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The chemical corrosion aging of plutonium is a very important topic. It is easy to be corroded and produces oxidation products of various valence states because of its 5f electron orbit between local and non-local. On the one hand, the phase diagram of plutonium and oxygen is complex, so there is still not enough research on typical structural phases. On the other hand, most of the studies on plutonium oxide focus on PuO2 and Pu2O3 with stoichiometric ratio, while the understanding of non-stoichiometric ratio, especially for Pu2O3-x, is not deep enough. Based on this, using the DFT + U theoretical scheme of density functional theory, we have systematically studied the structural stability, lattice parameters, electronic structure, mechanical and optical properties of six typical high temperature phases of β-Pu2O3, α-Pu2O3,γ-Pu2O3, PuO, α-PuO2,γ-PuO2. Further, the mechanical properties and optical behavior of Pu2O3-x under different oxygen vacancy concentrations are analyzed and discussed in detail. The result shows that the elasticity modulus of single crystal in mechanical properties is directly related to the oxygen/plutonium ratio and crystal system. As the number of oxygen vacancies increases, the mechanical constants continue to increase. In terms of optical properties, PuO has the best optical properties, and the light absorption rate decreases with the increase of oxygen vacancy concentration.

During an investigation of Xylariaceae from 2019 to 2020, isolates representing eight Nemania (Xylariacese) species were collected from Yunnan, Guizhou and Hainan Provinces in China. Morphological and multi-gene phylogenetic analyses, based on combined ITS, α-actin, rpb2 and β-tubulin sequences, confirmed that six of them are new to science, viz. Nemania camelliae, N. changningensis, N. cyclobalanopsina, N. feicuiensis, N. lishuicola and N. rubi; one is a new record (N. caries) for China and one is a known species (N. diffusa). Morphological descriptions and illustrations of all species are detailed. In addition, the characteristics of Nemania are summarised and prevailing contradictions in generic concepts are discussed.

Four species of Xylaria were collected from Guizhou and Hainan provinces in China. Morphological and phylogenetic analyses (based on β-tubulin, rpb2 and α-actin genes) revealed two new species (X. sylvatica sp. nov. and X. wuzhishanensis sp. nov.) and two known species (X. atrosphaerica and X. cubensis). Xylaria sylvatica is distinguished from X. spinulosa by lacking long thorns on the stromatal surface, and larger ascospores (23–28.5 × 7–9.5 μm vs. 19–23 × 6.5–8.5 μm) with a sigmoid germ slit. Xylaria wuzhishanensis differs from X. schweinitzii by its semi-globular or irregularly globose stromata, from X. atrosphaerica by its larger ascospores (23–30.5 × 7–9 μm vs. 17–25 × 6–10 μm). Their descriptions and illustrations are provided.

In this study, three species of Astrocystis were collected from bamboo culms in Guizhou and Yunnan Provinces in China. Morphological characteristics and phylogenetic analyses (based on ITS, rpb2, βtubulin and α-actin gene regions) supported the proposal of two new species viz., Astrocystis pseudomirabilis sp. nov. and A. tessellati sp. nov. and a new record of A. sublimbata from China. Astrocystis pseudomirabilis can be distinguished from A. mirabilis by its larger stromata (0.64–0.83 × 0.38–0.52 mm vs. 0.4–0.6 × 0.2–0.5 mm) and larger ascospores (11–14 × 6–8 μm vs. 10–12 × 4.5–6 μm). Astrocystis tessellati differs from A. multiloculata by its smaller ascospores (16.2–19.2 × 7.2–9 μm vs. 19–25 × 7–11 μm). Astrocystis pseudomirabilis and A. tessellati form two distinct clades within Astrocystis.

With the wide application of nuclear technology, the radiation field shows more and more characteristics of hybrid, complexity and versatility. In order to ensure the safety and data transparency of radiation field, online radiation monitoring system is usually established for all important radiation fields. Its purpose is to monitor the parameters of radiation field in real-time and accurately, and evaluate the status of radiation safety scientifically and reliably. Therefore, a basic model of online monitoring system for mixed radiation field is established, which can be carried out proper expansion in accordance with the different scales and styles of radiation field.

In certain special scenarios, there will be a mixed radiation field formed by a variety of nuclides or rays. The monitoring system for such radiation fields requires the capacity of comprehensive and automatic analysis. In this paper, a specific mixed radiation field is given, which contains gamma ray, neutron ray, α aerosol and tritium in a high radon concentration environment. An intelligent monitoring system is developed to measure and evaluate the complex radiation field rapidly and accurately. The radiation performance of the system is verified by experiments, which achieves the expected index requirements.

In this work, the functional requirements of the integrated management of physical protection system has been studied, by analyzing the composition of the physical protection system, as well as the development status and trend of the integrated management system. The design scheme is studied from two aspects of the composition of the physical protection integrated management system and the software architecture, so as to provide reference for the construction of the integrated management system of nuclear facilities.

As we know radon is harmful to people because of its radioactivity. Focusing on the technical requirements of radon mitigation by adsorption, the radon adsorption behavior of carbon nanotube bundles was studied under different diameter tube bundles and different tube spacing using the grand cononical ensemble Monte Carlo (GCMC) simulation method. The results show that the (10:10) type nanotubes have the strongest ability to adsorb radon with a tube spacing of 1 nm, followed by (7:7) type nanotubes with a tube spacing of 1 nm. The bundle of carbon nanotubes of the (8:8) type has the worst adsorption capacity. Moreover, the nanotube bundles of each type of tube have an increased ability to adsorb radon as the tube spacing increases.

M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.