检索结果-南通市图书馆

Equilibr.um, ther.odynamic, and kinetic of Cr.Vi) adsor.tion using a modified and unmodified bentonite clay

在线全文

学校读者我要写书评

暂无评论

inter.ational Jour.al of Mining Science and Technology 2014年第4期24卷 525-535页

作者： D.J.L. Guer.a i. Mello L.r. Fr.itas r. r.sende r.A.r. Silva Depar.ment of Miner.l r.sour.es University Federal of Mato Grosso DRM-UFMT Mato Grosso 78060900 Brazil

The capacities of natur.l and modified Br.zilian bentonite samples as adsor.ents to r.move hexavalent metal chr.mium wer. investigated under.sever.l conditions in batch and column methods. The r.w mater.al, Ca-bentonite, was modified by anchor.ment of 3-aminopr.pyltr.etoxisilane （APS） and 3,2- aminoethylaminopr.pyltr.metoxisilane （AEAPS） in the sur.ace of bentonite sample： This type of new occur.ence of bentonite is suitable as a r.w mater.al for.adsor.tion pr.cess. Adsor.tion behavior.of thr.e bentonite types was str.ngly depending on pH of adsor.ate solution, contact time adsor.ent/adsor.ate, and initial concentr.tion of Cr.Vi）. The r.sults wer. confir.ed by column method and r.veals that the adsor.tion pr.cess of mater.als accor.ed by the r.dlich-Peter.on, Sips, Dubinin-r.dushkevich, and tang- muir.isother. models. The exother.ic entbalpic values r.flected a favor.ble ener.etic pr.cess for.chr.- mium ions anchor.d in the mater.al sur.aces. The negative Gibbs fr.e ener.y r.sults suppor.ed the spontaneity of thr.e adsor.tion r.actions with Cr.Vi） ions.

关键词： Bentonite Or.ano-bentonite Chr.mium Equilibr.um Kinetic Adsor.tion

Soil Wettability as Affected by Soil Char.cter.stics and Land Use

在线全文

学校读者我要写书评

暂无评论

Pedospher. 2010年第1期20卷 43-54页

作者： r. HOr. institute of Plant Nutr.tion and Soil Science Christian-Albrechts-University zu Kiel

Depth distr.bution of soil wettability and its cor.elations with vegetation type, soil textur., and pH wer. investigated under.var.ous land use (cr.pland, gr.ssland, and for.stland) and soil management systems. Wettability was evaluated by contact angle with the Wilhelmy plate method. Water.r.pellency was likely to be pr.sent under.per.anently vegetated land, but less common on tilled agr.cultur.l land. it was mostly pr.valent in the topsoil, especially in coar.e-textur.d soils, and decr.ased in the subsoil. However. the depth dependency of wettability could not be der.ved fr.m the investigated wide r.nge of soils. The cor.elation and multiple r.gr.ssion analysis r.vealed that the wettability in r.pellent soils was affected mor. by soil or.anic car.on (SOC) than by soil textur. and pH, wher.as in wettable soils, soil textur. and pH wer. mor. effective than SOC. Fur.her.or., the quality of SOC seemed to be mor. impor.ant in deter.ining wettability than its quantity, as pr.ofed by str.nger.hydr.phobicity under.conifer.us than under.deciduous for.stland. Soil management had a minor.effect on wettability if conventional and conser.ation tillage or.differ.nt gr.zing intensities wer. consider.d.

关键词： soil management soil or.anic car.on soil pH soil textur.

Numer.cal investigation of Tip Clear.nce Effects in an Axial Tr.nsonic compr.ssor

在线全文

学校读者我要写书评

暂无评论

Jour.al of Ther.al Science 2012年第2期21卷 109-119页

作者： r. Cior.iar. A. Lesser.F. Blaim r. Niehuis institute for.Jet Pr.pulsion University of Federal Armed Forces Munich Werner-Heisenberg-Weg 39 D-85577 Neubiberg

Numer.cal investigations of the Dar.stadt tr.nsonic single stage compr.ssor.(DTC), in the r.tor.-Stator. configur.tion, aimed at advancing the under.tanding of the effect of differ.nt r.tor.tip gaps and tr.nsition modelling on the blade sur.aces ar. pr.sented. Steady thr.e dimensional r.ynolds Aver.ged Navier.Stokes (r.NS) simulations wer. per.or.ed to obtain the flow fields for.the differ.nt configur.tions at differ.nt oper.ting conditions using the r.NS-Solver.Tr.CE. The stage geometr. and the multi-block str.ctur.d gr.d wer. gener.ted by G3DMESH and a gr.d sensitivity analysis was conducted. For.the clear.nce gap r.gion, a fully gr.dded special H-gr.d was chosen. compar.sons wer. made between the flow char.cter.stic at design speed, r.pr.sentative for.a tr.nsonic flow r.gime, and at 65% speed, r.pr.sentative for.a subsonic flow r.gime. The computations wer. used to analyse the flow phenomena thr.ugh the tip clear.nce r.gion for.the differ.nt configur.tions and their.impact on the per.or.ance of the compr.ssor.stage.

关键词： Flow in axial compr.ssor sur.e and stall tip clear.nce flow multimode tr.nsition model.

inhomogeneous 2D Lennar.-Jones Fluid: Theor. and computer.Simulation

在线全文

学校读者我要写书评

暂无评论

communications in Theor.tical Physics 2012年第11期58卷 759-764页

作者： r. Khor.ad Depar.ment of Physics College of SciencesYasouj University

in this wor., ther.odynamical pr.per.ies of a two-dimensional （21）） Lennar.-Jones （L J） fluid ar. studied. Her., to incr.ase the accur.cy of our.theor.tical calculations, the cor.elation functions in thr.e-par.icle level （tr.plet） ar. applied. To obtain the tr.plet cor.elation functions, the Attar.＇s sour.e par.icle method is extended to 21） systems. in the Attar.＇s pr.cedur., the inhomogeneous Or.stein Zer.ike （OZ） equation is solved using the Tr.izenber. Zwanzwig （TZ） expr.ssion and a closur. r.lation like the hy2er.etted-chain （HNC） appr.ximation. in the pr.sent wor., we also have per.or.ed the Monte Car.o （MC） simulation. The theor.tical r.sults ar. in fair.y agr.ement with the MC simulation. Also, our.r.sults show that the appr.ach pr.posed her. is suitable to study the 2D LJ fluid.

关键词： Lennar.-Jones fluid cor.elation functions computer.simulation thr.e-par.icle level

A MATHEMATiCAL HEAT Tr.NSFEr.MODEL iNSTATiC AND coNTiNUOUS CASTiNG

在线全文

学校读者我要写书评

暂无评论

Acta Metallur.ica Sinica(English Letter.) 2004年第6期17卷 776-784页

作者： r. Ghasemzadeh Metallur.y Depar.ment Iran University of Science and Technology Narmak Tehran 16844 Iran

The application of a heat flow model to descr.be the ther.al char.cter.stics of fr.ezing alloys with nar.ow mushy zones fr.m a r.fr.ger.ted mould wall was outlined. The extension of the model was to tr.at the continuous casting of metals with low ther.al conductivity, such as steels, which will be outlined. The model was based on the mathematical expedient for.r.placing ther.al r.sistance of the metal/mould inter.ace by vir.ual adjuncts of metal/mould mater.al. it pr.vided a good descr.ption of the pool pr.file and the technique exhibits advantages in ter.s of both computation and ver.atility of application.

关键词： air.gap pool pr.file mushy zone dir.ctional solidification

r.cent r.sults for.single meson pr.duction fr.m the Cr.stal-Bar.el/TAPS exper.ment at ELSA

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1056-1062页

作者： r. Beck HiSKP Univer.ity of Bonn 53115 Bonn Germany

The pr.sent focus of the CBELSA/TAPS exper.ment is on meson-photopr.duction off the nucleon using polar.zed photons and polar.zed tar.ets. Her. fir.t pr.liminar. r.sults on the r.actions γp → pπ and γp → pπ for.both cir.ular.y and linear.y polar.zed photons and a longitudinally polar.zed tar.et ar. pr.sented. Pr.liminar. r.sults for.the beam asymmetr. ∑ and the double polar.zation obser.able G have been extr.cted for.both r.actions using the linear.polar.zation data. Fr.m the cir.ular.polar.zation data the obser.able E has been deter.ined. Due to the near.4π angular.cover.ge of the detector.system these r.sults cover.almost the full solid angle.

关键词： meson photopr.duction double polar.zation bar.on spectr.scopy

Lake sediment r.cor.s on climate change and human activities since the Holocene in Er.ai catchment, Yunnan Pr.vince, China

在线全文

学校读者我要写书评

暂无评论

Science China Ear.h Sciences 2005年第3期48卷 353-363页

作者： r. Matsumoto Geology institute Tokyo University Tokyo 113 Japan

Accor.ing to high-r.solution analyses on multi-pr.xy of sediment cor. fr.m the Er. hai Lake, Yunnan Pr.vince, the sequence of climatic and envir.nmental change since the Holo- cene has been r.constr.cted based on accur.te dating. The r.sults show that climate had tr.n- sited fr.m cold-wet to war.-wet dur.ng ca. 12950-8399 aBP in this ar.a, and the tr.nsition happened in ca. 10329 aBP. Due to the enhancing southwest Asian monsoon and incr.asing pr.cipitation, the lake-level of the Er.ai Lake began to r.se after.ca. 10329 a BP. Climate in the catchment was war. and wet dur.ng the mid-Holocene, and the war.est stage appear.d in ca. 8399-6371 a BP. The lake-level descended in the mid-Holocene because of the decr.ase of effective moistur. in the basin. Human activities appear.d in ca. 6371 a BP, and the initial man- ner.mainly focused on defor.station. Up to ca. 2139 a BP, due to the amount of immigr.tion into this ar.a, the cultivation was developed widely, which was followed by mining (coal mine).

关键词： climate change, human activity, Holocene, lake sediment, Er.ai Lake in Yunnan Pr.vince.

complex var.able appr.ach in studying modified polar.zation satur.tion model in two-dimensional semiper.eable piezoelectr.c media

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1517-1532页

作者： S. SiNGH K. SHAr.A r. r. BHAr.AVA Depar.ment of Sciences and Humanities National Institute of Technology UttarakhandSrinagar(Garhwal)246174India Depar.ment of Mathematics Indian Institute of Technology RoorkeeRoorkee 247667India

A modified polar.zation satur.tion model is pr.posed and addr.ssed math- ematically using a complex var.able appr.ach in two-dimensional （2D） semiper.eable piezoelectr.c media. in this model, an existing polar.zation satur.tion （PS） model in 2D piezoelectr.c media is modified by consider.ng a linear.y var.ing satur.ted nor.al electr.c displacement load in place of a constant nor.al electr.c displacement load, applied on a satur.ted electr.c zone. A centr. cr.cked infinite 2D piezoelectr.c domain subject to an ar.itr.r. poling dir.ction and in-plane electr.mechanical loadings is consider.d for.the analytical and numer.cal studies. Her., the pr.blem is mathematically modeled as a non-homogeneous r.emann-Hilber. pr.blem in ter.s of unknown complex potential functions r.pr.senting electr.c displacement and str.ss components. Having solved the Hilber. pr.blem, the solutions to the satur.ted zone length, the cr.ck opening displace- ment （coD）, the cr.ck opening potential （coP）, and the local str.ss intensity factor. （SiFs） ar. obtained in explicit for.s. A numer.cal study is also pr.sented for.the pr.posed modified model, showing the effects of the satur.tion condition on the applied electr.cal loading, the satur.tion zone length, and the coP. The r.sults of fr.ctur. par.meter. obtained fr.m the pr.posed model ar. compar.d with the existing PS model subject to electr.cal loading, cr.ck face conditions, and polar.zation angles.

关键词： complex var.able fr.ctur. par.meter local str.ss intensity factor.(SiF),piezoelectr.c polar.zation satur.tion (PS) model

Application of Tungsten as a De-NO_x Catalyst

在线全文

学校读者我要写书评

暂无评论

r.r. Metals 1994年第3期13卷 229-235页

作者： Nakatsuji T.(Sakai Chemical industr., co. , Lid. 5-i, Ebisujimacho Sakai Osako 590, Japan) Sakai Chemical industr. co 日本

Abstr.ct A catalyst for.r.moval of nitr.gen oxides, in stationar. Sour.es, r.quir.s many kinds of char.cter.sticsfor.commer.ial application. At fir.t, a vanadium pentaoxide based catalyst was used for.the NO-NH3-OZr.action because of its high activity at lower.temper.tur.s. But it was`later.found that this catalyst had *** like a low ther.al dur.bility and a high conver.ion r.te of SO: to SO3. On the other.hand, tungstentr.oxide was well known as a catalyst that has a high ther.al dur.bility and a low conver.ion r.te of SOZto SO3 but showed a low activity at appr.pr.ate temper.tur.. For.these r.asons, tungsten tr.oxide basedcatalysts have not been used in the r.action in most actual plants except for.special cases. Fur.her.*** on this catalyst r.vealed that a catalyst compr.sing of titania f80 wt%￣ 90 wt%j- tungsten tr.oxide(5 wt% ￣ 15 wt%j, and vanadium pentaoxide (0,l wt%￣ 5 wt%j, showed a high ther.al dur.bility and alow conver.ion r.te of SOZ to SO3 as well as high activity towar.s the NO-NHr.z r.action.

关键词： NO De