Seismic Reliability Assessment of Mid- and High-rise Post-tensioned CLT Shear Wall Structures

Sun, Xiaofeng,Li, Zheng,He, Minjuan Council on Tall Building and Urban Habitat Korea 2020 International journal of high-rise buildings Vol.9 No.2

Currently, few studies have been conducted to comprehend the seismic reliability of post-tensioned (PT) CLT shear wall structures, due to the complexity of this kind of structural system as well as due to lack of a reliable structural model. In this paper, a set of 4-, 8-, 12-, and 16-storey benchmark PT CLT shear wall structures (PT-CLTstrs) were designed using the direct displacement-based design method, and their calibrated structural models were developed. The seismic reliability of each PT-CLTstr was assessed based on the fragility analysis and based on the response surface method (RSM), respectively. The fragility-based reliability index and the RSM-based reliability index were then compared, for each PT-CLTstr and for each seismic hazard level. Results show that the RSM-based reliabilities are slightly less than the fragility-based reliabilities. Overall, both the RSM and the fragility-based reliability method can be used as efficient approaches for assessing the seismic reliabilities of the PT-CLTstrs. For these studied mid- and high-rise benchmark PT-CLTstrs, following their fragility-based reliabilities, the 8-storey PT-CLTstr is subjected to the least seismic vulnerability; while, following their RSM-based reliabilities, the 4-storey PT-CLTstr is subjected to the least seismic vulnerability

Adsorption of phosphate using calcined Mg3–Fe layered double hydroxides in a fixed-bed column study

XiaoFeng Sun,Tsuyoshi Imai,Masahiko Sekine,Takaya Higuchi,Koichi Yamamoto,Ariyo Kanno,Shiori Nakazono 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

A granular calcined Mg3–Fe LDH adsorbent was prepared by using co-precipitation method under low super saturation condition. The characteristic of the adsorbent was analyzed by powder X-ray diffraction (XRD) and scanning electron microscope (SEM). The continuous phosphate adsorption experiments were conducted in a glass fix-bed column. The results showed an increase in bed height and initial phosphate concentration improves the phosphate adsorption capacity probably due to the longer bed height allowing a longer empty bed contact time (EBCT) between the adsorbent and the adsorbate, meanwhile the higher initial phosphate concentration provides a higher driving force for the mass transfer; however, an increase in flow rate inhibits the phosphate adsorption due to the higher flow rate reduced the interaction time of the adsorbent in solution. The bed depth service time (BDST) model was found to predict the breakthrough curve well at a 0.024 L/h flow rate and 10 mg/L initial phosphate concentration using linear regression analysis. The Clark model was found to give a best fit to experiment data under various bed height, flow rate and initial phosphate concentration, followed by the Thomas and Yoon–Nelson models using non-linear regression analysis. The reusability experiment was conducted using actual anaerobic sludge filtrate as adsorbate. The results indicated that the adsorbent still had good selectivity in an anions coexisting solution, high phosphate adsorption capacity, and acceptable desorption efficiency.

Optimization of impedance boundarycontrolled casing treatment on subsonic compressors

Dakun Sun,Yuqing Wang,Jia Li,Zihan Shen,ChunWang Geng,Xu Dong,Xiaoyu Wang,Xiaofeng Sun 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

Foam-metal casing treatment (FMCT) has the potential to enhance the stall margin while attenuating the broadband noise of compressors. An optimized structure of FMCT backed with an air gap was developed in this study with the basis of a prediction model. The eigenvalue theory with a linear perturbation assumption was employed to judge the stability of the compression system, where the casing treatment was considered as an impedance boundary condition. The effect of this kind of casing treatment on the compression system is introduced through the equivalent surface source method. The transfer element method was applied to match the relations between perturbation parameters on the surface of each section. Prediction results showed that the double-layer configuration has better stall margin improving ability, with experimental results on the steady characteristics confirming a 39.5 % stall margin improvement. The mechanism of exerting damping on the system and thus suppressing stall precursors was proved.

Fuzzy system and Improved APIT (FIAPIT) combined range-free localization method for WSN

( Xiaofeng Li ),( Liangfeng Chen ),( Jianping Wang ),( Zhong Chu ),( Qiyue Li ),( Wei Sun ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.7

Among numerous localization schemes proposed specifically for Wireless Sensor Network (WSN), the range-free localization algorithms based on the received signal strength indication (RSSI) have attracted considerable research interest for their simplicity and low cost. As a typical range-free algorithm, Approximate Point In Triangulation test (APIT) suffers from significant estimation errors due to its theoretical defects and RSSI inaccuracy. To address these problems, a novel localization method called FIAPIT, which is a combination of an improved APIT (IAPIT) and a fuzzy logic system, is proposed. The proposed IAPIT addresses the theoretical defects of APIT in near (it`s defined as a point adjacent to a sensor is closer to three vertexes of a triangle area where the sensor resides simultaneously) and far (the opposite case of the near case) cases partly. To compensate for negative effects of RSSI inaccuracy, a fuzzy system, whose logic inference is based on IAPIT, is applied. Finally, the sensor`s coordinates are estimated as the weighted average of centers of gravity (COGs) of triangles` intersection areas. Each COG has a different weight inferred by FIAPIT. Numerical simulations were performed to compare four algorithms with varying system parameters. The results show that IAPIT corrects the defects of APIT when adjacent nodes are enough, and FIAPIT is better than others when RSSI is inaccuracy.

Highly-sensitive Detection of Salvianolic Acid B using Alumina Microfibers-modified Electrode

Sun, Dong,Zheng, Xiaoyong,Xie, Xiafeng,Yang, Xiaofeng,Zhang, Huajie Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.11

Alumina microfibers with porous structures were prepared through hydrothermal reaction, and then used to modify the surface of carbon paste electrode (CPE). After modification with alumina microfibers, the electrochemical activity of CPE was found to be greatly improved. On the surface of alumina microfibers-modified CPE, the oxidation peak current of salvianolic acid B, a main bioactive compound in Danshen with anti-oxidative and anti-inflammatory effects, was remarkably increased compared with that on the bare CPE surface. The influences of pH value, amount of alumina microfibers and accumulation time were studied. Based on the strong signal amplification effects of alumina microfibers, a novel electrochemical method was developed for the detection of salvianolic acid B. The linear range was from 5 ${\mu}gL^{-1}$ to 0.3 mg $L^{-1}$, and the detection limit was 2 ${\mu}gL^{-1}$ (2.78 nM) after 1-min accumulation. The new method was successfully used to detect salvianolic acid B in ShuangDan oral liquid samples, and the recovery was over the range from 97.4% to 102.9%.

Preparation of epoxypropyl functionalized graphene oxide and its anticorrosion properties complexed with epoxy resin

Xiaofeng Yang,Yuepeng Zhang,Zhiping Chen,Yinshuai Yang,Hongxia Jing,Zhenhao Sun,Huijie Wang 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

Functionalized graphene oxide (GO)/epoxy resin (EP) composite coating has attracted attention due to its advantages of epoxy resin in acid resistance, anticorrosion and having the characteristics of GO such as good chemical stability and strong electrolyte barrier properties. In this study, epoxypropyl functionalized graphene oxide (EFGO) was synthesized with a new strategy by grafting epichlorohydrin (ECH) onto the surface of GO. EFGO was then crosslinked with EP by diethylenetriamine (DETA) to fabricate EFGO/EP anticorrosive coating. The structure and property of EFGO and EFGO/EP were characterized and evaluated by various methods such as FTIR, Raman, XPS, SEM, and EIS. The results showed that the graft amount of epoxypropyl on GO surface could be effectively increased by using KI-KF catalysis system. The increase of the graft amount further improved the compatibility between EFGO and EP. EFGO/EP had a network structure with EFGO as the “central node”. The “central node” locked the movement of EP chain segment, as improving the thermal stability of EFGO/EP. The EFGO/EP coating fabricated by the EFGO, which grafted larger epoxypropyl, had good anticorrosion performance and adhesion with steel plates, showing a good barrier effect on electrolyte migration. The coating resistance reached up 4.88×108 cm2.

Object Detection Based on Multi-scale Contour Fragments

Xiaofeng Zhang,Qiaoyu Sun,Yue Lu 보안공학연구지원센터 2012 International Journal of Multimedia and Ubiquitous Vol.7 No.2

Two Arbuscular Mycorrhizal Fungi Alleviates Drought Stress and Improves Plant Growth in Cinnamomum migao Seedlings

( Xiaofeng Liao ),( Jingzhong Chen ),( Ruiting Guan ),( Jiming Liu ),( Qinwen Sun ) 한국균학회 2021 Mycobiology Vol.49 No.4

Cinnamomum migao plants often face different degrees of drought in karst habitats, which can lead to plants’ death, especially in the seedling stage. Widespread of arbuscular mycorrhizal (AM) fungi in karst soils have the potential to address this drought, which is a threat to C. migao seedlings. We inoculated C. migao seedlings with spores from Glomus lamellosum and Glomus etunicatum, two AM fungi widely distributed in karst soils, to observe seedling growth response after simulated drought. Our results showed that 40 g of G. lamellosum and G. etunicatum significantly promoted the growth of C. migao seedlings, 120 days after inoculation. Following a 15-day drought treatment, root colonization of the seedlings with G. lamellosum or G. etunicatum had lower the accumulation of malondialdehyde (MDA) and increased the accumulation of enzymes and osmotic substances in the seedlings. The relative water content in different organs (roots, stems, and leaves) of the drought-stressed seedlings was higher in plants with G. lamellosum or G. etunicatum than in plants without AM fungi colonization. Our results showed that inoculation with AM fungi was an effective means to improve the drought resistance of C. migao seedlings.

Electromagnetic Environment of Transmission Line Based on Full Parameter Online Estimation

Zidan Sun,Xiaofeng Zhou,Likai Liang,Yang Mo 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.2

The parameters of transmission lines have an influence on the electromagnetic environment surrounding theline. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and dataacquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance,reactance and susceptance. The proposed full parameter estimation method is compared with the traditionalmethod of estimating resistance independently based on SCADA system. Then, the electromagnetic environmentis analyzed based on the different parameter estimation methods. The example results illustrate that onlineestimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment,which further confirms its necessity and significance in engineering application.

Expression and Detection of Retinol-Binding Protein-4 Gene of Pig in E. coli

LiNa Sun,WanHong Li,ShuXiong Chen,Chao Chen,XiaoFeng Hou,Yun Zhao,Lu Chen,ChunJin Li,Xu Zhou 한국동물생명공학회(구 한국동물번식학회) 2014 한국동물번식학회 한중일 심포지엄 Vol.2014 No.1

Retinol-Binding Protein-4 (RBP-4) is a low molecular weight lipocalin, which mainly functions as a carrier for vitamin A. Though liver is the main machinery for synthesis of this protein, it is also detectable in other extrahepatic tissues, for example, ovary, uterus, and placenta. Recent evidences have shown that RBP-4 plays important roles in animal reproduction, for example, promoting the development of uterus and embryo. To the best of our knowledge, our laboratory firstly reported that high level of RBP-4 existed in follicular fluid from follicular cysts in sows. Moreover, we have also found that RBP-4 could be secreted by granulosa cells, and RBP-4 receptor was detected in granulosa cells. However, there is no any evidence on the role of RBP-4 in regulating the follicular development. Therefore, cloning and expression of RBP-4 and preparation of polyclonal antibody could help us to explore the role of RBP-4 in follicular development. The aim of this work was to construct prokaryotic expression system of swine RBP-4 gene. The total RNA was extracted from swine’s normal ovarian tissue. The sequence including the whole length of RBP-4 was amplified by RT-PCR and inserted into pEASY-E1.Then transformed into E. coli BL21(DE3)pLysS after gene sequencing. Three hours later, adding IPTG with the final concentration of 1mmol/L and inducing five hours. After centrifugation, the supernatant was discarded. By adding Glucose to Luria-Bertani broth, the expressions of protein were increased. SDS-PAGE showed that the RBP-4 gene expressed in the form of inclusion body with a molecular weight of 21KD. Western-Blot results showed that the target protein could be specifically recognized by mouse anti-human monoclonal antibody. Prokaryotic expression vector of RBP-4 gene was successfully established, and the gene was successfully expressed n E. coli, which is ready for purification and RBP-4 polyclone antibody. Meanwhile, these results were beneficial to investigate the function of RBP-4 in follicular development.