Analysis of restrained steel beams subjected to heating and cooling Part I: Theory

Guo-Qiang Li,Shi-Xiong Guo 국제구조공학회 2008 Steel and Composite Structures, An International J Vol.8 No.1

Observations from experiments and real fire indicate that restrained steel beams have better fireresistant capability than isolated beams. Due to the effects of restraints, a steel beam in fire condition can undergo very large deflections and the run away damage may be avoided. In addition, axial forces will be induced with temperature increasing and play an important role on the behaviour of the restrained beam. The factors influencing the behavior of a restrained beam subjected to fire include the stiffness of axial and rotational restraints, the load type on the beam and the distribution of temperature in the cross-section of the beam, etc. In this paper, a simplified model is proposed to analyze the performance of restrained steel beams in fire condition. Based on an assumption of the deflection curve of the beam, the axial force, together with the strain and stress distributions in the beam, can be determined. By integrating the stress, the combined moment and force in the cross-section of the beam can be obtained. Then, through substituting the moment and axial force into the equilibrium equation, the behavior of the restrained beam in fire condition can be worked out. Furthermore, for the safety evaluation and repair after a fire, the behaviour of restrained beams during cooling should be understood. For a restrained beam experiencing very high temperatures, the strength of the steel will recover when temperature decreases, but the contraction force, which is produced by thermal contraction, will aggravate the tensile stresses in the beam. In this paper, the behaviour of the restrained beam in cooling phase is analyzed, and the effect of the contraction force is discussed.

Microarray Analysis of Long Non-coding RNA Expression Profile Associated with 5-Fluorouracil-Based Chemoradiation Resistance in Colorectal Cancer Cells

Xiong, Wei,Jiang, Yong-Xin,Ai, Yi-Qin,Liu, Shan,Wu, Xing-Rao,Cui, Jian-Guo,Qin, Ji-Yong,Liu, Yan,Xia, Yao-Xiong,Ju, Yun-He,He, Wen-Jie,Wang, Yong,Li, Yun-Fen,Hou, Yu,Wang, Li,Li, Wen-Hui Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Preoperative 5-fluorouracil (5-FU)-based chemoradiotherapy is a standard treatment for locally advanced colorectal cancer (CRC). However, CRC cells often develop chemoradiation resistance (CRR). Recent studies have shown that long non-coding RNA (lncRNA) plays critical roles in a myriad of biological processes and human diseases, as well as chemotherapy resistance. Since the roles of lncRNAs in 5-FU-based CRR in human CRC cells remain unknown, they were investigated in this study. Materials and Methods: A 5-FU-based concurrent CRR cell model was established using human CRC cell line HCT116. Microarray expression profiling of lncRNAs and mRNAs was undertaken in parental HCT116 and 5-FU-based CRR cell lines. Results: In total, 2,662 differentially expressed lncRNAs and 2,398 mRNAs were identified in 5-FU-based CRR HCT116 cells when compared with those in parental HCT116. Moreover, 6 lncRNAs and 6 mRNAs found to be differentially expressed were validated by quantitative real time PCR (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for the differentially expressed mRNAs indicated involvement of many, such as Jak-STAT, PI3K-Akt and NF-kappa B signaling pathways. To better understand the molecular basis of 5-FU-based CRR in CRC cells, correlated expression networks were constructed based on 8 intergenic lncRNAs and their nearby coding genes. Conclusions: Changes in lncRNA expression are involved in 5-FU-based CRR in CRC cells. These findings may provide novel insight for the prognosis and prediction of response to therapy in CRC patients.

Analysis of restrained heated steel beams during cooling phase

Guo-Qiang Li,Shi-Xiong Guo 국제구조공학회 2009 Steel and Composite Structures, An International J Vol.9 No.3

Observations from experiments and real fire indicate that restrained steel beams have better fireresistant capability than isolated beams. Due to the effects of restraints, a steel beam in fire condition can undergo very large deflections and the run away damage may be avoided. However disgusting damages may occur in the beam-to-column connections, which is considered to be mainly caused by the enormous axial tensile forces in steel beams resulted from temperature decreasing after fire dies out. Over the past ten years, the behaviour of restrained steel beams subjected to fire during heating has been experimentally and theoretically investigated in detail, and some simplified analytical approaches have been proposed. While the performance of restrained steel beams during cooling has not been so deeply studied. For the safety evaluation and repair of steel structures against fire, more detailed investigation on the behaviour of restrained steel beams subjected to fire during cooling is necessary. When the temperature decreases, the elastic modulus and yield strength of steel recover, and the contraction force in restrained steel beams will be produced. In this paper, an incremental method is proposed for analyzing the behaviour of restrained steel beams subjected to cooling. In each temperature decrement, the development of deformation and internal forces of a restrained beam is divided into four steps, in order to consider the effect of the recovery of the elastic modulus and strength of steel and the contraction force generated by temperature decrease in the beam respectively. At last, the proposed approach is validated by FE method.

Simultaneous distillation-extraction for manufacturing ultra-high-purity electronic-grade octamethylcyclotetrasiloxane (D4)

Wenhui Guo,Shuhu Guo,Xu Zhao,Zhenjun Yuan,Yu Zhao,Xin Chang,Hong Li,Xiong Zhao,Ye Wan,Dazhou Yan,Zhongyuan Ren,Xiaolei Fan,Xin Gao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Ultra-high-purity (UHP) electronic-grade octamethylcyclotetrasiloxane (D4) is the key precursor of lowdielectricconstant (low-k) SiCOH films to manufacture integrated circuits (IC), meeting the stringentrequirements of the rapidly developing semiconductor industry. Commonly, metallic impurities in D4were removed by multiple unit operations of adsorption, filtration, and distillation, which could reducethe concentration of a single metallic impurity below 1 ppb. However, D4 with higher purity is requiredby semiconductor production due to an increase in transistor density. Herein, a novel method based onthe integrated simultaneous distillation–extraction (SDE) was developed for manufacturing UHPelectronic-grade D4. The lab and pilot scale experiments showed that the purity of water and D4 has apositive correlation. Based on the experimental data, a double-column process, consisting of azeotropic/extractive distillation column and precision distillation column with UNIQUAC method, was establishedto access the feasibility of scaling up the SDE process. According to the simulation results, D4with the purity > 99.999 wt.% and total metallic impurities (TMI) content below 1 ppb could be obtainedusing ultra-pure water.

One-dimensional consolidation with asymmetrical exponential drainage boundary

Mei, Guo-Xiong,Lok, Thomas M.H.,Xia, Jun,Wu, Sheng Shen Techno-Press 2014 Geomechanics & engineering Vol.6 No.1

In this paper, asymmetric drainage boundaries modeled by exponential functions which can simulate intermediate drainage from pervious to impervious boundary is proposed for the one-dimensional consolidation problem, and the solution for the new boundary conditions was derived. The new boundary conditions satisfy the initial and the steady state conditions, and the solution for the new boundary conditions can be degraded to the conventional solution by Terzaghi. Convergence study on the infinite series solution showed that only one term in the series is needed to meet the precision requirement for larger degree of consolidation, and that more terms in the series for smaller degree of consolidation. Comparisons between the present solution with those by Terzaghi and Gray are also provided.

Study on Flaking Resistance of Hot-dip Galvanizing Coating

( Tai Xiong Guo ),( Ping Yuan ),( Yong Qing Jin ),( Chun Fu Liu ),( Wei Li ) 한국부식방식학회(구 한국부식학회) 2010 Corrosion Science and Technology Vol.9 No.4

Analysis of restrained steel beams subjected to heating and cooling Part II: Validation and parametric studies

Shi-Xiong Guo,Guo-Qiang Li 국제구조공학회 2008 Steel and Composite Structures, An International J Vol.8 No.1

This paper presents the results of a validation and parametric study for the theory presented in the companion paper. The parameters investigated include the stiffness of axial and rotational restraints, load ratio, depth-span ratio of the beam, the yield strength of steel, load type and the temperature distribution in the crosssection of the beam.

Metformin Inhibits Growth of Hepatocellular Carcinoma Cells by Inducing Apoptosis Via Mitochondrion-mediated Pathway

Xiong, Yu,Lu, Qing-Jun,Zhao, Jing,Wu, Guo-Yang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Recently, population-based studies of type 2 diabetes patients have provided evidence that metformin treatment is associated with a reduced cancer incidence and mortality, but its mode of action remains unclear. Here we report effects of metformin on hepatocellular carcinoma (HCC) Hep-G2 cells and details of molecular mechanisms of metformin activity. Our research indicates that metformin displays anticancer activity against HCC through inhibition of the mTOR translational pathway in an AMPK-independent manner, leading to G1 arrest in the cell-cycle and subsequent cell apoptosis through the mitochondrion-dependent pathway. Furthermore, we showed that metformin strongly attenuated colony formation and dramatically inhibited Hep-G2 tumor growth in vivo. In conclusion, our studies suggested that metformin might have potential as a cytotoxic drug in the prevention and treatment of HCC.

Isolation, Characterization, and Molecular Cloning of the cDNA Encoding a Novel Phytase from Aspergillus niger 113 and High Expression in Pichia pastoris

Xiong, Ai Sheng,Yao, Quan-Hong,Peng, Ri-He,Li, Xian,Fan, Hui-Qin,Guo, Mei-Jin,Zhang, Si-Liang Korean Society for Biochemistry and Molecular Biol 2004 Journal of biochemistry and molecular biology Vol.37 No.3

Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyI1) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyI1 and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyI1 and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyI1s, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pastoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of P. pastoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that ~4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and an optimum temperature of $60^{\circ}C$.

An Embedded Software Power Consumption Model based on Software Architecture and Support Vector Machine Regression

Xiong Wei,Xiaobin Liu,Bing Guo,Shen Yan,Wenli Zhang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.3

As embedded devices prevail in daily life, high energy consumption caused by embedded software caught academic attentions. Multifarious testing and predicting methods are developed accordingly. This paper proposes a model about energy consumption of embedded device based on analysis of embedded software structure and support vector machine regression. The nonlinear relationship between energy consumption and software structure is revealed. The research finds software structure is determined by features like number of components, complexity of component interface, component coupling, and path length. These features are qualified and modeled by using support vector machine regression and energy consumption is predicted based on this model. The experiments results confirm the proposed model.