The polymerization of styrene is monitored by pyrene excimer formation. The ratio of monomer to excimer intensities ( I m/ I e) of pyrene increases as polymerization proceeds. The increase of I m/ I e...The polymerization of styrene is monitored by pyrene excimer formation. The ratio of monomer to excimer intensities ( I m/ I e) of pyrene increases as polymerization proceeds. The increase of I m/ I e is ascribed to the increase of microviscosity surrounding the probes forming excimer during polymerization. The linear relationship between the changing rate of I m/ I e and the polymerization rate of styrene is obtained. Therefore, I m/ I e may be used to monitor the progress of the polymerization of styrene.展开更多
A novel capacitive pressure sensor is presented, whose sensing structure is a solid-state capacitor consisting of three square membranes with Al/SiO2/n-type silicon. It was fabricated using pn junction self-stop etchi...A novel capacitive pressure sensor is presented, whose sensing structure is a solid-state capacitor consisting of three square membranes with Al/SiO2/n-type silicon. It was fabricated using pn junction self-stop etching combined with adhesive bonding,and only three masks were used during the process. Sensors with side lengths of 1000,1200,and 1400μm were fabricated,showing sensitivity of 1.8,2.3, and 3.6fF/hPa over the range of 410～ 1010hPa, respectively. The sensi- tivity of the sensor with a side length of 1500μm is 4. 6fF/hPa,the nonlinearity is 6. 4% ,and the max hysteresis is 3.6%. The results show that permittivity change plays an important part in the capacitance change.展开更多
文摘The polymerization of styrene is monitored by pyrene excimer formation. The ratio of monomer to excimer intensities ( I m/ I e) of pyrene increases as polymerization proceeds. The increase of I m/ I e is ascribed to the increase of microviscosity surrounding the probes forming excimer during polymerization. The linear relationship between the changing rate of I m/ I e and the polymerization rate of styrene is obtained. Therefore, I m/ I e may be used to monitor the progress of the polymerization of styrene.
文摘A novel capacitive pressure sensor is presented, whose sensing structure is a solid-state capacitor consisting of three square membranes with Al/SiO2/n-type silicon. It was fabricated using pn junction self-stop etching combined with adhesive bonding,and only three masks were used during the process. Sensors with side lengths of 1000,1200,and 1400μm were fabricated,showing sensitivity of 1.8,2.3, and 3.6fF/hPa over the range of 410～ 1010hPa, respectively. The sensi- tivity of the sensor with a side length of 1500μm is 4. 6fF/hPa,the nonlinearity is 6. 4% ,and the max hysteresis is 3.6%. The results show that permittivity change plays an important part in the capacitance change.
