Concentration sensor with multilayer thin film-coupled surface plasmon resonance

A concentration sensor based on silver(Ag)/silica(SiO2)/zirconium anhydride(ZrO2)multilayer structure is proposed.Two dominant dips can be observed in the reflection spectrum,which correspond to different sensing methods.Firstly,it is demonstrated that the coupling between the surface plasmon polariton(SPP)mode and a planar waveguide mode(WGM)leads to the Fano resonance(FR).The induced bonding hybridized modes have ultra-narrow full wave at half maximum(FWHM)as well as ultra-high quality factors(Q).We can achieve a theoretical value of the refractive index sensitivity 167 times higher than conventional surface plasmon resonance(SPR)sensors with a single metal layer.Secondly,the waveguide coupling mode was examined by measuring angular spectra.A deep and sharp waveguide coupling dip was obtained.The experimental results show that with an increase in the concentration of the fill dielectric material in the surface of the system,the resonance dip exhibits a remarkable red shift,and the measured angular sensitivity is 98.04°/RIU.

A novel SOI pressure sensor for high temperature application

The silicon on insulator（SOI） high temperature pressure sensor is a novel pressure sensor with highperformance and high-quality. A structure of a SOI high-temperature pressure sensor is presented in this paper.The key factors including doping concentration and power are analyzed. The process of the sensor is designed with the critical process parameters set appropriately. The test result at room temperature and high temperature shows that nonlinear error below is 0.1%, and hysteresis is less than 0.5%. High temperature measuring results show that the sensor can be used for from room temperature to 350℃ in harsh environments. It offers a reference for the development of high temperature piezoresistive pressure sensors.

Six-day measurement of size-resolved indoor fluorescent bioaerosols of outdoor origin in an office

Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on indoor bioaerosols originating from outdoors. In this study, indoor versus outdoor size-resolved concentrations and particle asymmetry factors of airborne fluorescent bioaerosols in an office room were measured continuously for 6 days （144 h） using a fluorescent bioaerosol detector. The windows and door of this room were closed to ensure that there was only air infiltration; moreover, any human activities were ceased during sampling to inhibit effects of indoor sources. We focused on fine particles, since few coarse particles enter indoor environments, when windows and doors are closed. Both indoor and outdoor fluorescent bioaerosol size distributions were fit with two-mode lognormal distributions （indoor R2 = 0.935, outdoor R2 = 0.938）. Asymmetry factor distributions were also fit with lognormal distributions （indoor R2 = 0.992, outdoor R2 = 0.992）. Correlations between indoor and outdoor fluorescent bioaerosol concentrations show significant concentration-attenuation and a time lag during the study period. A two-parameter, semi-empirical model was used to predict concentrations of indoor fluorescent bioaerosols of outdoor origin. The measured and predicted concentrations had a linear relationship for the studied size fractions, with an R2 for all size fractions of larger than 0.83.

Experimental measurements of gas-solid flow and splitting mechanisms of a coal pipe splitter with a perpendicularly arranged upstream elbow

The effect of the vertical pipe length on the performance of a coal pipe splitter with a perpendicularly arranged upstream elbow was investigated experimentally employing a fiber optic measuring system. The upstream elbow and coal pipe splitter were installed in two perpendicular planes. Contours of dis- tributions of the particle concentration and size were obtained in different transverse sections. The experimental data show that the maximum/minimum concentration ratio in transverse sections A, B, and C decreased rapidly as the length of the vertical pipe increased. The left/right-leg average concentration ratio remained about 1, and a balanced split was thus achieved. With a perpendicularly arranged upstream elbow, the vertical pipe length had little effect on the splitter performance, which is beneficial for engineering design and convenient for industrial application.