Measurements of H2S in the Atmosphere

Swamps and tidal flats are believed to he important natural sources of atmospheric H₂S, though it is very difficult to detect the low concentrations of this trace gas above the surface of these regions. In view of this problem an air sampling device has been developed for the sampling of atmospheric H₂S with chemically impregnated filters. The sulfide generated on the filter is analyzed in a washing solution employing a very sensitive fluorescence method. The quality of the method is demonstrated by comparative calibrations. The fluorescence method is calibrated in the liquid phase with standard solutions of sulfide. Furthermore the sampling and analyzing method is calibrated together by using H₂S calibration gases. The detection limit of the method is shown to he 10ng/m³ STP. Data of test-measurements in ambient air and some results of field-measurements in the lower troposphere are presented.     

TiO2光催化剂的可见光敏化研究

报道了共溶液掺杂法对二氧化钛光谱特性进行了可见光敏化的研究结果。实验结果表明：钡掺杂的二氧化钛光催化剂在可见照射下,对初始浓度为５０μｌ／Ｌ硫化氢,小时转化率高达９６．９％,ＸＰＳ结果证明了二氧化钛晶格中有钒离子存在。粉末电导结果进一步揭示了钒掺反杂二氧化钛中呈现两种导电机制和光谱响应红移的内在原因。