[en] The prior austenite grain size, bainite colony size and average grain size after intercritical quenching in A508-3 steel have been measured, and factors which have an effect on them have been discussed. The results have shown that a small amount of aluminium contained would induce serious mixed structure with fine and coarse grains in the prior austenite. Fast cooling rate would give fine bainite colony and very fine grain structure could be obtained by means of the intercritical quenching

[en] By means of optical and electron microscope, the microstructures of A508-3 steel after heat treatment have been investigated. The results indicated that the granular bainite can be formed by cooling at the intermediate rate (70-480 deg C/min), the island structure disappeared, and the alloy carbide Mo₂C uniformly precipitated in the matrix after high temperature tempering. The precipitation of Mo₂C would effect on strength and toughness. Addition of niobium in a small amount was suggested in order to prevent the precipitation

[en] By means of TEM technique the orientation relationships of cementite, precipitated from islands of granular bainite during tempering, with ferrite have been observed. By calculating the eigenvalue and eigenvector of transformation matrix, Isaichev relationship has been analyzed. The results indicate that Isaichev relationship indeed is the sum of Kurdjumov-Sachs relationship and Pitsch relationship, so the viewpoint that the cementite with Isaichev relationship precipitates from austenite, in stead of ferrite, is confirmed. Moreover, the matrix calculation shows that three reported orientation relationships among austenite, ferrite and cementite in pearlitic transformation cannot be simultaneously valid

[en] The improved Gear method-IGear for solving the point reactor neutron kinetics equations is presented. Because of its higher order and greater region of stability, it can not only retain the advantage of gear-better applicability and precision, but also improve its shortcoming. So the IGear method can be applied to different kinds of reactivity conditions with flexibility. The numeric results indicate: From the cpu time and accuracy, IGear can meet the demand of the practical engineering completely, so it is a better method for solving point reactor kinetics equations. (authors)

[en] By means of electron microscopy, the tempering transformation of granular bainite was investigated in A508-3 steel. The results showed that granular bainite possessed high stability against tempering. During tempering the recovery and recrystallization took place and Mo₂C was precipitated in the lathy bainite ferrite. In the island structure cementite was precipitated, as martensite and austenite decomposed in tempering. In addition, the effect of microstructural change on mechanical properties was discussed

[en] The corrosion-resistance in humid air at 70 degree C and 40 degree C of uranium treated with CO has been studied using weight gain method. The results show that the oxidation-resistance of treated uranium in moist air has not been enhanced obviously at 70 degree C, but has been improved clearly at 40 degree C. Increasing dose of CO in the experimental range gives the better results. The composition of surface layer of uranium and treated uranium have been analyzed respectively by Auger Electron Spectroscopy (AES). The analysis indicates that there is a rich-carbon layer formed in the surface layer after uranium has been treated with CO, and this rich-carbon layer is probably important to enhance the corrosion-resistance of uranium

[en] This article introduced the development background of the Operation Log Management System of Qinshan II, the implementation process, module's function and actual usage; discussed and summarized the beneficial experience from Qinshan II's operation information-based management that can be used for reference. (authors)

[en] The article describes the main point about overpressure accident analysis of the primary coolant system, the main steam system, containment system of nuclear power plant, involving the acceptance criteria, the initial boundary conditions and parameters, analysis scope, methodology and so on. It combines with the power plant license request and the latest research results, the specific principles of the requirements on the balance between interests and security around the nuclear power industry, outlining problems and solutions encountered in the review process. The aim is to explore how to further improve the overpressure analysis, promoting the power plant license requesting and review process. (authors)

[en] The relationship between the valence electron structure of alloys and their irradiation swelling behaviour is investigated, on basis of results of their valence electron structure calculated by means of the empirical electron theory. The difference of the irradiation swelling behaviour among three prior candidate alloys is explained by their different valence electron structure. The intrinsic relation between nickel amount of alloys, including austenitic stainless steels and nickel alloys, and their irradiation swelling behaviour is clarified. From the viewpoint of valence electron structure, intermetallic compounds are potential structural materials with excellent resistance to irradiation swelling

[en] In this article, we study the pseudoscalar bound state η _c 'f₀(980) (irrespective of the hadro-charmonium and the molecular state) with the QCD sum rules. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states η _c 'σ(400-1200), η _b '''f₀(980) and η _b ''' σ(400-1200), and make reasonable predictions for their masses. (orig.)