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641.
S. A. Aliev 《Semiconductors》2014,48(2):167-172
The thermal conductivity and thermopower are simultaneously studied in the semiconductors HgSe, HgTe, InP, GaAs, Cd x H1 ? x Te, and Ag2S in which the effect of electron drag by phonons was detected at low temperatures T. It is found that x = 1–3 in the dependences K ph ∝ T ?x . It is shown that the underestimated values of x are caused by phonon scattering at certain defects. It is also found that the maxima of K ph(T) and αph(T) coincide in all studied crystals, except for Ag2S. For the first time, it is found that the strong effect αph ∝ T ?3 is observed in Ag2S, the αph maximum is at T = 16 K, and the K ph maximum is at 27 K. The results obtained are in agreement with Callaway and Herring theory. The effect of magnetic field on the drag thermopower αph(T) in n-Cd x H1?x Te (in which the strong dependence αph ∝ T ?3 and the strong effect of the magnetic field on it are detected) is considered for the first time. The results are compared with the Askerov theory. The force parameter A ph(?) of the drag effect and its dependence on magnetic field are determined. 相似文献
642.
V. P. Povarov A. B. Tereshchenko Yu. N. Kravchenko I. V. Pozychanyuk L. I. Gorobtsov E. I. Golubev V. I. Bykov V. V. Likhanskii I. A. Evdokimov V. G. Zborovskii A. A. Sorokin V. D. Kanyukova T. N. Aliev 《Thermal Engineering》2014,61(2):123-132
The results of developing and implementing the modernized fuel leakage monitoring methods at the shut-down and running reactor of the Novovoronezh nuclear power plant (NPP) are presented. An automated computerized expert system integrated with an in-core monitoring system (ICMS) and installed at the Novovoronezh NPP unit no. 5 is described. If leaky fuel elements appear in the core, the system allows one to perform on-line assessment of the parameters of leaky fuel assemblies (FAs). The computer expert system units designed for optimizing the operating regimes and enhancing the fuel usage efficiency at the Novovoronezh NPP unit no. 5 are now being developed. 相似文献
643.
A continuously stirred tank reactor (CSTR) is largely used in water treatment and in chemical and biological processes. It is characterized by a complex non-linear behaviour. Operating large reactors in industry can be expensive, so a common trick used to reduce costs is to operate multiple CSTRs in series. Consequently, the CSTR is usually exposed to faults and noises. This paper addresses the design of a robust observer for estimation and fault diagnosis strategy on two CSTRs in series. The considered system is affected simultaneously by time-varying actuator and sensor faults with measurement noises. The Takagi-Sugeno multimodel approach is proposed to transform the non-linear model into an interpolation of several linear sub-models with non-measurable premise variables. The purpose of this brief is to provide the state and the fault estimation for the considered system using a proportional multiple integral (PMI) unknown input observer. The exponential stability conditions are studied with the Lyapunov theory and L2 optimization and formulated in terms of linear matrix inequalities. In addition, a comparative study with a PMI observer is conducted. Finally, the proposed observer is used for time-varying fault detection and isolation. 相似文献