Nuclear DNA content variation of three Miscanthus species in China

Xi Li,Die Hu,Manman Luo,Ming Zhu,Xinwei Li,Fan Luo,Jianqiang Li,Juan Yan 한국유전학회 2013 Genes & Genomics Vol.35 No.1

In order to estimate the variation in nuclear genome size in Miscanthus, flow cytometry of nuclei stained by propidium iodide was carried out using 36 populations of three Miscanthus species: M. lutarioriparius, M. sacchariflorus and M. sinensis, which were sampled from cold northern to warm and humid southern and central China, as well as near the sea level in eastern China to mountains in western China. The DNA content of diploid was 4.37 ±0.02 pg/2C in M. lutarioriparius, 4.37 ± 0.01 pg/2C in M. sacchariflorus, and 5.37 ± 0.03 pg/2C in M. sinensis,respectively. There was no intraspecific variation in the three Miscanthus species at the diploid level, suggesting that the genome size was stable within species and the diverse environments did not induce variation in genome size at the diploid level. However, tetraploid populations were found in M. lutarioriparius and M. sacchariflorus, and their genome sizes were 8.56 and 8.54 pg, respectively, which are lower than expected values (8.74 pg), indicating the genome downsizing after polyploidization in the genus. Our results showed that the plant height of M. lutarioriparius was the highest one among the three species and the species was more closely related to M. sacchariflorus than M. sinensis. The intra-species genomic variation and inter-species differentiation in Miscanthus species provide important genetic and genomic information for the development of Miscanthus,especially for the endemic species, M. lutarioriparius,(together with Miscanthus 9 giganteus) which are now emerging as a key bio-energy crop because of their high yields and strong adaptability.

Elastic Foundation Beam Solution of Tensile Flexible Retaining Wall

Xu Jianqiang,Xu Jiangbo,Yang Xiaohua,Yan Zhaobai,Li Haiping,Wang Huoming,Tan Ling,Fei Dongyang,Li Jianguo,Luo Yongzhen 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.2

The application of fl exible retaining walls in foundation pit engineering is gradually increasing. At present, many practical engineering problems need to be solved. This article takes a corrugated steel retaining wall with tensile reinforcement, for example, assuming that it is an elastic foundation beam model. A typical vertical thin layer unit is taken on the retaining wall for analysis. It uses the waveform integration method to calculate the moment of inertia, deriving the diff erential equation of fl exural deformation of corrugated steel retaining wall and establishing the theoretical formula for deformation of corrugated steel retaining wall under fi lling pressure behind the wall. Finally, a FLAC3D model was established to simulate the deformation of corrugated steel retaining walls in practical engineering, and the fi nal numerical simulation results were consistent with the theoretical formula. Thus, providing a theoretical basis for the deformation of such fl exible retaining structures.

Improvement and validation of aerosol models for natural deposition mechanism in reactor containment

Jishen Li,Bin Zhang,Pengcheng Gao,Fan Miao,Jianqiang Shan Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.7

Nuclear safety is the lifeline for the development and application of nuclear energy. In severe accidents of pressurized water reactor (PWR), aerosols, as the main carrier of fission products, are suspended in the containment vessel, posing a potential threat of radioactive contamination caused by leakage into the environment. The gas-phase aerosols suspended in the containment will settle onto the wall or sump water through the natural deposition mechanism, thereby reducing atmospheric radioactivity. Aiming at the low accuracy of the aerosol model in the ISAA code, this paper improves the natural deposition model of aerosol in the containment. The aerosol dynamic shape factor was introduced to correct the natural deposition rate of non-spherical aerosols. Moreover, the gravity, Brownian diffusion, thermophoresis and diffusiophoresis deposition models were improved. In addition, ABCOVE, AHMED and LACE experiments were selected to validate and evaluate the improved ISAA code. According to the calculation results, the improved model can more accurately simulate the peak aerosol mass and respond to the influence of the containment pressure and temperature on the natural deposition rate of aerosols. At the same time, it can significantly improve the calculation accuracy of the residual mass of aerosols in the containment. The performance of improved ISAA can meet the requirements for analyzing the natural deposition behavior of aerosol in containment of advanced PWRs in severe accident. In the future, further optimization will be made to address the problems found in the current aerosol model.

Mesoscopic investigation of frost crystal nucleation on cold surface based on the lattice-Boltzmann method

Jianying Gong,Jianqiang Hou,Liangwei Yang,Weifeng Wu,Guojun Li,Tieyu Gao 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

A lattice Boltzmann method (LBM) two-dimensional (2D) mesoscopic model is presented for studying the frost crystal nucleation process involved in liquid-solid phase change on a cold surface. In order to make the simulation more realistic, the actual frost crystal nucleus deformation process is considered in this model. The simulation results agree well with our experimental results. Detailed analysis was made on the dynamic behavior of liquid-solid phase change and heat transfer happening in the frost crystal nucleation process. Results are presented for the evolution law of frost crystal nucleus deformation, dynamic solid-liquid phase change process as well as the dynamic distribution of frost nucleus interior temperature during frost crystal nucleation. In addition, the occurrence of frost crystal nucleus deformation is explained by the theory of crystal growth. Finally, where and why the initial position of frost crystal growth happens is also revealed. Furthermore, the reason why the hydrophobic surface can delay the droplet freezing and why the frost growth is faster on the hydrophobic surface after the droplet is frozen is analyzed based on this model.

Microscopic Simulation and Optimization of Signal Timing based on Multi-Agent: A Case Study of the Intersection in Tianjin

Leiting Sun,Jianqiang Tao,Chunfa Li,Shengkai Wang,Ziqiang Tong 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.9

The purpose of this paper is to optimize the signal timing through multi-agent simulation technology. Firstly, a conceptual model of the actual intersection is described. Secondly, the social dynamics model of the vehicle and pedestrian evolution rules are established from the micro perspective, which is simulated respectively by Anylogic and Synchro on this basis. Finally, the signal timing strategies for the different vehicle priorities are discovered through the heuristic algorithm. The case study shows that: ①The actual signal timing is not reasonable. ②The optimization strategies of signal timing can improve traffic efficiency. ③By comparing the signal timing strategies of different vehicle priority, the study shows that the Anylogic is more superior to the Synchro, which provides a new way to solve the traffic congestion.

A Semi-Supervised Technique for LGA Prognosis

Faheem Akhtar,jianqiang Li,Yan Pei,Muhammad Azeem 한국정보기술학회 2019 Proceedings of The International Workshop on Futur Vol.2018 No.1

Sequence analysis of the spike gene of Porcine epidemic diarrhea virus isolated from South China during 2011–2015

Xiaoya Zhao,Zhili Li,Xiduo Zeng,Guanqun Zhang,Jianqiang Niu,Baoli Sun,Jingyun Ma 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.2

The spike gene of porcine epidemic diarrhea virus (PEDV) was sequenced from 55 South China field strains isolated from pigs with symptoms of diarrhea. The sequences were compared within the set of field strains as well as with reference strains available in GenBank. Within the 55 South China PEDV field strains, the deduced amino acid sequence identities ranged from 93.8% to 99.9 % and ranged from 90.7% to 99.5% when compared with the foreign reference strains in GenBank. Our phylogenetic analysis showed that 10 of the 55 South China PEDV strains belonged to G1b and 45 belonged to G2b.

Study on the influence of flow blockage in severe accident scenario of CAP1400 reactor

Gao Pengcheng,Zhang Bin,Li Jishen,Miao Fan,Tang Shaowei,Cao Sheng,Yang Hao,Shan Jianqiang 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.3

Deformed fuel rods can cause a partial blockage of the flow area in a subchannel. Such flow blockage will influence the core coolant flow and further the core heat transfer during the reflooding phase and subsequent severe accidents. Nevertheless, most of the system analysis codes simulate the accident process based on the assumed flow blockage ratio, resulting in inconsistencies between simulated results and actual conditions. This paper aims to study the influence of flow blockage in severe accident scenario of the CAP1400 reactor. First, the flow blockage model of ISAA code is improved based on the FRTMB module. Then, the ISAA-FRTMB coupling system is adopted to model and calculate the QUENCH-LOCA- 0 experiment. The correctness and validity of the flow blockage model are verified by comparing the peak cladding temperature. Finally, the DVI Line-SBLOCA accident is induced to analyze the influence of flow blockage on subsequent CAP1400 reactor core heat transfer and core degradation. From the results of the DVI Line-SBLOCA accident analysis, it can be concluded that the blockage ratio is in the range of 40%e60%, and the position of severe blockage is the same as that of cladding rupture. The blockage reduces the circulation area of the core coolant, which in turn impacts the heat exchange between the core and the coolant, leading to the early failure and collapse of some core assemblies and accelerating the core degradation process.

Genetic diversity and phylogenetic analysis of porcine reproductive and respiratory syndrome virus in southern China from 2007 to 2014

Qiwen Wu,Zhili Li,Guanqun Zhang,Jianqiang Niu,Xiduo Zeng,Baoli Sun,Jingyun Ma 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.3

Porcine reproductive and respiratory syndrome virus (PRRSV) has a high degree of genetic variation. In this study, we characterized the genetic variation and evolutionary relationships among circulating PRRSV strains in southern China. We analyzed 29 NSP2 strains and 150 ORF5 strains from clinical samples collected in southern China during 2007–2014. The alignment results showed that the nucleotide identity similarities of the two genes among these strains were 80.5%–99.7% and 80.9%–100%, respectively. Phylogenetic analysis based on the NSP2 gene showed that highly pathogenic (HP)-PRRSV was still the dominant virus in southern China from 2013 to 2014. Compared with reference strains CH-1a and VR-2332, the field strain 131101-GD-SHC, which shared high homology with JXA1-P170, had a novel 12 amino acid deletion at position 499-510. Phylogenetic analysis based on the ORF5 gene showed that HP-PRRSV, VR2332-like strains, and QYYZ-like strains were simultaneously circulating in southern China from 2007 to 2014, suggesting that, in recent years, the type 2 PRRSV was more diverse in southern China. In conclusion, mutations in the decoy epitope and primary neutralizing epitope could be markers of viral evolution and used to study evolutionary relationships among PRRSV strains in China.

Design and Implementation of a Novel Horizontal AFM Probe Utilizing a Quartz Tuning Fork

Yifu Chen,Yingzi Li,Guanqiao Shan,Yingxu Zhang,Zhenyu Wang,Mubing Wang,Hua Li,Jianqiang Qian 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.1

This paper presents a new structure of a novel horizontal atomic force microscope probe utilizing a quartz tuning fork. The horizontal structure exhibits high resistance to environmental noise, and thus the probe can maintain good stability throughout the imaging work. The quartz tuning fork, which is utilized as a force sensor due to its simple mechanical structure and self-actuating and self-sensing characteristics, can significantly simplify the mechanical structure of the probe. The probe is divided into three parts: an approximation device, a force sensor, and a three-dimensional scanner. Each part is carefully designed to guarantee the imaging performance. It is verified that the proposed horizontal AFM probe is stable by conducting finite-element analysis, including modal analysis and noise analysis. Furthermore, the probe is fabricated and the experiments are performed to verify its stability. The proposed horizontal AFM probe combined with the existing control system in the frequency modulation succeeds in imaging within 25 μm × 25 μm and 20 μm × 20 μm ranges stably.