Real-Time Rainfall Estimation Using Microwave Links: A Case Study in East China during the Plum Rain Season in 2020.

Accurate and real-time rainfall estimation is a pressing need for forecasting the flood disaster and reducing the loss. In this study, we exploit the potential of estimating the rainfall by microwave links in East China. Eight microwave links at 15 GHz and 23 GHz, operated by China Mobile, are used for estimating the rain rate in real-time in Jiangyin, China from June to July 2020. First, we analyze the correlation between the rain-induced attenuation of microwave links and the rain rate measured by rain gauges. The correlation coefficient values are higher than 0.77 with the highest one over 0.9, showing a strong positive correlation. The real-time results indicate that microwave links estimate the rainfall with a higher temporal resolution than the rain gauges. Meanwhile, the rain rate that was estimated by microwave links also correlates well with the actual rain rate, and most of the values of the mean absolute error are less than 1.50 mm/h. Besides, the total rainfall's relative deviation values are less than 5% with the smallest one reaching 1%. The quantitative results also indicate that microwave links could lead to better forecasting of water levels and, hence, better warnings for flood disasters.

Enhanced capacitive performance by improving the graphitized structure in carbon aerogel microspheres.

Herein, good electrical conductivity and high specific surface area carbon aerogel (CA) microspheres were synthesized by a facile and economical route using a high temperature carbonization and CO2 activation method. The electroconductive graphitized structure of the CA microspheres could be easily improved by increasing the carbonization temperature. Then the CA microspheres were activated with CO2 to increase the specific surface area of the electrode material for electric double layer capacitors (EDLC). The sample carbonized at 1500 °C for 0.5 h and CO2 activated at 950 °C for 8 h showed an acceptable specific surface area and excellent cycle performance and rate capability for EDLC: 98% of the initial value of the capacitance was retained after 10 000 cycles, a specific capacitance of 121 F g-1 at 0.2 A g-1 and 101 F g-1 at 2 A g-1.

Expression and clinical significance of doublecortin (DCX) in pituitary adenoma.

PURPOSE: To date, no studies have investigated the expression of Doublecortin (DCX) in pituitary adenomas or evaluated the clinical value of DCX in the diagnosis of pituitary adenomas. This study aims to determine the expression levels of DCX in pituitary adenomas and to investigate its role in the staging of this condition. METHODS: Forty-six patients with pituitary adenomas were recruited. The expression of DCX in tumor sections from pituitary adenomas was determined using immunohistochemistry and quantitative real-time polymerase chain reaction. Tumors were classified as either invasive or non-invasive on the basis of clinical stage and using the Knosp grading system. Differences in the expression of DCX and its association with clinical characteristics were investigated. The potential of the measurement of DCX levels for distinguishing between invasive and non-invasive tumors was estimated using receiver operating characteristic (ROC) analysis. RESULTS: Expression of DCX were correlated with Knosp grade. No significant association was observed between DCX level and the clinical stage of the tumors. The expression of DCX was higher in tumors with Knosp 3 and lowest in Knosp 1, at both the mRNA and protein levels. Using DCX as a biomarker for the prediction of tumor invasiveness in pituitary adenoma patients, the area under the ROC curve was 0.829 (95% confidence interval, 0.6-28.1), which is higher than that obtained using Knosp grade. CONCLUSIONS: The expression of DCX is related to the Knosp grade of pituitary adenoma. DCX levels can be used as a biomarker for tumor invasiveness prediction in pituitary adenoma patients.

Enhanced Photothermal Effect in Ultralow-Density Carbon Aerogels with Microporous Structures for Facile Optical Ignition Applications.

The exact mechanism responsible for the phenomenon known as photoignition with an enhanced photothermal effect in high-surface-area carbon with the addition of a metal catalyst is an open issue. Here, we report the first successful flash ignition of a pure carbon material in ambient air microporous carbon aerogels (CAs) with ultralow density and high surface area. Under flash exposure, the CAs show a strong local heat confinement effect near microporous structures (0.6-2 nm), and the graphite crystallite structures existing in single carbon nanoparticles (∼15 nm) are damaged. The local heat confinement effects are mainly derived from the low gaseous thermal conductivity in micropores and low solid thermal conductivity in low-density CAs. In addition, the limiting effects of the microporous structure on the vibration amplitude of free-state electrons in low-density CAs result in a dramatic increase in optical absorption. Numerical simulations of unsteady temperature fields of CAs with different densities and thicknesses are also performed, and the calculated maximum temperature of a 17 µm-thick 20 mg/cm3 CA bed is 1782 °C. CAs with higher density can also give rise to enhanced photothermal response and ignition with the addition of metal Fe nanoparticles. The metal catalyst increases both the light absorption capacity in the visible-light range and the heat accumulation capacity. These results are important for understanding the mechanism of flash ignition, especially the local high temperature and effects of metal catalyst in carbon materials during the photothermal process.

Nitrogen-Doped Multi-Scale Porous Carbon for High Voltage Aqueous Supercapacitors.

Recently, "Water-in-salt" electrolyte has been reported to extend the working voltage of aqueous supercapacitor. However, this electrolyte needs the electrode materials possess some good features such as proper pore structure, high electron and ion conductivity. Herein, we fabricated the nitrogen-doped multi-scale porous carbon (NMC) by the simple enriching melamine-resorcinol-formaldehyde xerogels method with integrating triblock copolymer for micro-pores formation. All the results confirmed that our NMC is provided with a very high specific surface area (3,170 m2 g-1) and its monoliths are composed of multi-scale porous structure. By employing the nanostructured NMC as electrode materials, we have investigated the capability for high-voltage aqueous supercapacitor applications. The superconcentrated "Water-in-salt" electrolyte expand stability operating potential window of aqueous symmetric supercapacitor up to 2.4 V with a high energy density of 33 Wh kg-1 at power density of 0.3 kW kg-1. Our studies indicate that the NMC is potential materials for high performance over wider voltage range.

Fabrication of WO3·2H2O/BC Hybrids by the Radiation Method for Enhanced Performance Supercapacitors.

In this study, we described a facile process for the fabrication of tungsten oxide dihydrate/bamboo charcoal hybrids (WO3·2H2O/BC) by the γ-irradiation method. The structural, morphological, and electrochemical properties of WO3·2H2O/BC hybrids were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and WO3·2H2O (pseudocapacitance) created a combined effect, which enhanced the specific capacitance and superior cyclic stability of the WO3·2H2O/BC hybrid electrode. The WO3·2H2O/BC hybrids showed the higher specific capacitance (391 F g-1 at 0.5 A g-1 over the voltage range from -1 to 0 V), compared with BC (108 F g-1) in 6 M KOH solution. Furthermore, the hybrid electrode showed superior long-term performance with 82% capacitance retention even after 10,000 cycles. The experimental results demonstrated that the high performance of WO3·2H2O/BC hybrids could be a potential electrode material for supercapacitors.

A Novel Radiation Method for Preparing MnO2/BC Monolith Hybrids with Outstanding Supercapacitance Performance.

A novel facile process for fabrication of amorphous MnO2/bamboo charcoal monolith hybrids (MnO2/BC) for potential supercapacitor applications using γ-irradiation methods is described. The structural, morphological and electrochemical properties of the MnO2/BC hybrids have been investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and MnO2 (pseudocapacitance) created a complementary effect, which enhanced the specific capacitance and good cyclic stability of the MnO2/BC hybrid electrodes. The MnO2/BC hybrids showed a higher specific capacitance (449 F g-1 at the constant current density of 0.5 A g-1 over the potential range from ⁻0.2 V to 0.8 V), compared with BC (101 F g-1) in 1 M of Na2SO4 aqueous electrolyte. Furthermore, the MnO2/BC hybrid electrodes showed superior cycling stability with 78% capacitance retention, even after 10,000 cycles. The experimental results demonstrated that the high performance of MnO2/BC hybrids could be a potential electrode material for supercapacitors.

A facile route to modify ferrous phosphate and its use as an iron-containing resource for LiFePO4 via a polyol process.

This study introduces an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries via two processes: (1) the synthesis of LiFePO4/C cathode material using a low cost divalent precursor ferrous phosphate, Fe3 (PO4)2·8H2O, as iron source in a polyol process and (2) the modification of the morphology of this precursor by varying the reaction time in a coprecipitation process. The study examines the effects of different structures and morphologies of the precursor on the structure and electrochemical performance of the as-synthesized LiFePO4/C. The LiFePO4/C shows an excellent rate capability and cycle performance, with initial discharge capacities of 153, 128, and 106 mA h g(-1) at 1 C, 5 C, and 10 C. The capacity retention is respectively 98.7%, 98.2%, and 98.7%, after 10 cycles at the corresponding rates. The capacity retention remains at 97% even after 300 cycles at the rate of 10 C. The outstanding electrochemical performance can be attributed to the improved rate of Li(+) diffusion and the excellent crystallinity of synthesized LiFePO4/C powders through the modified precursor. Therefore, this is an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries.