Seismic Coefficients and Earthquake Damage Predictions for a Space Truss with a Supporting Structure

Zailin Yang,Ziwen Wang,Yang Yong,Menghan Sun 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.4

Previous studies have shown that when the lower support structure is considered, the dynamic characteristics of grid structures change signifi cantly, and the stress distributions are also noticeably diff erent. Therefore, this paper discusses whether other simple and feasible structural seismic damage prediction methods could be proposed after accounting for the infl uence of the lower supporting structure. Considering diff erent site types and diff erent intensities, a time-history analysis was conducted using the mode decomposition response spectrum method for frequent 8- and 9-degree earthquake intensity. Then, the acceleration response spectra for diff erent sites experiencing 8- and 9-degree intensity of frequently occurring earthquakes specifi ed in the Code for Seismic Design of Buildings (GB50011-2010) were used to calculate and discuss the distribution law for the seismic internal forces of space truss structures. Based on the calculation conclusion, the design method and damage prediction method for a plate-like space truss structure under earthquake actions are discussed. Then, a new value of the seismic action coeffi cient was proposed in this paper, and the ground motion peaks for various types of earthquake damage for diff erent site types were obtained using the functional relationship.

Cloning and Functional Characterization of Putative Escherichia coli ABC Multidrug Efflux Transporter YddA

( Zhenyue Feng ),( Defu Liu ),( Ziwen Liu ),( Yimin Liang ),( Yanhong Wang ),( Qingpeng Liu ),( Zhenhua Liu ),( Zhongjing Zang ),( Yudong Cui ) 한국미생물 · 생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.7

A putative multidrug efflux gene, yddA, was cloned from the Escherichia coli K-12 strain. A drugsensitive strain of E. coli missing the main multidrug efflux pump AcrB was constructed as a host and the yddA gene was knocked out in wild-type (WT) and drug-sensitive E. coliΔacrB to study the yddA function. Sensitivity to different substrates of WT E.coli, E. coliΔyddA, E. coliΔacrB and E. coliΔacrBΔyddA strains was compared with minimal inhibitory concentration (MIC) assays and fluorescence tests. MIC assay and fluorescence test results showed that YddA protein was a multidrug efflux pump that exported multiple substrates. Three inhibitors, ortho-vanadate, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and reserpine, were used in fluorescence tests. Ortho-vanadate and reserpine significantly inhibited the efflux and increased accumulation of ethidium bromide and norfloxacin, while CCCP had no significant effect on YddA-regulated efflux. The results indicated that YddA relies on energy released from ATP hydrolysis to transfer the substrates and YddA is an ABC-type multidrug exporter. Functional study of unknown ATP-binding cassette (ABC) superfamily transporters in the model organism E. coli is conducive to discovering new multidrug resistance-reversal targets and providing references for studying other ABC proteins of unknown function.

Confinement models for high strength short square and rectangular concrete-filled steel tubular columns

Farhad Aslani,Brian Uy,Ziwen Wang,Vipul Patel 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.5

While extensive efforts have been made in the past to develop finite element models (FEMs) for concrete-filled steel tubular columns (CFSTCs), these models may not be suitable to be used in some cases, especially in view of the utilisation of high strength steel and high strength concrete. A method is presented herein to predict the complete stress-strain curve of concrete subjected to tri-axial compressive stresses caused by axial load coupled with lateral pressure due to the confinement action in square and rectangular CFSTCs with normal and high strength materials. To evaluate the lateral pressure exerted on the concrete in square and rectangular shaped columns, an accurately developed FEM which incorporates the effects of initial local imperfections and residual stresses using the commercial program ABAQUS is adopted. Subsequently, an extensive parametric study is conducted herein to propose an empirical equation for the maximum average lateral pressure, which depends on the material and geometric properties of the columns. The analysis parameters include the concrete compressive strength (<i>f</i>’<i>_c</i> = 20 - 110 N/mm²), steel yield strength (<i>f_y</i> = 220 - 850 N/mm²), width-to-thickness (<i>B/t</i>) ratios in the range of 15-52, as well as the length-to-width (<i>L/B</i>) ratios in the range of 2-4. The predictions of the behaviour, ultimate axial strengths, and failure modes are compared with the available experimental results to verify the accuracy of the models developed. Furthermore, a design model is proposed for short square and rectangular CFSTCs. Additionally, comparisons with the prediction of axial load capacity by using the proposed design model, Australian Standard and Eurocode 4 code provisions for box composite columns are carried out.

Settlement behaviours and control measures of twin-tube curved buildings-crossing shield tunnel

Jianwei Jia,Ruiqi Gao,Defeng Wang,Jianjun Li,Ziwen Song,Jinghui Tan 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.5

Settlement control techniques are critical for the safety of shield tunnel constructions, especially for facing complex situations. In this study, the shield tunnel structure from Huaita east road station to Heping Road station in Xuzhou metro No.3 line (China) is taken as engineering background, which has various complex problems of the upper-soft and lower-hard composite stratum conditions, twin curve shield tunnels, and underpass the foundation of the piled raft. The deformation characteristics of shield tunnelling passing through buildings are explored. Subsequently, comprehensive research methods of numerical simulation and field measurement are adopted to analyzing the effectiveness of settlement control by using the top grouting technique. The results show that the settlement of the buildings has obvious spatial characteristics, and the hysteresis effect can be obviously observed in soil deformation caused by shield construction. Meanwhile, the two shield constructions can cause repeated disturbances, reducing the soil deformation's hysteresis effect. Moreover, the shield tunnel's differential settlement is too large when a single line passes through, and the shield construction of the outer curve can cause more significant disturbance in the tunnel than the inside curve. Notably, the proposed process control parameters and secondary topgrouting method can effectively control the deformation of the shield tunnel, especially for the long-term deformation.

Spirodiclofen Analogues as Potential Lipid Biosynthesis Inhibitors: A Convenient Synthesis, Biological Evaluation, and Structure-Activity Relationship

Shaoyong Ke,Tingting Sun,Zhigang Zhang,Ya-Ni Zhang,Ying Liang,Kaimei Wang,Ziwen Yang 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

Twenty spirodiclofen analogues have been designed and conveniently synthesized via three steps including esterification,one-pot heterocyclization, and acylation reactions. The target molecules have been identified on the basis of analytical spectra (1H NMR, 13C NMR and ESI-MS) data. All newly synthesized compounds have been screened for their potential insecticidal and herbicidal activity by standard method. The preliminary assays indicated that some of analogues displayed moderate to good insecticidal activity against Plutella xylostella compared with spirodiclofen,and some compounds showed obvious activity against Brassica chinensis. Structure-activity relationship (SAR) is also discussed based on the experimental data.

Thermo- and pH-Responsive CeF3 Nanocrystals/HPC–PAA Complex Nanogel and Its Drug Release Behavior

Ben Liu,Qiusheng Song,Qiancheng Zhang,Haihong Ma,Ziwen Zhang,Dapeng Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.8

In this study, a kind of novel rare-earth nanocrystals/hydroxypropylcellulose–poly (acrylic acid) (HPC–PAA) complex fluorescent nanogel, its responsive behavior to environmental temperature and pH value were reported. For preparation, with HPC being used as template, HPC–PAA nanogel was first synthesized by polymerization and crosslinking reaction of acrylic acid (AA) in water solution. In the process, a redox initiator, which composed of ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED), was used to initiate the reaction. Then, the as-prepared nanogel reacted with Ce(NO3)3 and NH4F solution successively, and a novel CeF3 nanocrystals/HPC–PAA complex nanogel was fabricated. The microstructure of the nanogel was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Thermogravimetric (TG) and Transmission electron microscopy (TEM). The environmental sensitivity of the nanogel was investigated by photoluminescence (PL) and UV–Visible spectrophotometer (UV–Vis). The thermo- and pH-sensitive fluorescence were studied by PL at various temperatures and pH values; besides, the behavior of drug loading and release was researched by PL with a famous antibiotic of Ibuprofen as model drug. The results show that the PL intensity of the nanogel was largely affected by environmental temperature, or content of Ibuprofen loaded in the nanogel. The as-prepared nanogel can be used as useful sensitive material to detect temperature and pH value change, and drug loading or release property of Ibuprofen can be detected by PL emission of the nanogels conveniently.

Spirodiclofen Analogues as Potential Lipid Biosynthesis Inhibitors: A Convenient Synthesis, Biological Evaluation, and Structure-Activity Relationship

Ke, Shaoyong,Sun, Tingting,Zhang, Zhigang,Zhang, Ya-Ni,Liang, Ying,Wang, Kaimei,Yang, Ziwen Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

Twenty spirodiclofen analogues have been designed and conveniently synthesized via three steps including esterification, one-pot heterocyclization, and acylation reactions. The target molecules have been identified on the basis of analytical spectra ($^1H$ NMR, $^{13}C$ NMR and ESI-MS) data. All newly synthesized compounds have been screened for their potential insecticidal and herbicidal activity by standard method. The preliminary assays indicated that some of analogues displayed moderate to good insecticidal activity against Plutella xylostella compared with spirodiclofen, and some compounds showed obvious activity against Brassica chinensis. Structure-activity relationship (SAR) is also discussed based on the experimental data.

Acaricidal activity and structure-activity relationships of Spiro- Butyrolactone derivatives against Tetranychus cinnabarinus

Shaoyong Ke,Ting Ke,Zhigang Zhang,Liqiao Shi,Daye Huang,Kaimei Wang,Ziwen Yang,Nina Yang 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.3

The phytophagous mite is highly polyphagous and widespread in warmer regions and greenhouses around the world, and so the focus of novel acaricides is shifting towards more effective, ecofriendly new chemical entity with unique modes of action. In this study, eighteen spirobutyrolactones derived from natural tetronic acid have been synthesized and their acaricidal activities against Tetranychus cinnabarinus were investigated by slide-dip method. The results of preliminary bioassay indicate that some of these compounds exhibited promising acaricidal activities, especially, compounds 6 and 18 show significant activities against T. cinnabarinus than the commercial spirodiclofen 1 (27.37% mortality), and which present 58.55% and 82.24% mortality at tested dose, respectively. The relationship between structure and acaricidal activity was also discussed based on the experimental data, and which indicate that the compounds (16, 17 and 18) with non-substituted phenyl ring (R1=H) show obviously better activities. Especially, we also can find that substituted benzoyl unit will help to increase the activity than substituted phenylacetyl group.