排序方式: 共有37条查询结果,搜索用时 15 毫秒
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M. Földesová V. Tomková P. Lukáč P. Dillinger 《Journal of Thermal Analysis and Calorimetry》1996,46(2):565-571
The treatment of zeolite with a solution of NaOH at different concentrations creates modified forms of natural zeolites.These modified zeolites exhibit an increased uptake of caesium and a satisfactory uptake of cobalt. The structural changes in the modified zeolites were studied by XRD analysis, which reveals the mineral compositions of the studied materials. The thermodynamic properties of the modified zeolites were studied by means of DTA and thermogravimetry, and the chemical composition too was determined. 相似文献
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A. Müller E. Krickemeyer S. Dillinger H. Bgge W. Plass A. Proust L. Dloczik C. Menke J. Meyer R. Rohlfing 《无机化学与普通化学杂志》1994,620(4):599-619
The compounds (NMe4)5[As2Mo8V4AsO40] · 3 H2O 2a , (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O 3a , (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O 3b and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo17} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na3(NH4)12[H15Mo57Fe6(NO)6O183(H2O)18] · 76 H2O 7a . 相似文献
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A. Müller W. Plass E. Krickemeyer S. Dillinger H. Bögge A. Armatage C. Beugholt U. Bergmann 《Monatshefte für Chemie / Chemical Monthly》1994,125(5):525-533
Summary The X-ray crystal structure of the compound Na3(NH4)12[Mo57Fe6(NO)6O174(OH)3(H2O)24]·76H2O (3) [P63/mmc;a=2380.6(5),c=2763.4(7),Z=2], the giant cluster anion of which has the shape of a doughnut, shows remarkable details: The cluster [{Fe(H2O)2}6{Mo(-H2O)2(-OH)Mo}3{ Mo15(MoNO)
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O58(H2O)2}3]15– can be described as being composed of three transferable {Mo17} ligands bridged by cationic centers and contains a novel nanodimensional central cavity. 相似文献
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Santagostini L Gullotti M Monzani E Casella L Dillinger R Tuczek F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(3):519-522
The complex [Cu2(L-66)]2+ (L-66 = a,a'-bis?bis[2-(1'-methyl-2'-benzimidazolyl)ethyl]amino?-m-xylene) undergoes fully reversible oxygenation at low temperature in acetone. The optical [lambda(max) = 362 (epsilon 15000), 455 (epsilon 2000), and 550 nm (epsilon 900M(-1)cm(-1))] and resonance Raman features (760 cm(-1), shifted to 719cm(-1)(-1) with 18O2) of the dioxygen adduct [Cu2(L-66)(O2)]2+ indicate that it is a mu-eta2:eta2-peroxodicopper(II) complex. The kinetics of dioxygen binding, studied at - 78 degrees C, gave the rate constant k1 = 1.1M(-1) 5(-1) for adduct formation, and k(-1) =7.8 x 10(-5)s(-1), for dioxygen release from the Cu2O2 complex. From these values, the O2 binding constant K= 1.4 x 10(4)M(-1) at -78 degrees C could be determined. The [Cu2(L-66)(O2)]2+ complex performs the regiospecific ortho-hydroxylation of 4-carbomethoxyphenolate to the corresponding catecholate and the oxidation of 3,5-di-tert-butylcatechol to the quinone at -60 degrees C. Therefore, [Cu2(L-66)]2+ is the first synthetic complex to form a stable dioxygen adduct and exhibit true tyrosinase-like activity on exogenous phenolic compounds. 相似文献
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Cornelia Boberski Rainer Hamminger Marcell Peuckert Fritz Aldinger Reinhard Dillinger Jürgen Heinrich Jürgen Huber 《Angewandte Chemie (International ed. in English)》1989,28(11):1560-1569
The past decade has seen greatly increased interest in ceramic materials with special combinations of properties. Their hardness, high resistance to abrasive and erosive wear, and their good corrosion resistance when used under extreme mechanical and thermal conditions have made ceramics increasingly attractive for applications in mechanical and apparatus engineering. Silicon nitride (Si3N4) in particular, is suitable for the development of a high-performance, high-temperature material for vehicle engine construction. Although the properties of Si3N4 materials have been consistently improved in the last few years, they are still not adequate to allow these materials to be used in series production parts, for example as valves in automotive engines. One of the main reasons for this is the wide scatter and low reproducibility of the property parameters, which means that component reliability does not yet meet market requirements. Hence, one aim of Si3N4 materials development is to reduce the structural flaws resulting from physical and chemical inhomogeneity. This objective can only be achieved through a fundamental understanding of all the processing steps, from powder production to the final processing of the components. 相似文献
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J. Tölgyessy M. Harangozó P. Dillinger 《Journal of Radioanalytical and Nuclear Chemistry》1993,176(6):451-455
Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and238Pu exciting source was used for the determination of Cu, Ni, Zn and Pb in plant samples (Taraxacum officinale) from various localities near the highway D-61 Bratislava-Trnava (SR). 相似文献