~(13)Cu、~(65)Cu和~(15)N标记的二(2-羟基苯乙酮肟)—铜(Ⅱ)配合物的ESR波谱研究

本文解析了同位素标记的~(63)Cu-~(14)N-HAP,~(65)Cu-~(14)N-HAP,~(63)Cu-~(15)N-HAP。~(65)Cu-~(15)N-HAP,和Cu-~(15)N-HAP,等五种配合物在四氢呋喃中,在77K温度下测得的分辨较好的ESR波谱。从图上不仅得到了~(63)Cu和~(63)Cu的超精细分裂,而且还得出分辨较好的~(14)N和~(15)N的超超精细分裂。比较合理地确定了g_x,g_y,g_z;A_x~(65),A_y~(65),A_z~(65)和A_x~(63),A_y~(63),A_z~(63)以及A_∥~(15),A_⊥~(15)和A_∥~(14),A_⊥~(14)等张量参数。利用测得的波谱参数计算了键参数,并讨论了配合物的电子结构及成键特性,得到了较满意的结果。     

以CBP为主体的高色纯度红色磷光有机电致发光器件

以铱配合物红色磷光体Ir(piq)2(acac)为掺杂剂,制备了基于CBP材料的一系列红色电致磷光器件(PLED),其结构为ITO/CuPC(1nm)/Ir(piq)2(acac):CBP(25nm)/BCP(10nm)/Alq3(35nm)/LiF(1nm)/Al(100nm),对4种不同的掺杂剂浓度进行了比较,研究了它们的电致发光特性。得出了Ir(piq)2(acac)的最佳掺杂比为8%,此时器件的色坐标都非常接近标准红色,且色纯度超过了98%以上;在16V时,色坐标为(x=0.67,y=0.32),色纯度为99.74%,基本满足了全色显示对红色发光的要求。     

单分散CsPbBr_(3)@SiO_(2)纳米颗粒制备及其在柔性显示与荧光防伪中的应用EI北大核心CSCD

为了提高钙钛矿纳米晶CsPbX_(3)(X=Cl,Br,I)在水或热等环境中的稳定性,本文采用热注射法合成了3-氨丙基-三乙氧基硅烷(APTES)修饰的CsPbBr_(3)纳米晶,在此基础上,以正硅酸四甲基酯(TMOS)为硅源制备了CsPbBr_(3)@SiO_(2)核壳结构纳米颗粒。通过X射线衍射、透射电子显微镜和荧光光谱仪等测试手段对样品的结构、形貌、光谱特性及稳定性等进行了分析。结果表明,CsPbBr_(3)纳米晶表面形成了SiO_(2)壳层,同时,CsPbBr_(3)@SiO_(2)纳米颗粒仍保持优异的光学性能。更重要的是,SiO_(2)壳层显著提高了CsPbBr_(3)的水、热稳定性,CsPbBr_(3)@SiO_(2)在60℃加热30min后发光强度可以保持初始强度的81%,浸水100min后发光强度仍保持初始强度的75.2%。此外,我们设计了CsPbBr_(3)@SiO_(2)-聚二甲基硅氧烷(PDMS)复合薄膜,实现了CsPbBr_(3)@SiO_(2)在柔性显示与荧光防伪方面的应用,有望为柔性显示和荧光防伪材料的开发提供参考。     

PS-TPD空穴传输层的高亮度绿光有机电致发光器件的研究

研究了不同质量比的聚苯乙烯(PS)三苯基二胺(TPD)复合空穴传输层对有机电致发光器件(OLED)性能的影响。采用此掺杂体系作器件的空穴传输层,利用旋涂工艺制备了结构为indium-tin-oxide(ITO)/polystyrene(PS)∶N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine(TPD)/tris-(8-hydroxyquinoline)-aluminium(Alq3)/Mg∶Ag的双层有机电致发光器件。为便于比较,另直接蒸镀TPD薄膜做空穴传输层制备了相似结构的器件。利用飞行时间法对不同PS-TPD质量比例的薄膜的空穴迁移率进行了表征,并对器件的电致发光特性进行了测试。测试结果表明,掺杂薄膜的空穴迁移率比纯TPD膜的低1~2个数量级。当质量比为m(PS)∶m(TPD)=10∶90时,器件具有最高光亮度14280 cd/m2和最高流明效率1.2 l m/W。说明适当质量比PS的引入相对降低了薄膜的空穴迁移率,调节了TPD的空穴传输能力,更有效地平衡了复合区内正负载流子的数目,从而提高了器件的发光亮度和效率。     

基于MoOx层减反射膜调节白光色度的顶发射有机电致发光器件

为了改进白光顶发射器件的色纯度,使用高折射率的材料MoOx作为光输出耦合层,通过对器件的减反射膜厚度的优化,制作了硅基顶发射有机白光器件。器件结构为Si/Ag(60nm)/MoOx(2nm)/NPB(50nm)/DPVBi(7nm)/rubrene(0.2nm)/Alq3(43nm)/LiF(1nm)/Al(1nm)/Ag(20nm)/MoOx。并结合实验,优化了减反射膜的厚度。随着MoOx厚度的增加,在460nm左右的蓝光区域出现了一个明显的发光峰,色坐标逐渐向白光等能点(0.33,0.33)靠近,实现了对白光色度的调节,制作出了高效率的白光顶发射有机电致发光器件。     

原子核中的U(6/4)超对称

在本文中,我们讨论了原子核中可能存在的一种动力学超对称性——U(6/4)超对称性。具有U(6/4)超对称性的原子核含有若干个sd玻色子及0,1,2,3,4个角动量为3/2的费米子,它的波函数可以用超李代数链 U(6/4)?SU(6/4)?SU(6)?SU(4)?SU(4)?SU(4) ?SU(4)?Sp(4)?SO(3)来分类。在本文中,我们给出了按以上超李代数链分类的波函数,并推导出了能谱公式。     

氯化铯甲醇溶液对有机聚合物太阳能电池的影响

研究了氯化铯的甲醇溶液作为阴极修饰层,来提高传统有机聚合物太阳能电池器件性能。通过电容-电压(C-V)测试分析了铝电极和PTB7/PC_(70)BM之间的界面电荷积累情况,同时测试了紫外光电子能谱(UPS),对铝的功函数改变作了研究。结果表明,采用氯化铯的甲醇溶液作阴极修饰层的器件,其短路电流(J_(sc))、开路电压(V_(oc))、填充因子(FF)都有所提高,光电转化效率达到6.36%,与仅用甲醇处理过的器件相比,光电转化效率提高了11%;与未经甲醇处理的器件相比,光电转化效率提高了42.6%。这种一步溶液处理法能够减少电荷积累,同时降低铝电极的功函数,利于电子收集,进而提高器件性能。     

镧系离子间无辐射能量传递速率的教程综述（英文）

在本教程综述中,我们重新阐述和表达了镧系离子间无辐射能量传递(ET)速率的理论形式,并且强调了考虑镧系离子本身特异性所引发的与F?rster和Dexter理论不同之处。所给出的表达式遵循了Judd-Ofelt的4f-4f跃迁理论框架之下的Kushida方法,并计入了如下电多极机制：偶极-偶极(W_d-d)、偶极-四极(W_d-q)和四极-四极(W_q-q)。更为重要的是,当前的机制也扩展包括了交换(Wex)和磁偶极子-磁偶极子(W_md-md)作用,并经过改进进一步包含了屏蔽效应以及给出了F因子(费米黄金规则中的态密度)的解析表达式。与Kushida的原始方法类似,我们只考虑了强制电偶极子(FED)对Judd-Ofelt强度参数的贡献,并细节性地讨论了磁偶极-磁偶极相互作用的选择定则以及相关矩阵元的计算。此外,我们还以Tb(Ⅲ)-Eu(Ⅲ)和Yb(Ⅲ)-Er(Ⅲ)的能量传递速率计算为例,逐步展示了计算过程、主要的计算支撑信息以及所使用的计算脚本。     

光度法研究聚乙二醇-硫酸铵-邻苯三酚红体系中铋(Ⅲ), 铁(Ⅲ), 铜(Ⅱ), 镍(Ⅱ), 钴(Ⅱ), 铅(Ⅱ)的萃取分离

本文研究了在聚乙二醇(PEG)-硫酸铵[(NH_4)_2SO_4]-邻苯三酚红(PR)体系中Bi(Ⅲ),Fe(Ⅲ),Cu(Ⅱ),Ni(Ⅱ),Co(Ⅱ),Pb(Ⅱ)的萃取行为。实验结果表明,Bi(Ⅲ)在pH3.5～6.5及Fe(Ⅲ)在pH4.0～7.0范围内可以被PEG相几乎完全萃取,而Cu(Ⅱ),Co(Ⅱ)在pH1.0～7.0,Pb(Ⅱ)在pH2.0～7.0,Ni(Ⅱ)在pH1.0～4.5则不被萃取。从而实现了将Bi(Ⅲ)(pH3.5),Fe(Ⅲ)(pH5.0)与Cu(Ⅱ),Co(Ⅱ),Pb(Ⅱ),Ni(Ⅱ)混合离子的定量分离。同时探讨了PEG相的萃取机理。     

重离子束在等离子体靶中的能量损失

借助于线性Vlasov方程,我们研究了重离子束在等离子体靶中的有效电荷数和电子阻止本领。在高速情况下,分别得到了它们的解析表示式。以~(40)Ga,~(74)Ge,~(84)Kr,~(110)pd,~(208)pb及~(238)U等重离子束在氢等离子体中的能量损失为例,将我们的理论结果与Hoffmann等人的实验结果进行了比较。     

Optical near-field microscopy of light focusing through a photonic crystal flat lens

We report here the direct observation by using a scanning near-field microscopy technique of the light focusing through a photonic crystal flat lens designed and fabricated to operate at optical frequencies. The lens is fabricated using a III-V semiconductor slab, and we directly visualize the propagation of the electromagnetic waves by using a scanning near-field optical microscope. We directly evidence spatially, as well as spectrally, the focusing operating regime of the lens. At last, in light of the experimental scanning near-field optical microscope pictures, we discuss the lens ability to focus light at a subwavelength scale.     

双棱镜干涉实验装置的改进

对采用钠光灯做的双棱镜干涉实验进行改进。用半导体激光来替代钠光作光源,使干涉图样较之以前更清晰,调节更方便,并对激光器作光源的安全性及其特点进行了科学论证。     

Smartphone-based image analysis coupled to paper-based colorimetric devices

Advancements in technology have led to the use of smartphones as biosensor detectors. However, it is difficult to obtain stable color information of colorimetric sensors using multiple smartphones owing to different light conditions and image correction operations. In this study, we attempted color detection of the colorimetric paper chip using smartphone-embedded light-emitting diode (LED) and simple transformation calculation. This method enables the acquisition of stable color information using different smartphones by reducing the influence of external light sources. Moreover, we studied characteristics such as convergence and distinction of detection result details by the manufacturers and smartphones. These findings suggested the necessity of classification criteria for the use of smartphones to achieve optimal detection. In addition, white and black references were used to set the standard for color correction of various light sources. Based on our results, we conclude that this approach presents the possibility of smartphone-based colorimetric detection in practical applications.     

远程控制光场的量子统计性质

考虑双模纠缠相干光场,将其中一束光场注入腔中与一个二能级原子发生共振相互作用,总系统在腔量子电动力学演化过程中,对原子作选择性的测量,通过操纵参加相互作用的时间以及选择适当的光场参量可控制未参加相互作用光场的量子统计性质,在一定条件下可产生反聚束、压缩态等非经典光场,并且通过适当的控制和调整这些参量可以改变未参加相互作用光场的反聚束和压缩特性的强弱。这样,通过利用腔与原子之间简单的共振相互作用和相干光场之间的纠缠关联,实现了远程的、无直接量子测量的控制或改变相干光场的非经典性质这一目的。     

改善光源光谱特性提高光学多道分析器用于吸收光谱测量的信噪比

本文报道通过改善热辐射光源光谱特性,相对提高短波辐射光强,以提高ＣＣＤ光学多道分析器在可见区特别是短波段吸收光谱的信噪比。改善后光源的短波辐射信噪比比一般热辐射光源提高约８倍。实验证实用此光源易在整个可见光区得到高信噪比的吸收光谱曲线。     

Improved spring model-based collaborative indoor visible light positioning

Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user’s current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.     

Phototoxic effects of zinc oxide nanowires (ZnO NWs) complexed with 5-ALA in RD cell line

In this current study, we have manifested the photosensitizing effects of zinc oxide nanowires (ZnO NWs) in dark as well as under ultra violet light exposure with 240 nm of UV region, using human muscle cancer (Rhybdomyosarcoma cells, RD) as in vitro experimental model. We have fabricated ZnO-NWs on the tip of borosilicate glass capillaries (0.5 μm diameter) and were conjugated using 5-aminolevulinic acid (ALA) for the efficient intracellular drug delivery. When ZnO NWs were applied on tumor localizing drugs with non ionizing illumination, then excited drug liberates reactive oxygen species (ROS), effecting mitochondria and nucleus resulting in cell necrosis within few minutes. During investigations, we observed that when ZnO-NWs grown on intracellular tip was excited by using 240 nm of UV light, as a resultant 625 nm of emitted red light were used as appetizer in the presence of 5-ALA for chemical reaction, which produces singlet oxygen, responsible for cell necrosis. Morphological changes of necrosed cells were examined under microscopy. Moreover, Viability of controlled and treated RD cells with optimum dose of light (UV-Visible) has been assessed by MTT assay as well as reactive oxygen species (ROS) detection.     

Light scattering simulation for the characterization of sintered silver nanoparticles

Light scattering is a useful tool in optical particle characterization. It can help to understand the nature of single particles as well as systems or clusters of particles; information about particle sizes, materials or shapes can be gathered. In this paper we investigate the application of light scattering studies to the analysis of a sintering process of silver nanoparticles. For this we first simulate the scattering behavior of two silver spheres. Then we assume sintering between them, leading to a single particle with a concave, peanut-like shape. We approximate this shape by a Cassini-oval. For light scattering studies we use an advanced T-matrix algorithm, the Nullfield Method with Discrete Sources. This method proved to be capable of simulating light scattering by concave particles. To make sure that the calculated data are correct we do comparative simulations using the Discrete Sources Method.     

高量级光衰减时对线偏振片组衰光系数的研究

利用琼斯矢量法推导实际偏振片的琼斯矩阵和两片偏振片组的透射光强表达式和衰光系数表达式.通过计算说明,在高量级光衰减时用马吕斯定律计算偏振片的衰光率存在一定误差.因此,该衰光系数表达式可作为马吕斯定律实际运用时的修正式.依据该理论推导得出两偏振片组的最大衰光率为2ε2,并得到三偏振片组的关于θ2的透射光强表达式.该式以及相应实验表明在θ1,θ2=90°,135°和90°,315°时最大衰光率可达到2ε4.     

Experimentally faking the violation of Bell's inequalities

Entanglement witnesses such as Bell inequalities are frequently used to prove the nonclassicality of a light source and its suitability for further tasks. By demonstrating Bell inequality violations using classical light in common experimental arrangements, we highlight why strict locality and efficiency conditions are not optional, particularly in security-related scenarios.