bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Vanadium and Molybdenum Oxides Catalyze the Equivalent Formation of Ethane and Acetaldehyde from Ethanol
Authors: Nakamura Yoichi , Murayama Toru , Ueda Wataru 
Published: February 2014

AbstractCatalytic tests for ethanol conversion were performed on vanadium and molybdenum oxides with different oxidation states. We found for the first time that equivalent amounts of ethane and acetaldehyde were formed catalytically over V2O3 and MoO2. No influence of the reaction temperature was observed on the selectivity to ethane and acetaldehyde in the range of 533–653 K over V2O3 and MoO2. The reactions of methanol, 1‐propanol, and 2‐propanol also produced the corresponding alkanes and aldehydes in a 1:1 ratio. A reaction scheme for the formation of ethane and acetaldehyde from ethanol is proposed in which a hydrogen transfer reaction occurs between two ethanol molecules adsorbed on the adjacent metal cation–oxygen anion pair sites to form ethane, acetaldehyde, and water in one step.
Fe2O3@LaxSr1−xFeO3 Core–Shell Redox Catalyst for Methane Partial Oxidation
Authors: Shafiefarhood Arya , Galinsky Nathan , Huang Yan , Chen Yanguang , Li Fanxing 
Published: February 2014

AbstractEfficient and environmentally friendly conversion of methane into syngas is a topic of practical relevance for the production of hydrogen, chemicals, and synthetic fuels. At present, methane‐derived syngas is produced primarily through the steam methane reforming processes. The efficiencies of such processes are limited owing to the endothermic steam methane reforming reaction and the high steam to methane ratio required by the reforming catalysts. Chemical looping reforming represents an alternative approach for methane conversion. In the chemical looping reforming scheme, a solid oxygen carrier or “redox catalyst” is used to partially oxidize methane to syngas. The reduced redox catalyst is then regenerated with air. The cyclic redox operation reduces the steam usage while simplifying the heat integration scheme. Herein, a new Fe2O3@LaxSr1−xFeO3 (LSF) core–shell redox catalyst is synthesized and investigated. Compared with several other commonly investigated iron‐based redox catalysts, the newly developed core–shell redox catalyst is significantly more active and selective for syngas production from methane. It is also more resistant toward carbon formation and maintains high activity over cyclic redox operations.
Resistance‐Switchable Graphene Oxide–Polymer Nanocomposites for Molecular Electronics
Authors: Liu Gang , Chen Yu , Li Run‐Wei , Zhang Bin , Kang En‐Tang , Wang Cheng , Zhuang Xiaodong 
Published: February 2014

AbstractThe front cover artwork is provided by Prof. Dr. Yu Chen and his co‐workers. The image represents how deliberately designed, solution‐processable, and electroactive polymer‐functionalized graphene‐oxide nanosheets can be reversibly switched ON and OFF for the development of next‐generation nonvolatile information‐storage applications. Read the full text of the article at 10.1002/celc.201300158.
Direct Growth of Cobalt Hydroxide Rods on Nickel Foam and Its Application for Energy Storage
Authors: Salunkhe Rahul R. , Bastakoti Bishnu Prasad , Hsu Chun‐Tsung , Suzuki Norihiro , Kim Jung Ho , Dou Shi Xue , Hu Chi‐Chang , Yamauchi Yusuke 
Published: February 2014

AbstractThe present work reports synthesis of cobalt hydroxide (Co(OH)2) rods on nickel foam and its supercapacitor application. Hierarchical Co(OH)2 rods with length of approximately 3.5 μm and diameter of approximately 400 nm were prepared by one‐step, simple, and inexpensive chemical‐bath‐deposition method. The direct growth of Co(OH)2 rods on the Ni foam gave three dimensional (3D) structure for easy access of electrolyte throughout material surface. Also, well‐adhered interface between Co(OH)2 rods and Ni‐foam surface gave better conduction channels. Detailed electrochemical study was performed by using cyclic voltammetry and galvanostatic charge/discharge measurements. The results demonstrate that Co(OH)2 rods on Ni foam are efficient electrodes for supercapacitor application.
Synthesis of Highly Functionalized Diaryl Ethers by Copper‐Mediated O‐Arylation of Phenols using Trivalent Arylbismuth Reagents
Authors: Crifar Cynthia , Petiot Pauline , Ahmad Tabinda , Gagnon Alexandre 
Published: February 2014

AbstractHighly functionalized diaryl ethers were prepared by copper(II) acetate mediated O‐arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N‐arylation of pyridones is also reported.
Nickel‐Catalyzed Csp2Csp3 Bond Formation by CarbonFluorine Activation
Authors: Sun Alex D. , Leung Kaylyn , Restivo Anita D. , LaBerge Nicole A. , Takasaki Harumi , Love Jennifer A. 
Published: February 2014

AbstractWe report herein a general catalytic method for Csp2Csp3 bond formation through CF activation. The process uses an inexpensive nickel complex with either diorganozinc or alkylzinc halide reagents, including those with β‐hydrogen atoms. A variety of fluorine substitution patterns and functional groups can be readily incorporated. Sequential reactions involving different precatalysts and coupling partners permit the synthesis of densely functionalized fluorinated building blocks.
Regioselective Ruthenium‐Catalyzed Carbonylative Direct Arylation of Five‐Membered and Condensed Heterocycles
Authors: Pospech Jola , Tlili Anis , Spannenberg Anke , Neumann Helfried , Beller Matthias 
Published: February 2014

AbstractA ruthenium‐catalyzed carbonylative CH bond arylation process for the three‐component synthesis of complex aryl–(hetero)aryl ketones in an aqueous solution has been developed. By exploiting the ortho‐activating effect of nitrogen‐containing directing groups, a regioselective, successive twofold C(sp2)C(sp2) bond formation has been achieved. This straightforward catalytic process provides access to versatile products prevalent in multiple bioactive compounds and supplies a valuable functional group for subsequent transformations.
Manganese‐Containing Periodic Mesoporous Organosilica with Ionic‐Liquid Framework (Mn@PMO‐IL): A Powerful, Durable, and Reusable Nanocatalyst for the Biginelli Reaction
Authors: Elhamifar Dawood , Shábani Ahmad 
Published: February 2014

AbstractThe catalytic application of a novel manganese‐containing periodic mesoporous organosilica with ionic‐liquid framework (Mn@PMO‐IL) in the Biginelli reaction was investigated. First, the Mn@PMO‐IL nanocatalyst was prepared and characterized by TEM, SEM, X‐ray photoelectron spectroscopy, and nitrogen‐sorption analysis. The catalyst was then used in the one‐pot Biginelli condensation of various aldehydes with urea and alkyl acetoacetates under solvent‐free conditions. The corresponding dihydropyrimidone products were obtained in high to excellent yields and selectivities at short reaction times. Moreover, the catalyst was recovered and successfully reused many times with no notable decrease in activity and selectivity.
Transition‐Metal‐Free Catalytic Reduction of Carbon Dioxide
Authors: Fontaine Frédéric‐Georges , Courtemanche Marc‐André , Légaré Marc‐André 
Published: February 2014

AbstractMetal‐free systems, including frustrated Lewis pairs (FLPs) have been shown to bind CO2. By reducing the Lewis acidity and basicity of the ambiphilic system, it is possible to generate active catalysts for the deoxygenative hydroboration of carbon dioxide to methanol derivatives with conversion rates comparable to those of transition‐metal‐based catalysts.
An Imidazoline–Aminophenol (IAP) Nickel Catalyst: Structure and Catalytic Activity in the Enantioselective 1,4‐Addition of 3′‐Indolyl‐3‐Oxindoles to Nitroethylene
Authors: Awata Atsuko , Wasai Makiko , Masu Hyuma , Kado Sayaka , Arai Takayoshi 
Published: February 2014

AbstractThe structure of a nickel complex of imidazoline–aminophenol (IAP) prepared from IAP with Ni(OAc)2 was elucidated as cis‐bis(imidazolineaminophenoxide) [Ni(IAP)2]. The [Ni(IAP)2] complex smoothly promoted catalytic asymmetric 1,4‐addition of 3′‐indolyl‐3‐oxindole to nitroethylene to provide chiral mixed 3,3′‐bisindoles with high enantioselectivities. Mechanistic studies using ESI‐MS analyses suggest that one IAP ligand dissociated from [Ni(IAP)2] to generate the Ni–enolate of 3′‐indolyl‐3‐oxindole. From the optically active 3,3′‐mixed indole adduct, biologically important 3′‐indolyl‐3‐pyrrolidinoindoline was successfully synthesized in a three‐step reaction sequence.
Nanozeolite‐LTL with GdIII Deposited in the Large and EuIII in the Small Cavities as a Magnetic Resonance Optical Imaging Probe
Authors: Mayer Florian , Zhang Wuyuan , Brichart Thomas , Tillement Olivier , Bonnet Célia S. , Tóth Éva , Peters Joop A. , Djanashvili Kristina 
Published: February 2014

AbstractThe immense structural diversity of more than 200 known zeolites is the basis for the wide variety of applications of these fascinating materials ranging from catalysis and molecular filtration to agricultural uses. Despite this versatility, the potential of zeolites in medical imaging has not yet been much exploited. In this work a novel strategy is presented to selectively deposit different ions into distinct framework locations of zeolite‐LTL (Linde type L) and it is demonstrated that the carefully ion‐exchanged Gd/Eu‐containing nanocrystals acquire exceptional magnetic properties in combination with enhanced luminescence. This smart exploitation of the framework structure yields the highest relaxivity density (13.7 s−1 L g−1 at 60 MHz and 25 °C) reported so far for alumosilicates, rendering these materials promising candidates for the design of dual magnetic resonance/optical imaging probes, as demonstrated in preliminary phantom studies.
Gold‐Catalyzed Cycloisomerization of Yne‐Vinylidenecyclopropanes: A Three‐Carbon Synthon for [3+2] Cycloadditions
Authors: Yuan Wei , Tang Xiangying , Wei Yin , Shi Min 
Published: February 2014

AbstractA novel type of yne‐vinylidenecyclopropanes (VDCPs) has been synthesized and applied in gold‐catalyzed cycloisomerization reactions. It was found that these compounds can undergo an intramolecular cycloisomerization and perform as a three‐carbon synthon for [3+2] cycloaddition under gold catalysis to give fused [4.3.0] and [5.3.0] bicyclic derivatives and VDCP rearranged products in moderated to good yields under mild conditions. The substrate scope of these novel transformations has been explored and plausible reaction mechanisms have been presented on the basis of deuterium labeling experiments and DFT calculations.
Phase‐Transfer‐Catalysed Synthesis of Pyrroloindolines and Pyridoindolines by a Hydrogen‐Bond‐Assisted Isocyanide Cyclization Cascade
Authors: Knipe Peter C. , Gredičak Matija , Cernijenko Artiom , Paton Robert S. , Smith Martin D. 
Published: February 2014

AbstractA cascade reaction that generates pyrrolo‐ and pyridoindoline motifs from isocyanide precursors under phase‐transfer conditions is described. This transformation proceeds at room temperature in the presence of a quaternary ammonium catalyst and base to generate functionalized products containing an all‐carbon quaternary stereocentre. Quantum chemical calculations demonstrated that intramolecular general acid catalysis plays a key accelerating role through stabilization of developing charge in the transition state, and that the reaction is best described as a 5‐endo dig cyclization, rather than an anionic 6π electrocyclization. Investigations employing chiral phase‐transfer catalysts have given promising selectivities to date.
Characterization of Supramolecular Hidden Chirality of Hydrogen‐Bonded Networks by Advanced Graph Set Analysis
Authors: Sasaki Toshiyuki , Ida Yoko , Hisaki Ichiro , Yuge Tetsuharu , Uchida Yoshiaki , Tohnai Norimitsu , Miyata Mikiji 
Published: February 2014

AbstractInvited for the cover of this issue is the group of Mikiji Miyata at Osaka University. The image depicts the concept of supramolecular hidden chirality of hydrogen‐bonded networks characterized by advanced graph set analysis. Read the full text of the article at 10.1002/chem.201303770.
Geomagnetic Intensity and Direction for the Last 14 ka Recorded in the Core from the Bering Sea
Authors: Shu‐Lan GE , Xue‐Fa SHI , Yuan‐Hui HUANG , Zhi‐Hua CHEN , Jian‐Xing LIU , Shi‐Juan YAN 
Published: February 2014

AbstractPaleomagnetic and rock magnetic studies were conducted on the cores from the borehole B5‐4 in a continental slope of the Bering Sea to determine intensity and direction of the geomagnetic field. The results show that the magnetic properties are uniform except the finer magnetic grain size on the upper 0∼0.44 m. The relative paleointensity in the core is highly consistent with that of ODP983. According to the correlation between relative paleointensity in the borehole B5‐4 and ODP983 and an AMS 14C dating of foraminifera at 4.54∼4.56 m, three correlation points can be further determined, thus an age model for the borehole B5‐4 was obtained. The declination and inclination in B5‐4 agree highly with that of high latitude regions, such as the Lake Baikal, North America and Europe and the spherical harmonic model of local geomagnetic field, which provide additional tie points for the age model and a nearly linear sedimentation for the last 14 ka was revealed. The inclination correlation between B5‐4 and two cores from the China East Sea suggests the two discrete sections of shallow inclinations in B5‐4 are likely record of the Gothenburg event, but affected by the early diagenesis or smoothing effect. The above results prove that both relative paleointensity and direction can be obtained in appropriate sediments of the Bering Sea that serve as a time marker. This is very helpful in paleoenvironmental and paleoceanographic study in the Arctic and subarctic areas considering the awful scarcity of age information due to the shortage of calcareous tests and shells.
Rupture Details of the 20 April 2013 Lushan M7.0 Earthquake
Authors: Yan XU , Wen‐Li SHAO 
Published: February 2014

AbstractAn M7.0 earthquake struck Lushan, Sichuan, on 20 April 2013. We attempt to reveal its rupture details around 1 Hz using back‐projecting teleseismic P waves. The results show that this event was spawned by a 20‐km‐long and 26‐s‐duration rupturing of the source, which occurred bilaterally during the first 4 s, and unilaterally afterwards. The biggest energy release area is located north of the epicenter. We compared the rupture details of the Wenchuan and Lushan earthquakes, which occurred on the same fault, and found three common characters in rupture direction, location of the biggest energy burst and multi sub‐event. Two sources ruptured along the northeast trending Longmenshan fault zone. The biggest energy release regions are both off the epicenter. The source included more than one sub‐event, with the second one having the biggest energy release. The total rupture length of the Wenchuan and Lushan earthquakes accounts for about two thirds of the entire Longmenshan fault zone.
Study of Suppression of Diffracted Multiples from Steep Slope Zones in Deep Water
Authors: Song‐Lei XIE , Yi‐Ke LIU , Yi‐Bo WANG , Xu CHANG , Peng LI , De‐Gang JIN 
Published: February 2014

AbstractIn areas with steep slope zones in deep water and rugged seafloor, even using long acquisition cable, the reflected point out of the cable length, because of the variable direction of propagation of diffracted multiples. It makes diffracted multiple prediction without sufficient near offset or negative offset information, so that we cannot predict and suppress diffracted multiples exactly. This has been a big problem for us in suppression of diffracted multiples from steep slope zones in deep water. This paper presents a new method based on the feedback iteration model, introduces the adjacent shot record into the feedback iteration model, to supplement the near offset and negative offset data information. Tests on the Sigsbee2b model and real data show that this method can suppress well the diffracted multiples associated with the free surface of steep slopes in deep water.
Acoustic Wave Equation Modeling with New Time‐Space Domain Finite Difference Operators
Authors: Wen‐Quan LIANG , Chang‐Chun YANG , Yan‐Fei WANG , Hong‐Wei LIU 
Published: February 2014

AbstractNumerical simulation of acoustic wave equation is widely used to theoretically synthesize seismograms, and also constitutes the basis of the reverse time migration. Under some stability conditions, grid dispersion often exists because of the discretization of time and spatial derivatives in wave equations. How to suppress the grid dispersion is therefore a key problem for finite difference approaches. Time‐space domain methods using plane‐wave theory and Taylor series expansion are proposed to suppress grid dispersion recently. However, these methods can only preserve the wavefield in a small range of frequencies and angles of propagation. To further suppress the grid dispersion, we propose to preserve the grid dispersion relationship in a large range of frequencies and angles of propagation. Dispersion analysis and seismic numerical simulations demonstrate the effectiveness of the proposed method.
Symplectic RKN Schemes for Seismic Scalar Wave Simulations
Authors: Shao‐Lin LIU , Xiao‐Fan LI , You‐Shan LIU , Shi‐Zhong CHEN 
Published: February 2014

AbstractSeismic scalar wave equation is transformed into Hamiltonian system, and then a second‐order explicit Runge‐Kutta‐Nyström (RKN) scheme is proposed for high‐efficient acoustic wave simulations. The order conditions are obtained by the rooted tree theory. For order conditions with two free coefficients, one scheme with minimum error is obtained based on the optimal error truncation of the third‐order terms. We analyze the acoustic time advancing equation and choose coefficients to promote the stability upper bound, and then we develop an optimized scheme with strong stability. In the analysis of dispersion relation, the third optimized symplectic RKN scheme is constructed to substantially eliminate numerical dispersion. The theoretical properties of the three sets of symplectic RKN schemes have great advantages over other common schemes in terms of errors controlling, dispersion suppressing and stability promoting. Finally, we present numerical experiments to verify the theoretical analysis.
Two‐Dimensional Simulation of Magnetotelluric Anisotropy and Case Analysis
Authors: Xiang‐Yun HU , Guang‐Pu HUO , Rui GAO , Hai‐Yan WANG , Yi‐Fan HUANG , Yun‐Xia ZHANG , Bo‐Xin ZUO , Jian‐Chao CAI 
Published: February 2014

AbstractAfter more than half century development, remarkable achievements have been made in the study of earth's interior electrical structure by using the magnetotelluric (MT) method. The majority of these research results are based on the electrical isotropic assumption. However, the electrical anisotropy phenomenon is prevalent in the earth interior, and the presence of such anisotropy in the crust and upper mantle is an important link factor among geoelectric models, underground structure and tectonic models. In this paper, the tensor conductivity is first introduced by starting from the Maxwell equations, then we deduce a set of partial differential equations with respect to Ex and Hx according to the characteristic of two‐dimensional electrical anisotropic structure. By using the partial differential equations, the appropriate solutions of Ex and Hx are solved, and other field components are obtained on the basis of Ex and Hx. In order to recognize the characteristics of electromagnetic propagation under common and special geological conditions, the influence on the measured MT data is studied by the forward simulation on ordinary and special two‐dimension anisotropic electrical structure, which lays theoretical foundation for the subsequent processing and interpretation of MT data. Finally, the electrical anisotropy theory is introduced into processing and interpretation of MT data based on the results in the paper, and the widespread existence of electrical anisotropy is illuminated, and the exactness of this theory and practicability of the algorithm are verified by means of the two‐dimension forward fitting interpretation on the MT data from Xinjiang. This work would provide theoretical basis and technical guidance for analyzing and explaining the electrical anisotropy in MT data and help opens approaches for processing of measured MT data.
Immobilisation of Pb and Zn in Soils Using Stabilised Zero‐valent Iron Nanoparticles: Effects on Soil Properties
Authors: Mar Gil‐Díaz María , Pérez‐Sanz Araceli , Ángeles Vicente María , Carmen Lobo María 
Published: February 2014

AbstractThis study investigates the effectiveness of using nanoscale zero‐valent iron (nZVI) to immobilise Pb/Zn in two different soils (acidic and calcareous) and the effects of nZVI treatment on soil physico‐chemical and biological properties. Soil samples spiked with Pb(II) or Zn(II) were treated with commercial nZVI suspension at a dose of 20% (28–36 mg Fe(0)/g soil) for 72 h and one month. Sequential extraction procedures showed a significant decrease of Pb/Zn bound to exchangeable and carbonate fractions and an increase of residual fraction after the treatment with nZVI. There were no significant differences in the distribution of Pb/Zn in the soil fractions between the contact times studied; the immobilisation of Pb/Zn with nZVI in the described conditions was stable at least for a month. Better immobilisation results were found for Pb than for Zn. No negative effects on soil physico‐chemical and biological properties were observed. In fact, the application of nZVI stimulated the soil respiration and the dehydrogenase activity in both soils, especially in the case of Pb, probably due to the higher immobilisation percentages. These results suggest that the use of nZVI to remediate polluted soils with Pb or Zn is a promising in situ strategy, and more research is required both in the laboratory and field to investigate the effects of such a treatment to the soil ecosystem.
Computational and Experimental Insight into the Molecular Mechanism of Carboxamide Inhibitors of Succinate‐Ubquinone Oxidoreductase
Authors: Zhu Xiao‐Lei , Xiong Li , Li Hui , Song Xin‐Ya , Liu Jing‐Jing , Yang Guang‐Fu 
Published: February 2014

AbstractSuccinate‐ubiquinone oxidoreductase (SQR, EC 1.3.5.1), also known as mitochondrial respiratory complex II or succinate dehydrogenase (SDH), catalyzes the oxidation of succinate to fumarate as part of the tricarboxylic acid cycle. SQR has been identified as a novel target of a large family of agricultural fungicides. However, the detailed mechanism of action between the fungicides and SQR is still unclear, and the bioactive conformation of fungicides in the SQR binding pocket has not been identified. In this study, the kinetics of porcine SQR inhibition by ten commercial carboxamide fungicides were measured, and noncompetitive inhibition was observed with respect to succinate, DCIP, and cytochrome c, while competitive inhibition was observed with respect to ubiquinone. With the aim to uncover the binding conformation of these fungicides, molecular docking, molecular dynamics simulation, and molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) calculations were then performed. The excellent correlation (r2=0.94) between the calculated (ΔGcal) and experimental (ΔGexp) binding free energies indicates that the obtained docking conformation could be the bioactive conformation. The acid moiety of carboxamide fungicides inserts into the ubiquinone binding site (Q‐site) of SQR, forming van der Waals (vdW) interactions with C_R46, C_S42, B_I218, and B_P169, while the amine moiety extends to the mouth of the Q‐site, forming vdW interactions with C_W35, C_I43, and C_I30. The carbonyl oxygen atom of the carboxamide forms hydrogen bonds with B_W173 and D_Y91. These findings provide valuable information for the design of more potent and specific inhibitors of SQR.