Purification and Characterization of Novel Manganese Peroxidase from Rhizoctonia sp. SYBC-M3

Yujie Cai,Huiguang Wu,Xiangru Liao,Yanrui Ding,Jun Sun,Dabing Zhang 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6

A novel manganese peroxidase of Rhizoctonia sp. SYBC-M3 (R-MnP) was purified by (NH4)2SO4fractionation, DEAE-cellulose-32 column chromatography,and Sephadex G100 column chromatography. The molecular mass of R-MnP was determined to be approximately 40.4 kDa by SDS-PAGE. The optimum temperature and pH for R-MnP were 55°C and 4.5, respectively. R-MnP was highly stability when the temperature was below 50°C. R-MnP could retain about 60% of its activity when the pH was between 4 and 6.5. However, R-MnP activity was inhibited by Fe3+, Cu2+, and Co3+ as well as increased by Zn2+ and Ca2+. R-MnP demonstrated oxidation of DMP,ABTS, veratryl alcohol, and guaiacol. The Km values of RMnP for H2O2 and Mn2+ were 25.3 and 53.9 μmol/L,respectively.

Confinement coefficient of concrete-filled square stainless steel tubular stub columns

Fa-Xing Ding,Yi-xiang Yin,Liping Wang,Yujie Yu,Liang Luo,Zhi-wu Yu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.4

The objective of this paper is to investigate the confinement coefficient of concrete-filled square stainless steel tubular (CFSSST) stub columns under axial loading. A fine finite 3D solid element model was established, which utilized a constitutive model of stainless steel considering the strain-hardening characteristics and a triaxial plastic-damage constitutive model of concrete with features of the parameter certainty under axial compression. The finite element analysis results revealed that the increased ultimate bearing capacity of CFSSST stub columns compared with their carbon steel counterparts was mainly due to that the composite action of CFSSST stub columns is stronger than that of carbon steel counterparts. A further parametric study was carried out based on the verified model, and it was found that the stress contribution of the stainless steel tube is higher than the carbon steel tube. The stress nephogram was simplified reasonably in accordance with the limit state of core concrete and a theoretical formula was proposed to estimate the ultimate bearing capacity of square CFSSST stub columns using superposition method. The predicted results showed satisfactory agreement with both the experimental and FE results. Finally, the comparisons of the experimental and predicted results using the proposed formula and the existing codes were illustrated.

Field measurement and numerical simulation of excavation damaged zone in a 2000 m-deep cavern

Zhang, Yuting,Ding, Xiuli,Huang, Shuling,Qin, Yang,Li, Peng,Li, Yujie Techno-Press 2018 Geomechanics & engineering Vol.16 No.4

This paper addresses the issue of field measurement of excavation damage zone (EDZ) and its numerical simulation method considering both excavation unloading and blasting load effects. Firstly, a 2000 m-deep rock cavern in China is focused. A detailed analysis is conducted on the field measurement data regarding the mechanical response of rock masses subjected to excavation and blasting operation. The extent of EDZ is revealed 3.6 m-4.0 m, accounting for 28.6% of the cavern span, so it is significantly larger than rock caverns at conventional overburden depth. The rock mass mechanical response subjected to excavation and blasting is time-independent. Afterwards, based on findings of the field measurement data, a numerical evaluation method for EDZ determination considering both excavation unloading and blasting load effects is presented. The basic idea and general procedures are illustrated. It features a calibration operation of damage constant, which is defined in an elasto-plastic damage constitutive model, and a regression process of blasting load using field blasting vibration monitoring data. The numerical simulation results are basically consistent with the field measurement results. Further, some issues regarding the blasting loads, applicability of proposed numerical method, and some other factors are discussed. In conclusion, the field measurement data collected from the 2000 m-deep rock cavern and the corresponding findings will broaden the understanding of tunnel behavior subjected to excavation and blasting at great depth. Meanwhile, the presented numerical simulation method for EDZ determination considering both excavation unloading and blasting load effects can be used to evaluate rock caverns with similar characteristics.

Seismic Performance of Precast Concrete Columns with Improved U-type Reinforcement Ferrule Connections

Zhiwu Yu,Xiaoyong Lv,Yujie Yu,Faxing Ding,Xiaodan Peng 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.7

This paper proposes a new kind of U-type reinforcement ferrule (URF) connection for the assembly of precast concrete (PC) components, which has a good fault-tolerance ability and low cost of construction with a simple postgrouting process. The modified connection features welded U ferrules, which can increase the bonding mechanism and internal stress transmission in the spliced region. A series of quasi-static cyclic tests were performed on URF-connected PC columns with different welding patterns. Comprehensive comparisons were performed on the load-bearing capacity, the plastic energy dissipation ability, the internal force transmission, the column ductility and the stiffness. The results indicated that PC columns with welded URF connections can ensure better lateral resistance than the cast-in-place concrete column. The weld type and length influence the connection performance, and the 15d-welded and full-length welded URF connections presented better connection performance and were suggested for the assembly of PC columns. Then, finite element analyses were performed to further reveal the working and failure mechanisms and the affecting mechanism of some working parameters. Parametric simulations indicated that the increase in the axial load ratio and the concrete strength in the postcast region had a slight but limited effect on improving the lateral resistance of the column connection.

DAMAGE-COUPLED CONSTITUTIVE MODEL FOR UNIAXIAL RATCHETING AND FATIGHE FAILURE OF 304 STAINLESS STEEL

GUOZHENG KANG,JUN DING,YUJIE LIU 한국소성가공학회 2008 한국소성가공학회 컨퍼런스 Vol.2008 No.10

A Novel Technique of Polishing Gear Working Surface using PECMP

Jianjun YI,Jingjing ZHOU,Yujie DING,Shaohua ZHAO 한국정밀공학회 2009 International Journal of Precision Engineering and Vol. No.

Polishing is dispensable for maximizing the life and overall performance of gears. Pulse Electrochemical Mechanical Polishing (PECMP) is combined by pulse electrochemical and mechanical action, it can reduce the surface roughness value to Ra 0.02μm and even lower and meet the requirement of gear working surface(especially for gear hard surface) polishing. The processing mechanism of PECMP and its influencing factor are discussed in this paper. Some experiments are investigated to research the surface characteristics of gears polished using PECMP , their microtopography and machining texture. The results show that PECMP have many advantages over traditionally polished surfaces with regard to friction factor reduction, noise reduction, precision keeping and anti-conglutination. For the better application of PECMP, the influencing factors and future works are discussed as well.

Microfluidic Synthesis of Hybrid Nanoparticles with Controlled Lipid Layers: Understanding Flexibility-Regulated Cell–Nanoparticle Interaction

Zhang, Lu,Feng, Qiang,Wang, Jiuling,Zhang, Shuai,Ding, Baoquan,Wei, Yujie,Dong, Mingdong,Ryu, Ji-Young,Yoon, Tae-Young,Shi, Xinghua,Sun, Jiashu,Jiang, Xingyu American Chemical Society 2015 ACS NANO Vol.9 No.10

<P>The functionalized lipid shell of hybrid nanoparticles plays an important role for improving their biocompatibility and <I>in vivo</I> stability. Yet few efforts have been made to critically examine the shell structure of nanoparticles and its effect on cell–particle interaction. Here we develop a microfluidic chip allowing for the synthesis of structurally well-defined lipid-polymer nanoparticles of the same sizes, but covered with either lipid-monolayer-shell (MPs, monolayer nanoparticles) or lipid-bilayer-shell (BPs, bilayer nanoparticles). Atomic force microscope and atomistic simulations reveal that MPs have a lower flexibility than BPs, resulting in a more efficient cellular uptake and thus anticancer effect than BPs do. This flexibility-regulated cell–particle interaction may have important implications for designing drug nanocarriers.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-10/acsnano.5b05792/production/images/medium/nn-2015-05792e_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b05792'>ACS Electronic Supporting Info</A></P>