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In this work, high-entropy (HE) spinel ferrites of (FeCoNiCrM)xOy (M = Zn, Cu, and Mn) (named as HEO-Zn, HEO-Cu, and HEO-Mn, respectively) were synthesized by a simple solid-phase reaction. The as-prepared ferrite powders possess a uniform distribution of chemical components and homogeneous three-dimensional (3D) porous structures, which have a pore size ranging from tens to hundreds of nanometers. All three HE spinel ferrites exhibited ultrahigh structural thermostability at high temperatures even up to 800 °C. What is more, these spinel ferrites showed considerable minimum reflection loss (RLmin) and significantly enhanced effective absorption bandwidth (EAB). The RLmin and EAB values of HEO-Zn and HEO-Mn are about −27.8 dB at 15.7 GHz, 6.8 GHz, and −25.5 dB at 12.9 GHz, 6.9 GHz, with the matched thickness of 8.6 and 9.8 mm, respectively. Especially, the RLmin of HEO-Cu is −27.3 dB at 13.3 GHz with a matched thickness of 9.1 mm, and the EAB reaches about 7.5 GHz (10.5–18.0 GHz), which covers almost the whole X-band range. The superior absorbing properties are mainly attributed to the dielectric energy loss involving interface polarization and dipolar polarization, the magnetic energy loss referring to eddy current and natural resonance loss, and the specific functions of 3D porous structure, indicating a potential application prospect of the HE spinel ferrites as EM absorbing materials.

The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

For enhancing the corrosion resistance of the T6-aged high-strength Al alloys with higher strength, retrogression and reaging (RRA) treatments were used to optimize the morphologies, sizes, distribution of precipitates, especially grain boundary precipitates (GBPs). The effects of different retrogression treatments on the microstructures and mechanical properties were studied so as to gain suitable RRA process for 7B50 Al alloy plates. It is found that increasing the retrogression temperature or time will promote the coarsening of transgranular and intergranular precipitates in the center and surface layers of 7B50 Al alloy plates as well as the precipitation of stable η-MgZn2 phase, which will decrease the strength and raise the conductivity. The retrogression temperature will greatly affect the strength and conductivity. The continuously distributed GBPs induced by T6 aging become discontinuous after RRA treatment, accompanying with slightly increasing sizes of transgranular precipitates. Based on the strength and conductivity of the center and surface layers, 165℃/6 h is the suitable retrogression process for 7B50 Al alloy plates. However, the severe deformation of the surface grains compared to that of the central grains caused by hot rolling leads to a higher content of subgrains or substructures in the surficial grains, which promotes the surface layer to quickly reach the peak aging, and the subsequent retrogression treatment results in much more stable η phase in the surface layer. The formation of stable η phase as well as the coarsening or growth of transgranular precipitates could be mainly responsible for the strength difference between the surface and center layers. Although there are some differences about the grain structures between the surface and center layers after quenching/RRA treatments with some local subgrain growth, the positive impact of RRA treatment to the strength is apparently unable to compare with the obvious strength reduction caused by early precipitation of stable η phase in the surface layer. Thus, the RRA treatment cannot relieve the property difference between the center and surface layers of 7B50 Al alloy plates, but it can make the strength and conductivity of the center and surface layers to concurrently meet some working requirements.

This paper presents a three-dimensional formulation for the free vibrations of thick rectangular plates with general boundary conditions and resting on elastic foundations. The general boundary conditions are imposed by means of penalty function method. The displacements of the plates are expressed by a three-dimensional cosine series and some simple polynomial functions which introduced to ensure and accelerate the convergence of the series representation. All the unknown coefficients can be obtained by using the Rayleigh–Ritz method. Comparisons of the present results with those in available literature demonstrate the accuracy and reliability of the present formulation. Furthermore, parametric investigations are presented including the effects of boundary conditions, geometrical parameters, and elastic foundation.

A modified Fourier–Ritz method is developed for the flexural and in-plane vibration analysis of plates with two rectangular cutouts with arbitrary boundary conditions, aiming to provide a unified solving process for cases that the plate has various locations or sizes of cutout, and different kinds of boundary conditions. Under the current framework, modifying the position of the cutout or the boundary conditions of the plate is just as changing the geometric parameters of the plate, and there is no need to change the solution procedures. The arbitrary boundary conditions can be obtained by setting the stiffness constant of the boundary springs which are fixed uniformly along the edges of the plate at proper values. The strain and kinetic energy functions of a plate with rectangular cutout are derived in detail. The convergence and accuracy of the present method are demonstrated by comparing the present results with those obtained from the FEM software. In this paper, free in-plane and flexural vibration characteristics of the plate with rectangular cutout under general boundary conditions are studied. From the results, it can be found that the geometric parameters and positions of the cutout and the boundary conditions of the plate will obviously influence the natural vibration characteristics of the structures.

Damage stability is difficult to assess due to the complex hydrodynamic phenomena regarding interactions between fluid and structures. Therefore, a detailed analysis of the flooding progression and motion responses is important for improving ship safety. In this paper, numerical simulations are performed on the damaged DTMB 5415 ship at zero speed. All calculation are carried out using CD Adapco Star CCM + software, investigating the effect of damage openings on ship hydrodynamics, including the side damage and the bottom damage. The computational domain is modelled by the overset mesh and solved using the unsteady Reynold-average Navier-Stokes (URANS) solver. An implicit solver is used to find the field of all hydrodynamics unknown quantities, in conjunction with an iterative solver to solve each time step. The Volume of Fluid (VOF) method is applied to visualize the flooding process and capture the complex hydrodynamics behaviors. The simulation results indicated that two damage locations produce the characteristic flooding processes, and the motion responses corresponding to the hydrodynamic behaviors are different. Through comparative analysis, due to the difference between the horizontal impact on the longitudinal bulkhead and the vertical impact on the bottom plate, the bottom damage scenario always has a larger heel angle than the side damage scenario in the same period. However, the pitch motions are basically consistent. Generally, the visualization of the flooding process is efficient to explain the causes of the motion responses. Also, when the damage occurs, regardless of the bottom damage or the side damage, the excessive heel angle due to asymmetric flooding is often a threat to ship survivability with respect to the pitch angle.

This article discusses the scale effects on a planing boat, utilizing the computational fluid dynamics method. The simulation is compared with a tank test for verification and validation. The planing boat sails use both aerodynamics and hydrodynamics. Studying the performances and wave patterns of different dimensions of the models is the best way to investigate the scale effect without using experimental data. The resistance is discussed in two parts, namely residuary resistance and friction resistance, and is compared to the calculated data using the international towing tank conference (ITTC) formula. The computational fluid dynamics (CFD) calculations of the model are increased by 4.77% on average, and the boat computations are also increased by 3.57%. The computation shows the scale effect in detail. The residuary resistance coefficients at different scales are approximately equal, and the friction resistance coefficients show the scale effect. The scale effect for longitudinal steadiness is also captured for the period of the porpoising behavior. The rational for the full-scaled boat oscillation period and the model is the root of the scales.

A detailed description of the flooding process is crucial to analyze the complex hydrodynamic behaviors and enhance the survivability of the damaged ship. In this paper, through establishing three typical damage scenarios with various locations, the commercial software CD Adapco STAR-CCM+ based on the Reynolds-Averaged Navier-Stokes (RANS) solver is applied to simulate the flooding process involving multiple compartments. The basic computational fluid dynamics (CFD) models and specific simulation settings are elaborated. The volume of fluid (VOF) method combined with the user defined field function is developed to distribute the initial free surface. The captured flooding process indicates that the air compression due to the restricted ventilation decreases the flooding amount. The obtained flooding time can provide necessary data to support for appropriate rescue management and evacuation options.

Molybdenum (Mo) films were deposited by radio frequency (RF), direct current (DC) and mixed magnetron sputtering, respectively. With changing the deposition parameters including deposition pressure and power, the films show different surface morphology and crystallinity. Lower resistivity of the films is obtained in the DC mode and better reflectivity of the films is obtained in the RF mode. It is shown that the crystallinity increases when the deposition pressure decreases. The crystallinity and the grain size both increase as the deposition power increasing. The lowest resistivity of the single Mo film is 34×10-6 Ω·cm when the deposition pressure is 0.1 Pa and the deposition power is 300 W in the DC mode. In order to obtain lower resistivity, better adhesion and better reflectivity, bilayer films and tri-layer films were both deposited in different mode. They all show good adhesion and low resistivity. The Mo films deposited in mixed mode show better reflectivity. It is demonstrated that the resistivity of about 65×10-6 Ω·cm is achieved in DC/RF mode and the resistivity of about 61×10-6 Ω·cm is achieved in RF/DC/RF mode. And the tri-layer films achieved in RF/DC/RF mode have better reflectivity than bilayer films achieved in DC/RF mode. The tri-layer films achieved in RF/DC/RF mode is appropriate for using as the electrode of CIGS solar cells.

Abstract Background We investigated the distribution and clinical significance of mobilized endothelial progenitor cells (EPCs) in hepatocellular carcinoma (HCC). We found that many more EPCs were recruited to nonmalignant liver tissue (especially into adjacent non-tumor tissues (AT)) than to tumor vessels. These results suggest that the mechanism underlying the recruitment of EPCs into microvessels in AT merits further investigation Methods Angiogenic factors were detected in three tissue microarrays comprising normal liver, paired tumor tissue (TT) and AT from 105 patients (who had undergone hepatectomy for HCC) using immunohistochemistry. Also, the number of EPCs (positive for Sca-1, Flk-1 and c-Kit) in the blood and liver of cirrhotic mice were determined by flow cytometry and immunohistochemistry. The distribution of these labeled EPCs in tumor and non-tumor tissues was then studied. Results The results from the tissue microarrays showed that the expression levels of VEGF-A, bFGF, TGF-β, MCP-1, TSP-1, MMP-9, TIMP-2, and endostatin were significantly higher in AT than in either normal liver or TT (p < 0.05), but no significant difference was found in the expression levels of COX-2 and NOS-2 between AT and TT. The expression of VEGF-A, bFGF, TGF-β, MCP-1, TSP-1, MMP-9, TIMP-2, endostatin, COX-2, and NOS-2 in normal liver tissue was weaker than that in AT or TT. In cirrhotic mice, the number of circulating endothelial progenitor cells gradually increased, before decreasing again. In this mouse model, increased numbers of EPCs were recruited and homed specifically to the cirrhotic liver. Conclusions Both liver cirrhosis and HCC led to increased expression of pro-angiogenic factors, which resulted in the recruitment of EPCs into AT. Also, EPCs were mobilized, recruited and homed to cirrhotic liver. The unique pathology of HCC coupled with liver cirrhosis may, therefore, be associated with the distribution and function of EPCs.

Abstract Background To investigate dynamic fluctuations of serum viral load and peripheral T-lymphocyte subpopulations of chronic hepatitis B patients and their correlation during entecavir therapy. Methods Fifty-five patients received entecavir 0.5 mg/d therapy. Serum HBV DNA load was measured by Real-Time-PCR, and the levels of peripheral T-lymphocyte subpopulations by flow cytometry biweekly, every four weeks and every eight weeks during weeks 1–12, 13–24 and 24–48, respectively. Multilevel modelling was used to analyse the relationship between these variables. Results Of the 55 patients, all HBeAg positive and with detectable HBV DNA, the majority (81.8%) had serum levels of HBV DNA over 107 copies per milliliter. HBV viral load dropped sharply during the first two weeks. In 28 and 43 patients, the level became undetectable from week 24 and 48, respectively. Using pre-therapy level as the reference, a significant decrease in CD8+ T cells and increase in CD4+ T cells were found from week 12. Both parameters and CD4+/CD8+ ratio steadily improved throughout the 48 weeks. Multilevel analyses showed that the level of decrement of HBV DNA was associated with the increment of T-lymphocyte activities only in the later period (4–48 week). After 4 weeks of therapy, for each log10 scale decrement of HBV DNA, the percentage of CD4+ lymphocyte was increased by 0.49 and that of CD8+ decreased by 0.51. Conclusion T-lymphocyte subpopulations could be restored partially by entecavir treatment in patients with chronic hepatitis B concurrently with reduction of viremia.