Adaptive ANFIS-based filter for active control of sinusoidal primary noise in nonlinear path

Linear active noise control (ANC) system is promising in suppressing broadband and narrowband noise in a linear acoustic site.However,in some situations,the acoustic systems are nonlinear which make the primary noise being nonlinear distortion at the canceling point,and the linear ANC system maybe can not work well for these cases.This paper presents an adaptive network-based fuzzy inference system (ANFIS)-based nonlinear filter for active noise control,which is expected to be successfully applied to situations with nonlinear distortion.In the proposed adaptive control algorithm,the parameters are updated by gradient descent method.In the simulations,the secondary-path FIR model coefficients are estimated in advance by off-line system identification method,and one case for sinusoidal primary noise with nonlinear distortion is presented,which verifies the effectiveness of the proposed system in suppressing sinusoidal noise generated by rotating machines,e.g.,engines in vehicles.     

Preparation and performance evaluation of Er2O3 coating-type selective emitter

An Er2O3coating-type selective emitter for themophotovoltaic application was prepared by plasma spray technology.The test results show that plasma spray technology could be used to prepare the Er2O3coating-type selective emitter with good stability at 1400°C.Based on the measurements of the high temperature normal spectral emissivity and the spectral hemispherical emissivity of the samples at room temperature,the influence of the coating thickness was discussed,and the selective emission performance of the sample was evaluated using radiative efficiency as the criterion.The results demonstrate that the emission of substrate could not be neglected unless the coating thickness would be larger than the penetration depth,which is around100μm.The selective emission peak of the Er2O3coating occurs at 1550 nm,matching well with the GaSb cells.However,the radiative efficiency is not larger than that of the SiC emitter,because the non-convertible emission of 1.725–5 m accounts for a large proportion of the total radiation power,especially at high temperature.Effective suppression of this band emission is essential to the improvement of the radiation efficiency of the emitter.     

走进数字化

我们这些在视频领域中工作了一些时候的人们，还能清楚的记得，我们不再购买开盘机视频磁带，而是购买这种便利的卡带的时候。当我们在旧的模拟特技效果发生器上加上一个数字视频效果盒时，是那样的激动。当简单的VHS自身改变而成为如此完善的S-VHS时，是那样地印象深刻。但是我们仍然对面临的变化无所准备，我们已进入了数字化。无论在哪儿，整个视频界正在推进到数字领域。     

经受过适当培训的兼职者的经历

原作NIGEL BATESON是一个曾为BBC工作过的资深自由摄影记，在章中主要写了他在新闻行业中随着社会的发展而不断地学习，更新自己，从一个电视台普通的工作人员而成为职业的自由摄影记的过程及其体会。我把此篇章推荐给大家，是为了让我们每一个电视工作从中受到启发，如何不断地充实自己、完善自己跟上电视行业迅猛发展的步伐以面对这不断变化的世界。     

Fabrication of nanofibrous sensors by electrospinning

This article reviews the techniques and applications of electrospinning for the fabrication of nanofibrous sensors. Considering that nanosensors require a large specific surface area and a continuous structure for the conduction of current signals, electrospun nanofibers have the dominant advantage. The device preparation is mainly divided into surface treatment and high-temperature sintering, which are, respectively, used for preparing composite conductive fibers and inorganic semiconductor fibers. Typical applications include pressure sensing, gas sensing, photoelectric sensing, and temperature sensing. In addition, nano-selfpowered systems have been mentioned to emphasize the good performance of smart nanosystems that do not require external power. In addition, we have summarized some existing methods and suggestions for increasing the specific surface area and presented constructive ideas for the future development of these devices.