bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study of the nonlinear optical properties of Si nanocrystals fabricated by e‐beam evaporation, PECVD or LPCVD
Authors: Martinez A. , Hernändez S. , Pellegrino P. , Jambois O. , Miska P. , Grün M. , Rinnert H. , Vergnat M. , Izquierdo‐Roca V. , Fedeli J. M. , Garrido B. 
Published: February 2011

AbstractThe nonlinear optical properties of silicon nanocrystals (Si‐nc) embedded in oxide matrices have been studied in samples obtained by three different technological process: e‐beam evaporation, plasma enhanced or low pressure chemical vapor deposition (PECVD and LPCVD, respectively). Z ‐scan measurements were performed in all the samples at 1064 nm by using ns‐pulses of a Nd:YAG laser. Similar nonlinear refractive index was found in the three systems, while differences in the nonlinear absorption were found as a function of the deposition method.The nonlinear results have been evaluated in terms of the crystalline and amorphous fractions from Raman scattering and photoluminescence (PL) measurements. While PL measurements show a emission spectrum similar for all the samples, Raman spectra reveal a sizeably different Si crystalline/amorphous ratio, depending on the deposition method. Therefore, the interface between the SiO2 matrix and Si‐nc plays a crucial role in determining the nonlinear optical response of the Si‐nc rich layers. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanocrystalline silicon in biological studies
Authors: Fucikova Anna , Valenta Jan , Pelant Ivan , Kusova Katerina , Brezina Vitezslav 
Published: February 2011

AbstractPorous silicon and similar materials, like micro‐ and nanocrystalline silicon, are nowadays studied not only in physical research (e.g. optical gain studies, electro‐optical devices, solar energy conversion), but they are very promising also in biological research as fluorescent labels, biological sensors, drug delivery systems or scaffold for various tissues. We are giving an overview of various approaches of preparation of micro‐ and nanocrystalline silicon and current studies of applications with main focus on biology and medicine. In contrast to other nanomaterials used in biological studies (e.g. carbon nanotubes, fullerenes, cadmium containing quantum dots) silicon based nanomaterials show very good biocompatibility and low cytotoxicity. Therefore, these materials have potential to become powerful tools for in vivo investigation of life processes on subcellular and molecular level. Our group concentrates on developing of gentle florescent label based on porous silicon for single molecule detection in the cell. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transition from excitonic to plasma emission from localized electron‐hole pair states in GaAs‐AlGaAs quantum wells
Authors: Manzke G. , Richter F. , Semkat D. , Burau G. K. G. , Kieseling F. , Stolz H. 
Published: February 2011

AbstractWe present a theoretical analysis of the emission of localized excitons in GaAs‐AlGaAs quantum wells, which shows a strong nonlinear behavior with increasing excitation. Considering the influence of dynamical screening both on the one‐particle properties of carriers and on the whole spectrum of electron‐hole pair states, we are able to explain the nonlinearity as a transition of the emission from excitonic to electron‐hole pair states in the continuum (electron‐hole plasma). Moreover, our theoretical approach based on the quasi‐particle approximation for the carriers states and quantum kinetic effects in the screening describes the observed changes of the shift of the exciton energy from higher to lower energies at a temperature of T = 10 K (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oscillatory excitation energy dependence of injection currents in GaAs/AlGaAs quantum wells
Authors: Thanh Duc Huynh , Förstner Jens , Meier Torsten , Priyadarshi Shekhar , Racu Ana Maria , Pierz Klaus , Siegner Uwe , Bieler Mark 
Published: February 2011

AbstractThe injection of photocurrents by femtosecond laser pulses in (110)‐oriented GaAs/AlGaAs quantum wells is investigated theoretically and experimentally. The roomtemperature measurements show an oscillatory dependence of the injection current amplitude and direction on the excitation photon energy.Microscopic calculations using the semiconductor Bloch equations that are set up on the basis of k·p band structure calculations provide a detailed understanding of the experimental findings (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase separation of multicomponent excitonic Bose–Einstein condensates
Authors: Sobkowiak S. , Semkat D. , Stolz H. , Koch Th. , Fehske H. 
Published: February 2011

AbstractFor the observation of Bose–Einstein condensation, excitons in cuprous oxide are regarded as promising candidates due to their large binding energy and long lifetime. High particle densities may be achieved by entrapment in a stress induced potential. We consider a multicomponent gas of interacting para‐ and orthoexcitons in cuprous oxide confined in a three‐dimensional potential trap. Based on the Hartree–Fock–Bogoliubov theory, we calculate density profiles as well as decay luminescence spectra which exhibit signatures of the separation of the Bose‐condensed phases (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second‐order polaron resonances in self‐assembled quantum dots
Authors: Kaczmarkiewicz Piotr , Machnikowski Paweł 
Published: February 2011

AbstractWe theoretically study the optical properties of an InAs/GaAs quantum dot (QD) near the area of the second‐order resonance between an electron confined in the QD and two longitudinal optical phonons. We present the absorption spectra of an inhomogeneously broadened QD ensemble and show that the minimal model needed for an accurate description of such a system needs to account for 3‐phonon states.We study also the influence of the QD height to width ratio on the optical properties of the polaron system. The dependence of the width of the resonance and the position of the second‐orderresonant feature on the height to width ratio is presented (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InAs quantum dot site‐selective growth on GaAs substrates
Authors: Hendrickson Joshua , Helfrich Mathieu , Gehl Michael , Hu Dongzhi , Schaadt Daniel , Linden Stefan , Wegener Martin , Richards Benjamin , Gibbs Hyatt , Khitrova Galina 
Published: February 2011

AbstractPhotoluminescence (PL) spectra and AFM measurements of InAs quantum dots grown in a site‐selective manner on pre‐patterned GaAs substrates are presented. A number of processing steps are described including a Ga‐assisted deoxidation step to remove native oxides from the sample surface. Furthermore, post growth annealing is shown to be a promising technique for improving the quantum dot density and likelihood of single site‐selective nucleation. Morphological transitions are shown to occur during the annealing process with two initial quantum dots in a given nucleation site transforming into one slightly larger quantum dot. Density measurements performed by AFM combined with PL spectroscopic measurements show that we have achieved optically active, site‐selective dot growth, and additionally allow us to calculate that our site‐selective dots are on average 30% as efficient as unpatterned dots. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design for volume optimization of packaging for durable goods
Authors: Wever R. 
Published: February 2011

AbstractIn the literature, there are several authors arguing for the optimization of the packaging volume as an important factor in distribution efficiency. Within the context of packaging of durable goods, these authors present significant economic savings, usually illustrated by qualitative examples of redesigns. So far, these papers are limited to: (a) the economic aspect of volume (b) packaging for which the main functionality is distribution‐related, and (c) mostly qualitative empirical data. This current paper aims to contribute to this literature by: (a) arguing that volume is also a significant factor from an environmental perspective (b) including packaging for which the main functionality is marketing‐related, and (c) presenting quantitative data of over 1000 packed durable goods, covering consumer electronics, domestic appliances, toys, power tools and furniture. Several strategies for volume optimization are discussed in relation to different packaging functionalities. Copyright © 2011 John Wiley & Sons, Ltd.
High‐resolution simulation over central Europe: assimilation experiments during COPS IOP 9c
Authors: Schwitalla Thomas , Bauer Hans‐Stefan , Wulfmeyer Volker , Aoshima Fumiko 
Published: February 2011

AbstractThe impact of assimilating conventional and Global Positioning System (GPS) Zenith Total Delay (ZTD) data over France into the Weather Research and Forecasting (WRF) model is investigated during COPS IOP 9c. A convection‐permitting horizontal resolution of 3.6 km covering the whole of central Europe was chosen. Four different simulations were conducted to show the influence of assimilating different observation types on the forecast. Additionally, a comparison with the models COSMO‐DE and COSMO‐EU from the German Meteorological Service (DWD) was performed.The results show a clear positive impact of assimilating data into a convection‐permitting configuration of the WRF model over Europe. The additional assimilation of GPS‐ZTD data shows a further improvement of integrated water vapour (IWV) correlation, but the influence on prediction of precipitation was not necessarily clear. A comparison with radiosonde data shows a positive impact on the humidity structure after 12 hours, while an overestimation of precipitation still remains.A further comparison with the operational high‐resolution models of DWD during this COPS IOP reveals a strong dependence on the initial boundary‐layer wind field especially as the near‐surface wind field is better represented in the ECMWF analysis than in the COSMO analysis.As this is, to our knowledge, the first study applying a convection‐permitting configuration of WRF over Europe, it can be used as a guidance for further studies. Copyright © 2011 Royal Meteorological Society
DFT calculations of amine‐imine tautomerism in some pyrimidine derivatives and their 1:1 and 1:2 complexes with water
Authors: Hasanein Ahmed A. , Senior Samir A. 
Published: February 2011

AbstractAmine‐Imine tautomerization in 2‐amino‐pyrimidine (I), 2‐amino‐4,6‐dichloropyrimidine (II), 2‐amino‐4,6‐dimethylpyrimidine (III), and 2‐amino‐4,6‐dimethoxypyrimidine (IV) and their 1:1 and 1:2 H‐bonded complexes with water have been studied using the B3LYP/6‐31++G** method. Optimum molecular geometries, electronic properties, and energetics of these systems have been discussed. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Properties of polypropylene/(natural rubber)/organomontmorillonite nanocomposites prepared by melt blending
Authors: Bendjaouahdou C. , Bensaad S. 
Published: February 2011

AbstractThe aim of this work was to study the effects of an organomontmorillonite or organoclay (OMMT) on the properties of a thermoplastic elastomer blend prepared by melt blending and based on polypropylene (PP) and natural rubber (NR). The results obtained showed a slight improvement of the blend mechanical (strength, modulus, and elongation), thermal, and solvent resistance properties when the amount of the organoclay was 3 phr. Results obtained by XRD analysis showed that at 3 phr of organoclay loading there was a shift toward low angles of the organoclay (001) plane diffraction peak and a disappearance of the PP β–phase peak. This shift signifies an intercalation of the polypropylene/(natural rubber) chains between organoclay platelets. An SEM study revealed that at the 3 phr organoclay concentration the blend became tougher, and the organoclay was located both at the PP/NR interface and inside the NR dispersed phase. A DSC study showed a decrease of the melting temperature of the PP phase at the 3 phr organoclay loading. A rheological study revealed that the addition of organoclay had not increased the melt viscosity of the PP/NR blend, and the stiffness was related to the maximum torque increase as a function of the organoclay loading. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Dietary Cocoa Butter or Refined Olive Oil Does Not Alter Postprandial hsCRP and IL‐6 Concentrations in Healthy Women
Authors: Tholstrup Tine , Teng Kim‐Tiu , Raff Marianne 
Published: February 2011

AbstractContrary to other long chain saturated fatty acids (SFA), fats high in stearic acid do not raise plasma cholesterol concentrations, however, a slight elevation in inflammatory markers, plasma fibrinogen and interleukin‐6 (IL‐6), has been observed in the fasting state. The effect of stearic acid on inflammation in the postprandial state has not yet been reported. We conducted a single blind crossover, randomized, postprandial study to compare the effects of a fat load of cocoa butter high in stearic acid and olive oil in ten healthy women. The test meals contained 1 g of fat per kg body weight (mean 62 g). Blood samples were collected at 0 (fasting), 4 and 6 h. Both diets resulted in a significant increase in serum triacylglycerol (TAG) concentration over time (P = 0.003) and a decrease in serum IL‐6 concentration after 4 h followed by an increase to post absorptive values after 6 h (P < 0.001); whereas serum high sensitivity C‐reactive protein (hsCRP) concentration was not affected. There was no difference between diets in effects on serum TAG, hsCRP and IL‐6 concentrations and no association between postprandial lipemia and inflammatory markers. High intake of dietary fats increase postprandial serum TAG, however, may not affect inflammatory markers postprandially. Thus, fat rich in stearic acid does not seem to increase postprandial inflammation.
Improvement of Canola Oil Frying Stability by Bene Kernel Oil's Unsaponifiable Matter
Authors: Sharayei Parvin , Farhoosh Reza , Poorazrang Hashem , Khodaparast Mohammad Hossein Haddad 
Published: February 2011

AbstractThe anti‐rancidity effect of the unsaponifiable matter fraction of bene kernel (UFB) oil on canola oil (CAO) during frying was compared to that of tert‐butyl hydroquinone (TBHQ). The UFB was separated into hydrocarbons (12.9%), carotenes (9.6%), tocopherols and tocotrienols (65.8%, mainly γ‐tocopherol), linear and triterpenic alcohols (3.8%), methyl sterols (2.8%), sterols (3.0%, mainly β‐sitosterol, stigmasterol, Δ5‐avenasterol, and Δ7‐avenasterol, respectively), and triterpenic dialcohols (2.2%). The results obtained from the measurements of the total polar compounds, the conjugated diene value, the carbonyl value, and total tocopherols showed that the stability of CAO improves similarly in the presence of UFB or TBHQ, and even more in the presence of UFB in some cases (especially inhibition of oxidized triglyceride monomers and triglyceride dimers). The analysis of polar components showed that the antioxidative additives were more effective to resist the formation of thermo‐oxidative than hydrolytic products during the frying of CAO.
Global well-posedness for an advection–diffusion equation arising in magneto-geostrophic dynamics
Authors: Friedlander Susan , Vicol Vlad 
Published: February 2011

We use De Giorgi techniques to prove Hölder continuity of weak solutions to a class of drift-diffusion equations, with

L^{2}

initial data and divergence free drift velocity that lies in

L_{t}^{\infty }\mathrm{BMO}_{x}^{−1}

. We apply this result to prove global regularity for a family of active scalar equations which includes the advection–diffusion equation that has been proposed by Moffatt in the context of magnetostrophic turbulence in the Earthʼs fluid core.

Résumé

Nous utilisons des techniques de De Giorgi pour démontrer la continuité Hölder de solutions faibles pour une classe dʼéquations de dérive-diffusion, avec données initiales

L^{2}

et champ de vitesse incompressible appartenant à

L_{t}^{\infty }\mathrm{BMO}_{x}^{−1}

. Nous appliquons ce résultat pour démontrer la régularité globale pour une famille dʼéquations du scalaire actif qui comprend lʼéquation dʼadvection–diffusion qui a été proposée par Moffatt dans le contexte de la turbulence magnétostrophique dans le noyau fluide de la Terre.
Violence and phases of illness: Differential risk and predictors
Authors: Hodgins S. , Riaz M. 
Published: February 2011

AbstractThis study tested the hypothesis that among patients with schizophrenia the risk and correlates of aggressive behavior differ depending on the level of positive symptoms. Two hundred and fifty-one adults with schizophrenia who were living in the community were assessed by psychiatrists using validated instruments. Patients and collaterals reported aggressive behavior. In a final multivariate model, aggressive behavior was significantly and positively associated with childhood conduct disorder, current use of illicit drugs, positive, threat-control-override (TCO), and depression symptoms. While 16% of the patients with two or fewer positive symptoms engaged in aggressive behavior in the previous six months, this was true of 28.4% of those with three or more positive symptoms (X2(n= 251,1) = 5.48,P= 0.019). Among patients with high positive symptoms, even univariate analyses failed to detect any factors associated with aggressive behavior other than medication non-compliance, typical antipsychotic medication, and clozapine. By contrast, among patients with few positive symptoms, aggressive behavior was associated with TCO and depression symptoms, young age, male sex, the number of childhood conduct disorder symptoms, prior aggressive behavior, and current illicit drug use. In phases of illness characterized by different levels of positive symptoms, the risk of aggressive behavior and the associated factors differ.
A taxonomic study of Melanelixia fuliginosa in Europe
Authors: ARUP Ulf , BERLIN Emma SANDLER 
Published: February 2011

AbstractFor a long time it has been discussed as to whether Melanelixia fuliginosa comprises one or two species: one darker, mainly saxicolous, and one lighter, mainly corticolous. To settle the question, a morphometric and a molecular analysis were carried out and analyzed using a principal component analysis (PCA). The morphometric analysis indicates a differentiation in several characters between material previously recognized as subspecies fuliginosa and glabratula, but also a considerable overlap in some of them. The molecular analysis of the nrITS DNA gene reveals a clear division of the taxa. Specimens belonging to Melanelia fuliginosa fall out in two different clades, which have good bootstrap support, corresponding to the subspecies fuliginosa and glabratula. Accordingly, we propose that the subspecies should be acknowledged as separate species, Melanelixia fuliginosa (Fr. ex Duby) O. Blanco et al. and Melanelixia glabratula (Lamy) Sandler & Arup.
Taxonomy and phylogeny of theCaloplaca cerinagroup in Europe
Authors: ŠOUN Jaroslav , VONDRÁK Jan , SØCHTING Ulrik , HROUZEK Pavel , KHODOSOVTSEV Alexander , ARUP Ulf 
Published: February 2011

AbstractUsing ITS nrDNA sequence data, theCaloplaca cerinagroup (Teloschistaceae) is defined here as a monophyletic, but internally richly branched lineage. The group is also characterized by a combination of morphological and anatomical characters. Its internal lineages are supported by phenotypic characters in addition to ecology and distribution. Within the largeC. cerinagroup, we have found at least 20 phylospecies in the temperate zone of the Northern Hemisphere. Two species complexes do not produce any vegetative diaspores: the polyphyletic, corticolousCaloplaca cerinas. lat. (six separated cryptic or semi-cryptic species) and the monophyleticC. stillicidiorums. lat. that grows mainly on plant debris, small shrubs and bryophytes and consists of at least four internal lineages. All lineages producing vegetative diaspores (soredia, blastidia, isidia or lobules) are phenotypically characteristic and represent fairly easily distinguishable species:C. chlorina,C. isidiigera,C. monacensis,C. subalpina,C. thracopontica,C. turkuensisandC. ulmorum. Only the North American sorediateC. pinicolapossibly represents an aggregate of species.Caloplaca sterilisis described as a new species. A key to the phenotypically distinguishable species is provided.Lectotypes are designated forC. albolutea,Caloplaca cerinaf.coronulataand forC. monacensis. The AustralianC. hannesherteliibelongs to this group, but this and other possible species from the Southern Hemisphere are not treated here in detail. Some species traditionally placed in theC. cerinagroup due to their similar morphology are excluded here on the basis of our phenotype examinations and molecular data.Caloplaca albolutea,C. mydalaeaandC. virescensare uncertain taxa and their identities still remain unclear.
Pilophorus fruticosus (Cladoniaceae), a new species from south-western China
Authors: WANG Xin Yu , JOSHI Yogesh , OH Soon Ok , HUR Jae-Seoun , WANG Li Song 
Published: February 2011

AbstractPilophorus fruticosus Li S. Wang & Xin Y. Wang is described from south-west China. It is characterized by the presence of densely dichotomously branched, partly decorticated pseudopodetia, and by having single, spherical apothecia on the apices of the pseudopodetia. The species grows on siliceous rocks in alpine regions of the Yunnan Province. A detailed description and illustrations are provided. The new taxon is compared with other Pilophorus species.
Description ofSantelmoa elviraesp. nov. (Teleostei: Zoarcidae) from the Southern Ocean
Authors: Matallanas Jesús 
Published: February 2011

Santelmoais diagnosed by the following characters: anterior portion of frontals fused; scapular foramen open; anterior ceratohyal–posterior ceratohyal (=epihyal) articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; ascending rami of the parasphenoid wing high; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. A new species ofSantelmoa, Santelmoa elviraesp. nov., is described on the basis of four specimens collected from the Bellingshausen Sea, Southern Ocean, at a depth of 1837 m. The new species can be distinguished fromSantelmoa carmenae, the type species of the genus and the sole knownSantelmoaspecies, by the following characters: mouth inferior; vertical folds on posterior end of the upper lip and on the lower lip lobe; oral valve nearly reaching the anterior edge of vomer; two posterior nasal pores; lateral line double with ventral and medio-lateral branches; single row of palatine teeth; dorsal fin rays 108–111; anal fin rays 93–94; pectoral fin rays 18–19 and vertebrae asymmetrical, 26–27 + 90–93 = 116–119.