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Facial Attribute Classification (FAC) has attracted increasing attention in computer vision and pattern recognition. However, state-of-the-art FAC methods perform face detection/alignment and FAC independently. The inherent dependencies between these tasks are not fully exploited. In addition, most methods predict all facial attributes using the same CNN network architecture, which ignores the different learning complexities of facial attributes. To address the above problems, we propose a novel deep multi-task multi-label CNN, termed DMM-CNN, for effective FAC. Specifically, DMM-CNN jointly optimizes two closely-related tasks (i.e., facial landmark detection and FAC) to improve the performance of FAC by taking advantage of multi-task learning. To deal with the diverse learning complexities of facial attributes, we divide the attributes into two groups: objective attributes and subjective attributes. Two different network architectures are respectively designed to extract features for two groups of attributes, and a novel dynamic weighting scheme is proposed to automatically assign the loss weight to each facial attribute during training. Furthermore, an adaptive thresholding strategy is developed to effectively alleviate the problem of class imbalance for multi-label learning. Experimental results on the challenging CelebA and LFWA datasets show the superiority of the proposed DMM-CNN method compared with several state-of-the-art FAC methods.

Eugenol is an important phenylpropanoid in strawberry and the accumulation is affected by various abiotic stresses. In this study, the expression patterns of two transcription factors (TFs) (FaMYB10 and FaEOBII) and two synthetic genes (FaEGS1 and FaEGS2) involved in eugenol synthesis were characterized in Fragaria × ananassa cv. ‘Xiaobai’. Sequence analysis showed the four genes contained several cis-acting elements that were related to phytohormones and environmental stress signal responsiveness. FaEGS1 and FaEGS2 were clustered in the same group clade. The four genes were expressed in all analysed tissues and, in particular, expressed to higher relative expression levels in leaves. The expression of FaEGS1, FaEGS2, and FaEOBII was the highest in large green fruits, and FaMYB10 had the highest expression in red-ripening fruits. The amount of eugenol showed a stage-specific profile. The expression of these four genes was up-regulated by ethephon (ETH), dark, drought, heat, and salt treatments accompanied by the increase of eugenol production. Concentration and timing of cadmium treatment affected gene expression. Cadmium inhibited the expression of FaEGS1 and FaEOBII, but significantly promoted the expression of FaEGS2 and FaMYB10 and eugenol content. The results provide a basis for elucidating the role of these genes in response to abiotic stresses, and regulating the accumulation of eugenol, an important constituent of volatile compounds in many economically important and aromatic plants.

Multi-focus image fusion, a technique to generate an all-in-focus image from two or more partially-focused source images, can benefit many computer vision tasks. However, currently there is no large and realistic dataset to perform convincing evaluation and comparison of algorithms in multi-focus image fusion. Moreover, it is difficult to train a deep neural network for multi-focus image fusion without a suitable dataset. In this letter, we introduce a large and realistic multi-focus dataset called Real-MFF, which contains 710 pairs of source images with corresponding ground truth images. The dataset is generated by light field images, and both the source images and the ground truth images are realistic. To serve as both a well-established benchmark for existing multi-focus image fusion algorithms and an appropriate training dataset for future development of deep-learning-based methods, the dataset contains a variety of scenes, including buildings, plants, humans, shopping malls, squares and so on. We also evaluate 10 typical multi-focus algorithms on this dataset for the purpose of illustration.

Summary Salt stress dramatically impedes plant growth and development as well as crop yield. The apple production regions are reduced every year, because of the secondary salt damage by improper fertilization and irrigation. To expand the cultivation area of apple (Malus domestica) and select salt‐resistant varieties, the mechanism of salt tolerance in apple is necessary to be clarified. The miR156/SPL regulatory module plays key roles in embryogenesis, morphogenesis, life cycle stage transformation, flower formation and other processes. However, its roles in the mechanisms of salt tolerance are unknown. In order to elucidate the mechanism of 156/SPL regulating salt stress in apple, we performed RLM‐5’ RACE and stable genetic transformation technology to verify that both mdm‐MIR156a and MdSPL13 responded to salt stress in apple and that the latter was the target of the former. MIR156a overexpression weakened salt resistance in apple whereas MdSPL13 overexpression strengthened it. A total of 6094 differentially expressed genes relative to nontransgenic apple plants were found by RNA‐Seq analysis of MdSPL13OE. Further verification indicated that MdSPL13 targeted the MdWRKY100 gene promoter. Moreover, MdWRKY100 overexpression enhanced salt tolerance in apple. Our results revealed that the miR156/SPL module regulates salt tolerance by up‐regulating MdWRKY100 in apple. This study is the first to elucidate the mechanism underlying the miRNA network response to salt stress in apple and provides theoretical and empirical bases and genetic resources for the molecular breeding of salt tolerance in apple.

Perovskite oxides have been recognized as one of the most attractive oxygen evolution reaction (OER) catalysts because of their low cost, earth abundance, and robust nature. Herein, one-dimensional porous LaFe1-xNixO3 (LFNO) perovskite oxide nanofibers (LFNO NFs) are fabricated with a feasible electrospinning route and its further post-calcination treatment. By tailoring the atomic percent of Fe and Ni in the perovskite oxide, we determined that LaFe0.25Ni0.75O3 (LFNO-III) NFs afford the best OER activity among all the prepared perovskite oxides. Especially remarkable is that the further selenide-doped LaFe0.25Ni0.75O3 (LFNOSe-III) NFs exhibit outstanding OER activity with a low overpotential of 287 mV at 10 mA cm-2 and a small Tafel slope of 87 mV dec-1 in 1 M KOH solution, markedly exceeding that of the parent perovskite oxide and the commercial RuO2. It also delivers decent durability with no significant degradation after 22 h of stability test. In the meanwhile, density functional theory calculations are also conducted to justify the optimized adsorption features of *OH, *O, and *OOH intermediates and unveil that the electrocatalytic active sites are the Ni atoms adjacent to Fe in the Ni- and Se codoped perovskite. This work provides an effective method for the development of highly efficient perovskite oxide catalysts.

MdHAL3 has PPCDC activity and is involved in the salt tolerance of autotetraploid apple. Apple (Malus × domestica) is the most widely planted fruit tree species worldwide. However, the growth and development of apple have been increasingly affected by abiotic stress, such as high salinity. In our previous study, RNA sequencing (RNA-seq) analysis revealed that the expression level of the MdHAL3 gene was significantly upregulated in the autotetraploid apple cultivar Hanfu. In the present study, we first isolated HAL3, whose product was shown to exert 4′-phosphopantothenoylcysteine decarboxylase (PPCDC) activity, from apple. MdHAL3 was expressed in all organs of apple, and its expression was rapidly induced by salt stress. The MdHAL3 protein was localized to the cytomembrane and cytoplasm. Five MdHAL3 overexpression (OE) lines and five MdHAL3-RNAi apple lines were obtained. We found that MdHAL3 enhanced the salt stress tolerance of apple and that the OE plants rooted more easily than the wild-type (WT) plants. The coenzyme A (CoA) content in the leaves of the OE plants was greater than that in the leaves of the WT plants, and the CoA content in the MdHAL3-RNAi plants was lower than that in the WT plants. Taken together, our findings indicate that MdHAL3 plays an essential role in the response to salt stress in apple.

Metal halide perovskites have recently been reported as excellent scintillators for X-ray detection. However, perovskite based scintillators are susceptible to moisture and oxygen atmosphere, such as the water solubility of CsPbBr3, and oxidation vulnerability of Sn2+, Cu+. The traditional metal halide scintillators (NaI: Tl, LaBr3, etc.) are also severely restricted by their high hygroscopicity. Here we report a new kind of lead free perovskite with excellent water and radiation stability, Rb2Sn1-x Te x Cl6. The equivalent doping of Te could break the in-phase bonding interaction between neighboring octahedra in Rb2SnCl6, and thus decrease the electron and hole dimensionality. The optimized Te content of 5% resulted in high photoluminescence quantum yield of 92.4%, and low X-ray detection limit of 0.7 µGyair s−1. The photoluminescence and radioluminescence could be maintained without any loss when immersing in water or after 480,000 Gy radiations, outperforming previous perovskite and traditional metal halides scintillators.

Class-imbalance extent metrics measure how imbalanced the data are. In pattern classification, it is usually expected that the higher the imbalance extent, the worse the classification performance, and thus an appropriate imbalance extent metric should show a negative correlation with the classification performance. Existing metrics, such as the popular imbalance ratio (IR), only consider the effect of the sample sizes of different classes. However, we note that the dimensionality of imbalanced data also affects the classification performance. Datasets with the same IR can present distinct classification performances when their dimensionalities are different, making IR suboptimal to reflect the imbalance extent for classification. We also observe that the classification performance becomes better with more discriminative features. Inspired by these observations, we propose a new imbalance extent metric, the adjusted IR, by adding a penalty term of the number of discriminative features that is effectively determined by the Pearson correlation test. The adjusted IR adaptively revises the IR when the number of discriminative features varies. The empirical studies demonstrate the effectiveness of the adjusted IR, in terms of its better negative correlation with the classification performance.

Through oxygen profile engineering, we fabricated W/AlO $_{\mathbf {x}}$ /Al $_{\mathbf {{2}}}~\text{O}_{\mathbf {{3}}}$ /Pt bilayer memristors with a 250-nm feature size. The AlO $_{{\mathbf {x}}}$ fabricated by sputtering serves as an oxygen vacancy source, whereas the Al $_{{\mathbf {{2}}}}~\text{O}_{{\mathbf {{3}}}}$ deposited by atomic layer deposition acts as a dominant resistive switching (RS) layer. Our devices show forming-free RS behaviors with high speed (28 ns), uniform resistance distribution, large on/off ratio ( $\sim 10^{{\mathbf {{3}}}}$ @100K, $\sim 10^{{\mathbf {{3}}}}$ @298K, and $\sim 80$ @400K), and good retention. Besides, temperature stability with record high endurance from cryogenic to high-temperature ( $10^{{\mathbf {{8}}}}$ @100K, $10^{{\mathbf {{10}}}}$ @298K, and $10^{{\mathbf {{7}}}}$ @400K) is demonstrated, to the best of our knowledge.

Contact-electrification is a universal effect for all existing materials, but it still lacks a quantitative materials database to systematically understand its scientific mechanisms. Using an established measurement method, this study quantifies the triboelectric charge densities of nearly 30 inorganic nonmetallic materials. From the matrix of their triboelectric charge densities and band structures, it is found that the triboelectric output is strongly related to the work functions of the materials. Our study verifies that contact-electrification is an electronic quantum transition effect under ambient conditions. The basic driving force for contact-electrification is that electrons seek to fill the lowest available states once two materials are forced to reach atomically close distance so that electron transitions are possible through strongly overlapping electron wave functions. We hope that the quantified series could serve as a textbook standard and a fundamental database for scientific research, practical manufacturing, and engineering., The mechanism of contact electrification remains a topic of debate. Here, the authors present a quantitative database of the triboelectric charge density and band structure of many inorganic materials, verifying that contact electrification between solids is an electron quantum transition effect.

Electrocatalysts with high activities toward multiple electrode reactions are scarce and therefore highly sought. Here, we investigate the electrocatalytic performance of the two-dimensional (2D) Pt5Se4 monolayer toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Our density functional theory calculations show that the Pt5Se4 monolayer can serve as a low-Pt-loading trifunctional electrocatalyst with good kinetic and thermal stabilities. Specifically, the HER performance of the Pt5Se4 basal plane is predicted to be superior to that of 2D layered Pd or Pt dichalcogenides. Even considering the solvent effect, the catalytic OER performance of the Pt5Se4 monolayer is predicted to be comparable to the prevalent OER catalyst-IrO2, while the catalytic ORR performance of the Pt5Se4 monolayer is even higher than the predominating Pt(111) surface. Overall, the Pt5Se4 monolayer can be a promising trifunctional catalyst that exhibits high activities toward all hydrogen and oxygen electrode reactions.

Lead halide perovskites have recently shown great potential as X-ray scintillators; however, the toxicity of the lead element seriously restricts their applications. Herein we report a new lead-free and self-absorption-free scintillator based on Rb

Pt and Pt-based materials are still the most common catalysts for oxygen reduction reaction (ORR), but it is highly desirable to develop efficient ORR electrocatalysts based on inexpensive metals. ...

Phase change memory is an excellent candidate for next-generation memory technologies with a high operation speed, but the memory capacity is not very satisfactory, due to which engineers have to add the 3D stacking technology (3D XPoint) for new products. Alternatively, multi-level storage is an easy approach to enable large data density and probably future neuromorphic computing. Lately, K2Sb8Se13 has attracted considerable attention as a multi-level phase change material because it exhibits an interesting amorphous-to-amorphous (polyamorphic) transformation before crystallization, and these two polyamorphic states as well as the crystalline phase show distinct resistances, adding a new data state to the existing “0” and “1”. Understanding and stabilizing this new amorphous state is the key to the application of this material; here, we have investigated these two amorphous states through ab initio simulations. We found that these two states showed obvious differences in the local structures, and the void concentration revealed by the low-electron-density areas indicated stronger interactions between the atomic clusters in the denser phase. The density of states and electron localization function were analyzed and we confirmed that adding electronic holes were largely responsible for the decrease in resistance. In this work, we have discovered the origin of multi-level resistance states in K2Sb8Se13, paving the way for the design of new phase change memory devices based on this material.

In this letter, we discuss the application of low pressure chemical vapor deposition (LPCVD) grown SiNx passivation-first process to improve the power density and linearity performance of a metal oxide chemical vapor deposition (MOCVD) grown AlGaN channel polarization-graded field-effect transistor (PolFET). Significantly improved dispersion behavior was observed compared to plasma enhanced chemical vapor deposition (PECVD) grown SiNx passivation. The Current collapse at 30 V drain quiescent condition for pulsed I-V was reduced to 8% (LPCVD) from 25% (PECVD). 10 GHz load-pull measurement showed a maximum output power density of 3.4 W/mm with a peak power added efficiency (PAE) of 40%. Two-tone intermodulation distortion measurement at 10 GHz for devices with $150\boldsymbol {\mu }\text{m}$ width revealed an OIP3 of 39 dBm and an excellent corresponding linearity figure of merit OIP3/ $\text{P}_{{\textit {DC}}}$ of 13.3 dB. This is the best device level OIP3/ $\text{P}_{{\textit {DC}}}$ reported to date at X-band for III-Nitride microwave transistors.

Recently, two-dimensional (2D) ternary layered telluride materials have attracted enormous attention due to their exotic electronic properties. Here, we propose two new monolayer 2D semiconductors Nb2SiTe4 and Nb2GeTe4, which show high dynamic, thermodynamic and mechanical stability. Nb2SiTe4 and Nb2GeTe4 have stable three-dimensional layered bulk counterparts, and monolayer Nb2SiTe4 and Nb2GeTe4 have low cleavage energies such that exfoliation of bulk material becomes a viable means for the preparation of mono- and few-layer materials. Indirect band gap of 0.80 eV and 0.63 eV have been revealed in monolayer Nb2SiTe4 and Nb2GeTe4. Acoustic phono-limited carrier mobilities are estimated, where monolayer Nb2SiTe4 exhibits high electron mobilities up to 1775 cm2 V−1 s−1 and 1222 cm2 V−1 s−1 along a and b directions, respectively. Analysis of mechanical properties reveals that 2D Nb2SiTe4 and Nb2GeTe4 are positive Poisson’s ratio materials with moderate Young’s moduli. The bonding characteristics have been investigated through electron localization function and Bader charges. Pronounced light absorption is predicted in the visible light and ultraviolet regions. These findings render 2D Nb2SiTe4 and Nb2GeTe4 attractive candidates for future nanoelectronics and optoelectronics.

CaSiO3 (CS) ceramics exhibit excellent microwave performance as a microwave material, however, its sintering temperature is too high and limits its application in the microwave field. In this work, the densification process and microwave performance of the BaCu(B2O5) (BCB) doped CS ceramics were researched. The results showed that the sintering temperature of CS ceramics can be lowered from 1340 °C to 930 °C by BCB additive. In order to obtain ceramic samples with excellent microwave properties and high density, adding 4 wt% BCB to CS ceramics was considered to be optimal. Under this formulation, BCB-CS ceramics sintered at low sintering temperatures (950 °C for 3 h), possessed outstanding microwave performance of e r = 4.7 , Q × f = 34807.5 G H z , τ f = − 21.5 p p m / ° C . Moreover, CS ceramics doped with BCB had a good chemical compatibility with silver powder, which indicated that BCB-CS ceramic was a prospective candidate for low temperature co-fired ceramic (LTCC) applications.

Monolayer Ge2P4S2 and Ge2As4S2 are proposed as a new type of efficient photocatalyst for water splitting, based on first-principles calculations. Monolayer Ge2As4S2 exhibits a direct band gap of 1.89 eV (based on HSE06 calculation), while monolayer Ge2P4S2 is an indirect gap semiconductor that can turn into direct band gap by applying 3% compressive strain. Moreover, the band edge positions of monolayer Ge2P4S2 and Ge2As4S2 perfectly cover the redox potentials of water. Remarkably, the Ge2P4S2 and Ge2As4S2 monolayers possess rather high carrier mobilities (∼103–104 cm2 V−1 s−1), and have moderate optical absorption performance in the range of visible light. In addition, the adsorption and decomposition of water molecules on monolayer Ge2P4S2 and Ge2As4S2 are explored to illustrate the mechanism of photocatalytic hydrogen formation. These results demonstrate that the monolayer Ge2P4S2 and Ge2As4S2 hold great potential for photocatalytic water splitting.

The matched subspace detector (MSD) is a classical subspace-based method for hyperspectral subpixel target detection. However, the model assumes that noise has the same variance over different bands, which is usually unrealistic in practice. In this letter, we relax the equal variance assumption and propose a matched subspace detector with heterogeneous noise (MSDH). In essence, the noise variances are different for different bands and they can be estimated by using iteratively reweighted least squares methods. Experiments on two benchmark real hyperspectral datasets demonstrate the superiority of MSDH over MSD for subpixel target detection.

As an ultra-wide bandgap semiconductor, $\beta $ -Ga2O3 has attracted great attention for high-power, high-voltage, and optoelectronic applications. However, until now, high-frequency performance of gallium oxide devices has been limited to relatively low current gain cutoff frequencies below 5 GHz. Here, we show that highly localized delta-doping designs can enable high-sheet-charge density to enable devices with short gate lengths that allow high-frequency operation. Field-effect transistors with a gate length of 120 nm on such delta-doped $\beta $ -Ga2O3 are reported here with extrinsic unity current gain frequency of 27 GHz. The device has a peak drain current of 260 mA/mm, transconductance (gm) of 44 mS/mm, and three-terminal off-state breakdown voltage of 150 V. These results demonstrate that the potential of $\beta $ -Ga2O3 for future RF and millimeter-wave device applications.

Zn2SiO4 ceramics with nano-sized TiO2 addition (ZST) were synthesized by conventional solid state method. The association between the new composite's microstructures and dielectric properties reveals that reduced pores, increased density and average grain sizes with increasing sintering temperatures, have contributed to the increased permittivities at kHz and microwave bands; the decrease of the permittivities at 1275 °C is due to the form of twin planes. At the terahertz band, the competition of generating oxygen vacancies and forming them into twin crystallographic shear planes dominates the change of permittivities: the crystallographic shear planes decrease the permittivity at the sintering temperature 1225 °C and 1250 °C, and the high-rate generation of oxygen vacancies at 1275 °C increases the permittivities. The ZST ceramics demonstrate stable permittivity and low dielectric losses (

Ferroelectric materials with a perovskite structure have various shortcomings, including poor Si compatibility, large physical thickness, and small bandgap. HfO2-based ferroelectric materials provide a new solution for ferroelectric semiconductor devices. HfO2-ZrO2 solid solution (HZO) thin films have been widely studied due to their low crystallization temperature and wide stoichiometric range. Considering its low cost and flexible deposition conditions, the sputtering technique is a useful method for HZO deposition. However, sputtered HZO ferroelectric films have been rarely reported, and the composition effect on the ferroelectric properties of HfXZr1−XO2 thin films is still unclear. In this letter, sputtered HfXZr1−XO2 thin films were studied with different Zr contents (from 12.49 to 20.34 mol%) by varying the sputtering power ratio of ZrO2 to HfO2. We found that the dopant concentration with the best ferroelectric properties in the HfXZr1−XO2 system is ~15–16 mol%, which is much lower than that in the ALD-based HZO film. First-principle calculation shows that oxygen vacancies doped in the HZO film lead to a change in the Helmholtz free energy of different phases, which affected the optimal Zr concentration for the largest ferroelectric polarization.

Using first principle calculations we have investigated the structure stabilities, electronic and optical properties of single layer planar penta-X2N4 (X = Ni, Pd and Pt). According to the calculated phonon dispersion relation and elastic constants, as well as ab initio molecular dynamics simulation results, monolayers of planar penta-X2N4 are dynamically, mechanically, and thermally stable. In addition, these monolayers are direct-gap semiconductors with bandgaps ranging from 0.92 eV to 1.11 eV, which can be further tuned by external strains. Besides, the bonding characteristics and the optical properties in these monolayers are investigated based on HSE06 calculations, where strong in-plane optical absorption with wide spectral range has been revealed. Our results indicate that planar penta-X2N4 monolayers possess excellent electrical and optical properties, and may find potential applications in solar cells and nanoelectronics.

Herein, the tape-casting technique was used to fabricate an Er-doped (K0.5Na0.5)NbO3 (KNN:0.02Er) laminar ceramic, which possesses a pseudo-cubic phase structure with regular cube-shaped grains. Considering the substitution behavior of the Er dopant in the KNN lattice, X-ray diffraction analysis and density functional theory simulations both verify that Er can replace K and Na sites. And Er-induced enlargement of the energy band gap of KNN:0.02Er has been obtained in the reflectance spectra and simulations. Furthermore, the ceramic exhibits dual-mode down-conversion and up-conversion photoluminescence (PL). As a lead-free luminescent ferroelectric, the PL intensity of KNN:0.02Er can be enhanced by polarization induced by electric poling. And the dual-mode PL can be obviously modulated under an electric field in an in situ, reversible, real-time and dynamical way. Our results offer an effective theoretical way to bridge the relationship between the crystal structure/chemical bonding environment and the performance of the KNN system, and also provide an opportunity to realize electrically controlled tuning of the PL response in KNN-based luminescent ferroelectrics and the corresponding optoelectronic devices.

Two-dimensional materials with high carrier mobility and tunable magnetism are in high demand for nanoelectronic and spintronic applications. Herein, we predict a novel two-dimensional monolayer KTlO that possesses an indirect band gap of 2.25 eV (based on HSE06 calculations) and high carrier mobility (450 cm2 V-1 s-1 for electrons and 160 cm2 V-1 s-1 for holes) by means of ab initio calculations. The electron mobility can be increased up to 26 280 cm2 V-1 s-1 and 54 150 cm2 V-1 s-1 for bilayer and trilayer KTlO, respectively. The KTlO monolayer has a calculated cleavage energy of 0.56 J m-2, which suggests exfoliation of the bulk material as a viable means for the preparation of mono- and few-layer materials. Remarkably, the KTlO monolayer demonstrates tunable magnetism and half-metallicity with hole doping, which are attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure. Furthermore, monolayer KTlO exhibits moderate optical absorption over the visible light and ultraviolet regions. The band gap value and band characteristics of monolayer KTlO can be substantially manipulated by biaxial and uniaxial strains to meet the requirement of various applications. All these novel properties make monolayer KTlO a promising functional material for future nanoelectronic and spintronic applications.

Understanding the ecological mechanisms driving the dynamics of field rotifer populations remains a challenge in ecology. Brachionus angularis (Rotifera) is preferred in such studies because of their planktonic behavior, high fecundity, and absence of cryptic species. In this study, one-year zooplankton samples were collected twice a month from a subtropical lake and the roles of abiotic and biotic factors regulating the population dynamics of B. angularis were analyzed. The sampled B. angularis were composed of two discontinuous populations: ‘summer and autumn’ and ‘spring and winter’, segmented by high mixis rates. The ‘summer and autumn’ population had high egg ratios, but low egg volumes. Water temperature was the main factor driving temporal dynamics in density, thereby counteracting the negative effect of top-down force. Based on the synchronous dynamics of two fractions of chlorophyll-a, the densities of B. angularis, its potential competitors and predators, together with the reverse correlations between the egg ratio and population density, and Secchi-disk depth, we found that bottom-up and top-down forces were plausible factors regulating variations in population density in spring (March and April). However, the density peak of B. angularis in winter might be primarily ascribed to recruitment from the sediment. We further addressed the necessity for diverse evidence from the speciation of cryptic species, abundance, reproduction, and morphology, in understanding the population dynamics of a field rotifer population.

Visible-light driven photocatalytic Cr(VI) reduction is a promising pathway to moderate environmental pollution, in which the development of photocatalysts is pivotal. Herein, three hourglass-type phosphomolybdate-based hybrids with the formula of: (H2bpe)3[Zn(H2PO4)][Zn(bpe)(H2O)2]H{Zn[P4Mo6O31H6]2}·6H2O (1) Na6[H2bz]2[ZnNa4(H2O)5]{Zn [P4Mo6O31H3]2}·2H2O (2) and (H2mbpy) {[Zn(mbpy)(H2O)]2[Zn(H2O)]2}{Zn[P4Mo6O31H6]2}·10H2O (3) (bpe = trans-1,2-bi(4-pyridyl)-ethylene; bz = 4,4'-diaminobiphenyl; mbpy = 4,4'-dimethyl-2,2'bipyridine) were synthesized under the guidance of the functional organic moiety modification strategy. Structural analysis showed that hybrids 1-3 have similar 2-D layer-like spatial arrangements constructed by {Zn[P4Mo6]2} clusters and organic components with different conjugated degree. With excellent redox properties and wide visible-light absorption capacities, hybrids 1-3 display favourable photocatalytic activity for Cr(VI) reduction with 79%, 70% and 64% reduction rates, which are superior to that of only inorganic {Zn[P4Mo6]2} itself (21%). The investigation of organic components on photocatalytic performance of hybrids 1-3 suggested that the organic counter cations (bpe, bz and mbpy) can effectively affect the visible-light absorption, as well as the recombination of photogenerated carriers stemmed from {Zn[P4Mo6]2} clusters, further promoting their photocatalytic performances towards Cr(VI) reduction. This work provides an experimental basis for the design of functionalized photocatalysts via the modification of organic species.

Change Point Detection (CPD) methods identify the times associated with changes in the trends and properties of time series data in order to describe the underlying behaviour of the system. For instance, detecting the changes and anomalies associated with web service usage, application usage or human behaviour can provide valuable insights for downstream modelling tasks. We propose a novel approach for self-supervised Time Series Change Point detection method based onContrastivePredictive coding (TS-CP^2). TS-CP^2 is the first approach to employ a contrastive learning strategy for CPD by learning an embedded representation that separates pairs of embeddings of time adjacent intervals from pairs of interval embeddings separated across time. Through extensive experiments on three diverse, widely used time series datasets, we demonstrate that our method outperforms five state-of-the-art CPD methods, which include unsupervised and semi-supervisedapproaches. TS-CP^2 is shown to improve the performance of methods that use either handcrafted statistical or temporal features by 79.4% and deep learning-based methods by 17.0% with respect to the F1-score averaged across the three datasets., Accepted at The WEB Conference 2021 (WWW'21)

In this paper, the microscopic mechanisms of the transition metal oxides/RuO 2 memristor showing great performance in the recent advances were presented using ab initio theoretical methods. The calculations of oxygen vacancy formation, the Schottky barrier height, and the migration barriers for the HfO 2 /RuO 2 interface model suggest that there is mediated oxygen balance at the interface which contributes to the improvement of the device.

Bacterial wilt caused by the soil-borne plant pathogen Ralstonia solanacearum is a devastating disease worldwide. Upon plant colonization, R. solanacearum replicates massively, causing plant wilting and death; collapsed infected tissues then serve as a source of inoculum. In this work, we show that the plant metabolic pathway mediated by pyruvate decarboxylases (PDCs) contributes to plant tolerance to bacterial wilt disease. Arabidopsis and tomato plants respond to R. solanacearum infection by increasing PDC activity, and plants with deficient PDC activity are more susceptible to bacterial wilt. Treatment with either pyruvic acid or acetic acid (substrate and product of the PDC pathway, respectively) enhances plant tolerance to bacterial wilt disease. An effector protein secreted by R. solanacearum, RipAK, interacts with PDCs and inhibits their oligomerization and enzymatic activity. Collectively, our work reveals a metabolic pathway involved in plant resistance to biotic and abiotic stresses, and a bacterial virulence strategy to promote disease and the completion of the pathogenic life cycle.

The viscoelastic behavior and reinforcement mechanism of polyethylene glycol (PEG) as an interfacial modifier in green tire tread composites were investigated in this study. The results show a clear positive effect on overall performance, and it significantly improved all the parameters of the “magic triangle” properties, the abrasion resistance, wet grip and ice traction, as well as the tire rolling resistance, simultaneously. For the preparation of the compounds, two mixing steps were used, as PEG 4000 was added on the second stage in order to avoid the competing reaction between silica/PEG and silanization. Fourier transform infrared spectroscopy (FTIR) confirmed that PEG could cover the silanol groups on the silica surface, resulting in the shortening of cure times and facilitating an increase of productivity. At low content of PEG, the strength was enhanced by the improvement of silica dispersion and the slippage of PEG chains, which are chemically and physically adsorbed on silica surface, but the use of excess PEG uncombined with silica in the compound, i.e., 5 phr, increases the possibility to shield the disulfide bonds of bis(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT), and, thus, the properties were deteriorated. A constrained polymer model was proposed to explain the constrained chains of PEG in the silica-loaded composites on the basis of these results. An optimum PEG content is necessary for moderately strong matrix–filler interaction and, hence, for the enhancement in the mechanical properties.

When the labelling information is not deterministic, traditional supervised learning algorithms cannot be applied. In this case, stochastic supervision models provide a valuable alternative to classification. However, these models are restricted in several aspects, which critically limits their applicability. In this paper, we provide four generalisations of stochastic supervision models, extending them to asymmetric assessments, multiple classes, feature-dependent assessments and multi-modal classes, respectively. Corresponding to these generalisations, we derive four new EM algorithms. We show the effectiveness of our generalisations through illustrative examples of simulated datasets, as well as real-world examples of three famous datasets, the MNIST dataset, the CIFAR-10 dataset and the EMNIST dataset.

In this paper, a generation method procedure based on a reflective metasurface is proposed to generate multiple pseudo Bessel beams with accurately controllable propagation directions and high efficiency. Firstly, by adjusting the miniaturized unit cell of the reflective metasurface to modulate the electromagnetic waves using the proposed method, some off-axis pseudo Bessel beams with different propagation directions are generated. Then, by achieving the large-angle deflection and comparing the results with previous existing methods, the superiority of the proposed method is demonstrated. Based on the generated single off-axis pseudo Bessel beam and the superposition principle of the electromagnetic wave, a reflective metasurface with 47 &times, 47 elements is designed and fabricated at 10 GHz to generate dual pseudo Bessel beams. Full-wave simulation and experimental measurement results validate that the dual pseudo Bessel beams were generated successfully. The propagation directions of the dual pseudo Bessel beams can be controlled accurately by the reflective metasurface, and the efficiency of the beams is 59.2% at a propagation distance of 400 mm. The energy of the beams keeps concentrating along the propagation axes, which provides a new choice for wireless power transfer and wireless communication with one source to multiple receiving targets.

In this work, we present interpGaze, a novel framework for controllable gaze redirection that achieves both precise redirection and continuous interpolation. Given two gaze images with different attributes, our goal is to redirect the eye gaze of one person into any gaze direction depicted in the reference image or to generate continuous intermediate results. To accomplish this, we design a model including three cooperative components: an encoder, a controller and a decoder. The encoder maps images into a well-disentangled and hierarchically-organized latent space. The controller adjusts the magnitudes of latent vectors to the desired strength of corresponding attributes by altering a control vector. The decoder converts the desired representations from the attribute space to the image space. To facilitate covering the full space of gaze directions, we introduce a high-quality gaze image dataset with a large range of directions, which also benefits researchers in related areas. Extensive experimental validation and comparisons to several baseline methods show that the proposed interpGaze outperforms state-of-the-art methods in terms of image quality and redirection precision., accepted by ACM International Conference on Multimedia (ACM MM), 2020

Stress sensing is the basis of human-machine interface, biomedical engineering, and mechanical structure detection systems. Stress sensing based on mechanoluminescence (ML) shows significant advantages of distributed detection and remote response to mechanical stimuli and is thus expected to be a key technology of next-generation tactile sensors and stress recorders. However, the instantaneous photon emission in ML materials generally requires real-time recording with a photodetector, thus limiting their application fields to real-time stress sensing. In this paper, we report a force-induced charge carrier storage (FICS) effect in deep-trap ML materials, which enables storage of the applied mechanical energy in deep traps and then release of the stored energy as photon emission under thermal stimulation. The FICS effect was confirmed in five ML materials with piezoelectric structures, efficient emission centres and deep trap distributions, and its mechanism was investigated through detailed spectroscopic characterizations. Furthermore, we demonstrated three applications of the FICS effect in electronic signature recording, falling point monitoring and vehicle collision recording, which exhibited outstanding advantages of distributed recording, long-term storage, and no need for a continuous power supply. The FICS effect reported in this paper provides not only a breakthrough for ML materials in the field of stress recording but also a new idea for developing mechanical energy storage and conversion systems., Lung disease: Mechanoluminescence: stress-sensitive phosphors hold deep memories A material that records mechanical impacts and provides optical readouts at later dates shows promise for anti-counterfeiting devices and structural damage analysis. Phosphors, such as rare earth-doped silicates, can emit light in response to physical stress because they store charge carriers in easy-to-access energy states. Rong-Jun Xie from China’s Xiamen University and colleagues now report development of phosphors that release charges to less accessible ‘deep’ energy states after being stimulated mechanically. These carriers are retained in the deep states and then released on-demand as photon emissions following thermal treatments. The team demonstrated several applications for the new phosphors including sensors that can record signature traces and composite films that attach to vehicles to monitor for potential collisions.

The performance of subspace-based methods such as matched subspace detector (MSD) and MSD with interaction effects (MSDinter) heavily depends on the background subspace and the target subspace. Nonetheless, constructing a representative target subspace is challenging due to the limited availability of target spectra in a collected hyperspectral image. In this paper, we propose two new hyperspectral target detection methods termed data-augmented MSD (DAMSD) and data-augmented MSDinter (DAMSDI) that can effectively solve the scarcity problem of target spectra and from which a representative target-background mixed subspace can be learned. We first synthesise target-background mixed spectra based on classical hyperspectral mixing models and then learn a target-background mixed subspace via principal component analysis. Compared with MSD and MSDinter, the learned mixed subspace is more representative as spectral variability of target spectra is explained to the largest extent and it leads to an improvement in computational speed and numerical stability. We demonstrate the efficacy of DAMSD and DAMSDI for subpixel target detection on two public hyperspectral image datasets.

Anammox bacteria are widely found to grow in bioaggregates form, but the reason for their high aggregation ability remains elusive. In this study, four kinds of sludge, i.e., anammox granules, anaerobic granules, aerobic granules, and partial nitrification flocs, were studied and compared to investigate their differences in adherence properties. We directly explored the adherence properties of sludge samples before and after extracellular polymeric substances (EPS) extraction, using quartz-crystal microbalance technique with dissipation monitoring technique. Results showed that EPS indeed stimulated the adherence properties of all sludge samples. The most striking feature here is that anammox consortia had the highest adhesion rate and mass, and formed the most compact layer on the gold-coated sensor surfaces both before and after EPS extraction among the four sludge samples, indicating their inherent high adhesion ability. The composition and spectral characteristics of EPS samples were also investigated, and it reveals that the relatively high extracellular proteins/polysaccharides ratio of anammox granules (3.2 ± 0.4) rather than total EPS concentration had contributed to their high adhesion ability. The findings are helpful for understanding the adherence properties of anammox bacteria, and will serve as a guide for further researches to exploring the aggregation process of anammox bacteria.

In order to improve the battlefield survival ability of individual soldiers, countries strive to computer aided design camouflage schemes suitable for different combat backgrounds. The use of camouflage clothing greatly reduces the difference between the combatant and the background, but it is difficult to protect the human body exposed to the external skin such as the face, the back of the hand and so on. In military operations, because combatants need to constantly observe the surrounding situation, resulting in their faces easily exposed to the background. The computer aided design of the camouflage pattern provides a variety of facial camouflage. This subject mainly through wearing style, drawing two ways, collect and organize seven camouflage schemes to explore a variety of computer aided designed facial camouflage methods.

Facial camouflage is an extremely important link in individual camouflage, human face has obvious exposure symptoms, facial camouflage can effectively reduce the probability of recognition by enemy reconnaissance, improve the battlefield survival of their own personnel. This paper explores and determines the design principles of camouflage spots, and then designs the two kinds of speckle libraries needed according to the principles. Selecting the terrain background to be tested, calculating the main color of the background by k-means mean clustering algorithm or chroma histogram algorithm, selecting a blank face to be divided according to the concave and convex parts of the face, writing program code to randomly call the two speckle libraries to obtain the two results, optimal scheme, and then draw a conclusion.

Lead halide perovskites have exhibited excellent performance in solar cells, LEDs and detectors. Thermal properties of perovskites, such as heat capacity and thermal conductivity, have rarely been studied and corresponding devices have barely been explored. Considering the high absorption coefficient (104~105 cm−1), low specific heat capacity (296–326 J kg−1 K−1) and small thermal diffusion coefficient (0.145 mm2 s−1), herein we showcase the successful use of perovskite in optoacoustic transducers. The theoretically calculated phonon spectrum shows that the overlap of optical phonons and acoustic phonons leads to the up-conversion of acoustic phonons, and thus results in experimentally measured low thermal diffusion coefficient. The assembled device of PDMS/MAPbI3/PDMS simultaneously achieves broad bandwidths (−6 dB bandwidth: 40.8 MHz; central frequency: 29.2 MHz), and high conversion efficiency (2.97 × 10−2), while all these parameters are the record values for optoacoustic transducers. We also fabricate miniatured devices by assembling perovskite film onto fibers, and clearly resolve the fine structure of fisheyes, which demonstrates the strong competitiveness of perovskite based optoacoustic transducers for ultrasound imaging., Lead halide perovskites are widely used e.g. in solar cells and LEDs, but devices based on thermal properties have received little attention. Here, the authors take advantage of the thermal properties to fabricate an optoacoustic transducer with both broad bandwidth and high conversion efficiency.

In this paper, a single elliptical patch antenna is proposed to generate double-deflection orbital angular momentum (OAM) vortex beams. The physical mechanism of an equivalent uniform elliptical array (UEA) is constructed and analyzed by using the theory of characteristic modes. The elliptical patch antenna can be fed with a 3dB directional coupler to generate the double-deflection vortex beams with single OAM mode or mixed OAM modes. The simulation and measurement results verify that the proposed single elliptical patch antenna is a simple, miniaturized, and multifunctional generator for OAM vortex beams.

Reject water contains complex components of organic compounds, which have significant influences on the nitrogen removal performance when treated using biological autotrophic nitrogen removal technology. In this study, a two-stage partial nitritation (PN)-anammox (floc-granule) system was established to treat reject water (COD/NH4+-N = 0.97 ± 0.15), and the evolution of organic compounds along PN and annamox bioreactors was investigated using gas chromatography–mass spectrometry and excitation-emission matrix. Also, the variation of PN and anammox sludge properties relating to COD reduction was examined. The PN-anammox system removed approximately 80% of total inorganic nitrogen and COD with hydraulic reaction time of 16 h. The influent organics (330–600 mg COD/L) in reject water were primarily composed of volatile, protein-like and humic acid-like organic compounds. PN process contributed 53 ± 18% of the overall COD removal, primarily including oxygen-containing organics (e.g. phenol), proteins and humic acids. Anammox process contributed 22 ± 15% of the overall COD removal, but large molecule acids (e.g. lactic acid) and small molecule alcohols (e.g. glycerol) were reoccurred, contributing to the effluent COD with recalcitrant hydrocarbons (e.g. n-Octadecane). Reject water increased the extracellular proteins/polysaccharides ratio of PN and anammox sludge, promoting the adsorption and degradation of organic compounds. High-throughput sequencing results showed that denitrifying bacteria of Ottowia increased from 0.03% to 14.4% in PN reactor, and of Denitratisoma increased from 9.6% to 15.4% in anammox reactor. The occurrence of these denitrifiers might mitigate the negative impact of organics to functional organisms. This study highlights the organics fate during PN-anammox treatment system, which is important to maintain the robust nitrogen removal when treating organics-containing and high ammonium concentration wastewater.

Nanomaterials form the main thrust for modern day technological and industrial applications, including but not limited to, super-capacitors, membranes, batteries, filters, sensors, tissue engineering, wound dressing, protecting vesture, reinforcement in composite materials, etc. Ceramic nanofibers are at the forefront of these materials due to their high surface area and tunable nano structures and porosity. However, obtaining nanofibers with a well-developed uniform crystallinity and a perfect morphology is a challenging task. Among various techniques utilized for preparation of nanofibers centrifugal jet spinning covets merits due to its high efficiency production rate, cost adequacy and operational safety. In the present manuscript we report preparation of TiO2 nanofibers by Sol–Gel Course with Centrifugal Jet Spinning using tetrabutyl titanate as main organic titanium precursor. Herein we demonstrate that a well-developed crystallinity and a perfect morphology of TiO2, from Nano to micro-scales, can be achieved after decomposition of polymer and removal of carbon. Effect of various factors such as PVP content, speed of rotation, humidity and heat treatment on the fiber growth was investigated. Effect of variation in soaking time and different temperatures on the TiO2 nanofiber grain growth was also investigated. Phase structure of TiO2 nanofibers was characterized by X-ray diffraction (XRD). Microstructure of the nanofibers was analyzed using Scanning Electron Microscopic (SEM) studies and Transmission Electron Microscope (TEM) studies. Kinetic exponents of grain growth were likewise acquired by with the help of an image processing software. Outcomes of our investigations show that crystallinity and morphology of grains of fibers are highly sensitive to temperature and soaking time. Image analysis demonstrates that sintering temperature greatly affects the crystallinity and grain size of the nanofibers over 700 °C.

Pedestrian trajectory prediction is a challenging task as there are three properties of human movement behaviors which need to be addressed, namely, the social influence from other pedestrians, the scene constraints, and the multimodal (multi-route) nature of predictions. Although existing methods have explored these key properties, the prediction process of these methods is autoregressive. This means they can only predict future locations sequentially. In this paper, we present NAP, a non-autoregressive method for trajectory prediction. Our method comprises specifically designed feature encoders and a latent variable generator to handle the three properties above. It also has a future-time-agnostic context generator and a future-time-oriented context generator for non-autoregressive prediction. Through extensive experiments that compare NAP against eleven recent methods, we show that NAP achieves state-of-the-art trajectory prediction performance.

The grain size and the ferroelectric morphology are the two most important factors in the research and development of advanced dielectric devices. It is important to synthesize nanostructures in order to achieve optimal grain size and inhibit grain growth while controlling the sintering parameters. It is also important to find new methods to study the grain growth during densification. BaTiO3 films were successfully obtained via the sol-gel spin coating method. In this paper, we report the deposition of nanostructured BaTiO3 thin film by spin coating of sol-gel precursors. The densification, grain growth and microstructure evolution have been studied. Moreover, a novel physical and mathematical fractal analysis have been applied successfully to the densification and nano grain growth of BaTiO3 thin film. The discrepancy between the fractal dimension and the grain growth with increasing temperatures and soaking time are presented and discussed. This is the peer-reviewed version of the article: Aminirastabi, H., Xue, H., Mitić, V.V., Lazović, G., Ji, G., Peng, D., 2020. Novel fractal analysis of nanograin growth in BaTiO3 thin film. Materials Chemistry and Physics 239, 122261. [https://doi.org/10.1016/j.matchemphys.2019.122261] Published version: [https://hdl.handle.net/21.15107/rcub_dais_6886]

Construction of transition metal oxides-based carbonaceous nanostructures has been regarded as one of the most effective strategies to prepare the electrodes for high-performance supercapacitors. I...

We report on the power and linearity performance of metal organic chemical vapor deposition grown AlGaN channel polarization-graded field-effect transistor (PolFET). The fabricated transistors with 3-D electron channels showed nearly flat transconductance profiles. Maximum ${f}_{T}$ and ${f}_{\text {max}}$ of 23 and 65 GHz were measured for 0.7- $\mu \text{m}$ gate-length transistors, corresponding to an ${f}_{T}$ - ${L}_{G}$ product of 16.2 GHz $\cdot \mu \text{m}$ . Load-pull measurement at 10 GHz revealed a maximum output power of 2 W/mm with a maximum small signal gain of 16 dB. Two-tone measurement at 10 GHz showed an OIP3 of 33 dBm for 150- $\mu \text{m}$ device width and a corresponding linearity figure-of-merit OIP3/ $\text{P}_{\text {DC}}$ of 3.4 dB. These results suggest that PolFETs could be useful for high-frequency applications requiring high linearity.

In this paper, we introduce a new likelihood ratio imbalance degree (LRID) to measure the class-imbalance extent of multi-class data. Imbalance ratio (IR) is usually used to measure class-imbalance extent in imbalanced learning problems. However, IR cannot capture the detailed information in the class distribution of multi-class data, because it only utilises the information of the largest majority class and the smallest minority class. Imbalance degree (ID) has been proposed to solve the problem of IR for multi-class data. However, we note that improper use of distance metric in ID can have harmful effect on the results. In addition, ID assumes that data with more minority classes are more imbalanced than data with less minority classes, which is not always true in practice. Thus ID cannot provide reliable measurement when the assumption is violated. In this paper, we propose a new metric based on the likelihood-ratio test, LRID, to provide a more reliable measurement of class-imbalance extent for multi-class data. Experiments on both simulated and real data show that LRID is competitive with IR and ID, and can reduce the negative correlation with F1 scores by up to 0.55.

The LDA-1/2 method for self-energy correction is a powerful tool for calculating accurate band structures of semiconductors, while keeping the computational load as low as standard LDA. Nevertheless, controversies remain regarding the choice between (1/2)e and (1/4)e charge stripping from the atoms in group IV semiconductors, the incorrect direct band gap predicted for Ge, and inaccurate band structures for III–V semiconductors. Here we propose an improved method named shell-LDA-1/2 (shLDA-1/2 for short), which is based on a shell-like trimming function for the self-energy potential. With the new approach, we obtained improved band structures for group IV, and for III–V and II–VI compound semiconductors. In particular, with shLDA-1/2 we reproduced the complete band structures of Ge in good agreement with experimental data. Moreover, we have defined clear rules for choosing the amount of charge that ought to be stripped in covalent semiconductors, i.e., (1/2)e or (1/4)e.

Industrial application of superhydrophobic surfaces is often hindered by complicated process and sophisticated machines. A facile wet etching method (sandblast, HCl and sandblast/HCl) with vapor deposition of PFDS (1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane) was applied to fabricate superhydrophobic surface of heat-resistant steel used for vane. The coating component, surface morphology and surface roughness parameters of sample were observed by attenuated total reflectance Fourier transform infrared spectroscopy, scanning electron microscopy and atomic force microscopy. Static water contact angle (WCA) of samples with and without PFDS coating was measured by contact angle goniometer. The results showed that WCA values of polished, sandblast, HCl and sandblast/HCl-etched samples are 98°, 97°, 100° and 101°, respectively, and increase to 112°, 148°, 151° and 154° after vapor deposition of PFDS. The sandblast/HCl-etched sample with PFDS coating shows higher superhydrophobicity because of very large surface roughness and lotus protrusion-like structure. The superhydrophobicity of this fabricated surface has no obvious change after 38 cycles of the film adhesion test, indicating excellent durability.