[en] This article describes the responsibilities of nuclear power plant radiation protection personnel and discusses the radiation work management to be established in Sanmen Nuclear Power Plant from the perspectives of workplace environment dose rate data acquisition, radiation job classification, radiation protection equipment selection, foreign material exclusion, high flow passage pollution investigation and management, RWP management, as well as radiation dose control points, etc. (author)

[en] The diffusion reaction kinetics of weathered crust elution-deposited rare earth with mixed ammonium salts was studied. The influence of concentration of reagents and particle size of ore on diffusion rate was investigated. The results showed that the diffusion process and diffusion rate could be improved by increasing reagents concentration and decreasing diffusion flowing rate and particle size. The diffusion process could be explained with the shrinking core Model, which could be controlled by the diffusion rate of reacting reagents in porous solid layer.

[en] This paper demonstrates the discovery of coal-derived hydrocarbon in Dongsheng area with evidences in several aspects and expounds the relation between uranium mineralization and coal-derived hydrocarbon. The authors indicate that coal-derived hydrocarbon not only provide important reductant to uranium mineralization but also preserve the deposit. This study has supplied an new organic criteria for the uranium exploration and expended the field of organic geochemistry for uranium deposit research. (authors)

[en] Highlights: • The microstructures of as-cast BMGs undergo a composite-amorphous evolution. • The 15.1% of plasticity and the 2205 MPa of fracture strength are achieved. • The dispersed crystals in glassy matrix enhance the plasticity of BMG. - Abstract: This paper reports the microstructure evolution of Cu_5_0_._2 Zr_4_0_._8Ti_9_−_xNb_x (x = 0.5, 1.0, and 2.0 at.%) bulk metallic glass and bulk metallic glass composites accompanied with the addition of Nb and the corresponding mechanical properties. The X-ray diffraction and characterization of microstructures demonstrate that the microstructures of as-cast alloys undergo a composite-amorphous evolution. DSC analysis indicates that the glass-forming ability of as-cast alloys increases with addition of Nb. The microstructure evolution can be contributed to the combination of the stabilization of Nb on precipitated crystalline phases and cooling time. 1.0 at.% Nb-alloyed sample has the best plasticity (15.1%) and the highest fracture strength (2205 MPa) among three as-cast alloys. This work suggests that the uniformly dispersed tiny crystalline phases in glassy matrix can enhance the plasticity of bulk metallic glasses

[en] Highlights: • The equation, T_rg = T_g/T_l, was rotationally modified to T_rg = κ(T_m/T_l) + C/T_l. • The newly generalized equation suggests a way for describing glass-forming ability. • Several new Cu-based bulk metallic glasses were discovered by solidification range. - Abstract: In this paper, a new equation was rationally generalized from the reduced glass transition temperature. This equation indicates that solidification range can be used for describing glass-forming ability, which can be calculated with the aid of computational thermodynamic approach. Based on this scenario, several new Cu-based bulk metallic glasses in the ternary Cu–Zr–Ti alloy system were discovered. The as-cast samples were characterized by X-ray diffraction and transmission electronic microscopy. The results indicate that as-cast samples have monolithic amorphous nature. Thermal analysis validates that the smaller solidification range is closely related to the higher glass-forming ability, which is contributed to the effect of solidification time on the formation of bulk metallic glasses. This work also suggests that solidus can influence glass formation

[en] Herein, we reported a two-dimensional, two-phase mass transport model for a flat-plate microbial fuel cell (MFC) by evoking a membrane phase and a solid phase that employed in direct methanol fuel cells. In the present proposed MFC modeling, the liquid phase and solid phase correspond to proton transfer and electron transfer, respectively. The model established by this method overcomes the problem that it is difficult to establish the relationship between cathode and anode through the internal relation of the MFC in previous models. Finally the proposed model was employed to investigate the distribution of the concentration of the chemical components in the MFC, the overpotential and the bio-electrochemical reaction rates in biofilm and cathode catalyst layer. This model can be used as a framework for other types of MFC and it is suitable for optimization of the structure and internal mechanisms.

[en] Recovering uranium from uranium-rich coal ash is an important way to utilize unconventional uranium resource. Although it might be expected that the uranium in residual form would prevent uranium recovery from coal ash, raising the recovery rate in way of controlling residual uranium has not yet been studied. In this study, three different kinds of combustion promoting additives were investigated by coal combustion experiments, in order to decrease the proportion of residual-form uranium in ash and increase the acid leaching rate. Analytical procedures included Tessier sequential extraction, acidleaching, and characterization(ICP-MS, XRF, BET and SEM-EDS). It was showed that the effects of additives in reducing residual uranium were as the following order: alkaline earth metal compounds > transition metal compounds> alkali metal compounds. Adding alkali metal additives(KCl, NaCl, K₂CO₃, Na₂CO₃) raised the percentage of residual uranium largely. Additionally, one transition metal additive(Fe₂O₃) reached a decreasing amplitude of 5.15%, while the other two additives(MnO₂ and Fe₃O₄)made the rates increased. However, coal combustion with alkaline earth metal compounds mixed had target effects. Among this kind of additives(Ca(OH)₂, CaCO₃, CaO, CaCl₂), CaCO₃ displayed the best effect on restricting the rising proportion of residual uranium by 18%. Moreover, the leaching recovery research indicated that CaCO₃ could raise the recovery rate by 10.8%. The XRF profiles supported that the CaCO₃ could lower the concentration of SiO₂ in the bottom ash from 79.76% to 49.69%. Besides, The BET and SEM revealed that the decomposition of CaCO₃ brought about a variation of surface structures and area, which promoted the contact between the leaching agent and bottom ash. The uranium content increase was determined by ICP-MS and EDS. These findings suggest that CaCO₃ could be a favorable additive for the controlling of residual uranium and improvement of uranium recovery rates.

[en] Rock-Eval pyrolysis is introduced into the research of uranium geology by means of oil-gas geochemical evaluation. Hydrocarbon (oil-gas) components in DS sandstone-type uranium deposit are detected quantitatively. Through analyzing the oil-gas bearing categories of the uranium-bearing sandstones, the internal relationships between the uranium deposit and the oil-gas are revealed. Rock-Eval pyrolysis is an effective method to study the interaction between inorganic and organic matters, and should be extended to the study of sandstone-type uranium deposits. (authors)

[en] Atmospheric environment has become the focus of global attention. Fine particulate matter has posed a serious threat to human respiratory system. In order to effectively control atmospheric environment and protect human health, pollutant prediction has become a necessary work for human survival and development. In order to improve the accuracy of PM2.5 prediction, this paper developed a new combined prediction model — SSA-LSTM. Firstly, the observed time series are decomposed into periodic component and noise component by SSA (Singular spectrum analysis). Then, LSTM (Long short-term memory) neural network was used to forecast the decomposed components. Finally, the predicted results of different components are integrated to generate the final predicted results. The results show that the proposed model has a significant improvement in the accuracy of prediction. (paper)

[en] The lepton-flavor violating process J/ψ→ll'(l≠l') serves as an ideal place to probe the unparticle theory. Such a process can only occur at loop level in the Standard model (SM), so that should be very suppressed; by contrast, in the unparticle scenario, it happens at tree level and its contribution may be sizable for practical measurement. Moreover, the BESIII will offer the largest database on J/ψ, which makes more accurate measurements possible. Furthermore, for such purely leptonic decays the background is relatively low and the signal would be cleaner. Our work carefully investigates the possibility of observing such processes from both theoretical and experimental aspects. (orig.)