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The paper analyzed implementation principle of double closed-loop control strategy for shunt active power filter. In view of problems that PI control cannot track AC signal without static error and repetitive control has slow dynamic response speed, the paper proposed a composite control strategy based on repetitive control and PI control for current loop to improve stable tracking performance of control system of shunt active power filter by repetitive control and dynamic performance of control system of shunt active power filter by PI control. In view of problems that PI control is difficult to determine transfer function of control system of shunt active power filter and cannot online set PI parameters, the paper proposed a fuzzy PID control strategy for voltage loop to control DC voltage. Matlab/Simulink simulation result validates correctness and feasibility of the control strategy.

For problem that traditional video compression technology is not suitable for application in bad network environment, the paper proposed a design scheme of remote video monitoring system based on H.264. The system combines embedded technology, network technology and video coding technology together, video signal collected by camera of the embedded system was transferred to remote monitoring terminal in real time through built-in Web server of the system after it was compressed according to H.264 standard code, so as to realize interconnection communication between browser of the remote monitoring terminal and embedded Web server. The test result shows that the system has high video compression ratio, clear image and strong real-time performance.

The paper designed an industrial wireless data collector based on ZigBee. The collector uses a MCU of AVR to communicate with the ZigBee module to complete data collection and transmittance with good reliability in a short distance, and it can solve problem of the data collection at industrial field effectively.

Objective: To study the effect of electromagnetic pulse (EMP) on the permeability of blood-brain barrier, tight junction (TJ)-associated protein expression and localization in rats., Methods: 66 male SD rats, weighing (200 approximately 250) g, were sham or whole-body exposed to EMP at 200 kV/m for 200 pulses. The repetition rate was 1 Hz. The permeability of the blood-brain barrier in rats was assessed by albumin immunohistochemistry. The expression of typical tight junction protein ZO-1 and occludin in both cerebral cortex homogenate and cerebral cortex microvessel homogenate was analyzed by the Western blotting and the distribution of ZO-1 and occludin was examined by immunofluorescence microscopy., Results: In the sham exposure rats, no brain capillaries showed albumin leakage, at 0.5 h after 200 kV/m EMP exposure for 200 pulses; a few brain capillaries with extravasated serum albumin was found, with the time extended, the number of brain capillaries with extravasated serum albumin increased, and reached the peak at 3 h, then began to recover at 6 h. In addition, no change in the distribution of the occludin was found after EMP exposure. Total occludin expression had no significant change compared with the control. However, the expression level of ZO-1 significantly decreased at 1 h and 3 h after EMP exposure in both cerebral cortex homogenate and cerebral cortex microvessel homogenate. Furthermore, immunofluorescence studies also showed alterations in ZO-1 protein localization in cerebral cortex microvessel., Conclusion: The EMP exposure (200 kV/m, 200 pulses) could increase blood-brain barrier permeability in rat, and this change is associated with specific alterations in tight junction protein ZO-1.