bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monomers from CO2: Superbases as Catalysts for Formate‐to‐Oxalate Coupling
Authors: Schuler Eric , Ermolich Pavel A. , Shiju N. Raveendran , Gruter Gert‐Jan M. 
Published: January 2021

AbstractAn interesting contribution to solving the climate crisis involves the use of CO2 as a feedstock for monomers to produce sustainable plastics. In the European Horizon 2020 project “OCEAN” a continuous multistep process from CO2 to oxalic acid and derivatives is developed, starting with the electrochemical reduction of CO2 to potassium formate. The subsequent formate‐to‐oxalate coupling is a reaction that has been studied and commercially used for over 150 years. With the introduction of superbases as catalysts under moisture‐free conditions unprecedented improvements were shown for the formate coupling reaction. With isotopic labelling experiments the presence of carbonite as an intermediate was proven during the reaction, and with a unique operando set‐up the kinetics were studied. Ultimately, the required reaction temperature could be dropped from 400 to below 200 °C, and the reaction time could be reduced from 10 to 1 min whilst achieving 99 % oxalate yield.
Efficient Sulfur Host Based on Yolk‐Shell Iron Oxide/Sulfide‐Carbon Nanospindles for Lithium‐Sulfur Batteries
Authors: Xie Dongjiu , Mei Shilin , Xu Yaolin , Quan Ting , Härk Eneli , Kochovski Zdravko , Lu Yan 
Published: January 2021

AbstractNumerous nanostructured materials have been reported as efficient sulfur hosts to suppress the problematic “shuttling” of lithium polysulfides (LiPSs) in lithium‐sulfur (Li−S) batteries. However, direct comparison of these materials in their efficiency of suppressing LiPSs shuttling is challenging, owing to the structural and morphological differences between individual materials. This study introduces a simple route to synthesize a series of sulfur host materials with the same yolk‐shell nanospindle morphology but tunable compositions (Fe3O4, FeS, or FeS2), which allows for a systematic investigation into the specific effect of chemical composition on the electrochemical performances of Li−S batteries. Among them, the S/FeS2−C electrode exhibits the best performance and delivers an initial capacity of 877.6 mAh g−1 at 0.5 C with a retention ratio of 86.7 % after 350 cycles. This approach can also be extended to the optimization of materials for other functionalities and applications.
Cold electrons acceleration in TNSA laser‐generated plasma using a low‐contrast fs laser
Authors: Torrisi L. , Cutroneo M. , Torrisi A. 
Published: January 2021

AbstractThe fs laser facility in Bordeaux, delivering an intensity of 1018 W/cm2 at normal incidence on thin foils, has been used to induce forward electron and ion acceleration in target‐normal‐sheath‐acceleration (TNSA) regime. Micrometric thin foils with different composition, thickness, and electron density, were prepared to promote the charge particle acceleration in the forward direction. The plasma electron and ion emission monitoring were performed on‐line using SiC semiconductor detectors in time‐of‐flight (TOF) configuration and gaf‐chromics films both covered by thin absorber filters. The experiment has permitted to accelerate electrons and protons. A special attention was placed to detect relativistic hot electrons escaping from the plasma and cold electrons returning to the target position. The electron energies of the order of 100 keV and of about 1 keV were detected as representative of hot and cold electrons, respectively. A high cold electron contribution was measured using low‐contrast fs laser, while it is less evident using high‐contrast fs lasers. The charge particle acceleration depends on the laser parameters, irradiation conditions, and target properties, as will be presented and discussed.
Small amplitude dust‐acoustic soliton energy in dusty plasmas with suprathermal polarization force
Authors: Mayout Saliha , Benzekka Moufida , Amour Rabia 
Published: January 2021

AbstractThe effect of suprathermal polarization force on both linear and weakly nonlinear dust‐acoustic solitary structures in a three‐component dusty plasma is investigated. For this purpose, a new expression of the polarization force acting on dust particles that include the electronic suprathermal effect is derived. The results are applied to two different experimental dusty plasmas. We have found that the polarization force acting on the dust grains decreases as the electron suprathermality becomes more significant. In addition, we have shown that, for a given value of the spectral index κ, the polarization force magnitude fluctuates from one plasma to another. The changes arising in the propagation of small‐amplitude dust‐acoustic (DA) solitons due to the presence of this suprathermal polarization force are also analysed. Interestingly, an increase in the magnitude of the polarization force leads to an increase in the amplitude and width of DA soliton and provides more energy to the motion of this soliton.
Excitation of kinetic Alfvén waves by streaming ions in a dusty magnetoplasma with generalized (r, q) distribution function
Authors: Rubab Nazish , Riaz Farrukh , Zaheer Sadia , Noreen Naila , Shah Hassan A. 
Published: January 2021

AbstractWe investigate the parallel streaming effects on the dispersion characteristics of a kinetic Alfvén wave (KAW) in a low β dusty magnetoplasma. To analyse the influence of streaming ions obeying generalized (r, q) distribution function, hot and magnetized electrons, and mobile charged dust, a theoretical approach has been used for the instability analysis by employing two potential theories. A linear kinetic dispersion relation of Alfvén waves is derived, whose solutions are used to interpret the numerical and analytical results. The solutions of dispersion relation indicate that the characteristics of KAWs are transformed when generalized (r, q) distribution function is employed instead of its Maxwellian counterpart. We also found that the unstable modes have a strong dependence on spectral indices r and q, dust parameters, and plasma β. For the excitation of KAWs, the streaming velocity has been observed to be within the sub‐Alfvén range, whereas when it extends to the super‐Alfvén range, the growth rates are significantly suppressed. The observations further show that an ambient magnetic field and superthermal particles inhibit the growth of an electromagnetic wave to a significant degree and have a stabilizing effect on the wave mode, whereas an increasing concentration of low‐energy particles contributes to enhancing growth rates.
A pharmacokinetic study of morphine‐6‐O‐sulfate in rat plasma and brain
Authors: Yadlapalli Jai Shankar K. , Albayati Zaineb A. F. , Breen Philip J. , Dobretsov Maxim , Penthala Narsimha R. , Hendrickson Howard P. , Crooks Peter A. 
Published: January 2021

AbstractMorphine‐6‐O‐sulfate (M6S), a polar, zwitterionic sulfate ester of morphine, is a powerful and safe analgesic in several rat models of pain. A sensitive liquid chromatography–tandem mass spectrometry bioanalytical method was developed and validated for the simultaneous determination of M6S and morphine (MOR) in rat plasma and brain after M6S administration. Morphine‐d6 was used as internal standard. Multiple reaction monitoring was used for detection and quantitation of M6S, MOR, and morphine‐d6 in the turbo ion spray positive mode. The chromatographic separation was carried out on an Alltech Altima C18 column. The analytical method was validated for linearity, precision, accuracy, specificity, and stability over a concentration range of 3–8000 ng/ml in rat plasma and 10–10,000 ng/ml in brain samples for both M6S and MOR. The validated method was applied to determine the PK profile of M6S in plasma after i.v., i.p., and oral dosing in male Sprague–Dawley rats. Rats were administered M6S by i.p. administration (5.6 and 10.0 mg/kg) or orally (10 and 30 mg/kg) and bioavailability compared to an i.v. injection (1 mg/kg) of M6S. The in vivo results indicate that M6S is not a prodrug of morphine, since M6S is not biotransformed into MOR in plasma after either i.p. or oral administration, and MOR was not detected in brain. The bioavailability of M6S was >93% and about 5% after i.p. and oral dosing, respectively. The low oral bioavailability of M6S may be due to poor permeation of the intestinal epithelial membrane. After i.p.‐administration, M6S appears to reach brain tissues in low, but significant, concentrations.
An approach to quantify climate–productivity relationships: an example from a widespreadNothofagusforest
Authors: Salas‐Eljatib Christian 
Published: January 2021

AbstractUnique combinations of geographic and environmental conditions make quantifying the importance of factors that influence forest productivity difficult. I aimed to model the height growth of dominantNothofagus alpinatrees in temperate forests of Chile, as a proxy for forest productivity, by building a dynamic model that accounts for topography, habitat type, and climate conditions. Using stem analysis data of 169 dominant trees sampled throughout south‐central Chile (35°50′ and 41°30′ S), I estimated growth model parameters using a nonlinear mixed‐effects framework that takes into account the hierarchical structure of the data. Based on the proposed model, I used a system‐dynamics approach to analyze growth rates as a function of topographic, habitat type, and climatic variability. I found that the interaction between aspect, slope, and elevation, as well as the effect of habitat type, play an essential role in determining tree height growth rates ofN. alpina. Furthermore, the precipitation in the warmest quarter, precipitation seasonality, and annual mean temperature are critical climatic drivers of forest productivity. Given a forecasted climate condition for the region by 2100, where precipitation seasonality and mean annual temperature increase by 10% and 1°C, respectively, and precipitation in the warmest quarter decreases by 10 mm, I predict a reduction of 1.4 m in height growth of 100‐yr‐old dominant trees. This study shows that the sensitivity ofN. alpina‐dominated forests to precipitation and temperature patterns could lead to a reduction of tree height growth rates as a result of climate change, suggesting a decrease in carbon sequestration too. By implementing a system dynamics approach, I provide a new perspective on climate‐productivity relationships, bettering the quantitative understanding of forest ecosystem dynamics under climate change. The results highlight that while temperature rising might favor forest growth, the decreasing in both amount and distribution within a year of precipitation can be even more critical to reduce forest productivity.
Experimental simulation of environmental warming selects against pigmented morphs of land snails
Authors: Köhler Heinz‐R. , Capowiez Yvan , Mazzia Christophe , Eckstein Helene , Kaczmarek Nils , Bilton Mark C. , Burmester Janne K. Y. , Capowiez Line , Chueca Luis J. , Favilli Leonardo , Florit Gomila Josep , Manganelli Giuseppe , Mazzuca Silvia , Moreno‐Rueda Gregorio , Peschke Katharina , Piro Amalia , Quintana Cardona Josep , Sawallich Lilith , Staikou Alexandra E. , Thomassen Henri A. , Triebskorn Rita 
Published: January 2021

AbstractIn terrestrial snails, thermal selection acts on shell coloration. However, the biological relevance of small differences in the intensity of shell pigmentation and the associated thermodynamic, physiological, and evolutionary consequences for snail diversity within the course of environmental warming are still insufficiently understood. To relate temperature‐driven internal heating, protein and membrane integrity impairment, escape behavior, place of residence selection, water loss, and mortality, we used experimentally warmed open‐top chambers and field observations with a total of >11,000 naturally or experimentally colored individuals of the highly polymorphic species Theba pisana (O.F. MÜLLER, 1774). We show that solar radiation in their natural Mediterranean habitat in Southern France poses intensifying thermal stress on increasingly pigmented snails that cannot be compensated for by behavioral responses. Individuals of all morphs acted neither jointly nor actively competed in climbing behavior, but acted similarly regardless of neighbor pigmentation intensity. Consequently, dark morphs progressively suffered from high internal temperatures, oxidative stress, and a breakdown of the chaperone system. Concomitant with increasing water loss, mortality increased with more intense pigmentation under simulated global warming conditions. In parallel with an increase in mean ambient temperature of 1.34°C over the past 30 years, the mortality rate of pigmented individuals in the field is, currently, about 50% higher than that of white morphs. A further increase of 1.12°C, as experimentally simulated in our study, would elevate this rate by another 26%. For 34 T. pisana populations from locations that are up to 2.7°C warmer than our experimental site, we show that both the frequency of pigmented morphs and overall pigmentation intensity decrease with an increase in average summer temperatures. We therefore predict a continuing strong decline in the frequency of pigmented morphs and a decrease in overall pigmentation intensity with ongoing global change in areas with strong solar radiation.
Disentangling the links between habitat complexity and biodiversity in a kelp‐dominated subantarctic community
Authors: Velasco‐Charpentier Catalina , Pizarro‐Mora Felipe , Navarro Nelso P. , Valdivia Nelson 
Published: January 2021

AbstractHabitat complexity is one of the most important factors modulating species diversity. This feature comprises several interrelated attributes, such as number, size, and spatial arrangement of complexity‐forming elements. However, the separate and joint effects of these attributes on diversity and community structure are still not well understood. Here, we assess the relationships between several structural‐complexity attributes of the subantarctic kelp Lessonia flavicans and species richness, total abundance, and structure of kelp‐associated macrobenthic communities. We predicted that longer thalli and larger holdfasts favor greater species richness and total abundance of invertebrate organisms. To test the prediction, an observational sampling program was established in two sites of the Strait of Magellan. Uni‐ and multivariate analyses revealed both positive and negative effects of kelp structural‐complexity attributes on diversity. Holdfast diameter and maximum frond length, followed by thallus wet weight, had the strongest positive fits to species richness and total abundance; the number of stipes, on the other hand, was negatively associated with both response variables. Longer fronds were associated with greater abundances of spirorbid polychaetes. Larger holdfasts supported larger abundances of Nereididae and Terebelidae polychaetes and the limpet Nacella mytilina. Contrarily, kelps with longer fronds and more stipes supported fewer amphipods. In this way, we demonstrate that different dimensions of habitat complexity can have contrasting effects on diversity and community structure, highlighting the fundamental role of multiple dimensions of kelp habitat complexity for local biodiversity.
High performance fully paper‐based all‐solid‐state supercapacitor fabricated by a papermaking process with silver nanoparticles and reduced graphene oxide‐modified pulp fibers
Authors: Huang Quanbo , Yang Yang , Chen Ruwei , Wang Xiaohui 
Published: January 2021

AbstractHerein, a fully paper‐based all‐solid‐state supercapacitor with functionalized cellulose paper as electrodes, carboxymethyl cellulose gel as solid electrolyte and cellulose paper as separator was fabricated. The electrode was fabricated by a conventional papermaking process with silver‐modified fibers and graphene oxide (GO)‐modified fibers followed by reduction of GO. The Ag‐modified fibers and GO‐modified fibers were obtained by in situ growth of Ag nanoparticles and self‐assembly of GO sheets on cellulose fibers, respectively. Ag‐modified fibers act as a flexible current collector with rich three‐dimensional interconnected electron transport pathways to make the reduced GO‐modified fibers as electrode materials to achieve high conductivity (1.93 Ω sq−1) and high‐rate capability. Simple drying can reduce 40% weight of the supercapacitor to facilitate transportation and storage, and its capacitance efficiency can be recovered by wetting when needed. This work opens up a new way of developing cheap, green and high performance full‐paper flexible electronics by conventional papermaking process.image
DPS1 regulates cuticle development and leaf senescence in rice
Authors: Adeel Zafar Syed , Uzair Muhammad , Ramzan Khan Muhammad , Patil Suyash B. , Fang Jingjing , Zhao Jinfeng , Lata Singla‐Pareek Sneh , Pareek Ashwani , Li Xueyong 
Published: January 2021

AbstractLeaves are the primary food‐producing organs for a plant that carry out photosynthesis and contribute to biomass and grain yield. Leaf senescence is a developmentally regulated physiological process but early leaf senescence is known to negatively affect plant yield. The cuticle is an outer waxy protective layer on the leaf surface which protects plants from pathogens attack as well as dehydration. Our understanding of the molecular mechanisms underlying cuticle development and leaf senescence is still immature. The present study reports the role of the DEGENERATED PANICLE AND PARTIAL STERILITY 1 (DPS1) gene encoding a cystathionine β‐synthase (CBS) domain‐containing protein in cuticle development and leaf senescence in rice. The dps1 loss‐of‐function mutant showed leaf senescence phenotype with twisted leaves, significantly reduced chlorophyll content and degenerated chloroplasts characterized by a reduced number of starch granules and an abundance of osmiophilic bodies. Furthermore, dps1 leaves displayed defective cuticle development, reduced wax and cutin compounds, and lower relative water content as compared with wild type. Physiological assays showed significantly higher accumulation of reactive oxygen species (ROS) accompanied by enhanced DNA fragmentation in dps1 leaves, which could be associated with chloroplast degeneration and defective cuticle development. Transcriptome analysis revealed altered expression of several critical genes related to photosynthesis and wax/cutin pathway. This study revealed a crucial role of DPS1 in regulating leaf cuticle development and senescence by affecting the expression of several genes. Thus, a moderate expression of DPS1 is necessary for better plant growth and productivity.
A flexible gradient method for unstructured‐grid solvers
Authors: Nishikawa Hiroaki 
Published: January 2021

AbstractIn this short note, we introduce a flexible explicit gradient method for efficient and robust unstructured‐grid computations. As shown, the method serves as a memory‐efficient alternative to the multiple least‐squares gradients needed by conflicting requirements for inviscid, viscous, and turbulence‐model source terms (e.g., vorticity), in practical computational‐fluid‐dynamics solvers. The flexible method computes the gradient of a numerical solution in a cell by averaging the face gradients defined by the alpha‐damped formula with a parameter based on a single set of least‐squares gradients. We show that a small gives less‐accurate gradients similar to unweighted least‐squares gradients, and a large produces accurate gradients similar to weighted least‐squares gradients. Therefore, it allows us to obtain two types of gradients by changing the value of without storing more than one set of least‐squares coefficients. Moreover, the method yields fourth‐order accurate gradients with on a regular grid. The method is demonstrated for two‐dimensional inviscid and viscous flows on unstructured grids.
Strategic bias and popularity effect in the prediction of economic surprises
Authors: Félix Luiz , Kräussl Roman , Stork Philip 
Published: January 2021

AbstractProfessional forecasters of economic data are remunerated based on accuracy and positive publicity generated for their firms. This remuneration structure incentivizes them to stick to the median forecast but also to make bold forecasts when they perceive to have superior private information. We find that skewness in the distribution of expectations, potentially created by bold forecasts, predicts economic surprises across a wide range of US economic indicators in‐sample and out‐of‐sample, confirming our hypothesis that forecasters behave strategically and possess private information. This strategic bias found in US economic forecasts is also exhibited in individual forecasters' data as well as in continental Europe, the United Kingdom, and Japan. We show that it has been increasing both through time and in relation to the behavioral anchor bias. Our results suggest that the pervasiveness of the biases depends on the popularity of the economic indicator being released, both in the United States and internationally.
Effect of Preparation Parameters on the Catalytic Performance of Solid Acid Catalyst SO42−/ZrO2‐CeO2 in Biodiesel Production▴
Authors: Li X. F. , Ma W. H. , Bao G. R. , Lv G. Q. , Wan X. H. , Li Q. J. 
Published: January 2021

AbstractA new solid acid catalyst SO42−/ZrO2‐CeO2 (SZC) was prepared by co‐precipitation method and used in biodiesel production. Different from considering several parameters in available literatures, the effect of all 10 parameters in the preparation process on the catalytic activities of SZC were studied systematically and comprehensively. The catalytic performance was tested by the conversion of Jatropha oil fatty acids (CFA) in esterification. TG, XRD, BET, TEM, NH3‐TPD, FTIR were used to characterize the catalyst aiming to analyze the influence mechanisms of each factor. The results indicated that the surface area and acidity of sulfated zirconia increased by doping of Ce. The most important preparation parameters included loading amounts of CeO2, aging time, and calcination temperature, their proper values were 5%, 21 h, 773 K, respectively. Moreover, novel findings included: the ammonia concentration influences the acid strength of catalyst which was more important than the amount of acid sites for the catalytic activities and drying before calcination was a necessary step.
Nonlinear analysis of the effect of viscoelasticity on ferroconvection
Authors: Melson Anthony C. , Siddheshwar Pradeep G. , Sekhar Gummadi N. 
Published: January 2021

AbstractThis paper concerns a nonlinear analysis of the effects of viscoelasticity on convection in ferroliquids. We consider the Oldroyd model for the constitutive equation of the liquid. The linear stability analysis yields the critical value of the Rayleigh number for the onset of oscillatory convection in Maxwell and Jeffrey ferroliquids. The use of a minimal mode double Fourier series in the nonlinear perturbation equations yields a Khayat–Lorenz model for the ferromagnetic liquid, and that is scaled further to get the classical Lorenz model as a limiting case. The scaled Khayat–Lorenz model thus obtained is solved numerically and the solution is used to compute the time‐dependent Nusselt number, which quantifies the heat transport. The results are analyzed for the dependence of the time‐averaged Nusselt number on different parameters.