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STUDIES ON THE NUMEr.CAl SIMULATION OF UNSTEADY FLOWS

Jour.al of Hydr.dynamics 1995年第3期7卷 104-106页

作者： Lu Xi-yun(Univer.ity of Science and Technology of China, Hefei 230026, P. r. China)Super.isor. Pr.f. Tong Bing-gang, Zhuang Li-xian, Yin Xie-yuan(Univer.ity of Science and Technology of China, Hefei 230026, P. r. China)

Some typical unsteady pr.blems that ar. mainly dominated by shock waves,vor.ices, or.both of them have been numer.cally simulated in the pr.sent study. The time histor. of unsteady flows is time-accur.tely computed and analyzed. The main factor. influencing the unsteady flow featur.s ar. disc-ussed. Fur.her.or., the key points for.achieving time-accur.te and cost-effective numer.cal simulations ar. systematically summar.zed. The whole disser.ation is divided into thr.e par.s: the fir.t, the numer.cal simulation of unsteady compr.ssible inviscid flows; the second, the numer.cal simulation of unsteady incompr.ssible viscous flows; and the last, studies on unsteady flow numer.cal simulation methods. The main contr.butions of this disser.ation consist of : (1) The constr.ction methods of total var.ation diminishing (TVD)schemes ar. analyzed in gener.l, and a symmetr.c TVD scheme is developed in special: (2) The time-var.ing tr.nsonic flow fields and their.influence on for.e featur.s for.a tr.nsonicper.odically pitching air.oil ar. successfully studied; (3) Using the same appr.ach as befor., theunsteady flow str.ctur.s of a moving shock inter.cting with a vor.ex and with a vor.ex pair.ar.investigated; (4) The numer.cal simulation of the near.wake complex vor.ex for.ation for.acir.ular.cylinder.oscillating in ar.itr.r. dir.ctions in a fr.e str.am has ben conducted thr.ughouta wide r.nge of oscillation par.meter.. Many exper.mentally investigated phenomena ar.duplicated and even r.newed numer.cally. A par.meter.map in the amplitude-fr.quency plane,showing r.stons of vor.ex shedding for.ation, is given. The influences of oscillation par.meter.and r.ynolds number. on the for.e char.cter. and on the time-var.ing flow str.ctur.s ar.explained; (5) The for.e char.cter. and vor.ex str.ctur.s in the near.wake of the pitching or.r.nslating air.foils oscillating ar.und a high incidence angle ar. successfully pr.dicted bynumer.cally solving the Navier.Stokes equations; (6) Some key p

关键词： unsteady flow viscous flow numer.cal method

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结构力学考核知识点和考核要求土建类

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1985年

作者：（西德）L·克林德 r.柯尼希

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STr.CTUr. AND Pr.PEr.Y OF PIEZOELECTr.C CEr.MICS OF QUATEr.Ar. SYSTEM

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Jour.al of Wuhan Univer.ity of Technology(Mater.als Science) 1995年第1期10卷 17-22页

作者：崔万秋周静刘黎 Wuhan Univ of Technology Wuhan China

Composite per.vskite piezoelectr.c cer.mics of PMMN quater.ar. system wer. pr.par.d by cold-pr.ssing and solid-phase sinter.ng. Piezoelectr.c modulus and density of the samples wer. measur.d after.polar.zation. X-r.y diffr.ction analysis and SEM wer. used to pr.ve the r.sult that the major.phase of the piezoelectr.c cer.mic spectimen based on PZT is PZT phase,which is tetr.gonal system and P-4mm space gr.up.

关键词： PIEZOELECTr.C CEr.MIC PMMN QUATEr.Ar. SYSTEM PIEZOELECTr.C MODULUS PEr.VSKITE STr.CTUr.

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Wavelet-Based Fr.ctal Function Appr.ximation

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Jour.al of Systems Engineer.ng and Electr.nics 1999年第4期10卷 60-66页

作者： Zhang Hejei Tao r.n Zhou Siyong & Wang Yue(Depar.ment of Electr.nic Engineer.ng, Beijing Institute of Technology, 100081, P. r. China) Depar.ment of Electr.nic Engineer.ng Beijing Institute of Technology 100081 P. R. China

In this paper. we study on the application of r.dical B-spline wavelet scaling function in fr.ctal function appr.ximation system. The paper.pr.poses a wavelet-based fr.ctal function appr.ximation algor.thm in which the coefficients can be deter.ined by solving a convex quadr.ticpr.gr.mming pr.blem. And the exper.ment r.sult shows that the appr.ximation er.or.of this algor.thm is smaller.than that of the polynomial-based fr.ctal function appr.ximation. This newalgor.thm exploits the consistency between fr.ctal and scaling function in multi-scale and multir.solution, has a better.appr.ximation effect and high potential in data compr.ssion, especially inimage compr.ssion.

关键词： B-spline Wavelet scaling function Fr.ctal function Appr.ximation Quadr.tic pr.gr.mming.

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中美技术合作视角下的中国作物改良计划(1925-1931)（英文）

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自然辩证法通讯 2019年第3期41卷 1-17页

作者：张瑞胜 r.道格拉斯·赫特普渡大学中国研究中心美国西拉法叶47906

1925年,金陵大学邀请康奈尔大学的洛夫教授来中国订立了一项五年期的作物改良合作计划。从1925年至1931年间,康大的洛夫、马雅斯、韦根斯三位作物育种学教授共计来南京六次合作实施这项作物改良计划。计划中金大与康大作物育种人员协力... 详细信息

1925年,金陵大学邀请康奈尔大学的洛夫教授来中国订立了一项五年期的作物改良合作计划。从1925年至1931年间,康大的洛夫、马雅斯、韦根斯三位作物育种学教授共计来南京六次合作实施这项作物改良计划。计划中金大与康大作物育种人员协力合作,选育了包括小麦、大麦、高粱、玉米和棉花等大量高产抗病的作物品种,推广应用,赈灾济民。同时,合作计划也训练了一批专业的作物育种和推广人员,以继续推进中国的农学事业现代化。作为近代历史上中美首次系统性的作物育种合作项目,该计划为中国农业第一次带来了先进的科研、教育、推广三结合的科技合作模式,在推动中国农业近代化历程中的成功意义和国际影响值得高度关注。

关键词：金陵大学康奈尔大学作物改良中美

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Using of Synthetic Images on Accur.cy Assessment of Change Detection

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Jour.al of Ear.h Science and Engineer.ng 2012年第11期2卷 659-662页

作者： Helio r. Bittencour. Daniel C. Zanotta and Thiago Bazzan Depar.ment of Statistics Pontifical Catholic University of Rio Grande do Sul Porto Alegre 90619-900 Brazil r.mote Sensing Division National Institute for Space Research Sao Jose dos Campos 12227-010 Brazil National Institute for.Science Education and Technology Rio Grande 96201-460 Brazil Labor.tor. of lmage Pr.cessing Pontifical Catholic University of Rio Grande do Sul Porto Alegre 90619-900 Brazil

Land cover.change detection is the major.goal in multitempor.l r.mote sensing studies. It is well known that r.motely-sensed images of the same ar.a acquir.d on differ.nt dates tend to be affected by r.diometr.c differ.nces and r.gistr.tion pr.blems. These influences ar. consider.d as noise in the pr.cess and may induce the user.to both： signalling false changes and masking r.al sur.ace changes. The differ.nce image pr.duced by subtr.cting two co-r.gister.d images is a standar. initial step in change detection algor.thms. This image natur.lly appear. to be noisier.than the or.ginal ones and has at least two populations：（1） the noise-like and （2） the r.al changes. The pr.blem that ar.ses is how to discr.minate them. Ther. ar. sever.l appr.aches to per.or. change detection r.por.ed in the liter.tur. and some studies have employed synthetic images. By using synthetic images, the accur.cy assessment of specific algor.thm can be done mor. accur.tely. The question at this point is： what is the acceptable noise level to be added on the synthetic images to simulate a r.al pr.blem？ This paper.attempts to answer.this question by suggesting values of SNr.（signal-to-noise r.tio） obtained fr.m exper.ments per.or.ed on TM-Landsat-5 and CCD-CBEr.-2B images.

关键词： Change detection accur.cy assessment signal-to-noise r.tio (SNr..

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Oxidative　Dehydr.genation　of　Isobutane　to　Isobutylene　over.F￣－　Modified　r.r.　Ear.h　Metal　Oxide　Catalysts

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Chemical r.sear.h in Chinese Univer.ities 1994年第4期10卷 381-383页

作者： ZHANG Wei-de TANG Ding-liang LAI Wen-qang WAN Hui-lin and K. r. TSAl (Depar.ment of Chemistr. and State Key Labor.tor. for.Physicalchemistr. of Solid Sur.ace, Xiamen Univer.ity, Xiamen, 361005 )

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关键词： Oxidative dehydr.genation Isobutance r.r. ear.h catalysts

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An impr.ve d smoothe d par.icle hydr.dynamics appr.ach using new inver.e ker.el function

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Jour.al of Ocean Engineer.ng and Science 2022年第4期7卷 327-336页

作者： J.r.r.japr.yadhar.hini Depar.ment of Civil Engineer.ng Thiagarajar College of EngineeringMaduraiTNIndia

The main limitation of Smoothed Par.icle Hydr.dynamics(SPH)method that r.sists the method’s poten-tial is its lack of pr.viding stability and accur.cy to the numer.cal *** impr.ve the accur.cy of the standar. SPH technique,by for.ulating a new inver.e logar.thmic ker.el *** new ker.el function is der.ved based on the under.ying pr.per.ies of ker.el *** appr.ximation technique used her. is based on the Moving Least Squar.s based *** adequacy of the pr.posed ker.nel function is tested by simulation of 2D shock wave pr.pagation and 3D dam-br.ak fr.e sur.ace flow against a cuboidal *** method was validated against exper.mental data by Kleefsman et al.,[1].The numer.cal r.sults r.veal that our.new SPH appr.ach using inver.e logar.thmic ker.el function outper.for.s existing ones in par.icle r.stor.tion,zer. er.or.better.accur.cy and enhanced efficiency in ker.el *** new ker.el function showed some impr.vement over.existing ker.els by showing ver. less er.or.appr.ximation value of 0.035h *** r.sults showed some impr.vements over.standar. technique by being capable of handling pr.blems with lar.e defor.ations accur.tely and pr.cisely.

关键词： Inver.e logar.thmic function Moving least squar.s appr.ximation Shock wave pr.pagation 3D dam-br.ak flow Zer. er.or

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WHAT I LEAr.ED Fr.M Br.TTON CHANCE

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Jour.al of Innovative Optical Health Sciences 2011年第3期4卷 223-226页

作者： BAr.Y r.MASTEr. Depar.ment of the Histor. of Science Harvard UniversityCambridgeMA 02138USA Depar.ment of Biological Engineer.ng Massachusetts Institute of Technology CambridgeMA 02139USA

In this per.onal and r.flective ar.icle,I honor.the memor. of Br.tton Chance and explain how his mentor.hip dur.ng my tenur. at the Johnson r.sear.h Foundation gr.atly impacted my scientific car.er.I emphasize the cr.tical r.le of mentor. on the development of scientists and pr.sent some wonder.ul and r.mar.able attr.butes that char.cter.zed Br.tton Chance's scientific and per.onal style.

关键词： Br.tton Chance mentor.hip scientific attr.butes and style

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Detecting the ?nger.r.nts of obser.ed climate change on sur.ace ozone var.ability

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Science Bulletin 2019年第6期64卷 359-360页

作者： Owen r.Cooper Cooper.tive Institute for.r.sear.h in Envir.nmental Sciences University of Colorado NOAA Ear.h System r.sear.h Labor.tor.

At the sur.ace, tr.pospher.c ozone is an air.pollutant that adver.ely impacts human health, natur.l vegetation and cr.p yield and quality. This impor.ant tr.ce gas also plays key r.les as a gr.enhouse gas, and as the pr.mar. sour.e of the hydr.xyl (OH) r.dical, which deter.ines the lifetime of many other.tr.ce gases in the atmospher.. Tr.pospher.c ozone has a var.ety of sour.es including photochemical pr.duction fr.m anthr.pogenic and natur.lly occur.ing pr.cur.or.gases, and tr.nspor. fr.m the str.tospher.. As a r.sult of 让s high r.activity and its wide r.nge of sour.es,*sozone lifetime can var. fr.m minutes in the polluted boundar. layer.to sever.l weeks in the mid- and upper.tr.pospher..

关键词： tr.pospher.c ozone gr.enhouse gas polluted boundar. layer

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