bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reprocessable Thermoset Soft Actuators
Authors: Yang Yang , Terentjev Eugene M. , Zhang Yubai , Chen Qiaomei , Zhao Yuan , Wei Yen , Ji Yan 
Published: September 2019

AbstractWidely used traditional thermosets are good candidates for construction of 3D soft actuators because of their excellent stability; however, it is generally acknowledged that they cannot be reprocessed. The time–temperature equivalence principle enables reprocessing of traditional liquid crystalline epoxy thermosets (LCETs) into 3D soft actuators. Even though the transesterification reaction of LCETs is extremely slow, it is fast enough to induce a topology rearrangement and subsequent reprocessing when prolonging the transesterification time according to aforementioned principle. Therefore, LCETs can be aligned by a simple procedure. The alignment is quite stable at high temperature and remains after more than 1000 heating–cooling actuation cycles. The resulting 3D soft actuators are remouldable, reprogrammable, reconfigurable, weldable, self‐healable, recyclable, and stable, which is impossible for any traditional thermosets and is therefore a compelling advance in terms of the applications open to 3D soft actuators.
Ternary Monolithic ZnS/CdS/rGO Photomembrane with Desirable Charge Separation/Transfer Routes for Effective Photocatalytic and Photoelectrochemical Hydrogen Generation
Authors: Zhang Wanli , Huo Siying , Yang Siyuan , Zhong Yongming , Zhang Shengsen , Wang Hongqiang , Zhong Xinhua , Fang Yueping 
Published: September 2019

AbstractHighly efficient and easy recyclable monolithic photocatalysts with ideal separation/transport route for photogenerated charge carriers are much desired. In this work, a ZnO seed‐induced growth approach is developed to fabricate a ternary monolithic photomembrane, that is, ZnS/CdS heterojunction nanorods in situ grow into the interspaces of multilayer reduced graphene oxide (rGO) sheets (denoted as ZnS/CdS/rGO). The monolithic ZnS/CdS/rGO photomembrane can serve as an efficient visible‐light photoactive membrane for photocatalytic (PC) or photoelectrochemical (PEC) hydrogen generation. The fast electron transport of 1D CdS nanorods, the excellent electronic conductivity of multilayer stacked rGO sheets, the intense visible‐light absorption of CdS, the unique hierarchical structure, and double heterojunctions (ZnS/CdS and CdS/rGO) efficiently boost the photogenerated electron‐hole pairs separation and transfer across the interfacial domain of the photomembrane under visible‐light irradiation. Furthermore, the superior stability and reusability of the photomembrane is achieved by the ideal process of photogenerated electron‐hole pair separation/transfer, i.e., holes transfer to ZnS and electrons transfer to rGO to inhibit CdS from photocorrosion.
Synthetic Strategies for (−)‐Cannabidiol and Its Structural Analogs
Authors: Jung Byunghyuck , Lee Jungkyu K. , Kim Jungnam , Kang Eunhye K. , Han Sang Yeong , Lee Hee‐Yoon , Choi Insung S. 
Published: September 2019

Abstract(−)‐Cannabidiol ((−)‐CBD), a non‐psychoactive phytocannabinoid from Cannabis, and its structural analogs have received growing attention in recent years because of their potential therapeutic benefits, including neuroprotective, anti‐epileptic, anti‐inflammatory, anxiolytic, and anti‐cancer properties. (−)‐CBD and its analogs have been obtained mainly based on extraction from the natural source; however, the conventional extraction‐based methods have some drawbacks, such as poor quality control along with purification difficulty. Chemical‐synthetic strategies for (−)‐CBD could tackle these issues, and, additionally, generate novel (−)‐CBD analogs that exhibit advanced biological activities. This review concisely summarizes the historic and recent milestones in the synthetic strategies for (−)‐CBD and its analogs.
Functionalizing Reduced Graphene Oxide with Ru‐Organometallic Compounds as an Effective Strategy to Produce High‐Performance Pt Nanocatalysts for the Methanol Oxidation Reaction
Authors: Siller‐Ceniceros Adriana A. , Sánchez‐Castro Esther , Morales‐Acosta Diana , Torres‐Lubián José R. , Martínez‐Guerra Eduardo , Rodríguez‐Varela Javier 
Published: September 2019

AbstractAn efficient route to chemically functionalize reduced graphene oxide (rGO) with ruthenium organometallic compounds and the subsequent anchorage of Pt nanoparticles is reported. Two organometallic complexes, [(η6‐C6H5OCH2CH2OH) RuCl2]2 (Ru‐dim) and [(η6‐C6H4(CHMe2)Me)RuCl2]2 (Ru‐cym), as well as commercial RuCl3 ⋅ XH2O (Ru‐com) have been synthetized an used as functionalizing agents. By implementing a conventional polyol synthesis method, the Pt/rGORu‐dim, Pt/rGORu‐cym, Pt/rGORu‐com and Pt/rGO nanocatalysts have been synthetized. Characterization by XRD indicates that the presence of Ru leads to the formation of Pt−Ru alloyed phases due to overlapping of Pt fcc and Ru hcp reflections. When characterized for the methanol oxidation reaction (MOR) in acid media, Pt/rGORu‐dim reached a mass current density of 491.49 mA mgPt−1, higher than those generated by the other nanocatalysts. The results show that the functionalization of rGO with Ru‐dim remarkably increases the catalytic activity of Pt for the MOR, suggesting Pt−Ru metal−metal interactions that promotes the anodic reaction.
Selective Hydrogenation of Furfural in a Proton Exchange Membrane Reactor Using Hybrid Pd/Pd Black on Alumina
Authors: Carl Sarah , Waldrop Krysta , Pintauro Peter , Thompson Levi T. , Tarpeh William A. 
Published: September 2019

AbstractConventional thermocatalytic hydrogenation employs high temperatures and pressures and often exhibits low selectivity toward desired products. Electrochemical hydrogenation can reduce energy input by operating at ambient conditions and improving process control and selectivity; however, electrocatalysts face stability and conductivity limitations. To overcome these obstacles, we physically mixed a traditional electrocatalyst (Pd black) with a hydrogenation‐active metal (Pd) supported on a conventional metal oxide support (alumina, Al2O3) and investigated electrochemical hydrogenation of furfural, a model biomass compound. Experiments were conducted in a proton exchange membrane (PEM) reactor, in which synthesized electrocatalysts were used as cathodes. Catalysts with Pd black and varying loadings of Pd on Al2O3 were used to determine the impact of hydrogen spillover on electrocatalytic hydrogenation mechanisms, selectivity, and rates. Observed hydrogenation rates and selectivities were linked to structural and compositional properties of the catalyst mixtures. Of the Pd black cathodes tested, 5 wt % Pd/Al2O3 exhibited production rates as high as pure Pd black and higher selectivity towards completely hydrogenated products. Improved selectivity and rates were attributed to a synergistic interaction between Pd black and 5 wt % Pd/Al2O3 in which Pd/Al2O3 increased the number of active sites, while Pd black provided stable conductivity.
Synergistic Catalytic Effect of Ion Tunnels with Polar Dopants to Boost the Electrochemical Kinetics for High‐Performance Sulfur Cathodes
Authors: Zhang Jing , You Caiyin , Wang Jian , Guo Shaohua , Zhang Weihua , Yang Rong , Fu Ping 
Published: September 2019

AbstractRechargeable lithium−sulfur (Li−S) batteries with high areal capacity are hindered by the ion/electron pathway and sluggish reaction kinetics of sulfur species, resulting from high energy barriers. Inspired by the nature of biomass and efficient nutrition transfer, we present a high‐performance sulfur cathode based on nanocarbon tunnels with natural polar catalytic sites. The inherited tunnels can propel lithium‐ion transport across the interface to reach the active materials and the interior heteroatom dopants provide abundant catalytic sites to further reduce the energy barriers. The as‐fabricated sulfur cathode displays much higher rate performance of 565 mA h g−1 at 6 C and a low decay rates of 0.029 % per cycle for 2000 cycles at 3 C. Most importantly, a high initial areal capacity of 5.1 mA h cm−2 with enhanced loading up to 5.8 mg cm−2 at 1 C is achieved, corresponding to volumetric capacity of 638 A h L−1.
Use of Nitrogen‐Doped Carbon Nanodots for the Photocatalytic Fluoroalkylation of Organic Compounds
Authors: Rosso Cristian , Filippini Giacomo , Prato Maurizio 
Published: September 2019

AbstractThe use of amine‐rich N‐doped carbon nanodots (NCNDs) for the photochemical radical perfluoroalkylation of organic compounds is reported. This operationally simple approach occurs under mild conditions producing valuable new C−C bonds. The chemistry is driven by the ability of NCNDs to directly reach an electronically excited state upon light absorption, thereby successively triggering the formation of reactive radical species from simple perfluoroalkyl iodides. Preliminary mechanistic studies are also reported.
Spectroscopic Studies of the Magnetic Excitation and Spin‐Phonon Couplings in a Single‐Molecule Magnet
Authors: Stavretis Shelby E. , Moseley Duncan H. , Fei Fan , Cui Hui‐Hui , Cheng Yongqiang , Podlesnyak Andrey A. , Wang Xiaoping , Daemen Luke L. , Hoffmann Christina M. , Ozerov Mykhaylo , Lu Zhengguang , Thirunavukkuarasu Komalavalli , Smirnov Dmitry , Chang Tieyan , Chen Yu‐Sheng , Ramirez‐Cuesta Anibal J. , Chen Xue‐Tai , Xue Zi‐Ling (Ben) 
Published: September 2019

AbstractLarge separations between ground and excited magnetic states in single‐molecule magnets (SMMs) are desirable to reduce the likelihood of spin reversal in the molecules. Spin‐phonon coupling is a process leading to magnetic relaxation. Both the reversal and coupling, making SMMs lose magnetic moments, are undesirable. However, direct determination of large magnetic states separations (>45 cm−1) is challenging, and few detailed investigations of the spin‐phonon coupling have been conducted. The magnetic separation in [Co(12‐crown‐4)2](I3)2(12‐crown‐4) (1) is determined and its spin‐phonon coupling is probed by inelastic neutron scattering (INS) and far‐IR spectroscopy. INS, using oriented single crystals, shows a magnetic transition at 49.4(1.0) cm−1. Far‐IR reveals that the magnetic transition and nearby phonons are coupled, a rarely observed phenomenon, with spin‐phonon coupling constants of 1.7–2.5 cm−1. The current work spectroscopically determines the ground–excited magnetic states separation in an SMM and quantifies its spin‐phonon coupling, shedding light on the process causing magnetic relaxation.
When a Red–NIR‐Emissive Cs2[Mo6Br14] Interacts with an Active Diureasil–PEO Matrix: Design of Tunable and White‐Light‐Emitting Hybrid Material
Authors: Ferreira Molina Eduardo , Martins de Jesus Natana Aparecida , Paofai Serge , Hammer Peter , Amela‐Cortes Maria , Robin Malo , Cordier Stephane , Molard Yann 
Published: September 2019

AbstractHybrid materials that combine diureasil matrices and octahedral molybdenum clusters have been synthesized to design lead‐, cadmium‐ and rare‐earth‐free emitters for lighting or optoelectronic applications. This association leads to homogeneous and stable hybrids, for which the emission color can be tailored in the entire visible range, including white light; this is thanks to effective energy transfers from the host to the nanocluster.
Solid Solutions of Grimm–Sommerfeld Analogous Nitride Semiconductors II‐IV‐N2 (II=Mg, Mn, Zn; IV=Si, Ge): Ammonothermal Synthesis and DFT Calculations
Authors: Mallmann Mathias , Niklaus Robin , Rackl Tobias , Benz Maximilian , Chau Thanh G. , Johrendt Dirk , Minár Ján , Schnick Wolfgang 
Published: September 2019

AbstractGrimm–Sommerfeld analogous II‐IV‐N2 nitrides such as ZnSiN2, ZnGeN2, and MgGeN2 are promising semiconductor materials for substitution of commonly used (Al,Ga,In)N. Herein, the ammonothermal synthesis of solid solutions of II‐IV‐N2 compounds (II=Mg, Mn, Zn; IV=Si, Ge) having the general formula (IIa1−xIIbx)‐IV‐N2 with x≈0.5 and ab initio DFT calculations of their electronic and optical properties are presented. The ammonothermal reactions were conducted in custom‐built, high‐temperature, high‐pressure autoclaves by using the corresponding elements as starting materials. NaNH2 and KNH2 act as ammonobasic mineralizers that increase the solubility of the reactants in supercritical ammonia. Temperatures between 870 and 1070 K and pressures up to 200 MPa were chosen as reaction conditions. All solid solutions crystallize in wurtzite‐type superstructures with space group Pna21 (no. 33), confirmed by powder XRD. The chemical compositions were analyzed by energy‐dispersive X‐ray spectroscopy. Diffuse reflectance spectroscopy was used for estimation of optical bandgaps of all compounds, which ranged from 2.6 to 3.5 eV (Ge compounds) and from 3.6 to 4.4 eV (Si compounds), and thus demonstrated bandgap tunability between the respective boundary phases. Experimental findings were corroborated by DFT calculations of the electronic structure of pseudorelaxed mixed‐occupancy structures by using the KKR+CPA approach.
The Crystalline Sponge Method in Water
Authors: de Poel Wester , Tinnemans Paul , Duchateau Alexander L. L. , Honing Maarten , Rutjes Floris P. J. T. , Vlieg Elias , de Gelder René 
Published: September 2019

AbstractThe crystalline sponge method entails the elucidation of the (absolute) structure of molecules from a solution phase using single‐crystal X‐ray diffraction and eliminates the need for crystals of the target compound. An important limitation for the application of the crystalline sponge method is the instability of the available crystalline sponges that can act as host crystals. The host crystal that is most often used decomposes in protic or nucleophilic solvents, or when guest molecules with Lewis basic substituents are introduced. Here a new class of (water) stable host crystals based on f‐block metals is disclosed. It can be shown that these hosts not only increase the scope of the crystalline sponge method to a wider array of solvents and guests, but that they can even be applied to aqueous solutions containing hydrophilic guest molecules, thereby extending the crystalline sponge method to the important field of water‐based chemistry.
Methane Oxidation in the Water Column of Xiangxi Bay, Three Gorges Reservoir
Authors: Lei Dan , Liu Jia , Zhang Junwei , Lorke Andreas , Xiao Shangbin , Wang Yuchun , Wang Wei , Li Ye 
Published: September 2019

AbstractFour field campaigns are carried out to quantify the methane (CH4) oxidation rate in Xiangxi Bay (XXB) of the Three Gorges Reservoir (TGR), China. The water depth of the sampling site varied from 13 to 30 m resulting from the water level fluctuation of the TGR. The CH4 oxidation rates are measured in situ as the decline of dissolved CH4 concentration versus time in incubated, and those rates. The CH4 oxidation rates range from 1.18 × 10−3 to 3.69 × 10−3 µmol L−1 h−1, with higher values and stronger variation during summer. A static floating chamber method is used to measure CH4 emitted to the atmosphere resulting in an annual mean flux of 4.79 µmol m−2 h−1. The CH4 emission rate is significantly negatively correlated with the water level. The results show that a large fraction of CH4 is consumed in the water column with a range of 28.97–55.90 µmol m−2 h−1, accounting for ≈69–98% of the total CH4 input into the water column, and more than 90% is consumed outside the summer, when the water level is lowest. Water depth, which is dominated by water level of the TGR, is a potentially important driver for CH4 oxidation and atmospheric emission in the tributary bay.
Single Crystal Growth of FeGa3 and FeGa3−xGex from High‐Temperature Solution Using the Czochralski Method
Authors: Bader Kristian , Gille Peter 
Published: September 2019

AbstractSingle crystal growth and characterization of the binary semiconducting compound FeGa3 and its Ge‐substitute FeGa3–xGex are reported. Whereas there have been several investigations on the thermoelectric properties based on small samples grown by the flux method, this study is the first approach using the Czochralski growth technique from well‐oriented single‐crystalline seeds. Problems and solutions of the growth of cm3‐size single crystals are discussed in detail. Ge segregation in FeGa3–xGex is described by a segregation coefficient lower than unity which leads to an axially increasing Ge content along the pulling direction. Consequences with respect to lattice parameter changes and thermoanalytic measurements are reported.
Hierarchical modeling strengthens evidence for density dependence in observational time series of population dynamics
Authors: Thibaut Loïc M. , Connolly Sean R. 
Published: September 2019

AbstractThe extent to which populations in nature are regulated by density‐dependent processes is unresolved. While experiments increasingly find evidence of strong density dependence, unmanipulated population time series yield much more ambiguous evidence of regulation, especially when accounting for effects of observation error. Here, we reexamine the evidence for density dependence in time series of population sizes in nature, by conducting an aggregate analysis of the populations in the Global Population Dynamics Database (GPDD). First, following the conventional approach, we fit a density‐dependent and a density‐independent variant of the Gompertz state‐space model to each time series. Then, we conduct an aggregate analysis of the entire database by considering two random‐effects density‐dependent models that leverage information across data sets. When individual time series are tested independently, we find very little evidence for density dependence. However, in the aggregate, we find very strong evidence for density dependence, even though, paradoxically, estimated strengths of density dependence for individual time series tend to be weaker than when each individual time series is analyzed independently. Furthermore, a hierarchical model that accounts for taxonomic variation in the strength of density dependence reveals that density dependence is consistently stronger in insects and fish than in birds and mammals. Our findings resolve apparent inconsistencies between observational and experimental studies of density dependence by revealing that the observational record does indeed contain strong support for the hypothesis that density dependence is widespread in nature.
Reporting the limits of detection and quantification for environmental DNA assays
Authors: Klymus Katy E. , Merkes Christopher M. , Allison Michael J. , Goldberg Caren S. , Helbing Caren C. , Hunter Margaret E. , Jackson Craig A. , Lance Richard F. , Mangan Anna M. , Monroe Emy M. , Piaggio Antoinette J. , Stokdyk Joel P. , Wilson Chris C. , Richter Catherine A. 
Published: September 2019

AbstractBackgroundEnvironmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully established, with one area being the calculation and interpretation of assay limit of detection (LOD) and limit of quantification (LOQ).AimsHere, we propose establishing consistent methods for determining and reporting of LOD and LOQ for single‐species quantitative PCR (qPCR) eDNA studies.Materials & Methods/ ResultsWe utilize datasets from multiple cooperating laboratories to demonstrate both a discrete threshold approach and a curve‐fitting modeling approach for determining LODs and LOQs for eDNA qPCR assays. We also provide details of an R script developed and applied for the modeling method.Discussion/ConclusionsUltimately, standardization of how LOD and LOQ are determined, interpreted, and reported for eDNA assays will allow for more informed interpretation of assay results, more meaningful interlaboratory comparisons of experiments, and enhanced capacity for assessing the relative technical quality and performance of different eDNA qPCR assays.
Design of novel, simple, and inexpensive 3D printing‐based miniaturized electrochemical platform containing embedded disposable detector for analytical applications
Authors: de Moraes Natalia Canhete , da Silva Eiva Natiele Tiago , Petroni Jacqueline Marques , Ferreira Valdir Souza , Lucca Bruno Gabriel 
Published: September 2019

AbstractThis paper describes the development of a novel, simple, and inexpensive electrochemical device containing an integrated and disposable three‐electrode system for detection. The base of this platform consists on a PDMS structure containing microchannels which were prototyped using 3D‐printed molds. Pencil graphite leads were inserted into these microchannels and utilized as working, counter and reference electrodes in a novel design. Morphological analysis and electrochemical experiments with benchmark redox probes were carried out in order to evaluate the performance and characterize the miniaturized device proposed. Even using inexpensive materials and a simple fabrication protocol, the electrochemical platform developed provided good repeatability and reproducibility over a low cost (ca. $2 per device), acceptable lifetime (ca. 250 voltammetric runs) and extremely reduced consumption of samples and reagents (order of µL). As proof of concept, the analytical feasibility of the platform was investigated through the simultaneous determination of dopamine (DOPA) and acetaminophen (AC). The two analytes showed linear dependence on the concentration range from 1 to 15 µM and the LODs achieved were 0.21 µM for DOPA and 0.29 µM for AC. Moreover, the platform was successfully applied on the determination of DOPA and AC in spiked blood serum and urine samples. The results obtained with the device described here were better than some reports in literature that use more costly electrodic materials and complex modification steps for the detection of the same analytes.
Experimental study on the corrosion of a downhole string under flue gas injection conditions
Authors: Li Songyan , Zhang Kaiqiang , Wang Qun 
Published: September 2019

AbstractFlue gas collection from steam generators and its utilization in enhanced oil recovery (EOR) can reduce CO2 emissions into the atmosphere and improve oil recovery efficiency. Under the environments of flue gas corrosion in oilfields, the effects of corrosion time, temperature, pressure, velocity, and concentrations of O2, SO2, H2O, and NaCl on corrosion rates of steels used for a downhole string were investigated through physical simulation experiments. The corrosion mechanisms were analyzed by component, and the morphology of the corrosion products tested by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). In the gas phase, the corrosion rates of X70, P110, and N80 notably increase with temperature and O2 concentration. The corrosion rates first increase rapidly with pressure from 1.0 to 3.0 MPa and then remain largely stable. Meanwhile, the corrosion rates of X70, P110, and N80 in the liquid phase first increase and then decrease with temperature and reach maximum values at 90°C. The corrosion rates of X70, P110, and N80 increase notably with velocity and the concentrations of O2, SO2, H2O, and NaCl. The corrosion rate of 13Cr is considerably lower than those of N80, P110, and X70, which shows good corrosion resistance performance. To reduce the flue gas corrosion of a downhole string, the relative humidity of the flue gas should be lower than 0.7, the temperature of the flue gas in the wellbore should avoid the range between 80 and 100°C, the excess air coefficient of the boiler should be kept at a reasonable value to reduce the O2 content in the flue gas, and the flue gas should not be coinjected into wellbores with brine. The injection of flue gas is technically feasible considering the corrosion of downhole string.