Melamine trisulfonic acid-catalyzed N-formylation of amines under solvent-free conditions

A highly convenient method for N-formylation of amines via treatment by formic acid in the presence of melamine trisulfonic acid as a catalyst has been developed. This method showed improvements over previous reports in terms of yield, reaction time and chemoselectivity.     

THE COMPACTION OF TIME-DEPENDENT VISCOUS GRANULAR MATERIALS CONSIDERING INERTIAL FORCES

In the present paper, compactions of time-dependent viscous granular materials are simulated step by step using the automatic adaptive mesh generation schemes. Inertial forces of the viscous incompressible aggregates are taken into account. The corresponding conservation equations, the weighted-integral formulations, and penalty finite element model are investigated. The fully discrete finite element equations for the simulation are derived. Polygonal particles of aggregates are simplified as mixed three-node and four-node elements. The automatic adaptive mesh generation schemes include contact detection algorithms, and mesh upgrade schemes. Solutions of the numerical simulation are in good agreement with some results from literatures. With minor modification, the proposed numerical model can be applied in several industries, including the pharmaceutical, ceramic, food, and household product manufacturing.     

Synthesis and mesomorphic properties of novel tolane-type liquid crystals

Two series of novel tolane-type liquid crystals(LCs) comprising of hydrogen-bonded organic acids were synthesized.The formation of dimerized H-bond LCs was confirmed by IR spectroscopy,and mesomorphic properties of the LCs were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties.     

N-二氯乙酰基噁唑烷合成反应的薄层色谱法研究

用薄层色谱法监测了用二氯乙酰氯、醇胺和酮合成的除草剂的安全剂N 二氯乙酰基 口恶唑烷的反应过程。方法操作简便、快速、准确。     

南昌市前湖区春季鸟类群落结构

2007年3～5月我们通过调查南昌市前湖区春季鸟类群落结构,结果表明共记录了959只鸟类个体,隶属于11目、26科、54种,其中雀形目和鹳形目鸟类属于绝对的优势目.鸟类居留型组成不管是个体数量还是种数的分布,留鸟占有的比例都最高,分别为45%和41%.前湖地区鸟类群落多样性指数为2.86,均匀度指数为0.72.在划分的7个生境中,洼地群落具有最高的多样性和均匀度,分别为2.93和0.92.总之,前湖地区生境受到人类活动影响深刻,该区分布的优势种主要为一些与人类关系比较密切的伴生种.     

Liposome Electrokinetic Chromatography: An in vitro Approach for Predicting Ecotoxicity

Liposome electrokinetic chromatography (LEKC) is a powerful tool for the study of drug membrane interactions. An investigation of the use of the retention in LEKC as an in vitro approach to predict the ecotoxicity is proposed. The ecotoxicity parameters (LC₅₀ in fish, daphnia and mysid shrimp, EC₅₀ in green algae and daphnia, and values of chronic ecotoxicity in fish and green algae) for 15 aromatic compounds were extracted from ECOTOX database from the US Environmental Protection Agency. Quantitative retention–activity relationship (QRAR) models for the estimation of ecotoxicity were established. The r ² of the fitted linear equations ranged from 0.80 to 0.87, which suggested good correlation between the retention in LEKC and the ecotoxicity parameters. The predictive ability of the models was evaluated by cross-validation. The results obtained indicated the usefulness of the LEKC systems investigated for the rapid ecotoxicity assessment of aromatic compounds.     

p‐Methoxy­benz­aldehyde benzoyl­hydrazone monohydrate

The crystal structure of the title compound, C₁₅H₁₄N₂O₂·H₂O, is in the keto tautomeric form and the configuration at the azomethine C=N double bond is E. The mol­ecule is non‐planar, with a dihedral angle of 27.3 (1)° between the aromatic rings. The crystal structure is stabilized by extensive hydrogen bonding involving the water mol­ecule and hydrazone moiety.     

Red Electroluminescence and Photoluminescence from Novel Binuclear Europium Complex with Squaric Acid Ligand

Organic electroluminescent devices (OELDs) have attracted much attention for several years because of their potential application in large area, multi-colored flat panel displays1-5. The green organic EL display using Alq3 as emitter was commercialized in 19976. However, red-emitting OELD with excellent properties has not been well developed. In order to realize practical full-color OELDs, it is considered very important to develop red and blue emitting materials with excellent propert…