Experimental Study of the Shear Capacity of Steel Beam-to-L-CFST Column Connections

Qingqing Xiong,Wang Zhang,Zhi-Hua Chen,Yansheng Du,Ting Zhou 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.3

This paper aims to investigate the shear performance of a new and innovative type of vertical stiff ener connection between steel beams and L-shaped columns composed of concrete-fi lled steel tubes connected by transverse and vertical steel plates (L-CFST columns) in high-rise residential buildings. Quasi-static cyclic loading tests were performed on fi ve full-scale specimens to investigate the panel zone behaviours. Based on the experimental results, the hysteretic responses, skeleton curves of the shear force–deformation, ductility, stiff ness degradation, energy dissipation and strain are discussed. The variables studied in these experiments include the joint type, axial compression ratio, cross-sectional area and width-to-thickness ratio of the vertical stiff ener, and presence of concrete. The results indicate that the cross-sectional area of the vertical stiff eners plays a critical role in the performance of the panel zone. Two types of failure modes were observed outside the panel zone: fracturing of the vertical stiff eners and fracturing of the beam fl ange connecting plate. Shear deformation of the panel zone was obvious in the exterior joint specimens, and the corresponding maximum shear deformation reached 0.05 rad. Furthermore, the scopes of the panel zone in the corner and exterior joint specimens were determined by the strain distribution.

Antisense oligodeoxynucleotides against dynamin-related protein 1 reduce remifentanilinduced hyperalgesia by modulating spinal N-methyl-D-aspartate receptor expression in rats

Songyi Zhou,Yizhao Pan,Yan Zhang,Lijun Gu,Leikai Ma,Qingqing Xu,Weijian Wang,Jiehao Sun 대한통증학회 2023 The Korean Journal of Pain Vol.36 No.3

Background: Spinal N-methyl-D-aspartate (NMDA) receptor activation is attributed to remifentanil-induced hyperalgesia (RIH). However, the specific mechanism and subsequent treatment is still unknown. Previous studies have shown that the dynamin-related protein 1 (DRP1)-mitochondria-reactive oxygen species (ROS) pathway plays an important role in neuropathic pain. This study examined whether antisense oligodeoxynucleotides against DRP1 (AS-DRP1) could reverse RIH. Methods: The authors first measured changes in paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) at 24 hours before remifentanil infusion and 4, 8, 24, and 48 hours after infusion. The expression levels of DRP1 and NR2B were measured after behavioral testing using Western blotting. In addition, DRP1 expression was knocked down by intrathecal administration of AS-DRP1 to investigate the effects of DRP1 on RIH. The behavioral testing, the expression levels of spinal DRP1 and NR2B, and dorsal mitochondrial superoxide were measured. Changes in mitochondrial morphology were assessed using electron microscopy. Results: After remifentanil exposure, upregulation of spinal DRP1 and NR2B was observed along with a reduction in PWMT and PWTL. In addition, AS-DRP1 improved RIH-induced PWTL and PWMT (P < 0.001 and P < 0.001) and reduced remifentanil-mediated enhancement of spinal DRP1 and NR2B expression (P = 0.020 and P = 0.022). More importantly, AS-DRP1 reversed RIH-induced mitochondrial fission (P = 0.020) and mitochondrial superoxide upregulation (P = 0.031). Conclusions: These results indicate that AS-DRP1 could modulate NMDA receptor expression to prevent RIH through the DRP1-mitochondria-ROS pathway.

Degradation of ultrahigh concentration pollutant by Fe/Cu bimetallic system at high operating temperature

Bo Lai,Qingqing Ji,Yue Yuan,Donghai Yuan,Yuexi Zhou,Juling Wang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1

To investigate the degradation of high concentration pollutant by Fe/Cu bimetallic system at a high operating temperature, 10,000mg/L acid orange 7 (AO7) aqueous solution was treated by Fe/Cu bimetallic system at 80 oC. First, the effect of the operating temperature (30-80 oC) on the reactivity of Fe/Cu bimetallic particles was investigated thoroughly. Then, the studies on the effect of theoretical Cu mass loading, Fe/Cu dosage, stirring speed and initial pH on the reactivity of Fe/Cu bimetallic particles at a high temperature (i.e., 80 oC) were carried out, respectively. The degradation and transformation process of AO7 was studied by using COD, TOC and UV-Vis spectra. The results indicate that high concentration pollutant could be removed effectively by Fe/Cu bimetallic system at a high operating temperature. And the removal efficiencies of AO7 by Fe/Cu bimetallic system were in accordance with the pseudofirst- order model. Finally, it was observed that the high temperature could accelerate mass transport rate and overcome the high activation energy barrier to significantly improve the reactivity of Fe/Cu bimetallic particles. Therefore, the higher removal efficiency could be obtained by Fe/Cu system at a high operating temperature. Thus, the high operating temperature played a leading role in the degradation of high concentration pollutant.

Network Selection Algorithm Based on Spectral Bandwidth Mapping and an Economic Model in WLAN<E heterogeneous networks

( Pan Su ),( Zhou Weiwei ),( Gu Qingqing ),( Ye Qiang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.1

Future wireless network aims to integrate different radio access networks (RANs) to provide a seamless access and service continuity. In this paper, a new resource denotation method is proposed in the WLAN and LTE heterogeneous networks based on a concept of spectral bandwidth mapping. This method simplifies the denotation of system resources and makes it possible to calculate system residual capacity, upon which an economic model-based network selection algorithm is designed in both under-loaded and over-loaded scenarios in the heterogeneous networks. The simulation results show that this algorithm achieves better performance than the utility function-based access selection (UFAS) method proposed in [12] in increasing system capacity and system revenue, achieving load balancing and reducing the new call blocking probability in the heterogeneous networks.

Cyclophosphamide-induced HCN1 channel upregulation in interstitial Cajal-like cells leads to bladder hyperactivity in mice

Qian Liu,Zhou Long,Xingyou Dong,Teng Zhang,Jiang Zhao,Bishao Sun,Jingzhen Zhu,Jia Li,Qingqing Wang,Zhenxing Yang,Xiaoyan Hu,Longkun Li 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively. Cyclophosphamide (CYP)-induced cystitis models were successfully established in these mice. CYP treatment significantly enhanced HCN channel protein expression and Ih density and significantly altered bladder HCN1 channel regulatory proteins. Carbachol (CCH) and forskolin (FSK) exerted significant effects on bladder ICC-LC [Ca2+]i in CYP-treated wild-type (WT) mice, and HCN1 channel ablation significantly decreased the effects of CCH and FSK on bladder ICC-LC [Ca2+]i in both naive and CYP-treated mice. CYP treatment significantly potentiated the spontaneous contractions and CCH (0.001–10 μM)-induced phasic contractions of detrusor strips, and HCN1 channel deletion significantly abated such effects. Finally, we demonstrated that the development of CYP-induced bladder overactivity was reversed in HCN1 / mice. Taken together, our results suggest that CYP-induced enhancements of HCN1 channel expression and function in bladder ICC-LCs are essential for cystitis-associated bladder hyperactivity development, indicating that the HCN1 channel may be a novel therapeutic target for managing bladder hyperactivity.

Colorimetric H2O2 Detection Using Ag-Nanoparticle-Decorated Silica Microspheres

Zhikun Zhang,Qingqing Liu,Yumin Liu,Ran Qi,Lilong Zhou,Zhengjie Li,Jimmy Yun,Runjing Liu,Yongqi Hu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

In view of the importance of convenient and rapid H2O2 detection for biological analysis, we herein propose Ag nanoparticle (NP)-decorated silica microspheres as a probe for instant and non-enzymatic on-site colorimetric detection of H2O2. The surface hydroxyl groups of silica microspheres were reacted with (3-mercaptopropyl)trimethoxysilane to afford thiolated microspheres that subsequently bind Ag NPs. The oxidation of residual –SH groups on the silica surface to –S–S– moieties in the presence of H2O2 induces the aggregation of decorated microspheres and is accompanied by a color change. Sensor response is found to be proportional to H2O2 concentration in the range from 100 nM to 1 mM, with UV–Vis and colorimetric detection limits determined as 10 -8 M and 10 -5 M, respectively. The developed platform is successfully used to detect H2O2 in simulated human urine and is, therefore, concluded to be sufficiently stable and selective for practical applications.

Evaluation of Ecological Function of Mangrove Soil on Absorbing Heavy Metals: A Case Study from the Dongzhaigang Mangrove in China

Xin, Kun,Huang, Xing,Zhou, Qingqing,Chen, Zhili The Ecological Society of Korea 2010 Journal of Ecology and Environment Vol.33 No.1

Mangroves are special plant communities that live along intertidal zones in tropical and subtropical areas. They are regarded as one of the most important types of natural ecosystem in the world because of the many ecosystem functions that they perform, of which water purification is the most complex. Mangrove ecosystems are conducive to the deposition and retention of heavy metals. So it is important to understand the impact of heavy metals on mangrove ecosystems, and especially on soil subsystems. We examined the levels of heavy metals in the soil of mangroves in the Dongzhaigang Mangrove National Nature Reserve. Dongzhaigang, the first mangrove nature reserve established in China, is located south of Haikou in Hainan Island and encompasses $33.37\;km^2$, of which mangroves comprise $20.56\;km^2$. To assess the impact of human activities, we collected a large number of soil samples in four sampling areas (the protection station, the harbor, a tour area, and Yeboluo island) in the study area. We measured the concentrations of Cu, Pb, Zn and Cd in the soil samples using the spectra of polyatomic molecules. The average concentrations of Cu, Pb, Zn and Cd were $5.04\;{\mu}g/g$, $10.36\;{\mu}g/g$, $20.06\;{\mu}g/g$ and $0.06\;{\mu}g/g$, respectively, and the heavy metal concentrations were lowest in the protected area, highest in the harbor, and intermediate in Yeboluo Island and the tour area. The heavy metal concentrations in the soil collected from different sample plots are related not only to the physical and chemical properties of the soil, but also to the heavy metal emitted by nearby pollution sources. Our analysis indicates that tourist boats are the main pollution sources in the study area.

Distributed Model Predictive Control of Iron Precipitation Process by Goethite Based on Dual Iterative Method

Ning Chen,Jiayang Dai,Xiaojun Zhou,Qingqing Yang,Weihua Gui 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.5

Iron precipitation is a key process in zinc hydrometallurgy. The process consists of a series of continuousreactors arranged in descending order, overflowing zinc leach solution from one reactor to the next. In this paper,according to the law of mass conservation and the reaction kinetics, a continuously stirred tank reactor model ofa single reactor is first established. Then, a distributed model of cascade reactors is built with coupled controlbased on the single reactor model, considering the unreacted oxygen in leaching solution. Secondly, four reactorsin the iron precipitation process are considered as four subsystems, the optimization control problem of the processis solved by a distributed model predictive control strategy. Moreover, the control information feedback betweensuccessive subsystems is used to solve the optimization problem of each subsystem, because of the existing controlcoupling in their optimization objective function of pre and post subsystems. Next, considering the intractability ofthe optimization problem for subsystems with various constraints, a distributed dual iterative algorithm is proposedto simplify the calculation. With the consideration of its cascade structure and control couplings, the proposedalgorithm iteratively solves the primal problem and the dual problem of each subsystem. The application case showsthat distributed model predictive control based on dual iteration algorithm can handle coupled control effectivelyand reduce the oxygen consumption.

Experimental seismic behaviour of L-CFST column to H-beam connections

Wang Zhang,Zhi-Hua Chen,Qingqing Xiong,Ting Zhou,Xian Rong,Yansheng Du 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.6

In this study, the seismic performance of the connections between L-shaped columns composed of concrete-filled steel tubes (L-CFST columns) and H-beams used in high-rise steel frame structures was investigated. Seven full-scale specimens were tested under quasi-static cyclic loading. The variables studied in the tests included the joint type, the axial compression ratio, the presence of concrete, the width-to-thickness ratio and the internal extension length of the side plates. The hysteretic response, strength degradation, stiffness degradation, ductility, plastic rotation capacity, energy dissipation capacity and the strain distribution were evaluated at different load cycles. The test results indicated that both the corner and exterior joint specimens failed due to local buckling and crack within the beam flange adjacent to the end of the side plates. However, the failure modes of the interior joint specimens primarily included local buckling and crack at the end plates and curved corners of the beam flange. A design method was proposed for the flexural capacity of the end plate connection in the interior joint. Good agreement was observed between the theoretical and test results of both the yield and ultimate flexural capacity of the end plate connection.

OsSPL13 controls grain size in cultivated rice

Si, Lizhen,Chen, Jiaying,Huang, Xuehui,Gong, Hao,Luo, Jianghong,Hou, Qingqing,Zhou, Taoying,Lu, Tingting,Zhu, Jingjie,Shangguan, Yingying,Chen, Erwang,Gong, Chengxiang,Zhao, Qiang,Jing, Yufeng,Zhao, Y Nature Publishing Group, a division of Macmillan P 2016 Nature genetics Vol.48 No.4

<P>Although genetic diversity has a cardinal role in domestication, abundant natural allelic variations across the rice genome that cause agronomically important differences between diverse varieties have not been fully explored. Here we implement an approach integrating genome-wide association testing with functional analysis on grain size in a diverse rice population. We report that a major quantitative trait locus, GLW7, encoding the plant-specific transcription factor OsSPL13, positively regulates cell size in the grain hull, resulting in enhanced rice grain length and yield. We determine that a tandem-repeat sequence in the 5'UTR of OsSPL13 alters its expression by affecting transcription and translation and that high expression of OsSPL13 is associated with large grains in tropical japonica rice. Further analysis indicates that the large-grain allele of GLW7 in tropical japonica rice was introgressed from indica varieties under artificial selection. Our study demonstrates that new genes can be effectively identified on the basis of genome-wide association data.</P>