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945.
F. J. Coetzer T. C. Kotzé P. B. Kotzé F. J. Mostert P. van der Westhuizen 《Zeitschrift für Physik A Hadrons and Nuclei》1985,320(3):359-362
Detailed measurements on the 5p 4 S 3 2/0 and 5p~' 2 D 5 2/0 levels in Kr II are reported. Cascade effects were taken into account with the aid of the arbitrarily normalized decay curve (ANDC) technique. Experimental values are compared to values obtained by other investigators as well as to theoretical values. 相似文献
946.
J. Lédé 《Journal of Thermal Analysis and Calorimetry》1996,46(1):67-84
This paper deals with models describing the thermal and chemical behaviour of solid particles undergoing fast endothermic reactions under the influence of an external heat flux. The heat source temperature is supposed to be constant, to increase with time, or to deliver a simple thermal flash. It is shown that the pyrolysis conditions (reaction temperature, conversion, etc.) depend on the chemical characteristics of the reaction and also to a large extent on the external heating conditions. Relationships are proposed to take into account these parameters. The results are applied to the thermal decomposition of NaHCO3. The pyrolysis of cellulose is finally chosen in order to show how these operating parameters can also affect the selectivity of a more complex reaction. 相似文献
947.
Electrochromatography (EC) in microfluidic chips is emerging as an attractive alternative to capillary electrophoresis (CE) for on-chip separations. This review summarizes recent developments in the rapidly growing area of chip electrochromatography with a focus on "column" technologies. Relevant achievements are summarized according to the types of stationary phase used for the separations including open channels, microfabricated structures, and channels packed with beads or containing a porous monolith. The advantages and disadvantages of each, as well as practical aspects of their application, are discussed. The analytical performance of these devices is demonstrated with separations involving various families of compounds mostly in the reversed-phase chromatographic mode. 相似文献
948.
Kinetic studies on the thermal degradation of polypropylene and polystyrene have been carried out using the thermogravimetric technique. Experimental thermograms have been interpreted by means of a simulation model which takes into account several simultaneous or consecutive reactions. In nitrogen, polypropylene degradation involves two reactions. The activation energy calculated for the second reaction, which corresponds to the main part of the weight loss curve, agrees with values obtained by means of calculation methods based on only one overall reaction. In air, a third reaction is added. Its activation energy is also in agreement with published values. However, for the two studied materials, orders of reaction are different. 相似文献
949.
Verdejo B Aguilar J Doménech A Miranda C Navarro P Jiménez HR Soriano C García-España E 《Chemical communications (Cambridge, England)》2005,(24):3086-3088
L-glutamate and L-aspartate selectivity is achieved by the action of two Cu2+ metal ions rightly disposed in a cyclophane-type macrocyclic framework; electrochemical sensing of glutamate has been achieved by adsorption of the copper complexes on graphite electrodes. 相似文献
950.
V. R. Polishchuk L. A. Leites E. I. Mysov A. F. Aérov E. M. Kagramanova 《Russian Chemical Bulletin》1992,41(2):358-359
Trifluoroacetic acid adds to 2,3-difluorobicyclohepta[2.2.1]diene-2,5 at the FC=CF bond to give mainly the cis-exo adduct.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 450–452, February, 1992. 相似文献