bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced gain and miniaturisation method of stacked dielectric resonator antenna using metallic cap
Authors: Kim Tae‐Wan , Pak Seong‐Ook
Published: March 2019

The authors introduce a miniature and gain enhancement method of dielectric resonator antenna (DRA) using a metallic cap. The structure of the proposed antenna consists of a stacked cylindrical dielectric resonator, a metallic cap that is located on the resonator, and a ground plane. By adjusting the size of the metallic cap while retaining the size of the antenna, the proposed antenna operates in the lower frequency band and shows improved realised gain. As the radius of metallic cap increases, wavelength at z‐axis increases and the resonance frequency gets lower. In addition, tangential field at side wall surface increases, which leads to the enhancement of realised gain at resonance frequency. The authors have fabricated a prototype of the antenna for the experimental verification. The simulation results are in a close agreement with the experimental finding.
Wideband dual‐band dual‐polarised antenna with less layer radiating patch
Authors: Huang Daiwei , Du Zhengwei
Published: March 2019

A wideband dual‐band dual‐polarised patch antenna is proposed here. It consists of a ground that has a cross slot and a rectangle hole, a feeding structure that consists of two π‐shape strips, and a radiating patch that consists of a square loop strip and a small square patch with a cross slot. Two feeding ports are used to generate two orthogonal polarisations. A prototype has been fabricated and measured. The measured −10 dB impedance operating bands of the two ports can cover the bands of 3.59–4.21 GHz and 5.42–6.34 GHz, the relative bandwidth are 15.9% and 15.6%. The measured isolations between the two ports are more than 20 and 15 dB at the lower and higher bands, respectively. The antenna has a good radiation performance at the lower and higher bands.
New thin wide‐band bracelet‐like antenna with low SAR for on‐arm WBAN applications
Authors: Zahran Sherif R. , Abdalla Mahmoud A. , Gaafar Abdelhamid
Published: March 2019

Here, a novel design of a planar monopole antenna is presented for wireless body area network (WBAN) wearable applications. The design is fabricated on flexible liquid crystalline polymer (LCP) substrate. The antenna is fed by a uni‐planar coplanar waveguide transmission line and has total size of 51 × 22 mm2. In comparison with its recent published peers, the antenna has the thinnest thickness of 0.1 mm. The antenna is simulated and tested while physically bent. Proposed design along with simulation and experimental results are discussed in this work. Bottom rectangular slabs were added as a modification to the design in order to restore gain at higher frequencies. For the entire operational bandwidth, numerical far field simulations show the suitability of the proposed design to human body loading. A full study targeting specific absorption rate (SAR) has been performed to calculate the maximum input power to the proposed design. The objective has been to prevent any harm to human body as specified by the relevant international non‐ionising radiation exposure standards.
Compact near zero index metasurface lens with high aperture efficiency for antenna radiation characteristic enhancement
Authors: Singh Amit Kumar , Abegaonkar Mahesh P. , Koul Shiban K.
Published: March 2019

In this paper, a high gain, aperture efficient, low profile compact, near zero index (NZI) metasurface (MS) lens antenna with enhanced radiation characteristic is proposed. A high‐performance transmissive MS is designed by using modified double circular ring resonator as unit cell with measured 3 dB transmission band from 8.80 to 11.90 GHz. It is observed that a triple layer stacked MS lens has the maximum ability to converge the electromagnetic radiation. The focusing mechanism of multiple stacked MS is studied by using measured E‐ and H‐plane radiation pattern plot and H‐Field distribution. A high gain low profile antenna is designed by placing the proposed small single surface NZI MS lens over a microstrip patch antenna acting as a microwave source. The proposed NZI MS lens is found to increase the measured gain of E‐ and H‐plane by 10.70 dB in boresight direction at operating frequency 10.15 GHz. The front to back ratio is improved by 8 and 3 dB in E‐ and H‐plane, respectively. The proposed MS lens antenna is able to achieve a broadside gain of 97.50% of the maximum gain achieved due to ideal effective radiation surface.
Miniaturised band‐absorptive frequency selective rasorbers with wide absorption band
Authors: Yu Weiliang , Luo Guo Qing , Yu Yufeng , Zhang Xiao Hong , Fan Kuikui
Published: March 2019

Miniaturised band‐absorptive frequency selective rasorbers (FSRs) with wide absorption bands for single‐polarised and dual‐polarised applications are proposed here. These FSRs are both constructed by a lossy layer and a lossless layer, in which I‐type metal strips are utilised to reduce the size of the unit cell of the FSRs. The equivalent circuit models (ECM) of the FSRs are presented and analysed. A prototype of the dual‐polarised band‐absorptive FSR is fabricated, assembled, and tested. The measured results show that a wide absorption band (|S21|≤–10 dB and |S11|≤–10 dB) from 3.93 GHz to 8.07 GHz with a bandwidth of 69%, and a low‐pass band (|S21|≥–1 dB) with frequency lower than 880 MHz has been achieved for the dual‐polarised band‐absorptive FSR.
Use one‐bit technique to measure the coherence in the time, frequency and space domain in a reverberation chamber
Authors: Xu Qian , Xing Lei , Zhao Yongjiu , Jia Tianyuan , Huang Yi
Published: March 2019

High speed data streams are everywhere in the fifth generation (5G) system measurement. To develop a high efficient and low cost 5G testbed in a reverberation chamber, the authors propose a high efficient measurement method in the time, frequency and space coherence measurement. In this study, the one‐bit technique is introduced to measure the time domain, frequency domain and space domain correlations in a reverberation chamber. The coherence time, coherence bandwidth and correlated angle can all be measured using the one‐bit correlation; float number calculations are simplified to logical operations which accelerate the data processing greatly. Measurements are performed to verify the results.
Discovery of a directly imaged disk in scattered light around the Sco-Cen member Wray 15-788
Authors: Bohn A. J. , Kenworthy M. A. , Ginski C. , Benisty M. , de Boer J. , Keller C. U. , Mamajek E. E. , Meshkat T. , Muro-Arena G. A. , Pecaut M. J. , Snik F. , Wolff S. G. , Reggiani M.
Published: March 2019

Context. Protoplanetary disks are the birth environments of planetary systems. Therefore, the study of young, circumstellar environments is essential in understanding the processes taking place in planet formation and the evolution of planetary systems.

Aims. We detect and characterize circumstellar disks and potential companions around solar-type, pre-main sequence stars in the Scorpius-Centaurus association (Sco-Cen).

Methods. As part of our ongoing survey we carried out high-contrast imaging with VLT/SPHERE/IRDIS to obtain polarized and total intensity images of the young (11−7+16 Myr old) K3IV star Wray 15-788 within the Lower Centaurus Crux subgroup of Sco-Cen. For the total intensity images, we remove the stellar halo via an approach based on reference star differential imaging in combination with principal component analysis.

Results. Both total intensity and polarimetric data resolve a disk around the young, solar-like Sco-Cen member Wray 15-788. Modeling of the stellar spectral energy distribution suggests that this is a protoplanetary disk at a transition stage. We detect a bright outer ring at a projected separation of ~370 mas (≈56 au), hints of inner substructures at ~170 mas (≈28 au), and a gap in between. Within a position angle range of only 60° < ϕ < 240°, we are confident at the 5σ level that we detect actual scattered light flux from the outer ring of the disk; the remaining part is indistinguishable from background noise. For the detected part of the outer ring we determine a disk inclination of i = 21° ± 6° and a position angle of φ = 76° ± 16°. Furthermore, we find that Wray 15-788 is part of a binary system with the A2V star HD 98363 at a separation of ~50′′ (≈6900 au).

Conclusions. The detection of only half of the outer ring might be due to shadowing by a misaligned inner disk. A potential substellar companion can cause the misalignment of the inner structures and can be responsible for clearing the detected gap from scattering material. However, we cannot rule out the possibility of a non-detection due to our limited signal-to-noise ratio (S/N), combined with brightness azimuthal asymmetry. From our data we can exclude companions more massive than 10 Mjup within the gap at a separation of ~230 mas (≈35 au). Additional data are required to characterize the disk’s peculiar morphology and to set tighter constraints on the potential perturber’s orbital parameters and mass.
Gas phase Elemental abundances in Molecular cloudS (GEMS)
Authors: Fuente A. , Navarro D. G. , Caselli P. , Gerin M. , Kramer C. , Roueff E. , Alonso-Albi T. , Bachiller R. , Cazaux S. , Commercon B. , Friesen R. , García-Burillo S. , Giuliano B. M. , Goicoechea J. R. , Gratier P. , Hacar A. , Jiménez-Serra I. , Kirk J. , Lattanzi V. , Loison J. C. , Malinen J. , Marcelino N. , Martín-Doménech R. , Muñoz-Caro G. , Pineda J. , Tafalla M. , Tercero B. , Ward-Thompson D. , Treviño-Morales S. P. , Riviére-Marichalar P. , Roncero O. , Vidal T. , Ballester M. Y.
Published: March 2019

GEMS is an IRAM 30 m Large Program whose aim is determining the elemental depletions and the ionization fraction in a set of prototypical star-forming regions. This paper presents the first results from the prototypical dark cloud Taurus molecular cloud (TMC) 1. Extensive millimeter observations have been carried out with the IRAM 30 m telescope (3 and 2 mm) and the 40 m Yebes telescope (1.3 cm and 7 mm) to determine the fractional abundances of CO, HCO+, HCN, CS, SO, HCS+, and N2H+ in three cuts which intersect the dense filament at the well-known positions TMC 1-CP, TMC 1-NH3, and TMC 1-C, covering a visual extinction range from AV ~ 3 to ~20 mag. Two phases with differentiated chemistry can be distinguished: (i) the translucent envelope with molecular hydrogen densities of 1−5 × 103 cm−3; and (ii) the dense phase, located at AV > 10 mag, with molecular hydrogen densities >104 cm−3. Observations and modeling show that the gas phase abundances of C and O progressively decrease along the C+/C/CO transition zone (AV ~ 3 mag) where C/H ~ 8 × 10−5 and C/O ~ 0.8−1, until the beginning of the dense phase at AV ~ 10 mag. This is consistent with the grain temperatures being below the CO evaporation temperature in this region. In the case of sulfur, a strong depletion should occur before the translucent phase where we estimate an S∕H ~ (0.4−2.2) × 10−6, an abundance ~7–40 times lower than the solar value. A second strong depletion must be present during the formation of the thick icy mantles to achieve the values of S/H measured in the dense cold cores (S∕H ~ 8 × 10−8). Based on our chemical modeling, we constrain the value of ζH2 to ~(0.5–1.8) × 10−16 s−1 in the translucent cloud.
Diffuse polarized emission in the LOFAR Two-meter Sky Survey
Authors: Van Eck C. L. , Haverkorn M. , Alves M. I. R. , Beck R. , Best P. , Carretti E. , Chyży K. T. , Enßlin T. , Farnes J. S. , Ferrière K. , Heald G. , Iacobelli M. , Jelić V. , Reich W. , Röttgering H. J. A. , Schnitzeler D. H. F. M.
Published: March 2019

Faraday tomography allows us to map diffuse polarized synchrotron emission from our Galaxy and use it to interpret the magnetic field in the interstellar medium (ISM). We have applied Faraday tomography to 60 observations from the LOFAR Two-meter Sky Survey (LOTSS) and produced a Faraday depth cube mosaic covering 568 square degrees at high Galactic latitudes, at 4.′3 angular resolution and 1 rad m−2 Faraday depth resolution, with a typical noise level of 50–100 μJy per point spread function (PSF) per rotation measure spread function (RMSF; 40–80 mK RMSF−1). While parts of the images are strongly affected by instrumental polarization, we observed diffuse polarized emission throughout most of the field, with typical brightness between 1 and 6 K RMSF−1, and Faraday depths between − 7 and +25 rad m−2. We observed many new polarization features, some up to 15° in length. These include two regions with very uniformly structured, linear gradients in the Faraday depth; we measured the steepness of these gradients as 2.6 and 13 rad m−2 deg−1. We also observed a relationship between one of the gradients and an H I filament in the local ISM. Other ISM tracers were also checked for correlations with our polarization data and none were found, but very little signal was seen in most tracers in this region. We conclude that the LOTSS data are very well suited for Faraday tomography, and that a full-scale survey with all the LOTSS data has the potential to reveal many new Galactic polarization features and map out diffuse Faraday depth structure across the entire northern hemisphere.
FliPerClass: In search of solar-like pulsators among TESS targets
Authors: Bugnet L. , García R. A. , Mathur S. , Davies G. R. , Hall O. J. , Lund M. N. , Rendle B. M.
Published: March 2019

The NASA Transiting Exoplanet Survey Satellite (TESS) is about to provide full-frame images of almost the entire sky. The amount of stellar data to be analysed represents hundreds of millions stars, which is several orders of magnitude more than the number of stars observed by the Convection, Rotation and planetary Transits satellite (CoRoT), and NASA Kepler and K2 missions. We aim at automatically classifying the newly observed stars with near real-time algorithms to better guide the subsequent detailed studies. In this paper, we present a classification algorithm built to recognise solar-like pulsators among classical pulsators. This algorithm relies on the global amount of power contained in the power spectral density (PSD), also known as the flicker in spectral power density (FliPer). Because each type of pulsating star has a characteristic background or pulsation pattern, the shape of the PSD at different frequencies can be used to characterise the type of pulsating star. The FliPer classifier (FliPerClass) uses different FliPer parameters along with the effective temperature as input parameters to feed a ML algorithm in order to automatically classify the pulsating stars observed by TESS. Using noisy TESS-simulated data from the TESS Asteroseismic Science Consortium (TASC), we classify pulsators with a 98% accuracy. Among them, solar-like pulsating stars are recognised with a 99% accuracy, which is of great interest for a further seismic analysis of these stars, which are like our Sun. Similar results are obtained when we trained our classifier and applied it to 27-day subsets of real Kepler data. FliPerClass is part of the large TASC classification pipeline developed by the TESS Data for Asteroseismology (T’DA) classification working group.
Surface magnetic activity of the fast-rotating G5 giant IN Comae, central star of the faint planetary nebula LoTr 5
Authors: Kővári Zs. , Strassmeier K. G. , Oláh K. , Kriskovics L. , Vida K. , Carroll T. A. , Granzer T. , Ilyin I. , Jurcsik J. , Kővári E. , Weber M.
Published: March 2019

Context. On the asymptotic giant branch, low to intermediate mass stars blow away their outer envelopes, forming planetary nebulae. Dynamic interaction between the planetary nebula and its central progenitor is poorly understood. The interaction is even more complex when the central object is a binary star with a magnetically active component, as is the case for the target in this paper.

Aims. We aim to quantify the stellar surface activity of the cool binary component of IN Com and aim to explain its origin. In general, we need a better understanding of how central binary stars in planetary nebulae evolve and how this evolution could develop such magnetically active stars as IN Com.

Methods. We present a time series of 13 consecutive Doppler images covering six months in 2017 that we used to measure the surface differential rotation with a cross-correlation method. Hitherto unpublished high-precision photometric data from 1989 to 2017 are presented. We applied Fourier-transformation-based frequency analysis to both photometry and spectra. Very high resolution (R ≈ 200 000) spectra were used to update IN Com’s astrophysical parameters by means of spectral synthesis.

Results. Our time-series Doppler images show cool and warm spots coexisting with an average surface temperature contrast of −1000 K and +300 K with respect to the effective temperature. Approximately 8% of the stellar surface is covered with cool spots and ∼3% with warm spots. A consistent cool polar spot is seen in all images. The average lifetime of the cool spots is not much more than a few stellar rotations (one month), while the warm spots appear to live longer (three months) and are mostly confined to high latitudes. We found anti-solar surface differential rotation with a shear coefficient ofα = −0.026 ± 0.005 suggesting an equatorial rotation period of 5.973 ± 0.008 d. We reconfirm the 5.9 day rotation period of the cool star from photometry, radial velocities, and Hαline-profile variations. A long-termV-brightness variation with a likely period of 7.2 yr is also found. It appears in phase with the orbital radial velocity of the binary system in the sense that it is brightest at highest velocity and faintest at lowest velocity, that is, at the two phases of quadrature. We redetermine [Ba/Fe], [Y/Fe], and [Sr/Fe] ratios and confirm the overabundance of theses-process elements in the atmosphere of IN Com.
Unveiling the Role of Prolactin and its Receptor in Male Reproduction
Authors: Raut Sanketa , Deshpande Sharvari , Balasinor Nafisa
Published: March 2019

Prolactin is a peptide hormone known to have multiple functions. However, the role of prolactin has been extensively studied only in female physiology and its function in male reproduction still remains majorly unexplored. Studies in rodents and humans have demonstrated the presence of prolactin and its receptor in testes, thereby suggesting a possible role during spermatogenesis. Experimental evidences from prolactin and prolactin receptor deficient male rodent models as well as studies done in hypo- and hyper-prolactinemic males hint at neuroendocrine and reproductive abnormalities. Nonetheless, there still remains a lot of ambiguity on the exact role of prolactin and its receptor in male reproduction. This review summarizes in depth on the role of prolactin in spermatogenesis.
Baseline Leptin/Adiponectin Ratio is a Significant Predictor of BMI Changes in Children/Adolescents after Intensive Lifestyle Intervention
Authors: Pejsova Hana , Hubacek Jaroslav A. , Zemankova Petra , Zlatohlavek Lukas
Published: March 2019

Introduction Abdominal obesity is a strong cardiometabolic risk factor that often occurs as early as in childhood. The negative effect of abdominal obesity on the metabolism is partially mediated by changes to the production of the major adipocyte hormones leptin and adiponectin. Leptin/adiponectin imbalance is associated with increased risk of developing obesity and type 2 diabetes mellitus.

Aim To determine whether leptin, adiponectin and the leptin/adiponectin ratio are significant predictors of body weight loss in intensively treated children/adolescents.

Methods 183 paediatric overweight or obese patients (71 boys and 112 girls), aged 7–16 years, were enrolled in a one-month intensive lifestyle intervention programme. Participants reduced their energy intake and engaged in a supervised exercise programme consisting of 5 physical activity units per day. The subjects were examined both before and after the intervention.

Results The mean BMI decrease achieved was−2.38±0.07 kg/m² (P<0.01). The decrease in plasma leptin concentration was−16.59±0.84 ng/mL (P<0.001) and CRP−0.38±0.04 mg/L (P<0.001). Changes in adiponectin concentrations were not statistically significant. The baseline leptin/adiponectin ratio was a significant predictor of decreases in body weight (P<0.005), BMI (P<0.0001) and waist circumference (P<0.05).

Conclusion The leptin/adiponectin ratio at baseline may be a useful predictor of results from interventions focused on decreasing BMIs in children/adolescents.
Prestige-biased social learning: current evidence and outstanding questions
Authors: Jiménez Ángel V. , Mesoudi Alex
Published: March 2019

Cultural evolution theory posits that a major factor in human ecological success is our high-fidelity and selective social learning, which permits the accumulation of adaptive knowledge and skills over successive generations. One way to acquire adaptive social information is by preferentially copying competent individuals within a valuable domain (success bias). However, competence within a domain is often difficult or impossible to directly assess. Almost 20 years ago, Henrich and Gil-White (H&GW) suggested that people use indirect cues of success (e.g., differential levels of attention paid to models by other social learners) as adaptive short-cuts to select models from whom to learn. They called this use of indirect markers of successprestige bias. In this review, we re-visit H&GW’s proposal, examining the evidence amassed since for the adaptiveness and use of prestige bias in humans. First, we briefly outline H&GW’s theory. Second, we analyse whether prestige is associated with competence within valuable domains, which is a crucial assumption underlying the adaptiveness of prestige bias. Third, we discuss prestige cues that people use to infer success (e.g., the amount of voluntary deference and attention received by models). Fourth, we examine the evidence for and against the use of prestige bias in human adults and children. Finally, we point out limitations in the current literature and present new avenues for research on prestige bias.
Solitary dispersive Alfvén wave in a plasma composed of hot positrons, cold electrons and ions
Authors: Liu Y. , Bai Y.
Published: March 2019

The nonlinear solitary structure of the dispersive Alfvén wave in an three-component plasma with hot positron, cold electron and ion is studied from the multi-fluid theory. It is found that when the equilibrium number density ratio of ion to electron is finite, there only exists the super-Alfvén rarefactive solitons. The increase of the ion concentration or the speed of soliton will lead a deeper depletion of the electron number density. The width of soliton decreases with the increase of the speed of soliton and the ion concentration. When the equilibrium number density ratio of ion to electron is much less than unity, there are only sub-Alfvén rarefactive solitons. In the case, the larger speed of soliton or the smaller concentration of ions result the deeper depletion of the electron number density. The width of the soliton increases with the ion concentration and the speed of soliton. The results obtained may be related to the observations and experimental results in the electron positron plasma.
Experimental investigation of three-dimensional flow regimes in a cross-shaped reactor
Authors: Zhang Jing-Wei , Li Wei-Feng , Xu Xin-Lei , Liu Hai-Feng , Wang Fu-Chen
Published: March 2019

Flow regimes in a cross-shaped reactor with square cross sections of two inlets and two outlets were investigated at 20 ≤ Re ≤ 500, where Re is the Reynolds number. Visualization images on cross sections were obtained by planar laser induced fluorescence, and several flow regimes were identified. Results show that, with increasing Re, a symmetric segregated flow, a steady engulfment flow, an unsteady engulfment flow, and an unsteady symmetric flow emerge in turns. First, the symmetric segregated flow is formed at Re < 48. At 48 ≤ Re < 300, the flow becomes asymmetric and a spiral vortex is formed in the center of the outlet chamber, which is called steady engulfment flow. At 300 ≤ Re ≤ 400, the unsteady engulfment flow occurs and a periodic oscillation is established. With a further increase in Re, the flow regains symmetry to a large extent and is characterized by axial oscillation of the impingement plane in the outlet chamber. For steady engulfment flow, an interesting three-dimensional vortical structure was observed, which rotates around the center axis of the outlet chamber along both outlet channels. For unsteady engulfment flow, the periodic oscillation is characterized by vortex merging and breakup. The flow mechanisms of both steady and unsteady engulfment flows were discussed.
Infiltration growth processing of single grain (Gd,Dy)BCO bulk superconductors: Optimization of liquid phase mass and characterization of physical properties
Authors: Pavan Kumar Naik S. , Muralidhar Miryala , Takemura Kento , Jirsa Milos , Murakami Masato
Published: March 2019

Infiltration of an optimal amount of liquid (Ba3Cu5O8 denoted further as “035”) for efficient peritectic growth is a primary requirement in the infiltration growth (IG) processing of high-quality REBa2Cu3O7-δ products. Recently, we optimized the Dy content and the time-temperature schedules for top-seeded IG processing of (Gd,Dy)Ba2Cu3O7–δ [(Gd,Dy)BCO] single grain superconductors. Aiming to fabricate larger sized (Gd,Dy)BCO (80 wt. % Gd2BaCuO5 and 20 wt. % of Dy2BaCuO5) single grain bulk superconductors, different liquid phase [LP = ErBa2Cu3O7–δ (Er-123) and mixed with 035] sources were employed and the LP content was optimized by varying its mass. The increase in Er-123+035 mass assured an abundant amount of liquids for peritectic reaction. The Er-123+035 ratio of 1:1.4 was found to be optimum. The optimized liquid phase infiltration enabled an effective control of (Gd,Dy)2BaCuO5 (211) secondary phase size and content in final microstructures. Bulk single-grain (Gd,Dy)BCO superconductors were fabricated by the top-seeded IG process with an LP mass of 1 and 1.4 wt. %. A fully grown single grain bulk (Gd,Dy)BCO superconductor was attained. The sufficient LP infiltration resulted in a greatly improved critical current and trapped field performance. Scaling of bulk volume flux pinning force was studied with the aim of identifying flux pinning mechanisms effectively occurring in the material.
Defect engineering of black phosphorene towards an enhanced polysulfide host and catalyst for lithium-sulfur batteries: A first principles study
Authors: Lin He , Yang Dong-Dong , Lou Nan , Wang Ai-Li , Zhu Shun-Guan , Li Hong-Zhen
Published: March 2019

Although lithium-sulfur (Li-S) batteries are widely regarded as one of the most promising next-generation high energy density storage systems, their large-scale applications are seriously impeded by rapid capacity fading and poor Coulombic efficiency owing to the shuttling of lithium polysulfides (LiPSs) and irreversible discharge product Li2S. Here, by means of first principles calculations, we studied defective black phosphorene (BP) as a host material to realize high-performance Li-S batteries, including Stone Wales [SW(55-77)], single, and double vacancy [SV(5-9) and DV(5-9-5)] defects. Our results demonstrate that while BP has moderate adsorption energies towards LiPSs, the presence of defects could enhance the adsorption strength between LiPSs and BP because of increased charge transfer. Particularly, defective BP could strike a good balance between adsorption energy and integrity of LiPSs, which is beneficial to prevent the shuttling of LiPSs. Moreover, during the lithiation process, defective BP not only has narrow bandgaps but also decreases the dissociation energy of Li2S, facilitating the catalytic oxidation of Li2S back to sulfur. Therefore, it is highly desirable to fabricate defective BP to improve the reversible capacity and cycle stability of Li-S batteries.
Subcritical turbulence spreading and avalanche birth
Authors: Heinonen R. A. , Diamond P. H.
Published: March 2019

In confined plasmas, a localized fluctuation in a marginal or weakly damped region will propagate and generate an avalanche if it exceeds a threshold. In this letter, a new model for turbulence spreading based on subcritical instability in the turbulence intensity is introduced. We derive a quantitative threshold for spreading from a seed in a stable region, based on a competition between diffusion and nonlinear growth of the turbulence intensity. The model resolves issues with the established Fisher equation model for turbulence spreading, which is supercritical and cannot support the stationary coexistence of multiple turbulence levels. Implications for turbulence spreading are discussed, including the dynamics of ballistic penetration of turbulence into the stable zone. Tests of the theory are suggested.
The development of 2D materials for electrochemical energy applications: A mechanistic approach
Authors: Hynek David J. , Pondick Joshua V. , Cha Judy J.
Published: March 2019

Energy production and storage is one of the foremost challenges of the 21st century. Rising energy demands coupled with increasing materials scarcity have motivated the search for new materials for energy technology development. Nanomaterials are an excellent class of materials to drive this innovation due to their emergent properties at the nanoscale. In recent years, two dimensional (2D) layered materials have shown promise in a variety of energy related applications due to van der Waals interlayer bonding, large surface area, and the ability to engineer material properties through heterostructure formation. Despite notable results, their development has largely followed a guess and check approach. To realize the full potential of 2D materials, more efforts must be made towards achieving a mechanistic understanding of the processes that make these 2D systems promising. In this perspective, we bring attention to a series of techniques used to probe fundamental energy related processes in 2D materials, focusing on electrochemical catalysis and energy storage. We highlight studies that have advanced development due to mechanistic insights they uncovered. In doing so, we hope to provide a pathway for advancing our mechanistic understanding of 2D energy materials for further research.
Linear theory of instabilities generated by an electron beam in a metamaterial-loaded waveguide
Authors: Lu Xueying , Shapiro Michael A. , Temkin Richard J.
Published: March 2019

We present the linear theory of the starting current of Cherenkov-cyclotron and Cherenkov instabilities generated by an electron beam passing through a metamaterial-loaded waveguide. Effective medium theory is used to represent the metamaterial structure properties. The theory predicts that the instabilities compete with the Cherenkov-cyclotron mode dominating at a lower magnetic field and the Cherenkov instability at a higher magnetic field. The theoretical results are compared to results from recent experiments at MIT using a 490 kV, 84 A electron beam in magnetic fields of 300 G to 1500 G. For an effective medium model fitted to the MIT experimental parameters, theory predicts that the Cherenkov-cyclotron mode will dominate below 780 G and the Cherenkov mode above 780 G, in good agreement with experimental observations of switching between these modes at 750 G. The analytical theory allows a better understanding of the mode competition and the dependence of the instabilities on key parameters such as voltage, current, and magnetic fields.
Collimated quasi-monoenergetic protons from interaction of two intersecting lasers with thin double-layer target
Authors: Tong Sheng-Fei , Sheng Zheng-Mao , Yu M. Y.
Published: March 2019

The acceleration of protons from the interaction of two intersecting laser pulses in a double-layer target, consisting of a carbon slab with a thin hydrogen layer behind it, is investigated. It is found that a bunch of well-collimated, up to 270 MeV, quasi-monoenergetic protons can be generated. The affected target electrons are heated and accelerated forward by the laser pulses so that the target gradually becomes transparent as the lasers bore into it. Eventually, the thin target becomes fully transparent. The converging laser pulses can then pass through it and the hot backside electron cloud, together with the electrons trapped in them. As a result, behind the target, an inhomogeneous sheath electric field is formed, which not only accelerates the protons but also merges them into a quasi-monoenergetic bunch with low divergence. The energy and spatial spread of the bunch, as well as the peak energy, can be controlled by manipulating the locations of the two lasers.
More superior pyroelectric performance of synthesized dravite by high-pressure solid-state method
Authors: Shan You , Zhou Guojun , Chen Kairen , Zhao Changchun , Shen Kun , Liu Hao , Fan Zhenjun , Hao Munan
Published: March 2019

It’s of great significance to explore the synthesis of tourmaline with simple chemical composition to study the mechanism of its pyroelectric properties due to the presence of crystal defects and isomorphous substitution in natural tourmaline. In the present work, dravite is firstly synthesized by high pressure solid-state method at 5-6 GPa and 550-650 °C. X-ray powder diffraction and electron microprobe analysis data indicate that the synthesized sample is the compound of the dravite with the formula of NaMg3Al6Si6B3O27(OH)4 and a small amount of SiO2. Compared with the natural dravite, the pyroelectric coefficient of the synthesized dravite is improved by an order of magnitude due to the great increase of the intrinsic dipole moment in synthesized dravite. The temperature dependent infrared spectra shows that the dipole moment of each ionic group in the synthesized dravite increases with temperature, leading to the raise of the pyroelectric coefficient with the increment of temperature. And in all ionic groups, [SiO4] tetrahedron and [BO3] triangle are the most important ionic groups that caused the pyroelectricity of tourmaline.
Uncovering what triggers avalanches in plasma
Authors: Patrick Chris
Published: March 2019

A new, unified model of turbulence spreading and avalanching is the first to propose a mechanism for plasma avalanches.
Updating global coastal wetland areas presented in Davidson and Finlayson (2018)
Authors: Davidson Nick C. , Finlayson C. Max
Published: March 2019

Global and regional areas and trends in area of unvegetated tidal flats, salt marshes, mangroves and seagrass beds are updated and corrected from those published in Davidson and Finlayson (2018). The global area of coastal wetlands is now estimated as a minimum of 1.42×106 km2, ~8.9–9.5% of an updated global wetland area of 15.0×106–16.0×106 km2.
A SIR-independent role for cohesin in subtelomeric silencing and organization
Authors: Kothiwal Deepash , Laloraya Shikha
Published: March 2019

Cohesin is a key determinant of chromosome architecture due to its DNA binding and tethering ability. Cohesin binds near centromeres and chromosome arms and also close to telomeres, but its role near telomeres remains elusive. In budding yeast, transcription within 20 kb of telomeres is repressed, in part by the histone-modifying silent information regulator (SIR) complex. However, extensive subtelomeric repressed domains lie outside the SIR-binding region, but the mechanism of silencing in these regions remains poorly understood. Here, we report a role for cohesin in subtelomeric silencing that extends even beyond the zone of SIR binding. Clusters of subtelomeric genes were preferentially derepressed in a cohesin mutant, whereas SIR binding was unaltered. Genetic interactions with known telomere silencing factors indicate that cohesin operates independent of the SIR-mediated pathway for telomeric silencing. Mutant cells exhibited Mpk1-dependent Sir3 hyperphosphorylation that contributes to subtelomeric derepression to a limited extent. Compaction of subtelomeric domains and tethering to the nuclear envelope were impaired in mutant cells. Our findings provide evidence for a unique SIR-independent mechanism of subtelomeric repression mediated by cohesin.
Long-term population spike-timing-dependent plasticity promotes synaptic tagging but not cross-tagging in rat hippocampal area CA1
Authors: Pang Karen Ka Lam , Sharma Mahima , Krishna-K. Kumar , Behnisch Thomas , Sajikumar Sreedharan
Published: March 2019

Significance

Deciphering the rules that shape neuronal connections is critical to our understanding of information processing in a neural network. Our study describes how the relative timing of the activities of afferents and their associated postsynaptic neurons determines synaptic strength at the hippocampal CA1 circuit, an area important for learning and memory. A low number of repeated, paired activities between afferents and their neurons differentially shapes the hippocampal CA3–CA1 synaptic pathway for hours and even affects how future information is processed in the neuronal ensemble.
Materializing gay identity
Authors: Osatananda Varisa , Gadavanij Savitri
Published: March 2019

This paper aims at investigating (1) whether young Thai adults can distinguish between straight male and
gay-sounding speech and (2) how listeners feel about speech sounds performed by Thai straight and gay speakers in varying
situations in terms of likeability and annoyance. Two experiments were conducted: first, straight males, gay males and females
listened to voice stimuli of self-identified straight males and gay males and were asked to identify the sexual orientation of the
speakers; second, another three groups of listeners were asked to rate the speakers’ levels of likeability and annoyance using a
5-point Likert scale. The findings indicate that there exist voice characteristics of gay- as opposed to straight-male sounding
speech. Regarding the listeners’ perception in relation to speech style in four varying situations, the results indicate that
listeners’ perception is not affected by situations in which the speech is delivered.
National identity and belonging among gay ‘new speakers’ of Irish
Authors: Walsh John
Published: March 2019

‘New speakers’ refer to people who use a language regularly but are not traditional ‘native’ speakers of that language. Although this discussion has been going on for some time in other sub-disciplines of linguistics, it is more recent in research about European minoritised languages. A feature of discourse around such languages relates to their perceived suitability for diverse urban settings removed from their historical rural heartlands. Irish is an example of a minoritised language which was long associated with conservative rural communities, a reified Catholic discourse of national identity and language ideologies based on nativism. Such an approach not only marginalised urban new speakers of Irish but also exhibited hostility to LGBTQ citizens who did not befit its particular version of Irishness. In this paper, a framework of Critical Sociolinguistics is used to analyse identity positions and ideologies expressed by urban new speakers of Irish who identify as gay and/or queer.
Sexuality in Goytisolo’sAntagonía
Authors: Jódar-Sánchez José Antonio
Published: March 2019

Antagoníais Luis Goytisolo’s masterpiece. In this article I present a quantitative and qualitative study of his prose with regards to sexuality. Through an analysis of keywords, concordances, dispersion, and discourses, I show thatAntagoníafeeds from two historical periods, namely the ending dictatorship and the new democratic transition. Some of its discourses are the product of the Spain of the 1970s and 80s. Among them, we find sexist, male chauvinist, and homophobic discourses latent during those times. Women and queer people are frequently characterized in a negative fashion. However, we also find more subversive discourses that empower women. In sum, I consider Goytisolo’s tetralogy a “fluid” or “transitional” novel in that it is imbued with contradictory discourses rooted in different historical periods.
Cosmopolitanism in ethnic foodscapes
Authors: Abas Suriati
Published: March 2019

This paper opens up a perspective for viewing the effect of globalization on ethnic restaurants in a college town, Bloomington, at Indiana, in the US. While existing scholarship on shop signs were focused on interpreting signages that are mostly visible from the exterior (e.g.Collins & Slembrouck, 2007;Malinowski, 2009;Ong, Ghesquière, & Serwe, 2013), this study examines publicly displayed material artefacts, and the dialogical relationship between customers and waiters, taking into account one aspect ofScollon and Scollon’s (2003)perceptual space which is highly visible in a restaurant: tastes. Through interviews, participant observations and geosemiotic analysis of signs inside and on the exterior of restaurants, I evinced a configuration of semiotic aggregates (Scollon & Scollon, 2003) drawing from my ethnographic work on ethnic foodscapes. Findings from the study suggest that multiple social actors contributed to shaping cosmopolitanism in a college town.
Transforming the urban public space
Authors: Moustaoui Adil
Published: March 2019

This article examines the use of Moroccan Arabic (MA) in the new Linguistic Landscape (LL) in Morocco, and in
particular in the city of Meknés, in a new neighbourhood known as (حمرية)
Hamriya or La Ville Nouvelle. In particular, the ways in which current socio-economic
transformations produce new spaces of communications are explored, highlighting the extent to which MA is used in urban public
spaces as new linguistic practices. In turn, the increasing visibility of MA in the LL and its subsequent nourishing of hybrid
practices are discussed. The data points to a re-semiotisation of space in a Moroccan linguistic regime historically characterized
by a well-established linguistic hierarchy. Ultimately, the use of MA creates new language practices and policies that resist and
transform the sociolinguistic regime which is analysed here by a close examination of linguistic variation in Arabic in the public
space.
Managing relationships through repetition
Authors: Machi Saeko
Published: March 2019

This study examines cross-speaker repetition in triadic conversations in the Japanese language. For the analysis, three sets of triadic conversations between close friends taken from a TV talk show are used. The results reveal that repetition in triadic conversations performs distinctive functions that are not observed in dyadic conversations: repetition often takes place between only two participants of the triad and allows the two to team up and strengthen their bond exclusively (teaming repetition), or even playfully tease the third participant (teasing repetition). Repetition is also shared between the three participants. In such cases, it allows the participants to create an instant bond by joking or referring to shared circumstances (immediate threefold repetition), or to gradually establish rapport by connecting their utterances and co-constructing a story (repetition relay). All these types of repetition express the participants’ points of view and contribute efficiently to their relationships that shift from moment to moment. The study further demonstrates cases in which one participant makes good use of various repetition types in a short period of time and efficiently allocates thoughts and feelings to the other two participants. The study concludes that repetition plays a significant role in Japanese conversation, helping speakers to converse smoothly and manage the dynamic relationships efficiently.
The historical present in Spanish and semantic/pragmatic structure
Authors: Benavides Carlos
Published: March 2019

The historical present (HP) is the use of the present tense to refer to past events, usually as part of a narrative. Most work on this topic has dealt with the functions of English HP, mainly within the context of tense switching in conversational narrative. Relatively little work focuses exclusively on HP in Spanish, and most of it deals with the function of HP in conversational narratives. There is a gap in the literature regarding the specific interaction between the semantics and pragmatics involved in the use of HP, especially with respect to the formal representation of this interaction. In order to fill this gap, this paper analyzes the use of HP within the Parallel Architecture framework (Jackendoff 2002) and examines the implications for the semantic/pragmatic structure. Language samples produced by native speakers of Spanish and data from a large Spanish corpus are used as part of the basis for analysis. The present study also explores how the use of the preterite and imperfect in narrative in the past parallels the use of the simple present and the present progressive in narrative within the present timeframe, and shows how this can also be fruitfully analyzed employing the Parallel Architecture. The result is an original model that extends the formal apparatus of the Parallel Architecture to an area where it has not been applied before, the interface between semantics and narrative structure.
Searches and clicks in Peninsular Spanish
Authors: Pinto Derrin , Vigil Donny
Published: March 2019

The current study analyzes the use of click sounds in Peninsular Spanish with a focus on those that occur when
speakers are searching for what to say and signaling a particular stance. The data corpus consists of interviews with 18 speakers
from Spain who produce a total of 281 clicks. We consider clicks to be a non-lexical discourse marker that conveys information to
the listener regarding how an utterance should be interpreted. By applying a discourse-pragmatic approach from both quantitative
and qualitative perspectives, we examine contextual and co-textual factors that co-occur with the click and contribute to a
multimodal display consisting of pauses, fillers, repetitions, prolongations, gestures and object of search. The quantitative
results indicate some statistically significant differences with regard to how clicks interact with the linguistic and
extralinguistic environments. Qualitatively, we show evidence supporting the idea that clicks are part of a larger multimodal
communicative activity.
‘Monitoring’ in translation
Authors: Schaeffer Moritz J. , Halverson Sandra L. , Hansen-Schirra Silvia
Published: March 2019

We assume that visual feedback from the written trace during translation plays an important role in monitoring the
emerging translation. In this study, 44 participants translated with and without visual feedback from the target text (TT).
Numerous measures were used to explore the differences between the texts that were created in the two conditions and the
characteristics of the task performance in the two conditions. The impact of ST-TT semantic and syntactic relationships showed
that there were differences on two of three behavioural measures across conditions. In the comparison of features of the
translation process, findings show that ST reading times were longer without visual feedback, while increased translational choice
(implying more monitoring) affected eye movements on the source text (ST) in the same way in both conditions. We found that,
without visual feedback, when faced with more translational options, translators read the ST less linearly. Participants were more
likely to look at the TT screen or read the TT the longer they read the ST and the more the more translational options the ST
offered, even if the TT window was blank.