Abstract ：

The improvement of solar thermochemical reactor performance is crucial in solar energy utilization technology. This study presents an integrated design method for solar thermochemical concentrator-reactor to enhance performance and safety guided by the ideal optimized solar radiation distribution. T...

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Concentrator design Genetic algorithm Multi-physics field model Shape optimization Solar methane reforming Thermodynamic equilibrium temperature

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Deep learning (DL) has demonstrated splendid performance in fault diagnosis with sufficient samples and ideal operating environments. However, in practice, it is hard to acquire adequate fault samples from high-reliability equipment, thus inducing challenges in applying DL for intelligent diagnosis. Moreover, data distribution shift occurs due to working load variation or environment noise interference, severely degrading DL models' performance. Aiming at the above problems, this article proposes a method called Q networks calibrated ensemble (QCE). Specifically, two improved deep Q networks are employed to enhance the attention to critical feature samples and fault samples by quantifying feature distribution and utilizing fault prior knowledge. Afterward, the calibrated Choquet integral is adopted to achieve the models' ensemble, further enhancing the generalization ability and robustness of the diagnosis results. The proposed method has been verified on the nuclear circulating water pump (NCWP) test bench. Results indicate the superiority and reliability of the QCE method. In addition, results when working load changes demonstrate the outstanding generalization ability of the proposed method for cross-domain fault diagnosis with class imbalance. Furthermore, gradient-weighted class activation mapping (Grad-CAM) visualization verifies that the proposed method effectively learns fault features instead of noise. © 1963-2012 IEEE.

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Class imbalance; data distribution shift; gearbox fault diagnosis; nuclear circulating water pump (NCWP)

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The key to critical bone regeneration in tissue engineering relies on an ideal bio-scaffold coated with a controlled release of growth factors. Gelatin methacrylate (GelMA) and Hyaluronic acid methacrylate (HAMA) have been a novel topic of interest in bone regeneration while introducing appropriate nano-hydroxyapatite (nHAP) to improve its mechanical properties. And the exosomes derived from human urine-derived stem cells (human USCEXOs) have also been reported to promote osteogenesis in tissue engineering. The present study aimed to design a new GelMA-HAMA/nHAP composite hydrogel as a drug delivery system. The USCEXOs were encapsulated and slow-released in the hydrogel for better osteogenesis. The characterization of the GelMA-based hydrogel showed excellent controlled release performance and appropriate mechanical properties. The in vitro studies showed that the USCEXOs/GelMA-HAMA/nHAP composite hydrogel could promote the osteogenesis of bone marrow mesenchymal stem cells (BMSCs) and the angiogenesis of endothelial progenitor cells (EPCs), respectively. Meanwhile, the in vivo results confirmed that this composite hydrogel could significantly promote the defect repair of cranial bone in the rat model. In addition, we also found that USCEXOs/GelMA-HAMA/nHAP composite hydrogel can promote the formation of H-type vessels in the bone regeneration area, enhancing the therapeutic effect. In conclusion, our findings suggested that this controllable and biocompatible USCEXOs/GelMA-HAMA/nHAP composite hydrogel may effectively promote bone regeneration by coupling osteogenesis and angiogenesis. © 2023 The Authors

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Bone regeneration; Exosomes; GelMA; H-type vessels; HAMA

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Abstract ：

Temperature stability and strain hysteresis are two extremely important parameters for high-precision piezoelectric actuators applications. Piezoelectric ceramics with high temperature stability and low strain hysteresis are eagerly expected. In this work, the strain characteristics of xBi(Zn1/2Ti1/2)O3-(1-x)(0.55PbZrO3-0.45PbTiO3) [xBZT-(1-x)(PZ-PT)] ferroelectric ceramics were investigated meticulously, and temperature-insensitive strain response and low strain hysteresis were simultaneously acquired at x = 0.15. The strain variation was less than 10% in the temperature range of 30–100 °C and the strain hysteresis was only 6% at 7 kV/mm. The incorporation of BZT transforms the crystal structure of PZ-PT ceramics from morphotropic phase boundary (MPB) to tetragonal phase. Strong relaxation behaviors occurred and a large piezoelectric coefficient of 500 p.m./V at 2 kV/mm were obtained at x = 0.15. The above merits will make this ferroelectric ceramic an ideal material for the fabrication of high-precision actuators and their use in harsh environment conditions. © 2022 Elsevier Ltd and Techna Group S.r.l.

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BZT-PZ-PT; Dielectric; Ferroelectric; Hysteresis; Strain; Temperature stability

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It is extremely common in engineering to design algorithms to perform various tasks. In data-driven decision making in any field one needs to ascertain the quality of an algorithm. Therefore, a robust assessment of algorithms is essential in deciding the best algorithm as well as in improving algorithms. To perform such an assessment objectively is obvious in the case of a single performance metric, but it is unclear in the case of multiple metrics. Nonetheless, F1 measure is widely used in cases with two metrics; F1 measure represents the harmonic mean (HM) of two metrics. Of course, there are other means, e.g., the arithmetic mean (AM) and the geometric mean (GM). As motivations for using them are intuitive and none of them are based on any objective function, it is difficult to judge objectively which is the best one. In this paper, the single metric case is examined to develop two objective functions that are applicable for any number of metrics. These two objective functions lead to two different performance measures - the distance from the origin (DO) and the distance from the ideal position (DIP). It introduces a new concept of the remaining phase space for the evaluation of the quality of a performance measure. On further and closer examinations of the original goal and the phase space of the metrics, amongst these five measures, either HM or DIP is found to be the best. Specifically, it is found that HM is the best measure at the lower performance end, while DIP is clearly the best measure at the higher performance end and is of much practical interest. Rules for deciding the best algorithm and the order of a set of algorithms are presented. These results are derived in the context of multiple independent and bounded metrics. Furthermore, several properties and detailed discussions are provided, following which some published results are reviewed in the present context to elucidate some points. © 2013 IEEE.

Keyword ：

Algorithms; data; decision making; distance from the ideal position; distance from the origin; robust assessment

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Precise design of oxygen electrode catalysts can alleviate the problems of slow kinetic reaction and high overpotential in the rechargeable zinc-air flow batteries (ZAFBs). Herein, an ideal 3D carbon-based material for FeCo alloy inlaid to Fe/Co and N co-doped bamboo-like carbon nanotubes (CNTs) is prepared by means of a one-pot high-temperature pyrolysis strategy of three metal organic frameworks (MOFs) mixed-precursors. The concentration of active metal species, the amount of conductive CNTs and the hierarchical porous structure with high specific surface area in this material are regulated. The optimal catalyst, Fe/12Zn/Co-NCNTs, demonstrates excellent electrochemical activity with a high half-wave potential of 0.879 V for oxygen reduction reaction (ORR) and low overpotential of 340 mV at 10 mA cm−2 for oxygen evolution reaction (OER) in the half-cell. Moreover, the smaller bifunctional ΔE value of Fe/12Zn/Co-NCNTs and Fe/(12Zn/Co)-NCNTs catalyst are 0.693 V and 0.717 V, respectively, less than the commercial Pt/C+IrO2 (ΔE = 0.77 V). The ZAFB yields a high open circuit voltage of 1.518 V, peak power density of 166 mW cm−2, and specific capacity of 809.1 mAh g−1 when employing Fe/12Zn/Co-NCNTs as air cathode because of the synergistic effect that improves both OER and ORR. More importantly, both Fe/12Zn/Co-NCNTs and Fe/(12Zn/Co)-NCNTs as the bifunctional catalysts produce a low charge-discharge voltage gap and high cycle lifespan of more than 320 h at 10 mA cm−2. This work provides a facile strategy for fabricating high-efficiency and low-cost bifunctional electrocatalysts for ZAFBs and other clean energy applications. © 2023 Elsevier Ltd

Keyword ：

Bamboo-like carbon nanotubes; Fe/Co-Nx; FeCo alloy; Metal organic frameworks; Zinc-air flow battery

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Abstract ：

Theoretically, sisal fiber (SF) is an ideal reinforcing material for green composites due to its high specific strength and specific modulus. However, the weak interface performance between SFs and resin affects the mechanical properties of composites. Therefore, the surface modification of SFs was carried out by enzymatic treatment to enhance the interfacial properties between SFs and bio-based epoxy resin in this work. It was found that the interfacial strength was effectively increased by 108% after the SF was treated with xylanase and pectinase for 6 h. The experiment study showed that the enzymatic treatment mainly caused the hydrolysis and cleavage of pectin and hemicellulose of SFs, which increased the surface grooves and surface roughness of SFs. The further finite element analysis proved that the mechanical interlocking effect at the nano-scale induced by surface roughness of SFs was the primary reason for the increase of interfacial strength between SFs and bio-based epoxy resin. Enzymatic treatment provides a green and large-scale production method for interface modification of SFs reinforced composites, which also can be used for the other bast fiber reinforced composites. © 2023 Elsevier B.V.

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Enzymatic treatment; Fiber/resin interface; Finite element analysis; Sisal fibers

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Abstract ：

Quantum properties are the prerequisite for quantum states to be applied in quantum state engineering. Here, we first propose a theoretical scheme of generating a novel kind of non-Gaussian state by repeatedly using a coherent superposition (CS) of photon subtraction and addition on each mode of an input two-mode squeezed coherent (TMSC) state, and then consider its nonclassicality in terms of the antibunching effect and the Wigner function. The simulation results shed more light on that for the high-order CS operations, the increase in coherent amplitudes of the CS-based TMSC is helpful to show the advantage of the existence and improvement of the nonclassicality over the TMSC case. After that, we also analyze the entanglement of the proposed CS-based TMSC by means of the Einstein–Podolsky–Rosen correlation, and finally focus on its applications in the quantum teleportation under an ideal Braunstein and Kimble scheme. Dramatically, the proposed state not only can be used for enhancing the entanglement and fidelity, but also shows distinct advantages over another non-Gaussian states involving the photon-subtracted TMSC states and the photon-excited TMSC states in terms of the optimal entanglement and fidelity at small-initial squeezing ranges. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Keyword ：

Coherent superposition; Non-Gaussian entangled states; Quantum properties; Quantum teleportation

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Developing πelectron conjugated groups as covalent bonded bridges between fullerenes in their oligomers is key to optimizing and maximizing functions of the fullerene-based materials. In this work, a series of novel conjugated chain bonded fullerene C60 oligomers (CBFOs) with a well-defined nano-architecture and "grape bunches"shapes are rationally designed and viably constructed based on fullerene-carbenes by means of DFT calculations. The results show that the presently designed CBFOs present a much better electron-accepting ability together with a much lower reorganization energy than the isolated fullerene C60, and characterized as the potential ideal candidate for electron acceptors. The frontier molecular orbital and electron density analysis can well support the results of diabatic electron affinity (EAa) and vertical electron affinity (EAv) calculations. Moreover, these CBFOs exhibit strong absorption in the visible region but no obvious absorption in the ultraviolet region. In addition, the optical properties of the CBFOs and two dimensional structure are also simulated and explored theoretically. We hope that the present study would be helpful for developing covalent-bonded-fullerene based electron trap molecular materials, building blocks of nano-devices and nano-machinery applications. © 2023 Royal Society of Chemistry. All rights reserved.

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BACKGROUND: In domestic and foreign literature, an in vitro model is an important tool to study the pathogenesis and effective treatment of osteoarthritis. All kinds of in vitro models have their advantages and disadvantages and related applications; however, so far, there is no ideal experimental model that can study all the characteristics of osteoarthritis. OBJECTIVE: To review relevant literature in recent years and summarize the advantages and disadvantages of various osteoarthritis models in vitro and their related applications, providing further understanding of osteoarthritis and its therapeutic methods. METHODS: The articles related to PubMed, CNKI, VIP, and WanFang databases from 2010 to 2021 were searched by computer with the English search words: “osteoarthritis, in vitro, model” in English and Chinese. Sixty-three qualified literature with strong correlation and relatively new publication years were selected for review. RESULTS AND CONCLUSION: Two-dimensional cell culture models of osteoarthritis are easy to be constructed and produced on a large scale, but they are only suitable for studies at the cellular level due to the lack of typical three-dimensional microstructure and interactions with surrounding cells and extracellular matrix. Explant model and three-dimensional cell culture provide an internal environment close to the physical condition of the human body, which can be used to study not only cytokines stimulation but also physical injuries and biomechanical changes. Therefore, we can better study the molecular mechanism of osteoarthritis and propose available interventions. However, from the view of tissue volume and cell vitality, mass production of these models is difficult. In addition, the article also discusses advanced tissue engineering models such as three-dimensional biofabrication models, organoids, and organ-on-a-chip models. Three-dimensional bio-printing technologies and bioreactors have obvious advantages in precise control of tissue structure, transport of bioactive molecules, dynamic cell culture and other aspects, but it still needs further improvement and innovation at present. In general, compared with the two-dimensional cell culture model, the in vitro three-dimensional tissue model is more suitable for current research and individualized treatment of osteoarthritis. In the future, it is expected to integrate emerging technologies such as organ chip technology, three-dimensional bio-printing technology and bioreactor, and eventually develop a more suitable platform for osteoarthritis treatment and drug testing. © 2023, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.

Keyword ：

cost; in vitro model; osteoarthritis; research progress; review; three-dimensional; tissue explant; treatment; two-dimensional

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