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.

CONJUGACY SEPARABILITY OF GENERALIZED FREE PRODUCTS OF FINITELY GENERATED NILPOTENT GROUPS

Wei Zhou,김관수,Wujie Shi,C. Y. Tang 대한수학회 2010 대한수학회보 Vol.47 No.6

In this paper, we prove a criterion of conjugacy separability of generalized free products of polycyclic-by-finite groups with a non-cyclic amalgamated subgroup. Applying this criterion,we prove that certain generalized free products of polycyclic-by-finite groups are conjugacy separable.

Genome-wide identification and comparative analysis of Alfin-like transcription factors in maize

Wei Zhou,Jiandong Wu,Qianqian Zheng,Yingli Jiang,Min Zhang,Suwen Zhu 한국유전학회 2017 Genes & Genomics Vol.39 No.3

Members of the Alfin-like (AL) transcription factor family, which contain a highly conserved DUF3594 domain and a PHD-finger motif, play important roles in the responses of plants to abiotic stress during various metabolic and physiological processes. To date, no systematic, comprehensive study of this family has been reported in maize. In this study, we identified 18 nonredundant ZmAL genes and classified them into four groups. These genes are unevenly distributed among all ten maize chromosomes except chromosome 9. Our results suggest that segmental duplication has played an important role in the expansion of the AL family in maize. Ka/Ks ratio analysis showed that most duplicated ZmALs have undergone large-scale purifying selection in the maize genome. We detected interspecies microsynteny among three graminaceous species, suggesting that there were independent duplication events in addition to the whole-genome duplication of the maize genome. Furthermore, microarray analysis showed that most ZmALs are differentially expressed in diverse tissues and stages. We also performed expression profiling of the ZmALs under salt, cold and drought stress conditions using quantitative reverse-transcription PCR (qRT-PCR). The results of this study provide useful clues for further functional analysis of the AL gene family in maize.

Transverse Tensile Deformation and Failure of Three-dimensional Five-directional Braided Carbon Fiber Composites

Wei Zhou,Zhi-yuan Wei,Guang-fei Wang,Kang-ning Han,Ran Liu,Lian-Hua Ma 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

Accurate characterisation of transverse tensile deformation and damage evolution is of importance for evaluatingthe failure behaviors of three-dimensional (3D) braided composites. In the present study, a finite element method (FEM) andseveral non-destructive testing methods including acoustic emission, digital image correlation, and infrared thermography aredeveloped to investigate the transverse tensile deformation and damage evolution of 3D five-directional braided composites. In the finite element approach, a matrix-impregnated fiber bundles (MIFB) model and a representative volume cell (RVC)model, which take into account the fiber bundles and matrix, are respectively established to predict the effective mechanicalproperties of fiber bundles and simulate the deformation and progressive damage of such composites. The damaged locationsand the failure modes including matrix crack, fiber debonding and shear fracture of fiber are predicted and verified byexperimental tests. The non-destructive tests show that the transverse tensile fracture process can be divided into four stageswhich correspond to acoustic emission signals severally. The combination of the FEM based numerical modeling andmultiple non-destructive characterisation methods can accurately monitor the deformation and damage behaviors of 3Dbraided composites under transverse tensile loads and thus provide a reference for structural health monitoring of compositesin practical application.

Interface engineering for improving reliability of resistance switching in Cu/HfO₂/TiO₂/Pt structure

Wei Zhou, Li,Long Shao, Xing,Yuan Li, Xiang,Jiang, Hao,Chen, Ran,Jean Yoon, Kyung,Jin Kim, Hae,Zhang, Kailiang,Zhao, Jinshi,Seong Hwang, Cheol American Institute of Physics 2015 APPLIED PHYSICS LETTERS Vol.107 No.7

Significance of “Deqi” Response in Acupuncture Treatment: Myth or Reality

wei zhou,peyman benharash 사단법인약침학회 2014 Journal of Acupuncture & Meridian Studies Vol.7 No.4

Acupuncture has been practiced in China for over 2000 years to treat a variety of diseases based on the “meridian theory,” as described in the “Yellow Emperor’s Classics of Inter- nal Medicine.” Deqi refers to the excitation of qi or vital energy inside meridians by acupuncture needle stimulation. Patients often experience multidimensional and intense needling sensations such as numbness, soreness, distention, heaviness, dull pain, and sharp pain during acupuncture stimulation. Deqi is considered as an important parameter in the process of achieving therapeutic effectiveness in acupuncture treatment. Under- standing this phenomenon from neurophysiological aspects is important for clinical prac- tice and enables practitioners to perform quantitative acupuncture evaluation to obtain a reliable prognosis of acupuncture treatment. This review paper describes our current knowledge and understanding of Deqi from a physiological aspect.

Preparation and Spectroscopic Characterization of Ilmenite-Type $CoTiO_3$ Nanoparticles

Zhou, Guo Wei,Lee, Don-Geun,Kim, Young-Hwan,Kim, Chang-Woo,Kang, Young-Soo Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.3

The cobalt titanate, $CoTiO_3$ nanoparticles have been prepared by calcinations of precursor obtained from a mixture of $TiO_2$ and $Co(OH)_2$ in aqueous cetyltrimethylammonium bromide (CTAB) solution. The nanoparticles were investigated with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric/differential thermal analysis (TGA/DTA) to determine the crystallite size and the phase composition. The spectroscopic characterizations of these nanoparticles were also done with UV-Vis spectroscopy and FT-Raman spectroscopy. XRD patterns show that $CoTiO_3$ phase was formed at calcinations temperature above 600 ${^{\circ}C}$. UV-Vis absorption spectra indicate that the $CoTiO_3$ nanoparticles have significant red shift to the visible region (400-700 nm) with $\lambda_{max}$ = 500 nm compared to pure $TiO_2$ powder ($\lambda_{max}$ = 320 nm). The new absorption peaks (absorption at 696, 604, 520, 478,456, 383, 336, 267, 238, 208 $c m ^{-1}$), which were not appeared in FT-Raman spectra of P-25, also confirm the formation of Ti-O-Co bonds at above 600 ${^{\circ}C}$ and just not the mixtures of titanium dioxide with cobalt oxides.

Whether can Posner-Schlossman syndrome be treated through a physiotherapy, ciliary muscle training method?

Wei Zhou,Xiaoyan Zhang 셀메드 세포교정의약학회 2015 TANG Vol.5 No.4

A new physiotherapy named Ciliary Muscle Training method and one successful case had been reported first for treatment of Posner-Schlossman Syndrome (PSS), also known as Glaucomatocyclitic Crisis. When a person observed a back and forth moving object, the ciliary muscle would involuntarily do sometimes tense and sometimes relaxant exercise which can relieve the tensive state of the ciliary muscle of patients suffering PSS disease. Through this period of continued treatment, this ciliary muscle training method can improve the health status of the ciliary muscle and finally achieve the purpose of curing PSS disease. In this successful case, the patient’s feedback result was very good after receiving our suggested ciliary muscle training method as an attempt to treat PSS, ill right eye of this PSS patient showed normal appearance without any differences from the other normal eye, his vision test values of naked eye were both 4.9 under nearly 200 degrees of myopia. High intraocular pressure (IOP) was mitigated, measured IOP value was in the normal (≦ 21 mmHg) and comfortable state without PSS relapse until now. Therefore, ciliary muscle training method could be a potential clinical treatment approach to PSS disease.

Phytochemical Studies of Korean Endangered Plants: A New Flavone from Rhododendron brachycarpum G.Don

Zhou, Wei,Oh, Joonseok,Li, Wei,Kim, Dong Woo,Lee, Seung Ho,Na, MinKyun Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

Soluble Expression and Purification of the Catalytic Domain of Human Vascular Endothelial Growth Factor Receptor 2 in Escherichia coli

Wei, Jia,Cao, Xiaodan,Zhou, Shengmin,Chen, Chao,Yu, Haijun,Zhou, Yao,Wang, Ping The Korean Society for Microbiology and Biotechnol 2015 Journal of microbiology and biotechnology Vol.25 No.8

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptors, which mainly occurs to VEGF receptor 2 (VEGFR-2), a kinase insert domain-containing receptor. Therefore, the disruption of VEGFR-2 signaling provides a promising therapeutic approach for the treatment of cancer by inhibiting abnormal or tumorinduced angiogenesis. To explore this potential, we expressed the catalytic domain of VEGFR-2 (VEGFR-2-CD) as a soluble active kinase in Escherichia coli. The recombinant protein was purified and the VEGFR-2-CD activity was investigated. The obtained VEGFR-2-CD showed autophosphorylation activity and phosphate transfer activity comparable to the commercial enzyme. Furthermore, the IC₅₀ value of known VEGFR-2 inhibitor was determined using the purified VEGFR-2-CD. These results indicated a possibility for functional and economical VEGFR-2-CD expression in E. coli to use for inhibitor screening.