Influence of Brittle Fracture of Shear Connectors on Flexural Behavior of Steel–Plate Concrete Composite Beams Under Cyclic Loading

Bing Lu,Chang-Hai Zhai,Shuang Li,Duofa Ji,Xianbin Lu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

The existing push-out test results showed that the ultimate shear capacities and ultimate slips of tie-bars and studs under cyclic loading were signifi cantly lower than those under monotonic loading, which could signifi cantly aff ect the seismic performance of steel–plate concrete composite (SC) structures. The fl exural behavior of two SC beams subjected to cyclic loading was investigated. Specimen SCB1 using tie-bars was partial shear connection, and specimen SCB2 using tie-bars and studs was full shear connection. The failure modes, hysteresis curves, skeleton curves, equivalent lateral stiff ness, energy dissipation, interfacial slip distribution, interfacial shear distributions, and strain in steel plates were researched. The experimental results show that two SC specimens were brittle failure, which primarily resulted from premature shear fracture of shear connectors at the interfaces between steel plate and concrete. Finally, two existing codes for SC structures were used to analyze the bending moment and shear of SC beams as well as interfacial shear of tie-bars and studs. This indicates that due to the diff erence of shear connection ratio between two specimens, the interfacial shear distributions of two SC beams were signifi cantly diff erent.

A lithium–oxygen battery based on lithium superoxide

Lu, Jun,Jung Lee, Yun,Luo, Xiangyi,Chun Lau, Kah,Asadi, Mohammad,Wang, Hsien-Hau,Brombosz, Scott,Wen, Jianguo,Zhai, Dengyun,Chen, Zonghai,Miller, Dean J.,Sub Jeong, Yo,Park, Jin-Bum,Zak Fang, Zhigang Nature Publishing Group, a division of Macmillan P 2016 Nature Vol.529 No.7586

<P>Batteries based on sodium superoxide and on potassium superoxide have recently been reported(1-3). However, there have been no reports of a battery based on lithium superoxide (LiO2), despite much research(4-8) into the lithium-oxygen (Li-O-2) battery because of its potential high energy density. Several studies(9-16) of Li-O-2 batteries have found evidence of LiO2 being formed as one component of the discharge product along with lithium peroxide (Li2O2). In addition, theoretical calculations have indicated that some forms of LiO2 may have a long lifetime(17). These studies also suggest that it might be possible to form LiO2 alone for use in a battery. However, solid LiO2 has been difficult to synthesize in pure form(18) because it is thermodynamically unstable with respect to disproportionation, giving Li2O2 (refs 19, 20). Here we show that crystalline LiO2 can be stabilized in a Li-O-2 battery by using a suitable graphene-based cathode. Various characterization techniques reveal no evidence for the presence of Li2O2. A novel templating growth mechanism involving the use of iridium nanoparticles on the cathode surface may be responsible for the growth of crystalline LiO2. Our results demonstrate that the LiO2 formed in the Li-O-2 battery is stable enough for the battery to be repeatedly charged and discharged with a very low charge potential (about 3.2 volts). We anticipate that this discovery will lead to methods of synthesizing and stabilizing LiO2, which could open the way to high-energy-density batteries based on LiO2 as well as to other possible uses of this compound, such as oxygen storage.</P>

Impact response of a novel flat steel-concrete-corrugated steel panel

Jingyi Lu,Yonghui Wang,Ximei Zhai,Hongyuan Zhou 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.2

A novel flat steel plate-concrete-corrugated steel plate (FS-C-CS) sandwich panel was proposed for resisting impact load. The failure mode, impact force and displacement response of the FS-C-CS panel under impact loading were studied via drop-weight impact tests. The combined global flexure and local indentation deformation mode of the FS-C-CS panel was observed, and three stages of impact process were identified. Moreover, the effects of corrugated plate height and steel plate thickness on the impact responses of the FS-C-CS panels were quantitatively analysed, and the impact resistant performance of the FS-C-CS panel was found to be generally improved on increasing corrugated plate height and thickness in terms of smaller deformation as well as larger impact force and post-peak mean force. The Finite Element (FE) model of the FS-C-CS panel under impact loading was established to predict its dynamic response and further reveal its failure mode and impact energy dissipation mechanism. The numerical results indicated that the concrete core and corrugated steel plate dissipated the majority of impact energy. In addition, employing end plates and high strength bolts as shear connectors could prevent the slip between steel plates and concrete core and assure the full composite action of the FS-C-CS panel.

INTERLAYER COUPLING AND MAGNETOOPTICS IN MULTILAYERS

M. Lu,Q. S. Bie,Y. B. Xu,H. R. Zhai,S.M.Zhou,Liangyao Chen,Q.Y.Jin 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

Additional magnetooptical Kerr effect (AMOKE) was observed in several multilayer structures. For Fe/Pd and Co/Cu multilayers, AMOKE enhanced the Kerr rotation in short wavelength side. while for Fe/Ag and FeSi/Cu multilayer systems the Kerr rotation enhancement appeared in long wavelength side. A number of ferromagnetic/nonmagnetic/ferromagnetic(FM/NM/FM) sandwiches showed that the AMOKE led to oscillations of Kerr rotation and Kerr ellipticity in Certain wavelength range with changing NM layer thickness similar to the oscillatory interlayer coupling. The oscillation of effective optical constants related to the MOKE oscillation was observed for the first time. The mechanisms of the AMOKE were discussed.

The In Situ and In Vivo Study on Enhancing Effect of Borneol in Nasal Absorption of Geniposide in Rats

Yang Lu,Xiaolan Chen,Shouying Du,Qing Wu,Zongling Yao,Yongsong Zhai 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

The objective of this research was to study the in situ and in vivo nasal absorption of Geniposide (Ge) co-administered with borneol. A rat in situ nasal perfusion technique with a novel volumeadjusted calculation was used to examine the absorption rate and extent of Ge. The influence of different experimental conditions such as purity of extract, drug concentration, co-administration with synthetic borneol or natural borneol were also investigated. Results indicated nasal absorption of Ge was primarily by passive diffusion that resembled first order kinetics. Following co-administration with borenol, the drug absorption was increased by 1.4 and 1.7 folds for natural borneol and synthetic borneol , respectively. However, the effect of other factors on drug absorption was not significant. In addition, it was also observed that there is a positive correlation between the absorption of water and Ge by the nasal route. In vivo studies carried out in rats where Ge was co-administered with NB and the pharmacokinetic profile obtained following intranasal administration were compared with those after intravenous administration. The bioavailability of Ge by intranasal was 101.5% and Tmax was 2.04 ± 0.64 min. MRT was 218.7 ± 74.1 min and 44.4 ± 8.9 min for intranasal and intravenous, respectively. Combined with the borneol,Ge can be promptly and thoroughly absorbed intranasally in rats.

Halomonas tibetensis sp. nov., isolated from saline lakes on Tibetan Plateau

Hui-bin Lu,Peng Xing,Lei Zhai,Dorji Phurbu,Qian Tang,Qing-long Wu 한국미생물학회 2018 The journal of microbiology Vol.56 No.7

Strains pyc13T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEnT as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C18:1 ω6c/C18:1 ω7c, C16:1 ω6c/C16:1 ω7c, C16:0, and C12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEnT, H. sediminicola CPS11T, H. mongoliensis Z-7009T, H. ventosae Al12T, and H. fontilapidosi 5CRT, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13T (= CGMCC 1.15949T = KCTC 52660T).

Influences on Distribution of Solute Atoms in Cu‑8Fe Alloy Solidification Process Under Rotating Magnetic Field

Jin Zou,Qi‑Jie Zhai,Fang‑Yu Liu,Ke‑Ming Liu,De‑Ping Lu 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

A rotating magnetic field (RMF) was applied in the solidification process of Cu-8Fe alloy. Focus on the mechanism of RMFon the solid solution Fe(Cu) atoms in Cu-8Fe alloy, the influences of RMF on solidification structure, solute distribution, andmaterial properties were discussed. Results show that the solidification behavior of Cu–Fe alloy have influenced through thechange of temperature and solute fields in the presence of an applied RMF. The Fe dendrites were refined and transformed torosettes or spherical grains under forced convection. The solute distribution in Cu-rich phase and Fe-rich phase were changedbecause of the variation of the supercooling degree and the solidification rate. Further, the variation in solute distributionwas impacted the strengthening mechanism and conductive mechanism of the material.

Background Prior-based Salient Object Detection via Adaptive Figure-Ground Classification

( Jingbo Zhou ),( Jiyou Zhai ),( Yongfeng Ren ),( Ali Lu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.3

In this paper, a novel background prior-based salient object detection framework is proposed to deal with images those are more complicated. We take the superpixels located in four borders into consideration and exploit a mechanism based on image boundary information to remove the foreground noises, which are used to form the background prior. Afterward, an initial foreground prior is obtained by selecting superpixels that are the most dissimilar to the background prior. To determine the regions of foreground and background based on the prior of them, a threshold is needed in this process. According to a fixed threshold, the remaining superpixels are iteratively assigned based on their proximity to the foreground or background prior. As the threshold changes, different foreground priors generate multiple different partitions that are assigned a likelihood of being foreground. Last, all segments are combined into a saliency map based on the idea of similarity voting. Experiments on five benchmark databases demonstrate the proposed method performs well when it compares with the state-of-the-art methods in terms of accuracy and robustness.

Ginsenosides repair UVB-induced skin barrier damage in BALB/c hairless mice and HaCaT keratinocytes

Zhenzhuo Li,Rui Jiang,Manying Wang,Lu Zhai,Jianzeng Liu,Xiaohao Xu,Liwei Sun,Daqing Zhao 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.1

Background: Ginsenosides (GS) have potential value as cosmetic additives for prevention of skin photoaging. However, their protective mechanisms against skin barrier damage and their active monomeric constituents are unknown. Methods: GS monomer types and their relative proportions were identified. A UVB-irradiated BALB/c hairless mouse model was used to assess protective effects of GS components on skin epidermal thickness and transepidermal water loss (TEWL). Skin barrier function, reflected by filaggrin (FLG), involucrin (IVL), claudin-1 (Cldn-1), and aquaporin 3 (AQP3) levels and MAPK phosphorylation patterns, were analyzed in UVB-irradiated hairless mice or HaCaT cells. Results: Total GS monomeric content detected by UPLC was 85.45% and was largely attributed to 17 main monomers that included Re (16.73%), Rd (13.36%), and Rg1 (13.38%). In hairless mice, GS ameliorated UVB-induced epidermal barrier dysfunction manifesting as increased epidermal thickness, increased TEWL, and decreased stratum corneum water content without weight change. Furthermore, GS treatment of UVB-irradiated mice restored protein expression levels and epidermal tissue distributions of FLG, IVL, Cldn-1, and AQP3, with consistent mRNA and protein expression results obtained in UVB-irradiated HaCaT cells (except for unchanging Cldn-1 expression). Mechanistically, GS inhibited JNK, p38, and ERK phosphorylation in UVB-irradiated HaCaT cells, with a mixture of Rg2, Rg3, Rk3, F2, Rd, and Rb3 providing the same protective MAPK pathway inhibition-associated upregulation of IVL and AQP3 expression as provided by intact GS treatment. Conclusion: GS protection against UVB-irradiated skin barrier damage depends on activities of six ginsenoside monomeric constituents that inhibit the MAPK signaling pathway.

Enhanced corrosion resistance by polypyrrole and Ti3C2Tx-acrylic epoxy double-layer coating for 304SS bipolar plates of PEMFC

Haifeng Bian,Guoli Zhang,Qingxi Zhai,Yanyan Du,Yujie Ma,Beibei Yang,Shaochun Tang,Duan Bin,Xiangkang Meng,Hongbin Lu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

Stainless steel (SS) is a promising material for designing bipolar plates (BPs), but their further applicationis limited by serious corrosion problems in the acidic environment. Ti3C2Tx is expected to be used for SSBPs coatings, while galvanic corrosion will occur after the damage of Ti3C2Tx coating. Herein, a PPY/Ti3C2Tx-AE double-layer coating (DC) is well-designed and prepared on 304SS BP, which is composedof an inner electropolymerized PPY layer and an outer Ti3C2Tx-acrylic epoxy layer. When tested in0.2 M HCl solution, the corrosion potential and corrosion current density of the DC are 38 mV and0.00927 lA cm2 respectively, which are superior to those of the PPY coating and the Ti3C2Tx coating. Moreover, the DC presents the best long-term stability among the three coatings. The excellent corrosionresistance is attributed to the barrier and anodic protection effects as well as the solution of galvanic corrosion. The new coating system provides a new insight into the design of DC coatings of SS BPs.