钙掺杂自激活锗酸锌长余辉材料的多色余辉及动态防伪应用

长余辉材料在安全指示、防伪和生物成像等领域具有广泛应用前景,但其缺陷调控及余辉机理尚不清晰。自激活长余辉材料以其物质组成及晶体结构简单,便于研究余辉机理而受到关注。本研究以自激活长余辉材料锗酸锌为基质,采用高温固相反应合成得到了一系列钙掺杂的长余辉材料Zn_2–xCa_xGeO₄(x=0、0.1、0.2、0.3、0.4、0.5)。实验表明,在锗酸锌中掺杂钙元素后,使用376nm紫外光激发时,观察到锗酸锌基质样品的黄色发光峰;同时在267 nm激发下, Zn_1.5Ca_0.5GeO₄荧光强度增强了6.2倍。从余辉光谱和余辉衰减曲线上看, Zn_1.5Ca_0.5GeO₄初始余辉强度增强了25.1倍;并且在所考察的300 s余辉时间里,与锗酸锌相比, Zn_1.5Ca_0.5GeO₄保持了近5倍的余辉强度。进一步热释曲线表征显示,材料主要陷阱的...     

长余辉发光材料研究进展

第一次观察到Sm~(3 )、Tm~(3 )、Yb~(3 )的红色和橙红色长余辉发光;首次在含镉的氧化物中观察到红、绿、蓝等多种颜色的新型长余辉发光,特别第一次观察到非稀土离子如Pb~(2 )、Bi~(3 )、Sn~(2 )、Sb~(3 )的长余辉发光现象;首先发现在一种基质中由一种稀土离子(Dy~(3 ))激活产生的发白色光的长余辉发光材料;第一次观察到Er~(3 )、Ho~(3 )的绿色长余辉发光;在掺Tm~(3 )的材料中发现迄今为止未见国内外报道的800nm最长波长的长余辉发射;在掺Tm~(3 )的材料中初步观察到既有上转换发光又具有长余辉发射的新的发光现象;开展了长余辉发光材料的纳米组装,以及开拓这类材料在环境和生物医学领域的应用研究。研究的能产生长余辉发光的激活离子和基质化合物已有较大扩展,并发现了一些变化规律及用现有模型和规则难以说明和解释的新的现象。迄今,文献报道的具有长余辉发光的基质和离子主要是铝酸盐、硅酸盐、硫氧化钇等基质和Eu~(2 )、Eu~(3 )、Ce~(3 )、Tb~(3 )、Pr~(3 )、Mn~(2 )等离子,拓展到锗酸盐、钨酸盐、镓酸盐、石榴石、含镉的氧化物以及稀土硫氧化物等...     

长余辉发光材料的研究进展

长余辉发光材料因其具有特殊的储能发光性能,是一类绿色环保型材料.综述了主要体系长余辉发光材料的研究历程,总结了长余辉材料的制备方法和余辉效应,概括了长余辉发光研究上存在的问题,提出了今后研究和应用的发展方向.     

长余辉发光材料的研究进展

长余辉发光材料在太阳能转换和利用方面具有独特的优势,是一类重要的光-光转换和节能材料。综述了长余辉发光材料的光谱特性、余辉时间以及相应的发光机理,简单介绍了长余辉发光材料的一些常见制备方法,并对今后研究的重点和方向做了展望。     

长余辉发光材料的研究进展

铝酸盐长余辉发光材料因为其优异的性能,是一类新型储能和环保材料.本文主要综述了90年代发展起来的铝酸盐体系长余辉发光材料的研究进展.总结了铝酸盐长余辉材料的发光特征和长余辉特性,指出了制备技术上的最新方法,概括了长余辉发光模型,并提出了今后研究和应用的发展方向.     

长余辉发光材料研究进展

主要综述了长余辉发光材料的制备方法的进展及其发光机理,并根据最近研究的热点综述主要激活剂组分在发光材料中的作用和助熔剂组分B2O3对发光材料晶相的稳定和发光性质的作用.     

硅酸盐长余辉发光材料的最新研究进展

系统地分析和概括了稀土离子激活硅酸盐体系长余辉发光材料的种类、特性、组成、结构、发光机理和制备技术。并根据长余辉发光材料研究现状，探讨了硅酸盐长余辉发光材料的研究方向与发展前景。     

掺杂长余辉发光材料的研究概况

长余辉发光材料是一种光致发光材料,具有广阔的应用前景。按照基质材料的不同,长余辉发光材料从最初的硫化物基质,逐渐发展形成了几大体系。系统地介绍了长余辉发光材料的分类,给出了各类型发光材料的典型代表,并对掺杂长余辉发光材料的研究历史和现状进行了综述。对各类型掺杂长余辉材料进行了横向和纵向对比,指出了存在的问题和进一步的研究方向,最后对长余辉材料的应用现状进行了简单介绍。     

稀土长余辉发光材料的研究进展

介绍了长余辉材料的类型(主要为硫化物型、碱土铝酸盐型及其它基质型余辉发光材料)及发展历史,总结了其研究现状与发光机制,概括了常规制备方法,指出了长余辉发光材料存在的问题和今后研究与应用的方向.     

长余辉材料及其力致发光现象

长余辉发光材料是一种在外在激发源(紫外线-可见光,X射线,β射线等)停止后仍能在相当时间内(几秒到十几个小时)维持肉眼可见的荧光余辉的材料,在应急照明、警示标识等方面开始得到广泛的应用。然而,长余辉材料的力致发光现象却是近几年来在国际上得到相关领域研究人员重视的一个研究方向,在力学传感器、材料应力分析、建筑物安全、地震及火山爆发预测等方面具有重要的应用前景。本文简单介绍了长余辉发光材料的力致发光现象及其发光机制、研究现状和应用等方面研究进展,供有关研究人员参考。     

Coloring Afterglow Nanoparticles for High-Contrast Time-Gating-Free Multiplex Luminescence Imaging

Afterglow nanoparticles (AGNPs) possessing inherently long lifetime with tailorable emission colors and uniform size have long been sought due to their time-gating-free high-contrast multiplexing imaging. Herein, via a straightforward template method, it is reported that such multicolor AGNPs can be accomplished. The resultant AGNPs exhibit a series of tunable afterglow emissions, including blue, yellow, green, and white. These multicolor AGNPs are found to be highly bright, enabling them to perform high-contrast multichannel afterglow imaging in vitro and in vivo without the use of any complicated time-gating algorithms or systems, which existing tools are unable to do.     

Excited State Modulation for Organic Afterglow: Materials and Applications

Organic afterglow materials, developed recently by breaking through the difficulties in modulating ultrafast‐decayed excited states, exhibit ultralong‐lived emission for persistent luminescence with lifetimes of several orders of magnitude longer than traditional fluorescent and phosphorescent emissions at room temperature. Their exceptional properties, namely ultralong luminescent lifetime, large Stokes shifts, facile excited state transformation, and environmentally sensitive emission, have led to a diverse range of advanced optoelectronic applications. Here, the organic afterglow is reviewed from the perspective of fundamental concepts on both phenomenon and mechanism, examining the technical challenges in relation to excited state tuning and lifetime elongation. In particular, the advances in material design strategies that afford a large variety of organic afterglow materials for a broad utility in optoelectronics including lighting and displays, anti‐counterfeiting, optical recording, chemical sensors and bio‐imaging are highlighted.     

热致变色液晶材料在防伪包装领域的应用

开发新的防伪包装技术一直受到有关研究者的高度重视.介绍了热致变色液晶材料的变色机理及其在防伪包装领域的一些应用,指出应用多种防伪技术组合的研发思路,其中热致变色液晶的应用,将是防伪包装技术领域的一个值得重视且亟待深入研究的工作.     

烧成条件对长余辉蓄光玻璃光学性能的影响

以ＳｒＡｌ_２Ｏ_４：Ｅｕ,Ｄｙ长余辉发光粉体和低熔点硼硅酸盐玻璃为原料,在一定条件下合成了长余辉蓄光玻璃．研究结果表明,烧成温度和保温时间对该玻璃的发光效果影响较大．温度越高,保温时间越长,由于空气的氧化作用,蓄光玻璃的发光效果越差,本试验控制烧成温度在７５０～８００℃间,保温时间在 １０ｍｉｎ以内,能合成性能较好的蓄光玻璃．余辉衰减曲线表明蓄光玻璃的发光性能较之原始发光粉体有所下降．ＳＥＭ分析表明,低温合成的蓄光玻璃中,所含能继续保持发光性质的粉体料,明显比高温合成样要多．     

In Vivo Repeatedly Activated Persistent Luminescence Nanoparticles by Radiopharmaceuticals for Long‐Lasting Tumor Optical Imaging

Persistent luminescence nanoparticles (PLNPs) with rechargeable near‐infrared afterglow properties attract much attention for tumor diagnosis in living animals since they can avoid tissue autofluorescence and greatly improve the signal‐to‐background ratio. Using UV, visible light, or X‐ray as excitation sources to power up persistent luminescence (PL) faces the challenges such as limited tissue penetration, inefficient charging capability, or tissue damage caused by irradiation. Here, it is proved that radiopharmaceuticals can efficiently excite ZnGa₂O₄:Cr³⁺ nanoparticles (ZGCs) for both fluorescence and afterglow luminescence via Cerenkov resonance energy transfer as well as ionizing radiation. ¹⁸F‐FDG, a clinically approved tumor‐imaging radiopharmaceutical with a short decay half‐life around 110 min, is successfully used as the internal light source to in vivo excite intravenously injected ZGCs for tumor luminescence imaging over 3 h. The luminescence with similar decay time can be re‐obtained for multiple times upon injection of ¹⁸F‐FDG at any time needed with no health concern. It is believed this strategy can not only provide tumor luminescence imaging with high sensitivity, high contrast, and long decay time at desired time, but also guarantee the patients much less radiation exposure, greatly benefiting image‐guided surgery in the future.     

打击假冒伪造有赖于实施防伪技术标准

本文描述了国内外防伪领域标准化工作的情况,介绍了防伪国家标准对于提升我国防伪技术整体水平、促进我国防伪行业技术进步、提高企业核心竞争力所发挥的作用。根据防伪技术的发展趋势,对我国防伪标准化工作提出了一些建议。     

双余弦型像素光变防伪商标

目的建立一种光变防伪商标的微镜像素模型。方法基于色光反射,利用双余弦函数所构成的微镜曲面,满足反射光亮度和反射光强稳定度的雅可比行列式判据特性。结果构建出了适用于商标的RGBS结构型印刷防伪微镜模型,模拟并分析了函数表面形状随参数变化的情况。结论该模型利用余弦函数的周期性,可通过调节结构参量达到防伪的效果。     

长余辉(寿命)发光材料研究的最新进展

综述了近几年来长余辉发光材料研究的最新进展,包括三方面:新材料研制,新应用领域的开拓和发光机理研究的模型.材料方面,主要介绍了红光、蓝光研究的进展与获得长余辉发光的关键因素-结构缺陷形成的陷阱态,以及稀土掺杂的作用.为促进新材料的研究着重概述了对长余辉发光机理研究的新进展,除了载流子传输与隧穿效应外,还介绍了两种最新观点;双光子吸收与V_K中心模型,并对其存在的问题作了评述.应用方面,除了已有的弱光照明与显示领域外,还在向光电信息功能,特别是二维图像存储,高能粒子射线探测方面发展.     

Design,Properties, and In Vivo Behavior of Super­paramagnetic Persistent Luminescence Nanohybrids

With the fast development of noninvasive diagnosis, the design of multimodal imaging probes has become a promising challenge. If many monofunctional nanocarriers have already proven their efficiency, only few multifunctional nanoprobes have been able to combine the advantages of diverse imaging modalities. An innovative nanoprobe called mesoporous persistent luminescence magnetic nanohybrids (MPNHs) is described that shows both optical and magnetic resonance imaging (MRI) properties intended for in vivo multimodal imaging in small animals. MPNHs are based on the assembly of chromium‐doped zinc gallate oxide and ultrasmall superparamagnetic iron oxide nanoparticles embedded in a mesoporous silica shell. MPNHs combine the optical advantages of persistent luminescence, such as real time imaging with highly sensitive and photostable detection, and MRI negative contrast properties that ensure in vivo imaging with rather high spatial resolution. In addition to their imaging capabilities, these MPNHs can be motioned in vitro with a magnet, which opens multiple perspectives in magnetic vectorization and cell therapy research.