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Method for prevention and control of spontaneous combustion of coal seam and its application in mining field

International Journal of Mining Science and Technology 2017年第5期27卷 839-846页

作者： Wei Lu Ying-Jiazi Cao Jerry C.Tien College of Mining and Safety Engineering Shandong University of Science & Technology Department of Civil Engineering Monash University

Spontaneous combustion of coal seam has been and continues to be a big problem in coal mines. It could pose great threat to the safety of the whole mine and all miners, especially when it occurs in or nearby coal mines. Besides, environment of area surrounded mines during combustion can be threatened where large amount of toxic gases including CO_2, CO, SO_2 and H_2S can be leased by fire in mine. Hence, it is important and significant for scholars to study the controlling and preventing of the coal seam fire. In this paper, the complicated reasons for the occurrence and development of spontaneous combustion in coal seam are analysed and different models under various air leakage situations are built as well. Based on the model and approximately calculation, the difficulty of fire extinguishment in coal seam is pointed out as the difficulty and poor effect to remove the large amount of heat released. Detailed measurements about backfilling and case analyses are also provided on the basis of the recent ten years' practice of controlling spontaneous combustion in coal seams in China. A technical fire prevention and control method has been concluded as five steps including detection, prevention, sealing, injection and pressure adjustment. However, various backfill materials require different application and environmental factors, so in this paper, analyses and discussion about the effect and engineering application of prevention of spontaneous combustion are provided according to different backfilling technologies and methods. Once the aforementioned fire prevention can be widely applied and regulated in mines, green mining will be achievable concerning mine fire prevention and control.

关键词： Spontaneous combustion of coal Prevention and control Pressure adjustment Mining field

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Biomechanical effects of pedicle screw adjustments on the thoracolumbar burst fractures

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Chinese Medical Journal 2013年第2期126卷 300-305页

作者： SHANG Jian LING Xiao-dong LIU Yuan-chao LIU Wei XIAO Xi-gang YUAN Shao-hui The First Affiliated Hospital of Harbin Medical University Haerbin Heilongjiang 150001 China The Third Affiliated Hospital of Harbin Medical University Haerbin Heilongjiang 150081 China Harbin Institute of Technology Haerbin Heilongoiang 150081China

Background Posterior pedicle screw device is widely used in treatment of thoracolumbar burst fractures. As the clinical operation is not based upon quantitative data of adjustments, the results are not optimal. At present, no study has assessed the associations between the device adjustments and the restoration of stiffness. We investigated the biomechanical effects that adjustments of a pedicle screw device had on the burst fracture, and explored an optimal adjustment. Methods Burst fractures were produced at L1 vertebra in 24 fresh calf spines （T12-L3）. The specimens were divided into four groups at random. Pedicle screw devices were attached to T13 and L2. Four device adjustments, consisting of distraction and extension, were applied. adjustment 1 was pure 6~ extension, adjustment 2 was pure 5 mm distraction, adjustment 3 was 6~ extension followed by 5 mm distraction, and adjustment 4 was 5 mm distraction followed by 6~ extension. The effect of each adjustment on the stiffness restoration, anatomical reduction, and neural decompression for the burst fractures was analyzed and evaluated. Results Pure extension （Group 1） produced the closest segment height and the least restoration of the canal to the intact. Pure distraction （Group 2） restored stiffness most, but with only 60% stiffness of the intact value, and lost the segmental angle most to the intact. The combination of extension-distraction （Group 3 and Group 4） produced the maximum reduction of the anatomy and restoration of the canal in the burst fracture, and the least stiffness restoration. The sequence of extension and distraction did not affect stiffness restoration, anatomical reduction, and neural decompression. Conclusions The device adjustments affected stiffness restoration, anatomical reduction, and neural decompression. The combined extension-distraction adjustment may be the most suitable considering the anatomical reduction and neural decompression, but the stiffness decreased the most; it should be considered to reconstruct L1 vertebra.

关键词： burst fracture pedicle screw, stiffness adjustment

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When parasitoids deal with the spatial distribution of their hosts: consequences for both partners

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Insect Science 2019年第5期26卷 923-931页

作者： Philippe Louapre Cecile Le Lann Thierry Hance Earth and Life Institue Universite Catholique de LouvainLouvain-la-NeuveBelgium CNRS Biogeosciences UMR 6282Universite Bourgogne Franche-ComteDijonFrance UMR CNRS 6553 Ecobio University of Rennes 1Rennes CedexFrance

Insect parasitoids developing inside hosts face a true challenge: hosts are scattered in the field and their localization and selection require the use of complex and sometime confusing information. It was assumed for a long time that small-brained organisms like parasitoids have evolved simple and efficient behavioral mechanisms, leading them to be adapted to a given ecological situation, for example, the spatial distribution o f hosts in the habitat. However, hosts are not static and their distribution may also vary through generations and within the life of parasitoid individuals. We investigated if and how parasitoids deal with such a spatial com plexity in a m esocosm experiment. We used the Aphidius rhopalosiphi/Sitobion avenae parasitoid/host system to investigate if parasitoid females experiencing different host aggregation levels exhibit different foraging behaviors independently of the number of hosts in the environment. We showed that A. rhopalosiphi females exploited hosts more intensively both within and among patches at higher host aggregation levels. We discussed the adaptiveness of such behaviors in the light of evolution and biological control.

关键词： Aphidius rhopalosiphi foraging behavior parasitoid sequential adjustment Sitobion avenae spatial distribution

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Algorithm of neural-network about solving nonlinear least squares adjustment by parameters

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中国有色金属学会会刊：英文版 2005年第S1期15卷 145-147页

作者： QING Xi-hong~1, NING Wei~(1,2), TAO Hua-xue~1 (1. Shandong University of Science and Technology, Tai’an 271019, China 2. Shandong Agriculture University, Tai’an 271018, China)

Study on solving nonlinear least squares adjustment by parameters is one of the most important and new subjects in modern surveying and mapping field . Many researchers have done a lot of work and gained some solving methods. These methods mainly include iterative algorithms and direct algorithms mainly. The former searches some methods of rapid convergence based on which surveying adjustment is a kind of problem of nonlinear programming. Among them the iterative algorithms of the most in common use are the Gauss-Newton method, damped least quares, quasi-Newton method and some mutations etc. Although these methods improved the quantity of the observation results to a certain degree, and increased the accuracy of the adjustment results, what we want is whether the initial values of unknown parameters are close to their real values. Of course, the model of the latter has better degree in linearity, that is to say, they nearly have the meaning of deeper theories researches. This paper puts forward a kind of method of solving the problems of nonlinear least squares adjustment by parameters based on neural network theory, and studies its stability and convergency. The results of calculating of living example indicate the method acts well for solving parameters problems by nonlinear least squares adjustment without giving exact approximation of parameters.

关键词： neural network nonlinear least squares adjustment by parameters stability convergency

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Adaptive algorithm for solving different types and different precisions and nonlinear surveying and mapping parameters adjustment

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中国有色金属学会会刊：英文版 2005年第S1期15卷 221-224页

作者： NING Wei~(1,2), QING Xi-hong~2, TAO Hua-xue~2 (1. College of Information Science and Engineering, Shandong Agricultural University, Tai’an 271018,China 2. College of Geo-science and Engineering, Shandong University of Science and Technology, Tai’an 271019, China)

Approximate linear methods and nonlinear methods were adopted usually for solving models of nonlinear surveying and mapping parameters adjustment. But, these iterative algorithms need to compare harsh initial value. A kind of new algorithm-adaptive algorithm based on analyzing the general methods was put forward. The new algorithm has quick rate of convergence and low dependence for initial value, so it can avoid calculating complex second derivative of the target function. The results indicate that its performance is better than those of the others.

关键词： parameters adjustment least square method adaptive algorithm

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adjustment of Gravity Observations towards a Microgal Precision

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International Journal of Geosciences 2013年第1期4卷 98-107页

作者： Iris Pereira Escobar Francismar Rimoli Berquó Andrés R.R. Papa Observatório Nacional/MCTI Rio de Janeiro Brazil Universidade do Estado do Rio de Janeiro Rio de Janeiro Brazil

Gravity observations adjustment is studied having in view to take full advantage of the modern technology of gravity measurement. We present here results of a test performed with the mathematical model proposed by our group, on the adjustment of gravity observations carried out on network design. Additionally, considering the recent improvement on instrumental technology in gravimetry, that model was modified to take into account possible nonlinear local datum scale factors, in a 1900 mGal range network, and to check its significance for microgal precision measurements. The data set of the Brazilian Fundamental Gravity Network was used as case study. With about 1900 mGal gravity range and 11 control stations the Brazilian Fundamental Gravity Network (BFGN) was used as case study. It was established mainly with the use of LaCoste & Romberg, model G, gravimeters and new additional observations with Scintrex CG-5 gravimeters. The observables involved in the model are instrumental reading, calibration functions of the gravimeters used and the absolute gravity values at the control stations. Gravity values at the gravity stations and local datum scale factors for each gravimeter were determined by least square method. The results indicate good adaptation of the tested model to network adjustments. The gravity value in the IFE-172 control station, located in Santa Maria, had the largest estimated correction of ?10.4 μGal (1 μGal = 10 nm/s2), and the largest residual for an observed reading was estimated in 0.043 reading unit. The largest correction to the calibration functions was estimated in 6.9 × 10-6mGal/reading unit.

关键词： Calibration Gravimeter Gravity Network adjustment Modeling

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adjustment of Liquid Production in Reservoir with Handling Capacity Constraints

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Journal of Geoscience and Environment Protection 2019年第4期7卷 18-25页

作者： Jie Tan Dong Zhang Dongdong Yang Songru Mou Qin Peng Bohai Oilfield Research Institute of CNOOC Ltd.-Tianjin Branch Tianjin China

A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increase oil. The processing capacity of oilfield fluid was limited by the conditions. By using Petrel-RE-2017 software, combining reservoir engineering and percolation mechanics methods, this paper analyzes the effect of large-scale liquid pumping, expand coverage and shut-in coning in oil reservoirs with bottom water, and formulates the adjustment strategy of single well production structure of the whole oilfield. It was confirmed that large-scale liquid production can expand coverage and shutting down well can reduce water cut. It can provide reference and guidance for oil field with strong bottom water when it encounters bottleneck of liquid treatment capacity.

关键词： Strong Bottom Water Reservoir High Water Cut Liquid Production Structure adjustment Maximum Liquid Production Capacity Maximum Reasonable Pressure Bottom Water Coning

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adjustment of Model Parameters to Estimate Distribution Transformers Remaining Lifespan

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Smart Grid and Renewable Energy 2018年第9期9卷 151-170页

作者： Victor A. Jimenez Adrian Will Jorge Gotay Sebastián Rodríguez Grupo de Investigación en Tecnologías Informáticas Avanzadas—U.T.N.-F.R.T Tucumán Argentina Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires Argentina

Currently, the electrical system in Argentina is working at its maximum capacity, decreasing the margin between the installed power and demanded consumption, and drastically reducing the service life of transformer substations due to overload (since the margin for summer peaks is small). The advent of the Smart Grids allows electricity distribution companies to apply data analysis techniques to manage resources more efficiently at different levels (avoiding damages, better contingency management, maintenance planning, etc.). The Smart Grids in Argentina progresses slowly due to the high costs involved. In this context, the estimation of the lifespan reduction of distribution transformers is a key tool to efficiently manage human and material resources, maximizing the lifetime of this equipment. Despite the current state of the smart grids, the electricity distribution companies can implement it using the available data. Thermal models provide guidelines for lifespan estimation, but the adjustment to particular conditions, brands, or material quality is done by adjusting parameters. In this work we propose a method to adjust the parameters of a thermal model using Genetic Algorithms, comparing the estimation values of top-oil temperature with measurements from 315 kVA distribution transformers, located in the province of Tucumán, Argentina. The results show that, despite limited data availability, the adjusted model is suitable to implement a transformer monitoring system.

关键词： Distribution Transformer Thermal Model Transformer Lifespan Parameters adjustment Genetic Algorithms

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adjustment and Optimization of Public Art to the Folk Psychology

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Journal of Landscape Research 2015年第1期7卷 55-60页

作者： WANG Lijun CHEN Juan School of Architecture and Design Beijing Jiaotong University

Public art has practical significance by showing a variety of forms to explore the various design factors on the psychological reactions of different people. Public art should fit the characteristics of human physiology and psychology. The mental aberration phenomenon induced by unhealthy circumstance could be adjusted and compensated by certain style of public art, and from which the optimization of psychological ecology is resulted. A variety of psychological ecology environment, such as gestalt, artistic exaggeration, implicit, pleasure, interesting, relax, mystery, intricacy, metaphor, and so on, could be constructed by different methods in public art. The excellent public art design optimizes the person's mental spiritual ecology, reduces the burden on people's lives and enhances the quality of life by using the meaningful forms and combinations to achieve the living environment and people's coordination.

关键词： Public art adjustment Compensation Optimization

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adjustment Model and Colored Noise Compensation of Continuous Observation System

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Journal of Geodesy and Geoinformation Science 2018年第1期1卷 39-45页

作者： Shuqiang XUE Yuanxi YANG School of Geological and Surveying Engineering Chang’an UniversityXi’an 710054China Chinese Academy of Surveying and Mapping Beijing 100830China National Key Laboratory of Geo-spatial Information Xi’an Research Institute of Surveying and MappingXi’an 710054China

The affection caused by the colored noises should be taken into account to the adjustment model.As useful signals,these colored noises should be accurately identified and extracted by Fourier analysis.A continuous adjustment model is introduced with respect to the colored noises,and then it can be generalized from the finite space to the infinite space so called as Hilbert space.This extension is to provide a new technique to perform the continuous observational system design,Fourier analysis as well as the parameter estimation.It shows that the Gramer’s determinant provides maximization criteria in the system optimization design as well as a rule in diagnosing the adjustment model.Related with the definition of the integral,the least squares solution of the continuous adjustment model becomes the limit of the traditional least squares solution in finite space.Moreover,the influence caused by the colored noises is systematic,but it can be eliminated or compensated by optimally designing the observational system.

关键词： adjustment continuous observation least squares colored noise Hilbert space

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