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[en] Highlights: • Co doped ZnO:Co nanorods were grown by hydrothermal method. • The NO_2 response reaches a maximum value of 88 at 210 °C. • The stability of NO_2 on ZnO is enhanced with the presence of V_O. - Abstract: Highly ordered Co doped ZnO:Co nanorods arrays with Co concentrations of 1.6, 1.9 and 3.1 at% were uniformly grown on FTO glass substrate by hydrothermal method. The X-ray diffraction patterns of the undoped and Co doped ZnO nanorods revealed characteristic peaks of (1 0 0), (0 0 2), (1 0 1), (1 0 3) and (1 1 2), corresponding to the hexagonal wurtzite phase of ZnO. For ZnO:Co nanorods with Co concentrations of 3.1 at%, the NO_2 response reached a maximum value of 88 at temperature of 210 °C. However, the response of ZnO:Co nanorods with Co concentrations of 3.1 at% decreased from 82 to 29 with the increasing of O_2 annealing temperature from 0 to 700 °C. As confirmed by the XPS, PL, Raman and I–V results, the oxygen vacancies and electron concentrations were the dominating effects and an oxygen vacancy mediated NO_2 sensing mechanism was presented and discussed.
[en] As a new-emerging method for strontium disposal, biosorption has shown advantages such as high sorption capacity; low cost. In this study, we investigated the potential of Saccharomyces cerevisiae (S. cerevisiae) in strontium disposal under culture conditions and the effects of irradiation on their biosorption capabilities. We found that S. cerevisiae can survive irradiation and grow. Pre-exposure to irradiation rendered S. cerevisiae resistant to further irradiation. Surprisingly, the pre-exposure to irradiation can increase the biosorption capability of S. cerevisiae. We further investigated the factors that influenced the biosorption efficiency, which were (strongest to weakest): pH > strontium concentration > time > temperature. In our orthogonal experiment, the optimal conditions for strontium biosorption by irradiated S. cerevisiae were: pH 7, 150 mg L-1 strontium at the temperature of 32 °C with 30 h. The equilibrium of strontium biosorption was analyzed by Langmuir and Freundlich models, from which the formal model is found to provide a better fit for the experimental results. The kinetics of strontium biosorption by living irradiated S. cerevisiae was found to be comprised of three phases: dramatically increased during 0–9 h, decreased during 12–24 h, and increased during 30–50 h. These results provide a systematic understanding of the biosorption capabilities of irradiated S. cerevisiae, which can contribute to the development of remediating nuclear waste water. - Highlights: • A new biological materials was designed (irradiated S. cerevisiae). • Removal of strontium from culture conditions by Saccharomyces cerevisiae (normal and irradiated) is studied. • Both normal and irradiated biomass can reduce strontium ion from culture conditions and the latter have a better results. • Using statistical analysis to find the optimal conditions. • Langmuir model fitting suggested a monolayer sorption of total strontium bound to biomass.
[en] Highlights: • Design towards high temperature, high vacuum and high radiation at the same time. • Use common servo components for manipulator joints in real tokamak environment. • Working chamber seals up normal atmosphere ambience from high vacuum surrounding. • Achieve rotary joint movement through common metallic bellow. • Prototype survived several hours’ mobility test in high vacuum environment. - Abstract: The remote handling in-vessel inspection manipulator for China’s Experimental Advanced Superconducting Tokamak (EAST) has proven its survivability in 120 °C high temperature environment and its kinematics feasibility in full-scale tokamak mock-up. To adapt this manipulator for real in-vessel operation use, most of its joint components, such as motors, reducers, and transmission structures must be considered for possible contamination to the tokamak in-vessel ambient. In order to verify the feasibility of combining vacuum sealing techniques with the previous in-vessel inspection manipulator solution, we have designed a standalone rotary joint module as prototype for relevant experimental tests. The joint module has a standard stainless steel metallic bellow to seal all its ordinary commercial joint components from tokamak environment, while the servo control wires, sensor wires and active cooling tubes inside the sealed chamber are led out by special vacuum feedthroughs. Basic mobility tests have been carried out under equivalent vacuum environment. This paper mainly presents the joint module design and related vacuum environment tests result of this prototype joint module. Further work will concentrate on adapting the whole in-vessel manipulator for vacuum environment operation based on this joint module design and tokamak environment tests result.
[en] With the increasing ability of Member States to analyse stable isotopes on their own, the Isotope Hydrology Laboratory (IHL) is turning its focus to radioisotopes, including tritium-helium-3 and noble gas isotopes, for groundwater dating. Noble gas isotopes dissolved in groundwater provide valuable information about climatic conditions during recharge, as well as the residence time of groundwater and its renewal rate. The isotope composition of noble gases can also serve as a geochemical fingerprint to decipher the origin of groundwater and its flow patterns. The Isotope Hydrology Laboratory (IHL) of the IAEA is fully equipped with the equipment required to measure with high precision noble gas concentrations and stable isotopes of noble gases from groundwater samples (such as 3He, 4He, 20Ar, 22Ar, etc.)
[en] The cold or thermal neutron energy spectra on China Advanced Research Reactor (CARR) could be directly measured by neutron time of flight spectrometer. Spectrometer structure and selected parameters of its key components were introduced. The impact of chopper slit and flux limit slit on neutron counts and pulse width was analyzed. The formulas of neutron counts and pulse width which were dependent on neutron wavelength were acquired. According to neutron energy spectrum measurement requirement for high fluence rate neutron beam, low-sensitivity detector, detector flux limit slit and multi-channel scaler for data acquisition were selected. These would ensure that the count loss rate was less than 0.5%. Electronics framework of detection system was designed and the total resolution time was 22.15-29.46 μs. (authors)
[en] Objective: To discuss the CT and clinical manifestations of adenolymphomas in the parotid gland. Methods: The CT characteristics of 15 cases with operation and pathology confirmed adenolymphoma were studied retrospectively. Results: Of the 15 cases (male n=12, female n=3), 13 patients (86.7%) were over 50 years age. 13 cases had history of smoking. There were 21 lesions, with solitary (n=13), multiple (n=2). 17 lesions (81.0%) were located in the posterior and inferior quadrant of the parotid gland. CT findings were round, oval or lobulated, well defined soft tissue, with homogeneous or inhomogeneous attenuation. After contrast administration, most of the lesion showed early moderate or obvious enhancement; 13 (61.9%) lesions showed small vessels penetrating through or surrounding the mass. Conclusion: Clinical materials including age, gender, location and imaging manifestations of lesion play a helpful role in diagnosis of adenolymphomas. (authors)
[en] China Advanced Research Reactor is just under building, neutron scattering is one of its important applications, and neutron guide system is an important facility for neutron scattering project. Using program VITESS, the simulation and optimization of the neutron guide system are performed in the paper, and the optimized parameters for CNGA, CNGB, CNGD are obtained. The position calculation program NGPS is developed, and the results are also shown in the paper. (authors)
[en] Highlights: • Flow-regime characteristics in pool sloshing behavior with solid particles modeled. • A regime map developed based on competitive role between bubble impulsion and bed inertia. • Respectable agreement between experiments and regime-map predictions obtained. • Reasonability of developed map confirmed through parametric analyses. - Abstract: To understand the pool sloshing behavior with unmelted core materials during a core disruptive accident of sodium-cooled fast reactors, in our earlier publication a series of simulated experiments was performed using different solid particles. It was recognized that due to the different interaction mechanisms between solid particles and the gas bubble injected, three kinds of flow regimes, termed respectively as the bubble-impulsion dominant regime, the transitional regime and the bed-inertia dominant regime, could be identified. In this work, a regime map is developed to describe the regime transition by considering the competitive role between the bubble impulsion and bed inertia during the sloshing process. It is found that a respectable agreement between experiments and the regime-map predictions could be achieved given current range of conditions including much difference in particle size, particle bed height, particle density and the gas-injection pressure.
[en] Highlights: • The optimal concentration of Pr3+ ions in CaO was experimentally calculated to be 0.05 mol%. • The energy transfer process from host to Pr3+ ions was discussed. • The reddish orange emitting long afterglow that can last nearly 1 h was observed in CaO:Pr3+ for the first time. • The mechanism of long afterglow was discussed in detail. -- Abstract: A novel reddish orange emitting long persistent phosphor CaO:Pr was prepared by a high temperature solid-state reaction method. All as-prepared phosphors were studied systematically by X-ray diffraction, photoluminescence (PL) spectra, decay curves, afterglow spectra and thermoluminescence (TL) glow curves. The intensity of PL and the performance of afterglow are dependent on the concentration of Pr3+ ions. The trap depth in the range between 0.5 and 0.7 eV is suitable for long afterglow (LAG). The optimal concentrations of Pr3+ ions for the best characteristic PL emission and afterglow were experimentally calculated to be 0.05 mol%. After irradiation by 273 nm for 3 min, the duration of reddish orange afterglow can last nearly 1 h. The decay processes and mechanism of LAG in CaO:Pr3+ were also discussed in detail
[en] Objective: To analyse the treatment effect of non-small cell lung cancer of three dimensional conformal radiotherapy (3D-CRT) and to study the effect of patient survival related factors. Methods: Retrospective analysis was mack for 136 cases of non-small cell lung cancer, all accept 3D-CRT, through the case data collection and long-term follow-up, using the single factor and multiple factor analysis survival time and its influencing factors. Results: The recent curative effects of 136 cases of patients with three dimensional conformal radiotherapy: Complete response (CR) 14.7% (20/136), partial response (PR) 60.3 (82/136), stable disease(SD) 19.9% (27/136), progression disease (PD) 5.1% (7/136), total effective rate is 75% (102/136). One, two, three, five year survival rate is 79.4%, 45.4%, 22.1%, 12.5%. Side effects: Class 1 radiated esophagitis 35 cases, Class 2 radiated esophagitis 16 cases, Class 3 and above radiated esophagitis 0 case. Class I radiated pneumonia 20 cases, Class 2 radiated pneumonia 9 cases, Class 3 radiated pneumonia 0 case. Single factor analysis shows the influence of gender, age, pathology, phase, dose, and first-phase curative effect to the survival time are of a statistical significance, Multiple factor analysis showed KPS score, phase, dose, first-phase curative effect are the survival time independent factors. Conclusion: 3D-CRT for patients with non-small cell lung carcinoma is a safe, effective treatment method, Side effects are relatively low, and the patients survival time is long after radiotherapy. (authors)