Correlation between hue angle and lightness of light irradiated wood

The objective of this study was to investigate irradiation characteristics of Beech (Fagus crenata Blume), black locust (Robinia pseudoacacia L.), Japanese cedar (Cryptomeria japonica D. Don) and spruce (Picea abies Karst.) wood samples by sunlight, xenon light and mercury vapour light. The colour change of the samples was evaluated by CIE L*a*b* and L*h*c* colour co-ordinate systems. It was found that the samples showed a rapid colour change at the initial period of treatment but the rate of change decreased with treatment time. It was determined that neither xenon nor mercury lamp light can accurately simulate sunlight. A wide range of colour changes were caused by the applied light sources. In spite of this wide colour range a good linear correlation was found between the lightness and the colour hue. The coefficients of determination (R²) are between 0.7 and 0.96. Accordingly, this linear correlation gives the possibility of following the colour change during photodegradation by measuring only the lightness.     

1-(2-苯并咪唑)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与镉(Ⅱ)的显色反应

报道了1-(2-苯并咪唑)-3-[4-(苯基偶氮)苯基]-三氮烯(PIPAPT)的合成及与镉(Ⅱ)的显色反应。在非离子表面活性剂OP存在下,于pH 11.0 Na2B4O7-NaOH缓冲体系中,试剂与镉(Ⅱ)形成4∶1的橘红色配合物,其最大吸收波长位于523 nm,表观摩尔吸光系数为1.19×105L.mol-1.cm-1。镉质量浓度在0~0.7μg/mL范围内符合比尔定律。方法可用于水中微量镉的测定。     

1-transitive cyclic orderings

We give a classification of all the countable 1-transitive cyclic orderings, being those on which the automorphism group acts singly transitively. We also classify all the countable 1-transitive coloured cyclic orderings, where these are countable cyclic orderings in which each point is assigned a member of a set C, thought of as its ‘colour’, and by ‘1-transitivity’ we now mean that the automorphism group acts singly transitively on each set of points coloured by a fixed colour. We conclude by giving constructions of some uncountable cyclic orderings whose automorphism groups enjoy certain special properties.     

Al3+对Ge/Al-SiO2薄膜光致发光的影响

采用磁控溅射及后退火技术制备了不同组份和不同退火温度的Ge、Al共掺SiO₂薄膜。通过对样品的X射线光电子能谱(XPS)测试,确定了薄膜的成分和结构特征;同时还测试了样品的光致发光谱(PL谱),得到了峰值位于420 nm附近的紫光发射峰和峰值位于470 nm的蓝光发射峰。实验结果表明, Al的掺杂不仅可以显著地提高GeNOV中心和SiNOV中心的光发射效率,还可以促进GeNOV缺陷和SiNOV缺陷中心的形成,进而有利于薄膜的光致发光。     

Nitrogen-Doped TiO2 Nanotubes-Catalyzed Synthesis of Small D-π-A-Type Knoevenagel Adducts and β-Enaminones

For the first time, interstitial nitrogen-doped TiO₂ nanotubes (INDTNTs) have been utilized as heterogeneous green catalysts for the synthesis of D-π-A-type Knoevenagel adducts ( 3 ) and β-enaminones ( 6 ). Notable advantages of the present method include its wide substrate scope, low catalyst loading, avoiding the use of hazardous bases and solvents, products do not require chromatographic purification, high yields, catalyst reusability, etc. The optimized catalyst, INDTNTs-4 has been characterized by XRD, HRTEM, and XPS techniques. The photophysical and electrochemical properties of D-π-A-type 3 and 6 have been evaluated. The study revealed that the colour tunability (cold white light to orange light) and the HOMO/LUMO levels depend mainly on the presence of various electron donating and withdrawing groups on the aromatic/heteroaromatic rings of 3 and 6 . The results indicate that the D-π-A-type 3 and 6 could be promising materials for the fabrication of optoelectronic devices.