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Summary The epidemic theory of dispersion of ideas among scientists is discussed by the example of flow-injection analysis. The citation frequency is investigated in detail and the forces are pointed out which are to be accounted for changes in a science.
Die Epidemiologie der Forschung auf dem Gebiet der Fließinjektions-Analyse: Eine unkonventionelle Betrachtung
Zusammenfassung Am Beispiel der Fließinjektionsanalyse wird die epidemische Theorie der Ideenverbreitung unter Wissenschaftlern diskutiert. Die Zitierungshäufigkeit wird eingehend untersucht und die Kräfte werden aufgezeigt, die für Änderungen in der Wissenschaft verantwortlich sind.相似文献
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The ac impedance method has been used to investigate the conductivity of pressed HUP pellets. The activation energy for the ionic conduction process at high frequencies (30 kJ mol?1) was attributed to a simple proton hopping step. At lower frequencies (32 Hz) a Warburg diffusional impedance was observed with a much higher activation energy. This was attributed to the higher energy process of vacancy rotations needed for ion transfer over significant distances. Using a concentration cell, with HUP as the electrolyte, the thermodynamics of the hydrogen-tungsten oxide system was investigated. 相似文献
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F. S. Diver D. Littlejohn T. D. B. Lyon G. S. Fell 《Fresenius' Journal of Analytical Chemistry》1988,332(6):627-629
Summary An investigation through interlaboratory comparison using different analytical techniques has been carried out in order to assess the suitability of a plasma protein solution as a source for a trace element reference material in clinical analysis. Reasonable agreement was obtained for a number of elements from the range studied: Al, Ba, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Sr, V and Zn. The techniques used included flame and furnace atomic absorption spectrometry (FAAS and ETA-AAS), furnace atomic emission spectrometry (ETA-AES), inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and simultaneous multi-element atomic absorption spectrometry (SIMAAC). Results indicated that this plasma protein solution may prove useful as a source for a reference material covering trace element levels outwith the range found in normal human plasma.
Humanalbumin als Referenzmaterial für Spurenelemente相似文献
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William G. Lyon Darrell W. Osborne Howard E. Flotow 《The Journal of chemical thermodynamics》1975,7(12):1189-1194
The heat capacity of a sample of Cs2CrO4 was determined in the temperature range 5 to 350 K by aneroid adiabatic calorimetry. The heat capacity at constant pressure Cpo(298.15 K), the entropy So(298.15 K), the enthalpy {Ho(298.15 K) - Ho(0)} and the function were found to be (146.06 ± 0.15) J K?1 mol?1, (228.59 ± 0.23) J K?1 mol?1, (30161 ± 30) J mol?1, and (127.43 ± 0.13) J K?1 mol?1, respectively. The heat capacity Cpo(298.15 K) and entropy So(298.15 K) and entropy So(298.15 K) of Rb2CrO4 are estimated to be (146.0 ± 1.0) J K?1 mol?1 and (217.6 ± 3.0) J K?1 mol?1, respectively. 相似文献
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Generations of chemists and biologists have conducted research on natural products and other metabolites produced by bacteria and other microorganisms. This has led to an explosion in knowledge concerning the mechanism by which such natural products are made, ultimately allowing custom redesign of many of these molecules for increased potency and selectivity as therapeutic drugs. Along the way, scientists have begun to appreciate that the bacterial world is teeming with life on a scale hardly conceivable, with constant communication within the bacterial world and with outside neighbors, such as plants and mammals. Only in recent years have some of the signaling molecules that comprise these elaborate forms of communication been characterized in any sort of chemical detail, which has in turn peaked interest in the intricate biology of this micro-world and its interactions with the macro-world. 相似文献
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