bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly(butylene succinate) bionanocomposites: a novel bio-organo-modified layered double hydroxide for superior mechanical properties
Authors: Totaro G. , Sisti L. , Celli A. , Askanian H. , Verney V. , Leroux F.
Published: January 2016

Bionanocomposites based on poly(butylene succinate) and a novel organo-modified layered double hydroxide have been prepared by in situ polymerization.
Bis(2-(benzo[d]thiazol-2-yl)-5-fluorophenolate)beryllium: a high-performance electron transport material for phosphorescent organic light-emitting devices
Authors: Chen Dong , Han Liang , Chen Weiping , Zhang Zhenyu , Zhang Shitong , Yang Bing , Zhang Zuolun , Zhang Jingying , Wang Yue
Published: January 2016

A beryllium complex with a low-lying LUMO level, high triplet energy and high electron mobility served as an excellent electron transport material for green, yellow and red phosphorescent OLEDs.
Gold nanoparticle incorporation into nanoporous anatase TiO2mesocrystal using a simple deposition–precipitation method for photocatalytic applications
Authors: Han Tiehu , Wang Huigang , Zheng Xuming
Published: January 2016

Schottky junction plasmonic photocatalysts were synthesized by the modification of spindle-shaped TiO2mesocrystals with Au nanoparticles, and their photocatalysis degradation mechanisms are proposed.
Investigation on temperature stability performance of giant permittivity (In + Nb) in co-doped TiO2 ceramic: a crucial aspect for practical electronic applications
Authors: Tuichai Wattana , Danwittayakul Supamas , Maensiri Santi , Thongbai Prasit
Published: January 2016

In this work, it was shown that the crucial aspect for practical applications of a newly discovered (In + Nb) co-doped TiO2 material is the temperature stability of its dielectric permittivity (ε′).
Sequential crystallization and morphology of triple crystalline biodegradable PEO-b-PCL-b-PLLA triblock terpolymers
Authors: Palacios Jordana K. , Mugica Agurtzane , Zubitur Manuela , Iturrospe Amaia , Arbe Arantxa , Liu Guoming , Wang Dujin , Zhao Junpeng , Hadjichristidis Nikos , Müller Alejandro J.
Published: January 2016

The sequential crystallization of poly(ethylene oxide)-b-poly(ε-caprolactone)-b-poly(l-lactide) (PEO-b-PCL-b-PLLA) triblock terpolymers, in which the three blocks are able to crystallize separately and sequentially from the melt, is presented.
Multi-functional branched polysiloxanes polymers for high refractive index and flame retardant LED encapsulants
Authors: Hsu Chih-Yuan , Han Wei-Gang , Chiang Shu-Jen , Su Wen-Chiung , Liu Ying-Ling
Published: January 2016

Multi-functional branched polysiloxanes exhibiting good thermal stability, high thermal resistance, self-extinguishing properties, high transparency at ultraviolet to blue light region, and relatively high RI value (1.59).
Tough dual nanocomposite hydrogels with inorganic hybrid crosslinking
Authors: Du Juan , Xu Shimei , Feng Shun , Yu Lina , Wang Jide , Liu Yumei
Published: January 2016

Due to the multi-strengthening mechanism of the dual nanocomposite, a super tough and strong hydrogel with inorganic hybrid crosslinking was fabricated.
Tracking a photo-switchable surface-localised supramolecular interaction via refractive index
Authors: Parker Richard M. , Wales Dominic J. , Gates James C. , Smith Peter G. R. , Grossel Martin C.
Published: January 2016

An integrated optical Bragg grating sensor, capable of evanescently detecting small changes in refractive index, is employed to probe the dynamic surface-localised supramolecular interaction between an azobenzene-functionalised monolayer and cyclodextrin in solution.
Correction: Structure and local polar domains of Dy-modified BiFeO3–PbTiO3 multiferroic solid solutions
Authors: Zhuang Jian , Su Lun-Wei , Zhao Jinyan , Wu Hua , Bokov Alexei A. , Ren Wei , Ye Zuo-Guang
Published: January 2016

Correction for ‘Structure and local polar domains of Dy-modified BiFeO3–PbTiO3 multiferroic solid solutions’ by Jian Zhuang et al., J. Mater. Chem. C, 2015, 3, 12450–12456.
Covalent interlocking of glucose oxidase and peroxidase in the voids of paper: enzyme–polymer “spider webs”
Authors: Riccardi C. M. , Mistri D. , Hart O. , Anuganti M. , Lin Y. , Kasi R. M. , Kumar C. V.
Published: January 2016

A modular, general method for trapping enzymes within the voids of paper, without chemical activation of cellulose, is reported.
Adaptive integral sliding mode control for nuclear research reactor with system uncertainties and input perturbation
Authors: Eom Myunghwan , Chwa Dongkyoung
Published: January 2016

A chattering free adaptive integral sliding mode control (AISMC) for a nuclear research reactor system in the presence of system uncertainties and input perturbation is presented. The proposed control method ensures finite time stability and also eliminates the chattering phenomenon. Also, using a deadzone technique, the upper bound of unknown system uncertainty can be estimated. The proposed AISMC can compensate for a reactivity feedback term significantly affecting the reactor system in the form of input perturbation, which is not possible in the case of integral sliding mode control (ISMC). Through simulation results, the effectiveness of the proposed controller is compared with the ISMC method for a nuclear research reactor system, and the effectiveness of the proposed control method is confirmed.
Straight‐forward impedance measurement for balanced RFID tag antenna
Authors: Ge Hongbin , Yao Yuan , Yu Junsheng , Chen Xiaodong , Valderas Daniel
Published: January 2016

A method using 180° hybrid coupler and vector network analyser to measure the radio frequency identification tag antenna impedance is presented. The impedance of a prototype antenna is measured by different experimental methods and compared with simulation results. The comparison results show that the proposed method has a good accuracy and it is more convenient.
Compact ultra‐wideband bandpass filter with good selectivity
Authors: Zhang Ting , Xiao Fei , Bao Jingfu , Tang Xiaohong
Published: January 2016

A compact ultra‐wideband (UWB) bandpass filter based on a novel multi‐mode resonator (MMR) is proposed. The MMR consists of a pair of open‐circuited stubs and three pairs of coupled‐line sections, which can generate four main resonant modes in the desired band, i.e. two odd modes and two even modes. The measured results of a fabricated one show that its bandwidth can cover the UWB frequency range and it has a sharp skirt due to two transmission zeros near its passband. Return loss in the passband is better than −10 dB. Meanwhile, at least −40 dB suppression can be achieved from 11.86 to 15.13 GHz and −30 dB suppression from 12 to 16 GHz.
Photo-detector diode based on thermally oxidized TiO2 nanostructures/p-Si heterojunction
Authors: Hosseini Z. S. , Shasti M. , Ramezani Sani S. , Mortezaali A.
Published: January 2016

Titanium oxide (TiO2)-based photodetectors were fabricated using a thermal oxidation technique. The effect of two different annealing temperatures on morphology, structure, and I-V characteristics has been investigated. TiO2/Si heterostructure exhibited diode-like rectifying I-V behavior both in dark and under illumination. Dependence in photoresponse on annealing temperature was observed that was related to effective surface area of quasi-one-dimensional TiO2 nanostructures. Fabricated TiO2/Si diodes in 850 °C as the lower annealing temperature showed higher responsivity and sensitivity compared with grown ones in 950 °C (R850 °C/R950 °C ∼ 5 and S850 °C/S950 °C ∼ 1.6). Rather good photoresponse and simple fabrication process make the 850 °C-TiO2/Si diode a promising candidate for practical applications.
Theoretical and experimental investigation on magneto-hydrodynamics of plasma window
Authors: Wang S. Z. , Zhu K. , Huang S. , Lu Y. R. , Hershcovitch A. , Yuan Z. X. , Shi B. L. , Gan P. P.
Published: January 2016

As a new device, plasma window has been designed to use plasma discharge to separate atmosphere from vacuum with high difference of pressure. It has many excellent properties, being able to be used as available passage for ion beam with negligible energy loss, also impervious to radiation damage and thermal damage. Normally beam focusing by accelerators is not that easy to achieve within channel of small cross section. 10 mm diameter plasma window's experimental realization could contribute to its further application in accelerator system. In this paper, 10 mm diameter 60 mm long plasma window has first been designed and managed to generate arc discharge with argon gas experimentally. The result proves that it has the ability to separate at least 28.8 kPa (not the upper limit) from 360 Pa with 50 A direct current and 2.5 kW power supplied. Current increase leads to linear inlet pressure increase obviously, while it has less impact on outlet pressure and voltage, coming to the conclusion that the higher current of plasma discharge, the larger pressure difference it creates. Theoretical analysis of 10 mm diameter plasma window in axis symmetrical configuration using argon also has been provided, in which a numerical 2D FLUENT-based magneto-hydrodynamic simulation model is settled. It has a good agreement with experimental result on voltage and mass flow rate when inlet pressure is increased.
Breakup of capillary jets with different disturbances
Authors: Moallemi Nima , Li Ri , Mehravaran Kian
Published: January 2016

The disturbance on a capillary jet can be imposed by radius modulation, velocity modulation, or jet vibration. The objective of the study is to understand the equivalence between the three types of disturbances. Theoretical analysis based on the Bernoulli equation for unsteady flows is conducted. It is found that a radius-modulated disturbance is equivalent to a velocity-modulated disturbance with the same wave number if the non-dimensional amplitude of the radius disturbance is 1.5 times that of the velocity disturbance. This is validated by carrying out numerical simulation based on velocity modulation and comparing with the linear theory based on radius modulation. It is also revealed that disturbance generated by a vibrating nozzle with small amplitude is equivalent to velocity disturbance. The non-dimensional amplitude of the equivalent velocity disturbance is a function of non-dimensional vibration amplitude and vibration wave number. The wave number of the velocity disturbance is shown to be twice of the vibration wave number. Validated by experimental observation, if the vibration wave number is less than 0.5, each nozzle vibration cycle generates two droplets. If the vibration wave number is between 0.5 and 1, each vibration cycle generates one droplet.
Influence of rigid core permittivity and double layer polarization on the electrophoresis of a soft particle: A numerical study
Authors: Bhattacharyya S. , De Simanta
Published: January 2016

The nonlinear electrophoresis of a soft particle with a polarizable uncharged rigid core coated with a polyelectrolyte layer is studied. Due to the coupled nature of the governing electrokinetic equations, a numerical approach is adopted. Our numerical solutions are in good agreement with the existing experimental and theoretical results for a particle with a non-polarizable core when the impacts of the nonlinear effects are low. The induced surface potential of the dielectric rigid core has an impact on the soft particle electrophoresis. The combined effects of the solid polarization of the core and double layer polarization have not been addressed previously in the context of soft particle electrophoresis. We have found that both these effects create retardation on the electrophoresis and are significant when the applied electric field is not weak. The double layer polarization is significant when the Debye length is in the order of the particle size. The range of the applied electric field for which the electrophoretic velocity of a soft particle with a non-polarizable core varies linearly with the applied electric field may create a nonlinear variation in electrophoretic velocity when the core is considered to be polarizable.
Energy efficiency measures for airlines: An application of virtual frontier dynamic range adjusted measure
Authors: Li Ye , Wang Yan-zhang , Cui Qiang
Published: January 2016

In this paper, the energy efficiency of airlines is measured. Number of employees and tons of aviation kerosene are chosen as the inputs. Revenue tonne kilometers, revenue passenger kilometers, and total business income are the outputs. Capital stock is selected as the dynamic factor. A new model, Virtual Frontier Dynamic range adjusted measure (RAM), is proposed to calculate the energy efficiencies of 22 airlines from 2008 to 2012. In Virtual Frontier Dynamic RAM, the reference DMU (decision-making unit) set and the evaluated DMU set are two different sets to distinguish between efficient DMUs. The results demonstrate the following: (1) Air Greenland exhibits the highest energy efficiency, while the efficiency score of Air France-KLM is at the bottom of the 22 airlines. (2) Aggregate airline energy efficiency consistently increased from 2008 to 2012.
Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction
Authors: Xu Lijun , Liu Chang , Jing Wenyang , Cao Zhang , Xue Xin , Lin Yuzhen
Published: January 2016

To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors’ knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm−1 (1343.3 nm) and 7185.6 cm−1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.
Kinetic theory of passing energetic ion transport in presence of the resonant interactions with a rotating magnetic island
Authors: Cao Jinjia , Wang Aike , Gong Xueyu , Xiang Dong , Huang Qianhong , Yu Jun
Published: January 2016

The enhanced transport of passing energetic ions (PEIs) in presence of the resonant interactions with a rotating magnetic island is investigated within the drift kinetic framework. When the island rotation plays a role in the resonant interaction, we find that the velocities of PEIs satisfy a constraint relation of resonant flux surface in phase space. The resonant flux surfaces overlap with the magnetic flux surfaces in real space. A new transport channel responsible for the PEIs moving across the magnetic flux surfaces, i.e., continuously overlapping, is found. Two kinds of radial motions can be induced by the surface overlapping: one arises from the coupling between the resonance and the collision with the background plasma and the other from not completely overlapping of the two surfaces. The two radial motions and the symmetry-breaking induced radial motion constitute the total radial motion. When the pitch-angle scattering rate is very weak, the surface-shear induced transport is dominant. Only a small increase in the collision rate can significantly influence the total transport.
Strain-mediated converse magnetoelectric coupling strength manipulation by a thin titanium layer
Authors: Yang Wei-Gang , Morley Nicola A. , Sharp Joanne , Tian Ye , Rainforth W. Mark
Published: January 2016

The manipulation of the strain-mediated magnetoelectric (ME) coupling strength is investigated by inserting a thin Ti layer (0–10 nm) between a 50 nm Co50Fe50 layer and a (011) oriented lead magnesium niobate-lead titanate (PMN-PT) substrate. A record high remanence ratio (Mr/Ms) tunability of 100% has been demonstrated in the 50 nm CoFe/8 nm Ti/PMN-PT heterostructure, when a total in-plane piezoelectric strain of −1821 ppm was applied at an electric field (E-field) of 16 kV/cm. The ME coupling strength is gradually optimized as the Ti layer thickness increases. Magnetic energy calculation showed that with increasing Ti layer thickness the uniaxial magnetic anisotropy energy (Euni) was reduced from 43 ± 1 kJ/m3 to 29.8 ± 1 kJ/m3. The reduction of Euni makes the strain effect dominant in the total magnetic energy, thus gives an obvious enhanced ME coupling strength.
Sign Learning Kink-based (SiLK) Quantum Monte Carlo for molecular systems
Authors: Ma Xiaoyao , Hall Randall W. , Löffler Frank , Kowalski Karol , Bhaskaran-Nair Kiran , Jarrell Mark , Moreno Juana
Published: January 2016

The Sign Learning Kink (SiLK) based Quantum Monte Carlo (QMC) method is used to calculate the ab initio ground state energies for multiple geometries of the H2O, N2, and F2 molecules. The method is based on Feynman’s path integral formulation of quantum mechanics and has two stages. The first stage is called the learning stage and reduces the well-known QMC minus sign problem by optimizing the linear combinations of Slater determinants which are used in the second stage, a conventional QMC simulation. The method is tested using different vector spaces and compared to the results of other quantum chemical methods and to exact diagonalization. Our findings demonstrate that the SiLK method is accurate and reduces or eliminates the minus sign problem.
Manipulation of a neutral and nonpolar nanoparticle in water using a nonuniform electric field
Authors: Xu Zhen , Wang Chunlei , Sheng Nan , Hu Guohui , Zhou Zhewei , Fang Haiping
Published: January 2016

The manipulation of nanoparticles in water is of essential importance in chemical physics, nanotechnology, medical technology, and biotechnology applications. Generally, a particle with net charges or charge polarity can be driven by an electric field. However, many practical particles only have weak and even negligible charge and polarity, which hinders the electric field to exert a force large enough to drive these nanoparticles directly. Here, we use molecular dynamics simulations to show that a neutral and nonpolar nanoparticle in liquid water can be driven directionally by an external electric field. The directed motion benefits from a nonuniform water environment produced by a nonuniform external electric field, since lower water energies exist under a higher intensity electric field. The nanoparticle spontaneously moves toward locations with a weaker electric field intensity to minimize the energy of the whole system. Considering that the distance between adjacent regions of nonuniform field intensity can reach the micrometer scale, this finding provides a new mechanism of manipulating nanoparticles from the nanoscale to the microscale.
Antisymmetric tensor generalizations of affine vector fields
Authors: Houri Tsuyoshi , Morisawa Yoshiyuki , Tomoda Kentaro
Published: January 2016

Tensor generalizations of affine vector fields called symmetric and antisymmetric affine tensor fields are discussed as symmetry of spacetimes. We review the properties of the symmetric ones, which have been studied in earlier works, and investigate the properties of the antisymmetric ones, which are the main theme in this paper. It is shown that antisymmetric affine tensor fields are closely related to one-lower-rank antisymmetric tensor fields which are parallelly transported along geodesics. It is also shown that the number of linear independent rank-p antisymmetric affine tensor fields in n-dimensions is bounded by (n + 1)!/p!(n − p)!. We also derive the integrability conditions for antisymmetric affine tensor fields. Using the integrability conditions, we discuss the existence of antisymmetric affine tensor fields on various spacetimes.
In-situ visualization of stress-dependent bulk magnetic domain formation by neutron grating interferometry
Authors: Betz B. , Rauscher P. , Harti R. P. , Schäfer R. , Van Swygenhoven H. , Kaestner A. , Hovind J. , Lehmann E. , Grünzweig C.
Published: January 2016

The performance and degree of efficiency of industrial transformers are directly influenced by the magnetic properties of high-permeability steel laminations (HPSLs). Industrial transformer cores are built of stacks of single HPSLs. While the insulating coating on each HPSL reduces eddy-current losses in the transformer core, the coating also induces favorable inter-granular tensile stresses that significantly influence the underlying magnetic domain structure. Here, we show that the neutron dark-field image can be used to analyze the influence of the coating on the volume and supplementary surface magnetic domain structures. To visualize the stress effect of the coating on the bulk domain formation, we used an uncoated HPSL and stepwise increased the applied external tensile stress up to 20 MPa. We imaged the domain configuration of the intermediate stress states and were able to reproduce the original domain structure of the coated state. Furthermore, we were able to visualize how the applied stresses lead to a refinement of the volume domain structure and the suppression and reoccurrence of supplementary domains.
A thin permeable-membrane device for single-molecule manipulation
Authors: Park Chang-Young , Jacobson David R. , Nguyen Dan T. , Willardson Sam , Saleh Omar A.
Published: January 2016

Single-molecule manipulation instruments have unparalleled abilities to interrogate the structure and elasticity of single biomolecules. Key insights are derived by measuring the system response in varying solution conditions; yet, typical solution control strategies require imposing a direct fluid flow on the measured biomolecule that perturbs the high-sensitivity measurement and/or removes interacting molecules by advection. An alternate approach is to fabricate devices that permit solution changes by diffusion of the introduced species through permeable membranes, rather than by direct solution flow through the sensing region. Prior implementations of permeable-membrane devices are relatively thick, disallowing their use in apparatus that require the simultaneous close approach of external instrumentation from two sides, as occurs in single-molecule manipulation devices like the magnetic tweezer. Here, we describe the construction and use of a thin microfluidic device appropriate for single-molecule studies. We create a flow cell of only ∼500 μm total thickness by sandwiching glass coverslips around a thin plastic gasket and then create permeable walls between laterally separated channels in situ through photo-induced cross-linking of poly(ethylene glycol) diacrylate hydrogels. We show that these membranes permit passage of ions and small molecules (thus permitting solution equilibration in the absence of direct flow), but the membranes block the passage of larger biomolecules (thus retaining precious samples). Finally, we demonstrate the suitability of the device for high-resolution magnetic-tweezer experiments by measuring the salt-dependent folding of a single RNA hairpin under force.
Phonon transport at interfaces: Determining the correct modes of vibration
Authors: Gordiz Kiarash , Henry Asegun
Published: January 2016

For many decades, phonon transport at interfaces has been interpreted in terms of phonons impinging on an interface and subsequently transmitting a certain fraction of their energy into the other material. It has also been largely assumed that when one joins two bulk materials, interfacial phonon transport can be described in terms of the modes that exist in each material separately. However, a new formalism for calculating the modal contributions to thermal interface conductance with full inclusion of anharmonicity has been recently developed, which now offers a means for checking the validity of this assumption. Here, we examine the assumption of using the bulk materials' modes to describe the interfacial transport. The results indicate that when two materials are joined, a new set of vibrational modes are required to correctly describe the transport. As the modes are analyzed, certain classifications emerge and some of the most important modes are localized at the interface and can exhibit large conductance contributions that cannot be explained by the current physical picture based on transmission probability.
Quantifying local exciton, charge resonance, and multiexciton character in correlated wave functions of multichromophoric systems
Authors: Casanova David , Krylov Anna I.
Published: January 2016

A new method for quantifying the contributions of local excitation, charge resonance, and multiexciton configurations in correlated wave functions of multichromophoric systems is presented. The approach relies on fragment-localized orbitals and employs spin correlators. Its utility is illustrated by calculations on model clusters of hydrogen, ethylene, and tetracene molecules using adiabatic restricted-active-space configuration interaction wave functions. In addition to the wave function analysis, this approach provides a basis for a simple state-specific energy correction accounting for insufficient description of electron correlation. The decomposition scheme also allows one to compute energies of the diabatic states of the local excitonic, charge-resonance, and multi-excitonic character. The new method provides insight into electronic structure of multichromophoric systems and delivers valuable reference data for validating excitonic models.
An organic dye with very large Stokes-shift and broad tunability of fluorescence: Potential two-photon probe for bioimaging and ultra-sensitive solid-state gas sensor
Authors: He Tingchao , Wang Yue , Tian Xiaoqing , Gao Yang , Zhao Xin , Grimsdale Andrew C. , Lin Xiaodong , Sun Handong
Published: January 2016

Light-emitting nonlinear optical molecules, especially those with large Stokes shifts and broad tunability of their emission wavelength, have attracted considerable attention for various applications including biomedical imaging and fluorescent sensors. However, most fluorescent chromophores have only limited potential for such applications due to small Stokes shifts, narrow tunability of fluorescence emissions, and small optical nonlinearity in highly polar solvents. In this work, we demonstrate that a two-photon absorbing stilbene chromophore exhibits a large two-photon absorption action cross-section (ηδ = 320 GM) in dimethylsulfoxide (DMSO) and shows broad fluorescence tunability (125 nm) by manipulating the polarity of the surrounding medium. Importantly, a very large Stokes shift of up to 227 nm is achieved in DMSO. Thanks to these features, this chromophore can be utilized as a two-photon probe for bioimaging applications and in an ultrasensitive solid-state gas detector.
Elastic properties of suspended black phosphorus nanosheets
Authors: Wang Jia-Ying , Li Yang , Zhan Zhao-Yao , Li Tie , Zhen Liang , Xu Cheng-Yan
Published: January 2016

The mechanical properties of black phosphorus (BP) nanosheets suspended over circular holes were measured by an atomic force microscope nanoindentation method. The continuum mechanic model was introduced to calculate the elastic modulus and pretension of BP nanosheets with thicknesses ranging from 14.3 to 34 nm. Elastic modulus of BP nanosheets declines with thickness, and the maximum value is 276 ± 32.4 GPa. Besides, the effective strain of BP ranges from 8 to 17% with a breaking strength of 25 GPa. Our results show that BP nanosheets serve as a promising candidate for flexible electronic applications.
One-step fabrication of submicrostructures by low one-photon absorption direct laser writing technique with local thermal effect
Authors: Nguyen Dam Thuy Trang , Tong Quang Cong , Ledoux-Rak Isabelle , Lai Ngoc Diep
Published: January 2016

In this work, local thermal effect induced by a continuous-wave laser has been investigated and exploited to optimize the low one-photon absorption (LOPA) direct laser writing (DLW) technique for fabrication of polymer-based microstructures. It was demonstrated that the temperature of excited SU8 photoresist at the focusing area increases to above 100 °C due to high excitation intensity and becomes stable at that temperature thanks to the use of a continuous-wave laser at 532 nm-wavelength. This optically induced thermal effect immediately completes the crosslinking process at the photopolymerized region, allowing obtain desired structures without using the conventional post-exposure bake (PEB) step, which is usually realized after the exposure. Theoretical calculation of the temperature distribution induced by local optical excitation using finite element method confirmed the experimental results. LOPA-based DLW technique combined with optically induced thermal effect (local PEB) shows great advantages over the traditional PEB, such as simple, short fabrication time, high resolution. In particular, it allowed the overcoming of the accumulation effect inherently existed in optical lithography by one-photon absorption process, resulting in small and uniform structures with very short lattice constant.
Highly sensitive photodetectors based on hybrid 2D-0D SnS2-copper indium sulfide quantum dots
Authors: Huang Yun , Zhan Xueying , Xu Kai , Yin Lei , Cheng Zhongzhou , Jiang Chao , Wang Zhenxing , He Jun
Published: January 2016

Both high speed and efficiency of photoelectric conversion are essential for photodetectors. As an emerging layered metal dichalcogenide (LMD), tin disulfide owns intrinsic faster photodetection ability than most other LMDs but poor light absorption and low photoelectric conversion efficiency. We develop an efficient method to enhance its performance by constructing a SnS2-copper indium sulfide hybrid structure. As a result, the responsivity reaches 630 A/W, six times stronger than pristine SnS2 and much higher than most other LMDs photodetectors. Additionally, the photocurrents are enhanced by more than 1 order of magnitude. Our work may open up a pathway to improve the performance of photodetectors based on LMDs.
Microwave-induced zero-resistance state in two-dimensional electron systems with unidirectional periodic modulation
Authors: Bykov A. A. , Strygin I. S. , Goran A. V. , Kalagin A. K. , Rodyakina E. E. , Latyshev A. V.
Published: January 2016

In this study we fabricated lateral superlattices (LSLs) based on the selectively doped GaAs/AlAs heterostructures with a high-mobility two-dimensional (2D) electron gas. The LSLs were formed using the electron-beam lithography and lift-off techniques, which produced a set of metallic strips on top of a heterojunction. The amplitude of the 2D electron gas modulation in the LSL was controlled by the gate voltage applied to the metallic strips. The LSLs with two different periods (a = 200 nm and 500 nm) were used to investigate the influence of microwave radiation with the frequency of 110–150 GHz on the 2D electron transport at the temperature T = 1.6 K in the magnetic field B < 1 T. We have found that zero-resistance states (ZRSs) appear under the microwave radiation in the 2D systems with a unidirectional periodic modulation. These ZRSs are located at the minima of commensurability oscillations.
Widely tunable and monochromatic terahertz difference frequency generation with organic crystal 2-(3-(4-hydroxystyryl)-5,5-dime-thylcyclohex-2-enylidene) malononitrile
Authors: Liu Pengxiang , Zhang Xinyuan , Yan Chao , Xu Degang , Li Yin , Shi Wei , Zhang Guochun , Zhang Xinzheng , Yao Jianquan , Wu Yicheng
Published: January 2016

We report an experimental study on widely tunable terahertz (THz) wave difference frequency generation (DFG) with hydrogen-bonded crystals 2-(3-(4-hydroxystyryl)-5,5-dime-thylcyclohex-2-enylidene) malononitrile (OH1). The organic crystals were pumped by a ∼1.3 μm double-pass KTiOPO4 optical parametric oscillator. A tuning range of 0.02–20 THz was achieved. OH1 crystals offer a long effective interaction length (also high output) for the generation below 3 THz, owing to the low absorption and favorable phase-matching. The highest energy of 507 nJ/pulse was generated at 1.92 THz with a 1.89-mm-thick crystal. Comprehensive explanations were provided, on the basis of theoretical calculations. Cascading phenomenon during the DFG process was demonstrated. The photon conversion efficiency could reach 2.9%.
The anisotropic structure of turbulence and its energy spectrum
Authors: Elsinga G. E. , Marusic I.
Published: January 2016

The spectral energy distribution in turbulent flows is observed to follow a k−5/3 power scaling, as originally predicted by Kolmogorov’s theory. However, the underlying assumptions in Kolmogorov’s theory appear not to hold with most experimental and numerical data showing evidence of small-scale anisotropy and significant direct energy transfer between the large- and the small-scales. Here, we present a flow structure that reconciles the k−5/3 spectrum with small-scale universality, small-scale anisotropy, and direct scale interactions. The flow structure is a shear layer, which contains the small-scales of motion and is bounded by the large-scales. The anisotropic shear layer reveals the expected scaling of the energy spectrum in nearly all directions.
Effects of gasket on coupled plastic flow and strain-induced phase transformations under high pressure and large torsion in a rotational diamond anvil cell
Authors: Feng Biao , Levitas Valery I.
Published: January 2016

Combined plastic flow and strain-induced phase transformations (PTs) under high pressure in a sample within a gasket subjected to three dimensional compression and torsion in a rotational diamond anvil cell (RDAC) are studied using a finite element approach. The results are obtained for the weaker, equal-strength, and stronger high-pressure phases in comparison with low-pressure phases. It is found that, due to the strong gasket, the pressure in the sample is relatively homogenous and the geometry of the transformed zones is mostly determined by heterogeneity in plastic flow. For the equal-strength phases, the PT rate is higher than for the weaker and stronger high-pressure phases. For the weaker high-pressure phase, transformation softening induces material instability and leads to strain and PT localization. For the stronger high-pressure phase, the PT is suppressed by strain hardening during PT. The effect of the kinetic parameter k that scales the PT rate in the strain-controlled kinetic equation is also examined. In comparison with a traditional diamond anvil cell without torsion, the PT progress is much faster in RDAC under the same maximum pressure in the sample. Finally, the gasket size and strength effects are discussed. For a shorter and weaker gasket, faster plastic flow in radial and thickness directions leads to faster PT kinetics in comparison with a longer and stronger gasket. The rates of PT and plastic flows are not very sensitive to the modest change in a gasket thickness. Multiple experimental results are reproduced and interpreted. Obtained results allow one to design the desired pressure-plastic strain loading program in the experiments for searching new phases, reducing PT pressure by plastic shear, extracting kinetic properties from experiments with heterogeneous fields, and controlling homogeneity of all fields and kinetics of PTs.
Polarization-sensitive electro-optic detection of terahertz wave using three different types of crystal symmetry: Toward broadband polarization spectroscopy
Authors: Oguchi Kenichi , Iwasaki Hotsumi , Okano Makoto , Watanabe Shinichi
Published: January 2016

We investigated polarization-sensitive electro-optic (EO) detection of terahertz (THz) waves by using two uniaxial crystals: a c-cut gallium selenide and a c-cut lithium niobate crystals. We formulated a general frequency-domain description of EO detection by in-plane isotropic EO crystals, which holds regardless of the frequency. Based on this description, the polarization of THz waves can be derived by analyzing EO sampling signals measured with two orthogonal configurations of the in-plane isotropic EO crystals as well as typical (111) zinc-blende EO crystals. In addition, we experimentally demonstrated that the frequency-dependent polarization of THz waves can be reproducibly retrieved using three EO crystals with different crystal symmetries and with different phase matching conditions. Our description provides essential information for practical polarization sensing in the THz frequency range as well as in the mid-infrared range.
Experimental study of an adaptive elastic metamaterial controlled by electric circuits
Authors: Zhu R. , Chen Y. Y. , Barnhart M. V. , Hu G. K. , Sun C. T. , Huang G. L.
Published: January 2016

The ability to control elastic wave propagation at a deep subwavelength scale makes locally resonant elastic metamaterials very relevant. A number of abilities have been demonstrated such as frequency filtering, wave guiding, and negative refraction. Unfortunately, few metamaterials develop into practical devices due to their lack of tunability for specific frequencies. With the help of multi-physics numerical modeling, experimental validation of an adaptive elastic metamaterial integrated with shunted piezoelectric patches has been performed in a deep subwavelength scale. The tunable bandgap capacity, as high as 45%, is physically realized by using both hardening and softening shunted circuits. It is also demonstrated that the effective mass density of the metamaterial can be fully tailored by adjusting parameters of the shunted electric circuits. Finally, to illustrate a practical application, transient wave propagation tests of the adaptive metamaterial subjected to impact loads are conducted to validate their tunable wave mitigation abilities in real-time.
Quasi-free-standing bilayer epitaxial graphene field-effect transistors on 4H-SiC (0001) substrates
Authors: Yu C. , He Z. Z. , Li J. , Song X. B. , Liu Q. B. , Cai S. J. , Feng Z. H.
Published: January 2016

Quasi-free-standing epitaxial graphene grown on wide band gap semiconductor SiC demonstrates high carrier mobility and good material uniformity, which make it promising for graphene-based electronic devices. In this work, quasi-free-standing bilayer epitaxial graphene is prepared and its transistors with gate lengths of 100 nm and 200 nm are fabricated and characterized. The 100 nm gate length graphene transistor shows improved DC and RF performances including a maximum current density Ids of 4.2 A/mm, and a peak transconductance gm of 2880 mS/mm. Intrinsic current-gain cutoff frequency fT of 407 GHz is obtained. The exciting DC and RF performances obtained in the quasi-free-standing bilayer epitaxial graphene transistor show the great application potential of this material system.
Mutual capacitance of liquid conductors in deformable tactile sensing arrays
Authors: Li Bin , Fontecchio Adam K. , Visell Yon
Published: January 2016

Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.
Polarization dependent switching of asymmetric nanorings with a circular field
Authors: Pradhan Nihar R. , Tuominen Mark T. , Aidala Katherine E.
Published: January 2016

We experimentally investigated the switching from onion to vortex states in asymmetric cobalt nanorings by an applied circular field. An in-plane field is applied along the symmetric or asymmetric axis of the ring to establish domain walls (DWs) with symmetric or asymmetric polarization. A circular field is then applied to switch from the onion state to the vortex state, moving the DWs in the process. The asymmetry of the ring leads to different switching fields depending on the location of the DWs and direction of applied field. For polarization along the asymmetric axis, the field required to move the DWs to the narrow side of the ring is smaller than the field required to move the DWs to the larger side of the ring. For polarization along the symmetric axis, establishing one DW in the narrow side and one on the wide side, the field required to switch to the vortex state is an intermediate value.
Brachypodium distachyon genotypes vary in resistance to Rhizoctonia solani AG8
Authors: Schneebeli Katharina , Mathesius Ulrike , Zwart Alexander B. , Bragg Jennifer N. , Vogel John P. , Watt Michelle
Published: January 2016

Brachypodium distachyon (L.)P.Beauv. (Bd) has previously been developed as a pathosystem model for the wheat root rot pathogen Rhizoctonia solani Kühn anastomosis group 8 (AG8). Here we explore variation in resistance to R. solani AG8 in Bd, to determine whether genomic tools could be used to find Bd genes involved in the grass defence response, with the aim of using this information for the improvement of Rhizoctonia root rot resistance in wheat. We looked for variation in resistance to R. solani AG8 in a diverse Bd natural accession collection and in Bd T-DNA insertion lines selected based on putative mechanisms reported for tagged genes. All lines were susceptible to the pathogen. Repeatable and significant variation in resistance was measured in both groups, with greater variation in resistance found across the natural accessions than in the T-DNA lines. The widest and most repeatable variation in resistance was between lines Koz-3 and BdTR 13a. The ratio of R. solani AG8-inoculated to uninoculated root length for line Koz-3 was 33% greater than the same ratio for line BdTR 13a. The increased resistance of Koz-3 was associated with nodal root initiation in response to the pathogen. A negative correlation between seedling vigour and resistance was observed, but found not to be the sole source of variation in resistance to R. solani AG8. The only T-DNA line with significantly greater resistance to R. solani AG8 than the reference line had an insertion in a putative galactosyltransferase gene; however, this result needs further confirmation. Genetic resistance to Rhizoctonia root rot is not available in wheat cultivars and only a few instances of quantitative resistance to the pathogen have been described within close relatives of wheat. Brachypodium distachyon offers potential for further investigation to find genes associated with quantitative resistance and mechanisms of tolerance to R. solani AG8.
Dynamic ocean management increases the efficiency and efficacy of fisheries management
Authors: Dunn Daniel C. , Maxwell Sara M. , Boustany Andre M. , Halpin Patrick N.
Published: January 2016

Significance

Food security and the economic well-being of millions of people depend on sustainable fisheries, which require innovative approaches to management that can balance ecological, economic, and social objectives. We offer empirical evidence that dynamic ocean management, or real-time ocean management, can increase the efficacy and efficiency of fisheries management over static approaches by better aligning human and ecological scales of use. Furthermore, we show that dynamic management can address critical ecological patterns previously considered to be largely intractable in fisheries management (e.g., competition, niche partitioning, predation, parasitism, or social aggregations) at appropriate scales. The evidence and theory offered supports the use of dynamic ocean management in a range of scenarios to improve the ecological, economic, and social sustainability of fisheries.
Forests synchronize their growth in contrasting Eurasian regions in response to climate warming
Authors: Shestakova Tatiana A. , Gutiérrez Emilia , Kirdyanov Alexander V. , Camarero Jesús Julio , Génova Mar , Knorre Anastasia A. , Linares Juan Carlos , Resco de Dios Víctor , Sánchez-Salguero Raúl , Voltas Jordi
Published: January 2016

Significance

Forests dominate carbon fluxes in terrestrial ecosystems. We demonstrate how an intensified climatic influence on tree growth during the last 120 y has increased spatial synchrony in annual ring-width patterns within contrasting (boreal and Mediterranean) Eurasian biomes and on broad spatial scales. Current trends in tree growth synchrony are related to regional changes in climate factors controlling productivity, overriding local and taxonomic imprints on forest carbon dynamics. Enhanced synchrony is becoming a widespread, although regionally dependent, phenomenon related to warmer springs and increased temperature variability in high latitudes and to warmer winters and drier growing seasons in mid-latitudes.
PMCA2 regulates HER2 protein kinase localization and signaling and promotes HER2-mediated breast cancer
Authors: Jeong Jaekwang , VanHouten Joshua N. , Dann Pamela , Kim Wonnam , Sullivan Catherine , Yu Herbert , Liotta Lance , Espina Virginia , Stern David F. , Friedman Peter A. , Wysolmerski John J.
Published: January 2016

Significance

Unlike other ErbB receptors, human epidermal growth factor receptor 2 (HER2) does not generally become internalized after activation but, instead, remains on the cell surface to signal for prolonged periods. This property is thought to contribute to HER2’s ability to transform cells when overexpressed. The current study demonstrates that HER2’s resistance to endocytosis depends on the presence of the calcium pump, plasma membrane calcium ATPase2 (PMCA2), in specific membrane signaling domains in which intracellular calcium must be kept low to permit continued HER2 biochemical signaling. The dramatic reduction of mammary tumors in mouse mammary tumor virus (MMTV)-Neu mice in the absence of PMCA2 demonstrates its importance in supporting the development of breast tumors. Therefore, targeting interactions between PMCA2 and HER2 may offer therapeutic strategies for breast cancer.