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71.
0IntroductionThefirstmolecule鄄basedmagnetswerereportedin1986[1].Duringthelasttwodecades,moreandmoreattentionhasbeenpaidtothesynthesisofmolecule鄄basedmagnets,especiallytoPrussianBlueanalogu鄄es[2].TheoldPrussianBlueanalogueshavebeenbroughtuptodateduetoth… 相似文献
72.
Nicolas Le Calvez 《中国化学会会志》2002,49(4):585-592
The aim of this study was to develop an analytical method to determine the organochlorine concentrations in sediments. Combination of Microwave assisted Solvent Extraction (MASE) and capillary gas chromatography with specific detection (electron capture detector) was a viable approach for the determination of pesticides in solid matrixes. In this study, MASE development was focused on the selection of a suitable extraction solvent for all the target analytes. MASE procedure was validated by comparison with conventional methods such as Soxhlet and sonication extraction. The proposed method was then applied to determine the organochlorine insecticides concentrations in samples from Authie Bay (France). Environmental water samples were analysed and five target analytes were detected in concentrations from 0.03 to 0.56 ng/g of dry sediment. These investigations showed the accumulation and the persistency of these products in sediments in spite of the fact they were banned a few decades ago. 相似文献
73.
74.
R. F. Bakeeva L. Yu. Tartykova L. A. Kudryavtseva V. E. Bel'skii N. V. Usol'tseva B. E. Ivanov 《Russian Chemical Bulletin》1992,41(5):817-821
The kinetics of decomposition of p-nitrophenyldimethyl thiophosphate (1) were investigated spectrophotometrically in the n-decylammonium chloride-n-decylamine-water system (DAC-DA-H2O), in which micellar or lamellar liquid-crystalline phases are formed as a function of the concentration of components. It was shown that1 is dealkylated in both phases. An increase in the surface charge density of associates decreases the rate of dealkylation. The activation energy in the lamellar phase is significantly higher than in the micellar phase.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1042–1048, May, 1992. 相似文献
75.
76.
ZhenshanPeng ChanglinYu TiejunCai QianDeng 《天然气化学杂志》2004,13(3):172-176
Mixed oxide catalyst Cs0.1Fe2Co6BiMnMo12Ox was prepared by the coprecipitation method.Selective oxidation of isobutene was carried out in a fixed-bed reactor over Cs0.1Fe2Co6BiMnMo12Ox.The results showed that the catalyst had high catalytic activity. Under the optimum reaction conditions(n(i-C4):n(O2)=1:2-1:4, space velocity=180 h^-1, T=360℃), the yields of methacrolein and methacrylic acid can reach 80% and 8%, respectively. The total yield of liquid products (methacrolein, methacrylic acid and acetic acid) can reach about 90%. 相似文献
77.
Delayed feedbacks are quite common in many physical and biological systems and in particular many physiological systems. Delay
can cause a stable system to become unstable and vice versa. One of the well-studied non-biological chemical oscillators is
the Belousov-Zhabotinskii (BZ) reaction. This gives relaxation oscillations for a considerable period of time under batch
conditions. This paper deals with the effect of perturbing the limit cycle oscillation of BZ reaction by employing a delayed
electrical feedback to the system under batch conditions. The parameters chosen to study are external resistance and delay.
For various resistances and delays the system was electrically perturbed and found to exhibit various complex mixed mode oscillations.
The dynamic features are accounted for by the Oregonator model, with time delay incorporated in one of the variables.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
78.
担载于ZrO2上的Ru3(CO)12-Fe(CO)9混合簇的红外光谱表明,Ru3(CO)12以Ru(CO)2O2表面络合物存在.混合族在真空中随温度升高而发生脱羰基作用,500℃左右羰基完全脱掉;以Al2O3为载体者其羰基不易脱除,升高温度出现多种羰基带.混合簇中的Fe2-(CO)9极易脱羰基.担载混合簇在Ar气中进行TPDE时,低温时以脱羰基为主,高于150℃时发生表面歧化反应而生成CO2;在H2气中,低温时仍以脱羰基为主,高于150℃时发生表面加氢反应而生成CH4.混合簇的脱羰基和表面反应能力与Ru/Fe比及载体有关.担载混合簇在CO加氢反应中以Ru(CO)2O2和分散Fe存在,还出现-CHx多种表面物种. 相似文献
79.
The rate of the Wolff-Kishner reaction of benzophenone hydrazone in butyl carbitol increases as the cation of the alkoxide base is varied in the order K>Na>Li>Mg. The replacement of butyl carbitol by 1-decanol also accelerates the reaction, and an additional increase is caused by the presence of crown ether. On the basis of changes in the activation parameters, it is concluded that the reactivity of the hydrazone anion increases as the contact ion pair becomes more fully solvated and dissociated. 相似文献
80.