The State Oriented Procedure (SOP) is developed to improve the existing emergency operation procedures, namely, the Event Oriented Procedure (EOP). It is developed based on the finite Nuclear Steam Supply system (NSSS...
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Metallic insulation is commonly used in reactor vessel because of its resistance to radiation and corrosion. Since the main mode of heat loss of reactor vessel is thermal radiation, the ability to prevent radiation he...
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Ni-ZrO2-CeO2 nanocomposites were prepared by double-pulse current in an ultrasonic field. The effect of average current density, duty ratio and frequency of double-pulse current on nanoparticles content of Ni-ZrO2-CeO...
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ISBN:
(纸本)9783037858271
Ni-ZrO2-CeO2 nanocomposites were prepared by double-pulse current in an ultrasonic field. The effect of average current density, duty ratio and frequency of double-pulse current on nanoparticles content of Ni-ZrO2-CeO2 nanocomposites was studied. Meanwhile, surface morphology and microhardness of nanocomposites were analyzed. The results show that, with the positive average current density, positive duty ratio and positive frequency increased, the nanoparticles contents increased at first and then decreased. On the contrary, it reduced while reverse average current density, reverse duty ratio and reverse frequency were increasing. Compared with Ni-ZrO2-CeO2 prepared by direct current and monopulse current, grain of Ni-ZrO2-CeO2 nanocomposite prepared by double-pulse current is finer, the microhardness is also higher.
Vacancy-type defects in Fe-2%A1_2O_3 (ODS-Fe) and pure Fe produced by helium ion irradiation at room temperature were investigated using positron beam Doppler broadening energy spectra (DBES). Defect profiles of the S...
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Vacancy-type defects in Fe-2%A1_2O_3 (ODS-Fe) and pure Fe produced by helium ion irradiation at room temperature were investigated using positron beam Doppler broadening energy spectra (DBES). Defect profiles of the S parameter derived from DBES as a function of positron incident energy up to 20 KeV were analyzed. The S parameter values of the damaged layer for the ODS-Fe are smaller than those of pure Fe for irradiation dose of le+16/cm~2. This finding indicates that ODS-Fe has a higher irradiation resistance than pure Fe. It also suggests that helium irradiation induced point defects in ODS-Fe were trapped and annihilated at the interfaces between the Fe matrix and the A1_2O_3 nanoparticles. The S-W curves indicate that only one type of defect was formed in the post-irradiated ODS-Fe. Vacancy clusters and helium-vacancy complexes were identified as the main defects. The defects are complicated for the irradiated pure Fe, for which the surface defects are different from the ones inside bulk.
Tribological properties of impregnated graphite are greatly influenced by preparation technology and working conditions and it’s highly susceptible to corrosion environmental impacts,but the experimental research abo...
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Tribological properties of impregnated graphite are greatly influenced by preparation technology and working conditions and it’s highly susceptible to corrosion environmental impacts,but the experimental research about it are *** this paper,three kinds of impregnated graphite samples are prepared with different degree of graphitization,the tribological properties of these samples in the dry friction environment and in a corrosive environment are analyzed and *** tribo-test results show that the friction coefficient of samples is reduced and the amount of wear of samples increase when the graphitization degree of samples increases in dry friction *** in a corrosive environment（samples are soaked N2O4）,the friction coefficient and amount of wear are changed little if the graphitization degree of samples are *** the degree of graphitization increase,the friction coefficient and amount of wear of samples increase too,the amount of wear is 2 to 3 times as the samples tested in the non-corrosive environment under pv value of 30MPa？m/*** impregnated graphite,which friction coefficient is stable and graphitization degree is in mid level,such#2,is more appropriate to have a work in the corrosion *** this paper,preparation and tribological properties especially in corrosive environment of the impregnated graphite is studied,the research conclusion can provide an experimental and theoretical basis for the selection and process improvement of graphite materials,and also provide some important design parameters for contact seal works in a corrosive environment.
Vibration characteristics analysis is important in the design of multi-span pipeline with different support conditions. In order to analyze the natural frequency and the vibration modal of the multi-span pipeline, a m...
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Vibration characteristics analysis is important in the design of multi-span pipeline with different support conditions. In order to analyze the natural frequency and the vibration modal of the multi-span pipeline, a matrix transfer method is proposed in this paper. With the multi-span pipeline divided into single-span pipes, the transmission formulas for the deflection, angle, bending and shear between two adjacent spans are deduced, in combination with the Krylov function solution of the free vibration equation for the single-span pipe, and the constraint condition between the two adjacent spans of the multi-span pipeline. According to the boundary conditions on the starting and ending spans, the natural frequency equation and the vibration modal function between two adjacent spans of the multi-span pipeline are presented. The FORTRAN program based on the above principle is written, and the natural vibration frequencies and the vibration modals of two typical multi-span pipelines are investigated and compared with the results from ABAQUS. It is shown that the model presented in this paper is efficient in the analysis of multi-span pipeline and has the advantages of high computational efficiency and convenience for engineering practice application.
In order to improve safety, economy and reliability of NPP(nuclear power plant) and to make the best of human, material and information resources in the NPP, a specific function model developing method for integrated ...
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