Increasing dissipation-free supercurrent has been the primary issue for practical application of superconducting wires. For magnesium diboride, MgB 2 , carbon is known to be the most effective dopant to enhance high-field properties. However, the critical role of carbon remains elusive, and also low-field critical current density has not been improved. Here, we have undertaken malic acid doping of MgB 2 and find that the microscopic origin for the enhancement of high-field properties is due to boron vacancies and associated stacking faults, as observed by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon from the malic acid almost uniformly encapsulates boron, preventing boron agglomeration and reducing porosity, as observed by three-dimensional X-ray tomography. The critical current density either exceeds or matches that of niobium titanium at 4.2 K. Our findings provide atomic-level insights, which could pave the way to further enhancement of the critical current density of MgB 2 up to the theoretical limit.
Experimental AspectsIn the experimental apparatus shown in Fig. 2 Fig. 3(a).Argon or oxygen could be blown on the melt surface.Gases were controlled by mass flow controller and introduced from the nozz]e as illustrated in Fig. 3(b).The melting parameters are given in Table 3. 3. (Fig. 4(a)) and 70~/ o (Fig. 4(b)) of the button melt samples was melted during each experlment (3.8 and 6.2kW, respectively). Higher power gave more molten silicon. Figure 5 showscarbon Electron beamfurnace for button melting.
Carbon‐encapsulated crystalline boron nanopowder and coarse magnesium powder are used as inexpensive tailored starting materials for the fabrication of high‐performance MgB2 superconducting wire. A low sintering temperature leads to a high critical current density, as a result of nanometer‐sized boron powder, surface oxidation preclusion by carbon encapsulation, and grain alignment by elongated magnesium coarse powder.
BackgroundHepatocellular carcinoma (HCC), the fifth most common cancer type and the third highest cause of cancer death worldwide, develops in different types of liver injuries, and is mostly associated with cirrhosis. However, non-alcoholic fatty liver disease often causes HCC with less fibrosis, and the number of patients with this disease is rapidly increasing. The high mortality rate and the pathological complexity of liver diseases and HCC require blood biomarkers that accurately reflect the state of liver damage and presence of HCC.Methods and FindingsHere we demonstrate that a circulating protein, apoptosis inhibitor of macrophage (AIM) may meet this requirement. A large-scale analysis of healthy individuals across a wide age range revealed a mean blood AIM of 4.99±1.8 µg/ml in men and 6.06±2.1 µg/ml in women. AIM levels were significantly augmented in the younger generation (20s–40s), particularly in women. Interestingly, AIM levels were markedly higher in patients with advanced liver damage, regardless of disease type, and correlated significantly with multiple parameters representing liver function. In mice, AIM levels increased in response to carbon tetrachloride, confirming that the high AIM observed in humans is the result of liver damage. In addition, carbon tetrachloride caused comparable states of liver damage in AIM-deficient and wild-type mice, indicating no influence of AIM levels on liver injury progression. Intriguingly, certain combinations of AIM indexes normalized to liver marker score significantly distinguished HCC patients from non-HCC patients and thus could be applicable for HCC diagnosis.ConclusionAIM potently reveals both liver damage and HCC. Thus, our results may provide the basis for novel diagnostic strategies for this widespread and fatal disease.
The drying characteristics of a single coarse lignite particle in superheated steam are investigated. Spherical particles of Loy Yang lignite 30 mm in diameter were used. The particles were dried with superheated steam at temperatures ranging from 110 to 170°C under atmospheric pressure, and their weights and temperatures were measured with electronic balance, thermocouples and infrared thermograph. Condensation of water droplets on the surface was observed initially, then constant drying rate period (CDRP) and decreasing drying rate period (DDRP) were observed successively. A numerical model of the drying process was developed based on the results, taking into account transfer of free water inside the particle, equilibrium moisture content and shrinkage of the lignite particle itself.
The infrared emission spectra of CaF 2 -CaO-SiO 2 melt were investigated by a method combining infrared emission spectroscopy and the hot-filament technique. Emission for spectra related to Si-O bond can be observed by this in situ technique. The influence of SiO 2 and fluoride content on the spectrum was investigated, and the emission attributable to bonds corresponding to silicon-bridging oxygen and silicon-non bridging oxygen was discussed. Results suggest that fluoride ion dominantly substitutes for a non-bridging bond in low SiO 2 concentration region. The structure of silicate was compared with calculated infrared emission of Si-F-O.
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