正交型发光二极管诱导荧光检测器的研制

以发光二极管为激发光源,以多模光纤代替透镜组作为激发光路,利用毛细管作为检测池,研制了一台小型、低功耗的荧光检测器。采用正交型光路设计,借助高精度机械加工的自校准平台,使光纤-毛细管-荧光收集透镜实现自校准。采用流动注射模式,以荧光素钠为标准样品对该检测器性能进行了测试,最低检测限为6.75×10-8 mol·L-1(S/N=3),在1.35×10-7~43.2×10-7 mol·L-1范围内线性关系良好(R2=0.9992),稳定性良好(RSD1%)。结合高效液相色谱系统,分离了异硫氰酸荧光素标记的4种氨基酸。     

有机电致发光二极管(OLED)的技术进展

OLED具有其他传统的显示器无法比拟的性能优势、卓越节能性能,使其具有广阔的市场应用前景。近几年来成为各大厂商的新宠,将其应用于显示领域的研究引起了人们的广泛关注。本文简要的介绍了OLED的发展历史、结构、原理及分类,并在此基础上重点综述了近年来有关OLED在显示及照明方面的应用现状,并对其未来发展方向及应用前景进行了展望。     

Controlling Polymer Solubility: Polyfluorenes with Branched Semiperfluorinated Side Chains for Polymer Light-Emitting Diodes

A series of novel polyfluorenes, soluble exclusively in perfluorinated solvents, were prepared. The new materials were studied with regard to orthogonal processing of organic electronic materials. The desired solubility was achieved by introducing semifluorinated side chains to the fluorene monomers. Since the use of long perfluoroalkyl chains (R^F) is restricted due to public health concerns, a synthetic route for polyfluorenes with short R^F chains branched by aromatic units has been developed. The photophysical behavior of the resulting polymers was investigated in solution and thin films by UV/Vis absorption and photoluminescence spectroscopy. The photoluminescence quantum yields were found to be in the range of those of alkylated polyfluorenes. The electroluminescent properties were studied in single-layer polymer light-emitting diodes, with the new polymers as active materials, which exhibited similar characteristics to previously published single-layer devices with polyfluorenes containing long R^F. The wetting properties of different polyfluorene films containing fluorinated, polar, polyethylene glycol, or nonpolar alkyl groups were investigated by contact angle measurements.     

Langmuir and Langmuir-Blodgett Films of Polyfluorenes and Their Use in Polymer Light-Emitting Diodes

The Langmuir and Langmuir-Blodgett (LB) film properties of two polyfluorene derivatives, namely poly(2,7-9,9′-dihexylfluorene-dyil) (PDHF) and poly(9,9 dihexylfluorene-dyil-vynilene-alt-1,4-phenylene-vyninele) (PDHF-PV), are reported. Surface pressure (П-A) and surface potential (ΔV-A) isotherms indicated that PDHF-PV forms true monolayers at the air/water interface, but PDHF does not. LB films could be transferred onto various types of substrate for both PDHF and PDHF-PV. Only the LB films from PDHF-PV could withstand deposition of a layer of evaporated metal to form a light-emitting diode (PLED), which had typical rectifying characteristics and emitted blue light. It is inferred that the ability of the polymer to form true monomolecular layers at the air/water interface seems to be associated with the viability of the LB films in PLEDs.     

White Electroluminescence Using ZnO Nanotubes/GaN Heterostructure Light-Emitting Diode

We report the fabrication of heterostructure white light–emitting diode (LED) comprised of n-ZnO nanotubes (NTs) aqueous chemically synthesized on p-GaN substrate. Room temperature electroluminescence (EL) of the LED demonstrates strong broadband white emission spectrum consisting of predominating peak centred at 560 nm and relatively weak violet–blue emission peak at 450 nm under forward bias. The broadband EL emission covering the whole visible spectrum has been attributed to the large surface area and high surface states of ZnO NTs produced during the etching process. In addition, comparison of the EL emission colour quality shows that ZnO nanotubes have much better quality than that of the ZnO nanorods. The colour-rendering index of the white light obtained from the nanotubes was 87, while the nanorods-based LED emit yellowish colour.     

Brightness and Luminance of Light-Emitting Diodes: Influence of Size and Defocus

When a narrow-band source is compared to a white source, through a simultaneous brightness match, the equibrightness condition does not necessarily imply that the luminances of the two sources coincide. This known fact is now checked by using as sources red and green light-emitting diodes (LEDs), compared to CIE source A. In addition, we check some predictions concerning the influence of saturation, wavelength dependence, and small-field effects. Some problems related to eye-lens accommodation are attacked by taking into account the chromatic aberration of the eye and the unpredictable role of psychological factors in determining the wavelength focused on the retina. Their influence on the brightness-luminance ratio is quantified.     

金刚烷双溴化物改性聚芴的Suzuki偶联聚合及光致发光性能

通过Suzuki偶联聚合反应合成了3种具有较高相对分子质量的主链含金刚烷共聚单体的聚芴P1~3,聚合产率均在90%以上。热重分析表明,P1~3的分解温度分别达到412、420和430℃。紫外和光致发光(PL)光谱表明,改性后的聚芴比均聚物聚(9,9-二己基芴)(PF6)具有抑制的链簇集行为。所有共聚物的PL主峰均位于423 nm左右,且P2的薄膜态荧光量子效率达到0.56。热退火PL光谱研究表明,共聚物的绿光发射强度随金刚烷摩尔分数的增加而降低,在200℃处理1 h后,P1、P2和P3在520 nm处的与绿光发射相关的荧光相对强度仅为0.084、0.083和0.065,均远远低于PF6的0.225。     

Brightness Reversion of Mechanical Pulps. III. Mechanistic Studies of Mercapto-Stabilizers for High Brightness Mechanical Pulps

The photo and thermal stabilizing effects of 2, 2′-thiodiethanol (1), 2, 2′-dithiodiethanol (2), and 2, 2′-oxydiethanethioI (3) were investigated for high brightness bleached chemithermomechanical pulps (BCTMP). The dithiol additive 3 was shown to be the most effective photostabilizing reagent for freshly impregnated handsheets. Mechanistic studies suggest that dithiol additives photostabilize BCTMP pulps no more effectively than monothiol additives. Long-term thermal reversion studies indicated that 2, 2′-oxydiethanethiol also stabilized BCTMP handsheets against thermal yellowing. Photolysis of the aged handsheets indicated that the photostabilizing efficiency of additive 3 was detrimentally impacted upon by long term storage prior to photolysis.     

高效溶液法小分子磷光电致发光器件研究

以小分子化合物CDBP[4，4＇-bis（carbazo1．9-yl）-9，9-dimethyl-fluorene]为主体材料，Ir（pppy）3[tris（5-phenyl-10，10-dimethyl-4-aza—tficycloundeca-2，4，6-triene）Iridium（Ⅲ）]为磷光客体材料，采用溶液法和真空蒸镀法相结合的制备工艺，制作了小分子磷光电致发光器件．研究表明，通过器件结构的优化，Ir（pppy）3（重量百分比为2）掺杂的多层绿光电致发光器件效率达22．0cd／A，最大亮度达到26600cd／m^2，这一结果可与当今基于真空蒸镀的小分子或基于溶液法的高分子磷光电致发光器件性能相媲美．本工作为降低有机电致发光器件的成本，扩展溶液法有机电致发光器件制备工艺中材料的选择范围提供了实验依据．     

A Functional Material Based Heterojunction Diode

In this study, the phosphotungstic acid /p-Si diode was fabricated by a drop coating method. The fabricated diode had excellent rectifying properties. The electrical properties of the diode were investigated in the temperature range of 50-400 K. The optical band gap of the phosphotungstic acid film was determined and found to be 3.66 eV. The electrical and photoresponse properties of an Al/p-Si-phosphotungstic acid/Al photodiode were studied. The electronic parameters such as ideality factor (n), barrier height (Φ _B ) and series resistance (R _s ) were found to be strongly temperature dependent.     

Supramolecular Phosphorescent Polymer Based on Cationic Iridium Complexes for Polymer Light-Emitting Diodes

Three novel orange emission supramolecular phosphorescent polymers (SPPs) with cationic iridium complex have been developed for polymer light-emitting diodes (PLEDs) through efficient self-assembly. The supramolecular assembly process was monitored by ¹H nuclear magnetic resonance (¹H NMR) and viscosity measurement. These SPPs give orange phosphorescence with a peak at about 595 nm and display good thermal properties with a glass-transition temperature (T_g) about 90 °C. The single-emissive-layer PLEDs with charged SPPs exhibited the highest device efficiency of 2.81 cd A^?1 with the Commission Internationale de L’Eclairage coordinates of (0.58, 0.40). The present work reported the charged SPPs self-assembled by the cationic iridium complex for the first time and provided a new guide to develop orange emitters for solution-processable optoelectronic devices.

     

高亮度LED用氯硅酸盐荧光粉的合成及光谱特性研究

采用高温固相法合成了二价Eu~(2+)与Ln(Ln=Gd~(3+),Cu~+,Sm~(3+),Dy~(3+))共激活氯硅酸镁钙[Ca_8Mg(SiO_4)_4Cl_2:Eu~(2+),Ln]绿色荧光粉,借助X射线衍射对其晶格结构进行了研究,结果表明该荧光粉体具有面心立方晶系结构,实验条件下共激活离子Ln的掺杂对晶体的结构没有产生较大影响。并报道了它们的激发光谱及发射光谱,观测到氯硅酸镁钙中辅助激活离子Ln的掺杂并没有改变荧光粉体的光谱位置,只是在一定程度上提高了荧光粉体的相对发射强度。     

论高掺量粉煤灰混凝土-绿色高性能混凝土

水泥混凝土是当代最大宗的人造工程材料。目前硅酸盐水泥生产中存在两大问题 :一是矿物资源、能源消耗大 ;二是对环境污染大 ,影响生态平衡。为了可持续发展 ,今后应向高性能、绿色化、多功能方向发展。高掺量粉煤灰混凝土的绿色环保作用主要体现在 :(1 )减少水泥生产中对环境的污染和破坏。生产普通硅酸盐水泥产生的CO2 约占人类活动产生二氧化碳的 6 %～ 7%。此外 ,为获得生产水泥的原料 ,会对自然环境造成直接破坏。在混凝土中使用高掺量粉煤灰取代 2 5 %以上的水泥 ,可最大限度地减少水泥熟料用量 ,从而减少水泥生产中产生的CO2 、SO…     

基于遗传算法的半导体激光器温度智能控制系统

半导体激光器输出波长随温度变化会发生漂移,影响其精度及使用寿命,为了使半导体激光器稳定工作,要保持它的温度稳定。设计了基于遗传算法的半导体激光器智能温度控制系统,采用MATLAB进行仿真,验证了温控系统的应用效果。     

Triazole and Pyridine Hybrid Molecules as Electron-Transport Materials for Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes

A series of triazole and pyridine hybrid molecules, with a triazole core and pyridine periphery, were designed and synthesized as an electron-transport layer (ETL) and a hole/exciton-block layer for green phosphorescent organic light-emitting diodes. Compared with the widely-used electron-transport material (ETM) of 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ) with a triazole core, lower-lying HOMO and LUMO energy levels were obtained with the introduction of pyridine rings onto the periphery of the molecules, giving improved electron injection and carrier confinement. Significantly reduced driving voltages were achieved in a device structure of ITO/HATCN (5 nm)/TAPC (40 nm)/CBP:8 wt % Ir(PPy)₃ (10 nm)/ETL (40 nm)/LiF (1 nm)/Al (90 nm), giving a maximum power efficiency of 72.2 lm W⁻¹ and an external quantum efficiency of 21.8 %, due to the improved electron injection and transport and thus, more balanced carrier recombination, which are much higher than those of the device based on TAZ.     

基于天然多糖的绿色表面活性剂

多糖是自然界中储量最大的天然高分子，其分子链通常具有结构上的两亲性，能够较好地吸附在相界面上并表现出改善固-液、液-液之间相容性的能力。 此外，多糖独特的理化结构使其在溶液中具有良好的流变学性质以及形成凝胶网络的能力，使多糖能够在较低表面活性下体现出较好的界面吸附能力，常被用于多相体系的乳化、分散、增稠和稳定。通过化学改性可对天然多糖进行亲水-疏水平衡，并赋予其一定的化学活性、表面电荷、流变性能等，能够获得性能更加优异的绿色大分子表面活性剂。基于此，该文主要介绍了多糖在表面活性剂中的应用，主要包括纤维素、淀粉、半纤维素、甲壳素、天然树胶等，并从多糖独特的理化性质、结构以及改性特点出发，剖析其对乳化、分散、破乳、增溶等表面活性作用的影响，阐述多糖及其衍生物在表面活性剂中的研究进展及应用潜力。 最后，对多糖表面活性功能增强改性的发展方向进行了展望。     

Defect-free Poly(9,9-bis(2-ethylhexyl)fluorene-2,7-vinylene) for Polymer Light-Emitting Diode (PLED) Devices

The π-conjugated light-emitting polymer poly(9,9-bis(2-ethylhexyl)fluorene-2,7-vinylene) (PEHFV), was synthesized in defect-free form via Horner-Emmons coupling. The structure and properties of the polymer were characterized by ¹H NMR, ¹³C NMR, UV-vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies as well as gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The weight-average molecular weight (M_w) and polydispersity of the PEHFV were 34,000 g/mol and 2.3, respectively. The UV-vis spectra showed absorption maxima at 425 and 452 nm, and the PL emission spectra showed a maximum at 505 nm with a shoulder at 541 nm. The polymer was soluble in common organic solvents and easily spin-coated on indium-tin oxide (ITO)-coated glass substrates. A double-layer light-emitting device with an ITO/PEDOT:PSS/PFV/Al configuration was fabricated. The turn-on voltage for the PEHFV device was observed at 3.0 V.     

高品质噻虫嗪的绿色合成研究

以3-甲基-4-硝基亚胺基全氢化-1,3,5-噁二嗪和2-氯-5-氯甲基噻唑为原料,碳酸钾为缚酸剂,臭氧为脱色剂,一锅法制得白色噻虫嗪结晶,收率92.0%(以2-氯-5-氯甲基噻唑计),含量99.2%。此方法具有实验操作简便、产品收率及含量较高、三废量少等优点,符合绿色化工和清洁生产的要求,适合工业化生产。     

Hybrid Organic Light-Emitting Diodes with Low Color-Temperature and High Efficiency for Physiologically-Friendly Night Illumination

Low color-temperature (CT) light sources are preferred for physiologically-friendly illumination at night due to their low suppression of melatonin secretion. We fabricated low-CT hybrid organic light-emitting diodes (OLEDs) by constructing a double emissive-layer (EML) structure, with a blue-red fluorescent-phosphorescent hybrid EML and a green phosphorescent EML, separated by a bipolar interlayer. By doping a red phosphor in a blue fluorescent mixed-host with a decent concentration, blue and red emissions from the host and dopant, respectively, were obtained. The CT of the optimized device was tuned to less than 2500 K, with the brightness ranging from 100 to 10,000 cd m⁻². In addition, the low-CT OLED exhibited much higher efficacy than other low-CT light sources, such as incandescent bulbs and candles. The maximum power efficiency and external quantum efficiency of the hybrid OLED reached 54.6 lm W⁻¹ and 24.3 %, respectively, which only rolled off to 44.2 lm W⁻¹ and 23.6 % at 1000 cd m⁻², with a CT of 1910 K. Low-CT OLEDs with high efficacy provide a promising alternative for night lighting that will safeguard human health.     

高性能砼--绿色砼

绿色高性能砼不仅具有良好的耐久性、工作性、力学性能及经济合理性,还具有节能、环保等特点。文章从节约资源、能源、提高砼耐久性及保护环境的角度,阐述了发展绿色高性能砼的必要性,对高性能砼存在的造价高、早期开裂等问题提出了解决办法。重点介绍了ＨＰＣ配合的设计方法。