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We used methods such as microorganism cultivation and PCR-DGGE to examine the influence of glyphosate, paraquat, and xiao suo (used exclusively in China) on biodiversity. Two weeks after herbicide application, the strongest herbicidal effect was observed from paraquat, followed by glyphosate and then xiao suo. Although weed suppression was maintained over the effective period of each herbicide, surface vegetation gradually recovered after one month. Levels of soil bacteria and fungi were noticeably altered by exposure to herbicide. Actinomycetes were unaffected, however. Bacterial genetic diversity obviously changed, with some DGGE bands disappearing. Although several DGGE bands were lost, fungal genetic diversity remained constant. Actinomycetes remained constant. Overall, glyphosate and paraquat had stronger culling effects on surface plants than xiao suo, whereas glyphosate and xiao suo had stronger effects on soil microorganisms than paraquat. The results have implications for agriculture production, and provide information related to soil ecological stability and recovery for use in ecological management of economic forests.

Intermittent gas-liquid flow with an unsteady, intermittent and high-pressure drop nature is common in vacuum transport pipelines. The characteristics of intermittent flow in vacuum pipelines were analyzed. A one-dimensional transient hydrodynamic model for two-phase transport of vacuum pipelines, which consists of the film model, the liquid slug model and the mix vortex model was deduced for the first time. The model outlines the relationship between hydrodynamic parameters and presents the calculation method of pressure drop, which would be helpful to uncover the transport mechanism of vacuum pipelines and propose a more seemly system design and simulation method for availability, reliability and energy-saving considerations.