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31.
Sono-induced cold vapor generation (SI-CVG) has been used for the first time in combination with a graphite furnace atomizer for determination of Hg in natural waters by electrothermal-atomic absorption spectrometry after in situ trapping onto a noble metal-pretreated platform (Pd, Pt or Rh) inserted into a graphite tube. The system allows ‘in-atomizer trapping’ of Hg without the use of conventional reduction reactions based on sodium borohydride or tin chloride in acid medium for cold vapor generation. The sono-induced reaction is accomplished by applying ultrasound irradiation to the sample solution containing Hg(II) in the presence of an organic compound such as formic acid. As this organic acid is partly degraded upon ultrasound irradiation to yield CO, CO2, H2 and H2O, the amount of lab wastes is minimized and a green methodology is achieved. 相似文献
32.
本文用自旋捕捉-ESR技术研究了二茂戊铁、环二烯和胺甲基类取代二茂铁的紫外光解过程中的活泼自由基。结果表明,二茂铁光解初级过程中生成的自由基为(C_5H_5Fe)·和C_5H_5·,其衍生物光解则生成(C_5H_5Fe)·和RC_5H_4·,而(C_5H_5Fe)·还可以进一步分解给出C_5H_5和Fe。 相似文献
34.
Liping Heng Jin Zhai Yong Zhao Jinjie Xu Xianliang Sheng Lei Jiang 《Chemphyschem》2006,7(12):2520-2525
A light-emitting poly (distyryldimethylbenzene-co-triethylene glycol) rod-coil block copolymer was used to fabricate films with three-dimensionally ordered honeycomb structures by the breath-figure method. Photocurrent generation and photovoltaic performance are studied, and the dependence of photocurrent on applied electric field is investigated. Introducing the ordered porous structure significantly improves the photoelectric conversion behavior, because porous structures not only enhance the light-harvesting efficiency but also benefit charge separation and charge transfer. This phenomenon may have great prospects for enhancing the photovoltaic behavior of organic thin-film devices. 相似文献
35.
WANG Qin-Sun ZHU Chang-Shou YAN Bing-WenNational Laboratory of Elemento-Organic Chemistry Nankai University Tianjin China 《中国化学》1995,(2)
A computer-assisted advanced simplex method is presented for the simultaneous optimization of multifactor ( stationary phase loading, carrier gas flow rate and column temperature ) for separation of ten compounds in gas chromatography. A three factors factorial design was used. The method was based on a special polynomial established from fifteen preliminary runs, using resolution as the selection criterion, with connection to a general simplex method. Excellent agreement is found between the predicted data and the experimental results, and most of experiments required in the general simplex method can be omitted. 相似文献
36.
The vanadium trapping effect of Mg and La containing additives in cracking catalyst contaminated with 2300 ppm Ni and 4700 ppm V has been analyzed by microactivity test (MAT) and imaging secondary ion mass spectrometry (SIMS). The results of SIMS imaging are consistent with cracking activity data and show that the La/spinel is a superior vanadium trap for the fluid catalytic cracking of hydrocarbons (FCC) operation. La/spinel serves as a dual function additive for both vanadium trap and SOx removal. The optimum amount of La/spinel added to the cracking catalyst is about 15% by weight. This results in an increased catalytic activity, an increase in gasoline yield, and a decrease in coke and gas factors. The MgAl2O4 phase of Mg/Al2O3 additive is found capable of trapping vanadium while its MgO of Mg/Al2O3 phase can migrate to zeolite particles (the active component of the FCC catalyst) that, in turn, causes a decline in the activity of that catalyst. 相似文献
37.
V. G. Berezkin A. A. Korolev I. V. Malyukova R. G. Mardanov 《Russian Chemical Bulletin》1997,46(12):2064-2073
The effects of the carrier gas nature and pressure on the relative retention values of organic compounds were studied using
a series of capillary columns differing in the film thickness of the polar stationary phase (PEG-20M). Relative retention
depends linearly on the carrier gas pressure. This dependence becomes more pronounced in the following order of carrier gases:
helium < nitrogen < carbon dioxide. The limiting relative retention at a carrier gas pressure approaching zero rather than
relative retention values measured experimentally (relative retention time, Kovats retention index,etc.) is an invariant characteristic of a compound subjected to chromatography. For the carrier gases studied, the limiting retention
values almost does not depend on the nature of the carrier gas used. The limiting indicating the complex absorption-adsorption
nature of these parameters. Dissolution of a carrier gas in the stationary liquid phase has an effect on the relative retention.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2177–2186, December, 1997. 相似文献
39.
乳状液膜法提取L-谷氨酸的研究徐占林(四平师范学院化学系四平136000)严忠张河哲(东北师范大学化学系长春130024)关键词L-谷氨酸乳状液膜载体萃取中图分类号O623.736氨基酸作为重要的生化产品,广泛应用于食品、饲料、医药、化工等许多领域,... 相似文献
40.
Suyao?Xiao Xuanming?LiuEmail author Chunyi?Tong Jun?Liu Dongying?Tang Lijian?Zhao 《中国科学B辑(英文版)》2005,48(2):162-166
Anion starch nanoparticle (StNP) with a diameter of 50 nm was prepared in water-in-oil microemulsion, with soluble starch
as raw materials and POCl3 as crosslinking agent. PLL-StNP was prepared by linking poly-L-lysine (PLL) on the surface of StNP. At the same time, the
size of PLL-StNP and its stability in aqueous solution were checked by AFM. The analysis of plasmid DNA binding, DNase I enzymatic
degradation, toxicity and transfection were done. We discovered that PLL-StNP may be used as non-virus nanoparticle gene carrier.
And we developed the method of preparing PLL-StNP gene carrier and used it in cell transfection. As non-virus gene carrier,
PLL-StNP has some advantages, such as large load of DNA, high transfection efficiency, low cell toxicity and biodegradability. 相似文献