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961.
Robert Pietrzak Mieczysław Kozłowski Helena Wachowska Jan Yperman 《Central European Journal of Chemistry》2004,2(2):278-289
Soluble products obtained from the oxidation of four types of coal, each characterised by different degree of coalification
and different degree of sulphur content, are studied. The coals are oxidised with peracetic acid (PAA) and nitric acid. Analyses
are performed by Atmospheric Pressure-Temperature Programmed Reduction (AP-TPR) and Fourier Transform Infrared Spectroscopy
(FTIR). The soluble products contain much more sulphur than the insoluble products of oxidation. The products obtained from
the reaction with HNO3 contain higher amounts of inorganic sulphur compounds, while those obtained from the reaction with PAA are characterised
by an increased content of organic sulphur species. 相似文献
962.
Melinda Fekete Pál Kolonits Ngo Thi Hien Lajos Novák 《Central European Journal of Chemistry》2005,3(4):792-802
New tryptamine 5, 7 and β-carboline derivatives 3 were preparated by palladium-catalyzed coupling reaction of 5-bromotryptamine 1 with aryl boronic acids.
Dedicated to Professor András Lipták on his 70th birthday. 相似文献
963.
Xiongyu Wu Xiaohong Liu Guangce Jiang Yongcheng Lin Willy Chan L. L. P. Vrijmoed 《Chemistry of Natural Compounds》2005,41(1):27-29
A novel metabolite 1, named xyloketal G, was isolated from cultures of marine derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by analysis of spectroscopic data.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 22–23, January–February, 2005. 相似文献
964.
FANG Fang ZHU Yu ZHAO Qian JIANG Gang WANG Hong-Yan 《结构化学》2007,26(9):1092-1096
Geometric and electronic properties of Pdn–1Pb and Pdn (n≤8) clusters have been studied by using density functional theory with effective core potentials, focusing on the differences between mono- and bimetallic clusters. The average bond length of Pdn–1Pb (n≤8) bimetallic clusters is longer than that of pure palladium clusters except for n = 2 and 3. The most stable structure of Pdn–1Pb (n≤7) is the singlet where there is at least a Pd or Pb atom on its excited state. The energy gaps of Pd–Pb binary clusters are narrower than those of Pdn clusters, and then the chemical activity is strengthened when Pdn clusters are doped with Pb. 相似文献
965.
Marie-Noelle Avettand-Fènoël N. David G. Reumont J. -M. Fiorani M. Vilasi P. Perrot 《Journal of Thermal Analysis and Calorimetry》2007,90(2):329-332
The Fe-Sn-Zn system is of interest because Sn is one element added to the Zn galvanizing bath to overcome the drawbacks due
to the presence of Si in semi-killed steels. This work has been undertaken with the aim to understand the tin effect on the
microstructure and the layers growth in batch galvanized coatings on low alloyed steels.
Various experimental techniques such as metallography, scanning electron microscopy (SEM) coupled with X-ray energy dispersive
spectroscopy (EDX) are used in order to characterize the microstructure and the properties of such coatings elaborated in
a zinc bath enriched with tin.
Solidification phenomena and layers growth mechanisms during galvanization are explained by means of the ternary phase diagram
Fe-Sn-Zn at 450°C. The Calphad method allows to obtain this phase diagram from the three optimized binary phase diagrams Fe-Sn,
Fe-Zn and Sn-Zn and some experimental data inside the ternary Fe-Sn-Zn system. 相似文献
966.
Chun-Yang Jina Dao-Dao Zhang Tetsuya Oguma Shi-Xiong Qian 《Journal of inclusion phenomena and macrocyclic chemistry》1996,24(4):301-310
Cycloisomalto-heptaose (CI-7) and cycloisomalto-octaose (CI-8) are two novel cyclodextrans. Treatment with C60 or C70 by kneading leads to the formation of four distinct water-soluble inclusion complexes: CI-7/C60 (2: 1), CI-8/C60 (2: 1), CI-7/C70 (2: 1) and CI-8/C70 (2: 1). Their formation and structures have been examined by UV vis spectroscopy, X-ray powder diffraction and fluorescence spectral studies. The reaction is a reversible process. 相似文献
967.
2,5—二取代—1,3—4—恶二唑和N,N‘—二酰基肼化合物的合成与生物活性 总被引:2,自引:0,他引:2
合成了18种新的对称与不对称的2,5-二取代-1,3,4-恶二唑及N,N“'-F二酰基肼化物,用元素分析,红外光谱,核磁氢谱和质谱确定了其结构,并对它们的杀虫,抗菌活性进行了测试,发现了数个具有较强生物活性的化合物。 相似文献
968.
铜对钌改性尖晶石催化剂结构和氧化性能的影响 总被引:4,自引:0,他引:4
通过湿化学法制备钌改性的纳米尖晶石MnFe1.95Ru0.05O4催化剂, 考察了添加助剂铜对该催化剂的影响.通过比表面积和孔径分布表征结果证实, 铜助剂的添加有效地增大了比表面积和孔容.XPS的测试结果表明, 钌的改性大大改变了尖晶石中各元素如锰和铁的化学环境;助剂铜的添加对于锰和铁等原子的影响不大, 但对钌原子的影响显著;EXAFS表征结果显示了铜助剂的导入影响了钌的周围环境, 形成了活性Ru=O键.以桂皮醇和苯甲醇的氧化反应为典型反应考察了添加助剂铜前后的影响. 相似文献
969.
Ramiro Pino Olivier Bokanowski Eduardo V. Ludeña Roberto López Boada 《Theoretical chemistry accounts》2007,118(3):557-561
Bearing in mind the insight into the Hohenberg–Kohn theorem for Coulomb systems provided recently by Kryachko (Int J Quantum
Chem 103:818, 2005), we present a re-statement of this theorem through an elaboration on Lieb’s proof as well as an extension
of this theorem to finite subspaces.
Contribution to the Serafin Fraga Memorial Issue. 相似文献
970.