Study on Sectional Nonuniform Corrosion and Bond Strength of Plain Rebar Embedded in Concrete

Changming Li,Li Song,Fulai Qu,Xiaoke Li,Shunbo Zhao 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.8

The assessment of nonuniform corrosion of rebar is a key issue concerning the reliability of reinforced concrete structures. In this paper, the sectional nonuniform corrosion of plain rebar and the effect of corrosion on bond strength with concrete are studied. The plain rebar in concrete of 52 specimens were fast corroded by using electrochemistry method in a 5% sodium chloride solution. The bond strength of corroded plain rebar in concrete was measured by the central pull-out test. The sectional contour, diameter loss and sectional area loss of corroded plain rebar were detected within the bond length corresponding to the mass loss from 0.1% to 11.9%. Based on the oretical analysis and test data, the predictive models of the corroded sectional contour line and the bond strength of corroded plain rebar to concrete are built up. The results indicate that the nonuniform corroded sectional contour of plain rebar is approximate elliptical shape, the bond strength can be predicted by using the diameter loss of corroded rebar. Finally, the adaptability of the predictive models is ascertained with the experimental results.

Study on Architecture and Implementation of Port Logistics Information Service Platform Based on Cloud Computing

Changming Li,Jie Shen,Yanfang Liu 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

This paper analyses service objects and functional positioning of port logistics information service platform firstly. The architecture of port logistics information service platform upon cloud computing is proposed Based on the research of the concept and service mode of cloud computing. The system configuration and function implementation on the basis of Windows Azure Platform is further discussed in detail.

Research on Comparative Analysis of Regional Logistics Information Platform Operation Mode Based on Cloud Computing

Changming Li,Xiangdong Zhang,Lijie Li 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.2

The Protective Roles of S-adenosylmethionine Decarboxylase (SAMDC) Gene in Melon Resistance to Powdery Mildew Infection

Changming Liu,Xiaoling Li,Ruiping Yang,Yanling Mo,Yongqi Wang,Feng Xian,Xian Zhang,Fei Wang 한국원예학회 2014 Horticulture, Environment, and Biotechnology Vol.55 No.6

Powdery mildew caused by Podosphaera xanthii (P. xanthii) is one of important diseases in melon. Wehave previously investigated the differential gene expression in the incompatible P. xanthii-melon interactions andidentified one EST containing homologous sequences to S-adenosylmethionine decarboxylase (SAMDC) cDNA. Giventhis, SAMDC gene of Cucumis melo was cloned and designated as CmSAMDC in this study. It was 1,095 bp longand encoded a 364-amino acid peptide with a molecular mass of 40 kD. By sequence analyzing, the deducedCmSAMDC protein was shown to have two conserved regions of a putative proenzyme cleavage site and a PESTdomain. In addition, the expressions of CmSAMDC in the resistant melon materials increased more sharply than inthe susceptible the melon materials, and the higher polyamines (PAs) and hydrogen peroxide (H2O2) contents inresistant melon materials were found as well, which were accompanied by up-regulation of the stress-responsive defenseenzyme activities. Over-expression of CmSAMDC in Arabidopsis resulted in greatly reduced pathogen infection in theinoculated leaves of transgenic lines, enhanced resistance to powdery mildew, and the enhanced resistance appearedto be associated with pathogen-induced cell death. Taken together, our results suggested that CmSAMDC and perhapsits orthologous genes might be involved in responses of plants to biotrophic pathogens.

Preconditioned Jacobian-free Newton–Krylov fully implicit high order WENO schemes and flux limiter methods for two-phase flow models

Xiafeng Zhou,Changming Zhong,Zhongchun Li,Fu Li 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

Motivated by the high-resolution properties of high-order Weighted Essentially Non-Oscillatory (WENO) and flux limiter (FL) for steep-gradient problems and the robust convergence of Jacobian-free Newton-Krylov (JFNK) methods for nonlinear systems, the preconditioned JFNK fully implicit high-order WENO and FL schemes are proposed to solve the transient two-phase two-fluid models. Specially, the second-order fully-implicit BDF2 is used for the temporal operator and then the third-order WENO schemes and various flux limiters can be adopted to discrete the spatial operator. For the sake of the generalization of the finite-difference-based preconditioning acceleration methods and the excellent convergence to solve the complicated and various operational conditions, the random vector instead of the initial condition is skillfully chosen as the solving variables to obtain better sparsity pattern or more positions of non-zero elements in this paper. Finally, the WENO_JFNK and FL_JFNK codes are developed and then the two-phase steep-gradient problem, phase appearance/disappearance problem, U-tube problem and linear advection problem are tested to analyze the convergence, computational cost and efficiency in detailed. Numerical results show that WENO_JFNK and FL_JFNK can significantly reduce numerical diffusion and obtain better solutions than traditional methods. WENO_JFNK gives more stable and accurate solutions than FL_JFNK for the test problems and the proposed finite-difference-based preconditioning acceleration methods based on the random vector can significantly improve the convergence speed and efficiency.

Simultaneous removal of particulates and NO by the catalytic bag filter containing V2O5-MoO3/TiO2

Abdullahi Abubakar,Changming Li,Lin Huangfu,Shiqiu Gao,Jian Yu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4

V2O5-MoO3/TiO2 based catalytic bag filters were developed for the simultaneous removal of particulates and NO in the temperature range of 200-250 oC. Good denitrification activity, dedust efficiency as well as high adhesion strength in the temperature range of 200-250 oC was exhibited. The study of catalyst powder for coating revealed that the increased V and Mo content in catalyst can elevate the low-temperature activity, and the chosen V10Mo10 sample for coating showed the best activity with 100% NO conversion at just 180 oC. The further research on catalytic bag filter found the low ratio of PTFE, high loading and long residence time (e.g., low filtration velocity or double layer filter) may help to achieve high DeNOx efficiency. The best performance was obtained with above 80% NO conversion at 200-250 oC even in the presence of SO2/H2O and 99.9% dust collection efficiency on the condition of 500 g/m2 loading, 10% PTFE, 0.5m/ min filtration velocity and double layers of filter, which demonstrated great feasibility for industrial application.

Delta-form-based method of solving high order spatial discretization schemes for neutron transport

Zhou, Xiafeng,Zhong, Changming,Li, Fu Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7

Delta-form-based methods for solving high order spatial discretization schemes are introduced into the reactor S_N transport equation. Due to the nature of the delta-form, the final numerical accuracy only depends on the residuals on the right side of the discrete equations and have nothing to do with the parts on the left side. Therefore, various high order spatial discretization methods can be easily adopted for only the transport term on the right side of the discrete equations. Then the simplest step or other robust schemes can be adopted to discretize the increment on the left hand side to ensure the good iterative convergence. The delta-form framework makes the sweeping and iterative strategies of various high order spatial discretization methods be completely the same with those of the traditional S_N codes, only by adding the residuals into the source terms. In this paper, the flux limiter method and weighted essentially non-oscillatory scheme are used for the verification purpose to only show the advantages of the introduction of delta-form-based solving methods and other high order spatial discretization methods can be also easily extended to solve the S_N transport equations. Numerical solutions indicate the correctness and effectiveness of delta-form-based solving method.

SOX11-dependent CATSPER1 expression controls colon cancer cell growth through regulation the PI3K/AKT signaling pathway

Huang Yang,Wang Yicheng,Wu Zhongmei,Li Tao,Li Shupei,Wang Chan,Ao Jine,Yang Changming,Zhou Yu 한국유전학회 2022 Genes & Genomics Vol.44 No.11

Background: Colorectal cancer (CRC) is one of the most common malignant tumors and the fourth leading cause of cancer death worldwide. Constitutive activation of the PI3K/AKT signaling pathway is a hallmark of colon tumor growth. CATSPER1 gene encodes a pore-forming and pH-sensing subunit of the CatSper Ca2+-permeable channel, a sperm-specific calcium channel essential for hyperactivated motility and male fertility. However, the function of CATSPER1 outside the male reproductive system is unclear. Objective: This study was designed to explore whether CatSper exerted its functional role in the progress of CRC, and investigate the possible mechanisms. Methods: Microarray data (GSE146587) from 6 patients diagnosed with stage III CRC post-surgery was analyzed by Limma R package. The Kaplan Meier plotter (KM plotter) database was used to assess the relevance of CATSPER1 mRNA expression to the overall survival (OS) rates in CRC. Western blot, real-time PCR and luciferase reporter assays were used to determine the SOX11-CATSPER1 axis in CRC cells. Clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing was used to generate CATSPER1 knockout (KO) CRC cells. The proliferation of CRC cells was determined by BrdU incorporation and colony formation assays. The effect of CATSPER1 on CRC tumor growth in vivo was investigated in a mice tumor xenograft model. Results: Here, we show that CATSPER1 expression was significantly up-regulated in CRC and elevated CATSPER1 was associated with poor overall survival (OS). Moreover, the transcription factor SOX11 (SRY-related high-mobility-group (HMG) box 11) activated CATSPER1 transcription in CRC cells. Functionally, we showed that CATSPER1 promoted CRC cells proliferation both in vitro and in vivo. At the molecular level, we demonstrated that CATSPER1 might maintain CRC malignant process partly through the activation of the PI3K/AKT signaling pathway. Conclusion: Increased CATSPER1 expression facilitates CRC cells proliferation, suggesting that targeting CATSPER1 might represent a promising strategy for colon cancer treatment.