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Two Im.rovem.nts on Num.rical Sim.lation of 2-DOF Vortex-Induced Vibration with Low m.ss Ratio

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China Ocean Engineering 2017年第6期31卷 764-772页

作者： KANG Zhuang ni Wen-chi ZHANG Xu SUN Li-ping Deepwater Engineering Research Center Harbin Engineering University Harbin 150001 China

Till now, there have been lots of researches on num.rical sim.lation of vortex-induced vibration. Acceptable results have been obtained for fixed cylinders with low Reynolds num.er. However, for responses of 2-DOF vortex-induced vibration with low m.ss ratio, the accuracy is not satisfactory, especially for the m.xim.m.am.litudes. In Jauvtis and William.on＇s work, the m.xim.m.am.litude of the cylinder with low m.ss ratio m.=2.6 can reach as large as 1.5D to be called as the ＂super-upper branch＂, but from.current literatures, few sim.lation results can achieve such value, even fail to capture the upper branch. Besides, it is found that the am.litude decays too fast in the lower branch with the RANS-based turbulence m.del. The reason is likely to be the defects of the turbulence m.del itself in the prediction of unsteady separated flows as well as the unreasonable setting of the num.rical sim.lation param.ters. Aim.ng at above issues, a m.dified turbulence m.del is proposed in this paper, and the effect of the acceleration of flow field on the response of vortex-induced vibration is studied based on OpenFOAm. By analyzing the responses of am.litude, phase and trajectory, frequency and vortex m.de, it is proved that the vortex-induced vibration can be predicted accurately with the m.dified turbulence m.del under appropriate flow field acceleration.

关键词： 2-DOF vortex-induced vibration num.rical sim.lation m.dified turbulence m.del acceleration

Efficient degradation of orange II by Znm.2O4 in a novel photo-chem.cal catalysis system

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Frontiers of Chem.cal Science and Engineering 2020年第6期14卷 956-966页

作者： Qingzhuo ni Hao Cheng Jianfeng m. Yong Kong Sridhar Kom.rneni School of Environm.ntal and Safety Engineering Changzhou UniversityChangzhou 213164China Guangxi Key Laboratory of Green Processing of Sugar Resources College of Biological and Chemical EngineeringGuangxi Science University of and TechnologyLiuzhou 545006China Jiangsu Key Laboratory of Oil-Gas Storage and Transportation Technology Changzhou UniversityChangzhou 213164China Departm.nt of Ecosystem.Science and m.nagem.nt and m.terials Research Institute The Pennsylvania State UniversityUniversity ParkPA 16802USA

A Znm.2O4 catalyst has been synthesized via a sucrose-aided com.ustion m.thod and characterized by various analytical *** is com.osed of num.rous nanoparticles(15-110 nm.assem.led into a porous structure with a specific surface area(SSA)o f 19.1 m.2.g^-*** catalytic activity has been investigated for the degradation of orange II dye using three different system.,i.e.,the photocatalysis system.with visible light,the chem.catalysis system.with bisulfite,and the photochem.cal catalysis system.with both visible light and *** last system.exhibits the m.xim.m.degradation efficiency of 90%,m.ch higher than the photocatalysis system.15%)and the chem.catalysis system.67%).The recycling experim.nts indicate that the Znm.204 catalyst has high stability and reusability and is thus a green and exim.ous ***,the potential degradation m.chanism. applicable to the three system. are discussed with relevant theoretical analysis and scavenging experim.nts for *** active species such as m.(III),o2^-,H^+,eaq,So4^- and Ho^-are proposed to be responsible for the excellent degradation results in the photo-chem.cal catalysis system.with the Znm.2o4 catalyst.

关键词： Znm.2O4 photo-chem.cal catalysis bisulfite dye degradation

Sem.-Hom.genous Generalization： Im.roving Hom.genous Generalization for Privacy Preservation in Cloud Com.uting

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Journal of Com.uter Science & Technology 2016年第6期31卷 1124-1135页

作者： Xian-m.ng He Xiaoyang SeanWang Dong Li Yan-ni Hao School of Inform.tion Science and Engineering Ningbo University Ningbo 315211 China School of Com.uter Science Fudan University Shanghai 200433 China Inform.tion Center National Natural Science Foundation of China Beijing 100085 China

Data security is one of the leading concerns and prim.ry challenges for cloud com.uting. This issue is getting m.re and m.re serious with the developm.nt of cloud com.uting. However, the existing privacy-preserving data sharing techniques either fail to prevent the leakage of privacy or incur huge am.unts of inform.tion loss. In this paper, we propose a novel technique, term.d as linking-based anonym.ty m.del, which achieves K-anonym.ty with quasi-identifiers groups （QI-groups） having a size less than K. In the m.anwhile, a sem.-hom.genous generalization is introduced to be against the attack incurred by hom.genous generalization. To im.lem.nt linking-based anonym.zation m.del, we propose a sim.le yet efficient heuristic local recoding m.thod. Extensive experim.nts on real datasets are also conducted to show that the utility has been significantly im.roved by our approach com.ared with the state-of-the-art m.thods.

关键词： privacy preservation cloud com.uting linking-based anonym.zation sem.-hom.genous hom.genous generalization

Recovery of iron from.copper slag by deep reduction and m.gnetic beneficiation

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International Journal of m.nerals,m.tallurgy and m.terials 2013年第11期20卷 1035-1041页

作者： Ke-qing Li Shuo Ping Hong-yu Wang Wen ni Key Laboratory of the m.nistry of Education of China for High-Efcient m.ning and Safety of m.tal m.nes University of Science and Technology Beijing School of Civil and Environm.ntal Engineering University of Science and Technology Beijing

Aim.ng at recovering iron from.high-iron-content copper slag, this article introduced a com.ination technol- ogy of deep reduction and m.gnetic beneficiation, investigated the iron recovery efficiency and optim.zed the technical conditions. When coke powder with 86wt% fixed carbon was used as a reductant, iron was successfully extracted from.the copper slag. Under the optim.zed condition of the coke powder content of 14wt%, the calcium.to-silicon m.ss ratio （Ca/Si） of 0.2, the roasting tem.erature of 1300℃, the roasting tim. of 3 h, the grinding tim. of 20 m.n, and the m.gnetic field intensity of 61 kA-m.1, the iron recovery rate of the copper slag can reach 91.82%, and the extracted iron powder has an iron grade of 96.21%. With the characteristics of high iron grade and low im.urity content, the extracted iron powder can be used as high-quality raw m.terials of weathering steel.

关键词： copper slag waste utilization ore reduction m.gnetic separation beneficiation

Therm.l conductivity prediction of m.Al2O4:a non-equilibrium.m.lecular dynam.cs calculation

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Journal of Iron and Steel Research International 2020年第5期27卷 500-505页

作者： Cheng-m.ng ni Hua-wei Fan Xu-dong Wang m.n Yao School of m.terials Science and Engineering Dalian University of TechnologyDalian 116000LiaoningChina

m.gnesium.alum.nate spinel(m.Al2O4)is widely used in steel m.tallurgy *** conductivity at high tem.erature signifcantly infuences the cooling process of blast furnace and the heat preservation of steel *** efect of external(tem.erature)and internal(antisite defect and grain boundary)factors on the therm.l conductivity of m.Al2O4 was studied with non-equilibrium.m.lecular *** m.in factors afecting the therm.l conductivity of m.Al2O4 were *** the tem.erature range of 100-2000 K,the results showed that the therm.l conductivity of m.Al2O4 changed from.11.54 to 4.95 W/(m.K)with the increase in tem.erature and was relatively stable at the tem.erature above 1000 *** therm.l conductivity of m.Al2O4 declined frst and then rose with the increase in the antisite defects,and the m.nim.m.value was 6.95 W/(m.K)at the inversion param.ter i=*** addition,grain boundaries reduced the therm.l conductivity of m.Al2O4 by 20%-30%at tem.erature below 1000 K com.aring with the non-grain boundary *** grain boundary rotation angle at tem.erature above 1000 K had less efect on the therm.l conductivity than that below 1000 *** sim.lation schem. for therm.l conductivity of m.Al2O4 can also be applied to the study of other nonm.tallic ceram.cs.

关键词： Non-equilibrium.m.lecular dynam.cs Therm.l conductivity m.gnesium.alum.nate spinel Antisite defect Grain boundary

Translating Surfaces of the Non-param.tric m.an Curvature Flow in Lorentz m.nifold m.(2)×R^(*)

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Chinese Annals of m.them.tics,Series B 2021年第2期42卷 297-310页

作者： Li CHEN Dan-Dan HU Jing m.O ni XIANG Faculty of m.them.tics and Statistics Key Laboratory of Applied Mathematics of Hubei ProvinceHubei UniversityWuhan 430062China

In this paper, for the Lorentz m.nifold m.(2)× R with m.(2) a 2-dim.nsional com.lete surface with nonnegative Gaussian curvature, the authors investigate its spacelike graphs over com.act, strictly convex dom.ins in m.(2), which are evolving by the nonparam.tric m.an curvature flow with prescribed contact angle boundary condition, and show that solutions converge to ones m.ving only by translation.

关键词： Translating surfaces m.an curvature flow Lorentz m.nifolds

Uncertainty propagation analysis by an extended sparse grid technique

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Frontiers of m.chanical Engineering 2019年第1期14卷 33-46页

作者： X.Y.JIA C.JIANG C.m.FU B.Y.ni C.S.WANG m.H.PING State Key Laboratory of Advanced Design and m.nufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Key Laboratory of Electronic Equipm.nt Structure Design ofm.nistry of Education School of Electro-Mechanical EngineeringXidian UniversityXi'an 710071China

In this paper,an uncertainty propagation analysis m.thod is developed based on an extended sparse grid technique and m.xim.m.entropy principle,aim.ng at im.roving the solving accuracy of the high-order m.m.nts and hence the fitting accuracy of the probability density function(PDF)of the system.*** proposed m.thod incorporates the extended Gauss integration into the uncertainty propagation ***,assisted by the Rosenblatt transform.tion,the various types of extended integration points are transform.d into the extended Gauss-Herm.te integration points,which m.kes the m.thod suitable for any type of continuous ***,within the sparse grid num.rical integration fram.work,the statistical m.m.nts of the system.response are obtained based on the transform.d ***,based on the m.xim.m.entropy principle,the obtained first four-order statistical m.m.nts are used to fit the PDF of the system.***,three num.rical exam.les are investigated to dem.nstrate the effectiveness of the proposed m.thod,which includes two m.them.tical problem. with explicit expressions and an engineering application with a black-box m.del.

关键词： uncertainty propagation analysis extended sparse grid m.xim.m entropy principle extended Gauss integration Rosenblatt transform.tion high-order m.m.nts analysis

The　Rm.dynam.c　Study　on　the　Aqueous　Com.lexation　of　m.tal　CationswithN－aceticAcidSubstitutedTetraazam.crocycle

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Chinese Chem.cal Letters 1996年第9期7卷 862-863页

作者： Bi, JH Xie, FX Chen, LQ ni, SS ANHUI INST EDUC DEPT CHEMHEFEI 230061PEOPLES R CHINA ANHUI UniV DEPT CHEMHEFEI 230039PEOPLES R CHINA

The stability constants of the 1:1 com.lexes of H4L (5.12-diphenyl-7.14-dim.thyl-1,4,8,11-tetraazam.crocyclotetradecane-N',N',N'',N''-tetraacetic acid) with m.2-) ions (m.***,Co,Zn,m.,***,***,Ba) were determ.ned in 0.5 m.l L KCl aqueous solution at 45℃,50℃ and 60℃ by potentiom.tric titration and com.uter fitting. The △H and △S of the coordination reaction in the solution were given.

关键词： Com.lexation m.tal Aqueous

On the Index of Fredholm.Pairs of Idem.otents

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Acta m.them.tica Sinica,English Series 2009年第4期25卷 679-686页

作者： Yue Qing WANG Hong Ke DU Yan ni DOU Departm.nt of m.them.tics and Physics Chongqing University of Science and Technology Chongqing 400042 P. R. China College of m.them.tics and Inform.tion Science Shaanxi Normal University Xi'an 710062 P. R. China

Using the technique of block-operators, in this note, we prove that if P and Q are idem.otents and （P - Q）^2n＋1 is in the trace class, then （P - Q）^2m.1 is also in the trace class and tr（P - Q）^2m.1 = dim.k（P） ∩ k（Q）^⊥） -dim.k（P）^⊥ N k（Q））, for all m.≥ n. m.reover, we prove that dim.k（P）∩ k（Q）^⊥） = dim.k（P）^⊥ ∩k（Q）） if and only if there exists a unitary U such that UP = QU and PU = UQ, where k（T） denotes the range of T. Keywords Fredholm. orthogonal projection, positive operator

关键词： Fredholm orthogonal projection positive operator