[en] There are several methods of measuring concentrations but nuclear track detector cylindrical dosimeters are widely used. It has the advantages of high sensitivity, availability, low cost and ease of operation due to smaller size. It can be used to measure the radon concentration of dwellings, atmosphere, soil and water. In this paper, a Monte Carlo code was given to calculate the detection efficiency of dosimeter with different radius, and the simulation result gave the optimum radius as 3.0 cm. This result can be seen as a reference when designing dosimeters. (authors)

[en] Modification of SrTiO₃ (STO) surface by nitrogen ion bombardment was performed in order to achieve a strong and broadband photocatalysis in STO via incorporations of nitrogen ions and surface defects. Enhanced UV photocatalysis and a fairly strong visible-light one were observed in nitrogen ion-bombarded STO. UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy, cross-sectional transmission electron microscopy, atomic force microscopy and contact angle measurements were performed. The characterization results revealed that nitrogen ions and surface defects were introduced simultaneously. The incorporated nitrogen ions were found to narrow the band gap of STO, and the surface defects acted as extra adsorptive sites, which make a strong and broadband photocatalysis possible. Our work indicates that nitrogen ion bombardment is an effective method to enhance the photocatalytic ability of STO in a synergetic manner.

[en] Highlights: • Fine-search strategy was proposed to improve the performance of RWCE. • Fine-search strategy can enhance the global search ability of continuous variables. • FS-RWCE could refine and enhance the evolution of integer variables in HENS. • FS-RWCE was demonstrated reliable and applicable to large-sized HENS problems. - Abstract: Heat exchanger network synthesis has been extensively studied in process system engineering for its complexity and difficulty resulting from stream matches and the nonlinearity of continuous variables. Stochastic methods have difficulties in finding the precise optimum solution on the near optimal regions and expanding the integer variables optimization in the late evolution. Therefore, a novel fine-search strategy was established on the basis of the evolutionary mechanism of random walk algorithm with compulsive evolution. The fine-search strategy was efficient in achieving the accuracy of solutions for a certain heat exchanger network structure. Then, the fine-search strategy and Random Walk algorithm with Compulsive Evolution were integrated to enhance and refine the optimization for continuous and integer variables in heat exchanger networks synthesis simultaneously. The integrated method could satisfy the needs of global and local search abilities for heat exchanger network synthesis. Finally, the proposed method was applied in three different-sized cases and more economical in contrast to the best results with no splits published thus far were obtained.

[en] Nuclear authority and endusers have reviewed the safety related impact of external flooding accident on nuclear power plant after Fukushima NPP accident. The present emergency operation procedures which are used in domestic second generation NPP, are not include the special procedure to deal with external flooding accident. This paper analyse the nuclear safety impact of external flooding accident on one domestic second generation NPP by flooding margin analysis (FMA). Based on the design of the protection system and engineered safety features, several successful path are selected that could bring the plant to a stable condition and maintain that condition. The capablity of anti-external flooding can be confirmed by the analysis of equipments in the key successful path, and offer technical supports for the improvement of anti-external flooding capability of a nuclear power plant. (authors)

[en] The draft of event orientation emergency operation procedure (EOP) is based on the research of accident evolution which has been defined in advance. With the feedback of nuclear events and accidents, and better understanding of nuclear safety, events and accidents which are not considered will be added in EOP. The design and application of new procedure High Activity of Primary Loop (I RCP 10) is based on this kind feedback, and the requirement of the nuclear authority. The purpose of this procedure is to control the nuclear power plant reasonably and effectively in loss of integrity of the fuel elements, and to ensure that the radioactivity will not cause any damage to operators and later waste processing. (authors)

[en] A code for simulating the passive containment heat removal system of nuclear power plants was developed. Code development methodology, subroutine dividing, code structure and physics model were investigated. And related test was done to validate that the code calculation result is reliable. The code development method, physics model and numerical solution method would be used as a support for the future design and analysis and engineering application. (authors)

[en] Interfaces play key roles in determining mechanical properties of materials. In current work we perform molecular dynamics simulations of diffusion bonding to evaluate the effect of temperature on the morphology of the Ni/Al interface and the strength of the diffusion bonded Ni/Al nanowires. The centro-symmetry parameter is adopted to identify defect atoms generated. Simulation results show that the thickness of the Ni/Al interface has strong dependence on the temperature of diffusion bonding. Following uniaxial tension tests indicate that the yield strength of Ni/Al nanowires is smaller than both the single crystalline Ni and Al nanowires, because of the Ni/Al interface acting as dislocation source and the mobilization of pre-existing dislocations at high temperature. It is shown that the mechanical properties of diffusion bonded Ni/Al nanowires strongly depend on the temperature.

[en] Objective: To evaluate the performance of fixed field Intensity modulated radiation therapy (IMRT) and RapidArc in the radiotherapy for multiple intracranial metastases. Methods: The clinical data of 10 patients with multiple intracranial metastases, 8 male and 2 female, aged 65-73, were used to design 3 plans: fixed field IMRT, RapidArc with single Arc (RA1), and RadpidArc with double Arc (Arc 2). Dose-volume-histogram analysis was used to compare dose results, monitor unit, and delivery time. Results: All 3 plans met the clinical requirements. The best target conformity and homogeneity were observed in the RA2 plan (Z=-2.803, -2.904, P<0.05) and there were no statistical differences between the IMRT plan and RA1 plan. The maximum doses to the lens, eyes, and brainstem of the two RapidArc plans were all significantly lower than those of the IMRT plan (Z=-2.803, -2.191, P<0.05), and the maximum dose to the optic nerves of the RA2 plan was significantly lower than that of the IMRT plan (Z=-2.293, -2.701, P<0.05). Compared with the IMRT plan, the average monitor units of the RA1 and RA2 plans were reduced by 29 % and 24 %, respectively, and the delivery time of these plans were significantly shorter by 84% and 69%, respectively. Conclusions: Compared to the IMRT plan, RapidArc plans with single or double Arcs show similar or better effects in the target dose distribution, reduction of irradiation doses on organs at risk and, moreover, significant decrease of the monitor units and delivery time. (authors)

[en] This work shows the design, setup and performance of a new radon detector calibration chamber developed at the Research Institute of Chemical Defence. We detailed discussed the method for establishment and indetermination of radon concentration, analyzed all kinds of factors that influence the performance of the radon chamber. (authors)

[en] Highlights: • The bubble departure diameter is proportional to g^−0.425 in quiescent fluid. • The bubble release frequency is proportional to g^0.678 in quiescent fluid. • The simulation result supports the transient micro-convection model. • The bubble departure diameter has exponential relation with inlet velocity. • The bubble release frequency has linear relation with inlet velocity. -- Abstract: Nucleate boiling flows on a horizontal plate are studied in this paper by a hybrid lattice Boltzmann method, where both quiescent and slowly flowing ambient are concerned. The process of a single bubble growth on and departure from the superheated wall is simulated. The simulation result supports the transient micro-convection model. The bubble departure diameter and the release frequency are investigated from the simulation result. It is found that the bubble departure diameter and the release frequency are proportional to g^−0.425 and g^0.678 in quiescent fluid, respectively, where g is the gravitational acceleration. Nucleate boiling in slowly flowing ambient is also calculated in consideration of forced convection. It is presented that the bubble departure diameter and the release frequency have exponential relationship and linear relationship with inlet velocity in slowly flowing fluid, respectively