Cyan Light Research Articles

Sealant Inspection System with Ambient Light Reduction Using YCbCr Color Space and Cyan Light

Recently, a variety of manufacturing has been being developed. In production lines of the factories, automatic inspection systems with lower cost and higher precision are expected. In existent inspection systems, image processing technologies are widely applied. However, the inspection systems using image processing cannot be applied in some conditions with optical limitations, i.e., room light or sunlight can greatly affect the performance. Another problem is high cost for capital investment of the inspection systems. In order to solve these problems, an image processing method using the YCbCr color space characteristics and cyan light is proposed. Our proposed method is effective on morphological operation processing. As an implementation of the proposed method, an inexpensive system was developed. The inspection system with image processing was realized for reducing the influence of ambient light.

Unique sharp photoluminescence of size-controlled sonochemically synthesized zirconia nanoparticles

The present study explores the features of tetragonally stabilized polycrystalline zirconia nanophosphors prepared by a sonochemistry based synthesis from zirconium oxalate precursor complex. The sonochemically prepared pristine zirconia, 3mol%, 5mol% and 8mol% yttrium doped zirconia nanophosphors were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The reaction mechanism of formation of zirconia nanophosphors is discussed in detail. The probable sonochemical formation mechanism is being proposed. Stabilization of tetragonal phase of pristine zirconia even at room temperature was effectively established by controlling the particle size using ultrasonic waves. Improved phase purity and good surface morphology of the nanophosphors is being achieved via sonochemical route. FE-SEM micrographs reveal that the nanoparticles have uniform spherical shape and size. The narrow particle size distribution (∼15–25nm) of the zirconia nanoparticles was found from FE-SEM statistical analysis and further confirmed by TEM. Zirconia nanophosphors exhibit a wide energy band gap and which was found to vary with yttrium dopant concentration. The highlight of the present study is the synthesis of novel nanocrystalline ZrO2 and Y-ZrO2 phosphor which simultaneously emits extremely sharp as well as intense UV, violet and cyan light on exciting the host atom. The yttrium ion dopant further enhances the photoluminescence property of zirconia. These nanocrystalline phosphors are likely to have remarkable optical applications as light emitting UV-LEDs, UV lasers and multi color displays.

Phosphorescent Sensor Based on Iridium Complex/Poly(vinylcarbazole) Orderly Assembled with Layered Double Hydroxide Nanosheets: Two-Dimensional Föster Resonance Energy Transfer and Reversible Luminescence Response for VOCs

The application study of phosphorescence complexes is important for further investigation and exploration of novel optofunctional materials. In this work, neutral poly(vinylcarbazole) (PVK) and tris[2-(4,6-difluorophenyl)pyridinato-C2,N]iridium(III) (Ir(F2ppy)3) were assembled with LDH nanosheets to form ordered ultrathin films (UTFs). These inorganic/organic composite UTFs exhibited cyan luminescence from Ir(F2ppy)3, peaking at 471 and 491 nm, due to triplet metal-to-ligand charge transfer and ligand-centered states, respectively. Under PVK maximal excitation at 294 nm, the photoluminescence spectra of the UTFs showed emission from Ir(F2ppy)3 rather than from PVK, demonstrating PVK transfer of resonance energy to Ir(F2ppy)3. Temporal luminescence spectroscopy revealed that the phosphorescence lifetime of Ir(F2ppy)3 molecules increased to 885 ns and fluorescence lifetime of PVK fell to 1.39 ns in the UTFs, which was typical character of the FRET process. This FRET process occurred within the interlayers of LDH nanosheets and can be described as a two-dimensional (2D) process with high efficiency (0.892). Moreover, it was found that the presence of volatile organic compound (VOC) vapors can interrupt this 2D process because of the unique hydrophobic character of the organic interlayers within the UTFs. This function was utilized for a phosphorescent sensor that enables reversible two-state photoemission switching (ON for cyan light of Ir(F2ppy)3 vs OFF for blue light of PVK). This phosphorescence sensor demonstrated a fast, highly sensitive, and reversible response toward common VOCs, and this 2D FRET with energy transfer involving the D(singlet) → A(triplet) process was more efficient compared with that of singlet–singlet processes. That is, to get the same luminescence intensity, these UTFs can be realized by less frequent excitation of PVK or lower concentrations of Ir(F2ppy)3 compared with intrinsic excitation of Ir(F2ppy)3.

Effect of light quality on growth, photosynthesis and effective components of Panax notoginseng

In order to discover light quality's effects on growth, photosynthesis and effective components content of Panax notoginseng, a pot experiment using 7 light qualities (red, orange, yellow, green, cyan, violet, and blue) was conducted. The growth, photosynthesis and content change of effective components were measured during plant growth. The results showed that light qualities had significant effect on plant growth, red light increased the plant height, while cyan, yellow, violet, and blue lights promoted accumulation of biomass underground, blue and yellow lights increased the photosynthesis, cyan light increased accumulation of ginsenoside Rd, yellow and cyan lights increased total effective components of individual plant.

Lateral charge carrier diffusion in InGaN quantum wells

AbstractWe investigated lateral charge carrier transport in indium gallium nitride InGaN/GaN multi‐quantum wells for two different samples, one sample emitting green light at about 510 nm and the other emitting cyan light at about 470 nm. For the cyan light emitting sample we found a diffusion constant of 1.2 cm2/s and for the green light emitting sample 0.25 cm2/s. The large difference in diffusion constant is due to a higher point defect density in the green light emitting quantum wells (QWs) as high indium incorporation tends to reduce material quality.

A novel kind of coordination polymers employing 2,5-diamino-1,4-benzenedithiol as a bridging ligand: synthesis, structure, optical and magnetic properties

A serials of organo-soluble transition metal–DABDT coordination polymers were successfully synthesized by the coordination of transition metal ions and DABDT. These coordination polymers were characterized by FTIR, TGA, XRD, UV-Vis spectroscopy, fluorescence spectroscopy, TEM, and vibrational sample magnetometry. Results showed that DABDT coordinated transition metal ions by its amino and sulfydryl groups. The coordination polymers of Co–DABDT, Ni–DABDT, Cu–DABDT and Zn–DABDT exhibited crystal or semi-crystal characteristics, while Fe–DABDT was almost amorphous. The synthesized coordination polymers were soluble in the mixed solvent of DMF and DMSO (volume ratio, 1:1). The main UV-Vis absorptions of the as-synthesized transition metal–DABDT coordination polymers were below 400 nm in the ultraviolet region. These coordination polymers emitted cyan light in the DMF and DMSO mixed solution, especially for Zn–DABDT, which emitted obviously stronger cyan light than the other coordination polymers. Fe–DABDT exhibited superparamagnetic character in the approximate range of −5000 G to +5000 G and simple paramagnetic character in the other fields. Co–DABDT and Ni–DABDT followed simple paramagnetic behavior. TEM analysis showed that Ni–DABDT were porous nanospheres with an average diameter of about 69 nm. The rigid molecules of Ni–DABDT arrayed in parallel in the coordination polymer sphere. And Co–DABDT also showed a lamellar structure. The rigid coordination polymer molecules arrayed in parallel due to the formation of hydrogen bond between the –SH and –NH2 groups of adjacent molecular chains in the same plane. And the arrangement between different molecular layers was stacked layer upon layer on account of the π–π stacking of the coordination polymer chains. The solubility of the prepared coordination polymers enabled us to carry out a first-time study on their photophysical behavior. What's more, this is the first time to report the planar and lamellar structure of the transition metal-DABDT coordination polymers through TEM analysis.

A ruthenium(ii) complex with environment-responsive dual emission and its application in the detection of cysteine/homocysteine

A ruthenium polypyridine complex [Ru(phen)(2)(IPBA)](PF(6))(2) (complex 1) (IPBA = 4-(1H-imidazo[4,5-f][1,9]phenanthroline-2-yl)benzaldehyde), which displays environment-responsive dual emissive properties, was designed and synthesized. In aprotic solvent, such as DMSO, DMF or CH(3)CN, the complex emits strong cyan light. When in protic solvent, it emits orange light. Similarly, the response of the complex to homocysteine and cysteine (Hcy/Cys) also shows obvious solvent dependence. TDDFT calculations reveal that the protonation of imidazole nitrogen in protic solution is responsible for the luminescent red shift. Hence, the complex could be used to detect Hcy/Cys in aprotic solvent, as well as in protic solvent.

Synthesis, Optical and Electrochemical Properties of Novel 3,4-Dialkyloxythiophene-Based D-A-D Organic Conjugated Molecules

基于Wittig反应合成了新型D-A-D型有机半导体材料——双（2-乙烯基-3,4-二烷氧基噻吩）-对-2,5-二苯基-1,3,4-噁二唑[（3,4DAOTV）2-OXD],用核磁共振氢谱（1HNMR）、傅里叶变换红外（FTIR）光谱、高效液相色谱（HPLC）和元素分析法（EA）对化合物的结构进行分析和表征.用紫外-可见（UV-Vis）光谱、荧光（PL）光谱及电化学分析研究其光学和电化学性能.在氯仿溶液中,各化合物的紫外最大吸收波长（λmabasx）在382-383nm之间,光学带能隙在2.92-2.97eV之间,荧光最大发射波长在448-452nm之间,发出明亮的青色光,荧光量子产率可达36.8%-37.6%;在固体薄膜状态下,各化合物于513-516nm处发射出亮蓝绿色光.循环伏安法研究显示：三种大π共轭分子在正、负向区域均表现出明显的氧化、还原现象.其中,5.65-5.70eV的电离势（Ip）,与噻吩类有机半导体材料的空穴传输特征相符;电子亲和势（Ia）在2.74-2.88eV之间,与有机电子传输材料的特性相近,这利于电子从阴极的注入和传输.理论计算结果表明,该D-A-D型共轭分子共平面性好和电荷离域程度高,对光电功能材料的分子界面组装、载流子的有效传输和器件量子效率的提高十分有利.

Crystal Structure and Raman Studies of dsFP483, a Cyan Fluorescent Protein from Discosoma striata

To better understand the diverse mechanisms of spectral tuning operational in fluorescent proteins (FPs), we determined the 2.1-Å X-ray structure of dsFP483 from the reef-building coral Discosoma. This protein is a member of the cyan class of Anthozoa FPs and exhibits broad, double-humped excitation and absorbance bands, with a maximum at 437–440 nm and a shoulder at 453 nm. Although these features support a heterogeneous ground state for the protein-intrinsic chromophore, peak fluorescence occurs at 483 nm for all excitation wavelengths, suggesting a common emissive state. Optical properties are insensitive to changes in pH over the entire range of protein stability. The refined crystal structure of the biological tetramer (space group C2) demonstrates that all protomers bear a cis-coplanar chromophore chemically identical with that in green fluorescent protein (GFP). To test the roles of specific residues in color modulation, we investigated the optical properties of the H163Q and K70M variants. Although absorbance bands remain broad, peak excitation maxima are red shifted to 455 and 460 nm, emitting cyan light and green light, respectively. To probe chromophore ground-state features, we collected Raman spectra using 752-nm excitation. Surprisingly, the positions of key Raman bands of wild-type dsFP483 are most similar to those of the neutral GFP chromophore, whereas the K70M spectra are more closely aligned with the anionic form. The Raman data provide further evidence of a mixed ground state with chromophore populations that are modulated by mutation. Possible internal protonation equilibria, structural heterogeneity in the binding sites, and excited-state proton transfer mechanisms are discussed. Structural alignments of dsFP483 with the homologs DsRed, amFP486, and zFP538-K66M suggest that natural selection for cyan is an exquisitely fine-tuned and highly cooperative process involving a network of electrostatic interactions that may vary substantially in composition and arrangement.

Preparation and characterization of an Hf4+-doped zinc silicate long-lasting phosphorescent material

Hf4+-doped Zn2SiO4 phosphor emitting long-lasting cyan light was prepared by the conventional high temperature solid-state technique. The emission spectrum of the Hf4+-doped phosphor exhibits one broad band peaking at 471 nm in the visible region excited by 254 nm. The cyan-light afterglow can last about 40 min in darkness after being irradiated with 254 nm UV lamp for 10 min (250 mW/cm2). The afterglow decay curve can be fitted into a second-order exponential curve. The thermoluminescence (TL) curve shows two glow bands centered at about 386 K (0.61 eV) and 440 K (1.56 eV), respectively, with the lower trap energy level being responsible for the long-lasting afterglow emission. A possible mechanism of the long-lasting phosphorescence based on the experimental results is proposed.