RESUMEN
Facile hydrothermally synthesized PbSnS2 nanosheets with various morphologies were developed to obtain high performance electrode materials for supercapacitors. A precipitation-dissolution mechanism was proposed to demonstrate the growth process of PbSnS2. The as-prepared nanosheets exhibited superior capacitance (678.8 F g-1 at 50 mV s-1) and a long cycle life (95.5% capacitance retention after 100 000 cycles at 5 A g-1).
RESUMEN
High-quality-factor Micro-Electro-Mechanical System (MEMS) resonators have been widely used in sensors and actuators to obtain great mechanical sensitivity. The frequency drift of resonator with temperature is a problem encountered practically. The paper focuses on the resonator frequency distribution law in the temperature range of-40 to 60 °C. The four-layer models were established to analyze thermal stress caused by temperature due to the mismatch of thermal expansion coefficients. The temperature variation leads to the transformation of stress, which leads to the shift of resonance frequency. The paper analyzes the influence of hard and soft adhesive package on the temperature coefficient of frequency. The resonant accelerometer was employed for the frequency measurements in the paper. In experiments, three types of adhesive dispensing patterns were implemented. The results are consistent with the simulation well. The optimal packaging method achieves -24.1 ppm/°C to -30.2 ppm/°C temperature coefficient of the resonator in the whole temperature range, close to the intrinsic property of silicon (-31 ppm).
