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.

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.

Di-2-ethylhexyl phthalate induced oxidative damage involving FasL-associated apoptotic pathway in mouse spermatogenic GC-2spd cells

Xiao Tang,Kun Tong,Lishan Zhu,Guoqing Fu,Wei Chang,Ting Zhou,Zhibing Zhang,Ling Tong,Ling Zhang,Yuqin Shi,Ling Zhang,Yuqin Shi 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.4

Di-2-ethylhexyl phthalate (DEHP) which belongs to phthalatic-acid esters, is a kind of harmful, global environmental pollutants. It is a known endocrine disrupting chemical and male reproductive toxicant. However, the mechanism by which DEHP exposure result in male reproductive toxicity is still unclear. To elucidate the productive toxicity mechanism of DEHP, we attemptted to investigate oxidative stress, apoptotic effects, mRNA and protein expression of apoptosis-associated genes including FasL, caspase-3, and caspase-8 in GC-2spd (mouse spermatogenic cells). The results showed that, with the increase of DEHP concentration, cell apoptosis rate increased; the activities of relation index of oxidative stress such as malondialdehyde (MDA), superoxide dismutase (SOD) and glutatione peroxidase (GSH-PX) changed significantly; the mRNA and protein expression levels of FasL, caspase-3, -8, altered obviously. These results suggested that DEHP could induce apoptosis of GC-2spd cells through oxidative stress and FasL-dependent pathway.

Shape Description and Retrieval Using Included-Angular Ternary Pattern

Xu, Guoqing,Xiao, Ke,Li, Chen Korea Information Processing Society 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 a number of shape description methods have been reported in the literature. For shape description, both global information and local contour variations play important roles. In this paper a new included-angular ternary pattern (IATP) based shape descriptor is proposed for shape image retrieval. For each point on the shape contour, IATP is derived from its neighbor points, and IATP has good properties for shape description. IATP is intrinsically invariant to rotation, translation and scaling. To enhance the description capability, multiscale IATP histogram is presented to describe both local and global information of shape. Then multiscale IATP histogram 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 the standard MPEG-7 shape database and Swedish leaf database. And the shape image retrieval performance of the proposed method is compared with other shape descriptors using the standard evaluation method. The experimental results of shape retrieval indicate that the proposed method reaches higher precision at the same recall value compared with other description method.

Beam position measurement system at HIRFL-CSRm

Li Min,Xiao Guoqing,Mao Ruishi,Zhao Tiecheng,Yuan Youjin,Li Weilong,Zhou Kai,Kang Xincai,Li Peng,Li Juan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

Beam position measurement system can not only provide the beam position monitoring, but also be used for global orbit correction to reduce beam loss risk and maximize acceptance. The Beam Position Monitors (BPM) are installed along the synchrotron to acquire beam position with the front-end electronics and data acquisition system (DAQ). To realize high precision orbit measurement in the main heavy ion synchrotron and cooling storage ring of heavy-ion research facility in Lanzhou (HIRFL-CSRm), a series of alignment and calibration work has been implemented on the BPM and its DAQ system. This paper analyzed the tests performed in the laboratory as well as with beam based on the developed algorithms and hardware. Several filtering algorithms were designed and implemented on the acquired BPM raw data, then the beam position and resolution were calculated and analyzed. The results show that the position precision was significantly improved from more than 100 μm to about 50 μm by implementing the new designed filtering algorithm. According to the analyzation of the measurement results and upcoming physical requirements, further upgrade scheme for the BPM DAQ system of CSRm based on field programmable gate array (FPGA) technology was proposed and discussed.

Seismic Response Analysis Method for Lining Structure in Underground Cavern of Hydropower Station

Hao Zhou,Ming Xiao,Yang Yang,Guoqing Liu 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.3

Based on the analysis of joint shear test, the complex shear strength model of the interface between surrounding rock and lining structure, considering the interfacial bonding characteristics, shear failure mechanism and seismic dynamic deterioration effect, is established. And based on the dynamic contact force method, the dynamic calculation method of contact surface is presented, which is suitable for the dynamic analysis of the contact system between surrounding rock and lining of underground powerhouse. Then the dynamic numerical simulation method for the lining structure of underground powerhouse is formed by coupling the complex shear strength model with the dynamic calculation method of the contact surface. By using this method and based on the independently developed dynamic calculation platform of underground powerhouse, the evolution process and characteristics of seismic damage of lining structure of Yingxiuwan underground powerhouse are studied. At the same time, the numerical simulation analysis is carried out on the vibration damping measures of the lining structure. The results shows that the dynamic numerical simulation method for lining structure is effective and reasonable. In addition, the idea on the aseismic design of lining structure of underground powerhouse is put forward.

Evaluation of the Immunomodulatory and Anti-inflammatory Activities of Honey Bee Larva Powder

Kejuan Li,Shuang Sun,Masakatsu Kageyama,Long Xiao,Guoqing Xing,Ran Gao,Fengming You,Xi Fu,Zhenya Zhang 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.7

Honey bee larva powder (HLP) has traditionally been used as a daily supplement and tonic for health promotion with an uncertain scientific basis. In this study, B16-F10 tumor-bearing mice were established to evaluate the immunomodulatory activity of HLP. The proliferation and apoptosis assays were performed to evaluate the anti-inflammatory activity of honey bee larva extract (HLE) in RAW 264.7 macrophage. The in vivo experimental results demonstrated that the oral administration of freeze-dried HLP (4 and 6 g/kg) significantly enhanced the spleen index, the percentage of CD4+cells, and the ratio of CD4+ and CD8+ T lymphocytes (CD4+/CD8+) in the peripheral blood compared with those in the tumor control mice. The in vitro studies demonstrated the potent immunomodulatory activities of HLE through the induction of RAW 264.7 macrophage proliferation and the mitigation of doxorubicin (DOX)-induced toxicity. HLE also exhibits anti-inflammatory activity by decreasing the production of nitric oxide (NO) and the cytokine level of interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage. The present study provides important scientific evidence for the immunomodulatory and anti-inflammatory activities of HLP and HLE.

The Influence of a Second Metal on the Ni/SiC Catalyst for the Methanation of Syngas

( Lan Lan Song ),( Yue Yu ),( Xiao Xiao Wang ),( Guoq Jang Jin ),( Ying Yong Wang ),( Xiang Yun Guo ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.5

The catalytic performance of silicon carbide supported nickel catalysts modified with or without secondmetal (Co, Cu and Zn) for the methanation of CO has been investigated in a fixed-bed reactor using a feed consisting of25% CO and 75% H2 without any diluent gas. It has been found that the introduction of Co species can clearly improvethe catalytic activity of Ni/SiC catalyst, whereas the addition of Cu or Zn can result in a significant decrease in the catalyticactivity. The characterizations by means of XRD, TEM, XPS, CO-TPD and H2-TPR indicate that the addition ofCo could decrease the particle size of active metal, increase active sites on the surface of methanation catalyst, improvethe chemisorption of CO and enhance the reducibility of methanation catalysts. Additionally, the special interaction betweenCo species and Ni species is likely favorable for the dissociation of adsorbed CO on the surface of catalyst, and this mayalso contribute to the high activity of 5Co-Ni/SiC catalyst for CO methanation reaction. For 5Cu-Ni/SiC catalyst and 5Zn-Ni/SiC catalyst, Cu and Zn species could cover partial nickel particles and decrease the chemisorption amount of CO. These could be responsible for the low methanation activity. In addition, a 150h stability test under 2 MPa and 300 oCshowed that 5Co-Ni/SiC catalyst was very stable for CO methanation reaction.

Delayed Terminal Ileal Perforation in a Relapsed/Refractory B-Cell Lymphoma Patient with Rapid Remission Following Chimeric Antigen Receptor T-Cell Therapy

Yongxian Hu,Jiasheng Wang,Chengfei Pu,Kui Zhao,Qu Cui,Guoqing Wei,Wenjun Wu,Lei Xiao,Yang Xiao,Jinping Wang,Zhao Wu,He Huang 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Chimeric antigen receptor T-cell strategy targeting CD19 (CART19) has prominent anti-tumor effect for relapsed/refractory B-cell lymphomas. CART19-associated complications have been gradually recognized, however, late-onset complications have not been extensively studied. Herein, for the first time we report a diffuse large B-cell lymphoma patient with terminal ileum involvement obtained rapid remission and developed spontaneous terminal ileal perforation 38 days following CART19 infusion. The late-onset perforation reminds us that, for the safety of CART treatment, more cautions are warranted for the management of delayed GI complications.

Whole-genome sequence association study identifies cyclin dependent kinase 8 as a key gene for the number of mummified piglets

Wu Pingxian,Chen Dejuan,Wang Kai,Wang Shujie,Liu Yihui,Jiang Anan,Xiao Weihang,Jiang Yanzhi,Zhu Li,Xu Xu,Qiu Xiaotian,Li Xuewei,Tang Guoqing 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.1

Objective: Pigs, an ideal biomedical model for human diseases, suffer from about 50% early embryonic and fetal death, a major cause of fertility loss worldwide. However, identifying the causal variant remains a huge challenge. This study aimed to detect single nucleotide polymorphisms (SNPs) and candidate genes for the number of mummified (NM) piglets using the imputed whole-genome sequence (WGS) and validate the potential candidate genes. Methods: The imputed WGS was introduced from genotyping-by-sequencing (GBS) using a multi-breed reference population. We performed genome-wide association studies (GWAS) for NM piglets at birth from a Landrace pig populatiGWAS peak located on SSC11: 0.10 to 7.11 Mbp (Top SNP, SSC11:1,889,658 bp; p = 9.98E-13) was identified in cyclin dependent kinase on. A total of 300 Landrace pigs were genotyped by GBS. The whole-genome variants were imputed, and 4,252,858 SNPs were obtained. Various molecular experiments were conducted to determine how the genes affected NM in pigs. Results: A strong GWAS peak located on SSC11: 0.10 to 7.11 Mbp (Top SNP, SSC11:1,889,658 bp; p = 9.98E-13) was identified in cyclin dependent kinase 8 (CDK8) gene, which plays a crucial role in embryonic retardation and lethality. Based on the molecular experiments, we found that Y-box binding protein 1 (YBX1) was a crucial transcription factor for CDK8, which mediated the effect of CDK8 in the proliferation of porcine ovarian granulosa cells via transforming growth factor beta/small mother against decapentaplegic signaling pathway, and, as a consequence, affected embryo quality, indicating that this pathway may be contributing to mummified fetal in pigs. Conclusion: A powerful imputation-based association study was performed to identify genes associated with NM in pigs. CDK8 was suggested as a functional gene for the proliferation of porcine ovarian granulosa cells, but further studies are required to determine causative mutations and the effect of loci on NM in pigs.