bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compressively strained Si/Si1−
xCx heterostructures formed on Ar ion implanted Si(100) substrates
Authors: Hoshi Yusuke , Arisawa You , Arimoto Keisuke , Yamanaka Junji , Nakagawa Kiyokazu , Sawano Kentarou , Usami Noritaka 
Published: February 2016

Abstract
We demonstrate that compressively strained Si/Si1−

x
C
x
heterostructures are epitaxially grown on Ar ion implanted Si substrates. The ion-implantation-induced defects are found to promote strain relaxation in the Si1−

x
C
x
layers, which accompanies an increase in the substitutional C concentrations. The top Si layers are strained on the Si1−

x
C
x
layers for all samples, and thus the increase in the substitutional C concentration based on strain relaxation in the Si1−

x
C
x
layers is very important for the control of the compressive strain in the top Si layer.
JOGOS PARA O ESTUDO DA MATEMÁTICA NO ENSINO FUNDAMENTAL
Authors: Da Silva Pfiffer Claudimara , Baier Tânia 
Published: January 2016

<p>Neste artigo, são apresentadas as possibilidades pedagógicas dos jogos, um recurso didático para o estudo da matemática, no ensino fundamental, sendo destacado o papel do professor como organizador e observador das ações realizadas pelas crianças durante as partidas. Trazendo o lúdico para a sala de aula, os jogos promovem: a sociabilidade e a interação entre estudantes e professor, a oportunidade de tomada de decisões e o desenvolvimento da autonomia. Jogos contribuem para que cada estudante conheça seus limites, possibilitam o exercício de concentração e do controle da ansiedade e podem estimular a prática do cálculo mental. Erros cometidos durante a realização de jogos são mais facilmente superados do que aqueles escritos em avaliações. Vencer um jogo demanda seguimento de regras e respeito aos colegas: atitudes exigidas no convívio social. </p>
A MODELAGEM MATEMÁTICA NOS CURSOS DE LICENCIATURA EM MATEMÁTICA DO ESTADO DO PARANÁ
Authors: Santos Junior Guataçara Dos , Soares Maria Rosana 
Published: January 2016

<p>A modelagem matemática como disciplina é essencial para que se contribua com a formação qualificada dos futuros professores de Matemática. Assim, objetivou-se analisar as faculdades/universidades do estado do Paraná que oferecem a disciplina de modelagem matemática inserida na matriz curricular nos cursos de Licenciatura em Matemática. O presente estudo desenvolveu-se à luz da pesquisa qualitativa, no qual a coleta de dados se deu por meio da observação e análise do material obtido nos endereços eletrônicos das instituições de ensino superior cadastradas no “e-mec”<a title="" href="#_ftn1">[1]</a>. Os resultados apontaram que a maioria dessas faculdades/universidades não insere a modelagem matemática na matriz curricular do curso mencionado. Logo, diversos licenciandos poderão não obter uma preparação para trabalhá-la no ensino e terem dificuldades para reconhecer sua importância no ensino e aprendizagem de Matemática.</p><p> </p><div> </div>
Measurements and modeling of contemporary radiocarbon in the stratosphere
Authors: Kanu A. M. , Comfort L. L. , Guilderson T. P. , Cameron‐Smith P. J. , Bergmann D. J. , Atlas E. L. , Schauffler S. , Boering K. A. 
Published: January 2016

AbstractMeasurements of the 14C content of carbon dioxide in air collected by high‐altitude balloon flights in 2003–2005 reveal the contemporary radiocarbon distribution in the northern midlatitude stratosphere, four decades after the Limited Test Ban Treaty restricted atmospheric testing of nuclear weapons. Comparisons with results from a 3‐D chemical‐transport model show that the 14CO2 distribution is now largely governed by the altitude/latitude dependence of the natural cosmogenic production rate, stratospheric transport, and propagation into the stratosphere of the decreasing radiocarbon trend in tropospheric CO2 due to fossil fuel combustion. From the observed correlation of 14CO2 with N2O mixing ratios, an annual global mean net flux of 14CO2 to the troposphere of 1.6(±0.4) × 1017‰ mol CO2 yr−1 and a global production rate of 2.2(±0.6) × 1026 atoms 14C yr−1 are empirically derived. The results also indicate that contemporary 14CO2 observations provide highly sensitive diagnostics for stratospheric transport and residence times in models.
Dipolarizing flux bundles in the cis‐geosynchronous magnetosphere: Relationship between electric fields and energetic particle injections
Authors: Liu Jiang , Angelopoulos V. , Zhang Xiao‐Jia , Turner D. L. , Gabrielse C. , Runov A. , Li Jinxing , Funsten H. O. , Spence H. E. 
Published: January 2016

AbstractDipolarizing flux bundles (DFBs) are small flux tubes (typically <3 RE in XGSM and YGSM) in the nightside magnetosphere that have magnetic field more dipolar than the background. Although DFBs are known to accelerate particles, creating energetic particle injections outside geosynchronous orbit (trans‐GEO), the nature of the acceleration mechanism and the importance of DFBs in generating injections inside geosynchronous orbit (cis‐GEO) are unclear. Our statistical study of cis‐GEO DFBs using data from the Van Allen Probes reveals that just like trans‐GEO DFBs, cis‐GEO DFBs occur most often in the premidnight sector, but their occurrence rate is ~1/3 that of trans‐GEO DFBs. Half the cis‐GEO DFBs are accompanied by an energetic particle injection and have an electric field 3 times stronger than that of the injectionless half. All DFB injections are dispersionless within the temporal resolution considered (11 s). Our findings suggest that these injections are ushered or produced locally by the DFB, and the DFB's strong electric field is an important aspect of the injection generation mechanism.
Reply to comment by E. W. Wolff et al. on “Low time resolution analysis of polar ice cores cannot detect impulsive nitrate events”
Authors: Smart D. F. , Shea M. A. , Melott A. L. , Laird C. M. 
Published: January 2016

AbstractWolff et al. (2016) comment on Smart et al. (2014) and in doing so concentrate on issues other than the main point. They do not dispute our central assertion, the inadequate resolution of nearly all extant ice cores for detection of impulsive nitrate events (spikes) from any source, including past solar proton events (SPEs). We explain why comparing two short‐length cores from other researchers and analyzed by different methods is insufficient for disputing subannual reproducibility, and call for a multiple, fine‐resolution, replicate core study to resolve this issue. While acknowledging the creation of nitrate by SPEs and the existence of ice core nitrate spikes detected by others, they present several weak arguments, such as alleged scavenging of nitrate by some unnamed and unmeasured aerosol, and why no enhanced nitrate signal for documenting SPE statistics should be distinguishable in the ice. These are not derived from the main points in our Smart et al. (2014) paper. We address these briefly and show that ionization from the February 1956 SPE was sufficient to produce a winter, likely acidic, nitrate spike at Summit, Greenland. While noting some convergence of interpretation, we show why their claim that nitrate spikes cannot be used for deriving SPE statistics is unproven and why rejection of fine resolution core studies as unreliable is premature.
Brewer‐Dobson circulation diagnosed from JRA‐55
Authors: Kobayashi Chiaki , Iwasaki Toshiki 
Published: January 2016

AbstractWe examine the Brewer‐Dobson circulation (BDC) in the lower stratosphere diagnosed from the Japanese 55 year Reanalysis (JRA‐55) data set and compare it with the BDCs diagnosed from the other reanalyses (i.e., ERA‐Interim and JRA‐25), and JRA‐55‐related data sets (i.e., JRA‐55C, created by assimilating only in situ observations, and JRA‐55AMIP, a simulation by a prediction model). The climatological mean seasonal change of the BDC in JRA‐55 is similar to that in ERA‐Interim but considerably different from that in JRA‐25. Dynamical and thermodynamical consistencies among the variables are greatly improved in the JRA‐55 data set. The interannual variations of the annual mean tropical upwellings in JRA‐55 are almost coincident with those in JRA‐55C. It suggests that the weakly increasing trend of the BDC found in JRA‐55 does not have anything to do with changes in the satellite observing system. The climatological mean tropical upwelling diagnosed from JRA‐55 is stronger than that from JRA‐55AMIP. This difference is presumed to partly link to the model's inability to simulate the quasi‐biennial oscillation (QBO). The JRA‐55AMIP data set, a simple simulation performed without data assimilation, does not simulate the QBO, whereas the JRA‐55 data set represents the QBO with the aid of data assimilation. The climatological mean zonal mean states of JRA‐55AMIP considerably deviate from those of JRA‐55 in the lower stratosphere. The deviation of JRA‐55AMIP is similar to the modulation pattern by the QBO in specific phase regions in which the BDC is rather weak. The simulated QBO might enhance the BDC and reduce the model biases in the tropical lower stratosphere.
Emissions and climate forcing from global and Arctic fishing vessels
Authors: McKuin Brandi , Campbell J. Elliott 
Published: January 2016

AbstractFishing vessels were recently found to be the largest source of black carbon ship emissions in the Arctic, suggesting that the fishing sector should be a focus for future studies. Here we developed a global and Arctic emissions inventory for fishing vessel emissions of short‐lived and long‐lived climate forcers based on data from a wide range of vessel sizes, fuel sulfur contents, engine types, and operational characteristics. We found that previous work generally underestimated emissions of short‐lived climate forcers due to a failure to account for small fishing vessels as well as variability in emission factors. In particular, global black carbon emissions were underestimated by an order of magnitude. Furthermore, our order of magnitude estimate of the net climate effect from these fishing vessel emissions suggests that short‐lived climate forcing may be particularly important in regions where fuel has a low sulfur content. These results have implications for proposed maritime policies and provide a foundation for future climate simulations to forecast climate change impacts in the Arctic.
Stratospheric polar vortex splits and displacements in the high‐top CMIP5 climate models
Authors: Seviour William J. M. , Gray Lesley J. , Mitchell Daniel M. 
Published: January 2016

AbstractSudden stratospheric warming (SSW) events can occur as either a split or a displacement of the stratospheric polar vortex. Recent observational studies have come to different conclusions about the relative impacts of these two types of SSW upon surface climate. A clearer understanding of their tropospheric impact would be beneficial for medium‐range weather forecasts and could improve understanding of the physical mechanism for stratosphere‐troposphere coupling. Here we perform the first multimodel comparison of stratospheric polar vortex splits and displacements, analyzing 13 stratosphere‐resolving models from the fifth Coupled Model Intercomparison Project (CMIP5) ensemble. We find a wide range of biases among models in both the mean state of the vortex and the frequency of vortex splits and displacements, although these biases are closely related. Consistent with observational results, almost all models show vortex splits to occur barotropically throughout the depth of the stratosphere, while vortex displacements are more baroclinic. Vortex splits show a slightly stronger North Atlantic surface signal in the month following onset. However, the most significant difference in the surface response is that vortex displacements show stronger negative pressure anomalies over Siberia. This region is shown to be colocated with differences in tropopause height, suggestive of a localized response to lower stratospheric potential vorticity anomalies.
Flow patterns and morphology of a prograding river delta
Authors: Shaw John B. , Mohrig David , Wagner R. Wayne 
Published: January 2016

AbstractThe transition of flow between laterally confined channels and the unchannelized delta front controls the morphodynamic evolution of river deltas but has rarely been measured at the field scale. We quantify flow patterns and bathymetry that define the evolution of the subaqueous delta front on the Wax Lake Delta, a rapidly prograding delta in coastal Louisiana. A significant portion of flow (∼59%) departs the channel network over lateral channel margins as opposed to the downstream channel tips. Bathymetric surveys and remotely sensed estimates of flow direction allow spatial changes in flow velocity to be quantified and patterns of erosion and deposition to be estimated. Shallowing along channel margins produces spatial acceleration and erosion. Lateral spreading, deceleration, and deposition occur within three to eight channel widths outside of the channel margins. In interdistributary bays, the shape of each flow path is constrained by “nourishment boundaries” that separate the outflows from neighboring channels. Deposit elevation decreases with a basinward slope of 2.4 × 10−4 with distance from a channel margin along any flow path, regardless of the channel or location that flow departed the network. Bathymetric depressions called “interdistributary troughs” form along nourishment boundaries where flow paths are the longest and deposit elevation is correspondingly low. We conclude that the deposit morphology exerts a strong control on bathymetric evolution and that interaction between neighboring channels and even neighboring deltas can influence delta front morphology.
Deviation of permeable coarse‐grained boundary resistance from Nikuradse's observations
Authors: Cheng Nian‐Sheng , Liu Xingnian , Chen Xingwei , Qiao Changkai 
Published: January 2016

AbstractNikuradse's (1933) rough pipe study is enormously influential in the understanding of flow resistance over a sediment bed. However, the rough boundary employed in Nikuradse's study differs from permeable sediment beds in rivers. This implies that the results derived from the rough pipe experiments may not be applicable for flows over a permeable coarse‐grained bed. The present study aimed to explore to what extent the flow resistance of a permeable coarse‐grained boundary deviates from the Nikuradse's observations. Experiments were conducted with rough pipes, which were prepared by overlaying the inner wall with one to four layers of spherical beads. The single layer roughness resembles the experimental setup reported in Nikuradse's study, while the multilayer of grains allows significant flow to pass through the porous roughness layer. In addition, the ratio of grain diameter, k, to pipe diameter, d, was chosen to be one to two orders greater than the range (0.001 < k/d < 0.033) adopted in Nikuradse's experiments. The data show that the friction factor deviates significantly from the prediction based on Nikuradse's rough pipe relation. For hydraulically rough pipes, the friction factor is found to be proportional to the squared ratio of the grain diameter to nominal pipe diameter. This result is different from the one‐third power function as implied by Nikuradse's rough pipe relation or the Manning‐Strickler formula but agrees well with laboratory observations of open channel resistance in the presence of large‐scale roughness. The measurements also suggest the existence of a laminar flow regime, in which the friction factor is inversely proportional to the Reynolds number. The observed variations in the flow resistance are attributed to both wall permeability and large‐scale roughness.
Effects of soil spatial variability at the hillslope and catchment scales on characteristics of rainfall‐induced landslides
Authors: Fan Linfeng , Lehmann Peter , Or Dani 
Published: January 2016

AbstractSpatial variations in soil properties affect key hydrological processes, yet their role in soil mechanical response to hydro‐mechanical loading is rarely considered. This study aims to fill this gap by systematically quantifying effects of spatial variations in soil type and initial water content on rapid rainfall‐induced shallow landslide predictions at the hillslope‐ and catchment‐scales. We employed a physically‐based landslide triggering model that considers mechanical interactions among soil columns governed by strength thresholds. At the hillslope scale, we found that the emergence of weak regions induced by spatial variations of soil type and initial water content resulted in early triggering of landslides with smaller volumes of released mass relative to a homogeneous slope. At the catchment scale, initial water content was linked to a topographic wetness index, whereas soil type varied deterministically with soil depth considering spatially correlated stochastic components. Results indicate that a strong spatial organization of initial water content delays landslide triggering, whereas spatially linked soil type with soil depth promoted landslide initiation. Increasing the standard deviation and correlation length of the stochastic component of soil type increases landslide volume and hastens onset of landslides. The study illustrates that for similar external boundary conditions and mean soil properties, landslide characteristics vary significantly with soil variability, hence it must be considered for improved landslide model predictions.
The ontogeny of nasal shape: An analysis of sexual dimorphism in a longitudinal sample
Authors: Holton Nathan E. , Alsamawi Ammar , Yokley Todd R. , Froehle Andrew W. 
Published: January 2016

ABSTRACTObjectivesPotential integration between the nasal region and noncranial components of the respiratory system has significant implications for understanding determinants of craniofacial variation. There is increasing evidence that sexual dimorphism in body size and associated male‐female differences in energetically relevant variables influence the development of the nasal region. To better understand this relationship, we examined the ontogeny of sexual dimorphism in nasal shape using a longitudinal series of lateral cephalograms.MethodsWe collected a series of two dimensional coordinate landmark data from n = 20 males and n = 18 females from 3.0 to 20.0+ years of age totaling n = 290 observations across nine age groups. First, we tested whether there are sex differences in the nasal shape related to ontogenetic increases in body size (i.e., sitting height). Additionally, we examined whether there are male‐female differences in patterns of nonallometric variation in nasal shape. Next, we tested whether there are sex differences in the strength of integration between the nasal region and other aspects of the facial skeleton.ResultsOur results indicate that there are a number of similarities in patterns of morphological variation in the nasal region between males and females. However, as sitting height increases males exhibit a disproportionate increase in nasal region height that is not present in the female sample. Moreover, the male nasal region is less integrated with the surrounding facial skeleton when compared to the female sample.ConclusionsThese results are consistent with the hypothesis that sex differences in nasal development are associated with male‐female differences in energetically relevant variables. Am J Phys Anthropol 160:52–61, 2016. © 2016 Wiley Periodicals, Inc.
Pyridyl Pyrrolide Boron Complexes: The Facile Generation of Thermally Activated Delayed Fluorescence and Preparation of Organic Light‐Emitting Diodes
Authors: Shiu Yi‐Jiun , Cheng Yung‐Chen , Tsai Wei‐Lung , Wu Chung‐Chih , Chao Chun‐Tien , Lu Chin‐Wei , Chi Yun , Chen Yi‐Ting , Liu Shih‐Hung , Chou Pi‐Tai 
Published: January 2016

AbstractThe electron positive boron atom usually does not contribute to the frontier orbitals for several lower‐lying electronic transitions, and thus is ideal to serve as a hub for the spiro linker of light‐emitting molecules, such that the electron donor (HOMO) and acceptor (LUMO) moieties can be spatially separated with orthogonal orientation. On this basis, we prepared a series of novel boron complexes bearing electron deficient pyridyl pyrrolide and electron donating phenylcarbazolyl fragments or triphenylamine. The new boron complexes show strong solvent‐polarity dependent charge‐transfer emission accompanied by a small, non‐negligible normal emission. The slim orbital overlap between HOMO and LUMO and hence the lack of electron correlation lead to a significant reduction of the energy gap between the lowest lying singlet and triplet excited states (ΔET‐S) and thereby the generation of thermally activated delay fluorescence (TADF).
CuSO4/H2O2‐Induced Rapid Deposition of Polydopamine Coatings with High Uniformity and Enhanced Stability
Authors: Zhang Chao , Ou Yang , Lei Wen‐Xi , Wan Ling‐Shu , Ji Jian , Xu Zhi‐Kang 
Published: January 2016

AbstractMussel‐inspired polydopamine (PDA) deposition offers a promising route to fabricate multifunctional coatings for various materials. However, PDA deposition is generally a time‐consuming process, and PDA coatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report a strategy to realize the rapid deposition of PDA by using CuSO4/H2O2 as a trigger. Compared to the conventional processes, our strategy shows the fastest deposition rate reported to date, and the PDA coatings exhibit high uniformity and enhanced stability. Furthermore, the PDA‐coated porous membranes have excellent hydrophilicity, anti‐oxidant properties, and antibacterial performance. This work demonstrates a useful method for the environmentally friendly, cost‐effective, and time‐saving fabrication of PDA coatings.
Phenyltrimethylammonium Salts as Methylation Reagents in the Nickel‐Catalyzed Methylation of C−H Bonds
Authors: Uemura Takeshi , Yamaguchi Mao , Chatani Naoto 
Published: January 2016

AbstractMethylation of C(sp2)−H bonds was achieved through the NiII‐catalyzed reaction of benzamides with phenyltrimethylammonium bromide or iodide as the source of the methyl group. The reaction has a broad scope and shows high functional‐group compatibility. The reaction is also applicable to the methylation of C(sp3)−H bonds in aliphatic amides.
Esterase‐Sensitive Prodrugs with Tunable Release Rates and Direct Generation of Hydrogen Sulfide
Authors: Zheng Yueqin , Yu Bingchen , Ji Kaili , Pan Zhixiang , Chittavong Vayou , Wang Binghe 
Published: January 2016

AbstractProdrugs that release hydrogen sulfide upon esterase‐mediated cleavage of an ester group followed by lactonization are described herein. By modifying the ester group and thus its susceptibility to esterase, and structural features critical to the lactonization rate, H2S release rates can be tuned. Such prodrugs directly release hydrogen sulfide without the involvement of perthiol species, which are commonly encountered with existing H2S donors. Additionally, such prodrugs can easily be conjugated to another non‐steroidal anti‐inflammatory agent, leading to easy synthesis of hybrid prodrugs. As a biological validation of the H2S prodrugs, the anti‐inflammatory effects of one such prodrug were examined by studying its ability to inhibit LPS‐induced TNF‐α production in RAW 264.7 cells. This type of H2S prodrugs shows great potential as both research tools and therapeutic agents.
Highly Efficient Transition Metal Nanoparticle Catalysts in Aqueous Solutions
Authors: Wang Changlong , Ciganda Roberto , Salmon Lionel , Gregurec Danijela , Irigoyen Joseba , Moya Sergio , Ruiz Jaime , Astruc Didier 
Published: January 2016

AbstractA ligand design is proposed for transition metal nanoparticle (TMNP) catalysts in aqueous solution. Thus, a tris(triazolyl)‐polyethylene glycol (tris‐trz‐PEG) amphiphilic ligand, 2, is used for the synthesis of very small TMNPs with Fe, Co, Ni, Cu, Ru, Pd, Ag, Pt, and Au. These TMNP‐2 catalysts were evaluated and compared for the model 4‐nitrophenol reduction, and proved to be extremely efficient. High catalytic efficiencies involving the use of only a few ppm metal of PdNPs, RuNPs, and CuNPs were also exemplified in Suzuki–Miyaura, transfer hydrogenation, and click reactions, respectively.