bluuebunny/crossref_metadata_2025 huggingface dataset:
INTER-AMERICAN NOTES: CONFERENCES
Authors: Chesterton Bridget María
Published: February 2015

Between July 23 and July 25, 2014, the University of Montevideo hosted the Fourth Jornadas Internacionales de Historia del Paraguay, with sponsorship from the Universities of Georgia, Köln, and Rennes 2. Organized by Thomas Whigham and Juan Manuel Casal, the conference included 45 presenters and 70 attendees traveling to the Uruguayan capital from the United States, Germany, Spain, Italy, Paraguay, Brazil, Chile, Uruguay, and Paraguay. Students from both the National and Catholic Universities of Asunción also took part with one of their number, Claudio José Fuentes Armadans (Universidad Católica), providing an interesting presentation on the history of the Liberal Party. First-time contributors to the conference included Carlos Gómez Florentín (SUNY Stony Brook), who discussed the environmental history of the hydroelectric complex at Itaipú, and Justin Michael Heath (University of Texas, Austin), who traced the evolution of frontier security in the early Jesuit missions. The Jornadas also benefited from repeat contributors, including Ignacio Telesca (Universidad Nacional de Formosa/CONICET), who analyzed the historical content of Paraguayan textbooks in the late nineteenth and early twentieth centuries, and Bridget María Chesterton, who discussed how the “sweet herb” ka’a he’e (stevia) has affected markets and habits of consumption in more recent times.
Atomic Scale Analysis of the Enhanced Electro- and Photo-Catalytic Activity in High-Index Faceted Porous NiO Nanowires
Authors: Shen Meng , Han Ali , Wang Xijun , Ro Yun Goo , Kargar Alireza , Lin Yue , Guo Hua , Du Pingwu , Jiang Jun , Zhang Jingyu , Dayeh Shadi A. , Xiang Bin
Published: February 2015

Catalysts play a significant role in clean renewable hydrogen fuel generation through water splitting reaction as the surface of most semiconductors proper for water splitting has poor performance for hydrogen gas evolution. The catalytic performance strongly depends on the atomic arrangement at the surface, which necessitates the correlation of the surface structure to the catalytic activity in well-controlled catalyst surfaces. Herein, we report a novel catalytic performance of simple-synthesized porous NiO nanowires (NWs) as catalyst/co-catalyst for the hydrogen evolution reaction (HER). The correlation of catalytic activity and atomic/surface structure is investigated by detailed high resolution transmission electron microscopy (HRTEM) exhibiting a strong dependence of NiO NW photo- and electrocatalytic HER performance on the density of exposed high-index-facet (HIF) atoms, which corroborates with theoretical calculations. Significantly, the optimized porous NiO NWs offer long-term electrocatalytic stability of over one day and 45 times higher photocatalytic hydrogen production compared to commercial NiO nanoparticles. Our results open new perspectives in the search for the development of structurally stable and chemically active semiconductor-based catalysts for cost-effective and efficient hydrogen fuel production at large scale.
Overlapped moving windows followed by principal component analysis to extract information from chromatograms and application to classification analysis
Authors: López-Ureña Sergio , Beneito-Cambra Miriam , Donat-Beneito Rosa M. , Ramis-Ramos Guillermo
Published: February 2015

The optimal width and overlapping degree of the windows, when moving windows are used to generate variables, are systematically studied.
Engineering of unsubstituted quinoid-like frameworks enabling 2 V vs. Li+/Li redox voltage tunability and related derivatives
Authors: Tomerini D. , Gatti C. , Frayret C.
Published: February 2015

Energy stabilization of atomic groups and spin density population estimates unearth key parameters governing voltage tunability (>2 V) in bridged quinoid-like systems.
Magnetically retrievable silica-based nickel nanocatalyst for Suzuki–Miyaura cross-coupling reaction
Authors: Sharma Rakesh Kumar , Yadav Manavi , Gaur Rashmi , Monga Yukti , Adholeya Alok
Published: February 2015

A new magnetically recoverable silica-based nickel nanocatalyst was synthesized, characterized and applied for the first time as a catalyst in Suzuki–Miyaura cross-coupling reaction.
A green and sustainable approach to utilize bio-ionic liquids for the selective precipitation of high purity agarose from an agarophyte extract
Authors: Sharma Mukesh , Prakash Chaudhary Jai , Mondal Dibyendu , Meena Ramavatar , Prasad Kamalesh
Published: February 2015

Preferential precipitation of agarose was observed upon addition of choline based bio-ionic liquids in the Gracilaria dura seaweed extract. Choline laurate was found to be the most effective for the work.
Effect of precursor concentration on the properties and tuning of conductivity between p-type and n-type Cu1−XCdXS2 thin films deposited by a single step solution process as a novel material for photovoltaic applications
Authors: Nirmal Kumar V. , Suryakarthick R. , Karuppusamy S. , Gupta Mukul , Hayakawa Y. , Gopalakrishnan R.
Published: February 2015

Cu1−XCdXS2 thin films were deposited from precursor solutions having different concentrations of cation sources, by a single step solution process at room temperature.
Catalyst-free synthesis of carbon nanospheres for potential biomedical applications: waste to wealth approach
Authors: Manaf Shoriya Aruni Abdul , Roy Partha , Sharma Korada V. , Ngaini Zainab , Malgras Victor , Aldalbahi Ali , Alshehri Saad M. , Yamauchi Yusuke , Hegde Gurumurthy
Published: February 2015

A single step and simple pyrolysis technique is used to prepare carbon nanospheres (CNSs) from natural biowaste sago hampas in a nitrogen atmosphere without any catalyst.
Novel pyridinium oximes: synthesis, molecular docking and in vitro reactivation studies
Authors: Pooja Pooja , Aggarwal S. , Tiwari A. K. , Kumar V. , Pratap R. , Singh G. , Mishra A. K.
Published: February 2015

A computational approach has been attempted for the screening of 4-pyridoxinium (4P) ring based reactivators for paraoxon inhibited AChE.
Synthesis of bismuth oxyiodides and their composites: characterization, photocatalytic activity, and degradation mechanisms
Authors: Lee Wenlian William , Lu Chung-Shin , Chuang Chung-Wei , Chen Yen-Ju , Fu Jing-Ya , Siao Ciao-Wei , Chen Chiing-Chang
Published: February 2015

Schematic diagram of synthesis method for as-prepared BiOxIy/BiOpIq under different conditions.
Oxidation of SO2 and NO by epoxy groups on graphene oxides: the role of the hydroxyl group
Authors: Cen Wanglai , Hou Meiling , Liu Jie , Yuan Shandong , Liu Yongjun , Chu Yinghao
Published: February 2015

Hydroxyl groups facilitate the oxidation of SO2 and NO by epoxy groups on carbon materials.
Selective growth of carbon nanotubes on boron-doped diamond for electrochemical biosensor application
Authors: Lee Seung-Koo , Song Min-Jung , Kim Jong-Hoon , Lim Young-Kyun , Chun Yoon-Soo , Lim Dae-Soon
Published: February 2015

Selective growth of MWCNTs on boron-doped diamond electrode was introduced and their electrochemical properties and glucose biosensing performances were reported.
A facile strategy for fabricating hierarchically mesoporous Co3O4 urchins and bundles and their application in Li-ion batteries with high electrochemical performance
Authors: Yang Tao , Liu Yangai , Huang Zhaohui , Yang Qian , Guan Ming , Fang Minghao , Wu Xiaowen
Published: February 2015

Hierarchical mesoporous urchin-like and bundle-like Co3O4 were selectively synthesized via calcining the novel precursor. The morphology evolution mechanism was revealed. The enhanced lithium storage properties of the mesoporous Co3O4 were investigated.
Colloid-probe AFM studies of the interaction forces of proteins adsorbed on colloidal crystals
Authors: Singh Gurvinder , Bremmell Kristen E. , Griesser Hans J. , Kingshott Peter
Published: February 2015

A colloid-probe AFM based approach investigates the interaction between protein coatings on colloid probes and surfaces decorated with close-packed colloidal crystal layers.
Binding of pyrazine-functionalized calix[4]arene ligands with lanthanides in an ionic liquid: thermodynamics and coordination modes
Authors: Ansari Seraj A. , Mohapatra Prasanta K. , Verboom Willem , Zhang Zhicheng , Dau Phuong D. , Gibson John K. , Rao Linfeng
Published: February 2015

Complexation thermodynamics of Eu3+ with pyrazine-functionalized calix[4]arene in ionic liquid was investigated by absorption spectroscopy, luminescence spectroscopy and microcalorimetry.
Iron catalysed Negishi cross-coupling using simple ethyl-monophosphines
Authors: Brown Caleb A. , Nile Terence A. , Mahon Mary F. , Webster Ruth L.
Published: February 2015

Reported is a rare example of the use of monophosphines in iron catalysed Negishi cross-coupling. Substrate scope in terms of alkyl bromide and diaryl zinc reagent is explored.
Unexpected fragmentations of triphosphaferrocene – formation of supramolecular assemblies containing the (1,2,4-P3C2Mes2)− ligand
Authors: Heindl Claudia , Kuntz Andrea , Peresypkina Eugenia V. , Virovets Alexander V. , Zabel Manfred , Lüdeker David , Brunklaus Gunther , Scheer Manfred
Published: February 2015

An unusual fragmentation of a triphosphaferrocene is observed, when it is reacted with Cu(i) halides. As a result, a large variety of different monomeric, dimeric and 1D and 2D polymeric coordination compounds are formed.
Synthesis and characterization of [Fe(BPMEN)ACC]SbF6: a structural and functional mimic of ACC-oxidase
Authors: Roux Y. , Ghattas W. , Avenier F. , Guillot R. , Simaan A. J. , Mahy J.-P.
Published: February 2015

Miming plants: an original synthesis led to the preparation of the first model of the active site of the ethylene-forming enzyme ACC-oxidase. The prepared complex is a structural and a functional model as it reacts with hydrogen peroxide to produce the phytohormone ethylene.
Partial oxidation of light alkanes by periodate and chloride salts
Authors: Kalman Steven E. , Munz Dominik , Fortman George C. , Boaz Nicholas C. , Groves John T. , Gunnoe T. Brent
Published: February 2015

The efficient and selective partial oxidation of light alkanes using potassium periodate and potassium chloride is reported.
Dalton Discussion 15 – Metal ions in medical imaging: optical, radiopharmaceutical and MRI contrast, 8th–10th September 2014, York
Authors: Archibald Stephen J. , Tripier Raphaël
Published: February 2015

Welcome to this Dalton Transactions themed issue including papers from Dalton Discussion 15 – Metal ions in medical imaging: optical, radiopharmaceutical and MRI contrast.
Tetraphenylethene modified [n]rotaxanes: synthesis, characterization and aggregation-induced emission behavior
Authors: Liu Guoxing , Wu Di , Liang Jinhua , Han Xie , Liu Sheng Hua , Yin Jun
Published: February 2015

A series of novel [n]rotaxanes based on a tetraphenylethene (TPE) backbone were constructed by a template-directed clipping approach and their structures were well-characterized.
Investigations into the decomposition of aminoacyl-substituted monosaccharide scaffolds from a drug discovery library
Authors: He Q. Q. , Wimmer N. , Verquin G. , Meutermans W. , Ferro V.
Published: February 2015

Decomposition of aminoacyl-substituted d-galactoside scaffolds under acidic conditions is dependent on the length of the side chain and is accelerated by the presence of a free hydroxyl group at C-6. In the latter case, evidence is provided that the reaction occurs via an N- to O-acyl transfer.
A novel approach for testing the teratogenic potential of chemicals on the platform of metabolomics: studies employing HR-MAS nuclear magnetic resonance spectroscopy
Authors: Sethi Nikunj , Mahar Rohit , Shukla Sanjeev K. , Kumar Akhilesh , Sinha Neeraj
Published: February 2015

The objective is to develop a quick, reliable method for testing the teratogenic potential of a new chemical entity (NCE) on the platform of metabonomics, as an alternative to conventional procedures.
Hydrothermal synthesis of zinc oxide-reduced graphene oxide nanocomposites for an electrochemical hydrazine sensor
Authors: Ding Junwei , Zhu Shiying , Zhu Tao , Sun Wei , Li Qing , Wei Gang , Su Zhiqiang
Published: February 2015

A facile hydrothermal method is utilized to synthesize zinc oxide-reduced graphene oxide nanocomposites for an electrochemical hydrazine sensor.
Acylation or phosphorylation of hydroxyurea unexpectedly takes place on N rather than on O, leading to the formation of amides instead of the expected esters
Authors: Pariente-Cohen Natalie , Weitman Michal , Tania Nassdyuk , Major Dan T. , Gottlieb Hugo E. , Hoz Shmaryahu , Nudelman Abraham
Published: February 2015

Attempted acylation of the anticancer agent hydroxyurea (HU) with acyl chlorides or anhydrides led to acylation on the NH group rather than on the OH.
Towards highly efficient photoanodes: the role of carrier dynamics on the photoelectrochemical performance of InGaN/GaN multiple quantum well coaxial nanowires
Authors: Ebaid Mohamed , Kang Jin-Ho , Lim Seung-Hyuk , Cho Yong-Hoon , Ryu Sang-Wan
Published: February 2015

The carrier dynamics in highly active InGaN/GaN coaxial nanowire photoanodes were studied for photoelectrochemical water splitting applications that can provide deeper insight to enhance the photon-to-electron conversion efficiency.
Hydrogen cycling in γ-Mg(BH4)2 with cobalt-based additives
Authors: Zavorotynska O. , Saldan I. , Hino S. , Humphries T. D. , Deledda S. , Hauback B. C.
Published: February 2015

Hydrogen desorption and absorption properties of magnesium borohydride (Mg(BH4)2) were studied for three cycles. Effect of cobalt additives and their local structure upon cycling were investigated in detail.
Modelling and performance of a hybrid synchronous reluctance machine with adjustable Xd/Xq ratio
Authors: Anih Linus U. , Obe Emeka S. , Abonyi Sylvester E.
Published: February 2015

Analytical and experimental studies of a hybridised synchronous reluctance machine with a variable Xd/Xq ratio characteristic is the subject of this study. The machine comprises a round rotor and a salient pole machine element that is mechanically coupled together and integrally wound. There are two sets of poly‐phase windings in each stator. The windings of one of the sets are transposed between the two sections of the machine. Either set of the windings may be connected to the supply while the other feeds a balanced capacitance load. It is shown that by tuning of the capacitance load that the Xd/Xq ratio varies theoretically from zero to infinity at very good power factors. The machine characteristics were verified using the generalised two‐axis theory and validated by experimentation. The experimental and analytical results obtained show good agreement. Saturation was investigated by using the variation of the d‐axis inductance with machine loading. A set of rotor windings may be introduced for the purpose that the machine be self‐starting and self‐synchronising as a motor. The rotor field windings when fed with dc, will make the machine also capable of operation as a stand‐alone salient‐pole generator. For this purpose, it was shown that for a very high saliency ratio, reluctance power can be considerably higher than the excitation power.
Switched flux hybrid magnet memory machine
Authors: Wu Di , Liu Xu , Zhu Zi Q. , Pride Adam , Deodhar Rajesh , Sasaki Toshinori
Published: February 2015

A novel switched flux permanent magnet machine (SFPMM) with both normal NdFeB and low coercive force (LCF) magnets has been developed in this paper. Outside a conventional SFPMM, the LCF magnets are mounted on the back of every U‐shaped stator lamination segment with parallel magnetisation direction and alternative polarities. A lamination ring yoke is placed around all the LCF magnets, while extra magnetisation coils are wound on each of them. By injecting different directions of current pulses into the magnetisation coils, the polarities of the LCF magnets can be rewritten in order to enhance or weaken the field generated by normal NdFeB magnets. Therefore the back EMF and torque capability could be adjusted in a wide range. In this paper, the operation principle and machine topology are introduced firstly. Then the stator/rotor pole combinations and design considerations of the machine have been discussed. With the help of two‐dimensional finite element software, a 6/5 stator/rotor pole machine has been globally optimised as an example to show the machine performances such as open‐circuit field and back EMF, dq‐axis inductances, torque capabilities and magnetisation. Finally, a prototype with the same dimensions has been manufactured and tested to validate the analysis results.
Hydrothermal synthesis and controlled growth of tungsten disulphide nanostructures from one‐dimension to three‐dimensions
Authors: Cao Shixiu , Liu Tianmo , Zeng Wen , Hussain Shahid , Peng Xianghe
Published: February 2015

Three kinds of tungsten disulphide (WS2) such as nanospheres, nanowires and nanobelts have been synthesised using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The structural features of the as‐prepared WS2 were characterised by X‐ray powder diffraction and scanning electron microscopy. The CTAB surfactants played a critical role in producing different WS2 nanostructures. The growth mechanism of WS2 nanostructures is proposed in detail and the schematic representation of the formation mechanism is also shown. Also, the optical absorption property of the WS2 nanostructures was investigated. This reported work may be helpful to investigate structurally other metal chalcogenide materials with different morphologies.
Influence of water on supra-molecular assembly of 4, 4′-dihydroxy azobenzene on Ag(111)
Authors: Henzl Jörg , Boom Konrad , Morgenstern Karina
Published: February 2015

We explore co-deposition of water and 4, 4′-dihydroxy azobenzene on Ag(111) by low-temperature scanning tunneling microscopy at different water-to-azobenzene ratios. At all ratios, the water interacts with the hydroxyl end groups of the molecule replacing the direct hydrogen bonding. The change in bonding reduces the azobenzene density as compared to the one in the closed-packed waterless azobenzene structure. At intermediate water-to-azobenzene ratios, pores are formed in the azobenzene layer at nanometer distance from the water. At high water-to-azobenzene ratios, a water superstructure with a 1.4 nm × 1.4 nm unit cell develops. Our results point to a method to vary the density of an organic layer by tuning the amount of an inorganic additive.
Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering
Authors: Sikdar Debabrata , Cheng Wenlong , Premaratne Malin
Published: February 2015

Cubic dielectric nanoparticles are promising candidates for futuristic low-loss, ultra-compact, nanophotonic applications owing to their larger optical coefficients, greater packing density, and relative ease of fabrication as compared to spherical nanoparticles; besides possessing negligible heating at nanoscale in contrast to their metallic counterparts. Here, we present the first theoretical demonstration of azimuthally symmetric, ultra-directional Kerker's-type scattering of simple dielectric nanocubes in visible and near-infrared regions via simultaneous excitation and interference of optically induced electric- and magnetic-resonances up to quadrupolar modes. Unidirectional forward-scattering by individual nanocubes is observed at the first generalized-Kerker's condition for backward-scattering suppression, having equal electric- and magnetic-dipolar responses. Both directionality and magnitude of these unidirectional-scattering patterns get enhanced where matching electric- and magnetic-quadrupolar responses spectrally overlap. While preserving azimuthal-symmetry and backscattering suppression, a nanocube homodimer provides further directionality improvement for increasing interparticle gap, but with reduced main-lobe magnitude due to emergence of side-scattering lobes from diffraction-grating effect. We thoroughly investigate the influence of interparticle gap on scattering patterns and propose optimal range of gap for minimizing side-scattering lobes. Besides suppressing undesired side-lobes, significant enhancement in scattering magnitude and directionality is attained with increasing number of nanocubes forming a linear chain. Optimal directionality, i.e., the narrowest main-scattering lobe, is found at the wavelength of interfering quadrupolar resonances; whereas the largest main-lobe magnitude is observed at the wavelength satisfying the first Kerker's condition. These unique optical properties of dielectric nanocubes thus can revolutionize their applications at visible and near-infrared regions in the fields of nanoantennas, nanolasers, photovoltaics, and even in biomedicine.
Correlation consistent basis sets for the atoms In–Xe
Authors: Mahler Andrew , Wilson Angela K.
Published: February 2015

In this work, the correlation consistent family of Gaussian basis sets has been expanded to include all-electron basis sets for In–Xe. The methodology for developing these basis sets is described, and several examples of the performance and utility of the new sets have been provided. Dissociation energies and bond lengths for both homonuclear and heteronuclear diatomics demonstrate the systematic convergence behavior with respect to increasing basis set quality expected by the family of correlation consistent basis sets in describing molecular properties. Comparison with recently developed correlation consistent sets designed for use with the Douglas-Kroll Hamiltonian is provided.
Selection of conformational states in self-assembled surface structures formed from an oligo(naphthylene–ethynylene) 3-bit binary switch
Authors: Ning Y. , Cramer J. R. , Nuermaimaiti A. , Svane K. , Yu M. , Lægsgaard E. , Besenbacher F. , Xue Q.-K. , Ma X. , Hammer B. , Gothelf K. V. , Linderoth T. R.
Published: February 2015

Supra-molecular self-assembly on surfaces often involves molecular conformational flexibility which may act to enrich the variation and complexity of the structures formed. However, systematic and explicit investigations of how molecular conformational states are selected in surface self-assembly processes are relatively scarce. Here, we use a combination of high-resolution scanning tunneling microscopy and Density Functional Theory (DFT) calculations to investigate self-assembly for a custom-designed molecule capable of assuming eight distinct surface conformations (four enantiomeric pairs). The conformations result from binary positions of n = 3 naphtalene units on a linear oligo(naphthylene-ethynylene) backbone. On Au(111), inter-molecular interactions involving carboxyl and bulky tert-butyl-phenyl functional groups induce the molecules to form two ordered phases with brick-wall and lamella structure, respectively. These structures each involve molecules in two conformational states, and there is a clear separation between the conformers involved in the two types of structures. On Cu(111), individual molecules isolated by carboxylate-substrate binding show a distribution involving all possible conformational states. Together these observations imply selection and adaptation of conformational states upon molecular self-assembly. From DFT modeling and statistical analysis of the molecular conformations, the observed selection of conformational states is attributed to steric interaction between the naphthalene units. The present study enhances our understanding of how ordering and selection of molecular conformations is controlled by intermolecular interactions in a complex situation with many distinct conformational states for the participating molecules.
Self-assembly of indole-2-carboxylic acid at graphite and gold surfaces
Authors: De Marchi Fabrizio , Cui Daling , Lipton-Duffin Josh , Santato Clara , MacLeod Jennifer M. , Rosei Federico
Published: February 2015

Model systems are critical to our understanding of self-assembly processes. As such, we have studied the surface self-assembly of a small and simple molecule, indole-2-carboxylic acid (I2CA). We combine density functional theory gas-phase (DFT) calculations with scanning tunneling microscopy to reveal details of I2CA assembly in two different solvents at the solution/solid interface, and on Au(111) in ultrahigh vacuum (UHV). In UHV and at the trichlorobenzene/highly oriented pyrolytic graphite (HOPG) interface, I2CA forms epitaxial lamellar structures based on cyclic OH⋯O carboxylic dimers. The structure formed at the heptanoic acid/HOPG interface is different and can be interpreted in a model where heptanoic acid molecules co-adsorb on the substrate with the I2CA, forming a bicomponent commensurate unit cell. DFT calculations of dimer energetics elucidate the basic building blocks of these structures, whereas calculations of periodic two-dimensional assemblies reveal the epitaxial effects introduced by the different substrates.
Coherent scattering of electromagnetic waves by self-organized dust structures: Degree of coherence
Authors: Tsytovich Vadim , Gusein-zade Namik , Ignatov Alexander
Published: February 2015

It is demonstrated explicitly that the scattering of electromagnetic waves by dust structures can be strongly enhanced as compared to incoherent scattering by random electrons. If the size of the dust structure is much less than the wavelength of the incident radiation, the scattering is coherent. In this case, the scattering is proportional to the square of the total number of electrons in the structure. In the opposite limit, the scattering is incoherent being proportional to the total number of electrons in the structure. The factor describing the degree of coherency is calculated numerically for several models of self-organized structures. It is demonstrated in general way that for sudden heating of electrons, the factor of coherency in scattering by structures can decrease by several orders of magnitude with subsequent increase after the heating is switched off. In laboratory dusty plasmas, the coherent scattering is proposed for diagnostics of universal structuring instability and as a probe for determining the properties typical for self-organized nature of structures that are observed in recent experiments.
Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time
Authors: Nguyen Vanthan , Yan Lihe , Si Jinhai , Hou Xun
Published: February 2015

Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG200N) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.
Dynamic properties of force fields
Authors: Vitalini F. , Mey A. S. J. S. , Noé F. , Keller B. G.
Published: February 2015

Molecular-dynamics simulations are increasingly used to study dynamic properties of biological systems. With this development, the ability of force fields to successfully predict relaxation timescales and the associated conformational exchange processes moves into focus. We assess to what extent the dynamic properties of model peptides (Ac-A-NHMe, Ac-V-NHMe, AVAVA, A10) differ when simulated with different force fields (AMBER ff99SB-ILDN, AMBER ff03, OPLS-AA/L, CHARMM27, and GROMOS43a1). The dynamic properties are extracted using Markov state models. For single-residue models (Ac-A-NHMe, Ac-V-NHMe), the slow conformational exchange processes are similar in all force fields, but the associated relaxation timescales differ by up to an order of magnitude. For the peptide systems, not only the relaxation timescales, but also the conformational exchange processes differ considerably across force fields. This finding calls the significance of dynamic interpretations of molecular-dynamics simulations into question.
Temperature dependence of the spin relaxation in highly degenerate ZnO thin films
Authors: Prestgard M. C. , Siegel G. , Roundy R. , Raikh M. , Tiwari A.
Published: February 2015

Zinc oxide is considered a potential candidate for fabricating next-generation transparent spintronic devices. However, before this can be achieved, a thorough scientific understanding of the various spin transport and relaxation processes undergone in this material is essential. In the present paper, we are reporting our investigations into these processes via temperature dependent Hanle experiments. ZnO thin films were deposited on c-axis sapphire substrates using a pulsed laser deposition technique. Careful structural, optical, and electrical characterizations of the films were performed. Temperature dependent non-local Hanle measurements were carried out using an all-electrical scheme for spin injection and detection over the temperature range of 20–300 K. From the Hanle data, spin relaxation time in the films was determined at different temperatures. A detailed analysis of the data showed that the temperature dependence of spin relaxation time follows the linear-in-momentum Dyakonov-Perel mechanism.
Thickness-dependent charge ordering state in Bi0.4Sr0.28Ca0.32MnO3 thin films under the anisotropic strain
Authors: Li Y. , Shen B. G. , Hu F. X. , Sun J. R.
Published: February 2015

We have achieved clear charge ordering (CO) state in Ca doped Bi0.4Sr0.6−xCaxMnO3 (BSCMO) films on (110)-orientated SrTiO3. The BSCMO film's CO transition temperature (TCO) was tuned to room temperature (RT) by optimum doping Ca (x = 0.32). Asymmetric x-ray reciprocal space mapping was used to determine the structure evolution of the films with thickness, in detail, under the anisotropic stress in films. We found that the CO phase only appears in thicker films, accompanied by an unique distortion in structure, in which twin-domains structure occurs with the [110] axis slightly tilting toward [1–10] and [−110] directions. The results demonstrate the effects of anisotropic stress on the structure and electronic phases in BSCMO films as thickness increases. Our works are valuable for allowing a RT study in the CO film and further operation of the devices for a practical use.
Perspective: On the relevance of slower-than-femtosecond time scales in chemical structural-dynamics studies
Authors: Coppens Philip
Published: February 2015

A number of examples illustrate structural-dynamics studies of picosecond and slower photo-induced processes. They include molecular rearrangements and excitations. The information that can be obtained from such studies is discussed. The results are complementary to the information obtained from femtosecond studies. The point is made that all pertinent time scales should be covered to obtain comprehensive insight in dynamic processes of chemical and biological importance.
Single-crystalline metal filament-based resistive switching in a nitrogen-doped carbon film containing conical nanopores
Authors: Zhuge Fei , Li Jun , Chen Hao , Wang Jun , Zhu Liqiang , Bian Baoru , Fu Bing , Wang Qin , Li Le , Pan Ruobing , Liang Lingyan , Zhang Hongliang , Cao Hongtao , Zhang Hong , Li Zhicheng , Gao Junhua , Li Kang
Published: February 2015

In this letter, we report on the resistive switching originating from the rupture/rejuvenation of single-crystalline Cu filaments in a nitrogen-doped porous carbon-based memristive device Cu/CN0.15/Pt. Cu filaments are confined in conical nanopores in CN0.15 thin films. Dislocations exist in the Cu filaments, resulting in obvious crystal lattice distortions. The Cu/CN0.15/Pt device shows outstanding high temperature retention performance for both ON and OFF states, indicating that it is promising for resistance memory applications. Furthermore, continuous RESET (ON-to-OFF switching) and SET (OFF-to-ON switching) processes could be realized indicating the adaptive learning ability of Cu/CN0.15/Pt, which has potential applications in synaptic devices.
White light emitting Ho3+-doped CdS nanocrystal ingrained glass nanocomposites
Authors: Dey Chirantan , Goswami Madhumita , Karmakar Basudeb
Published: February 2015

We report the generation of white light from Ho3+ ion doped CdS nanocrystal ingrained borosilicate glass nanocomposites prepared by the conventional melt-quench method. Near visible 405 nm diode laser excited white light emission is produced by tuning the blue emission from the Ho3+ ions, green band edge, and orange-red surface-state emissions of the nanocrystalline CdS, which are further controlled by the size of the nanocrystals. The absorption and emission spectra evidenced the excitation of Ho3+ ions by absorption of photons emitted by the CdS nanocrystals. The high color rendering index (CRI = 84–89) and befitting chromaticity coordinates (x = 0.308–0.309, y = 0.326–0.338) of white light emission, near visible harmless excitation wavelength (405 nm), and high absorbance values at excitation wavelength point out that these glass nanocomposites may serve as a prominent candidate for resin free high power white light emitting diodes.
Resonant second harmonic generation in a gallium nitride two-dimensional photonic crystal on silicon
Authors: Zeng Y. , Roland I. , Checoury X. , Han Z. , El Kurdi M. , Sauvage S. , Gayral B. , Brimont C. , Guillet T. , Mexis M. , Semond F. , Boucaud P.
Published: February 2015

We demonstrate second harmonic generation in a gallium nitride photonic crystal cavity embedded in a two-dimensional free-standing photonic crystal platform on silicon. The photonic crystal nanocavity is optically pumped with a continuous-wave laser at telecom wavelengths in the transparency window of the nitride material. The harmonic generation is evidenced by the spectral range of the emitted signal, the quadratic power dependence vs. input power, and the spectral dependence of second harmonic signal. The harmonic emission pattern is correlated to the harmonic polarization generated by the second-order nonlinear susceptibilities χzxx(2), χzyy(2) and the electric fields of the fundamental cavity mode.
Scaling relationship among indentation properties of electromagnetic materials at micro- and nanoscale
Authors: Zhou Hao , Zhang Honglong , Pei Yongmao , Chen Hao-Sen , Zhao Hongwei , Fang Daining
Published: February 2015

Electromagnetic materials have been widely employed in micro-functional devices. Using multi-field nanoindentation technique, we have investigated the local deformation behavior of various electromagnetic materials in the form of bulk materials, foils, and thin films under electric or magnetic field. Based on dimensional analysis and experimental data, a field tunable scaling relationship among hardness, reduced contact elastic modulus, and indentation work has been found. Furthermore, a method to determine the hardness and reduced modulus of electromagnetic materials is proposed, which avoids the error from estimating the indentation contact area. This work is meaningful for the characterization of mechanical properties and design of devices made of electromagnetic materials.
Intercalation of p-methycinnamic acid anion into Zn-Al layered double hydroxide to improve UV aging resistance of asphalt
Authors: Peng Chao , Dai Jing , Yu Jianying , Yin Jian
Published: February 2015

A UV absorber, p-methycinnamic acid (PMCA), was intercalated into Zn-Al layered double hydroxide (LDH) by calcination recovery. Fourier transform infrared spectroscopy showed that the PMCA anions completely replaced the CO32− anions in the interlayer galleries of Zn-Al-LDH containing PMCA anions (Zn-Al-PMCA-LDH). X-ray diffraction and transmission electron microscopy showed that the interlayer distance increased from 0.78 nm to 1.82 nm after the substitution of PMCA anions for CO32− anions. The similar diffraction angles of the CO32− anion-containing Zn-Al-LDH (Zn-Al-CO32−-LDH) and the Zn-Al-CO32−-LDH/styrene–butadiene–styrene (SBS) modified asphalt implied that the asphalt molecules do not enter into the LDH interlayer galleries to form separated-phase structures. The different diffraction angles of Zn-Al-PMCA-LDH and Zn-Al-PMCA-LDH/SBS modified asphalt indicated that the asphalt molecules penetrated into the LDH interlayer galleries to form an expanded-phase structure. UV-Vis absorbance analyses showed that Zn-Al-PMCA-LDH was better able to block UV light due to the synergistic effects of PMCA and Zn-Al-LDH. Conventional physical tests and atomic force microscopy images of the SBS modified asphalt, Zn-Al-CO32−-LDH/SBS modified asphalt and Zn-Al-PMCA-LDH/SBS modified asphalt before and after UV aging indicated that Zn-Al-PMCA-LDH improved the UV aging resistance of SBS modified asphalts.
Various pH-Dependent Copper(II) Coordination Architectures Constructed from N,N′-Di(3-pyridyl)succinamide and Two Different Dicarboxylates
Authors: Wang Xiu-Li , Sui Fang-Fang , Lin Hong-Yan , Liu Guo-Cheng
Published: February 2015

Using a bis-pyridyl-bis-amide N,N′-di(3-pyridyl)succinamide (L) and two dicarboxylates as mixed ligands, four 2D copper(ii) metal–organic networks, formulated as [Cu(1,4-chdc)(L)]·3H2O (1), [Cu(1,4-chdc)(L)]·H2O (2), [Cu(2,5-tdc)(L)]·H2O (3), and [Cu(2,5-tdc)(L)]·2H2O (4) (L = N,N′-di(3-pyridyl)succinimide; 1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid; 2,5-H2tdc = thiophen-2,5-dicarboxylic acid) have been hydrothermally synthesized under different pH conditions, and characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Compound 1, formed at pH 5.4, contains two rare types of left-, right-handed [Cu-L]n helix chains, which are further connected by [Cu-1,4-chdc]n zigzag chains, affording a 2D wave-like polymeric network. Compound 2 was obtained at pH 5.9, and shows a 2D square-grid layer constructed from zigzag [Cu-L]n chains and linear [Cu-1,4-chdc]n chains. Compounds 3 and 4 possess a similar 2D grid layer to that of 2 with 44-sql topology, formed at pH 4.8 and 5.4 respectively, and are constructed from zigzag [Cu-L]n chains and linear [Cu-2,5-tdc]n chains. The effects of pH and secondary dicarboxylates on the diversity of structures are discussed. In addition, the thermal stabilities, photoluminescence properties, and photocatalytic activity of compounds 1–4 were also studied.
Low knowledge of physical health behaviours is associated with poor diet and chronic illness in adults
Authors: Stanton Robert , Scott David , Happell Brenda
Published: February 2015

Governments invest heavily in health promotion strategies to improve physical health behaviours. However, the dietary and physical activity practices of many Australians fail to meet minimum levels for health, leading to the unacceptably high prevalence of chronic and complex illness. Health literacy is known to impact on health behaviour, and to be related to health knowledge; however, no studies have specifically examined knowledge of physical health behaviours in an Australian context. We assessed knowledge of physical health behaviours in 1244 adults in Queensland, Australia. Almost two-thirds of respondents had a ‘Good’ knowledge of physical health behaviour. People with ‘Good’ knowledge of physical health behaviours were more likely to be female, educated beyond secondary school, be employed and have an annual household income of >$52000 (P<0.05). People with ‘Low’ knowledge of physical health behaviours were significantly more likely to report insufficient intake of vegetables and have at least one chronic illness (P<0.05). Binary logistic regression shows low daily intake of vegetables to have the strongest association with low knowledge of physical health behaviours. Given the association between health knowledge and health literacy, assessment of the knowledge of physical health behaviours may provide considerable insight into the effectiveness of future health promotion interventions.
Increased profile wettability in texture-contrast soils from clay delving: case studies in South Australia
Authors: Betti Giacomo , Grant Cameron , Churchman Gordon , Murray Robert
Published: February 2015

Clay delving is becoming a popular practice to increase productivity of texture-contrast soils in southern Australia. The practice brings subsoil clay to the surface to be mixed with the sandy topsoil, and unlike clay spreading, it combines the addition of hydrophilic material with a ripping effect that disrupts the sharp boundary between the sandy topsoil and clayey subsoil. Our objective was to evaluate the magnitude of effects caused by delving on the spatial distribution of water through the profile for three Sodosols (Stagnic Solonetz soils) in the south-east of South Australia. We also wished to evaluate the extent to which clay delving might reduce water ponding at the A–B horizon interface. We wetted both delved and undelved texture-contrast soils with a Brilliant Blue dye solution under initially dry and wet conditions (to evaluate the effect of antecedent water content), and then took digital images of the stained profiles for quantitative comparison of the wetted areas.
The stained soil profiles indicated that clay delving reduced preferential water flow (finger flow) and resulted in deeper and more uniform wetting of the A horizon, particularly under initially dry conditions. Under wet conditions (where water repellence was largely overcome), finger flow was significantly reduced regardless of delving but it still occurred to varying degrees depending on site characteristics. Delving significantly reduced ponding of water at the A–B horizon boundary and allowed greater penetration into the B horizon. At all sites, greater effects occurred directly on the delving lines and diminished with distance, implying that closer spacing of delving tines would increase uniformity of wetting throughout the profile. The effectiveness of delving on profile wetting was highly variable across the three sites, indicating that the outcome depends inter alia on the intrinsic soil characteristics and the delving equipment used in the field.
Estimating Yield Losses Due to Barley Yellow Dwarf on Winter Wheat in Kansas Using Disease Phenotypic Data
Authors: Gaunce Genna M. , Bockus William W.
Published: February 2015

Barley yellow dwarf (BYD) is one of the most important wheat diseases in the state of Kansas. Despite the development of cultivars with improved resistance to BYD, little is known about the impact that this resistance has on yield loss from the disease. The intent of this research was to estimate yield loss in winter wheat cultivars in Kansas due to BYD and quantify the reduction in losses associated with resistant cultivars. During seven years, BYD incidence was visually assessed on numerous winter wheat cultivars in replicated field nurseries. When grain yields were regressed against BYD incidence scores, negative linear relationships significantly fit the data for each year and for the combined dataset covering all seven years. The models showed that, depending upon the year, 19–48% (average 33%) of the relative yields was explained by BYD incidence. For the combined dataset, 29% of the relative yield was explained by BYD incidence. The models indicated that cultivars showing the highest disease incidence that year had 25–86% (average 49%) lower yield than a hypothetical cultivar that showed zero incidence. Using the models, the moderate level of resistance in the cultivar Everest was calculated to reduce yield loss from BYD by about 73%. Therefore, utilizing visual BYD symptom evaluations in Kansas coupled with grain yields is useful to estimate yield loss from the disease.

Accepted for publication 1 December 2014. Published 9 January 2015.
Simulations of radiation damage as a function of the temporal pulse profile in femtosecond X-ray protein crystallography
Authors: Jönsson H. Olof , Tîmneanu Nicuşor , Östlin Christofer , Scott Howard A. , Caleman Carl
Published: February 2015

Serial femtosecond X-ray crystallography of protein nanocrystals using ultrashort and intense pulses from an X-ray free-electron laser has proved to be a successful method for structural determination. However, due to significant variations in diffraction pattern quality from pulse to pulse only a fraction of the collected frames can be used. Experimentally, the X-ray temporal pulse profile is not known and can vary with every shot. This simulation study describes how the pulse shape affects the damage dynamics, which ultimately affects the biological interpretation of electron density. The instantaneously detected signal varies during the pulse exposure due to the pulse properties, as well as the structural and electronic changes in the sample. Here ionization and atomic motion are simulated using a radiation transfer plasma code. Pulses with parameters typical for X-ray free-electron lasers are considered: pulse energies ranging from 104to 107 J cm−2with photon energies from 2 to 12 keV, up to 100 fs long. Radiation damage in the form of sample heating that will lead to a loss of crystalline periodicity and changes in scattering factor due to electronic reconfigurations of ionized atoms are considered here. The simulations show differences in the dynamics of the radiation damage processes for different temporal pulse profiles and intensities, where ionization or atomic motion could be predominant. The different dynamics influence the recorded diffracted signal in any given resolution and will affect the subsequent structure determination.
Mutual dependence and the “Goldilocks group”: exploring service user dependency on mutual aid recovery groups
Authors: Parkman Thomas James , Lloyd Charlie
Published: February 2015

Purpose

– The purpose of this paper is to explore the theme of dependence on mutual aid identified in a previous paper. It is a theme which to date, has had very little empirical attention, especially in a UK context.

Design/methodology/approach

– A phenomenological approach was adopted. Interviews with service users, mentors and professional staff involved with the Learning to Live Again project were undertaken over a ten-month period of data collection. Thematic analysis was used to analyse the data.

Findings

– It was found that service users with very little access to recovery capital or social support are at risk of developing a dependency on mutual aid. Dependence seemed to manifest itself in two different forms – those that over engaged with the project and those that under engaged with the project. Consequently, there were a cohort of service users identified that seemed to strike a balance with the project and their life outside the project that was “just right”. They were referred to as the “Goldilocks group”.

Originality/value

– This paper explored a theme which has had very little attention paid to it. The theme of dependence on mutual aid will raise the awareness of such a threat, thus helping to identify those in treatment most at risk of developing dependency on mutual aid, thus detrimentally impacting on mental wellbeing.
Are we doing enough to enhance attendance to aftercare? Service users’ evaluation of a group relapse prevention programme for alcohol dependence
Authors: Anand Indiresh , Smith Avril , Charge Kelly-Jo , Kouimtsidis Christos
Published: February 2015

Purpose

– The purpose of this paper was to evaluate and improve the quality of the aftercare services we provide for alcohol dependence. This presentation discusses the patient satisfaction of the Relapse Prevention Group.

Design/methodology/approach

– This was a prospective service users' satisfaction survey of those who attended the relapse prevention group programme at the Community Drug and Alcohol Team for the first 11 months of programme implementation.

Findings

– In all, 33 out of 36 people participated in the evaluation. The overall results were positive for the whole programme and people felt that the programme helped them in their recovery.

Originality/value

– Monitoring of service users’ satisfaction with aftercare services could provide insight into the barriers compromising engagement.