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The effects of surface treatment of flax fibers featuring vinyltrimethoxy silane (VTMO) and maleic anhydride-polypropylene (MAPP) on the mechanical properties of flax/PP composites were investigated. α-polypropylene (α-PP) and β-polypropylene (β-PP) were used as matrices for measuring the mechanical properties of the flax fiber/polypropylene (flax/PP) composites. Flax/PP composites composed of double-covered uncommingled yarn (DCUY) were prepared using a film-stacking technique. The influence of surface treatment on the tensile, flexural, impact, and water uptake properties of Flax/PP composites were investigated. MAPP treatment was suitable for flax/PP composites in terms of superior tensile and impact properties. VTMO treatment showed superior flexural properties and less influence on the impact properties after moisture absorption.

The electronic structure of WTe$_2$ and orthorhombic $\gamma-$MoTe$_2$, are claimed to contain pairs of Weyl type-II points. A series of ARPES experiments claim a broad agreement with these predictions. We synthesized single-crystals of MoTe$_2$ through a Te flux method to validate these predictions through measurements of its bulk Fermi surface (FS) \emph{via} quantum oscillatory phenomena. We find that the superconducting transition temperature of $\gamma-$MoTe$_2$ depends on disorder as quantified by the ratio between the room- and low-temperature resistivities, suggesting the possibility of an unconventional superconducting pairing symmetry. Similarly to WTe$_2$, the magnetoresistivity of $\gamma-$MoTe$_2$ does not saturate at high magnetic fields and can easily surpass $10^{6}$ \%. Remarkably, the analysis of the de Haas-van Alphen (dHvA) signal superimposed onto the magnetic torque, indicates that the geometry of its FS is markedly distinct from the calculated one. The dHvA signal also reveals that the FS is affected by the Zeeman-effect precluding the extraction of the Berry-phase. A direct comparison between the previous ARPES studies and density-functional-theory (DFT) calculations reveals a disagreement in the position of the valence bands relative to the Fermi level $\varepsilon_F$. Here, we show that a shift of the DFT valence bands relative to $\varepsilon_F$, in order to match the ARPES observations, and of the DFT electron bands to explain some of the observed dHvA frequencies, leads to a good agreement between the calculations and the angular dependence of the FS cross-sectional areas observed experimentally. However, this relative displacement between electron- and hole-bands eliminates their crossings and, therefore, the Weyl type-II points predicted for $\gamma-$MoTe$_2$., Comment: 13 pages, 7 figures, supplementary file not included (in press)

Asymptotic and transient stability analyses of unbounded uniform shear flows of dense, slightly inelastic, spherical particles were carried out using a frictional–kinetic theory. This model proposed for describing dense flows is based on a critical state plasticity theory and a simplified kinetic theory. In this model, the bulk and shear viscosities, the “thermal” conductivity, and the energy dissipation rate are proportional to a “mean pressure” which is composed of a quasistatic-frictional-contribution pressure considered for slow, plasticity deformations and a granular-kinetic-theory collisional-contribution pressure. We studied two-dimensional stability analyses of layering disturbances (i.e., the perturbations whose wave number vectors are aligned only in the gradient) as well as nonlayering disturbances (the wave number vectors have nonzero streamwise components). Although this model has a simpler framework, it predicted similar results to those obtained using a more elaborate frictional–kinetic model. For instance, nonlayering disturbances are asymptotically stable at large time; the maximum transient growth of disturbances increases as the solids fraction or the friction coefficient is increased; and transient growths of disturbances can be significant due to the non-normality of the system. However, the prediction of the asymptotic stability of layering disturbances may be questionable because the collisional-contribution terms of the present model were over-simplified.

This article proposes a stochastic version of the matching pursuit algorithm for Bayesian variable selection in linear regression. In the Bayesian formulation, the prior distribution of each regression coefficient is assumed to be a mixture of a point mass at 0 and a normal distribution with zero mean and a large variance. The proposed stochastic matching pursuit algorithm is designed for sampling from the posterior distribution of the coefficients for the purpose of variable selection. The proposed algorithm can be considered a modification of the componentwise Gibbs sampler. In the componentwise Gibbs sampler, the variables are visited by a random or a systematic scan. In the stochastic matching pursuit algorithm, the variables that better align with the current residual vector are given higher probabilities of being visited. The proposed algorithm combines the efficiency of the matching pursuit algorithm and the Bayesian formulation with well defined prior distributions on coefficients. Several simulated examples of small n and large p are used to illustrate the algorithm. These examples show that the algorithm is efficient for screening and selecting variables.

Nano-structured copper oxide thin films were deposited on glass substrates by dc reactive magnetron sputtering. The structural, morphological, electrical, and optical properties of the deposited copper oxide thin films were found to change with oxygen partial pressure. Changes in oxygen partial pressure during sputter deposition led to variations in Cu, Cu+ and Cu+2 concentrations, which resulted in corresponding changes in the electronic characteristics of sputtered semiconducting copper oxide films from initially n- to p-type and then from p-type back to n-type. These phenomena demonstrate that p-type copper oxide thin films can only be deposited by dc reactive magnetron sputtering within a narrow oxygen partial pressure range.

Cuprous oxide (Cu2O) and cupric oxide (CuO) thin films were deposited on glass substrates at different oxygen partial pressures by direct-current reactive magnetron sputtering of pure copper target in a mixture of argon and oxygen gases. Oxygen partial pressure was found to be a crucial parameter in controlling the phases and, thus, the physical properties of the deposited copper oxide thin films. Single-phase Cu2O thin films with cubic structure were obtained at low oxygen partial pressure between 0.147 Pa and 0.200 Pa while higher oxygen partial pressure promoted the formation of CuO thin films with base-centered monoclinic structure. Polycrystalline Cu2O thin films deposited with oxygen partial pressure at 0.147 Pa possessed the lowest p-type resistivity of 1.76 Ω cm as well as an optical band gap of 2.01 eV. On the other hand, polycrystalline CuO thin films deposited with oxygen partial pressure at 0.320 Pa were also single phase but showed a n-type resistivity of 0.19 Ω cm along with an optical band gap of 1.58 eV.

BODIPY dyes have some unique properties including high fluorescence quantum yield, large extinction coefficiency, narrow absorption and emission band. However, most of BODIPY dyes display short emission wavelength and small Stokes shift, which limits their applications in biosensing and bioimaging in vivo. For bioimaging application, a fluorescent dye with long emission wavelength and large Stokes shift is highly desired. To push the absorption and emission spectrum of BODIPY to red and even far-red region, a COOEt group was introduced to the meso position, and some aromatic group was attached to the 3, 5 position of BODIPY core. The structure of resulting compounds were comfirmed by 1H NMR, 13C NMR and HR-MS. Dye-1 displays a strong UV-Vis absorption band centered at 536 nm and a sharp emission band is located at 592 nm, which is significantly red-shifted (80 nm) compared to ordinary BODIPY analogs. In addition, the meso-COOEt substituted BODIPYs exhibit high quantum yield and red to far-red emission. Notably surprisingly, the meso-COOEt substituted BODIPYs display almost separated UV-Vis absorption and emission spectra with a large Stokes shift (-60 nm). Time-dependent density functional theory calculations were conducted to understand the structure-optical properties relationship, and it was revealed that the large Stokes shift was resulted from the geometric change from the ground state to the first excited singlet state. The spectroscopic properties of these BODIPY dyes display very subtle solvent-dependence effect. Furthermore, BODIPY was tested for its ability of imaging in living cells. The results indicate that Dye-1 is a water-soluble and membrane-permeable probe. Therefore, these BODIPYs are a new family dyes with excellent spectroscopic properties and can be good candidates for bioimaging in living cells.

Van der Waals heterostructures formed by assembling different two-dimensional atomic crystals into stacks can lead to many new phenomena and device functionalities. In particular, graphene/boron-nitride heterostructures have emerged as a very promising system for band engineering of graphene. However, the intrinsic value and origin of the bandgap in such heterostructures remain unresolved. Here we report the observation of an intrinsic bandgap in epitaxial graphene/boron-nitride heterostructures with zero crystallographic alignment angle. Magneto-optical spectroscopy provides a direct probe of the Landau level transitions in this system and reveals a bandgap of ~ 38 meV (440 K). Moreover, the Landau level transitions are characterized by effective Fermi velocities with a critical dependence on specific transitions and magnetic field. These findings highlight the important role of many body interactions in determining the fundamental properties of graphene heterostructures., To appear in Nature Communications

To analyze the stress distribution of temporomandibular joint (TMJ) in posterior cross-bite of individual teeth and in normal occlusion during the intercuspal occlusion (ICO).On the basis of the geometric TMJ model of normal occlusion, the TMJ finite element model of posterior cross-bite of individual teeth was reconstructed. The occlusal force and boundary conditions were applied on the model. Using three-dimensional finite element method (FEM), the stress distribution of TMJ in posterior cross-bite of individual teeth was analyzed by simulating the ICO load.No significant differences were found in stress distribution in various TMJ structures between posterior cross-bite of individual teeth and normal occlusion. However, the stress level was higher and the stress distribution was more inhomogeneous in posterior cross-bite of individual teeth than in normal occlusion. In the cross-bite malocclusion of individual posterior teeth, the maximum of von Mises stress was 0.792 MPa, the maximum principal stress was 0.598 MPa and the minimum principal stress was -0.744 MPa. But in normal occlusion, the maximum of von Mises stress was 0.592 MPa, the maximum principal stress was 0.395 MPa and the minimum principal stress was -0.554 MPa.When the ICO load was applied, the stress distribution of TMJ was more inhomogeneous and the stress level was higher in posterior cross-bite of individual teeth than in normal occlusion.

Energy-efficient scheduling problem in wireless communication system is investigated in this paper. We propose two near-optimal schedulers which have simple structures for the general hard delay constraint scenario. Both single-user and multiuser cases are considered. The first scheduler invokes Gaussian approximation while the second one is inspired by the inverse water-filling (IWF) approach. The scheduling policies consist of a channel-awareness term and a delay-awareness term. Numerical results show that the proposed policies achieve near optimal performance when the total required transmit bits, R, is large. For the multiuser scenario, our scheduling strategy consists of an initial resource (number of time slots) allocation and a slot-by-slot user selection and bit loading algorithm. The former depends on the rate requirement and a priori knowledge of user-dependent channel statistic while the latter use an order statistic based approach designed to minimize the expected total energy consumption.

The present work deals with an electron interacting strongly with both bulk longitudinal optical (LO) phonons and interface (IF) optical phonons in which we adopt and generalize the Tokuda's variational method for studying the interface polaron properties in polar crystals at zero temperature, In our approach, we can reduce the Hamiltonian equation of the system to a pair of integro-differential equations in two variational parameters of the electron wavefunction from which we can calculate various physical properties of an interface polaron including the ground state energy, average numbers of interacting phonons, the average distance from the interface and the anisotropic effective masses of the interface polaron. Numerical results are obtained explicitly for LiF crystal interfaced with NaF crystal as well as other similar systems with varying physical constants, which show the typical trends of variations for the effects of strong electron-phonon interactions on different physical properties of an interface polaron.

We demonstrate a GaN-based microcavity light emitter (MCLE) with an AlN current blocking layer. An AlN layer is inserted on the InGaN/GaN multiple quantum wells as a current blocking layer and an optical confinement layer.

The IEEE 802.16 standard for broadband wireless access, known as Worldwide Interoperability for Microwave Access (WiMAX), provides high throughput over long-range transmission. The key developments in the physical (PHY) layer include Orthogonal Frequency-Division Multiple Access (OFDMA) and the Multiple-Input-Multiple-Output (MIMO) antenna technology, which enhance transmission quality and throughput.

For an electron interacting strongly with both the interface optical phonons and the bulk longitudinal optical (LO) phonons, the properties of a polaron bound at the interface between two semi-infinite polar crystals are studied. The important effect of the normally ignored electron-bulk LO phonon interaction is demonstrated.

Intelligent control based on fuzzy model reference learning control (FMRLC) is being applied to hydraulic power sets, which are characterized by their nonlinearity, time variability and non-minimum phase free property, after having first studied principles of and methods used by FMRLC, and analyzed its capability of adjusting and correcting fuzzy rules. A FMRLC controller for a hydraulic power set was subsequently designed, which is capable of adjusting its fuzzy rules according to the controlled object's output deviations compared with the ideal reference model's output. Herewith, the hydro power set's output is made to follow that of the reference model on a real time basis. Simulation results show that this method of control not only suits to hydraulic power sets in cases of minor vacillation of operating conditions, but also for large ones. Nevertheless, further exploring work is required for practical application purposes.

A novel trend emerged in music exploration is to organize and search songs according to their emotions. However, research on automatic playlist generation (APG) primarily focuses on metadata and audio similarity. Mainstream solutions view APG as a static problem. This paper argues that the APG problem is better modeled as a continuous optimization problem, and proposes an adaptive preference model for personalized APG based on emotions. The main idea is to collect a user’s behavior in music playing, e.g., rating, skipping and replaying, as immediate feedback in learning the user’s preferences for music emotion within a playlist. Reinforcement learning is adopted to learn the user’s current preferences, which are used to generate personalized playlists. Learning parameters are tuned by simulation of two hypothetical users. A two-month user study is conducted to evaluate the APG solutions. The results show that the proposed approach reduces the Miss Ratio by 10% in comparison with the baseline approach.

The Hamiltonian of the exciton in an ultrafine particle (UFP) with a charge on and a dipole at its surface is given. The exciton energy is calculated as a function of the charge number, the dielectric constant of the medium outside the UFP, and the strength of the dipole. The results for ZnO and CdS UFP indicate that the changes of the exciton energy due to the charge and the dielectric constant outside the UFP are of the same order.

In this work, a novel architecture with stacked-type CMOS device is presented. The reformed CMOS switch was implemented by the TSMC 0.18 um 1P6M standard CMOS process. In order to improve power handling capability and strengthen the isolation, the proposed circuit is inserted with an excess transistor adjacent to the receiver side. The insertion loss of the designed CMOS T/R switch is about 1.9plusmn0.3 dB. The isolation is greater than 25 dB and the power handling is capable of 28 dBm at 5.8 GHz.

To investigate the method of the three-dimensional reconstruction of temporomandibular joint (TMJ) on the basis of CT and MRI medical image fusion technology, which establishes good foundation for a series biomechanical studies and clinical analysis.The geometric data for the TMJ model were obtained from a young and healthy male volunteer. Twelve spherical markers were located on the regions of both TMJ and mental tubercles, where CT and MRI scans can reach. The three-dimensional geometric of the hard and soft tissues of TMJ was reconstructed by CT and MRI scans data, which was based on the registration procedures of spherical markers located on the face of the volunteer.The three-dimensional geometric model of TMJ was obtained, including hibateral articular disc, mandible, glenoid fossa and inferior teeth, and it had better geometric similarity. The results showed that the methods of three-dimensional reconstruction of TMJ with CT and MRI medical image fusion technology can be operated easily and promptly. The constructed model had good morphology.It is feasible to construct the three-dimensional model of TMJ on the basis of the registration procedures of spherical markers and CT-MRI medical image fusion technology. It has the advantage of simulating both hard and soft tissues reasonably. The model well expresses the shape of the TMJ.

Nano-powders of p-type transparent conductive copper aluminum oxide (CAO) have been successfully synthesized by co-precipitation method. By adding sodium hydroxide into the mixed solution of copper chloride and aluminum chloride, co-precipitate precursors of CAO with particle size around 50-60 nm were produced After washing, filtering, and drying of the co-precipitates, nano-powders of CuAlO2 were produced when the dried co-precipitate precursors were calcined at temperature above 1100degC. By aging at pH = 3.5 for six hours and co-precipitating at pH = 8.0, the atomic ratio of Cu/Al of the nano-powders can be maintained throughout the synthesis. After calcining at 12000 in air for 4 hours, the CAO co-precipitate precursors totally transformed into nano-powders of CuAlO2 with crystal size around 64 nm. Continued calcining at 1200degC above 4 hours led to the decomposition of CuAlO2 into nano-powders of CuAl2O4 and volatile CuO with no significant change in crystal size. Finally, it was found that by calcining under inert atmosphere, the decomposition of CuAlO2 could be suppressed at the expense of decreasing its crystallinity.

Nano-sized powders of transparent conductive aluminum-doped zinc oxide (AZO) have been successfully prepared by electrolysis-modified co-precipitation method. By adding ammonium hydroxide into the precursor solution prepared by electrolytic dissolution of zinc metal in a buffered electrolyte solution of nitric acid and ammonium nitrate with adequate addition of aluminum nitrate, co-precipitate precursors of AZO with particle size between 30 to 60 nm were produced. After washing, filtering, and drying of the co-precipitates, nano-powders of AZO with wurtzite structure were produced when the dried co-precipitate precursors were calcined at temperature above 800degC. By aging at pH = 5 and co-precipitating at pH = 8.0, the atomic ratio of Al/Zn of the nano-powders could be maintained throughout the synthesis. After calcining at 1000degC in air for 2 hours, nano-sized powders of AZO with ZnO wurtzite structure and particle size between 200 to 500 nm were synthesized. Finally, it was found that both the particle sizes of co-precipitate precursors and calcined nano-powders of AZO could be decreased by increasing the pH of the electrolyte solution for electrolytic dissolution.

We present a detailed study of the optically and electrically pumped emission in the BSB-Cz/PVK bilayer waveguide devices. By optical pumping we demonstrate that PVK as a spacer between fluorescent BSB-Cz and ITO electrode allows the significant reduction of the threshold for amplified spontaneous emission (ASE) of BSB-Cz. The simulation provides a better understanding of how the PVK thickness affects the waveguide mode field distribution and hence the ASE threshold of BSB-Cz. On the other hand, the BSB-Cz/PVK bilayer OLED exhibits the external quantum efficiency of1% and anisotropic electroluminescence with spectrally narrowed edge emission at the cutoff wavelength controlled by the BSB-Cz thickness. When tuning the cutoff wavelength to match the peak gain of BSB-Cz, we demonstrate an intense, particularly narrow edge emission (~5 nm) without obvious degradation of efficiency at a high current density of 1000 mA/cmsup2/sup, suggesting a reliable device performance for high-power applications and further exploration of electrically-pumped ASE.

Wireless sensor networks are emerging as a popular research issue and tool for many applications. However, nodes in a sensor network are severely constrained by energy, storage capacity and computing power. In this paper, we propose an integrated network environment (sensor and ad hoc network) with IEEE 802.15.4a, ultra-wideband (UWB) and two-tier data dissemination (TTDD) routing protocol. We wish that sensor network could support fast dynamic location-tracking, information gathering and response. And base station use theses information to compute an optimal path for ad hoc mobile devices to offer good QoS level and reliable data transmission according to different requests

Poly(methacrylic acid- co -ethyl glycol dimethylacrylate) (poly(MAA- co -EGDMA)) imprinted with α-bilirubin was shown to be able to bind α-bilirubin in our previous work. In this work, the corresponding imprinted polymer thin film was synthesized onto a thiol treated Au electrode by surface grafting polymerization. Bilirubin was able to be detected by an Au electrode, however, the electrode was not be able to discriminate bilirubin from the other matrix components if clinical samples were used. Therefore, the imprinted material was introduced so that the modified Au electrode could specifically detect bilirubin. Optimal potential was found to be 0.55 V and this was set for the rest of experiments. The imprinting factor of 3.16 was confirmed by comparing the signals from the MIP-Au and the NIP (non-imprinted polymer)-Au electrode. Calibration of the bilirubin concentration with respect to the current by the MIP-Au electrode was made within the range of 5 mg/dl and a detection sensitivity of 0.644 μA/mg/dl (2.58 μA/cm 2 /mg/dl) was obtained. Furthermore, a linear correlation of the bilirubin concentration within 1.0 mg/dl versus detection current was also achieved. Bilirubin was further detected by the MIP-Au electrode in the presence of fetal bovine serum (FBS). Repeated detection of bilirubin with at least three detection batches was performed and the reproducibility of the same piece of MIP-Au electrode was confirmed. The result was compared to those obtained from the serum and the solvent solution. The results indicated the feasibility of using the bilirubin imprinted poly(MAA- co -EGDMA) film as a sensing electrode for the clinical detection of bilirubin in serum.

The third generation (3G) wireless networks are characterized by connectivity in anytime, anywhere, enhanced data services, and higher data rates to mobile users. It is an important and to be worthy of research issue which elucidates that how to provide mobile users for roaming among different access technology networks through seamless handoff mechanism. IPv6 plays an important role in wireless access networks. To integrate with heterogeneous wireless networks, adopting IP backbone is the best solution. Moreover, it supports that the mobile users roam seamlessly by mobile IP technology. The major objective of this paper is to propose an integrated architecture for UMTS network and IEEE 802.11 WLAN. We also propose a mobile IPv6 based seamless handoff strategy for heterogeneous wireless networks to provide mobility management between UMTS and IEEE 802.11 WLAN for the mobile users.

Asymptotic and transient stability analyses of unbounded uniform granular shear flow at high solids volume fractions were carried out in the paper, based on a model composed of the viscoplastic constitutive law [P. Jop, Y. Forterre, and O. Pouliquen, Nature (London) 441, 727 (2006)] and the dilatancy law [O. Pouliquen et al., J. Stat. Mech.: Theory Exp. (2006) P07020]. We refer to this model as the VPDL (meaning of the “viscoplastic and dilatancy laws”) thereinafter. In this model, dense granular flows were treated as a viscoplastic fluid with a Drucker–Prager-like yielding criterion. We compared our results to those obtained using the frictional-kinetic model (FKM) [M. Alam and P. R. Nott, J. Fluid Mech. 343, 267 (1997)]. Our main result is that unbounded uniform dense granular shear flows are always asymptotically stable at large time based on the VPDL model, at least for two-dimensional perturbations. This is valid for disturbances of layering modes (i.e., the perturbations whose wavenumber vectors are...

Time- and space- resolved x-ray spectrum diagnostic system has been established by coupling flat-field grating and gated-MCP (micro-channel plate) with an optic al CCD. A series of experimental investigations on the characterization of the d iagnostic system have been carried out to develop quantitative measurement techn ology of x-ray absorption spectrum. This diagnostic technology has been successf ully applied to the measurements of absorption.

Background Intracerebral hemorrhage (ICH) induces a series of inflammatory processes that contribute to neuronal damage and neurological deterioration. Liver X receptors (LXRs) are nuclear receptors that negatively regulate transcriptional processes involved in inflammatory responses, but their role in the pathology following ICH remains unclear. The present study investigated the neuroprotective effects and anti-inflammatory actions of TO901317, a synthetic LXR agonist, in a model of collagenase-induced ICH and in microglial cultures. Methods Mice subjected to collagenase-induced ICH injury were injected with either TO901317 (30 mg/kg) or vehicle 10 min after ICH and subsequently daily for 2 days. Behavioral studies, histology analysis, and assessments of hematoma volumes, brain water content, and blood-brain barrier (BBB) permeability were performed. The protein expression of LXR-α, LXR-β, ATP binding cassette transporter-1 (ABCA-1), and inflammatory molecules was analyzed. The anti-inflammatory mechanism of TO901317 was investigated in cultured microglia that were stimulated with either lipopolysaccharide (LPS) or thrombin. Results ICH induced an increase in LXR-α protein levels in the hemorrhagic hemisphere at 6 h whereas LXR-β expression remained unaffected. Both LXR-α and LXR-β were expressed in neurons and microglia in the peri-ICH region and but rarely in astrocytes. TO901317 significantly attenuated functional deficits and brain damage up to 28 days post-ICH. TO901317 also reduced neuronal death, BBB disruption, and brain edema at day 4 post-ICH. These changes were associated with marked reductions in microglial activation, neutrophil infiltration, and expression levels of inflammatory mediators at 4 and 7 days. However, TO901317 had no effect on matrix metalloproteinase-9 activity. In BV2 microglial cultures, TO901317 attenuated LPS- and thrombin-stimulated nitric oxide production and reduced LPS-induced p38, JNK, MAPK, and nuclear factor-kappa B (NF-κB) signaling. Moreover, delaying administration of TO901317 to 3 h post-ICH reduced brain tissue damage and neuronal death. Conclusions Our results suggest that enhancing LXR activation may provide a potential therapy for ICH by modulating the cytotoxic functions of microglia. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0524-8) contains supplementary material, which is available to authorized users.