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The kinetics and mechanism of chemical reactions in detonation waves propagating in mixtures of nitric acid with nitroglycol, ethylene glycol dinitrate, and acetic anhydride were studied within the framework of the Dremin—Trofimov theory of the detonation failure diameter. The state parameters in shock and detonation waves were calculated using the SGKR software package. It was shown that the decomposition of mixtures of nitric acid with organic substances in a detonation wave is a complex reaction which includes several stages. Various kinetic models are considered; effective values of the kinetic parameters are calculated for each model and for the entire process. 相似文献
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The enthalpy of formation and combustion is calculated for 15 aliphatic amines by various methods. These characteristics depend on the number of carbon atoms and the number of amino groups in the amine molecule. The combustion parameters are calculated when P = 1 atm and V = const, for mixtures of aliphatic amines with air. The adiabatic combustion temperature of mixtures of limiting composition is practically independent of the amine structure. The calculated values of the maximum pressure exceed 1000 kPa. 相似文献
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Strashilov Vesseline L. Alexieva Gergana E. Velichkov Velitchko N. Avramov Ivan D. Evans Stephen D. 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2009,56(5):1018-1023
A 1 GHz surface transverse wave resonator on 36° Y-cut quartz plate coated with organothiol-functionalized gold nanoparticle film has been studied as a chemical gas sensor. Considerable sensitivity of the resonant frequency to vapors of ethanol, methanol, chloroform, and acetic acid has been found. Owing to the high short-term stability of the oscillator built, the detection limit is in the low ppm range. The results qualitatively confirm previous results on the same film type obtained by conductivity measurements. In the present case, the conductivity effect resulting from variable separation of nanoparticles is accompanied with surface-attached mass of the absorbed gas. The film matrix exhibits considerable capacity to absorb large amounts of molecules at high gas concentrations. 相似文献
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Gergana I. Drandova Troy C. Messina Jae-Hyuk Choi Javier F. Hernandez John T. Markert 《Journal of Low Temperature Physics》2003,131(3-4):305-309
We report NMR lineshape, spin-lattice relaxation time T
1, and spin-spin relaxation time T
2 data at 17 MHz (8.07 T) for 89Y in the copper-oxide spin-chain compound Ca2+x
Y2–x
Cu5O10. For x=0, a broad, asymmetric line with width 90 kHz is observed for T=250–300 K. The spectra exhibit an appreciable average shift (H/H+0.7%) and sharpen at lower temperature, possibly due to increasing intrachain ferromagnetic correlations. T
1 and T
2 decrease with decreasing temperature. The Tl data imply a short correlation-time limit, with e=3–5×10–11 s. The T
2 data apparently include a contribution from dipolar interactions with copper nuclei. Relaxation time data for a doped (x=0.5) compound surprisingly show more rapid relaxation. 相似文献
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Iliyan Kolev Gergana Alexieva Vesselin Strashilov Ismail Ben Youssef Frederic Sarry Halima Alem 《应用聚合物科学杂志》2016,133(48)
The sensitivity of a thick layer (500 nm) of poly(urethaneimide) to toxic gases such as pyridine and hexamethyleneimine was studied by the quartz crystal microbalance method. The resonant frequency was registered by a spectrum analyzer. The successful overcoming of the unfavorable impact of the increased viscous damping, typical for the standard oscillator measurement method, allowed complete understanding of the behavior of a thick polymer layer toward highly pollutant gases. Quantitative information for polymer adsorption capacity and gas diffusivity was extracted. The comparison with our recent results for thinner layers revealed strong dependence on layer thickness for pyridine whereas the corresponding effect with hexamethyleneimine was found much less significant. Intermolecular interactions and the impact of the gas physical adsorption on the polymer matrix properties were shown as the driving parameters for the sensors response. The thickness dependence provides a tool for tuning the sensitivity of a potentially efficient poly(urethaneimide) sensor for pyridine. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44214. 相似文献
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The detonation failure diameter was determined for mixtures of dinitrotoluene in concentrated nitric acid with zero and negative
oxygen balance in flat glass dishes. For mixtures with negative oxygen balance, detonation was detected in layers 0.10 and
0.12 mm thick, and detonation failure took place in layers 0.08 mm thick. The data obtained gives complete form to the dependence
of the detonation failure diameter on composition for dinitrotoluene solutions in HNO3.
Translated fromFizika Goreniya i Vzryva, Vol. 35, No. 5, pp. 113–115, September–October 1999. 相似文献
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