Full-scale test of dampers for stay cable vibration mitigation and improvement measures

Zhou, Haijun,Xiang, Ning,Huang, Xigui,Sun, Limin,Xing, Feng,Zhou, Rui Techno-Press 2018 Structural monitoring and maintenance Vol.5 No.4

This paper reported test of full-scale cables attached with four types of dampers: viscous damper, passive Magneto-Rheological (MR) damper, friction damper and High Damping Rubber (HDR) damper. The logarithmic decrements of the cable with attached dampers were calculated from free vibration time history. The efficiency ratios of the mean damping ratios of the tested four dampers to theoretical maximum damping ratio were derived, which was very important for practical damper design and parameter optimization. Non-ideal factors affecting damper performance were discussed based on the test results. The effects of concentrated mass and negative stiffness were discussed in detail and compared theoretically. Approximate formulations were derived and verified using numerical solutions. The critical values for non-dimensional concentrated mass coefficient and negative stiffness were identified. Efficiency ratios were approximately 0.6, 0.6, and 0.3 for the viscous damper, passive MR damper and HDR damper, respectively. The efficiency ratio for the friction damper was between 0-1.0. The effects of concentrated mass and negative stiffness on cable damping were positive as both could increase damping ratio; the concentrated mass was more effective than negative stiffness for higher vibration modes.

The Synergistic Effect of 2-Chloromethylbenzimidazole and Potassium Iodide on the Corrosion behavior of Mild Steel in Hydrochloric Acid Solution

Zhou, Liben,Cheng, Weizhong,Wang, Deng,Li, Zhaolei,Zhou, Haijun,Guo, Weijie The Korean Electrochemical Society 2022 Journal of electrochemical science and technology Vol.13 No.1

The synergistic effect of 2-chloromethylbenzimidazole (2-CBI) and potassium iodide (KI) for mild steel in 1 M hydrochloric acid solution was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that, with the addition of 100 ppm potassium iodide, the inhibition efficiecy (IE) of 100 ppm 2-CBI in 1 M hydrochloric acid had been improved from 91.14% to 96.15%. And synergistic parameter of 100 ppm 2-CBI with different amounts of potassium iodide is always greater than 1. The adsorption of potassium iodide combining with 100 ppm 2-CBI obeys to the Langmuir adsorption isotherm. Thermodynamic adsorption parameters, including ∆G⁰_ads, ∆H_a and ∆S_a of the adsorption of the combinned inhibitor, as well as the E_a of the mild steel corrosion in 1 M HCl with the combinned inhibitor, were calculated.

Bond deterioration of corroded steel in two different concrete mixes

Haijun Zhou,Xuebing Liang,Zeqiang Wang,Xiaolin Zhang,Feng Xing 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.6

This paper investigated the effects of rebar corrosion on bond performance between rebar and two different concrete mixes (compressive strengths of 20.7 MPa and 44.4 MPa). The specimen was designed as a rebar centrally embedded in a 200 mm concrete cube, with two stirrups around the rebar to supply confinement. An electrochemical accelerated corrosion technique was applied to corrode the rebar. 120 specimens of two different concrete mixes with various reinforcing steel corrosion levels were manufactured. The corrosion crack opening width and length were recorded in detail during and after the corrosion process. Three different loading schemes: monotonic pull-out load, 10 cycles of constant slip loading followed by pullout and varied slip loading followed by pull-out, were carried out on the specimens. The effects of rebar corrosion with two different concrete mixes on corrosion crack opening, bond strength and corresponding slip value, initial slope of bond-slip curve, residual bond stress, mechanical interaction stress, and energy dissipation, were discussed in detail. The mean value and coefficient of variation of these parameters were also derived. It was found that the coefficient of variation of the parameters of the corroded specimens was larger than those with intact rebar. There is also obvious difference in the two different concrete mixes for the effects of rebar corrosion on bond-slip parameters.

Cloning and Characterization of Filamentous Fungal S-Nitrosoglutathione Reductase from Aspergillus nidulans

( Yao Zhou ),( Shengmin Zhou ),( Haijun Yu ),( Jingyi Li ),( Yang Xia ),( Baoyi Li ),( Xiaoli Wang ),( Ping Wang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.5

S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent Km and kcat values were 0.55 mM and 34,100 min-1, respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time.

Exosomes from adipose-derived stem cells overexpressing Nrf2 accelerate cutaneous wound healing by promoting vascularization in a diabetic foot ulcer rat model

Xue-Li Zhou,Xiaoyun Xie,Weishuai Lian,Rongfeng Shi,Shilong Han,Haijun Zhang,Ligong Lu,Maoquan Li 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Diabetic foot ulcers (DFU) increase the risks of infection and amputation in patients with diabetes mellitus (DM). The impaired function and senescence of endothelial progenitor cells (EPCs) and high glucose-induced ROS likely exacerbate DFUs. We assessed EPCs in 60 patients with DM in a hospital or primary care setting. We also evaluated the therapeutic effects of exosomes secreted from adipose-derived stem cells (ADSCs) on stress-mediated senescence of EPCs induced by high glucose. Additionally, the effects of exosomes and Nrf2 overexpression in ADSCs were investigated in vitro and in vivo in a diabetic rat model. We found that ADSCs that secreted exosomes promoted proliferation and angiopoiesis in EPCs in a high glucose environment and that overexpression of Nrf2 increased this protective effect. Wounds in the feet of diabetic rats had a significantly reduced ulcerated area when treated with exosomes from ADSCs overexpressing Nrf2. Increased granulation tissue formation, angiogenesis, and levels of growth factor expression as well as reduced levels of inflammation and oxidative stress-related proteins were detected in wound beds. Our data suggest that exosomes from ADSCs can potentially promote wound healing, particularly when overexpressing Nrf2 and therefore that the transplantation of exosomes may be suitable for clinical application in the treatment of DFUs.

miR-582-5p inhibits migration and chemo-resistant capabilities of colorectal cancer cells by targeting TNKS2

Xiao Weixing,Zhou Haijun,Chen Bingrong,Shen Bin,Zhou Jun 한국유전학회 2022 Genes & Genomics Vol.44 No.6

Background: Metastasis and chemo-resistance are still important factors that limit the overall efficacy of colorectal cancer treatment. Understanding the detailed molecular mechanism and identifying potential biomarkers are of great value in prognosis prediction and risk stratification. Objective: We investigated the role of miR-582-5p in colorectal cancer pathogenesis, progression and chemo-resistance. Furthermore, we explored the underlying molecular mechanism of miR-582-5p in modulation of malignant behaviors of colorectal cancer cells. Methods: Clinical samples and colorectal cancer cell lines were applied to explore miR-582-5p expression level and its significance on tumor cell metastasis and chemo-resistance. Transwell study and cellular survivability study were performed to explore the influences of miR-582-5p expression modulation on tumor cell chemo-resistance and invasion/migration. Dual-luciferase reporter gene assay was conducted to explore the influences of miR-582-5p on its target gene TNKS2. Results: Colorectal cancer patients with lymph node or distal organ metastatic diseases exhibited significantly lower level of miR-582-5p. In vitro studies have indicated that miR-582-5p inhibition significantly increased migration and chemo-resistant capabilities of tumor cells. And dual-luciferase reporter gene assay demonstrated that miR-582-5p exhibited its influences on the biological behavior of tumor cells by targeting TNKS2. Conclusions: Our study demonstrated for the first time that miR-582-5p played an important role for colorectal tumor cell metastasis and chemo-resistance. Our research also indicated that miR-582-5p and its target gene TNKS2 could be novel biomarkers for metastatic disease prediction, overall prognosis evaluation, as well as potential therapeutic target for colorectal cancer patients.

Peroxiredoxin System of Aspergillus nidulans Resists Inactivation by High Concentration of Hydrogen Peroxide-Mediated Oxidative Stress

( Yang Xia ),( Haijun Yu ),( Zhemin Zhou ),( Naoki Takaya ),( Shengmin Zhou ),( Ping Wang ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.1

Most eukaryotic peroxiredoxins (Prxs) are readily inactivated by a high concentration of hydrogen peroxide (H₂O₂) during catalysis owing to their “GGLG” and “YF” motifs. However, such oxidative stress sensitive motifs were not found in the previously identified filamentous fungal Prxs. Additionally, the information on filamentous fungal Prxs is limited and fragmentary. Herein, we cloned and gained insight into Aspergillus nidulans Prx (An.PrxA) in the aspects of protein properties, catalysis characteristics, and especially H₂O₂ tolerability. Our results indicated that An.PrxA belongs to the newly defined family of typical 2-Cys Prxs with a marked characteristic that the “resolving” cysteine (C_R) is invertedly located preceding the “peroxidatic” cysteine (C_P) in amino acid sequences. The inverted arrangement of C_R and C_P can only be found among some yeast, bacterial, and filamentous fungal deduced Prxs. The most surprising characteristic of An.PrxA is its extraordinary ability to resist inactivation by extremely high concentrations of H₂O₂, even that approaching 600 mM. By screening the H₂O₂-inactivation effects on the components of Prx systems, including Trx, Trx reductase (TrxR), and Prx, we ultimately determined that it is the robust filamentous fungal TrxR rather than Trx and Prx that is responsible for the extreme H₂O₂ tolerence of the An.PrxA system. This is the first investigation on the effect of the electron donor partner in the H₂O₂ tolerability of the Prx system.

Research Progress in SiC-Based Ceramic Matrix Composites

Dong, Shaoming,Wang, Zhen,Zhou, Haijun,Kan, Yan-Mei,Zhang, Xiangyu,Ding, Yusheng,Gao, Le,Wu, Bin,Hu, Jianbao The Korean Ceramic Society 2012 한국세라믹학회지 Vol.49 No.4

SiC-based ceramic matrix composites show many advantages over their monolithic ceramic counterparts, which makes them potential candidates for applications in various fields. Depending strongly on the chemical composition and microstructure of the fiber reinforcement, matrix as well as the fiber/matrix interphase in the material, the properties of ceramic matrix composites(CMCs) are highly tailorable. In this paper, the latest progresses in the interphase design, matrix modification and fiber reinforcement decoration of CMCs are reviewed, their effects on the properties of the CMCs are introduced.

Cathode interfacial layer-free all small-molecule solar cells with efficiency over 12%

Wu, Hao,Yue, Qihui,Zhou, Zichun,Chen, Shanshan,Zhang, Dongyang,Xu, Shengjie,Zhou, Huiqiong,Yang, Changduk,Fan, Haijun,Zhu, Xiaozhang The Royal Society of Chemistry 2019 Journal of materials chemistry. A, Materials for e Vol.7 No.26

<P>While nonfullerene small-molecule solar cells (NF-SMSCs) have relatively inferior performance compared with nonfullerene polymer solar cells, their performance is improving. In this work, a weak crystalline molecular donor BSFTR, was designed and synthesized to achieve efficient NF-SMSCs. By blending with a strong crystalline acceptor NBDTP-Fout, BSFTR achieves a well-intermixed blending morphology, which favors the formation of efficient charge percolation pathways with suppressed recombination. The BSFTR:NBDTP-Fout device obtains a power-conversion efficiency (PCE) of approximately 11.97% by achieving an efficient cathode interfacial layer (CIL)-free device that delivers an even higher PCE of 12.3%, which ranks among the top values for the reported NF-SMSCs. This work provides a simple solution for achieving high-performance NF-SMSCs by identifying the key factors for designing efficient, cost-saving, mass production-favorable CIL-free organic photovoltaic devices.</P>

Reconfigurable Flight Control System Design for Blended Wing Body UAV Based on Control Allocation

Xiaobo Qu,Jingping Shi,Haijun Zhou,Ling Zuo,Yongxi Lyu 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

The aircraft control surface fault reconfigurable scheme based on control allocation is an active approach to achieve fault-tolerant in flight control. It has obvious advantages such as the structure and parameters of the control law does not need to be redesigned as deflector failures occurs. The attainable moment subset and allocation efficiency with typical control allocation algorithms are evaluated. A modular scheme reconfigurable flight control system (FCS) of a miniature tailless Blended Wing Body UAV is studied by utilizing weighted pseudo-inverse, direct control, and fixed-point control allocation methods. The performance of the reconfigurable FCS is tested and verified with the simulation including typical failure modes such as deflector floating, loss-of-effectiveness and lock-in-place. Results validate that the reconfigurable FCS based on control allocation has preferable ability to handle deflector failures, improve the safety and reliability of aircraft. And the modular scheme proposed in the article demonstrates a good application prospect in the field of aviation and aerospace engineering.