The Mechanism of Rockbolt in the Jointed Rock Under Uniaxial Tension

Shen Zhou,Xiaoyu Ji,Li-Ping Li,Hong-liang Liu,Chun Zhu,Hongyun Fan,Qi Zhang,Caihua Shi,Xutong Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.11

In this research, the rockbolt mechanism of a jointed rock mass under uniaxial tension was systematically revealed with a laboratory test and a numerical simulation. It was found that the rockbolt rock mass experienced five stages under uniaxial tension, the densification stage, elastic stage, plastic deformation stage, progressive debonding stage, and complete debonding stage. The stress-strain curve and ultimate tensile strength of a rockbolt rock mass were analyzed by taking the rockbolt spacing and rockbolt angle as variables. It was found that the improvement effect of the reduction of the rockbolt spacing on the ultimate tensile strength was limited. When the rockbolt spacing was reduced to a certain limit, the stress concentration area between adjacent rockbolts was connected and destroyed, resulting in the increase of the rockbolt rock strength becoming smaller, and even having a downward trend. The increase of the rockbolt angle led to the change of the stress mode and failure mode of the whole structure, and the ultimate tensile strength first increased and then decreased. The optimal rockbolt angle was between 60° and 70°. It is worth noting that there was an obvious mechanical occlusion between the thread on the rockbolt surface and the rock mass, resulting in the multi-stage step-down characteristic of the stress-strain curve in the complete debonding stage. The results of this study can provide a reference for the design and construction of similar projects.

Stress-Release Law and Deformation Characteristics of Large-Span Tunnel Excavated with Semi Central Diaphragm Method

Shen Zhou,Liping Li,Zhimin An,Hongliang Liu,Guangyu Yang,Pengfei Zhou 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.6

The proportion of large-span tunnels in newly-built highway tunnels is getting higher and higher, revealing the stress release law and deformation characteristics of the tunnel at different excavation steps has important guiding significance for the rational design of the supporting structure parameters. In this paper, a typical section of the Laohushan Tunnel was selected to analyze the stress and deformation response of the large-span tunnel excavated with the semi central diaphragm method (SCDM), with the numerical simulation and field monitoring method. The study found that during the excavation of the large-span tunnel with the SCDM, the stress and deformation response characteristics are different from those ordinary tunnels. Influenced by the settlement of the vault, there was a significant outward expansion tendency, and a high degree of stress concentration in the sidewall. In particular, the supporting structure at the sidewall has a deformation characteristic of expanding outward and then converging inward. In this paper, the in-depth analysis of the stress release law and deformation characteristics of the excavation process of large-span tunnels can provide reference for the excavation and support parameter design of similar projects.

Assessment on the Progressive Collapse Resistance of a Long-Span Curved Spatial Grid Structure with Main Trusses

Guangpan Zhou,Qianen Song,Aiqun Li,Shungao Shen,Qing Zhou,Bin Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

The progressive collapse resistance of the terminal building of Zhongchuan Airport in Lanzhou, China was studied, which is a long-span curved spatial grid structure with main trusses. Firstly, the finite element model was built using MSC.Marc software adopting the fiber model based on material. Secondly, an improved method of zoned concept judgment and sensitivity analysis was proposed to determine the key components. Thirdly, the initial failure components were removed individually based on the alternate load path method (AP method). The responses of remaining structure were calculated using nonlinear dynamic analysis method. Lastly, the influences brought by the cross-sectional sizes of grid members were investigated through conducting parametric analysis. According to the results, the proposed selection method can avoid omitting the key components. The structural responses are significant when removing the concrete filled steel tubular (CFST) column SC14 directly supporting the front middle part of the roof, with a maximum vertical displacement of 10 m at cantilever end, which should be focused on for this kind of large-span spatial structure. In addition, the tensile strength and cross-sectional area of the upper and lower chords should be increased by 20% to enhance the progressive collapse resistance of the structure, and the changes of axial compression ratios of the columns supporting the roof have little effects.

An Iterative Space Alternative Tiling Parallel Algorithm for 3D Finite Difference Stencil Computations

Jing Shen,Jilin Zhang,Jian Wan,Li Zhou,Ming Jiang 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.6

Stencils are finite-difference algorithms for solving large-scale and high-dimension partial differential equations. Due to the data dependences among the iterative statements in Stencils, traditional Stencil computations are be executed serially, rather than in parallel. It’s challenging to design an effective and scalable Stencil parallelized method. To address the issue of 3D data space computing, we present a serial execution model based on multi-layers symmetric Stencil method and time skewing techniques. Within this model, the iteration space is divided to multiple tiles based on time skewing, where the executive process is ordered by the sequence of tiles, and the nodes in each individual tile can be swept repeatedly to improve the data locality. In addition, we propose a novel 3D iterative space alternate tiling Stencil parallel method, which subdivides the iteration space along high dimension, and changes the execution sequence of tiles to reduce the data dependency and communication cost, where the partial order of tiles is still guaranteed. Experimental results demonstrate our proposed alternative tiling parallel method achieves better parallel efficiency and scalability compared with the domain-decomposition methods.

THE RELATIONSHIP BETWEEN THE ASSETS LIQUIDITY AND THE TRADING LIQUIDITY: AN EMPIRICAL INVESTIGATION

Xu Shen Zhou,Yong H Kim People&Global Business Association 2007 Global Business and Finance Review Vol.12 No.1

In this paper. we examine the relationship between the liquidity of a firm's assets and trading liquidity of its stocks. The results show that the higher the firm's assets liquidity, the lower its stock's trading liquidity. This relationship does not hold for banks. Bank stocks have lower trading liquidity than other firms' stocks do. The results are consistent with market microstructure theory and support the paradox of assets liquidity suggested by recent theory. The results may suggest that firms with severe assets substitution and entrenching investment problems may have a different trading behavior of their stocks than those of others.

Effects of alanyl-glutamine supplementation on the small intestinal mucosa barrier in weaned piglets

Xing, Shen,Zhang, Bolin,Lin, Meng,Zhou, Ping,Li, Jiaolong,Zhang, Lin,Gao, Feng,Zhou, Guanghong Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

Objective: The study was to investigate the effects of alanyl-glutamine (Ala-Gln) and glutamine (Gln) supplementation on the intestinal mucosa barrier in piglets. Methods: A total of 180 barrows with initial weight $10.01{\pm}0.03kg$ were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala)], Ala-Gln diet (0.5% Ala-Gln), Gln diet (0.34% Gln and 0.21% Ala), respectively. Results: The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05), Gln supplementation increased the villi height of jejunum (p<0.05), Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05), raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1) and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05), Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05), Gln increased the number of goblet cells in duodenal epithelium (p<0.05) and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05). Conclusion: These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

쇄쇄중유무한연파 : 『紅樓夢』的欣賞

周先愼 연세대학교 인문과학연구소 1999 人文科學 Vol.81 No.-

以上業們從映射, 細節, 語言三個方面擧例談了『紅樓夢』的欣賞, 歸結到一點就是要把握『紅樓夢』的總體藝術特色--“瑣碎中有無限烟波”, 從小中見大, 細中見探, 平凡中見不平凡. 當我們從『紅樓夢』 那些看似瑣碎平凡的日常生活措寫中, 發現了其中包含的豊富的社會內容和深刻的思想意蘊時. 就會眞正領略刻『紅樓夢』獨特的藝術美, 得到同讀別的中國古典小說不同的審美愉悅.

중국고전시가적의경여독자적접수

조선신 중국어문학회 1999 中國語文學誌 Vol.6 No.-

Transition over 35 Years in the Incidence Rates of Primary Central Nervous System Tumors in Shanghai, China and Histological Subtyping Based on a Single Center Experience Spanning 60 Years

Shen, Fang,Wu, Chun-Xiao,Yao, Yu,Peng, Peng,Qin, Zhi-Yong,Wang, Yin,Zheng, Ying,Zhou, Liang-Fu Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Only few epidemiological data on primary central nervous system (CNS) tumors in Shanghai have been reported. Methods: All cases of primary CNS tumors that were registered at Center for Disease Control and Prevention (CDC) were collected (1973-2007: urban Shanghai; 2003-2007: whole Shanghai city). Trends were analyzed using joinpoint analysis and rates were stratified by age, gender and region. Histological data were collected from both CDC and Huashan Hospital. Results: From 1973 to 2007, the five-year average incidence rate in urban Shanghai increased in both genders, especially in the elderly population. Joinpoint analysis showed the age-adjusted incidence rate for males increased first but then plateaued, whilst rates for females continued increasing over the 35 years. For the five-year status quo (2003-2007), rural had a higher age-adjusted incidence rate than urban populations, and females higher than males, especially those with advanced age. According to CDC (2003-2007) and Huashan Hospital (1951-2011), the two most common histological subtypes were neuroepithelial tumors (with male predominance) and meningiomas (with female predominance). Conclusions: In Shanghai, a steadily increased incidence rate of primary CNS tumors was observed in general, and in the elderly and female population in particular.

Disease burden of prostate cancer from 2014 to 2019 in the United States: estimation from the Global Burden of Disease Study 2019 and Medical Expenditure Panel Survey

Shen Lin,Dong Lin,Yiyuan Li,Lixian Zhong,Wei Zhou,Yajing Wu,Chen Xie,Shaohong Luo,Xiaoting Huang,Xiongwei Xu,Xiuhua Weng 한국역학회 2023 Epidemiology and Health Vol.45 No.-

OBJECTIVES: The aim of this study was to evaluate the disease burden of prostate cancer (PC) and assess key influencing factors associated with the disease expenditures of PC in the United States. METHODS: The total deaths, incidence, prevalence, and disability-adjusted life-years of PC were obtained from the Global Burden of Disease Study 2019. The Medical Expenditure Panel Survey was used to estimate healthcare expenditures and productivity loss and to investigate patterns of payment and use of healthcare resources in the United States. A multivariable logistic regression model was conducted to identify key factors influencing expenditures. RESULTS: For patients aged 50 and older, the burden for all age groups showed a modest increase over the 6-year period. Annual medical expenditures were estimated to range from US$24.8 billion to US$39.2 billion from 2014 to 2019. The annual loss in productivity for patients was approximately US$1,200. The top 3 major components of medical costs were hospital inpatient stays, prescription medicines, and office-based visits. Medicare was the largest source of payments for survivors. In terms of drug consumption, genitourinary tract agents (57.0%) and antineoplastics (18.6%) were the main therapeutic drugs. High medical expenditures were positively associated with age (p=0.005), having private health insurance (p=0.016), more comorbidities, not currently smoking (p=0.001), and patient self-perception of fair/poor health status (p<0.001). CONCLUSIONS: From 2014 to 2019, the national real-world data of PC revealed that the disease burden in the United States continued to increase, which was partly related to patient characteristics.