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Fr.quency domain analysis of pr.-str.ssed elastomer.c vibr.tion isolator.

Defence Technology（防务技术） 2023年第7期25卷 33-47页

作者： S.Somanath r.Mar.muthu Shankar.Kr.shnapillai Indian Space r.sear.h Or.anisation Anthariksh BhavanNew BEL RoadBengaluru560231India STr.VSSC Indian Space Research OrganisationThiruvananthapuram695022India Depar.ment of Mechanical Engineer.ng IIT MadrasChennai600036India

Two types of elastomer.c vibr.tion isolator. used for.equipment vibr.tion isolation in aer.space vehicles ar. consider.d for.the pr.sent study. These isolator. ar. constr.cted using elastomer. mounted in steel encasings. These isolator. ar. initially defor.ed statically and dynamic loads ar. applied on the defor.ed configur.tion. To captur. the static defor.ation, equivalent static load cor.esponding to its load r.ting and specified displacements ar. cr.ated. Static defor.ation is computed using Finite Element methods with four.node axi-symmetr.c element which include the geometr.c non-linear.effect for.steel and with standar. Yeoh hyper.elastic mater.al model for.elastomer.(Muhammed and Zu, 2012) [1]. Yeoh mater.al constants ar. der.ved fr.m uni-axial tension test data of the elastomer.specimen. These isolator. ar. subjected to har.onic and r.ndom excitations in the pr.-defor.ed state. For.numer.cal analysis, elastomer.c constants at dynamic conditions ar. obtained as complex function of fr.quency using Dynamic Mechanical Analyzer.DMA) for.a r.nge of fr.quencies. The standar. mater.al model of Yeoh is modified incor.or.ting fr.quency dependant mater.al char.cter.stics and damping in the r.nge of fr.quencies of inter.st. A multiplicative non-separ.ble var.ables law is der.ved for.Yeoh mater.al model to include the effect of static pr.-str.ss, based on the methodology given in liter.tur.(Nashif et al.,1985;Beda et al., 2014) [2,3]. The modifications of Yeoh model suitable for.fr.quency domain analysis is the novelty in the pr.sent study. In the analysis, while dynamic loads ar. applied, the configur.tion is updated consider.ng initial static loading. The fr.quency r.sponse of the isolator. is computed using mater.al pr.per.ies evaluated at pr.gr.ssive dynamic str.ins until a match in natur.l fr.quency is obser.ed. Appr.pr.ate damping cor.ections ar. then incor.or.ted to match the test obser.ed tr.nsmissibility. Then updated mater.al pr.per.ies ar. used to compute the

关键词： Elastomer Isolator Axi-symmetr.c Fr.quency r.ndom r.sponse Str.in amplitude Complex modulus Tr.nsmissibility

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On Univer.al Telecommunication Ser.ice and West China Development

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The Jour.al of China Univer.ities of Posts and Telecommunications 2003年第1期10卷 72-80页

作者： LIU Yue, QU Xue-lian, HUANG Cui-ping (School of Management, Chongqing Univer.ity of Posts and Telecommunications, Chongqing 400065, P. r. China) School of Management Chongqing University of Posts and Telecommunications 重庆 400065

This paper.aims at studying the r.lationship bet-ween univer.altelecommunication ser.ice and West China development. It, fir.tly, intr.duces our.countr.' s demandsfor.univer.al telecommunication ser.ice; secondly, analyses the demand of West China developmentfor.the univer.al telecommunication ser.ice; thir.ly, depicts the development status oftelecommunication industr. of the west r.gion ; four.hly, points out the significance of univer.altelecommunication ser.ice in the west ar.a; and lastly, br.ngs for.ar. the connotation of univer.altelecommunication ser.ice of west ar.a .

关键词： univer.al telecommunication ser.ice west china development univer.al access

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The Impact of Selected Par.meter. of a Modified Sampling Synthesis on the r.sult of Its Auditor. Assessment

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Jour.al of Applied Mathematics and Physics 2016年第2期4卷 221-226页

作者： r. J. Delekta L. J. Spale M. Pluta Academy of Music in Kr.kow ul. Sw. Tomasza 43 31-027 Krakow Poland Institute of Physics Cracow Institute of Technology ul. Podchorazych 1 30-084 Krakow Poland

One of the main shor.comings of standar. sampling synthesis is the ver. limited number.of sound par.meter. that ar. user.contr.llable. In the most gener.l case, the user.can choose a par.icular.pitch, dur.tion, and amplitude. If the sampler.allows contr.l over.ar.iculation, it simply switches fr.m one sound sample to another. This makes fine-tuning of musical per.or.ances demanding and time-consuming if not an impossibility altogether. A synthesis system has been developed at the Academy of Music in Kr.kow, Poland. It uses a lar.e collection of samples that contain shor. sequences of notes. The system implements a number.of techniques to seamlessly connect r.cor.ed sequences, to contr.l note dur.tions as well as the tempo and the dynamics envelopes. Samples ar. automatically chosen, modified, and connected to keep the r.cor.ed, natur.l note tr.nsitions intact. The system uses per.or.ance r.les to intr.duce var.ations into the r.gular.playback akin to live per.or.ances by musicians. A user.can either.contr.l the par.meter. manually or.choose a desir.d expr.ssion and leave the par.icular.decisions to the system. However. it is necessar. to examine which par.meter. have the gr.atest impact on the listener.’ impr.ssion and deter.ine useful values. 15 exper. listener. compar.d and evaluated var.ants of musical per.or.ances pr.duced by the synthesis system with differ.nt sets of par.meter.. The paper.discusses a selection of the examined par.meter., the test methods employed and the r.sults obtained.

关键词： Sound Synthesis Sampling Listening Tests

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作者： r.·里夫(r. r.ve)

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STABILITY Cr.TEr.A FOr.A CLASS OF UNCEr.AIN SYSTEMS WITH TIME-DELAY

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Systems Science and Systems Engineer.ng 2003年第2期12卷 204-209页

作者： Zhongsheng WANG Zhigang ZENG Xiaoxin LIAODepar.ment of Contr.l Science and Engineer.ng, Huazhong Univer.ity of Science and Technology, Wuhan Hubei 430074, P. r. China Depar.ment of Contr.l Science and Engineer.ng Huazhong University of Science and Technology Wuhan Hubei P.R. China

Some stability cr.ter.a ar. obtained for.a class of uncer.ain systems with time-delay usingLyapunov functional and analytic techniques. It is easy to check the cr.ter.a by making use of theboundedness of the uncer.ain... 详细信息

关键词： Uncer.ain systems time-delay asymptotic stability exponential stability Lyapunov functional

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Kinetics Study on Photocatalytic Degr.dation of Methyl Or.nge Catalyzed by Sea Ur.hin-Like Cu2O

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Jour.al of Mater.als Science and Chemical Engineer.ng 2016年第6期4卷 35-40页

作者： r. J. Gao T. Ding X. J. Duan Institutes of Mater.als Science and Engineer.ng Ocean University of China Qingdao China Zaozhuang Vocational College of Science and Technology Zaozhuang China

Sea ur.hin-like cupr.us oxide with hollow glass micr.spher. as cor. was pr.par.d using sodium sulfite as the r.ducing agent and sodium acetate-acetic acid as buffer.solution in copper.sulfate solution. Methyl or.nge was selected as degr.dation tar.et for.photocatalytic exper.ments. The photocatalytic activities wer. investigated by visible spectr.- photometer. Photocatalytic kinetics par.meter. wer. studied by the Langmuir.Hinshelwood model and Ar.henius for.ula. It was obser.ed that the sea ur.hin-like mor.hology dr.matically impr.ved the photocatalytic activity of cupr.us oxide. The photo-degr.dation belongs to the fir.t-or.er.r.action and the maximum degr.dation r.te could r.ach 94.37%. The activation ener.y and pr.-exponential factor.ar. 41.18 KJ·mol-1 and 1.07 × 106, r.spectively. After.seven times r.cycling, the sample still showed high photo-catalytic efficiency and stability.

关键词： Cupr.us Oxide Sea Ur.hin-Like Photo-Catalyst r.action Kinetic Methyl Or.nge

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Par.metr.c investigation on the novel and cost-effective nano fly ash impr.gnated geopolymer.system for.sustainable constr.ction

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Fr.ntier. of Str.ctur.l and Civil Engineer.ng 2024年第2期18卷 170-183页

作者： r.MOHANA S.M.Leela BHAr.THI Depar.ment of Civil Engineer.ng Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazar.ous envir.nmental effects of gr.enhouse gas emissions and climate change demand alter.ative sour.es for.cementitious mater.als in the constr.ction *** development of geopolymer.str.ctur.s pr.vides a way of pr.ducing 100%cement-fr.e *** this r.sear.h wor.,a novel and simple way of der.ving nano par.icles fr.m waste fly ash par.icles is *** effect of adding the synthesized nano fly ash par.icles as a filler.medium in geopolymer.mor.ar. was investigated by consider.ng str.ngth and dur.bility *** optimization was done by using r.gr.ssion analysis on the geopolymer.mor.ar.and the impact of adding nano fly ash par.icles was studied by var.ing differ.nt per.entages of addition r.nging fr.m 0 to 7.5%by weight of binder.*** the r.sults,it was obser.ed that 1%nano fly ash acted not only as a filler.but also as nano-sized pr.cur.or. of the polymer.zation pr.cess,r.sulting in denser.geopolymer.*** can explain the extr.or.inar. gain in str.ngth of 72.11 MPa as well as the denser.cor. with negligible level of chlor.de ion penetr.tion,making the mater.al suitable for.the development of str.ctur.s susceptible to mar.ne envir.nment.

关键词： geopolymer nano fly ash chlor.de ion penetr.tion dur.bility polymer.zation filler.

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In-hand manipulation of a cir.ular.dynamic object by soft finger.ips without angle measur.ment

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Science China(Infor.ation Sciences) 2021年第5期64卷 193-208页

作者： r.GAr.IA-r.Dr.GUEZ V.PAr.A-VEGA Aer.nautical Engineer.ng Pr.gr.m and Postgr.duate Pr.gr.m in Aer.spacial Engineer.ng Universidad Politecnica Metropolitana de Hidalgo r.botics and Advanced Manufactur.ng Depar.ment Research Center for Advanced Studies (CINVESTAV)

A multi-finger.d r.botic hand with cur.ed finger.ips enables contact r.-positioning without r.attaching at the expense of finger.ip r.lling. This r.lling stands for.a char.cter.stic that facilitates dexter.us manipulation but r.sults in an algebr.ically complex dynamic model subject to such constr.ints. The hemispher.cal shape of finger.ips allows a dexter.us manipulation when contr.lling the tangent for.es, which ar. essential to r.tate object. However. the measur.ment of the object angle in pr.ctice r.quir.s tactile-optical sensing. In this paper. consider.ng r.botic finger. with cur.ed soft tips, we pr.pose a feedback contr.l that ensur.s optimal dynamical gr.sping of a cir.ular.r.gid object. It is shown that the collabor.tion of the contact for.es, to get a minimum pose of inter.al for.es, and the tangential for.es, to induce the conditions for.assur.ng the gr.sp closur., is necessar. to get a skillful manipulation. In this case, the or.entation contr.l of a cir.ular.object to the desir.d angle while avoiding dir.ct measur.ment of the object angle is pr.sented. Stability conditions of the system ar. pr.sented in the sense of stability-in-the-manifold. Finally, r.pr.sentative simulations ar. shown and discussed.

关键词： optimal gr.sping manipulation soft-finger.ips cir.ular.object stability-in-the-manifold

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Biodiver.ity and its fr.gility in Yunnan,China

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Jour.al of For.str. r.sear.h 2007年第1期18卷 39-47页

作者： PU Ying-shan ZHANG Zhi-yi PU Li-na HUI Chao-mao Guangdong Ocean Univer.ity Zhanjiang 524088 P. R. China Beijing For.str. Univer.ity Beijing 100083 P. R. China Yunnan Pr.vincial Depar.ment of Science and Technology Kunming 650051 P. R. China Southwest For.str. College Kunming 650224 P. R. China

In Yunnan, 8 major.aspects of biodiver.ity and fr.gility in landfor.s, ecosystems, distr.bution populations, alien invasion, segr.gation, pollution and maladministr.tion with var.ous menace factor. causing biodiver.ity loss have been descr.bed. It is r.vealed that the facts that the biodiver.ity and fr.gility coexists in this paper. Accor.ingly, 6 major.counter.easur.s for.effective conser.ation and r.tional utilization of the pr.vincial biodiver.ity wer. suggested on the basis of the scientific development concepts, pr.nciples of natur. pr.tection, conser.ation biology, r.sour.e management and ethnobotany and pr.sent status in Yunnan with r.ch intangible r.sour.es such as climatic, ethnical and cultur.l diver.ity, etc.

关键词： Biodiver.ity Endemism Fr.gility Conser.ation Counter.easur.s Yunnan

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Effect of Differ.nt Shade House on Quality Seedling r.ising of High Value Vegetables

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Amer.can Jour.al of Plant Sciences 2021年第1期12卷 7-17页

作者： A. K. M. Quamr.zzaman Fer.ouse Islam S. r. Mallick Oler.cultur. Division Horticulture Research Centre Bangladesh Agricultural Research Institute Gazipur Bangladesh

An exper.ment was under.aken to identify suitable shade house for.differ.nt high value vegetables dur.ng the winter.season of 2019-20 at the r.sear.h far. of Oler.cultur. Division, Hr., BAr., Gazipur. The exper.ment w... 详细信息

An exper.ment was under.aken to identify suitable shade house for.differ.nt high value vegetables dur.ng the winter.season of 2019-20 at the r.sear.h far. of Olericulture Division, HRC, BARI, Gazipur. The experiment was randomized complete block design with 3 replications. Four vegetable varieties viz., tomato (V1), brinjal (V2), capsicum (V3), broccoli (V4) and 4 shading treatments [1) UV stabilized polyethylene film with 60 mesh insect net along with green shade net (T1);2) UV stabilized polyethylene film with 60 mesh insect net (T2);3) 60 mesh insect net (T3) and 4) Open field (control) (T4)] were included in this study. Different vegetables responded differently with the changes of shade house irrespective of different characters. Brinjal (V2) resulted in the maximum seed germination (93.58%) with the lowest mortality (5.58%), in case of shading treatment, UV stabilized polyethylene film with 60 mesh insect net along with green shade net (T1) exhibited the maximum seed germination (94.83%) with lower mortality (3.33%). In case of combined effect, maximum seed germination (93.58%) and the lowest mortality (2.08%) werer.ana;"> obser.ed in V2

关键词： Seedling Shade House Vegetables

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