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In arid areas, vapor flow has been recognized to contribute significantly to the mass and energy transfers and to play a critical role in maintaining surface vegetation and ecosystems. To better understand the continuous spatial and temporal variations in liquid water and water vapor contents under different climatic conditions, soil water contents, temperatures, and micrometeorological variables were observed in-situ in the Mu Us Desert of northwestern China. The collected data were then used to calibrate and validate the Hydrus-1D model simulating either the coupled movement of water, vapor, and energy or only isothermal water flow in soils (the latter as a reference). The results of the coupled model were not only in better agreement with observed data, but also advanced our understanding of underlying mechanisms of soil water flow. For the coupled model, the isothermal liquid flux was the most significant component of the total water flux. Three diurnal stages were identified for thermal liquid and vapor fluxes on dry days, while the vapor flux became almost negligible during rainfall events. The results indicate that isothermal liquid, thermal liquid, and thermal vapor fluxes should be considered simultaneously when evaluating soil water flow in arid regions, while the isothermal vapor flux can be neglected. Vapor flow contributed, on average, about 13% of the total water flux in the uppermost soil layer during the analyzed period at the study area, and this ratio often exceeded 20%.

Due to be difficult for pregnant woman doing a periodic inspection at the hospital, a home uterine contraction pressure monitoring system has been developed, which consists of uterine contraction pressure signal collected unit, wireless transmission unit and PDA module. The system is built based on MCU chip-dsPIC33FJ128MC706. The uterine contraction pressure signal is acquired by load cell sensor is FSL1500N2C made by Honeywell, which can be wireless transmitted to PDA via Bluetooth. The signal can be analyzed real-time on PDA and the diagnosis can be made to prevent premature birth or occurrence of abortion effectively.

Large polarization effects in nitride-based heterostructures provide opportunities for controllably introducing negative charge, equivalent to acceptor-doping, in AlGaN/GaN HBT structures. This paper reviews evidence for polarization-based doping effects in nitride-based materials, and discusses potential applications of these effects for the improvement of p-contacts and p-type base conductivity. It is shown that in conventional HBTs grown with Ga-terminated faces in the emitter-up configuration, the polarization-induced charges detract from the acceptor doping of the base. In contrast, the polarization effects add to effective doping in the base in structures that are grown and processed as collector-up devices, or in devices that are grown emitter-up and utilize the transferred substrate approach.