Status and initial experiments of DRAGON-V facility for lithium-lead blanket technologies of hydrogen fusion reactors

A dual-coolant integrated experimental facility named DRAGON-V has been developed at the Institute of Nuclear Energy Safety Technology, Hefei Institute of Physical Science, Chinese Academy of Sciences, for the key technology research and performance evaluation of candidate liquid lithium-lead (PbLi) blanket of hydrogen fusion reactors. The loop is composed of a material test sub-loop and thermal-hydraulic test sub-loop, the design parameters are PbLi inventory 20 tons, PbLi temperature up to 550 °C, the maximum PbLi flow rate up to 40 kg/s. A novel cold trap system is designed to remove the suspended and crystalized impurities in PbLi fluid with three cooling zones and cross row arrangement of rod bundle filter elements. The paper describes the loop itself and its major components, initial loop testing, flow and measurement diagnostics and current experiments. The obtained test results of the loop and its components have demonstrated that the new facility is fully functioning and ready for experimental studies of material corrosion with/without a magnetic field, magnetohydrodynamic (MHD) effect, purification, heat and mass transfer phenomena in PbLi flows and can also be used in mock-up testing in conditions relevant to fusion applications.     

Engineering A-site cation deficiency into LaCoO3 thin sheets for improved microwave absorption performance

Journal of Materials Science - Rationally designing microwave absorption materials with highly efficient and tunable bandwidth is in great demand but remains a huge challenge. In this study,...     

Synthesis of bristlegrass-like Co-doped Ni2P composites on Ni foam for overall seawater splitting

Seawater is the most abundant resource on earth, so developing cost-effective, highly durable corrosion resistance and efficient electrocatalysts are crucial to enhance seawater splitting. Herein, we prepared 3D bristlegrass-like Co-doped Ni₂P (Co-Ni₂P) composites supported on Ni foam (NF) through a facile solvothermal method combined and a subsequent phosphatization treatment. Benefiting from the unique structure, Co-Ni₂P shows excellent electrocatalytic activity as an electrode material for both the hydrogen evolution reaction (HER, low overpotential of 116 mV at 50 mA cm^?2) and oxygen evolution reaction (OER, low overpotential of 266 mV at 50 mA cm^?2). Moreover, the as-prepared Co-Ni₂P composites exhibit excellent stability and corrosion resistance in an alkaline medium. Density functional theory (DFT) calculations were employed to evaluate the H1 adsorption of Co-Ni₂P, and the results proved the high catalytic activity for the HER. This study provides new materials with a unique morphology for overall water splitting.     

Reaction Mechanism of Lithium-Ion Battery Fire Extinguishing Agent-Perfluorinated Hexanone Oxidizes Metal-Al

Fire Technology - The use of perfluorinated hexanone as a fire extinguishing agent for lithium-ion batteries (LIBs) has been steadily increasing in China in recent years. It successfully handles...     

Efficiency evaluation of healthcare services in China based on stochastic multicriteria acceptability analysis and directional distance function

Evaluating the efficiency of healthcare services accurately can help in analyzing the rationality of inputs and outputs in such services. Considering the consistency and equity of assessment criteria, this study conducts the stochastic multicriteria acceptability analysis (SMAA-2) with a directional distance function to evaluate the efficiency of healthcare services in 31 provincial administrative regions of mainland China, as observed in 2018. We use SMAA-DDF to explore all the projection directions to the efficient frontier instead of a certain projection direction. We measure the maximum and average efficiencies for each of the 31 provincial healthcare services. Our empirical findings show that only seven provinces achieve optimal healthcare service efficiency; the eastern area performed the best, followed by the central, western, and northeast areas. Furthermore, the path along the projection directions is provided to help inefficient provinces improve their efficiency and obtain the best possible positions.     

Synthesis,characterization, and visible-light photocatalytic activity of transition metals doped ZTO nanoparticles

Transition metals doping has been proved to be a feasible way for tuning the physical properties on the surface and bulk of nanomaterials and also for the good performance in decontamination of emerging pollutants. In this context, doped samples of zinc tin oxide or zinc stannate nanoparticles (ZTO NPs) by several transition metals were synthesized in order to enhance the optical absorbance with the aims of reducing the band gap and therefore ameliorated their photocatalytic activity. They were characterized by the X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy, Raman spectroscopy and photoluminescence. The XRD patterns and the microscopic observations showed the formation of spherical nanoparticles with an average size of about 30 nm and highly pure ZTO phase with an inverse spinel structure. The Raman spectra were dominated by bands relatives to the F2g (2) and A1g symmetries modes of inverse spinel structure. The band gap Eg is estimated to be 3.75 eV for the undoped sample, and 3.67, 3.64, 3.78 and 3.21 eV, for 2% Fe, 2% Mg, 2% Gd, and 2% Mn doped ZTO samples, respectively.Furthermore, the undoped ZTO NPs have the intrinsic problem of recombination of photogenerated charge carriers. We have shown that the reduction of the band gap and oxygen vacancies resulting from the doping effect could be a useful tool for trapping and avoid the recombination of electrons coming from photosensitized rhodamine B (RhB) under visible light irradiation. Owing to the structural advantages and low band gap, 2% Mn doped ZTO NPs, with the kinetic rate constants k of 0.024 min⁻¹, show enhanced performance for the elimination of RhB in aqueous solution compared to undoped and other doped ZTO NPs.     

Grain size influence on the flexibility and luminous intensity of inorganic CaTiO3:Pr3+ crystal nanofibers

Traditional inorganic materials exhibit rigidity owing to the lack of polymer chains in polymer materials or atom slipping in metals. However, nanometerization has been recently proposed for the conversion of inorganic oxide materials into flexible materials. Herein, the flexible inorganic luminescent material, CaTiO₃:0.2%Pr³⁺, was synthesized through electrospinning, and the macroscopic flexibility of pure inorganic CaTiO₃:0.2%Pr³⁺ was achieved. The flexible membrane was characterized via X-ray diffraction, thermogravimetry, scanning electron microscopy (SEM), and photoluminescence analyses. The grain size was analyzed at various calcination temperatures via SEM, and the results suggested that the increase in the calcination temperature resulted in the growth of crystal grains. Studies have reported that the growth of crystal grains is beneficial for improving the luminescence performance; however, to obtain better flexibility, smaller crystal grains are required. This study provides an important reference for the design of flexible inorganic materials.