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The critical experimental device with spent fuel can be used to carry out critical experimental research on spent fuel storage. Considering its high radioactivity，the best way to carry out the experiment is to take the method of extrapolating water level to criticality. At present, the critical experimental device with spent fuel has not been built yet, thus the simulation experiment of water level extrapolation is carried out in a critical experimental device with similar core structure and physical characteristics, which is a uranium rod grid device with light water as moderator. In this experiment, the normal extrapolation curve cannot be obtained because of the shielding effect of water deepens with the rise of water level. In this paper, the extrapolation process was simulated by Monte Carlo program, and the characteristics of neutron count rate changing with water level were studied when the neutron source and detector were arranged in different relative positions, thus the optimal arrangement scheme of detector and neutron source was given. In addition, an extrapolation method with water level worth as extrapolation parameter was proposed, which eliminates the influence of uneven water level coefficient when extrapolating to criticality with water level, and makes the extrapolation result more accurate.

Modified polyvinylidene chloride (PVDC) resin was prepared using octafluoropentyl methacrylate and trimethylolpropane trimethacrylate as modifying monomers through seeded emulsion polymerization. The successful incorporation of octafluoropentyl methacrylate into the PVDC resin was confirmed by Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) analyses. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and XPS were utilized to investigate the element distribution in the modified monomer emulsion and the mechanism of monomer modification. The results demonstrated that the fluorine monomer was reacted in the resin, and mainly concentrated on the surface of the resin. The addition of octafluoropentyl methacrylate and trimethylolpropane trimethacrylate improved the water resistance of the resin. Compared to unmodified PVDC resin, the contact angle of the modified PVDC resin increased from 89.46° to 109.51°, and the water resistance at room temperature increased from 120 to 500 h. Furthermore, the modified resin exhibited excellent mechanical properties, thermal stability, and storage stability. [ABSTRACT FROM AUTHOR]

AbstractWe conducted this meta-analysis to investigate neurological toxicities with poly (ADP-ribose) polymerase inhibitors (PARPis) in cancer patients. Databases were searched for randomized controlled trials (RCTs) from 1 January 2000 to 1 November 2023. Forty-six RCTs and 9529 patients were included. PARPis could increase the risk of all-grade headache [risk ratio (RR), 1.22; 95% confidence intervals (CI), 1.14–1.30; P < 0.00001], dizziness (RR, 1.40; 95% CI, 1.28–1.53; P < 0.00001), dysgeusia (RR, 1.93; 95% CI, 1.44–2.60; P < 0.0001) and insomnia (RR, 1.32; 95% CI, 1.09–1.60; P < 0.0001) in cancer patients. Headache was the most common neurological toxicity. Niraparib was associated with a higher risk of headache and insomnia, talazoparib with a higher risk of dizziness and rucaparib with a higher risk of dysgeusia. Breast cancer patients receiving PARPis have a higher risk of dysgeusia, while ovarian cancer patients are at an increased risk of insomnia. PARPis may increase the risk of mild to moderate neurological toxicities, but not severe ones. [ABSTRACT FROM AUTHOR]

In order to further improve the accuracy of age estimation, a locally adjusted age estimation algorithm based on deep learning and directed acyclic graph SVM is proposed. In the training phase, SE-ResNet-50 network pre-trained by the VGGFace2 dataset is first fine-tuned. Once the network converges, and the vector consisting of the parameters of the last fully connected layer is used as a representation and train multiple One-Versus-One SVMs. In the test phase, we first sent the face image to be estimated into SE-ResNet-50 to obtain a rough age estimation value, then set the specific neighborhood, and finally combined the trained SVM into a directed acyclic graph SVM and set specific neighborhood with the global estimate as the center for accurate age estimate. In order to show the universality of the proposed coarse-to-fine or/and global-to-local method, experiments were carried out on MORPH and AFAD images of different races, and the results verified the effectiveness of the algorithm.

This work aims at improving the medium- and low-temperature strength of Al2O3-C unfired slide plate materials. Sucrose, nickel nitrate hexahydrate, ethyl orthosilicate and oxalic acid aqueous solution with the mass ratio of 1:0. 15:2. 7:0 0.03 were added to ethanol aqueous solution in turn, and dried at 110 °C for 18 h, obtaining SiC polymer precursor. Then, tabular corundum, α-Al2O3 micropowder and flake graphite were used as the main raw materials, added with the SiC polymer precursor and Zn powder, pressed at 150 MPa into green bodies of 150 mm x25 mm x25 mm, cured at 180 °C for 24 h, and then heat treated at 600, 800, 1 000, 1 200 and 1 400 °C for 3 h under carbon embedded conditions. The effects of the SiC polymer precursor and Zn powder on the properties of Al2O3-C materials were studied. The results show that the Al2O3-C material has the optimal comprehensive performance when adding 4.5% SiC polymer precursor and 1.5% Zn powder; at low temperatures, Zn powder melts and forms metal bonding phases in the material system; at medium temperatures, the pyrolysis reaction of the SiC polymer precursor and the catalysis of Zn powder after evaporation make the system form SiC fiber bonding phases. They work together to give Al2O3-C unfired slide plate material high medium- and low-temperature strength, which overcomes the failure problem caused by the low strength in application. [ABSTRACT FROM AUTHOR]

The relative neutron flux density distribution is one of the essential physical parameters of the reactor. Measuring the relative neutron flux density distribution of the annular fuel zero-power reactor core has guiding significance for understanding the physical characteristics of the annular fuel core reactor and conducting safety analysis. In this paper, the γ activity of the gold foil at different positions on the outer surface of the fuel cell after irradiation was measured by foil activation method under polygonal loading of annular fuel core. The axial and radial relative neutron flux density distributions of fuel cell at different positions were obtained, and the measured values were compared with the values calculated by Monte Carlo theory. The results show that the maximum relative deviation between experimental measurement and theoretical calculation is within 12%. The measurement results of relative neutron flux density distribution are in line with the measure design expectations. The existing Monte Carlo analysis methods can better analyze the axial flux density distribution of the components in the reactor. This study provides essential data support for the engineering application of annular fuel.