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Radioactive waste resin is generated during the operation of nuclear facilities such as nuclear fuel recycling，reactor cooling water treatment，and spent fuel pool purification. The treatment of radioactive waste resin must consider system radiation protection issues and adopt effective shielding measures to protect public and environmental safety. Design three different shielding combinations based on the type and location of shielding materials，calculate and analyze the shielding effects and applicable scenarios of each method，and provide relevant reference for engineering applications. Meanwhile，using SuperMC radiation shielding calculation software，the surface dose rate of waste resin flowing through equipment such as reactor vessels，resin grinding devices，waste resin transfer tanks，and booster pumps was calculated and analyzed with waste resin treatment facilities as the research object. The calculation results indicate that the surface dose rate of the relevant equipment is 22.13-48.64 μSv/h without shielding. The use of a lead shielding layer to shield and protect equipment with higher surface dose rates meets the requirements of a control area of 5 μSv/h or less after shielding.

The Kezhayi to Gongnaisi section of the Duku expressway is predominantly characterized by alpine landforms, with steep terrain cutting that provides conducive conditions for avalanche development. The study on the evaluation of snow avalanche susceptibility in this area is a crucial prerequisite for the safety construction and operation of the Duku expressway. The 149 snow avalanche points were collected by employing remote sensing interpretation and field investigations. Through correlation analysis of these factors, 10 evaluation factors were selected, forming the avalanche evaluation factor system. Subsequently, the non-avalanche points and original avalanche points were extracted using the K-means clustering method and random method to create a sample set. Machine learning techniques, including multilayer perceptron (MLP) and support vector machine (SVM) algorithms, were utilized to assess avalanche susceptibility in the study area. The results show that the sample datasets extracted by the random and K-means clustering methods were used for training, the Kappa coefficient of the R-SVM, R-MLP, K-SVM, and K-MLP models were greater than 0.6. These four sets of models exhibited a high degree of consistency between the predicted results and actual values of the validation dataset. The AUC (area under curve) value trained by MLP increased from 0.762 to 0.983, while the AUC value trained by SVM increased from 0.724 to 0.951. Based on the K-MLP model partition with the highest evaluation accuracy, the snow avalanche development in the research area has a relatively minor impact on the proposed route but may pose a threat to tunnel entrances. This study provides theoretical support and methodological references for the construction, operation and mitigation of sonw avalanche disasters for the Duku expressway.

Objective To study the relationship between serum neuron-specific enolase(NSE) and clinical features of pheochromocytoma/paraganglioma(PPGL). Methods Totally 501 PPGL patients diagnosed from January 2019 to December 2022 were divided into normal NSE group(NSE≤16.3 ng/mL) and elevated NSE group(NSE>16.3 ng/mL). The clinical characteristics were compared between the two groups. Results Compared with normal NSE group, patients in the elevated NSE group had larger diameter in primary tumor(5.00 cm vs. 4.60 cm), higher 24-hour urinary norepinephrine(NE) and 24-hour urinary dopamine(DA) levels, and a higher rate of metastasis(31.6% vs. 13.7%)(P＜0.05). NSE level was positively correlated with the primary tumor size(r=0.131, P＜0.05),24-hour urinary NE level(r=0.195, P＜0.05) and 24-hour urinary DA level(r=0.119, P＜0.05). Conclusions The level of NSE is related to tumor size, secretion function and metastasis in PPGL patients.

The development of marine resources and the construction of coastal islands need a reliable energy supply. The floating nuclear power plant (FNPP) is a combination of small nuclear reactors and offshore platforms, and it can be used in many fields such as offshore power supply, combined heat and power, and seawater desalination treatment. FNPP has the advantages of high power density, sustainable power generation, and low carbon emission. But due to environmental factors such as wind and waves on the sea or ship navigation, FNPP will generate complex motions in actual sea conditions. Liquid sloshing will occur in accumulators and other liquid storage tanks subjected to additional inertial forces under moving conditions. The free surface fluctuation will disturb the measurement of critical parameters such as liquid level, and the fluid impact load will affect the operation and maintenance of equipment. So measurement experiments were carried out based on the 6-DOF motion platform to study the sloshing characteristics and pressure variation rule of the accumulator. The pressure surge was studied by multi-directional pressure sensors, the free surface sloshing process was obtained by the high-speed camera system, and the natural frequency of the accumulator was obtained according to the model equivalent and mathematical analysis. The results show that under rolling motions, the pressure variation period is consistent with the motion period and the pressure amplitude can be determined by motion angle. The motion forms of liquid surface are basically stationary waves and marginal hydraulic jump, and the pressure measurement results show a regular sine and cosine variation, so the system analysis model under rolling conditions can be reasonably simplified based on the above analysis and safety margin assessment. Under horizontal sloshing, the additional inertial force will induce many kinds of nonlinear liquid surface sloshing. Based on time and frequency domain analysis, it can be seen that the pressure variation rule is mainly dominated by natural frequency, excitation frequency, and frequency multiplication. The pressure variation amplitude increases sharply and reaches the peak value under resonance conditions. There are unstable evolution processes and chaotic sections of pressure surge under specific sloshing conditions, where the pressure variation has randomness and initial value sensitivity. In addition, the breaking and rotation of the free surface will occur near the resonance frequency. Under the coupled motion, the pressure at the measurement point is affected by the characteristics of single degree of freedom motion and the coupling form of different motion. The coupled motion can be disassembled and analyzed based on considering the phase difference. In summary, the study can provide an analytical basis for sloshing research of liquid storage equipment and provide a reference for structural improvement and sloshing suppression optimization.