bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the Community Multiscale Air Quality Model for Simulating Winter Ozone Formation in the Uinta Basin
Authors: Matichuk Rebecca , Tonnesen Gail , Luecken Deborah , Gilliam Rob , Napelenok Sergey L. , Baker Kirk R. , Schwede Donna , Murphy Ben , Helmig Detlev , Lyman Seth N. , Roselle Shawn 
Published: December 2017

AbstractThe Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) models were used to simulate a 10 day high‐ozone episode observed during the 2013 Uinta Basin Winter Ozone Study (UBWOS). The baseline model had a large negative bias when compared to ozone (O3) and volatile organic compound (VOC) measurements across the basin. Contrary to other wintertime Uinta Basin studies, predicted nitrogen oxides (NOx) were typically low compared to measurements. Increases to oil and gas VOC emissions resulted in O3 predictions closer to observations, and nighttime O3 improved when reducing the deposition velocity for all chemical species. Vertical structures of these pollutants were similar to observations on multiple days. However, the predicted surface layer VOC mixing ratios were generally found to be underestimated during the day and overestimated at night. While temperature profiles compared well to observations, WRF was found to have a warm temperature bias and too low nighttime mixing heights. Analyses of more realistic snow heat capacity in WRF to account for the warm bias and vertical mixing resulted in improved temperature profiles, although the improved temperature profiles seldom resulted in improved O3 profiles. While additional work is needed to investigate meteorological impacts, results suggest that the uncertainty in the oil and gas emissions contributes more to the underestimation of O3. Further, model adjustments based on a single site may not be suitable across all sites within the basin.
Modeling the Origin of Anthropogenic Black Carbon and Its Climatic Effect Over the Tibetan Plateau and Surrounding Regions
Authors: Yang Junhua , Kang Shichang , Ji Zhenming , Chen Deliang 
Published: December 2017

AbstractBlack carbon (BC) in snow/ice induces enhanced snow and glacier melting. As over 60% of atmospheric BC is emitted from anthropogenic sources, which directly impacts the distribution and concentration of BC in snow/ice, it is essential to assess the origin of anthropogenic BC transported to the Tibetan Plateau (TP) where there are few direct emissions attributable to local human activities. In this study, we used a regional climate‐atmospheric chemistry model and a set of BC scenarios for quantitative evaluation of the impact of anthropogenic BC from various sources and its climate effects over the TP in 2013. The results showed that the model performed well in terms of climatology, aerosol optical properties, and near‐surface concentrations, which indicates that this modeling framework is appropriate to characterize anthropogenic BC source‐receptor relationships over the TP. The simulated surface concentration associated with the anthropogenic sources showed seasonal differences. In the monsoon season, the contribution of anthropogenic BC was less than in the nonmonsoon season. In the nonmonsoon season, westerly winds prevailed and transported BC from central Asia and north India to the western TP. In the monsoon season, BC aerosol was transported to the middle‐upper troposphere over the Indo‐Gangetic Plain and crossed the Himalayas via southwesterly winds. The majority of anthropogenic BC over the TP was transported from South Asia, which contributed to 40%–80% (mean of 61.3%) of surface BC in the nonmonsoon season, and 10%–50% (mean of 19.4%) in the monsoon season. For the northeastern TP, anthropogenic BC from eastern China accounted for less than 10% of the total in the nonmonsoon season but can be up to 50% in the monsoon season. Averaged over the TP, the eastern China anthropogenic sources accounted for 6.2% and 8.4% of surface BC in the nonmonsoon and monsoon seasons, respectively. The anthropogenic BC induced negative radiative forcing and cooling effects at the near surface over the TP.
Asymmetric Responses of the End of Growing Season to Daily Maximum and Minimum Temperatures on the Tibetan Plateau
Authors: Yang Zhiyong , Shen Miaogen , Jia Shugang , Guo Li , Yang Wei , Wang Cong , Chen Xuehong , Chen Jin 
Published: December 2017

AbstractClimate warming has delayed the end of the growing season (EOS) in temperate and cold ecosystems. However, it is unclear whether asymmetric warming (higher warming at night than during the day) has triggered different responses in the timing of EOS. Here we used satellite‐observed EOS of alpine vegetation to reveal its asymmetric responses to nighttime and daytime warming on the Tibetan Plateau. Increased preseason minimum temperature could postpone EOS by 7.92 day K−1 (P < 0.01), probably by slowing low‐temperature induced leaf senescence, whereas increased preseason maximum temperature could advance EOS by 3.57 day K−1 (P < 0.05), likely due to the confounding effects of water limitations. The delaying effect of nighttime warming was stronger in more arid areas of the plateau, where daytime warming has a stronger advancing effect on EOS. Our results provide new insights into understanding and modeling autumn vegetation phenology on the Tibetan Plateau and grassland ecosystems in other temperate and cold regions.
Carbon Dynamics Along a Temperate Fjord‐Head Delta: Linkages With Carbon Burial in Fjords
Authors: Cui Xingqian , Bianchi Thomas S. , Kenney William F. , Wang Jiaze , Curtis Jason H. , Xu Kehui , Savage Candida 
Published: December 2017

AbstractWe used seven 210Pb‐dated sediment cores from the Gaer Arm in the Doubtful Sound fjord complex, Fiordland, New Zealand to evaluate organic carbon (OC) dynamics in a temperate fjord‐head delta. The highly dynamic spatial features of this delta were clearly evident in the observed sediment properties such as mass accumulation rates that varied by a factor of 14, sediment grain size by a factor 5, and sedimentary OC content by a factor 6. Low lignin concentrations (e.g., 2.95 mg (100 mg OC)−1) and syringic/vanillic ratios of lignin phenols (S/V; e.g., 0.44) at the upper deltaic stations were representative of substantial autochthonous OC contributions to delta sediments. Significantly higher acid/aldehyde ratios of vanillic phenols [(Ad/Al)v] at the deltaic stations (0.45–0.82) than the surface grabs (0.26–0.30) indicated rapid degradation of OC within the delta. Despite being a “hot spot” for OC oxidation, the delta likely improves OC preservation in the adjacent fjord by filtering out coarse‐grained particles and exporting fine‐grained particles to fjord sediments. Our results showed that fjord‐head deltas can influence sedimentation and OC dynamics in select regions of fjords and thus warrant more examination of fjord‐head processes, particularly in areas where they are expanding. In particular, as Earth warms and glaciers retreat, the newly exposed fjord‐head platforms in high‐latitude environments may evolve into similar “hot spots” of OC oxidation, thereby altering the dynamics of OC burial in these systems.
Acclimation of Biogenic Volatile Organic Compound Emission From Subarctic Heath Under Long‐Term Moderate Warming
Authors: Tang J. , Valolahti H. , Kivimäenpää M. , Michelsen A. , Rinnan R. 
Published: December 2017

AbstractBiogenic volatile organic compound (BVOC) emissions from subarctic ecosystems have shown to increase drastically in response to a long‐term temperature increase of only 2°C. We assessed whether this increase takes place already after 3 years of warming and how the increase changes over time. To test this, we measured BVOC emissions and CO2 fluxes in a field experiment on a subarctic wet heath, where ecosystem plots were subjected to passive warming by open top chambers for 3 (OTC3) or 13 years (OTC13) or were kept as unmanipulated controls. Already after 3 years of moderate temperature increase of 1–2°C, warming increased the emissions of isoprene (five‐ to sixfold) and monoterpenes (three‐ to fourfold) from the subarctic heath. The several‐fold higher BVOC emissions in the warmed plots are likely a result of increased vegetation biomass and altered vegetation composition as a shift in the species coverage was observed already after 3 years of warming. Warming also increased gross ecosystem production and ecosystem respiration, but the increases were much lower than those for BVOCs. Our results demonstrate that the strong BVOC responses to warming already appeared after 3 years, and the BVOC and CO2 fluxes had acclimated to this warming after 3 years, showing no differences with another 10 years of warming. This finding has important implications for predicting CO2 and BVOC fluxes in subarctic ecosystems.
Enhanced thermal stability and flame resistance of polyurethane‐imide foams by adding silicon carbide
Authors: Tian Huafeng , Yao Yuanyuan , Ma Songbai , Wu Jiali , Xiang Aimin 
Published: December 2017

AbstractPolyurethane‐imide (PUI) foams containing both polyimide and polyurethane segments combined the advantage of fine mechanical properties as well as high thermal stability of the two polymers. To further improve the thermal stability and flame resistance ofPUIfoams, a series ofPUIcomposite foams with different content of SiC (silicon carbide) as fillers were prepared. The cell structure, mechanical properties, flame resistance, and thermal properties of resultingPUI/SiC composite foams were characterized in detail. The experimental results showed that the cell size distribution became uneven, the apparent density was increased, and the compressive strength decreased with the increase in silicon carbide content. Meanwhile, the limiting oxygen index (LOI) showed an increase from 24.7% to 28.1% with increasing of SiC content from 0% to 9.6%. The thermogravimetric analysis showed that the addition of SiC could significantly enhance the thermal stability and flame retardancy ofPUIfoams.
Softening dynamics of polymer blends and composites investigated by differentia spectra of dynamic mechanical analysis
Authors: Zhang Rui , He Xianru , Rodrigues Alisson M. , Guo Qipeng 
Published: December 2017

AbstractThe confinement effect on molecular motions has been widely observed in polymeric blends and composites. For polymers that have softening dynamics in glass–rubber transition region, the confinement effect can influence the molecular motions to different degrees. In this work, the differentia spectra of dynamic mechanical analysis were applied to analyze the confinement effect in butyl rubber (IIR)/ethylene‐vinyl acetate copolymer (EVA) blends,IIR/high‐density polyethylene (HDPE) blends, chlorobutyl rubber (CIIR)/polystyrene (PS) blends,IIR/silica composites, andCIIR/organophilic montmorillonite (OMMT) composites. In the differentia spectra, the confinement effect from additional components on local segment motions (LSM), sub‐Rouse modes, and Rouse modes was investigated, indicating that the effect on sub‐Rouse modes is smaller than that on Rouse modes but larger than that onLSM. Moreover, the coupling effects slightly change with introduction of the secondary components, which enables us to assume that the confinement effect has a linear relationship with the content of secondary components. Finally, it has been found that the decrease in tan δ exhibited a linear relationship with the content of secondary components.
A Kinetic Dearomatization Strategy for an Expedient Biomimetic Route to the Bielschowskysin Skeleton
Authors: Scesa Paul , Wangpaichitr Medhi , Savaraj Niramol , West Lyndon , Roche Stéphane P. 
Published: December 2017

AbstractBielschowskysin (1), the flagship of the furanocembranoid diterpene family, has attracted attention from chemists owing to its intriguing and daunting polycyclic architecture and medicinal potential against lung cancer. The high level of functionalization of 1 poses a considerable challenge to synthesis. Herein, a stereoselective furan dearomatization strategy of furanocembranoids was achieved via the intermediacy of chlorohydrins. The stereochemical course of the kinetic dearomatization was established, and the C3 configuration of the resulting exo‐enol ether intermediates proved to be essential to complete the late‐stage transannular [2+2] photocycloaddition. Overall, this biomimetic strategy starting from the natural product acerosolide (9) featured an unprecedented regio‐ and highly stereoselective furan dearomatization, which provided rapid access to the pivotal exo‐enol ethers en route to the intricate bielschowskyane skeleton.
Catalytic Asymmetric Synthesis of Trifluoromethylated γ‐Amino Acids through the Umpolung Addition of Trifluoromethyl Imines to Carboxylic Acid Derivatives
Authors: Hu Bin , Deng Li 
Published: December 2017

AbstractNovel cinchona alkaloid derived chiral phase‐transfer catalysts enabled the highly chemo‐, regio‐, diastereo‐, and enantioselective umpolung addition of trifluoromethyl imines to α,β‐unsaturated N‐acyl pyrroles. With a catalyst loading ranging from 0.2 to 5.0 mol %, this new catalytic asymmetric transformation provides facile and high‐yielding access to highly enantiomerically enriched chiral trifluoromethylated γ‐amino acids and γ‐lactams.
Laser confocal microscopical characterization of toughened epoxy resins: Correlations between structural features and mechanical properties
Authors: Hader‐Kregl Laura , Wallner Gernot M. , Lang Reinhold W. , Strauß Bernhard 
Published: December 2017

ABSTRACTLaser confocal microscopy is used to analyze the morphology of an epoxy resin (DGEBA) modified with different amounts of toughening agent carboxyl terminated butadiene acrylonitrile (CTBN). The size and phase volume of the distributed spherical toughening particles is ranging from 0.7 to 1.6 µm and 5 to 40 vol %, respectively. These morphological parameters and particles/µm2 reveal a nonlinear relationship with the amount of toughening agent. With increasing particle size and number the glass transition temperature and the tensile modulus are decreasing, whereas the fracture toughness increases. Particles larger than 1.3 µm and a value of particles/µm2 higher than 0.15 exhibit a more significant impact on the resin properties. Linear correlations between the rubber phase volume and the glass transition temperatures as well as the mechanical properties, i.e., tensile modulus and fracture toughness are ascertained. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46094.
Developmental Osteology of the Parafrontal Bones of the Sphaerodactylidae
Authors: Griffing Aaron H. , Daza Juan D. , DeBoer Jonathan C. , Bauer Aaron M. 
Published: December 2017

ABSTRACTWell‐resolved phylogenetic hypotheses and ontogenetic data are often necessary for investigating the evolution of structural novelty. The Sphaerodactylidae comprises 12 genera of predominantly miniaturized geckos. The genera Aristelliger and Teratoscincus are exceptions, with taxa reaching snout‐to‐vent lengths far exceeding those of other sphaerodactylids. These two genera possess enigmatic, supraorbital ossifications—parafrontal bones—which are encountered nowhere else among squamates. At the time of their discovery, these structures were believed to be the result of evolutionary convergence. Although relationships between other sphaerodactylids remain unresolved, recent molecular and morphological data have supported a close relationship between Aristelliger and Teratoscincus. We investigated the ontogeny of parafrontal bones to better understand relationships between sphaerodactylid body size and the presence of parafrontals, and to evaluate whether ontogenetic data support the homology of parafrontals between Aristelliger and Teratoscincus. We hypothesize that the parafrontals of Aristelliger and Teratoscincus are homologous and that there is a threshold body size in sphaerodactylids below which parafrontals do not develop, thus explaining their absence from the miniaturized taxa. The presence of parafrontals was investigated in all sphaerodactylid genera using cleared‐and‐stained, radiographed, and skeletonized specimens. Total surface area of parafrontals was measured for seven species of Aristelliger and six species of Teratoscincus throughout their ontogeny. Histology was used to investigate the cellular composition of the parafrontals throughout their ontogeny. Our data suggest that parafrontals have evolved in parallel from a homologous, parafrontal precursor and that the onset of parafrontal development is not strictly dependent on a threshold body size. Anat Rec, 301:581–606, 2018. © 2017 Wiley Periodicals, Inc.
Nonequivalent modulation of corticospinal excitability by positive and negative outcomes
Authors: Suzuki Makoto , Hamaguchi Toyohiro , Matsunaga Atsuhiko 
Published: December 2017

AbstractObjectiveThe difference between positive and negative outcomes is important in trial‐and‐error decision‐making processes and affects corticospinal excitability. This study investigated corticospinal excitability during the performance of trial‐and‐error decision‐making tasks with varying competing behavioral outcomes.MethodsEach trial began with one of five colored circles presented as a cue. Each color represented a different reward probability, ranging from 10% to 90%. The subjects were instructed to decide whether to perform wrist flexion in response to the cue. Two seconds after the presentation of the cue, a reward stimulus (picture of a coin) or penalty stimulus (mauve circle) was randomly presented to the subject. If the picture of a coin appeared, the subjects received the coin after the experiment if they had performed wrist flexion, but not if they had not performed wrist flexion. If a mauve circle appeared, a coin was deducted from the total reward if the subjects had performed wrist flexion, but not if they had not performed wrist flexion. One second after the reward or penalty stimulus, transcranial magnetic stimulation was delivered to the primary motor cortex at the midpoint between the centers of gravity of the flexor carpi radialis (agonist) and extensor carpi radialis (antagonist) muscles.ResultsCumulative wrist flexions were positively correlated with reward probabilities. Motor evoked potential (MEP) amplitudes in agonist muscles were significantly higher when wrist flexion incurred a penalty than when it incurred a reward, but there was no difference in the MEP amplitudes of antagonist muscles.ConclusionPositive and negative behavioral outcomes differentially altered behavior and corticospinal excitability, and unexpected penalties had a stronger effect on corticospinal excitability for agonist muscles.
The Role of Green Collaborative Strategies in Improving Environmental Sustainability in Supply Chains: Insights from a Case Study
Authors: Carballo‐Penela Adolfo , Mateo‐Mantecón Ingrid , Alvarez Sergio , Castromán‐Diz Juan Luis 
Published: December 2017

AbstractThis article aims to quantify to what extent collaborative strategies are more effective than internal or organization‐level actions to green supply chains. In this regard, the impact of decisions made at different stages of a supply chain in a product's carbon footprint is quantified. Organizational and product carbon footprints are calculated using the Compound Method Based on Financial Accounts (MC3). The results underline that concentrating reduction efforts in some stages of the supply chain is more effective than implementing individual actions by the participants. Collaboration among the participants is needed to decide what practices are implemented, at what stage they are needed and how they are to be implemented. This article adds to the literature on supply chains and sustainability. Previous research suggests that collaborative strategies have great potential for reducing the carbon footprint of products, while indicating the need for empirical research to support this statement. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Antibiotic Algae by Chemical Surface Engineering
Authors: Kerschgens Isabel P. , Gademann Karl 
Published: December 2017

AbstractChemical cell‐surface engineering is a tool for modifying and altering cellular functions. Herein, we report the introduction of an antibiotic phenotype to the green alga Chlamydomonas reinhardtii by chemically modifying its cell surface. Flow cytometry and confocal microscopy studies demonstrated that a hybrid of the antibiotic vancomycin and a 4‐hydroxyproline oligomer binds reversibly to the cell wall without affecting the viability or motility of the cells. The modified cells were used to inhibit bacterial growth of Gram‐positive Bacillus subtilis cultures. Delivery of the antibiotic from the microalgae to the bacterial cells was verified by microscopy. Our studies provide compelling evidence that 1) chemical surface engineering constitutes a useful tool for the introduction of new, previously unknown functionality, and 2) living microalgae can serve as new platforms for drug delivery.
Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol with Recyclable Al–Zr@Fe Mixed Oxides
Authors: He Jian , Li Hu , Riisager Anders , Yang Song 
Published: December 2017

AbstractA series of magnetic, acid/base bifunctional Al–Zr@Fe3O4 catalysts were successfully prepared by a facile coprecipitation method and utilized in the catalytic transfer hydrogenation (CTH) of furfural to furfuryl alcohol with 2‐propanol as hydrogen source. The physicochemical properties and morphologies of the as‐prepared catalysts were characterized by various techniques, including XRD analysis, N2 physisorption, vibrating sample magnetometry, thermal gravimetry analysis, X‐ray fluorescence spectroscopy, NH3/CO2 temperature‐programmed desorption, SEM, and TEM. The Al7Zr3@Fe3O4(1/1) catalyst with a Al3+/Zr4+/Fe3O4 molar ratio of 21:9:3 was found to exhibit a high furfuryl alcohol yield of 90.5 % in the CTH from furfural at 180 °C after 4 h with a comparatively low activation energy of 45.3 kJ mol−1, as calculated from the Arrhenius equation. Moreover, leaching and recyclability tests confirmed Al7Zr3@Fe3O4(1/1) to function as a heterogeneous catalyst that could be reused for at least five consecutive reaction runs without significant loss of catalytic activity after simple recovery by an external magnet. Notably, the catalyst proved also efficient for hydrogenation of other biomass‐derived furanic aldehydes.
Stereoselective Ring‐Opening of gem‐Difluorocyclopropanes: An Entry to Stereo‐defined (E,E)‐ and (E,Z)‐Conjugated Fluorodienes
Authors: Specklin Simon , Fenneteau Johan , Subramanian Parthasarathi , Cossy Janine 
Published: December 2017

AbstractThe ring‐opening of gem‐difluorocyclopropyl acetaldehydes producing selectively (E,E)‐ and (E,Z)‐conjugated fluorodienals is described. Two stereo‐divergent methods are presented to access both stereoisomers from a common precursor, in high yield and selectivity. The mechanistic aspect of these transformations is discussed.
Stable ZnI‐Containing MOFs with Large [Zn70] Nanocages from Assembly of ZnII Ions and Aromatic [ZnI8] Clusters
Authors: Hu Huan‐Cheng , Cui Ping , Hu Han‐Shi , Cheng Peng , Li Jun , Zhao Bin 
Published: December 2017

AbstractTwo unique ZnI‐containing MOFs {[ZnI8ZnII3(H2O)x(HL)12](OH)2⋅13 H2O}n (x=6, 1; x=2, 2) (HL=tetrazole monoanion) with high‐nuclearity Zn‐cages were prepared successfully. These Zn‐cages are constructed from [ZnI8] clusters with multi‐centered ZnI−ZnI bonds and ZnII ions. [ZnI8] clusters in 1 and 2 display Oh and D4h symmetry, respectively. Importantly, eight [ZnI8] clusters and six ZnII ions form a large [Zn70] nanocage in 1. To our knowledge, this is the first MOF based on polynuclear Zn‐cages consisting of ZnI and ZnII ions. Compared with reported ZnI‐species, 1 and 2 display high thermal and solvent stabilities. Theoretical investigations based on DFT calculations uncover that effective 4s‐4s orbital overlap and electron delocalization through these a1g+t1u molecular orbitals on [ZnI8] clusters lead to considerable aromatic stabilization, which can explain well the intrinsic stability of 1 and 2. Interestingly, 1 can behave as a luminescent probe to detect the toxic CrVI ions in aqueous.