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To detect the terahertz radiation of a low temperature blackbody accurately,the difference between infrared radiation and different terahertz radiations of the blackbody was researched.A low temperature blackbody terahertz radiometer was established with narrowband spectral filtering method.First,the emitted spectral radiances were calculated by Planck′s law in various terahertz wave bands.The results show that the radiances of blackbody in the infrared band are four to ten times than that in the terahertz band from 223 K to 323 K.Then a low-pass filter and several band-pass filters were made up a filter combination with high transmission in various wavelengths.The filter combination was used to filter the infrared radiation and to transmit the terahertz radiation to implement the terahertz spectral radiance measurement.Experimental results reveal the deviations of terahertz narrowband radiations at different bands for the blackbody and indicate that spectral filtering method can realize the detection of terahertz radiation of the blackbody.

Hydrocarbon pollution is a threat to the agricultural industry and the natural environment. Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants known for their carcinogenesis, teratogenesis and mutagenesis, making them harmful to humans and the ecological environment. This review paper critically assesses the environmental contamination issues associated with PAHs, with particular attention given to surface waters. An overview of the transport and transformation behaviours of various types of PAHs within surface waters, including the exchange between water and air, photodegradation, adsorption-desorption on particles, uptake by plants and biodegradation is given. Recent findings in areas such as phytoremediation and microbial degradation processes, which are relevant to agriculture, water resources management and environmental science, are highlighted. Finally, the paper recommends further research on the mechanisms of PAHs sorption to particles, and remediation and degradation of PAH by plants and microbes.