[en] A novel spectrophotometric method for the determination of methylene diphosphonate in a stannous methylene diphosphonate kit via complex formation with iron (III) chloride was established. The results show that the absorbance of complex obeys the Lambert-Beer law in the range of methylene diphosphonate mass concentration of 0.02-0.08 g/L, and the linear regression equation is y = 14.61 x + 0.0297, with the correlation coefficient of 0.9991. The recoveries are 98.8%-102.0%, and the relative standard deviation is 0.97% (n = 6). The proposed method is rapid, simple and sensitive, and therefore can be applied for routine analyses and quality control of methylene diphosphonate in its lyophilized kit. (authors)

[en] The weight of the radiation shielding seriously is with great effects on the maneuverability of the ship. It is important to improve the maneuverability of the ship by optimization of radiation shielding in a fixed shielding space and reducing the weight of the shielding. In this paper, the optimization methods of radiation shielding in a fixed space is studied based on SuperMC intelligent nuclear design module, and the shielding optimization design is carried out by using Savannah reactor to demonstrate the effectiveness of the method. The results show that the shielding weight of the optimized scheme is greatly reduced compared with the original design scheme, which proves that this approach provides a new technical means for guiding the material selection and shielding layout of ship reactor radiation shielding. (authors)

[en] Phase change memory (PCM) has been regarded as one of the most promising candidates for the next-generation nonvolatile memory. In this paper, we propose PtSb₂Te (PST) phase change material for phase change memory. The doping of Pt improves the crystallization temperature and Ten-year data-retention temperature of Sb₂Te to 180 °C, 192 °C, 204 °C and 117 °C,123 °C,137 °C, and refines the grain to about 10 nm. At the same time, the density change of Sb₂Te film after phase transition is reduced to 4.19% due to the addition of Pt. There are no other new phases formed in PST film except hexagonal Sb₂Te phase. For PST-based phase change memory cell, only 10 ns electrical pulse is required to complete the reversible operation with a Reset voltage lower than 4.3 V. At the same time, the number of cycle operations of the memory cell exceeds 10⁵ and it has a lower resistance drift coefficient as 0.019. (paper)

[en] The neutron and gamma time cross-correlation measurement could extract mass and multiplication coefficient of nuclear material, in which time resolution is an important parameter to characterize the correlation precision. Based on the means of digital data acquisition and processing, the time resolution was assessed for nuclear material time cross-correlation measurement system, which consisted of two novel plastic scintillator EJ299-33A detectors with particle discrimination capability, and the effect of the source was analyzed by comparing the ⁶⁰Co and ²²Na measurements. Furthermore, the equivalent electron energy threshold dependence of time resolution was given by off-line inversion, and the influences on different coincidence events were discussed by decoupling of the time-correlated spectrum of ²⁵²Cf. The results show that the time resolution of system decreases with the increase of equivalent threshold, and the time resolution of 560 ps was obtained at the threshold of 230 keVee by ⁶⁰Co measurement, which could meet the accuracy requirement of the nuclear material time cross-correlation measurements. Nevertheless, the result acquired by ²²Na measurement is widened to about 816 ps at the same threshold due to the uncertainty of positron annihilation position and the delayed coincidence. In the fission events correlated measurement, the relative influence of time resolution on n-n coincidences is smaller than that on γ-γ coincidences. (authors)

[en] Based on the digital pulses acquisition and processing technology, the optimization research on the n-γ discrimination for novel plastic scintillator detector by charge comparison method was presented. The influences of integral long gates and short gates, horizontal and vertical sampling precision of digitizers and equivalent electron energy thresholds on the figure of merit (FoM) parameters were investigated, also with the fitting functions of average pulses, the ratios of the tail integration to the long gate integration for neutron and gamma rays were calculated. The results showed that optimal integral short gate range was 35 ∼ 50 ns and 450 ns for the long gate;and the PSD capabilities of DT5730B are better than DT5751 with a threshold range of 100-500 keV. It could provide a helpful reference for the applications of detectors to the neutron-gamma mixed radiation measurement. (authors)