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New Method for Analysis of Sliding Cable Structures in Bridge Engineering
Xiang-min Yu,De-wei Chen,Zhi-zhou Bai 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.11
The Sliding Cable Structure (SCS) is widely used in bridge construction by cable crane method. The SCS generally consists of cables and fixed pulleys and the cables will slide around the pulleys when the cables are loaded until the balanced state is achieved. In this paper, an efficient Angle Bisector Method (ABM) is proposed for the mechanical analysis of SCS. The constraint effect of pulley on the cable is simulated by fixed hinge and the constraint force perpendicular to the angle bisector of cable elements adjacent to the pulley is therefore zero at balanced state. By utilizing “Unit Length Influence Matrix” (ULIM), the adjustment of unstressed length of each sub-cable can be determined. As the angle bisector at each pulley will change when the unstressed lengths of cables are changed, iterative procedures are necessary to find the convergence solutions. The proposed method is firstly verified by two examples and then applied to the analysis of cable crane during construction of the world’s longest steel truss cable-stayed bridge, namely Yachihe Bridge. Satisfactory numerical solutions can be obtained only with several iterations and are in good agreement with field measurements from the cable crane load tests, which confirms the accuracy and validity of the proposed method.
A Stability Study of the Longest Steel Truss Deck Cable-stayed Bridge during Construction
Xiang-min Yu,De-wei Chen,Zhi-zhou Bai 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.4
For long-span cable-stayed bridges, the stability performance during construction is vital from the point view of structural safety. This paper presents an extensive study of stability performance during construction for the world longest steel truss deck cable-stayed bridge-Yachihe Bridge. Based on the finite element analysis, the Linear Elastic Stability (LES), Nonlinear Elastic Stability (NLES) and Nonlinear Inelastic Stability (NLIES) of the bridge have been investigated to identify the effects of geometry nonlinearity and material nonlinearity on the structural stability performance. In addition, the influences of temperature variations and static lateral winds on stability performance are also focused. The results show that: 1) Under design ambient temperature, the corresponding design of steel truss deck yields the minimum stability coefficients of LES, NLES and NLIES by 5.72, 4.64 and 2.96, respectively, corresponding to the completion of superimposed dead loads; 2) both the geometry nonlinearity and material nonlinearity have been identified to make negative effects on the stability performance and the material nonlinearity will reduce the structural stabilitycoefficient largely; 3) during construction, the rise and drop in temperature will increase and decrease the stability coefficients, respectively. NLIES is the most sensitive one to variations of temperature; and 4) the lateral static winds slightly reduce the stability coefficients of LES, NLES and NLIES.
Covalent Immobilization of Penicillin G Acylase onto Fe₃O₄@Chitosan Magnetic Nanoparticles
( Xiao Min Ling ),( Xiang Yu Wang ),( Ping Ma ),( Yi Yang ),( Jie Mei Qin ),( Xue Jun Zhang ),( Ye Wang Zhang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.5
Penicillin G acylase (PGA) was immobilized on magnetic Fe₃O₄@chitosan nanoparticles through the Schiff base reaction. The immobilization conditions were optimized as follows: enzyme/support 8.8 mg/g, pH 6.0, time 40 min, and temperature 25℃. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 6.2 mg/g-support were obtained. Broader working pH and higher thermostability were achieved by the immobilization. In addition, the immobilized PGA retained 75% initial activity after ten cycles. Kinetic parameters Vmax and Km of the free and immobilized PGAs were determined as 0.113 mmol/min/mg-protein and 0.059 mmol/min/mg-protein, and 0.68 mM and 1.19 mM, respectively. Synthesis of amoxicillin with the immobilized PGA was carried out in 40% ethylene glycol at 25℃ and a conversion of 72% was obtained. These results showed that the immobilization of PGA onto magnetic chitosan nanoparticles is an efficient and simple way for preparation of stable PGA.
Lung-Targeting Delivery of Dexamethasone Acetalte Loaded Solid Lipid Nanoparticles
Xiang, Qing-Yu,Wang, Min-Ting,Chen, Fu,Gong, Tao,Jian, Yan-Lin,Zhang, Zhi-Rong,Huang, Yuan 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.4
The objective of the present study was to develop a novel solid lipid nanoparticle (SLN) for the lung-targeting delivery of dexamethasone acetate (DXM) by intravenous administration. DXM loaded SLN colloidal suspensions were prepared by the high pressure homogenization method. The mean particle size, drug loading capacity and drug entrapment efficiency (EE %) of SLNs were investigated. In vitro drug release was also determined. The biodistribution and lung-targeting efficiency of DXM-SLNs and DXM-solutions (DXM-sol) in mice after intravenous administration were studied using reversed-phase high-performance liquid chromatography(HPLC). The results (expressed as mean ${\pm}$ SD) showed that the DXM-SLNs had an average diameter of 552 ${\pm}$ 6.5 nm with a drug loading capacity of 8.79 ${\pm}$ 0.04% and an entrapment efficiency of 92.1 ${\pm}$ 0.41%. The in vitro drug release profile showed that the initial burst release of DXM from DXM-SLNs was about 68% during the first 2 h, and then the remaining drug was released gradually over the following 48 hours. The biodistribution of DXM-SLNs in mice was significantly different from that of DXM-sol. The concentration of DXM in the lung reached a maximum level at 0.5 h post DXM-SLNs injection. A 17.8-fold larger area under the curve of DXM-SLNs was achieved compared to that of DXM-sol. These results indicate that SLN may be promising lung-targeting drug carrier for lipophilic drugs such as DXM.
불소화 폴리아크릴레이트-폴리우레탄 라텍스 혼성필름의 그레디언트 구조와 표면성질
Min Zhu,Kun Chen,Yu Fang Zhang,Xiang Rong Wang,Xiang Dong Zhou 한국고분자학회 2014 폴리머 Vol.38 No.3
In order to investigate the characteristics of the gradient fluorinated polyacrylate and polyurethane latex blendfilms, the fluorinated polyacrylate emulsion and the polyurethane emulsion were synthesized, and then the both emulsionswere blended at a series of ratios. The effects of content of the fluorinated polyacrylate on the gradient structure and surfaceproperty of the blended films were assessed by AFM, XPS, SEM-EDX and surface free energy measurements. Itappeared that, while the content of the fluorinated polyacrylate latex was up to 30%, the fluorinated polyacrylate particleswere selectively gathered on the film-air (F-A) and film-glass (F-G) interfaces at room temperature. When the contentof the fluorinated polyacrylate was under 30%, the gradient structure of fluorinated component was not evident. The furtherincreasing of fluorinated polyacrylate in the mixed system facilitated the formation and enlargement of gradient structure,but the adhesion of film decreased a little.
Yu, Shu-Min,Yan, Xing-Rong,Chen, Dong-Mei,Cheng, Xiang,Dou, Zhong-Ying Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.1
Parthenogenetic embryonic stem (pES) cells could provide a valuable model for research into genomic imprinting and X-linked diseases. In this study, pES cell lines were established from oocytes of hybrid offspring of Kunming and 129/Sv mice, and pluripotency of pES cells was evaluated. The pES cells maintained in the undifferentiated state for more than 50 passages had normal karyotypes with XX sex chromosomes and exhibited high activities of alkaline phosphatase (AKP) and telomerase. Meanwhile, these cells expressed ES cell molecular markers SSEA-1, Oct-4, Nanog, and GDF3 but not SSEA-3 detected by immunohistochemistry and RT-PCR. The pES cells could be differentiated into various types of cells from three germ layers in vitro by analysis of embryoid bodies (EBs) with immunohistochemistry and RT-PCR, and in vivo by observation of pES cell-derived teratoma sections. Therefore, the established pES cell lines contained all features of mouse ES cells. This work provides a new strategy for isolating pES cells from Kunming mice, and the pES cell lines could be applied as the cell model in research into genomic imprinting and epigenetic regulation of Kunming mice.
도라지 잎 홍차 및 녹차 제품의 항산화활성 폴리페놀과 플라보노이드 비배당체 함량
Xiang Min Piao,Ying Yu,Sin Hee Han,Sang Won Lee,Seon Woo Cha,Ying Ping Wang,Jing Guo 한국약용작물학회 2016 한국약용작물학술대회 발표집 Vol.2016 No.10
Background : Invitro antioxidant activity, polyphenol and flavonoid aglycone contents in black and green tea products of balloon flower leaves were investigated to provide valuable information for the further development and utilization of resources of Platycodon grandiflorum. Methods and Results : Flavonoid aglycone contents were investigated using HPLC (SHIMADZU, Japan) with a hypersil ODS column (125 mm × 4 mm, 5-μm particle, HP). DPPH and ABTS radical scavenging activities were measured by method of Lee & Lee (2004) with slight modification. Antioxidant activity, polyphenol and flavonoid contents in green tea were significantly higher than these in black tea. PC analysis indicated that first principal components explained 79.9% of the total variability for five traits investigated. PC2 explained 19.7% of the variation. Conclusion : It can be concluded from these results that these characteristics can reveal the active compound variation of black and green tea products of balloon flower leaves. These results provide scientific evidence for the utilization of balloon flower leaves.
Lung-Targeting Delivery of Dexamethasone Acetate Loaded Solid Lipid Nanoparticles
Qing-yu Xiang,Yuan Huang,Zhi-rong Zhang,Min-ting Wang,Fu Chen,Tao Gong,Yan-lin Jian 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.4
The objective of the present study was to develop a novel solid lipid nanoparticle (SLN) for the lung-targeting delivery of dexamethasone acetate (DXM) by intravenous administration. DXM loaded SLN colloidal suspensions were prepared by the high pressure homogenization method. The mean particle size, drug loading capacity and drug entrapment efficiency (EE %) of SLNs were investigated. In vitro drug release was also determined. The biodistribution and lung-targeting efficiency of DXM-SLNs and DXM-solutions (DXM-sol) in mice after intravenous administration were studied using reversed-phase high-performance liquid chromatography (HPLC). The results (expressed as mean ± SD) showed that the DXM-SLNs had an average diameter of 552 ± 6.5 nm with a drug loading capacity of 8.79 ± 0.04% and an entrapment efficiency of 92.1 ± 0.41%. The in vitro drug release profile showed that the initial burst release of DXM from DXM-SLNs was about 68% during the first 2 h, and then the remaining drug was released gradually over the following 48 hours. The biodistribution of DXM-SLNs in mice was significantly different from that of DXM-sol. The concentration of DXM in the lung reached a maximum level at 0.5 h post DXM-SLNs injection. A 17.8-fold larger area under the curve of DXM-SLNs was achieved compared to that of DXM-sol. These results indicate that SLN may be promising lung-targeting drug carrier for lipophilic drugs such as DXM.