bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Inversion Technique for the Mechanisms of Local and Regional Earthquakes: Generalized Polarity and Amplitude Technique (I)—Principle and Numerical Tests
Authors: Chuan YAN , Li‐Sheng XU 
Published: October 2014

AbstractAn inversion technique for focal mechanisms of local and regional earthquakes, named Generalized Polarity and Amplitude Technique (GPAT), is proposed based on the progress already made over decades, and its feasibility and capability of resisting disturbance are tested by a series of numerical experiments. At first, an inversion equation system is constructed with the vectors consisting of the polarities of the P‐wave first‐motion and the maximal amplitudes of generalized phases on a basis of the concept of wave field, and a technique for solving the equation system is specified. Then, a series of experiments are conducted for testing the effect of various factors on inversion results, including distribution of observation stations, number of the stations, random noises, errors in epicenter location, errors in focal depth and errors in velocity model. Finally, a special experiment is designed to test the comprehensive effect of all the factors. The experiments suggest that the GPAT is feasible, and has a rather good capability of resisting disturbance. It must be stressed that the errors in velocity model have the strongest effect on inversion results compared with other factors.
Comparison of Inversion Method of Wide Angle Ocean Bottom Seismometer Profile: A Case Study of Profile OBS973‐2 Across Liyue Bank in the South China Sea
Authors: Xiong‐Wei NIU , Xiao‐Dong WEI , Ai‐Guo RUAN , Zhen‐Li WU 
Published: October 2014

AbstractDeep crust structure of the wide angle seismic profile OBS973‐2, which crosses the central sea basin and Liyue bank in the southern of South China Sea (SCS), represents one of the direct evidences for conjugate spreading and evolution of SCS. For this reason, we remodeled the data by using both forward and inversion methods for a detailed crustal velocity structure, and also compared results with depth profile of multi‐channel seismic (MCS) close to OBS973‐2 for more reliable crust thickness. Comparing to former works, and according to the new velocity models, we divided the profile to three parts of continental crust (0∼200 km in the profile), continent and ocean transition (COT, 200∼280 km in the profile) and ocean crust (280∼370 km in the profile). And their crust structures are obviously different. Sediment layer in the continental crust shows a feature of horizontal variations in both thickness and velocity, and total crust thickness in continental part is thick (about 20 km). In the COT, both thickness and velocity are horizontally smooth, and the total thickness of crust is thinner (about 8 km). And in the ocean crust, the crust thickness thins to 6 km. There are two main conclusions, (1) the method of using data collected by wide angle seismic and multi‐channel seismic and using both forward and inversion software in modeling will obtain more reliable information of crust structure, (2) the new insights on the crust structure are as follows. (a) We get the seaward thinning of Moho and its depth of about 12∼18 km below the sea level in COT from both wide angle and multi‐channel seismic profiles. (b) No high velocity layer was found beneath COT, which represents non volcanic passive continental margin and its conjugate spreading point is Zhongsha massif. (c) Heavy extension occurred in upper crust of continental part, which shows horizontal velocity anomalies and low velocity zone in the velocity model and a large number of normal faults in the multi‐channel seismic profile.
Ring Opening of N‐Sulfonyl Aziridines by Amines in Silica‐Water
Authors: Li Tiantian , Ma Xiaosi , Qi Junmei , Sun Feifei , Ma Ning 
Published: October 2014

AbstractRing opening reactions of N‐sulfonyl aziridines by primary and secondary amines in silica gel (SG)‐water system were achieved, which provided a mild, practical and environmentally benign method to synthesize mono‐ and bis‐sulfonyl substituted amines. When primary and secondary amines were used in excess, they reacted with N‐sulfonyl aziridines smoothly at room temperature, mainly affording 1:1 ring opening products. Reactions of primary amines with 2 equiv. of aziridines produced 2:1 ring opening products. Some 1:1 products can be cyclized with CS2 to synthesize N‐sulfonyl cyclothioureas also in water.
Synthesis and Surface Activity Study of a Novel Branched Fluorinated Anion Surfactant with CF3CF2CF2C(CF3)2 Group
Authors: Sha Min , Pan Renming , Zhan Lewu , Xing Ping , Jiang Biao 
Published: October 2014

AbstractA novel branched fluorinated anion surfactant 4‐(3,3,4,4,5,5,5‐heptafluoro‐2,2‐bis‐tri‐fluoromethyl‐pentyl)benzene lithium phosphonate was successfully synthesized via a four‐step route using perfluoro‐2‐methyl‐2‐pentene as starting material. The surface activity was investigated. The result showed that the cmc value of the surfactant in water is about 1.5×10−2 mol/L at 298 K and the surface tension of the aqueous solution is 19.2 mN/m at the cmc.
Ni(II) Ternary Complex Based on Antimicrobial Drug Enoxacin: Synthesis and Biological Properties
Authors: Huang Wanyun , Kong Shilin , Wang Zhongchang , Pan Chengxue , Zhu Hailiang 
Published: October 2014

AbstractFirst Ni(II) ternary complex using the quinolone antibacterial agent enoxacin (HEn) as ligand and 1,10‐phenanthroline as co‐ligand has been synthesized and characterized. It is a mononuclear structure, in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom. The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants (6.40×104 and 7.12×104, respectively). The investigation of the interaction of the complex with calf‐thymus (CT) DNA has been performed with UV and circular dichroism (CD) spectroscopies, indicating that they bind to CT DNA probably by the intercalative binding mode. The binding constant (Kb) of the complex with CT DNA calculated with UV is 2.03×105, which is higher than that of free enoxacin drug (2.09×104) and even higher than that of typical intercalation indicator (1.23×105) of ethidium bromide (EB). Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA‐bound EB using the intercalative binding site. In addition, the antimicrobial activity showed that the complex exhibited a little bit good inhibition (MIC=1.843 (g·mL−1) against B. subtilis than free HEn.
Diastereoselective Nitroaldol Reaction Catalyzed by Binuclear Copper(II) Complexes in Aqueous Medium
Authors: Arunachalam Rajendran , Aswathi Chirayil S. , Das Anjan , Kureshy Rukhsana I. , Subramanian Palani S. 
Published: October 2014

AbstractPolydentate ligands 1 and 2, which incorporate a terminal pyridyl moiety and an oxygen‐rich oxalate dihydrizide/malonic dihydrizide spacer moiety, as well as their binuclear metal complexes [Cu212] and [Cu222], which adopt a 1:1 metal/ligand ratio, were synthesized and characterized. Both complexes were screened for their catalytic activity in the nitroaldol reaction, in which [Cu212] worked efficiently as catalyst for both substituted benzaldehyde and pyridinecarboxaldehyde, whereas [Cu222] is highly substrate specific and showed activity towards nitro‐substituted aldehydes and pyridinecarboxaldehyde. Furthermore, as helicates are intrinsically chiral, the stereochemical architecture in the binuclear double‐stranded Cu2 helicates as catalyst favored the diastereoselective syn product with nitroethane and nitropropane and their respective diastereoselectivities were determined by using 1H NMR spectroscopy.
Multiple output differential OTA with linearizing bulk‐driven active‐error feedback loop for continuous‐time filter applications
Authors: Szczepanski Stanislaw , Pankiewicz Bogdan , Koziel Slawomir , Wojcikowski Marek 
Published: October 2014

SummaryA CMOS circuit realization of a highly linear multiple‐output differential operational transconductance amplifier (OTA) has been proposed. The presented approach exploits a differential pair as an input stage with both the gate and the bulk terminals as signal ports. For the proposed OTA, improved linearity is obtained by means of the active‐error feedback loop operating at the bulk terminals of the input stage. SPICE simulations of the OTA show that, for 0.35 µm AMS process, total harmonic distortion at 1.36Vpp is less than 1% with dynamic range equal to 60.1 dB at power consumption of 276 μW from 3.3 V supply. As an example, both single output and dual differential OTAs are used to design third‐order elliptic low‐pass filters. The cut‐off frequency of the filters is 1 MHz. The power consumption of the OTA‐C filter utilizing the dual output differential OTA is reduced to 1.24 mW in comparison to 2.2 mW consumed by the single output differential OTA‐C filter counterpart. Copyright © 2014 John Wiley & Sons, Ltd.
A metagenomics‐based approach to the top‐down effect on the detritivore food web: a salamanders influence on fungal communities within a deciduous forest
Authors: Walker Donald M. , Lawrence Brandy R. , Esterline Dakota , Graham Sean P. , Edelbrock Michael A. , Wooten Jessica A. 
Published: October 2014

AbstractThe flow of energy within an ecosystem can be considered either top‐down, where predators influence consumers, or bottom‐up, where producers influence consumers. Plethodon cinereus (Red‐backed Salamander) is a terrestrial keystone predator who feeds on invertebrates within the ecosystem. We investigated the impact of the removal of P. cinereus on the detritivore food web in an upland deciduous forest in northwest Ohio, U.S.A. A total of eight aluminum enclosures, each containing a single P. cinereus under a small log, were constructed in the deciduous forest. On Day 1 of the experiment, four salamanders were evicted from four of the eight enclosures. Organic matter and soil were collected from the center of each enclosure at Day 1 and Day 21. From each sample, DNA was extracted, fungal‐specific amplification performed, and 454 pyrosequencing was used to sequence the nuclear ribosomal internal transcribed spacer (ITS2) region and partial ribosomal large subunit (LSU). Changes in overall fungal community composition or species diversity were not statistically significant between treatments. Statistically significant shifts in the most abundant taxonomic groups of fungi were documented in presence but not absence enclosures. We concluded that P. cinereus does not affect the overall composition or diversity of fungal communities, but does have an impact on specific groups of fungi. This study used a metagenomics‐based approach to investigate a missing link among a keystone predator, P. cinereus, invertebrates, and fungal communities, all of which are critical in the detritivore food web.
Effects of Ultrasonic Agitation on the Structural and Magnetic Properties of CoFe2O4 Nanocrystals
Authors: Almeida Silva Anielle Christine , Gratens Xavier , Chitta Valmir Antonio , Franco Sinésio Domingues , Souza da Silva Ricardo , Condeles José Fernando , Dantas Noelio Oliveira 
Published: October 2014

AbstractCobalt ferrite nanocrystals (CoFe2O4) were synthesized by means of ultrasonic agitation and afterward subjected to different annealing temperatures. The structural and morphological properties of the nanocrystals were investigated by means of X‐ray diffraction and scanning electron microscopy. The results showed that the samples were composed of CoFe2O4 monophase nanocrystals. The particle size increased with increasing annealing temperatures. Infrared spectroscopy and magnetization showed that the samples exhibited the usual features of CoFe2O4 nanocrystals. Superparamagnetism was not observed at room temperature. However, the results indicated that the samples could be considered single‐domain particles with blocking temperatures greater than 300 K. Both infrared and magnetic results indicated possible diffusion of cobalt ions from tetrahedral to octahedral sites as a function of the annealing temperature.
β‐Tetrasubstituted meso‐Tetra(4′‐n‐butylphenyl)porphyrins and Their Metal Complexes: Synthesis and Structural Properties
Authors: Bhyrappa Puttaiah , Sarangi Ujwal K. , Velkannan Veerapandian , Ramkumar Venkatachalam 
Published: October 2014

AbstractA new family of ‐tetrasubstituted porphyrins, 2,3,12,13‐tetra[phenylethynyl (PE)/4‐methoxyphenyl (4″‐CH3OPh)/4‐carboxy methylesterphenyl (4″‐CH3CO2Ph)]‐5,10,15,20‐tetrakis(4′‐n‐butylphenyl)porphyrin, H2T(4′‐BuPh)P(R)4 and their metal (CoII, CuII and ZnII) complexes were synthesized using H2T(4′‐BuPh)PBr4 as the precursor. These porphyrins show red‐shifted absorption bands and follow the nature of the β‐pyrrole substituent, R: PE > Br > 4″‐CO2CH3Ph ≈ 4″‐OCH3Ph. Crystal structures of MT(4′‐BuPh)P(PE)4 (M = 2H, CoII, CuII and ZnII) derivatives were determined by single‐crystal XRD and they are isomorphous. The normal coordinate structure decomposition analysis of these structures reveal a slight wave‐type of distortion of the macrocycle. Electrochemical redox properties of these derivatives show an anodic shift in potentials relative to their metallotetraphenylporphyrins (MTPPs), and this has been ascribed mainly to the electronic effect of the substituents.
A Mononuclear Manganese Complex of a Tetradentate Nitrogen Ligand – Synthesis, Characterizations, and Application in the Asymmetric Epoxidation of Olefins
Authors: Shen Duyi , Miao Chengxia , Wang Shoufeng , Xia Chungu , Sun Wei 
Published: October 2014

AbstractA new chiral manganese complex (C1) bearing a tetradentate nitrogen ligand containing chiral bipyrrolidine and benzimidazole moieties was prepared. The structure of C1 was confirmed by ESI‐MS and crystallography. This manganese complex is an active catalyst for the asymmetric epoxidation of various olefins with excellent conversion (up to 99 %) and high enantiomeric excess (up to 96 % ee) with hydrogen peroxide as the oxidant in the presence of 2‐ethylhexanoic acid or acetic acid. Compared with previous structurally similar manganese complexes with different diamine backbones (C2, cyclohexanediamine; C3, diamine from L‐proline), C1 showed improved asymmetric induction, especially for simple olefins such as styrene derivatives and substituted chromene. The possible reasons for the improvement of the ee values are discussed in the text on the basis of the crystal structures of the manganese complexes.
Copper(II) Clusters of Two Pairs of 2,3‐Dihydroxybutanedioyl Dihydrazones: Synthesis, Structure, and Magnetic Properties
Authors: Chen Zilu , Zhou Suping , Shen Yanling , Zou Huahong , Liu Dongcheng , Liang Fupei 
Published: October 2014

AbstractCondensation reactions of (2R,3R)‐ and (2S,3S)‐2,3‐dihydroxybutanedihydrazide with salicylaldehyde and 3‐methoxysalicylaldehyde gave two enantiomeric pairs, (2R,3R)/(2S,3S)‐2,3‐dihydroxybutanedioylbis(salicylaldehydehydrazone) [(2R,3R)‐BSH and (2S,3S)‐BSH] and (2R,3R)/(2S,3S)‐2,3‐dihydroxybutanedioyl bis(3‐methoxysalicylaldehydehydrazone) [(2R,3R)‐MBSH and (2S,3S)‐MBSH]. Their reactions with CuII salts provided two chiral hexanuclear clusters [Cu6L2(C5H5N)10]2[C5H6N]3(ClO4)7·(CH3OH)·(C5H5N) [L = (2R,3R)‐BSH; (2S,3S)‐BSH] and four chiral tridecanuclear clusters [Cu13L3(OH)2(CH3COO)6(C5H5N)6(DMF)3]·6DMF·3H2O [L = (2R,3R)‐BSH; (2S,3S)‐BSH] and [Cu13X3(OH)2(CH3COO)6(C5H5N)2(DMF)8]·6H2O [X = (2R,3R)‐MBSH, (2S,3S)‐MBSH]. Their structures were determined by single‐crystal X‐ray diffraction analysis. All six compounds are enantiomers of each other. The two hexanuclear clusters exhibit two orthogonal linear trinuclear units. The two pairs of tridecanuclear clusters display esthetic structures with different symmetries; they feature rare heptanuclear vertex‐sharing dicubane cores and their six unshared CuII vertexes are linked to another six CuII ions. These represent the first examples of chiral clusters bearing dicubane cores. Magnetic studies revealed the presence of overall antiferromagnetic interactions in these compounds.
Microbial oils: A customizable feedstock through metabolic engineering
Authors: Ledesma‐Amaro Rodrigo 
Published: October 2014

In addition to animal fats and vegetable oils, microbial oils are gaining importance as a renewable feedstock for the chemical industry. One of the main advantages in the use of microorganisms to produce oils is the versatility and malleability of the microbial metabolism, which make it more easily manipulated. Thereby, the composition and properties of microbial oils can be designed through metabolic engineering. Consequently, the required chemical steps to synthesize a market product may be significantly reduced, together with the production costs. Accordingly, microorganisms have been engineered to: i) accumulate a high amount of lipids; ii) tune lipid composition; and iii) facilitate lipid extraction. Finally, microbial oils can be used as feedstock by the chemical industry to produce a huge variety of commodities, such as lubricants, polymers, fuels, coatings or surfactants.Microbial oils are considered promising alternatives to fossil fuels as feedstock for the chemical industry. Additionally they present advantages over vegetable oils and animal fats since microorganisms can be easily engineered: i) to accumulate high amount of lipids; ii) to be enriched in a desired kind of lipid; and iii) to facilitate the extraction of the oil from the cells. This short article is intended to present the concept of microbial oils to the general reader, taking into special consideration the malleability of microbial oils by metabolic engineering.
A high drying temperature causes degradation of sterols and tocopherols in yellow‐seeded Brassica napus oils
Authors: Gawrysiak‐Witulska Marzena , Rudzińska Magdalena , Siger Aleksander , Bartkowiak‐Broda Iwona 
Published: October 2014

The aim of the conducted investigations was to determine the effect of drying temperature on the changes in free fatty acid, phytosterol and tocopherol (T) contents in yellow‐seeded Brassica napus oils. Seeds were dried in a thin layer at 40, 60, 80, 100 and 120°C. Changes in phytosterols were assessed using GC‐MS, while tocopherols were assessed by HPLC. Degradation of phytosterols and tocopherols and an increased content of free fatty acids followed the applied drying temperature. During drying at 40 and 60°C, changes were statistically non‐significant, while at 120°C, losses of phytosterols reached 29% and tocopherols 23%.Practical applications: Drying of rapeseeds is an important stage of its production. However, we need to remember that these seeds are biological material highly sensitive to thermal treatment. Thus we need to search for the most advantageous conditions for their drying, with special emphasis on the preservation of bioactive components affecting human health. The analyses conducted compared the range of losses of bioactive components—phytosterols, tocopherols and plastochromanol‐8 during drying.Yellow‐seeded Brassica napus were dried in a thin layer at 40, 60, 80, 100 and 120°C. The effect of drying temperature on the free fatty acid, phytosterol and tocopherol content changes in oils was determined. Degradation of phytosterols, tocopherols and the increase in free fatty acid content were related to the applied drying temperature.
Mass propagation of Helianthus annuus suspension cells in orbitally shaken bioreactors: Improved growth rate in single‐use bag bioreactors
Authors: Werner Sören , Greulich Judith , Geipel Katja , Steingroewer Juliane , Bley Thomas , Eibl Dieter 
Published: October 2014

Stirred tank‐bioreactors made of glass or steel, wave‐mixed, and orbitally shaken bag bioreactors have all proven to be suitable for the rapid development and commercial production of bioactive compounds with plant cell suspensions. Although these bag bioreactors are characterized by reduced foam formation and less flotation in comparison to stirred systems, their power input is limited. Engineering parameters such as mixing time, oxygen transfer, and power input are dependent on the viscosity of the liquid and thus, investigations with plant cell suspensions are necessary. However, to save time and achieve better controllability, sodium carboxymethyl cellulose (Na‐CMC) solutions in concentrations ranging from 1 to 20 g L−1, with viscosities of between 0.005 and 0.4 Pa·s, were identified as appropriate model systems for mimicking plant cell suspensions with packed cell volumes of between 30 and 70 % and similar viscosities. The current study has shown that it is possible to transfer a Helianthus annuus cell suspension process from an orbitally shaken CultiBag RM 1 L to a CultiBag RM with a 10 L working volume by adjusting the operating parameters to achieve a constant kLa value. A maximum specific growth rate μmax of around 0.25 d−1 was achieved, which corresponds to optimized data for shake flasks and even exceeds the growth rate for stirred glass bioreactors.
Comparing simple and advanced tools for structural fire safety engineering
Authors: Henneton Nicolas , Renaud Christophe , Zhao Bin 
Published: October 2014

SummaryThe present paper gives an overview of the actual tools available for the estimation of the fire development and of the resulting thermal actions on structural members. A case study is developed on the basis of the Fire Safety Engineering methodology, respectively with two different approaches, one based on ‘advanced’ tools and another one based on ‘simplified’ tools. Indeed, three categories of fire models are used in this study, each of which corresponding to a different level of precision and complexity: hand calculations, zone models, and computational fluid dynamics (CFD) models. The case study is relative to the calculation of the heating of a portal frame in a gymnasium, under localised real fire conditions. It is shown through comparisons that, in this case, predictions of analytical methods are, to certain extent, in good agreement with predictions of the CFD model. In particular, it is demonstrated the relevance of using a simplified method of EN 1991‐1‐2 to predict thermal actions to vertical members. The obtained results also highlight the need to develop more relevant analytical methods in order to predict the temperature field during a fire in a large volume. Copyright © 2014 John Wiley & Sons, Ltd.
Forecast of Performance Parameters of Automotive Fuel Cell Systems – Delphi Study Results
Authors: Thoennes M. , Busse A. , Eckstein L. 
Published: October 2014

AbstractFuel cells are a promising propulsion technology option in sustainable and zero‐emission drivetrain strategies as they offer a high potential to significantly reduce well‐to‐wheel greenhouse gas emissions and the dependency on fossil energy resources. At the same time, the current technological performance of automotive fuel cell systems is not yet sufficient to meet market demands. Therefore, the technical development of fuel cells is a critical factor for a successful market introduction of fuel cell electric vehicles (FCEV). This paper describes the methodology and results of a two‐round Delphi Survey conducted by the Institut für Kraftfahrzeuge of RWTH Aachen University to assess the technological potential of polymer electrolyte membrane fuel cell (PEMFC) systems in automotive applications by 2030. The analysis of the current and future performance level of key performance indicators (KPI) of automotive fuel cell systems helps to identify critical performance parameters and to prioritize research and development demands. KPI analyzed in the Delphi Survey as forecast parameters include system efficiency, durability, power density, and specific power.