Experimental study on steel-concrete composite beams with Uplift-restricted and slip-permitted screw-type (URSP-S) connectors

Linli Duan,Hongbing Chen,Xin Nie,Sanwei Han 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.2

In steel-concrete composite beams, to improve the cracking resistance of the concrete slab in the hogging moment region, a new type of connector in the interface, named uplift-restricted and slip-permitted screw-type (URSP-S) connector has been proposed. This paper focuses on the behavior of steel-concrete composite beams with URSP-S connectors. A total of three beam specimens including a simply supported beam with URSP-S connectors and two continuous composite beams with different connectors arrangements were designed and tested. More specifically, one continuous composite beam was equipped with URSP-S connectors in negative moment region and traditional shear studs in other regions. For comparison, the other one was designed with only traditional shear studs. The failure modes, crack evolution process, ultimate capacities, strain responses at different locations as well as the interface slip of the three tested specimens were measured and evaluated in-depth. Based on the experimental study, the research findings indicate that the larger slip deformation is allowed while using URSP-S connectors. Meanwhile, the tensile stress reduces and the cracking resistance of the concrete slab improves accordingly. In addition, the overall stiffness and strength of the composite beam become slightly lower than those of the composite beam using traditional shear studs. Moreover, the arrangement suggestion of URSP-S connectors in the composite beam is discussed in this paper for its practical design and application.

Fluorometric determination of Fe3+ and polychlorinated benzenes based on Tb3+-pyromellitic acid coordination polymer

Linli Hou,Yonghai Song,Fengxiang Lang,Zhenrong Wang,Li Wang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.90 No.-

A luminescent Tb3+-pyromellitic acid (H4L = pyromellitic acid) coordination polymer (Tb-H4L CP, TbL0.5(H2L)0.5(H2O)DMF) was prepared for multiresponsive fluorescence sensor. The Tb-H4L CP exhibits uniform nanospheres with average diameter of 220 20 nm, good crystalline structure, and good dispersion in water. The Tb-H4L CP emitted the characteristic green fluorescence through antenna effect from H4L which was an excellent antenna molecule when excited at 270 nm and could be used to selectively determine Fe3+ and polychlorinated benzenes based on fluorescence quenching effect. The coordination between Fe3+ and carboxylic oxygen of Tb-H4L to damage the antenna effect and polychlorinated benzenes absorb the excitation light to result the inner-filter effect of fluorescence, which quenched the fluorescence of Tb-H4L CP. The linear range for Fe3+ was 2.0–100mM with a detection limit of 0.7mM and for 1,3,5-trichlorobenzene was 0–0.44 103 ppm with a detection limit of 0.087 ppm. The Tb-H4L CP demonstrates excellent fluorescence sensing performances, indicating that it can be used as a multi-response sensor to effectively measure toxic and harmful substances.

In situ directional formation of Co@CoO_x-embedded 1D carbon nanotubes as an efficient oxygen electrocatalyst for ultra-high rate Zn–air batteries

Lin, Chao,Shinde, Sambhaji S.,Jiang, Zheng,Song, Xiaokai,Sun, Yu,Guo, Linli,Zhang, Hao,Jung, Jin-Young,Li, Xiaopeng,Lee, Jung-Ho The Royal Society of Chemistry 2017 Journal of materials chemistry. A, Materials for e Vol.5 No.27

<▼1><P>A “three birds one stone” strategy for preparing 1D N-doped porous carbon nanotubes embedded with Co@CoOx nanoparticles results in the unprecedentedly high-rate Zn–air batteries.</P></▼1><▼2><P>In this work, we demonstrate a “three birds one stone” strategy for preparing 1D N-doped porous carbon nanotubes embedded with core–shell Co@CoOx nanoparticles (Co@CoOx/NCNTs) from bimetallic ZnO@Zn/Co-ZIF nanowires. The ZnO nanowires played three roles: (i) ZnO acted as a template for 1D metal–organic framework (MOF) growth, (ii) <I>in situ</I> evaporation of Zn during pyrolysis prevented the aggregation of the carbon framework and benefited the formation of hierarchical pores, and (iii) the excess oxygen species released from ZnO <I>in situ</I> reacted with metallic cobalt nanoparticles during pyrolysis, leading to the configuration of a Co@CoOx core–shell structure. The as-prepared 1D Co@CoOx/NCNTs exhibited excellent oxygen reduction reaction performance, including a high kinetic current (4.6 times better compared to 20 wt% Pt/C at 0.7 V), a low Tafel slope of 80 mV dec<SUP>−1</SUP>, outstanding stability, and strong tolerance to CH3OH crossover. The assembled Zn–air batteries with Co@CoOx/NCNTs yielded high open-circuit voltage (1.52 V), superior stability (over 100 h of operation), and unprecedented rate performance that ranged from 1 to 500 mA cm<SUP>−2</SUP>, while existing batteries have never achieved a galvanostatic discharge current density larger than 300 mA cm<SUP>−2</SUP>. Such exceptional rate capability was ascribed to the formation of a uniform interconnected nanotube network, facilitated electron transport, and an enlarged electrochemically accessible surface area in the unique 1D porous tubular structure.</P></▼2>

Evaluation and Application of Fengyun‑4A/LMI Data in Tropical Cyclone Monitoring Over the Southeast Coast of China

Linli Cui,Jun Shi,Wei Guo,Yinglong Xu 한국기상학회 2022 Asia-Pacific Journal of Atmospheric Sciences Vol.58 No.5

Taking 8 tropical cyclones (TCs) in 2018 as examples, the data quality and the application potential of Fengyun-4 A (FY-4 A)Lightning Mapping Imager (LMI) in monitoring lightning activity and analyzing the relationship between lightning activityand TC intensity are investigated and evaluated over the southeast coast of China. A comparison shows that the diurnal variationand the radial spatial distribution of lightning activity from FY-4 A/LMI data, and the relationship between FY-4 A/LMI lightning activity and tropical cyclone (TC) intensity are mainly consistent with the existing ground-based observations. FY-4 A/LMI data are further utilized to analyze some issues that are controversial or contradictory in the existing studies,and results show that there are obvious differences in the spatial distribution of TC lightning between land and sea. When TCis located on the sea and the land, lightning activity presents a radial spatial distribution of high-low-high and low-mediumhigh,respectively. Higher lightning density is mainly concentrated in the west and south side of TC track. During the changeof TC intensity, the lightning activity in the outer rainband continues to be active, but the lightning activity in the eyewallregion may be a better indicator for the early warning of TC intensity. We conclude that FY-4 A/LMI has good performanceand practical potential in TC lightning monitoring and early warning.

A New Diterpenoid Isolated from Isodon japonica Structure Elucidation by NMR Spectroscopy

Bao-LinLi,Yuan-JiangPan 대한화학회 2002 Bulletin of the Korean Chemical Society Vol.23 No.4

Lightweight and Ultrastrong Polymer Foams with Unusually Superior Flame Retardancy

Xu, Linli,Xiao, Linhong,Jia, Pan,Goossens, Karel,Liu, Peng,Li, Hui,Cheng, Chungui,Huang, Yong,Bielawski, Christopher W.,Geng, Jianxin American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.31

<P>High-performance flame-retardant materials are urgently needed to address outstanding issues that pertain to safety. Traditional flame retardants are toxic to the environment and/or lack the physical properties required for use in many contemporary applications. Here, we show that isocyanate-based polyimide (PI) foam, a flammable material, can exhibit unusually superior flame retardancy as well as, other excellent properties, such as being lightweight and displaying high mechanical strength, by incorporating red phosphorus (RP)-hybridized graphene. The covalent bonds formed between the graphene platelets and the PI matrix provide the resultant PI foam with a specific Young's modulus (83 kNm kg(-1)) that is comparable to or even higher than those displayed by state-of-the-art foams, including silica aerogels, polystyrene foams, and polyurethane foams. In addition, even a low content of the RP -hybridized graphene (2.2 wt %) results in an exceptionally higher limiting oxygen index (39.4) than those of traditional flame-retardant polymer-based materials (typically 20-30). The resultant PI foam also exhibits thermal insulation properties that are similar to that of air. Moreover, the RP -hybridized graphene is prepared using a one-step ball milling process in 100% yield, and does not require solvent or produce waste. The preparation of the flame-retardant PI foams can be scaled as the starting materials are commercially available and the techniques employed are industrially compatible.</P>

Phase transition, ferroelectric and piezoelectric properties of Ba1- xCaxTi1-yZryO3 lead-free ceramics

Wei Lin,Linli Fan,Dunmin Lin,Qiaoji Zheng,Ximing Fan,Hailing Sun 한국물리학회 2013 Current Applied Physics Vol.13 No.1

Lead-free piezoelectric ceramics Ba1xCaxTi1yZryO3þ1mol%CuO were prepared by an ordinary sintering technique and the effects of Ca2þ and Zr4þ on phase transition and electrical properties of the ceramics were studied. The results of X-ray diffraction show that the ceramics exhibit a pure perovskite structure at 0 x 0.175 and 0 y 0.175, suggesting that Ca2þ and Zr4þ diffuse into BaTiO3 lattices to form a solid solution. The substitution of Zr4þ for the B-site Ti4þ ions of BaTiO3 decreases greatly Curie temperature TC and strengthens the relaxor character of the ceramics, while the addition of Ca2þ has a weak influence on TC and leads to an inhibition of grain growth. Owing to the more possible polarization states resulting from the coexistence of tetragonal and orthorhombic phases near room temperature, the ceramics with x ¼ 0.075e0.125 and y ¼ 0.1 exhibit excellent piezoelectric properties: d33 ¼ 254e345 pC/N and kp ¼ 38.0e45.2%, respectively.

從中日常用漢字的對比看漢語水平考試如何貫徹對日本學習者的公平性原則

董琳莉(Dong Linli),劉德聯(Liu Delian),彭?(Peng jing) 중국어문학연구회 2020 중국어문학논집 Vol.0 No.120

The Hsk test is a standardized level test designed to measure the Chinese proficiency of the Chinese learners whose mother tongue is not Chinese. How to do a good basic research on this standardized test is very important. Fairness should always be the center of attention of the test developers and designers. A large number of Chinese characters are still used as writing symbols in Japanese. How much influence will these Chinese characters have on Japanese learners? Will the Japanese learners benefit from them while participating in HSK? How to solve a series of problems? This paper intends to compare the Chinese characters in the vocabulary of the Hsk test with the common Japanese characters, investigate the influence of mastering a certain number of Japanese Kanji on the Japanese students while they take Hsk, analyze their positive and negative transfer, and put forward suggestions to solve the related problems.

Damage assessment in periodic structures from measured natural frequencies by a sensitivity and transter matrix-based method

HongpingZhu,LinLi,DanshengWang 국제구조공학회 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.16 No.1

Synthesis of aminated calcium lignosulfonate and its adsorption properties for azo dyes

Yingying Wang,Linli Zhu,Xiaohong Wang,Wanru Zheng,Chen Hao,Chenglong Jiang,Jingbo Wu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

A low-cost adsorbent, aminated calcium lignosulfonate (ACLS) was prepared and successfully applied to the adsorption of Congo red and the Titan yellow dyes. The adsorbent was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), elemental mapping images (EMIs) and Brunauer–Emmett–Teller (BET) analysis. And the efficiency of ACLS for the removal of Congo red and the Titan yellow dyes was evaluated by several factors, such as temperature, pH, adsorbent dose, contact time and initial concentration of dyes solution. And the test ranges of temperature, pH, adsorbent dose, contact time and initial concentration of dye solution were 25–45 °C, 2–12, 0.005–0.05 g, 1–48 h, 10–200 mg L−1, respectively. The adsorption results demonstrated a good ability to remove dye with the removal rates of 97% and 91% for 30 mg L−1 Congo red and 40 mg L−1 Titan yellow, respectively. The adsorption kinetic and adsorption isotherms can be well described by the pseudo second order kinetic and the Langmuir isotherm model for the both dyes, respectively. Moreover, the maximum adsorption capacity of Congo red and Titan yellow reached 258.4 mg g−1 and 190.1 mg g−1 in the study of the Langmuir adsorption isotherm, respectively. Thermodynamic studies show that the adsorption of the two dyes is a spontaneous endothermic process. The results indicate that the ACLS has the potential to be used in the treatment of dye wastewater.