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Complete qth-Moment Convergence of Moving Average Process for m-WOD Random Variable

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wuhan University Journal of Natural Sciences 2022年第5期27卷 396-404页

作者： SONG Mingzhu wu yongfeng CHU Ying Department of Mathematics and Computer Science Tongling UniversityTongling 244000AnhuiChina

In this paper,we obtained complete qth-moment convergence of the moving average processes,which is generated by m-WOD moving random *** results in this article improve and extend the results of the moving average *** random variables include WOD,m-NA,m-NOD and mEND random variables,so the results in the paper also promote the corresponding ones in WOD,m-NA,m-NOD,m-END random variables.

关键词： m-WOD random variable moving average processes complete convergence complete qth-moment convergence

Synergistic extraction of rare earth elements and alumina from coal fly ash by potassium pyrosulfate

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Journal of Rare Earths 2024年第4期42卷 749-758页

作者： Jingjing Zou Yiping Sun Chunbin Guo Daye Chen Yonghong Song yongfeng wu Zhaotianhui Li Department of Environment Science and Engineering Liaoning Technical UniversityFuxin23000China Department of Materials Science and Engineering Liaoning Technical UniversityFuxin123000 China Technology Research and Development Department Chinese Institute of Coal ScienceBeijing100013China Shenhua Zhungeer Energy and Resource Comprehensive Development Co. Ltd.Erdos10300China Liaoning Yingguan High-tech Ceramic Co. Ltd.Jinzhou121213China

Although coal fly ash(CFA)contains a high content of rare earth elements(REEs),the related extraction methods have limitations because of their low efficiencies,high levels of energy consumption,and other *** address these problems,in this study,we examined the coextraction of REEs and Al_(2)O_(3)from two types of Al_(2)O_(3)-rich CFA,pulverized CFA(PCFA)and circulating fluidized bed fly ash(CFBFA)using low-temperature calcination in the presence of K_(2)S_(2)O_(7).The total REEs,heavy REEs(HREEs),and light REEs(LREEs)extraction efficiencies were determined using different K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratios and calcination temperatures and correlated with the Al_(2)O_(3) extraction efficiency using Pearson correlation coefficient *** REEs are concentrated within CFA particles encapsulated in an aluminosilicate glass phase,and the REEs extraction efficiency is related to the form of Al in *** extraction efficiencies of Al_(2)O_(3) and REEs increase as the K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratio and calcination temperature increase,and the extraction selectivity of the more industrially valuable HREEs from CFBFA is *** high K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratios,the extraction of REEs from PCFA is more efficient than that from CFBFA with the regeneration of the highly active Al-O-Si bonds in *** Al_(2)O_(3) extraction efficiencies of PCFA as well as CFBFA correlate strongly with the total REEs,HREEs,and LREEs extraction *** developed extraction technology has the potential to promote CFA valorization and expand REEs resources,thus mitigating the bottlenecks of REEs procurement.

关键词： Rare earths Alumina Coal fly ash Potassium pyrosulfate Calcination Extraction

A Note on Strong Law of Large Numbers for Partial Sums of Pairwise NQD Random Variables

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Journal of Mathematical Research with Applications 2014年第2期34卷 231-239页

作者： yongfeng wu Mingle GUO College of Mathematics and Computer Science Tongling University College of Mathematics and Computer Science Anhui Normal University

In this paper, the authors study the strong law of large numbers for partial sums of pairwise negatively quadrant dependent(NQD) random variables. The results obtained improve the corresponding theorems of Hu et al.(2... 详细信息

关键词： pairwise NQD random variables strong law of large numbers.

Land use pattern evolution and optimization in the Farming-Pastoral Zone of Northern China

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Science China(Technological Sciences) 2006年第z2期49卷 132-140页

作者： CHEN Yunhao SU Wei wu yongfeng YU Xiaomin ZHANG Jinshui College of Resources Science and Technology Beijing Normal University Beijing 100875 China College of Resources Science and Technology Beijing Normal University Beijing 100875 China College of Resources Science and Technology Beijing Normal University Beijing 100875 China College of Resources Science and Technology Beijing Normal University Beijing 100875 China College of Resources Science and Technology Beijing Normal University Beijing 100875 China

Using information about the land cover of the Farming-Pastoral Zone of Northern China retrieved from multi-temporal NOAA/AVHRR and SPOT VEGETAN images obtained in 1989, 1994 and 1999, the authors analyzed land-use pattern evolution over this 10-year period and built a land-use pattern simulation model, based on which land-use pattern evolution and optimization modeling in this region were studied. Results showed that the proposed model can effectively simulate regional land-use patterns and help improve regional ecological environments.

关键词： Farming-Pastoral Zone of Northern China, land use pattern optimization, grey linear programming, cellular automata, optimization simulation.

Nitrogen Removal in Wastewater Irrigation Systems and Its Influence on Groundwater Pollution

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Journal of Earth Science 1995年第2期14卷 108-113页

作者： Wang Min wu yongfeng Tang Minggao Zhong Zuoxin Shen ZhaoliHydrogeological Department , China University of Geosciences , Beijing 100083

The experiment included ten soil columns and field investigation in 1 - 2 year duration. Data on the columns continuously flooded with waste water indicated that when total input of NH4-N reached to above 70% of the NH4-N adsorption capacity in soil the breakthrough would appear in the output . Adequate removal of nitrogen from the waste water would require at least 170 cm deep groundwater table . Fine textured soil would promote denitrification . The columns simulating discontinuous waste water irrigation indicated that denitrification existed only in the partial microenvironment of reduction .Groundwater table depth had no strong influence on nitrogen removal . The investigation in field revealed that the groundwater recharged with waste water was not polluted by nitrogen when the aeration profile was in finer textures owing to the combined contribution of nitrification and denitrification .

关键词： wastewater irrigation system nitrogen removal groundwater pollution nitrification denitrification .

QPSK Signal Detection Based on Two Duffing Oscillator

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QPSK Signal Detection Based on Two Duffing Oscillator

Nearest neighbor vector analysis of SDSS DR5 galaxy distribution

2010 3rd International Conference on Computer and Electrical Engineering(ICCEE 2010)

作者： yongfeng wu Shiping Zhang Jinwei Sun School of Electrical Engineering and Automation Harbin Institute of Technology

Due to great noise interference and strong signal attenuation in low voltage power line, two Duffing oscillator methods is proposed to detect QPSK carrier signal. At the same time, after analyzing the law of system solution of Duffing Oscillator, the algorithm of difference distribution of system solution is proposed to identify phase transition, which can greatly decrease calculation. The experiment shows that two Duffing oscillator methods can detect the phase of QPSK signal accurately and obtain good detection effect in low SNR.

关键词： Two Duffing Oscillator QPSK phase transition identification

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