[en] Microcalorimetric titrations have been performed in acidic aqueous solution at 25 deg. C to calculate the complex stability constants (K_S) and thermodynamic parameters (ΔG deg., ΔH deg., and TΔS deg. ) for the stoichiometric 1:1 complexation of lanthanoid(III) nitrates (La-Gd, Tb) with 5,11,17,23-tetrasulfonato-25,26,27,28-tetrakis (hydroxycarbonylmethoxy)calix[4]arene (2) and 5,11,17,23-tetrasulfonato-thiacalix[4]arene (3). Using the present and previous reported data on water-soluble calix[4]arenesulfonates (1) and structurally related analogues 2 and 3, the complexation behavior is discussed comparatively from the thermodynamic point of view. Possessing four carboxyls at the lower rim of parent calix[4]arenesulfonate (1), the derivative 2 displays the enhanced binding abilities for Sm³⁺. As compared with 1 and 2, p-sulfonatothiacalix[4]arene (3) gives not only the lower binding constants for all of lanthanoid(III) ions but also lower cations selectivity. Thermodynamically, the resulting complexes of lanthanoid(III) ions with 1 and its derivatives 2 and 3 is absolutely entropy-driven in aqueous solution, typically showing larger positive entropy changes. These larger positive entropy changes (TΔS deg.) and somewhat smaller positive enthalpy changes (ΔH deg.) are directly contributed to the complexes stability as a compensative consequence

[en] In this paper a new coding and decoding method is presented in allusion to nuclear power plant reactor reloading optimization. Taking the advanced nuclear reactor as an example, optimization calculation has been carried out by Simulated Annealing (SA) algorithms. Comparison between the optimization results and the results by Genetic Algorithms (GA) shows that SA is as effective as the GA for this nuclear power plant reactor reloading optimization

[en] Aiming at infrared thermal images with different buried depth defects, we study a variety of image segmentation algorithms based on the threshold to develop global search ability and the ability to find the defect area accurately. Firstly, the iterative thresholding method, the maximum entropy method, the minimum error method, the Ostu method and the minimum skewness method are applied to image segmentation of the same infrared thermal image. The study shows that the maximum entropy method and the minimum error method have strong global search capability and can simultaneously extract defects at different depths. However none of these five methods can accurately calculate the defect area at different depths. In order to solve this problem, we put forward a strategy of “divide and conquer”. The infrared thermal image is divided into several local thermal maps, with each map containing only one defect, and the defect area is calculated after local image processing of the different buried defects one by one. The results show that, under the “divide and conquer” strategy, the iterative threshold method and the Ostu method have the advantage of high precision and can accurately extract the area of different defects at different depths, with an error of less than 5%.

[en] In recent years, power uprate is successfully applied in many nuclear power plants. Moreover, a longer cycle, higher uprate burnup and lower leakage fuel management strategy could enhance the fuel utilization. Therefore, the purpose of this article is to study a longer cycle, uprate burnup and lower leakage fuel management for a 300 MWe NPP after power uprate. The results show that the concluded fuel management scheme for a 300 MWe NPP after power uprate achieves the projected 18- month refueling cycle design objectives with the nominal thermal power of 1250 MW and meets the design criteria. As compared to the current fuel management strategy of a 300 MWe NPP, the advanced strategy in present study gains a power uprate, enhances the fuel utilization and improves the operation economy. As a technical support and reserve, the study will provide significant instructions on power uprate of a 300 MWe NPP and optimization of fuel management strategy. (authors)

[en] Highlights: • Two new “CO₂-philic” compounds were designed and synthesized. • The tested solubility data were calculated and correlated with three models. • Better agreements were obtained with JCF model between the tested and calculated data. • End group influence on solubility in scCO₂ has been discussed. • The partial molar volumes V^¯₂ for three compounds were estimated. -- Abstract: The modifications for the end group of 2-methyl-2-propyl-1,3-propanediol (compound 1) were achieved by reacting with methyl oxalyl chloride and methyl malonyl chloride to generate two new CO₂-philic compounds: bis(methoxyoxalic)-2-methyl-2-propyl propylene glycol ester (compound 2) and bis(methoxymalonic)-2-methyl-2-propyl propylene glycol ester (compound 3). After that, the solubilities of these three compounds were tested and compared in supercritical carbon dioxide (scCO₂) within the temperature range of (313 to 353) K and in the pressure range of (9.3 to 19.0) MPa. The influence of molar mass and end group on the solubility of compound was also studied. In addition, the experimental solubility data were correlated according to Bartle, Chrastil and JCF model, and good consistencies were obtained. The average absolute relative deviation (AARD) of the measured values were (5.83, 8.98, 8.77)% when using Bartle’s method, (10.95, 7.53, 7.55)% for Chrastil’s method, and (6.89, 4.10, 4.19)% for the JCF method, respectively. It is obvious that the JCF model was proven to be the best model because it had more adjustable parameters of temperature and pressure. Finally, the partial molar volumes V^¯₂ for each compound in the supercritical phase were estimated in accordance with Kumar and Johnston’s theory

[en] A five-year pilot Component Life Assessment of Nuclear Power Plant (NPP) Program was initiated in 1987 to investigate the aging mechanisms and develop the evaluation methodology for the operating nuclear power plant in Taiwan. In this program the components were categorized into structural and functional components for easy implementation of life assessment methodology. The aging trends of the functional components were investigated by analyzing the work request records. The evaluation of the structural components has mainly focused on the failure mechanism studies and the integrity analysis. Components reviewed in this study included part of the items where acute aging evaluations were required for 10-year operation license renewal application. The selected structural components for assessment were reactor pressure vessel, vessel internal components, and vessel support structure. The functional components were emphasized on mechanical components which included pumps, valves, and snubbers. In addition, some parallel research programs regarding to life assessment models for other components such as turbines, pipings and the heat exchangers were also briefly discussed in this paper. (author)

[en] The study on 1032-A type controllable neutron source is described. The source can meet with inelastic scattering of fast neutron and material, generate inelastic γ-ray and measure its characteristic energy, and examine explosive material and other substance component

[en] Highlights: • A 3D thermal model was developed to simulate the XPP melt packing process. • Simulations of 3D viscoelastic melt packing process were performed. • The heat transfer and flow-induced stresses in 3D cavities were analyzed. • Effects of processing conditions on the stress and density were studied. - Abstract: In this study, a 3D weakly compressible viscoelastic flow model with the thermal effect is developed for simulations of the non-isothermal XPP melt packing process. The 3D multi-field coupled model is solved by the collocated finite volume CLEAR algorithm with the AVLSMART scheme. The numerical model is validated against the benchmark problem. The XPP melt packing process in a rectangular cavity is simulated, and the predicted flow-induced birefringence is in agreement with the experimental and numerical results reported in the literature. For a case with a rather complex cavity, the XPP melt packing process in a 3D hemispherical shell cavity is further simulated. The distributions of melt temperatures, flow-induced stresses as well as the corresponding rheological characteristics of XPP melt in 3D cavity are vividly presented, which are difficult to be captured by previous simulations and experiments. Especially, the present model allows the effects of melt temperature and holding pressure on the first normal stress difference and density to be studied. It is shown that with an increase in melt temperature, the absolute values of the first normal stress difference increases slightly and the density decreases gradually, while the high holding pressure improves significantly the first normal stress difference and density. Numerical results demonstrate that the present 3D thermal model is an effective tool for simulating real-world viscoelastic polymer melt packing processes.

[en] Objective: To explore the imaging features and diagnostic value of ¹⁸F-FDG PET/CT in pulmonary lymphangitic carcinomatosis (PLC). Methods: Retrospective analysis on 53 PLC cases was performed. The patients underwent PET/CT + thin breath hold CT scanning. The PET images were attenuated by CT scanning data and reconstructed by TrueX + time of flight method. The mean standardized uptake value (SUVmean) of each region of interest was measured, and the standardized uptake ratios (SUR) value was calculated. The difference of the SUVmean and SUR values in different regions was compared. Results: Among the 53 patients with PLC, 51 (96%, 51/53) displayed interlobular septal thickening of the interlobular septa with radioactive uptake, and the lung SUVmean was significantly higher than that of the normal lung field (1.46 ± 0.92 vs. 0.58 ± 0.18, t = 19.85, P < 0.01). The interlobular septal thickening lung/mediastinal blood pool SUR was higher than that of the normal septal lung/mediastinal blood pool SUR (0.84 ± 0.38 vs. 0.40 ± 0.21, t = 12.77, P < 0.01), and 51 cases (96%, 51/53) manifested bronchovascular bundle uptake enhancement. The SUVmean of PLC involving bronchovascular bundle was significantly higher than that of normal bronchovascular bundle (3.85 ± 1.67 vs. 0.90 ± 0.19, t = 15.45, P < 0.01). The SUR of the thickened bronchi vascular bundle/mediastinal blood pool was higher than that of the normal bronchovascular bundle/mediastinal blood pool SUR (2.89 ± 0.94 vs. 0.59 ± 0.19, t = 12.62, P < 0.01). In 51 cases (96%, 51/53), the swelling of the hilum and mediastinal lymph nodes was enhanced with radioactivity. Conclusions: PET/CT fusion imaging of typical patients with PLC is characterized by the thickening of bronchial vascular bundles with radioactive concentration and thickening of the interlobular septal nodules with increased uptake of radioactivity. Moreover, the hilar and mediastinal lymph nodes were enlarged or normal with abnormal concentration of radioactivity. PET/CT fusion imaging combined with local SUVmean and SUR can measurements not only enables the early and accurate diagnosis of PLC lesions. (authors)

[en] EPM method for two dimensional elastic-plastic hydrodynamic calculation, which couples Eulerian and Lagrangian methods, is presented in this paper. The difference scheme is constructed by means of contour integral. This method includes sliding interfaces treatment, several generating meshes technique, and so on. It can be widely applied to calculations of many hydrodynamic problems