An Experimental Study on Negative Bending Behavior of Composite Bridge Decks with Steel-Fiber-Reinforced Concrete and Longitudinal Bulb-Flat Ribs

Chunlei Zhang,Changyu Shao,Qing-Tian Su,Changyuan Dai 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.3

Orthotropic steel–concrete composite bridge deck is a structure composed of an orthotropic steel bridge deck and a cement-based rigid overlay. In recent years, it has been increasingly used to strengthen existing steel decks and build new bridges. Although composite decks with various structural forms and materials have been widely used, studies on the structural behavior of composite bridge decks are still somewhat lacking, and the design approach has not been fully clear. In this study, the mechanical behaviors of a composite bridge deck composed of 80 mm steel-fiber-reinforced concrete (SFRC) and longitudinal bulb-flat ribs were investigated under negative bending. Loading tests of two full-scale composite decks were carried out to study the variations of stiffness, concrete cracks, and structural strain during the loading process. The elastoplastic cross-sectional analysis method and the rigid-plastic analysis method were used in theoretical calculation and the results were compared with the experimental results. It was found that when the composite bridge deck was subjected to negative bending, both the structural deformation and strain variation showed two stages, i.e., elastic stage and elastic–plastic stage, indicating good ductility. In the ultimate failure state, the longitudinal bulb-flat ribs buckled, and the adverse effect of the buckling on bending resistance was revealed. The contribution of the tensile strength of SFRC to the bending resistance was also studied. Furthermore, a new calculation method for the negative bending resistance of this type of composite decks was proposed.

Isolation and characterization of heat-responsive gene TaGASR1 from wheat (Triticum aestivum L.)

Liyuan Zhang,Xiaoli Geng,Haiyan Zhang,Chunlei Zhou,Aiju Zhao,Fei Wang,Yue Zhao,Xuejun Tian,Zhaorong Hu,Mingming Xin,Yingyin Yao,Zhongfu Ni;Qixin Sun,Qixin Sun,Huiru Peng 한국식물학회 2017 Journal of Plant Biology Vol.60 No.1

GA-stimulated transcript (GAST) family genes have been identified in numerous plant species. In this paper, we isolated and characterized a heat-responsive gene, TaGASR1, from heat tolerant variety TAM107. The complete ORF of TaGASR1 was cloned, which encoded a 98-kDa protein, and the sequence shared 51.52% similarity to OsGASR1. Analysis of the TaGASR1 promoter region showed that it contained a heat shock element (HSE) and several cis-elements involved in abiotic stress response and hormone signal transduction. Expression patterns of TaGASR1 revealed that it was strongly induced by stress factors, such as high temperature, drought, high salinity and oxidation, as well as the phytohormones, including MeJA, ACC and ABA, which suggested the TaGASR1 gene might participate in these stress and hormone signal transduction pathways. Transient expression of TaGASR1-GFP fusion proteins in onion epidermal cells indicated that TaGASR1 protein was localized to the cell membrane or cytosol. Further analysis showed that ectopic expression of TaGASR1 in Arabidopsis enhanced thermotolerance and reduced the accumulation of reactive oxygen species (ROS) after heat stress. Moreover, we also found that TaGASR1-overexpressing wheat improved tolerance to heat stress and oxidative stress.

An experimental study on positioning conformance control of starch gelant in the heterogeneous porous media by using CT technology

Lei Zhang,Hongming Xu,Chunsheng Pu,Guangyu Yuan,Guangyao Leng,Chunlei Zhang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

In order to increase the economic efficiency of conformance control in the time of low oil price, a gelant should be injected into the specified location (positioning conformance control) to improve the swept volume in the maximum extent in the heterogeneous oil reservoir. For this purpose, an in-situ crosslinking polymer gelant (it is consisting of modified starch, acrylamide, N, N'- methylene diacrylamide, and potassium persulfate) is taken as the object of study by CT scan. Based on the dynamic and visible images of fluids distribution in the porous media, the gelant can be used to achieve the positioning conformance control because it can almost maintain a whole slug during transportation in porous media. According to the relationship of transportation distance and injection volume of the gelant in porous media, the gelant can be displaced to the specified location in porous media. In addition, the characteristics of water flooding of heterogeneous porous media before and after positioning conformance control are studied by CT scan, which can investigate the function of positioning conformance control and the extent of improving the swept volume in the heterogeneous reservoirs. The experimental results in this paper can provide theoretical guidance for the practical application of positioning conformance control in the heterogeneous oil reservoirs.

《『雜譬喻經』譯注(四種)》校讀箚記

張春雷(Zhang Chunlei) 한국교통대학교 동아시아연구소 2009 동아문헌연구 Vol.- No.-

Vapor-phase selective hydrogenation of maleic anhydride to succinic anhydride over Ni/TiO2 catalysts

Weitao Huo,Chunlei Zhang,Hongjing Yuan,Mingjun Jia,Chunli Ning,Yong Tang,Yi Zhang,Jiahuan Luo,Zhenlu Wang,Wenxiang Zhang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

A series of supported Ni/TiO2 catalysts were prepared by incipient wetness impregnation method underdifferent calcination temperatures, and the as-prepared catalysts were characterized by X-ray diffraction(XRD), hydrogen temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy(XPS). The catalytic properties of these Ni/TiO2 catalysts were investigated in the vapor phasehydrogenation of maleic anhydride (MA) to succinic anhydride (SA). The results showed that thecatalytic activity and the selectivity of the Ni/TiO2 catalysts were strongly affected by the calcinationtemperature. The catalyst calcined at 1023 K showed a relatively higher SA selectivity of 96% at high MAconversion (96%) under the tested conditions (493 K and 0.2 MPa). The improvement of SA selectivitycould be mainly assigned to the presence of suitable metal–support interaction, which can play a role incatalytic property of active nickel species as electron promoter. Besides, the change of surface propertiesof TiO2 support with the increasing calcination temperatures, e.g., the decrease of Lewis acid sites, mightalso have some positive role in reducing the side-products like g-butyrolacetone (GBL).

Vapor phase condensation of methyl acetate with formaldehyde to preparing methyl acrylate over cesium supported SBA-15 catalyst

Jianbiao Yan,Chunlei Zhang,Chunli Ning,Yong Tang,Yi Zhang,Lili Chen,Shuang Gao,Zhenlu Wang,Wenxiang Zhang 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

A cesium ion-containing catalyst, on an SBA-15 mesoporous molecular support, was prepared by the impregnation method and applied to the aldol condensation of methyl acetate with formaldehyde. The catalyst showed high catalytic activity in the condensation reaction. XRD characterization indicated that the cesium nitrate below 5 wt% loading was highly dispersed on the SBA-15 support. FT-IR and XPS results confirmed that a Si–O–Cs species was formed on the surface of the catalyst. Pyridine-IR verified that an L-acid site existed on the surface. The NH3-TPD and CO2-TPD results indicated that weak Lewis acid–base pairs were loaded on the surface, and these weak acid–base active sites might favor the aldol condensation reaction. The 5Cs/SBA-15 catalyst demonstrated the highest (48.4%) conversion of methyl acetate reported and 95.0% selectivity for methyl acrylate. The deactivated catalyst was completely regenerated by calcination. The catalyst was regenerated nine times with a total operation time of more than 60 h, and the initial conversion of methyl acetate and the selectivity for methyl acrylate did not change. The high catalytic activity was mainly due to the suitable strength of weak acid–base properties, which were rooted in the Si–O–Cs species on the surface of the support.

Field measurements of wind effects on a super high-rise building during typhoons

Chunlei Liu,Zhuangning Xie,Lele Zhang,Biqing Shi,Jiyang Fu,Ting Deng 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.33 No.5

Field measurement is the most reliable method to evaluate wind effects on super high-rise building; it is also the only approach to obtain actual structural dynamic properties. A self-developed wireless acceleration sensor was used to continuously monitor a 201 m high building in Shenzhen, and acceleration response signals atop the building during Typhoon Pakhar and Typhoon Mangkhut were obtained. The field data of approximately 58 hours were analyzed using random decrement technique and modified Bayesian spectral density approach, and the variation characteristics of the first two-order modal frequencies and damping ratios of the measured building under strong vibrations were obtained. Finally, field measurements of the maximum peak accelerations were compared with wind tunnel test results. Results show that (1) the frequencies decrease with increasing amplitude. In addition, they decreased initially and then increased with time, showing a “V” shape change. The maximum change rate of the frequencies was 11.5%. (2) During Typhoon Pakhar, the damping ratios were discrete. During Typhoon Mangkhut, the damping ratios increased with increasing amplitude in general, but the damping ratios were relatively discrete at small amplitudes. During Typhoon Mangkhut, the damping ratios increased initially, and then decreased with time. In addition, the first two-order damping ratios during the maximum wind speed were approximately 1.7% and 1.5%. (3) The wind tunnel test results are in good agreement with the field measurement results, thereby verifying the reliability of the wind tunnel test.

Clusterin negatively modulates mechanical stress-mediated ligamentum flavum hypertrophy through TGF-β1 signaling

Liu Chunlei,Li Peng,Ao Xiang,Lian Zhengnan,Liu Jie,Li Chenglong,Huang Minjun,Wang Liang,Zhang Zhongmin 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Ligamentum flavum hypertrophy (LFH) is a major cause of lumbar spinal canal stenosis (LSCS). The pathomechanisms for LFH have not been fully elucidated. Isobaric tags for relative and absolute quantitation (iTRAQ) technology, proteomics assessments of human ligamentum flavum (LF), and successive assays were performed to explore the effect of clusterin (CLU) upregulation on LFH pathogenesis. LFH samples exhibited higher cell positive rates of the CLU, TGF-β1, α-SMA, ALK5 and p-SMAD3 proteins than non-LFH samples. Mechanical stress and TGF-β1 initiated CLU expression in LF cells. Notably, CLU inhibited the expression of mechanical stress-stimulated and TGF-β1-stimulated COL1A2 and α-SMA. Mechanistic studies showed that CLU inhibited mechanical stress-stimulated and TGF-β1-induced SMAD3 activities through suppression of the phosphorylation of SMAD3 and by inhibiting its nuclear translocation by competitively binding to ALK5. PRKD3 stabilized CLU protein by inhibiting lysosomal distribution and degradation of CLU. CLU attenuated mechanical stress-induced LFH in vivo. In summary, the findings showed that CLU attenuates mechanical stress-induced LFH by modulating the TGF-β1 pathways in vitro and in vivo. These findings imply that CLU is induced by mechanical stress and TGF-β1 and inhibits LF fibrotic responses via negative feedback regulation of the TGF-β1 pathway. These findings indicate that CLU is a potential treatment target for LFH.

The Phylotype of Thermus from the Rehai Geothermal Area, Tengchong, China

Guo, Chunlei,Wang, Tao,Zhu, Wei,Zhang, Donghua,Cui, Xiaolong,Xu, Lihua,Peng, Qian The Microbiological Society of Korea 2003 The journal of microbiology Vol.41 No.2

Through enrichment on two nutrient agars, 57 Thermus isolates were recovered from 15 hot spring samples taken from the Rehai geothermal area, Tengchong, China. Unique growth characteristics were observed when the strains were transferred from YIM14 medium to Thermus medium. Phylogenetic analysis showed that the 16S rDNA sequences of the isolates and clones from the Rehai geothermal area farmed a monophyletic group on the phylogenetic tree. A secondary structure comparison showed that their 16S rRNAs have unique secondary structure characteristics.

Two New Bithiophenes Derivatives Multielectrochromic Copolymer Based on Triphenylamine Unit and Their Application for Electrochromic Devices

Yan Zhang,Lingqian Kong,Xuezhong Liu,Chunlei Wang,Jinsheng Zhao 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.8

Two monomers including 4,4′,4″-tris(3-methoxythiophene-2-yl)triphenylamine (M1) and 4,4′,4″-tris(3,4-dimethoxythiophene-2-yl)triphenylamine (M2) with triphenylamine as their core were synthesized and the corresponding polymers were obtained by electrochemical polymerization. Their electrochemical properties were investigated using scanning electron microscopy, UV–Vis, and cyclic voltammetry. It was found that the two polymers had reversible redox behavior with the different color change under the applied potentials. Both the polymers displayed high switching efficiency and optical contrast. Moreover, the corresponding electrochromic devices (ECDs) employing the synthesized polymers and poly(3,4-ethylenedioxythiophene) were constructed. The spectroelectrochemical experiments illustrated that the ECDs exhibited fast response time, reasonable optical contrast, favorable optical memories, and redox stability.