To minimize cargo theft during transport, mobile radio frequency identification (RFID) grouping proof methods are generally employed to ensure the integrity of entire cargo loads. However, conventional grouping proofs cannot simultaneously generate grouping proofs for a specific group of RFID tags. The most serious problem of these methods is that nonexistent tags are included in the grouping proofs because of the considerable amount of time it takes to scan a high number of tags. Thus, applying grouping proof methods in the current logistics industry is difficult. To solve this problem, this paper proposes a method for generating multilayered offline grouping proofs. The proposed method provides tag anonymity; moreover, resolving disputes between recipients and transporters over the integrity of cargo deliveries can be expedited by generating grouping proofs and automatically authenticating the consistency between the receipt proof and pick proof. The proposed method can also protect against replay attacks, multi-session attacks, and concurrency attacks. Finally, experimental results verify that, compared with other methods for generating grouping proofs, the proposed method can efficiently generate offline grouping proofs involving several parties in a supply chain using mobile RFID.

Aeration was one of the common techniques which were focused in environmental engineering research. In this study, experiments were carried out to investigate the effect of aeration on nitrogen (N) fractions and its transformation in the sediment-water interface from urban lake. In addition, we measured the dehydrogenase (DHA) and Chla content in surface sediment to detect the changes of the microbial activity. The aim is to explore the regulation of N migration and transformation in the water-sediment interface during the treatment work of lake pollution. By mechanical aeration, we control the DO content of the overlying water at the range of 1.2-1.5 kg/L, 2.5-4.5 mg/L and 6.1-6.2 mg/L. Results showed that DO in overlying water play a role to the variation of N in water-sediment interface. NH4+-N was the mainly N fraction released from sediment, the lower DO concentration (1.2-1.5 mg/L) in overlying water is favorable to the release of NH4+-N from sediment. Whether under aerobic or anaerobic condition, the releasing of NH4+-N from sediment were both higher than its consumption in the overlying water. The benthic microbial activity of the surface sediment (0-2 cm) was higher than that from bottom (6-8 cm). And the microbial activity in surface sediment was in optimum range when the overlying water DO content was about 2.5-4.5 mg/L.

Spatial distribution of phosphorus in the buffer zone sediments of 16 rivers around Erhai Lake was investigated in July 2013 and different rivers are classified by hierarchical cluster. The average contents of TP, IP, Ca-P and Fe/Al-P were 822.18mg/kg, 602.42mg/kg, 396.79mg/kg and 150.64mg/kg. IP is the dominant mineral form in surface sediments. The order of the average contents of TP and IP conjects to be: West>South>North, West>North>South, respectively. The spatial distribution of TP, Ca-P and Fe/Al-P in the sediments shows a significant positive correlation with that of IP. All 16 investigated rivers are divided into five types according to the hierarchical cluster analysis: Shuangyuanxi River is one type, Zhonghexi River and Mocanxi River are one type, Boluojiang River and Baihexi River are one type, Yangxi River is one type and the other rivers are one type.