Influence of the axial radius of rigid arc-shaped rollers in 3D surface rolling

Xintong Wang,Ming-Zhe Li,Yuwei Liu,Xiang Chang,Weifeng Yang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

The research and development of flexible forming technology have a crucial role in the personalized production and manufacturing of three-dimensional (3D) surface sheet metal parts. Three-dimensional surface rolling with rigid arc-shaped rollers (TSRRAR), a new flexible forming technology, was investigated to effortlessly produce 3D surface parts. Numerical simulation and experimental analysis mainly include data at four values of the difference in axial radius of roller (-2, 2, 6 and 10 mm) to explore this technology’s forming ability. It was demonstrated that various shapes could be obtained only based on one group of rollers. The maximum resultant force decreased from 3.07 to 2.21 KN, and the required maximum compression rate from 4.22 to 2.48 % with the same longitudinal curvature radius (179 mm) to be obtained. Therefore, the forming difficulty can be reduced by selecting the difference in axial radius of roller.

Identification of MKI67, TPR and TCHH mutations as prognostic biomarkers for patients with defective mismatch repair in stage II/III colon cancer

Jingfang Lv,Wenbin Li,Lei Guo,Xintong Wang,Dongliang Wang,Beifang Niu,Xishan Wang,Zheng Liu 대한종양외과학회 2022 대한임상종양학회 학술대회지 Vol.2022 No.2

Forward Modelling and GPR Imaging in Leakage Detection and Grouting Evaluation in Tunnel Lining

Chunjin Lin,Xintong Wang,Yao Li,Fengkai Zhang,Zhenhao Xu,Yuchao Du 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.1

Tunnels in the operation period are faced with different types of diseases, such as lining fracture, lining containing voids and lining leakage. In this paper, the common tunnel lining diseases are classified and ground-penetrating radar (GPR) is adopted to detect the tunnel lining diseases rapidly and nondestructively. The finite-difference time-domain (FDTD) methodis used to carry out numerical experiments on GPR detection forward modelling and backwardprojection imaging. An interpretation criterion of GPR detection was established on typical lining diseases. Based on the dielectric differences between before and after grouting of tunnel lining, GPR is introduced into the evaluation of grouting on leakage in tunnel lining, and the numerical simulation of grouting effect is carried out. It can be concluded that GPR imaging can well-identify the dielectric changes before and after grouting and evaluate the grouting reinforcement effect more intuitively. Finally, this method was applied to a practical case in Kaiyuan tunnel, China. This paper provides an alternative way to detect tunnel lining leakage in operation period and a reference for the evaluation of structural defects reinforcement in underground engineering.

Parameter Optimization for the Thickness and Hydraulic Conductivity of Tunnel Lining and Grouting Rings

Zhenhao Xu,Xintong Wang,Shucai Li,Bin Gao,Shaoshuai Shi,Xinji Xu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.6

Water inrush is a serious geological hazard in the deep buried tunnel construction in karst areas. Lining and grouting ring are often built to prevent tunnel from water inrush. The estimation of external water pressure and water inflow is of great significance to the structure design of lining and grouting ring. In this paper, the axisymmetric analytic solutions of external water pressure and water inflow were derived for deep karst tunnels under saturated steady-state flow conditions. A simplified formula for the reduction coefficient of external water pressure was established. This paper analyzed the changing rule of water inflow coefficient and the reduction coefficient of external hydraulic pressure on linings, which varies with the parameters of lining and grouting circle. The rational and available coefficients of grouting circle in karst deep buried tunnel construction are drawn: the grouting ring thickness is 6 m and the hydraulic conductivity ratio of surrounding rock and lining is 100. In addition, the accuracy of the simplified formula was verified by the comparison of analytical solution and numerical analysis. This study provides a reliable calculation method for water inflow and lining water pressure of the deep buried tunnel and have certain reference value for the structural design of deep buried tunnel to reduce water inflow and ensure construction safety.

Synthesis of optically active chiral mesoporous molybdenum carbide film

Fusheng Zhang,Xintong Zheng,Cunli Wang,Dongdong Wang,Xingya Xue,Guangyan Qing 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

A chiral nematic mesoporous molybdenum carbidefilm (CN-Mo2C) was fabricated through the selfassemblyof cellulose nanocrystal with peroxomolybdate. CN-Mo2C exhibits a tunable chiral nematicstructure by varying the ratio of constituents, enabling a surface area of 210 m2 g 1. Importantly, it showsa typical chiroptical feature through polarized optical microscopy and circular dichroism spectralanalysis. As it has an excellent conductivity of 2.410 2 S cm 1, we try to use CN-Mo2C in theelectrocatalytic HER production, presenting an efficient H2 production capacity. It is a versatile syntheticstrategy that can conveniently enable other large-area macroscopic chiral metal-based materials.

Recent progress in the development of fluorescent, luminescent and colorimetric probes for detection of reactive oxygen and nitrogen species

Chen, Xiaoqiang,Wang, Fang,Hyun, Ji Young,Wei, Tingwen,Qiang, Jian,Ren, Xintong,Shin, Injae,Yoon, Juyoung The Royal Society of Chemistry 2016 Chemical Society reviews Vol.45 No.10

<P>Reactive oxygen (ROS) and nitrogen (RNS) species cause oxidative and nitrosative stresses, respectively. These stresses are implicated not only in diverse physiological processes but also in various pathological processes, including cancer and neurodegenerative disorders. In addition, some ROS and RNS in the environment are pollutants that threaten human health. As a consequence of these effects, sensitive methods, which can be employed to selectively monitor ROS and RNS in live cells, tissues and organisms as well as in environmental samples, are needed so that their biological roles can be understood and their concentrations in environmental samples can be determined. In this review, fluorescent, luminescent and colorimetric ROS and RNS probes, which have been developed since 2011, are comprehensively discussed.</P>

Parametric Study of Water Inrush in a Tunnel Crossing a Fault based on the “Three Zones” fault structure

Jing Wu,Xintong Wang,Li Wu,Ya-ni Lu,Yanhua Han 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.8

As tunnelling progresses into the complex geological environment such as fault zones, water inrush has become one of the main geological hazards during tunnel construction. Consequently, understanding the evolution of pore pressure and flow velocity when a tunnel is excavated in a fault zone is crucial to ensure safe working conditions and reduce construction risks. In this work, based on the concept of “Three Zones” fault structure, we simulate the nonlinear water inrush process by solving the Darcy-Brinkman flow equation for the host rock and the fault zone. We examine the impacts of 1) the angle between the tunnelling direction and the fault and 2) the relative position from the tunnel face to the fault on the evolution of pore pressure and flow velocity near the tunnel face. The results show that within 5 m to 20 m ahead of the working face, pore pressure, flow velocity, and water inrush rate are the smallest when the angle is 90°. As the angle decreases, both pore pressure and flow velocity ahead of the working face increase. The pore pressure is larger when the tunnel has not reached the fault zone than when the tunnel has crossed the fault zone. Flow velocity also exhibits similar behaviour as pore pressure. With different relative positions from the tunnel working face to the fault, the closer the tunnel face to the fault, the lower the pore pressure and the larger the flow velocity ahead of the tunnel face. The largest water inrush rate occurs when the tunnel face is excavated to the center of the fault core, and the water inrush rate declines as the distance away from the fault increases. The simulation results provided a new method for simulating water inrush when a tunnel crosses a fault and could provide valuable references for the prediction of water inrush for underground projects.