The Dynamic Construction Numerical Analysis of Large-Span Section, Long and Deep-Depth Tunnel

2012 ◽  
Vol 256-259 ◽  
pp. 1253-1257
Author(s):  
Hui Ming Bao ◽  
Xin Xiong

Using finite element principle, the numerical simulation analysis model of the tunnels with large-span, long and deep-depth was established. The killed cells excavated in part as, while supporting part as a unit was reactivated among the simulation analysis. The changing characteristics of the initial stress field, the circular soil excavation and supporting, the core soil excavation, as well as the down step excavation and supporting was simulated analysis during dynamic construction of the tunnel. Those will be provided a scientific basis for the safe construction.

2017 ◽  
Vol 7 (2) ◽  
pp. 78-85 ◽  
Author(s):  
Heikki Mansikka ◽  
Don Harris ◽  
Kai Virtanen

Abstract. The aim of this study was to investigate the relationship between the flight-related core competencies for professional airline pilots and to structuralize them as components in a team performance framework. To achieve this, the core competency scores from a total of 2,560 OPC (Operator Proficiency Check) missions were analyzed. A principal component analysis (PCA) of pilots’ performance scores across the different competencies was conducted. Four principal components were extracted and a path analysis model was constructed on the basis of these factors. The path analysis utilizing the core competencies extracted adopted an input–process–output’ (IPO) model of team performance related directly to the activities on the flight deck. The results of the PCA and the path analysis strongly supported the proposed IPO model.


Geoderma ◽  
2021 ◽  
Vol 404 ◽  
pp. 115275
Author(s):  
Newton Z. Lupwayi ◽  
H. Henry Janzen ◽  
Eric Bremer ◽  
Elwin G. Smith ◽  
Derrick A. Kanashiro ◽  
...  

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110167
Author(s):  
Xing-Pan Wu ◽  
Tian-Shun Wang ◽  
Zi-Xin Yuan ◽  
Yan-Fang Yang ◽  
He-Zhen Wu

Objective To explore the anti-COVID-19 active components and mechanism of Compound Houttuynia mixture by using network pharmacology and molecular docking. Methods First, the main chemical components of Compound Houttuynia mixture were obtained by using the TCMSP database and referring to relevant chemical composition literature. The components were screened for OB ≥30% and DL ≥0.18 as the threshold values. Then Swiss Target Prediction database was used to predict the target of the active components and map the targets of COVID-19 obtained through GeneCards database to obtain the gene pool of the potential target of COVID-19 resistance of the active components of Compound Houttuynia mixture. Next, DAVID database was used for GO enrichment and KEGG pathway annotation of targets function. Cytoscape 3.8.0 software was used to construct a “components-targets-pathways” network. Then String database was used to construct a “protein-protein interaction” network. Finally, the core targets, SARS-COV-2 3 Cl, ACE2 and the core active components of Compound Houttuyna Mixture were imported into the Discovery Studio 2016 Client database for molecular docking verification. Results Eighty-two active compounds, including Xylostosidine, Arctiin, ZINC12153652 and ZINC338038, were screened from Compound Houttuyniae mixture. The key targets involved 128 targets, including MAPK1, MAPK3, MAPK8, MAPK14, TP53, TNF, and IL6. The HIF-1 signaling, VEGF signaling, TNF signaling and another 127 signaling pathways associated with COVID-19 were affected ( P < 0.05). From the results of molecular docking, the binding ability between the selected active components and the core targets was strong. Conclusion Through the combination of network pharmacology and molecular docking technology, this study revealed that the therapeutic effect of Compound Houttuynia mixture on COVID-19 was realized through multiple components, multiple targets and multiple pathways, which provided a certain scientific basis of the clinical application of Compound Houttuynia mixture.


2018 ◽  
Vol 878 ◽  
pp. 89-94 ◽  
Author(s):  
Er Lei Wang

Implementing monitoring over construction process of old bridge’s reinforcement serves as an important measure to ensure construction quality and safety and realize the goal of reinforcement. This paper, with a case study of the maintenance and reinforcement project of Zhicheng Yangtze River Bridge (steel truss highway-railway combined bridge), adopted MIDAS to establish finite element analysis model, and with stress and deformation as monitoring parameters, completed the construction monitoring work, numerical simulation analysis and site test for the reinforcement project.


1985 ◽  
Vol 33 (2) ◽  
pp. 159 ◽  
Author(s):  
GC Marks ◽  
IW Smith

The rate at which root collar infection, caused by Phytophthora cinnamomi Rands, developed in Eucalyptus sieberi L. Johnson was tested by growing 40, 6-month-old seedlings in cores of disease- suppressive (DSS) krasnozem-type soil that had either been treated or not treated with steam. The core soil was inoculated by repotting the seedlings in a jacket of steamed or unsteamed sand or krasnozem that had been mixed with a mycelium-chlamydospore suspension. Disease development was of the compound interest type (sens. Van der Plank) and was slower in unsteamed DSS core soils. Inoculum density (ID) increased more than 10 times at the end of all tests, and the time taken for collar infection to appear was shortened when the inoculum was mixed with unsteamed DSS. The fungus was isolated more frequently from the collar of seedlings growing in steam-treated than in unsteamed DSS. The results showed that the soil used was only mildly disease-suppressive and suggest that post- infection antagonism may be the cause of slower disease development rates in DSS. Introduction


2014 ◽  
Vol 940 ◽  
pp. 132-135 ◽  
Author(s):  
Yi Fan Zhao ◽  
Ling Sha ◽  
Yi Zhu

Established the dynamics simulation analysis model of crane hoisting mechanism based on the theory of dynamics in Adams software, and then through the three dimensional model of lifting mechanism dynamics entities, the constraints, load, drive can be added, the motion law can be defined to simulation analysis the change of the force of wire rope, the change of displacement, velocity and acceleration of lifting weight in the lifting process. On the basis of the simulation results, it can make a great improvement for the structure of crane and provide a meaningful theoretical reference for the hoisting machinery innovation design.


2014 ◽  
Vol 988 ◽  
pp. 315-318
Author(s):  
Bo Yan ◽  
Bin Hu ◽  
Ya Yu Huang ◽  
Tao Yong Zhou

Railway ballast dynamic stability operations is an important work in the line maintenance and repair operations, the selection of dynamic parameter is usually dependent on field trials and practical experience, for lack of theoretical basis. This paper creates discrete element analysis model of railway ballast using the discrete element method, the numerical simulations are carried out to study the lateral ballast resistance during dynamic stability process. We focus on the influence of vibration frequency during dynamic stability process; an optimal vibration frequency of the simulation analysis is obtained and compared with the recommended vibration frequency of a product of a China Railway Large Maintenance Machinery Company, it is found that the two vibration frequencies are basically consistent. This result verifies the correct validity of the discrete element analysis model of railway ballast during dynamic stability process.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Jinsheng Li ◽  
Yi Shi ◽  
Lu Xu

Interfirm cooperation can be seen as a significant and effective way for exploring radical innovation. In this article, a framework of interfirm cooperation, with a core manufacture and upstream counterparties in industry, and its evolving mechanism in the reverse-chain radical innovation are established from the perspective of the fundamental role played by knowledge collaboration. Then, an evolution model of interfirm cooperation is constructed on the theory of vibration mechanics, and its evolutionary dynamics is explored through numerical and simulation analysis mainly on the key factors of knowledge potential difference and knowledge rent-seeking behaviour within the firms. The findings show that, if there is no knowledge-based rent-seeking behaviour from the upstream firms, the probable innovative performance from the interfirm cooperation should vary for the knowledge potential difference between the cooperative firms, but can come to a certain equilibrium state. Meanwhile, if the knowledge rent-seeking behaviour does exist, knowledge potential difference would lead the innovative performance evolving ultimately in divergence. What’s more, the negative effect caused by the rent-seeking behaviour could be alleviated or weakened to some extent by the excitation mechanisms presented by the core firms in the cooperation system. Therefore, the drawn conclusions should be useful for the core manufactures’ implementing various strategies to maintain or enhance the cooperation for radical innovation in industry.


2014 ◽  
Vol 1025-1026 ◽  
pp. 955-958 ◽  
Author(s):  
Jun Jie Shi ◽  
Ya Nan Li ◽  
Li Qin

The theoretical study of galloping can effectively promote anti-galloping techniques. Cable element is utilized to imitate the bundled conductor, and beam elements are used to simulated the spacers, established galloping finite element analysis model which can consider sub-conductors wake interference. The finite element equation was solved by time integration method and the calculation program was compiled by MATLAB. Through numerical simulation analysis, compared the dancing in the case of considering the effect of the sub-conductor wake and ignoring the effect of the sub-conductor wake. The results showed that considering the effect of the wake on aerodynamic loads has a greater vertical vibration amplitude. This method can provide reference for the study of prevention technology on dancing.


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