Syntheses, Structures, and Luminescence Properties of Two Copper(II) Complexes Constructed by Rigid Bis(triazole) and Nitrogen-containing Carboxylic Acid Ligands

Xiao-Xiao,Zuo-Xi Li,Bao-yi Yu,Guang-hua Cui 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.7

Two new copper(II) complexes with the formulas [Cu(btb)(pydc)(H2O)]n (1) and [Cu(btb)0.5(nph)(H2O)]n (2) have been synthesized under hydrothermal conditions by employing a rigid bis(triazole) ligand (btb = 4,4′-bis(1,2,4-triazolyl-1-yl)-biphenyl) and two carboxylic acids mixed ligands (H2pydc = pyridine-2,5-dicarboxylic acid and H2nph = 3-nitrophthalic acid). The copper atoms present different environments, with a tetragonal pyramidal geometry in 1 and octahedral configuration in 2. Complex 1 displays a dinuclear cluster, which is further packed into a 2D supramolecular layer by classical OH · · · O hydrogen bonds. Complex 2 possesses a trinodal 3,4,4-connected 3D framework with a rare sqc69 topology. In addition, thermal stability and luminescence property were investigated.

Numerical investigation on gypsum and ettringite formation in cement pastes subjected to sulfate attack

Xiao-Bao Zuo,Jia-Lin Wang,Wei Sun,Hua Li,Guang-Ji Yin 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.1

This paper uses modelling and experiment to perform a quantitative analysis for the gypsum and ettringite formations in cement pastes subjected to sulfate attack. Firstly, based on Fick’s law and chemical reaction kinetics, a diffusion model of sulfate ions in cement pastes is proposed, and then the model of the gypsum and ettringite formations is established to analyze its contents in cement pastes with corrosion time. Secondly, the corrosion experiment of the specimens with cement pastes immersed into 2.5%, 5.0% and 10.0% Na2SO4 solutions are carried out, and by using XRD-Rietveld method, the phases of powder samples from the specimens are quantitatively analyzed to obtain the contents of gypsum and ettringite in different surface depth, solution concentration and corrosion time. Finally, the contents of gypsum and ettringite calculated by the models are compared with the results from the XRD experiments, and then the effects of surface depth, corrosion time and solution concentration on the gypsum and ettringite formations in cement pastes are discussed.

Numerical investigation on tortuosity of transport paths in cement-based materials

Xiao-Bao Zuo,Wei Sun,Zhi-Yong Liu,Yu-Juan Tang 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.3

Based on the compositions and structures of cement-based materials, the geometrical models of the tortuosity of transport paths in hardened cement pastes, mortar and concrete, which are associated withthe capillary porosity, cement hydration degree, mixture particle shape, aggregate volume fraction andwater-cement ratio, are established by using a geometric approach. Numerical simulations are carried out to investigate the effects of material parameters such as water-cement ratio, volume fraction of the mixtures, shape and size of aggregates and cement hydration degree, on the tortuosity of transport paths in hardened cement pastes, mortar and concrete. Results indicate that the transport tortuosity in cement-based materials decreases with the increasing of water-cement ratio, and increases with the cement hydration degree, the volume fraction of cement and aggregate, the shape factor and diameter of aggregates, and the material parameters related to cement pastes, such as the water-cement ratio, cement hydration degree and cement volume fraction, are the primary factors that influence the transport tortuosity of cement-based materials.

Modeling of ion diffusion coefficient in saturated concrete

Xiao-Bao Zuo,Wei Sun,Cheng Yu,Xu-Rong Wan 사단법인 한국계산역학회 2010 Computers and Concrete, An International Journal Vol.7 No.5

This paper utilizes the modified Davis model and the mode coupling theory, as parts of the electrolyte solution theory, to investigate the diffusivity of the ion in concrete. Firstly, a computational model of the ion diffusion coefficient, which is associated with ion species, pore solution concentration, concrete mix parameters including water-cement ratio and cement volume fraction, and microstructure parameters such as the porosity and tortuosity, is proposed in the saturated concrete. Secondly, the experiments, on which the chloride diffusion coefficient is measured by the rapid chloride penetration test,have been carried out to investigate the validity of the proposed model. The results indicate that the chloride diffusion coefficient obtained by the proposed model is in agreement with the experimental result. Finally, numerical simulation has been completed to investigate the effects of the porosity, tortuosity, water-cement ratio, cement volume fraction and ion concentration in the pore solution on the ion diffusion coefficients. The results show that the ion diffusion coefficient in concrete increases with the porosity, water-cement ratio and cement volume fraction, while we see a decrease with the increasing of tortuosity. Meanwhile, the ion concentration produces more obvious effects on the diffusivity itself, but has almost no effects on the other ions.

Oxidation behavior of C/C composites with B4C-SiCZrC-ZrB2 coating prepared by infiltration and pyrolysis

Xiao-Hua Zuo,Zhi-Jun Dong,Guan-Ming Yuan,Zheng-Wei Cui,Xuan-Ke Li 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.1

Polycarbosilane, B-Si and B-Si-Zr modification coal tar pitch were used as impregnate agent for infiltration and pyrolysis formation of carbon/carbon (abbreviated as C/C) composites with B4C-SiC-ZrC-ZrB2 coating. The density of the composites was examined to be 1.0 g·cm-3, 1.4 g·cm-3 and 1.8 g·cm-3, respectively. The phase compositions, surface morphologies and element distributions of the coating were analyzed by X-ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispervive spectroscopy (EDS), respectively. The result showed that the two composites with a density of 1.4 g·cm-3 and 1.8 g·cm-3 displayed compact microstructures. The oxidation behavior of the composites was studied by oxidation in air at temperatures from 800 to 1,550 ℃ for 1 h. The composites with a density of 1.8 g·cm-3 exhibited a lower weight loss of 1.8 % after oxidation. B4C-SiC-ZrC-ZrB2 coating was found to provide the best protection by the precipitated B2O3, SiO2 and ZrO2 on the surface of the composites during the oxidation process, which were characterized by self-healing and antioxidation. The C/C composites with B4C-SiC-ZrC-ZrB2 coating performed well at high temperatures with the formation of complex oxides glass film that prevented oxygen from further spreading into the matrix.

Modeling of diffusion-reaction behavior of sulfate ion in concrete under sulfate environments

Xiao-Bao Zuo,Wei Sun,Hua Li,Yu-Kui Zhao 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.10 No.1

This paper estimates theoretically the diffusion-reaction behaviour of sulfate ion in concrete caused by environmental sulfate attack. Based on Fick’s second law and chemical reaction kinetics, a nonlinear and nonsteady diffusion-reaction equation of sulfate ion in concrete, in which the variable diffusion coefficient and the chemical reactions depleting sulfate ion concentration in concrete are considered, is proposed. The finite difference method is utilized to solve the diffusion-reaction equation of sulfate ion in concrete, and then it is used to simulate the diffusion-reaction process and the concentration distribution of sulfate ion in concrete. Afterwards, the experiments for measuring the sulfate ion concentration in concrete are carried out by using EDTA method to verify the proposal model, and results show that the proposed model is basically in agreement with the experimental results. Finally, Numerical example has been completed to investigate the diffusion-reaction behavior of sulfate ion in the concrete plate specimen immersed into sulfate solution.

中国大学的基础敎育

左小德(Zuo Xiao DE) 가천대학교 아시아문화연구소 2005 아시아문화연구 Vol.9 No.-

Dynamic changes of multi-notoginseng stem-leaf ginsenosides in reaction with ginsenosidase type-I

Xiao, Yongkun,Liu, Chunying,Im, Wan-Teak,Chen, Shuang,Zuo, Kangze,Yu, Hongshan,Song, Jianguo,Xu, Longquan,Yi, Tea-Hoo,Jin, Fengxie The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.2

Background: Notoginseng stem-leaf (NGL) ginsenosides have not been well used. To improve their utilization, the biotransformation of NGL ginsenosides was studied using ginsenosidase type-I from Aspergillus niger g.848. Methods: NGL ginsenosides were reacted with a crude enzyme in the RAT-5D bioreactor, and the dynamic changes of multi-ginsenosides of NGL were recognized by HPLC. The reaction products were separated using a silica gel column and identified by HPLC and NMR. Results: All the NGL ginsenosides are protopanaxadiol-type ginsenosides; the main ginsenoside contents are 27.1% Rb3, 15.7% C-Mx1, 13.8% Rc, 11.1% Fc, 7.10% Fa, 6.44% C-Mc, 5.08% Rb2, and 4.31% Rb1. In the reaction of NGL ginsenosides with crude enzyme, the main reaction of Rb3 and C-Mx1 occurred through Rb3${\rightarrow}$C-Mx1${\rightarrow}$C-Mx; when reacted for 1 h, Rb3 decreased from 27.1% to 9.82 %, C-Mx1 increased from 15.5% to 32.3%, C-Mx was produced to 6.46%, finally into C-Mx and a small amount of C-K. When reacted for 1.5 h, all the Rb1, Rd, and Gyp17 were completely reacted, and the reaction intermediate F2 was produced to 8.25%, finally into C-K. The main reaction of Rc (13.8%) occurred through Rc${\rightarrow}$C-Mc1${\rightarrow}$C-Mc${\rightarrow}$C-K. The enzyme barely hydrolyzed the terminal xyloside on 3-O- or 20-O-sugar-moiety of the substrate; therefore, 9.43 g C-Mx, 6.85 g C-K, 4.50 g R7, and 4.71 g Fc (hardly separating from the substrate) were obtained from 50 g NGL ginsenosides by the crude enzyme reaction. Conclusion: Four monomer ginsenosides were successfully produced and separated from NGL ginsenosides by the enzyme reaction.

Transcatheter Arterial Chemoembolization Combined with Interferon-α is Safe and Effective for Patients with Hepatocellular Carcinoma after Curative Resection

Zuo, Chaohui,Xia, Man,Liu, Jingshi,Qiu, Xiaoxin,Lei, Xiong,Xu, Ruocai,Liu, Hanchun,Li, Jianliang,Li, Yongguo,Li, Qinglong,Xiao, Hua,Hong, Yuan,Wang, Xiaohong,Zhu, Haizhen,Wu, Qunfeng,Burns, Michael,Li Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.1

Objectives: Intrahepatic recurrence is the major cause of death among patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after curative surgical resection. Several approaches have been reported to decrease the recurrence rate. The objective of our study was to compare the clinical effects of transcatheter arterial chemoembolization (TACE) combined with interferon-alpha (IFN-${\alpha}$) therapy on recurrence after hepatic resection in patients with HBV-related HCC with that of TACE chemotherapy alone. Methods: We retrospectively analyzed the data from 228 patients who were diagnosed with HBV-related HCC and underwent curative resection between January 2001 to December 2008. The patients were divided into TACE (n = 126) and TACE-IFN-${\alpha}$ (n = 102) groups for postoperative chemotherapy. The TACE regimen consisted of 5-fluorouracil (5-FU), cisplatin (DDP), and the emulsion mixed with mitomycin C (MMC) and lipiodol. The recurrence rates, disease-free survival (DFS), overall survival (OS), and risk of recurrence were evaluated. Results: The clinicopathological parameters and adverse effects were similar between the 2 groups (P > 0.05). The median OS for the TACE-IFN-${\alpha}$ group (36.3 months) was significantly longer than that of the TACE group (24.5 months, P < 0.05). The 3-and 5-year OS for the TACE-IFN-${\alpha}$ group were significantly longer than those of the TACE group (P < 0.05) and the recurrence rate was significantly lower (P < 0.05). The TACE and IFN-${\alpha}$ combination therapy, active hepatitis HBV infection, the number of tumor nodules, microvascular invasion, liver cirrhosis, and the BCLC stage were independent predictors of OS and DFS. Conclusions: The use of the TACE and IFN-${\alpha}$ combination chemotherapy after curative hepatic resection safely and effectively improves OS and decreases recurrence in patients with HBV-related HCC who are at high risk. Our findings can serve as a guide for the selection of postoperative adjuvant chemotherapy for patients with HBV-related HCC who are at high risk of recurrence.

A data fusion method for bridge displacement reconstruction based on LSTM networks

Zuo-Cai Wang,Da-You Duan,Xiao-Tong Sun,Yu Xin 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.4

Bridge displacement contains vital information for bridge condition and performance. Due to the limits of direct displacement measurement methods, the indirect displacement reconstruction methods based on the strain or acceleration data are also developed in engineering applications. There are still some deficiencies of the displacement reconstruction methods based on strain or acceleration in practice. This paper proposed a novel method based on long short-term memory (LSTM) networks to reconstruct the bridge dynamic displacements with the strain and acceleration data source. The LSTM networks with three hidden layers are utilized to map the relationships between the measured responses and the bridge displacement. To achieve the data fusion, the input strain and acceleration data need to be preprocessed by normalization and then the corresponding dynamic displacement responses can be reconstructed by the LSTM networks. In the numerical simulation, the errors of the displacement reconstruction are below 9% for different load cases, and the proposed method is robust when the input strain and acceleration data contains additive noise. The hyper-parameter effect is analyzed and the displacement reconstruction accuracies of different machine learning methods are compared. For experimental verification, the errors are below 6% for the simply supported beam and continuous beam cases. Both the numerical and experimental results indicate that the proposed data fusion method can accurately reconstruct the displacement.