bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of electrolyte composition on the electroreduction of CO2to CO on Ag based gas diffusion electrodes
Authors: Verma Sumit , Lu Xun , Ma Sichao , Masel Richard I. , Kenis Paul J. A.
Published: November 2015

We systematically investigate the effect of electrolytes on the electroreduction of CO2to CO on Ag.
Study of thermal conductivity of ice clusters after impact deposition on the silica surfaces using the ReaxFF reactive force field
Authors: Rahnamoun A. , van Duin A. C. T.
Published: November 2015

During aircraft or spacecraft missions, ice accumulates on different parts of their surface elements.
Engineering of hydrogenated two-dimensional h-BN/C superlattices as electrostatic substrates
Authors: Liu Zhun , Zhong Xiaoliang , Yan Hui , Wang Ru-Zhi
Published: November 2015

Engineering of hydrogenated two-dimensional h-BN/C superlattices as electrostatic substrates for laterally-varying doping of graphene.
S-doped mesoporous nanocomposite of HTiNbO5 nanosheets and TiO2 nanoparticles with enhanced visible light photocatalytic activity
Authors: Liu Chao , Han Ruirui , Ji Hongmei , Sun Tao , Zhao Jin , Chen Ningna , Chen Jing , Guo Xuefeng , Hou Wenhua , Ding Weiping
Published: November 2015

S-doped mesoporous TiO2/HTiNbO5 nanocomposite showed dramatically enhanced visible-light photocatalytic activity and stability owing to the combined effects of nano-heterojunction, S doping and morphology engineering.
Charge transport and mobility engineering in two-dimensional transition metal chalcogenide semiconductors
Authors: Li Song-Lin , Tsukagoshi Kazuhito , Orgiu Emanuele , Samorì Paolo
Published: November 2015

This review presents recent progress on charge transport properties, carrier scattering mechanisms, and carrier mobility engineering of two-dimensional transition metal chalcogenides.
Cascade enzymatic cleavage of the β-O-4 linkage in a lignin model compound
Authors: Rosini Elena , Allegretti Chiara , Melis Roberta , Cerioli Lorenzo , Conti Gianluca , Pollegioni Loredano , D'Arrigo Paola
Published: November 2015

The optimized Lig enzymatic system reached the full bioconversion of a racemic mixture of GGE, a lignin model compound.
En route to phosphonato iridium(i) complexes: the decisive effect of an intramolecular hydrogen bond
Authors: Passarelli Vincenzo , Pérez-Torrente Jesús J. , Oro Luis A.
Published: November 2015

The decisive role of an intramolecular NH⋯OP hydrogen bond in the formation of a dimethyl phosphonato iridium(i) complex is shown.
New mechanistic insight into intramolecular arene hydroxylation initiated by (μ-1,2-peroxo)diiron(iii) complexes with dinucleating ligands
Authors: Sekino Mio , Furutachi Hideki , Tasaki Kyosuke , Ishikawa Takanao , Mori Shigeki , Fujinami Shuhei , Akine Shigehisa , Sakata Yoko , Nomura Takashi , Ogura Takashi , Kitagawa Teizo , Suzuki Masatatsu
Published: November 2015

Intramolecular arene hydroxylation initiated by (μ-1,2-peroxo)diiron(iii) complexes (2-R) with dinucleating ligands (R-L) involves a diiron(iv)-oxo species.
The importance of pretreatment and feedstock purity in the reductive splitting of (ligno)cellulose by metal supported USY zeolite
Authors: Ennaert Thijs , Op de Beeck Beau , Vanneste Jens , Smit Arjan T. , Huijgen Wouter J. J. , Vanhulsel Annick , Jacobs Pierre A. , Sels Bert F.
Published: November 2015

The influence of physicochemical cellulose parameters and cellulose purity on the heterogeneous hydrolytic hydrogenation of (ligno)cellulose to hexitols.
A multiplexed miRNA and transgene expression platform for simultaneous repression and expression of protein coding sequences
Authors: Seyhan Attila A.
Published: November 2015

A multiplexed intronic miRNA and transgene expression platform for simultaneous delivery of multiple negative (RNAi) and positive (transgene) regulatory elements.
Revisiting demand rules for gene regulation
Authors: Prajapat Mahendra Kumar , Jain Kirti , Choudhury Debika , Raj Nikhil , Saini Supreet
Published: November 2015

Starting with Savageau's pioneering work regarding demand rules for gene regulation from the 1970s, here, we choose the simplest transcription network and ask: how does the cell choose a particular regulatory topology from all available possibilities?
Biogenic approaches using citrus extracts for the synthesis of metal nanoparticles: the role of flavonoids in gold reduction and stabilization
Authors: Sierra Jelver Alexander , Vanoni Caio Raphael , Tumelero Milton André , Plá Cid Cristiani Campos , Faccio Ricardo , Franceschini Dante Ferreira , Creczynski-Pasa Tânia Beatriz , Pasa André Avelino
Published: November 2015

Experimental and theoretical data support the easy reduction of Au3+ into self-stabilized nanoparticles by citrus flavonoids.
Selective detection of non-aromatic pesticides via cyclodextrin-promoted fluorescence modulation
Authors: DiScenza Dana J. , Levine Mindy
Published: November 2015

The introduction of pesticides to a cyclodextrin-fluorophore solution leads to highly specific fluorescence changes that are used for pesticide detection.
Elastic porous carbon material supported sulfur cathodes for Li–S battery design
Authors: Xiao Weidong , Mi Liwei , Cui Shizhong , Hou Hongwei , Chen Weihua
Published: November 2015

A three-dimensional elastic carbon foam as a current collector and freestanding electrode for Li–S batteries is presented, and its coulombic efficiency of 98% over 100 cycles is achieved.
Does p-type ohmic contact exist in WSe2–metal interfaces?
Authors: Wang Yangyang , Yang Ruo Xi , Quhe Ruge , Zhong Hongxia , Cong Linxiao , Ye Meng , Ni Zeyuan , Song Zhigang , Yang Jinbo , Shi Junjie , Li Ju , Lu Jing
Published: November 2015

P-type ohmic or quasi-ohmic contact appears in ML and BL WSe2–Pt interfaces with inclusion of spin–orbital coupling.
Pd(ii)-catalyzed intramolecular oxidative Heck dearomative reaction: approach to thiazole-fused pyrrolidinones with a C2-azaquarternary center
Authors: Gao Shang , Yang Chi , Huang Yue , Zhao Lei , Wu Xiaoming , Yao Hequan , Lin Aijun
Published: November 2015

A Pd(ii)-catalyzed intramolecular oxidative Heck dearomative reaction for the construction of thiazole-fused pyrrolidinones was achieved for the first time.
Mitoprotective activity of oxidized carbon nanotubes against mitochondrial swelling induced in multiple experimental conditions and predictions with new expected-value perturbation theory
Authors: González-Durruthy Michael , Monserrat Jose Maria , Alberici Luciane C. , Naal Zeki , Curti Carlos , González-Díaz Humberto
Published: November 2015

Mitochondrial Permeability Transition Pore (MPTP) is involved in neurodegeneration, hepatotoxicity, cardiac necrosis, nervous and muscular dystrophies.
Enhancement of selectivity toward ettringite during hydrothermal processes on fluidized bed combustion wastes for the manufacture of preformed building components
Authors: Telesca Antonio , Marroccoli Milena , Montagnaro Fabio , Tomasulo Michele , Valenti Gian Lorenzo
Published: November 2015

This advance is concerned with reactivity improvements of hydrating systems, based on fluidized bed combustion wastes, toward ettringite.
A novel Ag3PO4/Nb2O5 fiber composite with enhanced photocatalytic performance and stability
Authors: Shao Ruyi , Zeng Xi , Cao Zhenzhu , Dong Hongjie , Wang Liying , Wang Fang , Liu Jinrong , Li Zhi , Liang Qinghua
Published: November 2015

A novel Ag3PO4/Nb2O5 fiber composite was fabricated through depositing Ag3PO4 nanoparticles on wrinkled Nb2O5 fiber surfaces through a facile depositing precipitation approach.
Functional nanoparticle-decorated graphene oxide sheets as stabilizers for Pickering high internal phase emulsions and graphene oxide based foam monoliths
Authors: Hu Yang , Huang Jian , Zhang Qi , Yang Yu , Ma Shanshan , Wang Chaoyang
Published: November 2015

A facile and versatile approach was developed for the preparation of graphene oxide sheet-based Pickering high internal phase emulsions by nanoparticle decoration.
Homo- and heteroalumoxane silicates
Authors: García-Ríos Jessica , Hernández-Campos René Francisco , Rascón-Cruz Fernando , Moreno-Martínez Víctor Augusto , Huerta-Lavorie Raúl , Velázquez-Carmona Miguel-Ángel , Cea-Olivares Raymundo , Martínez-Otero Diego , Jancik Vojtech
Published: November 2015

Homo- or hetero alumoxanesilicates or bridged M–OH–M hydroxidesilicates with unusual or unprecedented inorganic cores have been obtained in reactions between1andnBuLi, AlMe3, GaMe3or ZnMe2. The aluminum derivatives serve as models for MAO.
Hydrothermal synthesis of defective TiO2nanoparticles for long-wavelength visible light-photocatalytic killing of cancer cells
Authors: Lee Jooran , Lee Young Hwa , Choi Joon Sig , Park Kwan Seob , Chang Ki Soo , Yoon Minjoong
Published: November 2015

Newly fabricatedd-TiO2NPs were demonstrated to be efficient in long wavelength visible light-triggered killing of cancer cells.
Novel polymorphism behavior of poly(butylene adipate) in its nanocomposites with carbon nanofibers
Authors: Song Yun-Yang , Ye Hai-Mu , Meng Xiao-Yu , Zhou Qiong , Lu Gui-Wu
Published: November 2015

Carbon nanofibers prominently enhance the formation of α-form crystal poly(butylene adipate) at low temperature and lead to a novel plateau phenomenon of α-form crystal content in their composites through specific CH–π interactions.
Kirkendall void formation and selective directional growth of urchin-like ZnO/Zn microspheres through thermal oxidation in air
Authors: Hsu Chia-Yen , Chang Kai-Hsiang , Gong Jyun-An , Tirén Jonas , Li Yuan-Yao , Sakoda Akiyoshi
Published: November 2015

Microparticles with nanostructures on the surface have the characteristics of nanomaterials, yet they avoid aggregation and dispersion problems due to the nature of the nanomaterials.
45S5 Bioglass analogue reinforced akermanite ceramic favorable for additive manufacturing mechanically strong scaffolds
Authors: Wang Xiaoqing , Zhang Lei , Ke Xiurong , Wang Juncheng , Yang Guojing , Yang Xianyan , He Dongshuang , Shao Huifeng , He Yong , Fu Jianzhong , Xu Sanzhong , Gou Zhongru
Published: November 2015

Mechanically strong akermanite-based porous bioceramic scaffolds with appreciable bioactivity and biodegradation were developedviaextrusion 3D-printing followed by a low-melt bioactive glass-assisted pressureless sintering process.
A model for the impact of the nanostructure size on its gas sensing properties
Authors: Alenezi Mohammad R. , Alzanki T. H. , Almeshal A. M. , Alshammari A. S. , Beliatis M. J. , Henley S. J. , Silva S. R. P.
Published: November 2015

The size of a metal oxide nanostructure plays a key role in its performance as a gas sensor.
Optimization and hydrolysis of cellulose under subcritical water treatment for the production of total reducing sugars
Authors: Mohan Mood , Timung Robinson , Deshavath Narendra Naik , Banerjee Tamal , Goud Vaibhav V. , Dasu Venkata V.
Published: November 2015

Subcritical water (SCW) treatment has gained enormous attention as an environmentally friendly technique for organic matter and an attractive reaction medium for a variety of applications. In the current work the process parameters were optimized by RSM model.
Synthesis and chemosensory properties of triphenylamine-substituted conjugated polyfluorene containing a terminal di(2-picolyl)amine moiety
Authors: Yang Po-Chih , Wen Hua-Wen , He Hsiao-Jou
Published: November 2015

This paper describes the synthesis of a triphenylamine-substituted alternating conjugated polyfluorene (PFAD) containing a pendant terminal di(2-picolyl)amine (DPA) group through the Heck coupling reaction.
Application of magnetite nano-hybrid epoxy as protective marine coatings for steel
Authors: Atta Ayman M. , El-Saeed Ashraf M. , El-Mahdy Gamal M. , Al-Lohedan Hamad A.
Published: November 2015

The present work aims to develop a method for preparation of porous iron oxide nanomaterials and to investigate the applicability as smart self-healing protective coatings for steel.
Facile bromine-termination of nonlinear optical chromophore: remarkable optimization in photophysical properties, surface morphology and electro-optic activity
Authors: Wu Jieyun , Bo Shuhui , Wang Wen , Deng Guowei , Zhen Zhen , Liu Xinhou , Chiang Kin-seng
Published: November 2015

This paper describes how a small molecular structure modification can enhance the microscopic and macroscopic properties of chromophore.
Synthesis and enhanced photoelectric performance of Au/ZnO hybrid hollow sphere
Authors: Wang Qin , Hu Linfeng , Chen Min , Wu Limin
Published: November 2015

The maximum responsivity (Rλ) and photocurrent of Au/ZnO nanodevice showed 10 times enhancement than that of pure ZnO hollow spheres.
A low-cost and one-step synthesis of a novel hierarchically porous Fe3O4/C composite with exceptional porosity and superior Li+ storage performance
Authors: Yang Luyu , Liu Wei , Wang Huanlei , Liu Shuang , Wang Jifei , Chen Jiaxin
Published: November 2015

A novel Fe3O4/C composite with a hierarchical pore carbon network has been synthesized simply by one-step pyrolysis synthesis using ferrous gluconate as the precursor, which shows excellent electrochemical properties as an anode material for LIBs.
Continuous flow Buchwald–Hartwig amination of a pharmaceutical intermediate
Authors: Yaseneva Polina , Hodgson Paul , Zakrzewski Jacek , Falß Sebastian , Meadows Rebecca E. , Lapkin Alexei A.
Published: November 2015

A flow process for direct amination of a pharmaceutically relevant substrate using a Pd-NHC based catalyst was demonstrated in a lab-scale mini-plant and in a pilot-scale plant.
A bioscaffolding strategy for hierarchical zeolites with a nanotube-trimodal network
Authors: Li Guannan , Huang Haibo , Yu Bowen , Wang Yun , Tao Jiawei , Wei Yingxu , Li Shougui , Liu Zhongmin , Xu Yan , Xu Ruren
Published: November 2015

Hierarchical zeolite sponges with a nanotube scaffolding architecture, nanotube-trimodal connectivity and self-generated nanotubes with tunable geometry.
Halogenation of carbyne complexes: isolation of unsaturated metallaiodirenium ion and metallabromirenium ion
Authors: Luo Ming , Zhu Congqing , Chen Lina , Zhang Hong , Xia Haiping
Published: November 2015

The halogenation of metallapentalyne led to the formation of metallapentalenes. Experimental and computational studies indicate that four resonance structures, including the first examples of metallaiodirenium and metallabromirenium ions, contribute to the overall structure of the complexes.
Surfactant-driven flow transitions in evaporating droplets
Authors: Marin Alvaro , Liepelt Robert , Rossi Massimiliano , Kähler Christian J.
Published: November 2015

The paper shows experiments revealing the surface and bulk flow on evaporating droplets using a 3D-PTV. The measurements permit to calculate the surface tension gradients and show how different surfactants can turn the droplet's surface either rigid or elastic.
Synthesis and characterization of carbon coated sponge-like tin oxide (SnOx) films and their application as electrode materials in lithium-ion batteries
Authors: Mohri Nils , Oschmann Bernd , Laszczynski Nina , Mueller Franziska , von Zamory Jan , Tahir Muhammad Nawaz , Passerini Stefano , Zentel Rudolf , Tremel Wolfgang
Published: November 2015

Carbon coated SnOx sponges were synthesized and applied as anode in Li-ion batteries.
Laser-driven absorption/desorption of catalysts for producing nanowire arrays in solution
Authors: Chen Xue-Min , Mao Jing , Zhou Yu-Zhu , Yang Jing , Du Xi-Wen , Qiao Shi-Zhang
Published: November 2015

Highly dense CdTe nanowire arrays were synthesized in solution by laser-driven absorption and desorption of gold catalysts.
Green preparation of nitrogen-doped carbon dots derived from silkworm chrysalis for cell imaging
Authors: Feng Ji , Wang Wen-Jing , Hai Xin , Yu Yong-Liang , Wang Jian-Hua
Published: November 2015

Carbon dots (CDs) with a high quantum yield of 46% are prepared using a green one-pot approach under microwaves with silkworm chrysalis which has been used for cell imaging.
Nanoporous gyroid metal oxides with controlled thickness and composition by atomic layer deposition from block copolymer templates
Authors: Ma Wei-Chun , Huang Wei-Shiang , Ku Ching-Shun , Ho Rong-Ming
Published: November 2015

Nanoporous gyroid metal oxides were fabricated with controlled tube thickness and composition by templated atomic layer deposition giving high porosity and large specific surface area as well as superior mechanical properties.
Structural evolution, photoinduced energy transfer in Au nanocluster–CdTe QD nanocomposites and amino acid sensing
Authors: Paramanik Bipattaran , Kundu Sangita , De Goutam , Patra Amitava
Published: November 2015

Photoluminescence quenching and enhancement of the Au NC–CdTe nanocomposite.
Cytotoxic and sublethal effects of silver nanoparticles on tendon-derived stem cells – implications for tendon engineering
Authors: Cheung Tik Shing , Lau Pui Man , Lu Haifei , Ho Ho Pui , Lui Pauline Po Yee , Kong Siu Kai
Published: November 2015

Tendon injuries occur commonly in sports and workplace. Tendon-derived stem cells (TDSCs) have great potential for tendon healing because they can differentiate into functional tenocytes. To grow TDSCs properly in vivo, a scaffold is needed. Silver nanoparticles (AgNPs) have been used in a range of biomedical applications for their anti-bacterial and -inflammatory effects. AgNPs are therefore expected to be a good scaffolding coating material for tendon engineering. Yet, their cytotoxicity in TDSCs remains unknown. Moreover, their sublethal effects were mysterious in TDSCs. In our study, decahedral AgNPs (43.5 nm in diameter) coated with polyvinylpyrrolidone (PVP) caused a decrease in TDSCs’ viability beginning at 37.5 μg ml−1 but showed non-cytotoxic effects at concentrations below 18.8 μg ml−1. Apoptosis was observed in the TDSCs when higher doses of AgNPs (75–150 μg ml−1) were used. Mechanistically, AgNPs induced reactive oxygen species (ROS) formation and mitochondrial membrane potential (MMP) depolarization, resulting in apoptosis. Interestingly, treating TDSCs with N-acetyl-l-cysteine (NAC) antioxidant significantly antagonized the ROS formation, MMP depolarization and apoptosis indicating that ROS accumulation was a prominent mediator in the AgNP-induced cytotoxicity. On the other hand, AgNPs inhibited the tendon markers’ mRNA expression (0–15 μg ml−1), proliferation and clonogenicity (0–15 μg ml−1) in TDSCs under non-cytotoxic concentrations. Taken together, we have reported here for the first time that the decahedral AgNPs are cytotoxic to rat TDSCs and their sublethal effects are also detrimental to stem cells’ proliferation and tenogenic differentiation. Therefore, AgNPs are not a good scaffolding coating material for tendon engineering.
Simple approach to calculate unity‐gain frequency of series–series compensated inductive power transfer
Authors: Gao Y. , Ginart A. , Duan C. , Farley K.B. , Tse Z.T.H.
Published: November 2015

The switching frequency of inductive power transfer may change along with the air gap between two coils due to mutual inductance variation. The mutual inductance is conventionally estimated through experimental measurement or finite element analysis. To simplify this process, a frequency‐gap model for series–series compensated inductive power transfer is proposed to calculate the unity‐gain frequency based on known air gap and coil geometric parameters. Neumann's formula is applied to compute the mutual inductance of the primary and secondary coils. The experimental results show that the unity‐gain frequency can be predicted with varying loads and air gaps (75–250 mm), and a demonstrated unity‐gain error of <6%.
Resolution enhancement in nonlinear photoacoustic imaging
Authors: Goy Alexandre S. , Fleischer Jason W.
Published: November 2015

Nonlinear processes can be exploited to gain access to more information than is possible in the linear regime. Nonlinearity modifies the spectra of the excitation signals through harmonic generation, frequency mixing, and spectral shifting, so that features originally outside the detector range can be detected. Here, we present an experimental study of resolution enhancement for photoacoustic imaging of thin metal layers immersed in water. In this case, there is a threshold in the excitation below which no acoustic signal is detected. Above threshold, the nonlinearity reduces the width of the active area of the excitation beam, resulting in a narrower absorption region and thus improved spatial resolution. This gain is limited only by noise, as the active area of the excitation can be arbitrarily reduced when the fluence becomes closer to the threshold. Here, we demonstrate a two-fold improvement in resolution and quantify the image quality as the excitation fluence goes through threshold.
Predicting protein dynamics from structural ensembles
Authors: Copperman J. , Guenza M. G.
Published: November 2015

The biological properties of proteins are uniquely determined by their structure and dynamics. A protein in solution populates a structural ensemble of metastable configurations around the global fold. From overall rotation to local fluctuations, the dynamics of proteins can cover several orders of magnitude in time scales. We propose a simulation-free coarse-grained approach which utilizes knowledge of the important metastable folded states of the protein to predict the protein dynamics. This approach is based upon the Langevin Equation for Protein Dynamics (LE4PD), a Langevin formalism in the coordinates of the protein backbone. The linear modes of this Langevin formalism organize the fluctuations of the protein, so that more extended dynamical cooperativity relates to increasing energy barriers to mode diffusion. The accuracy of the LE4PD is verified by analyzing the predicted dynamics across a set of seven different proteins for which both relaxation data and NMR solution structures are available. Using experimental NMR conformers as the input structural ensembles, LE4PD predicts quantitatively accurate results, with correlation coefficient ρ = 0.93 to NMR backbone relaxation measurements for the seven proteins. The NMR solution structure derived ensemble and predicted dynamical relaxation is compared with molecular dynamics simulation-derived structural ensembles and LE4PD predictions and is consistent in the time scale of the simulations. The use of the experimental NMR conformers frees the approach from computationally demanding simulations.
Genetic algorithm based fast alignment method for strap-down inertial navigation system with large azimuth misalignment
Authors: He Hongyang , Xu Jiangning , Qin Fangjun , Li Feng
Published: November 2015

In order to shorten the alignment time and eliminate the small initial misalignment limit for compass alignment of strap-down inertial navigation system (SINS), which is sometimes not easy to satisfy when the ship is moored or anchored, an optimal model based time-varying parameter compass alignment algorithm is proposed in this paper. The contributions of the work presented here are twofold. First, the optimization of compass alignment parameters, which involves a lot of trial-and-error traditionally, is achieved based on genetic algorithm. On this basis, second, the optimal parameter varying model is established by least-square polynomial fitting. Experiments are performed with a navigational grade fiber optical gyroscope SINS, which validate the efficiency of the proposed method.
Rotationally inelastic scattering of NO(A2Σ+) + Ar: Differential cross sections and rotational angular momentum polarization
Authors: Sharples Thomas R. , Luxford Thomas F. M. , Townsend Dave , McKendrick Kenneth G. , Costen Matthew L.
Published: November 2015

We present the implementation of a new crossed-molecular beam, velocity-map ion-imaging apparatus, optimized for collisions of electronically excited molecules. We have applied this apparatus to rotational energy transfer in NO(A2Σ+, v = 0, N = 0, j = 0.5) + Ar collisions, at an average energy of 525 cm−1. We report differential cross sections for scattering into NO(A2Σ+, v = 0, N′ = 3, 5, 6, 7, 8, and 9), together with quantum scattering calculations of the differential cross sections and angle dependent rotational alignment. The differential cross sections show dramatic forward scattered peaks, together with oscillatory behavior at larger scattering angles, while the rotational alignment moments are also found to oscillate as a function of scattering angle. In general, the quantum scattering calculations are found to agree well with experiment, reproducing the forward scattering and oscillatory behavior at larger scattering angles. Analysis of the quantum scattering calculations as a function of total rotational angular momentum indicates that the forward scattering peak originates from the attractive minimum in the potential energy surface at the N-end of the NO. Deviations in the quantum scattering predictions from the experimental results, for scattering at angles greater than 10°, are observed to be more significant for scattering to odd final N′. We suggest that this represents inaccuracies in the potential energy surface, and in particular in its representation of the difference between the N- and O-ends of the molecule, as given by the odd-order Legendre moments of the surface.
Lorentz transmission electron microscopy on nanometric magnetic bubbles and skyrmions in bilayered manganites La1.2Sr1.8(Mn1−yRuy)2O7 with controlled magnetic anisotropy
Authors: Morikawa D. , Yu X. Z. , Kaneko Y. , Tokunaga Y. , Nagai T. , Kimoto K. , Arima T. , Tokura Y.
Published: November 2015

We have investigated nanometric magnetic textures in thin (<150 nm) plates of Ru-doped bilayered manganites La1.2Sr1.8(Mn1−yRuy)2O7. Ru substitution for Mn site changes the magnetic anisotropy from in-plane to out-of-plane easy axis type without any significant change of global magnetic and crystal structures. The combination of conventional and Lorentz transmission electron microscopy observations confirms the emergence of magnetic bubbles and skyrmions in the absence of magnetic field. With the changing Ru concentration, systematic changes in the type of magnetic bubbles are observed. A tiny residual magnetic field also affects the generation and the type-change of magnetic bubbles.
Harmonic growth of spherical Rayleigh-Taylor instability in weakly nonlinear regime
Authors: Liu Wanhai , Chen Yulian , Yu Changping , Li Xinliang
Published: November 2015

Harmonic growth in classical Rayleigh-Taylor instability (RTI) on a spherical interface is analytically investigated using the method of the parameter expansion up to the third order. Our results show that the amplitudes of the first four harmonics will recover those in planar RTI as the interface radius tends to infinity compared against the initial perturbation wavelength. The initial radius dramatically influences the harmonic development. The appearance of the second-order feedback to the initial unperturbed interface (i.e., the zeroth harmonic) makes the interface move towards the spherical center. For these four harmonics, the smaller the initial radius is, the faster they grow.
Permutation blocking path integral Monte Carlo approach to the uniform electron gas at finite temperature
Authors: Dornheim Tobias , Schoof Tim , Groth Simon , Filinov Alexey , Bonitz Michael
Published: November 2015

The uniform electron gas (UEG) at finite temperature is of high current interest due to its key relevance for many applications including dense plasmas and laser excited solids. In particular, density functional theory heavily relies on accurate thermodynamic data for the UEG. Until recently, the only existing first-principle results had been obtained for N = 33 electrons with restricted path integral Monte Carlo (RPIMC), for low to moderate density, rs=r¯/aB≳1. These data have been complemented by configuration path integral Monte Carlo (CPIMC) simulations for rs ≤ 1 that substantially deviate from RPIMC towards smaller rs and low temperature. In this work, we present results from an independent third method—the recently developed permutation blocking path integral Monte Carlo (PB-PIMC) approach [T. Dornheim et al., New J. Phys. 17, 073017 (2015)] which we extend to the UEG. Interestingly, PB-PIMC allows us to perform simulations over the entire density range down to half the Fermi temperature (θ = kBT/EF = 0.5) and, therefore, to compare our results to both aforementioned methods. While we find excellent agreement with CPIMC, where results are available, we observe deviations from RPIMC that are beyond the statistical errors and increase with density.
Persistent currents in a magnetic bearing with coated conductors
Authors: Sass F. , Ramos de Castro André , Gonçalves Sotelo Guilherme , de Andrade R.
Published: November 2015

Superconducting magnetic bearings are normally built with bulk superconductors. Since coated conductors properties are far superior, we have proposed in a previous work the replacement of bulks for stacks of 2G wires in magnetic levitation devices. A major limitation of this replacement lies in the fact that the induced current is constrained in narrow loops along the available commercial widths of 2G wires. This work presents a technique to achieve wider loops of persistent current without the need of increasing the coated conductors width. As a result, the use of 2G wires in magnetic bearings took a step towards its economical feasibility.
Optimization and control of two-component radially self-accelerating beams
Authors: Vetter Christian , Eichelkraut Toni , Ornigotti Marco , Szameit Alexander
Published: November 2015

We report on the properties of radially self-accelerating intensity distributions consisting of two components in the angular frequency domain. We show how this subset of solutions, in literature also known as helicon beams, possesses peculiar characteristics that enable a better control over its properties. In this work, we present a step-by-step optimization procedure to achieve the best possible intensity contrast, a distinct rotation rate and long propagation lengths. All points are discussed on a theoretical basis and are experimentally verified.
Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells
Authors: Reichel Christian , Feldmann Frank , Müller Ralph , Reedy Robert C. , Lee Benjamin G. , Young David L. , Stradins Paul , Hermle Martin , Glunz Stefan W.
Published: November 2015

Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm−2 to 1 × 1016 cm−2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.
Luminescent carbon quantum dots with high quantum yield as a single white converter for white light emitting diodes
Authors: Feng X. T. , Zhang F. , Wang Y. L. , Zhang Y. , Yang Y. Z. , Liu X. G.
Published: November 2015

Carbon quantum dots (CQDs) with high quantum yield (51.4%) were synthesized by a one-step hydrothermal method using thiosalicylic acid and ethylenediamine as precursor. The CQDs have the average diameter of 2.3 nm and possess excitation-independent emission wavelength in the range from 320 to 440 nm excitation. Under an ultraviolet (UV) excitation, the CQDs aqueous solutions emit bright blue fluorescence directly and exhibit broad emission with a high spectral component ratio of 67.4% (blue to red intensity to total intensity). We applied the CQDs as a single white-light converter for white light emitting diodes (WLEDs) using a UV-LED chip as the excitation light source. The resulted WLED shows superior performance with corresponding color temperature of 5227 K and the color coordinates of (0.34, 0.38) belonging to the white gamut.
Polarization-sensitive interferometric synthetic aperture microscopy
Authors: South Fredrick A. , Liu Yuan-Zhi , Xu Yang , Shemonski Nathan D. , Carney P. Scott , Boppart Stephen A.
Published: November 2015

Three-dimensional optical microscopy suffers from the well-known compromise between transverse resolution and depth-of-field. This is true for both structural imaging methods and their functional extensions. Interferometric synthetic aperture microscopy (ISAM) is a solution to the 3D coherent microscopy inverse problem that provides depth-independent transverse resolution. We demonstrate the extension of ISAM to polarization sensitive imaging, termed polarization-sensitive interferometric synthetic aperture microscopy (PS-ISAM). This technique is the first functionalization of the ISAM method and provides improved depth-of-field for polarization-sensitive imaging. The basic assumptions of polarization-sensitive imaging are explored, and refocusing of birefringent structures is experimentally demonstrated. PS-ISAM enables high-resolution volumetric imaging of birefringent materials and tissue.
The configuration exchanging theory for transport properties and glass formation temperature of ionic liquids
Authors: Hu Yu-Feng , Zhang Xian-Ming , Qi Jian-Guang , Yin Liu-Yi
Published: November 2015

Understanding molecular motion in terms of molecular structure is an important issue for microscopic understanding of the nature of transport properties and glass transition, and for design of structured materials to meet specific demands in various applications. Herein, a novel molecular mechanism is proposed to connect macroscopic motion in ionic liquids with molecular structure via conformational conversions of the constituent ions or of the cation–anion pairs. New equations for description of relaxation time, diffusion coefficient, molar conductivity, and viscosity of ionic liquids are established. The equation parameters, which were determined from the temperature dependent heat capacities, self-diffusion coefficients, molar conductivities, and viscosities of typical ionic liquids, were used to produce predictions for the corresponding properties of other ionic liquids and for the glass transition temperatures of representative ionic liquids. All predictions are in nice agreements with the experimental results.
Self-referenced spectral interferometry for single-shot measurement of sub-5-fs pulses
Authors: Trabattoni A. , Oksenhendler T. , Jousselin H. , Tempea G. , De Silvestri S. , Sansone G. , Calegari F. , Nisoli M.
Published: November 2015

We demonstrate a novel approach for the extension of self-referenced spectral interferometry to the temporal characterization of few-optical cycle pulses. The new experimental setup is characterized by low dispersion and a collinear geometry. 4-fs pulses have been characterized by performing single-shot measurements, with high dynamic range on a broad temporal region. An independent measurement of the pulse duration, obtained by using attosecond streaking, allowed us to cross-check the experimental technique.
A 6 GW nanosecond solid-state generator based on semiconductor opening switch
Authors: Gusev A. I. , Pedos M. S. , Rukin S. N. , Timoshenkov S. P. , Tsyranov S. N.
Published: November 2015

In this paper, a nanosecond all solid-state generator providing peak power of up to 6 GW, output voltage of 500–900 kV, pulse length (full width at half maximum) of ∼7 ns across external loads of 40–100 Ω, and pulse repetition frequency up to 1 kHz in burst operation mode is described. The output pulse is generated by a semiconductor opening switch (SOS). A new SOS pumping circuit based on a double forming line (DFL) is proposed and its implementation described. As compared with a lumped capacitors-based pumping circuit, the DFL allows minimization of the inductance and stray capacitance of the reverse pumping circuit, and thus, an increase in the SOS cutoff current amplitude and generator output peak power as a whole. The pumping circuit provides a reverse current increasing through the SOS up to 14 kA within ∼12 ns. The SOS cuts off the current in ∼2 ns; the current cutoff rate reaches 7 kA/ns. The SOS braking power (the product of peak voltage and cutoff current) for an external load above 100 Ω is 13 GW.
Ultrafast carrier dynamics and resonant inter-miniband nonlinearity of a cubic GaN/AlN superlattice
Authors: Jostmeier Thorben , Wecker Tobias , Reuter Dirk , As Donat J. , Betz Markus
Published: November 2015

We investigate the linear and dynamical nonlinear optical properties of a superlattice composed of ultra-narrow n-doped GaN/AlN quantum wells. Owing to huge band offsets, the structures feature a broad inter-miniband transition in the telecom window at 1.55 μm. Resonant pump-probe experiments directly reveal ultrafast intersubband relaxation occurring within <100 fs. We estimate an associated third order nonlinear optical susceptibility of Im(χ(3))∼1.1×10−20 m2/V2. The polarization and angular dependences of the optical response confirm the nonlinearity as originating from inter-miniband transitions in the heterostructure.
Inorganic/organic nanocomposites: Reaching a high filler content without increasing viscosity using core-shell structured nanoparticles
Authors: Benhadjala W. , Gravoueille M. , Bord-Majek I. , Béchou L. , Suhir E. , Buet M. , Louarn M. , Weiss M. , Rougé F. , Gaud V. , Ousten Y.
Published: November 2015

Extensive research is being conducted on the development of inorganic/organic nanocomposites for a wide variety of applications in microelectronics, biotechnologies, photonics, adhesives, or optical coatings. High filler contents are usually required to fully optimize the nanocomposites properties. However, numerous studies demonstrated that traditional composite viscosity increases with increasing the filler concentration reducing therefore significantly the material processability. In this work, we synthesized inorganic/organic core-shell nanocomposites with different shell thicknesses. By reducing the shell thickness while maintaining a constant core size, the nanoparticle molecular mass decreases but the nanocomposite filler fraction is correlatively increased. We performed viscosity measurements, which clearly highlighted that intrinsic viscosity of hybrid nanoparticles decreases as the molecular mass decreases, and thus, as the filler fraction increases, as opposed to Einstein predictions about the viscosity of traditional inorganic/polymer two-phase mixtures. This exceptional behavior, modeled by Mark-Houwink-Sakurada equation, proves to be a significant breakthrough for the development of industrializable nanocomposites with high filler contents.
1.319 μm excited intense 800 nm frequency upconversion emission in Tm3+-doped fluorogermanate glass
Authors: Gouveia-Neto A. S. , Vermelho M. V. D. , Gouveia E. A. , Bueno L. A. , Jacinto C.
Published: November 2015

Generation of near-infrared light within the first biological optical window via frequency upconversion in Tm3+-doped PbGeO3-PbF2-CdF2 glass excited within the second biological window at 1.319 μm is reported. The upconversion emission at 800 nm is the sole light signal observed in the entire ultraviolet-visible-near-infrared spectral region making it possible obtaining high contrast imaging. The dependence of the 800 nm signal upon the sample temperature was investigated and results showed an increase by a factor of ×2.5 in the 30–280 °C range. Generation of detectable 690 nm for temperatures above 100 °C in addition to the intense 800 nm main signal was also observed. The proposed excitation mechanism for the 800 nm thulium emitting level is assigned to a multiphonon-assisted excitation from the ground-state 3H6 to the 3H5 excited-state level, a rapid relaxation to the 3F4 level and followed by an excited-state absorption of the pump photons mediated by multiphonons connecting the 3F4 level to the 3H4 emitting level.
Static magnetoelectric and magnetoelastic response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects
Authors: Krantz Matthias C. , Gugat Jascha L. , Gerken Martina
Published: November 2015

The static bending-mode transverse magnetoelectric effect and the magnetic field-induced bending response of composite cantilevers with thin magnetostrictive (MS), piezoelectric (PE), and substrate (Sub) layers is investigated for the PE layer subjected to open and short circuit conditions. Analytic theories are presented for strain-coupled three layer composites of PE, MS, and Sub layers in all layer sequences. We use constitutive equations with linear coupling of stress, strain, H, E, and D fields and present results for the open and short circuit magnetoelectric and bending responses for arbitrary layer thickness ratios for the FeCoBSi-AlN-Si materials system. Besides a rich sequence dependent behavior the theory predicts great and systematic differences between the open and short circuit magnetoelectric response yielding maxima at similar MS and PE layer thicknesses in the open circuit and near vanishing PE layer thicknesses in the short circuit cases. In contrast, the open vs. short circuit bending response differences are pronounced but much smaller. Layer sequence systematics and implications for static H-field sensors will be discussed.
The influences of geometric shape of cross section on equilibrium configuration of DNA in elastic rod model
Authors: Xiao Ye , Huang Zaixing
Published: November 2015

The equilibrium configuration equations of DNA chain with elastic rod model are derived in detail by the variation of the free energy functional, which depends on the curvature, torsion, twisting angle and its derivative with respect to the arc-length of central axis curve of rod. With the different shapes of rod, we obtain the equilibrium equations of DNA with circular and noncircular cross sections, which provide an approach to describe the physical behaviors of A-, B-, Z-DNA. The results show that the elastic rod model with circular cross section can accurately characterize the equilibrium configurations of A-, B-DNA, while the model with elliptical cross sections is more suitable for Z-DNA.
Reducing symmetry in topology optimization of two-dimensional porous phononic crystals
Authors: Dong Hao-Wen , Wang Yue-Sheng , Wang Yan-Feng , Zhang Chuanzeng
Published: November 2015

In this paper we present a comprehensive study on the multi-objective optimization of two-dimensional porous phononic crystals (PnCs) in both square and triangular lattices with the reduced topology symmetry of the unit-cell. The fast non-dominated sorting-based genetic algorithm II is used to perform the optimization, and the Pareto-optimal solutions are obtained. The results demonstrate that the symmetry reduction significantly influences the optimized structures. The physical mechanism of the optimized structures is analyzed. Topology optimization combined with the symmetry reduction can discover new structures and offer new degrees of freedom to design PnC-based devices. Especially, the rotationally symmetrical structures presented here can be utilized to explore and design new chiral metamaterials.
Effect of the magnetic material on AC losses in HTS conductors in AC magnetic field carrying AC transport current
Authors: Wan Xing-Xing , Huang Chen-Guang , Yong Hua-Dong , Zhou You-He
Published: November 2015

This paper presents an investigation on the AC losses in several typical superconducting composite conductors using the H-formulation model. A single superconducting strip with ferromagnetic substrate or cores and a stack of coated conductors with ferromagnetic substrates are studied. We consider all the coated conductors carrying AC transport currents and simultaneously exposed to perpendicular AC magnetic fields. The influences of the amplitude, frequency, phase difference and ferromagnetic materials on the AC losses are investigated. The results show that the magnetization losses of single strip and stacked strips have similar characteristics. The ferromagnetic substrate can increase the magnetization loss at low magnetic field, and decrease the loss at high magnetic field. The ferromagnetic substrate can obviously increase the transport loss in stacked strips. The trends of total AC losses of single strip and stacked strips are similar when they are carrying current or exposed to a perpendicular magnetic field. The effect of the frequency on the total AC losses of single strip is related to the amplitude of magnetic field. The AC losses decrease with increasing frequency in low magnetic field region while increase in high magnetic field region. As the phase difference changes, there is a periodic variation for the AC losses. Moreover, when the strip is under only the transport current and magnetic field, the ferromagnetic cores will increase the AC losses for large transport current or field.
Effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water
Authors: Ng Ding-Quan , Lin Yi-Pin
Published: November 2015

Environmental context Galvanic corrosion has been recently reported as the main cause of lead contamination in drinking water in urban cities. Conditions that can deter or promote galvanic corrosion, however, are not well understood. Fundamental investigations exploring the mechanisms and processes involved in galvanic corrosion in drinking water could help to implement proper corrective measures to safeguard public health from lead contamination. Abstract This study investigates the effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water. We hypothesised that galvanic corrosion would occur immediately when a lead–copper couple is first formed and that the release of lead would be suppressed by the subsequent formation of lead corrosion products. Therefore, unlike previous long-term studies using harvested lead pipes, batch experiments employing high-purity lead and copper (99.9%) wires under stagnant and completely mixed conditions were conducted for a 7-day period to test our hypotheses. It was found that enhanced lead release was indeed observed after the lead–copper couple was formed and the lead profiles after 48h were strongly influenced by lead corrosion products formed in the system. Under stagnant conditions, reducing pH and increasing either chloride or sulfate concentrations promoted lead release, leading to the formation of lead corrosion products such as cerussite and hydrocerussite as experiments proceeded. The effect of chloride concentration on total lead concentration measured in the aqueous phase was similar to that of sulfate at the same molar concentration, showing that the chloride-to-sulfate mass ratio may not provide a good indication for total lead concentration in water. This study provides essential information on fundamental mechanisms and processes involved in galvanic corrosion in drinking water and may be used to explain related phenomena observed in real drinking-water distribution systems.