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91.
The linewidth of a semiconductor laser was reduced and held to much less than 1 MHz using a simple DC scheme for the stabilisation of the phase of external optical feedback. This scheme was based on the antisymmetric response to feedback phase at the two laser facets. 相似文献
92.
It has been reported that the radiation characteristics of semiconductor antennas can be controlled by modulating their conductivity during fabrication and/or operation. This paper describes novel physical layouts integrating these versatile antennas with other components used in the realization of millimeter wave systems. The monolithic integration is discussed for GaAs as well as Si IC technologies. 相似文献
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An adiabatic constant pressure chemical kinetic study of the AP gas phase is conducted. The objective is to examine the importance of chemical kinetic studies for propellant deflagration modelling in general and for AP in particular. A reaction mechanism consisting of ninety five elementary reactions involving twenty one chemical species is developed to represent the AP gas phase. An important parameter that can be obtained from the kinetics is the time rate of change of temperature of the gas phase at the condensed phase-gas phase boundary (dT/dt at t = 0). This is directly related to the heat feedback from the gas phase to the condensed phase. Comparison with earlier work indicates that the use of a one-step overall reaction could lead to underestimates of heat feedback from the gas phase by a factor of about four. In addition it is found that the rate of decrease of dT/dt at t = 0, with pressure is much larger at lower pressures, suggesting a possible gas phase role in the low pressure deflagration limit. Further, the kinetic study does not support the conclusion of a constant fraction of AP reacting in the condensed phase in the pressure range 20–100 atmospheres. These results are at variance with what is obtained by use of a one-step overall reaction. Thus, the one-step overall reaction cannot represent even qualitatively several gas phase characteristics important for deflagration studies, and its use leads to erroneous results. It is concluded that a full reaction mechanism representation of gas phase chemical kinetics is essential to AP deflagration modelling. The same conclusion is probably valid for propellant deflagration modelling in general. 相似文献
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S. R. Jain 《Propellants, Explosives, Pyrotechnics》1987,12(6):188-195
A simple approach involving the chemical valences of the fuel and the oxidizer elements present in a combustible mixture is described to evaluate the energetics related parameters of propellants, fuels and explosives. It simplifies the stoichiometric balancing of complex combustion equations, and provides an easy method of calculating the elemental stoichiometric coefficient. The method correctly predicts whether a mixture is fuel-lean, fuel-rich or stoichiometrically balanced. The calorimetric value of various stoichiometrically balanced combustible systems has been shown to be linearly dependent upon their total oxidizing (or reducing) valences. This relationship has been used successfully to evaluate the calorific value of fossil fuels. For fuel-rich explosives, a new valence dependent parameter has been derived which is found to be related with properties such as detonation velocity, heat of explosion and impact sensitivity. 相似文献
99.
Singh Bikesh K. Jain Pankaj Banchhor Sumit K. Verma Kesari 《Multimedia Tools and Applications》2019,78(16):22421-22444
Multimedia Tools and Applications - Performance of computerized diagnostic systems yearning to be approved by medical regulatory bodies must meet the expectations of human experts. Highly accurate... 相似文献
100.
Advanced Heavy Water Reactor (AHWR) is a pressure tube type boiling water reactor employing natural circulation as the mode of heat removal under all the operating conditions. Main heat transport system (MHTS) of AHWR is essentially a multi-loop natural circulation system with all the loops connected to each other. Each loop of MHTS has a steam drum that provides for gravity based steam–water separation. Steam drum level is a very critical parameter especially in multi-loop natural circulation systems as large departures from the set point may lead to ineffective separation of steam–water or may affect the driving head. However, such a system is susceptible to steam drum level anomalies under postulated asymmetrical operating conditions among the different quadrants of the core like feedwater flow distribution anomaly among the steam drums or power anomaly among the core quadrants. Analyses were carried out to probe such scenarios and unravel the underlying dynamics of steam drum level using system code RELAP5/Mod3.2. In addition, a scheme to obviate such problem in a passive manner without dependence on level controller was examined. It was concluded that steam drums need to be connected in the liquid as well as steam space to make the system tolerant to asymmetrical operating conditions. 相似文献