bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of natural muscovite exfoliation with interlayer and solvation forces
Authors: Jia Feifei , Yang Lang , Wang Qingmiao , Song Shaoxian
Published: January 2017

Natural muscovite exfoliation was correlated with interlayer and solvation forces respectively in this work.
Low-temperature fabrication of lithium aluminum oxide phosphate solid electrolyte thin films from aqueous precursors
Authors: Clayton D. R. , Lepage D. , Plassmeyer P. N. , Page C. J. , Lonergan M. C.
Published: January 2017

The synthetic method presented herein provides a simple, inexpensive and environmentally benign deposition route for the fabrication of inorganic solid electrolyte thin films at low temperatures.
Correction: The biological in vitro effect and selectivity shown by a CoII complex of 2-(2-hydroxyphenylazo)-indole-3′-acetic acid on three distinctly different cancer cells
Authors: Ganguly Durba , Jain Chetan Kumar , Santra Ramesh Chandra , Roychoudhury Susanta , Majumder Hemanta Kumar , Das Saurabh
Published: January 2017

Correction for ‘The biological in vitro effect and selectivity shown by a CoII complex of 2-(2-hydroxyphenylazo)-indole-3′-acetic acid on three distinctly different cancer cells’ by Durba Ganguly et al., RSC Adv., 2016, 6, 114906–114915.
Correction: Engineering-scale superlubricity of the fingerprint-like carbon films based on high power pulsed plasma enhanced chemical vapor deposition
Authors: Gong Zhenbin , Shi Jing , Ma Wei , Zhang Bin , Zhang Junyan
Published: January 2017

Correction for ‘Engineering-scale superlubricity of the fingerprint-like carbon films based on high power pulsed plasma enhanced chemical vapor deposition’ by Zhenbin Gong et al., RSC Adv., 2016, 6, 115092–115100.
Segregation and binding energetics at grain boundaries in fluorite oxides
Authors: Arora Gaurav , Aidhy Dilpuneet S.
Published: January 2017

Improving oxygen conductivity in fluorite oxides is currently one of the main focus areas in the research of solid electrolytes for solid oxide fuel cells.
Correction: Robust liquid-repellent coatings based on polymer nanoparticles with excellent self-cleaning and antibacterial performances
Authors: Fu Yuchen , Jiang Jingxian , Zhang Qinghua , Zhan Xiaoli , Chen Fengqiu
Published: January 2017

Correction for ‘Robust liquid-repellent coatings based on polymer nanoparticles with excellent self-cleaning and antibacterial performances’ by Yuchen Fu et al., J. Mater. Chem. A, 2017, 5, 275–284.
Bone marrow mesenchymal stem cell-derived acellular matrix-coated chitosan/silk scaffolds for neural tissue regeneration
Authors: Xue Chengbin , Ren Hechun , Zhu Hui , Gu Xiaokun , Guo Qi , Zhou Yi , Huang Jing , Wang Shengran , Zha Guangbin , Gu Jianhui , Yang Yumin , Gu Yun , Gu Xiaosong
Published: January 2017

A novel tissue engineered nerve graft (TENG) was used for the first time to bridge a 60 mm long nerve gap in a dog sciatic nerve and achieved satisfactory results.
Progress of in vivo studies on the systemic toxicities induced by titanium dioxide nanoparticles
Authors: Hong Fashui , Yu Xiaohong , Wu Nan , Zhang Yu-Qing
Published: January 2017

Titanium dioxide nanoparticles (TiO2NPs) are inorganic materials with a diameter of 1–100 nm.
Identification of mouse cathepsin K structural elements that regulate the potency of odanacatib
Authors: Law Simon , Andrault Pierre-Marie , Aguda Adeleke H. , Nguyen Nham T. , Kruglyak Natasha , Brayer Gary D. , Brömme Dieter
Published: January 2017

Cathepsin K (CatK) is the predominant mammalian bone-degrading protease and thus an ideal target for antiosteoporotic drug development. Rodent models of osteoporosis are preferred due to their close reflection of the human disease and their ease of handling, genetic manipulation and economic affordability. However, large differences in the potency of CatK inhibitors for the mouse/rat vs. the human protease orthologs have made it impossible to use rodent models. This is even more of a problem considering that the most advanced CatK inhibitors, including odanacatib (ODN) and balicatib, failed in human clinical trials due to side effects and rodent models are not available to investigate the mechanism of these failures. Here, we elucidated the structural elements of the potency differences between mouse and human CatK (hCatK) using ODN. We determined and compared the structures of inhibitor-free mouse CatK (mCatK), hCatK and ODN bound to hCatK. Two structural differences were identified and investigated by mutational analysis. Humanizing subsite 2 in mCatK led to a 5-fold improvement of ODN binding, whereas the replacement of Tyr61 in mCatK with Asp resulted in an hCatK with comparable ODN potency. Combining both sites further improved the inhibition of the mCatK variant. Similar results were obtained for balicatib. These findings will allow the generation of transgenic CatK mice that will facilitate the evaluation of CatK inhibitor adverse effects and to explore routes to avoid them.
Low complexity MUSIC‐based direction‐of‐arrival algorithm for monostatic MIMO radar
Authors: Tan Jun , Nie Zaiping , Wen Dingbang
Published: January 2017

A low complexity multiple signal classification (MUSIC)‐based angle estimation method in monostatic multiple‐input multiple‐output (MIMO) radar has been proposed. To reduce the computational burden and maintain the accuracy of solution, the beam‐space reduced‐complexity MUISC algorithm is developed for monostatic MIMO radar. As the results, the lower computational cost and higher angle resolution in pseudo spectral domain have been obtained. Some simulation results have been given to show the effectiveness of the proposed method.
Weight‐transducerless control strategy based on active disturbance rejection theory for gearless elevator drives
Authors: Wang Gaolin , Wang Bowen , Li Chen , Xu Dianguo
Published: January 2017

Direct‐drive traction systems applying the permanent magnet synchronous motor have become the trend of modern gearless elevators. To estimate and reject the non‐linear and uncertain load disturbance effectively during the elevator startup, a novel active disturbance rejection control (ADRC) strategy adopting extended state observer (ESO) and non‐linear error feedback (NLEF) controller is proposed to attenuate the elevator car sliding without using weight‐transducer. By using the weight‐transducerless control strategy, the sliding distance and speed can be suppressed to the extent that it could ensure the riding comfort. The proposed ADRC scheme will also accelerate the dynamic response and enhance the system robustness. Both the parameter selection and the stability of ESO are analysed according to the application requirements, and the contrastive analysis of the functions selected in NLEF controller is performed via Lyapunov theory. The feasibility of the proposed strategy is verified by the experimental results on an 11.7 kW elevator traction machine.
Interval method for uncertain power flow analysis based on Taylor inclusion function
Authors: Liao Xiaobing , Liu Kaipei , Zhang Yachao , Wang Kun , Qin Liang
Published: January 2017

Interval arithmetic has been successfully applied to uncertain power flow analysis for power system, which aims at obtaining the upper and lower bounds of power flow solutions under interval uncertainties. However, traditional interval power flow (IPF) analysis method has embedded the interval computation into Newton iterative process, which makes interval solutions enlarge and huge computational load. In this study, the interval method based on Taylor inclusion function is proposed to solve the IPF problem. The interval mathematical model with interval variables is first established, and the solution of non‐linear algebraic equations with interval variables is transformed into three sets of certain equations by using Taylor inclusion function, which is formed from certain power flow equations. Several test cases under interval uncertainties are employed to demonstrate the effectiveness of the proposed methodology. The results show that the proposed methodology can supply sufficient numerical accuracy with high computational efficiency compared with the interval iterative method and Monte Carlo simulation method.
Period spacings in red giants
Authors: Mosser B. , Pinçon C. , Belkacem K. , Takata M. , Vrard M.
Published: January 2017

Context. The power of asteroseismology relies on the capability of global oscillations to infer the stellar structure. For evolved stars, we benefit from unique information directly carried out by mixed modes that probe their radiative cores. This third article of the series devoted to mixed modes in red giants focuses on their coupling factors, which have remained largely unexploited up to now.

Aims. With the measurement of coupling factors, we intend to give physical constraints on the regions surrounding the radiative core and the hydrogen-burning shell of subgiants and red giants.

Methods. A new method for measuring the coupling factor of mixed modes was implemented, which was derived from the method recently implemented for measuring period spacings. This new method was automated so that it could be applied to a large sample of stars.

Results. Coupling factors of mixed modes were measured for thousands of red giants. They show specific variation with mass and evolutionary stage. Weak coupling is observed for the most evolved stars on the red giant branch only; large coupling factors are measured at the transition between subgiants and red giants as well as in the red clump.

Conclusions. The measurement of coupling factors in dipole mixed modes provides a new insight into the inner interior structure of evolved stars. While the large frequency separation and the asymptotic period spacings probe the envelope and core, respectively, the coupling factor is directly sensitive to the intermediate region in between and helps determine its extent. Observationally, the determination of the coupling factor is a prior to precise fits of the mixed-mode pattern and can now be used to address further properties of the mixed-mode pattern, such as the signature of buoyancy glitches and core rotation.
A DEA model to evaluate Brazilian container terminals
Authors: Fagundes Costa Eduardo , Angulo Meza Lidia , Costa Roboredo Marcos
Published: January 2017

This study aims to evaluate the main Brazilian port terminals specialized in the operation of containers between the years 2010 and 2014. Therefore, it was applied Data Envelopment Analysis (DEA) and some of its complementary models, represented by the Cross Evaluation, in order to implement a peer-evaluation and improve the discrimination of the 100% efficient terminal; and a current model known as DEA-Game Cross Efficiency that combines DEA and Game Theory. This article proposes an adaptation to the original model, since it considers a radial output orientation, regarded as more compatible with the problem under analysis. DEA-Game was applied for the first time in port performance measurement and it was shown more suitable than the others, since the Decision Making Units (DMU) are seen from the perspective of a non-cooperative game and the results proved to be a Nash equilibrium.
Bilateral Vertebral Artery Dissection after a Chiropractic Therapy Session
Authors: Romero Flavio , Vieira Rodolfo , Freitas Carlos
Published: January 2017

Vertebral artery dissection (VAD) is a rare and sometimes unrecognized cause of stroke in patients younger than 45 years. Herein, we describe a very rare case of bilateral vertebral artery dissection after a session of cervical therapy manipulation (chiropractic).
Late-term Effects of Surgery on Nasal Functions in Patients who Underwent Total Laryngectomy Surgery
Authors: Karaoglu Deniz , Kocyigit Murat , Ortekin Safiye , Adali Mustafa
Published: January 2017

Introduction There is a common opinion that losing airway functions in total laryngectomy patients cause changes in nasal physiological rates. Studies conducted to review the subject present gaps, especially in terms of objective measurements.

Objective We evaluated late-term effects of surgery on nasal functions in patients who underwent total laryngectomy surgery more than two years ago.

Methods We included in the study 22 patients who had undergone total laryngectomy, as well as 24 healthy subjects with similar demographic characteristics as the control group. We performed acoustic rhinometry for intranasal volume and cross-sectional area measurements, saccharin test for measurement of nasal mucociliary clearance, and smell identification test for evaluation of olfactory function in the patient and control groups. We compared and statistically analyzed the data obtained from the groups.

Results In our study, although late-term (>2 years) measurements were not statistically significant, we detected more nasal passage patency in the patient group than in the control group. In smell identification test, lower scores were obtained in the patient group. The difference between measurements in both groups was statistically significant.

Conclusion We believe that since the upper respiratory tract is disabled due to tracheostomy in patients with total laryngectomy, atrophy occurs in the late term and, consequently, nasal mucociliary clearance is impaired. We also see diminished olfactory function in total laryngectomy patients.
Realization of compact tractor beams using acoustic delay-lines
Authors: Marzo A. , Ghobrial A. , Cox L. , Caleap M. , Croxford A. , Drinkwater B. W.
Published: January 2017

A method for generating stable ultrasonic levitation of physical matter in air using single beams (also known as tractor beams) is demonstrated. The method encodes the required phase modulation in passive unit cells into which the ultrasonic sources are mounted. These unit cells use waveguides such as straight and coiled tubes to act as delay-lines. It is shown that a static tractor beam can be generated using a single electrical driving signal, and a tractor beam with one-dimensional movement along the propagation direction can be created with two signals. Acoustic tractor beams capable of holding millimeter-sized polymer particles of density 1.25 g/cm3 and fruit-flies (Drosophila) are demonstrated. Based on these design concepts, we show that portable tractor beams can be constructed with simple components that are readily available and easily assembled, enabling applications in industrial contactless manipulation and biophysics.
Integral steric asymmetry in the inelastic scattering of NO(X2Π)
Authors: Brouard M. , Gordon S. D. S. , Hackett Boyle A. , Heid C. G. , Nichols B. , Walpole V. , Aoiz F. J. , Stolte S.
Published: January 2017

The integral steric asymmetry for the inelastic scattering of NO(X) by a variety of collision partners was recorded using a crossed molecular beam apparatus. The initial state of the NO(X, v = 0, j = 1/2, Ω=1/2, ϵ=−1,f) molecule was selected using a hexapole electric field, before the NO bond axis was oriented in a static electric field, allowing probing of the scattering of the collision partner at either the N- or O-end of the molecule. Scattered NO molecules were state selectively probed using (1 + 1′) resonantly enhanced multiphoton ionisation, coupled with velocity-map ion imaging. Experimental integral steric asymmetries are presented for NO(X) + Ar, for both spin-orbit manifolds, and Kr, for the spin-orbit conserving manifold. The integral steric asymmetry for spin-orbit conserving and changing transitions of the NO(X) + O2 system is also presented. Close-coupled quantum mechanical scattering calculations employing well-tested ab initio potential energy surfaces were able to reproduce the steric asymmetry observed for the NO–rare gas systems. Quantum mechanical scattering and quasi-classical trajectory calculations were further used to help interpret the integral steric asymmetry for NO + O2. Whilst the main features of the integral steric asymmetry of NO with the rare gases are also observed for the O2 collision partner, some subtle differences provide insight into the form of the underlying potentials for the more complex system.
Nonlinear stability analysis for a spin-torque nano-oscillator with a perpendicular spin polarizer: A pendulum-like model
Authors: Chen Hao-Hsuan , Zhang Zongzhi , Chang Ching-Ray , Liu Yaowen
Published: January 2017

An analytical pendulum-like model is developed to describe the dynamics of spin torque nano-oscillators that contain a perpendicular spin current polarizer combined with an in-plane magnetized free layer. Both the in-plane localized oscillation mode and out-of-plane (OP) large angle precession mode have been observed in the absence of damping effect, which can be attributed to the competition between the in-plane uniaxial anisotropic and demagnetization energies. These two types of dynamical oscillation modes correspond to the spin-transfer torque effect acting as a conservative or non-conservative driving force, respectively. We theoretically predict the critical currents for the excitation of the OP procession mode, which are well consistent with the macrospin simulations based on the Landau-Lifshitz-Gilbert equation. Moreover, we show the phase portrait of magnetization precession dynamics at different current and magnetic fields.
Kinetics modeling of nanoparticle growth on and evaporation off nanotubes
Authors: Privman Vladimir , Gorshkov Vyacheslav , Yaish Yuval E.
Published: January 2017

A kinetic Monte Carlo approach is developed for studying growth and evaporation of nanoparticles on/off nanotubes. This study has been motivated by the recent experimental advances in using nanoparticle evaporation (sublimation) off nanoparticle-decorated nanotubes for nanoscale “thermometry.” We demonstrate that the considered kinetic Monte Carlo approach can reproduce features of the process that are not included in the phenomenological thermodynamic modeling, as well as provide snapshots of the growth and evaporation process morphology.
Tunable dichroic polarization beam splitter created by one-step holographic photoalignment using four-beam polarization interferometry
Authors: Kawai Kotaro , Sakamoto Moritsugu , Noda Kohei , Sasaki Tomoyuki , Kawatsuki Nobuhiro , Ono Hiroshi
Published: January 2017

A tunable dichroic polarization beam splitter (tunable DPBS) simultaneously performs the follow functions: 1. Separation of a polarized incident beam into multiple pairs of orthogonally polarized beams; 2. Separation of the propagation direction of two wavelength incident beams after passing through the tunable DPBS; and 3. Control of both advanced polarization and wavelength separation capabilities by varying the temperature of the tunable DPBS. This novel complex optical property is realized by diffraction phenomena using a designed three-dimensional periodic structure of aligned liquid crystals in the tunable DPBS, which was fabricated quickly with precision in a one-step photoalignment using four-beam polarization interferometry. In experiments, we demonstrated that these diffraction properties are obtained by entering polarized beams of wavelengths 532 nm and 633 nm onto the tunable DPBS. These diffraction properties are described using the Jones calculus in a polarization propagation analysis. Of significance is that the aligned liquid crystal structure needed to obtain these diffraction properties was proposed based on a theoretical analysis, and these properties were then demonstrated experimentally. The tunable DPBS can perform several functions of a number of optical elements such as wave plates, polarization beam splitter, dichroic beam splitter, and tunable wavelength filter. Therefore, the tunable DPBS can contribute to greater miniaturization, sophistication, and cost reduction of optical systems used widely in applications, such as optical measurements, communications, and information processing.
Unique heating curves generated by radiofrequency electric-field interactions with semi-aqueous solutions
Authors: Lara Nadia C. , Haider Asad A. , Wilson Lon J. , Curley Steven A. , Corr Stuart J.
Published: January 2017

Aqueous and nanoparticle-based solutions have been reported to heat when exposed to an alternating radiofrequency (RF) electric-field. Although the theoretical models have been developed to accurately model such a behavior given the solution composition as well as the geometrical constraints of the sample holder, these models have not been investigated across a wide-range of solutions where the dielectric properties differ, especially with regard to the real permittivity. In this work, we investigate the RF heating properties of non-aqueous solutions composed of ethanol, propylene glycol, and glycine betaine with and without varying amounts of NaCl and LiCl. This allowed us to modulate the real permittivity across the range 25–132, as well as the imaginary permittivity across the range 37–177. Our results are in excellent agreement with the previously developed theoretical models. We have shown that different materials generate unique RF heating curves that differ from the standard aqueous heating curves. The theoretical model previously described is robust and accounts for the RF heating behavior of materials with a variety of dielectric properties, which may provide applications in non-invasive RF cancer hyperthermia.
A spatiotemporal tree model for turbulence in dispersed phase multiphase flows: Energy dissipation rate behavior in single particle and binary particles arrays
Authors: Sikiö Päivi , Tynjälä Tero , Jalali Payman
Published: January 2017

In this article, a spatiotemporal dynamical system model (tree model) is utilized for investigating the features of forced and unforced turbulence in a dispersed phase two-phase system. The tree model includes a variable for spatial dimension in addition to variables of wavenumber and time, which display both spatial and temporal intermittencies. The focus of this paper is to study the turbulence modulation due to the presence of rigid particles. The study considers particles with the sizes of 32, 64, and 128 times the Kolmogorov length scale. Specifically, the study of the energy dissipation rate (EDR) at the particle-fluid interface is considered. Two models, namely, A and B with different types of interaction connections between nearby shells, are used first to compare the results of the particle-laden case with decaying turbulence. The number of tree connections in the model is found to affect the amount of augmentation of EDR near the particle surface. Model B is studied further with different sizes of particles in forced turbulence cases and compared to the unladen case with the same parameters. Also, the model expression is studied in the forced turbulence case of dual particles separated by given distances. The results of spatiotemporal shell models provide new approach of handling high Reynolds turbulence in dispersed phase multiphase systems.
Competition between Al2O3 atomic layer etching and AlF3 atomic layer deposition using sequential exposures of trimethylaluminum and hydrogen fluoride
Authors: DuMont Jaime W. , George Steven M.
Published: January 2017

The thermal atomic layer etching (ALE) of Al2O3 can be performed using sequential and self-limiting reactions with trimethylaluminum (TMA) and hydrogen fluoride (HF) as the reactants. The atomic layer deposition (ALD) of AlF3 can also be accomplished using the same reactants. This paper examined the competition between Al2O3 ALE and AlF3 ALD using in situ Fourier transform infrared (FTIR) vibrational spectroscopy measurements on Al2O3 ALD-coated SiO2 nanoparticles. The FTIR spectra could observe an absorbance loss of the Al-O stretching vibrations during Al2O3 ALE or an absorbance gain of the Al-F stretching vibrations during AlF3 ALD. The transition from AlF3 ALD to Al2O3 ALE occurred versus reaction temperature and was also influenced by the N2 or He background gas pressure. Higher temperatures and lower background gas pressures led to Al2O3 ALE. Lower temperatures and higher background gas pressures led to AlF3 ALD. The FTIR measurements also monitored AlCH3* and HF* species on the surface after the TMA and HF reactant exposures. The loss of AlCH3* and HF* species at higher temperatures is believed to play a vital role in the transition between AlF3 ALD at lower temperatures and Al2O3 ALE at higher temperatures. The change between AlF3 ALD and Al2O3 ALE was defined by the transition temperature. Higher transition temperatures were observed using larger N2 or He background gas pressures. This correlation was associated with variations in the N2 or He gas thermal conductivity versus pressure. The fluorination reaction during Al2O3 ALE is very exothermic and leads to temperature rises in the SiO2 nanoparticles. These temperature transients influence the Al2O3 etching. The higher N2 and He gas thermal conductivities are able to cool the SiO2 nanoparticles more efficiently and minimize the size of the temperature rises. The competition between Al2O3 ALE and AlF3 ALD using TMA and HF illustrates the interplay between etching and growth and the importance of substrate temperature. Background gas pressure also plays a key role in determining the transition temperature for nanoparticle substrates.
Beam load structures in a basic relativistic interaction model
Authors: Thomas Johannes , Günther Marc M. , Pukhov Alexander
Published: January 2017

Some recent experiments have shown that the beam load in bubble and blow-out experiments is located in a volume as small as a few μm3. Now, we show what kinds of inner structures are possible in such a high dense electron ensemble. Our analysis starts from a first principles model for relativistically corrected mutual electron interaction in a phenomenological bubble model. Discussing 2D and 3D beam load configurations, we show that, depending on the bunch emittance, the beam load might be in a highly ordered and dense configuration, a less ordered but still dense state, or a configuration where each electron performs an individual random motion.
Spectra of keV protons related to ion-cyclotron wave packets
Authors: Khazanov G. V. , Sibeck D. G. , Tel'nikhin A. A. , Kronberg T. K.
Published: January 2017

We use the Fokker-Planck-Kolmogorov equation to study the statistical aspects of stochastic dynamics of the radiation belt (RB) protons driven by nonlinear electromagnetic ion-cyclotron (EMIC) wave packets. We obtain the spectra of keV protons scattered by these waves that show steeping near the gyroresonance, the signature of resonant wave-particle interaction that cannot be described by a simple power law. The most likely mechanism for proton precipitation events in RBs is shown to be nonlinear wave-particle interaction, namely, the scattering of RB protons into the loss cone by EMIC waves.
Impact of surface strain on the spin dynamics of deposited Co nanowires
Authors: Polyakov O. P. , Korobova J. G. , Stepanyuk O. V. , Bazhanov D. I.
Published: January 2017

Tailoring the magnetic properties at atomic-scale is essential in the engineering of modern spintronics devices. One of the main concerns in the novel nanostructured materials design is the decrease of the paid energy in the way of functioning, but allowing to switch between different magnetic states with a relative low-cost energy at the same time. Magnetic anisotropy (MA) energy defines the stability of a spin in the preferred direction and is a fundamental variable in magnetization switching processes. Transition-metal wires are known to develop large, stable spin and orbital magnetic moments together with MA energies that are orders of magnitude larger than in the corresponding solids. Different ways of controlling the MA have been exploited such as alloying, surface charging, and external electrical fields. Here we investigate from a first-principle approach together with dynamic calculations, the surface strain driven mechanism to tune the magnetic properties of deposited nanowires. We consider as a prototype system, the monoatomic Co wires deposited on strained Pt(111) and Au(111) surfaces. Our first-principles calculations reveal a monotonic increase/decrease of MA energy under compressive/tensile strain in supported Co wire. Moreover, the spin dynamics studies based on solving the Landau-Lifshitz-Gilbert equation show that the induced surface-strain leads to a substantial decrease of the required external magnetic field magnitude for magnetization switching in Co wire.
Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography
Authors: You Jiang , Li Ang , Du Congwu , Pan Yingtian
Published: January 2017

Ultrahigh-resolution optical coherence Doppler tomography (μODT) demonstrates great potential for quantitative blood flow imaging owing to its large field of view and capillary resolution. However, μODT only detects the axial flow velocity and requires Doppler angle correction to retrieve the absolute velocity. Although methods for Doppler angle tracking of single or few large vessels have been reported, a method that enables angle correction of the entire 3D microvascular networks remains a challenge. Here, we present a method based on eigenvalue analysis of 3D Hessian matrix to retrieve the orientation of each tubular vessel. As the algorithm is voxel based, it is suitable for effective tracking of Doppler angle matrix and restoring the absolute flow over the 3D vascular flow networks. We present results on simulation and flow phantom studies to show its efficacy for accurate 3D angle tracking and absolute flow correction. Then, we perform an in vivo validation study on mouse micro-circulatory cerebral blood flow (CBF) networks, which clearly demonstrates the capability of this method for tracking the Doppler angle matrix of the highly complex 3D CBF networks.
The many-body expansion combined with neural networks
Authors: Yao Kun , Herr John E. , Parkhill John
Published: January 2017

Fragmentation methods such as the many-body expansion (MBE) are a common strategy to model large systems by partitioning energies into a hierarchy of decreasingly significant contributions. The number of calculations required for chemical accuracy is still prohibitively expensive for the ab initio MBE to compete with force field approximations for applications beyond single-point energies. Alongside the MBE, empirical models of ab initio potential energy surfaces have improved, especially non-linear models based on neural networks (NNs) which can reproduce ab initio potential energy surfaces rapidly and accurately. Although they are fast, NNs suffer from their own curse of dimensionality; they must be trained on a representative sample of chemical space. In this paper we examine the synergy of the MBE and NN’s and explore their complementarity. The MBE offers a systematic way to treat systems of arbitrary size while reducing the scaling problem of large systems. NN’s reduce, by a factor in excess of 106, the computational overhead of the MBE and reproduce the accuracy of ab initio calculations without specialized force fields. We show that for a small molecule extended system like methanol, accuracy can be achieved with drastically different chemical embeddings. To assess this we test a new chemical embedding which can be inverted to predict molecules with desired properties. We also provide our open-source code for the neural network many-body expansion, Tensormol.
Observation of giant magnetoresistance in CoFeN/AlOx/CoFeN magnetic tunneling junctions employing a nitrogen-doped amorphous CoFeN free layer electrode
Authors: Yoon Kap Soo , Hong Jin Pyo
Published: January 2017

We examine the crystallographic and magnetic features of nitrogen-doped amorphous CoFe (CoFeN) electrodes for application as ferromagnetic free layers in magnetic tunnel junctions, in which precise control of the nitrogen content is crucial for achieving the desirable magnetic features. Incorporating nitrogen into the CoFe layer during growth provides numerous benefits including a remarkably reduced coercivity of 5 Oe, a phase transition from polycrystalline to amorphous, a low magnetization of 294 emu/cm3, and an enhanced thermal stability up to 400 °C. A high magnetic resistance ratio of about 220% was also obtained for annealed in-plane CoFeN/AlOx/CoFeN magnetic tunneling junctions containing a 1.2-nm-thick amorphous AlOx tunnel barrier. We anticipate that our experimental findings will aid in the development of a variety of future spintronic devices.
Stability, integrability, and nonlinear dynamics of PT-symmetric optical couplers with cubic cross-interactions or cubic-quintic nonlinearities
Authors: Li Xin , Yan Zhenya
Published: January 2017

We explore the parity-time-(PT)-symmetric optical couplers with the cubic both self- and cross-interactions corresponding to self- and cross-phase modulations. When the coefficient of the cubic cross-interaction is chosen as the different values, we find three distinct cases for two branches, including the stable-stable modes (linear unbroken PT-symmetric phase), stable-unstable modes (linear unbroken PT-symmetric phase), as well as unstable-unstable modes (linear broken PT-symmetric phase). Moreover, we find the periodic trajectories for some parameters. Similarly, we also explore the PT-symmetric optical couplers with cubic-quintic self-phase modulations. We numerically give the stable and unstable regions of the cubic-quintic system. Moreover, we also find the periodic trajectories for some parameters in the Stokes domain.
Non-equilibrium steady-state kinetics of He-air atmospheric pressure plasmas
Authors: Petrova Tz. B. , Petrov G. M. , Boris D. R. , Walton S. G.
Published: January 2017

A non-equilibrium, steady-state collisional-radiative kinetics model is developed to study atmospheric pressure discharges produced in He mixed with dry air (79% N2 and 21% O2). The model is based on a self-consistent solution of the Boltzmann equation for the electron energy distribution function coupled to a system of non-linear equations for species that govern plasma chemistry (electrons, ions, radicals, atoms, and molecules in ground and excited states). The main plasma parameters, including the maintaining electric field and species densities, are obtained as a function of He-to-air ratio. The results indicate that the concentration of air strongly influences the plasma. Notably, the He metastables and ion densities collapse at air concentrations above 0.1%, while the power required to maintain the plasma sharply increases as the concentration of air exceeds 1%. The model is applied to study the plasma characteristics along the length of an atmospheric pressure plasma jet using He as a carrier gas.
Time resolved anisotropic emission from an aluminium laser produced plasma
Authors: Wubetu G. A. , Fiedorowicz H. , Costello J. T. , Kelly T. J.
Published: January 2017

The polarisation anisotropy of the emission from a laser produced aluminium plasma has been studied using time and polarisation resolved spectroscopy at various background pressures of air. A Wollaston prism was used to resolve the emission from the plasma into polarisation components that are parallel and orthogonal to the plasma expansion axis. Spectroscopy reveals that as the background pressure is increased, strongly polarised continuum emission dominates at early stages of the plasma formation. The results are compared and contrasted to similar experiments and discussed in the framework of a recombining plasma.
Calcium-hydrogen interactions for collisional excitation and charge transfer
Authors: Mitrushchenkov A. , Guitou M. , Belyaev A. K. , Yakovleva S. A. , Spielfiedel A. , Feautrier N.
Published: January 2017

The accurate highly correlated ab initio calculations for ten low lying covalent Σ+2 states of CaH molecule, and one ionic Ca+H− state, are performed using large active space and extended basis set, with special attention to the long-range (6-20 Å) region where a number of avoided crossings between ionic and covalent states occur. These states are further transformed to a diabatic representation using a numerical diabatization scheme based on the minimization of derivative coupling. This results in a smooth diabatic Hamiltonian which can be easily fit to an analytic form. The diagonal elements of the diabatic potentials were then empirically corrected to reproduce experimental dissociation energies. Though the emphasis is on the asymptotic region, the obtained spectroscopic constants are in good agreement with available experimental and theoretical data. The resulting analytical Hamiltonian, after back transformation to adiabatic representation, is used to obtain cross sections for different inelastic processes using both the multichannel and the branching probability current approaches. It is shown that while for most intense transitions both approaches provide very close results, the multichannel approach underestimates the cross sections of weak transitions, as a consequence of the short-range avoided crossings that are accounted for only in the branching probability current method.
Fabrication of mirror templates in silica with micron-sized radii of curvature
Authors: Najer Daniel , Renggli Martina , Riedel Daniel , Starosielec Sebastian , Warburton Richard J.
Published: January 2017

We present the fabrication of exceptionally small-radius concave microoptics on fused silica substrates using CO2 laser ablation and subsequent reactive ion etching. The protocol yields on-axis near-Gaussian depressions with a radius of curvature ≲5 μm at shallow depth and low surface roughness of 2 Å. This geometry is appealing for cavity quantum electrodynamics where small mode volumes and low scattering losses are desired. We study the optical performance of the structures within a tunable Fabry-Pérot type microcavity and demonstrate near-coating-limited loss rates (F=25  000) and small focal lengths consistent with their geometrical dimensions.
Impact of the interface quality of Pt/YIG(111) hybrids on their spin Hall magnetoresistance
Authors: Pütter Sabine , Geprägs Stephan , Schlitz Richard , Althammer Matthias , Erb Andreas , Gross Rudolf , Goennenwein Sebastian T. B.
Published: January 2017

We study the influence of the interface quality of Pt/Y3Fe5O12(111) hybrids on their spin Hall magnetoresistance. This is achieved by exposing Y3Fe5O12(111) single crystal substrates to different well-defined surface treatments prior to the Pt deposition. The quality of the Y3Fe5O12(YIG) surface, the Pt/YIG interface and the Pt layer is monitored in-situ by reflection high-energy electron diffraction and Auger electron spectroscopy as well as ex-situ by atomic force microscopy and X-ray diffraction. To identify the impact of the different surface treatments on the spin Hall magnetoresistance, angle-dependent magnetoresistance measurements are carried out at room temperature. The largest spin Hall magnetoresistance is found in Pt/YIG fabricated by a two-step surface treatment consisting of a “piranha” etch process followed by an annealing step at 500 °C in pure oxygen atmosphere. Our data suggest that the small spin Hall magnetoresistance in Pt/YIG without any surface treatments of the YIG substrate prior to Pt deposition is caused by a considerable carbon agglomeration at the Y3Fe5O12 surface.
Low temperature deactivation of Ge heavily n-type doped by ion implantation and laser thermal annealing
Authors: Milazzo R. , Impellizzeri G. , Piccinotti D. , De Salvador D. , Portavoce A. , La Magna A. , Fortunato G. , Mangelinck D. , Privitera V. , Carnera A. , Napolitani E.
Published: January 2017

Heavy doping of Ge is crucial for several advanced micro- and optoelectronic applications, but, at the same time, it still remains extremely challenging. Ge heavily n-type doped at a concentration of 1 × 1020 cm−3 by As ion implantation and melting laser thermal annealing (LTA) is shown here to be highly metastable. Upon post-LTA conventional thermal annealing As electrically deactivates already at 350 °C reaching an active concentration of ∼4 × 1019 cm−3. No significant As diffusion is detected up to 450 °C, where the As activation decreases further to ∼3 × 1019 cm−3. The reason for the observed detrimental deactivation was investigated by Atom Probe Tomography and in situ High Resolution X-Ray Diffraction measurements. In general, the thermal stability of heavily doped Ge layers needs to be carefully evaluated because, as shown here, deactivation might occur at very low temperatures, close to those required for low resistivity Ohmic contacting of n-type Ge.
High-power broadband 30-GHz FEM amplifier operated in the grazing incident regime
Authors: Peskov N. Yu. , Bandurkin I. V. , Donetc D. E. , Kaminsky A. K. , Perelstein E. A. , Sedykh S. N. , Zaslavsky V. Yu.
Published: January 2017

A high-power broadband free electron maser (FEM) amplifier has been realized in collaboration between JINR (Dubna) and IAP RAS (Nizhny Novgorod) based on the linac LIU-3000 (0.8 MeV/200 A/250 ns). To achieve a wide frequency amplification band, the regime characterized by grazing of the dispersion curves of the beam electrons to the operating wave (the so-called grazing regime) was studied in the FEM. According to the simulations, such an operating regime allows an instant amplification band of up to 5%–7% with output power at the level ∼20 MW and a gain of about 30–35 dB to be obtained in the Ka band. The proof-of-principle experiments examined this scheme in the 30-GHz frequency range and confirmed the simulations. As a result, the predicted power level with design parameters has been achieved, and fast frequency tuning within the feeding magnetron band ±0.5 GHz has been demonstrated.
Giant isotropic magnetostriction in NaZn13-type LaFe13−xAlx compounds
Authors: Zhao Yuqiang , Huang Rongjin , Li Shaopeng , Liu Huiming , Wang Wei , Jiang Xingxing , Lin Zheshuai , Li Jiangtao , Li Laifeng
Published: January 2017

The unusual low-temperature magnetostrictive property is of fundamental interest due to significant applications in rapidly developing cryogenic engineering. Here, we report a giant isotropic magnetostriction (λ = 1500 ppm, ω = 4500 ppm) over a wide temperature range (∼210 K), and the saturated volume magnetostriction can be up to 8400 ppm in cubic NaZn13-type LaFe13−xAlx compounds by optimizing the chemical composition. The large magnetostrictive effect often occurs in ferromagnetic materials. However, we discovered that the magnetic-field-induced volume expansion originates from the change of lattice parameters across the first-order transition from the low-volume antiferromagnetic ground state to the high-volume ferromagnetic state. Moreover, the magnetostrictive materials show an excellent zero thermal expansion (ZTE) property, which guarantees their reliability and stability operating at various temperatures. The present study suggests potential applications of La(Fe, Al)13-based compounds as ZTE and magnetostrictive dual-function materials in cryogenic engineering.
An oscillator based on a single Au nanocluster
Authors: Gorshkov O. N. , Filatov D. O. , Antonov D. A. , Antonov I. N. , Shenina M. E. , Pavlov D. A.
Published: January 2017

Metal nanoclusters embedded into the ultrathin dielectric films attracted much attention in recent years due to their unusual electronic, optical, etc., properties differing from those of the bulk metals essentially and, hence, to the prospects of their applications in novel nanoelectronic, single electronic, non-volatile memory, etc., devices. Here, we report on the experimental observation of the electrical oscillations in an oscillating loop connected to a contact of a conductive probe of an Atomic Force Microscope to a tunnel-transparent (∼6.5 nm thick) yttria stabilized zirconia film with embedded Au nanoclusters on the Si substrate. The oscillations were attributed to the negative differential resistance of the probe-to-sample contact originating from the resonant electron tunnelling between the probe and the Si substrate via the quantum confined electron energy levels in small (≈2.5 nm in diameter) Au nanoclusters. This observation demonstrates the prospects of building an oscillator nanoelectronic device based on an individual nanometer-sized metal nanocluster.
Enhanced flow boiling in microchannels through integrating multiple micro-nozzles and reentry microcavities
Authors: Li Wenming , Qu Xiaopeng , Alam Tamanna , Yang Fanghao , Chang Wei , Khan Jamil , Li Chen
Published: January 2017

In a microchannel system, a higher mass velocity can lead to enhanced flow boiling performances, but at a cost of two-phase pressure drop. It is highly desirable to achieve a high heat transfer rate and critical heat flux (CHF) exceeding 1 kW/cm2 without elevating the pressure drop, particularly, at a reduced mass velocity. In this study, we developed a microchannel configuration that enables more efficient utilization of the coolant through integrating multiple microscale nozzles connected to auxiliary channels as well as microscale reentry cavities on sidewalls of main microchannels. We achieved a CHF of 1016 W/cm2 with a 50% less mass velocity, i.e., 680 kg/m2s, compared to the two-nozzle configuration developed in our previous studies. Two primary enhancement mechanisms are: (a) the enhanced global liquid supply by four evenly distributed micronozzles, particularly near the outlet region and (b) the effective management of local dryout by the capillary flow-induced sustainable thin liquid film resulting from an array of microscale cavities. A significantly improved heat transfer coefficient of 131 kW/m2 K at a mass velocity of 680 kg/m2s is attributed to the enhanced nucleate boiling, the established capillary/thin film evaporation, and the induced advection from the present microchannel configuration. All these significant enhancements have been achieved with a ∼55% lower two-phase pressure drop.
Two-photon interference from remote deterministic quantum dot microlenses
Authors: Thoma A. , Schnauber P. , Böhm J. , Gschrey M. , Schulze J.-H. , Strittmatter A. , Rodt S. , Heindel T. , Reitzenstein S.
Published: January 2017

We report on two-photon interference (TPI) experiments using remote deterministic single-photon sources. Employing 3D in-situ electron-beam lithography, we fabricate quantum-light sources at specific target wavelengths by integrating pre-selected semiconductor quantum dots within monolithic microlenses. The individual single-photon sources show TPI visibilities of 49% and 22%, respectively, under pulsed p-shell excitation at 80 MHz. For the mutual TPI of the remote sources, we observe an uncorrected visibility of 29%, in quantitative agreement with the pure dephasing of the individual sources. Due to its efficient photon extraction within a broad spectral range (>20 nm), our microlens-based approach is predestinated for future entanglement swapping experiments utilizing entangled photon pairs emitted by distant biexciton-exciton radiative cascades.
Self-forming graphene/Ni patterns on sapphire utilizing the pattern-controlled catalyst metal agglomeration technique
Authors: Miyoshi Makoto , Arima Yukinori , Kubo Toshiharu , Egawa Takashi
Published: January 2017

We fabricated graphene/Ni patterns directly on sapphire substrates through a self-forming process utilizing the pattern-controlled catalyst metal agglomeration technique, which was accomplished via a thermal annealing process of rectangular Ni patterns preformed on thin amorphous carbon films on sapphire. It was confirmed that graphene films were synthesized along with the preformed Ni patterns as a result of the progress of Ni agglomeration. Notably, a few-layer graphene film was observed in specific areas along the periphery of the preformed Ni patterns. The self-forming graphene/Ni patterns showed ohmic conductivity with a contact resistance ranging from 4 × 104 to 7 × 104 Ω μm.