[en] Based on the recommended level density formula of the Fermi gas model and considering the modifications at low excitation energy, a synthesis level density formula is proposed. From the mean neutron resonance spacing D-bar_exp for 248 nuclei and the cumulative numbers of levels for 529 nuclei, a set of parameters is determined

[en] Harshaw6600 is a more widely used thermoluminescent dosimeter system currently in China. A series of parameters is set inside of the system, to calculate the dose data and to ensure the accuracy of calculation. The definitions of these parameters are briefly introduced. Its principle of dose calculation is analyzed, and the accuracy of dose calculation is verified. Some suggestions on dose calculation for radiation of low energy ray are provided. (authors)

[en] The effect of pH on the sorption behavior of Eu(III) and Am(III) onto Al₂O₃ in the presence of organic ligands was studied by a batch technique. It was found that at the relatively low concentration (1-10 nmol/L), the same liquid-to-solid ratio V/m (100 mL/g) and the same ionic strength (0.05 mol/kg KNO₃), the sorption of both elements increases steeply with increasing pH from 3.5 to 5.0 and remains unchanged at relatively low pH (pH<3.5) or high pH (pH>5.0) in the presence and absence of phthalate, salicylate, and catechol. While in the presence of fulvic acid, the sorption of both elements increases steeply with increasing pH at relatively low pH (pH<4.5) and it is enhanced obviously relative to that in the presence of other organic ligands. But at relatively high pH (pH>5.0), the sorption of both elements is reduced obviously. (authors)

[en] Sorption of Eu(III) and Am(m) on attapulgite as a function of pH, ionic strength and Eu(III) and Am(III) concentrations was studied under ambient condition using batch technique. The results indicate that sorption of Eu(III) and Am(III) on attapulgite is strongly affected by pH values and weakly dependent on ionic strength. The sorption of both elements increases steeply with increasing pH from 2.5 to 5.5. Sorption of Eu(III) and Am(III) is mainly dominated by surface complexation, although ion exchange also contributes to Eu(III) and Am(III) sorption. (authors)

[en] Sorption of Eu(III) and Am(III) on thorium phosphate diphosphate as a function of equilibrium time, the ratio of adsorbent mass to solution volume (m/V), pH, ionic strength and fulvic acid (FA) were studied under ambient condition using batch technique. The experimental results indicate that sorption of Eu(III) and Am(III) on thorium phosphate diphosphate are strongly affected by pH values, as compared Eu(III) and Am(III) adsorption on the same adsorbent. The Eu(III) and Am (III) adsorption on thorium phosphate diphosphate has the similar pH adsorption curves. The sorption of Eu(III) and Am(III) increases steeply with in- creasing pH from 2 to 5. The positive effect of FA on the adsorption of Eu(III) and Am(III) on thorium phosphate diphosphate are found from the compare study, and it is assumed that surface complexes are formed on the surface of thorium phosphate diphosphate. The study of adsorbent surface characteristics and adsorption mechanism are the important aspects of farther experiment. (authors)

[en] The surface of TiO₂ photoanode films for CdS/CdSe quantum dot-sensitized solar cells (QDSSCs) was modified through in situ hydrolysis and condensation of tetrabutyl titanate (TBT). Results showed that the surface area of the film increased after TBT modification, which was due mainly to the generation of small TBT generated TiO₂ nanocrystallites (TBT-TiO₂) adjoined the gaps in TiO₂ photoanode films, resulting in the increase of quantum dots (QDs) loading and light absorption. The TBT-TiO₂ also facilitated the electron transfer through the TiO₂ photoanode films. Owing to these synergistic effects, the short-circuit current density, open-circuit voltage, and resultant power conversion efficiency were significantly increased for the designed QDSSCs. And a power conversion efficiency of 4.76% was achieved under the TBT modification with an optimal concentration that was 28% greater than the bare device. Meanwhile, a comparison of the photovoltaic performance for TBT modified photoanode was made with traditional TiCl₄ modified one. It was found that the TBT modification on photoanode film contributed to higher light absorption capability and less charge recombination compared to TiCl₄ modification. The findings suggest TBT modification to be an effective approach to improve the performance of QDSSCs. (paper)

[en] The triple reduced surface field (T-RESURF) technique allows the drift region to achieve a much higher doping concentration while maintaining its breakdown voltage unaffected. Yet, as a result of the missing design guidance, the optimization of the T-RESURF effect is difficult to be realized in practice. In light of that, in this paper, the Virtual Junction Concept is proposed to provide the optimization criterion and explore physical insight of the T-RESURF effect. The proposed method bypasses the complicated 2D analysis by equivalenting the 2D drift region to a 1D virtual junction. The effectiveness and correctness of such a method are validated by the good agreement between modeled and simulated results. Benefit from its simplicity and veracity, the proposed method can not only conduct qualitative and quantitative analysis on the T-RESURF effect but also capable of providing design guidance and optimization criterion. (author)

[en] We monitored the occupational external exposure in a hospital in Chongqing from 2012 to 2018, using the routine personal dose monitoring method. The results show that the average annual effective dose of radiation diagnosis and treatment staff is 0.3 to 0.8 mSv, which is far below the national limit. The most exposed is turn out to be those dedicated to interventional radiology, which is followed in turn by radiotherapy, nuclear medicine and radiological diagnosis. (authors)

[en] B and N co-doped SiC nanopowders were prepared by combustion synthesis under a nitrogen atmosphere from the Si/C system, using α-Si₃N₄ powder and B powder as solid nitriding agent and dopant, respectively. The prepared particles had spherical morphology and narrow size distribution. XPS analysis demonstrated that B and N atoms successfully incorporated into SiC crystal and formed Si_1-xB_xC_1-yN_y solid solution. Results of dielectric properties showed that the real part ε′ and imaginary part ε″ of the complex permittivities of the samples decreased first, and then increased with increasing N content. The sample with 5% B and 15% N revealed the greatest values in ε′ and ε″ and better microwave absorption performance. The corresponding mechanism of the dielectric properties of SiC improved by co-doping was discussed in detail.

[en] The drift in electrical properties (e. g., the resistivity and B-value) is vital to the practical application for negative temperature coefficient (NTC) ceramics. In this work, Cu-doped nickel manganite ceramics were prepared by solid-state method, to investigate the degradation mechanism of both the resistivity and B-value. Results showed that the as-prepared ceramics exhibited typical NTC characteristics with cubic spinel phase, and that Cu doping greatly reduced the resistivity and B-value. However, the increase of Cu content in system aggravated the drift in the resistivity and B-value after the samples were aged at 300 °C for 30 h. XPS was carried out to further clarify the change in electrical properties. It was found that the decline of properties was due to the decrease of Mn⁴⁺ content in system after aging, which derived from the increase of chemical valence of Cu.