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Co-adsorption of gaseous benzene, toluene, ethylbenzene,m-xylene(BTEX) and SO_2 on recyclable Fe_3O_4 nanoparticles at 0–101% relative humidities

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Journal of Environmental Sciences 2015年第5期27卷 164-174页

作者： Connie z.ye Parisa A.Ariya Department of Chemistry McGill University Department of Atmospheric and Oceanic Sciences McGill University

We herein used Fe3O4 nanoparticles（NPs） as an adsorption interface for the concurrent removal of gaseous benzene, toluene, ethylbenzene and m-xylene（BTEX） and sulfur dioxide（SO2）, at different relative humidities（RH）. X-ray diffraction, Brunauer-Emmett-Teller, and transmission electron microscopy were deployed for nanoparticle surface ***-dispersed Fe3O4（Fe2O3·Fe O） NPs synthesized with oleic acid（OA） as surfactant, and uncoated poly-dispersed Fe3O4 NPs demonstrated comparable removal *** experiments of BTEX on NPs were measured using gas chromatography equipped with flame ionization detection, which indicated high removal efficiencies（up to（95 ± 2）%） under dry conditions. The humidity effect and competitive adsorption were investigated using toluene as a model compound. It was observed that the removal efficiencies decreased as a function of the increase in RH, yet, under our experimental conditions, we observed（40 ± 4）% toluene removal at supersaturation for Fe3O4 NPs, and toluene removal of（83 ± 4）% to（59 ± 6）%, for OA-Fe3O4 NPs. In the presence of SO2, the toluene uptake was reduced under dry conditions to（89 ± 2）% and（75 ± 1）% for the uncoated and coated NPs, respectively, depicting competitive adsorption. At RH 〉 100%,competitive adsorption reduced the removal efficiency to（27 ± 1）% for uncoated NPs whereas OA-Fe3O4 NPs exhibited moderate efficiency loss of（55 ± 2）% at *** point to heterogeneous water coverage on the NP surface. The magnetic property of magnetite facilitated the recovery of both types of NPs, without the loss in efficiency when recycled and reused.

关键词： Fe3O4 nanoparticles Co-adsorption Competitive adsorption BTEX removal SO2 removal

Precipitation of multi-type nano-quasicrystals in a Mg-zn-Y alloy

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Journal of Magnesium and Alloys 2024年第3期12卷 997-1008页

作者： W.z.Wang X.z.z.ou L.F.zhang H.Q.ye z.Q.Yang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China Ji Hua Laboratory Foshan 528251China Foshan University Foshan 528231China

Mg-6zn-1Y(at.%)ribbons with strengthening precipitates of multi-type nanoquasicrystals were prepared by melt-spinning followed by aging *** evolution of the rapidly solidified ribbons during isothermal aging was comprehensively studied using various electron microscopy *** new kinds of decagonal quasicrystals were formed in aged ribbons,in addition to precipitation of nanometer icosahedral ***-resolution observations reveal that both decagonal quasicrystals can be modeled by quasiperiodic tiling with decagonal clusters of 2.5 nm in diameter,but overlap of neighboring clusters in both decagonal quasicrystals is different from the Gummelt model observed in other quasicrystals.A shell composed of complex Laves Mg-zn domains was formed surrounding each decagonal quasicrystal precipitate upon prolonged *** addition,all kinds of nanoprecipitates exhibit excellent structure and size stability at 573 *** findings may have implications for not only fundamental studies about quasicrystals,but also microstructural manipulation of high-performance Mg alloys.

关键词： Quasicrystal Mg alloys Rapid solidification Scanning-transmission electron microscopy.

Surface deformation-dependent mechanical properties of bending nanowires:an ab initio core-shell model

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Applied Mathematics and Mechanics(English Edition) 2022年第2期43卷 219-232页

作者： ye XIAO J.SHANG L.z.KOU Chun LI School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an710072China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbaneQLD4000Australia

An ab initio core-shell model is proposed to evaluate the surface effect in bending nanowires,in which the elastic modulus depends on the surface relaxation and deformation induced by external *** using first-principles calculations based on the density functional theory(DFT),the surface and bulk properties are calculated for Ag,Pb,and Si *** obtained theoretical predictions of the effective Young’s modulus of nanowires agree well with the experimental data,which shows that the fixed-fixed nanowire is stiffened and the cantilevered nanowire is softened as the characteristic size of the cross section ***,the contrastive analysis on the two kinds of nanowires demonstrates that increasing the nanowire aspect ratio would enhance the surface *** present results could be helpful for understanding the size effect in nanowires and designing nanobeam-based devices in nanoelectromechanical systems(NEMSs).

关键词： surface effect density functional theory(DFT) surface relaxation surface stress nanowire

Y-Ba-Cu-O mixed oxides for production of diphenols in liquid-solid phase

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Chinese Journal of Chemistry 1996年第6期14卷 516-524页

作者： Liu, CB zhao, z Yang, XG ye, XK Wu, Y CHINESE ACAD SCI CHANGCHUN INST APPL CHEMCHANGCHUN 130022JILINPEOPLES R CHINA

Superconductor mixed oxides were often used as catalysts at higher temperature in gas phase oxidations, and considered not suitable for lower temperature reactions in the liquid-solid phase; here the catalysis of YBa2Cu3O7+/-x and Y2BaCuO5+/-x in the phenol hydroxylation at lower temperature with H2O2 as oxygen donor was studied, and found that the superconductor YBa2Cu3O7+/-x, has no catalytic activity for phenol hydroxylation, but Y2BaCuO5+/-x does, even has better catalytic activity and stability than most previously reported ones. With the studies of catalysis of other simple metal oxides and perovskite-like mixed oxides, a radical substitution mechanism is proposed and the experimental facts are explained clearly, and draw a conclusion that the perovskite-like mixed oxides with (AO)(ABO(3)) and (AO)2(ABO(3)) structure have better catalytic activity than the simple perovskite oxides with (ABO(3))(3) structure alone, and (AO) structure unit is the key for the mixed oxides to have the phenol hydroxylation activity. No pollution of this process is very important for its further industrial application.

关键词： superconductor mixed oxides phenol hydroxylation radical substitution

A Review of the Effects of Fly Ash on Durability of Concrete：Hydration Chemistry and Microstructure

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武汉理工大学学报 2010年第17期32卷 235-240页

作者： YU z Q ye G VAN BREUGEL K Faculty of Civil Engineering and Geosciences Delft University of TechnologyP.O. Box 50482600 GA DelftThe Netherlands

Fly ash (FA) is widely used in construction industry as a pozzolanic material for its economic and environmental advantages. However,the variety and the complexity of the chemical composition of FA make it difficult to control the quality in engineering practice. Especially the durability of FA concrete has to be considered in the design. This durability is strongly influenced by the internal chemistry and the microstructure of cement paste. The aim of this article is to present a review on the effect of FA on the durability of concrete with particularly focus on the hydration chemistry and the development of microstructure. Meanwhile,existing hydration models for hydration kinetics and microstructure development of concrete blended with FA is discussed. The results of this research will provide a modelling perspective for predicting durability of concrete when FA is used as a blending material in the mixtures.

关键词： durability fly ash hydration chemistry microstructure modelling

State estimation over a communication network:measurement or estimate communication?

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控制理论与应用（英文版） 2010年第1期8卷 20-26页

作者： Ling SHI ye YUAN Michael z. Q. CHEN Electronic and Computer Engineering Hong Kong University of Science and Technology Hong Kong China Control Group Department of Engineering University of Cambridge Cambridge CB2 IPZ UK Department of Automation Nanjing University of Science and Technology Nanjing Jiangsu 210094 China)

In this paper we consider the problem of state estimation over a communication network. Using estimation quality as a metric, two communication schemes are studied and compared. In scheme one, each sensor node communicates its measurement data to the remote estimator, while in scheme two, each sensor node communicates its local state estimate to the remote estimator. We show that with perfect communication link, if the sensor has unlimited computation capability, the two schemes produce the same estimate at the estimator, and if the sensor has limited computation capability, scheme one is always better than scheme two. On the other hand, when data packet drops occur over the communication link, we show that if the sensor has unlimited computation capability, scheme two always outperforms scheme one, and if the sensor has limited computation capability, we show that in general there exists a critical packet arrival rate, above which scheme one outperforms scheme two. Simulations are provided to demonstrate the two schemes under various circumstances.

关键词： Networked estimation Kalman filtering Packet-dropping network

The spatial distribution of major and trace elements of surface sediments in the northeastern Beibu Gulf of the South China Sea

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Acta Oceanologica Sinica 2019年第3期38卷 93-102页

作者： Qian Ge George z Xue Liming ye Dong Xu Jianru zhao Fengyou Chu Second Institute of Oceanography Ministry of Natural Resources Key Laboratory of Submarine Geosciences State Oceanic Administration Department of Oceanography and Coastal Sciences Louisiana State University Center for Computation and Technology Louisiana State University Coastal Studies Institute Louisiana State University

A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c(SiO_2)>c(Al_2O_3)>c(Fe_2O_3)>c(CaO)>c(MgO)>c(K_2O)>c(Na_2O)>c(TiO_2)>c(P_2O_5)>c(MnO), while those of trace elements exhibit a descending order of c(Sr)>c(Rb)>c(V)>c(zn)>c(Cr)>c(Pb)>c(Ni)>c(Cu)>c(As). On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the zhujiang River and Hainan; zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary ***, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.

关键词： grain size major and trace elements Beibu Gulf spatial distribution sediment source

Derimorphisms over Algebras and Applications

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Algebra Colloquium 2023年第2期30卷 193-204页

作者： X.Cao S.H.Liu X.S.Lu z.J.ye z.R.Yu Y.H.zhang School of Mathematical Sciences Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China MoE Key Lab of Scientific and Engineering Computing Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China

The new concept"derimorphism"generalizing both derivation and homomor-phism is *** a derimorphism is invertible,its inverse is a Rota-Baxter *** general theory of derimorphism is *** classification of all derimorphisms over an associative unital algebra is *** to the nonexistence of nontriv-ial positive derivations,it is shown that nontrivial positive derimorphisms do exist over any pair of opposite orderings over R[x],the lattice-ordered full matrix algebra and upper triangular matrix algebra over a totally ordered field.

关键词： derimorphism Rota-Baxter operator opposite orderings positive derimor-phism

DOUBLE S-BREAKING CUBIC TURNING POINTS AND THEIR COMPUTATION

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Journal of Computational Mathematics 1996年第1期14卷 8-22页

作者： R.S. ye z.H. Yang(Department of Mathematics, Shanghai University of Science and Technology, Shanghai,China) SHANGHAI UNIV SCI & TECHNOL DEPT MATHSHANGHAI 201800PEOPLES R CHINA

In the paper we are concerned with double S-breaking cubic turning points of two-parameter nonlinear problems in the presence of z(2)-symmetry. Three extended systems are proposed to determine double S-breaking cubic turning points. We show that there exist two kinds of singular point path passing through double S-breaking cubic turning point, One is the simple quadratic turning point path, the other is the pitchfork bifurcation point path.

关键词： DOUBLE S-BREAKING CUBIC TURNING POINTS AND THEIR COMPUTATION Pro