Experimental and Numerical Investigation of the Effect of Blast-induced Vibration from Adjacent Tunnel on Existing Tunnel

Hua-bing Zhao,Yuan Long,Xing-hua Li,Liang Lu 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.1

Since the new tunnel is close to existing tunnel, the vibration wave induced by blasting endangers the safety and stabilization of the surrounding rock and the lining of existing tunnel. In the tunnel blasting vibration monitoring and safety prediction, Peak Particle Velocity (PPV) and vibration frequency are used widely as safety standards. To investigate the effect of blast-induced vibration from adjacent tunnel on existing tunnel, field monitoring experiments and a numerical method that is Finite Element Method (FEM) were adopted to study the blasting vibration velocity and vibration frequency of existing tunnel. Combined blasting vibration velocity with vibration frequency, the paper studied axial and radial blasting vibration velocity distributions and the corresponding Power Spectral Density (PSD) distributions of the existing tunnel under the effect of blast-induced vibration from adjacent subway tunnel. And the parameters of constitutive model and blasting loads were also discussed. It is shown that field monitoring experiment and numerical simulation can optimize blasting excavation program and provide a reference for other similar engineering projects.

Preparation of 2,3,4,5-Tetrafluorobenzoic Acid

Li, Hua,Wang, Hongkai,Zhao, Ruiju,Liu, Juan,Zhao, Zhengui,Hu, Guoqin,Liang, Zhengyong Korean Chemical Society 2010 대한화학회지 Vol.54 No.6

Fluoroquinolone 항생제의 중요한 중간체인 2,3,4,5-tetrafluorobenzoic acid를 tetrachloride phthalic anhydride에서 출발 하여 imidation, fluorination, hydrolysis과 decarboxylation단계를 거쳐서 합성하였다. Imdation 단계에서는 상전이 촉매를 이용하여 98.2%의 수율로 합성하였으며, fluorination 단계에서는 81.3%, 가수분해 단계에서는 88.6%, 마지막으로 decarboxylation단계에서는 81.6%의 수율로 합성하였다. 2,3,4,5-Tetrafluorobenzoic acid, an important intermediates of fluoroquinolone antibiotics, was synthesized from tetrachloride phthalic anhydride through imidation, fluorination, hydrolysis and decarboxylation. The effects of phase transfer catalyst on imidation and fluorination reaction and the effects of surfactants on the hydrolysis reaction were studied, respectively. Experimental results showed that the imidation reaction time was greatly reduced in the presence of a phase transfer catalyst, hexadecyltrimethyl, resulting in imidation yield as high as 98.2%. The fluorination yield reached 81.3% when tetrabutylammonium bromide was chosen as a phase transfer catalyst. The hydrolysis reaction time was also decreased by adding hexadecyltrimethyl while increasing the yield to 88.6%. In the post-processing, the sublimation method was used to purify the product, and ideal effect was obtained. In the decarboxylation reaction, tetrafluoride phthalic acid was obtained by decarboxylation in the solvent of tri-n-butyl amine and decarboxylation yield reached 81.6%. Compared with the literature method, the overall reaction time of the improved method decreased from 53 h to 20.5 h and the total yield increased from 47.3% to 57.4%.

Exact solution for free vibration of curved beams with variable curvature and torsion

Li-li Zhu,Ying-hua Zhao,Guang-xin Wang 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.3

For the purpose of investigating the free vibration response of the spatial curved beams, the governing equations are derived in matrix formats, considering the variable curvature and torsion. The theory includes all the effects of rotary inertia, shear and axial deformations. Frobenius’ scheme and the dynamic stiffness method are then applied to solve these equations. A computer program is coded in Mathematica according to the proposed method. As a special case, the dynamic stiffness and further the natural frequencies of a cylindrical helical spring under fixed-fixed boundary condition are carried out. Comparison of the present results with the FEM results using body elements in I-DEAS shows good accuracy in computation and validity of the model. Further, the present model is used for reciprocal spiral rods with different boundary conditions, and the comparison with FEM results shows that only a limited number of terms in the resultant provide a relatively accurate solution.

Bioremediation of Coastal Saline-Alkali Marshy Soil by the Irrigation with Pulp & Paper Wastewater

LI Jia-liang,LU Zhao-hua,TIAN Jia-yi,WANG Lin,LI Peng-hui,XIAO Zhong-feng 대전대학교 환경문제연구소 2009 환경문제연구소 논문집 Vol.13 No.-

Based on the importance of coastal saline-alkali soil remediation in Yellow River Delta, China, the Cl-、Na+ transferring tendency in soil and the saline-alkali soil eco-remediation effects were researched by measuring soil Cl-、Na+ 、soluble salt、soil respire rate and dry biomass weight of reed, etc. periodically. The results shows: the concentration of irrigated soil Cl-、Na+ and soluble salt were decreased 57.7-70%、45.7-47.1% and 53.2-59.7%, respectively, and soil salt decreasing level were little influenced by the hydraulic load, inundation depth varies in some degree, but it was influenced by dry-wet alternative irrigating mode The concentration of soil total nitrogen、organic mass、microbial respire rate, and the reed biomass above ground were increased averagely to 2.17、1.20、1.46 and 1.34 multiple respectively afterirrigation with wastewater, which have complex remediation effects on the coastal saline-alkali wetland, but there are some differences among the different irrigating crafts.

Pseudonocardia rhizophila sp. nov., a novel actinomycete isolated from a rhizosphere soil

Li, Jie,Zhao, Guo-Zhen,Huang, Hai-Yu,Zhu, Wen-Yong,Lee, Jae-Chan,Kim, Chang-Jin,Xu, Li-Hua,Zhang, Li-Xin,Li, Wen-Jun Springer-Verlag 2010 Antonie van Leeuwenhoek Vol.98 No.1

Pre-treatment Metabolic Tumor Volume and Total Lesion Glycolysis are Useful Prognostic Factors for Esophageal Squamous Cell Cancer Patients

Li, Yi-Min,Lin, Qin,Zhao, Long,Wang, Li-Chen,Sun, Long,Dai, Ming-Ming,Luo, Zuo-Ming,Zheng, Hua,Wu, Hua Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.

Modulation of Drug Resistance in Ovarian Cancer Cells by Inhibition of Protein Kinase C-alpha (PKC-α) with Small Interference RNA (siRNA) Agents

Zhao, Li-Jun,Xu, Heng,Qu, Jun-Wei,Zhao, Wan-Zhou,Zhao, Yi-Bing,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: To determine whether silence of $PKC-{\alpha}$ expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. Methods: We measured gene and protein expression of MDR1 and $PKC-{\alpha}$ in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking $PKC-{\alpha}$ by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. Results: The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and $PKC-{\alpha}$ than their counterpart sensitive cell line, OV1228. SiRNA depressed $PKC-{\alpha}$ gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. Conclusion: These results indicated that decreasing $PKC-{\alpha}$ expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of $PKC-{\alpha}$ and MDR1. A new siRNA-based therapeutic strategy targeting $PKC-{\alpha}$ gene could be designed to overcome the chemoresistance of ovarian cancer.

Test and Analysis on the Interference to the CBTC Systems by Wi-Fi Signals

Li Ming,Wang Hua-shen,Zhao Hong-li,Zhu Li 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.3

Communication-Based Train Control (CBTC) system is an automated train control system using bidirectional train-ground communications to ensure the safe operation of rail vehicles. The interference from Wi-Fi signals to the CBTC signals has significant impacts on the train control performance. Most of previous works use data from simulation platform. This paper proposes a method to test the Wi-Fi interference to the Communication Based Train Control(CBTC) systems. The test is made mainly based on real subway, and supplemented by laboratory simulation platform. The collected data is to be compared and analyzed. The test result shows that the signal transmission mode of waveguide is the most reliable, followed by the leaky cable. The transmission mode of free wave has the worst anti-interference capability to Wi-Fi signals. This is because that both the waveguide and leaky cable transmission have a better encapsulation compared with the free space transmission. Also applying for specific bands can effectively reduce the interference transferred from Wi-Fi signals to the CBTC.

Microstructure and viscoelastic behavior of waterborne polyurethane/cellulose nanofiber nanocomposite

Hui Zhao,Kui-Can Li,Wei Wu,Qing Li,Yan Jiang,Bing-Xu Cheng,Chong-Xing Huang,Hua-Nan Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

Cellulose nanofiber (CNF) has been widely used to reinforce the mechanical properties of waterbornepolyurethane (WPU). There are, however, few works that focus on structure, rheological behavior, andcreep resistance of WPU/CNF composites. To fill this research gap, in this work, the m-CNF was obtainedby c-aminopropyltriethoxysilane modification to improve the interfacial strength of CNF and WPU, andthen it was introduced into the polyurethane matrix. Structure characterization of WPU/m-CNFnanocomposites is performed using Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction(XRD), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The obtainedresults show that with the increase of m-CNF, the hydrogen bonding index (HBI) increased, which meanta significant improvement in the mechanical properties. The tensile strength improved by 480%. Moreover, with the increase of m-CNF content, the viscosity, storage modulus, and loss modulus of thedispersions increased and showed more obvious shear-thinning behavior. In addition, m-CNF improvedthe thermal stability and creep resistance of WPU. The creep strain of WPU decreased from 3% to 0.2%. This work offers a simply feasible way to prepare environmental friendly green nanocomposites.

Glycosylation and Production Characteristics of Epothilones in Alkali-Tolerant Sorangium cellulosum Strain So0157-2

Lin Zhao,Peng-fei Li,Chun-hua Lu,Shu-guang Li,Yue-mao Shen,Yue-zhong Li 한국미생물학회 2010 The journal of microbiology Vol.48 No.4

3-O-α-D-ribofuranosyl epothilone A (epothiloneoside A) is a major component of glycosylated epothilones in Sorangium cellulosum strain So0157-2. The production and glycosylation ratios of epothiloneoside A in both solid and liquid culture conditions with various pH values and carbon sources were studied. The results showed that glycosylation occurs whenever epothilones are produced, regardless of changes in pH values,production time curves, and different carbon sources. We suggest that glycosylation is a stable process,paralleling the biosynthesis of epothilones in the So0157-2 strain.