Supramolecular isomerism in the hydrogen-bonded network of (5<Emphasis Type="Italic">R</Emphasis>,10<Emphasis Type="Italic">R</Emphasis>)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-<Emphasis Type="Italic">cde</Emphasis>]chromene monohydrate

A new compound (5R, 10R)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-cde]chromene monohydrate was obtained from 3,4-dihydroxybenzaldehyde in aerobic basic aqueous ethanol solution in the presence of manganese chloride and triethylamine and crystallized in orthorhombic P2₁2₁2₁ space group (denoted as 1). When 1 was recrystallized from aqueous methanol, it was transformed to another crystal (2) with the same composition but in P2₁/n space group. The drastic difference in the extensive hydrogen bond network makes 1 a 3D and 2 a 2D infinite supramolecular structure, respectively.     

树脂吸附法处理3,6-二氯水杨酸生产废水

研究了树脂吸附法处理3,6-二氯水杨酸生产废水的工艺过程。结果表明,NDA-77吸附树脂对该废水具有良好的吸附-脱附效果。经树脂吸附处理,废水中主要有机污染物2,5-二氯苯酚和3,6-二氯水杨酸均得到去除,总有机碳(TOC)由210mg/L降为20mg/L以下,吸附饱和的树脂可采用稀碱液实现完全再生。经吸附处理去除有机物后,废水中含有20%的KCl,可进入工厂现有的KCl隔膜电解装置,用于KOH的生产。     

Contribution of UV light to the decomposition of toluene in dielectric barrier discharge plasma/photocatalysis system

The contribution of UV light from plasma and an external UV lamp to the decomposition of toluene in a dielectric barrier discharge (DBD) plasma/UV system, as well as in a plasma/photocatalysis system was investigated. It was found that UV light from the DBD reactor was very weak. Its contribution to the removal of toluene in the plasma/photocatalysis system could be ignored. Whereas, the introduction of external UV light to the plasma significantly improves the removal efficiency of toluene by 20%. The removal efficiency of toluene in the plasma/photocatalysis system increased about 22% and 16% when compared with a plasma only system and plasma driven photocatalyst system, respectively. The increased toluene removal efficiency was mostly attributed to the contribution of the synergy between plasma and UV light, but not to the synergy between plasma and photocatalysis. The synergetic effect between plasma and photocatalysis was not significant.     

Determination of pesticides in water by cone-shaped membrane protected liquid phase microextraction prior to micro-liquid chromatography

A new sample pre-treatment technique termed cone-shaped membrane liquid phase microextraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Four pesticides (hexaconazole, procymidone, quinalphos and vinclozolin) were considered as target analytes. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were optimized. Enrichment factors of > 50 folds were easily achieved within 20 min of extraction. The analytical data demonstrated relative standard deviations for the reproducibility of the optimized CSM-LPME method ranging from 6.3 to 7.5%. The correlation coefficients of the calibration curves were at least 0.9995 across a concentration range of 2-100 microg/L. The detection limits for all the analytes were found to be in the range of 1.1-1.9 microg/L.     

纤维素的均相化学反应

本文回顾了近10多年来的纤维素均相反应发展过程,研究了PF/DMSO、LiCl/DMAc、N₂O₄/DMF、苯/DMSO、LiCl/DMI和水等溶剂体系的纤维素均相反应条件(如酯化反应、交联反应、醚化反应、接枝共聚等),并总结了纤维素均相衍生化的分析方法,讨论了各种方法的优缺点以及发展前景.     

PEG辅助氧化锌纳米棒的水热法制备

采用PEG辅助水热法合成了ZnO纳米棒,XRD显示产物为结晶良好的六角结构晶体ZnO,PL谱表明适当退火处理后产物有较好的光致发光性能.利用TEM和SAED研究了纳米棒的形貌和生长机制,并研究了氢氧化钠浓度和反应时间对产物形态和尺寸的影响.     

Composite Electrode SnO2／TiO2 for Dye-Sensitized Solar Cells

Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.     

First Total Synthesis of (±)-Aiphanol

Aiphanol was isolated from the seeds of Aiphanes aculeate Willd. (Arecaceae) collected in Peru and was reported to exhibit significant inhibitory activities against cyclooxyge- nases-1 and -2. The structure of aiphanol was elucidated by spectroscopic methods as an unprecedented stilbenolignan skeleton in which a stilbene moiety is linked to a phenylpropane unit through a dioxane bridge1. In our previous works the synthetic approach to 1,4-benzodioxane lignans were achieved2. Since aiphanol…     

Formation and photoluminescence of silver nanoparticles stabilized by a two-armed polymer with a crown ether core

Silver nanoparticles were synthesized by the use of a two-armed polymer with a crown ether core [poly(styrene)]-dibenzo-18-crown-6-[poly(styrene)] based on the flexibility of the polymer chains and the complex effect of crown ether with Ag(+) and Ag. The size of silver nanoparticles could be tailored by controlling the initial concentrations of the polymer and Ag(+), and the molecular weight of the polymer. The emission of silver nanoparticles was blue-shifted, and the intensity of the photoluminescence of silver nanoparticles stabilized by the polymer was significantly increased due to the complex effect between the crown ether embedded in the polymer and the silver nanoparticles.     

Identification and quantification of 13 components in Angelica sinensis (Danggui) by gas chromatography-mass spectrometry coupled with pressurized liquid extraction

Angelica sinensis (Danggui in Chinese), a well-known traditional Chinese medicine, is also used as a health food product for women's care in Europe and America. Therefore, the demand for Danggui is enormous throughout the world. Due to the shortage of Angelica sinensis, Angelica acutiloba and Angelica gigas are commonly used as the substitutes of Danggui in the market of southeast Asia. However, the three common Angelica roots showed variation in their genetic and chemical composition. Up to date, it is thought that ferulic acid, ligustilide and other phthalides such as butylidenephthalide are the biologically active components of Danggui. In this paper, the contents of 13 compounds including ferulic acid, Z-ligustilide, E-ligustilide, Z-butylidenephthalide, E-butylidenephthalide, 3-butylphthalide, 3-butylidene-4-hydroxyphthalide, senkyunolide A, 6,7-epoxyligustilide, senkyunolide F, senkyunolide H, senkyunolide I, and 6,7-dihydroxyligustilide were determined or estimated by using gas chromatography-mass spectrometry (GC-MS) coupled with pressurized liquid extraction (PLE). The results showed that GC-MS coupled with PLE offered a simple, rapid and high sensitive method to analysis of components in Angelica root. And the contents of investigated compounds in Angelica sinensis, Angelica acutiloba and Angelica gigas, which are used as Danggui in China, Japan and Korea, respectively, were highly variant. It is thought that interaction of multiple chemical compounds contributes to the therapeutic effects of Chinese medicines. However, the overall clinical efficacy of these different Danggui has not been determined. Therefore, comparison of chemical components and pharmacological activities of different Angelica root is helpful to elucidate the mechanism of therapeutic effects of Danggui.