bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of ridges in a stable lithosphere in mantle convection models with a viscoplastic rheology
Authors: Rozel A. , Golabek G. J. , Näf R. , Tackley P. J. 
Published: May 2015

AbstractNumerical simulations of mantle convection with a viscoplastic rheology usually display mobile, episodic or stagnant lid regimes. In this study, we report a new convective regime in which a ridge can form without destabilizing the surrounding lithosphere or forming subduction zones. Using simulations in 2‐D spherical annulus geometry, we show that a depth‐dependent yield stress is sufficient to reach this ridge only regime. This regime occurs when the friction coefficient is close to the critical value between mobile lid and stagnant lid regimes. Maps of convective regime as a function of the parameters friction coefficients and depth dependence of viscosity are provided for both basal heating and mixed heating situations. The ridge only regime appears for both pure basal heating and mixed heating mode. For basal heating, this regime can occur for all vertical viscosity contrasts, while for mixed heating, a highly viscous deep mantle is required.
Investigating uncertainties in empirical Green's function analysis of earthquake source parameters
Authors: Abercrombie Rachel E. 
Published: May 2015

AbstractI use a well‐recorded earthquake sequence to investigate the uncertainties of earthquake stress drops calculated using an empirical Green's function (EGF) approach. The earthquakes in the largest (M ~ 2.1) repeating sequence targeted by the San Andreas Observatory at Depth (SAFOD), Parkfield, California, are recorded by multiple borehole stations and have simple sources, well‐constrained stress drops, and abundant smaller earthquakes to use as EGFs. I perform three tests to estimate quantitatively the likely uncertainties to arise in less optimal settings. I use EGF earthquakes with a range of cross‐correlation values and separation distances from the main earthquakes. The stress drop measurements decrease by a factor of 3 as the quality of the EGF assumption decreases; a good EGF must be located within approximately one source dimension of the large earthquake, with high cross correlation. I subsample the large number of measurements for the main earthquakes to investigate the expected stress drop uncertainties in studies where fewer stations or EGFs are available. If only one measurement is available, the uncertainties are likely to be at least 50%. The uncertainties decrease to <20% with five or more measurements; using multiple EGFs is a good alternative to multiple stations. To investigate the effects of limited frequency bandwidth, I recalculate the corner frequencies after progressively decimating the sample rate. Decreasing the high‐frequency limit of the bandwidth decreases the estimate of the corner frequency (and stress drop). The corner frequency may be underestimated if it is within a factor of 3 of the maximum frequency of the signal.
Climate change signal and uncertainty inCMIP5‐based projections of global ocean surface wave heights
Authors: Wang Xiaolan L. , Feng Yang , Swail Val R. 
Published: May 2015

AbstractThis study uses the analysis of variance approaches to quantify the climate change signal and uncertainty in multimodel ensembles of statistical simulations of significant wave height (Hs), which are based on the CMIP5 historical, RCP4.5 and RCP8.5 forcing scenario simulations of sea level pressure. Here the signal of climate change refers to the temporal variations caused by the prescribed forcing. “Significant” means “significantly different from zero at 5% level.” In a four‐model ensemble ofHssimulations, the common signal—the signal that is simulated in all the four models—is found to strengthen over time. For the historical followed by RCP8.5 scenario, the common signal in annual meanHsis found to be significant in 16.6% and 82.2% of the area by year 2005 and 2099, respectively. The global average of the variance proportion of the common signal increases from 0.75% in year 2005 to 12.0% by year 2099. The signal is strongest in the eastern tropical Pacific (ETP), featuring significant increases in both the annual mean and maximum ofHsin this region. The climate model uncertainty (i.e., intermodel variability) is significant nearly globally; its magnitude is comparable to or greater than that of the common signal in most areas, except in the ETP where the signal is much larger. In a 20‐model ensemble ofHssimulations for the period 2006–2099, the model uncertainty is found to be significant globally; it is about 10 times as large as the variability between the RCP4.5 and RCP8.5 scenarios.
Changes in dissolved organic carbon and total dissolved nitrogen fluxes across subtropical forest ecosystems at different successional stages
Authors: Yan Junhua , Li Kun , Wang Wantong , Zhang Deqiang , Zhou Guoyi 
Published: May 2015

AbstractLateral transports of carbon and nitrogen are important processes linking terrestrial ecosystems and aquatic systems. Most previous studies made in temperate forests found that fluxes of carbon and nitrogen by runoff water varied in different forests, but few studies have been made in subtropical forests. This study was to investigate dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) fluxes at the catchment scale along a subtropical forest succession gradient from pine forest (pioneer) to coniferous and broadleaved mixed forest (transitional) to broadleaved forest (mature). Our results showed that DOC concentration significantly decreased (p<0.001) while TDN concentration significantly increased (p<0.001) in runoff water from pioneer to mature forests, which in turn resulted in a decrease in DOC flux and an increase in TDN flux, as mean annual runoff did not vary significantly among three succession forest catchments. The mean (±standard deviation) annual DOC flux was 118.1±43.6, 88.3±16.7 and 77.2±11.7 kg ha−1 yr−1for pioneer, transitional and mature forest catchments, respectively; and the mean annual TDN flux was 9.9 ±2.7, 18.2±3.0 and 21.2 ±4.5 kg ha−1 yr−1for pioneer, transitional and mature forest catchments, respectively. The mature forest reduced DOC flux by increased soil chemical adsorption and physical protection. An increase in TDN flux from pioneer to mature forests was consistent with the previous finding that mature forest was nitrogen saturated while pioneer forest was nitrogen limited. Therefore large‐scale conversion of pioneer forests to transitional or mature forests in subtropical China will reduce DOC concentration and increase TDN concentration in the down‐stream water, which may have significant impact on its water quality and aquatic biological activities.
Short‐Term Power Generation Scheduling via Robust Optimization
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Authors: Zhao Chaoyue , Chen Yonghong , Guan Yongpei , Wang Qianfan , Wang Xing 
Published: May 2015

Abstract
Recently, the portion of renewable energy in power supply has been increasing dramatically. Meanwhile, renewable energy's intermittent nature brings challenges for power system operations, in particular for short‐term power generation scheduling. Recently developed robust optimization approaches can help reliability unit commitment runs at ISOs to maintain system reliability. In this article, we review selected recent studies, mainly the ones co‐authored by one of the authors for this article, on exploring robust optimization models and solution approaches to solve reliability unit commitment problems at ISOs.
A cooperative formation‐based collision avoidance approach for a group of autonomous vehicles
Authors: Yang Aolei , Naeem Wasif , Fei Minrui , Tu Xiaowei 
Published: May 2015

SummaryThis paper employs a unique decentralised cooperative control method to realise a formation‐based collision avoidance strategy for a group of autonomous vehicles. In this approach, the vehicles' role in the formation and their alert and danger areas are first defined, and the formation‐based intra‐group and external collision avoidance methods are then proposed to translate the collision avoidance problem into the formation stability problem. The extension–decomposition–aggregation formation control method is next employed to stabilise the original and modified formations, whilst manoeuvring, and subsequently solve their collision avoidance problem indirectly. Simulation study verifies the feasibility and effectiveness of the intra‐group and external collision avoidance strategy. It is demonstrated that both formation control and collision avoidance problems can be simultaneously solved if the stability of the expanded formation including external obstacles can be satisfied. Copyright © 2015 John Wiley & Sons, Ltd.
Sinusoidal disturbance rejection in chaotic planar oscillators
Authors: Menini Laura , Possieri Corrado , Tornambè Antonio 
Published: May 2015

SummaryThe main goal of this paper is to design a compensator able to restore the nominal behavior of a planar system, which is rendered chaotic by an unmeasurable sinusoidal disturbance input. To reach such a goal, some instruments, taken from algebraic geometry, are used to estimate the unmeasurable disturbance from the time derivatives of the output of the system and of the control input. Copyright © 2015 John Wiley & Sons, Ltd.
State estimation and data fusion for multirate sensor networks
Authors: Yan Liping , Jiang Lu , Xia Yuanqing , Fu Mengyin 
Published: May 2015

SummaryThis article is concerned with state estimation and data fusion of a linear dynamic system observed by multirate sensors in the environment of wireless sensor networks. The sampling, estimation, and transmission rates in the wireless sensor networks are different. We derive the optimal linear estimation in the centralized, sequential, and distributed forms. A numerical example is given to show the feasibility and effectiveness of the proposed algorithms. Copyright © 2015 John Wiley & Sons, Ltd.
Artificial Metalloenzymes in Asymmetric Catalysis: Key Developments and Future Directions
Authors: Pàmies Oscar , Diéguez Montserrat , Bäckvall Jan‐E. 
Published: May 2015

AbstractArtificial metalloenzymes combine the excellent selective recognition/binding properties of enzymes with transition metal catalysts, and therefore many asymmetric transformations can benefit from these entities. The search for new successful strategies in the construction of metal‐enzyme hybrid catalysts has therefore become a very active area of research. This review discusses all the developed strategies and the latest advances in the synthesis and application in asymmetric catalysis of artificial metalloenzymes with future directions for their design, synthesis and application (Sections 2–4). Finally, advice is presented (to the non‐specialist) on how to prepare and use artificial metalloenzymes (Section 5).magnified image
The First Introduction of Graphene to Rechargeable Li–CO2 Batteries
Authors: Zhang Zhang , Zhang Qiang , Chen Yanan , Bao Jie , Zhou Xianlong , Xie Zhaojun , Wei Jinping , Zhou Zhen 
Published: May 2015

AbstractThe utilization of the greenhouse gas CO2 in energy‐storage systems is highly desirable. It is now shown that the introduction of graphene as a cathode material significantly improves the performance of Li–CO2 batteries. Such batteries display a superior discharge capacity and enhanced cycle stability. Therefore, graphene can act as an efficient cathode in Li–CO2 batteries, and it provides a novel approach for simultaneously capturing CO2 and storing energy.
Sigillin A, eine einzigartige polychlorierte Wehrsubstanz gegen Arthropoden aus dem Schneefloh Ceratophysella sigillata
Authors: Schmidt Witali , Schulze Thies M. , Brasse Gregor , Nagrodzka Edyta , Maczka Michael , Zettel Jürg , Jones Peter G. , Grunenberg Jörg , Hilker Monika , Trauer‐Kizilelma Ute , Braun Ute , Schulz Stefan 
Published: May 2015

AbstractDer winteraktive Springschwanz Ceratophysella sigillata produziert einzigartige polychlorierte Octahydroisocumarine um Fressfeinde abzuschrecken. Die Struktur der Hauptverbindung Sigillin A wurde durch Isolierung, spektroskopische Untersuchungen und Röntgenstrukturanalyse aufgeklärt. Sigillin A zeigte in einem Biotest mit räuberischen Ameisen eine hohe abschreckende Wirkung. Ein vielversprechender Syntheseansatz für diese neue Klasse von Naturstoffen wurde entwickelt.
A Universal Strategy for Aptamer‐Based Nanopore Sensing through Host–Guest Interactions inside α‐Hemolysin
Authors: Li Ting , Liu Lei , Li Yuru , Xie Jiani , Wu Hai‐Chen 
Published: May 2015

AbstractNanopore emerged as a powerful single‐molecule technique over the past two decades, and has shown applications in the stochastic sensing and biophysical studies of individual molecules. Here, we report a versatile strategy for nanopore sensing by employing the combination of aptamers and host–guest interactions. An aptamer is first hybridized with a DNA probe which is modified with a ferrocene⊂cucurbit[7]uril complex. The presence of analytes causes the aptamer–probe duplex to unwind and release the DNA probe which can quantitatively produce signature current events when translocated through an α‐hemolysin nanopore. The integrated use of magnetic beads can further lower the detection limit by approximately two to three orders of magnitude. Because aptamers have shown robust binding affinities with a wide variety of target molecules, our proposed strategy should be universally applicable for sensing different types of analytes with nanopore sensors.
Copper‐Promoted Sandmeyer Difluoromethylthiolation of Aryl and Heteroaryl Diazonium Salts
Authors: Wu Jiang , Gu Yang , Leng Xuebing , Shen Qilong 
Published: May 2015

AbstractAn efficient copper‐promoted difluoromethylthiolation of aryl and heteroaryl diazonium salts is described. The reaction is conducted under mild reaction conditions and various functional groups were compatible. In addition, reactions of heteroaryl diazonium salts such as pyridyl, quinolinyl, benzothiazolyl, thiophenyl, carbazolyl, and pyrazolyl diazonium salts occurred smoothly to afford the medicinally important difluoromethylthiolated heteroarenes. Furthermore, a more practical one‐pot direct diazotization and difluoromethylthiolation protocol was developed, and it converts the aniline derivatives into difluoromethylthiolated arenes. The utility of the method is demonstrated by difluoromethylthiolation of a number of natural products and drug molecules.
Sigillin A, a Unique Polychlorinated Arthropod Deterrent from the Snow Flea Ceratophysella sigillata
Authors: Schmidt Witali , Schulze Thies M. , Brasse Gregor , Nagrodzka Edyta , Maczka Michael , Zettel Jürg , Jones Peter G. , Grunenberg Jörg , Hilker Monika , Trauer‐Kizilelma Ute , Braun Ute , Schulz Stefan 
Published: May 2015

AbstractThe snow flea Ceratophysella sigillata, a winter‐active species of springtail, produces unique polychlorinated octahydroisocoumarins to repel predators. The structure of the major compound, sigillin A, was elucidated through isolation, spectroscopic analysis, and X‐ray crystallography. Sigillin A showed high repellent activity in a bioassay with predatory ants. A promising approach for the total synthesis of members of this new class of natural compounds was also developed.
Preparation and characterization of a type of ladder‐like poly(phenyl silsesquioxane) based hybrid star‐shaped copolymer of ε‐caprolactone
Authors: Yang Xiongfa , Cao Cheng , Chen Zhonghong , Liu Jia , Bassindale Alan R. , Lai Guoqiao 
Published: May 2015

ABSTRACTCombination of the organic–inorganic hybrid such as silsesquioxane with ε‐caprolactone will lead to materials expected to be environmentally friendly and applicable to biomedical usages. A ladder‐like poly(phenyl silsesquioxane) based hybrid star‐shaped copolymer of ε‐caprolactone was prepared by ring opening polymerization of ε‐caprolactone catalyzed by Sn(Oct)2 with hydroxyl terminated ladder‐like poly(phenyl silsesquioxane) as initiator. The copolymers were characterized by proton nuclear magnetic resonance (1H‐NMR), silicon nuclear magnetic resonance (29Si‐NMR), Fourier‐transform infrared spectrometer (FT‐IR), size exclusion chromatography (SEC), thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC) in detail. Furthermore, the enzymatic degradation property of the copolymers was also investigated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42335.
PEGylation of MnO nanoparticles via catechol–Mn chelation to improving T1‐weighted magnetic resonance imaging application
Authors: Huang Haitao , Yue Tao , Xu Yanyun , Xu Ke , Xu Haibo , Liu Shiyuan , Yu Jiahui , Huang Jin 
Published: May 2015

ABSTRACTTo enhance biocompatibility and physiological stability of hydrophobic MnO nanoparticles as contrast agent of T1‐weighted magnetic resonance imaging (MRI), dopamine‐functionalized poly(ethylene glycol) (PEG) was used to coat the surface of about 5 nm MnO nanoparticles. Although hydrophilic coating might decrease longitudinal relaxivity due to inhibiting the intimate contact between manganese of nanoparticle surface and proton in water molecules, higher longitudinal relaxivity was still maintained by manipulating the PEGylation degree of MnO nanoparticles. Moreover, in vivo MRI demonstrated considerable signal enhancement in liver and kidney using PEGylated MnO nanoparticles. Interestedly, the PEGylation induced the formation of about 120 nm clusters with high stability in storing and physiological conditions, indicating passive targeting potential to tumor and prolonged circulation in blood. In addition, the cytotoxicity of PEGylated MnO nanoparticles also proved negligible. Consequently, the convenient PEGylation strategy toward MnO nanoparticles could not only realize a good “trade‐off” between hydrophilic modification and high longitudinal relaxivity but also contribute additional advantages, such as passive targeting to tumor and long blood circulation, to MRI diagnosis of tumor. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42360.
A highly selective polybenzimidazole‐4,4′‐(hexafluoroisopropylidene)bis(benzoic acid) membrane for high‐temperature hydrogen separation
Authors: Choi Sun Hee , Kim Da Hye , Kim Do Young , Han Jun Young , Yoon Chang Won , Ham Hyung Chul , Kim Jin‐Ho , Kim Hyoung‐Juhn , Nam Suk Woo , Lim Tae‐Hoon , Han Jonghee 
Published: May 2015

ABSTRACTA polymeric gas separation membrane utilizing polybenzimidazole based on 4,4′‐(hexafluoroisopropylidene)bis(benzoic acid) was prepared. The synthesized membrane has an effective permeating area of 8.3 cm2and a thickness of 30 ± 2 µm. Gas permeation properties of the membrane were determined using H2, CO2, CO, and N2at temperatures ranging from 24°C to 200°C. The PBI‐HFA membranes not only exhibited excellent H2permeability, but it also displayed superior gas separation performance particularly for H2/N2and H2/CO2. The permeation parameters for both permeability and selectivity [and α(H2/N2);and α(H2/CO2)] obtained for the new material were found to be dependent on trans‐membrane pressure difference as well as temperature, and were found to surpass those reported by Robeson in 2008. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42371.
Effects of shell crosslinking on polyurea microcapsules containing a free‐radical initiator
Authors: McFarland Brian , Pojman John A. 
Published: May 2015

ABSTRACTMicroencapsulation of a material is often used when a controlled release of a substance is desired. This study examines the effects of crosslinking in polyurea microcapsule shells on stability of microcapsules containing the free‐radical initiator cumene hydroperoxide (CHP). Crosslinking of polyurea shells was varied by using amine monomers containing different amine functionalities, and/or changing the isocyanate/primary amine ratio. Thermogravimetric analysis was performed to determine thermal properties of these microcapsules, and the pot lives of monomer systems containing these microcapsules were measured. Thermal stability is greater with a moderate degree of crosslinking from a trifunctional amine, and decreases when crosslinking is increased through use of higher amine functionality. Stability in monomer media generally increases with increased crosslinking through higher amine functionality, but is less predictable due to crosslinks formed between capsules. Generally, increasing crosslinking through altering the isocyanate to primary amine ratio decreases capsule stability in both dry and monomer storage. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42408.
2D Inorganic–Antimalarial Drug–Polymer Hybrid with pH‐Responsive Solubility
Authors: Kim Ji‐Yeong , Yang Jae‐Hun , Lee Ji‐Hee , Choi Goeun , Park Dae‐Hwan , Jo Mi‐Rea , Choi Soo‐Jin , Choy Jin‐Ho 
Published: May 2015

AbstractArtesunic acid (ASH), an antimalarial drug, has low oral bioavailability due to its low aqueous solubility. To overcome this problem, artesunate (AS) was intercalated into zinc basic salt (ZBS) via co‐precipitation. AS was immobilized with a tilted double layer arrangement, which was also confirmed by XRD and 1‐D electron density mapping. In order to decrease the release rate of AS under gastrointestinal conditions and to simultaneously increase the release rate of AS under intestinal conditions, ZBS‐AS was coated with EUDRAGIT L100 (ZBS‐AS‐L100). Finally, we performed an in‐vivo pharmacokinetic study to compare the oral bioavailability of AS of ZBS‐AS‐L100 with that of ASH. Surprisingly, it was found that the former is 5.5 times greater than the latter due to an enhanced solubility of AS thanks to the ternary hybridization with ZBS and EUDRAGIT L100. Therefore, the present ZBS‐AS‐L100 system has a great potential as a novel antimalarial drug formulation with pH selectivity and enhanced bioavailability.
Simultaneous Perturbation Stochastic Approximation with Norm‐Limited Update Vector
Authors: Tanaka Yosuke , Azuma Shun‐ichi , Sugie Toshiharu 
Published: May 2015

AbstractThis paper addresses the convergence of simultaneous perturbation stochastic approximation (SPSA) with a norm‐limited update vector. We first illustrate an unstable solution of the standard SPSA algorithm which motivates the consideration of a modified version, where the norm of the update vector is limited to a certain value. Next, a result on the almost‐sure convergence is presented by reducing the modified algorithm into the standard SPSA algorithm and restricting the probability distribution for the perturbation to a Bernoulli distribution. Finally, we apply the modified algorithm to a system identification problem to demonstrate its performance.
A model for the layout of bike stations in public bike‐sharing systems
Authors: Chen Qun , Sun Tingyuan 
Published: May 2015

SummaryThe problem of designing a layout of bike stations for public bike‐sharing systems entails selecting a number of stations and then constructing them within a planning area having many bike traffic zones and candidate bike stations. In this paper, we proposed a mathematical model to formulate the layout of public bike stations with the objective of minimizing users' total travel time and investment budget constraints. The model can guarantee that the needs for picking up and dropping off bikes amidst all bike travel demands are satisfied. Using this model, the number and locations of bike stations and the number of bikes and parking lockers at each bike station can be simultaneously determined. A typical example solved by lingo solver is created to illustrate the proposed model. Copyright © 2015 John Wiley & Sons, Ltd.