Experimental Studies on Progressive Collapse Behavior of RC Frame Structures: Advances and Future Needs

Wei?Jian Yi,Fan Yi,Yun Zhou 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.4

In the recent two decades, the progressive collapse of reinforced concrete (RC) frame structures attracted unprecedented research interests in the structural engineering community. Experiments are regarded as an essential method in this field since actual cases can barely provide sufficient and effective data to support rigorous research. In this paper, prevailing experimental assumptions and configurations among over 100 series of experiments are quantitatively revealed by a bibliometric collection based on systematic search in an academic database. Since numerous experiments have been reported on the progressive collapse of RC frame structures, this paper subsequently presents a state-of-the-art review summarizing both experimental consensuses and controversies constituted by three main aspects: (a) static mechanisms, (b) dynamic behavior, and (c) threat-dependent research. The significance of secondary mechanisms, existing problems of dynamic effects, and potential flaws of the threat-independent assumption are discussed in detail with experimental findings. Future needs are emphasized on research targets, correlations between experiments and design, dynamic effects, threat-dependent issues, and retrofitting. These recommendations might help researchers or designers realize a more reliable and realistic progressive collapse design of RC frame structures in the future.

Dynamic simulation and control of a triple column process for dimethyl carbonate- methanol separation

Hong-Mei Wei,Qiang Gao,Wei-zhou Jiao,Wei Wei 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

Separation of dimethyl carbonate/methanol azeotropic mixture by using pressure-swing distillation processhas been a hot-point in the study of the synthesis process of dimethyl carbonate by urea methanolysis method. Thisstudy updates the work of the writers (Ind.Eng.Chem.Res,2013,52,11463-11478), which explores the dynamic controlstructure of the three-column separation dimethyl carbonate (DMC)/methanol (MeOH) process from an actual pilotplant. At first, the conventional DMC/MeOH separation process in the pilot test of the DMC synthesis process throughalcoholysis of urea was described in detail. Then an optimized control structure for the entire DMC/MeOH separationunit was obtained by implementing a general heuristic design procedure. An economic analysis was performed to evaluatethe optimized process. Finally, three dynamic control schemes were proposed and evaluated with several large disturbances,an improved control scheme CS3, using the multiplier blocks “QR1/F1” and “RR1” in T1, “QR1/F1” and “R/F”in both T2 and T3, outperformed CS1 and CS2 by maintaining the product specification in each column.

Preparation and Catalytic Application of Rh3+/Ru3+ Bimetallic Catalyst Stabilized by Triolefinic Macrocycle-Terminated Poly(propylene imine) Dendrimer

Wei Zhou,Xiaohong Peng 한국고분자학회 2016 Macromolecular Research Vol.24 No.11

The novel homogeneous bimetallic Rh3+/Ru3+ catalyst (G2-M(Rh3+ xRu3+ 10-x)) was prepared within a second- generation poly(propylene imine) dendrimer terminated by nitrogen-containing triolefinic macrocycle (G2-M) by a co-complexation route. The G2-M(Rh3+ x Ru3+ 10-x) catalyst was analyzed by 1H NMR (nuclear magnetic resonance), XPS (X-ray photoelectron spectroscopy), and XRD (X-ray diffraction). As a novel catalyst system, The bimetallic ions of Rh3+ and Ru3+ influenced on the catalytic activity for the hydrogenation of nitrile-butadiene rubber (NBR), which can be related to electron-deficiency effect resulting from the electron density shift from the Rh3+ to the Ru3+. The G2-M (Rh3+ 10) and G2-M(Rh3+ 7Ru3+ 3) displayed more excellent activity and favorable separation capability for the hydrogenation of NBR than the Rh nanoparticle catalyst stabilized by G2-M (G2-M(Rh10)).

Overexpression of Capsular Polysaccharide Biosynthesis Protein in Lactobacillus plantarum P1 to Enhance Capsular Polysaccharide Production for Di-n-butyl Phthalate Adsorption

( Wei-bing Liu ),( Zhi-wei Lin ),( Ying Zhou ),( Bang-ce Ye ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.11

Exopolysaccharides (EPSs) such as capsular polysaccharide (CPS) are important bioactive carbohydrate compounds and are often used as bioenrichment agents and bioabsorbers to remove environmental pollutants like di-n-butyl phthalate (DBP). Among the EPS-producing bacteria, lactic acid bacteria (LAB) have gained the most attention. As generally recognized as safe (GRAS) microorganisms, LAB can produce EPSs having many different structures and no health risks. However, EPS production by LAB does not meet the needs of large-scale application on an industrial scale. Here, the capA gene (encoding CPS biosynthesis protein) was overexpressed in Lactobacillus plantarum P1 to improve the production of EPSs and further enhance the DBP adsorption capability. Compared with P1, the CPS production in capA overexpressed strain was increased by 11.3 mg/l, and the EPS thickness was increased from 0.0786 ± 0.0224 μm in P1 to 0.1160 ± 0.0480 μm in P1-capA. These increases caused the DBP adsorption ratio of P1-capA to be doubled. Overall, the findings in this study provide a safe method for the adsorption and removal of DBP.

Competition and Coordination for the Dual-channel Supply Chain with Channel Preference

ZHOU Yong-wei,FAN He-hua,LI Yan-chao 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.2

Aiming at the dual-channel supply chain system with the manufacturer owned direct channel and retail channel simultaneously, the consumers are divided into retail channel loyalty and brand loyalty two parts, under the condition of market demand are depend on the consumers’ channel preference, we studied to the pricing game and coordination between the manufacturer and retailer. The research result showed that the Nash equilibrium of price exists in centralized and decentralized supply chain system, the channel preference degree of consumers, the number of brand loyalty consumers are all have certain influence on supply chain’s optimal pricing strategy, and the price markup contract can realize the coordination of supply chain. The numerical experiment has showed the effectiveness of the conclusions.

New metabolites from the biotransformation of ginsenoside Rb1 by Paecilomyces bainier sp.229 and activities in inducing osteogenic differentiation by Wnt/β-catenin signaling activation

Zhou, Wei,Huang, Hai,Zhu, Haiyan,Zhou, Pei,Shi, Xunlong The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.2

Background: Ginseng is a well-known traditional Chinese medicine that has been widely used in a range of therapeutic and healthcare applications in East Asian countries. Microbial transformation is regarded as an effective and useful technology in modification of nature products for finding new chemical derivatives with potent bioactivities. In this study, three minor derivatives of ginsenoside compound K were isolated and the inducing effects in the Wingless-type MMTV integration site (Wnt) signaling pathway were also investigated. Methods: New compounds were purified from scale-up fermentation of ginsenoside Rb1 by Paecilomyces bainier sp. 229 through repeated silica gel column chromatography and high pressure liquid chromatography. Their structures were determined based on spectral data and X-ray diffraction. The inductive activities of these compounds on the Wnt signaling pathway were conducted on MC3T3-E1 cells by quantitative real-time polymerase chain reaction analysis. Results: The structures of a known 3-keto derivative and two new dehydrogenated metabolites were elucidated. The crystal structure of the 3-keto derivative was reported for the first time and its conformation was compared with that of ginsenoside compound K. The inductive effects of these compounds on osteogenic differentiation by activating the Wnt/b-catenin signaling pathway were explained for the first time. Conclusion: This study may provide a new insight into the metabolic pathway of ginsenoside by microbial transformation. In addition, the results might provide a reasonable explanation for the activity of ginseng in treating osteoporosis and supply good monomer ginsenoside resources for nutraceutical or pharmaceutical development.

LAMP, PCR, and real-time PCR detection of Acetobacter aceti in yogurt

Wei Zhou,Yan Zhang,Shuang Wang,Yuehua Li,Jingjing Zhang,Cuixia Zhang,Zan Wang,Zhisheng Zhang 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.1

Acetic acid bacteria (AAB) can spoil food. Acetobacter aceti as a core subgroup of AAB is usually isolated from yogurt. A. aceti should be timely and effectively detected to prevent yogurt contamination. The present study focused on A. aceti to establish an assay that can be performed to detect AAB in yogurt. LAMP, PCR, and real-time PCR were applied and compared for detecting A. aceti from pure culture and artificially contaminated yogurt samples. In pure culture, LAMP showed the highest detection sensitivity with 10−1 CFU/mL. For yogurt samples, the sensitivity limit of LAMP was 102 CFU/mL, which was lower than that of real-time PCR (101 CFU/mL). The results indicated that these methods could be quickly and efficiently applied to detect A. aceti. As LAMP technology has low cost and high detection efficiency, it can potentially be applied for detecting A. aceti in production and quality control programs of yogurt.

Abelian subgroup separability of certain HNN extensions

Zhou, Wei,Kim, Goansu World Scientific Publishing Company 2018 International journal of algebra and computation Vol.28 No.3

<P>In this paper, we prove that certain HNN extensions of finitely generated abelian subgroup separable groups are finitely generated abelian subgroup separable. Using this, we show that certain HNN extensions of finitely generated nilpotent groups are finitely generated abelian subgroup separable.</P>

Assessment of the crest cracks of the Pubugou rockfill dam based on parameters back analysis

Zhou, Wei,Li, Shao-Lin,Ma, Gang,Chang, Xiao-Lin,Cheng, Yong-Gang,Ma, Xing Techno-Press 2016 Geomechanics & engineering Vol.11 No.4

The crest of the Pubugou central core rockfill dam (CCRD) cracked in the first and second impounding periods. To evaluate the safety of the Pubugou CCRD, an inversion analysis of the constitutive model parameters for rockfill materials is performed based on the in situ deformation monitoring data. The aim of this work is to truly reflect the deformation state of the Pubugou CCRD and determine the causes of the dam crest cracks. A novel real-coded genetic algorithm based upon the differences in gene fragments (DGFX) is proposed. It is used in combination with the radial based function neural network (RBFNN) to perform the parameters back analysis. The simulated settlements show good agreements with the monitoring data, illustrating that the back analysis is reasonable and accurate. Furthermore, the deformation gradient of the dam crest has been analysed. The dam crest has a great possibility of cracking due to the uncoordinated deformation, which agrees well with the field investigation. The deformation gradient decreases to the value lower than the critical one and reaches a stable state after the second full reservoir.

Broadband and ultra-low reflection metamaterial absorber embedded with magnetic materials

Zhou Wei,Zhu Zhenghou,Zou Qiang,Yuan Zhifen,Liu Rongyu 한국물리학회 2022 Current Applied Physics Vol.41 No.-

In this study, we design, prepare and characterize a broadband, ultra-low reflectivity and incidence angle-insensitive metamaterial absorber. The design of this absorber not only provides a novel idea for the design of broadband absorbers, but also enhances the application prospects of metamaterial absorbers. By introducing FeSiAlp/epoxy magnetic composite and optimizing the structural parameters, the absorption performance of the metamaterial absorber has been significantly improved. The effective absorption bandwidth (bandwidth with reflectivity less than -10dB) is increased by 3.4 times from 2.19 GHz to 7.49 GHz, and the RLmin (minimum reflection loss) value reaches -38.31 dB at 17.83 GHz, that is the absorption rate reaches 99.99%. Meanwhile, the experimental results also verify the simulation design results. Therefore, the absorber not only plays the characteristics of strong absorption of metamaterial, but also absorbs the advantages of broadband of magnetic material.