bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of magnetic fields on the morphology and pseudocapacitive properties of NiO on nickel foam
Authors: Lu Yisheng , Zhu Tao , Zhang Guoxiong , He Zhenni , Lin Chuan , Chen Yigang , Guo Haibo
Published: November 2015

Nanostructured nickel oxide (NiO) films have been successfully deposited on nickel foam by a simple magnetic-field-assisted hydrothermal method, followed by calcination in air.
Nanocomposites of nitrogen-doped graphene decorated with a palladium silver bimetallic alloy for use as a biosensor for methotrexate detection
Authors: Ghadimi Hanieh , Nasiri-Tabrizi Bahman , Nia Pooria Moozarm , Basirun Wan Jefrey , Tehrani Ramin M. A. , Lorestani Farnaz
Published: November 2015

Pd1Ag1/NG–GCE is a promising platform for the highly sensitive electrochemical detection of MTX.
Preparation and characterization of magnetic nanocomposite catalysts with double Au nanoparticle layers
Authors: Rahman Zia Ur , Zhang Tingting , Cui Siwen , Wang Daoai
Published: November 2015

Nanocomposite catalysts, with single and double gold layers, and with one gold layer and one silver layer were prepared through simple steps, and showed excellent activity in the reduction of nitrophenols.
Enhanced electrical and luminescent performance of a porous silicon/MEH-PPV nanohybrid synthesized by anodization and repeated spin coating
Authors: Salem A. M. S. , Harraz F. A. , El-Sheikh S. M. , Hafez H. S. , Ibrahim I. A. , Abdel-Mottaleb M. S. A.
Published: November 2015

The electrochemical anodization of a single crystalline silicon in hydrofluoric acid-based solution leads to the formation of porous silicon (PSi) with tunable pore sizes and morphology for a wide range of technological applications.
Synthesis and characterization of pyrimidine-containing hexaarylbenzene derivatives
Authors: Zhang Dengqing , Wang Gang , Li Rong , Li Xianying , Xiang Yunjie , Zhang Zhen , Jin Wusong
Published: November 2015

Three claw-shaped hexaarylbenzene derivatives containing pyrimidines have been synthesized by cobalt-catalyzed corresponding tolan derivatives.
Ultrathin graphene-based solar cells
Authors: Hsieh Ya-Ping , Hong Bang-Jian , Ting Chu-Chi , Hofmann Mario
Published: November 2015

By employing graphene as a top electrode, 10 nm leakage-free ultra-thin solar cells were produced and the competition between interfacial electric fields and bulk carrier recombination could be probed.
Real-time observation of self-limiting SiO2/Si decomposition catalysed by gold silicide droplets
Authors: Bábor Petr , Duda Radek , Polčák Josef , Průša Stanislav , Potoček Michal , Varga Peter , Čechal Jan , Šikola Tomáš
Published: November 2015

Gold enhances the decomposition rate of thin SiO2 layers on Si(001) in a self-limiting fashion.
Phenothiazine dioxide based high triplet energy host materials for blue phosphorescent organic light-emitting diodes
Authors: Lee In Ho , Lee Jun Yeob
Published: November 2015

Donor–acceptor type high triplet energy host materials were derived from a phenothiazine dioxide based electron transport moiety and a carbazole based hole transport moiety.
Understanding in crystallization of polyethylene: the role of boron nitride (BN) particles
Authors: Zhang Xianlong , Wu Hong , Guo Shaoyun , Wang Yuzhong
Published: November 2015

The nano-Tmof the PE near the BN aggregates was higher 4–8 °C than that in other areas.
Chemistry of heterocyclic-2-thiones: in situ generated 1-(4,5-dihydro-3-alkyl-imidazolidin-2-yl)-3-alkyl-imidazolidine-2-thione and triiodide form novel mixed valent CuI–II/CuIIcomplexes
Authors: Sultana Razia , Lobana Tarlok S. , Castineiras Alfonso
Published: November 2015

Copper(i) iodide transformsN-n-butyl-imidazolidine-2-thione in air into 1-(4,5-dihydro-3-butyl-imidazolidin-2-yl)-3-butyl-imidazolidine-2-thione (L-NBun) which formed novel complex, [Cu(κ2-N,S-L-NBun)2](I3)2.
Preparation of Rh–SiO2 fiber catalyst with superior activity and reusability by electrospinning
Authors: Zou Rui , Wen Shipeng , Zhang Liqun , Liu Li , Yue Dongmei
Published: November 2015

Rh–SiO2 fiber catalyst prepared by electrospinning for room temperature hydrogenation of alkenes with superior catalytic activity and reusability.
A NIR-to-NIR upconversion luminescence system for security printing applications
Authors: Baride A. , Meruga J. M. , Douma C. , Langerman D. , Crawford G. , Kellar J. J. , Cross W. M. , May P. S.
Published: November 2015

A covert print-and-read system is demonstrated based on NIR-to-NIR upconversion luminescence.
Giant UV-sensitivity of ion beam irradiated nanocrystalline CdS thin films
Authors: Kumar Pragati , Saxena Nupur , Dewan Sheetal , Singh Fouran , Gupta Vinay
Published: November 2015

A highly sensitive UV-detector is devised for the first time from ion beam irradiated nanocrystalline CdS thin films. The sensor exhibits improvements in the responsivity, photosensitivity, and efficiency as a function of ion fluence.
Au-catalyzed intramolecular annulations toward fused tricyclic [1,3]oxazino[3,4-a]indol-1-ones under extremely mild conditions
Authors: Chen Zhiyuan , Zeng Xingping , Yan Bingyu , Zhao Yanlu , Fu Yang
Published: November 2015

We report a general and efficient method for the rapid generation of tricyclic [1,3]oxazino[3,4-a]indol-1-ones under extremely mild conditions.
Ionic liquid – containing ionogels by thiol–ene photopolymerization. Kinetics and solvent effect
Authors: Zgrzeba A. , Andrzejewska E. , Marcinkowska A.
Published: November 2015

Vinyl ether/thiol photopolymerization is accelerated by solvents; it occurs faster in non-ionic solvents than in ionic liquids.
Dibenzo[a,c]phenazine-derived near-infrared fluorescence biosensor for detection of lysophosphatidic acid based on aggregation-induced emission
Authors: Jiang Tao , Lu Niannian , Yang Ji , Hang Yandi , Wang Jian , Zhao Ping , Hua Jianli
Published: November 2015

A new near-infrared fluorescence turn-on detector forLPAis developed by taking advantage of aggregation-induced emission behaviour. It exhibits good sensitivity and selectivity toLPAwith the limit of detection of 4.47 × 10−7M.
One-step electrodeposition fabrication of a superhydrophobic surface on an aluminum substrate with enhanced self-cleaning and anticorrosion properties
Authors: Zhang Binbin , Li Yantao , Hou Baorong
Published: November 2015

Superhydrophobic surface was successfully fabricated via a facile, low-cost one-step electrodeposition approach on aluminum substrate with excellent anticorrosion and self-cleaning properties.
Rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes with terminal alkenes
Authors: Kang Lei , Zhang Feng , Ding Lin-Ting , Yang Luo
Published: November 2015

A rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes and terminal alkenes to afford 1,2-disubstituted alkenes with good regio- and E-selectivity is developed.
Nanoparticle-based hierarchical zinc oxide chains for enhanced efficiency of dye-sensitized solar cells
Authors: Li Zhengdao , Zhou Yong , Sun Ruixue , Yang Yuhan , Zhang Kaijun
Published: November 2015

One-dimensional ZnO chains composed of nanoparticles were prepared as the working electrodes of DSSCs, which can take both the advantages of 1D-structures and nanoparticles, showing superior photoelectric conversion performance.
Preparation and application of tubular assemblies based on amphiphilic tetramethoxyresorcinarenes
Authors: Li Liang , Yao Yong , Sun Jing , Yan Chao-Guo
Published: November 2015

A silver nanoparticle/organic hybrid micro-tubular material was prepared by fabricating tetramethoxyresorcinarene tetraaminoamide-functionalized silver nanoparticles on templates of microtubular assemblies.
Correction: Dietary flavone chrysin (5,7-dihydroxyflavone ChR) functionalized highly-stable metal nanoformulations for improved anticancer applications
Authors: Sathishkumar G. , Bharti Rashmi , Jha Pradeep K. , Selvakumar M. , Dey Goutam , Jha Rakhi , Jeyaraj M. , Mandal Mahitosh , Sivaramakrishnan S.
Published: November 2015

Correction for ‘Dietary flavone chrysin (5,7-dihydroxyflavone ChR) functionalized highly-stable metal nanoformulations for improved anticancer applications’ by G. Sathishkumar et al., RSC Adv., 2015, 5, 89869–89878.
Incorporation of plasmonic Au nanostars into photoanodes for high efficiency dye-sensitized solar cells
Authors: Elbohy Hytham , Kim Mee Rahn , Dubey Ashish , Reza Khan Mamun , Ma Dongling , Zai Jiantao , Qian Xuefeng , Qiao Qiquan
Published: November 2015

Incorporation of plasmonic Au nanostars into the TiO2 photoanode significantly improved the performance of dye-sensitized solar cells (DSSCs).
Preparation of microvillus-like nitrogen-doped carbon nanotubes as the cathode of a microbial fuel cell
Authors: He Yan-Rong , Du Feng , Huang Yu-Xi , Dai Li-Ming , Li Wen-Wei , Yu Han-Qing
Published: November 2015

The efficiency of a microbial fuel cell (MFC) generally suffers from its poor cathode performance. To improve this, a novel cathode material was prepared by growing vertically aligned nitrogen-doped carbon nanotubes on carbon cloth, offering an efficient, metal-free, and low-cost alternative to Pt/C.
Self-activated continuous pulverization film: an insight into the mechanism of the extraordinary long-life cyclability of hexagonal H4.5Mo5.25O18·(H2O)1.36microrods
Authors: Li Zihua , Wang Hai , Sun Zhuangzhi , Su Jian , Wang Zuyun , Wang Linjiang
Published: November 2015

Novel hexagonal H4.5Mo5.25O18·(H2O)1.36microrods exhibit unusual and intriguing electrochemical behavior. The specific capacity first fades, then continuously increases without any capacity fading at a high current density of 2 A g−1.
A cocatalyst-free CdS nanorod/ZnS nanoparticle composite for high-performance visible-light-driven hydrogen production from water
Authors: Jiang Daochuan , Sun Zijun , Jia Hongxing , Lu Dapeng , Du Pingwu
Published: November 2015

Highly efficient, visible-light-induced hydrogen (H2) production via water splitting can be achieved without the help of a cocatalyst by using a noble-metal-free core–shell photocatalyst, in which zinc sulfide (ZnS) nanoparticles are anchored on cadmium sulfide nanorods (CdS NRs).
Dopamine-mediated fabrication of ultralight graphene aerogels with low volume shrinkage
Authors: Li Lingxiao , Li Bucheng , Zhang Junping
Published: November 2015

Ultralight graphene aerogels with low volume shrinkage are fabricated via hydrothermal reactions at low temperature with the help of dopamine.
Structure-solubility relationships in fluoride-containing phosphate based bioactive glasses
Authors: Shaharyar Yaqoot , Wein Eric , Kim Jung-Ju , Youngman Randall E. , Muñoz Francisco , Kim Hae-Won , Tilocca Antonio , Goel Ashutosh
Published: November 2015

Structural role of fluoride on chemical dissolution behavior of bioactive phosphate glasses has been studied.
Synthesis and characterization of waterborne polyurethane containing poly(3-hydroxybutyrate) as new biodegradable elastomers
Authors: Hsu Shan-hui , Hsieh Cheng-Tien , Sun Yi-Ming
Published: November 2015

Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer with good biocompatibility.
Reactive oxygen species (ROS) responsive PEG–PCL nanoparticles with pH-controlled negative-to-positive charge reversal for intracellular delivery of doxorubicin
Authors: Deng Hongzhang , Zhao Xuefei , Liu Jinjian , Deng Liandong , Zhang Jianhua , Liu Jianfeng , Dong Anjie
Published: November 2015

The charge-conversional behavior and ROS-sensitivity of mPEG-ros-P(CL-co-DCL) NPs for active loading and triggered release of DOX.
Nd3+-doped LiYF4nanocrystals for bio-imaging in the second near-infrared window
Authors: Jiang Xinyi , Cao Cong , Feng Wei , Li Fuyou
Published: November 2015

In vivobioimaging of high spatial resolution based on LiYF4:Nd in the second near-infrared window.
Tumor-targeting, enzyme-activated nanoparticles for simultaneous cancer diagnosis and photodynamic therapy
Authors: Shi Huaxia , Sun Wucheng , Liu Changbing , Gu Guiying , Ma Bo , Si Weili , Fu Nina , Zhang Qi , Huang Wei , Dong Xiaochen
Published: November 2015

On-site activated diiodostyryl bodipy conjugated HA nanoparticles with specific targets synthesized via self-assembly were used for the suppression of tumor growth and exact tumor diagnosis with reduced side effects.
The band structure of graphene oxide examined using photoluminescence spectroscopy
Authors: Liang H. F. , Smith C. T. G. , Mills C. A. , Silva S. R. P.
Published: November 2015

In situ reduction of aqueous graphene oxide is undertaken to challenge the prevailing assignation of molecular transitions in photoluminescence spectra.
Spray coated ultrathin films from aqueous tungsten molybdenum oxide nanoparticle ink for high contrast electrochromic applications
Authors: Li Haizeng , Chen Jingwei , Cui Mengqi , Cai Guofa , Eh Alice Lee-Sie , Lee Pooi See , Wang Hongzhi , Zhang Qinghong , Li Yaogang
Published: November 2015

Crystal defects induced by molybdenum doping are utilized to synthesize aqueous tungsten molybdenum oxide nanoparticle ink and enhanced electrochromism is obtained with a spray coating technique.
Solution processed vertically stacked ZnO sheet-like nanorod p–n homojunctions and their application as UV photodetectors
Authors: Ko WonBae , Lee SangHyo , Myoung NoSoung , Hong JinPyo
Published: November 2015

Herein, we address the ZnO SLNR p–n homojunctions as UV photodetectors via a multi-step solution based hydrothermal route. Li was selected for manipulation of conduction type in ZnO and p-type ZnO:Li SLNRs were systematically investigated for crystallographic and luminescence features.
Single parabolic band behavior of thermoelectric p-type CuGaTe2
Authors: Shen Jiawen , Chen Zhiwei , lin Siqi , Zheng Linglang , Li Wen , Pei Yanzhong
Published: November 2015

Single parabolic band conduction not only explains but also evaluates the thermoelectric properties of p-type CuGaTe2.
Mobility propagation and dynamic facilitation in superionic conductors
Authors: Annamareddy Ajay , Eapen Jacob
Published: November 2015

In an earlier work [V. A. Annamareddy et al., Phys. Rev. E 89, 010301(R) (2014)], we showed the manifestation of dynamical heterogeneity (DH)—the presence of clustered mobile and immobile regions—in UO2, a model type II superionic conductor. In the current work, we demonstrate the mechanism of dynamic facilitation (DF) in two superionic conductors (CaF2 and UO2) using atomistic simulations. Using the mobility transfer function, DF is shown to vary non-monotonically with temperature with the intensity of DF peaking at temperatures close to the superionic transition temperature (Tλ). Both the metrics quantifying DH and DF show remarkable correspondence implying that DF, in the framework of kinematically constrained models, underpins the heterogeneous dynamics in type II superionic conductors.
Vibrational dynamics of aqueous hydroxide solutions probed using broadband 2DIR spectroscopy
Authors: Mandal Aritra , Tokmakoff Andrei
Published: November 2015

We employed ultrafast transient absorption and broadband 2DIR spectroscopy to study the vibrational dynamics of aqueous hydroxide solutions by exciting the O–H stretch vibrations of the strongly hydrogen-bonded hydroxide solvation shell water and probing the continuum absorption of the solvated ion between 1500 and 3800 cm−1. We observe rapid vibrational relaxation processes on 150–250 fs time scales across the entire probed spectral region as well as slower vibrational dynamics on 1–2 ps time scales. Furthermore, the O–H stretch excitation loses its frequency memory in 180 fs, and vibrational energy exchange between bulk-like water vibrations and hydroxide-associated water vibrations occurs in ∼200 fs. The fast dynamics in this system originate in strong nonlinear coupling between intra- and intermolecular vibrations and are explained in terms of non-adiabatic vibrational relaxation. These measurements indicate that the vibrational dynamics of the aqueous hydroxide complex are faster than the time scales reported for long-range transport of protons in aqueous hydroxide solutions.
Mixing transition in a shocked variable-density flow
Authors: Orlicz G. C. , Balasubramanian Sridhar , Vorobieff P. , Prestridge K. P.
Published: November 2015

We measure two-dimensional velocity and density fluctuations in a shock-driven heavy gas curtain for three different incident Mach numbers (M = 1.21, 1.36, and 1.50) and a fixed initial perturbation. We study the time evolution of the velocity and density fields and observe two different mixing transitions in this unsteady flow. The first transition is caused by small-scale mixing in vortex cores, while the second transition is related to increased homogenization across the mixing layer and a drive towards isotropy. By measuring the anisotropy of the velocity fluctuations and the evolution of the turbulent kinetic energy, we are able to assess the anisotropy of the flow. For the first time in Richtmyer-Meshkov (RM) flows, we measure and compare turbulent length scales derived from both the density and velocity field measurements, and we find ratios of Liepmann-Taylor to inner-viscous scales (λL/λν) that are inconsistent with those found using Reynolds number scaling based on circulation, ReΓ, or based on turbulent kinetic energy, ReK. At late times, ReK better reflects the decay of the mixing field than Reynolds numbers that are based upon mixing width or circulation. We also estimate the time evolution of dissipation and Kolmogorov scales for the first time in RM flows. When we estimate the Taylor microscale (λT) for our experiments using both density and velocity, the density microscale agrees well with the relationship λT=10δRe−1/2 where Re = ReK and δ is the mixing layer width, but the velocity-based Taylor microscale follows a new scaling of λT = 10δRe−1/2.
A closed-loop phase-locked interferometer for wide bandwidth position sensing
Authors: Fleming Andrew J. , Routley Ben S.
Published: November 2015

This article describes a position sensitive interferometer with closed-loop control of the reference mirror. A calibrated nanopositioner is used to lock the interferometer phase to the most sensitive point in the interferogram. In this configuration, large low-frequency movements of the sensor mirror can be detected from the control signal applied to the nanopositioner and high-frequency short-range signals can be measured directly from the photodiode. It is demonstrated that these two signals are complementary and can be summed to find the total displacement. The resulting interferometer has a number of desirable characteristics: it is optically simple, does not require polarization or modulation to detect the direction of motion, does not require fringe-counting or interpolation electronics, and has a bandwidth equal to that of the photodiode. Experimental results demonstrate the frequency response analysis of a high-speed positioning stage. The proposed instrument is ideal for measuring the frequency response of nanopositioners, electro-optical components, MEMs devices, ultrasonic devices, and sensors such as surface acoustic wave detectors.
Highly sensitive pseudo-differential ac-nanocalorimeter for the study of the glass transition
Authors: Laarraj Mohcine , Adhiri Rahma , Ouaskit Said , Moussetad Mohamed , Guttin Christophe , Richard Jacques , Garden Jean-Luc
Published: November 2015

We present a nanocalorimeter designed for the measurement of the dynamic heat capacity of thin films. The microfabricated sensor, the thermal conditioning of the sensor, as well as the highly stable and low noise electronic chain allow measurements of the real and imaginary parts of the complex specific heat with a resolution Δ C/C of about 10−5. The performances of this quasi-differential nanocalorimeter were tested on a model of polymeric glass-former, the polyvinyl acetate (PVAc). The high stability and low noise of the device are essential for accurate studies on non-equilibrium slow relaxing systems such as glasses.
Non-destructive single-pass low-noise detection of ions in a beamline
Authors: Schmidt Stefan , Murböck Tobias , Andelkovic Zoran , Birkl Gerhard , Nörtershäuser Wilfried , Stahl Stefan , Vogel Manuel
Published: November 2015

We have conceived, built, and operated a device for the non-destructive single-pass detection of charged particles in a beamline. The detector is based on the non-resonant pick-up and subsequent low-noise amplification of the image charges induced in a cylindrical electrode surrounding the particles’ beam path. The first stage of the amplification electronics is designed to be operated from room temperature down to liquid helium temperature. The device represents a non-destructive charge counter as well as a sensitive timing circuit. We present the concept and design details of the device. We have characterized its performance and show measurements with low-energy highly charged ions (such as Ar13+) passing through one of the electrodes of a cylindrical Penning trap. This work demonstrates a novel approach of non-destructive, low noise detection of charged particles which is, depending on the bunch structure, suitable, e.g., for ion traps, low-energy beamlines or accelerator transfer sections.
Measurement of colloidal phenomena during flow through refractive index matched porous media
Authors: Roth Eric J. , Mont-Eton Michael E. , Gilbert Benjamin , Lei Tim C. , Mays David C.
Published: November 2015

Colloidal phenomena in porous media, natural or engineered, are important in a breadth of science and technology applications, but fundamental understanding is hampered by the difficulty in measuring colloid deposit morphology in situ. To partially address this need, this paper describes a static light scattering apparatus using a flow cell filled with refractive index matched (RIM) porous media, allowing real-time measurement of colloidal phenomena as a function of depth within the flow cell. A laser interacts with the colloids in the pore space and their structures, but not with the RIM media. The intensity of scattered light is measured as a function of scattering angle, which allows characterization of colloid deposit morphology as a fractal dimension and a radius of gyration. In parallel, fluid discharge rate and pressure drop are recorded to determine permeability, a key parameter for any application involving flow through porous media. This apparatus should prove useful in any application requiring characterization of colloidal phenomena within porous media. Additionally, this paper describes how to use granular Nafion as RIM porous media.
A practical and efficient diabatization that combines Lorentz and Laplace functions to approximate nonadiabatic coupling terms
Authors: An Heesun , Baeck Kyoung Koo
Published: November 2015

A fixed relation of α × β = 1.397 between the α- and β-parameters of a Lorentz function and a Laplace function that approximates nonadiabatic coupling terms and maximizes the overlap area between the two functions was found. The mixing angle corresponding to the geometric average between the potential couplings calculated using the individual path-integral of the two functions was then used in the construction of diabatic states and the coupling of the states. Employing the new method, the actual computation of nonadiabatic coupling terms at just a few geometries before and after the guessed conical intersection is enough, and the remaining steps are straightforward and almost automatic. The new method was tested for the one-dimensional LiF system and the two-dimensional space of the collinear case of NH3Cl, and promising results were achieved.
Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow
Authors: Jaiswal S. , Bandyopadhyay P. , Sen A.
Published: November 2015

A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.
Cyclotron instability in the afterglow mode of minimum-B ECRIS
Authors: Izotov I. , Kalvas T. , Koivisto H. , Komppula J. , Kronholm R. , Laulainen J. , Mansfeld D. , Skalyga V. , Tarvainen O.
Published: November 2015

It was shown recently that cyclotron instability in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source (ECRIS) causes perturbation of the extracted ion current and generation of strong bursts of bremsstrahlung emission, which limit the performance of the ion source. The present work is devoted to the dynamic regimes of plasma instability in ECRIS operated in pulsed mode. Instability develops in decaying plasma shortly after heating microwaves are switched off and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high energy electrons. Time-resolved measurements of microwave emission bursts are presented. It was found that even in various gases (helium and oxygen were studied) and at different values of magnetic field and heating power, the dynamic spectra demonstrate common features: decreasing frequency within a single burst as well as from one burst to another.
Optical pendulum effect in one-dimensional diffraction-thick porous silicon based photonic crystals
Authors: Novikov V. B. , Svyakhovskiy S. E. , Maydykovskiy A. I. , Murzina T. V. , Mantsyzov B. I.
Published: November 2015

We present the realization of the multiperiodic optical pendulum effect in 1D porous silicon photonic crystals (PhCs) under dynamical Bragg diffraction in the Laue scheme. The diffraction-thick PhC contained 360 spatial periods with a large variation of the refractive index of adjacent layers of 0.4. The experiments reveal switching of the light leaving the PhC between the two spatial directions, which correspond to Laue diffraction maxima, as the fundamental wavelength or polarization of the incident light is varied. A similar effect can be achieved when the temperature of the sample or the intensity of the additional laser beam illuminating the crystal are changed. We show that in our PhC structures, the spectral period of the pendulum effect is down to 5 nm, while the thermal period is about 10 °C.
Measurement of the dispersion relation of a convectively unstable capillary jet under confinement
Authors: Horvath Camila , Arratia Cristóbal , Cordero María Luisa
Published: November 2015

The dispersion relation of a confined capillary jet with negligible inertia is measured by Fourier analysis of the jet radius. The real part of the dispersion relation, obtained through the spatiotemporal Fourier spectrum, demonstrates that the phase velocity is independent of the perturbation frequency, at least in the accessible range of frequencies. The imaginary part of the dispersion relation, i.e., the spatial growth rate, is frequency dependent. To measure this dependence, an external forcing is used to amplify modes with different frequencies. The spatial growth rate is then obtained from the exponential growth of the corresponding Fourier mode. The phase velocity and the spatial growth rate are found to increase and decrease, respectively, with the capillary number and to depend only weakly on the degree of confinement. These observations are consistent with a spatial instability that convects the perturbations downstream with velocity proportional to the capillary number. The frequency of the dominant mode in the absence of forcing, on the contrary, depends mainly on the degree of confinement, i.e., on the jet diameter, and only weakly on the capillary number, which is consistent with the mode selection of the Rayleigh-Plateau instability. Experimental measurements are compared to predicted dispersion relations reported in the literature, and good qualitative agreement is observed.
Device performance simulations of multilayer black phosphorus tunneling transistors
Authors: Liu Fei , Shi Qing , Wang Jian , Guo Hong
Published: November 2015

We report a theoretical investigation of ballistic transport in multilayer black phosphorus (BP) tunneling transistors (TFETs) with HfO2 as the gate oxide. First-principles calculations show that monolayer BP can be preserved well on HfO2 (111) surface. For a better device performance, the optimum layer and transport direction at different channel lengths are investigated. It is shown that BP TFETs have larger drain current in the armchair direction (AD) than in the zigzag direction, and the current difference can be several orders of magnitude. On-state current can be enhanced in the BP TFETs using thicker BP film, while the minimal leakage current is increased at the same time. To reduce the leakage current and subthreshold swing in the multilayer BP TFETs, lower source/drain doping concentration and smaller drain voltage should be applied. Compared to monolayer MoS2, MoSe2, and MoTe2 TFETs monolayer BP TFETs in AD can reach larger on-state current at the same Ion/Ioff ratio.
Modelling and experimental verification of tip-induced polarization in Kelvin probe force microscopy measurements on dielectric surfaces
Authors: Nielsen Dennis A. , Popok Vladimir N. , Pedersen Kjeld
Published: November 2015

Kelvin probe force microscopy is a widely used technique for measuring surface potential distributions on the micro- and nanometer scale. The data are, however, often analyzed qualitatively, especially for dielectrics. In many cases, the phenomenon of polarization and its influence on the measured signals is disregarded leading to misinterpretation of the results. In this work, we present a model that allows prediction of the surface potential on a metal/polymer heterostructure as measured by Kelvin probe force microscopy by including the tip-induced polarization of the dielectric that arises during measurement. The model is successfully verified using test samples.
Galvanomagnetic properties and electronic structure of iron-doped PbTe
Authors: Skipetrov E. P. , Kruleveckaya O. V. , Skipetrova L. A. , Knotko A. V. , Slynko E. I. , Slynko V. E.
Published: November 2015

We synthesize an iron-doped PbTe single-crystal ingot and investigate the phase composition and distribution of the iron impurity along the ingot as well as galvanomagnetic properties in weak magnetic fields (4.2 K ≤ T ≤ 300 K, B ≤ 0.07 T) of Pb1−yFeyTe alloys. We find microscopic inclusions enriched with iron and regions with a chemical composition close to FeTe in the heavily doped samples, while the iron impurity content in the main phase rises only slightly along the length of the ingot reaching the impurity solubility limit at approximately 0.6 mol. %. Samples from the initial and the middle parts of the ingot are characterized by p-type metal conductivity. An increase of the iron impurity content leads to a decrease in the free hole concentration and to a stabilization of galvanomagnetic parameters due to the pinning of the Fermi level by the iron resonant impurity level EFe lying under the bottom of the valence band (Ev − EFe ≈ 16 meV). In the samples from the end of the ingot, a p-n inversion of the conductivity type and an increase of the free electron concentration along the ingot are revealed despite the impurity solubility limit being reached. The kinetics of changes of charge carrier concentration and of the Fermi energy along the ingot is analyzed in the framework of the six-band Dimmock dispersion relation. A model is proposed for the electronic structure rearrangement of Pb1−yFeyTe with doping, which may also be used for PbTe doped with other transition metals.
Composition mediated serration dynamics in Zr-based bulk metallic glasses
Authors: Wang Z. , Qiao J. W. , Tian H. , Sun B. A. , Wang B. C. , Xu B. S. , Chen M. W.
Published: November 2015

The composition mediated serration dynamics in Zr-based bulk metallic glasses (BMGs) is investigated by statistics analyses of the elastic-energy density, and free volumes during shear-banding are beneficial to understand serrated-flow behavior. The amplitude and elastic-energy density display a gradually increasing and then decreasing trend with increasing the content of Zr. It is based on the free-volume theory describing the atomic-level structure of ternary Zr-Cu-Al BMGs. The good agreement between the molecular dynamics simulation and experimental results provides evidence for the variation of free volumes as the elementary mechanism of composition mediated serration dynamics.
A world-line framework for 1D topological conformal σ-models
Authors: Baulieu L. , Holanda N. L. , Toppan F.
Published: November 2015

We use world-line methods for pseudo-supersymmetry to construct sl(2|1)-invariant actions for the (2, 2, 0) chiral and (1, 2, 1) real supermultiplets of the twisted D-module representations of the sl(2|1) superalgebra. The derived one-dimensional topological conformal σ-models are invariant under nilpotent operators. The actions are constructed for both parabolic and hyperbolic/trigonometric realizations (with extra potential terms in the latter case). The scaling dimension λ of the supermultiplets defines a coupling constant, 2λ + 1, the free theories being recovered at λ=−12. We also present, generalizing previous works, the D-module representations of one-dimensional superconformal algebras induced by N=(p,q) pseudo-supersymmetry acting on (k, n, n − k) supermultiplets. Besides sl(2|1), we obtain the superalgebras A(1, 1), D(2, 1; α), D(3, 1), D(4, 1), A(2, 1) from (p, q) = (1, 1), (2, 2), (3, 3), (4, 4), (5, 1), at given k, n and critical values of λ.
Nanoparticles inside nanodishes for plasmon excitations
Authors: Wi Jung-Sub , Son Jin Gyeong , Han Sang Woo , Lee Tae Geol
Published: November 2015

We demonstrate a simple route to hybridize two different nanomaterials by using three-dimensional nanodishes that can serve as small plasmonic containers to host guest nanoparticles. The nanodishes were fabricated using nanoimprint lithography and oblique-angle film deposition, and the guest nanoparticles were drop-cast onto the host nanodishes. Based on the proposed method, colloidal Au nanoparticles were assembled inside the Au nanodishes in the form of a labyrinth. These Au nanoparticle–nanodish hybrids excited a strong surface plasmon resonance, as verified by a numerical simulation of the local field enhancement and by direct observation of both the enhanced Raman signals and photochemical reactions. Our results point to the potential of the nanodishes as a useful platform for combining diverse nanomaterials and their functionalities.
Metal induced crystallized poly-Si-based conductive bridge resistive switching memory device with one transistor and one resistor architecture
Authors: Chand Umesh , Huang Chun-Yang , Kumar Dayanand , Tseng Tseung-Yuen
Published: November 2015

In this letter, the metal induced crystallization (MIC) process is used in the Si-based conductive bridging resistive random access memory (CBRAM) application. The amorphous Si (a-Si) is transformed to crystallized poly-silicon (poly-Si) at a low temperature by using Ni metal for inducing poly-Si to provide the resistive switching. The MIC process can produce a highly preferred orientation poly-Si film, which can create the exact paths or grain boundaries through the top and down electrodes in the present CBRAM device. The grain boundary in MIC poly-Si layer can confine the conductive filament of metal bridging growth in it, which can improve the switching fluctuation behavior in the nonvolatile memory application. Compared with the a-Si based device, a significant improvement in terms of resistive switching parameters such as stability and resistance distribution is demonstrated in the MIC poly-Si CBRAM device. Moreover, the well-behaved memory performance, such as high ON/OFF resistance ratio (4 order), a large AC endurance (106), and good retention characteristics (104 s at 125 °C) are achieved in the Cu/poly-Si/n+-Si CMOS compatible cross bar structure.
Flexible complementary metal oxide semiconductor microelectrode arrays with applications in single cell characterization
Authors: Pajouhi H. , Jou A. Y. , Jain R. , Ziabari A. , Shakouri A. , Savran C. A. , Mohammadi S.
Published: November 2015

A highly flexible microelectrode array with an embedded complementary metal oxide semiconductor (CMOS) instrumentation amplifier suitable for sensing surfaces of biological entities is developed. The array is based on ultrathin CMOS islands that are thermally isolated from each other and are interconnected by meandered nano-scale wires that can adapt to cellular surfaces with micro-scale curvatures. CMOS temperature sensors are placed in the islands and are optimally biased to have high temperature sensitivity. While no live cell thermometry is conducted, a measured temperature sensitivity of 0.15 °C in the temperature range of 35 to 40 °C is achieved by utilizing a low noise CMOS lock-in amplifier implemented in the same technology. The monolithic nature of CMOS sensors and amplifier circuits and their versatile flexible interconnecting wires overcome the sensitivity and yield limitations of microelectrode arrays fabricated in competing technologies.
Effect of space layer doping on photoelectric conversion efficiency of InAs/GaAs quantum dot solar cells
Authors: Lee Kyoung Su , Lee Dong Uk , Kim Eun Kyu , Choi Won Jun
Published: November 2015

We report an effect of photoelectric conversion efficiency (PCE) by space layer doping in InAs/GaAs quantum dot solar cells (QDSC) and δ-doped QDSC grown by molecular beam epitaxy. The PCEs of QDSC and δ-doped QDSC without anti-reflection coating were 10.8% and 4.3%, respectively. The QDSC had about four electrons per QD, and its ideality factor was temperature-independent, which implies that recombination of electron-hole pairs is suppressed by strong potential barriers around charged dots. From the deep level transient spectroscopy measurements, four defect levels, including QD with the activation energy ranges from 0.08 eV to 0.50 eV below GaAs conduction band edge, appeared. Especially, the M1 defect (Ec-0.14 eV) was newly formed in δ-doped QDSC and its density was higher than those of M3 (Ec-0.35 eV) and M4 (Ec-0.50 eV) levels in QDSC. These results suggest that the photo-carriers recombining at M1 defect might be responsible for the reduction of PCE in δ-doped QDSC.
Frequency dependence of the maximum operating temperature for quantum-cascade lasers up to 5.4 THz
Authors: Wienold M. , Röben B. , Lü X. , Rozas G. , Schrottke L. , Biermann K. , Grahn H. T.
Published: November 2015

We report on the observation of an approximately linear reduction in the maximum operating temperature with an increasing emission frequency for terahertz quantum-cascade lasers between 4.2 and 5.4 THz. These lasers are based on the same design type, but vary in period length and barrier height for the cascade structure. The sample emitting at the highest frequency around 5.4 THz can be operated in pulsed mode up to 56 K. We identify an additional relaxation channel for electrons by longitudinal optical phonon scattering from the upper to the lower laser level and increasing optical losses toward higher frequencies as major processes, leading to the observed temperature behavior.
Temperature-dependent reversible and irreversible processes in Nb-doped PbZrO3 relaxor ferroelectric thin films
Authors: Ye Mao , Huang Haitao , Li Tao , Ke Shanming , Lin Peng , Peng Biaolin , Mai Manfang , Sun Qiu , Peng Xiang , Zeng Xierong
Published: November 2015

The dielectric and ferroelectric nonlinearity of Nb-doped PbZrO3 relaxor ferroelectric thin films was investigated. The ac field dependence of the permittivity of relaxor ferroelectric thin films is demonstrated to be described by a Rayleigh type relation. Both reversible and irreversible components of dielectric permittivity decrease linearly with the logarithm of the frequency of the ac field. The irreversible Rayleigh coefficient α′(T) shows a peak around the “freezing temperature” Tf, which is probably according to the transition from polar nano-regions (PNRs) to dipole-glass state in relaxor ferroelectrics. The results demonstrate that the models describing the interaction of domain walls and randomly distributed pinning centers in ferroelectric materials can be extended to the displacement of nanoscale walls in relaxors.
Dual-band trapping of spoof surface plasmon polaritons and negative group velocity realization through microstrip line with gradient holes
Authors: Liu Liangliang , Li Zhuo , Xu Bingzheng , Ning Pingping , Chen Chen , Xu Jia , Chen Xinlei , Gu Changqing
Published: November 2015

In this letter, dual-band trapping of spoof surface plasmon polaritons (SSPPs) is realized by a simple surface plasmon waveguide (SPW), which takes the form of a microstrip line with periodic holes. A tapered microstrip line with periodic gradient holes is built for efficient mode conversion between the quasi-transverse electromagnetic waves in the common microstrip line and the SSPPs on the SPW. It is interesting to note that negative group velocity can be clearly observed on the first high-order mode of such SPW due to the strong coupling between the corrugated microstrip line and ground. A curved SPW of the same form is also investigated for testing its field confinement and circuitry function. Measurement results agree quite well with the simulation ones, which indicate this SPW can find potential applications in plasmonic integrated circuits at microwave and terahertz frequencies.
Quantum ballistic transport by interacting two-electron states in quasi-one-dimensional channels
Authors: Huang Danhong , Gumbs Godfrey , Abranyos Yonatan , Pepper Michael , Kumar Sanjeev
Published: November 2015

For quantum ballistic transport of electrons through a short conduction channel, the role of Coulomb interaction may significantly modify the energy levels of two-electron states at low temperatures as the channel becomes wide. In this regime, the Coulomb effect on the two-electron states is calculated and found to lead to four split energy levels, including two anticrossing-level and two crossing-level states. Moreover, due to the interplay of anticrossing and crossing effects, our calculations reveal that the ground two-electron state will switch from one anticrossing state (strong confinement) to a crossing state (intermediate confinement) as the channel width gradually increases and then back to the original anticrossing state (weak confinement) as the channel width becomes larger than a threshold value. This switching behavior leaves a footprint in the ballistic conductance as well as in the diffusion thermoelectric power of electrons. Such a switching is related to the triple spin degeneracy as well as to the Coulomb repulsion in the central region of the channel, which separates two electrons away and pushes them to different channel edges. The conductance reoccurrence region expands from the weak to the intermediate confinement regime with increasing electron density.
Translocation of a top-order carnivore: tracking the initial survival, spatial movement, home-range establishment and habitat use of Tasmanian devils on Maria Island
Authors: Thalmann Sam , Peck Sarah , Wise Phil , Potts Joanne M. , Clarke Judy , Richley Jim
Published: November 2015

The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial threatened with extinction from the emergence of Devil Facial Tumour Disease. The establishment of ex situ populations is a key management action for the species. We examined the initial survival, movement pattern, home range, and habit use of six devils from a total of 15 individuals translocated to Maria Island (south-east Tasmania). A total of 14 devils (93%) survived the initial monitoring phase within this study (122 days after translocation). The maximum and minimum distance recorded during one night was 21.73 km (range = 14.12–25.40 km) and 1.94 km (range = 0.07–7.71 km), respectively, while the average nightly distance travelled varied significantly (range = 7.24–13.07 km) between individuals. Short-term home-range size (90% kernel) varied from 936 to 3501 ha, with an average of 2180 (±836) ha for all devils. The habitat preference of devils on Maria Island shows a positive association with agricultural and urban habitats, and an avoidance of wet eucalypt forest. The home range and habitat associations may change as competitive pressures increase with population growth; however, this initial research indicates that translocation as a management action is a powerful tool for the establishment of ex situ populations, assisting in the continued conservation of this species.
Arsenic metabolism in cyanobacteria
Authors: Miyashita Shin-ichi , Murota Chisato , Kondo Keisuke , Fujiwara Shoko , Tsuzuki Mikio
Published: November 2015

Environmental context Cyanobacteria are ecologically important, photosynthetic organisms that are widely distributed throughout the environment. They play a central role in arsenic transformations in terms of both mineralisation and formation of organoarsenic species as the primary producers in aquatic ecosystems. In this review, arsenic resistance, transport and biotransformation in cyanobacteria are reviewed and compared with those in other organisms. Abstract Arsenic is a toxic element that is widely distributed in the lithosphere, hydrosphere and biosphere. Some species of cyanobacteria can grow in high concentrations of arsenate (pentavalent inorganic arsenic compound) (100mM) and in low-millimolar concentrations of arsenite (trivalent inorganic arsenic compound). Arsenate, which is a molecular analogue of phosphate, is taken up by cells through phosphate transporters, and inhibits oxidative phosphorylation and photophosphorylation. Arsenite, which enters the cell through a concentration gradient, shows higher toxicity than arsenate by binding to sulfhydryl groups and impairing the functions of many proteins. Detoxification mechanisms for arsenic in cyanobacterial cells include efflux of intracellular inorganic arsenic compounds, and biosynthesis of methylarsonic acid and dimethylarsinic acid through methylation of intracellular inorganic arsenic compounds. In some cyanobacteria, ars genes coding for an arsenate reductase (arsC), a membrane-bound protein involved in arsenic efflux (arsB) and an arsenite S-adenosylmethionine methyltransferase (arsM) have been found. Furthermore, cyanobacteria can produce more complex arsenic species such as arsenosugars. In this review, arsenic metabolism in cyanobacteria is reviewed, compared with that in other organisms. Knowledge gaps remain regarding both arsenic transport (e.g. uptake of methylated arsenicals and excretion of arsenate) and biotransformation (especially production of lipid-soluble arsenicals). Further studies in these areas are required, not only for a better understanding of the role of cyanobacteria in the circulation of arsenic in aquatic environments, but also for their application to arsenic bioremediation.