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Underwater gliders are winged, autonomous underwater vehicles that are broadly applied in physical and biological oceanography. The position of the wing has an important effect on the movement performance of the underwater glider. In this paper, the dynamic motion of a series of underwater glider models with different longitudinal wing positions are simulated, which provides guidance for the design of underwater gliders. The results show that when the net buoyancy is constant, the wing position affects the gliding angle, but does not affect the relationship between the gliding angle and the gliding speed. In addition, the farther the wing position of the glider is from the buoyancy centre, the longer it takes for the attitude of a glider to change, whether the wing is in front of, or behind, the buoyancy centre.

Two novel complexes, namely [Cu2(L)2] (1) and [Ni4(L)4] (2, H2L = 1-{3-[(5-bromo-2-hydroxy-benzylidene)-amino]-2-hydroxyphenyl}-ethanone) were synthesized through solvothermal methods at the same condition. The complexes 1 and 2 were characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. 1 is dinuclear copper complex while 2 is a cubane nickel cluster. The L ligand displays two different coordination modes. One is the μ1-L-κ3N1:O1:N2 coordination mode and the other is μ3-L-κ6O1:O2:O2:O2:N1:O3 coordination mode. Magnetic studies reveal that the complex 2 displays dominant antiferromagnetic intracluster interactions between the NiII ions through the μ3 oxide bridges with g = 2.29, J = − 0.939 cm−1, and zJ′ = − 0.333 cm−1. Hirshfeld surface analysis revealed that H···H interaction was the dominant intermolecular interaction.

One novel decanuclear copper cluster, {[Cu10(L)8(CH3COO)2(μ3- OH)2]·(DMF)2·(H2O)5} (1, H2L = (E)- 2-(((4H-1,2,4-triazol-3-yl)imino)methyl)-6-methoxyphenol, DMF = N,N’-dimethyl-formamide), were obtained by room temperature micro-bottle reaction. The complex 1 was characterized using elemental analysis, infrared spectroscopy and single-crystal X-ray diffractometry. 1 is decanuclear copper cluster. The {Cu10O4(N2triazol)8} core displays dominant antiferromagnetic interactions owing to the μ3-OH, and μ2-Ophenoxo bridged binding modes with g = 2.126, J = − 6.81 $$\times {10}^{-4}$$ cm−1, and zJ’ = − 0.577 cm−1.

The bow-flared section may be simplified in the prediction of slamming loads and whipping responses of ships. However, the difference of hydrodynamic characteristics between the water entry of the simplified sections and that of the original section has not been well documented. In this study, the water entry of several different bow-flared sections was numerically investigated using the computational fluid dynamics method based on Reynolds-averaged Navier&ndash, Stokes equations. The motion of the grid around the section was realized using the overset mesh method. Reasonable grid size and time step were determined through convergence studies. The application of the numerical method in the water entry of bow-flared sections was validated by comparing the present predictions with previous numerical and experimental results. Through a comparative study on the water entry of one original section and three simplified sections, the influences of simplification of the bow-flared section on hydrodynamic characteristics, free surface evolution, pressure field, and impact force were investigated and are discussed here.

A new ionic pentanuclear FeIII cluster, namely, triethylazanium tetrakis(μ2-5-amino-1,2,3,4-tetrazolido)tetrakis(μ3-4-chloro-2-{[(1H-tetrazol-1-id-5-yl)imino]methyl}phenolato)di-μ3-oxido-pentairon(III) acetonitrile monosolvate monohydrate, (C6H16N)[Fe5(C8H4ClN5O)4(CH2N5)4O2]·CH3CN·H2O, was synthesized using microvial synthesis methods and characterized by elemental analysis, FT–IR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. Magnetic studies reveal that the complex displays dominant antiferromagnetic intracluster interactions between the FeIII ions through the μ3-oxide bridges.

The microstructure evolution and mechanical properties of the compressively deformed AgInCd alloy during annealing treatment have been investigated in the present study. In the deformed AgInCd alloy, many deformation markings are formed and these deformation markings are mainly composed of nanoscale deformation twins. The AgInCd alloy exhibits a significant work hardening capability because of the formation of deformation twins. The recrystallization temperature of the deformed AgInCd alloy is between 300 °C and 350 °C. In the AgInCd alloy annealed at 300 °C, the deformation twins are eliminated and a large number of dark strips consisting of stacking faults are presented in the un-recrystallized regions, indicating that the deformation twins are transformed into stacking faults by the detwinning mechanism. The annealing twins show higher thermal stability than the deformation twins. The strength and microhardness of the deformed AgInCd alloy gradually decrease with the increase of annealing temperature.

The compressive deformation mechanisms of a coarse-grained AgInCd alloy have been investigated in the present study. When compressive strain is not higher than 30%, the deformation mechanisms transform from full dislocation slip and multiplication into the two coefficient mechanisms of full dislocation slip and partial dislocation emission with increasing compressive strain. When compressive strain reaches 50%, the dominant deformation mechanisms convert into deformation twinning. With further increasing strain, the dislocation densities decrease and the twin thicknesses reduce in the nano-twinned grains. Twin boundary possesses a weaker strengthening effect comparing with grain boundary for the AgInCd alloys.

A novel 5-Acetoxy-1-(6-chloropyridin-2-yl)-1H-pyrazole-3-carboxylic acid methyl ester derivatives Htcdodtta (1), and it’s five complexes, [Cu2(L1)2]·(CH3CN) (2), [Cu2(L2)1.63(L3)0.37]·(CH3OH)0.5 (3), [Cu2(L3)(L4)]·(C2H5OH)0.5·(CH3OH)0.5 (4), [Cu2(L4)(L5)]·(H2O) (5) and [Cu2(L1)1.18(L2)0.82] (6) have been synthesized. The Htcdodtta, HL1-HL5 were formed in-situ reaction. HL1-HL5 are homologues which possess two chiral carbons. Compounds 1–6 were characterized using single-crystal X-ray diffraction, IR, and elemental analysis. Compounds 2–6 are dinuclear copper complexes. The in vitro cytotoxicities of compounds 1–4 against a variety of cell lines were evaluated by MTT assays. Hela cancer cell apoptosis assay of 1 and 2 were examined by flow cytometry. The cell apoptosis in NP69, A549, Capan-2, Hela, HepG2, and HUVECs cell lines induced by compound 2 was further affirmed by cellular morphology observations.

Ba(Cu0.5W0.5)O3 (BCW) ceramic has been fabricated and its dielectric properties investigated for use in energy-storage applications, revealing a very large dielectric constant (∼104) at 1 kHz. Moreover, the colossal-permittivity BCW ceramic exhibited fine microstructure and optimal temperature stability over a wide temperature range from room temperature to 500°C. The internal barrier layer capacitor mechanism was considered to be responsible for its high dielectric properties. Based on activation values, it is concluded that doubly ionized oxygen vacancies make a substantial contribution to the conduction and relaxation behaviors at grain boundaries. This study suggests that this kind of material has potential for use in high-density energy storage applications.

Composites with damping–absorption performance and storage-loss behavior based on carbon nanotubes as a modifier and zinc titanate/room temperature vulcanized silicone rubbers as a matrix were fabricated by a reactive solution mixing process, wet ball milling, and the three-roller milling method. The microstructures, chemical structures, and morphologies of the composites were characterized by scanning electron microscopy, infrared spectroscopy, and X-ray diffraction. The thermal stabilities were investigated by thermogravimetric analysis. The effect of carbon nanotubes on the comprehensive performance of the carbon nanotube/zinc titanate/room temperature vulcanized silicon rubber composites was investigated. It was found that doping with carbon nanotubes can improve the comprehensive performance of the zinc titanate/room temperature vulcanized silicon rubber complex matrix. The best comprehensive properties were d33 = 72 pC/N, storage modulus = 4,100 MPa, loss modulus = 400 MPa, damping coefficie...

The dielectric composite ceramics copper calcium titanate/poly vinylidene fluoride (CaCu3Ti4O12/PVDF) with Cu powder as a modified agent are successfully prepared by solution mixing processing and hot pressing method. The relative dielectric constants of these composites are significantly enhanced with increase in the volume fraction of copper powder. These composites also possess stable frequency and thermal stability properties in the frequency range of 100–1 MHz. The dielectric permittivity of the 60 vol%PVDF/20 vol%CCTO/20 vol%Cu composite ceramics is higher two times than those with undoped Cu powder and reaches the maximum value of 135 (1 kHz) at Cu powder concentration of 20 vol%. The results indicate that using Cu powder as a modification agent can greatly enhance the dielectric permittivity of the ceramic–polymer composite and achieve high-stability for super capacitor applications.

In this work, aluminium particles were added to epoxy resin to improve its anti-UV aging properties. The prepared composite samples were placed in a UV aging tester for 100 days to accelerate the composite aging. The results showed that the aluminium particles improved the anti-UV aging properties of the epoxy resin effectively. After long-term UV illumination, the tensile and bending strengths of the composite with 6 wt.% aluminium particles were 39.6 MPa and 83.9 MPa, respectively, 59.7% and 57.5% lower, than those of the pure epoxy, and its yellowing value was 8.8, 65% lower than that of pure epoxy resin.

Electric contacts were inserted into a carbon fiber epoxy resin composite to research the relationship between water absorption and resistance, which allowed the diagnosis of composite water absorption in a nondestructive way. The results show that the carbon fiber in the composite form does not absorb water from the environment, and its resistance remained unchanged when immersed in water. However, the resistance of the composite increased after water was absorbed along the fiber until the specimen reached saturation, which resulted in a sudden increase in resistance. The transverse resistance changed logarithmically in relation to water absorption. The data fitting equation is y = 2.03 × lg(x)−6.26 (R2 = 0.98), where x is the transverse resistance after water absorption (Ω), and y is the weight gain rate after water absorption (%). According to this equation, the weight gain rate of the composite can be calculated from the transverse resistance.

Because flammable organic solvents are emitted during the construction process, oil-based conductive coatings generally result in potential safety problems. A high content of conductive mediums can also weaken the adhesive and protective abilities of existing conductive coatings. Therefore, an anticorrosive and conductive coating was prepared on Q235 steel substrate by spraying the multi-walled carbon nanotubes (MWCNTs)/waterborne polyurethane (WPU) dispersion with a low MWCNT content in this work. The effect of the MWCNT content on the electrical conductivity, corrosion resistance, and adhesive strength of the WPU conductive coating was investigated. It was concluded that a spatial network structure of MWCNTs-WPU was formed to make the coating structure more compact. The electrical conductivity, corrosion resistance, and adhesive strength of the WPU conductive coating first increased and then decreased as the MWCNT content increased. When the MWCNT content was only 0.2 wt % (which was far lower than that of the existing conductive coatings at 1 wt %), the coating began to conduct electricity, its resistivity was 12,675.0 &Omega, &middot, m. The best combination property was the 0.3 wt % MWCNTs/WPU conductive coating. Its adhesive strength was 19.99% higher than that of pure WPU coating. Its corrosion rate was about one order of magnitude lower than that of pure WPU coating after being immersed in 3.5 wt % NaCl solution for 17 days.

To research effect of raw materials TiO2 with the phase structures on the crystal structure, microstructure and electrical properties of lead-free (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 (BCZT) ceramics, BCZT ceramics using either anatase or rutile as Ti source were synthesized by solid-state reaction. Titanium dioxide (TiO2) with anatase/rutile phase structures had interesting influence on the crystal structure, microstructure and the sintering temperature by the X-ray diffraction and SEM, which also played an important role in improved electrical properties. The BCZT ceramics with rutile titanium dioxide demonstrated optimal piezoelectric and dielectric properties: d33 = 590 pC/N, kp = 0.46, er = 2810, tanδ = 0.014 and Tc = 91 °C, which was obviously superior to BCZT ceramics with anatase titanium dioxide.

To improve the corrosion resistance of the steel ground grid and its discharge property, in the present work, multi-walled carbon nanotube (MWCNT)/polyurethane (PU) composite coatings were prepared on the steel surface utilizing a novel electrostatic spraying method. The MWCNT/PU composite coatings fabricated via the electrostatic spraying route were found to have the advantage that the CNTs were uniformly dispersed in the matrix. The effect of the morphology and the content of CNTs on the resistivity of the steel ground grid, its corrosion resistance in the soil, and the contact resistance between the coating and the soil, were systematically investigated. When the content of MWCNTs was 6 wt.%, the resistivity of the composite coating reached a low value of 9.2 × 10 −2 Ω m. Moreover, a low coating/soil contact resistance of 10.6 Ω m was obtained in the coating with 6 wt.% MWCNTs, smaller than that (15.4 Ω m) of neat carbon steel. In addition, the corrosion resistance of the MWCNT/PU coated carbon steel ground grid was improved apparently. Its resistance was more than 8 times higher than that of the neat steel. These values met the requirements of ground grid.

To solve the problem of low interlayer strength of 3D plastic powder printing, in this work, magnetized carbon nanotubes (CNTs) are added to the epoxy powder of 3D printing, and a 0.3 T magnetic field is introduced on the printed powder box to explore the interfacial enhancement effect of CNTs on the interlayer strength of 3D printing of plastic powder. The results show that the magnetized CNTs are vertically arranged in the interlayer, which greatly improves the interlayer bonding strength of 3D plastic printing. When the content of magnetized CNTs is below 4 wt. %, the interlayer bonding strength of epoxy resin 3D printing increases as the content of CNTs increases; when the content of CNTs was 4 wt. %, the interlayer bonding strength increased to a maximum of 4.5 MPa, 50% higher than the unadded specimen; when the content of CNTs increased to 4–6 wt. %, the interlayer bonding strength of the specimens is between 4.5 MPa and 4.3 MPa, basically unchanged; when the content of CNTs increased to more than 7 wt. %, the interfacial strength decreased.

A thicker layer of multi-walled carbon nanotubes (MWCNTs)/waterborne polyurethane (WPU) anticorrosive and conductive coating was respectively prepared on the Q235 steel substrate by brushing (Br) and electrostatic spraying (ES) in this work. The effect of coating process on the dispersion of the MWCNTs and the electrical conductivity, corrosion resistance, and bond strength of the coating was investigated. It was shown that the coating prepared by ES (ES coating) had a smooth surface, few defects and evenly dispersed MWCNTs. The coating prepared by Br (Br coating) had a rough surface, some defects and obviously agglomerated MWCNTs. The electrical conductivity, corrosion resistance, and bond strength of the ES coating were higher than those of the Br coating with the same MWCNT content. As the MWCNT content increased, the electrical conductivity of the ES coating increased, however, its corrosion resistance and bond strength first increased and then decreased. The resistivity of ES 0.3 wt% MWCNTs/WPU coating (12808.4 Ω·m) met the standard requirement of the conductive coating. Its corrosion rate was 3.50×10-5 mm/a immersed in 3.5 wt% NaCl solution. Its bond strength to the Q235 steel substrate was higher than that of ES pure WPU coating. As the MWCNT content increased, the electrical conductivity of the Br coating increased, however, its corrosion resistance and bond strength decreased. When the MWCNT content was 0.6 wt%, the Br coating would conduct electricity. Its corrosion rate was 5.24×10-2 mm/a.