Cyclic test for beam-to-column abnormal joints in steel moment-resisting frames

Zu Q. Liu,Jian Y. Xue,Xiu N. Peng,Liang Gao 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.5

Six specimens are tested to investigate the cyclic behavior of beam-to-column abnormal joints in steel moment-resisting frames, which are designed according to the principle of strong-member and weak-panel zone. Key parameters include the axial compression ratio of column and the section depth ratio of beams. Experimental results indicate that four types of failure patterns occurred during the loading process. The P-hysteretic loops are stable and plentiful, but have different changing tendency at the positive and negative direction in the later of loading process due to mechanical behaviors of specimens. The ultimate strength tends to increase with the decrease of the section depth ratio of beams, but it is not apparent relationship to the axial compression ratio of column, which is less than 0.5. The top panel zone has good deformation capacity and the shear rotation can reach to 0.04 rad. The top panel zone and the bottom panel zone don't work as a whole. Based on the experimental results, the equation for shear strength of the abnormal joint panel zone is established by considering the restriction of the bottom panel zone to the top panel zone, which is suitable for the abnormal joint of H-shaped or box column and beams with different depths.

A generalized adaptive variational mode decomposition method for nonstationary signals with mode overlapped components

Jing-Liang Liu,Fu-Lian Qiu,Zhi-Ping Lin,Yu-Zu Li,Fei-Yu Liao 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.30 No.1

Engineering structures in operation essentially belong to time-varying or nonlinear structures and the resultant response signals are usually non-stationary. For such time-varying structures, it is of great importance to extract time-dependent dynamic parameters from non-stationary response signals, which benefits structural health monitoring, safety assessment and vibration control. However, various traditional signal processing methods are unable to extract the embedded meaningful information. As a newly developed technique, variational mode decomposition (VMD) shows its superiority on signal decomposition, however, it still suffers two main problems. The foremost problem is that the number of modal components is required to be defined in advance. Another problem needs to be addressed is that VMD cannot effectively separate nonstationary signals composed of closely spaced or overlapped modes. As such, a new method named generalized adaptive variational modal decomposition (GAVMD) is proposed. In this new method, the number of component signals is adaptively estimated by an index of mean frequency, while the generalized demodulation algorithm is introduced to yield a generalized VMD that can decompose mode overlapped signals successfully. After that, synchrosqueezing wavelet transform (SWT) is applied to extract instantaneous frequencies (IFs) of the decomposed mono-component signals. To verify the validity and accuracy of the proposed method, three numerical examples and a steel cable with time-varying tension force are investigated. The results demonstrate that the proposed GAVMD method can decompose the multi-component signal with overlapped modes well and its combination with SWT enables a successful IF extraction of each individual component.

Reusable and Efficient Polystryrene-supported Acidic Ionic Liquid Catalyst for Mononitration of Aromatic Compounds

Li, Li Xia,Ling, Qi Long,Liu, Zu Liang,Xing, Xiao Dong,Zhu, Xiao Qin,Meng, Xiao Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl-imidazolium hydrosulfate acidic ionic liquid (PS-$[SO_3H-PMIM][HSO_4]$) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing $[SO_3H-PMIM][HSO_4]$ content. The para-selectivity was not only related to the $[SO_3H-PMIM][HSO_4]$ content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

Reusable and Efficient Polystryrene-supported Acidic Ionic Liquid Catalyst for Mononitration of Aromatic Compounds

Li Xia Li,Qi Long Ling,Zu Liang Liu,Xiao Dong Xing,Xiao Qin Zhu,Xiao Meng 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl-imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO4]) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing [SO3HPMIM][ HSO4] content. The para-selectivity was not only related to the [SO3H-PMIM][HSO4] content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

Antibacterial Magnetic Nanoparticles Functionalized with N-Halamine/Quaternary Ammonium Polymer Coatings

Xiaoqin Chen,Qian Xiang,Chunyan Yong,Zu Liang Liu,Xiao Dong Xing 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.12

The bactericidal magnetic nanoparticles were prepared by modifying magnetic nanoparticles (MNPs) with N-halamine polymer coating and quaternary ammonium polymer coating via a two-step soap-free emulsion polymerization method. The success of the surface functionalization was confirmed by Fourier transform infrared (FT-IR), X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and zeta-potential measurement. The results of antibacterial tests showed that the functional MNPs exhibited excellent antibacterial efficiency against both Gram negative bacteria E. coli and Gram positive bacteria S. aureus. Meanwhile the nanoparticles could be removed easily from water by an external magnetic field after antibacterial tests.

DFT Studies on Two Novel Explosives Based on the Guanidine-Fused Bicyclic Structure

Xing-Hui Ji,Bing-Cheng Hu,Huan-Qing Jia,Zu Liang Liu,Chun-Xu Lu 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

Density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) theoretical level were performed for two novel explosives (compounds B and C) based on the guanidine-fused bicyclic skeleton C4N6H8 (A). The heats of formation (HOFs) were calculated via isodesmic reaction. The detonation properties were evaluated by using the Kamlet-Jacobs equations. The bond dissociation energies (BDEs) for the thermolysis initiation bond were also analyzed to investigate the thermal stability. The results show that the compounds have high positive HOF values (B, 1064.68 kJ·mol−1; C, 724.02 kJ·mol−1), high detonation properties (ρ, D and P values of 2.04 g·cm−3 and 2.21 g·cm−3, 9.98 km·s−1 and 10.99 km·s−1, 46.44 GPa and 59.91 Gpa, respectively) and meet the basic stability requirement. Additionally, feasible synthetic routes of the these high energy density compounds (HEDCs) were also proposed via retrosynthetic analysis.

DFT Studies on Two Novel Explosives Based on the Guanidine-Fused Bicyclic Structure

Jin, Xing-Hui,Hu, Bing-Cheng,Jia, Huan-Qing,Liu, Zu-Liang,Lu, Chun-Xu Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

Density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) theoretical level were performed for two novel explosives (compounds B and C) based on the guanidine-fused bicyclic skeleton $C_4N_6H_8$ (A). The heats of formation (HOFs) were calculated via isodesmic reaction. The detonation properties were evaluated by using the Kamlet-Jacobs equations. The bond dissociation energies (BDEs) for the thermolysis initiation bond were also analyzed to investigate the thermal stability. The results show that the compounds have high positive HOF values (B, 1064.68 $kJ{\cdot}mol^{-1}$; C, 724.02 $kJ{\cdot}mol^{-1}$), high detonation properties (${\rho}$, D and P values of 2.04 $g{\cdot}cm^{-3}$ and 2.21 $g{\cdot}cm^{-3}$, 9.98 $km{\cdot}s^{-1}$ and 10.99 $km{\cdot}s^{-1}$, 46.44 GPa and 59.91 Gpa, respectively) and meet the basic stability requirement. Additionally, feasible synthetic routes of the these high energy density compounds (HEDCs) were also proposed via retrosynthetic analysis.

Scaling up the in-hospital hepatitis C virus care cascade in Taiwan

( Chung-feng Huang ),( Pey-fang Wu ),( Ming-lun Yeh ),( Ching-i Huang ),( Po-cheng Liang ),( Cheng-ting Hsu ),( Po-yao Hsu ),( Hung-yin Liu ),( Ying-chou Huang ),( Zu-yau Lin ),( Shinn-cherng Chen ),( 대한간학회 2021 Clinical and Molecular Hepatology(대한간학회지) Vol.27 No.1

Background/Aims: Obstacles exist in facilitating hepatitis C virus (HCV) care cascade. To increase timely and accurate diagnosis, disease awareness and accessibility, in-hospital HCV reflex testing followed by automatic appointments and a late call-back strategy (R.N.A. model) was applied. We aimed to compare the HCV treatment rate of patients treated with this strategy compared to those without. Methods: One hundred and twenty-five anti-HCV seropositive patients who adopted the R.N.A. model in 2020 and another 1,396 controls treated in 2019 were enrolled to compare the gaps in accurate HCV RNA diagnosis to final treatment allocation. Results: The HCV RNA testing rate was significantly higher in patients who received reflex testing than in those without reflex testing (100% vs. 84.8%, P<0.001). When patients were stratified according to the referring outpatient department, a significant improvement in the HCV RNA testing rate was particularly noted in patients from non-hepatology departments (100% vs. 23.3%, P<0.001). The treatment rate in HCV RNA seropositive patients was 83% (83/100) after the adoption of the R.N.A. model, among whom 96.1% and 73.9% of patients were from the hepatology and non-hepatology departments, respectively. Compared to subjects without R.N.A. model application, a significant improvement in the treatment rate was observed for patients from non-hepatology departments (73.9% vs. 27.8%, P=0.001). The application of the R.N.A. model significantly increased the in-hospital HCV treatment uptake from 6.4% to 73.9% for patients from non-hepatology departments (P<0.001). Conclusions: The care cascade increased the treatment uptake and set up a model for enhancing in-hospital HCV elimination. (Clin Mol Hepatol 2021;27:136-143)