Numerical modeling of a self-propagating high-temperature synthesis process of the TiC system

Guoqing Xiao,Quncheng Fan,Gang Zhang 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.5

A self-propagating high-temperature synthesis process of the TiC reactive system was numerically simulated to investigate the effect of porosity and diluent on the SHS reaction and its activating mechanism by an implicit difference method (IDM) and a Gauss-Seidel iteration procedure. The new features of the model include a consideration of the melting of each constituent of the reactants and product and the inclusion of considerations involving dilution and porosity. The results show that as the porosity is varied, there is not a significant effect on the combustion temperature and mode of the combustion front, and the nature of the combustion front is steady and uniform because of the lower activation energy in this system. As the reactant porosity values are decreased, the combustion velocity first increases because of an increase in the thermal conductivity. The combustion velocity, after reaching a maximum, decreases with a further decrease in the porosity because of the high value of the thermal conductivity of the reactants. To study the effect of the diluent, the product itself is considered as the diluent. The effect of adding the diluent to the initial reactants is to decrease the combustion temperature and the combustion velocity. A self-propagating high-temperature synthesis process of the TiC reactive system was numerically simulated to investigate the effect of porosity and diluent on the SHS reaction and its activating mechanism by an implicit difference method (IDM) and a Gauss-Seidel iteration procedure. The new features of the model include a consideration of the melting of each constituent of the reactants and product and the inclusion of considerations involving dilution and porosity. The results show that as the porosity is varied, there is not a significant effect on the combustion temperature and mode of the combustion front, and the nature of the combustion front is steady and uniform because of the lower activation energy in this system. As the reactant porosity values are decreased, the combustion velocity first increases because of an increase in the thermal conductivity. The combustion velocity, after reaching a maximum, decreases with a further decrease in the porosity because of the high value of the thermal conductivity of the reactants. To study the effect of the diluent, the product itself is considered as the diluent. The effect of adding the diluent to the initial reactants is to decrease the combustion temperature and the combustion velocity.

Kinetic model of asymmetric reduction of 3-oxo-3-phenylpropionic acid ethyl ester using Saccharomyces cerevisiae CGMCC No.2266

Guoqing Ying,Xiaoyan Chen,Zhimin Ou 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

The kinetic model of asymmetric reduction of 3-oxo-3-phenylpropionic acid ethyl ester using Saccharomyces cerevisiae CGMCC No.2266 with 10% glucose as co-substrate to realize the regeneration of NADPH was established. The effect factors on reduction, the type and the content of co-substrate and coenzyme, and the changes of the substrate and product content vs. time during the reaction process were investigated. The results indicate that 10%glucose can increase the reaction conversion from 23.0% to 98.4% and NADPH is reducer. The reduction process conforms with sequence mechanisms. The model parameters are as follows: vm=5.0×10−4 mol·L−1·h−1, k1=1.5×10−6 mol·L−1·h−1, k2=3.0×10−3 mol·L−1·h−1. The kinetic model is in good agreement with the experimental data.

Shape Description and Retrieval Using Included-Angular Ternary Pattern

Guoqing Xu,Ke Xiao,Chen Li 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.4

Shape description is an important and fundamental issue in content-based image retrieval (CBIR), and anumber of shape description methods have been reported in the literature. For shape description, both globalinformation and local contour variations play important roles. In this paper a new included-angular ternarypattern (IATP) based shape descriptor is proposed for shape image retrieval. For each point on the shapecontour, IATP is derived from its neighbor points, and IATP has good properties for shape description. IATPis intrinsically invariant to rotation, translation and scaling. To enhance the description capability, multiscaleIATP histogram is presented to describe both local and global information of shape. Then multiscale IATPhistogram is combined with included-angular histogram for efficient shape retrieval. In the matching stage,cosine distance is used to measure shape features’ similarity. Image retrieval experiments are conducted on thestandard MPEG-7 shape database and Swedish leaf database. And the shape image retrieval performance of theproposed method is compared with other shape descriptors using the standard evaluation method. Theexperimental results of shape retrieval indicate that the proposed method reaches higher precision at the samerecall value compared with other description method.

Postbuckling and nonlinear vibration of composite laminated trapezoidal plates

Guoqing Jiang,Fengming Li,Chuanzeng Zhang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.1

The thermal effects on the buckling, postbuckling and nonlinear vibration behaviors of composite laminated trapezoidal plates are studied. Aiming at the complex plate structure and to simulate the temperature distribution of the plate, a finite element method (FEM) is applied in this paper. In the temperature model, based on the thermal diffusion equation, the Galerkin’s method is employed to establish the temperature equation of the composite laminated trapezoidal plate. The geometrical nonlinearity of the plate is considered by using the von Karman large deformation theory, and combining the thermal model and aeroelastic model, Hamilton’s principle is employed to establish the thermoelastic equation of motion of the composite laminated trapezoidal plate. The thermal buckling and postbuckling of the composite laminated rectangular plate are analyzed to verify the validity and correctness of the present methodology by comparing with the results reported in the literature. Moreover, the effects of the temperature with the ply-angle on the thermal buckling and postbuckling of the composite laminated trapezoidal plates are studied, the thermal effects on the nonlinear vibration behaviors of the composite laminated trapezoidal plates are discussed, and the frequency-response curves are also presented for the different temperatures and ply angles.

Parametric Analyses for Effects of RPM and Diameter on Tiltrotor Aerodynamic Performances in Hovering and Cruise Mode

Guoqing Zhao,Qijun Zhao,Peng Li,Bo Wang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.3

Numerical simulations are performed to investigate the effects of different RPM (revolutions per minute) and different diameter on aerodynamic performances of tiltrotor in both hovering and cruise flight modes. The CLORNS code based on embedded grid and Reynold averaged Navier–Stokes equations is employed. According to the flight state of the tiltrotor, the corresponding comprehensive performance evaluation criteria and aerodynamic trimming strategy are established. On these bases, the numerical investigations on figure of merit and cruise efficiency of XV-15 tiltrotor with different RPM and diameter are conducted, and the results indicate that a large RPM is good for improving the hovering efficiency of tiltrotor, while in cruise mode, tiltrotor with small diameter (root-cut) and RPM helps to enhance the cruise efficiency.

Search for Sliding Surface of Slope Based on Dynamic Strength Reduction Method

( Guoqing Chen ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The failure of slope is a progressive process where the whole sliding surface gradually evolves from the local damaged region in the slope. Based on the yield weakening of geotechnical material, a new sliding surface search method that can simulate the progressive failure of slope was proposed. The strength parameter of the damaged region was reduced, and then mechanical equilibrium of slope was calculated. Through the continuous local damage reduction of the strength parameters of the damaged slope body, the potential sliding surface damaged gradually and evolved to breakthrough finally. The weak layer is closely associated with the stability of the heterogeneous rocky slope, but traditional calculation method is difficult to determine the failure mode. Present article mainly deals with the analysis of the stability of Dagangshan Mountain slope of Sichuan Province in China. The prevention flow of sliding disaster for heterogeneous rocky slope is presented. At first, Dynamic Strength Reduction Method (DSRM) was used to search the sliding surface, failure position and sliding direction. The case study of Dagangshan Mountain slope shows that DSRM is reasonable and correct when it is compared with the field observations. The study indicates that the sliding disaster of the slope is connected with f231 fault. The calculation results provide theoretical basis for the support and reinforcement program. In conclusion, DSRM provides a new calculation method for the stability and disaster forecast of similar heterogeneous rocky slopes.

TRANSITION AND INFLUENTIAL ELEMENTS OF TRAVEL DESTINATIONS OF JAPANESE PACKAGE TOURS IN CHINA

Guoqing Du 한국관광학회 2008 International Journal of Tourism Sciences Vol.8 No.1

This research assumes to clarify the distribution of visiting destinations from 1980 to 2004 by package tours in newspaper advertisement. We analyze the advertisement inserted in Asahi Shimbun (Tokyo version). Because the China visit package tour was published for the first time in 1980, we collected the advertisements in 1980, 1984, 1994 and 2004. According to the statistic data by JTB (Japan Tourism Bureau) and JNTO (Japan National Tourist Organization), March, August and November are always peak periods of China travel to Japanese tourists. Therefore, we select the advertisements published in January, June and October, which are two months before peak periods as our research objects. First of all, Hong Kong played the role of gateway or relay city in the age when the infrastructure in China was insufficiently equipped. Hong Kong didn't appear in the advertisement of China travel in 2004, and it can be thought as a result of the improvement of infrastructure in China. Secondly, tourism policy of Chinese government also accomplished important role in destinations change. Thirdly, the registration of World Heritage influenced destination selection of China travel. There were only 6 World Heritages in China in 1987, but the number of World Heritages increased to 30 in 2004 with a rapid and aimed speed. Fourthly, effect can be recognized in the tourism promotion activities of Chinese government. Fifityly, mass communication media in sending country Japan is also an important factor which can't be disregarded.

Ginseng saponin metabolite 20(S)-protopanaxadiol relieves pulmonary fibrosis by multiple-targets signaling pathways

Guoqing Ren,Weichao Lv,Yue Ding,Lei Wang,ZhengGuo Cui,Renshi Li,Jiangwei Tian,Chaofeng Zhang 고려인삼학회 2023 Journal of Ginseng Research Vol.47 No.4

Multi-granular Angle Description for Plant Leaf Classification and Retrieval Based on Quotient Space

Guoqing Xu,Ran Wu,Qi Wang 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.3

Plant leaf classification is a significant application of image processing techniques in modern agriculture. Inthis paper, a multi-granular angle description method is proposed for plant leaf classification and retrieval. Theproposed method can describe leaf information from coarse to fine using multi-granular angle features. In theproposed method, each leaf contour is partitioned first with equal arc length under different granularities. Andthen three kinds of angle features are derived under each granular partition of leaf contour: angle value, anglehistogram, and angular ternary pattern. These multi-granular angle features can capture both local and globeinformation of the leaf contour, and make a comprehensive description. In leaf matching stage, the simple cityblock metric is used to compute the dissimilarity of each pair of leaf under different granularities. And thematching scores at different granularities are fused based on quotient space theory to obtain the final leafsimilarity measurement. Plant leaf classification and retrieval experiments are conducted on two challengingleaf image databases: Swedish leaf database and Flavia leaf database. The experimental results and thecomparison with state-of-the-art methods indicate that proposed method has promising classification andretrieval performance.

Structural Relationship of Sports Service Quality, Perceived Value, Satisfaction, and Behavioral Loyalty among Customers of Commercial Sport Centers in Hunan Province, China

Guoqing Zhang,Kyungsik Kim 아시아스포츠융합과학회 2022 Asia Pacific Journal of Applied Sport Sciences Vol.3 No.3

PURPOSE The purpose of this study is to verify the fit of the behavioral loyalty (BL) model for customers in commercial sport centers in Hunan Province, China, and verify the relationship between sport service quality (SSQ), perceived value (PV), satisfaction (S) and BL. METHOD The research subject is the customers of the commercial sport centers in Hunan Province, China. A total of 995 questionnaires were collected and after deleting 28 incomplete or incorrect questionnaires, 967 questionnaires were retained for data analysis. We used CFA to validate the measurement model and SEM for hypothesis testing. RESULT First, SSQ influences customers’ PV and S but does not influence BL. That is to say, a high level of SSQ in a sport centers can improve customers’ PV and S. Second, PV influences BL and S, and S also affects BL. In other words, a high level of PV can improve S and BL. CONCLUSION The results of this research provide some effective suggestions for the sport industry of commercial sport centers, and provide a reference direction for the future sport industry research field.