检索结果-南通市图书馆

Suppressed concentration quenching and tunable photoluminescence in Eu^(2+)-activated Rb_(3)Y(PO_(4))_(2)phosphors for full-spectrum lighting

引用

Light(Science & Applications) 2024年第11期13卷 2688-2698页

作者： Ming Zhao Yeping Ge Yurong Li Xiaoyan Song Zhiguo Xia Xinping Zhang Institute of Information Photonics Technology School of Physics and Optoelectronic EngineeringBeijing University of TechnologyBeijing 10083China College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of TechnologyBeijing 10083China State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied TechniquesGuangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and DevicesSchool of Physics and OptoelectronicsSouth China University of TechnologyGuangzhou 510641China

Highly efficient inorganic phosphors are desirable for lighting-emitting diode light sources,and increasing the doping concentration of activators is a common approach for enhancing the photoluminescence quantum yield(PLQY).However,the constraint of concentration quenching poses a great challenge for improving the ***,we propose a fundamental design principle by separating activators and prolonging their distance in Eu^(2+)-activated Rb_(3)Y(PO_(4))_(2)phosphors to inhibit concentration quenching,in which different quenching rates are controlled by the Eu distribution at various crystallographic *** blue-violet-emitting Rb_(3)Y(PO_(4))2:xEu(x=0.1%–15%)phosphors,with the occupation of Rb1,Rb2 and Y sites by Eu^(2+),exhibit rapid luminescence quenching with optimum external PLQY of 10%due to multi-channel energy ***,as the Eu concentration increases above 20%,Eu^(2+)prefer to occupy the Rb1 and Y sites with separated polyhedra and large interionic distances,resulting in green emission with suppressed concentration quenching,achieving an improved external PLQY of 41%.Our study provides a unique design perspective for elevating the efficiency of Eu^(2+)-activated phosphors toward high-performance inorganic luminescent materials for full-spectrum lighting.

关键词： quenching lighting concentration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Glass crystallization making red phosphor for high-power warm white lighting

引用

Light(Science & Applications) 2021年第4期10卷 570-581页

作者： Tao Hu Lixin Ning Yan Gao Jianwei Qiao Enhai Song Zitao Chen Yayun Zhou Jing Wang Maxim S.Molokeev Xiaoxing Ke Zhiguo Xia Qinyuan Zhang School of Physics and Optoelectronics State Key Laboratory of Lum inescent Materials and Devices and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied TechniquesSouth China University of TechnologyGuangzhouGuangdongChina Anhui Key Laboratory of Optoelearic Materials Science and Technology Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Normal UniversityWuhuAnhuiChina School of Applied Physic and Materials Wuyi UniversityJiangmenGuangdongChina Ministry of Education Key Laboratory of Bioinorganic and Synthetic Chemistry State Key Laboratory of Optoelectronic Materials and TechnologiesKLGHEI of Environment and Energy ChemistrySchool of Chemistry and Chemical EngineeringSun Yat-sen UniversityGuangzhouGuangdongChina Laboratory of Crystal Physics Kirensky Institute of PhysicsFederal Research Center KSC SB RASKrasnoyarskRussia Siberian Federal University KrasnoyarskRussia Research and Developm ent Department Kemerovo State UniversityKemerovoRussia lnstitute of Microstructure and Property of Advanced Materials Beijing University of Technology BeijingBeijingChina

Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence,and especially relies on blue light pumped red phosphors for improved light ***,we discovered an unprecedented red-emitting Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor(λex=450 nm,λem=620 nm)via the crystallization of MgO-AI_(2)O_(3)-Sio_(2) aluminosilicate *** experimental measurement and first-principles calculations verify that Eu^(2+)dopants insert at the vacant channel of Mg_(2)AI_(4)Si_(5)0_(18)crystal with six-fold coordination responsible for the peculiar red ***,the resulting phosphor exhibits high internal/external quantum efficiency of 94.5/70.6%,and stable emission against thermal quenching,which reaches industry *** maximum luminous flux and luminous efficiency of the constructed laser driven red emitting device reaches as high as 274 Im and 54lm W^(-1),*** combinations of extraordinary optical properties coupled with economically favorable and innovative preparation method indicate,that the Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor will provide a significant step towards the development of high-power solid-state lighting.

关键词： power pumped lighting

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Deep graph learning for spatially-varying indoor lighting prediction

引用

Science China(Information Sciences) 2023年第3期66卷 173-187页

作者： Jiayang BAI Jie GUO Chenchen WANG Zhenyu CHEN Zhen HE Shan YANG Piaopiao YU Yan ZHANG Yanwen GUO State Key Lab for Novel Software Technology Nanjing University

lighting prediction from a single image is becoming increasingly important in many vision and augmented reality(AR) applications in which shading and shadow consistency between virtual and real objects should be guaranteed. However, this is a notoriously ill-posed problem, especially for indoor scenarios,because of the complexity of indoor luminaires and the limited information involved in 2D images. In this paper, we propose a graph learning-based framework for indoor lighting estimation. The core is a new lighting model(DSGLight) based on depth-augmented spherical Gaussians(SGs) and a graph convolutional network(GCN) that infers the new lighting representation from a single low dynamic range(LDR) image of limited field-of-view. Our lighting model builds 128 evenly distributed SGs over the indoor panorama, where each SG encodes the lighting and the depth around that node. The proposed GCN then learns the mapping from the input image to DSGLight. Compared with existing lighting models, our DSGLight encodes both direct lighting and indirect environmental lighting more faithfully and compactly. It also makes network training and inference more stable. The estimated depth distribution enables temporally stable shading and shadows under spatially-varying lighting. Through thorough experiments, we show that our method obviously outperforms existing methods both qualitatively and quantitatively.

关键词： lighting graph learning augmented reality spherical Gaussians rendering

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chromaticity of white sensation for LED lighting

引用

Chinese Optics Letters 2015年第7期13卷 115-118页

作者：王庆徐海松蔡建奇 State Key Laboratory of Modern Optical Instrumentation Department of Optical EngineeringZhejiang University Visual Health and Safety Institute China National Institute of Standardization

In this work, a psychophysical experiment is implemented to assess the white sensation of light-emitting diode （LED） lighting in illuminant mode via a categorical judgment method by a panel of 10 observers. The visual data indicates that the higher values of white sensation estimations locate near the Planckian locus within a correlated color temperature （CCT） range of 5000-9000 K. A model of white sensation for LED lighting in illuminant mode is proposed, from which the predicted maximal white sensation locates near the Planckian locus with a CCT of 6622 K, and the 95% white sensation covers a narrow two-dimensional region.

关键词： lighting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on calculation model of road lighting visibility

引用

Science China(Technological Sciences) 2010年第7期53卷 1768-1773页

作者： WENG Ji1, HU YingKui2 & YING Wen1 1College of Architecture and Urban Planning, Chongqing University, Chongqing 400045, China 2College of Civil Engineering, Chongqing University, Chongqing 400045, China 1. College of Architecture and Urban Planning Chongqing University Chongqing 400045 China2. College of Civil Engineering Chongqing University Chongqing 400045 China

Visibility is an evaluation index for road lighting, which comprehensively influences the vision reliability of drivers and is a key factor for road lighting safety and energy saving. This paper introduces the concept of road lighting visibility and its influencing factors. It also explains the small target visibility calculation model for road lighting design, and describes the significance of establishing urban road lighting visibility standards from a point of view of visual function and visual comfort of drivers.

关键词： road lighting visibility calculation model design standard

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Overhead supplemental far-red light stimulates tomato growth under intra-canopy lighting with LEDs

引用

Journal of Integrative Agriculture 2019年第1期18卷 62-69页

作者： ZHANG Ya-ting ZHANG Yu-qi YANG Qi-chang LI Tao Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures Ministry of Agriculture and Rural Affairs/Institute of Environment and Sustainable Development in AgricultureChinese Academy of Agriculture Sciences

Far-red(FR) light regulates phytochrome-mediated morphological and physiological plant *** study aims to investigate how greenhouse tomato morphology and production response to different durations of FR light during daytime and at the end of day(EOD).High-wire tomato plants were grown under intra-canopy lighting consisting of red(peak wavelength at 640 nm) and blue(peak wavelength at 450 nm) light-emitting diodes(LEDs) with photosynthetic photon flux density(PPFD) of 144 μmol m–2 s–1 at 10 cm away from the lamps,and combined with overhead supplemental FR light(peak wavelength at 735 nm) with PPFD of 43 μmol m–2 s–1 at 20 cm below the *** were exposed to three durations of FR supplemental lighting including: 06:00–18:00(FR12),18:00–19:30(EOD-FR1.5),18:00–18:30(EOD-FR0.5),and control that without supplemental FR *** results showed that supplemental FR light significantly stimulated stem elongation thereby resulting in longer plants compared with the ***,FR light altered leaf morphology toward higher leaf length/width ratio and larger leaf *** altered plant architecture in FR supplemented plants led to a more homogeneous light distribution inside the *** plant biomass was increased by 9–16% under supplemental FR light in comparison with control,which led to 7–12% increase in ripe fruit *** sugar content of the ripe tomato fruit was slightly decreased by longer exposure of the plants to FR *** matter partitioning to different plant organs were not substantially affected by the FR light *** significant differences were observed among the three FR light treatments in plant morphology as well as yield and biomass *** conclude that under intra-canopy lighting,overhead supplemental FR light stimulates tomato growth and *** supplementary of EOD-FR0.5 is more favorable,as it consumes less electricity but induces similar effects on plant morphology and yield.

关键词： Solanum lycopersicum far-red light LEDs intro-canopy lighting morphology yield

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cyan phosphors for full-visible-spectrum lighting: shining new light on high-CRI white pc-LEDs

引用

Science Bulletin 2019年第22期64卷 1649-1651页

作者： Xiaoyong Huang Institute for Advanced Study Shenzhen University College of Physics and Optoelectronics Taiyuan University of Technology

Nowadays,solid-state lighting sources based on white lightemitting diodes(LEDs)are extensively replacing the traditional illumination devices(incandescent and fluorescent lamps)due to their unique and appealing properties,such as high efficiency,high brightness,long working lifetime,small size,fast response time and eco-friendliness[1-4].Because of this,white LEDs have permeated deeply into many important sectors,including indoor and outdoor lightings,signals,displays and therapeutic *** order to make sure that white LEDs can provide artificial lighting source with good color quality and high vision performance,there are several important figures of merit that are used to characterize white LEDs:color rendering index(CRI),correlated color temperature,luminous efficacy of radiation and luminous efficacy.

关键词： lighting white luminous

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new method to create depth information based on lighting analysis for 2D/3D conversion

引用

Journal of Central South University 2013年第10期20卷 2715-2719页

作者： Hyunho Han Gangseong Lee Jongyong Lee Jinsoo Kim Sanghun Lee Department of Plasmabiodisplay Kwangwoon University Department of General Education Kwangwoon University IDP System. CoLtd

A new method creating depth information for 2D/3D conversion was proposed. The distance between objects is determined by the distances between objects and light source position which is estimated by the analysis of the image. The estimated lighting value is used to normalize the image. A threshold value is determined by some weighted operation between the original image and the normalized image. By applying the threshold value to the original image, background area is removed. Depth information of interested area is calculated from the lighting changes. The final 3D images converted with the proposed method are used to verify its effectiveness.

关键词： lighting analysis depth information focus/defocus information 2D/3D conversion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A tunnel lighting control system based on human vision and variable reduction coefficient

引用

Optoelectronics Letters 2021年第12期17卷 710-716页

作者： LIU Mohan LIU Hong School of Electronics Information Shanghai Dianji UniversityShanghai 201306China

Due to the changeable brightness outside the tunnel,the lighting brightness at the exit and entrance of the tunnel needs to be adjusted in time,so as to ensure that the driver can feel the difference of light intensity within the range that the human eye can adapt to when passing through the *** this paper,a tunnel lighting control strategy based on variable reduction factor is proposed,which can ensure that the lighting around the tunnel is within the range that the human eye can adapt to at any *** the field data collection and comparison and experiments,it can be shown that the lighting control method not only can improve the lighting quality in the tunnel,but also have better energy-saving effect and can reduce the cost of manual operation and maintenance.

关键词： lighting tunnel coefficient

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Space Habitat Astronautics:Multicolour lighting Psychology in a 7-Day Simulated Habitat

引用

Space(Science & Technology) 2022年第1期2022卷 109-119页

作者： Ao Jiang Irene Lia Schlacht Xiang Yao Bernard Foing Zhixiong Fang Stephen Westland Caroline Hemingray Wenhao Yao ILEWG EuroMoonMars at ESTEC ESA Netherlands School of Design University of LeedsLeedsUK HMKW University Germany Xiangtan University China Leiden University Netherlands Vrije Universiteit Amsterdam Netherlands Xiangtan Central Hospital China

During space missions,astronauts live in a confined technological environment,completely isolated and deprived of the variety and variation found in the environment on *** circumstance has a strong impact on the psycho-physiological states of the *** in light of the plans for long-duration missions,new research needs to be carried *** goal of this study,conducted at Xiangtan Central Hospital in China,was to test whether multicolour lighting can improve people’s psychological state in an isolated and confined environment over a period of seven *** participants(10 male and 10 female)were randomly divided into two groups:one group that was exposed to multicolour lighting and a control group,which was exposed to a static,monotonous white *** participants’psychological state was recorded on the first day,the fourth day,and the seventh *** results of the control group showed that the participants’negative emotions and anxiety continued to increase over time,whereas the group randomly exposed to multicolour lighting that changed every three hours did not show any significant increase in negative emotions and ***,the random change of light colour in the isolated environment appeared to help the participants increase their sense of surprise,thereby counteracting ***,during this experiment,it was observed that when people who are accustomed to being connected to social networks were deprived of this,they experienced insomnia and unaccustomed reactions,in particular on the first days of *** article contributes to future space exploration and to social and psychological support of life in isolated and confined environments.

关键词： lighting colour thereby

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：