Formation Mechanisms for (Cr,Co)7C3/(Cr,Co)23C6 Heterogeneous Precipitates and Stacking Faults Around Carbides in Surfacing Welding of Stellite Alloy on Stainless Steel

Jiankun Xiong,Haibo Zhang,Fuheng Nie,Fen He,Jianping Yang,Zhan Hu,Zhongbo Wen,Haiyan Zhao,Xinjian Yuan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The formation mechanisms for two carbides with co-existence and increasing stacking faults nearby the carbides duringsurfacing welding were investigated in this study. The results indicated that the surfacing layer had a two-phase structure ofa matrix phase and a second phase, the density of the second phase was relatively small and the second phase was discontinuous,by contrast with the as-received welding wire. Relatively uniform microstructure of surfacing layer and the weldinginterface without melting of base metal were obtained, resulting in an inapparent change in the microhardness. A few carbideswith blocky shape were identified in the surfacing layer. The mechanisms for (Cr,Co)23C6 of face-centered cubic crystalstructure co-existing with (Cr,Co)7C3 of hexagonal close-packed crystal structure and (Cr,Co)23C6 subsequently forming closeto the pre-formed (Cr,Co)7C3 during the cooling process were discussed in alloying element, calculated equilibrium phasediagram, Gibbs energy, etc. The relatively higher density of the stacking fault present around the carbides was understoodfrom forming energy of stacking faults.

Debonding defect quantification method of building decoration layers via UAV-thermography and deep learning

Xiong Peng,Xiong Peng,Anhua Chen,Chao Zhao,Canlong Liu,Y. Frank Chen 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.1

The falling offs of building decorative layers (BDLs) on exterior walls are quite common, especially in Asia, which presents great concerns to human safety and properties. Presently, there is no effective technique to detect the debonding of the exterior finish because debonding are hidden defect. In this study, the debonding defect identification method of building decoration layers via UAV-thermography and deep learning is proposed. Firstly, the temperature field characteristics of debonding defects are tested and analyzed, showing that it is feasible to identify the debonding of BDLs based on UAV. Then, a debonding defect recognition and quantification method combining CenterNet (Point Network) and fuzzy clustering is proposed. Further, the actual area of debonding defect is quantified through the optical imaging principle using the real-time measured distance. Finally, a case study of the old teaching-building inspection is carried out to demonstrate the effectiveness of the proposed method, showing that the proposed model performs well with an accuracy above 90%, which is valuable to the society.

Lake Surface Area Estimation Method based on Error Mechanism Model for Satellite Imagery and Its Application in Ebinur Lake

Rong Xu,Chunzhe Zhao,Jiang Xiong 보안공학연구지원센터(IJSIP) 2015 International Journal of Signal Processing, Image Vol.8 No.1

A novel mechanism model is proposed for the difference between the lake water areas derived from the remote sensing images at high spatial resolution and low spatial resolution. The areas estimated by images at different spatial resolution are calculated theoretically for the elliptical (including circular), triangular and hexagonal areal ground features. Based on the ideal cases, the quantitative rule between the two kinds of area is summarized. According to the theoretical results, the mechanism model is established for the error of the lake surface area. Especially, the surface area of Ebinur Lake derived with SPOT/VEGETATION (VGT), Landsat EM/ETM+ and MODIS are employed to validate the effectiveness and applicability of this model. With the help of the linear regression method, this model can be used to estimate the error between the Ebinur Lake surface areas derived from satellite images at different spatial resolutions, and promote the lake surface area from low spatial resolution imagery. Consequently, this model is helpful for estimating the lake surface area more accurately in a large region, and its effectiveness can be improved with more historical data.

Simultaneous distillation-extraction for manufacturing ultra-high-purity electronic-grade octamethylcyclotetrasiloxane (D4)

Wenhui Guo,Shuhu Guo,Xu Zhao,Zhenjun Yuan,Yu Zhao,Xin Chang,Hong Li,Xiong Zhao,Ye Wan,Dazhou Yan,Zhongyuan Ren,Xiaolei Fan,Xin Gao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Ultra-high-purity (UHP) electronic-grade octamethylcyclotetrasiloxane (D4) is the key precursor of lowdielectricconstant (low-k) SiCOH films to manufacture integrated circuits (IC), meeting the stringentrequirements of the rapidly developing semiconductor industry. Commonly, metallic impurities in D4were removed by multiple unit operations of adsorption, filtration, and distillation, which could reducethe concentration of a single metallic impurity below 1 ppb. However, D4 with higher purity is requiredby semiconductor production due to an increase in transistor density. Herein, a novel method based onthe integrated simultaneous distillation–extraction (SDE) was developed for manufacturing UHPelectronic-grade D4. The lab and pilot scale experiments showed that the purity of water and D4 has apositive correlation. Based on the experimental data, a double-column process, consisting of azeotropic/extractive distillation column and precision distillation column with UNIQUAC method, was establishedto access the feasibility of scaling up the SDE process. According to the simulation results, D4with the purity > 99.999 wt.% and total metallic impurities (TMI) content below 1 ppb could be obtainedusing ultra-pure water.

Metformin Inhibits Growth of Hepatocellular Carcinoma Cells by Inducing Apoptosis Via Mitochondrion-mediated Pathway

Xiong, Yu,Lu, Qing-Jun,Zhao, Jing,Wu, Guo-Yang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Recently, population-based studies of type 2 diabetes patients have provided evidence that metformin treatment is associated with a reduced cancer incidence and mortality, but its mode of action remains unclear. Here we report effects of metformin on hepatocellular carcinoma (HCC) Hep-G2 cells and details of molecular mechanisms of metformin activity. Our research indicates that metformin displays anticancer activity against HCC through inhibition of the mTOR translational pathway in an AMPK-independent manner, leading to G1 arrest in the cell-cycle and subsequent cell apoptosis through the mitochondrion-dependent pathway. Furthermore, we showed that metformin strongly attenuated colony formation and dramatically inhibited Hep-G2 tumor growth in vivo. In conclusion, our studies suggested that metformin might have potential as a cytotoxic drug in the prevention and treatment of HCC.

Directed Evolution of Beta-galactosidase from Escherichia coli into Beta-glucuronidase

Xiong, Ai-Sheng,Peng, Ri-He,Zhuang, Jing,Liu, Jin-Ge,Xu, Fang,Cai, Bin,Guo, Zhao-Kui,Qiao, Yu-Shan,Chen, Jian-Min,Zhang, Zhen,Yao, Quan-Hong Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

In vitro directed evolution through DNA shuffling is a powerful molecular tool for creation of new biological phenotypes. E. coli $\beta$-galactosidase and $\beta$-glucuronidase are widely used, and their biological function, catalytic mechanism, and molecular structures are well characterized. We applied an in vitro directed evolution strategy through DNA shuffling and obtained five mutants named YG6764, YG6768, YG6769, YG6770 and YG6771 after two rounds of DNA shuffling and screening, which exhibited more $\beta$-glucuronidase activity than wild-type $\beta$-galactosidase. These variants had mutations at fourteen nucleic acid sites, resulting in changes in ten amino acids: S193N, T266A, Q267R, V411A, D448G, G466A, L527I, M543I, Q626R and Q951R. We expressed and purified those mutant proteins. Compared to the wild-type protein, five mutant proteins exhibited high $\beta$-glucuronidase activity. The comparison of molecular models of the mutated and wildtype enzymes revealed the relationship between protein function and structural modification.

Chemiluminescence Determination of Balofloxacin Based on Europium (III)-Sensitized KBrO₃-Na₂S₂O₄ Reaction in Micellar Medium

Zhao, Fang,Qi, Yu,Xiong, Wei Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.1

A novel chemiluminescence (CL) flow injection method for the determination of balofloxacin is described. The method is based on the weak CL signal arising from the reaction of $KBrO_3$ with $Na_2S_2O_4$ in acidic medium being significantly enhanced by balofloxacin in the presence of europium (III) ion and sodium dodecyl benzene sulfonate (SDBS). The experimental conditions that affected CL intensity were carefully optimized and the CL reaction mechanism was briefly discussed. Under the optimum conditions, the relative CL intensity was proportional to the concentration of balofloxacin in the range of $7.0{\times}10^{-11}$ to $3.0{\times}10^{-7}g\;mL^{-1}$. The detection limit was $2.7{\times}10^{-11}g\;mL^{-1}$ and the relative standard deviation was 2.1% for $7.0{\times}10^{-10}g\;mL^{-1}$ balofloxacin (n = 13). The proposed method was successfully applied to the determination of balofloxacin in pharmaceutical formulations and biological fluids.

Attenuation of Beryllium Induced Hepatorenal Dysfunction and Oxidative Stress in Rodents by Combined Effect of Gallic Acid and Piperine

Zhao, Jun-Quan,Du, Guo-Zhen,Xiong, You-Cai,Wen, Yi-Fu,Bhadauria, Monika,Nirala, Satendra Kumar 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.12

We determined a minimum effective dose of gallic acid (3,4,5-trihydroxy benzoic acid; 50 mg/kg, Lp.) and piperine (10 mg/kg, p.o.) through their therapeutic potential and further evaluated them individually and in combination against beryllium-induced biochemical alterations and oxidative stress-consequences in female albino rats. The administration of beryllium altered blood biochemical variables by significantly depleting hemoglobin, albumin and urea, whereas it enhanced bilirubin and creatinine. The release of serum transaminase, lactate dehydrogenase and ${\gamma}-glutamyl$ transpeptidase was significantly greater, and was concomitant with a decreasein serum alkaline phosphatase. A significant increase in lipid peroxidation and a decrease in glutathione, superoxide dismutase and catalase in the liver and kidney was an indication of oxidative stress due to beryllium exposure. Individual administration of gallic acid and piperine moderately reversed the altered biochemical variables, whereas the combination of these was found to completely reverse the beryllium-induced biochemical alterations and oxidative stress consequences. We concluded that gallic acid exerts a synergistic effect when administered with piperine and provides a more pronounced therapeutic potential in reducing beryllium-induced hepatorenal dysfunction and oxidative stress consequences.

Effects of Lonicera japonica extract on performance, blood biomarkers of inflammation and oxidative stress during perinatal period in dairy cows

Zhao Yiguang,Tang Zhiwen,Nan Xuemei,Sun Fuyu,Jiang Linshu,Xiong Benhai 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.7

Objective: An experiment was conducted to evaluate the effects of Lonicera japonica extract (LJE) on milk production, rumen fermentation and blood biomarkers of energy metabolism, inflammation and oxidative stress during the perinatal period of Holstein dairy cows. Methods: Eighteen Holstein dairy cows were used in a complete randomized design experiment with 3 dietary treatments and 6 cows per treatment. All cows received the same basal total mixed ration (TMR) including a prepartal diet (1.35 Mcal of net energy for lactation [NEL]/kg of dry matter [DM], 13.23% crude protein [CP]) from –60 d to calving and a postpartal diet (1.61 Mcal of NEL/kg of DM, 17.39% CP) from calving to 30 days in milk (DIM). The 3 dietary treatments were TMR supplemented with LJE at 0 (control), 1 and 2 g/kg DM, respectively. LJE was offered from 21 d before calving to 30 DIM. Dry matter intake (DMI) and milk production were measured daily after calving. Milk and rumen fluid samples were collected on 29 and 30 d after calving. On –10, 4, 14, and 30 d relative to calving, blood samples were collected to analyze the biomarkers of energy metabolism, inflammation and oxidative stress. Results: Compared with control diet, LJE supplementation at 1 and 2 g/kg DM increased DMI, milk yield and reduced milk somatic cell count. LJE supplementation also decreased the concentrations of blood biomarkers of pro-inflammation (interleukin-1β [IL-1β], IL-6, and haptoglobin), energy metabolism (nonesterified fatty acid and β-hydroxybutyric acid) and oxidative stress (reactive oxygen metabolites), meanwhile increased the total antioxidant capacity and superoxide dismutase concentrations in blood. No differences were observed in rumen pH, volatile fatty acid, and ammonia-N (NH3-N) concentrations between LJE supplemented diets and the control diet. Conclusion: Supplementation with 1 and 2 g LJE/kg DM could increase DMI, improve lactation performance, and enhance anti-inflammatory and antioxidant capacities of dairy cows during perinatal period.

Acoustic emission characterization of the fracture process in steel fiber reinforced concrete

Xiong Zhou,Yuyou Yang,Xiangqian Li,Guoqing Zhao 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.18 No.4

The correlation between the characteristics of acoustic emission signals and the strength parameters of concretes is investigated by combining the acoustic emission (AE) technique and steel fiber reinforced concrete (SFRC). By means of AE detection system, three kinds of steel fibers of varying content were used as reinforcement in concrete and their influence on the fracture process and the acoustic activity was considered in this paper. Analysis of the AE test results revealed that for different steel fiber contents, the role of steel fiber is different. Concave-convex steel fiber has an inhibitory effect on the control of crack expansion. Bow steel fiber has a better effect on the control of crack propagation when the fiber content is lower. The compressive strength of SFRC decrease when bow steel fiber content rises. Ultra-short can prevent early cracks of concrete.