bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct numerical simulations of laminar separation bubbles: investigation of absolute instability and active flow control of transition to turbulence
Authors: Embacher Martin , Fasel H. F.
Published: April 2014

Laminar separation bubbles generated on a flat plate by an adverse pressure gradient are investigated using direct numerical simulations (DNSs). Two-dimensional periodic forcing is applied at a blowing/suction slot upstream of separation. Control of separation through forcing with various frequencies and amplitudes is examined. For the investigation of absolute instability mechanisms, baseflows provided by two-dimensional Navier–Stokes calculations are analysed by introducing pulse disturbances and computing the three-dimensional flow response using DNS. The primary instability of the time-averaged flow is investigated with a local linear stability analysis. Employing a steady flow solution as baseflow, the nonlinear and non-parallel effects on the self-sustained disturbance development are illustrated, and a feedback mechanism facilitated by the upstream flow deformation is identified. Secondary instability is investigated locally using spatially periodic baseflows. The flow response to pulsed forcing indicates the existence of an absolute secondary instability mechanism, and the results indicate that this mechanism is dependent on the periodic forcing. Results from three-dimensional DNS provide insight into the global instability mechanisms of separation bubbles and complement the local analysis. A forcing strategy was devised that suppresses the temporal growth of three-dimensional disturbances, and as a consequence, breakdown to turbulence does not occur. Even for a separation bubble that has transitioned to turbulence, the flow relaminarizes when applying two-dimensional periodic forcing with proper frequencies and amplitudes.
Effect of sampling and diagnostic effort on the assessment of schistosomiasis and soil-transmitted helminthiasis and drug efficacy: a meta-analysis of six drug efficacy trials and one epidemiological survey
Authors: LEVECKE BRUNO , BROOKER SIMON J. , KNOPP STEFANIE , STEINMANN PETER , SOUSA-FIGUEIREDO JOSE CARLOS , STOTHARD J. RUSSELL , UTZINGER JÜRG , VERCRUYSSE JOZEF
Published: April 2014

It is generally recommended to perform multiple stool examinations in order to improve the diagnostic accuracy when assessing the impact of mass drug administration programmes to control human intestinal worm infections and determining efficacy of the drugs administered. However, the collection and diagnostic work-up of multiple stool samples increases costs and workload. It has been hypothesized that these increased efforts provide more accurate results when infection and drug efficacy are summarized by prevalence (proportion of subjects infected) and cure rate (CR, proportion of infected subjects that become egg-negative after drug administration), respectively, but not when these indicators are expressed in terms of infection intensity and egg reduction rate (ERR). We performed a meta-analysis of six drug efficacy trials and one epidemiological survey. We compared prevalence and intensity of infection, CR and ERR based on collection of one or two stool samples that were processed with single or duplicate Kato-Katz thick smears. We found that the accuracy of prevalence estimates and CR was lowest with the minimal sampling effort, but that this was not the case for estimating infection intensity and ERR. Hence, a single Kato-Katz thick smear is sufficient for reporting infection intensity and ERR following drug treatment.
Changing social contact patterns under tropical weather conditions relevant for the spread of infectious diseases
Authors: CHAN T.-C. , FU Y.-C. , HWANG J.-S.
Published: April 2014

Weather conditions and social contact patterns provide some clues to understanding year-round influenza epidemics in the tropics. Recent studies suggest that contact patterns may direct influenza transmission in the tropics as critically as the aerosol channel in temperate regions. To examine this argument, we analysed a representative nationwide survey dataset of contact diaries with comprehensive weather data in Taiwan. Methods we used included model-free estimated relative changes in reproduction number, R0; relative changes in the number of contacts; and model-based estimated relative changes in mean contacts using zero-inflated negative binomial regression models. Overall, social contact patterns clearly differ by demographics (such as age groups), personal idiosyncrasies (such as personality and happiness), and social institutions (such as the division of weekdays and weekend days). Further, weather conditions also turn out to be closely linked to contact patterns under various circumstances. Fleeting contacts, for example, tend to diminish when it rains hard on weekdays, while physical contacts also decrease during weekend days with heavy rain. Frequent social contacts on weekdays and under good weather conditions, including high temperature and low absolute humidity, all might facilitate the transmission of infectious diseases in tropical regions.
Dimensions of Citizenship: Associations among Adolescents’ Sociopolitical Values and Civic Judgments
Authors: Metzger Aaron , Oosterhoff Benjamin , Palmer Cara A. , Ferris Kaitlyn
Published: April 2014

This study used a sample of 467 middle and high school students (Mage= 15.26) from a mid-Atlantic state. Structural equation models controlling for demographic variables (age, gender, and parents’ education) examined associations between three developing sociopolitical values (spiritualty, patriotism, and authoritarianism) and adolescents’ social and moral judgments (obligation and social praise) concerning four civic activities (community service, standard political involvement, social movement, and community gathering). Spirituality was associated with judgments for community service and community gathering involvement while authoritarian values were associated with the prioritization of all forms of civic activity. Multigroup analyses indicated that associations between authoritarianism and both community service and social movement judgments were stronger for younger adolescents while spirituality was more strongly associated with community service judgments for older adolescents. Patriotic beliefs were associated with civic judgments for children of college-educated parents, but not children of noncollege-educated parents.
Using a Gaming Site to Teach Campaign Strategies in the 2012 US Presidential Election
Authors: Abramson Paul R. , Kraitzman Alon P.
Published: April 2014

During the six weeks before the 2012 elections, we conducted a contest for the 54 students enrolled in an upper-division political science course on campaigns and elections. We modified and improved on a similar contest conducted by the first-named author (Abramson 2010) during the 2008 election campaign. Using contract prices posted byIntrade.com, an electronic gaming market in Dublin, we asked students to choose among 10 political outcomes. The contest was designed to help students learn about campaign strategies, understand how electoral rules affect political outcomes, and encourage them to talk about the campaign. We discuss ways we improved on Abramson’s 2008 contest and show that student participation increased substantially.
Teaching Political Theory at a Prison in South Texas
Authors: Sokoloff William W.
Published: April 2014

Taking students to a prison for a field trip creates an opportunity to engage students on issues central to democratic citizenship including democracy, power, and punishment. Although some students opt out of the prison visit, a field trip to a prison creates a vibrant learning environment where students can share their experience with other classmates as well as reflect on their experiences with authority figures. It also disrupts power relationships between students and instructors because all prison field trip participants are virtual inmates for a day.
Voters are not fools, or are they? Party profile, individual sophistication and party choice
Authors: Gerber Dominik , Nicolet Sarah , Sciarini Pascal
Published: April 2014

This article builds on V.O. Key’s postulate that voters are not fools and that they function as an echo chamber reflecting the clarity of alternatives presented to them. We first propose a reassessment of Key’s claim by examining whether and to what extent the impact of issue preferences on the vote choice depends on the clarity of parties’ profile on these issues. Our empirical tests are based on data from the 2007 Swiss election study and cover three different issues that voters may use as decision-making criteria. Our results confirm that the clearer a party’s profile on a given issue, the higher the impact of that issue on the vote for the party. Second, we offer a refinement of Key’s argument by arguing that voters’ political sophistication conditions the strength of issue voting. Empirical evidence supports this argument, but shows that the effect of political sophistication is curvilinear: sophistication exerts a stronger mediating role when a party has a moderately clear profile than when it has a low or high profile.
Timescales for detecting a significant acceleration in sea level rise
Authors: Haigh Ivan D. , Wahl Thomas , Rohling Eelco J. , Price René M. , Pattiaratchi Charitha B. , Calafat Francisco M. , Dangendorf Sönke
Published: April 2014

There is observational evidence that global sea level is rising and there is concern that the rate of rise will increase, significantly threatening coastal communities. However, considerable debate remains as to whether the rate of sea level rise is currently increasing and, if so, by how much. Here we provide new insights into sea level accelerations by applying the main methods that have been used previously to search for accelerations in historical data, to identify the timings (with uncertainties) at which accelerations might first be recognized in a statistically significant manner (if not apparent already) in sea level records that we have artificially extended to 2100. We find that the most important approach to earliest possible detection of a significant sea level acceleration lies in improved understanding (and subsequent removal) of interannual to multidecadal variability in sea level records.
Determination of eleven flavonoids in chamomile and linden extracts by capillary electrophoresis
Authors: Şanlı Senem , Lunte Craig
Published: April 2014

A sensitive, dependable, simple and rapid method based on capillary electrophoresis with diode array detection (CE-DAD) was developed for identification and determination of eleven flavonoids (apigetrin,naringin,naringenin,catechin,galangin,apigenin,luteolin,quercetin,myricetin,kaempferol, andkaempferide) in chamomile and linden flower extracts.
Boronic acid ester with dopamine as a tool for bioconjugation and for visualization of cell apoptosis
Authors: Scarano Wei , Lu Hongxu , Stenzel Martina H.
Published: April 2014

Boronic esters between 1,2-benzodiols and boronic acids are an efficient way for bioconjugation. The ester is stable at physiological condition, but it cleaves very slowly at acidic pH values found in the endosomes and lysosomes. During apoptosis, the boronic ester is cleaved, most likely due to the influx of Ca2+ ions and the oxidation of 1,2-benzodiols.
Isotope labelling – paired homologous double neutral loss scan-mass spectrometry for profiling of metabolites with a carboxyl group
Authors: Huang Yun-Qing , Wang Qiu-Yi , Liu Jia-Qi , Hao Yan-Hong , Yuan Bi-Feng , Feng Yu-Qi
Published: April 2014

The development of a method for non-targeted screening of metabolites with a carboxyl group by high performance liquid chromatography-mass spectrometry with paired homologous double neutral loss scan mode afterin vitroisotope labelling was reported.
A systematic quality control method of Huangqi decoction: simultaneous determination of eleven flavonoids and seven triterpenoid saponins by UHPLC-MS
Authors: Luo Hui-Long , Zhong Jie , Ye Fu-Yuan , Wang Qian , Ma Yue-Ming , Liu Ping , Zhang Hua , Sun Ming-Yu , Jiang Jian
Published: April 2014

A novel UHPLC-MS method was developed for the quantitative analysis of 18 major bioactive components from Huangqi decoction (HQD).
THz-TDS combined with a fuzzy rule-building expert system applied to the identification of official rhubarb samples
Authors: Wang Jingrong , Zhang Zhuoyong , Zhang Zhenwei , Xiang Yuhong , Harrington Peter de B.
Published: April 2014

Terahertz time domain spectroscopy (THz-TDS) combined with fuzzy rule-building expert systems was used for the identification of rhubarb samples.
Detection of quinolone antibiotics with electrochemiluminescence of bimetallic ruthenium complex [(bpy)2Ru(bpy)(CH2)8(bpy)Ru(bpy)2]4+
Authors: Liu Fengyu , Gao Yulong , Zhao Yinqi
Published: April 2014

Electrochemiluminescence (ECL) of bimetallic ruthenium tris-bipyridyl complex [(bpy)2Ru(bpy)(CH2)8(bpy)Ru(bpy)2]4+ has been employed for the determination of ofloxacin (OFLX), levofloxacin (LVFX), norfloxacin (NFLX) and ciprofloxacin (CPFX) in milk samples with good reproducibility and stability.
Inhibitive effect of calcium on the primary nucleation of sodium carbonate in the evaporation process of the caustic liquor
Authors: Guo Tao , Cao Shaotao , Zhang Yifei , Zhang Yi
Published: April 2014

Unusual nucleation of sodium carbonate in caustic liquor could be observed from the data of a focused beam reflectance measurement during evaporation in a batch evaporator.
Which intermolecular interactions have a significant influence on crystal packing?
Authors: Taylor Robin
Published: April 2014

The tendency for an interaction to occur in crystal structures is not a simple function of its calculated energyin vacuo.
Enhancing photo-induced ultrafast charge transfer across heterojunctions of CdS and laser-sintered TiO2 nanocrystals
Authors: Spann Bryan T. , Bhat S. Venkataprasad , Nian Qiong , Rickey Kelly M. , Cheng Gary J. , Ruan Xiulin , Xu Xianfan
Published: April 2014

We show a means of increasing charge transfer in CdS–TiO2 heterojunctions by laser sintering TiO2 nanocrystals.
Asymmetric hydrogenation by RuCl2(R-Binap)(dmf)n encapsulated in silica-based nanoreactors
Authors: Peng Juan , Wang Xuefeng , Zhang Xiaoming , Bai Shiyang , Zhao Yaopeng , Li Can , Yang Qihua
Published: April 2014

RuCl2-(R-Binap)(dmf)n encapsulated in silica-based nanoreactors: a solid catalyst as a whole, but a homogeneous catalyst on the nanoscale.
Forming a ruthenium isomerisation catalyst from Grubbs II: a DFT study
Authors: Young Allan , Vincent Mark A. , Hillier Ian H. , Percy Jonathan M. , Tuttle Tell
Published: April 2014

A pathway for methanolysis of Grubbs’ second generation catalyst has been computed.
Polyoxometalate complexes for oxidative kinetic resolution of secondary alcohols: unique effects of chiral environment, immobilization and aggregation
Authors: Shi Lei , Wang Yizhan , Li Bao , Wu Lixin
Published: April 2014

Chiral polyoxometalate complexes were covalently immobilized into silica and evaluated in the kinetic resolution of secondary alcohols.
Magnetic anisotropy in a spin 1/2 quasi-one-dimensional antiferromagnetic copper(ii) complex CuCl2(pdz) with a staggered g-tensor
Authors: Takaishi Shinya , Kitagawa Hiroshi , Tanaka Hisaaki , Kuroda Shin-ichi , Ikeda Ryuichi
Published: April 2014

We report an unusual magnetic anisotropy in aS= 1/2 1D antiferromagnetic (AF) compound CuCl2(pdz) (pdz = pyridazine).
Synthesis and thermal decomposition of a pyridylene-bridged bis-β-diketiminate magnesium hydride cluster
Authors: Harder Sjoerd , Spielmann Jan , Intemann Julia
Published: April 2014

Thermal decomposition of a magnesium hydride complex with four Mg2+ and four H− ions leads to H2 elimination and ligand reduction.
The sensitivities of high-harmonic generation and strong-field ionization to coupled electronic and nuclear dynamics
Authors: Baykusheva Denitsa , Kraus Peter M. , Zhang Song Bin , Rohringer Nina , Wörner Hans Jakob
Published: April 2014

The sensitivities of high-harmonic generation (HHG) and strong-field ionization (SFI) to coupled electronic and nuclear dynamics are studied, using the nitric oxide (NO) molecule as an example. A coherent superposition of electronic and rotational states of NO is prepared by impulsive stimulated Raman scattering and probed by simultaneous detection of HHG and SFI yields. We observe a fourfold higher sensitivity of high-harmonic generation to electronic dynamics and attribute it to the presence of inelastic quantum paths connecting coherently related electronic states [Kraus et al., Phys. Rev. Lett.111, 243005 (2013)]. Whereas different harmonic orders display very different sensitivities to rotational or electronic dynamics, strong-field ionization is found to be most sensitive to electronic motion. We introduce a general theoretical formalism for high-harmonic generation from coupled nuclear-electronic wave packets. We show that the unequal sensitivities of different harmonic orders to electronic or rotational dynamics result from the angle dependence of the photorecombination matrix elements which encode several autoionizing and shape resonances in the photoionization continuum of NO. We further study the dependence of rotational and electronic coherences on the intensity of the excitation pulse and support the observations with calculations.
Multiple ionization and fragmentation dynamics of molecular iodine studied in IR–XUV pump–probe experiments
Authors: Schnorr K. , Senftleben A. , Schmid G. , Rudenko A. , Kurka M. , Meyer K. , Foucar L. , Kübel M. , Kling M. F. , Jiang Y. H. , Düsterer S. , Treusch R. , Schröter C. D. , Ullrich J. , Pfeifer T. , Moshammer R.
Published: April 2014

The ionization and fragmentation dynamics of iodine molecules (I2) are traced using very intense (∼1014 W cm−2) ultra-short (∼60 fs) light pulses with 87 eV photons of the Free-electron LASer at Hamburg (FLASH) in combination with a synchronized femtosecond optical laser. Within a pump–probe scheme the IR pulse initiates a molecular fragmentation and then, after an adjustable time delay, the system is exposed to an intense FEL pulse. This way we follow the creation of highly-charged molecular fragments as a function of time, and probe the dynamics of multi-photon absorption during the transition from a molecule to individual atoms.
X-ray absorption spectroscopy with time-tagged photon counting: application to study the structure of a Co(i) intermediate of H2 evolving photo-catalyst
Authors: Smolentsev Grigory , Guda Alexander A. , Janousch Markus , Frieh Cristophe , Jud Gaudenz , Zamponi Flavio , Chavarot-Kerlidou Murielle , Artero Vincent , van Bokhoven Jeroen A. , Nachtegaal Maarten
Published: April 2014

In order to probe the structure of reaction intermediates of photochemical reactions a new setup for laser-initiated time-resolved X-ray absorption (XAS) measurements has been developed. With this approach the arrival time of each photon in respect to the laser pulse is measured and therefore full kinetic information is obtained. All X-rays that reach the detector are used to measure this kinetic information and therefore the detection efficiency of this method is high. The newly developed setup is optimized for time-resolved experiments in the microsecond range for samples with relatively low metal concentration (∼1mM). This setup has been applied to study a multicomponent photocatalytic system with a Co(dmgBF2)2 catalyst (dmg2− = dimethylglyoximato dianion), [Ru(bpy)3]2+ chromophore (bpy = 2,2′-bipyridine) and methyl viologen as the electron relay. On the basis of the analysis of hundreds of Co K-edge XAS spectra corresponding to different delay times after the laser excitation of the chromophore, the presence of a Co(i) intermediate is confirmed. The calculated X-ray transient signal for a model of Co(i) state with a 0.14 Å displacement of Co out of the dmg ligand plane and with the closest solvent molecule at a distance of 2.06 Å gives reasonable agreement with the experimental data.
Laser heated boron doped diamond electrodes: effect of temperature on outer sphere electron transfer processes
Authors: Meng Lingcong , Iacobini James G. , Joseph Maxim B. , Macpherson Julie V. , Newton Mark E.
Published: April 2014

Thermoelectrochemical experiments can reveal significant information about electrochemical processes compared to ambient only measurements. Typical thermoelectrochemistry is performed using resistively heated wires or laser heated electrodes, both of which can suffer drawbacks associated with the electrode material employed. Boron doped diamond (BDD) is ideal for thermoelectrochemical investigations due to its extremely high thermal conductivity and diffusivity, extreme resistance to thermal ablation (can withstand laser power densities, Pd, of GW cm−2 for nanosecond pulses) and excellent electrochemical properties (low background currents and wide potential window). In this paper we describe the use of a pulsed laser technique to heat the rear of a 1 mm diameter conducting BDD disc electrode, which drives electrochemical solution reactions at the front face. Maximum electrode temperatures of 90.0 °C were recorded experimentally and confirmed by finite element modelling (FEM). The effect of laser pulsed heating (maximum 3.8 kW cm−2; 10 ms on and 90 ms off) on the cyclic voltammetric response of two fast (reversible) outer sphere electron transfer redox mediators (Ru(NH3)63+/2+ and IrCl62−/3−) are investigated. In particular, we observe pulsed increases in the current, which increase with increasing Pd. The potential of the peak current is shifted positively for the Ru(NH3)63+/2+ couple (in accordance with a positive temperature coefficient, β, +0.68 mV K−1) and negatively for the IrCl63−/2− couple (β = −0.48 mV K−1). Scanning backwards, in contrast to that observed for a macrodisc electrode in ambient solution, a cathodic peak is again observed for Ru(NH3)63+/2+ and an anodic peak for IrCl63−/2− couple. We attribute this response to the entropy of the redox reaction and the time-dependant change in mass transport due to the induced thermal gradients at the electrode/electrolyte interface. The observed responses are in qualitative agreement with FEM simulations.
A novel calibration strategy for the quantitative imaging of iron in biological tissues by LA-ICP-MS using matrix-matched standards and internal standardisation
Authors: O'Reilly Jennifer , Douglas David , Braybrook Julian , So P.-W. , Vergucht Eva , Garrevoet Jan , Vekemans Bart , Vincze Laszlo , Goenaga-Infante Heidi
Published: April 2014

This paper describes the development of a simple and straightforward approach for preparation of matrix-matched calibration standards for Fe quantitative tissue imaging by LA-ICP-MS.
Evaluation of dietary exposure of crabs to inorganic mercury or methylmercury, with or without co-exposure to selenium
Authors: Torres Daiane Placido , Cadore Solange , Raab Andrea , Feldmann Jörg , Krupp Eva M.
Published: April 2014

Dietary exposure of crabs to mercury species, w/o selenium co-exposure, showed the antagonistic role that selenium may play against mercury.
Effect of dwell time on single particle inductively coupled plasma mass spectrometry data acquisition quality
Authors: Hineman Aaron , Stephan Chady
Published: April 2014

Effect of dwell time on mean particle size calculation for 250 000 particles per mL of 60 nm Au NPs nebulized at 300 μL min−1.
An extremely simple method for fabricating 3D protein microarrays with an anti-fouling background and high protein capacity
Authors: Lin Zhifeng , Ma Yuhong , Zhao Changwen , Chen Ruichao , Zhu Xing , Zhang Lihua , Yan Xu , Yang Wantai
Published: April 2014

Creation of 3D protein microarrays with an anti-fouling background and a high protein capacity by photo-induced surface sequential controlled/living graft polymerization.
A flake-tube structured BiOBr–TiO2nanotube array heterojunction with enhanced visible light photocatalytic activity
Authors: Ruan Lili , Liu Jiaqin , Zhou Qi , Hu Jiajia , Xu Guangqing , Shu Xia , Wu Yucheng
Published: April 2014

A new flake-tube structured BiOBr–TiO2nanotube array heterojunction exhibits highly enhanced visible-light photocatalytic activity in pollutant treatment.
Synthesis, X-ray structural features, DFT calculations and fluorescence studies of a new pyridoxal-benzimidazole ligand and its respective molybdenum complex
Authors: Pereira Mateus Brum , Kopp Cristiéli R. , Fontana Liniquer A. , de Oliveira Gelson Manzoni , Back Davi Fernando , Piquini Paulo C. , Villetti Marcos A.
Published: April 2014

Studies based on FPDFT helped us to elucidate the reaction mechanism involving the BIMIPY–H++ (MoO2+2) species in the first complexation of molybdenum by a vitamin B6 constituent.
Vacancy inter-layer migration in multi-layered graphene
Authors: Liu Lili , Gao Junfeng , Zhang Xiuyun , Yan Tianying , Ding Feng
Published: April 2014

Vacancy migration between graphene layers leads to vacancies holes formation in one layer and the healing of other layers.
Metal-free aerobic oxidative C–N bond cleavage of tertiary amines for the synthesis of N-heterocycles with high atom efficiency
Authors: Chen Xiuling , Chen Tieqiao , Zhou Yongbo , Han Daoqing , Han Li-Biao , Yin Shuang-Feng
Published: April 2014

An efficient metal-free aerobic C–N bond cleavage of tertiary amines has been developed to construct N-heterocycles using molecular oxygen as the sole oxidant with high atom efficiency. All of the three alkyl groups in tertiary amines can be utilized and transformed into N-heterocycles.
Practical synthesis of natural plant-growth regulator 2-azahypoxanthine, its derivatives, and biotin-labeled probes
Authors: Ikeuchi Kazutada , Fujii Ryosuke , Sugiyama Shimpei , Asakawa Tomohiro , Inai Makoto , Hamashima Yoshitaka , Choi Jae-Hoon , Suzuki Tomohiro , Kawagishi Hirokazu , Kan Toshiyuki
Published: April 2014

AHX derivatives and their probe molecules.
Segmental dynamics and physical aging of polystyrene/silver nanocomposites
Authors: Lin Yu , Liu Langping , Cheng Jiaqi , Shangguan Yonggang , Yu Wenwen , Qiu Biwei , Zheng Qiang
Published: April 2014

We report the complicated variation trend of calorimetric Tg and physical aging in PS/Ag nanocomposites, despite the invariant segmental dynamics with increasing silver nanoparticle loading.
Green synthesis and catalytic performance of nanoscale CeO2 sheets
Authors: Zhang Guoqing , Ao Ju , Guo Yili , Zhang Zhaoxia , Shao Min , Wang Lina , Zhou Lan , Shao Jianzhong
Published: April 2014

Nanoscale CeO2 sheets, synthesized by a green and facile method, have higher photocatalytic efficiency owing to more surface defects.
Palladium-catalyzed desulfitative C–P coupling of arylsulfinate metal salts and H-phosphonates
Authors: Li Junchen , Bi Xiaojing , Wang Hongmei , Xiao Junhua
Published: April 2014

An efficient desulfitative C–P coupling was accomplished with versatile arylsulfinate metal salts and H-phosphonates.
Nitrogen/sulfur co-doped non-noble metal material as an efficient electrocatalyst for the oxygen reduction reaction in alkaline media
Authors: Xu Li , Pan Guoshun , Liang Xiaolu
Published: April 2014

Nitrogen/sulfur co-doped non-novel metal material as an efficient electrocatalyst for oxygen reduction reaction in alkaline media.
Reduction of RGO by BH3: a facile route to partially hydrogenated RGO preparation
Authors: Zhang Miao , Xu Danyun , Ji Junyi , Wang Yuhong , Li Yang , Zhang Guoliang , Zhang Fengbao , Fan Xiaobin
Published: April 2014

A facile route which opened a narrow band gap to hydrogenate reduced graphene oxide (RGO) with borane was reported.
Ti powder-assisted synthesis of Ti3+ self-doped TiO2 nanosheets with enhanced visible-light photoactivity
Authors: Cai Jinghua , Huang Ze'ai , Lv Kangle , Sun Jie , Deng Kejian
Published: April 2014

Visible-light responsive Ti3+ self-doped TiO2 nanosheets with exposed high-energy (001) facets were fabricated using Ti powder as a reductant.
Magic sol–gel silica films encapsulating hydrophobic and hydrophilic quantum dots for white-light-emission
Authors: Yang Ping , Chen Hsueh-Shin , Wang Junpeng , Che Quande , Ma Qian , Cao Yongqiang , Zhu Yuanna
Published: April 2014

A sol–gel silica film was fabricated by a spraying approach on various substrates with a 3-dimensional surface for white LEDs.
Au/montmorillonite/polyaniline nanoflakes: facile fabrication by self-assembly and application as catalyst
Authors: Xia Youyi , Li Tenjiao , Ma Cong , Gao Chang , Chen Jun
Published: April 2014

Hydrogen bonding between citrate-stabilized Au NPs and the PANI backbone is proposed to play a pivotal role in driving the self-assembly between Au NPs and dedoped PANI, from which a highly catalytic Au NP/PANI/MMT nanocomposite was then synthesized.
A fast room-temperature strategy for direct reduction of graphene oxide films towards flexible transparent conductive films
Authors: Ning Jing , Wang Jie , Li Xianglong , Qiu Tengfei , Luo Bin , Hao Long , Liang Minghui , Wang Bin , Zhi Linjie
Published: April 2014

Fast room-temperature reduction of GO films on PET for flexible transparent conductive films.
Guest-modulation of the mechanical properties of flexible porous metal–organic frameworks
Authors: Ma Qintian , Yang Qingyuan , Ghoufi Aziz , Yang Ke , Lei Ming , Férey Gérard , Zhong Chongli , Maurin Guillaume
Published: April 2014

The highly flexible hybrid nanoporous MOF MIL-53(Cr) was evoked as a potential medium to store mechanical energy via a structural switching from an open to a close pore form under moderate applied external pressures.
In situ cross-linked superwetting nanofibrous membranes for ultrafast oil–water separation
Authors: Raza Aikifa , Ding Bin , Zainab Ghazala , El-Newehy Mohamed , Al-Deyab Salem S. , Yu Jianyong
Published: April 2014

Creating a practical and energy-efficient method with high efficacy to separate oil–water mixtures, especially those stabilized by surfactants, has proven to be extremely challenging.
Highly conductive carbon–CoO hybrid nanostructure arrays with enhanced electrochemical performance for asymmetric supercapacitors
Authors: Wang Hai , Qing Chen , Guo Junling , Aref A. A. , Sun Daming , Wang Bixiao , Tang Yiwen
Published: April 2014

Highly conductive carbon–CoO nanowire array electrodes on 3D nickel foam were designed with ultrahigh specific capacitance (3282.2 F g−1), approaching the CoO theoretical value. Assembled into an asymmetric supercapacitor, the energy density is ∼58.9 W h kg−1, a record among Co-based supercapacitors.
Zinc oxide films grown by galvanic deposition from 99% metals basis zinc nitrate electrolyte
Authors: Calnan S. , Riedel W. , Gledhill S. , Stannowski B. , Schlatmann R. , Lux-Steiner M. Ch.
Published: April 2014

The use of relatively low purity zinc nitrate for electrochemical deposition of compact ZnO films is attractive for large scale production because of the cost saving potential.
A chitin nanofibril reinforced multifunctional monolith poly(vinyl alcohol) cryogel
Authors: Nata Iryanti Fatyasari , Wu Tsai-Mao , Chen Jung-Kung , Lee Cheng-Kang
Published: April 2014

The antioxidant and antimicrobial functionalization of a chitin nanofibril (CNF) reinforced poly(vinyl alcohol) cryogel prepared by immersing in an alkaline dopamine solution followed by reducing AgNO3 into Ag nanoparticles on the macroporous structure of a spongy cryogel.
Electrochemically color tunable poly(N-isopropylacrylamide) microgel-based etalons
Authors: Xu Wenwen , Gao Yongfeng , Serpe Michael J.
Published: April 2014

Polymer-based materials capable of dramatic color changes in response to electrical stimulation were fabricated and their responses characterized.
Synthesis of linear multi‐beam arrays through hierarchical almost difference set‐based interleaving
Authors: Oliveri Giacomo , Viani Federico , Massa Andrea
Published: April 2014

The study presents an innovative ‘almost difference set (ADS)’‐based analytical approach for the design of fully interleaved arrays supporting Q > 2 independent functions on a shared aperture. Such a hierarchical subarraying methodology allows one to interweave, on the same lattice, Q = 2P non‐overlapped arrangements with beam properties a‐priori predictable from the descriptive parameters of the chosen ADSs. A general formulation for the pattern analysis of subarray layouts is derived and successively employed to assess features and potentialities of the multi‐level ‘ADS’ interleaved scheme. A set of representative numerical results, concerned with different apertures, balancing factors and number of interleaved functions, is presented to give some indications on the effectiveness, the efficiency and the reliability of the proposed approach.
Analysis of Hanle-effect signals observed in Si-channel spin accumulation devices
Authors: Takamura Yota , Akushichi Taiju , Sadano Adiyudha , Okishio Takao , Shuto Yusuke , Sugahara Satoshi
Published: April 2014

We reexamined curve-fitting analysis for spin-accumulation signals observed in Si-channel spin-accumulation devices, employing widely-used Lorentz functions and a new formula developed from the spin diffusion equation. A Si-channel spin-accumulation device with a high quality ferromagnetic spin injector was fabricated, and its observed spin-accumulation signals were verified. Experimentally obtained Hanle-effect signals for spin accumulation were not able to be fitted by a single Lorentz function and were reproduced by the newly developed formula. Our developed formula can represent spin-accumulation signals and thus analyze Hanle-effect signals.
General displaced SU(1, 1) number states: Revisited
Authors: Dehghani A.
Published: April 2014

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features.
The effects of Dzyaloshinskii-Moriya interactions on the ferromagnetic resonance response in nanosized devices
Authors: Eason Kwaku , Feng Kong Jian , Wei Kho Zhe , Hin Sim Cheow , Tran Michael , Cheng Huang Jian , Sabino Maria , Kun He Shi
Published: April 2014

The effects of Dzyaloshinskii-Moriya interaction (DMI) on the ferromagnetic resonance response are investigated in nanometer-sized disks using 3D micromagnetics with the inclusion of DMI energy. A rich complexity is found in the effects on the spinwave eigenmodes and their behavior when varying parameters. Two distinct results are demonstrated: first, unique DMI modes are found to form, instead of the expected modes forming in the absence of DMI and they can be uniquely accessed using field rotation; and second, modal evolution with the DMI parameter involves distinct modal twisting and rotations.
Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy
Authors: Loganathan Muthukumaran , Bristow Douglas A.
Published: April 2014

This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.
Electric-field induced alignment of nanoparticle-coated channels in thin-film polymer membranes
Authors: Millett Paul C.
Published: April 2014

Microscopic phase separation in immiscible polymer melts can be significantly altered by the presence of dispersed nanoparticles and externally applied electric fields. Inducing order or directionality to the resulting microstructure can lead to novel materials with efficient synthesis. Here, the coupled morphology of an immiscible binary polymer blend with dispersed nanoparticles in a thin-film geometry is investigated under the influence of an applied electric field using a unique mesoscale computational approach. For asymmetric binary blends (e.g., 70–30), the resulting microstructure consists of columnar channels of the B-phase perpendicular to the major plane of the film (aligned with the electric field), with the particles segregated along the channel interfaces. The simulations reveal the variability of the average channel diameter and the interfacial arrangement of the particles. The high density of exposed particles makes these structures viable candidates for catalytically active porous membranes or macromolecular manipulation devices.
FOHI-D: An iterative Hirshfeld procedure including atomic dipoles
Authors: Geldof D. , Krishtal A. , Blockhuys F. , Van Alsenoy C.
Published: April 2014

In this work, a new partitioning method based on the FOHI method (fractional occupation Hirshfeld-I method) will be discussed. The new FOHI-D method uses an iterative scheme in which both the atomic charge and atomic dipole are calculated self-consistently. In order to induce the dipole moment on the atom, an electric field is applied during the atomic SCF calculations. Based on two sets of molecules, the atomic charge and intrinsic atomic dipole moment of hydrogen and chlorine atoms are compared using the iterative Hirshfeld (HI) method, the iterative Stockholder atoms (ISA) method, the FOHI method, and the FOHI-D method. The results obtained are further analyzed as a function of the group electronegativity of Boyd et al. [J. Am. Chem. Soc. 110, 4182 (1988); Boyd et al., J. Am. Chem. Soc. 114, 1652 (1992)] and De Proft et al. [J. Phys. Chem. 97, 1826 (1993)]. The molecular electrostatic potential (ESP) based on the HI, ISA, FOHI, and FOHI-D charges is compared with the ab initio ESP. Finally, the effect of adding HI, ISA, FOHI, and FOHI-D atomic dipoles to the multipole expansion as a function of the precision of the ESP is analyzed.
Non-covalent interactions of nitrous oxide with aromatic compounds: Spectroscopic and computational evidence for the formation of 1:1 complexes
Authors: Cao Qian , Gor Gennady Y. , Krogh-Jespersen Karsten , Khriachtchev Leonid
Published: April 2014

We present the first study of intermolecular interactions between nitrous oxide (N2O) and three representative aromatic compounds (ACs): phenol, cresol, and toluene. The infrared spectroscopic experiments were performed in a Ne matrix and were supported by high-level quantum chemical calculations. Comparisons of the calculated and experimental vibrational spectra provide direct identification and characterization of the 1:1 N2O-AC complexes. Our results show that N2O is capable of forming non-covalently bonded complexes with ACs. Complex formation is dominated by dispersion forces, and the interaction energies are relatively low (about −3 kcal mol−1); however, the complexes are clearly detected by frequency shifts of the characteristic bands. These results suggest that N2O can be bound to the amino-acid residues tyrosine or phenylalanine in the form of π complexes.
Natural nanostructure and superlattice nanodomains in AgSbTe2
Authors: Carlton Christopher E. , De Armas Ricardo , Ma Jie , May Andrew F. , Delaire Olivier , Shao-Horn Yang
Published: April 2014

AgSbTe2 has long been of interest for thermoelectric applications because of its favorable electronic properties and its low lattice thermal conductivity of ∼0.7 W/mK. In this work, we report new findings from a high-resolution transmission electron microscopy study revealing two nanostructures in single crystal Ag1−xSb1+xSb2+x (with x = 0, 0.1, 0.2); (i) a rippled natural nanostructure with a period of ∼2.5–5 nm and (ii) superlattice ordered nanodomains consistent with cation ordering predicted in previous density functional theory studies. These nanostructures, combined with point-defects, probably serve as sources of scattering for phonons, thereby yielding a low lattice thermal conductivity over a wide temperature range.
Single crystal diamond detector measurements of deuterium-deuterium and deuterium-tritium neutrons in Joint European Torus fusion plasmas
Authors: Cazzaniga C. , Sundén E. Andersson , Binda F. , Croci G. , Ericsson G. , Giacomelli L. , Gorini G. , Griesmayer E. , Grosso G. , Kaveney G. , Nocente M. , Cippo E. Perelli , Rebai M. , Syme B. , Tardocchi M. ,   JET-EFDA Contributors
Published: April 2014

First simultaneous measurements of deuterium-deuterium (DD) and deuterium-tritium neutrons from deuterium plasmas using a Single crystal Diamond Detector are presented in this paper. The measurements were performed at JET with a dedicated electronic chain that combined high count rate capabilities and high energy resolution. The deposited energy spectrum from DD neutrons was successfully reproduced by means of Monte Carlo calculations of the detector response function and simulations of neutron emission from the plasma, including background contributions. The reported results are of relevance for the development of compact neutron detectors with spectroscopy capabilities for installation in camera systems of present and future high power fusion experiments.
Solvation of molecules in superfluid helium enhances the “interaction induced localization” effect
Authors: Walewski Łukasz , Forbert Harald , Marx Dominik
Published: April 2014

Atomic nuclei become delocalized at low temperatures as a result of quantum effects, whereas they are point-like in the high temperature (classical) limit. For non-interacting nuclei, the delocalization upon lowering the temperature is quantitatively described in terms of the thermal de Broglie wavelength of free particles. Clearly, light non-interacting nuclei – the proton being a prominent one – are much more delocalized at low temperatures compared to heavy nuclei, such as non-interacting oxygen having water in mind. However, strong interactions due to chemical bonding in conjunction with ultra-low temperatures characteristic to superfluid helium nanodroplets change this common picture substantially for nuclei in molecules or clusters. It turns out that protons shared in hydrogen bonds undergo an extreme “interaction induced localization” at temperatures on the order of 1 K, which compresses the protonic spatial distributions to the size of the much heavier donor or acceptor atoms, such as O or Cl nuclei, corresponding to about 0.1% of the volume occupied by a non-interacting proton at the same temperature. Moreover, applying our recently developed hybrid ab initio path integral molecular dynamics/bosonic path integral Monte Carlo quantum simulation technique to a HCl/water cluster, HCl(H2O)4, we find that helium solvation has a significant additional localizing effect of up to about 30% in volume. In particular, the solvent-induced excess localization is the stronger the lesser the given nucleus is already localized in the gas phase reference situation.
Derivatives of the Pochhammer and reciprocal Pochhammer symbols and their use in epsilon-expansions of Appell and Kampé de Fériet functions
Authors: Greynat David , Sesma Javier , Vulvert Grégory
Published: April 2014

Useful expressions of the derivatives, to any order, of Pochhammer and reciprocal Pochhammer symbols with respect to their arguments are presented. They are building blocks of a procedure, recently suggested, for obtaining the ɛ-expansion of functions of the hypergeometric class related to Feynman integrals. The procedure is applied to some examples of such kind of functions taken from the literature.
Nonequilibrium fluctuation-dissipation relations for one- and two-particle correlation functions in steady-state quantum transport
Authors: Ness H. , Dash L. K.
Published: April 2014

We study the non-equilibrium (NE) fluctuation-dissipation (FD) relations in the context of quantum thermoelectric transport through a two-terminal nanodevice in the steady-state. The FD relations for the one- and two-particle correlation functions are derived for a model of the central region consisting of a single electron level. Explicit expressions for the FD relations of the Green's functions (one-particle correlations) are provided. The FD relations for the current-current and charge-charge (two-particle) correlations are calculated numerically. We use self-consistent NE Green's functions calculations to treat the system in the absence and in the presence of interaction (electron-phonon) in the central region. We show that, for this model, there is no single universal FD theorem for the NE steady state. There are different FD relations for each different class of problems. We find that the FD relations for the one-particle correlation function are strongly dependent on both the NE conditions and the interactions, while the FD relations of the current-current correlation function are much less dependent on the interaction. The latter property suggests interesting applications for single-molecule and other nanoscale transport experiments.
A recipe for free-energy functionals of polarizable molecular fluids
Authors: Sundararaman Ravishankar , Letchworth-Weaver Kendra , Arias T. A.
Published: April 2014

Classical density-functional theory is the most direct approach to equilibrium structures and free energies of inhomogeneous liquids, but requires the construction of an approximate free-energy functional for each liquid of interest. We present a general recipe for constructing functionals for small-molecular liquids based only on bulk experimental properties and ab initio calculations of a single solvent molecule. This recipe combines the exact free energy of the non-interacting system with fundamental measure theory for the repulsive contribution and a weighted density functional for the short-ranged attractive interactions. We add to these ingredients a weighted polarization functional for the long-range correlations in both the rotational and molecular-polarizability contributions to the dielectric response. We also perform molecular dynamics calculations for the free energy of cavity formation and the high-field dielectric response, and show that our free-energy functional adequately describes these properties (which are key for accurate solvation calculations) for all three solvents in our study: water, chloroform, and carbon tetrachloride.