建立了紫外光非视距通信模型,基于眼图原理,对紫外光非视距通信的通信距离和系统稳定性进行了深入研究,分析了散粒噪声和热噪声对通信性能的影响,并利用Opt i syst em进行实验。结果显示,一般环境下紫外光非视距通信距离可达到0.3km,热...建立了紫外光非视距通信模型,基于眼图原理,对紫外光非视距通信的通信距离和系统稳定性进行了深入研究,分析了散粒噪声和热噪声对通信性能的影响,并利用Opt i syst em进行实验。结果显示,一般环境下紫外光非视距通信距离可达到0.3km,热噪声对通信性能的影响比较大,并且得出一定环境下紫外光通信系统可接受的热噪声最大值为1×10-20W/Hz。展开更多
目的:探讨疟疾Dia Med Opti MAL-IT快速检测技术在临床运用的效果。方法:用疟疾Dia MedOpti MAL-IT快速检测法与疟原虫染色镜检法对144例疑似病例进行检测比较。结果:镜检法阴性92例,间日疟45例,恶性疟7例,Dia Med Opti MAL-IT快速法检...目的:探讨疟疾Dia Med Opti MAL-IT快速检测技术在临床运用的效果。方法:用疟疾Dia MedOpti MAL-IT快速检测法与疟原虫染色镜检法对144例疑似病例进行检测比较。结果:镜检法阴性92例,间日疟45例,恶性疟7例,Dia Med Opti MAL-IT快速法检测阴性94例,间日疟43例,恶性疟7例,二种检测方法差异无统计学意义(T=2,P=0.368)。结论:Opti MAL-IT快速检测法与镜检法无差别,且具有简便、快速的优点,适合对疟疾疑似病例开展临床检测。展开更多
An efficient method employing a Principal Component Analysis(PCA)-Deep Belief Network(DBN)-based surrogate model is developed for robust aerodynamic design optimization in this study.In order to reduce the number of d...An efficient method employing a Principal Component Analysis(PCA)-Deep Belief Network(DBN)-based surrogate model is developed for robust aerodynamic design optimization in this study.In order to reduce the number of design variables for aerodynamic optimizations,the PCA technique is implemented to the geometric parameters obtained by parameterization method.For the purpose of predicting aerodynamic parameters,the DBN model is established with the reduced design variables as input and the aerodynamic parameters as output,and it is trained using the k-step contrastive divergence algorithm.The established PCA-DBN-based surrogate model is validated through predicting lift-to-drag ratios of a set of airfoils,and the results indicate that the PCA-DBN-based surrogate model is reliable and obtains more accurate predictions than three other surrogate models.Then the efficient optimization method is established by embedding the PCA-DBN-based surrogate model into an improved Particle Swarm Optimization(PSO)framework,and applied to the robust aerodynamic design optimizations of Natural Laminar Flow(NLF)airfoil and transonic wing.The optimization results indicate that the PCA-DBN-based surrogate model works very well as a prediction model in the robust optimization processes of both NLF airfoil and transonic wing.By employing the PCA-DBN-based surrogate model,the developed efficient method improves the optimization efficiency obviously.展开更多
Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving mul...Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving multispectral and in particular multi-polarization detection.Here we develop a plasmonic approach toward broadband infrared polarimetric crypsis,where the polarized thermal emission near the pseudo-Brewster angle is the main signal source and no existing polarizing camouflage technique has been discovered in nature.Based on all-metallic subwavelength structures,an electrodynamic resistance-reduction mechanism is proposed to avoid the significant polarization-dependent infrared absorption/radiation.It is also found that the structured metal surface presents giant extrinsic anisotropy regarding the phase shift between orthogonal polarization states,which helps to realize ultrahigh-efficiency and tunable polarization conversion in an unprecedented manner.Finally,we note that the catenary optical theory may provide a useful means to explain and predict these unusual performances.展开更多
文摘建立了紫外光非视距通信模型,基于眼图原理,对紫外光非视距通信的通信距离和系统稳定性进行了深入研究,分析了散粒噪声和热噪声对通信性能的影响,并利用Opt i syst em进行实验。结果显示,一般环境下紫外光非视距通信距离可达到0.3km,热噪声对通信性能的影响比较大,并且得出一定环境下紫外光通信系统可接受的热噪声最大值为1×10-20W/Hz。
文摘目的:探讨疟疾Dia Med Opti MAL-IT快速检测技术在临床运用的效果。方法:用疟疾Dia MedOpti MAL-IT快速检测法与疟原虫染色镜检法对144例疑似病例进行检测比较。结果:镜检法阴性92例,间日疟45例,恶性疟7例,Dia Med Opti MAL-IT快速法检测阴性94例,间日疟43例,恶性疟7例,二种检测方法差异无统计学意义(T=2,P=0.368)。结论:Opti MAL-IT快速检测法与镜检法无差别,且具有简便、快速的优点,适合对疟疾疑似病例开展临床检测。
基金co-supported by Aeronautical Science Foundation of China(No.2015ZBP9002)China Scholarship Council。
文摘An efficient method employing a Principal Component Analysis(PCA)-Deep Belief Network(DBN)-based surrogate model is developed for robust aerodynamic design optimization in this study.In order to reduce the number of design variables for aerodynamic optimizations,the PCA technique is implemented to the geometric parameters obtained by parameterization method.For the purpose of predicting aerodynamic parameters,the DBN model is established with the reduced design variables as input and the aerodynamic parameters as output,and it is trained using the k-step contrastive divergence algorithm.The established PCA-DBN-based surrogate model is validated through predicting lift-to-drag ratios of a set of airfoils,and the results indicate that the PCA-DBN-based surrogate model is reliable and obtains more accurate predictions than three other surrogate models.Then the efficient optimization method is established by embedding the PCA-DBN-based surrogate model into an improved Particle Swarm Optimization(PSO)framework,and applied to the robust aerodynamic design optimizations of Natural Laminar Flow(NLF)airfoil and transonic wing.The optimization results indicate that the PCA-DBN-based surrogate model works very well as a prediction model in the robust optimization processes of both NLF airfoil and transonic wing.By employing the PCA-DBN-based surrogate model,the developed efficient method improves the optimization efficiency obviously.
基金National Natural Science Foundation of China under contact Nos.61622508,61622509,and 61675208.
文摘Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving multispectral and in particular multi-polarization detection.Here we develop a plasmonic approach toward broadband infrared polarimetric crypsis,where the polarized thermal emission near the pseudo-Brewster angle is the main signal source and no existing polarizing camouflage technique has been discovered in nature.Based on all-metallic subwavelength structures,an electrodynamic resistance-reduction mechanism is proposed to avoid the significant polarization-dependent infrared absorption/radiation.It is also found that the structured metal surface presents giant extrinsic anisotropy regarding the phase shift between orthogonal polarization states,which helps to realize ultrahigh-efficiency and tunable polarization conversion in an unprecedented manner.Finally,we note that the catenary optical theory may provide a useful means to explain and predict these unusual performances.
