Seismic Performance of a Full-Scale Precast Concrete L-Shaped Column Frame Structure with a Grouted Connection

Wei-Bin Ni,De-Hao Qiao,Hong-Wei Sun,Xu Zhang,Zhong-Wen Zhang,Shao-Jie Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

Precast concrete frame structure with nonrectangular columns are becoming attractive to researchers and engineers owing to advantages such as avoiding column protrusion from walls and saving space. This paper presents the experimental investigation of a full-scale precast concrete frame structure with L-shaped columns (PCFS) subjected to reverse cyclic loading. The precast connection adopted grouted anchor connection. As a comparison and benchmark, one full-scale monolithic sample (RCFS) was also tested. The results indicates that the greater steel ratio in the grouted anchor connection region leads to a high local stiffness of the elements, which contributed to delaying occurrence of the first crack at the grouting holes. The failure mode, lateral load capacity, stiffness degradation, load-carrying capacity degradation, energy-dissipating capacity, ductility and interlayer residual deformation were compared between two specimens. PCFS specimen exhibited comparatively better hysteretic behavior, energy-dissipating capacity, residual deformation-resisting capacity and ductility. For RCFS and PCFS specimens, the peak load difference was within 7%. About 15% increases in ductility were observed for PCFS specimen compared with RCFS specimen. The test results would provide reference for the application of the precast concrete structure with nonrectangular columns in the new residential buildings.

Content Delivery Mechanism for ISP

Qiao Li,Hui He,Bin-Xing Fang,Hong-Li Zhang,Wei-Zhe Zhang 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.4

A new high-order response surface method for structural reliability analysis

Hong-Shuang Li,Zhen-Zhou Lu,Hong-Wei Qiao 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.6

In order to consider high-order effects on the actual limit state function, a new response surface method is proposed for structural reliability analysis by the use of high-order approximation concept in this study. Hermite polynomials are used to determine the highest orders of input random variables, and the sampling points for the determination of highest orders are located on Gaussian points of Gauss-Hermite integration. The cross terms between two random variables, only in case that their corresponding percent contributions to the total variation of limit state function are significant, will be added to the response surface function to improve the approximation accuracy. As a result, significant reduction in computational cost is achieved with this strategy. Due to the addition of cross terms, the additional sampling points, laid on two-dimensional Gaussian points off axis on the plane of two significant variables, are required to determine the coefficients of the approximated limit state function. All available sampling points are employed to construct the final response surface function. Then, Monte Carlo Simulation is carried out on the final approximation response surface function to estimate the failure probability. Due to the use of high order polynomial, the proposed method is more accurate than the traditional second-order or linear response surface method. It also provides much more efficient solutions than the available high-order response surface method with less loss in accuracy. The efficiency and the accuracy of the proposed method compared with those of various response surface methods available are illustrated by five numerical examples.

A new high-order response surface method for structural reliability analysis

Li, Hong-Shuang,Lu, Zhen-Zhou,Qiao, Hong-Wei Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.6

In order to consider high-order effects on the actual limit state function, a new response surface method is proposed for structural reliability analysis by the use of high-order approximation concept in this study. Hermite polynomials are used to determine the highest orders of input random variables, and the sampling points for the determination of highest orders are located on Gaussian points of Gauss-Hermite integration. The cross terms between two random variables, only in case that their corresponding percent contributions to the total variation of limit state function are significant, will be added to the response surface function to improve the approximation accuracy. As a result, significant reduction in computational cost is achieved with this strategy. Due to the addition of cross terms, the additional sampling points, laid on two-dimensional Gaussian points off axis on the plane of two significant variables, are required to determine the coefficients of the approximated limit state function. All available sampling points are employed to construct the final response surface function. Then, Monte Carlo Simulation is carried out on the final approximation response surface function to estimate the failure probability. Due to the use of high order polynomial, the proposed method is more accurate than the traditional second-order or linear response surface method. It also provides much more efficient solutions than the available high-order response surface method with less loss in accuracy. The efficiency and the accuracy of the proposed method compared with those of various response surface methods available are illustrated by five numerical examples.

Phytochemistry and pharmacology of natural prenylated flavonoids

Hua-Wei Lv,Qiao-Liang Wang,Meng Luo,Meng-Di Zhu,Hui-Min Liang,Wen-Jing Li,Hai Cai,Zhong-Bo Zhou,Hong Wang,Sheng-Qiang Tong,Xing-Nuo Li 대한약학회 2023 Archives of Pharmacal Research Vol.46 No.4

Prenylated flavonoids are a special kind of flavonoid derivative possessing one or more prenyl groups in the parent nucleus of the flavonoid. The presence of the prenyl side chain enriched the structural diversity of flavonoids and increased their bioactivity and bioavailability. Prenylated flavonoids show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic, anti-obesity, cardioprotective effects, and anti-osteoclastogenic activities. In recent years, many compounds with significant activity have been discovered with the continuous excavation of the medicinal value of prenylated flavonoids, and have attracted the extensive attention of pharmacologists. This review summarizes recent progress on research into natural active prenylated flavonoids to promote new discoveries of their medicinal value.

Visualization of Peripheral Pulmonary Artery Red Thrombi Utilizing Optical Coherence Tomography

Cheng Hong,Wei Wang,Nan-shan Zhong,Guang-qiao Zeng,Nuo-fu Zhang 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.5

Optical coherence tomography (OCT) is a new imaging technique capable of obtaining high-resolution intravascular images and has been used in interventional cardiology. However, an application of OCT in pulmonary arteries had seldom been documented. In this case, OCT imaging is performed in peripheral pulmonary arteries and shows mural red thrombi. Subsequently, the red thrombi are aspirated and confirmed by a histological examination. These findings suggest that OCT may be a useful tool to depict peripheral pulmonary artery thrombi.

Nanophotonic-Engineered Photothermal Harnessing for Waste Heat Management and Pyroelectric Generation

Wang, Xiao-Qiao,Tan, Chuan Fu,Chan, Kwok Hoe,Xu, Kaichen,Hong, Minghui,Kim, Sang-Woo,Ho, Ghim Wei American Chemical Society 2017 ACS NANO Vol.11 No.10

<P>At present, there are various limitations to harvesting ambient waste heat which include the lack of economically viable material and innovative design features that can efficiently recover low grade heat for useful energy conversion. In this work, a thermal nanophotonic-pyroelectric (TNPh-pyro) scheme consisting of a metamaterial multilayer and pyroelectric material, which performs synergistic waste heat rejection and photothermal heat-to-electricity conversion, is presented. Unlike any other pyroelectric configuration, this conceptual design deviates from the conventional by deliberately employing back-reflecting NIR to enable waste heat reutilization/recuperation to enhance pyroelectric generation, avoiding excessive solar heat uptake and also retaining high visual transparency of the device. Passive solar reflective cooling up to 4.1 degrees C is demonstrated. Meanwhile, the photothermal pyroelectric performance capitalizing on the back-reflecting effect shows an open circuit voltage (V-oc) and short circuit current (I-sc) enhancement of 152 and 146%, respectively. In addition, the designed photoactive component (TiO2/Cu) within the metamaterial multilayer provides the TNPh-pyro system with an effective air pollutant photodegradation functionality. Finally, proof-of-concept for concurrent photothermal management and enhanced solar pyroelectric generation under a real outdoor environment is demonstrated.</P>

Structural and Ferromagnetic Properties SnO2/TiO2 Nanotubes Obtained by Electrospinning

JIAN-GUO ZHAO,Yan-Hong Gu,Hong Jia,Zhuan Hu,Shuqian Qiao,Mengjing Jin,Panting Ge,WEI-YING ZHANG,Shijiang Liu,ZHAO-JUN LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

SnO2/TiO2 (Sn/Ti = 5/1) nanotubes were prepared by the electrospinning method. The morphology was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the inner diameter of prepared materials was about 100 nm and the wall thickness was about 10 nm. The results of X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) showed that SnO2/TiO2 nanotubes had a mixed phase of SnO2 rutile and TiO2 anatase structures and no impurity phases. The magnetic properties of the SnO2/TiO2 nanotubes were characterized by a superconducting quantum interferometer (SQUID). The results indicated that the samples exhibited room temperature ferromagnetism which may be attributed to the interface between TiO2 and SnO2 phases.

Diversity, distribution, and antagonistic activities of rhizobacteria of Panax notoginseng

Fan, Ze-Yan,Miao, Cui-Ping,Qiao, Xin-Guo,Zheng, You-Kun,Chen, Hua-Hong,Chen, You-Wei,Xu, Li-Hua,Zhao, Li-Xing,Guan, Hui-Lin The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.2

Background: Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. This study aimed to screen antagonistic bacteria and develop a biocontrol system for root rot complex of Panax notoginseng. Methods: Pure-culture methods were used to isolate bacteria from the rhizosphere soil of notoginseng plants. The identification of isolates was based on the analysis of 16S ribosomal RNA (rRNA) sequences. Results: A total of 279 bacteria were obtained from rhizosphere soils of healthy and root-rot notoginseng plants, and uncultivated soil. Among all the isolates, 88 showed antagonistic activity to at least one of three phytopathogenic fungi, Fusarium oxysporum, Fusarium solani, and Phoma herbarum mainly causing root rot disease of P. notoginseng. Based on the 16S rRNA sequencing, the antagonistic bacteria were characterized into four clusters, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetesi. The genus Bacillus was the most frequently isolated, and Bacillus siamensis (Hs02), Bacillus atrophaeus (Hs09) showed strong antagonistic activity to the three pathogens. The distribution pattern differed in soil types, genera Achromobacter, Acidovorax, Brevibacterium, Brevundimonas, Flavimonas, and Streptomyces were only found in rhizosphere of healthy plants, while Delftia, Leclercia, Brevibacillus, Microbacterium, Pantoea, Rhizobium, and Stenotrophomonas only exist in soil of diseased plant, and Acinetobacter only exist in uncultivated soil. Conclusion: The results suggest that diverse bacteria exist in the P. notoginseng rhizosphere soil, with differences in community in the same field, and antagonistic isolates may be good potential biological control agent for the notoginseng root-rot diseases caused by F. oxysporum, Fusarium solani, and Panax herbarum.

Privet golden leaves adapt unexpectedly well to light changes

Ming Yuan,Bo Huang,Li-Hua Dong,Qiao-Hong Han,Yong Yang,Chun-Bang Ding,Chao Hu,Yang-Er Chen,Zhong-Wei Zhang,Shu Yuan 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.4

Golden-leaf privet ( Ligustrum × vicaryi ) is widely used as a horticultural shrub because of its upper golden leaves, butits lower leaves are green. However, the putative mechanisms of its upper golden leaves and the leaf color changes inresponse to light shifts have not been well studied so far. Here, chlorophylls (Chl), carotenoids, and Chl precursors from bothgolden and green leaves grown in full sunlight (approximately 1200 μmol photons m −2 s −1 at noon) or low-light conditions(180 μmol m −2 s −1 ) were determined spectrophotometrically. In addition, their gas exchange parameters and Chl fl uorescencewere measured in situ. Metabolic fl ux analysis of chlorophyll intermediates indicated that the conversion of prochlorophyllideto chlorophyllide was signifi cantly blocked in golden leaves when compared with green leaves. Green leaves showed higherphotosynthetic capacity in low light than golden leaves, but golden leaves presented unexpectedly stronger photosyntheticcapacity and lower reactive oxygen species accumulation under the high-light condition. Furthermore, golden leaves showeda higher level of nonphotochemical quenching (NPQ) after the light-to-dark shift and presented a stronger adaptive abilityto a broad range of light environments. Higher NPQ values and less oxidative damage in golden leaves may be correlatedwith their higher carotenoid levels. The results imply that lower chlorophyll levels and higher carotenoid levels in canopyleaves may help privet plants acclimate better to illumination changes. This study demonstrates the key role of irradiance ingenerating the two types of Ligustrum × vicaryi leaves and sheds a light on cultivation of other ornamental foliage plants.