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Synthetic materials of polyacrylamide (PAM) are known as the flocculating agent as well as water retention agents. In this study, ten types of water-soluble PAM as well as four types of water-insoluble ones were selected and the influences of relative molecular weight, ion types, charge density and particle size on water retention and service life were determined. Based on the results, evaluation method for performance of water retention agent was established and two optimal PAM (water-insoluble JB and water-soluble WSN20) were screened for further study. It showed that JB increased the degree of hydration of testing soil for 32% compared with that of control. Moreover, multiple-step-outflow test using municipal waste showed that addition of JB (0.1%) had significantly effect on its moisture characteristic curve as evidenced by increasing of equilibrium moisture content over 12% under high matrix potential.

While the role of attention in determining the neural fate of unattended emotional items has been investigated in the past, it remains unclear whether bottom-up and top-down factors have differential effects in shaping responses evoked by such stimuli. To study the effects of bottom-up and top-down factors on the processing of neutral and fearful faces, we employed functional magnetic resonance imaging (fMRI) while participants performed attentional tasks that manipulated these factors. To probe the impact of top-down mechanisms on the processing of face distractors, target letters either had to be found among several distinct nontarget letters (attentional load condition) or among identical nontarget letters (baseline condition). To probe the impact of bottom-up factors, we decreased the salience of the targets by reducing their size and contrast relative to baseline (salience condition). Our findings revealed that bottom-up and top-down manipulations produced dissociable effects on amygdala and fusiform gyrus responses to fearful-face distractors when task difficulty was equated. When the attentional load of the main task was high, weaker responses were evoked by fearful-face distractors relative to baseline during the early trials. By contrast, decreasing target salience resulted in increased responses relative to baseline. The present findings suggest that responses evoked by unattended fearful faces are modulated by several factors, including attention and stimulus salience.

Aiming at requirements of the first national undergraduate intelligent car contest we had designed and made a cruising and contesting robot. Through using methods of selecting the power regulator optimized, using a virtual coder to measure the robot speed, recognizing the roadway by a image sensor and process of real time N-1 data compression and offering switching control method to the cruising and contesting robot's control, all they made our the cruising and contesting robot take the tenth in the first national undergraduate intelligent car contest having 112 delegation.