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Metric-based methods have attained promising performance for few-shot image classification. Maximum Mean Discrepancy (MMD) is a typical distance between distributions, requiring to compute expectations w.r.t. data distributions. In this paper, we propose Attentive Maximum Mean Discrepancy (AMMD) to measure the distances between query images and support classes for few-shot classification. Each query image is classified as the support class with minimal AMMD distance. The proposed AMMD assists MMD with distributions adaptively estimated by an Attention-based Distribution Generation Module (ADGM). ADGM is learned to put more mass on more discriminative features, which makes the proposed AMMD distance emphasize discriminative features and overlook spurious features. Extensive experiments show that our AMMD achieves competitive or state-of-the-art performance on multiple few-shot classification benchmark datasets. Code is available at https://github.com/WuJi1/AMMD. • We propose Attentive Maximum Mean Discrepancy (AMMD) metric in few-shot learning. • We use attention mechanisms to learn the importance of features in distributions. • Extensive experiments and analyses verify the effectiveness of the proposed AMMD. [ABSTRACT FROM AUTHOR]

• The rapid development of electronic sensors triggered the research of optical tactile sensor. • We review the recent progress in the field of optical tactile sensor, focusing on the latest research results. • We guide the reader to review paper and compare those different types of optical tactile sensors. Over the past decade, flexible electronics has become a cutting-edge technology owing to its broad applications in robotics, health monitoring, and human-machine interface. The recent development of flexible electrical tactile sensor triggers the research of optical tactile sensors due to their potentials in high-sensitivity, high-precision, low power consumption, and anti-electromagnetic interference. Here, this review mainly discusses the advances and applications of silica fiber, polymer fiber, hydrogel, and micro/nanofiber based tactile sensors, specifically, focusing on the latest research results and on the necessary technologies to enable the health monitoring, robotics, and human-machine interface applications. Furthermore, future outlooks in developing skin-like optical tactile sensors are also presented. [ABSTRACT FROM AUTHOR]

• Corporate mergers and acquisitions effectively mitigate expected default frequency. • Mergers and acquisitions alleviate corporate financing constraints and boost information transparency. • Effect more pronounced in younger firms with weaker governance in less marketized areas. This study investigates the influence of corporate mergers and acquisitions on debt default risk by analyzing a dataset of 14,990 A-share listed companies from 2010 to 2021. The results demonstrate that corporate mergers and acquisitions effectively mitigate expected default frequency, a conclusion that withstands a variety of robustness checks. Through mechanism testing, it's found that mergers and acquisitions alleviate corporate financing constraints and boost information transparency, subsequently lowering debt default risk. The heterogeneity analysis further reveals that this mitigating effect is particularly pronounced in younger companies, those with weaker internal governance, and companies situated in less marketized regions. [ABSTRACT FROM AUTHOR]

Deep neural networks suffer from the catastrophic forgetting phenomenon when trained on sequential tasks in continual learning, especially when data from previous tasks are unavailable. To mitigate catastrophic forgetting, various methods either store data from previous tasks, which may raise privacy concerns, or require large memory storage. Particularly, the distillation-based methods mitigate catastrophic forgetting by using proxy datasets. However, proxy datasets may not match the distributions of the original datasets of previous tasks. To address these problems in a setting where the full training data of previous tasks are unavailable and memory resources are limited, we propose a novel data-free distillation method. Our method encodes knowledge of previous tasks into network parameter gradients by Taylor expansion, deducing a regularizer relying on gradients in network training loss. To improve memory efficiency, we design an approach to compressing the gradients in the regularizer. Moreover, we theoretically analyze the approximation error of our method. Experimental results on multiple datasets demonstrate that our proposed method outperforms the existing approaches in continual learning. • We focus on the setting that the training data of previous tasks are unavailable. • We propose a novel memory efficient data-free distillation method. • Our method encodes knowledge of previous datasets into parameters for distillation. • Our method shows superiority on multiple continual learning benchmark datasets. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-omics approach was first used to explore stress resistance mechanisms. • Pseudomonas sp. LW60 removed 100 % nitrogen at C/N 10 and 4 °C. • High ammonia nitrogen removal efficiency (81.31 %) at C/N < 6 and 4 °C. • Central carbon and amino acid pathways were enhanced under low C/N ratio stress. In practical engineering, nitrogen removal at low temperatures or low C/N ratios is difficult. Although strains can remove nitrogen well at low temperatures, there is no research on the performance and deep mechanism of strains under low C/N ratio stress. In this study, Pseudomonas sp. LW60 with superior nitrogen removal efficiency under low C/N ratio stress was isolated at 4 °C. With a C/N ratio of 2–10, the NH 4 +-N removal efficiency was 40.02 %-100 % at 4 °C. Furthermore, the resistance mechanism of Pseudomonas sp. LW60 to low C/N ratio stress was deeply investigated by multi-omics. The results of transcriptome, proteome, and metabolome revealed that the resistance of strain LW60 to low C/N ratio stress was attributed to enhanced central carbon metabolism, amino acid metabolism, and ABC transporters, rather than nitrogen removal pathways. This study isolated a strain with low C/N ratio tolerance and deeply explored its tolerance mechanism by multi-omics. [ABSTRACT FROM AUTHOR]

Metal-free graphene-based nanocomposites with small organic molecules interaction are studied as a lightweight, wide bandwidth, and strong absorption microwave absorption material. During hydrothermal process, graphene oxide (GO) precursors are reduced and aggregated into 3D porous network structure. Meanwhile, anthraquinone molecules are intercalated and immobilized on RGO surface through noncovalent π–π stacking. For the obtained RGO@anthraquinone, noncovalent functionalization at interface can modify the electronic states and regulate the electrical conductivity of graphene substrate and its sheet-like structure can be largely maintained. Integrating the intrinsic 3D porous structure, good impedance matching, high conductive loss, and noncovalent interaction, the as-achieved RGO@anthraquinone composites exhibit excellent microwave absorption performance in the X and Ku band. Such as RGO@2-hydroxyanthraquinone (2-HAQ), its optimal absorption toward microwave can reach −54.2 dB at 12.8 GHz with a thickness of 3.0 mm, and its effective absorption bandwidth lower than −10 dB exceeds 7.0 GHz (from 10.96 to 18.0 GHz). When the thickness is controlled between 2.8 and 3.5 mm, the effective absorption bandwidth can cover the whole X and Ku bands (8.0–18.0 GHz). This opens ways to achieve new microwave absorbers with high-performance and provides more opportunities to activate MA behavior on carbon-based metal-free absorbers. Image 1 [ABSTRACT FROM AUTHOR]

• The coordination and interaction between different dimensions of the dynamic capacities help the enterprises achieve high-maturity digitalization. • Innovation capacity has a universal effect on the high-maturity digitalization. • Different configurations have different effects on enterprise market performance and financial performance. Based on the dynamic capability theory, this paper integrates the fsQCA and PSM methods to examine the antecedent configuration and subsequent performance of the digital transformation of Chinese listed manufacturing enterprises. The study shows that the following three configurations can lead to high-maturity digital transformation: efficient innovation, robust adaptation, and forward-looking innovation. At the same time, different configurations have different effects on enterprise performance. For instance, "efficient innovation" and "robust adaptation" can significantly improve the financial performance of enterprises but have no significant effect on market performance. While on the other hand, "forward-looking innovation" can negatively affect the market performance of enterprises but has no significant effect on the financial performance. [ABSTRACT FROM AUTHOR]

Let H = { H 1 , … , H k } be a set of connected graphs. A graph is said to be H -free if it does not contain any member of H as an induced subgraph. We show that if the following statements hold, • | H | ≥ 2 , • K 1 , 3 ∈ H , • for any integer n 0 , every 2 -connected H -free graph G of order at least n 0 is supereulerian, i . e . , G has a spanning closed trail, then H ∖ { K 1 , 3 } contains an N i , j , k or a path where N i , j , k denotes the graph obtained by attaching three vertex-disjoint paths of lengths i , j , k ≥ 0 to a triangle. As an application, we characterize all the forbidden triples H with K 1 , 3 ∈ H such that every 2 -connected H -free graph is supereulerian. As a byproduct, we also characterize minimal 2-connected non-supereulerian claw-free graphs. [ABSTRACT FROM AUTHOR]

Steam is an important medium for energy transmission in industrial parks. For providing steam to multiple users, it is key to determine the optimal number of steam levels in the design of steam system. With the increasing number of steam levels, the energy demand and supply can be better matched but the investment of steam pipeline network increases. In this paper, this trade-off is solved by a two-stage method. In the first step, a mixed-integer nonlinear programming (MINLP) model is established to minimize the total cost of the steam system of the industrial park, while a simple pipeline network optimization model is involved. The optimal scheme of steam production including the number of steam levels can be obtained automatically. In the second step, GeoSteiner algorithm is used for solving Rectilinear Steiner Minimum Tree (RSMT) model to further optimize the pipeline network separately. In a case study, the optimal number of steam levels is 3. The total annual cost (TAC) of the optimal steam system is 11.4%, 5.28%, and 1.43% lower than the schemes with the lowest pipeline network cost (1 level of steam), the best matching between heat supply and heat demand (6 levels of steam), and the largest electricity generation capacity (4 levels of steam), respectively. The sensitivity analysis indicates that the overall heat load required by consumers and the distance between the energy station and consumers can make a difference to the optimal number of steam levels. • Steam production and steam supply in industrial park are optimized simultaneously. • Trade-off between electricity generation and pipeline cost is considered. • Effects of the load and distance of consumers and economic parameters are discussed. [ABSTRACT FROM AUTHOR]

Electromagnetic forming is a high-speed forming method that can significantly improve the forming limit of metals. A high-density pulse current is induced on the workpiece during the forming process, however, research on the effects of the induced current on the material properties is lacking. This paper presents an experimental study designed to ensure the sheet is not deformed after discharge of the coil. Properties of rolled 5052 aluminum alloy treated by induced current were studied using mechanical testing, electron backscatter diffraction, and electron microscopy. The tensile strength, yield strength and elongation of the material increased by 6.9%, 8.7%, and 13.2%, respectively, after treatment using a voltage discharge of 6 kV, compared with the original rolled sheet. After an induced current is applied, dimples on the material are larger and more uniform, indicating better plasticity characteristics. Furthermore, the average grain size increases slightly and the subgrain content increases. The texture strength changes, as the Brass and Goss textures increase. The dislocation density is reduced, the distribution of dislocations becomes more uniform, and dislocation accumulation at grain boundaries weakens. • The influence of induced pulse current on the material mechanical properties and microstructure is analyzed. • The elongation, yield strength, and tensile strength of the alloy improve after induced current treatment. • After induced current treatment, the cube and copper texture decrease, whereas the brass texture increases, and the dislocation density of the material is reduced. [ABSTRACT FROM AUTHOR]

Fowl adenovirus serotype-4 (FAdV-4) is highly lethal to poultry, making it one of the leading causes of economic losses in the poultry industry. However, a small proportion of poultry can survive after FAdV-4 infection. It is unclear whether there are genetic factors that protect chickens from FAdV-4 infection. Therefore, the livers from chickens uninfected with FAdV-4 (Normal), dead after FAdV-4 infection (Dead) or surviving after FAdV-4 infection (Survivor) were collected for RNA-seq, and 2,649 differentially expressed genes (DEGs) were identified. Among these, many immune-related cytokines and chemokines were significantly upregulated in the Dead group compared with the Survivor group, which might indicate that death is related to an excessive inflammatory immune response (cytokine storm). Subsequently, the KEGG results for DEGs specifically expressed in each comparison group indicated that cell cycle and apoptosis-related DEGs were upregulated and metabolism-related DEGs were downregulated in the Dead group, which also validated the reliability of the samples. Furthermore, GO and KEGG results showed DEGs expressed in all three groups were mainly associated with cell cycle. Among them, BRCA1, CDK1, ODC1 , and MCM3 were screened as factors that might influence FAdV-4 infection. The qPCR results demonstrated that these 4 factors were not only upregulated in the Dead group but also significantly upregulated in the LMH cells after 24 h infection by FAdV-4. Moreover, interfering with BRCA1, CDK1, ODC1 , and MCM3 significantly attenuated viral replication of FAdV-4. And interfering of BRCA1, CDK1 , and MCM3 had more substantial hindering effects. These results provided novel insights into the molecular changes following FAdV-4 infection but also shed light on potential factors driving the survival of FAdV-4 infection in chickens. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metagenomic analysis was employed to explore bioleaching based on mixed cultures. • Long-term repeated inoculation of acidified sludge (AS) enriched Acidithiobacillus. • Functional genes encoding iron transport protein were enriched significantly. • Promotion of electron transport pathway was revealed at the gene level. • Microbial contribution of key genes related with electron transport was identified. The bioleaching utilizing indigenous microbial inoculation can continuously improve the dewaterability of sludge. In this study, metagenomic analysis was innovative employed to identify the key microorganisms and functional genes that affect the dewatering performance of sludge in the bioleaching conditioning process. The results demonstrated that long-term repeated inoculation of acidified sludge resulted in increased abundance of many functional genes associated with the transport of carbohydrate and amino acid. Additionally, genes encoding key iron transport proteins (such as afuA , fhuC , and fhuD) and genes related to electron transfer carriers in ferrous iron oxidation process (such as rus and cyc2) were significantly enriched, thereby promoting the improvement of sludge dewatering performance through enhanced iron oxidation. Notably, Acidithiobacillus , Betaproteobacteria , and Hyphomicrobium were the major sources of functional genes. This study reveals the microscopic mechanisms underlying the improvement of sludge dewaterability through bioleaching based on mixed culture from a novel perspective of gene metabolism. [ABSTRACT FROM AUTHOR]

Autonomous ship with intelligent collision avoidance and maneuvering is one of the most effective ways to solve the problem of maritime traffic accidents caused by human factors. This paper proposed a multi-stage collision avoidance model based on fuzzy set theory and Deep Reinforcement Learning(DRL). It can assist autonomous ships in achieving precise collision avoidance guidance in complex waterway traffic environments. When designing the reward function, the multi-stage collision avoidance model divides the collision avoidance process into different stages according to the relative locations and situations between ships, and adopts different fuzzy membership functions to reward the autonomous ship. When designing the training framework, Transfer Learning-Double Deep Q Network(TL-DDQN) transfers the trained neural network parameters and experience playback pool parameters to the test DRL according to the situation encountered. Simulations are conducted to verify the performance of the multi-stage collision avoidance model. The results show that the proposed model can handle the complex encounter situation well and make autonomous ship reach the target safely. • A multi stage collision avoidance decision-making strategy based on fuzzy set theory is proposed to better balance the straight-line navigation and collision avoidance operations of the ship. • A TL-DDQN deep reinforcement learning framework is proposed. • Several reward functions considering navigation characteristics, COLREGs, ship-to-ship distance are designed to ensure safety of ship navigation and avoid collision. [ABSTRACT FROM AUTHOR]

The effect of induced electro-pulsing of 7075 aluminum alloy in solid solution and pre-deformation was studied. The tensile test results show that material plasticity is recovered and strength is increased by induced electro-pulsing treatment (IEPT). As the discharge time increases, the increase in elongation becomes more obvious. Yield strength, tensile strength, and elongation of once-treated samples increased by 3.7%, 1.3%, and 9.7%, respectively, compared with the untreated sample; Those of twice-treated samples increased by 6.4%, 6.4%, and 27.8%. Microstructure characterization showed that the induced current reduces the dislocation density of the material and promotes advanced precipitation of Guinier-Preston (GP) zones. In addition, the strength of treated samples and untreated samples was almost the same after peak aging treatment, while the elongation increased by 12.15%. High resolution transmission electron microscopy (HRTEM) images show that the size of the η' phase in the treated alloy is smaller and the alloy exhibits better ductility. • Induced electro-pulsing treatment (IEPT) is used to improve the properties of 7075 aluminum alloy. • After IEPT, the plasticity of the alloy is significantly improved and the strength is slightly increased. • Induced current can promote the advance precipitation of GP region, which results in smaller η' phase after aging. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) derived carbon materials have attracted much attention as hopeful electromagnetic microwave absorbents. However, the poor impedance matching and high filler content severely limited its electromagnetic absorption application. The introduction of hollow structural engineering is beneficial to improving microwave absorption performance. Herein, we designed and constructed Ni-incorporated hollow N-doped carbon nanocages (Ni/NCNs) to reveal interfacial charge transfer in electromagnetic wave attenuation. The hollow carbon structure facilitates impedance matching, highly dispersive Ni nanoparticles not only build a dense magnetic coupling network but also generate a series of Ohmic contact heterogeneous interfaces with hollow NCNs, extremely accelerating the charge transfer and enhancing conduction loss. Thanks to hollow structure, optimized impedance matching, and abundant Ohmic contact heterogeneous interfaces, the Ni 50 /NCNs exhibit a minimum reflection loss of −57.3 dB. The results demonstrate that Ni 50 /NCNs composites have great potential to be considered efficient electromagnetic wave materials, and the designed Ohmic contact heterogeneous interfaces pave the way in the study of electromagnetic wave absorption mechanisms. Metal organic frameworks (MOFs) derived carbon materials have attracted much attention as hopeful electromagnetic microwave absorbents. However, the poor impedance matching and high filler content severely limited its electromagnetic absorption application. The introduction of hollow structural engineering is beneficial to improve microwave absorption performance. Herein, we designed and constructed Ni-incorporated hollow N-doped carbon nanocages (Ni/NCNs) to reveal interfacial charge transfer in electromagnetic wave attenuation. The hollow carbon structure facilitates impedance matching, highly dispersive Ni nanoparticles not only build dense magnetic coupling network, but also generate a series of Ohmic contact heterogeneous interfaces with hollow NCNs, extremely accelerated the charge transfer and enhanced conduction loss. Thanks to hollow structure, optimized impedance matching and abundant ohmic contact heterogeneous interfaces, the Ni 50 /NCNs exhibit a minimum reflection loss of −57.3 dB. The results demonstrate that Ni 50 /NCNs composites have great potential to be considered as the efficient electromagnetic wave materials, and the designed ohmic contact heterogeneous interfaces pave the way in the study of electromagnetic wave absorption mechanism. [Display omitted] • The microwave absorber of Ni-incorporated hollow N-doped carbon nanocages were prepared. • The RL min reaches −57.3 dB and the effective absorption bandwidth is 5.8 GHz. • Highly dispersive Ni nanoparticles generate abundant Ohmic contact heterogeneous interfaces with hollow NCNs, extremely accelerated the charge transfer and enhanced the conduction loss. [ABSTRACT FROM AUTHOR]

Abstract: The influences of Bi3+ doping on the optical properties of Er3+:Y2O3 are investigated under UV and IR excitations. The emission intensity of Er3+ is remarkably enhanced by the introduction of Bi3+ under both two excitations. The emission enhancement under UV excitation originates from the energy transfer from Bi3+ to Er3+, while under IR excitation it can be attributed to the modification of the local crystal field around the Er3+. [ABSTRACT FROM AUTHOR]

Abstract: Single crystal La2/3Sr1/3MnO3−δ manganite with an unusual structure was obtained by the optical-floating method with controlled growth in a flowing argon atmosphere. A modulated twin-like structure with phase separation characteristics in the long-range order is found. The energy-dispersive X-ray spectroscopy measurement reveals that there is a strong chemical fluctuation for different stripes, i.e. resulting from the nonstoichiometry due to oxygen deficiency. After annealing, the twin-like stripe phase disappears and the single crystal shows excellent properties. These results may be of great significance for controlled growth of oxide electronics materials with artificial superstructure-like technique. [Copyright &y& Elsevier]

Abstract: The influence of site occupancy of Li+, including substitutional and interstitial sites, on the upconversion emissions of Er3+ doped Y3Al5O12 powders is reported. The intensity of green emission increases slightly when the Li+ occupies substitutional site, but when the Li+ enters into interstitial site it enhances drastically accompanied with a change of emission spectra. These phenomena originate from the increase, induced by interstitial Li+, in the lifetime of level, the ratio of radiation rate in green emission and the absorptivity at 980nm. [Copyright &y& Elsevier]

The shuttle effect of soluble polysulfides as one of the primary bottlenecks has retard the widespread use of lithium-sulfur (Li-S) batteries. In this work, a new functional separator coating composed of pristine zirconium metal-organic framework (Co-PCN-222) with catalytic cobalt-porphyrin linker decorated carbon nanotubes (PCN@CNT) was presented for addressing this problem. Benefiting from powerful adsorption and catalytic activity of the uniformly dispersed cobalt and nitrogen sites in porphyrin linkers as well as the fast electron transport network provided by highly conductive CNT, the polysulfide redox kinetics is greatly boosted and the shuttle effect is inhibited to a large extent. Accordingly, the Li-S batteries coupling with PCN@CNT coated separator delivers a specific capacity as high as 1157 mAh g−1 at 0.1 C, good rate capability with a reversible capacity of 696 mAh g−1 under 2 C as well as excellent cyclic performance with a low average capacity attenuation rate of 0.067% upon 500 cycles at 1 C. This work will open up great opportunities in the development of pristine MOFs-based separator coating for advanced Li-S batteries. [ABSTRACT FROM AUTHOR]

Abstract: The magnetic and transport properties of Pr0.5Ca0.5MnO3 with a CE-type antiferromagnetic structure were systematically investigated. A distinctive sequence of multiple magnetic transitions is found: paramagnetic (PM)–ferromagnetic (FM)–antiferromagnetic (AFM)–spin glass (SG) transitions. The results show that the low-temperature SG state is different from a conventional SG but has a reentrant character. The reentrant SG behavior accompanied with colossal magnetoresistance might be due to the competing interaction between FM and the CE-type AFM matrix. Also, this phase may be related to the disorder due to the variance of tolerance factor t and characteristic parameter (reflecting A-site cation size variance). Meanwhile, this kind of reentrant SG state exists in most manganites and it shows a complex magnetic ground state. The present experimental data establishes that Pr0.5Ca0.5MnO3 compound shows the coexistence of FM clusters and SG clusters in the background of an AFM matrix. Here, all the rich variety of phases can be explained by the bandgap modified locally by strain within each grain. At the same time, the present results indicate also that Pr0.5Ca0.5MnO3 has a ground state, which shows the presence of some FM clusters in the background of the remaining region in a spin frozen state. The RSG phenomena should be a universal characteristic of manganites with CE-type AFM structure and it is very sensitive to the subtle disorder. [Copyright &y& Elsevier]

The exploitation of multicomponent nanocomposites with suitable hierarchical heterostructures is an attractive strategy to obtain high-performance microwave absorption materials. In this work, a versatile strategy is proposed for synthesizing 1D hierarchical core-shell structure with Co-ZIF arrays derived carbon nanotubes (CNTs) coupled on cotton fiber (CF)-supported MXene shell (Co/CNTs-MXene@CF). The advantages of Co-ZIF arrays derived CNTs and MXene dielectric layer can be efficiently integrated to realize multiple electron transfer paths by the construction of the well-designed hierarchical structure. The designed heterogeneous composites consist of the interlayer MXene and CNTs grow sequentially from the outermost Co-ZIF nanosheet arrays with appropriate conductivity and abundant heterointerfaces, which can improve the conduction loss and interfacial polarization response. As expected, the elaborate 1D Co/CNTs-MXene@CF heterostructures exhibit the optimal reflection loss of −61.41 dB at 2.52 mm and effective absorption bandwidth reaches 5.04 GHz with a thickness of only 1.5 mm. The experimental results demonstrate that the optimized structure dramatically improves the electromagnetic wave attenuation behavior. This work illuminates a new design strategy for the preparation of multicomponent composites with reasonable hierarchical structure that enables high-performance microwave absorption materials. The advantages of Co-ZIF arrays derived CNTs and MXene dielectric layer can be efficiently integrated to realize multiple electron transfer paths by the construction of the well-designed hierarchical structure. The reasonable design of hierarchical heterostructures provides new inspiration in the field of microwave absorption research. [Display omitted] [ABSTRACT FROM AUTHOR]

Here, we synthesized LaNiO 3 microspheres by a simple hydrothermal synthesis and subsequent annealing process. The LaNiO 3 microspheres are characterized by TG-DSC, XRD, FESEM, TEM and VAN. Noticeably, owing to the effective synergism between significant dielectric loss and optimum impedance match, LaNiO 3 microspheres exhibit significantly remarkable attenuation capability and wide-band respond. Therefore, the possible mechanism of microwave absorption enhancement is carefully investigated. A minimum reflection loss intensity −30.6 dB of LaNiO 3 microspheres can be achieved and a broad effective absorbing bandwidth (reflection loss reaches −10.0 dB) of 4.72 GHz (8.16–12.88 GHz) at the thickness of 2.0 mm. Furthermore, the overall effective bandwidth is obtained up to 14.5 GHz from 3.5 GHz to 18 GHz, covering more than 90% of the measured frequency range. It is expected that the LaNiO 3 microspheres could be used to design efficient microwave absorption materials. • The LaNiO 3 microspheres were obtained by a hydrothermal synthesis and subsequent annealing process and firstly tried for microwave absorption. • Enhanced dielectric loss and promoted impedance matching are achieved. • The minimum reflection loss reaches −30.6 dB, with a broad effective absorbing bandwidth of 4.72 GHz (8.16-12.88 GHz) at the thickness of 2.0 mm. [ABSTRACT FROM AUTHOR]

Abstract: A typical reentrant spin-glass (RSG) behavior was observed and discussed for the phase-separated (Sm,Nd)0.5Ca0.5MnO3 manganites. The characteristic time constants of the spin-glass state were calculated based on the critical slowing down model. It was found that the characteristic time constant of the phase-separated (Sm,Nd)0.5Ca0.5MnO3 manganites are larger than those of the conventional SG state. Such results indicate that most probably there exist complicated magnetic interplays in the ground state of the compounds. [Copyright &y& Elsevier]

• There were two oscillation patterns for adhered oil drop in the flow water, which can be transformed into each other. • The contact angle evolution of oscillating oil drop was analyzed. • The force mechanism of the three-phase contact point of the oil drop on the surfaces was carried out. • The sensitivity analysis of the factors affecting the oil drop oscillation behaviors was obtained. The oscillation of oil droplets on surfaces with different wettability in laminar flow field affected the initial movement behaviors of oil droplets, which was studied experimentally and theoretically in the paper. In the initial oscillation stage, the contact line of the oil drop on the substrate did not move, while the center mass and contact angle hysteresis of the droplet have changed. It was found that there were two oscillation patterns for adhered oil drop in the flow water, one was the up-down oscillation, the other was left-right oscillation, which can be transformed into each other. The contact angle evolution of oscillating oil drop was analyzed. It was found that with the increase of water flow velocity, the difference between the maximum and minimum contact angles of adhered oil drops on different surfaces was increasing, and the contact angle of oil drops on oleophobic surfaces underwater was more likely to exceed the advancing contact angle during the oscillation process. The force analysis of the three-phase contact point of the oil drop on the surfaces was carried out, and the oscillation behaviors of the oil drop were explained theoretically. The sensitivity analysis of the factors affecting the oil drop oscillation behaviors was carried out, and the influences of the oil drop height and the surface wettability on the oil drop oscillation frequency and amplitude was obtained. [ABSTRACT FROM AUTHOR]

Let H be a set of connected graphs. A graph G is said to be H -free if G does not contain any member of H as an induced subgraph. A graph G having a perfect matching is called k -extendable if every matching of size k in G can be extended to a perfect matching. In this paper, we characterize the sets H with | H | = 2 such that every (k + 1) -connected H -free graph G of sufficiently large order permitting a perfect matching is k -extendable for k ∈ { 1 , 2 }. [ABSTRACT FROM AUTHOR]

Springback is a key challenge in quasi-static (QS) stamping, which seriously affects the forming accuracy of aluminum alloy. A multi-pulse and low-amplitude current is widely used to reduce the springback of aluminum alloys. However, the increase in workpiece of current severely affects the material performance. Herein, a single-pulse and high-amplitude current is employed to eliminate springback of V-shaped parts in a short time (<500 μs). With an increase in discharge voltage, the springback of V-shaped parts decreases. Compared with QS stamping, the average values of yield strength and tensile strength decrease by 9.2% and 1.2%, while the average values of elongation increases by 18.9% after discharge under 10 kV. The increase in temperature of tensile specimen is found to be 5.6 °C at 10 kV. Thus, the thermal effect caused by a pulse current renders a small influence on the properties of V-shaped components. Moreover, the texture and microstructure before and after discharge are studied using electron backscattered diffraction electron backscattered diffraction and transmission electron microscopy measurements. Briefly, the grain size increases and texture strength decreases under the influence of pulse current. Also, dislocation entanglement at grain boundaries is reduced, compromising the strength and springback effect. This study provides experimental and theoretical bases for eliminating springback of Al alloys with a large pulse current. • The springback of the V-shaped parts is completely eliminated in the presence of pulse current • The influence of single-pulse and high-amplitude current on the material mechanical properties and microstructure is analyzed. • The yield strength and tensile strength decrease after discharge treatment, whereas the elongation increases. • After pulse current treatment, the proportion of low-angle grain boundaries (LAGBs) decreased [ABSTRACT FROM AUTHOR]

The effect of high hydrostatic pressure (HHP) on the solubilization of a class-A G protein-coupled receptor, the silkmoth pheromone biosynthesis-activating neuropeptide receptor (PBANR), was investigated. PBANR was expressed in expresSF + insect cells as a C-terminal fusion protein with EGFP. The membrane fraction was subjected to HHP treatment (200 MPa) at room temperature for 1–16 h in the presence of 0–2.0% (w/v) n -dodecyl-β-D-maltopyranoside (DDM). The solubilization yield of PBANR-EGFP in the presence of 0.6% (w/v) DDM increased to ~ 1.5-fold after 1 h HHP treatment. Fluorescence-detection size-exclusion chromatography demonstrated that the PBANR-EGFP ligand binding ability was retained after HHP-mediated solubilization. The PBANR-EGFP solubilized with 1.0% DDM under HHP at room temperature for 6 h retained ligand binding ability, whereas solubilization in the absence of HHP treatment resulted in denaturation. [ABSTRACT FROM AUTHOR]

In order for thin film solar cells to have high conversion efficiency, their front electrodes must have high electrical conductivity and optical transparency. The front electrode is made of transparent conductive oxide films. In this work, boron-doped ZnO films were grown using the low pressure chemical vapor deposition technique, and they were used as the front electrodes for amorphous silicon thin film solar cells. The as-grown boron-doped ZnO films have good optical properties, but their electrical properties still need to be improved for applications in thin film solar cells. This work demonstrated that the electrical properties of the as-grown boron-doped ZnO films can be significantly enhanced by annealing in hydrogen atmosphere, and at the same time their good optical properties were maintained. By using the annealed boron-doped ZnO films in amorphous silicon thin film solar cells, it was found that their conversion efficiency was remarkably increased from 7.32% to 8.92%. [ABSTRACT FROM AUTHOR]

7075 aluminum alloy has high strength but its formability is poor at room temperature. To improve its plastic deformation capability, a new forming method, electrically assisted electromagnetic forming (EAEMF), is introduced and investigated. Our results indicate that the major and minor strain (i.e. the forming limits) of the material following EAEMF increases by 42.3% and 40.0%, respectively, compared to (conventional) electromagnetic forming (EMF). The respective increase thanks to the new method is even higher (by 76.4% and 83.9%) compared to quasi-static (QS) deformation. Furthermore, the yield strength and tensile strength of the material are reduced by 3.6% and 2.6%, compared with conventional EMF, while the elongation can be increased by 21.6% using EAEMF. The texture and microstructure of the alloy were investigated by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The results show that both grain size and texture strength decrease after EAEMF, while the brass and S textures become more dominant. The dislocation density of the material used for EAEMF is low, and directional alignment of dislocations occurs. This is related to the impulse current promoting the dislocation motion. In addition, Joule heating (by the electric current) enables a dynamic recovery during the deformation process, which reduces both the flow stress and the effect of work hardening. However, it also increases elongation. • The technology of electrically-assisted electromagnetic forming(EAEMF) is proposed for the first time, which is used to break through the limitation of EMF. • EAEMF process can improve the forming limit and energy efficiency. • Under the action of pulse current, the dislocation density decreases, and a part of dislocations show directional arrangement. • The pulse current did not change the types of texture, but changed the volume fraction of different textures. [ABSTRACT FROM AUTHOR]