Bidirectional cascaded deep neural networks with a pretrained autoencoder for dielectric metasurfaces

Metasurfaces composed of meta-atoms provide promising platforms for manipulating amplitude,phase,and polarization of light.However,the traditional design methods of metasurfaces are time consuming and laborious.Here,we propose a bidirectional cascaded deep neural network with a pretrained autoencoder for rapid design of dielectric metasurfaces in the range of 450 nm to 850 nm.The forward model realizes a prediction of amplitude and phase responses with a mean absolute error of 0.03.Meanwhile,the backward model can retrieve patterns of meta-atoms in an inverse-design manner.The availability of this model is demonstrated by database establishment,model evaluation,and generalization testing.Furthermore,we try to reveal the mechanism behind the model in a visualization way.The proposed approach is beneficial to reduce the cost of computation burden and improve nanophotonic design efficiency for solving electromagnetic on-demand design issues automatically.

A novel and effective hyperthermia method for Schistosomiasis japonica prevention and treatment

The emerging resistance to schistosoma has been paid much attention and is in urgent need for a novel strategy to control the prevalent parasitic zoonosis. In this study, the efficiency of hyperthermia therapy was investigated by the skin hyperthermia device. The survival rate of cercariae decreased from 68.15 % （37 ℃, 5 min） to 0 （49℃, 10 min） with the thermal dosages increased, which proved the preventing effect of hyperthermia therapy （P 〈 0.05）. Therapeutic effects were assessed in Schistosoma japonicum-infected BALB/c mice. When the cercarial contact region of the skin was treated at 45-49℃ for 5 min within 8 h of infection, worm reduction rate （WRR） reached 74 %-83 % （P 〈 0.01）. The sensitivity of adult schistosoma to heat was also investigated using microwave intraperitoneal hyperthermia （thermal dosages 42-43℃, 20 min）. The WRR, hepatic shift rates and egg reduction rates were 23.7 %, 40 % and 30 %, respectively, comparing with 80.2 %, 59.6 % and 53.9 % of praziquantel （PZQ）-treated group. Encouraging results have been obtained that hyperthermia can effectively kill schistosomula, especially with the appearance of cercarial dermatitis, while PZQ lacks efficacy against the cercariae. Thus, hyperthermia therapy would show significant benefit in preventing and treatment of schistosoma, especially in the early stage.

ENHANCED BLOCK-SPARSE SIGNAL RECOVERY PERFORMANCE VIA TRUNCATED l2\l1-2 MINIMIZATION

In this paper,we investigate truncated l2\l1-2 minimization and its associated alternating direction method of multipliers(ADMM)algorithm for recovering the block sparse signals.Based on the block restricted isometry property(Block-RIP),a theoretical analysis is presen ted to guarantee the validity of proposed method.Our theore tical resul ts not only show a less error upper bound,but also promote the former recovery condition of truncated l1-2 method for sparse signal recovery.Besides,the algorithm has been compared with some state-of-the-art algorithms and numerical experiments have shown excellent performances on recovering the block sparse signals.