Authors:Shi Xu, Sheng Li, Yun Wei, Li Zhang and Fei Xu
Titanium dioxide (TiO2), polythiophene and polythiophene/TiO2 were prepared by sol–gel and solid-state reaction methods. Water-free iron(III) chloride (FeCl3) was used as an oxidant. The phase composition, morphology and the spectral properties of the products were characterized by XRD, TEM, UV–Vis and FT-IR techniques. The photocatalytic activity of the products was evaluated by the degradation of methyl orange under sunlight irradiation. TEM results showed that the polythiophene/TiO2 composite particles were well dispersed, rod-like shaped with 20 × 80 nm dimensions. UV–Vis analysis indicated that the absorption edge of polythiophene/TiO2 was 605 nm. Compared with the unmodified TiO2 and bare polythiophene, polythiophene/TiO2 exhibited largely enhanced activity for the photocatalytic degradation of methyl orange under sunlight irradiation. A degradation efficiency of methyl orange of 85.6% could be obtained within 120 min. The sensitization mechanism of polythiophene for the TiO2 photocatalyst is discussed briefly.
Authors:Gui-Hua Gu, Da-Jian Yang, Shi-Yun Wang, Wei Zeng, Wei Wang and Jing-Song Yuan
A high-performance liquid chromatography—diode-array detection method was developed and validated to determine simultaneously eleven major alkaloids in Corydalis decumbens (Thunb.) Pers. The alkaloids detected were corlumidine, protopine, coptisine, tetrahydrojatrorrhizine, palmatine, berberine, sanguinarine, papaverine hydrochloride, tetrahydropalmatine, bicuculline, and corydaline. Chromatographic separation was achieved using a C-18 column with a mobile phase composed of A (0.2% acetic acid solution, adjusted with triethylamine to pH 5.0) and B (acetonitrile), with stepwise gradient elution. Ultraviolet diode-array detection was used; chromatograms were examined at the wavelength of 280 nm. The regression equations showed a good linear relationship between the peak area of each marker and concentration (r = 0.9994–0.9999). The recovery values ranged between 93.66% and 100.54%. The method was fully validated with respect to detection and quantification limits, precision, reproducibility, and accuracy. The described high-performance liquid chromatography (HPLC) method was successfully used for the differentiation and quantification of the eleven major alkaloids in C. decumbens (Thunb.) Pers. and can be considered an effective procedure for the analyses of this important class of natural compounds.
Authors:Lun-cun Wei, Yun-cheng Zhong, Jian-wei Han, Bin Liang, Xiao-tang Ren, Jin-xiang Yu and Ren-xing Li
By using the coincident measurement, an ERD method has been established and used for hydrogen profiling in thin foils. In the present study, 6 MeV has been used as incident particle, the scattered and the recoiled proton from one collision were coincidentally detected at 150 (proton) and 173.9 (). This method has been used for hydrogen profiling of 5.6 m Mylar and 8.6 m aluminium foils. Because of the coincident measurement, the background is largely reduced, and its minimum detection limit is about 0.5% (atomic), lower than the conventional ERD method. The measured depth resolution in 5.6 m Mylar is 0.6 m. It is possible to use this method for hydrogen profiling in thin foils of several micron thickness.
Authors:Jian Feng, Wei Xiong, Yun Jia, Jinbo Wang, Derong Liu and Ruixiang Qin
The hydrogenation of biomass-derived ethyl lactate was studied over several ruthenium catalysts (Ru/TiO2, Ru/SiO2, Ru/γ-Al2O3, Ru/NaY and Ru/C), with the intent of developing a simple and additive-free catalytic system. The catalytic performance is dependent on the nature of the support. Ru/SiO2 was found to be an efficient catalyst for the hydrogenation of ethyl lactate to 1,2-propanediol (1,2-PDO). Parametric studies show that the reaction temperature, hydrogen pressure and catalyst amount can significantly influence the catalytic performance. Under optimal reaction conditions (433 K, 5 MPa), high yield of 1,2-PDO (82.1%) was obtained without the introduction of any additives. Form a practical point of view, this study may open the way to a new approach for the production of 1,2-PDO.
Authors:Xingfeng Li, Cheng Jin, Wei Liu, Jian Zhou, Weijun Kong, Bing Dai, Jiabo Wang, Dan Yan, Yanling Zhao, Yun Luo and Xiaohe Xiao
Using microcalorimetry, the characteristic metabolic heat flow power-time curves of S. aureus growth affected by Ursodesoxycholic acid and Hyodeoxycholic acid were measured at 37 °C. The thermal-kinetic parameters such as, growth rate constant k, the maximum power output (Pm), the time corresponding to the maximum power output (tp), total heat-production Qt, half inhibitory concentration of the drugs (IC50) were calculated from the growth curves. For both HDCA and UDCA, with the increasing of concentration, k, Pm, and Qt decreased, meanwhile, k–c fit a linear equation, tp was prolonged correspondingly. Principle component analysis, the results indicated tp might be the main parameter in evaluating the antibacterial activity of HDCA and UDCA in microcalorimetric method. Combining with tp and IC50, the results revealed that the differences and trends of antibacterial activity of these bile acid derivatives were: HDCA > UDCA. Structure-activity relationship (SAR) analysis showed that the α-OH at C-3 and C-6 position at equal pace on the steroid nucleus enhanced the hydrophilicity of HDCA, which led to a stronger antibacterial effect than UDCA. In this study, a useful tool was provided to accurately evaluate the antibacterial effects of bile acid derivatives. The thermolysis curve recorded by microcalorimetry could provide a lot of kinetic and thermodynamic information for the study of growth process of living microbial, which could be helpful in the screening of high efficacy antibacterial agents.
Authors:Guo Jin-xin, Sun Si-xiu, Zhu Rong-xiu, Yin Zhi-lei, Yu Hai-yun, Li Da-zhi, Zhang Wei-min, Xu Xian-gang, Sun Xuan and Shao Hua
The mechanism of solvent extraction of uranium(VI) from highly concentrated chloride solution with a quaternary ammonium salt,
benzyloctadecyldimethylammonium chloride (BODMAC, R4NCl), dissolved in chloroform was studied. The compositions of the extracted species were R4N.UO2Cl3 and (R4N)2.UO2Cl4. The extraction process is exothermic (ΔH° = -8.42±0.54 KJ/mol). Kex1 and Kex2 are calculated to be (3.62±0.55).10-2 and (1.06±0.17).103, respectively. In the extraction process, a W/O uranium(VI) rich emulsion solution has been formed between the organic and
aqueous phases, its volume increased with the increase of BODMAC in the system. The influences of temperature, NaCl, MgCl2 and MgSO4 concentrations on the extraction equilibrium were also studied.
Authors:Jun Yuan, Wei Yue, Cheng Su, Zheng Wu, Zheng Ma, Yun Pan, Nan Ma, Zhi Hu, Fei Shi, Zheng Yu and Yi Wu
This research intends to investigate the patent activity on water pollution and treatment in China (1985–2007), and then compares
the results with patents data about Triadic patents, South Korea, Brazil and India over the same periods, patents data were
collected from Derwent World Patents Index between 1985 and May 2008. For this study, 169,312 patents were chosen and examined.
Total volume of patents, technology focus, assignee sector, priority date and the comparison with other countries are analyzed.
It is found that patents on water pollution and treatment filed at China have experienced a remarkable increase and the increase
rate of patents filed at China change simultaneous with the percentage of domestic applications. However, the number of high
quality Triadic patents with priority country as China remains small. Furthermore, in addition to individual patent assignees,
both Chinese universities and enterprises also play important roles in patent activity of water pollution and treatment. In
addition, the pattern of South Korea’s development can provide short-term implications for China and the regularity in Triadic
patents’ development can provide some guidance to China’s long-term development. In contrast, the development pattern of Brazil
and India is less influential to China’s development. Furthermore, China’s technology focuses on water pollution and treatment
seem to parallel global and triadic patent trends. This research provides a comprehensive picture of China’s innovation capability
in the area of water pollution and treatment. It will help China’s local governments to improve their regional S&T capability
and will provide support the National Water Pollution Control and Treatment Project in China.