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1.
V. A. Krylov O. Yu. Chernova Yu. M. Salganskii L. S. Malygina A. P. Kotkov 《Journal of Analytical Chemistry》2003,58(8):750-755
It is shown that the results of determining methane in high-purity arsine by reaction gas chromatography can be overestimated by more than two orders of magnitude. This overestimation is caused by the formation of methane as a side product of the reaction. Cryogenic preconcentration at the injection stage is proposed to improve the accuracy of determination of methane, and the cryofocusing of impurity hydrocarbons is proposed to improve separation. Detection limits of (3–10) × 10–6 vol % are achieved for C1–C5 hydrocarbons. 相似文献
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Yu. M. Andreev A. A. Ionin I. O. Kinyaevskii Yu. M. Klimachev A. Yu. Kozlov A. A. Kotkov G. V. Lanskii 《Bulletin of the Lebedev Physics Institute》2010,37(1):11-12
The experimental results of the study of CO laser frequency doubling in ZnGeP2 and GaSe nonlinear crystals of high optical quality are presented. A multifrequency low-pressure Q-switched CO laser and
a selective pulsed electroionization mode-locked CO laser with cryogenic cooling were used in the experiments. The highest
external factor of radiation conversion into the second harmonic of the pulse-periodic Q-switched CO laser and pulsed mode-locked
CO laser was 1% and 3.5%, respectively. Theoretical calculations showed the possibility of obtaining far IR and terahertz
radiation using difference frequency generation of CO laser lines in these crystals. 相似文献
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Yu. N. Nozdrin A. V. Okomel’kov A. P. Kotkov A. N. Moiseev N. D. Grishnova 《JETP Letters》2004,80(1):23-25
The results are reported on the observation of the induced emission from CdxHg1?x Te samples optically pumped by a pulsed Nd:YAG laser at temperatures T<77 K. In the wave range λ~ 3300–3600 nm, both stimulated and spontaneous emission were observed. The experimentally measured emission spectra are analyzed. The properties of the spectra from the samples are discussed and the possible applications are considered. 相似文献
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AA Yan LI Kai CAO ZhongHua & HU WenRui Key Laboratory of Microgravity 《中国科学:物理学 力学 天文学(英文版)》2011,(2)
The dependency of the critical Marangoni number on the geometrical aspect ratio of the floating half zone is essential to predict the onset of oscillatory thermocapillary convection.The experimental studies in the microgravity conditions on floating half zones of several centimeters in diameter have predicted that the critical Marangoni number increases with the increasing aspect ratio,and the terrestrial experimental studies have predicted the contradictory conclusion for floating half zones of several mil... 相似文献
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Non-Gravitational Effects with Density-Matching in Evaluating the Influence of Sedimentation on Colloidal Coagulation 下载免费PDF全文
The method of density matching between the solid and liquid phases is often adopted to effectively eliminate the effect of sedimentation of suspensions in studies on dynamic behaviour of a colloidal system. However, the associated changes in the solvent composition may bring side effects to the properties investigated and therefore might lead to a faulty conclusion if the relevant correction is not made. To illustrate the importance of this side effect, we present an example of the sedimentation influence on the coagulation rate of suspensions of 2μm (diameter) polystyrene. The liquid mixtures, in the proper proportions of water (H2O), deuterium oxide (D2O) and methanol (MeOH) as the liquid phase, density-matched and unmatched experiments are performed. Besides the influence of viscosity, the presence of methanol in solvent media, used to enhance the sedimentation effect, causes significant changes (reduction) in rapid coagulation rates compared to that in pure water. Without the relevant corrections for those non-gravitational factors it seems that gravitational sedimentation would retard the coagulation. The magnitude of the contribution from the non-gravitational factor is quantitatively determined, making the relevant correction possible. After necessary the influence of the sedimentation on coagulation rates at corrections for all factors, our experiments show that the initial stage of the coagulation is not observable. 相似文献
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