Experimental Study on the Damage of Steel Tubular Structural Components by Near-Field Detonations

Wanyue Wang,Shaobo Geng,Hua Wang,Wenqiang Li,Yaling Liu,Jianying Xue,Tingbian Zhan,Ying Gao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.2

This paper describes three blast-loading trials on three kinds of steel tubular structural components at the same explosive charge and standoff distance. Specimen one is a hollowsteel tube (HST), another is a HST wrapped with glass fibre-reinforced plastic (GFRP) with epoxy resin and the third is a HST infilled with concrete. The main objective of the trials is to investigate the effect of near-field detonations on circular steel tubular components. The experimental data, such as the overpressure time history, front local deformation, rear residual deflection and strain time history, are all recorded and collected. Analysis of the trial results shows that the experimental peak overpressure values of shot 1-3 are all larger than that of numerical simulation. The failure of these three specimens mainly experiences local damage, at the same time, the HST and HST with GFRP exhibit obvious global deformation. With the initiation point at one end of the cylinder explosive, both the maximum depth deformation on the front surface and the maximum residual deflection on the rear surface are all located on the side of the another end of the cylinder explosive. The blast-resistant approach by covering 10-layer GFRP on the surface of the HST can reduce the local damage, the global deformationand the dynamic strain value to certain extent, while the approach by infilling the steel tube with concrete can greatly decrease the local damage and the dynamic strain value and without any global deformation.

Research on soil net nitrogen mineralization in Stipa grandis grassland with different stages of degradation

Wanyu Wen,Xiaobing Li,Lihong Chen,Dandan Wei,Han Wang,Meng Zhang,Jing Yu 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.4

Net nitrogen mineralization is one of the nitrogen cycling process, and it is very important to understand nitrogen mineralization characteristics in degradation grassland. In the upper 0–10 cm soil layer of Stipa grandis P. A. Smirn. grassland in the Xilin river basin, Inner Mongolia, we studied the soil net nitrogen mineralization and nitrification among three varying stages of degradation grassland and analyzed the relationship between the mineralization rate of the soil net nitrogen and environmental factors, using the resin-core incubation method. Our results demonstrated that, from May to October 2012, the accumulated net nitrogen mineralization was 21.620 mg kg–1, 12.486 mg kg–1, and 48.053 mg kg–1 in the slightly, medium, and heavily degraded grasslands, respectively and varied greatly among the three stages of degradation shown by the S. grandis grassland plots. During the cultivation period, the variation of net nitrogen mineralization and nitrification was similar to the variation of soil mineral nitrogen. The higher soil mineral nitrogen content indicated higher mineralization of net nitrogen. In July and August, soil moisture was positively correlated with the net nitrogen mineralization rate, and the correlation coefficients between these two factors of 0.73, 0.58, and 0.79 for the slightly, medium, and heavily degraded plots, respectively. The rates of net nitrogen mineralization and nitrification were negatively correlated with soil total nitrogen, but positively correlated with C/N ratio, and weakly correlated with other physicochemical properties.

Human Face Recognition using Multi-Class Projection Extreme Learning Machine

Xu, Xuebin,Wang, Zhixiao,Zhang, Xinman,Yan, Wenyao,Deng, Wanyu,Lu, Longbin The Institute of Electronics and Information Engin 2013 IEIE Transactions on Smart Processing & Computing Vol.2 No.6

An extreme learning machine (ELM) is an efficient learning algorithm that is based on the generalized single, hidden-layer feed-forward networks (SLFNs), which perform well in classification applications. Many studies have demonstrated its superiority over the existing classical algorithms: support vector machine (SVM) and BP neural network. This paper presents a novel face recognition approach based on a multi-class project extreme learning machine (MPELM) classifier and 2D Gabor transform. First, all face image features were extracted using 2D Gabor filters, and the MPELM classifier was used to determine the final face classification. Two well-known face databases (CMU-PIE and ORL) were used to evaluate the performance. The experimental results showed that the MPELM-based method outperformed the ELM-based method as well as other methods.

IL-17A Secreted by Th17 Cells Is Essential for the Host against Streptococcus agalactiae Infections

( Jing Chen ),( Siyu Yang ),( Wanyu Li ),( Wei Yu ),( Zhaowei Fan ),( Mengyao Wang ),( Zhenyue Feng ),( Chunyu Tong ),( Baifen Song ),( Jinzhu Ma ),( Yudong Cui ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Streptococcus agalactiae is an important bacterial pathogen and causative agent of diseases including neonatal sepsis and meningitis, as well as infections in healthy adults and pregnant women. Although antibiotic treatments effectively relieve symptoms, the emergence and transmission of multidrug-resistant strains indicate the need for an effective immunotherapy. Effector T helper (Th) 17 cells are a relatively newly discovered subpopulation of helper CD4⁺ T lymphocytes, and which, by expressing interleukin (IL)-17A, play crucial roles in host defenses against a variety of pathogens, including bacteria and viruses. However, whether S. agalactiae infection can induce the differentiation of CD4⁺ T cells into Th17 cells, and whether IL-17A can play an effective role against S. agalactiae infections, are still unclear. In this study, we analyzed the responses of CD4⁺ T cells and their defensive effects after S. agalactiae infection. The results showed that S. agalactiae infection induces not only the formation of Th1 cells expressing interferon (IFN)-γ, but also the differentiation of mouse splenic CD4⁺ T cells into Th17 cells, which highly express IL-17A. In addition, the bacterial load of S. agalactiae was significantly increased and decreased in organs as determined by antibody neutralization and IL-17A addition experiments, respectively. The results confirmed that IL-17A is required by the host to defend against S. agalactiae and that it plays an important role in effectively eliminating S. agalactiae. Our findings therefore prompt us to adopt effective methods to regulate the expression of IL-17A as a potent strategy for the prevention and treatment of S. agalactiae infection.

Research on Angle Connector in Composite Beam

Kewei Ding,Xinqi Zhang,Yunlin Liu,Shulin He,Jingfeng Wang,Wanyu Shen 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.3

As a critical component for steel beam and concrete slab to work together, the strength of the shear connector affects the flexural load capacity and stiffness of the composite beam. Connectors were generally studied for longitudinal shear resistance. However, transverse shear needs to be considered when the main beam is far away and the transverse connection is weak. In this paper, an angle connector pre-embedded in the precast slab was proposed, and its pre-embedded position makes it exhibit better transverse shear resistance. To assess the strength, stiffness, and slip capacity of the angle connector, two groups of composite beam with precast slabs negative moment flexural were tested, then several finite element groups were simulated in push-out test. The test variable was the existence of angle connectors, and the variables simulated were the yield strength of the angle connector and its flange thickness. The results showed that the composite beam with angle connectors has greater stiffness than ordinary ones, with little difference in flexural strength capacity and less slippage. The results show that angle connectors can replace extending rebars in precast slabs, which will reduce construction costs. In addition, a new design equation was proposed, including the yield strength of the connector and the thickness of its flange which are not unified in the current equations. The simulations determined the strength of the angle connectors in relation to the yield strength of the angle connector and its web thickness.