingual individuals who might have more difficulty than their monolingual counterparts on such tasks.

Method
Four hundred English speech-perception-in-noise (SPIN) sentences with high and low context were presented in combinations of noise (signal-to-noise ratio: +6 and 0 dB) and reverberation (reverberation time: 1.2 and 3.6 s) to 10 monolingual and 50 bilingual listeners. A detailed linguistic profile was obtained for bilingual listeners using the Language Experience and Proficiency Questionnaire.

Results
Variables per reading in English (age of fluency, proficiency, and preference) emerged as strong predictors of performance across noise, reverberation, and context effects. Via discriminant analyses, bilingual listeners who rated their accent to be perceptible and reported shorter length of immersion in an English-spoken country or school tended to score significantly lower on the SPIN test than monolingual listeners.

Conclusions
Bilingual listeners' linguistic background plays a major role in their use of context in degraded English sentences. Rather than conventional variables such as age of acquisition, variables pertaining to reading, proficiency, immersion, and accent severity may be obtained for improved prediction of bilingual performance on the task.