Push-out tests on stud shear connectors with constrained structure of steel-concrete composite beams

Jingjing Qi,Zuwei Xie,Hua Cao,Zhi Huang,Weirong Lv,Weihua Shi 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.6

The stud shear connector is the main force transfer member in the steel-concrete composite member, and the mechanical behavior is very complicated in the concrete. The concrete around the stud is subjected to the pry-out local pressure concentration of the stud, which can easily produce splitting mirco-cracks. In order to solve the problem of pry-out local splitting of stud shear connector, a kind of stud shear connector with constraint measure is proposed in this paper. Through the push-out test, the interface shear behavior of the new stud shear connector between steel and concrete flange plate was studied, and the difference between the new stud shear connector and the traditional stud connector was compared. The results show that the stud shear connector with constraint measure can effectively avoid the adverse effect of local pressure splitting by relying on its own constraint measure. The shear stiffness of the interface between steel and concrete flange plates is greatly improved, which provides a theoretical basis for the design of strong connection coefficient of steel-concrete composite structures.

The investigation of pH threshold value on the corrosion of steel reinforcement in concrete

Qi Pu,Yan Yao,Ling Wang,Xingxiang Shi,Jingjing Luo,Yifei Xie 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.3

The aim of this study is to investigate the pH threshold value for the corrosion of steel reinforcement in concrete. A method was designed to attain the pH value of the pore solution on the location of the steel in concrete. Then the pH values of the pore solution on the location of steel in concrete were changed by exposing the samples to the environment (CO25%, RH 40%) to accelerate carbonation with different periods. Based on this, the pH threshold value for the corrosion of steel reinforcement had been examined by the methods of half-cell potential and electrochemical impedance spectra (EIS). The results have indicated that the pH threshold value for the initial corrosion of steel reinforcement in concrete was 11.21. However, in the carbonated concrete, agreement among whether steel corrosion was initiatory determined by the detection methods mentioned above could be found.

Sanguinarine impairs lysosomal function and induces ROS-dependent mitophagy and apoptosis in human hepatocellular carcinoma cells

Jingjing Wang,Qi Su,Qing Wu,Kun Chen,Asmat Ullah,Mohsin Ahmad Ghauri,Yanmin Zhang 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.11

Hepatocellular carcinoma (HCC) is one of themost common tumor types globally. Despite the progressmade in surgical procedures and therapeutic options, HCCremains a considerable cause of cancer-related mortality. In this study, we investigated the antitumor eff ects of sanguinarine(Sang) on HCC and its potential mechanisms. Our fi ndings showed that Sang impairs the acidic environmentof lysosomes by inhibiting cathepsin D maturation. Inaddition, Sang inhibited the formation of autolysosomes inRFP-GFP-LC3 transfected cells, subsequently suppressinglate mitophagy. Sang also induced reactive oxygen species(ROS)-dependent autophagy and apoptosis in HCC cells,which was signifi cantly attenuated following treatment witha ROS scavenger. Further investigation using autophagyinhibitors revealed that sanguinarine-induced mitochondrialdysfunction and mitophagy led to mitochondrial apoptosisin HCC cells. Immunohistochemical staining of sanguinarine-treated xenograft samples revealed that it initiated andblocked autophagy. In summary, our fi ndings suggest thatin HCC cells, Sang impairs lysosomal function and inducesROS-dependent mitophagy and apoptosis.

Research on Thermal Conductivity of Electrospun Polyacrilonitrile-Multi-Walled Carbon Nanotubes Composite Carbon Nanofiber Papers

Dong, Qi,Yoon, Su Jong,Zhang, Jingjing,Yoon, Hyun Sik,Kim, Tae Gyu American Scientific Publishers 2018 Journal of Nanoscience and Nanotechnology Vol.18 No.10

Analysis of Emergency Demand Response Levels of Central Air-Conditioning

Xianjun Qi,Zongshuo Ji,Hongbin Wu,Jingjing Zhang,Hejun Yang 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6

Central air-conditioning (CAC) is a fl exible load which can be dispatched during an emergency demand response (EDR) program. However, consumers’ trade-off between thermal comfort levels (TCLs) and profi ts will aff ect the potential of CAC. Therefore, this paper proposes a method to evaluate CAC’S response levels. An EDR optimization model simulating consumers’ trade-off between TCLs and profi ts is established and it is solved by a particle swarm optimization (PSO) algorithm. Then the defi nition of EDR levels is presented to quantitatively analyze the capability of CAC providing the EDR. Furthermore, uncertainty of EDR levels caused by stochastic initial indoor temperature is analyzed through a Monte Carlo (MC) simulation. A case study shows the rationality of the presented method, and the eff ects of weight coeffi cients, compensation prices and penalty prices on EDR levels are also analyzed.

Fault Detection for Interconnected Systems Subject to Packet Dropouts via Switching Scheme

Jian Li,Jingjing Wang,Qingyu Su,Chun-Yu Wu,Xiao-Qi Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.12

The design of fault detection filter for interconnected systems with packet dropouts occurring in measurement channels is proposed in this paper. Taking into account arbitrary disconnected interconnection among subsystems, switching scheme is introduced to simplify the analysis of the problem. By modeling these situations as independent subsystems, the novel systems based on arbitrary switched systems are remodeled. The design of the filter makes the augmented system exponentially stable and satisfies the disturbance attenuation performance. A feasible linear matrix inequality for the existence of filter is derived by switched Lyapunov method based on stochastic function. Finally, two examples are shown to illustrate the method and its effectiveness.

Distortional and local buckling of steel-concrete composite box-beam

Lizhong Jiang,Jingjing Qi,Andrew Scanlon,Linlin Sun 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.14 No.3

Distortional and local buckling are important factors that influences the bearing capacity of steel-concrete composite box-beam. Through theoretical analysis of distortional buckling forms, a stability analysis calculation model of composite box beam considering rotation of steel beam top flange is resented. The critical bending moment calculation formula of distortional buckling is established. In addition, mechanical behaviors of a steel beam web in the negative moment zone subjected separately to bending stress, shear stress and combined stress are investigated. Elastic buckling factors of steel web under different stress conditions are calculated. On the basis of local buckling analysis results, a limiting value for height-to thickness ratio of a steel web in the elastic stage is proposed. Numerical examples are presented to verify the proposed models.

Polarization Properties of Quasi-Homogeneous Beams Propagating in Oceanic Turbulence

Feinan Chen,Qi Zhao,Yanru Chen,Jingjing Chen 한국광학회 2013 Current Optics and Photonics Vol.17 No.2

Based on the extended Huygens-Fresnel principle and generalized Stokes theory, the evolution of polarization properties of beams generated by quasi-homogenous (QH) sources propagating in clear oceanic water was studied by the use of the oceanic turbulence spatial spectrum function. The results show that the beams have similar polarization self-reconstructed behavior under different turbulence conditions in the far field, but if the propagation distance is not long enough, the degree of polarization (DOP) fluctuates with much more complexity than state of polarization (SOP) of QH beams. The self-reconstructed ability of DOP at the special distance in turbulence would get to the best value if the values of coherence of width were chosen suitably, but for SOP, it has no best value.

Bio-base Metal Organic Frameworks as Potential CO2 Adsorbents

Zhang Jiawei,Ma Jingjing,Liu Chen,Wang Qi,Xu Yiling,Fang Long,Xia Kai,Sun Deshuai 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.7

Environmental friendliness and high adsorption capacity are important properties of CO 2 adsorbents. Bio-based metal– organic framework (bioMOFs) materials off er notable benefi ts for CO 2 capture. Amino acids like L -glutamic acid (Glu) and L-aspartate (Asp) are employed as ligands for the synthesis of bioMOFs, Asp-Cu and Glu-Cu. Characterization results confi rmed that Asp-Cu and Glu-Cu possessed tertiary amine and secondary amine structures, respectively. The adsorption capacities of Glu-Cu and Asp-Cu were up to 253 mg·g −1 and 277 mg·g −1 at 1 bar CO 2 pressure and 190 mg·g −1 and 223 mg·g −1 at 0.15 bar CO 2 pressure. The CO 2 adsorption properties of bioMOFs were comprehensively evaluated under various conditions, including temperature, water content, SO 2 concentration, and other compositions. Adsorption data were fi tted well with the pseudo-fi rst-order kinetics and Weber-Morris intraparticle diff usion model. The kinetic studies revealed that a small amount of water signifi cantly accelerated the pseudo-fi rst-order kinetic constants, whereas excess water vapor greatly hindered the intra-diff usion constants of CO 2 . The presence of SO 2 led to a decrease in the adsorption capacity of both MOFs due to rapid reactions occurring with active sites on the MOF surface. Furthermore, these bioMOFs were easily recovered and regenerated for at least 20 cycles. The primary CO 2 adsorption mechanism involved catalytic hydration reactions on Asp-Cu, while chemical adsorption occurred on Glu-Cu. Both mechanisms were accompanied by physical adsorption.

miR-101 Inhibiting Cell Proliferation, Migration and Invasion in Hepatocellular Carcinoma through Downregulating Girdin

Cao, Ke,Li, Jingjing,Zhao, Yong,Wang, Qi,Zeng, Qinghai,He, Siqi,Yu, Li,Zhou, Jianda,Cao, Peiguo Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.2

miR-101 is considered to play an important role in hepatocellular carcinoma (HCC), but the underlying molecular mechanism remains to be elucidated. Here, we aimed to confirm whether Girdin is a target gene of miR-101 and determine the tumor suppressor of miR-101 through Girdin pathway. In our previous studies, we firstly found Girdin protein was overexpressed in HCC tissues, and it closely correlated to tumor size, T stage, TNM stage and Edmondson-Steiner stage of HCC patients. After specific small interfering RNA of Girdin was transfected into HepG2 and Huh7.5.1 cells, the proliferation and invasion ability of tumor cells were significantly inhibited. In this study, we further explored the detailed molecular mechanism of Girdin in HCC. Interestingly, we found that miR-101 significantly low-expressed in HCC tissues compared with that in matched normal tissues while Girdin had a relative higher expression, and miR-101 was inversely correlated with Girdin expression. In addition, after miR-101 transfection, the proliferation, migration and invasion abilities of HepG2 cells were weakened. Furthermore, we confirmed that Girdin is a direct target gene of miR-101. Finally we confirmed Talen-mediated Girdin knockout markedly suppressed cell proliferation, migration and invasion in HCC while downregulation of miR-101 significantly restored the inhibitory effect. Our findings suggested that miR-101/Girdin axis could be a potential application of HCC treatment.