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Converter blown limestone powder steelmaking process has the advantages of energy saving and high efficiency to meet the needs of low carbon metallurgy. Based on a thermogravimetric-differential thermal analyzer, the effect of high CO2 partial pressure on the pyrolysis behavior of limestone at steelmaking temperatures was investigated at 20 °C/min, 30 °C/min, and 40 °C/min, the kinetic parameters of limestone pyrolysis were calculated by the improved double extrapolation method. [ABSTRACT FROM AUTHOR]

Under ultraviolet (UV) excitation with photon energy larger than 4.5 eV, a charge-state conversion from negatively to neutrally charged nitrogen-vacancy (NV− to NV0) centers in diamond samples is realized. The UV-induced charge-state conversion is found to strongly depend on the N concentration in the sample and the irradiation fluence of the electron beam. For the samples with high N concentrations, low-fluence (2.5 × 1017 cm−2) 10-MeV electron beam irradiation usually leads to UV-induced charge-state conversion efficiency higher than that of the samples irradiated with high fluences (≥2.5 × 1018 cm−2). For the samples with a few ppm N, however, the charge-state conversion efficiency is relatively low in the cases of irradiation fluences in this work. Meanwhile, UV-induced NV0 luminescence exhibits temperature dependence different from that of visible-light excited NV0 or NV− centers; that is, the photoluminescence intensity does not reach saturation at temperatures lower than 135 K but decreases with the decrease in temperature. Based on the photoluminescence excitation spectra of NV0 centers in the UV region, the UV-induced charge-state conversion is suggested to involve free-hole generation, diffusion, and the capture by ground-state NV− centers. [ABSTRACT FROM AUTHOR]

Contact angle hysteresis (CAH) is a significant factor affecting the drop motion on solid substrates. A model of CAH is introduced to explore the influence of CAH on the dynamics of a sessile drop on a uniformly heated surface, and a two-dimensional evolution equation of the drop thickness is established using the lubrication approximation and Navier slip boundary conditions. A numerical simulation is performed to examine the dynamic behaviors of an evaporating drop, and the drop profile, contact angle, contact line, and moving speed are investigated. Simulated results indicate that the drop evolution process involves drop spreading, pinning, and depinning of the contact line. In the drop spreading stage, when the hysteresis angle increases, the spreading period is shortened, and the spreading radius and spreading speed are reduced; in contrast, the pinning period is raised, and the mass of the drop is apparently reduced with increasing hysteresis angle. In the depinning stage, the CAH declines the contact angle, and a flatter pattern is evolved, thereby improving the heat transfer performance, promoting drop evaporation, and shortening the depinning time. The presence of CAH can speed up the drying of the drop, and the large hysteresis angle leads to faster evaporation. Regulating the CAH is an effective way to manipulate the motion of the contact line for an evaporating drop. [ABSTRACT FROM AUTHOR]

In recent years, the frequency and intensity of drought–flood abrupt alterations due to global climate change have drastically increased. In contrast, plant response to the drought-flood abrupt alternations remains unclear. In the current study to reveal maize’s physiological response to drought-flood abrupt alternations, these were carried out in two stages in this study, i.e., three levels of water deficit (WD, i.e., 75%, 65%, and 55% of the field capacity) in stage I, and then five durations of flooding (75%-WDi, 65%-WDi and 55%-WDi) in stage II. The results indicated that the 65%-WDi treatment significantly decreased the leaf area and biomass of maize seedlings in stage I, while maintaining plant growth and reaching the control level in stage II. Abscisic acid (ABA) concentration in maize leaves and roots of 0-5 cm depth was sensitive to drought stress. Under drought–flood abrupt alternations, the root system in 55%- WD5 and 65%-WD7 exhibited strong ABA signal, which was sensitive to drought-flood abrupt alternations. Therefore, at the maize seedling stage, proper control of soil moisture is beneficial for improving stress tolerance at later stages, but stress tolerance after drought–flood abrupt alterations is related to the degree of drought exposure at the early stage. [ABSTRACT FROM AUTHOR]