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Plasmonic metamaterial absorbers are particularly important in different applications such as photodetectors, microbolometers and solar cells. In this paper, we propose a tungsten boride (WB, a refractory ceramic) based broadband metamaterial absorber whose optical properties is numerically analyzed and experimentally characterized. We have also analyzed the damage characteristics of this absorber using a femtosecond laser and compared with an ordinary Au metamaterial absorber. We observe that WB has almost the double absorption bandwidth with absorption more than 90% over the spectral range of 950 to 1400 nm when compared with the Au counterpart. Furthermore, we show that Au metamaterial is damaged at the power of around 36.4 mW whereas WB metamaterial is not damaged at that power (WB has high Tammann temperature than Au)-however the atom of WB material was knocked off by the bombardment of a femtosecond laser.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Rapid histopathological evaluation of fresh, unfixed human tissue using optical sectioning microscopy would have applications to intraoperative surgical margin assessment. Microscopy with ultraviolet surface excitation (MUSE) is a low-cost optical sectioning technique using ultraviolet illumination which limits fluorescence excitation to the specimen surface. In this paper, we characterize MUSE using high incident angle, water immersion illumination to improve sectioning. Propidium iodide is used as a nuclear stain and eosin yellow as a counterstain. Histologic features of specimens using MUSE, nonlinear microscopy (NLM) and conventional hematoxylin and eosin (H&E) histology were evaluated by pathologists to assess potential application in Mohs surgery for skin cancer and lumpectomy for breast cancer. MUSE images of basal cell carcinoma showed high correspondence with frozen section H&E histology, suggesting that MUSE may be applicable to Mohs surgery. However, correspondence in breast tissue between MUSE and paraffin embedded H&E histology was limited due to the thicker optical sectioning in MUSE, suggesting that further development is needed for breast surgical applications. We further demonstrate that the transverse image resolution of MUSE is limited by the optical sectioning thickness and use co-registered NLM to quantify the improvement in MUSE optical sectioning from high incident angle water immersion illumination.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Depressive disorder (DD) is a mental illness affecting more than 300 million people worldwide, whereas social stigma and subtle, variant symptoms impede diagnosis. Psychomotor retardation is a common component of DD with a negative impact on motor function, usually reflected on patients’ routine activities, including, nowadays, their interaction with mobile devices. Therefore, such interactions constitute an enticing source of information towards unsupervised screening for DD symptoms in daily life. In this vein, this paper proposes a machine learning-based method for discriminating between subjects with depressive tendency and healthy controls, as denoted by self-reported Patient Health Questionnaire-9 (PHQ-9) compound scores, based on typing patterns captured in-the-wild. The latter consisted of keystroke timing sequences and typing metadata, passively collected during natural typing on touchscreen smartphones by 11/14 subjects with/without depressive tendency. Statistical features were extracted and tested in univariate and multivariate classification pipelines to reach a decision on subjects’ status. The best-performing pipeline achieved an AUC = 0.89 (0.72–1.00; 95% Confidence Interval) and 0.82/0.86 sensitivity/specificity, with the outputted probabilities significantly correlating (>0.60) with the respective PHQ-9 scores. This work adds to the findings of previous research associating typing patterns with psycho-motor impairment and contributes to the development of an unobtrusive, high-frequency monitoring of depressive tendency in everyday living.

Replacing platinum (Pt) metal-based electrocatalysts used in the oxygen reduction reaction (ORR) in fuel cells is an important research topic due to the high cost and scarcity of Pt, which have restricted the commercialization of these clean-energy technologies. The ABO3-type perovskite family of an ACu3Ti4O12 (A = Ca, Y, Bi, and La) polycrystalline material can serve as an alternative electrocatalyst for the ORR in terms of low-cost, activity, and stability. These perovskite materials may be considered the next generation electro-catalyst for the ORR because of their photocatalytic activity and physical and chemical properties capable of containing a wide range of A- and B-site metals. This paper reports the ORR activity of a new Y2/3Cu3Ti4O12 perovskite, synthesized via a rapid and facile automatic flame synthesis technique using rotating disk electrode (RDE) measurements. Y2/3Cu3Ti4O12/C has superior ORR activity, stability, and durability compared to commercial Pt/C. The results presented in this article will provide the future perspectives to research based on ACu3Ti4O12 (A = Ca, Y, Bi, Sm, Cd, and La) perovskite as the next generation electro-catalyst for the ORR in various electrochemical devices, such as fuel cells, metal–air batteries, and electrolysis.

SuperAbsorbent Polymers (SAPs) can be applied as an admixture in cementitious materials. As the polymers are able to swell, they will absorb part of the mixing water and can then release that water back towards the cementitious matrix for internal curing. This is interesting in terms of autogenous shrinkage mitigation as the internal relative humidity is maintained. The mechanism is theoretically described by the Powers and Brownyard model, but the kinetics and water release still remain subject of detailed investigation. This paper uses Nuclear Magnetic Resonance (NMR) to study the release of water from the superabsorbent polymers towards the cementitious matrix during cement hydration. The release of water by the SAPs is monitored as a function of time and degree of hydration. The internal humidity is also monitored in time by means of sensitive relative-humidity sensors.

The Dirac-like cone dispersion of the photonic crystal induced by the three-fold accidental degeneracy at the Brillouin center is calculated in this paper. Such photonic crystals can be mapped to zero-refractive-index materials at the vicinity of the Dirac-like point frequency, and utilized to construct beam splitter of high transmission efficiency. The splitting ratio is studied as a function of the position of the input/output waveguides. Furthermore, variant beam splitters with asymmetric structures, bulk defects, and some certain bending angles are numerically simulated. Finally, we show that 1 × 2 to 1 × N beam splitting can be realized with high transmission efficiency in such a zero-refractive-index photonic crystal at the frequency of Dirac-like point. The proposed structure could be a fundamental component of the high density photonic integrated circuit technique.

In-situ exploration and remote thermal infrared observation revealed that a large fraction of Solar System small bodies should be covered with granular regolith. The complex and varied geology of the regolith layer may preserve the historical records of the surface modification and topographic evolution experienced by asteroids, especially cratering processes, in which the projectile shape plays a crucial role. Regarding the impact sampling scheme, the projectile-shape dependence of both the cavity morphology and the collected mass remains to be explored. This paper studies the process of the low-speed impact sampling on granular regolith using projectiles of different shapes. The results demonstrate that the projectile shape significantly influences the excavation stage, forming cavities with different morphologies, i.e., cone-shaped, bowl-shaped and U-shaped. We further indicate that the different velocity distributions of the ejecta curtains due to the various projectile shapes result in various amounts of collected mass in sampler canister, regarding which the 60° conical projectile exhibits preferable performance for impact sampling scheme. The results presented in this article are expected to reveal the dependence of the excavation process on projectile shape under micro gravity and provide further information on the optimal designs of impact sampling devices for future sample-return space missions.

Inappropriate use of ethanol (EtOH) had led to noticeable health problems, but a beneficial phenomenon was found that EtOH displayed unique influences for toxic trans-crotonaldehyde (TCA) derived from mitochondrial lipid peroxidation. The influences of EtOH on the structure of TCA were systematically probed by UV-vis & Raman spectroscopy in the absence and presence of mitochondria, respectively. The maximum UV-vis peak at 301 nm of TCA was red shifted by hydroxyl (-OH) and methyl (-CH3) of EtOH, respectively. Raman stretching band of aldehyde (-CH=O) of TCA (TCA-CH=O) was split by the -CH3 of EtOH. The -CH3 increased TCA-CH=O stretching frequency while the -OH induced it. The more exposed -OH, the less stretching frequency. The ectopic -CH3 red shifted the UV-vis peak at 301 nm and Raman band of TCA-CH=O. In mitochondria, EtOH red shifted Raman stretching band of TCA-CH=O. Raman stretching bands of C-H, C-O and C-C of EtOH were red shifted, while Raman stretching bands of -CH2 and C-C-O of EtOH disappeared. The paper unearths the influences of EtOH to trap and transform the structure of TCA-CH=O. This discovery has an important contribution to eliminate TCA in order to protect and repair mtDNA by means of the decrease of 8-oxoG.

We introduce high-performance metal mesh/graphene hybrid transparent conductive layers (TCLs) using prime-location and metal-doped graphene in near-ultraviolet light-emitting diodes (NUV LEDs). Despite the transparency and sheet resistance values being similar for hybrid TCLs, there were huge differences in the NUV LEDs’ electrical and optical properties depending on the location of the graphene layer. We achieved better physical stability and current spreading when the graphene layer was located beneath the metal mesh, in direct contact with the p-GaN layer. We further improved the contact properties by adding a very thin Au mesh between the thick Ag mesh and the graphene layer to produce a dual-layered metal mesh. The Au mesh effectively doped the graphene layer to create a p-type electrode. Using Raman spectra, work function variations, and the transfer length method (TLM), we verified the effect of doping the graphene layer after depositing a very thin metal layer on the graphene layers. From our results, we suggest that the nature of the contact is an important criterion for improving the electrical and optical performance of hybrid TCLs, and the method of doping graphene layers provides new opportunities for solving contact issues in other semiconductor devices.

In this paper, the lattice Boltzmann method (LBM) is employed to simulate wave propagation in viscous media. LBM is a kind of microscopic method for modelling waves through tracking the evolution states of a large number of discrete particles. By choosing different relaxation times in LBM experiments and using spectrum ratio method, we can reveal the relationship between the quality factor Q and the parameter τ in LBM. A two-dimensional (2D) homogeneous model and a two-layered model are tested in the numerical experiments, and the LBM results are compared against the reference solution of the viscoacoustic equations based on the Kelvin-Voigt model calculated by finite difference method (FDM). The wavefields and amplitude spectra obtained by LBM coincide with those by FDM, which demonstrates the capability of the LBM with one relaxation time. The new scheme is relatively simple and efficient to implement compared with the traditional lattice methods. In addition, through a mass of experiments, we find that the relaxation time of LBM has a quantitative relationship with Q. Such a novel scheme offers an alternative forward modelling kernel for seismic inversion and a new model to describe the underground media.

We confirm in this paper that Trichel pulse of negative corona is a common phenomenon that can occur in various gases rather than only in electronegative gases as considered in the last 70 years since G W Trichel firstly reported. Trichel pulse is exactly a mode transition between low-current Townsend and high-current normal glow regime, two pulseless stages of negative corona with different operating conditions and ion flux threshold. The rising of the pulse corresponds to the breakdown and formation of temporal glow discharge, the decay corresponds to the destroy of temporal sheath, and the interval (or repetition frequency of pulses) is determined by the re-building of the positive ion cloud to enhance significantly the local electric field for glow discharge to form again. The positive ions play a predominant role for the pulse formation and the mode transition, while the negative ions in electronegative gas are not necessary even if they affect greatly the pulsing process.

In order to investigate the time-dependent cross-correlations of fine particulate (PM2.5) series among neighboring cities in Northern China, in this paper, we propose a new cross-correlation coefficient, the time-lagged q-L dependent height crosscorrelation coefficient (denoted by p q (τ, L)), which incorporates the time-lag factor and the fluctuation amplitude information into the analogous height cross-correlation analysis coefficient. Numerical tests are performed to illustrate that the newly proposed coefficient ρ q (τ, L) can be used to detect cross-correlations between two series with time lags and to identify different range of fluctuations at which two series possess cross-correlations. Applying the new coefficient to analyze the time-dependent cross-correlations of PM2.5 series between Beijing and the three neighboring cities of Tianjin, Zhangjiakou, and Baoding, we find that time lags between the PM2.5 series with larger fluctuations are longer than those between PM2.5 series withsmaller fluctuations. Our analysis also shows that cross-correlations between the PM2.5 series of two neighboring cities are significant and the time lags between two PM2.5 series of neighboring cities are significantly non-zero. These findings providenew scientific support on the view that air pollution in neighboring cities can affect one another not simultaneously but with a time lag.

Traditional radiomics models mainly rely on explicitly-designed handcrafted features from medical images. This paper aimed to investigate if deep features extracted via transfer learning can generate radiomics signatures for prediction of overall survival (OS) in patients with Glioblastoma Multiforme (GBM). This study comprised a discovery data set of 75 patients and an independent validation data set of 37 patients. A total of 1403 handcrafted features and 98304 deep features were extracted from preoperative multi-modality MR images. After feature selection, a six-deep-feature signature was constructed by using the least absolute shrinkage and selection operator (LASSO) Cox regression model. A radiomics nomogram was further presented by combining the signature and clinical risk factors such as age and Karnofsky Performance Score. Compared with traditional risk factors, the proposed signature achieved better performance for prediction of OS (C-index = 0.710, 95% CI: 0.588, 0.932) and significant stratification of patients into prognostically distinct groups (P

We investigated cytosolic calcium (Ca2+) and sarcoplasmic reticulum Ca2+ regulation in skeletal muscle fibers of hibernating Daurian ground squirrels (Spermophilus dauricus), non-hibernating hindlimb-unloaded (HLU) squirrels, and HLU rats to clarify the molecular mechanisms involved in preventing muscle atrophy in hibernators. The Na+, K+-ATPase and Ca2+-ATPase activities in the soleus muscle (SOL) of squirrels were maintained in hibernation, decreased during interbout arousal (IB-A), and increased to autumn/pre-hibernation (AUT/Pre-H) levels in torpor after interbout arousal (Post-IBA), whereas activities in the extensor digitorum longus muscle (EDL) were stable during hibernation, but increased during post-hibernation (Post-H). Activities increased in the SOL of HLU rats, but were stable in HLU squirrels. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity in the SOL decreased in IB-A squirrels, but returned to AUT/Pre-H levels in the Post-IBA group; no significant changes were found in the EDL. SERCA activity increased in the EDL of HLU squirrels and SOL of HLU rats. Compared with AUT/Pre-H, SERCA type 2 protein expression increased in the SOL and EDL of IB-A and Post-IBA squirrels, but increased in the SOL only in HLU animals. We also describe the protein kinase A changes in this paper. Thus, hibernating ground squirrels displayed remarkable Na+, K+-ATPase, Ca2+-ATPase, and SERCA plasticity.

Because radiation is harmful to patients, it is important to reduce X-ray exposure in the clinic. For CT, reconstructions from sparse views or limited angle tomography are being used more frequently for low dose imaging. However, insufficient sampling data causes severe streak artifacts in images reconstructed using conventional methods. To solve this issue, various methods have recently been developed. In this paper, we improve a statistical iterative algorithm based on the minimization of the image total variation (TV) for sparse or limited projection views during CT image reconstruction. Considering the statistical nature of the projection data, the TV is performed under a penalized weighted least-squares (PWLS-TV) criterion. During implementation of the proposed method, the image reconstructed using the filtered back-projection (FBP) method is used as the initial value of the first iteration. Next, the feature refinement (FR) step is performed after each PWLS-TV iteration to extract the fine features lost in the TV minimization, which we refer to as ‘PWLS-TV-FR’.

As an ancient protein family, the WD40 repeat proteins often play essential roles in fundamental cellular processes in eukaryotes. Although investigations of eukaryotic WD40 proteins have been frequently reported, prokaryotic ones remain largely uncharacterized. In this paper, we report a systematic analysis of prokaryotic WD40 proteins and detailed comparisons with eukaryotic ones. About 4,000 prokaryotic WD40 proteins have been identified, accounting for 6.5% of all WD40s. While their abundances are less than 0.1% in most prokaryotes, they are enriched in certain species from Cyanobacteria and Planctomycetes, and participate in various functions such as prokaryotic signal transduction and nutrient synthesis. Comparisons show that a higher proportion of prokaryotic WD40s tend to contain multiple WD40 domains and a large number of hydrogen bond networks. The observation that prokaryotic WD40 proteins tend to show high internal sequence identity suggests that a substantial proportion of them (~20%) should be formed by recent or young repeat duplication events. Further studies demonstrate that the very young WD40 proteins, i.e., Highly-Repetitive WD40s, should be of higher stability. Our results have presented a catalogue of prokaryotic WD40 proteins, and have shed light on their evolutionary origins.

The current economics of the fish protein industry demand rapid, accurate and expressive prediction algorithms at every step of protein production especially with the challenge of global climate change. This help to predict and analyze functional and nutritional quality then consequently control food allergies in hyper allergic patients. As, it is quite expensive and time-consuming to know these concentrations by the lab experimental tests, especially to conduct large-scale projects. Therefore, this paper introduced a new intelligent algorithm using adaptive neuro-fuzzy inference system based on whale optimization algorithm. This algorithm is used to predict the concentration levels of bioactive amino acids in fish protein hydrolysates at different times during the year. The whale optimization algorithm is used to determine the optimal parameters in adaptive neuro-fuzzy inference system. The results of proposed algorithm are compared with others and it is indicated the higher performance of the proposed algorithm.

In this paper, we present a knowledge diffusion (SKD) model for dynamic networks by taking into account the interaction frequency which always used to measure the social closeness. A set of agents, which are initially interconnected to form a random network, either exchange knowledge with their neighbors or move toward a new location through an edge-rewiring procedure. The activity of knowledge exchange between agents is determined by a knowledge transfer rule that the target node would preferentially select one neighbor node to transfer knowledge with probability p according to their interaction frequency instead of the knowledge distance, otherwise, the target node would build a new link with its second-order neighbor preferentially or select one node in the system randomly with probability 1 − p. The simulation results show that, comparing with the Null model defined by the random selection mechanism and the traditional knowledge diffusion (TKD) model driven by knowledge distance, the knowledge would spread more fast based on SKD driven by interaction frequency. In particular, the network structure of SKD would evolve as an assortative one, which is a fundamental feature of social networks. This work would be helpful for deeply understanding the coevolution of the knowledge diffusion and network structure.

In this paper, we report the analysis of a concentric circular ring plasmonic optical antenna (POA) array using a simple lumped coupled circuit (LCC) model. The currents in the circular rings of the POA array and their mutual couplings are analyzed using the LCC model. The results agree well with the numerical simulation using CST’s Microwave Studio®. The LCC model reveals the mutual couplings between the antenna rings. It is found that the mutual couplings are not only between the adjacent antenna rings, but also involve their second (2nd) nearest or farther neighbors. Since the near-fields of the optical antennas are related to the currents in the optical antennas, the LCC model provides a useful tool for the analysis of the near-field and their mutual interactions in the circular ring POA array.

Urban green spaces provide various ecosystem services, especially cultural services. Previous assessment methods depend either on hypothetic payments for ecosystems or real payments not directly related to ecosystems. In this paper, we established a method for assessing the cultural ecosystem services in any location in urban area using only two variables, green space (ecosystem) and land rent (real payment). We integrated the cultural and the regulating services into the total ecosystem services because urban green spaces provide almost no provisioning services. Results showed that the same area of green spaces near the center provided much higher cultural services than that near the urban edge; the regulating services accounted for 5% to 40% of the total ecosystem services from the center to the edge of urban area; along the center-edge gradient, there was a threshold out which the ecosystem services were lower than the maintenance cost of green spaces.

The structural stability and mechanical integrity of boron nitride nanotubes (BNNTs) in high temperature environments are of importance in pursuit of their applications that are involved with extreme thermal processing and/or working conditions, but remain not well understood. In this paper, we perform an extensive study of the impacts of high temperature exposure on the structural and mechanical properties of BNNTs with a full structural size spectrum from nano- to micro- to macro-scale by using a variety of in situ and ex situ material characterization techniques. Atomic force microscopy (AFM) and high resolution transmission electron microscopy measurements reveal that the structures of individual BNNTs can survive at up to 850 °C in air and capture the signs of their structural degradation at 900 °C or above. In situ Raman spectroscopy measurements reveal that the BN bonds in BNNT micro-fibrils undergo substantial softening at elevated temperatures of up to 900 °C. The AFM-based nanomechanical compression measurements demonstrate that the mechanical integrity of individual BNNTs remain intact after being thermally baked at up to 850 °C in air. The studies reveal that BNNTs are structurally and mechanically stable materials in high temperature environments, which enables their usages in high temperature applications.

Multispectral imaging (MSI) creates a series of en-face fundus spectral sections by leveraging an extensive range of discrete monochromatic light sources and allows for an examination of the retina’s early morphologic changes that are not generally visible with traditional fundus imaging modalities. An Ophthalmologist’s interpretation of MSI images is commonly conducted by qualitatively analyzing the spectral consistency between degenerated areas and normal ones, which characterizes the image variation across different spectra. Unfortunately, an ophthalmologist’s interpretation is practically difficult considering the fact that human perception is limited to the RGB color space, while an MSI sequence contains typically more than ten spectra. In this paper, we propose a method for measuring the spectral inconsistency of MSI images without supervision, which yields quantitative information indicating the pathological property of the tissue. Specifically, we define mathematically the spectral consistency as an existence of a pixel-specific latent feature vector and a spectrum-specific projection matrix, which can be used to reconstruct the representative features of pixels. The spectral inconsistency is then measured using the number of latent feature vectors required to reconstruct the representative features in practice. Experimental results from 54 MSI sequences show that our spectral inconsistency measurement is potentially invaluable for MSI-based ocular disease diagnosis.

Measurement-device-independent quantum key distribution (MDI-QKD) with the active decoy state method can remove all detector loopholes, and resist the imperfections of sources. But it may lead to side channel attacks and break the security of QKD system. In this paper, we apply the passive decoy state method to the MDI-QKD based on polarization encoding mode. Not only all attacks on detectors can be removed, but also the side channel attacks on sources can be overcome. We get that the MDI-QKD with our passive decoy state method can have a performance comparable to the protocol with the active decoy state method. To fit for the demand of practical application, we discuss intensity fluctuation in the security analysis of MDI-QKD protocol using passive decoy state method, and derive the key generation rate for our protocol with intensity fluctuation. It shows that intensity fluctuation has an adverse effect on the key generation rate which is non-negligible, especially in the case of small data size of total transmitting signals and long distance transmission. We give specific simulations on the relationship between intensity fluctuation and the key generation rate. Furthermore, the statistical fluctuation due to the finite length of data is also taken into account.

Atmospheric aerosol particles (especially particles with aerodynamic diameters equal to or less than 2.5 μm, called PM2.5) can affect the surface energy balance and atmospheric heating rates and thus may impact the intensity of urban heat islands. In this paper, the effect of fine particles on the urban heat island intensity in Nanjing was investigated via the analysis of observational data and numerical modelling. The observations showed that higher PM2.5 concentrations over the urban area corresponded to lower urban heat island (UHI) intensities, especially during the day. Under heavily polluted conditions, the UHI intensity was reduced by up to 1 K. The numerical simulation results confirmed the weakening of the UHI intensity due to PM2.5 via the higher PM2.5 concentrations present in the urban region than those in the suburban areas. The effects of the fine particles on the UHI reduction were limited to the lowest 500–1000 m. The daily range of the surface air temperature was also reduced by up to 1.1 K due to the particles’ radiative effects. In summary, PM2.5 noticeably impacts UHI intensity, which should be considered in future studies on air pollution and urban climates.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

In this paper, a novel explanation on high directive emission of Fabry-Perot resonator antenna with subwavelength metasurface is proposed. Based on image theory and effective constitutive parameter retrieval, the whole Fabry-Perot resonant cavity structure composed of a single-layer metasurface with square ring element and a PEC ground plate can be acted as an effective metamaterial media with very low refractive index (near zero index). According to Snell’s theory, this property can be used to enhance the directive emission. Based on this, with tapered size square ring unitcell, the overlapped bandwidth in which the effective refractive index is near to zero is obtained to widen the bandwidth of high directive emission. It is demonstrated that the maximum of directivity is nearly approaching to 19 dBi, and its 3-dB bandwidth can be improved to 19.5%. A final prototype has been fabricated and measured to validate the proposed design concept. The measured 3-dB gain bandwidth is approximately 20.3% with a peak gain of 17.9 dBi. These results indicate the feasibility of such kind of antenna for broadband and high directivity applications simultaneously.

An extended atomic data base with sufficiently high precision is required in astrophysics studies and the energy researches. For example, there are “infinite” energy levels in discrete energy region as well as overlapping resonances in autoionization region. We show in this paper the merits of our relativistic eigenchannel R-matrix method R-R-Eigen based on the analytical continuation properties of scattering matrices for the calculations of the energy levels, overlapping resonances and the related transitions. Using Ne+ as an illustration example, the scattering matrices of Ne+ in both discrete and continuum energy regions are calculated by our R-R-Eigen method directly. Based on our proposed projected high dimensional quantum-defect graph (symmetrized), one can readily determine the accuracies of the calculated scattering matrices using the experimental energy levels in a systematical way. The calculated resonant photoionization cross sections in the autoionization region are in excellent agreement with the benchmark high resolution experiments. With the scattering matrices checked/calibrated against spectroscopy data in both discrete and continuum energy regions, the relevant dynamical processes should be calculated with adequate accuracies. It should then satisfy the needs of the astrophysical and energy researches.

Engineering the compositional gradient for core/shell semiconductor nanocrystals improves their optical properties. To date, however, the structure of graded core/shell nanocrystal emitters has only been qualitatively described. In this paper, we demonstrate an approach to quantify nanocrystal structure, selecting graded Ag-In-Se/ZnSe core/shell nanocrystals as a proof-of-concept material. A combination of multi-energy small-angle X-ray scattering and electron microscopy techniques enables us to establish the radial distribution of ZnSe with sub-nanometer resolution. Using ab initio shape-retrieval analysis of X-ray scattering spectra, we further determine the average shape of nanocrystals. These results allow us to generate three-dimensional, atomistic reconstructions of graded core/shell nanocrystals. We use these reconstructions to calculate solid-state Zn diffusion in the Ag-In-Se nanocrystals and the lattice mismatch between nanocrystal monolayers. Finally, we apply these findings to propose design rules for optimal shell structure and record-luminescent core/shell nanocrystals., Scientific Reports, 7, ISSN:2045-2322

Fourier single-pixel imaging (FSI) employs Fourier basis patterns for encoding spatial information and is capable of reconstructing high-quality two-dimensional and three-dimensional images. Fourier-domain sparsity in natural scenes allows FSI to recover sharp images from undersampled data. The original FSI demonstration, however, requires grayscale Fourier basis patterns for illumination. This requirement imposes a limitation on the imaging speed as digital micro-mirror devices (DMDs) generate grayscale patterns at a low refreshing rate. In this paper, we report a new strategy to increase the speed of FSI by two orders of magnitude. In this strategy, we binarize the Fourier basis patterns based on upsampling and error diffusion dithering. We demonstrate a 20,000 Hz projection rate using a DMD and capture 256-by-256-pixel dynamic scenes at a speed of 10 frames per second. The reported technique substantially accelerates image acquisition speed of FSI. It may find broad imaging applications at wavebands that are not accessible using conventional two-dimensional image sensors.

Quantum coherence as an important quantum resource plays a key role in quantum theory. In this paper, using entropy-based measures, we investigate the relations between quantum correlated coherence, which is the coherence between subsystems [K. C. Tan, H. Kwon, C. Y. Park, and H. Jeong, Phys. Rev. A 94, 022329 (2016)], and two main kinds of quantum correlations as defined by quantum discord as well as quantum entanglement. In particular, we show that quantum discord and quantum entanglement can be well characterized by quantum correlated coherence. Moreover, we prove that the entanglement measure formulated by quantum correlated coherence is lower and upper bounded by the relative entropy of entanglement and the entanglement of formation, respectively, and equal to the relative entropy of entanglement for maximally correlated states., 15 pages

Stanene is a single layer of tin atoms which has been discovered as an emerging material for quantum spin Hall related applications. In this paper, we present an accurate tight-binding model for single layer stanene near the Fermi level. We parameterized the onsite and hopping energies for the nearest, second nearest, and third nearest neighbor tight-binding method, both without and with spin orbital coupling. We derived the analytical solution for the $$\overrightarrow{{\boldsymbol{\Gamma }}}$$ Γ → and $$\overrightarrow{{\boldsymbol{K}}}$$ K → points and numerically investigated the buckling effect on the material electronic properties. In these points of the reciprocal space, we also discuss a corresponding $$\overrightarrow{{\boldsymbol{k}}}\cdot \overrightarrow{{\boldsymbol{p}}}$$ k → ⋅ p → description, obtaining the value of the $$\overrightarrow{{\boldsymbol{k}}}\cdot \overrightarrow{{\boldsymbol{p}}}$$ k → ⋅ p → parameters both analytically from the tight-binding ones, and numerically, fitting the ab-initio dispersion relations. Our models provide a foundation for large scale atomistic device transport calculations.

In this paper, we investigate a stochastic hybrid switching DS-I-A epidemic model. The extinction and the prevalence of the disease are discussed, and so, the threshold is given. Furthermore, the sufficient conditions for the existence of positive recurrence of the solutions are established by stochastic Lyapunov functions. At last, some examples and simulations are provided to illustrate our results.

Direct growth of graphene integrated into electronic devices is highly desirable but difficult due to the nominal ~1000 °C chemical vapor deposition (CVD) temperature, which can seriously deteriorate the substrates. Here we report a great reduction of graphene CVD temperature, down to 50 °C on sapphire and 100 °C on polycarbonate, by using dilute methane as the source and molten gallium (Ga) as catalysts. The very low temperature graphene synthesis is made possible by carbon attachment to the island edges of pre-existing graphene nuclei islands, and causes no damages to the substrates. A key benefit of using molten Ga catalyst is the enhanced methane absorption in Ga at lower temperatures; this leads to a surprisingly low apparent reaction barrier of ~0.16 eV below 300 °C. The faster growth kinetics due to a low reaction barrier and a demonstrated low-temperature graphene nuclei transfer protocol can facilitate practical direct graphene synthesis on many kinds of substrates down to 50–100 °C. Our results represent a significant progress in reducing graphene synthesis temperature and understanding its mechanism.

The development of methods for obtaining new materials with antimicrobial properties, based on green chemistry principles has been a target of research over the past few years. The present paper describes the phyto-mediated synthesis of metallic nano-architectures (gold and silver) via an ethanolic extract of Melissa officinalis L. (obtained by accelerated solvent extraction). Different analytic methods were applied for the evaluation of the extract composition, as well as for the characterization of the phyto-synthesized materials. The cytogenotoxicity of the synthesized materials was evaluated by Allium cepa assay, while the antimicrobial activity was examined by applying both qualitative and quantitative methods. The results demonstrate the synthesis of silver nanoparticles (average diameter 13 nm) and gold nanoparticles (diameter of ca. 10 nm); the bi-metallic nanoparticles proved to have a core-shell flower-like structure, composed of smaller particles (ca. 8 nm). The Ag nanoparticles were found not active on nuclear DNA damage. The Au nanoparticles appeared nucleoprotective, but were aggressive in generating clastogenic aberrations in A. cepa root meristematic cells. Results of the antimicrobial assays show that silver nanoparticles were active against most of the tested strains, as the lowest MIC value being obtained against B. cereus (approx. 0.0015 mM).

This paper addresses whether a tropical cyclone can trigger the onset of the South China Sea (SCS) summer monsoon (SM). We conducted a statistical analysis of tropical cyclones (TCs) generated over the western North Pacific (WNP) between late-April and May. The results showed that there were cases in which TCs were generated before the onset of the SCSSM, accounting for 43.2% of the TCs generated during this season. This study examined a representative case, Super Typhoon Chanchu (0601), which was determined to be influential in the onset of the SCSSM. With a northwestward track, Chanchu brought strong convection and westerly winds to the SCS on 12 May, which triggered the intrusion of the southwesterly winds from the Bay of Bengal and the eastward retreat of the western Pacific subtropical high. Super Typhoon Chanchu provides an example in which a TC triggered the onset of the SCSSM. The negative correlation between the onset date of the SCSSM and the number of TCs generated over the WNP used to be interpreted as the influence of the monsoon trough on TC genesis. This work provides a supplementary illustration that this relationship also includes the impact of TCs on the onset of the SCSSM.

In this paper we show the first broad experimental confirmation of the basin stability approach. The basin stability is one of the sample-based approach methods for analysis of the complex, multidimensional dynamical systems. We show that investigated method is a reliable tool for the analysis of dynamical systems and we prove that it has a significant advantages which make it appropriate for many applications in which classical analysis methods are difficult to apply. We study theoretically and experimentally the dynamics of a forced double pendulum. We examine the ranges of stability for nine different solutions of the system in a two parameter space, namely the amplitude and the frequency of excitation. We apply the path-following and the extended basin stability methods (Brzeski et al., Meccanica 51(11), 2016) and we verify obtained theoretical results in experimental investigations. Comparison of the presented results show that the sample-based approach offers comparable precision to the classical method of analysis. However, it is much simpler to apply and can be used despite the type of dynamical system and its dimensions. Moreover, the sample-based approach has some unique advantages and can be applied without the precise knowledge of parameter values.

Short-wavelength luminescence is essential for high-performance optoelectronic device applications. There have been efforts to obtain intense ultraviolet (UV) emission by encapsulating ZnO one-dimensional (1D) nanostructures with materials such as ZnS. However, the encapsulation of ZnS 1D nanostructures with ZnO has not been reported. In this paper, we report ultraintense UV emission from ZnS nanorods coated with ZnO, i.e., ZnS-core/ZnO-shell nanorods. UV emission from the ZnS-core/ZnO-shell nanorods was much more intense than that obtained from the extensively studied ZnO-core/ZnS-shell nanorods. The highest intensity of the near-band-edge emission from the ZnS-core/ZnO-shell nanorods was obtained with a ZnO shell layer thickness of 35 nm, which is ∼16 times higher than that of pristine ZnS nanorods. Moreover, the deep level (DL) emission was suppressed completely. The substantial enhancement of the UV emission from the ZnS nanorods and the complete suppression of the DL emission by ZnO sheathing can be rationalized by combining the following four effects: the reinforcement of the UV emission by the overlap of the UV emissions from the ZnS core and ZnO shell, enhancement of the emission from the ZnO shell by the carrier transfer from the ZnS core to the ZnO shell, suppression of the capture of carriers by the surface states on the ZnS surface, and suppression of the visible emission and nonradiative recombination in ZnS.

In this paper, we propose to use multi-folded transformation optics method to design a non-contact illusion device that can distantly and freely manipulate the radiation behavior of antenna located at a certain distance and such manipulation is enabled by the use of mapped electromagnetic medium coated with the transformed medium. The proposed design aims to achieve the radiation pattern of our choice from the antenna that does not possess any electromagnetic medium. Based on this, the functionality of parabolic antenna is distantly achieved from the point source. We further extended our idea to array of antennas in which the proposed device distantly makes the linear array of antennas behave like a geometrically different array of antennas. Our work extends the concept of illusion optics for active scatterer that will be very helpful for future antenna design.

On account of the disturbance from the distribution phase, the concentration-time curve of drugs cannot fully reflect the characteristics of elimination, and thus, it is difficult for present methods to obtain ideal pharmacokinetic parameters. This paper presents a method to determine pharmacokinetic parameters based on an andante constant-rate intravenous infusion. A mathematical model of the constant-rate intravenous infusion combined with the elimination of first-order kinetics was established. During infusion, the accumulation tendency of drugs was deduced as $${C}_{t}={C}_{{0}}+({C}_{ss}-{C}_{{0}})\cdot (1-{e}^{-Kt})$$ C t = C 0 + ( C s s − C 0 ) ⋅ ( 1 − e − K t ) using the principle of calculus. Then, the method to determine the pharmacokinetic parameters was summed up. After collecting the blood drug concentration (C t ) -time (t) data from a constant-rate (v) infusion period, an exponential regression analysis was conducted to obtain the elimination rate constant (K) and plateau concentration (C ss ). Then, the half-life (t 1/2 ), apparent volume of distribution (V d ) and clearance rate (CL) were calculated based on the equations, t 1/2 = 0.693/K, V d = (v/K)/C ss and CL = v/C ss , respectively. In addition, an application example of cimetidine in a beagle dog was used to demonstrate the implementation process of the method.

Specification of PM2.5 transmission characteristics is important for pollution control and policymaking. We apply higher-order organization of complex networks to identify major potential PM2.5 contributors and PM2.5 transport pathways of a network of 189 cities in China. The network we create in this paper consists of major cities in China and contains information on meteorological conditions of wind speed and wind direction, data on geographic distance, mountains, and PM2.5 concentrations. We aim to reveal PM2.5 mobility between cities in China. Two major conclusions are revealed through motif analysis of complex networks. First, major potential PM2.5 pollution contributors are identified for each cluster by one motif, which reflects movements from source to target. Second, transport pathways of PM2.5 are revealed by another motif, which reflects transmission routes. To our knowledge, this is the first work to apply higher-order network analysis to study PM2.5 transport.

This paper reports a study of time-resolved deformation process at the atomic scale of a nanocrystalline Pt thin film captured in situ under a transmission electron microscope. The main mechanism of plastic deformation was found to evolve from full dislocation activity-enabled plasticity in large grains (with grain size d > 10 nm), to partial dislocation plasticity in smaller grains (with grain size 10 nm d d

The sedimentary record in the Guadix-Baza Basin (southern Spain) has proved to be a great source of information for the Miocene through the Pleistocene periods, due to the abundant faunal remains preserved, in some cases associated with lithic tools. The Solana del Zamborino (SZ) section has been the subject of controversy ever since a magnetostratigraphic analysis resulted in an age of 750–770 Kyr for Acheulean tools, a chronology significantly older than the ~600 Kyr established chronology for the first Acheulean record in Europe. Although recent findings at the “Barranc de la Boella” site (north-east of the Iberian Peninsula) seem to indicate that an earlier introduction of such technique in Europe around 0.96–0.781 Ma is possible, the precise age of the classical site at SZ is still controversial. The aim of this paper is to constrain the chronology of the site by developing a longer magnetostratigraphic record. For this purpose, we carried out an exhaustive sampling in a new succession at SZ. Our results provide a ~65 m magnetostratigraphic record in which 4 magnetozones of normal polarity are found. Our new magnetostratigraphic data suggest an age range between 300–480 Kyr for the lithic tools, closer to the age of traditional Acheulean sites in Europe.

Curved and spiral microfluidic channels are widely used in particle and cell sorting applications. However, the average Dean velocity of secondary vortices which is an important design parameter in these devices cannot be estimated precisely with the current knowledge in the field. In this paper, we used co-flows of dyed liquids in curved microchannels with different radii of curvatures and monitored the lateral displacement of fluids using optical microscopy. A quantitative Switching Index parameter was then introduced to calculate the average Dean velocity in these channels. Additionally, we developed a validated numerical model to expand our investigations to elucidating the effects of channel hydraulic diameter, width, and height as well as fluid kinematic viscosity on Dean velocity. Accordingly, a non-dimensional comprehensive correlation was developed based on our numerical model and validated against experimental results. The proposed correlation can be used extensively for the design of curved microchannels for manipulation of fluids, particles, and biological substances in spiral microfluidic devices.

Identifying drug target genes in gene expression profiles is not straightforward. Because a drug targets proteins and not mRNAs, the mRNA expression of drug target genes is not always altered. In addition, the interaction between a drug and protein can be context dependent; this means that simple drug incubation experiments on cell lines do not always reflect the real situation during active disease. In this paper, I applied tensor-decomposition-based unsupervised feature extraction to the integrated analysis using a mathematical product of gene expression in various diseases and gene expression in the DrugMatrix dataset, where comprehensive data on gene expression during various drug treatments of rats are reported. I found that this strategy, in a fully unsupervised manner, enables researchers to identify a combined set of genes and compounds that significantly overlap with gene and drug interactions identified in the past. As an example illustrating the usefulness of this strategy in drug discovery experiments, I considered cirrhosis, for which no effective drugs have ever been proposed. The present strategy identified two promising therapeutic-target genes, CYPOR and HNFA4; for their protein products, bezafibrate was identified as a promising candidate drug, supported by in silico docking analysis.

Early medical diagnostic in nanomedicine requires the implementation of innovative nanosensors with highly sensitive, selective, and reliable biomarker detection abilities. In this paper, a dual Localized Surface Plasmon Resonance - Surface Enhanced Raman Scattering (LSPR- SERS) immunosensor based on a flexible three-dimensional (3D) gold (Au) nanocups platform has been implemented for the first time to operate as a relevant “proof-of-concept” for the specific detection of antigen-antibody binding events, using the human IgG - anti-human IgG recognition interaction as a model. Specifically, polydimethylsilane (PDMS) elastomer mold coated with a thin Au film employed for pattern replication of hexagonally close-packed monolayer of polystyrene nanospheres configuration has been employed as plasmonic nanoplatform to convey both SERS and LSPR readout signals, exhibiting both well-defined LSPR response and enhanced 3D electromagnetic field. Synergistic LSPR and SERS sensing use the same reproducible and large-area plasmonic nanoplatform providing complimentary information not only on the presence of anti-human IgG (by LSPR) but also to identify its specific molecular signature by SERS. The development of such smart flexible healthcare nanosensor platforms holds promise for mass production, opening thereby the doors for the next generation of portable point-of-care devices.

The multi-device open-circuit fault is a common fault of ANPC (Active Neutral-Point Clamped) three-level inverter and effect the operation stability of the whole system. To improve the operation stability, this paper summarized the main solutions currently firstly and analyzed all the possible states of multi-device open-circuit fault. Secondly, an order-reduction optimal control strategy was proposed under multi-device open-circuit fault to realize fault-tolerant control based on the topology and control requirement of ANPC three-level inverter and operation stability. This control strategy can solve the faults with different operation states, and can works in order-reduction state under specific open-circuit faults with specific combined devices, which sacrifices the control quality to obtain the stability priority control. Finally, the simulation and experiment proved the effectiveness of the proposed strategy.

The validity of the Lophophorata as a monophyletic group remains controversial. New data on the innervation of the lophophore, which is a unique feature of the lophophorates, may help clarify the status of the Lophophorata and provide new information on the early evolution of the group. In this paper, the organization of the nervous system of the lophophore is described in adults of the minute phoronid Phoronis ovalis. The lophophore nervous system includes a dorsal ganglion, a tentacular nerve ring, an inner ganglion, an inner nerve ring, and six nerves in each tentacle. The inner ganglion and inner nerve ring, which is associated with sensory cells, are described for the first time in adult phoronids. The general plan of the nervous system of the lophophore and tentacles is similar in P. ovalis and bryozoans. These new results suggest the presence of two nerve centers and two nerve rings in the last common ancestor of phoronids and bryozoans. During evolution, bryozoans may have lost the outer nerve center and outer nerve ring, whereas phoronids may have lost the inner nerve center and inner nerve ring. These morphological results evidence the lophophorates are monophyletic.