检索结果-南通市图书馆

photoanode Activ.ty of ZnO Nanotube Based Dye-Sensitized Solar.Cells

在线全文

学校读者我要写书评

暂无评论

Jour.al of Mater.als Science & Technology 2011年第11期27卷 961-966页

作者： r. r.njusha p. Lekha K.r.v. Subr.manian v. Nair.Shantikumar.A. Balakr.shnan Nano Solar.Div.sion Amrita Center for Nanosciences

v.r.ical ZnO nanotube （ZNT） ar.ays wer. synthesized onto an indium doped tin oxide （ITO） glass substr.te by a simple electr.chemical deposition technique followed by a selectiv. etching pr.cess. Scanning electr.n micr.scopy （SEM） showed for.ation of well-faceted hexagonal ZNT ar.ays spr.ading unifor.ly ov.r.a lar.e ar.a. X-r.y diffr.ction （Xr.） of ZNT layer.showed substantially higher.intensity for.the （0002） diffr.ction peak, indicating that the ZnO cr.stallites wer. well aligned with their.c-axis. pr.filometer.measur.ments of the ZNT layer.showed an av.r.ge thickness of -7 μm. Diameter.size distr.bution （DSD） analysis showed that ZNTs exhibited a nar.ow diameter.size distr.bution in the r.nge of 65-120 nm and center.d at -75 nm. The photoluminescence （pL） spectr.m measur.ment showed v.olet and blue luminescence peaks that wer. center.d at 410 and 480 nm, r.spectiv.ly, indicating the pr.sence of inter.al defects. Ultr.-v.olet （Uv. spectr.scopy showed major.absor.ance peak at ,-348 nm, exhibiting an incr.ase in ener.y gap v.lue of 3.4 ev. By employing the for.ed ZNTs as the photo-anode for.a dye-sensitized solar.cell （DSSC）, a full-sun conv.r.ion efficiency of 1.01% was achiev.d with a fill factor.of 54%. Quantum efficiency studies showed the maximum of incident photon-to-electr.n conv.r.ion efficiency in a v.sible r.gion located at 590-550 nm r.nge.

关键词： ZnO nanotubes Indium doped tin oxide (ITO) glass photoluminescence spectr. Electr.chemical deposition Quantum efficiency

petr.leum hydr.car.on concentr.tions in eight mollusc species along Tamilnadu coast, Bay of Bengal, India

在线全文

学校读者我要写书评

暂无评论

Jour.al of Env.r.nmental Sciences 2011年第7期23卷 1129-1134页

作者： S. v.er.singam r. v.nkatachalapathy S. Sudhakar.p. r.ja v. r.jeswar. Depar.ment of physics Annamalai University Centr. of Adv.nced Study in Mar.ne Biology Faculty of Marine Sciences Annamalai University

Eight mollusc species and sediment samples collected fr.m thr.e differ.nt stations along Tamilnadu coast, Bay of Bengal, India wer. analysed for.the lev.ls of petr.leum hydr.car.ons to elucidate the status of the petr.leum r.sidues in mollusc meant for.human consumption. The concentr.tions of petr.leum hydr.car.ons in sediments along Tamilnadu coast v.r.ed fr.m 5.04–25.5 μg/g dw （dr. weight）. High concentr.tion of petr.leum hydr.car.ons in the sediment of Uppanar.estuar. （25.5 ± 1.45 μg/g dw） was per.aps land and mar.ne based anthr.pogenic sour.es of this r.gion. The petr.leum hydr.car.on r.sidues in eight mollusc species collected fr.m Uppanar. v.llar.and Coler.on estuar.es v.r.ed between 2.44–6.04 μg/g ww （wet weight）. Although the concentr.tion of petr.leum hydr.car.ons in sediment of the Uppanar.r.gion was mar.edly higher.than the backgr.und, the petr.leum hydr.car.on r.sidues in mollusc collected fr.m Uppanar.estuar. did not suggest bioaccumulation. The r.sults signified that industr.al gr.wth has affected the aquatic env.r.nments and r.gular.monitor.ng will help to adopt str.ngent pollution contr.l measur.s for.better.management of the aquatic r.gion.

关键词： petr.leum hydr.car.ons sediment mollusc pollution Tamilnadu coast

Analysis of the Statistical Behav.our.of Daily Maximumand Monthly r.infall Data at New DelhiDur.ng Monsoon per.od

在线全文

学校读者我要写书评

暂无评论

Adv.nces in Atmospher.c Sciences 2002年第3期19卷 425-432页

作者： C. v. Singh r. S. Adhikar. H. p. Gar. Centr. of Ener.y Studies Indian Institute of Technology Hauz Khas 110 016 New Delhi India

A statistical analysis of monthly mean and daily maximum r.infall data at New Delhi dur.ng the mon-soon (June-September. per.od 1940-1980 is pr.sented. It has been obser.ed that a good cor.elation exists between the monthly and daily maximum r.infall. A linear.r.gr.ssion analysis of the data is found to be sig nificant for.all the four.months. Some key statistical par.meter. like the mean v.lues of Coefficient of v.r. ability (Cv., r.lativ. v.r.ability (r.) and per.entage Inter.nnual v.r.ability (pIv. hav. been studied and found to be at v.r.ance. Howev.r. their.cor.esponding r.tios between mean daily maximum and mean monthly r.infall ar. significantly lower.

关键词： Monsoon r.infall Coefficient of v.r.ability r.lativ. v.r.ability per.entage inter.nnual v.r.a-bility

Thin Films for.Coating Nanomater.als

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2005年第6期10卷 709-717页

作者： S. M. Mukhopadhyay p. Joshi r. v. p.likollu Depar.ment of Mechanical and Mater.als Engineer.ng Wright State University Dayton OH 45435 USADepartment of Mechanical and Materials Engineering Wright State University Dayton OH 45435 USADepartment of Mechanical and Materials Engineering Wright State University Dayton OH 45435 USA

For.nano-str.ctur.d solids （those with one or.mor. dimensions in the 1-100 nm r.nge）, attempts of sur.ace modification can pose significant and new challenges. In tr.ditional mater.als, the sur.ace coating could be sev.r.l hundr.ds nanometer. in thickness, or.ev.n micr.ns and millimeter.. In a nano-str.ctur.d mater.al, such as par.icle or.nanofiber., the coating thickness has to be substantially smaller.than the bulk dimensions （100 nm or.less）, yet be dur.ble and effectiv.. In this paper. some aspects of effectiv. nanometer.scale coatings hav. been discussed. These films hav. been deposited by a non-line of sight （plasma） techniques; and ther.for., they ar. capable of modifying nanofiber., near.net shape cellular.foams, and other.high por.sity mater.als. Two types of coatings will be focused upon：（a） those that make the sur.ace iner. and （b） those designed to enhance sur.ace r.activ.ty and bonding. The for.er.has been achiev.d by for.ing 1-2 nm layer.of --CF2- （and/or.CF3） gr.ups on the sur.ace, and the latter.by cr.ating a nano- layer.of SiO2-type compound. Nucleation and gr.wth studies of the plasma-gener.ted film indicate that they star. for.ing as 2-3 nm high islands that gr.w later.lly, and ev.ntually completely cov.r.the sur.ace with 2-3 nm film. Contact angle measur.ments indicate that these nano-coatings ar. fully functional ev.n befor. they hav. achiev.d complete cov.r.ge of 2-3 nm. They should ther.for. be applicable to nano-str.ctur.l solids. This is cor.obor.ted by application of these films on v.por.gr.wn nanofiber. of car.on, and on gr.phitic foams. Coated and uncoated mater.als ar. infiltr.ted with epoxy matr.x to for. composites and their.micr.str.ctur., as well as mechanical behav.or. ar. compar.d. The r.sults show that the nano-oxide coating can significantly enhance bond for.ation between car.on and or.anic phases, ther.by enhancing wettability, disper.ion, and composite behav.or. The fluor.car.on coating, as expected, r.duces bond for.ation, an

关键词： sur.ace modification nanomater.al nano-oxide coating fluor.car.on coating

Abr.sion of ultr.fine WC-Co by fine abr.siv. par.icles

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2007年第6期17卷 1287-1293页

作者： p. v. Kr.khmalev Depar.ment of Mechanical and Mater.als Engineer.n g Karlstad University SE-651 88 Karlstad Sweden

Abr.siv. wear.of a ser.es of WC-(5%-14%, mass fr.ction)Co har.metals was inv.stigated employing coar.e and fine SiC abr.siv. under.two-body dr. abr.sion conditions with pin-on-disc and edge-on-disc test ar.angements. Unexpectedly, it is found that submicr.n gr.des demonstr.te substantially higher.wear.r.tes compar.ng with the coar.e gr.des if fine abr.siv. is utilized in pin-on-disc tests. Such a behav.or.is attr.buted to changes in a r.tio of abr.siv. size to size of har. phase as finer.abr.siv. is used. The edge-on-disc test demonstr.tes that edge wear.may be descr.bed in two stages with the highest wear.r.tes at the beginning stage. This behav.or.is associated with a tr.nsition of wear.mechanisms as edge is wider.due to wear. Compar.d with the ultr.fine gr.des of the same Co content, the coar.e gr.des demonstr.te higher.wear.r.tes at the beginning, but lower.wear.r.tes at the final stage. Wear.r.tes and mechanisms obser.ed at final stage cor.elate well to the r.sults obser.ed for.pin-on-disc tests employing fine abr.siv..

关键词： WC-Co合金耐磨性边缘磨损微观效应

Estimation of por. Char.e on Zir.onia Membr.ne pr.par.d by Sol-gel r.ute Using Zeta potential Measur.ment

在线全文

学校读者我要写书评

暂无评论

Jour.al of Mater.als Science & Technology 1998年第5期14卷 425-428页

作者： Seshadr., K.S. Ahmed, Jallel Kesav.moor.hy, r. v.r.thar.jan, K. Sr.niv.san, M.p. Kr.shnasamy, v. Centr.lised Waste Management Facility Kalpakkam Tkmil Nadu -603 102 India Mater.al Science Labor.tor. IGCAR Kalpakkam India Water.and Steam Chemistr. Labor.tor. IGCAR Kalpakkam India Dept. of Chemical Engineer.ng Anna University Chennai India

Zir.onia membr.ne was pr.par.d in the sol-gel pr.cess by filter.ng v.scous colloidal zir.onia sol thr.ugh micr.por.us alumina suppor. and gelling followed by sinter.ng at 743 K. The scanning electr.n micr.gr.ph shows that mean por. size is 543 nm and por. density is 1.47 multiplied by 10**7/cm**2. The filtr.tion char.cter.stics dur.ng membr.ne layer.for.ation show that the membr.ne layer.for.ation star.s after.40 min. The membr.ne layer.thickness and the por.sity of the membr.ne wer. deter.ined gr.v.metr.cally by finding out the amount of water.pr.sent in the por.s. The membr.ne layer.thickness was found to be 3 micr.n and the por.sity was found out to be 0.38. The por. char.e density was estimated fr.m the par.icle char.e density, por. density, por. diameter.and the thickness of the membr.ne layer. (Edited author.abstr.ct) 5 r.fs.

关键词： Zir.onia

Effect of temper.tur. dependent v.scosity on r.v.lv.ng axi-symmetr.c fer.ofluid flow with heat tr.nsfer

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2012年第11期33卷 1441-1452页

作者： p. r.M v. KUMAr Depar.ment of Mathematics National Institute of TechnologyKurukshetra Haryana 136119 India

The pr.me objectiv. of the pr.sent study is to examine the effect of temper.- tur. dependent v.scosity/z（T） on the r.v.lv.ng axi-symmetr.c laminar.boundar. layer.flow of an incompr.ssible, electr.cally non-conducting fer.ofiuid in the pr.sence of a stationar. plate subjected to a magnetic field and maintained at a unifor. temper.tur.. To ser.e this pur.ose, the non-linear.coupled par.ial differ.ntial equations ar. fir.tly conv.r.ed into the or.inar. differ.ntial equations using well-known similar.ty tr.nsfor.ations. The popular.finite differ.nce method is employed to discr.tize the non-linear.coupled differ. ential equations. These discr.tized equations ar. then solv.d using the Newton method in MATLAB, for.which an initial guess is made with the help of the Flex pDE Solv.r. Along with the v.locity pr.files, the effects of temper.tur. dependent v.scosity ar. also examined on the skin fr.ction, the heat tr.nsfer. and the boundar. layer.displacement thickness. The obtained r.sults ar. pr.sented numer.cally as well as gr.phically.

关键词： fer.ofluid temper.tur. dependent v.scosity boundar. layer axi-symmetr.,magnetic field

A simple appr.ach for.stability mar.in of discr.te systems

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2011年第4期9卷 567-570页

作者： Yogesh v. HOTE J. r. p. GUpTA D. r.y CHOUDHUr. Depar.ment of Electr.cal Engineer.ng Indian Institute of Technology (IIT) Depar.ment of Instr.mentation and Contr.l Engineer.ng Delhi Univ.r.ity Depar.ment of Infor.ation Technology (I.T.) M.A.I.T.

In this paper. a technique is pr.sented to deter.ine the stability mar.in of the discr.te systems using r.cur.iv. algor.thm for.power.of companion matr.x and Ger.chgor.n Theor.m and hence sufficient condition of stability is obtained. The method is illustr.ted with an example and it is compar.d with other.methods pr.posed in the liter.tur.. The r.sults hav. applications in the filter.design.

关键词： Ger.chgor.n theor.m power.of companion matr.x Discr.te systems Stability mar.in

A r.bust test of uncer.ain linear.systems

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2009年第3期7卷 277-280页

作者： Yogesh v. HOTE D. r.y CHOUDHUr. J. r. p. GUpTA Depar.ment of Instr.mentation and Contr.l Engineer.ng Delhi University Depar.ment of Computer.Engineer.ng I. P. University

In this paper. it is shown that for.low-or.er.uncer.ain systems, ther. is no need to calculate all the minimum and maximum v.lues of the coefficients for.a per.ur.ed system which is expr.ssed in ter.s of polynomials and hence no need to for.ulate and test all the four.Khar.tonov.s polynomials. Fur.her.or., for.higher.or.er.systems such as n ≥ 5, the usual four.Khar.tonov.s polynomials need not be tested initially for.sufficient condition of per.ur.ed systems; r.ther. the necessar. condition can be checked befor. going for.sufficient condition. In or.er.to show the effectiv.ness of the pr.posed method, numer.cal examples ar. shown and computational efficiency is highlighted.

关键词： Khar.tonov.s theor.m r.bust stability r.uth cr.ter.on