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Improvement and upgrade of mine fire simulation program MFIRE

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Journal of Coal Science & Engineering(China) 2011年第3期17卷 275-280页

作者： ZHOU li-hong LUO yi Department of Mining Engineering West Virginia University Morgantown WV26505 USA

MFIRE, an underground mine fire simulation program developed in 1980＇s, is a tool that can be used to simulate the impacts of a mine fire event to a mine ventilation network. However, the lack of the abilities to simulate some of the important mine fire phenomena realistically hindered its wide applications. This research carried out to improve and upgrade the MFIRE 2.20 program to MFIRE 2.30. The new additions of MFIRE 2.30 including a time dependent fire model, smoke rollback prediction, the incorporation of a moving fire source, and a rewriting of MFIRE in Microsoft Visual C＋＋ were interpreted.

关键词： mine fire simulation MFIRE t-square fire smoke rollback conveyor belt fire

HISTORICAL DESERTIFICATION PROCESS IN HEXI CORRIDOR,CHINA

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Chinese Geographical Science 2005年第3期15卷 245-253页

作者： WANG Nai-ang ZHANG Chun-hui li Gang CHENG hong-yi College of Earth and Environment Sciences Lanzhou University Lanzhou 730000P. R. China

Over the last 2000 years, approximately 38 ancient cities were abandoned through desertification in Hexi Corridor, Northwest China. Among them, 21.05% were abandoned during the Northern and Southern Dynasties, 21.05% during the end of the Tang Dynasty and the Five Dynasties, and 57.9% during the Ming and Qing dynasties. At the same time, main lakes were shrinking rapidly from the 5th Century to the 6th Century and the end of the Qing Dynasty. The climate in these periods was relatively arid and cold with frequent dusts. The phase of these changes indicated that there were three periods of desertification enlargement in the northern China. They were Northern and Southern Dynasties, the end of Tang Dynasty and Five Dynasties, the Ming and Qing dynasties. The macro-process of desertification in the study area was controlled mainly by the climatic changes. But from the facts that the population density in the middle of Qing Dynasty had exceeded the critical index of population pressure in arid area and the usage rate of water resources had exceeded 40% in Hexi Corridor, this paper also suggests that human activities have played an important role in desertification processes of the study area mainly during the recent 300 years.

关键词： historical desertification climate change human activities Hexi Corridor

Fabrication and Photoelectrochemical Properties of[Ru(bpy)_2dppz]^(2+) on ITO Electrode Associated with the Oxidation of Guanine

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Chemical Research in Chinese Universities 2010年第4期26卷 649-655页

作者： GUO Qing-yu li hong YANG Hui-yi SHAO Jiang-yang Key Lab of Technology on Electrochemical Energy Storage and Power Generation in Guangdong Universities School of Chemistry and Environment South China Normal University Guangzhou 510006 P. R. China

Electrochemical assembly of [Ru（bpy）2dppz]^2＋{bpy=2,2＇-bipyridine, dppz=dipyrido[3,2-a：＂2＇,3＇-c]phenazine} on an ITO electrode in the presence of guanine and photoelectroehemical properties of the assembled layer were investigated. It has been found that [Ru（bpy）2dppz]^3＋/2＋ can be assembled onto the ITO electrode by the method of repetitive voltammetric sweeping, and the assembly is enhanced by guanine. The peak currents of prewaves increase linearly up to a guanine concentration of 0.25 mmol/L. More importantly, upon illumination with 470 nm light source and at an applied potential of 0.2 V, cathodic current for the fabricated layer on the ITO electrode indicate a linear enhancement with the rise of guanine concentration. Meanwhile, [Ru（bpy）2dppz]^2＋ can be served as an excellent mediator to prompt the oxidation of guanine, and the mediated peak current increases linearly with added guanine concentration from 0.01 to 0.25 mmol/L. In addition, the assembly mechanism of [Ru（bpy）2dppz]^2＋ on the ITO electrode associated with the oxidation of guanine and the assistance of light irradiation were discussed.

关键词： Polypyridvl ruthenium(II) complex Guanine ITO Assembly Photoelectrochemistrv

Interdecadal Variability of Spring Precipitation over South China and Its Associated Atmospheric Water Vapor Transport

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Atmospheric and Oceanic Science Letters 2009年第2期2卷 113-118页

作者： li hong-yi liN Zhao-Hui CHEN hong International Center for Climate and Environment Science Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The characteristics of spring precipitation and water vapor transport in South China were analyzed by using observational data and the National Centers for Environmental Prediction (NCEP) reanalysis data. The results show that, during the spring, each component of the water cycle (precipitation, wind field, specific humidity, water vapor transport, etc.) in South China exhibits a notable interdecadal variability. An abrupt increase in spring precipitation occurred in the early 1970s. During the dry period from 1958 to 1971, a water vapor flux divergence (positive divQ) existed in South China, which may have led to the deficiency in rainfall. However, during the wet period from 1973 to 1989, there was a remarkable water vapor flux convergence (negative divQ) in South China, which may have resulted in the higher rainfall. The interdecadal variability of water vapor transport is closely related to the interdecadal variability of wind fields, although the interdecadal variability of specific humidity also plays a role to some extent, and the interdecadal variability of the zonal water vapor transport contributes much more to the interdecadal variability of spring precipitation than the meridional water vapor transport.

关键词： interdecadal variability rainfall anomalies water vapor transport South China

Optimised Spatial Sampling Scheme for Soil Electriclal Conductivity Based on Variance Quad-Tree (VQT) Method

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Agricultural Sciences in China 2007年第12期6卷 1463-1471页

作者： li Yan SHI Zhou WU Ci-fang li Feng li hong-yi Institute of Land Science and Property Management College of Southeast Land Management Zhejiang University Hangzhou 310029 P.R.China Institute of Agricultural Remote Sensing and Information Technology Application College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 P.R.China Department of Environmental Engineering Zhe.iiang University Hangzhou 310029 P.R.China

The acquisition of precise soil data representative of the entire survey area, is a critical issue for many treatments such as irrigation or fertilization in precision agriculture. The aim of this study was to investigate the spatial variability of soil bulk electrical conductivity （ECb） in a coastal saline field and design an optimized spatial sampling scheme of ECb based on a sampling design algorithm, the variance quad-tree （VQT） method. Soil ECb data were collected from the field at 20 m interval in a regular grid scheme. The smooth contour map of the whole field was obtained by ordinary kriging interpolation, VQT algorithm was then used to split the smooth contour map into strata of different number desired, the sampling locations can be selected within each stratum in subsequent sampling. The result indicated that the probability of choosing representative sampling sites was increased significantly by using VQT method with the sampling number being greatly reduced compared to grid sampling design while retaining the same prediction accuracy. The advantage of the VQT method is that this scheme samples sparsely in fields where the spatial variability is relatively uniform and more intensive where the variability is large. Thus the sampling efficiency can be improved, hence facilitate an assessment methodology that can be applied in a rapid, practical and cost-effective manner.

关键词： variance quad-tree (VQT) sampling scheme spatial variability kriging interpolation precision agriculture

Improved Prediction and Reduction of Sampling Density for Soil Salinity by Different Geostatistical Methods

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Agricultural Sciences in China 2007年第7期6卷 832-841页

作者： li Yan SHI Zhou WU Ci-fang li hong-yi li Feng Institute of Land Science and Property Management College of Southeast Land Management Zhejiang University Hangzhou 310029 P. R. China Institute of Agricultural Remote Sensing and Information Technology Application College of Environmental and Resource Sciencea Zhejiang University Hangzhou 310029 P.R. China Department of Environmental Engineering Zhejiang University Hangzhou 310029 P.R. China

The spatial estimation for soil properties was improved and sampling intensities also decreased in terms of incorporated auxiliary data. In this study, kriging and two interpolation methods were proven well to estimate auxiliary variables： cokriging and regression-kriging, and using the salinity data from the first two stages as auxiliary variables, the methods both improved the interpolation of soil salinity in coastal saline land. The prediction accuracy of the three methods was observed under different sampling density of the target variable by comparison with another group of 80 validation sample points, from which the root-mean-square error （RMSE） and correlation coefficient （r） between the predicted and measured values were calculated. The results showed, with the help of auxiliary data, whatever the sample size of the target variable may be, cokriging and regression-kriging performed better than ordinary kriging. Moreover, regression-kriging produced on average more accurate predictions than cokriging. Compared with the kriging results, cokriging improved the estimations by reducing RMSE from 23.3 to 29% and increasing r from 16.6 to 25.5%, regression-kriging improved the estimations by reducing RMSE from 25 to 41.5% and increasing r from 16.8 to 27.2%. Therefore, regression-kriging shows promise for improved prediction for soil salinity and reduction of soil sampling intensity considerably while maintaining high prediction accuracy. Moreover, in regression-kriging, the regression model can have any form, such as generalized linear models, non-linear models or tree-based models, which provide a possibility to include more ancillary variables.

关键词： auxiliary data prediction precision sampling density soil salinity kriging

Induction of systemic lupus erythematosus syndrome in BALB/c mice by immunization with active chromatin

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Acta Pharmacologica Sinica 2004年第6期25卷 105-109页

作者： hong li, Yun-yi ZHANG, Ya-nan SUN, Xi-yi HUANG, Yong-feng JIA, Duan li2 Department of Pharmacology, Schoolof Pharmacy, Fudan University, Shanghai 200032, China Department of Pharmacology School of Pharmacy Fudan University Shanghai 200032 China

AIM: To establish an animal model for systemic lupus erythematosus (SLE)-like syndrome in mice. METHODS: BALB/c mice were immunized with active chromatin isolated from ConA-actived syngeneic spleno-lymphocytes. Plasma samples of mice were tested by enzyme-linked immunosorbent assays (EliSA) for the presence of IgG anti-dsDNA, -ssDNA, and anti-histone antibodies. Tumor necrosis factor-α (TNF-α) in serum was measured by EliSA. Spleno-lymphocyte proliferation assays and the levels of interferon-γ (IFN-γ) in supernatants were tested respectively. Proteinuria was measured. Kidneys were examined by direct immunohistochemical method and light microscopy. RESULTS: Anti-ds DNA, ssDNA, and histone antibodies were induced in active chromatin-immu- nized mice, the proliferation response of splenocytes to ConA and LPS were reduced, levels of interferon-γ in supernatants and TNF-α in serum were lowered. Lupus nephritis was assessed by the presence of Ig deposits, glomerular pathology and proteinuria. CONCLUSION: The active chromatin-induced SLE-like mouse model was similar to idiopathic SLE in human.

关键词： systemic lupus erythematosus chromatin autoantibody tumor necrosis factor interferon type II B-lymphocytes T-lymphocytes female enzyme-linked immunosorbent assay

Low-Frequency Stability Analysis of Power Electronic Traction Transformer Based Train-Network System

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1608-1617页

作者： yi hong Yang li Zhikang Shuai Hanyu Yang College of Electrical and Information Engineering Hunan University and the Advanced Energy Technology Center of State Grid Shanghai Energy Interconnection Research Institute Co.Ltd.Shanghai 201203China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China College of Electrical Engineering and Controal Science in Nanjing Tech University Nanjing 211816China

Power electronic traction transformers(PETTs)will be increasingly applied to locomotives in the future for their small volume and light ***,similar to conventional trains,PETTs behave as constant power loads and may cause low-frequency oscillation(LFO)to the train-network *** solve this issue,a mathematical model of the PETT is firstly proposed and verified based on the extended describing function(EDF)method in this *** the proposed model,the LLC converter is simplified to an equivalent circuit consisting of a capacitor and a resistor in *** is further demonstrated that the model can apply to various LLC converters with different topologies and ***,when the parameter differences between cells are not obvious,the PETT can be simplified to a single-phase rectifier(i.e.,conventional train)by equivalent *** on the model of PETT,the system low-frequency stability and influential factors are analyzed by using the generalized Nyquist ***,the correctness and accuracy of theoretical analyses are validated by off-line and hardware-in-the-loop simulation results.

关键词： Extended describing function method impedance model low-frequency oscillation power electronic traction transformer train-network system

A Non-Parametric Scheme for Identifying Data Characteristic Based on Curve Similarity Matching

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1424-1437页

作者： Quanbo Ge Yang Cheng hong li Ziyi Ye yi Zhu Gang Yao School of Automation Nanjing University of Information Science&TechnologyJiangsu Provincial University Key Laboratory of Big Data Analysis and Intelligent SystemsNanjing University of Information Science&Technologyand the Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET)Nanjing University of Information Science&TechnologyNanjing 210044China School of Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China China Classification Society Nantong Office Nantong 226006China Chinese Flight Test Establishment Xi’an 710089China School of Mathematics Tsinghua UniversityBeijing 100084China School of Automation Nanjing University of Information Science&TechnologyNanjing 210044China Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China IEEE

For accurately identifying the distribution charac-teristic of Gaussian-like noises in unmanned aerial vehicle(UAV)state estimation,this paper proposes a non-parametric scheme based on curve similarity *** the framework of the pro-posed scheme,a Parzen window(kernel density estimation,KDE)method on sliding window technology is applied for roughly esti-mating the sample probability density,a precise data probability density function(PDF)model is constructed with the least square method on K-fold cross validation,and the testing result based on evaluation method is obtained based on some data characteristic analyses of curve shape,abruptness and *** com-parison simulations with classical methods and UAV flight exper-iment shows that the proposed scheme has higher recognition accuracy than classical methods for some kinds of Gaussian-like data,which provides better reference for the design of Kalman filter(KF)in complex water environment.

关键词： Curve similarity matching Gaussian-like noise non-parametric scheme parzen window.