Changes of Indocyanine Green and Fluorescein Angiography in Multiple Evanescent White-dot Syndrome: A Case Report

Purpose: To study the clinicopathological change on "Multiple Evanescent White-dot Syndrome (MEWDS)"through fundus angiogrphy analyses.Methods:Examing the case with fluorescein angiography (FFA) and indocyanine green angiography(ICGA), visual field and following up for 15 months.Results :There exist multiple white dots in the fundus photo and angiography. The changes on ICGA maintain longer than fundus photo and FFA. Papille may be edematous and macula could present with special hypofluorescent flecks.Conclusions:MEWDS has specific angiographic features. Its pathological changes involve deep retinal pigment epithelium(RPE) as well as choroidal capillaries. The prognosis of the visual acuity for MEWDS is very good.

绿色荧光碳点的合成及其在铁离子检测中的应用

以还原型谷胱甘肽为碳源,丙烯酸异辛酯为溶剂通过溶剂热法制备了具有绿色荧光发射的氮硫共掺杂碳点(G-CDs)。所制备的碳点在水中分散性良好,尺寸为(5.17±0.23)nm。在398 nm的激发波长下,其发射波长为517 nm,荧光量子产率为13.2%,且具有激发独立性。因为Fe 3+与G-CDs之间存在特异性内滤效应和电子转移,可以有效淬灭G-CDs的荧光。基于此类性能,我们开发了一种新的Fe 3+荧光检测方法,线性范围为20~80μmol/L,检测限为8.16μmol/L。在实际样品检测中,G-CDs具有良好的灵敏度,在荧光探针领域具有应用潜力。

Characteristics and Creation Techniques of Visual Originality for Dotted Landscapes

Dot,line,plane,body are dominant elements for creating visual originality of modern landscapes,among which dot is the fundamental one in the visual design.It is a significant subject in modern landscape design to create visual originality and style of dotted landscapes,and also a premise for humanistic design.The visual characteristics of dotted landscapes were analyzed from the perspectives of style,size,location,configuration and so on.The principles of creating green visual originality for dotted landscapes were concluded,that is,coordination and unification,ratio and scale,balance and stability,rhythm and tempo.Then novel and elegant dotted landscapes can be created by using new materials and techniques,applying deformation,cutting and connection,alternation,distortion and rotation;by adopting motif composition method,motif with outstanding features can be selected as dotted landscapes to form contrast with background and break the rigid atmosphere.

Dynamical localization effect in a coupled quantum dot array driven by an AC magnetic field

We have studied the transport properties of a ring-coupled quantum dot array driven by an AC magnetic field, which is connected to two leads, and we give the response of the transport current to the dynamical localization. We found that when the ratio of the magnetic flux to the total quantum dots number is a root of the zeroth order Bessel function, dynamical localization and collapse of quasi-energy occurs and importantly~ the transport current displays a dip which is the signal of dynamical localization. The dynamical localization effect is strengthened as a result of the increase of the quantum dot number, and it is weakened on account of the increase of the dots-lead hopping rate.

Photon-assisted electronic structure and transport for a quantum dot

This paper investigates theoretically the electronic structure and transport of a two-level quantum dot irradiated under a strong laser field at low temperatures. Using the method of Keldysh equation of motion for nonequilibrium Green functions, it examines the time-averaged density of states and conductance for the system with photon polarization parallel with and perpendicular to the tunnelling current direction respectively. It is demonstrated that, by analysing some numerical examples, more photon sidebands resonance states and multi-and single-photon transitions are found when diagonal matrix elements dominate the interaction, while the electronic transitions due to multiphoton absorption are more or less suppressed when off-diagonal interaction dominates.

Fano effect of a parallel-coupled triple Rashba quantum dot system

Using the nonequilibrium Keldysh Green＇s function technique, the Fano effect of a parallel-coupled triple Rashba quantum dot system is investigated. The conductance as a function of electron energy is numerically calculated. Compared with the case of a parallel-coupled double quantum dot system, two additional Fano resonance peaks occur in the conductance spectrum. By adjusting the structural parameters, the two Fano resonance peaks may change into the resoaance peaks. In addition, the influence of Rashba spin-orbit interaction on the conductance is studied.

Fano effect of a laterally coupled vertical triple quantum dot system

Using the nonequilibrium Green＇s function technique,electron transport through a laterally coupled vertical triple quantum dot is investigated.The conductance as a function of electron energy is numerically calculated.The evolution of the conductance strongly depends on the configuration of dot levels and interdot coupling strengths.

Phonon-dependent transport through a serially coupled double quantum dot system

Using Keldysh nonequilibrium Green function formalism and mapping a many-body electron-phonon interaction onto a one body problem, the electron transport through a serially coupled double quantum dot system is analyzed. The influence of the electron-phonon interaction, temperature, detuning, and interdot tunneling on the transmission coefficient and current is studied. Our results show that the electron-phonon interaction results in the appearance of the side peaks in the transmission coefficient, whose height is strongly dependent on the phonon temperature. We have also found that the inequality of the electron-phonon interaction strength in two dots gives rise to an asymmetry in the current-voltage characteristic. In addition, the temperature difference between the phonon and electron subsystems results in the reduction of the saturated current and the destruction of the step-like behavior of the current. It is also observed that the detuning can improve the magnitude of the current by compensating the mismatch of the quantum dots energy levels induced by the electron-phonon interaction.

A Theoretical Study of Light Absorption in Self Assembled Quantum Dots

Self assembled quantum dots have shown a great promise as a leading candidate for infrared detection at room temperature. In this paper, a theoretical model of the absorption coefficient of quantum dot devices is presented. Both of bound to bound absorption and bound to continuum absorption are taken into consideration in this model. This model is based on the effective mass theory and the Non Equilibrium Greens Function (NEGF) formalism. NEGF formalism is used to calculate the bound to continuum absorption coefficient. The results of the model have been compared with a published experimental work and a good agreement is obtained. Based on the presented model, the bound to bound absorption coefficient component is compared to the bound to continuum absorption coefficient component. In addition, the effects of the dot dimensions and electron filling on the bound to continuum absorption coefficient are also investigated. In general, increasing the dot filling increases the absorption and decreasing the dots dimensions will increase the absorption and move the absorption peak towards longer wavelengths.

生物质碳量子点的绿色制备及对Cu^(2+)的检测

向日葵作为我国主要的油料作物之一,其秸秆是天然的纤维素材料,具有绿色无毒,成本低廉的优势,是制备生物质碳量子点的理想材料之一。近年来,由于含铜农药和化学肥料的不规范使用,大量含铜污染物被排放导致农田土壤和水环境中的铜含量远高于环境背景值。因此,迫切需要开发出一种选择性好、灵敏性强且对环境友好的Cu^(2+)检测方法。碳量子点(CDs)是一种粒径小于10 nm的准球形荧光碳纳米材料,因其表面含有丰富的极性官能团,具有良好的水溶性而被广泛研究。与传统的半导体量子点(CdSe,CdTe)相比,CDs具有合成原料广泛、生物相容性好等优点。主要应用于生物成像、光催化、光电转化以及传感检测等领域。然而目前用于碳化合成CDs的前驱体大多为昂贵的化学品,且合成过程复杂污染环境,限制了CDs的大规模生产与应用。开发出一种生态友好,简单、廉价的CDs合成方法是很有意义的。本研究以废弃的向日葵秸秆为碳源,采用简便的水热法合成生物质碳量子点(S-CDs)作为荧光探针,用于检测识别Cu^(2+)。通过对S-CDs的一系列光学性质分析与表征,鉴定出其表面官能团主要包括O—H,N—H以及C N等,其中丰富的O—H可以提供胶体稳定性,有效地控制纳米颗粒的形态和粒径分布,从而提高S-CDs的量子产率(QYs)。ex=317 nm,em=456 nm,S-CDs在pH为2.0~12.0的范围内具有优异的光学性能和良好的光稳定性,受高盐度环境的影响较小,QYs约为8.42%,在365 nm的紫外分析仪照射下发射出蓝色荧光。此外,以合成的S-CDs作为荧光探针,进一步研究了基于Cu^(2+)诱导S-CDs的荧光猝灭效应。结果表明,制备的S-CDs在0~10μmol·L^(-1)浓度范围内对Cu^(2+)反应灵敏,呈良好的线性关系(R^(2)=0.9714),检出限(LOD)低至167 nmol·L^(-1)。在实际应用中,湖水中的Cu^(2+)检测回收率在96.18%~109.22%。该研究在资源化利用秸秆废弃物的基础上,介绍了一种基于荧光碳量子点的Cu^(2+)检测方法。

利用绿色碳点-流动注射荧光法测定环境水中化学需氧量

为了达到快速、在线监测水质指标化学需氧量(COD)的目的,首次以废弃物核桃绿皮为碳源、乙二胺为氮源,水热法制备得到绿色碳点,并利用紫外可见光谱、荧光光谱及透射电镜对碳点进行了表征。基于高锰酸根内滤光效应及氧化作用猝灭碳点荧光的机理,建立了流动注射荧光猝灭法快速、自动测定水样中COD的方法。在最佳条件下,测定COD的线性范围为0.5~80 mg/L,检出限为0.15 mg/L,Cl^(-)质量浓度至10000 mg/L时不干扰测定。最后,采用该方法测定了几种环境水样的COD,结果与国标法一致。

传统缠花点翠珐琅工艺在现代饰品中创新应用

为了探索非物质文化遗产在现代背景下的创新设计与应用,本文从缠花、点翠、珐琅工艺出发,对传统技艺进行创新融合改造,研究如何将其融合体在结构、衔接、色彩等3个方面进行创新,解决现代人们的文化审美需求。加入新的设计理念,使这3种工艺能够在飞速发展的时代里紧跟潮流,在不断求索中寻求传统工艺的保护与传承。

基于复合配体改性的CsPbBr_(3)钙钛矿量子点及其器件性能研究

量子点纯化工艺对铯铅溴(CsPbBr_(3))钙钛矿量子点(PQDs)光学和电学性能影响极其重要。提出一种简单可行的复合配体钝化策略,用来修饰PQDs表面缺陷。溴化胍(GuaBr)和二癸基二甲基溴化铵(DDeAB)在纯化过程中被引入共同修饰钙钛矿量子点。这种配体钝化策略能够有效地抑制空位缺陷,并提高胶体稳定性和电学性能。最终,基于复合配体改性的量子点,绿色的PeLED器件具有低的性能滚降和15786 cd/m^(2)的最大亮度。

绿色来源荧光碳点的合成及应用进展

碳点(carbon dots,CDs)作为一类低毒、高生物相容性的新型荧光纳米材料,被广泛应用于生物医药、临床诊疗、环境监测等领域。近年来,生物质衍生CDs因成本低、来源广、可再生,受到相关领域研究者的广泛关注。此外,相比于传统化学合成物质,生物质本身富含糖类、黄酮以及其它天然成分,无需额外修饰即可合成功能基团丰富、荧光性能优异的绿色CDs,有助于其在真实世界的广泛应用。本文综述了绿色来源CDs的主要来源、绿色合成方法及相关应用,并展望了其未来的研究重点及发展方向。

碳点的绿色合成、纯化及其生物医学应用的研究进展

碳点(CDs)是近年来合成的一类具有碳基纳米结构的零维(0D)纳米材料。自2004年发现CDs以来,对其进行了大量的研究。绿色合成的CDs由于其发光效果优异、稳定性强、生物相容性好等独特性能,在生物成像、生物传感、纳米医学等生物医学领域有着广泛的应用。系统性地介绍了碳点的绿色合成、纯化方法以及碳点在生物医学方面的应用。

荧光碳量子点的绿色合成及高灵敏高选择性检测汞离子

本实验以苹果汁为原料,通过一步水热法合成得到了水溶性好及稳定性高的蓝色荧光碳量子点。研究发现Hg2+对碳量子点荧光有良好的猝灭作用,从而建立了一种快速检测Hg2+的新方法。实验发现在pH 7.0磷酸盐缓冲介质中碳量子点荧光猝灭强度与Hg2+浓度在5~100 nmol/L和1~50μmol/L范围内呈线性关系,检出限为2.3 nmol/L(S/N=3)。本方法可用于实际水样中Hg2+的测定。

量子点标记与绿色荧光素标记对survivin反义寡核苷酸生物功能影响的比较

目的观察量子点和绿色荧光素分别标记的survivin反义寡核苷酸(ASODN)转染人乳腺癌细胞株MCF-7后,在标记存在时间、survivin的表达及细胞增殖、凋亡方面有无差异。方法将量子点和绿色荧光素分别标记的survivin ASODN通过脂质体转染MCF-7,MTT法检测细胞生长抑制率,RT-PCR检测survivin mRNA,Western blot检测survivin蛋白表达,流式细胞仪分析细胞凋亡率变化,荧光倒置显微镜观察细胞内荧光物质分布。结果量子点与绿色荧光素分别标记的survivin ASODN作用MCF-7后,survivin mRNA和survivin蛋白表达均下降,但两者间无显著差异(P>0.05)。两者细胞生长抑制率、凋亡率间无显著差异(P>0.05)。转染后4d绿色荧光素标记组细胞内荧光消失,而量子点标记组荧光1周仍存在。结论量子点标记survivin ASODN与绿色荧光素标记比较,对survivin的表达及细胞增殖、凋亡方面无差异,而标记更稳定,存在时间更长。

磁性壳聚糖/ZnS∶Fe复合纳米粒子的制备及其对孔雀石绿的光催化降解（英文）

采用化学共沉淀法制备了磁性壳聚糖,然后以制得磁性壳聚糖纳米粒子为基体,利用层层自组装原理,在磁性壳聚糖表面原位生长ZnS∶Fe纳米晶,制备得到磁性壳聚糖/ZnS∶Fe复合纳米粒子。采用XRD和VSM对其进行表征,结果表明,制备得到的磁性壳聚糖/ZnS∶Fe复合纳米粒子具有超顺磁性能,室温下饱和磁化强度为15.88A·m2·kg^-1。以孔雀石绿为模型污染物,采用UV-Vis手段研究磁性壳聚糖/ZnS∶Fe复合纳米粒子的光催化降解性能。实验结果表明,向初始浓度为10mg/L孔雀石绿溶液中加入100mg/L磁性壳聚糖/ZnS∶Fe复合纳米粒子,60min时孔雀石绿的去除率为95.3%,重复使用5次后,降解率略有降低(从95.3%降低到80.8%),其反应过程符合假一级动力学的假设。因此,磁性壳聚糖/ZnS∶Fe复合纳米粒子可以光催化降解孔雀石绿。

Mn掺杂ZnS量子点与孔雀石绿和隐性孔雀石绿的相互作用

研究了Mn掺杂ZnS量子点与孔雀石绿和隐性孔雀石绿的相互作用。首先采用水热法以壳聚糖为基质,利用成核掺杂原理制备量子点,然后分别采用紫外-可见吸收和荧光光谱技术研究了量子点与孔雀石绿和隐性孔雀石绿的相互作用。结果表明,向初始浓度为20 mg·L^(-1)孔雀石绿溶液中加入200 mg·L^(-1)量子点,60 min孔雀石绿的去除率约为82%,量子点可以光催化降解孔雀石绿,其反应过程符合假一级动力学的假设;量子点对隐性孔雀石绿具有荧光猝灭作用,猝灭作用为动态猝灭,相互作用力为氢键和范德华力,吉布斯自由能小于零,量子点与隐性孔雀石绿的相互作用是一个自发的过程。因此,量子点可以用于光催化降解孔雀石绿和快速无毒检测隐性孔雀石绿。

葡萄糖胺稳定CdS量子点的绿色合成及光谱特性

以葡萄糖胺(Glucosamine,GlcN)为稳定剂,以Cd(Ac)2.2H2O和Na2S.9H2O作为反应剂,在室温下水相合成了CdS量子点。通过X射线衍射(XRD)、透射电镜(TEM)、紫外-可见吸收光谱(UV-Vis)和荧光发射光谱(PL)对样品的结构、形貌和光学性能进行了表征,考察了反应体系的pH值、GlcN/Cd的物质的量比对量子点光谱性能的影响。结果表明,所获得的CdS量子点为立方闪锌矿结构,且尺寸分布均一,结晶度高,具有丰富的表面缺陷和量子尺寸限域效应。同时,对CdS量子点形成的可能机理进行了初步的探讨。