CuInS2 quantum-dot sensitized TiO2 photoanodes with In2S3 buffer layer were in situ prepared via chemical bath deposition of In2S3, where the Cd-free In2S3 layer then reacted with TiO2/CuxS which employed a facile SILAR process to deposit CuxS quantum dots on TiO2 film, followed by a covering process with ZnS layer. Polysulfide electrolyte and Cu2S on FTO glass counter electrode were used to provide higher photovoltaic performance of the constructed devices. The characteristics of the quantum dots sensitized solar cells were studied in more detail by optical measurements, photocurrent-voltage performance measurements, and impedance spectroscopy. On the basis of optimal CuxS SILAR cycles, the best photovoltaic performance with power conversion efficiency (η) of 1.62% (Jsc = 6.49 mA cm(-2), Voc = 0.50 V, FF = 0.50) under full one-sun illumination was achieved by using Cu2S counter electrode. Cu2S-FTO electrode exhibits superior electrocatalytic ability for the polysulfide redox reactions relative to that of Pt-FTO electrode.

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In Beijing, dewatering has been strictly prohibited in foundation-pit excavation since March 1, 2008. Therefore, the deep foundation pit has to be constructed under groundwater level, which make the construction of the water-resisting curtain and anchor quite difficult in granular soil. This paper introduces the construction of a foundation pit of underground garage with the excavation depth of 20.6 m. By improving construction techniques, a water-resisting curtain was constructed with good performance under a water head of up to 6 m in a granular soil layer with high permeability. The anchoring force is guaranteed in the case that cement slurry is lost after the water-resisting curtain is perforated under groundwater level. The project is a successful example of foundation pit engineering construction in the Beijing area.