314 research outputs found

    Combat Network Synchronization of UCAV Formation Based on RTBA Model

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    The paper aims at developing an efficient method to acquire a proper UCAV formation structure with robust and synchronized features. Here we introduce the RTBA (Route Temporary Blindness Avoidance) model to keep the structure stable and the HPSO (hybrid particle swarm optimization) method is given to find an optimal synchronized formation. The major contributions include the following: (1) setting up the dynamic hierarchy topologic structure of UCAV formation; (2) the RTB phenomenon is described and the RTBA model is put forward; (3) the node choosing rules are used to keep the invulnerability of the formation and the detective information quantifying method is given to measure the effectiveness of the connected nodes; and (4) the hybrid particle swarm optimization method is given to find an optimal synchronized topologic structure. According to the related principles and models, the simulations are given in the end, and the results show that the simplification of the model is available in engineering, and the RTBA model is useful to solve the real problems in combat in some degree

    On-chip electro-optic tuning of a lithium niobate microresonator with integrated in-plane microelectrodes

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    We demonstrate electro-optic tuning of an on-chip lithium niobate microresonator with integrated in-plane microelectrodes. First two metallic microelectrodes on the substrate were formed via femtosecond laser process. Then a high-Q lithium niobate microresonator located between the microelectrodes was fabricated by femtosecond laser direct writing accompanied by focused ion beam milling. Due to the efficient structure designing, high electro-optical tuning coefficient of 3.41 pm/V was observed.Comment: 6 pages, 3 figure

    Functional role of MicroRNA/PI3K/AKT axis in osteosarcoma

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    Osteosarcoma (OS) is a primary malignant bone tumor that occurs in children and adolescents, and the PI3K/AKT pathway is overactivated in most OS patients. MicroRNAs (miRNAs) are highly conserved endogenous non-protein-coding RNAs that can regulate gene expression by repressing mRNA translation or degrading mRNA. MiRNAs are enriched in the PI3K/AKT pathway, and aberrant PI3K/AKT pathway activation is involved in the development of osteosarcoma. There is increasing evidence that miRNAs can regulate the biological functions of cells by regulating the PI3K/AKT pathway. MiRNA/PI3K/AKT axis can regulate the expression of osteosarcoma-related genes and then regulate cancer progression. MiRNA expression associated with PI3K/AKT pathway is also clearly associated with many clinical features. In addition, PI3K/AKT pathway-associated miRNAs are potential biomarkers for osteosarcoma diagnosis, treatment and prognostic assessment. This article reviews recent research advances on the role and clinical application of PI3K/AKT pathway and miRNA/PI3K/AKT axis in the development of osteosarcoma

    Effect of in vitro gastrointestinal digestion on the chemical composition and antioxidant properties of Ginkgo biloba leaves decoction and commercial capsules

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    In this study Ginkgo biloba leaves (GBL) decoction and commercial capsules were digested using an in vitro model. Thirty-six active compounds were identified and quantified by HPLC-ESI-MS analysis based on the MS/MS patterns (precursor ions and product ions) and retention times, in comparison with reference standards. Most compounds in GBL showed a significant decrease during intestinal digestion, with an exception of vanillic acid and biflavonoids. Bioaccessibility values of chemical compositions varied between decoction and capsules samples. Also, significant reductions of total flavonoids and total phenolic content was observed after in vitro digestion. Both, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity decreased after gastric digestion, but increased during intestinal digestion. Nevertheless, different behaviour was observed in reducing antioxidant power (FRAP) assay. Compared to the pH of digestion, the influence of digestive enzymes on the chemical composition and antioxidant activity of GBL was relatively minor. Overall, these results may help provide a valid foundation for further investigations on bioactive compounds and the pharmacodynamics of GBL

    Ultra-low threshold continuous-wave quantum dot mini-BIC lasers

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    Highly compact lasers with ultra-low threshold and single-mode continuous wave (CW) operation have been a long sought-after component for photonic integrated circuits (PICs). Photonic bound states in the continuum (BICs), due to their excellent ability of trapping light and enhancing light-matter interaction, have been investigated in lasing configurations combining various BIC cavities and optical gain materials. However, the realization of BIC laser with a highly compact size and an ultra-low CW threshold has remained elusive. We demonstrate room temperature CW BIC lasers in the 1310 nm O-band wavelength range, by fabricating a miniaturized BIC cavity in an InAs/GaAs epitaxial quantum dot (QD) gain membrane. By enabling effective trapping of both light and carriers in all three dimensions, ultra-low threshold of 12 {\mu}W (0.052 kW/cm^2) is achieved. Single-mode lasing is also realized in cavities as small as only 5*5 unit-cells (~2.5*2.5 {\mu}m^2 cavity size) with a mode volume of 1.16({\lambda}/n)^3. With its advantages in terms of a small footprint, ultralow power consumption, robustness of fabrication and adaptability for integration, the mini-BIC lasers offer a perspective light source for future PICs aimed at high-capacity optical communications, sensing and quantum information

    Strengthening dendrite suppression in lithium metal anode by in-situ construction of Li–Zn alloy layer

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    Abstract(#br)The lithium metal anode is one of the most attractive candidates for high-energy lithium rechargeable batteries because it has an ultrahigh theoretical specific capacity and the lowest electrode potential. Unfortunately, uncontrollable growth of dendritic Li leads to problems such as safety hazards and low cycling reversibility, which greatly hinder its commercial application. Here, a Li–Zn alloy layer is constructed in situ on Li metal foil by a simple chemical reaction of zinc trifluoromethanesulfonate with Li metal. The modified Li metal anode forms an interface with fast charge transfer kinetics and high chemical resistance to the electrolyte, which enables deposition of Li with a smooth, dense morphology without the growth of dendritic Li. In symmetrical cells, the Li metal anode with the Li–Zn alloy layer can reach a cycling lifetime of more than 500 h under a current density of 2 mA cm −2 . This work provides a simple and effective strategy to suppress the formation of Li dendrites

    Preparation of Well-Compatibilized PP/PC Blends and Foams Thereof

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    The performance of polypropylene-poly(ethylene brassylate) block and graft copolymers and a polypropylene-polycaprolactone graft copolymer as compatibilizers for polypropylene-rich polypropylene/bisphenol A polycarbonate (PP/PC, 80/20 wt/wt) blends was elucidated. The copolymers were synthesized either by metal-catalyzed ring-opening polymerization or transesterification of a presynthesized polyester, initiated by hydroxyl-functionalized PPs, which themselves were obtained by catalytic routes or reactive extrusion, respectively. Spectroscopic fingerprints of the copolymers from liquid-state nuclear magnetic resonance (NMR) in combination with scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic mechanical thermal analysis (DMTA), and rheology analyses of the blends indicated that the compatibilizers spontaneously organize at the interface of the two immiscible polymers leading to the formation of uniform, stable, nanophase morphologies. The effect of the compatibilizers on the performance of the PP/PC blends was evaluated, and well-compatibilized PP/PC blends showed improved melt strength and strain hardening when compared to pure PP. This was verified by the successful foam extrusion using isobutane as a blowing agent of well-compatibilized PP/PC blends to low-density PP-based foams, for which normally long-chain branched PP is required
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