Ambient concentrations of PANs and other related air pollutants were monitored at an urban site in Beijing each August from 2006 to 2014. The NO_x concentration decreased at a rate of 1.7 nL/(L/yr) (about 4%/yr), and the PAN concentration decreased at a rate of 0.03 nL/(L/yr) (about 3%/yr), while the O₃ concentration increased at a rate of 1.5 nL/(L/yr) (about 4%/yr), indicating that the measures taken to cut NO_x were effective for controlling PAN concentration. Beijing needs to strengthen the control of VOCs with reducing NO_x emissions for reducing O₃ concentration.

Online measurement and analysis were taken for PAN and PPN during the 2010 World Expo in Pudong New District, Shanghai. The highest concentration were 5500 pptv and 709 pptv, respectively. PAN was higher in the month of May and June than that in July and August. The diurnal variations for PAN and PPN changed significantly, the lowest concentration occurred at 6:00 and the highest value occurred at 12:00. The ratio between PAN and PPN in July, August and October was lower than that in the other months, indicating that the maganitude of the anthropogenic VOCs declined. Average ratio of daily maximum PAN and O₃ was 0.034 with 93.4% ratio lower than 0.07, which was smaller than the typical urban ratio value.

The multiple access control (MAC) protocol in broadband satellite access network is investigated. A novel combined dynamic allocation multi-access scheme is proposed, which is based on the chaotic prediction of self-similar traffic. The OPNET simulation system is developed for comparing the performance of different schemes. Simulation results indicate that the novel scheme has better performance when the traffic data exhibit self-similarity. The superiority of centralized access control with satellite onboard processing (OBP) is also proved.

The experimental investigation on the intensity-dependent photorefractive response of the proton-implanted KNbO₃ crystals is presented. The decay time constant was measured. The results revealed that two gratings existed simultaneously, one was caused by the photorefractive effect, and the other was contributed from the proton-implantation. The experimental results also reflect that low dose implantation hardly influence the photorefractive decay time.