bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controllable fabrication and characterization of conical nanocarbon structures on polymer substrate for transparent and flexible field emission displays
Authors: Ghosh Pradip , Satou Shunsaku , Tsuchiya Takuma , Hayashi Yasuhiko , Tanemura Masaki 
Published: February 2012

AbstractThe direct fabrication of fully transparent conical nanocarbon structures (CNCSs) of controlled nanoscopic dimension on a flexible nafion substrate was achieved, using field electron source, by a novel room temperature ion irradiation technique. By controlling the sizes (below the wavelength of visible light) of the CNCSs, the transparency of the substrate can be tailored satisfactorily. The transparency of the CNCSs was observed to be around 90% in the visible regime depending on the ion irradiation time. Our results suggest that the direct fabrication of well controlled fully transparent CNCSs on any transparent and flexible substrate at room temperature could open a novel route for potential applications in future highly transparent, flexible (bendable), low weight and portable field emission displays (FEDs). (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The impact of multi‐group multi‐layer network structure on the performance of distributed consensus building strategies
Authors: Wan Yan , Namuduri Kamesh , Akula Swathik , Varanasi Murali 
Published: February 2012

SUMMARYWe consider a structural approach to the consensus building problem in multi‐group multi‐layer (MGML) distributed sensor networks (DSNs) common in many natural and engineering applications. From among the possible network structures, we focus on bipartite graph structure as it represents a typical MGML structure and has a wide applicability in the real world. We establish exact conditions for consensus and derive a precise relationship between the consensus value and the degree distribution of nodes in a bipartite MGML DSN. We also demonstrate that for subclasses of connectivity patterns, convergence time and simple characteristics of network topology can be captured by explicit algebra. Direct inference of the convergence behavior of consensus strategies from MGML DSN structure is the main contribution of this paper. The insights gained from our analysis facilitate the design and development of large‐scale DSNs that meet specific performance criteria. Copyright © 2012 John Wiley & Sons, Ltd.
New results on static output feedback H ∞  control for fuzzy singularly perturbed systems: a linear matrix inequality approach
Authors: Chen Jinxiang , Sun Yanguang , Min Haibo , Sun Fuchun , Zhang Yungui 
Published: February 2012

SUMMARYThis paper presents the novel approaches of designing robust fuzzy static output feedback H ∞  controller for a class of nonlinear singularly perturbed systems. Specifically, the considered system is approximated by a fuzzy singularly perturbed model. With the use of linear matrix inequality (LMI) methods, two methods are provided to design fuzzy static output feedback H ∞  controllers. The resulted controllers can guarantee that the closed‐loop systems are asymptotically stable and satisfy H ∞  performances for sufficiently small ϵ. In contrast to the existing results, the proposed approaches have two advantages: (i) the gains of controller are solved directly by a set of ϵ‐independent LMIs, and therefore, the problem of selecting the initial values in iterative LMIs algorithm can be avoided, and (ii) the smaller control input efforts are needed. The given methods are easy to implement and can be applied to both standard and nonstandard nonlinear singularly perturbed systems. Two numerical examples are provided to illustrate the effectiveness of the developed methods. Copyright © 2012 John Wiley & Sons, Ltd.
Finite‐time consensus tracking for harmonic oscillators using both state feedback control and output feedback control
Authors: Zhang Yanjiao , Yang Ying , Zhao Yu 
Published: February 2012

SUMMARYThis paper investigates the distributed finite‐time consensus‐tracking problem for coupled harmonic oscillators. The objective is to guarantee a team of followers modeled by harmonic oscillators to track a dynamic virtual leader in finite time. Only a subset of followers can access the information of the virtual leader, and the interactions between followers are assumed to be local. We consider two cases: (i) The followers can obtain the relative states between their neighbors and their own; and (ii) Only relative outputs between neighboring agents are available. In the former case, a distributed consensus protocol is adopted to achieve the finite‐time consensus tracking. In the latter case, we propose a novel observer‐based dynamic protocol to guarantee the consensus tracking in finite time. Simulation examples are finally presented to verify the theoretical analysis. Copyright © 2012 John Wiley & Sons, Ltd.
STRUCTURAL EQUATION MODELLING: A NOVEL STATISTICAL FRAMEWORK FOR EXPLORING THE SPATIAL DISTRIBUTION OF BENTHIC MACROINVERTEBRATES IN RIVERINE ECOSYSTEMS
Authors: Bizzi S. , Surridge Ben W. J. , Lerner David N. 
Published: February 2012

ABSTRACTBenthic macroinvertebrates have been used widely as bioindicators to assess the condition of riverine ecosystems. However, understanding and modelling the spatial distribution of benthic macroinvertebrates within these ecosystems remain significant challenges for research and management. Statistical analyses of multivariate data sets offer opportunities to explore the ecological systems controlling the distribution of biota. This article reports a novel statistical analysis of a national‐scale data set from England and Wales using the structural equation modelling (SEM) framework. Relationships between water quality, physical habitat structure and indices reflecting benthic macroinvertebrate community structure were analysed using SEM. On the basis of data from 219 monitoring sites, structural equation models were built. These models explained 87% of the spatial variation in the average score per taxon index and 76% of the spatial variation in the Lotic Invertebrate Index for Flow Evaluation. Significant direct and indirect effects on these indices were exerted by water quality variables, particularly the concentrations of dissolved oxygen, biochemical oxygen demand and orthophosphate. Independent of water quality conditions, both biotic indices were directly affected by variables describing the structure and the degradation of physical habitat. The strengths of the SEM framework include (i) direct evaluation of a priori models against observed data, thereby supporting confirmatory analysis of theoretical models of ecological systems; (ii) specification of latent variables representing unmeasured constructs; and (iii) simultaneous assessment of multiple direct and indirect paths between variables within a model. These strengths define a framework with the potential to be applied widely in the development and testing of hypotheses regarding the processes operating within riverine ecosystems. Copyright © 2012 John Wiley & Sons, Ltd.
Nanostructure Formation and Passivation of Large‐Area Black Silicon for Solar Cell Applications
Authors: Liu Yaoping , Lai Tao , Li Hailing , Wang Yan , Mei Zengxia , Liang Huili , Li Zhilei , Zhang Fengming , Wang Wenjing , Kuznetsov Andrej Yu , Du Xiaolong 
Published: February 2012

AbstractNanoscale textured silicon and its passivation are explored by simple low‐cost metal‐assisted chemical etching and thermal oxidation, and large‐area black silicon was fabricated both on single‐crystalline Si and multicrystalline Si for solar cell applications. When the Si surface was etched by HF/AgNO3 solution for 4 or 5 min, nanopores formed in the Si surface, 50–100 nm in diameter and 200–300 nm deep. The nanoscale textured silicon surface turns into an effective medium with a gradually varying refractive index, which leads to the low reflectivity and black appearance of the samples. Mean reflectance was reduced to as low as 2% for crystalline Si and 4% for multicrystalline Si from 300 to 1000 nm, with no antireflective (AR) coating. A black‐etched multicrystalline‐Si of 156 mm × 156 mm was used to fabricate a primary solar cell with no surface passivation or AR coating. Its conversion efficiency (η) was 11.5%. The cell conversion efficiency was increased greatly by using surface passivation process, which proved very useful in suppressing excess carrier recombination on the nanostructured surface. Finally, a black m‐Si cell with efficiency of 15.8% was achieved by using SiO2 and SiNX bilayer passivation structure, indicating that passivation plays a key role in large‐scale manufacture of black silicon solar cells.
Evidence for a Crucial Role Played by Oxygen Vacancies in LaMnO3 Resistive Switching Memories
Authors: Xu Zhong‐tang , Jin Kui‐juan , Gu Lin , Jin Yu‐ling , Ge Chen , Wang Can , Guo Hai‐zhong , Lu Hui‐bin , Zhao Rui‐qiang , Yang Guo‐zhen 
Published: February 2012

AbstractLaMnO3 (LMO) films are deposited on SrTiO3:Nb (0.8 wt%) substrates under various oxygen pressures to obtain different concentrations of oxygen vacancies in the films. The results of X‐ray diffraction verify that with a decrease of the oxygen pressure, the c‐axis lattice constant of the LMO films becomes larger, owing to an increase of the oxygen vacancies. Aberration‐corrected annular‐bright‐field scanning transmission electron microscopy with atomic resolution and sensitivity for light elements is used, which clearly shows that the number of oxygen vacancies increases with the decrease of oxygen pressure during fabrication. Correspondingly, the resistive switching property becomes more pronounced with more oxygen vacancies in the LMO films. Furthermore, a numerical model based on the modification of the interface property induced by the migration of oxygen vacancies in these structures is proposed to elucidate the underlying physical origins. The calculated results are in good agreement with the experimental data, which reveal from a theoretical point of view that the migration of oxygen vacancies and the variation of the Schottky barrier at the interface with applied bias dominate the resistive switching characteristic. It is promising that the resistive switching property in perovskite oxides can be manipulated by controlling the oxygen vacancies during fabrication or later annealing in an oxygen atmosphere.
Direct Evidence of Lipid Rafts by in situ Atomic Force Microscopy
Authors: Cai Mingjun , Zhao Weidong , Shang Xin , Jiang Junguang , Ji Hongbin , Tang Zhiyong , Wang Hongda 
Published: February 2012

AbstractLipid rafts are membrane microdomains enriched with cholesterol, glycosphingolipids, and proteins. Although they are broadly presumed to play a pivotal role in various cellular functions, there are still fierce debates about the composition, functions, and even existence of lipid rafts. Here high‐resolution and time‐lapse in situ atomic force microscopy is used to directly confirm the existence of lipid rafts in native erythrocyte membranes. The results indicate some important aspects of lipid rafts: most of the lipid rafts are in the size range of 100–300 nm and have irregular shape; the detergent‐resistant membranes consist of cholesterol microdomains and are not likely the same as the lipid rafts; cholesterol contributes significantly to the formation and stability of the protein domains; and Band III is an important protein of lipid rafts in the inner leaflet of erythrocyte membranes, indicating that lipid rafts are exactly the functional domains in plasma membrane. This work provides direct evidence of the presence, size, and main constitutive protein of lipid rafts at a resolution of a few nanometers, which will pave the way for studying their structure and functions in detail.
Three‐Dimensional Morphological and Crystallographic Investigation of Lamellar Alpha and Retained Beta in a Near Alpha Titanium Alloy by Combination of Focused Ion Beam and Electron Backscattering Diffraction
Authors: He Dong , Zaefferer Stefan , Zhu Jingchuan , Lai Zhonghong 
Published: February 2012

AbstractWe studied the three‐dimensional (3D) morphology and crystal orientation distribution of coarse primary α, fine second α lamellae, and retained β layers in a near α titanium alloy using a 3D microtomographic electron backscattering diffraction method (3D EBSD). The results demonstrate that primary α lamellae are more like a thick plate in 3D space. The second α lamellae have lower in‐grain (mis)orientation gradients than primary α. The retained β is a continuous network structure and contains many cavities for α lamellae embedding.
Fetal cerebrovascular resistance and neonatal EEG predict 18‐month neurodevelopmental outcome in infants with congenital heart disease
Authors: Williams I. A. , Tarullo A. R. , Grieve P. G. , Wilpers A. , Vignola E. F. , Myers M. M. , Fifer W. P. 
Published: February 2012

AbstractObjectivesThe purpose of this study was to investigate early markers of risk for neurobehavioral compromise in survivors with congenital heart disease (CHD).MethodsPregnant women in whom a fetal CHD had been diagnosed before 24 weeks' gestational age (GA) were enrolled in this prospective pilot study for serial Doppler ultrasound assessment of the fetal middle cerebral artery (MCA) and umbilical arteries. The cerebral‐to‐placental resistance ratio (CPR) and MCA pulsatility index (PI) Z‐scores for GA were calculated. After birth, subjects underwent high‐density (128‐lead) electroencephalography (EEG), and beta frequency (12–24 Hz) band EEG power, a measure of local neural synchrony, was analyzed. Neurodevelopment was assessed at 18 months with the Bayley Scales of Infant Development (BSID)‐III.ResultsThirteen subjects were enrolled: four with hypoplastic left heart syndrome (HLHS), four with transposition of the great arteries (TGA) and five with tetralogy of Fallot (TOF). Compared with subjects with normal CPR, those with CPR < 1 (n = 7) had lower mean BSID cognitive scores (91.4 ± 4.8 vs. 99.2 ± 3.8, P = 0.008). Fetal MCA‐PI Z‐score also correlated with BSID cognitive score (r = 0.589, P = 0.03) as did neonatal EEG left frontal polar (r = 0.58, P = 0.037) and left frontal (r = 0.77, P = 0.002) beta power. Furthermore, fetal Doppler measures were associated with EEG power: fetuses with CPR < 1 had lower left frontal polar (t = 2.36, P = 0.038) and left frontal (t = 2.85, P = 0.016) beta power as newborns than did fetuses with normal CPR, and fetal MCA‐PI Z‐score correlated with neonatal EEG left frontal polar (r = 0.596, P = 0.04) and left frontal (r = 0.598, P = 0.04) beta power.ConclusionIn fetuses with HLHS, TGA and TOF, abnormal cerebrovascular resistance predicts decreased neonatal EEG left frontal beta power and lower 18‐month cognitive development scores. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Deletion of ku homologs increases gene targeting frequency in Streptomyces avermitilis
Authors: Zhang Xiaojuan , Chen Wei , Zhang Yang , Jiang Libin , Chen Zhi , Wen Ying , Li Jilun 
Published: February 2012

Abstract
Streptomyces avermitilis is an industrially important soil bacterium known for production of avermectins, which are antiparasitic agents useful in animal health care, agriculture, and treatment of human infections. ku genes play a key role in the non-homologous end-joining pathway for repair of DNA double strand breaks. We identified homologs of eukaryotic ku70 and ku80 genes, termed ku1 and ku2, in S. avermitilis. Mutants with deletion of ku1, ku2, and both genes were constructed and their phenotypic changes were characterized. Deletion of ku genes had no apparent adverse effects on growth, spore formation, or avermectin production. The ku mutants, in comparison to wild-type strain, were slightly more sensitive to the DNA-damaging agent ethyl methanesulfonate, but not to UV exposure or to bleomycin. Gene targeting frequencies by homologous recombination were higher in the ku mutants than in wild-type strain. We conclude that ku-deleted strains will be useful hosts for efficient gene targeting and will facilitate functional analysis of genes in S. avermitilis and other industrially important bacterial strains.
The cognitive profile of type 1 Gaucher disease patients
Authors: Biegstraaten Marieke , Wesnes Keith A. , Luzy Cécile , Petakov Milan , Mrsic Mirando , Niederau Claus , Giraldo Pilar , Hughes Derralynn , Mehta Atul , Mengel Karl‐Eugen , Hollak Carla E. M , Maródi László , van Schaik Ivo N. 
Published: February 2012

AbstractBackgroundThe absence of neurological symptoms and signs is traditionally considered mandatory for a diagnosis of type 1 Gaucher disease (GD1), but in recent years many reports have emerged on neurological manifestations in GD1 patients. Nevertheless, it has been unclear whether cognitive deficits are part of the disease as well.MethodsCognitive function was assessed in a large cohort of GD1 patients with the use of the CDR system, a set of computerised cognitive tests. Testing was performed at baseline and every 6 months thereafter during a two‐year study period.ResultsOur patient cohort (84 patients, median age 40 years, median time from diagnosis 15 years) showed mild deficits relative to healthy age‐matched subjects on the composite scores: power of attention (Z‐score (mean ± SD) ‐0.9 ± 1.37) and speed of memory (Z‐score (mean ± SD) ‐1.39 ± 1.49). No decline in cognitive function was seen during the two‐year period. Age correlated with the composite scores variability of attention and quality of working memory. Moreover, severely affected patients (Zimran severity score (SSI) ≥ 15) scored more poorly compared to mildly affected patients (SSI ≤ 5) on the composite measure power of attention, reflecting the ability to concentrate.ConclusionsGD1 patients exhibit mild deficits in power of attention and speed of memory, reflecting a decreased ability to focus attention and process information, together with a slowing in the speed of retrieval of items from memory. The clinical relevance of these findings is uncertain.
Instability and hydraulics of turbulent stratified shear flows
Authors: Liu Zhiyu , Thorpe S. A. , Smyth W. D. 
Published: February 2012

AbstractThe Taylor–Goldstein (T–G) equation is extended to include the effects of small-scale turbulence represented by non-uniform vertical and horizontal eddy viscosity and diffusion coefficients. The vertical coefficients of viscosity and diffusion, ${A}_{V} $ and ${K}_{V} $, respectively, are assumed to be equal and are expressed in terms of the buoyancy frequency of the flow, $N$, and the dissipation rate of turbulent kinetic energy per unit mass, $\varepsilon $, quantities that can be measured in the sea. The horizontal eddy coefficients, ${A}_{H} $ and ${K}_{H} $, are taken to be proportional to the dimensionally correct form, ${\varepsilon }^{1/ 3} {l}^{4/ 3} $, found appropriate in the description of horizontal dispersion of a field of passive markers of scale $l$. The extended T–G equation is applied to examine the stability and greatest growth rates in a turbulent shear flow in stratified waters near a sill, that at the entrance to the Clyde Sea in the west of Scotland. Here the main effect of turbulence is a tendency towards stabilizing the flow; the greatest growth rates of small unstable disturbances decrease, and in some cases flows that are unstable in the absence of turbulence are stabilized when its effects are included. It is conjectured that stabilization of a flow by turbulence may lead to a repeating cycle in which a flow with low levels of turbulence becomes unstable, increasing the turbulent dissipation rate and so stabilizing the flow. The collapse of turbulence then leads to a condition in which the flow may again become unstable, the cycle repeating. Two parameters are used to describe the ‘marginality’ of the observed flows. One is based on the proximity of the minimum flow Richardson number to the critical Richardson number, the other on the change in dissipation rate required to stabilize or destabilize an observed flow. The latter is related to the change needed in the flow Reynolds number to achieve zero growth rate. The unstable flows, typical of the Clyde Sea site, are relatively further from neutral stability in Reynolds number than in Richardson number. The effects of turbulence on the hydraulic state of the flow are assessed by examining the speed and propagation direction of long waves in the Clyde Sea. Results are compared to those obtained using the T–G equation without turbulent viscosity or diffusivity. Turbulence may change the state of a flow from subcritical to supercritical.
High-enthalpy flow over a rearward-facing step – a computational study
Authors: Deepak N. R. , Gai S. L. , Neely A. J. 
Published: February 2012

AbstractHypersonic, high-enthalpy flow over a rearward-facing step has been numerically investigated using computational fluid dynamics (CFD). Two conditions relevant to suborbital and superorbital flow with total specific enthalpies of$26$and$50~\mathrm{MJ} ~{\mathrm{kg} }^{\ensuremath{-} 1} $, are considered. The Mach number and unit Reynolds number per metre were 7.6, 11.0 and$1. 82\ensuremath{\times} 1{0}^{6} $,$6. 23\ensuremath{\times} 1{0}^{5} $respectively. The Reynolds number based on the step height was correspondingly$3. 64\ensuremath{\times} 1{0}^{3} $and$12. 5\ensuremath{\times} 1{0}^{2} $. The computations were carried out assuming the flow to be laminar throughout and the real gas effects such as thermal and chemical non-equilibrium are studied using Park’s two-temperature model with finite-rate chemistry and Gupta’s finite-rate chemistry models. In the close vicinity of the step, detailed quantification of flow features is emphasised. In particular, the presence of the Goldstein singularity at the lip and separation on the face of the step have been elucidated. Within the separated region and downstream of reattachment, the influence of real gas effects has been identified and shown to be negligible. The numerical results are compared with the available experimental data of surface heat flux downstream of the step and reasonable agreement is shown up to 30 step heights downstream.
An evaluation of crustal assimilation within the Late Devonian South Mountain Batholith, SW Nova Scotia
Authors: SHELLNUTT J. GREGORY , DOSTAL JAROSLAV 
Published: February 2012

AbstractThe Late Devonian South Mountain Batholith (SMB) of southwestern Nova Scotia is the largest batholith in the Appalachian Orogen of Eastern North America and contains economic deposits of U and Sn. The SMB comprises at least 11 individual plutons, which range in composition from granodiorite to biotite monzogranite, leucomonzogranite and leucogranite. Previous studies have suggested that a combination of fractional crystallization, assimilation of Meguma Supergroup country rocks and an influx of magmatic fluids contributed to the chemical evolution of the SMB. The amount of crustal assimilation is estimated to be as high as 33%. MELTS modelling assuming a starting composition of granodiorite with H2O = 4 wt%, pressure = 4 kbar (~12 km) and fO2 = FMQ can reproduce the chemical evolution observed in the SMB. However, some leucogranites likely require an additional component (e.g. hydrothermal fluids) to explain their alkali metal enrichment (e.g. Na, K, Rb). Zircon saturation thermometry estimates indicate the Salmontail Lake and Scrag Lake granodiorite plutons had high minimum initial temperatures of 823 ± 6°C and 832 ± 2°C, respectively, which are similar to low zircon-inheritance granitoids. The TiO2/Al2O3 and alkali-lime ratios of the surrounding country rocks and the leucogranites indicate the amount of crustal assimilation is likely to be between 10% and 20%. Our findings suggest the granodiorites of the SMB were likely produced by partial melting of the sub-Meguma Supergroup (e.g. Avalon terrane) lower crust caused by the contemporaneous injection of high temperature mafic to ultramafic magmas.