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Non-homogeneous Tb Theorem for Bi-parameter g-function

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Acta Mathematica Sinica,English Series 2018年第9期34卷 1445-1459页

作者： Ming Ming CAO qing Ying xue School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education

The main result of this paper is a bi-parameter Tb theorem for Littlewood-Paley g-function, where b is a tensor product of two pseudo-accretive function. Instead of the doubling measure, we work with a product measure μ = μn × μm, where the measures μn and μm are only assumed to be upper doubling. The main techniques of the proof include a bi-parameter b-adapted Haar function decomposition and an averaging identity over good double Whitney regions. Moreover, the non-homogeneous analysis and probabilistic methods are used again.

关键词： Bi-parameter square function probabilistic method b-adapted Haar functions

A DFT study of the CO adsorption and oxidation at ZnO surfaces and its implication for CO detection

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Chinese Chemical Letters 2020年第6期31卷 1674-1679页

作者： Zibin Ni Shenyuan Bao xue-qing Gong Key Laboratory for Advanced Materials Centre for Computational Chemistry and Research Institute of Industrial CatalysisSchool of Chemistry&Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Recently,ZnO-based gas sensors have been successfully fabricated and widely studied for their excellent sensitivity and selectivity,especially in CO ***,detailed explorations of their mechanisms are rather ***,aiming at clarifying the sensing mechanism,we carried out density functional theory(DFT)calculations to track down the CO adsorption and oxidation on the ZnO(1010)and(1120)*** calculated results show that the lattice O of ZnO(1010)is more reactive than that of ZnO(1120)for CO *** the calculated energetics and structures,the main reaction product on both surfaces can be determined to be CO2 rather than ***,the surface conductivity changes during the adsorption and reaction processes of CO were also *** both ZnO(1010)and(1120),the conductivity would increase upon CO adsorption and decrease following CO oxidation,in consistence with the reported experimental *** work can help understand the origins of ZnO-based sensors’performances and the development of novel gas sensors with higher sensitivity and selectivity.

关键词： Density functional theory ZnO Gas sensor CO oxidation Surface conductivity

Reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet

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Journal of Iron and Steel Research International 2018年第3期25卷 310-319页

作者： Guang Wang qing-guo xue Jing-song Wang State Key Laboratory of Advanced Metallurgy University ofScience and Technology Beijing Beijing 100083 China

Realizing the boron and iron separation through selective reduction and melting separation of boron-bearing iron con- centrate is of great significance for the utilization of crude ludwigite. The reduction and melting separation mechanism of boron-bearing iron concentrate/coal composite pellet was systematically investigated. The reduction and melting separation test of small size pellet was performed to reveal the evolution of slag and iron in the melting separation process. The isothermal reduction experiment showed the relationship between reduction stage and melting separation stage, and the step reduction and melting separation was perfectly achieved. Coal particles existed through the reduction and melting separation process and finally formed brown residue around the separated product. The pellet could not realize melting separation when the B2O3 content in the concentrate was lower than 6.00 wt%.

关键词： Boron-bearing iron concentrate Composite pellet-Reduction Melting separation-Mechanism

Carbothermic reduction characteristics of ludwigite and boron–iron magnetic separation

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International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1000-1009页

作者： Guang Wang qing-guo xue Jing-song Wang State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Ludwigite is a kind of complex iron ore containing boron, iron, and magnesium, and it is the most promising boron resource in China. Selective reduction of iron oxide is the key step for the comprehensive utilization of ludwigite. In the present work, the reduction mechanism of ludwigite was investigated. The thermogravimetry and differential scanning calorimetry analysis and isothermal reduction of ludwigite/coal composite pellet were performed. Ludwigite yielded a lower reduction starting temperature and a higher final reduction degree compared with the traditional iron concentrates. Higher specific surface area and more fine cracks might be the main reasons for the better reducibility of ludwigite. Reducing temperature highly affected the reaction fraction and microstructure of the reduced pellets, which are closely related to the separation degree of boron and iron. Increasing reducing temperature benefited the boron and iron magnetic separation. Optimum magnetic separation results could be obtained when the pellet was reduced at 1300°C. The separated boron-rich non-magnetic concentrate presented poor crystalline structure, and its extraction efficiency for boron reached 64.3%. The obtained experimental results can provide reference for the determination of the comprehensive utilization flow sheet of ludwigite.

关键词： complex iron ore boron resource carbothermic reduction magnetic separation

Investment in deepwater oil and gas exploration projects:a multi-factor analysis with a real options model

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Petroleum Science 2015年第3期12卷 525-533页

作者： Xin-Hua Qiu Zhen Wang qing xue School of Business Administration China University of Petroleum Academy of Chinese Energy Strategy China University of Petroleum

Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncer- tainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engi- neering uncertainties, which provides more accurate and reliable valuation information for decision makers.

关键词： Investment decision - Real options Multi-factor model Option pricing - Deepwater oil and gas

Parabolic Littlewood-Paley g-Function with Rough Kernel

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Acta Mathematica Sinica,English Series 2008年第12期24卷 2049-2060页

作者： qing Ying xue Yong DING Kozo YABUTA School of Mathematical Sciences Laboratory of Mathematics and Complex Systems( BNU) Ministry of Education China Beijing Normal University Beijing 100875 P. R. China School of Science and Technology Kwansei Gakuin University Gakuen 2-1 Sanda 669-1337 Japan

In this note, we give the L^p （1 〈 p 〈∞） boundedness of the parabolic Littlewood Paley g-function with rough kernel.

关键词： parabolic Littlewood-Paley g-function mixed homogeneity spaces rough kernel

Transgenic Brassica chinensis plants expressing a bacterial codA gene exhibit enhanced tolerance to extreme temperature and high salinity

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第11期11卷 851-861页

作者： qing-bin WANG Wen XU qing-zhong xue Wei-ai SU Department of Agronomy College of Agriculture and Biotechnology Zhejiang University Hangzhou 310029 China Shanghai Institute of Plant Physiology and Ecology Chinese Academy of Science Shanghai 200032 China School of Resource and Environment Management Guizhou College of Finance and Economics Guiyang 550004 China

Transgenic Brassica compestris *** plants expressing a choline oxidase(codA) gene from Arthrobacter globiformis were obtained through Agrobacterium tumefaciens-mediated *** the transgenic plants,codA gene expression and its product transportation to chloroplasts were detected by the enzyme-linked immunosorbent assay(ELISA) examination,immunogold localization,and 1 H-nuclear magnetic resonance( 1 H-NMR) . Stress tolerance was evaluated in the T3 plants under extreme temperature and salinity *** plants of transgenic line 1(L1) showed significantly higher net photosynthetic rate(Pn) and Pn recovery rate under high(45°C,4 h) and low temperature(1°C,48 h) treatments,and higher photosynthetic rate under high salinity conditions(100,200,and 300 mmol/L NaCl,respectively) than the wild-type *** enhanced tolerance to high temperature and high salinity stresses in transgenic plants is associated with the accumulation of betaine,which is not found in the wild-type *** results indicate that the introduction of codA gene from Arthrobacter globiformis into Brassica compestris *** could be a potential strategy for improving the plant tolerance to multiple stresses.

关键词： Brassica compestris L. spp. chinensis codA Stress Glycine betaine Net photosynthetic rate (Pn)

Effect of carbon species on the reduction and melting behavior of boron-bearing iron concentrate/carbon composite pellets

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International Journal of Minerals,Metallurgy and Materials 2013年第6期20卷 522-528页

作者： Guang Wang Yin-gui Ding Jing-song Wang xue-feng She qing-guo xue State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Iron nugget and boron-rich slag can be obtained in a short time through high-temperature reduction of boron- bearing iron concentrate by carbonaceous material, both of which are agglomerated together as a carbon composite pellet. This is a novel flow sheet for the comprehensive utilization of boron-bearing iron concentrate to produce a new kind of man-made boron ore. The effect of reducing agent species （i.e., carbon species） on the reduction and melting process of the composite pellet was investigated at a laboratory scale in the present work. The results show that, the reduction rate of the composite pellet increases from bituminite, anthracite, to coke at temperatures ranging from 950 to 1300~C. Reduction temperature has an important effect on the microstructure of reduced pellets. Carbon species also affects the behavior of reduced metallic iron particles. The anthracite-bearing composite pellet melts faster than the bituminite- bearing composite pellet, and the coke-bearing composite pellet cannot melt due to the high fusion point of coke ash. With anthracite as the reducing agent, the recovery rates of iron and boron are 96.5% and 95.7%, respectively. This work can help us get a further understanding of the new process mechanism.

关键词： iron ore pellets iron ore reduction boron bituminite anthracite coke

Preparation of CaO-containing carbon pellets from coking coal and calcium oxide:Effects of temperature,pore distribution and carbon structure on compressive strength in pyrolysis furnace

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International Journal of Minerals,Metallurgy and Materials 2021年第7期28卷 1153-1163页

作者： Xiao-min You xue-feng She Jing-song Wang qing-guo xue Ze-yi Jiang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China

CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis *** effects of temperature,pore distribution,and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace(350-750℃).The results showed that as the roasting temperature increased,the compressive strength also increased and furthermore,structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures,thus forming high-ordered ***,the CCCP preheated at 750℃exhibited the highest compressive strength.A positive relationship between the compressive strength and pore-size homogeneity was established.A linear relationship between the com-pressive strength of the CCCP and the average stack height of CC was ***,a four-stage caking mechanism was developed.

关键词： calcium oxide-containing carbon pellets calcium carbide coking coal compressive strength pyrolysis furnace