Self-adjusting inverse design method for nanophotonic devices.

Nanophotonic devices, which consist of multiple cell structures of the same size, are easy to manufacture. To avoid the optical proximity effect in the ultraviolet lithography process, the cell structures must be maintained at a distance from one another. In the inverse design process, the distance is maintained by limiting the optimized range of the location. However, this implementation can weaken the performance of the devices designed during transmission. To solve this problem, a self-adjusting inverse design method based on the adjoint variable method is developed. By introducing artificial potential field method, the location of one cell structure is modified only when the distances between this cell structure and other cell structures are smaller than a threshold. In this case, the range of the location can be expanded, and thus the performance of the designed devices can be improved. A wavelength demultiplexer with a channel spacing of 1.6 nm is designed to verify the performance of the proposed method. The experiment reveals that the transmission of the designed devices can be improved by 20%, and the self-adjusting inverse design process is 100 times faster than the inverse-design process based on the genetic algorithm.

[Aniline removal by aerobic granules and high-efficiency aniline-degrading bacteria].

Aerobic granules were successfully cultivated with aniline as the sole source of carbon and nitrogen. This system could effectively degrade aniline as high as 6 000 mg/L. Two aniline-degrading strains which were named as adx1 and adx3, were isolated and purified from the aerobic granular sludge. The degradation characteristics of these two bacteria were different. The strain adxl possessed a relatively higher degradation rate of aniline, while the strain adx3 could stand up to a higher concentration of aniline than the strain adx1. The degrading process of these two strains followed the Haldane kinetic model. The maximum aniline biodegradation rates of adx1 and adx3 were up to 0.924 g/(g x h) and 0.645 g/(g x h), respectively. The maximum specific growth rates were as high as 0.487 g/(g x h) and 0.440 g/(g x h), respectively. Identification by 16S rDNA gene sequence analysis showed that adx1 and adx3 were Pseudomonas sp. and Achromobacter sp., which was consistent with the identification by the bands 1 and 4 in the PCR-DGGE profile of the aerobic aniline-degrading granules. Therefore, it could be proposed that the strains adx1 and adx3 were one of the main functional microorganisms inhabited in the aerobic granules.