Numerical Investigation and Design of Cold-formed Steel Angle Columns with Complex Edges under Axial Compression

Jun-Feng Zhang,Mengmeng Feng,En-Feng Deng,Shiyun Pang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

Currently, cold-formed steel (CFS) is widely used in fabricated steel structures for high strength-to-weight ratio and ease for installation. However, limited research is available in the literature on the CFS angle columns with complex edges under axial compression. In this paper, the axial compressive capacity of the CFS angle columns with complex edges was numerically studied. The distortional buckling characteristics of 1008 CFS angle sections with complex edges were analyzed by finite strip software CUFSM. Detailed non-linear finite element model (FEM) was developed based on finite element program ABAQUS and verified by comparing with test results. The verification indicated that the developed FEM could well predict the ultimate strength and failure model of the specimens. Using the validated FEM, an extensive parametric study comprised of 330 models was conducted. The influences of the specimen length, the edge ratio and the limb-width ratio of the angle section on the axial compressive capacity of CFS angle columns with complex edges were evaluated. Then an improved direct strength method (DSM) was proposed based on the existing DSM. The evaluations based on tests and FEA results showed that using the modified DSM to predict the load-bearing capacity of the CFS angle columns with complex edges was feasible.

Macrophages Promote Coal Tar Pitch Extract-induced Tumorigenesis of BEAS-2B Cells and Tumor Metastasis in Nude Mice Mediated by AP-1

Zhang, Peng,Jin, Yue-Fei,Zhang, Qiao,Wu, Yi-Ming,Wu, Wei-Dong,Yao, Wu,Wu, Yong-Jun,Li, Zhi-Tao,Zhao, Yong,Liu, Yu,Feng, Fei-Fei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: We sought to evaluate the role of tumor associated macrophages (TAMs) on the promotion of coal tar pitch extract (CTPE)-induced tumorigenesis of human bronchial epithelial cells (BEAS-2B) and tumor metastasis in nude mice, and related mechanisms. Materials and Methods: BEAS-2B cells were first treated with 2.4 mg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured and passaged using trypsin-EDTA. THP-1 cells were used as macrophage-like cells. BEAS-2B cells under different conditions (n=6/group) were injected into the back necks of nude mice, and alterations of tumor xenograft growth, indicative of tumorigenicity, and tumor metastasis were determined. Pathological changes (tumor nests and microvascular lesions) of HE-stained tumor tissues were also evaluated. The expression of AP-1(c-Jun) in xenografts and metastatic tumors was determined using immunohistochemistry. Results: Tumor size and weight in nude mice transplanted with the mixture of CTPE-induced passage 30 BEAS-2B and THP-1 cells (2:1) were increased compared to those from the CTPE-treated BEAS-2B cells at passage 30 alone at different observation time points. Tumor metastasis to lymph nodes and liver was only detected after transplantation of a mixture the two kinds of cells. The numbers of tumor nests and microvascular lesions, and the expression levels of AP-1 (c-Jun) in tumors from the mixture of two kinds of cells were increased apparently in contrast to those in tumor from the CTPE-treated BEAS-2B cells of passage 30 alone. In addition, there was positive correlation between AP-1 (c-Jun) expression level and the number of microvascular lesions, or between AP-1 (c-Jun) expression level and tumor metastasis in these two groups. Conclusions: TAMs not only facilitate tumorigenesis transformation of CTPE-induced BEAS-2B cells, but also promote tumor growth, angiogenesis and metastasis in nude mice in vivo, which may be mediated by AP-1.

A novel and simple approach for the synthesis of Fe3O4-graphene composite

Feng-Jun Zhang,Jin Liu,장칸,Wei Zhao,장원권,오원춘 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.8

High crystalline Fe3O4-graphene composite has been successfully synthesized via one-step thermolysis reaction. The results demonstrated that the attachment of iron-organic complex with graphene oxide sheets can facilely lead to magnetic graphene composites with a time-dependent calcination process. The composite was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The high efficient removal of methylene blue determined that Fe3O4-graphene is a promising sorbent material for wastewater treatment.

A novel M2e-multiple antigenic peptide providing heterologous protection in mice

Feng Wen,Ji-Hong Ma,Hai Yu,Fu-Ru Yang,Meng Huang,Yan-Jun Zhou,Ze-Jun Li,Xiu-Hui Wang,Guo-Xin Li,Yi-Feng Jiang,Wu Tong,Guangzhi Tong 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

Swine influenza viruses (SwIVs) cause considerable morbidity and mortality in domestic pigs, resulting in a significant economic burden. Moreover, pigs have been considered to be a possible mixing vessel in which novel strains loom. Here, we developed and evaluated a novel M2e-multiple antigenic peptide (M2e-MAP) as a supplemental antigen for inactivated H3N2 vaccine to provide cross-protection against two main subtypes of SwIVs, H1N1 and H3N2. The novel tetra-branched MAP was constructed by fusing four copies of M2e to one copy of foreign T helper cell epitopes. A high-yield reassortant H3N2 virus was generated by plasmid based reverse genetics. The efficacy of the novel H3N2 inactivated vaccines with or without M2e-MAP supplementation was evaluated in a mouse model. M2e-MAP conjugated vaccine induced strong antibody responses in mice. Complete protection against the heterologous swine H1N1 virus was observed in mice vaccinated with M2e-MAP combined vaccine. Moreover, this novel peptide confers protection against lethal challenge of A/Puerto Rico/8/34 (H1N1). Taken together, our results suggest the combined immunization of reassortant inactivated H3N2 vaccine and the novel M2e-MAP provided cross-protection against swine and human viruses and may serve as a promising approach for influenza vaccine development.

Growth and fixed points of meromorphic solutions of higher-order linear differential equations

Jun-Feng Xu,Hong-Xun Yi 대한수학회 2009 대한수학회지 Vol.46 No.4

In this paper, we investigate the growth and fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives. Because of the restriction of differential equations, we obtain that the properties of fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives are more interesting than that of general transcendental meromorphic functions. Our results extend the previous results due to M. Frei, M. Ozawa, G. Gundersen, and J. K. Langley and Z. Chen and K. Shon. In this paper, we investigate the growth and fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives. Because of the restriction of differential equations, we obtain that the properties of fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives are more interesting than that of general transcendental meromorphic functions. Our results extend the previous results due to M. Frei, M. Ozawa, G. Gundersen, and J. K. Langley and Z. Chen and K. Shon.

Photoelectrocatalytic Degradation of Dyes in Aqueous Solution Using CNT/TiO₂ Electrode

Feng-Jun Zhang,Jin Liu,Ming-Liang Chen,Won-Chun Oh 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.3

The effect of photoelectrocatalytic (PEC) degradation for different dyes with the CNT/TiO₂ electrode was studied. The prepared electrode was characterized with surface properties, structural crystallinity, elemental identification, and PEC activity. The N2 adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via FESEM. XRD patterns of the composites showed that the CNT/TiO₂ composite contained a mixing anatase and rutile phase. EDX spectra showed the presence of C, O and Ti peaks for all samples. The decomposition efifciency of the prepared electrode was evaluated by the PEC degradation of three dyes (methylene blue (MB), rhodamine B (RH.B), methyl orange (MO)). The variations of the FT-IR spectra and pH value of dye solutions were measured during the PEC system; it was found that the CNT/ TiO₂ electrode has better PEC degradation for MB solution than that of RH.B and MO. The proposed degradation mechanism was present.

Expression patterns of octoploid strawberry TGA genes reveal a potential role in response to Podosphaera aphanis infection

Jun Feng,Yang Cheng,Caixia Zheng 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.1

TGA family transcription factors are downstream components of the salicylic acid (SA) pathway and play a crucial role in the penetration defense against powdery mildew, a disease caused by the biotrophic pathogen Podosphaera aphanis that can cause enormous financial losses. However, the TGA genes in the octoploid strawberry (Benihoppe) remain largely unexplored. In this study, 11 FaTGA genes were identified and grouped into five subgroups based on the Strawberry GARDEN database. The evolution of TGAs has been relatively conservative, maintaining nearly the same protein domain and motif architectures. RT-qPCR showed that FaTGA s have different expression patterns in roots, stems, and leaves. The characteristics of their gene expression patterns indicate that FaTGA1, FaTGA2, FaTGA5, FaTGA7, FaTGA8, FaTGA9, and FaTGA10, as well as SA-responsive genes, were responsive to P. aphanis infection. In particular, exogenous SA induced significant upregulation of FaTGA and SA-responsive genes. Further correlation analysis suggested that FaTGA1, FaTGA2, FaTGA5, FaTGA7, FaTGA8, and FaTGA10 may play a crucial role in the response to powdery mildew disease. Taken together, our results reveal the responses of TGA genes in the strawberry P. aphanis interaction, which will provide further insight into the strawberry defense against powdery mildew.

Synthesis and characterization of polysilane with double bonds by an electrochemical method

Feng-Jun Zhang,Ming-Liang Chen,Lai Chen,Shi Wu,오원춘 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

Polysilanes with double bonds have been synthesized by the electroreduction of trichloromethylsilane and allyl chloride in a single compartment cell. The polymers have been characterized using FTIR, GPC and 1H NMR. The effects of monomer ratio, monomer concentration, electrode materials, the electrode’s interval time and the amount of electricity supplied were investigated. The results indicate that the ideal molar ratio of MeSiCl3/allyl chloride is 3:1 with a Mg electrode material. The molecular weight and yield of polysilanes became higher with an increase of the charge passed, a shortening of the electrode’s interval time, and a decrease of the monomer concentration.

The Action Research of Game Sense on Elementary School Soccer Team Training

Jun-Feng Zhong,Yuh-Chih Chen 한국스포츠교육학회 2011 한국스포츠교육학회 국제학술대회 자료집 Vol.2011 No.12

Fabrication of CNT/TiO2 electrodes and their photoelectrocatalytic properties for methylene blue degradation

Feng-Jun Zhang,Ming-Liang Chen,임창성,오원춘 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.5

In this study, three kinds of CNT/TiO2 electrodes were prepared. The electrodes prepared were characterized by BET surface area, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and it illuminated that the electrodes developed consisted of well mixed anatase and rutile TiO2 particles with the CNTs and they exhibited a higher catalytic activity. The catalytic efficiency of the electrodes developed was evaluated by the photoelectrodegradation of methylene blue (MB). The photoelectrodegradation of MB using the proposed electrode under different experimental conditions was investigated. The positive potential applied in photoelectrocatalytic (PEC) oxidation was also studied. It was found that catalytic decomposition of the MB solution could be attributed to the combination effects between TiO2 photocatalyst and the electro-assistance of the CNTs, with the conductive of CNT network facilitating the electron transfer between the adsorbed MB molecules and the catalyst substrate, and that PEC oxidation increased with an increase of the CNT composition.