bluuebunny/crossref_metadata_2025_split huggingface dataset:
The global structure of upper troposphere‐lower stratosphere ozone in GEOS‐5: A multiyear assimilation of EOS Aura data
Authors: Wargan Krzysztof , Pawson Steven , Olsen Mark A. , Witte Jacquelyn C. , Douglass Anne R. , Ziemke Jerald R. , Strahan Susan E. , Nielsen J. Eric 
Published: January 2015

AbstractEight years of ozone measurements retrieved from the Ozone Monitoring Instrument and the Microwave Limb Sounder, both on the EOS Aura satellite, have been assimilated into the Goddard Earth Observing System Version 5 (GEOS‐5) data assimilation system. This study evaluates this assimilated product, highlighting its potential for science. The impact of observations on the GEOS‐5 system is explored by examining the spatial distribution of the observation‐minus‐forecast statistics. Independent data are used for product validation. The correlation of the lower stratospheric (the tropopause to 50 hPa) ozone column with ozonesondes is 0.99 and the (high) bias is 0.5%, indicating the success of the assimilation in reproducing the ozone variability in that layer. The upper tropospheric (500 hPa to the tropopause) assimilated ozone column is about 10% lower than the ozonesonde column, but the correlation is still high (0.87). The assimilation is shown to realistically capture the sharp cross‐tropopause gradient in ozone mixing ratio. Occurrence of transport‐driven low ozone laminae in the assimilation system is similar to that obtained from the High Resolution Dynamics Limb Sounder (HIRDLS) above the 400 K potential temperature surface, but the assimilation produces fewer laminae than seen by HIRDLS below that surface. Although the assimilation produces about 25% fewer occurrences per day during the 3 years of HIRDLS data, the interannual variability is captured correctly. This data‐driven assimilated product is complementary to ozone fields generated from chemistry and transport models. Applications include study of the radiative forcing by ozone and tracer transport near the tropopause.
Spatial variability in tropical forest leaf area density from multireturn lidar and modeling
Authors: Detto Matteo , Asner Gregory P. , Muller‐Landau Helene C. , Sonnentag Oliver 
Published: January 2015

AbstractLeaf area index and leaf area density profiles are key variables for upscaling from leaves to ecosystems yet are difficult to measure well in dense and tall forest canopies. We present a new model to estimate leaf area density profiles from discrete multireturn data derived by airborne waveform light detection and ranging (lidar), a model based on stochastic radiative transfer theory. We tested the method on simulated ray tracing data for highly clumped forest canopies, both vertically homogenous and vertically inhomogeneous. Our method was able to reproduce simulated vertical foliage profiles with small errors and predictable biases in dense canopies (leaf area index = 6) including layers below densely foliated upper canopies. As a case study, we then applied the method to real multireturn airborne lidar data for a 50 ha plot of moist tropical forest on Barro Colorado Island, Panama. The method is suitable for estimating foliage profiles in a complex tropical forest, which opens new avenues for analyses of spatial and temporal variations in foliage distributions.
Self‐consistency tests of large‐scale dynamics parameterizations for single‐column modeling
Authors: Edman Jacob P. , Romps David M. 
Published: January 2015

AbstractLarge‐scale dynamics parameterizations are tested numerically in cloud‐resolving simulations, including a new version of the weak‐pressure‐gradient approximation (WPG) introduced by Edman and Romps (2014), the weak‐temperature‐gradient approximation (WTG), and a prior implementation of WPG. We perform a series of self‐consistency tests with each large‐scale dynamics parameterization, in which we compare the result of a cloud‐resolving simulation coupled to WTG or WPG with an otherwise identical simulation with prescribed large‐scale convergence. In self‐consistency tests based on radiative‐convective equilibrium (RCE; i.e., no large‐scale convergence), we find that simulations either weakly coupled or strongly coupled to either WPG or WTG are self‐consistent, but WPG‐coupled simulations exhibit a nonmonotonic behavior as the strength of the coupling to WPG is varied. We also perform self‐consistency tests based on observed forcings from two observational campaigns: the Tropical Warm Pool International Cloud Experiment (TWP‐ICE) and the ARM Southern Great Plains (SGP) Summer 1995 IOP. In these tests, we show that the new version of WPG improves upon prior versions of WPG by eliminating a potentially troublesome gravity‐wave resonance.
Copper‐Catalyzed Cross Dehydrogenative Coupling of N,N‐Disubstituted Formamides and Phenols: A Direct Access to Carbamates
Authors: Ali Wajid , Rout Saroj K. , Guin Srimanta , Modi Anju , Banerjee Arghya , Patel Bhisma K. 
Published: January 2015

AbstractAn efficient copper‐catalyzed protocol has been developed for the synthesis of carbamates from dialkylformamides and phenols possessing directing groups such as benzothiazole, quinoline and formyl at the ortho‐position. In this chelation assisted approach, CO bond formation takes place via a cross dehydrogenative coupling (CDC) between the formyl CH of dialkylformamide and phenolic OH in the presence of copper(II)acetate/aqueous tert‐butyl hydroperoxide. Under identical reaction conditions, salicylic acid derivatives underwent amidation with the carboxylic group rather than formamidation of the phenolic OH. The use of a cheap and environmentally benign catalyst along with the tolerance of a wide range of functional groups makes this an easy, phosgene‐free route to carbamates.magnified image
Genetic modifiers of ambulation in the cooperative international Neuromuscular research group Duchenne natural history study
Authors: Bello Luca , Kesari Akanchha , Gordish‐Dressman Heather , Cnaan Avital , Morgenroth Lauren P. , Punetha Jaya , Duong Tina , Henricson Erik K. , Pegoraro Elena , McDonald Craig M. , Hoffman Eric P. ,   on behalf of the Cooperative International Neuromuscular Research Group Investigators
Published: January 2015

ObjectiveWe studied the effects of LTBP4 and SPP1 polymorphisms on age at loss of ambulation (LoA) in a multiethnic Duchenne muscular dystrophy (DMD) cohort.MethodsWe genotyped SPP1 rs28357094 and LTBP4 haplotype in 283 of 340 participants in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG‐DNHS). Median ages at LoA were compared by Kaplan–Meier analysis and log‐rank test. We controlled polymorphism analyses for concurrent effects of glucocorticoid corticosteroid (GC) treatment (time‐varying Cox regression) and for population stratification (multidimensional scaling of genome‐wide markers).ResultsHispanic and South Asian participants (n = 18, 41) lost ambulation 2.7 and 2 years earlier than Caucasian subjects (p = 0.003, <0.001). The TG/GG genotype at SPP1 rs28357094 was associated to 1.2‐year‐earlier median LoA (p = 0.048). This difference was greater (1.9 years, p = 0.038) in GC‐treated participants, whereas no difference was observed in untreated subjects. Cox regression confirmed a significant effect of SPP1 genotype in GC‐treated participants (hazard ratio = 1.61, p = 0.016). LTBP4 genotype showed a direction of association with age at LoA as previously reported, but it was not statistically significant. After controlling for population stratification, we confirmed a strong effect of LTBP4 genotype in Caucasians (2.4 years, p = 0.024). Median age at LoA with the protective LTBP4 genotype in this cohort was 15.0 years, 16.0 for those who were treated with GC.InterpretationSPP1 rs28357094 acts as a pharmacodynamic biomarker of GC response, and LTBP4 haplotype modifies age at LoA in the CINRG‐DNHS cohort. Adjustment for GC treatment and population stratification appears crucial in assessing genetic modifiers in DMD. Ann Neurol 2015;77:684–696
Eine effiziente Synthese von chiralen Allyloxyaminen durch stereospezifische Allylierung von Nitrosoarenen mit chiralen Allylboronaten
Authors: Li Yuanming , Chakrabarty Shyamal , Studer Armido 
Published: January 2015

AbstractEs wird ein neuartiger und effizienter Zugang zu Allyloxyaminen über die Allylierung von Nitrosoarenen mit α‐chiralen Allylboronaten vorgestellt. Die C‐O‐Bindungsknüpfung erfolgt mit hoher Stereospezifität, und die erhaltenen Allyloxyamine lassen sich leicht zu wertvollen chiralen Bausteinen wie Isoxazolidinen und Allylalkoholen umwandeln. Die Reaktion verläuft mit vollständiger Regioselektivität (O‐Selektivität), hoher E/Z‐Selektivität und mit exzellentem Chiralitätstransfer.
General Method for the Synthesis of Salicylic Acids from Phenols through Palladium‐Catalyzed Silanol‐Directed CH Carboxylation
Authors: Wang Yang , Gevorgyan Vladimir 
Published: January 2015

AbstractA silanol‐directed, palladium‐catalyzed CH carboxylation reaction of phenols to give salicylic acids has been developed. This method features high efficiency and selectivity, and excellent functional‐group tolerance. The generality of this method was demonstrated by the carboxylation of estrone and by the synthesis of an unsymmetrically o,o′‐disubstituted phenolic compound through two sequential CH functionalization processes.
Quadruple Switching of Pleated Foldamers of Tetrathiafulvalene–Bipyridinium Alternating Dynamic Covalent Polymers
Authors: Chen Lan , Wang Hui , Zhang Dan‐Wei , Zhou Yaming , Li Zhan‐Ting 
Published: January 2015

AbstractTwo dynamic covalent polymers P1 and P2 were prepared by alternately linking electron‐rich tetrathiafulvalene (TTF) and electron‐deficient bipyridinium (BIPY2+) through hydrazone bonds. In acetonitrile, the polymers were induced by intramolecular donor–acceptor interactions to form pleated foldamers, which unfolded upon oxidation of the TTF units to the radical cation TTF.+. Reduction of the BIPY2+ units to BIPY.+ led to the formation of another kind of pleated secondary structures, which are stabilized by intramolecular dimerization of the BIPY.+ units. The diradical dicationic cyclophane cyclobis(paraquat‐p‐phenylene) (CBPQT2(.+)) could further force the folded structures to unfold by including the BIPY.+ units of the polymers. Upon oxidation of the BIPY.+ units of the cyclophane and polymers to BIPY2+, the first folded state was regenerated. Switching or conversion between the four conformational states was confirmed by UV/Vis spectroscopic experiments.
Metal Redox Processes for the Controlled Synthesis of Metal Alloy Nanoparticles
Authors: Kirkeminde Alec , Spurlin Stan , Draxler‐Sixta Laura , Cooper Jamie , Ren Shenqiang 
Published: January 2015

AbstractNanocrystalline metals have received widespread interest and found various applications owing to their magnetic and catalytic properties and in energy‐related fields. A flexible approach for the growth of nanoalloys with controlled properties and well‐defined structures on the atomic scale is thus greatly desired. A new synthetic method that avoids incompatible reduction potentials and rates would be critical to grow metal nanostructures with high purities and the desired stoichiometries. A metal‐redox strategy that employs spontaneous oxidation/reduction reactions to grow nanocrystalline alloys using molecular‐scale zerovalent metal precursors is now described. The selection of suitable zerovalent metal species allows for thermodynamic control of the compositional stoichiometry during the temperature‐dependent formation of the metal alloy nanoparticles. A practical and scalable strategy for nanoalloy growth that can potentially produce key metal components of superior metallurgical quality for catalytic and magnetic systems has thus been developed.
Thermal and mechanical properties of PA12/C30B nanocomposites in relationship with nanostructure
Authors: Hassan Hanaya , Aït Hocine Nourredine , Médéric Pascal , Deffarges Marie‐Pierre , Poirot Nathalie 
Published: January 2015

ABSTRACTThis work focuses on the effect of nanoclay mass fraction on the properties of polyamide 12 matrix. Relationships between mechanical, thermal, and structural properties of polyamide 12/Cloisite® 30B nanocomposites were studied. The material structure, previously described from XRD and TEM experiments, was more thoroughly characterized in the present work using SEM and FTIR techniques. The FTIR results clearly showed that clay galleries are intercalated by PA chains, which leads to a partially exfoliated nanostructure, confirming the TEM observations and the XRD analysis. However, a few micrometric aggregates are evidenced by SEM analysis, particularly at high clay fractions. TGA and DTA measurements showed that the thermal stability of PA12 matrix is slightly modified by the Cloisite® 30B content. Viscoelastic properties of the nanocomposites in solid‐state were analyzed as functions of strain, frequency, and temperature. The extent of the linear response regime of the material is shown to be sensitive to the amount of clay: nonlinearities appear at lower strain values as the clay mass fraction increases. Both relative dynamical moduli also increase with increasing clay mass fraction, with frequency dependence for the viscous modulus and without frequency dependence for the elastic modulus. Finally, similarities have been pointed out between viscoelastic properties of the nanocomposites in solid and melt states. For example, the percolation threshold is highlighted at the same clay mass fraction, ∼2%, in both states. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41938.
Mono‐ and bifunctional six‐membered cyclic carbonates synthesized by diphenyl carbonate toward networked polycarbonate films
Authors: Matsukizono Hiroyuki , Endo Takeshi 
Published: January 2015

ABSTRACTThe synthesis of six‐membered cyclic carbonates from diols utilizing less toxic and easily‐handled diphenyl carbonate (DPC) is carried out based on the reactivity and selectivity at different conditions. Commercially‐available neopentylglycol (NPG) or di(trimethylolproapane) (DTMP) react effectively with DPC at 140°C and converted to their corresponding monofunctional NPG‐carbonate (NPGC) or bifunctional DTMPC‐carboante (DTMPC), respectively. The selectivity of these carbonates changes depending on a feed ratio of DPC and these diols. After a NPG/DPC mixture with the DPC/NPG feed ratio of 4 was heated at 140°C for 48 h, the NPGC is isolated with a yield of 74%. A 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU)‐catalyzed ring‐opening polymerization (ROP) of NPGC with DTMPC can form effectively networked structures. By only drying of THF solutions containing NPGC, DTMPC, and a catalytic amount of DBU at 60°C for 12 h, the ROP efficiently proceeds and networked polycarbonate films with well transparency and flexibility are easily obtained. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41956.
Control of thermal degradation of poly(lactic acid) using functional polysilsesquioxane microspheres as chain extenders
Authors: Han Ting , Xin Zhong , Shi Yaoqi , Zhao Shicheng , Meng Xin , Xu Hui , Zhou Shuai 
Published: January 2015

ABSTRACTTwo functional polysilsesquioxane microspheres, poly(epoxypropoxy)silsesquioxane (PESQ) and poly(epoxypropoxy/amino)silsesquioxane (PEASQ), were grafted onto commercial polylactic acid (PLA) via functional group reactions through melt processing and directly used as novel chain extenders to improve the thermal stability of PLA. During the whole reaction time of 35 min, the torques of P‐2PESQ and P‐1PEASQ were 60% higher than that of processed PLA. Thermal gravimetric analysis (TGA) revealed that the addition of PESQ or PEASQ into PLA increased the onset temperature for thermal degradation. PEASQ was found to be a potential chain extender for PLA. Compared with the processed PLA, the thermal decomposition temperatures of PEASQ modified PLA increased from 318 to 334°C at 5% weight loss. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41977.
Breathing in a box: Constraints on lung ventilation in giant pterosaurs
Authors: Geist Nicholas R. , Hillenius Willem J. , Frey Eberhard , Jones Terry D. , Elgin Ross A. 
Published: January 2015

ABSTRACTPterosaurs were the first vertebrates to achieve active flight, with some derived forms reaching enormous size. Accumulating fossil evidence confirms earlier indications that selection for large size in these flying forms resulted in a light, yet strong skeleton characterized by fusion of many bones of the trunk. However, this process also added mechanical constraints on the mobility of the thorax of large pterosaurs that likely limited the options available for lung ventilation. We present an alternative hypothesis to recent suggestions of an avian‐like mechanism of costosternal pumping as the primary means of aspiration. An analysis of the joints among the vertebrae, ribs, sternum, and pectoral girdle of large pterosaurs indicates limited mobility of the ribcage and sternum. Comparisons with modes of lung ventilation in extant amniotes suggests that the stiffened thorax, coupled with mobile gastralia and prepubic bones, may be most consistent with an extracostal mechanism for lung ventilation in large pterodactyloids, perhaps similar to a crocodile‐like visceral displacement system Anat Rec, 297:2233–2253, 2014. © 2013 Wiley Periodicals, Inc.
ZnCr Layered Double Hydroxide (LDH) Nanosheets Assisted Formation of Hierarchical Flower‐Like CdZnS@LDH Microstructures with Improved Visible‐Light‐Driven H2 Production
Authors: Yao Lihua , Wei Ding , Yan Dongpeng , Hu Changwen 
Published: January 2015

AbstractThe development of new semiconductor photocatalysts toward splitting water has supplied a promising way to obtain sustainable and clean hydrogen energy. Herein, CdZnS@layered double hydroxide (LDH) composites with a hierarchical flower‐like microstructure have been fabricated with the aid of ZnCr–LDH nanosheets as templates. XRD, SEM and HRTEM show that the ZnCr–LDH nanosheets are uniformly dispersed within the composites. The surface of the hierarchical structures is rough and composed of numerous nanocrystals of CdZnS. The HRTEM images indicate that the surface of CdZnS nanocrystals is mainly composed of the (111) plane. Moreover, the visible‐light‐driven H2 production performance of the CdZnS in the presence and absence of ZnCr–LDH nanosheets has been measured. The results show that ZnCr–LDH nanosheets play an important role in the hierarchical morphology and photocatalytic activity of the as‐prepared samples. In the water‐splitting process, the visible‐light‐driven H2‐production rate of hierarchical flower‐like CdZnS@LDH is 4.03 times and nearly 10 times higher than that of pristine CdZnS microsphere and pure commercial CdS, respectively. Therefore, this work not only achieves enhanced catalytic performance of the CdZnS by the introduction of ZnCr–LDH nanosheets, but also supplies an insight into the relationship between the hierarchical morphology and the semiconductor photocatalytic activity.
Controllability of Stochastic Delay Systems with Impulse in a Separable Hilbert Space
Authors: Guo Yingxin , Xu Chao 
Published: January 2015

AbstractIn this paper, we study the controllability of a kind of nonlinear stochastic impulsive system with infinite delay in abstract space. Sufficient conditions for the controllability are obtained via the generalization of the contraction mapping principle and with none of the compactness condition restriction on the evolution family of operators for the system. Finally, a numerical example is given to illustrate the effectiveness of our results.
Asymptotical Synchronization of Coupled Nonlinear Partial Differential Systems With Impulsive Effects
Authors: Wu Kai‐Ning , Zhu Ya‐Nan , Chen Bor‐Sen , Yao Yu 
Published: January 2015

AbstractThis paper considers the asymptotical synchronization of coupled nonlinear impulsive partial differential systems (PDSs) in complex networks. The cases of both complex networks with fixed topology and switching topology are studied. Based on the Lyapunov–Krasoviskii functional method, sufficient conditions are presented to guarantee the asymptotical synchronization of nonlinear impulsive PDSs, under the cases of fixed topology or switching topology. The effect of the spatial domain is exhibited in these sufficient conditions. Moreover, these sufficient conditions provide a method for selecting a suitable impulsive strategy for the coupled PDSs to achieve the asymptotical synchronization. Finally, numerical examples are given to illustrate the correctness.
Simple Tuning Rules for Integrating Processes with Large Time Delay
Authors: Ajmeri Moina , Ali Ahmad 
Published: January 2015

AbstractIn the present article, controllers of the modified Smith predictor are designed for pure integrating, integrating plus first order and double integrating processes with large time delays. The direct synthesis approach is used to tune the set point tracking controller. Suitable values of the desired closed loop time constant that satisfies both robust stability and robust performance conditions are provided based on extensive simulation studies. The PD controller, which is used for load disturbance rejection, is designed so as to achieve a specified slope (ψ) of the Nyquist curve at the gain crossover frequency. The gain crossover frequency that corresponds to a phase margin of 45 degrees is suggested for all three considered integrating processes. Furthermore, ψ is recommended as 45 degrees for double integrating processes and 90 degrees for pure integrating and integrating plus first order process models. Two simulation examples are considered to illustrate the usefulness of the proposed tuning rules.
Luminescence and energy transfer in Ce3+, Mn2+‐doped K2AEP2O7 (AE = Ca, Sr) phosphor
Authors: Hatwar L. R. , Wankhede S. P. , Moharil S. V. , Muthal P. L. , Dhopte S. M. 
Published: January 2015

AbstractPyrophosphates K2AEP2O7 (AE = Ca, Sr) prepared by the classical solid‐state technique and activated with Ce3+ are described. Intense emission was observed in K2AEP2O7 (AE = Ca, Sr). The effect of Mn2+ co‐doping was studied. The broad emission peak of Mn2+ was observed at 534 nm in K2SrP2O7:Ce3+ and at 539 nm in K2CaP2O7:Ce3+, Mn2+. Mn2+ emission was greatly enhanced by addition of the sensitizer Ce3+ due to efficient energy transfer from Ce3+ to Mn2+. Copyright © 2015 John Wiley & Sons, Ltd.
Determination of manganese‐ and manganese‐containing fungicides with lucigenin–Tween‐20‐enhanced chemiluminescence detection
Authors: Yaqoob Mohammad , Asghar Mohammad , Nabi Abdul 
Published: January 2015

AbstractA flow‐injection (FI) method is reported for the determination of Mn(II), maneb and mancozeb fungicides based on the catalytic effect of Mn(II) on the oxidation of lucigenin and dissolved oxygen in a basic solution. The Tween‐20 surfactant has been reported for first time to enhance lucigenin chemiluminescence (CL) intensity in the presence of Mn(II) (53%) and maneb and mancozeb (89%). The calibration graphs were linear in the concentration range of 0.001–1.5 mg L–1 (R2 = 0.9982 (n = 11) with a limit of detection (S/N = 3) of 0.1 µg L–1 for Mn(II) and 0.01–3.0 mg L–1 [R2 = 0.9989 and R2 = 0.9992 (n = 6)] with a limit of detection (S/N =3) of 1.0 µg L–1 for maneb and mancozeb respectively. Injection throughputs of 90 and 120 h–1 for Mn(II) and maneb and mancozeb respectively, and relative standard deviations of 1.0–3.4% were obtained in the concentration range studied. The experimental variables, e.g., reagents concentrations, flow rates, sample volume, and photomultiplier tube voltage, were optimized and potential interferences were investigated. The analysis of Mn(II) in river water reference materials (SLRS‐4 and SLRS‐5) showed good agreement with the certified values incorporating an on‐line 8‐hydroxyquinoline chelating column in the manifold for removing interfering metal ions. Recoveries for maneb and mancozeb were in the range of 92 ± 5 to 104 ± 3% and 91 ± 2 to 100 ± 4% (n = 3) respectively. The effect of 30 other pesticides (fungicides, herbicides and insecticides) was also examined in the lucigenin–Tween‐20 CL system. Copyright © 2015 John Wiley & Sons, Ltd.