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This study investigated the force–frequency characteristics of quartz wafers inside a cantilever beam frame. Firstly, the force–frequency coefficient formula of quartz wafers with fixed ends under axial force was analyzed. Firstly, the formula for the force–frequency coefficient of quartz wafers with fixed ends under axial force was analyzed. A force–frequency coefficient formula suitable for cantilever beam structures was derived by considering the changes in surface stress and stiffness of quartz wafers with fixed ends and one end under force on the other. Subsequently, the formula's accuracy was verified by experiments, and the accuracy was more than 92%. In addition, strain simulation analysis was performed on three different shapes of quartz wafers, and experimental verification was carried out on two of them. The results revealed that trapezoidal quartz wafers and cantilever beam structures exhibited superior stress distribution to rectangular chips. Furthermore, by positioning electrodes at various locations on the surface of the quartz chip, it was observed that, as the electrodes moved closer to the fixed end, the force–frequency coefficient of the rectangular quartz chip increased, along with an increase in chip strain under the cantilever structure. In summary, this study provides a new approach for designing cantilever quartz resonator sensors in the future. [ABSTRACT FROM AUTHOR]

In order to investigate the gasification performance of coal with high water content, a two‐stage fluidized bed gasification (TSFBG) system was systematically simulated by Aspen Plus to identify the effect of pre‐drying for coal with its initial water content varying from 10‐65 wt% on gasification performance, particularly energy efficiency. The results show that the energy efficiency based on lower heating value (LHV) (ηLHV) and higher heating value (HHV) (ηHHV) of feed coal are about 1.5%‐7% and 1.5%‐5% higher when coal is fed to the system directly without pre‐drying. For the TSFBG system, the higher the water content, the greater the energy efficiency reduction by pre‐drying. The analysis of energy allocations reveals that heat loss due to the pre‐drying of coal is mainly responsible for the decrease of energy efficiency in operations with pre‐drying. With an increase in the initial water content from 10 to 65 wt%, the ηLHV of the TSFBG system without the pre‐drying of coal using air/steam as gasification agent reaches its maximum of about 91% at an initial water content of 26 wt%. The ηLHV and ηHHV of the TSFBG system using oxygen/steam as gasification agent increases energy efficiency by about 1%‐2% compared to that using air/steam. For TSFBG using air/steam to gasify coal without the pre‐drying, the preferred initial water content of coal is below 50 wt%. [ABSTRACT FROM AUTHOR]