bluuebunny/crossref_metadata_2025 huggingface dataset:
Graded quivers and B-branes at Calabi-Yau singularities
Authors: Closset Cyril , Franco Sebastián , Guo Jirui , Hasan Azeem
Published: March 2019

Abstract

A graded quiver with superpotential is a quiver whose arrows are assigned degrees c ∈ {0, 1, ⋯ , m}, for some integer m ≥ 0, with relations generated by a superpotential of degree m − 1. Ordinary quivers (m = 1) often describe the open string sector of D-brane systems; in particular, they capture the physics of D3-branes at local Calabi-Yau (CY) 3-fold singularities in type IIB string theory, in the guise of 4d

$$ \mathcal{N} $$

N

= 1 supersymmetric quiver gauge theories. It was pointed out recently that graded quivers with m = 2 and m=3 similarly describe systems of D-branes at CY 4-fold and 5-fold singularities, as 2d

$$ \mathcal{N} $$

N

= (0, 2) and 0d

$$ \mathcal{N} $$

N

= 1 gauge theories, respectively. In this work, we further explore the correspondence between m-graded quivers with superpotential, Q
(m), and CY (m + 2)-fold singularities, X

m+2. For any m, the open string sector of the topological B-model on X

m+2 can be described in terms of a graded quiver. We illustrate this correspondence explicitly with a few infinite families of toric singularities indexed by m ∈ ℕ, for which we derive “toric” graded quivers associated to the geometry, using several complementary perspectives. Many interesting aspects of supersymmetric quiver gauge theories can be formally extended to any m; for instance, for one family of singularities, dubbed C(Y
1,0(ℙ
m
)), that generalizes the conifold singularity to m > 1, we point out the existence of a formal “duality cascade” for the corresponding graded quivers.
Learning vector quantization and relevances in complex coefficient space
Authors: Straat M. , Kaden M. , Gay M. , Villmann T. , Lampe A. , Seiffert U. , Biehl M. , Melchert F.
Published: March 2019

In this contribution, we consider the classification of time series and similar functional data which can be represented in complex Fourier and wavelet coefficient space. We apply versions of learning vector quantization (LVQ) which are suitable for complex-valued data, based on the so-called Wirtinger calculus. It allows for the formulation of gradient-based update rules in the framework of cost-function-based generalized matrix relevance LVQ (GMLVQ). Alternatively, we consider the concatenation of real and imaginary parts of Fourier coefficients in a real-valued feature vector and the classification of time-domain representations by means of conventional GMLVQ. In addition, we consider the application of the method in combination with wavelet-space features to heartbeat classification.
Too Much of a Good Thing? On the Relationship Between CSR and Employee Work Addiction
Authors: Brieger Steven A. , Anderer Stefan , Fröhlich Andreas , Bäro Anne , Meynhardt Timo
Published: March 2019

Recent research highlights the positive effects of organizational CSR engagement on employee outcomes, such as job and life satisfaction, performance, and trust. We argue that the current debate fails to recognize the potential risks associated with CSR. In this study, we focus on the risk of work addiction. We hypothesize that CSR has per se a positive effect on employees and can be classified as a resource. However, we also suggest the existence of an array of unintended negative effects of CSR. Since CSR positively influences an employee’s organizational identification, as well as his or her perception of engaging in meaningful work, which in turn motivates them to work harder while neglecting other spheres of their lives such as private relationships or health, CSR indirectly increases work addiction. Accordingly, organizational identification and work meaningfulness both act as buffering variables in the relationship, thus suppressing the negative effect of CSR on work addiction, which weakens the positive role of CSR in the workplace. Drawing on a sample of 565 Swiss employees taken from the 2017 Swiss Public Value Atlas dataset, our results provide support for our rationale. Our results also provide evidence that the positive indirect effects of organizational CSR engagement on work addiction, via organizational identification and work meaningfulness, become even stronger when employees care for the welfare of the wider public (i.e., the community, nation, or world). Implications for research and practice are discussed.
Correction to: Answering biological questions by analysis of the strawberry metabolome
Authors: Haugeneder Annika , Trinkl Johanna , Härtl Katja , Hoffmann Thomas , Allwood James William , Schwab Wilfried
Published: March 2019

The article Answering biological questions by analysis of the strawberry metabolome, written by Annika Haugeneder, Johanna Trinkl, Katja Härtl, Thomas Hoffman, James William Allwood and Wilfred Schwab, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 26 OCtober, 2018 without open access. After publication in volume 14. Issue 11, Citation Id 145, with the author(s)’ decision to opt for Open Choice the copyright of the article changed on 20 December, 2018 to © The Author(s) [Year] and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.
Durability of building fabric components and ventilation systems in passive houses
Authors: Feist Wolfgang , Pfluger Rainer , Hasper Wolfgang
Published: March 2019

The passive house concept specifically improves insulation of exterior building components, utilisation of passive solar gains, airtightness and heat recovery from ventilation air. Reducing also heat losses from thermal bridges, the energy balance is improved significantly resulting in net heating demands lower than 15 kWh/(m2a) which is less than one-tenth of the typical heating energy in the average of existing buildings. The design concept can be used for every new building, and many thousand examples have so far been built for different use, in several climates and based on different construction type (e.g. concrete, timber, mixed). The very first prototype is a terraced house with four dwellings built 1990/1991 in Darmstadt. This building uses typical masonry external walls, concrete floors and a timber roof and can be seen as a representative example for highly energy-efficient construction. By monitoring all relevant energy flows through the building’s envelope during a period of more than 25 years, it has been confirmed that the energy consumption is as extraordinarily low as designed and stable over the whole period. This article especially investigates how this has affected the indoor climate, the indoor air quality and the durability of all components. By thorough investigation, an assessment of the maintenance cycles is given, which are representative for this construction type. The main characteristics of the components and the ventilation system after 25 years of performance of the pilot building have been determined; these are typical for passive house quality components; therefore, the results are indicative for the concept. The passive house concept turns out to be not only energy-saving but also most notably very durable and extraordinarily low-maintenance.
Density-dependent growth in ‘catch-and-wait’ fisheries has implications for fisheries management and Marine Protected Areas
Authors: Merder Julian , Browne Patricia , Freund Jan A. , Fullbrook Liam , Graham Conor , Johnson Mark P. , Wieczorek Alina , Power Anne Marie
Published: March 2019

Stock enhancement activities provide an opportunity to examine density-dependent suppression of population biomass which is a fundamental issue for resource management and design of no-take-zones. We document ‘catch-and-wait’ fisheries enhancement where all but the largest lobsters are thrown back, recapturing them later after they have grown to a larger size. The residency, rate of return, and potential negative density-dependent effects of this activity are described using a combination of tagging and v-notching and by relating spatial growth patterns to population density defined with Catch Per Unit Effort. The results successfully demonstrated the concept of catch-and-wait practices. However, a density-dependent suppression of growth (in body size) was observed in male lobsters. This demonstrates a mechanism to explain differences in lobster sizes previously observed across EU fishing grounds with different stock densities. This negative effect of density could also affect individual biomass production in marine reserve or no-take zones.
Novel Graphene Biosensor Based on the Functionalization of Multifunctional Nano-bovine Serum Albumin for the Highly Sensitive Detection of Cancer Biomarkers
Authors: Zhou Lin , Wang Kun , Sun Hao , Zhao Simin , Chen Xianfeng , Qian Dahong , Mao Hongju , Zhao Jianlong
Published: March 2019

A simple, convenient, and highly sensitive bio-interface for graphene field-effect transistors (GFETs) based on multifunctional nano-denatured bovine serum albumin (nano-dBSA) functionalization was developed to target cancer biomarkers. The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface. The formed nano-dBSA film served as the cross-linker to immobilize monoclonal antibody against carcinoembryonic antigen (anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS. The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing. The improved GFET biosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL−1. The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction, indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82 × 10−10 M. The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing, nanomedicine, and drug delivery.
Nitrogen-Doped Sponge Ni Fibers as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction
Authors: Zhang Kaili , Xia Xinhui , Deng Shengjue , Zhong Yu , Xie Dong , Pan Guoxiang , Wu Jianbo , Liu Qi , Wang Xiuli , Tu Jiangping
Published: March 2019

Controllable synthesis of highly active micro/nanostructured metal electrocatalysts for oxygen evolution reaction (OER) is a particularly significant and challenging target. Herein, we report a 3D porous sponge-like Ni material, prepared by a facile hydrothermal method and consisting of cross-linked micro/nanofibers, as an integrated binder-free OER electrocatalyst. To further enhance the electrocatalytic performance, an N-doping strategy is applied to obtain N-doped sponge Ni (N-SN) for the first time, via NH3 annealing. Due to the combination of the unique conductive sponge structure and N doping, the as-obtained N-SN material shows improved conductivity and a higher number of active sites, resulting in enhanced OER performance and excellent stability. Remarkably, N-SN exhibits a low overpotential of 365 mV at 100 mA cm−2 and an extremely small Tafel slope of 33 mV dec−1, as well as superior long-term stability, outperforming unmodified sponge Ni. Importantly, the combination of X-ray photoelectron spectroscopy and near-edge X-ray adsorption fine structure analyses shows that γ-NiOOH is the surface-active phase for OER. Therefore, the combination of conductive sponge structure and N-doping modification opens a new avenue for fabricating new types of high-performance electrodes with application in electrochemical energy conversion devices.
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism
Authors: ter Maat Geertje W. , McEnroe Suzanne A. , Church Nathan S. , Larsen Rune B.
Published: March 2019

Magnetic properties from the Reinfjord Ultramafic Complex, in northern Norway, which formed as part of a deep magmatic conduit system, have been investigated to determine the magnetic signature of ultramafic rocks now exposed at the surface and deeper in the lower crust. The dominant carriers in these ultramafic rocks are a chrome‐spinel with Fe‐rich exsolution blebs and exsolution lamellae of magnetite in clinopyroxene. Except locally, in a fault zone and in discrete small fractures, these rocks show only minor to no alteration. We infer that the magnetic oxides characterized here are representative of pristine magnetic carriers in similar rocks deeper in the crust. These oxides can be stable in lower crustal, possibly upper mantle, depths when temperatures are below the Curie temperature of magnetite, taking into account pressure effects. These ultramafic rocks are candidates for potential sources of long‐wavelength anomalies.
Comprehensive Study of Low‐Latitude Pi2 Pulsations Using Observations From Multisatellite Swarm Mission and Global Network of Ground Observatories
Authors: Thomas Neethal , Shiokawa Kazuo , Vichare Geeta
Published: March 2019

To understand the spatial features of low‐latitude Pi2 (6.6–25 mHz) pulsations, a comprehensive study is carried out for the first time using magnetic field measurements from a global network of low‐latitude ground stations (Mlat: ± 2° − 51°) and the Swarm multisatellites located simultaneously at day and night local times. We have investigated 1‐year data from 2014 and found 15 Pi2 events with coherent oscillations at satellite and ground. The Pi2 oscillations in the compressional, toroidal, and poloidal components at satellite and H, D, and Z components at ground are investigated by estimating its coherence, amplitude, and cross phase with respect to midnight ground H variations. The analogous pairs of magnetic field components (satellite compressional with ground H and satellite toroidal with ground D) above and below the ionosphere are found to have identical phase during night and opposite phase during day, indicating the magnetospheric and ionospheric sources for nighttime and daytime Pi2s, respectively. During nighttime, Pi2 oscillations identified in the poloidal component are found to oscillate in phase (out of phase) in the Southern (Northern) Hemisphere. At ground, the phase and amplitude of H showed significant change near the dawn terminator, whereas H oscillates mostly in phase with respect to midnight ground H at other local times. The oscillations in D component have phase reversal near midnight, dawn, dusk, and noon meridians with opposite hemispheres having opposite phase. These Pi2 characteristics observed globally at ground and at the topside ionosphere suggest that the sources for nighttime and daytime low‐latitude Pi2s are oscillating field‐aligned currents and ionospheric currents, respectively.
Determination of the Signal Fluctuation Threshold of the Temperature‐Ion Composition Ambiguity Problem Using Monte Carlo Simulations
Authors: Martínez‐Ledesma Miguel , Díaz Quezada Marcos Andrés
Published: March 2019

Unambiguously estimating the plasma parameters of the ionosphere at altitudes between 130 and 300 km presents a problem for the incoherent scatter radar (ISR). At these ranges, ISR is unable to distinguish between different mixtures of molecular ions (NO+ and O2+) and atomic oxygen ions (O+). Common solutions to this problem are either to employ empirical or theoretical models of the ionosphere or to add a priori known plasma parameter information obtained from the plasma line of the ISR spectrum. Studies have demonstrated that plasma parameters can be unambiguously estimated in almost noiseless scenarios, not commonly feasible during routine monitoring. In this study, we define a theoretical framework to quantify the ambiguity problem and determine the maximum signal fluctuation levels of the ISR signal to unambiguously estimate plasma parameters. We conduct Monte Carlo simulations for different plasma parameters to evaluate the estimation performance of the most commonly used nonlinear least squares optimization algorithm. Results are shown as probability curves of valid convergence and correct estimation. We use simulations to quantify the estimation error when using ionospheric models as initial conditions of the optimization algorithm. We also determine the contribution to the estimation process of different combinations of parameters known from the plasma line, the particular contribution of each plasma parameter, and the effect of increasing the level of uncertainty of the parameters known a priori. Results suggest that knowing a priori both electron density and electron temperature parameters allows an unambiguous estimation even at high fluctuation levels.
Analysis of the Steady State Available Energy Budget in the High‐Latitude Lower Thermosphere
Authors: Kwak Young‐Sil , Richmond Arthur D.
Published: March 2019

We evaluate the budgets of available energy (AE) production, transport, and loss under steady state forcing of the high‐latitude lower thermosphere during the southern summer time for weak or strong southward interplanetary magnetic field (IMF,Bz = −2.0 or −10.0 nT), using the National Center for Atmospheric Research Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model. The AE below 150‐km altitude is partitioned into commensurable reservoirs of kinetic energy (KE) and available potential energy (APE). KE density is larger than APE density above 123 km, but they are comparable below 123 km. Whereas Pedersen ion drag generates strong winds and KE, vertical winds and adiabatic cooling above 123 km tend to offset temperature perturbations caused by Joule heating, thereby reducing APE. Below 123 km Hall ion drag and associated vertical motions are important for creating temperature perturbations and APE. With increasingly negative IMFBzvalues APE density intensifies more significantly than KE density above about 123 km, while KE density intensifies more significantly than APE density below. KE is generated primarily where the ion‐drag force associated with plasma convection accelerates the neutral gas and is destroyed primarily where the ion‐drag force opposes the wind. APE is generated primarily where Joule heat is deposited in regions of elevated temperatures and destroyed where the heat is deposited in regions of reduced temperatures. Ion drag is generally more important than Joule heating for generating AE for steady‐state conditions, but the relative contribution of the ion‐drag forcing compared with heating decreases with descending altitude. AE generation by Joule heating intensifies more significantly than generation by ion drag with increasingly negative IMFBzvalues. Transport of AE by horizontal and vertical winds is a significant component of the AE budget. Conversion of APE to KE, and of KE to APE, constitutes an important part of their budgets.
Kinetic Equilibrium and Stability Analysis of Dipolarization Fronts
Authors: Fletcher Alex C. , Crabtree Chris , Ganguli Gurudas , Malaspina David , Tejero Erik , Chu Xiangning
Published: March 2019

Dipolarization fronts are typically observed with a density gradient of scale size comparable to an ion gyroradius, which naturally results in an ambipolar electric field in the direction of the gradient. Prevailing models ignore this ambipolar electric field, the separation of ion and electron scale physics, and consequent non‐Maxwellian plasma distributions with strong spatial gradients in velocity, all of which we investigate in this paper. We examine two dipolarization front events observed by the Magnetospheric Multiscale mission (one with low plasma beta, one with high plasma beta), develop a rigorous kinetic equilibrium for dipolarization fronts, analyze the linear stability, and explore the nonlinear evolution and observable signatures with kinetic simulations. There are two major drivers of instability in the lower‐hybrid frequency range: the density gradient (lower‐hybrid drift instability) and the velocity shear (electron‐ion hybrid instability). We argue the electron‐ion hybrid mode is dominant, and consequently a dipolarization front approaches a steady or saturated state through the emission of waves that relax the velocity shear. A key aspect of these shear‐driven waves is a broadband frequency spectrum that is consistent with satellite observation.
Daytime Periodic Wave‐like Structures in the Ionosphere Observed at Low Latitudes over the Asian‐Australian Sector Using Total Electron Content from Beidou Geostationary Satellites
Authors: Huang Fuqing , Otsuka Yuichi , Lei Jiuhou , Luan Xiaoli , Dou Xiankang , Li Guozhu
Published: March 2019

Daytime periodic wave‐like structures are statistically analyzed for the first time in the low‐latitude ionosphere over the Asian‐Australian sector using total electron content from Beidou geostationary satellites during 2016–2017. These structures have periods of about 18–28 min, which frequently occur during 11:00–17:00 local time in the winter at latitudes ranging between 17 and 25°N (10–18°N magnetic latitude [MLAT]) in the Northern Hemisphere, where they have a maximum occurrence rate of 80% at ~21°N (14°N MLAT). In the Southern Hemisphere, daytime periodic wave‐like structures are also observed during 11:00–15:00 local time in the winter within latitudes ranging between 6.0 and 11.1°S (15.4–21.6°S MLAT), although the peak occurrence rate is only approximately 40%. Compared with stratospheric gravity waves (GWs), the seasonal and latitudinal variations of daytime periodic wave‐like structures are generally consistent with those of stratospheric GWs. This gives a possible argument that daytime periodic wave‐like structures in the low‐latitude ionosphere could be generated in the low‐latitude ionosphere and triggered by GWs from the lower atmosphere.
Diurnal and Seasonal Variability of Near‐Surface Oxygen in the Strait of Georgia
Authors: Wang Chuning , Pawlowicz Rich , Sastri Akash R.
Published: March 2019

Dissolved oxygen (O2) concentrations in waters of the ocean surface mixed layer are generally close to thermodynamic equilibrium with atmospheric concentrations. However, near‐surface O2 levels are also affected by other processes, including primary productivity, and thus measurements of near‐surface O2 can in theory be used to estimate productivity. Here we discuss variations in near‐surface O2 concentrations in the Strait of Georgia by examining a variety of data sets, focusing primarily on ferry‐based measurements over a 3‐year period (2015–2017). Both diurnal, seasonal, and interannual variations are quantified, and various fluxes into and out of the surface waters are estimated so that the degree to the measured oxygen variations representing biological activity can be assessed. On average, advective and vertical transport makes only a small negative contribution, while other budget terms show a strong seasonal cycle, lowest in winter, peaking in spring and slowly dropping to winter level during summer and autumn. For most of the year, the air‐sea flux is the largest term, but the storage term is important during the spring blooms. Diurnal variations of 5–10% saturation in measured oxygen levels must therefore largely reflect diurnal cycles in productivity and respiration. We estimate respiration effects from the rate of decay of O2 at night, which yields an average respiration rate of 459 mmol·m−2·day−1. This value is almost an order of magnitude larger than the other budget terms we have discussed, suggesting that a future focus on diurnal variations might provide most insight into biological processes in the Strait.
Precipitation Microphysics of Tropical Cyclones Over the Western North Pacific Based on GPM DPR Observations: A Preliminary Analysis
Authors: Huang Hao , Chen Fengjiao
Published: March 2019

Using observations from the dual‐frequency precipitation radar (DPR) onboard the Global Precipitation Measurement mission (GPM) satellite, this study analyzes the microphysical structures and processes of tropical cyclone (TC) precipitation over the western North Pacific in terms of different precipitation efficiency indices (PEIs). The statistical results show that the mean mass‐weighted mean diameter of raindrops (Dm) at 2 km is 1.67 mm (1.37 mm) for convective (stratiform) precipitating clouds. Precipitating clouds with high PEI have higher liquid water path than nonliquid water path for both convective and stratiform clouds. The mean Dm of convective and stratiform precipitation increases as the PEI increases. The vertical profiles of Dm and reflectivity (Ze) for convective and stratiform precipitating clouds in TCs differ substantially as the PEI changes. Below the melting level, there is a clear decrease (increase) in Dm and Ze toward the surface for clouds with low (high) PEI. In general, clouds within TCs producing the most efficient precipitation are characterized by strong coalescence, not only for small droplets but also for relatively large raindrops; in contrast, the breakup of hydrometeors is the dominant process in convective and stratiform precipitating clouds with low PEI. These results will help validate and improve the hydrometeor parameterization schemes in cloud and climate models.
Abundance and Diurnal Trends of Fluorescent Bioaerosols in the Troposphere over Mt. Tai, China, in Spring
Authors: Yue Siyao , Ren Lujie , Song Tianli , Li Linjie , Xie Qiaorong , Li Weijun , Kang Mingjie , Zhao Wanyu , Wei Lianfang , Ren Hong , Sun Yele , Wang Zifa , Ellam Robert Mark , Liu Cong‐Qiang , Kawamura Kimitaka , Fu Pingqing
Published: March 2019

Primary biological aerosol particles are ubiquitous in the global atmosphere and can affect cloud formation, deteriorate air quality, and cause human infections. Mt. Tai (1,534 m a.s.l.) is an elevated site in the North China Plain where atmospheric aerosols reflect both regional advection and long‐range transport. In this study, we deployed a Wideband Integrated Bioaerosol Sensor (WIBS‐4A) and collected total suspended particles and eight‐stage size‐segregated aerosol samples at the summit of Mt. Tai in spring from 21 March to 8 April 2017 to quantify the abundance, size distributions, and diurnal variations of fluorescent bioaerosols and to investigate the effect of different fluorescence thresholds of WIBS for ambient bioaerosol recognition. During the whole sampling period, the number concentration of fluorescent particles (>0.8 μm) was 647 ± 533 L−1, accounting for 26.9% ± 10.0% by number of the total particles in that size range. Three‐dimensional excitation‐emission matrix fluorescence of water‐soluble organic matter in size‐segregated aerosols shows that humic‐like substances (HULIS) are mainly in the fine mode (<2.1 μm) while protein‐like substances are mainly in the coarse mode (>2.1 μm). From the diurnal variation, it is shown that bioaerosols can undergo transformation during long‐range transport and contribute to HULIS. For bioaerosol recognition, we find that 6σ‐threshold can lead to better classification of fluorescent aerosol particles for fungal spores. Overall, our results constrain the abundance of primary bioaerosols in the troposphere over East Asia and elucidate the processes for their evolution via mountain/valley breezes and long‐range transport.
Cloud Heterogeneity in the Marine Midlatitudes: Dependence on Large‐Scale Meteorology and Implications for General Circulation Models
Authors: Loveridge Jesse , Davies Roger
Published: March 2019

We examine the sensitivity of cloud heterogeneity to large‐scale meteorology in the marine midlatitudes using satellite observations from the Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer instruments aboard the Terra satellite and nudged simulations from the UK Met Office's Global Atmosphere 7.0 (GA7) for the year 2007. Using Multiangle Imaging Spectroradiometer observations, we quantify several sources of observational uncertainty due to cloud heterogeneity such as finite‐resolution cloud fraction biases and subpixel heterogeneity. With a simple measure of cloud geometry, we show that these sources of observational uncertainty are maximized in post–cold‐frontal conditions, where scattered subpixel clouds are frequent, and are minimized in the warm sector, where subpixel clouds are infrequent. These results demonstrate the greater difficulty in interpreting remote sensing measurements in post–cold‐frontal conditions compared to quiescent or warm‐sector conditions. We show that the neglect of this observational uncertainty can qualitatively alter the interpretation of how cloud properties respond to large‐scale meteorology in GA7 and general circulation models in general. However, conservative application of the satellite data still allows robust evaluation of the simulated clouds. For overcast domains, Moderate Resolution Imaging Spectroradiometer observations show that overcast cloud heterogeneity is independent of large‐scale meteorology. However, heterogeneity increases when moving from warm sector to post‐cold‐frontal conditions in GA7. GA7 overestimates the heterogeneity of the low‐topped clouds that populate these regimes. For overcast domains, this bias is equivalent to a 15% underestimation in the mean cloud optical depth. These results suggest a systematic error in the subgrid‐scale variability parameterization, which, when corrected, will improve the simulation of the midlatitudes in GA7.
Microstructure evolution and kinetics of B-site nanoparticle exsolution from an A-site-deficient perovskite surface: a phase-field modeling and simulation study
Authors: Jiang Guang , Yan Fuyao , Wan Shuaibin , Zhang Yanxiang , Yan Mufu
Published: March 2019

The entire picture from segregation to exsolution is described, including effects of composition, PO2 and segregation energy.
Dynamic protein corona influences immune-modulating osteogenesis in magnetic nanoparticle (MNP)-infiltrated bone regeneration scaffoldsin vivo
Authors: Zhu Yue , Jiang Peipei , Luo Bin , Lan Fang , He Jing , Wu Yao
Published: March 2019

An inflammatory reaction initiates fracture healing and directly influences the osteoinductive effect of the magnetic hydroxyapatite (MHA) scaffold, but the underlying mechanism is yet to be elucidated.
Rapid and sensitive colorimetric detection of pathogens based on silver–urease interactions
Authors: Singh Pargat , Kakkar Saloni , Bharti Bharti , Kumar Rajesh , Bhalla Vijayender
Published: March 2019

Herein, we demonstrate a facile and economic approach for colorimetric detection of microbial pathogens in drinking water, employing silver–urease interactions.
Hydrogen-bonded 3D network of d10-metal halide coordination polymer containing N-(3-pyridinyl) nicotinamide: influence of ligand conformation, halide anions and solvent
Authors: Nezhadali Baghan Zahra , Salimi Alireza , Eshtiagh-Hosseini Hossein , Oliver Allen G.
Published: March 2019

The crystal structures of four new d10-metal halide coordination polymers are determined as one-dimensional (1D) zigzag chains which are in contact with each other by C/N–H⋯X (X = Cl, Br, I) hydrogen bonds.
Nano-gate opening pressures for the adsorption of isobutane, n-butane, propane, and propylene gases on bimetallic Co–Zn based zeolitic imidazolate frameworks
Authors: Awadallah-F Ahmed , Hillman Febrian , Al-Muhtaseb Shaheen A. , Jeong Hae-Kwon
Published: March 2019

In this article, zeolitic-imidazolate framework-8 (ZIF-8) and its mixed metal CoZn-ZIF-8 were synthesized via a rapid microwave method. They exhibited a nanogate opening pressure threshold for the adsorption of C3 and C4 compounds.
Mono- and dinuclear copper complexes coordinated on NNO-tridentate Schiff-base derivatives for copolymerization of cyclohexene oxide and cyclic anhydrides
Authors: Cheng Fu-Yin , Tsai Chen-Yen , Huang Bor-Hunn , Lu Kuan-Yeh , Lin Chu-Chieh , Ko Bao-Tsan
Published: March 2019

The dinuclear copper complexes 1 and 2 performed satisfactorily to produce polyesters with controllable molecular weights and high ester linkages.
Why are nanoparticles trapped at cell junctions when the cell density is high?
Authors: Yue Tongtao , Zhou Hongyu , Sun Hainan , Li Shixin , Zhang Xianren , Cao Dapeng , Yi Xin , Yan Bing
Published: March 2019

We show experimentally and theoretically that when cells are tightly packed, cellular uptake of nanoparticles is strongly hindered.
An efficient multi-doping strategy to enhance Li-ion conductivity in the garnet-type solid electrolyte Li7La3Zr2O12
Authors: Meesala Yedukondalu , Liao Yu-Kai , Jena Anirudha , Yang Nai-Hsuan , Pang Wei Kong , Hu Shu-Fen , Chang Ho , Liu Chia-Erh , Liao Shih-Chieh , Chen Jin-Ming , Guo Xiangxin , Liu Ru-Shi
Published: March 2019

A systematic multi-doping strategy to enhance Li-ion conductivity of the garnet-type Li7La3Zr2O12 by doping Ga(iii) Ba(ii) and Ta(v) ions into the garnet framework.
Highly stable lithium–sulfur batteries based on p–n heterojunctions embedded on hollow sheath carbon propelling polysulfides conversion
Authors: Zhang Han , Zhao Zongbin , Hou Ya-Nan , Tang Yongchao , Liang Jingjing , Liu Xuguang , Zhang Zhichao , Wang Xuzhen , Qiu Jieshan
Published: March 2019

The p–n typed sulfide/nitride heterostructures embedded onto carbon hollow nanosheet arrays for highly stable lithium–sulfur batteries owing to anchoring-conversion of polysulfides.
Efficient methylammonium lead trihalide perovskite solar cells with chloroformamidinium chloride (Cl-FACl) as an additive
Authors: Wu Yulei , Li Xiaodong , Fu Sheng , Wan Li , Fang Junfeng
Published: March 2019

Highly efficient and stable mixed halide perovskite (MAPbI3–xClx) solar cells are fabricated with the incorporation of chloroformamidinium chloride (Cl-FACl).
An immunochromatographic strip sensor for sildenafil and its analogues
Authors: Wang Zhongxing , Wu Xiaoling , Liu Liqiang , Xu Liguang , Kuang Hua , Xu Chuanlai
Published: March 2019

A novel Sild hapten was successfully synthesized and a sensitive anti-Sild mAb was produced based on this hapten. The immunochromatographic assay (ICA) allowed qualitative and quantitative detection of Sild and its analogues in food samples within 15 min. The ICA was successfully applied to real samples and showed a good correlation with ic-ELISA.
Secure and energy aware load balancing framework for cloud data centre networks
Authors: Singh A.K. , Kumar J.
Published: March 2019

In a cloud system, a malicious user initiates the side channel attacks to steal the private information of other users that share the computing resources through virtualisation. In this Letter, the authors propose a multi‐objective load balancing framework to minimise the likelihood of these attacks by reducing the number of shared servers along with efficient use of computing resources and power. The proposed framework significantly improves the security by reducing the shared servers up to 55.83% and improves the resource and power usage up to 96.54 and 21.97%, respectively, over best fit, first fit and random heuristic schemes.
Automatic waterline detection and 3D reconstruction in model ship tests using stereo vision
Authors: Hong S. , Kim J. , Hwang S.
Published: March 2019

The changes of the waterlines alongside ship hulls in model ship tests provide important information to estimate the resistance performance of the full‐scale ships and to improve its hull form design. This Letter presents a systematic procedure for detecting a waterline and reconstructing its three‐dimensional (3D) geometry using a stereo vision system. The proposed method utilises the information from non‐distinctive geometric features and shapes characterised in the waterline around a model ship without using any specified colours or artificial landmarks. For reconstructing the 3D geometry of the detected waterline, a vertical stereo system and a direct disparity estimation method are employed along with the consideration of uncertainties in the stereo correspondence matching. Experimental results are shown to demonstrate the feasibility of the proposed method using an image dataset obtained in a model ship test in a towing tank environment.
Polarisation independent dual‐band conformal metamaterial absorber for X‐band microwave application
Authors: Kalraiya S. , Chaudhary R.K. , Abdalla M.A. , Gangwar R.K.
Published: March 2019

A polarisation independent conformal absorber has been proposed for X‐band microwave application. The absorber unit cell consists of three resonators, which generate three absorption bands at 9.1, 11.04 and 11.44 GHz with more than 90% absorption. The full wave at half maximum bandwidth of the absorber is 320 and 720 MHz at lower and upper‐frequency bands. The absorber is conformal as it has a low‐profile flexible substrate with an ultrathin thickness of 0.01λo, where λo is the wavelength at 9.1 GHz. The proposed absorber unit cell has a fourfold symmetry, which makes the absorber polarisation independent and possesses a wide angle stability under oblique incident angle up to 50°. The absorption performance of the absorber on various radii of cylindrically curved surface has been confirmed through the simulated and measured results.
Determination of LO frequency for reception of maximum number of GNSS signals in presence of interference
Authors: Park K.W. , Park C.
Published: March 2019

A method for the frequency determination of a local oscillator (LO) is presented to facilitate reception of the maximum number of satellite signals via the use of a multi‐global navigation satellite system (GNSS) receiver under interference. The authors have herein suggested a model for estimating the number of GNSS satellites with changing LO frequency. This estimation model was derived based on GNSS and interference spectra, used to determine the LO‐frequency value to avoid interference and facilitate reception of maximum GNSS signals. The proposed method was verified by means of an experiment involving the use of software‐defined radio receiver and actual GNSS signals. The authors expect the proposed method to be the basis of anti‐interference processes in reconfigurable GNSS receivers.
Markov decision process‐based routing algorithm in hybrid Satellites/UAVs disruption‐tolerant sensing networks
Authors: Yuan Peng , Wang Ye , Su Min , Yang Zhihua , Zhang Qinyu
Published: March 2019

Recently, a hybrid remote sensing network constituted by satellites in constellation and Unmanned Aerial Vehicles (UAVs) in formation attracts a lot of interests, benefiting from the flexible architecture and excellent rapid responsiveness. Considering frequently intermittent connectivity and limited resource onboard, Disruption‐Tolerant Networking (DTN) develops a feasible solution for the remote sensing scenarios. However, the intrinsic motion models of multifarious nodes lead to deterministic or semi‐deterministic contacts, which makes finding a reliable end‐to‐end routing path for timely data delivery difficult, with typical routing strategies such as Contact Graph Routing (CGR). To cope with such routing challenge in the hybrid network, a Probabilistic Contact Graph (PCG) is designed, taking the diverse node properties into consideration. In particular, a probability prediction model for semi‐deterministic contacts between the UAV nodes is proposed, with a semi‐Markov motion model for the UAV nodes. Besides, a Markov Decision Process based Routing (MDPR) algorithm is designed to search for a feasible data transmission path with a series of hybrid deterministic and semi‐deterministic contacts. Through the numerical and experimental simulations with Interplanetary Overlay Network (ION), the proposed MDPR algorithm shows excellent routing performance concerning delivery delay and delivery ratio, compared with the typical CGR strategy.
Two‐dimensional shape‐adaptive windowing functions for image analysis
Authors: Walek Petr , Jan Jiri
Published: March 2019

Two‐dimensional (2D) windowing functions (e.g. Hann's) defined on square (or rectangular) sub‐matrices are routinely used in image processing when the local 2D Fourier transform has to be computed. However, in applications where the square‐shaped 2D Fourier transform has to be computed from a spatially limited subset of image data of irregular shape (e.g. from an area obtained by segmenting), windowing functions defined on square sub‐matrices cannot be used. Therefore, there is a need for 2D weighting functions whose support shape is adaptable to the shape of a given binary object. Several design variants of 2D shape‐adaptive windowing functions (SAW) are presented as a proposed solution to this problem. In order to quantitatively assess and compare the design variants, five criteria for measurement of 2D SAW qualities are proposed. Based on extensive testing undertaken on both simulated and real‐life data, it can be concluded that qualities of each of the proposed 2D SAW design variants are generally superior to the quality of an evenly‐weighting window according to these test criteria. In conclusion, one of these 2D SAW design variants is recommended as superior for generic use in image processing.
Maximum power extraction from a hydrokinetic energy conversion system
Authors: Michas Marios , Ugalde‐Loo Carlos E. , Ming Wenlong , Jenkins Nick , Runge Stefan
Published: March 2019

Hydrokinetic energy conversion systems capture the power available in the water flowing in waterways. An electrical interface for the power take‐off of a hydrokinetic energy conversion system was designed and a control strategy for the maximum power extraction was investigated. A laboratory prototype was used for the experimental characterisation of the system. High efficiencies were observed because of the restricted flow conditions. The power curves obtained from the experimental results were used for the simulation of the system in MATLAB/Simulink. A ‘perturb and observe’ method was used for the maximum power point tracking (MPPT). A control scheme based on a heuristic algorithm suitable for restricted and turbulent water flows was developed. A practical advantage of this scheme is that it does not require the use of mechanical sensors. The MPPT of the laboratory prototype was simulated and experimental validation undertaken, with simulation and experimental results agreeing well. The MPPT of a full‐scale hydrokinetic energy conversion system was simulated to assess its performance towards practical deployment.
Compound G2 model of coherent radar sea clutter
Authors: Bocquet Stephen
Published: March 2019

A two‐component compound Gaussian model is proposed for coherent radar sea clutter, with each component having its own spatial correlation. The slow component, centred near zero Doppler, is modulated in both frequency and intensity by gravity waves, while the fast component, offset in Doppler frequency, models scattering from breaking waves. The intensity of each component is represented by an independent gamma variate with its own scale and shape parameter, with the overall texture distributed as the sum of these two gamma variates, denoted G2. The model is compared to data collected at medium grazing angles with the DST Ingara airborne X‐band radar. It can produce realistic simulations of coherent radar sea clutter.
Comparison of point‐of‐load versus mid‐feeder compensation in LV distribution networks with high penetration of solar photovoltaic generation and electric vehicle charging stations
Authors: Akhtar Zohaib , Opatovsky Martin , Chaudhuri Balarko , Hui Shu Yuen Ron
Published: March 2019

Increasing use of distributed generation (DG), mainly roof‐top photovoltaic (PV) panels and electric vehicle (EV) charging would cause over‐ and under‐voltage problems generally at the remote sections of the low‐voltage (LV) distribution feeders. As these voltage problems are sustained for a few hours, power electronic compensators (PECs) with input voltage control, i.e. electric springs cannot be used due to the unavailability of non‐critical loads that can be subjected to non‐rated voltages for a long duration of time. However, PECs in output voltage control mode could be used to inject a controllable series voltage either somewhere on the feeder (mid‐feeder compensation, MFC) or between the feeder and each customer (point‐of‐load compensation, PoLC) both of which are effective in tackling the voltage problem without disrupting PV power output and EV charging. In this study, a comparison between the MFC and PoLC option is presented in terms of their voltage control capability, required compensator capacity, network losses, PV throughput, and demand response capability. The criteria for selection of the optimal location of these compensators are also discussed. Stochastic demand profile for different types of residential customers in the UK and a typical European LV network is used for the case study.
Multiband signal acquisition using improved modulated wideband converter
Authors: Cai Changxin , Wen Fangqing , Huang Dongmei
Published: March 2019

In this study, the authors stress the problem of sampling and recovering sparse wideband signals. A new methodology for sparse multiband signal acquisition using sinusoidal frequency modulation (SMF) multiplier‐based modulated wideband converter (MWC) is presented. The harmonic property of the SMF signals enables sparse multiband signal to be precisely recovered from the sub‐Nyquist measurements without any high‐speed devices. The proposed architecture offers very close recovery accuracy to the existing pseudorandom binary sequences (PRBS)‐based MWC in the absence of the prior knowledge of sparse wideband signals, while it provides more accurate recovery performance than the PRBS‐MWC in the presence of prior information concerning sparsity. Besides, the proposed architecture is easier for hardware implementation than the PRBS‐MWC. The experimental results demonstrate the effectiveness of the proposed scheme.
Biosynthesis, characterisation and antibacterial activity of Mikania micrantha leaf extract‐mediated AgNPs
Authors: Biswas Aayushi , Vanlalveni Chhangte , Adhikari Partha Pradip , Lalfakzuala Ralte , Rokhum Lalthazuala
Published: March 2019

In the present years, nanobiotechnology has to turn out to be an important division of research. Here, this work reported a novel Mikania micrantha leaf extract‐mediated silver nanoparticle (AgNP) under room temperature condition. The biosynthesised AgNPs were further characterised by various analysis techniques such as ultraviolet–visible spectrophotometer, Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and transmission electron microscope (TEM) energy‐dispersive X‐ray spectroscopy. The formation of AgNPs was confirmed by XRD spectrum which displayed intense peaks corresponding to the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) lattice planes of Ag. The plant extracts stirred with Ag nitrate solution gradually changes its colour from light yellow to dark brown. The biogenic AgNPs were mostly spherical in shape with varying sizes ranging from 5 to 20 nm, as evident by TEM analysis. FT‐IR spectra of the extract revealed the presence of amide I and amide II bonds of the proteins. The synthesised AgNPs showed excellent activity results against various Gram‐positive and Gram‐negative bacterial strains.