Spectral Properties of Yellow Fluorescent Powder for White LEDs

Much attention has been paid to white LEDs because of their potential applications in the illumination.The doping of rare earth ions plays an important role in the optical properties of yellow fluorescent powder.And mainly aiming to raise the intensity and the luminous rate of the white LEDs and by photoluminescence and electroluminescence,the luminescence spectrum of yellow fluorescent powder bought from different places is measured.Furthermore, the luminous intensity in the normal direction and the angle distribution of half maximum power for the white LEDs packed with cylindrical Φ 5 epoxy on the same blue GaN chips are also measured under the same manufacture conditions. The results show that the yellow fluorescent powder bought from China mainland has higher optical output rate than that bought from China Taiwan and hence is more suitable to fabricate the white LEDs for practical use.

Construction of the Enhanced Yellow Fluorescent Protein Expression Vector Carrying IFN-γ Gene

Purpose: To construct the enhanced yellow fluorescent protein (EYFP) vector carryinginterferon-y gene (ifn-γ) in order to provide an ideal reporter in the expression of ifn-γand location of protein in vitro and in vivo.Method: According to the nucleotide sequence of ifn-y gene, a pair of oligonucleotideswas designed as primer whose two end contained nucleotide sequence of EcoR V and NotⅠ restriction endonuclease respectively. The gene encoding for inf-y was amplified usingPCR technique. After the PCR product was retrieved and purified, it was digested withEcoR V and Not Ⅰ restriction endonuclease, and then cloned into the plasmidpIRES-EYFP. The recombinant plasmid plRES-EYFPIFN-γwas identified by restrictionendonuclease enzyme analysis and DNA sequence analysis.Results: The ifn-γ was successfully amplified and verified by partial DNA sequenceanalysis. The recombinant plasmid was correctly screened.Conclusion: The EYFP expression vector carrying ifn-γgene was successfully established.This research work has formed a base for monitoring the ifn-y gene expression andprotein position in living cells.

Detection of Rice Yellow Mottle at the Asymptomatic Stage by Hyperspectral Fluorescence and Reflectance Spectroscopies

Rice yellow mottle is considered the most destructive disease threatening rice production in Africa. Early detection of this infection in rice is essential to limit its expansion and proliferation. However, there is no research devoted to the spectral detection of rice yellow mottle virus (RYMV) infection, especially in the asymptomatic or early stages. This work proposes the use of hyperspectral fluorescence and reflectance data at leaf level for the detection of this disease in asymptomatic stages. A greenhouse experiment was therefore conducted to collect hyperspectral fluorescence and reflectance data at different stages of infection. These data allowed to calculate nine vegetation indices: one from fluorescence spectra and eight from reflectance spectra. A t-test made it possible to identify, from the second day after infection, four relevant reflectance vegetation indices to discriminate healthy leaves from those infected: these are Photochemical Reflectance Index (PRI), Transformed Chlorophyll Absorption in Reflectance Index (TCARI), Structure Intensive Pigment Index (SIPI) and Simple Ratio Pigment Index (SRPI). The fluorescence index was less sensitive in detecting infection. The four significant vegetation indices for the detection of RYMV were then used to build and evaluate models for discriminating plants according to their health status by the supervised classification of support vector machine (SVM) at different stages of infection. The maximum overall accuracy is 92.5% six days after inoculation (6 DAI). The sixth day after inoculation would be the adequate day to detect RYMV. This plants discrimination was validated by the mean reflectance spectra and by the histograms showing the differences between the average reflectance vegetation indices values of the two types of plants. Our results demonstrate the feasibility of differentiating RYMV-infected samples. They suggest that support vector machine learning models could be developed to diagnose RYMV-infected plants based on vegetation indices derived from spectral profiles at early stages of disease development.

荧光逆行追踪结合离体固定脑片细胞内Lucifer Yellow染色和荧光免疫组化──共聚焦激光扫描显微镜观察

本文介绍一种由多种方法组合的技术，包括荧光素（FastBlae）逆行追踪．离体固定脑片细胞内LuciferYellow染色、荧光免疫组织化学染色和共聚焦激光扫描显微镜观察。通过这项组合技术．可以在1μm厚度的光学切片和连续光学切片三维重构图象中同时显示传出神经元的结构和免疫阳性传入纤维及其终未．进而可判断两种成分之间的联系。在单细胞水平的突触学研究中．此项技术提供了一个简单、有效的定性和初步定量相结合的实验方法．

Establishment of a Spleen Cell Line from Large Yellow Croaker Pseudosciaena crocea and its Primitive Application in Foreign Gene Transfection

A large yellow croaker,Pseudosciaena crocea,spleen(LYCS)cell line was established and the feasibility of using it for foreign gene transfection was evaluaed in this study.Primary culture of LYCS cells was initiated from spleen tissue pieces,which were cultured at 25℃ in Dulbecco's modiced Eagle medium/F12 medium(DMEM/F12,1:1)(pH7.2),supplemented with 20% fetal bovine serum,carboxymethyl chitosan,chondroitin sulfate,basic fibroblast growth factor(bFGF)and insulin-like growth factor-I(IGF-I).The cultured LYCS cells,in fibroblast shape,proliferated to 100% confluency 20 days later.Chromosome analyses indicated that the LYCS cells exhibited chromosomal aneuploidy with a modal chromosome number of 48 which displayed the normal diploid karyotype of P.crocea(6m+6sm+36t,NF=60).A LYCS cell line,with a population doubling time of 48.7 h at passage 60,has been established and subcultured to passage 70.Transgenic feasibility test demonstrated that positive green fluorescence protein(GFP)expression was observed in LYCS cells after pcDNA3.1-GFP plasmid transfection.In conclusion,a continuous foreign gene trans-fection feasible LYCS cell line has been established successfully.The cell line might serve as a valuable tool for studies of transgenic breeding and has potential applications for different kinds of cytotechnological studies.

A red-emitting water-soluble fluorescent probe for biothiol detection with a large Stokes shift

In this work, we presented a fluorescent probe(MCQ-DNBS) for selective and sensitive detection of biothiols based on a methylated chromenoquinoline(MCQ) derivative. Probe MCQ-DNBS was constructed by masking the OH group in MCQ with a common sensing unit, 2,4-dinitrobezensulfonate group(DNBS) for biothiols. Due to the photo-induced electron transfer(PET) process between MCQ and DNBS, this probe was weekly fluorescent. Upon the addition of biothiols(Cys, Hcy and GSH), this probe emitted a strong red fluorescence(λ_(em max)=613 nm) with a large Stokes shift(115 nm). In addition,fluorescence imaging of biothiols in living cells was successfully realized using MCQ-DNBS as a detector.

Si-rhodamine based water-soluble fluorescent probe for bioimaging of Cu^(+)

A Si-substituted rhodamine based water-soluble fluorescent probe bearing a tetrathia-azacrown was designed for fluorescence imaging of Cu^(+) with substantial affinity and selectivity.In physiological condition,the developed probe with outstanding water-solubility exhibits ultrahigh sensitivity to Cu^(+),ensuring the reliable fluorescence imaging in vivo.

Water-soluble Porphyrin as Temperature Sensor Based on Fluorescent Enhancement

A novel water-soluble porphyrin[5,10,15,20-tetra（3-ethoxy-4-hydroxy-5-sulfonate）phenyl porphyrin, H2TEHPPS] was designed and synthesized, which could be used as a potential fluorescence sensor to detect temperature changes. The studies were performed in solution phase and the concentration of H2TEHPPS was 2.0×10^-5 mol/L. The optical properties of H2TEHPPS were investigated based on the UV and fluorescence spectra. The results show that the fluorescence intensity of H2TEHPPS is directly proportional to temperature in the range of 293-353 K So H,TEHPPS can be used as a molecular temoerature sensor in biomedical and other fields.

Synthesis of a Rhodamine-Appended Cyclophane as a Fluorescence Host in Water

A cationic water-soluble cyclophane (1a) having a rhodamine moiety as a red-fluorescence fluorophore was prepared by reaction of a monoamine derivative of tetraaza[6.1.6.1]paracyclophane having three N-t-butoxycarbonyl-β-alanine residues with rhodamine B isothiocyanate, followed by removal of the protecting groups. The guest-binding behavior of 1a toward anionic guests such as dabsyl derivative and 4-(1-pyrene)butanoate was investigated by fluorescence spectroscopy. The results suggested the formation of host-guest complexes with a stoichiometric ratio of 1:1 and the binding constants (K) of the host-guest complexes were evaluated.

C16醇改性SiO 2基体材料对荧光强度的影响因素研究

黄磷炉渣大量堆积不仅会造成资源浪费,还会污染环境,针对黄磷炉渣能够得到合理利用,研究了以黄磷炉渣为主要原料,经过硝酸酸浸制备SiO_(2)这一工艺流程。因SiO_(2)生物相容性好、化学稳定性高、表面易于功能化等优点,可以作为制备荧光材料的基体材料。稀土金属Ce^(3+)直接掺杂到SiO_(2)上很难实现,所以SiO_(2)的表面改性是稀土金属掺杂SiO_(2)基制备荧光材料的一项关键因素,C16醇原料便宜,操作简单,并且改性效果明显,能够显著提高SiO_(2)基的接枝率,因此采用C16醇对SiO_(2)进行表面改性。为了探究优化的实验条件,考察C16醇投入量、改性时间、溶剂体积、改性温度和洗水用量对材料荧光强度的影响。结果表明:0.2g C16醇与30mL乙醇溶剂在175℃温度下反应2h,洗水用量为70mL为优化改性条件。

Water-soluble phosphate-functionalized polyfluorene as fluorescence biosensors toward cytochrome c

An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6′-phosphatehexyl)fluorene-alt-1,4-pheny lene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well soluble in water with a strong blue fluorescence emission. Effect of the side chain length on fluorescence sensory properties was studied by comparing quenching efficiencies toward different quenchers of PFHPNa with a reported polymer poly(9,9-bis(3′-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPPNa), which have different side chains in length. For small molecular quenchers (methylviologen, MV2+) and meso-5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphine (TMPyP4), polymer PFHPNa had lower sensitivity due to the much longer side chain length. The positively charged metalloprotein cytochrome c could quench fluorescence of conjugated polymers via energy transfer and electron transfer. Moreover, polymer PFHPNa showed higher fluorescence quenching toward large biomolecules than PFPPNa. The corresponding Stern-Volmer (Ksv) value of polymer PFHPNa was determined to be 2.1×108 M-1 for cytochrome c. It could be used as a sensitive and selective fluorescence sensor for protein cytochrome c.

2022年黄河调水调沙对下游有机物和营养盐年内变化的影响

2021年11月至2022年10月,在黄河下游泺口站进行了为期一年、每月一次的采样,测定了河水中溶解有机碳(Dissolved Organic Carbon,DOC)、有色溶解有机物(Chromophoric Dissolved Organic Matter,CDOM)、荧光溶解有机物(Fluorescent Dissolved Organic Matter,FDOM)、营养盐,以及悬浮颗粒态(Suspended Particulate Matter,SPM)中颗粒有机碳(Particulate Organic Carbon,POC)占比(POC占SPM的质量百分比,POC%)、δ^(13)C和δ^(15)N等生源要素相关指标。结果表明,调水调沙已经成为控制黄河下游多种生源要素在一年之中变化格局的关键因素,决定着其全年变化范围的上限和下限。在调水调沙的调水阶段,脉冲式激增的径流量通过稀释作用使得DOC浓度、CDOM浓度、FDOM中的类腐殖质组分含量,以及SPM中δ^(13)C和δ^(15)N达到全年的最低值,而CDOM光谱斜率(S_(275-295))达到最高值。在调水调沙的排沙阶段,上述指标则在相反方向上达到全年的极值。最近20年间,在调水调沙、流域生态环境保护、气候变化等一系列措施的影响下,黄河下游营养盐和DOC浓度呈现明显的下降趋势,而POC%的上升迹象也初步显现。黄河下游生源要素浓度、组成、性质、输出通量正经历着复杂而深刻的变化,将直接影响到黄河口的海洋生态环境。本研究有助于进一步理解在人类活动背景下大河生源要素的响应特征和反馈机制及其对邻近海洋生态环境的潜在影响。

Bi^(3+)掺杂无铅双钙钛矿Cs_(2)Ag_(0.6)Na0_(.4)InCl_(6)的发光性质

现需开发一种低耗能、绿色环保制备双钙钛矿荧光粉的工艺,并将其他金属离子掺入该基质,获得一种高量子效率的新型发光材料.本文采用微波固相法制备了Bi^(3+)掺杂无铅双钙钛矿Cs_(2)Ag_(0.6)Na0_(.4)InCl_(6)荧光粉,该方法无需配体辅助,绿色环保.通过X射线衍射仪和扫描电子显微镜对晶体结构和形貌进行表征,并通过激发光谱、发射光谱和时间分辨光谱以及量子效率对其发光性能进行研究.结果表明:1)Cs_(2)Ag_(0.6)Na0_(.4)InCl_(6)为立方晶体,属于Fm3 m空间群,晶粒形貌为不规则颗粒;2)当Bi^(3+)的最佳掺杂浓度为0.0013 mmol时,Cs_(2)Ag_(0.6)Na0_(.4)InCl_(6)材料发射中心波长为562 nm,平均荧光寿命达到2.60μs,量子效率达到45.28%;3)当Bi^(3+)离子浓度超过0.0013 mmol时,会产生明显的浓度猝灭效应,主要是因为Bi^(3+)离子之间电四极-电四极(q-q)相互作用;4)Cs_(2)Ag_(0.6)Na0_(.4)InCl_(6)掺杂Bi^(3+)荧光粉的色度坐标(CIE)位于黄光区域,是一种具有潜在应用价值的暖白光LED用黄色荧光粉.

锦纶与改性涤纶织物增白和抗酚黄变一浴工艺

为解决锦纶与改性涤纶混纺织物常规增白和抗酚黄变两浴法工艺中效率低、资源浪费和异味等问题,通过单因素试验,研究一浴法中温度、时间、冰醋酸和抗酚黄变剂N用量对织物的白度、抗酚黄变等级和异味的影响,并与常规两浴法工艺进行了对比。总结得出最优的一浴法工艺为:酸性荧光增白剂BA2670.3%,抗酚黄变剂N 3.0 g/L,匀染剂P 1.0 g/L,浴比1∶10,95℃处理20 min。结果表明,最优一浴法工艺应用于生产实践,可节约水、电、汽和冰醋酸等资源,处理后织物的白度和抗酚黄变等级与常规工艺相当,且无异味,满足客户对生态健康纺织品的需求。

黄色18K金首饰金含量检测及异常分析

使用X射线荧光光谱法(XRF)和火试金法对黄色18K金首饰金含量进行检测分析比较,同时针对首饰表面金含量异常偏高情况,使用显微镜放大观察样品表面形貌、XRF图谱分析以及走访调研工厂,分析样品表面金含量异常偏高原因。实验结果表明,X射线荧光光谱法(XRF)和火试金法结果存在较大差异,通过分析得知样品表面金含量异常偏高是因为电镀了一层高含量的黄金镀层。我们在日常检测工作中碰到此类表面含量异常样品时,一定要谨慎对待,重点分析,必要时需联合多种检测方法进行结果确认。

不同水源特征水库中溶解性有机物的光学特性对比

为考察A水库(“引黄工程”水源水库)与B水库(普通类型水库)的溶解性有机物(DOM)在相对分子质量大小、组成特征及来源方面的差异,采用紫外-可见光谱技术以及三维荧光光谱技术结合平行因子分析法,针对A水库和B水库水体中DOM的吸收参数特征和荧光特征进行了研究。结果显示:A水库和B水库的DOM均有较强的自生源特征,但两水库的DOM在组成特征和来源上存在一定差异。B水库样本中存在长波类腐殖质C1(E_(x)=350 nm,E_(m)=454 nm)、类色氨酸物质C2(E_(x)=300 nm,E_(m)=361 nm)和类色氨酸C3(E_(x)=220 nm/250 nm,E_(m)=347 nm)3个荧光组分,而A水库样本中存在长波类腐殖质C1、类色氨酸物质C2两个荧光组分,说明A水库的组成特征相对更加简单。DOM吸收参数特征分析显示,A水库水质状况良好,其DOM相对分子质量较大,主要来自自生源;而B水库处于富营养状态,其DOM相对分子质量较小,富里酸成分和水体芳香性较高,水生环境中维管束植物输入较为丰富,主要来自入库河流和自生源。光谱指标差异性分析显示,A水库DOM外源输入比例小于B水库,同时A水库的水质污染源更多以陆源输入为主。研究揭示了水库中DOM的光学特性,可反映水库的环境污染程度和富营养化程度,为进一步探究DOM在不同水源特征水库的环境行为特征及水库水质保护等提供参考。

胶州湾海水黄色物质荧光分布初步研究

研究海水黄色物质 ,在实验室研究的基础上 ,于 1999年 9月 1— 2日 ,利用荧光测量法 ,现场测量了胶州湾黄色物质荧光相对强度 ,首次获得了我国海区黄色物质分布数据。胶州湾黄色物质荧光强度主要分布特征为 :胶州湾黄色物质荧光强度高度区分布在沿岸 ,尤其在河口附近 ;湾口次之 ;湾中部区域再次之 ,湾口外侧最小 ;胶州湾黄色物质垂直分布不均匀。这种分布与胶州湾的自然环境密切相关 ,尤其与沿岸径流有关 ,因此 ,初步认定胶州湾黄色物质为陆源物质 ,由沿岸径流携带入海湾。

海水黄色物质荧光特性的初步研究

用荧光测量方法，对被认为可作本底水样的几种水体进行了荧光特性的测量研究，确认了即时处理的Milli-Q水是无荧光效应的高纯度水，可作为本研究的本底水样。同时，对海水黄色物质Milli-Q水溶液、市售草炭腐殖质Milli－Q水溶液、青岛近岸海水和褐藻培养液样品进行了光谱特性测量研究。结果表明，海水黄色物质和培养液的黄色物质的激发光谱峰值波长在340nm附近、荧光光谱峰值波长在435nm附近；而草炭腐殖质的激发峰值波长在320nm附近，荧光峰值波长在440nm附近。测量得出了海水黄色物质Milli-Q水溶液的荧光强度与其浓度的关系曲线。其最低检测浓度高达1×10－9／ml以上。同时也测量得出了青岛近岸海水样品不同稀释度的稀释液与对应的荧光强度的良好正相关关系。用荧光法测量得出青岛近岸海水的黄色物质浓度为3．2×10－7g／ml。

PAR-吖啶黄能量转移荧光猝灭法测定痕量铁(Ⅱ)的研究

对 4 (2 吡啶偶氮 ) 间苯二酚 (PAR)与吖啶黄间荧光能量转移进行了探讨 ,研究了其能量转移的最佳条件 ,并应用该体系测定痕量铁 (Ⅱ ) ,由此建立了能量转移荧光测定痕量铁的新方法。在λex/em =46 5nm/5 0 5nm ,十二烷基硫酸钠 (SDS)作用下 ,pH =9 2时 ,吖啶黄与PAR 铁 (Ⅱ )络合物间能发生有效能量转移 ,使吖啶黄的荧光猝灭。铁的量在 0～ 10 μg·L-1范围内呈良好的线性关系。最低检出限 0 0 6 μg·L-1。该方法用于水样、发样中痕量铁的测定 ,结果满意。

具有荧光增白作用的新型返黄抑制剂的合成及性能

以4,4′-二氨基二苯乙烯-2,2′-二磺酸(DSD酸)为原料,三聚氯氰为交联单体,将自由基捕获剂2,2′,6,6′-四甲基哌啶胺(4-氨基哌啶)与二苯乙烯荧光增白剂引入同一分子中,经过亲核取代等设计出既含有荧光增白基团又具备自由基捕获功能的双三嗪氨基二苯乙烯荧光增白型的新型返黄抑制剂。采用红外和核磁光谱、紫外光谱、荧光光谱分析方法对其结构及其光学性质进行了初步研究,并通过紫外线加速老化实验考察了目标产物对化机浆纸张的返黄抑制效果。实验结果表明:合成的目标产物在涂布中的最佳浓度用量为0.8%,经过48h光老化处理后,合成的产物光抑制效果更好,更适合作光诱导返黄抑制剂,与单独使用荧光增白剂和受阻胺类返黄抑制剂相比,老化后纸张的白度分别少下降了3.38%ISO和6.49%ISO。