基于MOSFET电路的非视觉感光系统建模及其照明应用

目的为合理解释非视觉感光系统响应量与光照之间的关系,探讨LED照度光环境对学习者学习效率及疲劳度的影响。方法首先利用等效类比的方法建立了基于MOSFET电路的非视觉感光系统模型,然后利用Multisim 12.0软件进行了MOSFET电路仿真,并验证了非视觉感光系统与MOSFET电路模型一致性。最后结合新型学习工具——平板显示器,通过改变光环境照度,采用安菲莫夫字母表测试了6名学习者的学习效率与疲劳度。结果结果显示,学习效率随着照度增加而增加,照度在700 lx附近达到最大,视疲劳与脑疲劳较小。结论利用本文所建立的基于MOSFET电路的非视觉感光系统模型,较好地解释了光感受系统作用机制,并综合考虑学习效率、视疲劳和脑疲劳三方面因素,提出合理照明建议:在多数学习任务情境下,应尽可能选择700 lx附近LED光源作为光环境照度。

基于深度学习的打印件中感光鼓损伤印迹识别系统设计

传统的打印机感光鼓损伤印迹识别系统识别时间长,工作过程稳定性差,为了解决上述问题,基于深度学习设计了一种新的打印机感光鼓损伤印迹识别系统。在传统卷积神经网络基础上增加训练模型,设计了一种新的卷积神经网络,将该网络引入到系统硬件中,构建出系统硬件总结构,包括输入层、卷积层、下采样层、特征提出层和输出层五层。根据硬件设计软件程序,共分为信息预处理、感光鼓损伤印迹定位、感光鼓损伤印迹分割、感光鼓损伤印迹识别四步。为检测识别系统的工作效果,与传统识别系统进行实验对比,结果表明,基于深度学习设计的识别系统能够有效缩短感光鼓损伤印迹识别时间,工作过程稳定性高。

光照对畜牧生产的影响

光照作为主要的环境因素之一,影响动物的方方面面,随着畜牧业的不断发展如何提高生产效率成为关注的重点。其中光照与动物生活环境密切相关,一方面可以影响畜禽的生长,如降低料重比,提高肉品质和多种畜禽水产的成活率等。另一方面光照通过不同的光周期影响禽类产蛋率、哺乳动物发情等方面,提高畜禽繁殖性能。该文简要概述了不同光照来源、光照强度、光照时长、光波长等条件下的光照对畜牧生产的影响,简单介绍光照的作用机理,哺乳动物和禽类的感光系统,以及光照在生产管理方面的作用,旨在为畜牧生产中合理使用光照提供依据,提高畜禽的生产效率,并为后续的研究建立基础。

高速公路隧道火灾自动报警系统优化改造与应用分析

通过福宁高速8条长隧道线型光纤感温火灾自动报警系统在运行、维护过程中发现的缺陷与不足,介绍了针对不足之处所采取的优化改造方案,同时结合本公司其他路段上使用的感光型双波长火灾自动报警系统、光纤光栅感温火灾自动报警系统的运维实际,分析了感光和感温两种类型隧道火灾自动报警系统在投资造价、后期维护及实际应用等方面的差异,为高速公路隧道火灾自动报警系统建设提供借鉴参考。

Cultural and luminescent Conditions of a Marine luminous Bacterium

Study of marine noctilucence in marine is important to fishery, environmental monitoring and military affairs. A luminous bacterial strain D2 was isolated from the marine sediment samples collected near Donghai Island in Zhanjiang, China. The primary cultural and luminescent conditions of luminous bacterium D2 which was identified as Vibrio sp. were determined in liquid culture. The results showed that pH 7.0, 35 ℃, with 2.0 % NaCI, were the best growth conditions, and pH5 - 6, 20℃, OD600 0.08, with 3.0 % NaCI, were the optimal luminescent conditions.

又见轻、薄——顶星W800笔记本

很久以前,当笔记本厂商看准中国这一广大市场的时候,可能还没几个厂家敢去想自己生产笔记本。有实力的厂商往往都采用国内总代理或者贴牌国外厂家产品的方法分一杯羹。最近几年才有为数不名的国内厂商自主研发笔记本,并且以不错的价格和质量吸引了消费者的目光。顶星的笔记本就是其中一家,其产品的设计风格也曾经在网上吵的沸沸扬扬,我们评测是最近才面市的W800笔记本。

全面的稳定——歌美迪后视镜导航测评

最近,后视镜的小电子产品越来越火,后视镜行车记录仪、后视镜电子狗、后视镜导航、后视镜几合一等产品层出不穷,顺应时下火热的后视镜浪潮,今天给大家带来歌美迪的后视镜导航测评报告。后视镜的外观就不作多描述了,与普通的后视镜没有多大区别。对于一个导航而言4.3英寸的显示屏略显小气,当它出现在后视镜的时候,就有了刚刚好的感觉,这个4.3英寸的显示屏是一个高亮屏,带有自动感光系统,亮度可以随着环境的变化自动调节,这个显示屏还是一个电容屏,所有的操作都能直接触控完成,操控体验不输普通的车机触摸屏。后视镜的玻璃厚度有4mm,反射率高的同时还有防炫目的功能,实实在在的达到了车规级的要求。

Monitoring and Warning of Landslides and Debris Flows Using an Optical Fiber Sensor Technology

Landslides and debris flows are typical geo-hazards which occur in hilly or mountainous regions. Debris flows may result from landslides. Geotechnical instrumentation plays an important role in monitoring and warning of landslides and resulted debris flows. Traditional technologies for monitoring landslides and debris flows have certain limitations. The new optical fiber sensors presented in this paper can overcome those limitations. This paper presents two new optical fiber sensor systems: one is the Fiber Bragg Grating (FBG)-based in-place inclinometer for monitoring landslides and the other is the FBG-based column-net system for monitoring debris flows. This paper presents the calibration results of FBG-based in-place inclinometers in laboratory. It is found that the calibration results are in good agreement with theoretical results. Both the FBG-based in-place inclinometers and the FBG-based column-net system have been installed at a site in Weijiagou valley, Beichuan County, Sichuan Province of China. Some preliminary results have been obtained and reported in the paper. The advantages of the FBG monitoring systems and their potential applications are also presented.

Analysis of a FBG sensing system with transverse uniform press by using genetic algorithm

An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio to genetic algorithm, and the optimization parameters of genetic algorithm were given. The relevant experimental system is constructed. The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasistatic FBG sensing system at transverse uniform press, the strain measurement with high-precision of 0.91% can be realized

An optical sensing system for the concentration of methane based on fiber Bragg gratings

Based on a special catalyst and fiber Bragg gratings (FBGs), an optical sensing system is proposed to measure the concen- tration of methane. The temperature of the catalyst rises rapidly as the concentration of methane increases, and hence it can be detected by an FBG-type sensor through monitoring the wavelength shift of the reflection spectrum. The experimental results show the good performances of our system, such as the high resolution and temperature stability.

Techniques for DFB Fiber Laser Based Accelerometer

A distributed feedback fiber laser based Bragg grating vibration sensor system is proposed.Demodulated by using an unbalanced M-Z interferometer,experiment demonstrates that the system runs at a sensing sensitivity of about 257.2 rad·s2/m and a resolution of 4.2×10-5 m/s2 for monitoring acceleration.Experimental results show that the phase-shift changes with the acceleration linearly.

Digital Synthetic-heterodyne Interferometric Demodulation Based on Embedded System

Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide whole system’s performance to some extent because it will affect directly the factors such as resolving power, precision and dynamic range. The signal processing is usually realized by analog circuits which was more inferior in stability, flexibility and anti-jamming to digital processing system. A digital processing system of optical fiber acceleration seismometer has been designed based on the embedded system design scheme. Synthetic-heterodyne demodulation has been studied, and signal processing has been realized. The double processors of ARM and DSP are employed to implement respectively the system control and signal processing, and to provide the output interfaces such as LCD, DAC and Ethernet interface. This system can vary with the measured signal in real time and linearly, and its work frequency bandwidth is between 10Hz and 1kHz. The system has better anti-jamming ability and can work normally when the SNR is 40dB.

Two-function light source in a FBG multi-point sensing system

In this paper,a two-function light source is recommended. It can both amplify the light power and demodulate the wave-length signal. Its output power is 1000 times as high as traditional broadband light source(BBS) and it can demodulate the signal by scanning wavelength in 30 nm of bandwidth range in the situation of 1550 nm central wavelength. This kind of light source effectively solves the problem of light energy supply in more-point measurement of FBG and simplifies the structure of sensing measurement.

New High Sensitivity Pressure Transducer with Optical Fibre Link

The principle of new optical fibre pressure transducer is analysed, and ingenious design scheme of this transducer is given. This new transducer specimen is provided with following characteristics: experimental transmitting distance is 20 m (actually up to 1 000 m ); system sensitivity is 0. 1 mV/Pa; power consumption of the probe is less than 125 μW. Finally, some points of the appraisement are given in this paper.

New Monitoring Technologies for Overhead Contact Line at 400 km.h-1

Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h： to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class current collection performance evaluation methods that have been developed and demonstrated by Korea. Specifically, this paper reports details of the video-based monitoring techniques that have been adopted to inspect the stability of overhead contact line （OCL） components at 400 km.h-1 without direct contact with any components of the power supply system. Unlike conventional OCL monitoring systems, which detect contact wire positions using either laser sensors or line cameras, the developed system measures parameters in the active state by video data. According to experimental results that were obtained at a field-test site established at a commercial line, it is claimed that the proposed mea- surement system is capable of effectively measuring OCL parameters.

Signal Processing for Fibre-optic Distributed Sensing Techniques Employing Brillouin Scattering

As fibre optic distributed scattering sensing systems are providing innovative solutions for the monitoring of large structures,Brillouin-based distributed scattering sensing techniques represent a new physical approach for structures health monitoring,which seems extremely promising and is receiving most attentions.This paper comprehensively presents some methods of signal interrogation for fibre optic Brillouin-based distributed scattering sensing technology,especially establishes an accurate Pseudo-Voigt model of Brillouin gain spectrum and gives some results on spectrum analysis and data processing.

Design and nonlinearity compensation of Fabry-Perot type tunable optical filters for dynamic strain sensing systems

The collected spectrum of the fiber Bragg grating(FBG) and the loss of the detected optical power are discussed with respect to the 3-dB bandwidth of a Fabry-Perot(F-P) type tunable optical filter(TOF),respectively.And the optimized parameters of the TOF are obtained consequently.It is demonstrated that the relationship between the transmission wave-length of the TOF and its drive voltage is nonlinear.A new method to compensate the nonlinearity of the TOF is proposed.The linear sweeping of the transmission wavelength of the TOF is achieved through modifying the drive voltage using interpolation algorithm.It is observed that the average error and the maximum error of the transmission wavelength are reduced sharply under linear fit.The dynamic strain sensing is realized by use of a reference FBG and moving averaging algorithm in this system.

Experimental Research on Quantitative Inversion Models of Suspended Sediment Concentration Using Remote Sensing Technology

Research on quantitative models of suspended sediment concentration （SSC） using remote sensing technology is very important to understand the scouting and siltation variation in harbors and water channels. Based onlaboratory study of the relationship between different suspended sediment concentrations and reflectance spectra measured synchronously, quantitative inversion models of SSC based on single factor, band ratio and sediment parameter were developed, which provides an effective method to retrieve the SSC from satellite images. Results show that the bl （430-500nm） and b3 （670-735nm） are the optimal wavelengths for the estimation of lower SSC and the b4 （780-835nm） is the optimal wavelength to estimate the higher SSC. Furthermore the band ratio B2/B3 can be used to simulate the variation of lower SSC better and the B4/B1 to estimate the higher SSC accurately. Also the inversion models developed by sediment parameters of higher and lower SSCs can get a relatively higher accuracy than the single factor and band ratio models.

Study on Coaxiality Measurement System of Compound Gear Shaft Based on Non⁃contact Optic

Aiming at the shortcomings of traditional contact measurement methods such as low measurement efficiency,high cost and low accuracy,a non-contact optical measurement method based on the laser displacement sensor is proposed.According to the relevant regulations of the coaxiality error evaluation standard and the structural characteristics of the compound gear shaft,we have designed and built a set of supporting software system as well as a hardware test platform.In this paper,the distance difference threshold and scale threshold methods are used to eliminate outlier data.The least squares circle is selected to calculate the center of the circle and the minimum containment cylinder axis method is used as the reference axis of the composite gear shaft.Compensated by the standard step shaft calibration,the coaxiality error of the composite gear shaft can be measured to be within 0.01 mm in less than two minutes.The range value of the multi-section measurement test is 0.065 mm.The average coaxiality error is∅0.476 mm.

Automatic separation system for marine meiobenthos based on laser-induced fluorescence technology

An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.