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Predicting connection integrity with consideration of thermo stress
Yong Qin Cheng,Shuo Qiong Liu,Feng Zhong Qi,Hui Ting Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8
In the conventional gas seal analysis of special threaded joints, the influence of temperature stress caused by the difference between formation temperature and fluid temperature in casing is often neglected. However, the influence mechanism of temperature stress is prerequisite information for accurately predicting the safe operating conditions that prevent a premium connection from being damaged. In this paper, we propose a model that includes these effects to predict the safe operating pressures and temperatures that will prevent seal failure. For the temperature stress, we propose a finite element model of thermal solid coupling. Subsequent stress changes are evaluated by a fully coupled model of thermal solid coupling to analyze the mechanical behavior of the premium connection. We predict the safe operating envelope (SOE) for premium connection failures caused by pressure and temperature perturbations after make-up. Our model predicts that radial pressure is a key factor for connection failure, especially for rapid temperature changes. If the formation temperature is high and the casing fluid temperature is low, the influence of temperature stress will increase under this working condition, resulting in an increase in the probability of failure of premium connections. Compared with conventional premium connection models, the model of thermal solid coupling predicts a smaller SOE when heating the internal casing fluid and a larger envelope when cooling the internal casing fluid. Finally, the heating rate was considered with respect to field applications. The heating rate was also considered, and slower heating/cooling rates can prevent damage to the seal integrity. Finally, the model was applied to explain several laboratory and field experiments and achieved good matches.
Structure and bioactivity of triterpenoids from the stems of Schisandra sphenanthera
Cheng-Qin Liang,Rong-Hua Luo,Ju-Ming Yan,Yan Li,Xiao-Nian Li,Yi-Ming Shi,Shan-Zhai Shang,Zhong-Hua Gao,Liu-Meng Yang,Yong-Tang Zheng,Wei-Lie Xiao,Hong-Bin Zhang,Han Dong Sun 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.2
Two new triterpenoids, schisphendilactoneA and B (1 and 2), together with three known triterpenoids,were isolated from the stems of Schisandra sphenanthera. Their structures were elucidated by spectroscopic methods,and the absolute configuration of 1 was determined bysingle-crystal X-ray diffraction. Compound 2 showedmoderate inhibitory activity against SW480 cancer cellline, and compound 5 exhibited promising anti-HIV-1activity with EC50 value of 0.52 lg ml-1 and therapeuticindex value of 117.12.
Position error compensation of the multi-purpose overload robot in nuclear power plants
Qin, Guodong,Ji, Aihong,Cheng, Yong,Zhao, Wenlong,Pan, Hongtao,Shi, Shanshuang,Song, Yuntao Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.8
The Multi-Purpose Overload Robot (CMOR) is a key subsystem of China Fusion Engineering Test Reactor (CFETR) remote handling system. Due to the long cantilever and large loads of the CMOR, it has a large rigid-flexible coupling deformation that results in a poor position accuracy of the end-effector. In this study, based on the Levenberg-Marquardt algorithm, the spatial grid, and the linearized variable load principle, a variable parameter compensation model was designed to identify the parameters of the CMOR's kinematics models under different loads and at different poses so as to improve the trajectory tracking accuracy. Finally, through Adams-MATLAB/Simulink, the trajectory tracking accuracy of the CMOR's rigid-flexible coupling model was analyzed, and the end position error exceeded 0.1 m. After the variable parameter compensation model, the average position error of the end-effector became less than 0.02 m, which provides a reference for CMOR error compensation.
Conditional Mutual Information-Based Feature Selection Analyzing for Synergy and Redundancy
Hongrong Cheng,Zhiguang Qin,Chaosheng Feng,Yong Wang,Fagen Li 한국전자통신연구원 2011 ETRI Journal Vol.33 No.2
Battiti’s mutual information feature selector (MIFS) and its variant algorithms are used for many classification applications. Since they ignore feature synergy, MIFS and its variants may cause a big bias when features are combined to cooperate together. Besides, MIFS and its variants estimate feature redundancy regardless of the corresponding classification task. In this paper, we propose an automated greedy feature selection algorithm called conditional mutual information-based feature selection (CMIFS). Based on the link between interaction information and conditional mutual information, CMIFS takes account of both redundancy and synergy interactions of features and identifies discriminative features. In addition, CMIFS combines feature redundancy evaluation with classification tasks. It can decrease the probability of mistaking important features as redundant features in searching process. The experimental results show that CMIFS can achieve higher best-classification-accuracy than MIFS and its variants, with the same or less (nearly 50%) number of features.
Research on the cable-driven endoscopic manipulator for fusion reactors
Guodong Qin,Yong Cheng,Aihong Ji,Hongtao Pan,Yang Yang,Zhixin Yao,Yuntao Song Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2
In this paper, a cable-driven endoscopic manipulator (CEM) is designed for the Chinese latest compact fusion reactor. The whole CEM arm is more than 3000 mm long and includes end vision tools, an endoscopic manipulator/control system, a feeding system, a drag chain system, support systems, a neutron shield door, etc. It can cover a range of ±45° of the vacuum chamber by working in a wrap-around mode, etc., to meet the need for observation at any position and angle. By placing all drive motors in the end drive box via a cable drive, cooling, and radiation protection of the entire robot can be facilitated. To address the CEM motion control problem, a discrete trajectory tracking method is proposed. By restricting each joint of the CEM to the target curve through segmental fitting, the trajectory tracking control is completed. To avoid the joint rotation angle overrun, a joint limit rotation angle optimization method is proposed based on the equivalent rod length principle. Finally, the CEM simulation system is established. The rationality of the structure design and the effectiveness of the motion control algorithm are verified by the simulation.
Chen, Keping,Yao, Qin,Wang, Yong,Cheng, Jialin Korean Society of Sericultural Science 2003 International Journal of Industrial Entomology Vol.7 No.1
The nuclear polyhedrosis virus (NPV) resistance of silkworm is controlled by a pair of dominant genes on autosome and micro-effect modificator genes on sex chromosome Z and has the phenomenon of patroclinal inheritance. Based on its hereditary characteristics, methods of preparing near isogenic lines and their $F_2$ populations for screening molecular markers were designed.
Yang, Xiao-Li,Zhang, Cheng-Dong,Wu, Hua-Yu,Wu, Yong-Hu,Zhang, Yue-Ning,Qin, Meng-Bin,Wu, Hua,Liu, Xiao-Chun,Lina, Xing,Lu, Shao-Ming Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11
Trichostatin A (TSA) is a histone deacetylase (HDAC) inhibitor. We here investigated its effects on proliferation and apoptosis of the CNE2 carcinoma cell line, and attempted to establish genome-wide DNA methylation alteration due to differentially histone acetylation status. After cells were treated by TSA, the inhibitory rate of cell proliferation was examined with a CCK8 kit, and cell apoptosis was determined by flow cytometry. Compared to control, TSA inhibited CNE2 cell growth and induced apoptosis. Furthermore, TSA was found to induce genome-wide methylation alteration as assessed by genome-wide methylation array. Overall DNA methylation level of cells treated with TSA was higher than in controls. Function and pathway analysis revealed that many genes with methylation alteration were involved in key biological roles, such as apoptosis and cell proliferation. Three genes (DAP3, HSPB1 and CLDN) were independently confirmed by quantitative real-time PCR. Finally, we conclude that TSA inhibits CNE2 cell growth and induces apoptosis in vitro involving genome-wide DNA methylation alteration, so that it has promising application prospects in treatment of NPC in vivo. Although many unreported hypermethylated/hypomethylated genes should be further analyzed and validated, the pointers to new biomarkers and therapeutic strategies in the treatment of NPC should be stressed.
Phenolic constituents from Parakmeria yunnanensis and their anti-HIV-1 activity
Shan-Zhai Shang,Huan Chen,Cheng-Qin Liang,Zhong-Hua Gao,Xue Du,Rui-Rui Wang,Yi-Ming Shi,Yong-Tang Zheng,Wei-Lie Xiao,Han Dong Sun 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.10
Three new phenolic compounds, yunnanensinsA–C (1–3), together with fourteen known ones (4–17),were isolated from the leaves and stems of Parakmeriayunnanensis. The structures of new compounds wereestablished on the basis of extensive spectroscopic analyses. Several compounds showed weak anti-HIV-1 activity.
IL-33 promotes IL-10 production in macrophages: a role for IL-33 in macrophage foam cell formation
Hai-Feng Zhang,Mao-Xiong Wu,Yong-Qing Lin,Shuang-Lun Xie,Tu-Cheng Huang,Pin-Ming Liu,Ru-Qiong Nie,Qin-Qi Meng,Nian-Sang Luo,Yang-Xin Chen,Jing-Feng Wang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-
We evaluated the role of IL-10- in IL-33-mediated cholesterol reduction in macrophage-derived foam cells (MFCs) and the mechanism by which IL-33 upregulates IL-10. Serum IL-33 and IL-10 levels in coronary artery disease patients were measured. The effects of IL-33 on intra-MFC cholesterol level, IL-10, ABCA1 and CD36 expression, ERK 1/2, Sp1, STAT3 and STAT4 activation, and IL-10 promoter activity were determined. Core sequences were identified using bioinformatic analysis and sitespecific mutagenesis. The serum IL-33 levels positively correlated with those of IL-10. IL-33 decreased cellular cholesterol level and upregulated IL-10 and ABCA1 but had no effect on CD36 expression. siRNA-IL-10 partially abolished cellular cholesterol reduction and ABCA1 elevation by IL-33 but did not reverse the decreased CD36 levels. IL-33 increased IL-10 mRNA production but had little effect on its stability. IL-33 induced ERK 1/2 phosphorylation and increased the luciferase expression driven by the IL-10 promoter, with the highest extent within the − 2000 to − 1752 bp segment of the 5′-flank of the transcription start site; these effects were counteracted by U0126. IL-33 activated Sp1, STAT3 and STAT4, but only the STAT3 binding site was predicted in the above segment. Site-directed mutagenesis of the predicted STAT3-binding sites (CTGCTTCCTGGCAGCAGAA→CTGCCTGGCAGCAGAA) reduced luciferase activity, and a STAT3 inhibitor blocked the regulatory effects of IL-33 on IL-10 expression. Chromatin immunoprecipitation (CHIP) confirmed the STAT3-binding sequences within the − 1997 to − 1700 and − 1091 to − 811 bp locus regions. IL-33 increased IL-10 expression in MFCs via activating ERK 1/2 and STAT3, which subsequently promoted IL-10 transcription and thus contributed to the beneficial effects of IL-33 on MFCs.