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J. E. Caffyn 《Colloid and polymer science》1952,129(2-3):77-81
Zusammenfassung Es werden einige Eigenschaften viskoelastischer Flüssigkeiten beschrieben und die Relaxationszeit einer Substanz, die der
Nuttingschen Gleichung folgt, abgeleitet. Diese Relaxationszeit wird verglichen mit der der klassischen Maxwellschen und Kelvinschen
Stoffe. Die natürliche Zeit der Reiner-Rivlinschen Flüssigkeit wird beschrieben und einige ihrer Auswirkungen werden angedeutet.
Weiter wird der Durchflu\ einiger idealer Flüssigkeiten durch R?hren verglichen und die Bedeutung für Me\geschwindigkeitsverteilung
im Raum hervorgehoben. Eine neue Methode für ihre Messung wird angegeben und einige Ergebnisse für den Durchflu\ von Ammoniumoleaten
durch R?hren mit kreisf?rmigem Querschnitt werden angegeben.
Vorgetragen auf der Rheologie-Tagung Berlin, September 1951. 相似文献
Summary Some properties of viscoelastic liquids are described and a natural time for a substance which obeys Nutting's equation is deduced. This natural time is compared to that of the classical Maxwell and Kelvin materials. The flow of a few ideal fluids through tubes is compared and the necessity for measuring velocity profiles is stressed. A new method for their measurement is described and some results are given for the flow of Ammonium Oleate through tubes of circular cross section.
Vorgetragen auf der Rheologie-Tagung Berlin, September 1951. 相似文献
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CM Silva MF Duarte ML Mira MH Florêncio K Versluis AJ Heck 《Rapid communications in mass spectrometry : RCM》1999,13(12):1098-1103
Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Reaction of P2Ph4 with the diyne-diol complex [{Co2(CO)6}2(μ-η2:μ-η2-HOCH2CCCCCH2OH)] in toluene at 65 °C gives [{Co2(μ-P2Ph4)(CO)4}{Co2(CO)6}(μ-η2:μ-η2-HOCH2CCCCCH2OH)] (1). Thermolysis of 1 at 95 °C leads to [{Co2(CO)5}2(μ-P2Ph4)(μ-η2:μ-η2-HOCH2CCCCCH2OH)](2) and (μ2-PPh2)(μ2-CO)(CO)7] (3). The structures of 1-3 have been established by X-ray crystallography. In 1, a pseudoequatorial P2Ph4 ligand bridges the cobalt-cobalt bond of a Co2(CC)(CO)4 unit. By contrast, in isomeric 2, a pseudoaxial P2Ph4 ligand spans two Co2(CC)(CO)5 units, a new coordination mode for [{Co2(CO)5L}2(μ-η2:μ-η2-diyne)] complexes. Complex 3 arises from dehydration-cyclocarbonylation of the diyne-diol in 1 to give a 2(5H)-furanone, a process that has not been previously reported. Reaction of HOCH2CCCCCH2OH with [Co2(μ-PPh2)2(CO)6] at 80 °C in toluene gave [Co3(μ-PPh2)3(CO)6], [Co2(CO)6(μ-η2-HOCH2CCCCCH2OH)] and [Co2{μ-η4-PPh2C(CCCH2OH)C(CH2OH)CO}(μ-PPh2)(CO)4] (4). The regiochemistry of 4 was confirmed by X-ray crystallography. 相似文献
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The reaction of perfluoroalkyl Grignard reagents with phosphorus(III) halides was explored. In the process a new convenient, one-pot, high yield method for the synthesis of (perfluoroalkyl)phosphonic acids has been developed. Perfluoroalkyl Grignard reagents react with phosphorus trichloride or phosphorus tribromide to form (perfluoroalkyl)phosphonous dihalides. Hydrolysis gives the corresponding (perfluoroalkyl)phosphonous acids. Oxidation of the phosphonous acids with H(2)O(2) produces (perfluoroalkyl)phosphonic acids in 60-78% overall yields, based on the corresponding perfluoroalkyl iodide. The X-ray crystal structures of the toluidinium salts, [MeC(6)H(4)NH(3)](2)[C(2)F(5)PO(3)] and [MeC(6)H(4)NH(3)][C(8)F(17)P(O)(2)OH], are reported. 相似文献
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A procedure is explained to determined the amount of several pairs of diametrical loads applied to the outside boundary of
a ring when stresses at selected points of the inside or outside boundaries are known. Coefficients of influence are used,
following an approach similar to the one presented in a previous paper. Examples of application are given and the possible
increase in precision is shown when the number of points of measurements is larger than the number of loads to be determined. 相似文献