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甲基硫酸新斯的明的ICP-AES测定 总被引:1,自引:0,他引:1
研究了电感耦合等离子体原子发射光谱法间接测定甲基硫酸新斯的明,在溶液pH为5.0,四苯硼钠过量时可完全沉淀甲基硫酸新斯的明,测定滤液中的四苯硼钠可以计算得到甲基硫酸新斯的明的含量;方法简单快速,回收率在95%-101%之间,相对标准偏差为1.8%。 相似文献
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建立了原子吸收光谱法间接测定甲基硫酸新斯的明的方法。在pH5.0溶液中,当四苯硼钠过量时可完全沉淀甲基硫酸新斯的明,在滤液中加入过量的KCl沉淀剩余的四苯硼钠,再测定滤液中的过量的钾,可以计算得到甲基硫酸新斯的明的质量分数。方法回收率在97%~103%之间,相对标准偏差为1.5%。 相似文献
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本文选择醋酸乙烯酯/二乙烯苯共聚物(VD)及其醇解物(SVD)为亲水性吸附剂,考察了它们笃水溶液及血清中芳香氨基酸(AAA)的吸附性能,实验结果表明:SVD比VD吸附AAA的功效高,该吸附剂不权在水溶液及在血清中选择性吸附AAA较高,血清相容性亦良好。 相似文献
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9月9日杰出的学者和科学组织者,苏联科学院院长亚历山大·尼古拉也维奇·涅斯米扬诺夫院士已满六十岁了。最卓越的有机化学家之一——А.Н.涅斯米扬诺夫在自己创造性的工作中,将经典的俄罗斯有机化学学派的伟大传统(Н.Н.齐宁、А.М.布特列洛夫、В.В.马尔柯夫尼柯夫、Н.Д.泽林斯基等等)与基于电子观念的新的现代科学方向巧妙地结合了起 相似文献
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一、引言有机化合物中氮元素的測定,多半采用普雷格耳杜馬斯法,凱达尔(Kjeldahl)法和催化氫化三种方法。由于普雷格耳-杜馬斯法操作簡单,迅速,尤其是近年来經过不断的改进,在分析的准确度方面,得到了很大的提高;因此,使用較为广泛。其基本原理,可以簡单地用下式表示: 有机含氮化合物(?)N_2+氮的氧化物+GO_2+ 相似文献
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S. Ya. Kuchmii B. F. Minaev A. V. Korzhak A. I. Kryukov 《Theoretical and Experimental Chemistry》1997,33(1):16-20
A mechanism of photocatalytic synthesis of chlorohydrins from olefins and peroxo complexes of titanium (IV) is proposed. It
consists of formation of radical-containing complexes, their reactions with olefins, and decomposition of the α-oxides obtained
by hydrogen chlorides.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prosp. Nauki, 252039 Kiev,
Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 1, pp. 17–21, January–February, 1997. 相似文献
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Mustafa R. Ibrahim Zacharia A. Fataftah Paul von Ragu Schleyer Peter D. Stout 《Journal of computational chemistry》1987,8(8):1131-1138
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases. 相似文献
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论述了单元教学是落实化学新课程三维目标的基本教学过程,同时对教学单元的含义、教学单元的选择与建构、化学单元教学设计及其意义进行了阐述。 相似文献
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E. O. Koval’ V. V. Kolyagin I. G. Klimov E. A. Maier 《Russian Journal of Applied Chemistry》2010,83(6):1115-1120
The comparative analysis of the molecular mass distribution, temperatures and heat effect of phase transitions, degree of
crystallinity of defect materials and matrix polyethylene film were carried out. Possible reasons of deterioration of the
quality of polyethylene on stages of its synthesis, transportation, storage, and processing were determined. 相似文献
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Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin
E. I. Kapinus V. A. Ganzha B. M. Dzhagarov E. I. Sagun V. B. Pavlenko 《Theoretical and Experimental Chemistry》1989,25(2):146-151
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989. 相似文献
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E. N. Datunashvili V. Ya. Chirva V. N. Ezhov V. I. Rcheulishvili G. V. Vel'mizeva 《Chemistry of Natural Compounds》1984,20(5):530-533
The complex of high-molecular-weight substances of the cell walls of the grape has been studied. It has been shown that the complex contains polysaccharides, proteins, and phenolic substances presumably linked through O-glycosidic bonds."Magarach" Scientific-Research Institute of Wine-Making and Wine-Growing, Yalta, M. V. Frunze Simferopol' State University, Khimiya Prirodnykh Soedinenii, No. 5, pp. 564–567, September–October, 1984. 相似文献
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栽培草莓品种果实香气特性研究 总被引:15,自引:0,他引:15
通过对4个不同栽培草莓(Fragaria ananassa Duch.)品种果实糖和氨基酸测定及香气的GC-MS分析,结果表明:不同品种间氨基酸和糖含量不同,氨基酸含量由高到低依次为丰香、瓦尔达、哈达和全明星;哈达、丰香、全明星和瓦尔达4个品种果实分别检测出39、46、37和44种香气成分,各占总峰面积98.52%、99.15%、98.77%和95.4l%,检测成分的多少与氨基酸总量显著正相关,相关系数为0.967;哈达有5种独有的成分,丰香有9种独有的成分,全明星有3种独有的成分,瓦尔达有2种独有的成分,4个品种共有的成分有19种。 相似文献
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Robert Shaw 《国际化学动力学杂志》1973,5(2):261-269
Heats of formation of solid, liquid, and gaseous nitroalkanes have been shown mostly to obey group additivity. Group values have been obtained for carbon atoms attached to one, two, and three nitro groups. The heat of formation of 1,1,1,3,5,5,5,-heptanitropentane, either solid or liquid, cannot be fitted to the scheme, even allowing for gauche effects. The differences between observed and estimated values for 1,1,1-fluorodinitroalkanes and 1,2-dinitroethane are larger than expected and should be further investigated. Activation energies have been calculated for decomposition by five-center elimination of HONO from mononitro- and dinitroalkanes using thermochemistry and estimated activation energies for the reverse reactions. The key data for these estimates were previously reported activation energies for the decomposition of nitroethane and 1,2-dinitropropane. The calculations also gave values for the heats of formation (in kcal/mole) of nitroethylene 12.4, and 1-nitropropylene 5.6, and 2-nitropropylene 1.6. Activation energies were calculated for the competing unimolecular reaction, C? N bond fission, from thermochemistry and previously reported activation energies for the decomposition of 1,1- and 2,2-dinitropropane. Comparison of Arrhenius parameters for the two competing processes, namely, HONO and C? N bond fission, shows that, for the geminate dinitroethanes and dinitropropanes, C? N bond fission is faster about 370°K and, for the mononitroalkanes and for all the mononitroalkanes and dinitroalkanes, C? N bond fission is faster above 770°K. 相似文献
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The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献