Effect of Partially Coherent Light on the Contrast of Speckle Patterns Obtained Using Digital Image Processing of Speckle Photography

The paper is devoted to study theoretically, the effects of some parameters on the visibility of the speckle patterns. For this propose, a theoretical model for a periodic rough surface was considered. Using this theoretical model, the effects of grain height, its density, the band width and spectral distribution of the line profile (Gaussian and Lorentzian) illuminating a rough surface on the visibility of speckle pattern are investigated. An experimental setup was constructed to study the effect of surface roughness and coherence of the illuminating light beam on the contrast of speckle pattern. The general behavior of the experimental results, which agree with published data, is compatible with the new theoretical model.

基于LightGBM-GA-Seq2Seq的照明负荷预测研究

照明负荷是建筑能耗的重要组成部分,在提高照明品质和降低照明能耗的双重要求下,照明负荷预测的关键性逐渐凸显。随着信息技术的发展,负荷数据采集平台日益完善,负荷数据规模不断扩大,同时也伴随着数据复杂化。为了进一步精确预测照明负荷,分析与获取负荷的行为模式愈发重要,基于此提出一种集成学习照明负荷预测方法。通过K-means和Light Gradient Boosting Machine(LightGBM)算法对预测日的模式标签进行分析与获取,并与照明负荷以及气候特征一起作为Sequenceto Sequence(Seq2Seq)模型的输入以预测照明负荷。通过分析实际案例,本研究所提出方法相较于未采用行为模式标签的传统方法,显著改善了归一化均方根误差(NRMSE)和决定系数(R2)两项性能指标,分别提升了18%和8%,验证了该方法在照明负荷预测领域具备可行性与优越性。

Steering light into logic patterns with two-dimensional cascaded multimode waveguide

Steering light into logic patterns with two-dimensional cascaded multimode waveguide is demonstrated. By employing the imaging properties of 2D multimode interference （MMI） and partial phase modulation method, the design ideas and the implementing methods of the 2^（2×2） bits type spatial logic steering are discussed; therefore the structure of logical pattern is proposed. Numerical simulation is carried out to verify the design in detail by using the beam propagation method. It is expected to realize logic coders by using the integrated optical methods and exploit their potential applications in the field of optical logic.

Design of patterned sapphire substrates for GaN-based light-emitting diodes

A new method for patterned sapphire substrate （PSS） design is developed and proven to be reliable and cost-effective. As progress is made with LEDs＇ luminous efficiency, the pattern units of PSS become more complicated, and the effect of complicated geometrical features is almost impossible to study systematically by experiments only. By employing our new method, the influence of pattern parameters can be systematically studied, and various novel patterns are designed and optimized within a reasonable time span, with great improvement in LEDs＇ light extraction efficiency （LEE）. Clearly, PSS pattern design with such a method deserves particular attention. We foresee that GaN-based LEDs on these newly designed PSSs will achieve more progress in the coming years.

Spatial-Temporal Features of Wuhan Urban Agglomeration Regional Development Pattern—Based on DMSP/OLS Night Light Data

Based on the night light data, urban area data, and economic data of Wuhan Urban Agglomeration from 2009 to 2015, we use spatial correlation dimension, spatial self-correlation analysis and weighted standard deviation ellipse to identify the general characteristics and dynamic evolution characteristics of urban spatial pattern and economic disparity pattern. The research results prove that: between 2009 and 2013, Wuhan Urban Agglomeration expanded gradually from northwest to southeast and presented the dynamic evolution features of “along the river and the road”. The spatial structure is obvious, forming the pattern of “core-periphery”. The development of Wuhan Urban Agglomeration has obvious imbalance in economic geography space, presenting the development tendency of “One prominent, stronger in the west and weaker in the east”. The contract within Wuhan Urban Agglomeration is gradually decreased. Wuhan city and its surrounding areas have stronger economic growth strength as well as the cities along The Yangtze River. However, the relative development rate of Wuhan city area is still far higher than other cities and counties.

Machining characteristics of complex prism pattern on electroplated roll by copper

The BLU (back light unit) is the core component of the LCD for notebook, mobile-phone, navigation, as well as large sized TV, PID (public information display), etc. In order to enhance optical efficiency of LCD, optical films with the uniform prism patterns have been used for BLU by stacking two films up orthogonally. In this case, light interference-phenomenon occurred such as Morie, wet-out, u-turning, etc. It caused several problems such as low brightness, spots and stripes in LCD. Recently, the high-luminance micro complex prism patterns are actively studied to avoid the light interference-phenomenon and enhance the optical efficiency. In this study, the roll master to manufacture complex micro prism pattern film was machined by using the high precision lathe. The machined patterns on the roll master were 50, 45, 40, 35, 30, 25, 20, 15, 10 and 5 μm in the pitch with 25.0, 22.5, 20.0, 17.5, 15.0, 12.5, 10.0, 7.5, 5.0 and 2.5 μm in the peak height, respectively. The roll was 2 000 mm in length and 320 mm in diameter. The electroplated roll by copper and the natural single crystal diamond tool was used for machining the patterns. The cutting force was measured and analyzed for each cutting condition by using the dynamometer. The chips and the surfaces after being machined were analyzed by SEM and microscope.

Improving InGaN-LED performance by optimizing the patterned sapphire substrate shape

The epitaxial growths of GaN films and GaN-based LEDs on various patterned sapphire substrates （PSSes） with different values of fill factor （f） and slanted angle （0） are investigated in detail. The threading dislocation （TD） density is lower in the film grown on the PSS with a smaller fill factor, resulting in a higher internal quantum efficiency （IQE）. Also the ability of the LED to withstand the electrostatic discharge （ESD） increases as the fill factor decreases. The illumination output power of the LED is affected by both 0 and f. It is found that the illumination output power of the LED grown on the PSS with a lower production of tan 0 and f is higher than that with a higher production of tan 0 and f.

Numerical simulation of neuronal spike patterns in a retinal network model

This study utilized a neuronal compartment model and NEURON software to study the effects of external light stimulation on retinal photoreceptors and spike patterns of neurons in a retinal network Following light stimulation of different shapes and sizes, changes in the spike features of ganglion cells indicated that different shapes of light stimulation elicited different retinal responses. By manipulating the shape of light stimulation, we investigated the effects of the large number of electrical synapses existing between retinal neurons. Model simulation and analysis suggested that interplexiform cells play an important role in visual signal information processing in the retina, and the findings indicated that our constructed retinal network model was reliable and feasible. In addition, the simulation results demonstrated that ganglion cells exhibited a variety of spike patterns under different light stimulation sizes and different stimulation shapes, which reflect the functions of the retina in signal transmission and processing.

基于LightGBM的蛋白质类泛素化修饰位点预测

蛋白质类泛素化修饰位点的准确识别对基础研究和药物开发都具有重要意义。该文提出了一种基于蛋白质序列特征的类泛素化修饰位点预测模型。该模型结合氨基酸的物理化学属性统计特征和氨基酸序列二元语法模式特征,训练一种轻量型梯度提升机(Light gradient boosting machine,LightGBM)分类器预测某个蛋白质序列的类泛素化修饰位点。该文对比了不同特征的鉴别性,以及不同分类模型的预测性能。在基准数据集上的试验结果证明了该文所提方法的有效性,相比于现有方法在性能上取得了明显的提升,马修斯相关系数为91.64%。

Safer Design and Less Cost Operation for Low-Traffic Long-Road Illumination Using Control System Based on Pattern Recognition Technique

The paper covers analysis and investigation of lighting automation system in low-traffic long-roads. The main objective is to provide optimal solution between expensive safe design that utilizes continuous street lighting system at night for the entire road, or inexpensive design that sacrifices the safety, relying on using vehicles lighting, to eliminate the problem of high cost energy consumption during the night operation of the road. By taking into account both of these factors, smart lighting automation system is proposed using Pattern Recognition Technique applied on vehicle number-plates. In this proposal, the road is sectionalized into zones, and based on smart Pattern Recognition Technique, the control system of the road lighting illuminates only the zone that the vehicles pass through. Economic analysis is provided in this paper to support the value of using this design of lighting control system.

基于夜光数据的昆明市城市扩张格局演变分析

基于夜光数据采用POI&NPP综合指数提取建成区,然后进行建成区面积精度评定,从定性和定量两个角度进行城市扩张空间形态及格局演变分析。结果表明:1)POI融入夜光数据后,提高了提取的精度,提取边界与实际的分布范围更为接近。2)扩张速度和强度较快区域主要集中在呈贡区、嵩明县等,而较慢区域集中在北部的禄劝县、东川区、寻甸县等;嵩明县的动态变化率最高,中心城区的区域动态变化率较低,北部的寻甸县、东南部的宜良县、石林县动态变化率反而较高。3)昆明市整体上经济重心经度方向为向东偏移,纬度方向为向南偏移。

谷子SiNADP-ME1基因的光响应模式

为探究谷子光合基因SiNADP-ME1(Seita.3G109300)对光照强度和光质的响应模式,本研究以豫谷1号为材料,采用反转录PCR(RT-PCR)克隆SiNADP-ME1的编码序列(CDS序列),利用MEGA软件构建多物种进化树,构建PCAMBIA1300-SiNADP-ME1-GFP载体,转化农杆菌,注射烟草进行亚细胞定位,利用实时荧光定量PCR(qRT-PCR)研究其在不同光照强度、光质处理下的表达模式。结果表明,SiNADP-ME1全长CDS序列为1731 bp,共编码576个氨基酸,定位于内质网,与狗尾草中SvNADP-ME1(XP_034584220.1)亲缘关系最近。该基因在不同组织器官及不同生育期表达量存在显著差异,在灌浆期穗中表达量最高,同时响应不同光强和光质,在不同光照强度处理下,SiNADP-ME1的表达呈显著变化,在1200μmol·m^(-2)·s^(-1)光照3 h表达量最高,是对照(正常光照,250μmol·m^(-2)·s^(-1))的4.25倍;在不同光质处理下,受红光影响最大,红光下表达量是黑暗处理表达量的47.27倍,是白光处理表达量的2.69倍。本研究结果为深入探讨SiNADP-ME1基因的生物学功能提供了一定的参考依据。

基于夜光遥感的我国春运人口流动时空特征研究

基于2013、2019和2021年的NPP/VIIRS夜间灯光数据,构建春节夜光差值指数,在省域尺度上证明了差值指数与流动人口量具有显著相关性(R=0.61,P<0.01),并以该指数研究了全国春运期间人口流动的时空特征。结果发现:1)我国春运强度在胡焕庸线两侧差异明显,东南地区人口流动是西北地区的6倍左右。春运在东南地区呈现连片式特征,在西北地区呈现离散零星式的流动特征。2)2013—2021年间,我国春运期间总体人口流动格局大致稳定,但流入地和流出地在空间上存在一定变化。3)经济发展状况和新冠疫情可能导致了这种格局演化特征的发生。尤其新冠疫情防疫和“就地过年”政策的推出,导致2021年春节期间大规模人口流动的减少,春运强度的下降。

基于激光视觉传达的光照变化复杂图形元素细节增强方法

复杂图形元素的细节增强会受到光照变化影响,导致人眼观测下图形细节的对比度与清晰度降低,因此提出基于激光视觉传达的光照变化复杂图形元素细节增强方法。该方法利用具有颜色恢复功能的多尺度视网膜算法对采集到的图形展开颜色校正,通过激光视觉传达方法将图形从RGB颜色空间转换到便于人眼观察的HIS颜色空间。采取自适应补偿法和限制对比度自适应直方图均衡化算法,对图形的饱和度I值和亮度S值展开增强,并将增强后的图像转换回RGB颜色空间。实验结果表明,该方法的颜色校正效果好、图形细节增强的稳定性强。

基于膦氧化物钝化的热蒸发像素化钙钛矿发光二极管

热蒸发法是实现钙钛矿发光二极管商业化显示应用的可靠技术。然而,热蒸发沉积的钙钛矿薄膜的PLQY经常较低,并且钝化手段不如溶液法丰富。本文报道了一种通过原位共蒸技术将钝化剂引入钙钛矿层的方法,这种方法能够钝化真空沉积钙钛矿中的缺陷,增强辐射复合,并提高钙钛矿的PLQY。氧膦基团与不饱和位点形成配位络合,钝化了钙钛矿的晶界缺陷,并抑制了带尾态缺陷。基于最佳比例的钙钛矿薄膜所制备的LED器件表现出最大6.3%的EQE,最大亮度为35642 cd/m^(2)。更进一步地,基于全真空的器件制备工艺,获得了最大EQE为5.0%的312 ppi高分辨率PeLEDs。总之,本文为热蒸发PeLEDs的缺陷钝化提供了有用的指导,证明热蒸发PeLEDs在效率和亮度提升方面具有巨大潜力,并具备商业化前景。

变温下暗期LED光照对丝棉木金星尺蛾生命活动节律的影响

【目的】探明变温下暗期给予不同LED光源对丝棉木金星尺蛾Calospilos suspecta化蛹、羽化、交配、产卵和卵孵化活动节律的影响。【方法】在实验室条件下以光周期14L∶10D为对照组,以暗期分别给予10 h红色LED和10 h黄色LED 2种不同光源照射为处理组(分别记为14L∶10R和14L∶10Y),分别对丝棉木金星尺蛾的化蛹、羽化、交配、产卵和卵孵化进行连续5 d的观察,每小时观察1次,计算化蛹率、羽化率、交配率、产卵率和卵孵化率,并比较这些参数在不同试验组间光期或暗期差异以及各组内光期与暗期间的差异。【结果】红色和黄色LED光照射下丝棉木金星尺蛾化蛹不具明显的节律性,14L∶10D组和14L∶10Y组的化蛹主要发生在光期,化蛹高峰分别在7:00-8:00和18:00-19:00;14L∶10R组主要在暗期化蛹,化蛹高峰在22:00-23:00;但暗期不同LED光处理对平均单时段化蛹率无显著影响。红色和黄色LED光照射下羽化节律亦不明显,14L∶10D组和14L∶10R组的雌雄成虫羽化主要发生在光期,14L∶10Y组雌雄成虫的羽化主要发生在暗期;14L∶10D组和14L∶10R组羽化高峰均在光期开启的第1-2小时;暗期LED光处理显著影响雌成虫平均单时段羽化率,且14L∶10D组光期雌成虫平均单时段羽化率显著高于暗期;暗期两个LED光处理对雄成虫平均单时段羽化率影响不显著。交配行为具有明显的节律性,各组交配行为均主要发生在暗期,交配高峰在光期开启前的1-2 h(4:00-6:00);14L∶10D组和14L∶10Y组暗期平均单时段交配率显著高于光期。产卵亦具有明显的节律性,14L∶10D组和14L∶10R组产卵高峰及4L∶10Y组产卵次高峰均发生在暗期20:00-21:00, 14L∶10Y组产卵高峰在16:00-17:00;暗期不同LED光处理对平均单时段产卵率均无显著影响。卵孵化具有明显的节律性,各组孵化高峰均在光期开始的第1小时;暗期不同LED光处理对平均单时段卵孵化率影响均不显著。【结论】红色和黄色LED处理下,丝棉木金星尺蛾化蛹和羽化不具明显的节律性,而交配、产卵及卵孵化具有明显的节律性,表明丝棉木金星尺蛾有的生命活动节律性受暗期LED光照影响,并因LED光色不同而异。

苗族装饰图案元素在现代灯具设计中的应用研究

针对当下灯具产品同质化严重、设计形式单一、忽略艺术价值和文化内涵的现象,以苗族装饰图案元素为切入点,通过调研收集苗族图案进行图案创新设计,研究苗族装饰图案元素在现代灯具设计中的应用研究。

基于声纹识别的智能照明系统安全控制系统模型

针对传统智能照明安全控制系统中由于声纹特征提取单一而影响识别准确率的问题,文章提出融合梅尔频率倒谱系数(Mel Frequency Cepstrum Coefficient,MFCC)与伽马通频率倒谱系数(Gammatone Frequency Cepstral Coefficients,GFCC)特征参数,采用费希尔准则对融合后的特征参数进行降维,利用卷积神经网络(Convolutional Neural Networks,CNN)构建智能照明系统声纹识别模型,通过搭建实验环境对改进后的方式进行测试。实验结果表明,改进后的方式能够有效提升系统声纹识别的准确性,提升系统整体的安全性。

基于相位测量偏折术的透明物体表面缺陷检测

目前国内对玻璃、透镜等透明物体的质量控制仍使用传统方法,传统的肉眼评估方法效率低下。为实现透明物体表面缺陷的自动化检测,提出一种基于相位测量偏折术(Phase Measuring Deflectometry,PMD)的透射式检测方法。利用结合了新相移图案生成计算式的PMD算法生成结构光条纹图案,使用透射式系统将该条纹图案投射到被测物体表面。相机采集经被测物体折射后的变形条纹图片,生成绝对相位图,通过识别绝对相位图中的局部畸变提取缺陷。通过分析周期错位导致误检的原因,提出一种绝对相位周期错位修正的方法。新相移图案生成计算式能提前修正周期错位现象,二者结合使用能提高相位展开的精度。以焦距为300 mm的凹、凸透镜为例进行实验,结果表明该方法能准确地提取出因表面缺陷导致的绝对相位图中的局部畸变,精度为0.1 mm。