[en] Highlights: • Crystal structure of the C-terminal (CT) domain of Swt1 was determined at 2.3 Å. • Structure of the CT domain was identified as HEPN domain superfamily member. • Low-resolution envelope of Swt1 full-length in solution was analyzed by SAXS. • The middle and CT domains gave good fit to SAXS structural model. - Abstract: Swt1 is an RNA endonuclease that plays an important role in quality control of nuclear messenger ribonucleoprotein particles (mRNPs) in eukaryotes; however, its structural details remain to be elucidated. Here, we report the crystal structure of the C-terminal (CT) domain of Swt1 from Saccharomyces cerevisiae, which shares common characteristics of higher eukaryotes and prokaryotes nucleotide binding (HEPN) domain superfamily. To study in detail the full-length protein structure, we analyzed the low-resolution architecture of Swt1 in solution using small angle X-ray scattering (SAXS) method. Both the CT domain and middle domain exhibited a good fit upon superimposing onto the molecular envelope of Swt1. Our study provides the necessary structural information for detailed analysis of the functional role of Swt1, and its importance in the process of nuclear mRNP surveillance

[en] The self-designed integrated small module reactor (SMR) operates with boric core, which determines that the boron transportation and reactivity feedback process cannot be simulated by system code THEMIS. In this study, a simulation method for boron reactivity was established based on the best estimation system code RELAP5, then the sequence of a postulated main steam pipeline broken accident of domestic generation III nuclear power plant was analyzed basing on this method to validate this method. At last, the postulated boron dilution accident sequence of self-designed SMR was simulated; the result showed that the core will return to be critical at 5110.0 second after the starting of the accident, and corresponding countermeasures should be taken to cease the boron dilution process. (authors)

[en] The reactor coolant pump is the key equipment of nuclear power plant. The pump-induced pulsation will induce the vibration of main components of primary equipment, which is one of the main reasons for component fatigue failure. For AP1000 nuclear power plant, the special layout of RCP and SG aggravate this influence. A simplified modeling is established for the pump-induced pulsation of heat transfer tubes of AP1000 steam generator, and the calculation results can be used for the fatigue analysis and assessment for the heat transfer tubes of steam generator. (authors)

[en] To make sure the quick load tracking and stable operation in particular cases, the control system of nuclear power plant demands not only the control of typical working condition(such as: fast power increase/reduction, load dump), but also stable operation of nuclear power plant in special working condition(such as single-reactor and Multi-turbine, Multi-reactor and single-turbine), to improve the ability of quick load tracking of Multi-reactor and Multi-turbine Nuclear Power Plant (MM-NPP). In this paper, as the system of MM-NPP, the simulation models of nuclear power plant are established, which include the models of controlled member and control system. And its dynamic characteristic of MM-NNP in special working condition is simulated. The simulation and research results show that the control system can meet the need of condition transformation in special working condition and MM-NNP stable operation, keep the marine load and power smooth and steady. (authors)

[en] Flow inversion and residual heat removal is both important problem for research reactor, as during normal operation, coolant flow up to down in the core. Tank in pool layout is usually used in high power and high pressure research reactor, the process of those problems is more complicated. For these reactors, the pressure vessel is immerged in the reactor pool, it is better choosing passive residual heat removal method, during long time after shutdown, there are many method to remove residual heat. The heat removal method during long time for tank in pool research reactor was studied in the paper, many ways was researched for the ability of heat removal and safety of core, a more safe, efficient and simplified way was achieved in the paper. (authors)

[en] Surface plasmon interference lithography based on grating diffraction has been studied both theoretically and experimentally in recent years. In this paper, we demonstrate that the cavity resonance in the grating slits can improve the subwavelength interference, not only the intensity but also the uniformity of the pattern. Both the typical lithography structure which merely consists of periodic metallic gratings and the modified structure equipped with a reflection layer are studied. The finite element method has been performed to study the interference pattern. Numerical simulations show that the property of the interference pattern is the optimum when cavity resonance happens. This enhancement can be applied to all the lithography structures which are based on the grating diffraction. (paper)

[en] PLA-PEG copolymer is wildly applied in medical and pharmaceutical fields, but its mechanical properties are not so good, such as the tensile intensity and elongation at break. To improve these properties, PLA-PEG copolymers were synthesized and irradiated using low energy electron beams (EB) with various irradiation doses in the presence of 3 wt% polyfunctional monomer (triallylcyanurate, TAC) as crosslinking agent to introduce crosslinking between polymer chains. It was found that with the increase of the irradiation doses, the tensile intensity of the PLA-PEG increased, while the elongation at break decreased, the most optimal irradiation dose was 80 kGy, the tensile intensity was 12.5 MPa and 19.9 MPa, corresponding to the elongation at break of 282.8 % and 28.7% for PLA9-PEG6 and PLA11-PEG6, respectively. Meanwhile, the solvent resistance of crosslinked sample was improved obviously at this dose. The crosslinked PLA-PEG copolymer can be applied to packaging materials, tubes and so on. (Author)

[en] Layout of reactor vessel in a pool is usually used in high power and high pressure research reactor. For these reactors, the pressure vessel is immerged in a pool, both active and passive residual heat removal system was adopted by the reactor. The paper study the defensive strategy after station blackout accident, multi-condition was analyzed using Relap5 code, heat removal ability and safety of the core was studied, the suggestion was given to the strategy for the reactor after SBO accident. (authors)

[en] Highlights: • All-polymer solar cells (All-PSCs) based on PTzBI:N2200 system were fabricated by blade-coating in ambient environment. • A weakly ordered molecular packing morphology as well as small phase separation was obtained in N2200-based system. • All-PSCs simultaneously exhibited good photovoltaic performance (8.36%) and prominent mechanical characteristic (15.6% COS). -- Abstract: All-polymer solar cells (all-PSCs) are the most promising power generators for flexible and portable devices due to excellent morphology stability and outstanding mechanical property. Previous work indicates high crystallinity is beneficial to device performance but detrimental to mechanical property, therefore identifying the optimized ratio between crystalline and amorphous domains becomes important. In this work, we demonstrated highly efficient and mechanically robust all-PSCs by blade-coating technology in ambient environment based on PTzBI:N2200 system. By controlling the aggregation in solution state and ultrafast film formation process, a weakly ordered molecular packing morphology as well as small phase separation is obtained, which leads to not only the good photovoltaic performance (8.36%-one of the best blade-cast device in air) but also prominent mechanical characteristic. The controlled film shows a remarkable elongation with the crack onset strain of 15.6%, which is the highest result in organic solar cells without adding elastomers. These observations indicate the great promise of the developed all-PSCs for practical applications toward large-area processing technology.

[en] Will the CO₂ capture be affected by the N-doping? This question remains conflict due to the effect of oxygen content in N-doped porous carbons on CO₂ uptake has not been systematically investigated. Herein, the effects of N-free and N-doped porous carbons on CO₂ uptake were investigated by experiments and theoretical calculations. To elucidate the relative influences of nitrogen functional groups, we synthesized a series of carbons without or with N-doping (2.73–9.44% N) by varying the synthesis conditions. Experimental results show that the introduction of oxygen and nitrogen into carbon framework improves CO₂ capture in porous carbons (PCs) and N-doped porous carbons (NPCs). Among these samples, the NPC600 exhibits an exceptionally high CO₂ adsorption capacity (5.01 mmol g⁻¹ at 1 bar and 25 °C). Based on the theoretical calculations, the introduction of nitrogen into carbon framework with high oxygen content further enhances electrostatic interaction for CO₂ adsorption. Moreover, the doping of nitrogen to carbon framework also has a greater effect on both the selectivity for CO₂/N₂ and the isosteric heat of CO₂ adsorption. It is predicted that this investigation will eliminate any ambiguities and better explain the influence of N-doping on CO₂ capture.