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Continuous carbon fiber reinforced composites (CCFRCs) 3D printing technology facilitates the rapid prototyping of lightweight honeycomb sandwich structures. The principal cause of failure in honeycomb sandwich structures is the poor bonding quality between the core units, which adversely affects their compression properties. This paper introduced a novel printing path design strategy termed “core interleaved alignment printing approach”, aiming to enhance the planar compressive performance of honeycomb sandwich structures. The proposed approach involved staggering the adjacent printing paths within the core units to mutually reinforce their two adjoining unit edges. This method could increase the effective bonding length between core units by 30 % and significantly improve the bond quality between core units, consequently improving the compressive performance of honeycomb sandwich structures. Experimental validations were conducted to analyze the planar compression behavior of printed honeycomb sandwich structures, comparing the proposed paths design strategy with the commonly used strategy. The damages in 3D printed honeycomb sandwich structures typically included delamination between adjacent layers and debonding among the honeycomb units. The proposed approach can effectively inhibit the rapid damage expansion and significantly improve the compressive performance of honeycomb structures, elevating their compressive strength by 96 % and compressive modulus by 67.5 %. Moreover, this strategy exhibits substantial enhancements in compressive performance, especially as the honeycomb core size decreases, and in the test condtion, the increases in compressive strength and modulus could reached over 167 % and 116 %, respectively.

We propose a geodesic distance (GD)-based scattering power decomposition for compact polarimetric (CP) synthetic aperture radar (SAR) data acquired over agricultural landscapes. The proposed technique decomposes the polarized portion of the total backscattered power in proportion to the normalized target similarity measures. The measures are derived from the GDs, which are computed between the Kennaugh matrices of observed and canonical targets (dihedral or trihedral). We observed a pseudo-power component in the double bounce power, which can be attributed to target irregularities. To compensate for the pseudo-power component, we proposed a compensation strategy by utilizing the CP radar vegetation index (CpRVI). The compensation factor assists in readjusting the polarized power components. The proposed approach was tested with real (RADARSAT Constellation Mission: RCM) and simulated (RADARSAT-2: RS2) hybrid CP data over agricultural sites in Canada. The effectiveness of the approach was demonstrated by comparing the decomposed powers with a recently proposed CP scattering power decomposition.

The high interface impedance between inorganic material electrodes and solid electrolytes results in a high Li+diffusion energy barrier, which limits the electrochemical performance of active materials. To solve this issue, an integrated configuration of organic active material electrode-solid polymer electrolyte (SPE) is synthesized via in situ polymerization. In the integrated aminoanthraquinone-solid polymer electrolyte (AQ-SPE), the naphthalene urethane bond acts as a bridge that links the organic material electrode and the SPE and acts as a channel for Li+transport at the electrode/SPE interface. Compared to the activation energy of the conventional aminoanthraquinone/solid polymer electrolyte (AQ/SPE), the activation energy of the charge transfer process for the integrated AQ-SPE decreases from 71.2 to 42.1 kJ mol–1, and the charge transfer impedance decreases from 1140 to 198 Ω at 50 °C. The first and 625th discharge capacity densities of AQ in the integrated AQ-SPE at 0.1 mA cm–1and 50 °C are 139.7 and 125.3 mAh g–1, respectively. Moreover, pouch batteries with the integrated AQ-SPE show excellent safety performance. The in situ fabrication of integrated electrode-SPE provides an enlightening and extended method for realizing efficient, safe, and environmentally friendly batteries.

The distributed consensus control problem for nonlinear multi-agent systems (MASs) with external disturbances under switching directed topologies is investigated. Distributed sliding-mode observers are designed considering both nonlinear dynamics and disturbances in MASs. Utilizing estimated states information via sliding-mode observers, a control protocol is constructed and analyzed to ensure the MASs reach consensus, and additionally guarantee the desired disturbance rejection criterion. Furthermore, the simulation experiment is carried out by taking multiple simple-pendulum network systems. By comparing this work with the related existing results, our designed observers are superior in estimating states information simultaneously considering both nonlinear dynamics and external disturbances, and the experiment result analysis shows validity of distributed consensus algorithm based on sliding-mode observers for MASs.

Death of grass carp (Ctenopharyngodon idella) caused by grass carp reovirus (GCRV) infection severely restricts the development of the grass carp industry. The interaction of C5a and C5a receptor (C5aR) in the complement system promotes inflammation and aggravates bleeding in grass carps. To reveal the regulatory mechanism of the C5a/C5aR pro-inflammatory response after GCRV infection, the expression of C5 in the liver and muscle tissues of grass carp after GCRV infection was analyzed using immunofluorescence. The effects of over expression of C5a and the C5aR antagonist PMX205 in grass carp kidney cell line (CIK) on the phosphorylation of p38 and ERK and the gene and protein expression of IL-6 and TNF-α were also analyzed using RT-qPCR and western blot. The results showed that the expression of the C5a protein in the liver and muscle of grass carp infected with GCRV first increased and then decreased, and the C5a protein level peaked on the 5th day after infection. In CIK cells, over expression of C5a significantly increased C5aR expression, phosphorylation of p38 and ERK, and overexpression of IL-6 and TNF-α. Treatment of CIK cells with PMX205 significantly decreased the expression of C5a and C5aR, phosphorylation of p38 and ERK proteins, and expression of IL-6 and TNF-α after GCRV infection. These results implied that the interaction of C5a and C5aR in grass carp resulted in the phosphorylation of p38 and ERK proteins, a significant increase in the expression of IL-6 and TNF-α, and ultimately induction of an inflammatory response of grass carp infected with GCRV. These results provide a theoretical basis for relieving grass carp hemorrhagic diseases by regulating the interaction of C5a and C5aR.

•3D printing methods for synchronous reinforcement at all positions are proposed.•A comparison between two printing methods for S/C-CFRTPs part is conducted.•S/C-CFRTPs part printed by towpreg extrusion process exhibits great performance.•The way to fabricate high-performance S/C-CFRTPs prepreg filament is proposed.

The detoxification and immobilization of Cr(VI) using metakaolin-based geopolymer coupled with ferrous chloride was solved successfully. Adding potassium dichromate and ferrous chloride in the base colloid formed by mixing metakaolin and the alkaline activator, Cr(VI)-contaminated metakaolin-based geopolymer was prepared, whose compressive strength was more than 30MPa. The optimized capacity of chromium in the geopolymer was 0.8wt.% with an optimized Fe2+/Cr(VI) mole ratio of 4:1, which ensured a low leached chromium concentration below 5mg/L. This product was mainly amorphous except by-product sodium chloride. According to XRD, SEM and XPS, the mechanism of Cr detoxification/immobilization was speculated and explained. In the colloid, the negatively charged [AlO4] was first formed because of the geopolymerization, and at the same time, Cr(VI) was reduced to Cr3+under the participation of Fe2+. Then, Cr3+was attracted by [AlO4] due to the electrostatic attraction and stabilized in geopolymerical matrices. Therefore, the immobilization of Cr(VI) in geopolymer contained a redox and a fixation process. This method is expected to be used for the disposal of Cr(VI)-contaminated solid wastes.

Abstract

The aim of this study was to investigate the role of rhizosphere organic phosphorus (P) in soil P supply in semiarid forests and the effects of tree species on rihizosphere organic P. We examined organic P fractions in rhizosphere and bulk soils of mono-specific Simon poplar (Populus simonii) and Mongolian pine (Pinus sylvestrisvar. mongolica) plantations in a semiarid sandy soil of Horqin Sandy Land in Northeast China. Total organic P (TPo) accounted for 76% of total P across the two stands. The concentration of organic P (Po) fractions decreased in the order of NaOH-Po>Res-Po>HCl-Po>NaHCO3-Po in both plantations. The concentration of NaHCO3-Po was 38% and 43% lower in rhizosphere soil than in bulk soil in Simon poplar and Mongolian pine plantations, respectively. In contrast, total P, TPo and NaOH-Po significantly accumulated in rhizosphere soil in Simon poplar plantations, but no change in Mongolian pine plantations. Soil recalcitrant organic P fractions were positively correlated with soil organic carbon. The results suggest that rhizosphere labile organic P was an important source of plant-available P in this semiarid region, but the dynamic of rhizosphere recalcitrant organic P fractions varied with tree species and was correlated to organic carbon dynamics.

In this study, a novel poly (acrylic acid-aniline)-grafted MCC conducting composite were synthesized by a simple two-step method. The radical copolymerization of MCC and AA was based on Electron Beam Irradiation Grafting. The synthesized MCC-AA matrix was further grafted with aniline through oxidative-radical copolymerization using APS in acidic media. The resultant MCC-PANI was characterized using X-ray diffraction, thermo gravimetric analysis, and electrical conductivity. It was found that acrylic acid was successfully grafted onto cellulose, and polyaniline was successfully coupled to modified cellulose. and the thermal stability of modified polyaniline composite cellulose was improved. The electrochemical activity of the composites was the best while the mass ratio of aniline monomer to MCC is 3:1. These novel nanorods are desirable for applications in supercapacitor devices.

An irregular globules structured Polymer/Microcrystalline cellulose composite is synthesized as a promising material for conductivity. In this work, the eco-friendly microcrystalline cellulose (MCC) were used as templates, and 1:1 mixture of aniline (PANI) and pyrrole (PPy) monomers in the presence of MCC were synthesized via in situ oxidative polymerization. The experimental results show that the conductive, thermal stability and hydrophobicity of the MCC/PPy-co-PANI composite are indeed optimized to enhance.