High Precision FE Modeling for Predicting Inner Polygon Defect of Hot Rolled Seamless Steel Tubes

Yong-Zheng Jiang,Yong-Zheng Jiang,Xiao-Ping Zhang,Kuan-Fang He,Guan-Fu Bin 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.11

A high precision FE model is the key basis for cause analysis and overcoming of inner polygon defect of hot rolled seamless steel tubes. In this paper, the viscoelastic-plastic FEM is adopted in order to develop a high precision FE model for predicting the defect of inner polygon. Mechanical properties of tube material under rolling environment is obtained through five sets of high temperature compression tests, thus the viscoelastic-plastic constitutive equation of tube material is regressed and agrees with the tests results. Heat transfer boundary conditions, roll constant speed and contact friction boundary conditions are applied simultaneously on the FE model and thermo-mechanical coupled explicit algorithm is adopted for solution. The precision of the FE model is verified through industry experiments. Results shows the simulated inner wall shape is in good accordance with the experiment results, and the friction force, stress, strain and temperature distribution in the deformation zone are also discussed. It can be concluded that the viscoelastic-plastic FE model is of high precision and can be applied for better analysis of the hot rolling results.

The comparative study of Chinese Design Higher Education before and after the Reform and Opening-up

Jiang Zheng-Qing,Lee Dong-Hun 한국콘텐츠학회 2010 International Journal of Contents Vol.6 No.4

Optimization of a double crystal monochromator

Jiang Zheng,Wang Eryan,Song Ruiqiang,Guo Siming,Wu Jinjie,Hou Dongjie,An Zhenghua,Zhou Pengyue 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.8

The double crystal diffraction structure based on Bragg diffraction is the core component of the monochromator that is widely used in synchrotron radiation beam lines and monochromatic X-ray radiation devices. The stability of monochromatic X-rays produced by using the T-structure double crystal monochromator at National Institute of Metrology was investigated experimentally. Due to its structural defects, the X-ray flux of the T-structured double crystal monochromator shows poor long-term stability. Inspired by the Channel-cut monochromator structure, we designed a new double crystal monochromator structure to improve the long-term stability of the X-ray flux. Experiments showed that the stability of the monochromatic X-ray flux for the new double crystal monochromator structure was better than 1.0%@1 h, and the energy region and flux rate of the monochromatic X-rays are significantly improved. This work provides a stable and reliable monochromatic X-ray source for the calibration of X/γ detectors such as satellite load detectors, which will contribute to the development of X/γ detection technology.

Inhibitory Action of Exogenous Serotonin on the Pancreatic Exocrine Secretion in Rats

Zheng er Jiang,Hyo Jin Koh,Kyoung Hee Lee,Hyun Joo Lee,Min-Jae Lee,Moo-Ho Won,Yun Lyul Lee 한국실험동물학회 2008 Laboratory Animal Research Vol.24 No.4

Serotonin (5-HT) is synthesized and released from enterochomaffin cells in the gastrointestinal mucosa and platelets. Most of these serotonins are existed in the gastro-intestine, and only few amounts are existed in the central nervous system. Although most of serotonins are existed in the gastrointestinal tract, a role of serotonin in the gut is still unclear.We previously reported that electrical field stimulation (EFS)-evoked pancreatic volume flow and amylase output further elevated by spiperone hydrochloride, serotonin (5-hydroxytryptamine, 5-HT) antagonist, in the isolated rat pancreas. This study was aimed to investigate roles and the action mechanisms of exogenous serotonin and serotonergic nerves on pancreatic exocrine secretion using the two experimental models (in vivo and exo vivo model). Results of exo vivo experiment: CCK elevated pancreatic volume flow and amylase output in rats. Endogenous insulin released by glucose potentiated the action of CCK. CCK-stimulated pancreatic volume flow and amylase output were not change by exogenous serotonin under hypoglycemic condition. However, exogenous serotonin significantly inhibited CCK-stimulated pancreatic volume flow and amylase. Results of in vivo experiment: CCK elevated pancreatic volume flow and amylase output in the isolated perfused rat pancreas. Endogenous insulin released by 18mM glucose potentiated the action of CCK. CCKstimulated pancreatic volume flow and amylase output were not change by exogenous serotonin under 5.6 mM glucose backgroud. However, exogenous serotonin significantly inhibited potentiated the action of CCK by insulin. These observations are good agreement with our previous in vitro results and strongly indicate that serotonin play a inhibitory role in pancreatic exocrine secretion and insulin may be involved the inhibitory actions.

Probiotic supplements alleviate gestational diabetes mellitus by restoring the diversity of gut microbiota: a study based on 16S rRNA sequencing

Zheng Qing-Xiang,Jiang Xiu-Min,Wang Hai-Wei,Ge Li,Lai Yu-Ting,Jiang Xin-Yong,Chen Fan,Huang Ping-Ping 한국미생물학회 2021 The journal of microbiology Vol.59 No.9

Probiotics effectively prevent and improve metabolic diseases such as diabetes by regulating the intestinal microenvironment and gut microbiota. However, the effects of probiotics in gestational diabetes mellitus are not clear. Here, we showed that probiotic supplements significantly improved fasting blood glucose in a gestational diabetes mellitus rat model. To further understand the mechanisms of probiotics in gestational diabetes mellitus, the gut microbiota were analyzed via 16S rRNA sequencing. We found that compared with the normal pregnant group, the gestational diabetes mellitus rats had decreased diversity of gut microbiota. Moreover, probiotic supplementation restored the diversity of the gut microbiota in gestational diabetes mellitus rats, and the gut microbiota structure tended to be similar to that of normal pregnant rats. In particular, compared with gestational diabetes mellitus rats, the abundance of Firmicutes and Actinobacteria was higher after probiotic supplementation. Furthermore, activating carbohydrate metabolism and membrane transport pathways may be involved in the potential mechanisms by which probiotic supplements alleviate gestational diabetes mellitus. Overall, our results suggested that probiotic supplementation might be a novel approach to restore the gut microbiota of gestational diabetes mellitus rats and provided an experimental evidence for the use of probiotic supplements to treat gestational diabetes melitus.

Improvement of the Spectral Reconstruction Process with Pretreatment of Matrix in Convex Optimization

Zheng-shuai Jiang,Xin-yang Zhao,WEI HUANG,Tao Yang 한국광학회 2021 Current Optics and Photonics Vol.5 No.3

In this paper, a pretreatment method for a matrix in convex optimization is proposed to optimize the spectral reconstruction process of a disordered dispersion spectrometer. Unlike the reconstruction process of traditional spectrometers using Fourier transforms, the reconstruction process of disordered dispersion spectrometers involves solving a large-scale matrix equation. However, since the matrices in the matrix equation are obtained through measurement, they contain uncertainties due to out of band signals, background noise, rounding errors, temperature variations and so on. It is difficult to solve such a matrix equation by using ordinary nonstationary iterative methods, owing to instability problems. Although the smoothing Tikhonov regularization approach has the ability to approximatively solve the matrix equation and reconstruct most simple spectral shapes, it still suffers the limitations of reconstructing complex and irregular spectral shapes that are commonly used to distinguish different elements of detected targets with mixed substances by characteristic spectral peaks. Therefore, we propose a special pretreatment method for a matrix in convex optimization, which has been proved to be useful for reducing the condition number of matrices in the equation. In comparison with the reconstructed spectra gotten by the previous ordinary iterative method, the spectra obtained by the pretreatment method show obvious accuracy.

Roles of Non-cholinergic Intrapancreatic Nerves, Serotonergic Nerves, on Pancreatic Exocrine Secretion in the Isolated Perfused Rat Pancreas

Zheng er Jiang,신빛나,김인혜,이현주,용준환,이민재,원무호,이윤렬 대한약리학회 2011 The Korean Journal of Physiology & Pharmacology Vol.15 No.5

It has been rereported that axons which display 5-hydroxytryptamine (5-HT) immunoreactivity are abundant in the pancreas and the majority of serotonergic axons terminate within intrapancreatic ganglia, islet and acini. This histological result strongly suggests that intrapancreatic serotonergic nerves could affect to the pancreatic endocrine and exocrine secretion. Thus, this study was aimed to investigate whether intrapancreatic serotonergic nerves could affect pancreatic exocrine secretion and an action mechanism of the intrapancreatic serotonergic nerves. The rats were anesthetized with a single injection of urethane. The median line and the abdominal aorta was carefully dissected and cannulated with PE-50 tubing just above the celiac artery, and then tightly ligated just below the superior mesenteric artery. The pancreatic duct was also cannulated with Tygon microbore tubing. With the addition of serotonin, pancreatic volume flow and amylase output were significantly inhibited electrical field stimulation (EFS). On the other hand, pancreatic volume flow and amylase output were significantly elevated in EFS with the addition of spiperone. EFS application, however, pancreatic volume flow and amylase output had no significant change in cholecystokinin (CCK) alone when serotonin was applied under a 5.6 mM glucose background. Pancreatic volume flow and amylase output under 18 mM glucose background were significantly elevated in CCK plus serotonin than in CCK alone. These data suggest that intrapancreatic serotonergic nerves play an inhibitory role in pancreatic exocrine secretion and an important role in the insulin action or release.

Numerical simulation on mining effect influenced by a normal fault and its induced effect on rock burst

Jiang, Jin-Quan,Wang, Pu,Jiang, Li-Shuai,Zheng, Peng-Qiang,Feng, Fan Techno-Press 2018 Geomechanics & engineering Vol.14 No.4

The study of the mining effect influenced by a normal fault has great significance concerning the prediction and prevention of fault rock burst. According to the occurrence condition of a normal fault, the stress evolution of the working face and fault plane, the movement characteristics of overlying strata, and the law of fault slipping when the working face advances from footwall to hanging wall are studied utilizing UDEC numerical simulation. Then the inducing-mechanism of fault rock burst is revealed. Results show that in pre-mining, the in situ stress distribution of two fault walls in the fault-affected zone is notably different. When the working face mines in the footwall, the abutment stress distributes in a "double peak" pattern. The ratio of shear stress to normal stress and the fault slipping have the obvious spatial and temporal characteristics because they vary gradually from the higher layer to the lower one orderly. The variation of roof subsidence is in S-shape which includes slow deformation, violent slipping, deformation induced by the hanging wall strata rotation, and movement stability. The simulation results are verified via several engineering cases of fault rock burst. Moreover, it can provide a reference for prevention and control of rock burst in a fault-affected zone under similar conditions.

Exploration of Chinese-Korean Cooperative Multimedia Design Education

Jiang, Zheng-Qing,Lee, Dong-Hun The Korea Contents Association 2009 International Journal of Contents Vol.5 No.4

This paper has done a study of Chinese-Korean cooperative multimedia design education. Sino-Korean school of multimedia was set up by Shanghai University of Engineering Science (SUES) and Korea Dongseo University in October 2002. We have created "3.5+0.5 Teaching Model". In this model, Chinese and Korea professors take courses together. Firstly, paper points our the Chinese government policy background of Chinese-Foreign Cooperation in running schools and the development of Chinese-Korean cooperative multimedia design education in SUES. Secondly, by analyzing the multimedia design industry to understand the Chinese multi-media design education. Thirdly, paper made in-depth studies for "3.5+0.5 Teaching Model" so as to draw the experience of successes and problems. Through analysis of "Questionnaires for students' learning and living conditions in Dongseo University in 2009" by spss 16.0, paper made a research of mode of "A semester studying in Korea". Finally, paper points out the development direction of Chinese-Korean cooperative multimedia design.

Age-associated changes in pancreatic exocrine secretion of the isolated perfused rat pancreas

Zheng-er Jiang,ChengZhe Jiang,Baihui Chen,Chin Su Koh,Jun-Hwan Yong,Dae-Hun Park,Moo-Ho Won,Yun-Lyul Lee 한국실험동물학회 2013 Laboratory Animal Research Vol.29 No.1

Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and β-cell"s sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCKstimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.