Influence of creep on dynamic behavior of concrete filled steel tube arch bridges

Yuan-Feng Wang,Yi-Shuo Ma,Li Su,Shengqi Mei 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

Concrete creep, while significantly changing the static behaviors of concrete filled steel tube (CFST) structures, do alter the structures' dynamic behaviors as well, which is studied quite limitedly. The attempt to investigate the influence of concrete creep on the dynamic property and response of CFST arch bridges was made in this paper. The mechanism through which creep exerts its influence was analyzed first; then a predicative formula was proposed for the concrete elastic modulus after creep based on available test data; finally a numerical analysis for the effect of creep on the dynamic behaviors of a long-span half-through CFST arch bridge was conducted. It is demonstrated that the presence of concrete creep increases the elastic modulus of concrete, and further magnifies the seismic responses of the displacement and internal force in some sections of the bridge. This influence is related closely to the excitation and the structure, and should be analyzed case-by-case.

Kinesin Family Member 11 Enhances the Self-Renewal Ability of Breast Cancer Cells by Participating in the Wnt/β-Catenin Pathway

Yuan-yuan Pei,Gao-chi Li,Jian Ran,Xin-hong Wan,Feng-xiang Wei,Lan Wang 한국유방암학회 2019 Journal of breast cancer Vol.22 No.4

Purpose: Our previous studies have shown that kinesin family member 11 (KIF11) is markedly overexpressed in human breast cancer cells or tissues and positively correlated with distant metastasis and prognosis in patients with breast cancer, suggesting an important role in the regulation of cancer stem cells. Herein, we examined the role of KIF11 in breast cancer stem cells. Methods: In the current study, we validated our previous findings through analysis of data collected in The Cancer Genome Atlas. Endogenous KIF11 was stably silenced in MCF-7 and SKBR-3 cells. Flow cytometry was used to measure the proportion of side-population (SP) cells. Mammosphere culture and tumor implantation experiments in immunodeficient mice were used to assess the self-renewal ability of breast cancer cells. Real-time polymerase chain reaction, western blot, immunofluorescence staining, luciferase reporter assays and Wnt agonist treatment were conducted to investigate the signaling pathways regulated by KIF11. Results: We found that the expression level of KIF11 was positively correlated with stem cell-enrichment genes. The proportion of SP cells was significantly reduced in KIF11-silenced cells. Silencing endogenous KIF11 not only reduced the size and number of mammospheres in vitro, but also reduced the ability of breast cancer cells to form tumors in mice. Simultaneously, we found that KIF11 was involved in regulating the activation of the Wnt/β-catenin signaling pathway. Conclusion: Endogenous KIF11 enhances the self-renewal of breast cancer cells by activating the Wnt/β-catenin signaling pathway, thereby enhancing the characteristics of breast cancer stem cells.

Structure of Penta-Alanine Investigated by Two-Dimensional Infrared Spectroscopy and Molecular Dynamics Simulation

Feng, Yuan,Huang, Jing,Kim, Seongheun,Shim, Ji Hyun,MacKerell, Alexander D.,Ge, Nien-Hui American Chemical Society 2016 The Journal of physical chemistry B Vol.120 No.24

<P>We have studied the structure of (Ala)(5), a model unfolded peptide, using a combination of 2D IR spectroscopy and molecular dynamics (MD) simulation. Two different isotopomers, each bis-labeled with C-13=O and C-13=O-18, were strategically designed to shift individual site frequencies and uncouple neighboring amide-I' modes. 2D IR. spectra taken under the double-crossed <pi/4, -pi/4, Y, Z > polarization show that the labeled four-oscillator systems can be approximated by three two-oscillator systems. By utilizing the different polarization dependence of diagonal and cross peaks, we extracted the coupling constants and angles between three pairs of amide-I' transition dipoles through spectral fitting. These parameters were related to the peptide backbone dihedral angles through DFT calculated maps. The derived dihedral angles are all located in the polyproline-II (ppII) region of the Ramachandran plot. These results were compared to the conformations sampled by Hamiltonian replica-exchange MD simulations with three different CHARMM force fields. The C36 force field predicted that ppII is the dominant conformation, consistent with the experimental findings, whereas C22/CMAP predicted similar population for alpha(+), beta, and ppII, and the polarizable Drude-2013 predicted dominating beta structure. Spectral simulation based on MD representative conformations and structure ensembles demonstrated the need to include multiple 2D spectral features, especially the cross-peak intensity ratio and shape, in structure determination. Using 2D reference spectra defined by the C36 structure ensemble, the best spectral simulation is achieved with nearly 100% ppII population, although the agreement with the experimental cross-peak intensity ratio is still insufficient. The dependence of population determination on the choice of reference structures/spectra and the current limitations on theoretical modeling relating peptide structures to spectral parameters are discussed. Compared with the previous results on alanine based oligopeptides, the dihedral angles of our fitted structure, and the most populated ppII structure from the C36 simulation are in good agreement with those suggesting a major ppII population. Our results provide further support for the importance of ppII conformation in the ensemble of unfolded peptides.</P>

Damping determination of FRP-confined reinforced concrete columns

Yuan-Feng Wang,Xiaoran Li,Li Su 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.14 No.2

Damping as a material property plays an important role in decreasing dynamic response of structures. However, very little is known about the evaluation and application of the actual damping of Fiber Reinforced Polymer Confined Reinforced Concrete (FRP-C RC) material which is widely adopted in civil engineering at present. This paper first proposes a stress-dependent damping model for FRP-C RC material using a validated Finite Element Model (FEM), then based on this damping-stress relation, an iterative scheme is developed for the computations of the non-linear damping and dynamic response of FRP-C RC columns at any given harmonic exciting frequency. Numerical results show that at resonance, a considerable increase of the loss factor of the FRP-C RC columns effectively reduces the dynamic response of the columns, and the columns with lower concrete strength, FRP volume ratio and axial compression ratio or higher longitudinal reinforcement ratio have stronger damping values, and can relatively reduce the resonant response.

The Effect of Electron-withdrawing Group Functionalization on Antibacterial and Catalytic Activity of Palladium(II) Complexes

Feng, Zhi-Qiang,Yang, Xiao-Li,Ye, Yuan-Feng,Hao, Lin-Yun Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

The design, synthesis, and structural characterization of two new palladium complexes based on Schiff base ligands is reported; $[Pd(L1)_2]$ (1) and $[Pd(L2)_2]$ (2), [HL1 = 2-((E)-(2,6-diethylphenylimino)methyl)-4,6-dibromophenol, L2 = (E)-N-benzylidene-2,6-diethylbenzenamine], which are obtained by functionalizing Schiff base ligands with or without electron-withdrawing groups. Both compounds are mononuclear structures. Comparisons are made to the compounds 1 and 2 to analyze and understand the effect of electron-withdrawing groups. Antibacterial activity studies indicate the electron-withdrawing groups on Schiff base ligands enhance antibacterial activity. Catalytic activity, however, is reduced due to the enhanced steric-hindrance of the electron-withdrawing groups. Electronic absorption and emission properties of HL1, L2, 1 and 2 are also reported.

An Analysis of the embodiment of Freud’s personality structure in Chinese Realistic Films - Focus on 〈Dying to Survive, 2018〉

Feng-Yi Yuan,Dong-Hyuk Choi 한국콘텐츠학회 2021 한국콘텐츠학회 ICCC 논문집 Vol.2021 No.12

Experimental Investigation on Mechanical Properties of Hybrid Steel and Polyethylene Fiber-Reinforced No-Slump High-Strength Concrete

Yuan, Tian-Feng,Lee, Jin-Young,Min, Kyung-Hwan,Yoon, Young-Soo Hindawi Limited 2019 International journal of polymer science Vol.2019 No.-

<P>This paper presents experimental investigations on the mechanical properties of no-slump high-strength concrete (NSHSC), such as the compressive and flexural strength. First, to determine the proper NSHSC mixtures, the compressive and flexural strength of three different water-to-binder ratios (w/b) of specimens with and without polyethylene (PE) fiber was tested at test ages. Then, the effect of hybrid combinations of PE fiber and steel fiber (SF) on the compressive strength, flexural strength, flexural toughness, and flexural energy dissipation capacity was experimentally investigated. Furthermore, the various hybrid fiber-reinforced NSHSCs were evaluated, and their synergy was calculated, after deriving the benefits from each of the individual fibers to exhibit a synergetic response. The test results indicate that a w/b of 16.8% with or without fibers had lower strength and flexural strength (toughness) than those of other mixtures (w/b of 16.4% and 17.2%). Specimens with a hybrid of SF and short PE fibers exhibited a higher compressive and flexural strength, flexural toughness, energy dissipation capacity, and fiber synergy in all considered instances.</P>

Computer Aided Diagnosis Based on K-means Collaborative Filtering Algorithm

Feng Xue-yuan,Li Peng,Qiao Pei-li 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.4

In computer aided diagnosis (CAD) process, one of the most challenging problems is data sparsity, which leads to the diagnosis results are not reliable. This paper proposes a clustering collaborative filtering based algorithm to solve the problem of data sparsity. In this paper, we use k-means clustering algorithm to cluster the same type of patients, and then adopt collaborative filtering method to fill the missing data values for each cluster, in this way to reduce the complexity of similarity calculation of collaborative filtering. The proposed method makes full use of the information-sharing mechanism of "similar patient population" to predict and fill the missing values. A hepatitis dataset is used for evaluating the performance of the algorithm. Results indicate that the proposed algorithm has better performance for medical record data sparsity problem.

Punicic Acid from Trichosanthes kirilowii Seed Oil Is Rapidly Metabolized to Conjugated Linoleic Acid in Rats

Yuan, Gao-Feng,Yuan, Jing-Qun,Li, Duo The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.2

The incorporation and metabolism of orally administered punicic acid (PA), one isomer of conjugated linolenic acid (CLNA), in rat tissues and plasma were studied over a 24-hour period. The punic acid was derived from Trichosanthes kirilowii Maxim seed oil, a unique PA-containing material, and identified and analyzed by high-performance liquid chromatography and gas chromatography-mass spectrometry. The results show that PA was incorporated and metabolized to 9c,11t-conjugated linoleic acid (CLA) in rat plasma, liver, kidney, heart, brain, and adipose tissue. The level of PA and CLA in liver and plasma was higher than in brain, heart, kidney, and adipose tissue, and the lowest accumulation occurred in the brain. The observation that PA can be converted into 9c,11t-CLA has gained increased importance since it has been demonstrated that 9c,11t-CLA exerts many biological activities. Therefore natural resources containing CLNA, especially edible T. kirilowii seed, could be a potential dietary source of CLA, following PA metabolism. PA is expected to be used as a functional food and nutraceutical.

Hierarchical porous carbons derived from corncob: study on adsorption mechanism for gas and wastewater

Feng Zhi-Yuan,Meng Long-Yue 한국탄소학회 2021 Carbon Letters Vol.31 No.4

Hierarchical porous carbons (HPCs) have been successfully prepared by a facile carbonization and subsequent CO2 activation process using corncob as a natural carbon precursor and Mg(C2H3O2)2 as a MgO nano-template precursor. The prepared corncob-based hierarchical porous carbons (C-HPCs) with desirable micropores and mesopores feature the excellent absorbency of gas (i.e., CO2 and CH4) and solution (i.e., methylene blue (MB)). Increasing the ratio of Mg(C2H3O2)2/corncob enlarged the specifc surface area up to 1004 m2 /g, micropore and mesopore volumes, CO2, CH4, and MB adsorption capacities (112, 31 and 230 mg/g after 325 min, respectively). The results indicated that the pore structures of C-HPCs can be easily and suitably controlled by the amount of the template precursor and CO2 activation efecting concurrently, which leads to fascinating adsorption capacity for CO2, CH4, and MB.