In-pile tritium release behavior and the post-irradiation experiments of Li4SiO4 fabricated by melting process

Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

Bacterial and Fungal Diversity in the Starter Production Process of Fen Liquor, a Traditional Chinese Liquor

Xiao-Ran Li,En-Bo Ma,Liang-Zhen Yan,Han Meng,Xiao-Wei Du,Zhe-Xue Quan 한국미생물학회 2013 The journal of microbiology Vol.51 No.4

Fermented foods and beverages are important parts of human diet. Fen liquor, a Chinese liquor is a fermented beverage that uses a traditional fermentation process. Starters are the main microbial source and also provide nutrients for microorganisms during fermentation. In this study, starters of Fen liquor were produced through a complex traditional fermentation process. To investigate the community structure and the composition of microorganisms in the starter production process, bacterial 16S rRNA and fungal internal transcribed spacer (ITS) regions were sequenced using clone libraries and pyrosequencing, respectively. There was much higher diversity among the bacteria than among the fungi in the starter production process. Bacteria on the surface of the starters belonged mostly to the Lactobacillaceae family,while members of the Bacillacae family were dominant in the interior of the samples that lacked access to air and water. In the fungi population, diversity was high only in the raw material. In all other samples, nearly all of the fungal sequences were from Pichia kudriavzevii, a member of the Saccharomycetaceae family. Nearly all samples showed similar fungal community structures, indicating that there was little change in the fungal community. To the best of our knowledge, this is the first report to reveal the whole process of the starter production of Chinese traditional liquor. The findings obtained in this study provide new insights into understanding the composition of the microbial community during the traditional Chinese liquor starter production process and information about the production process control and monitoring.

Reliability assessment method based on the meta-action unit for complex mechanical system

Xiao Zhu,Yan Ran,Xinglong Li 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3

In this paper, a functionality unit named as meta-action unit (MAU) is proposed to correlate the system function with the part actions and assess reliability of mechanical system. Firstly, the function of system is decomposed into multiple MAUs by function-movementaction (FMA). Then, the lifetime of MAU is fitted by Weibull distribution, and its parameters are estimated by support vector regression (SVR). In addition, taking the distributions of MAU as marginal distributions, the lifetime distribution of mechanical system is constructed by copula function to assess system reliability, and its parameters are estimated using the maximum likelihood estimator (MLE). Further, the reliability assessment accuracy based on MAU is compared with that from traditional method based on mechanical part failure modes. Finally, the reliability assessment of the indexing turntable (IT) is performed as an example to illustrate the feasibility and reasonability of the proposed method.

Global and Local Moth-flame Optimization Algorithm for UAV Formation Path Planning Under Multi-constraints

Xiao-Jing Wu,Lei Xu,Ran Zhen,Xue-Li Wu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.3

To improve the global and local search ability of moth-flame optimization algorithm, three optimization strategies are proposed in this paper, namely chaos-based moth initialization, adaptive weighted position update strategy and population diversity improvement strategy. In moth initialization process, chaos-based Logistic map is adopted to improve population diversity. Then, a nonlinear weighting factor is introduced into the spiral function to adaptively balance the global and local search ability. Besides, new moth is generated by population diversity improvement strategy, which improves diversity and optimality of the population. Finally, simulation tests of unmanned aerial vehicle (UAV) formation under multi-constraints are carried out and comparison results show that the proposed global and local moth-flame optimization algorithm has the superiority in rapidity and optimality in UAV path planning problem compared with the latest path planning algorithms.

Selection of Reference Genes for Real-time Quantitative PCR Normalization in the Process of Gaeumannomyces graminis var. tritici Infecting Wheat

Li-hua Xie,Xin Quan,Jie Zhang,Yan-yan Yang,Run-hong Sun,Ming-cong Xia,Bao-guo Xue,Chao Wu,Xiao-yun Han,Ya-nan Xue,Li-rong Yang 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.1

Gaeumannomyces graminis var. tritici is a soil borne pathogenic fungus associated with wheat roots. The accurate quantification of gene expression during the process of infection might be helpful to understand the pathogenic molecular mechanism. However, this method requires suitable reference genes for transcript normalization. In this study, nine candidate reference genes were chosen, and the specificity of the primers were investigated by melting curves of PCR products. The expression stability of these nine candidates was determined with three programs-geNorm, Norm Finder, and Best Keeper. TUBβ was identified as the most stable reference gene. Furthermore, the exopolygalacturonase gene (ExoPG) was selected to verify the reliability of TUBβ expression. The expression profile of ExoPG assessed using TUBβ agreed with the results of digital gene expression analysis by RNA-Seq. This study is the first systematic exploration of the optimal reference genes in the infection process of Gaeumannomyces graminis var. tritici.

Linear stability analysis of Rayleigh-Bénard convection of cold water near its density maximum in a vertically heated annular container

Xiao-Ran Ma,Li Zhang,You-Rong Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.4

In order to understand the onset of Rayleigh-Bénard convection of cold water near its density maximum in a vertical annular container heated from below and cooled from above, the instability of the static diffusive state was investigated by linear stability analysis. Two kinds of thermal boundary conditions, perfect insulating and conducting sidewalls, were used. The aspect ratio and radius ratio of the annular container varied from 0.5 to 4.5 and 0.1 to 0.8, respectively. Results indicate that the critical Rayleigh number and the critical wave number increase with the increase of density inversion parameter. There are some new flow modes with large azimuthal wave number near the convection onset for cold water with density maximum, which are not observed in Rayleigh-Bénard convection of the Boussinesq fluids. The stratified flow phenomenon in cold water with density maximum is certified. The larger the density inversion parameter is, the more obvious the stratified flow phenomenon becomes. With the increase of the aspect ratio, the critical Rayleigh number decreases, but the critical wave number increases. However, with the increase of the radius ratio, both the critical Rayleigh number and the critical wave number increase continuously. Furthermore, the effect of thermal boundary conditions at the sidewalls on the convection stability is also validated.

Selection of Reference Genes for Real-time Quantitative PCR Normalization in the Process of Gaeumannomyces graminis var. tritici Infecting Wheat

Xie, Li-hua,Quan, Xin,Zhang, Jie,Yang, Yan-yan,Sun, Run-hong,Xia, Ming-cong,Xue, Bao-guo,Wu, Chao,Han, Xiao-yun,Xue, Ya-nan,Yang, Li-rong The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.1

Gaeumannomyces graminis var. tritici is a soil borne pathogenic fungus associated with wheat roots. The accurate quantification of gene expression during the process of infection might be helpful to understand the pathogenic molecular mechanism. However, this method requires suitable reference genes for transcript normalization. In this study, nine candidate reference genes were chosen, and the specificity of the primers were investigated by melting curves of PCR products. The expression stability of these nine candidates was determined with three programs-geNorm, Norm Finder, and Best Keeper. $TUB{\beta}$ was identified as the most stable reference gene. Furthermore, the exopolygalacturonase gene (ExoPG) was selected to verify the reliability of $TUB{\beta}$ expression. The expression profile of ExoPG assessed using $TUB{\beta}$ agreed with the results of digital gene expression analysis by RNA-Seq. This study is the first systematic exploration of the optimal reference genes in the infection process of Gaeumannomyces graminis var. tritici.

Identification of drug target candidates of the swine pathogen Actinobacillus pleuropneumoniae by construction of protein–protein interaction network

Siqi Li,Zhipeng Su,Chengjun Zhang,Zhuofei Xu,Xiaoping Chang,Jiawen Zhu,Ran Xiao,Lu Li,Rui Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae has led to severe economic losses in the pig industry worldwide. A. pleuropneumoniae displays various levels of antimicrobial resistance, leading to the dire need to identify new drug targets. Protein–protein interaction (PPI) network can aid the identification of drug targets by discovering essential proteins during the life of bacteria. The aim of this study is to identify drug target candidates of A. pleuropneumoniae from essential proteins in PPI network. The homologous protein mapping method (HPM) was utilized to construct A. pleuropneumoniae PPI network. Afterwards, the subnetwork centered with H-NS was selected to verify the PPI network using bacterial two-hybrid assays. Drug target candidates were identified from the hub proteins by analyzing the topology of the network using interaction degree and homologous comparison with the pig proteome. An A. pleuropneumoniae PPI network containing 2737 non-redundant interaction pairs among 533 proteins was constructed. These proteins were distributed in 21 COG functional categories and 28 KEGG metabolic pathways. The A. pleuropneumoniae PPI network was scale free and the similar topological tendencies were found when compared with other bacteria PPI network. Furthermore, 56.3% of the H-NS subnetwork interactions were validated. 57 highly connected proteins (hub proteins) were identified from the A. pleuropneumoniae PPI network. Finally, 9 potential drug targets were identified from the hub proteins, with no homologs in swine. This study provides drug target candidates, which are promising for further investigations to explore lead compounds against A. pleuropneumoniae.

Grenville-age orogenic event along the northeastern margin of the Quanji massif, NW China: constraints from ~1.1 Ga migmatite

Zhouxuan Xiao,Licheng Ma,Wan Jiang,Ran Wang,Yuyan Yao,Jie Cai,Jingyu Lin,Lu Li 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.3

Detailed petrologic, geochemical and geochronological investigation on migmatites provide key information on the tectonic-magmatic history of the Quanji Massif, NW China. The studied migmatites are mainly composed of granitic gneisses, with lenticular refractory residua spread along its foliation. Zircon U-Pb ages of 1129.2 ± 7.4 Ma (1σ, MSWD = 0.34, N = 31) and 1135.1 ± 9.5 Ma (1σ, MSWD = 0.05, N = 22) were determined for the granitic gneiss and refractory residue, respectively. Garnet grains from the refractory residue show no distinctive intra-crystalline zonation, and are rich in Fe and Mg, but poor in Ca and Mn, akin to those from metapelite. Samples from the granitic gneisses have high contents of SiO2 (from 67.92% to 69.89%), K2O (from 3.94% to 5.00%) and A/CNK (1.11–1.17), with LREE enrichment and distinctly negative Eu anomalies (Eu/Eu* = 0.49–0.53) in the chondrite-normalized REE patterns, and significantly negative Nb, Ta, Ti and Sr anomalies in the primitive mantle-normalized spider diagrams. Granitic gneisses samples have consistent Nd isotope compositions with negative εNd(t) values ranging from –1.06 to –6.04, and TDM model ages ranging from 1.83 to 2.23 Ga. These geochemical features suggest that the granitic rocks belong to the S-type granites, which were predominately derived from a late Paleoproterozoic crustal source. The granitic gneiss was probably formed by partial melting of the sediments which had been suffered graunlite-facies metamorphism. The components with low melting points (e.g., felsic minerals) might replace the sediments to form migmatites and migmatitic granites, and thus preserved the refractory residua. Therefore, the late Mesoproterozoic orogenic event is the coeval response of the global Grenvillian orogeny, indicating an important crustal remelting episode in the Quanji Massif.

Reliability Modeling and Analysis on Metallized Film Capacitors for MMC

Yao Ran,Zheng Meimei,Li Hui,Lai Wei,Wang Xiao,Long Haiyang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Metallized film capacitor’s (MFC’s) reliability directly affects the stable operation of MMC valve. Conventional reliability assessment method based on data statistics is limited. This paper studies the reliability modeling of MFC considering aging for the application condition of MMC valve. Firstly, the temperature field and electric field model of MFC is established, and the temperature and electric stress distribution are explored. Secondly, the lifetime model of MFC is established based on the electrical-thermal aging of dielectric films. Finally, the aging model of MFC is established from the aspect of equivalent series resistance. Results show that the aging rate of MFC increase with the service time going by, and increase sharply after 21 years. The failure rate of MFC is small at the beginning of operation, and there is a turning point in the 23rd year. Since then, the failure rate of MFC increases sharply. The lifetime of MFC is concentrated.