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In this paper, we study the nonlinear Choquard equation { − Δ u + λ u = (I 2 ∗ | u | p) | u | p − 2 u in Ω , u ∈ H 0 1 (Ω) , where Ω ⊂ R N is an unbounded domain, ∂ Ω ≠ ∅ is bounded, λ ∈ R + , p = 2 if N = 3, 4, 5 or 2 < p < 7 3 if N = 3. By global compactness analysis, we show that the problem has at least one positive high energy solution. [ABSTRACT FROM AUTHOR]

Although the sealing mechanism of the embedded magnetic fluid seal is unclear, it is an effective way to improve the performance of the ordinary magnetic fluid seal. Embedded magnetic seals can be divided into diverging and converging embedded magnetic fluid seals, according to the direction of leakage of the sealed medium. This article mainly focuses on presenting a sealing device that can observe the change in the shape of the magnetic fluid film and investigate the mechanism of diverging and converging embedded magnetic fluid seals. The pressure transfer mechanism of the embedded magnetic fluid seal with a large gap was studied through experiments. Numerical analysis of the magnetic field distribution in the seal gap and calculation of the theoretical pressure capacity of the embedded magnetic fluid seal are produced on the basis of embedded magnetic fluid seal theory. The experimental pressure capacity is compared with the theoretical pressure capacity to verify the correctness of the embedded magnetic fluid seal pressure capacity theory. The research has investigated the effect of the number of magnetic fluid film ruptures on the self-restoring capacity of embedded magnetic fluid seals, compared with the self-restoring capacity of diverging and converging embedded magnetic fluid seals, and analyzed the data. The results illustrated that the experimental pressure capacity of the embedded magnetic fluid seal matched well with the theoretical pressure capacity, which verifies the correctness of the embedded magnetic fluid seal theory. The pressure transfers from one chamber to another when the pressure difference between the two sides of the magnetic fluid film under the pole tooth is larger than the pressure capacity of the magnetic fluid seal, and the air will enter from the high-pressure side seal chamber to the low-pressure side seal chamber, in turn. As the inlet pressure increases, the pressure trend in the radial chamber of the embedded magnetic fluid seal differs from that in the axial chamber. When the seal fails, the magnetic fluid shows microleakage and complete leakage. As the number of magnetic fluid film ruptures increases, the self-restoring capacity first decreases and then increases. The self-restoring capacity of the converging embedded magnetic fluid seals is better than that of the diverging embedded magnetic fluid seals. [ABSTRACT FROM AUTHOR]

In order to enhance the adsorption property of adsorbent, surface modification of existing adsorption materials has always been an interesting and challenging topic. Herein, the flower-like MnO2 nanowires (MNs) with three dimensions surface area and great adsorption property was successfully prepared by two-step hydrothermal route via MnO2 nanosheets in-situ growth on MnO2 nanowires. As an adsorbent, the MNs was evaluated for the removal of methylene blue (MB) from the aqueous solution. The effect of pH value, contact time, adsorbent dose, adsorption equilibrium, kinetics adsorption process, and isothermal models was investigated. The results showed that the maximum adsorption capacity of MNs of 2 g/L attained 34.247 mg/g at 5 minutes, and kinetics of MB were found fitting using the Langmuir model and the pseudo-first-order model, respectively. Furthermore, the adsorption capacity can be kept over 90% after five adsorption cycles. Therefore, the composite material can be a promising tool for developing a large variety of efficient and stable adsorbents by combining with different nanostructures for dyeing wastewater treatment. [ABSTRACT FROM AUTHOR]

The general design equations are derived for arbitrary odd-way Bagley polygon power divider (BPPD) with filtering response and notch band. Firstly, conditions are derived to achieve a perfect input port impedance matching at centre frequency. Then, the formulas of introduced transmission zeros (TZs) are obtained for high-frequency selectivity, wide upper stopband and notch band. Based on the deduced equations, wideband BPPD (WBPPD), filtering BPPD (FBPPD) and FBPPD integrating notch band (FBPPD-N) with arbitrary odd-way power splitting are designed. Finally, a FBPPD-N with a wide passband bandwidth is fabricated and measured to verify the presented ideal. The experimental results indicate that the proposed FBPPD-N has compact size, high-frequency selectivity, wide upper stopband and required notch band. Consequently, the presented general design equations can provide effective guidance for the design of arbitrary odd-way power splitting FBPPD-N. [ABSTRACT FROM AUTHOR]

To improve the pressure capability of ferrofluid seals with small clearance, a converging ferrofluid seal with double magnetic sources was designed. The magnetic field distribution in the clearances of the converging ferrofluid seal was studied by employing the finite-element method, and the theoretical pressure capability of the seal is calculated. The effects of ferrofluid injection volume, radial clearance, axial clearance, and the numbers of radial pole teeth and axial pole teeth on the pressure capabilities of converging ferrofluid seal device were investigated by experimental methods and compared with the experimental pressure capability of the stepless ferrofluid seal. The results show that the experimental and theoretical pressure capabilities of the converging ferrofluid seal are in good agreement. The saturated ferrofluid injection volume of the converging ferrofluid seal device is 1 mL. The experimental pressure capability of the converging ferrofluid seal does not decrease with increasing clearance or decreasing number of pole teeth. The pressure capability of the converging ferrofluid seal is related not only to the size of the clearance but also to the number of pole teeth. The pressure capability of the converging ferrofluid seal is better than that of the stepless ferrofluid seal. [ABSTRACT FROM AUTHOR]

The moisture stability of an asphalt mixture was enhanced with cement, hydrated lime, and an anti-stripping agent (called AMR II) to improve the adhesive bond of asphalt with the aggregate. A total of eight asphalt binders and three aggregates (crushed gravel, limestone, and granite) were used for the preparation of different asphalt mixtures. Indirect tensile strength and residual stability tests were carried out to determine the moisture stability. The surface free energy (SFE) of the asphalt binder and aggregates were measured using the sessile drop method and universal sorption device method, respectively. Based on the SFE method, the cohesive, adhesive, and stripping energies of the asphalt and asphalt mixtures were studied. Moreover, the SFE parameters were introduced while analyzing the correlation of the cohesive, adhesive, and stripping energies of the asphalt with the moisture stability. The results show that the incorporation of a single or compound anti-stripping agent can improve the moisture stability of the asphalt mixture, and the improvement effect of compound agents is greater. Furthermore, the SFE components improved after the addition of the anti-stripping agent. The addition of the anti-stripping agent influenced the cohesive and adhesive energy remarkably, whereas the aggregate type, especially its silica content and specific surface area, has a significant effect on the adhesive and stripping energy of the asphalt mixture. A linear regression analysis suggested that the SFE parameters have a good correlation with the moisture damage properties. The SFE parameters can be used to determine the moisture damage performance, and the SFE method can be used to verify the moisture stability of asphalt mixtures. [ABSTRACT FROM AUTHOR]

This article aims to elucidate the long-term water stability of a steel slag asphalt mixture. Both chemical composition and physical morphology of the steel slag were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), the Vickers hardness test and mercury injection testing. Methods of testing wet-dry (W–D) cycles and freeze-thaw (F–T) cycles were designed, and corresponding indices were proposed. The immersion rutting test was conducted to explore the variation in rutting depth, and consequently, the long-term dynamic water coefficient Kl was proposed to analyze the resistance to dynamic water flushing. A regression model was used to analyze the relationship between steel slag content and long-term water stability. Finally, the long-term corrosion characteristics of the steel slag asphalt mixture were analyzed by SEM. The results show that the addition of steel slag can improve the long-term water stability of the asphalt mixture. The water stability of the steel slag asphalt mixture declines with increasing W–D and F–T cycles. The degradation trend becomes gentle after 6 W–D cycles. The attenuation of the water stability of the mixture slows after 15 F–T cycles. The long-term water stability of the steel slag asphalt mixture was evaluated by comparing the residual stability after 6 W–D cycles (MS6) and the tensile strength ratio (TSR) of the steel slag asphalt mixture after 15 F–T cycles (TSR15). The Kl value of the steel slag asphalt mixture first increases and then decreases with increasing steel slag content, and the best effect in terms of long-term dynamic water corrosion resistance is observed for a 30% steel slag asphalt mixture. The SEM results show that, for steel slag asphalt mixture water damage, the steel slag hydrates and produces microcracking on the surface. [ABSTRACT FROM AUTHOR]

Steel slag, an industrial by-product of steel industry, has great potential in asphalt mixture as an alternative aggregate. The use of steel slag can reduce environmental pollution effectively. Meanwhile, rubber asphalt also has good eco-friendly performance. To study the adhesion between steel slag and rubber asphalt, pull-out test and net adsorption test were utilized to evaluate the adhesion between different aggregates and rubber asphalt. The morphology of different aggregates and the microstructure of aggregate-asphalt interface transition zone were observed using scanning electron microscopy (SEM). Moreover, Fourier Transform Infrared (FTIR) Spectrometer was applied to study the chemical reaction mechanism between steel slag and rubber asphalt. The results show that the adhesion property between steel slag aggregate and rubber asphalt is higher than that between diabase and rubber asphalt. The results of net adsorption and SEM test demonstrated the porous structure of steel slag can improve the adhesion between the steel slag and asphalt effectively. In addition, FTIR test results demonstrated there exists chemical reaction between steel slag and asphalt, contributing to the enhancement of the adhesion property between asphalt and steel slag aggregate. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the rheological properties and modification mechanism of crumb rubber modified asphalt (CRMA) with different reaction parameters. The test results indicate that the high reaction temperature can increase the rutting resistance but decreases the temperature stability of CRMA. At low reaction temperature, there is mainly swelling reaction in CRMA. However, the rubber particles begin to degrade in high temperature condition. The results can be confirmed by Fourier infrared spectroscopy (FTIR) and LMS tests. The LMS was well correlated with the rheological properties. The LMS may provide a simple means to determine the mechanical properties of binders. [ABSTRACT FROM AUTHOR]

To evaluate sensitivity of moisture damage resistance with chemical composition of asphalt, the adhesion energy, debonding energy as well as compatibility ratio of 69 asphalt-aggregate combinations were calculated with thermodynamical models. Pearson correlation analysis and regression analysis were carried out to correlate the relationships between asphalt chemical composition (saturates, aromatics, resins, asphaltenes, and wax) and moisture stability of asphalt mixture. The results showed that more resins and less asphaltenes in asphalt could lead to better moisture stability of asphalt mixture under dry and wet conditions, which can be effectively predicted by multiple regression models with different asphalt chemical components. [ABSTRACT FROM AUTHOR]

Styrene-butadiene-styrene (SBS) modified asphalt used in road engineering is a complicated mixture of various compositions. The present study was undertaken to evaluate the influence of different raw materials and their content on the moisture stability of SBS copolymer modified asphalt mixture. A total of 18 different combinations of base asphalt, SBS, furfural extract oil (FEO), and stabilizer were considered to prepare different SBS modified asphalt samples, and the contact angle test was carried out to determine the work of adhesion and the work of debonding of SBS modified asphalt with aggregate. Moreover, a multi-factor Analysis of Variance (ANOVA) was conducted to investigate the statistical effects of the material composition factors. The results show that the bond strength between SBS modified asphalt and aggregate is significantly affected by the source of base asphalt, but it is insensitive to the change of SBS type under dry and wet conditions. Besides, the moisture damage resistance of SBS modified asphalt improves firstly and then reduces with the rising storage of SBS, FEO, and stabilizer. Furthermore, linear regression analysis suggests that the work of adhesion under dry condition has excellent correlation with the work of debonding under wet condition. [ABSTRACT FROM AUTHOR]

Electron affinity (EA) is the energy released when an additional electron is attached to an atom or a molecule. EA is a fundamental thermochemical property, and it is closely pertinent to other important properties such as electronegativity and hardness. However, accurate prediction of EA is difficult with density functional theory methods. The somewhat large error of the calculated EAs originates mainly from the intrinsic delocalisation error associated with the approximate exchange—correlation functional. In this work, we employ a previously developed non-empirical global scaling correction approach, which explicitly imposes the Perdew-Parr-Levy-Balduz condition to the approximate functional, and achieve a substantially improved accuracy for the calculated EAs. In our approach, the EA is given by the scaling corrected Kohn-Sham lowest unoccupied molecular orbital energy of the neutral molecule, without the need to carry out the self-consistent-field calculation for the anion. [ABSTRACT FROM AUTHOR]

In this study, the population genetic structure and historical demography of the blue swimming crab,Portunus pelagicus, from southeastern sea of China were investigated using cytochromecoxidase subunit I (COI) gene of mitochondrion. A total of 889 bp segment of COI gene was sequenced, which showed a high haplotype diversity (0.6833–0.8142) and low nucleotide diversity (0.0021–0.0034). Among 30 haplotypes defined in this study, one (H1) was the most dominant (47.7%) and shared by each locality, while the majority (23) were rare and only existed in one individual. The AMOVA analysis revealed a limited population genetic structure, which suggested a high level of gene flow along the distribution areas of China. This conclusion was supported by the pairwiseFSTcomparison values. The topology of the neighbour-joining tree constructed using 30 haplotypes from four localities presented two distinct clades (clade A and clade B). Meanwhile, three sequences ofP. pelagicusdownloaded from NCBI database showed a high-level divergence with the individuals collected in our study, which might form a new cryptical species. The individuals of clade B were cryptically embedded in the whole population, with a low frequency (7.7–24.2%), while clade A accounted for 75.8–92.3%. Neutrality tests and mismatch analyses suggested a late Pleistocene population expansion for both clade A (47,000–66,000 years ago) and clade B (74,000–100,000 years ago). This study should provide insight into phylogeny, population genetic structure, conservation genetics, and sustainable management ofP. pelagicus. [ABSTRACT FROM AUTHOR]

This paper proposes a simple, precise, and controllable method to fabricate wettability-gradient surfaces. Combining electrochemical etching and lithography, different micro/nanostructures can be obtained by adjusting the etching time. After being modified by low energy substances, low adhesive superhydrophobic and sticky hydrophobic regions can be obtained on one surface. Based on the obtained adhesion gradient, droplets of different volumes can be controlled to roll off at dissimilar tilted angles via designing sticky hydrophobic tracks with different widths. Directional transportation of water droplets on curve tracks is also realized based on the anisotropic sliding angles parallel and perpendicular to the tracks. [ABSTRACT FROM AUTHOR]

Selective fabrication of superhydrophilic (S-philic) region on a superhydrophobic (S-phobic) surface requires complex technology and high cost, which has limited applications of extreme wettability patterns. In this paper, a twice-chemical-etching approach without special modification is used to prepare the extreme wettability patterns. Superhydrophobicity and superhydrophilicity can be successfully achieved after twice chemical etching for 20 seconds. The obtained patterns can maintain their extreme wettability for at least 30 days. Functional platforms with single-S-philic and multi-S-philic regions are fabricated to manipulate water and various organic liquids with water-film protection in an air environment. [ABSTRACT FROM PUBLISHER]

We determined the mortality of adult tickDermacentor silvarumOlenev after it was exposed to five entomopathogenic nematode species:Steinernema carpocapsaeBJ (Sc BJ),S. glaseriNC32 (Sg NC32),S. ceratophorumD43 (Sc D43),S. feltiaeOtio (Sf Otio) andHeterorhabditis bacteriophoraE-6-7 (Hb E-6-7). All five species had lethal effects on adult ticks, and caused significant decreases in the amount of eggs laid by engorged female ticks (P< 0.05). Among them, Hb E-6-7 and Sc BJ were the most pathogenic to female adult ticks, with mortalities ranging from 70 to 90% (P< 0.05). Engorged females were more susceptible than unfed and partially fed females. The cumulative mortalities of engorged females exposed to Hb E-6-7 and Sc BJ for 14 days were 90%, with LT50at 6.3 and 7.0 days, respectively. Dose-dependent effect was observed in the oviposition of the ticks after they were exposed to nematodes at concentrations of 1000–5000 IJs/dish. When the concentration was higher than 5000 IJs/dish, dose dependent effects disappeared (P> 0.05). All five nematode species were lethal to unfed male ticks, and there was significant difference in mortality when compared to the control group (P< 0.05); however, the pathogenicity varied among them. [ABSTRACT FROM AUTHOR]

The large-eddy simulation (LES) equations are obtained by spatially filtering the Navier-Stokes equations. The nature of the LES solution strongly depends on the filtering operation. In this paper, the effect of some smooth and discrete filters on the LES is studied with the truncated Navier-Stokes (TNS) equations model. These filters are tested with the k- 5/3 spectrum and LES of the three-dimensional homogeneous flow. Through the comparisons of the energy spectrum, the evolution of the total energy as well as the subgrid scale (SGS) dissipation with the filtered direct numerical simulation (DNS) data, the filter shape is understood to have strong influence on the final results. It is shown in this study that the physical filter is the best among the smooth filters while for the discrete filters the Pade filter delivers better results. The results of the low-order Vasilyev filter can also be improved with the same idea of the smooth physical filter. [ABSTRACT FROM AUTHOR]

Ticks are vectors to a wide range of pathogens with veterinary and medical significance. The control of ticks has created a huge public health and veterinary challenge, and it has been widely recognized that the current use of chemical acaricides has serious environmental implications. There is scant information about antlion predation on ticks. Here we present an interesting predatory behaviour of the antlion Euroleon coreaus on Haemaphysalis longicornis, which provided evidence that antlions might be one of the predators of ticks. Additionally, the antlions may synthesize potential tick biocontrol agents which can rapidly kill ticks in minutes. Further laboratory purification of the venom from ant lions, and subsequent application on ticks may provide more options for integrative control of ticks and tick-borne diseases. [ABSTRACT FROM AUTHOR]

Abstract—A mathematical model is presented describing a physical system of detonation waves propagating in a solid particle/air mixture with a wide range of solid phase concentrations. The mathematical model was solved numerically using the Second Order Godunov method, and numerical solutions were validated for detonation waves propagating in mixtures with concentrations of solid phase from 0.75 kg/m3 to 1000 kg/m. Numerical solution was obtained for detonation waves propagating in a system consisting of clouds with a small concentration of particles and a ground layer in which solid particle densities are three orders of magnitude larger than in the cloud. Three different particle concentration distributions in the ground layer were simulated and compared in terms of detonation wave structure and parameters. [ABSTRACT FROM PUBLISHER]

The complete mitochondrial genome plays an important role in the research on phylogenetic relationship. Here, we reported the first complete mitochondrial genome sequence of Varuna yui Hwang & Takeda, 1986 (Varunidae). The complete mtDNA (15,915 bp in length) consisted of 13 protein-coding genes, 22 tRNAs, two rRNA genes, and a control region. The gene arrangement was identical to those observed in the Varunidae species. The phylogenetic analysis suggested that V. yui had close relationship with other Varunidae species (Helicetient sinensis, Eriocher sinesis, etc.). The newly described genome may facilitate further comparative mitogenomic analysis within Varunidae species. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome ofCharybdis natator(family Portunidae) was obtained using Illumina and Sanger dideoxy sequencing. This genome was a typically circular molecule with a length of 15,664 bp and encoded 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. The overall base composition of this mitogenome was 34.00% for A, 11.06% for G, 36.36% for T, and 18.58% for C, respectively, with a higher A + T content (70.36%). The gene composition and arrangement were accordant to the closely published species. The phylogenetic analysis suggested thatC. natatorhad the closest relationship withC. japonica. [ABSTRACT FROM PUBLISHER]