33 research outputs found

    A Review of Current Electric Power Network Expansion Models

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    Electric power transmission expansion planning (TEP), which involves identifying the areas where the existing transmission infrastructure is inadequate, determining the optimal locations and routes for new transmission lines and substations, and evaluating each option in detail. TEP is important for ensuring the reliable and cost-effective delivery of electricity to consumers, and it requires consideration of technical, economic, environmental, and social factors. In this paper, we briefly compare different TEP models, while addressing the advantages and disadvantages of each approach

    Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

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    As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

    Mechanical Properties and Resistance to Acid Corrosion of Polymer Concrete Incorporating Ceramsite, Fly Ash and Glass Fibers

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    A novel polymer concrete (PC) using an aggregate of ceramsite, fly ash and glass fiber was created. Specimens were used in experiments to investigate its anticorrosion properties to determine the viability of its use in flue gas desulfurization (FGD) stacks. The inclusion of ceramsite reduces both the weight and the cost of the material. The effects of ceramsite and glass fiber on the flexural strength and compressive strength of the concrete were investigated. The experimental results showed that ceramsite reduces the flexural strength and the compressive strength of the concrete, but that the glass fiber increases both. Surface resistance to sulfuric acid corrosion and the microstructure of the corroded concrete were investigated. Specimens of the novel PC and the control PC strongly resisted acid corrosion. Although the specimen surfaces deteriorated, the interior structure of the PC was unaffected after 50 days of acid immersion. Processes by which sulfuric acid corrodes PC surfaces were determined

    Development of Multimode Flight Transition Strategy for Tilt-Rotor VTOL UAVs

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    The purpose of this paper is to establish a transition strategy for tilt-rotor vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) based on an optimal design method. Firstly, The flyable transition corridor was calculated based on both the UAV’s dynamic equations and its aerodynamic and dynamic characteristics. The dynamic equations of the UAV were organized into state equation forms. The initial and final value constraints of the control and state variables in the transition process were recorded, as were the constraints of the transition process. The transition strategy design problem was transformed into an optimal control problem with constraints, while the Gauss pseudospectral method (GPM) was employed to transform and solve the problem. In addition, performance indicators were designed based on the transition quality requirements for transition time, attitude stability, and control continuity. Sensitivity was analyzed according to different index terms with different dimensions and effects. Finally, the rationality of the transition strategy designed in this paper was verified according to different simulation scenarios

    Selenoprotein P inhibits cell proliferation and ROX production in HCC cells.

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    Selenoprotein P (SEPP1) is a kind of secretory glycoproteins with an antioxidant effect during the development of some diseases. In this study, we attempted to observe the expression of SEPP1 in livers from the patients with hepatocellular carcinoma (HCC) and explore its effect on HCC cells. All the tissues from patients with HCC were obtained from Affiliated Hospital of Nantong University. Western blot and immunohistochemical results showed that SEPP1 was reduced in HCC liver tissues. Its expression was negatively correlated with Ki67 expression in tissues. The expression of SEPP1 in normal liver cell line was significantly higher than those in the liver cancer cell lines. Serum starvation and release experiment demonstrated that SEPP1 expression was reduced and PCNA expression was increased, when the serum was re-added into cell culture system and the cells were on a proliferation state. After SEPP1 over-expression plasmid was transfected into HepG2 cells, cell proliferation of HepG2 cells and PCNA expression level were all inhibited by SEPP1. Results obtained via 8-isoprostane ELISA further indicated that inhibited ROS level was found in HepG2 cells transfected with SEPP1 over-expression plasmid. In addition, RT-qPCR results demonstrated that GPX1 expression levels increased in HepG2 cells transfected with SEPP1 over-expression plasmid. In conclusion, SEPP1 may inhibit the proliferation of HCC cells, accompanied by the reduction of ROS production and the increasing of GPX1 expression
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