聚氨酯纳米复合材料(英语原文)

Designed Monomers and Polymers12(2009)279–290

www.brill.nl/dmp

Review

Polyurethane Nanocomposites

Igor V.Khudyakov a,R.David Zopf a and Nicholas J.Turro b,?

a Bomar Specialties,Torrington,CT06790,USA

b Chemistry Department,Columbia University,New York,NY10027,USA

Abstract

This review describes the present state of science and technology of photopolymerizable(UV-curable) polyurethane(PU)nanocomposites which include nanosilica and organically-modi?ed clay(organoclay).

A number of documented improvements of properties of PU nanocomposites compared to the pristine PU are presented.Many data on the structure and properties of PU nanocomposites were obtained not only for UV-cured urethane acrylate oligomers,but also for nanocomposites produced in the dark reactions.These data are critically reviewed.There is an expectation in the?eld of dramatic improvement of properties of PU nanocomposites under low loading(1–5wt%)of organoclay.

?Koninklijke Brill NV,Leiden,2009

Keywords

Polyurethane,organoclay,UV-cure,nanosilica,nanocomposite,montrillomonite

1.Introduction

Nanocomposites are polymers containing nano?llers[1–3].The microstructure of nanocomposites has inhomogeneities in the scale range of nanometers.Nanocom-posite materials cover the range between inorganic glasses and organic polymers [4].Fillers of polymers have been used for a long time with the goal of enhanced performance of polymers,and especially of rubber.The present paper provides a brief critical review of the literature and some our results on polyurethane(PU) nanocomposites studies.Polymer–clay nanocomposites were reported in the litera-ture as early as1961[5].Nanocomposites demonstrate often unusual and bene?cial for the user properties.Scienti?c and technical literature report the improvement or enhancement of properties of polymer nanocomposites compared to the pristine polymers.This vague statement means an improvement of polymer properties from the standpoint of polymer application.However,different applications may have *To whom correspondence should be addressed.E-mail:njt3@https://www.sodocs.net/doc/851592737.html,

?Koninklijke Brill NV,Leiden,2009DOI:10.1163/156855509X448253

280I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

quite different if not opposite requirements.Increase of polymer toughness(J/m3) is always considered as an improvement.

2.Types of Nanocomposites

Two types of nano?llers are under active investigation:nanoparticles and nanoclays. The main paradigm is that a valuable nanocomposite is one with the largest possible surface of nano?ller.In practice it means avoiding aggregation of nanoparticles and exfoliation of nanoclays,see below.Nanoparticles are commercially available from different sources.Sols of nanosilica as colloid solutions in water or in organic solvents are used in preparation of PU nanocomposites.Fumed silica is available as individual particles ranging from10–20nm to micrometers,and can be more or less successfully dispersed in a polymer[6,7].

Layered alumosilicates clays and especially montrillomonite(bentonite)are widely used in nanocomposites.Silicates have a characteristic distance between galleries of1nm;the basal spacing of a gallery is also ca.1nm.Inorganic cations like Na+between galleries hold negatively charged galleries together.The replace-ment of the inorganic cations in the galleries of the native clay by alkylammonium (onium)salts or quarternary amines with long alkyl substituents(surfactants)leads to a better compatibility between the inorganic clay and hydrophobic polymer ma-trix.The replacement leads to an increase of the space between galleries facilitating intercalation of polymer molecules into the clay.Unless stated otherwise,in this paper we will describe only such onium salt modi?ed montrillomonites.We term them organoclay.Three main types of nanocomposites are schematically presented in Fig.1.

In most cases exfoliated nanocomposites with a high aspect ratio demonstrate en-hanced properties compared to the same pristine polymers or polymer with smectic https://www.sodocs.net/doc/851592737.html,ually the exfoliation of clay nanolayers in a polymer matrix requires polar-ity match between the clay surface and the prepolymer precursors to allow optimal access to the gallery[10].There is a number of ways to increase a degree of exfo-

Figure1.A common pictorial presentation of three types of polymer composites with clay(top).Bot-tom left,conventional composite;bottom center,intercalated nanocomposite;bottom right,exfoliated nanocomposite.After Refs[3,8,9].

I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290281 liation in a nanocomposite,such as in situ polymerization,melt blending,solution blending,sonication,high shear mixing,melt intercalation,and some others[2,10]. The morphology of nanocomposites is usually studied by X-ray techniques(XRD), transmission electron microscopy(TEM)and scanning electron microscopy(SEM) [11].

3.PU-Nanosilica Composites

PU nanocomposites with colloidal silica and alumina were prepared and their phys-ical properties were studied[12–15].The following is a straightforward way of preparation of nanocomposites.Colloidal silica of in organic solvent is blended with polyol,organic solvent is stripped off,and one obtains a sol of nanosilica in polyol.After that,polyol with silica reacts with diisocyanate with a formation of PU.The loading by nanosilica in some experiments was as high as50wt%[12–14].Silica sol can be added to monomers at the stage of polyester preparation by polycondensation[16].Nanosilica in PU can be prepared by in situ hydrolysis and condensation of silane-terminated oligomers[15].Note that everything should be done to avoid agglomeration of nanoparticles.

Some bene?cial properties of silica nanocomposites of PU were observed.Stor-age moduli of elastomers with nanosilica demonstrated an increase in the rubbery region with increasing?ller content[12].The density of PU nanocomposites is lower than the density of microcomposites(with distributed silica particles ofμm size)under the same loading(in wt%)[12].Nanosilica has a profound effect on ten-sile strength of PU composites under a high load[9,12,13].Elongation-at-break of PU nanocomposites demonstrated a strong dependence on a level of nanosilica.

A pronounced effect of nanosilica on physical properties of PU nanocomposites was observed under load of10–20wt%[12,13].

A dependence of physical properties of PU with nanosilica of different particle size was studied[15].It was found that maximum values of the glass-transition temperature(T g),tensile properties and abrasion resistance were obtained when the particle size of silica was about28nm[15].

We were interested in the increase of abrasion resistance of the UV-cured ure-thane acrylates oligomers upon addition of colloidal silica.Colloidal silica of Nissan was added as a solution in methyl ethyl ketone(MEK)to polyol;MEK was stripped off,cf.,the beginning of this section.We obtained6.0wt%of sil-ica on solids in urethane acrylates oligomers.We did not observe any increase of abrasion-resistance of the UV-cured coating within the accuracy of our mea-surements.Apparently surface concentration of nanoparticles was too low to affect abrasion.

No regular dependences are observed in one or another property of PU upon loading of nanoparticles.It was noticed,‘no regular pattern can be said to be emerging’[14].Usually these dependencies,‘property-loading’,have at least one maximum or minimum.

282I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

4.PU-Organoclay Composites

A very impressive industrial application of nanocomposites was demonstrated by the Toyota Group in1988(see,e.g.,Ref.[17]).By using organoclay,they were able to polymerizeε-caprolactam in the interlayer gallery region of clay to form Nylon6-clay hybrid.At a loading of only4.2wt%the tensile modulus doubled,the tensile strength increased more than50%,and heat distortion temperature(HDT) increased by80?C compared to the pristine polymer.The key to this extraordinary performance of Nylon6-clay nanocomposites was explained as the complete ex-foliation of the clay nanolayers in the polymer matrix[17].This remarkable result stimulated many chemists to search for dramatic improvement of polymer proper-ties upon addition of low level of organoclay.

The effects of organoclays on the properties of PU were studied[1,3,18–33].PU were prepared by the following procedures:(i)distribution of clay in polyol with a subsequent reaction with diisocyanate;(ii)interaction of PU with clay in organic solvent with a subsequent evaporation of solvent;(iii)reaction of diisocyanate with hydroxyalkyl groups of organic modi?er in the clay with a subsequent reaction with polyol.

PU nanocomposites prepared with1–6wt%of clay demonstrate peaks on XRD patterns with a distance between galleries(basal spacing)in the range of1.6–3.2nm depending on the clay nature and its level[18].It is possible to conclude based on XRD and SEM and other spectroscopy,that polymer intercalated into the organ-oclay,it is not exfoliated,and organoclay is not homogeneously dispersed in a PU matrix[18].Many composites with an added non-exfoliated clay still demonstrate improved mechanical and physical properties and thermal stability,lower perme-ability of dioxygen compared to the pristine PU[18].At the same time presented data of property vs organoclay level are not simple in a series of similar nanocom-posites:it can be a curve with a maximum(minimum),it can be a permanent decrease or an increase of a property.This con?rms the statement made in the pre-vious section on the lack of a regular pattern in property vs nano?ller load[18].

It is documented that high temperature resistance of PU nanaocomposites is higher than that of pristine PU[18,19,27,30,33].

Wang and Pinnavaia prepared PU nanocomposites by solvation of organoclay by polyol?rst.Loading of polyol with clay up to10–20wt%makes a pourable mixture [19].XRD demonstrates that intercalation of polyol into clay results in an increase of with basal spacing from1.8–2.3nm to3.2–3.9nm[19].Such spacing testi?es of intercalation of polyol into clay.Formation of PU results in further increase of basal spacing up to more than5nm[19].The latter case may be considered as exfoliation of a clay or dispersal of nanolayers.Important,that onium ions of the clay were considered as active reagents for coupling with diisocyanate[19].Loading of PU with5–10wt%of clay results in a two-three times improvement of tensile prop-erties of a polymer,namely increase of strain-at-break,tensile modulus and tensile strength[19].

I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290283

Common inorganic?llers are commonly used in PU chemistry to reduce for-mation cost and to increase stiffness,but the improvements in modulus for con-ventional PU composites are compromised by a sacri?ce of elastomer properties. The nanocomposites reported in Ref.[19]exhibited an improvement in both elas-ticity and tensile modulus.Clay nanolayers,even when aggregated in the form of intercalated tactoids,strengthen,stiffen and toughen the matrix in the studied case. The enhancement in strength and modulus is directly attributed to the reinforce-ment provided by the disperse clay nanolayers.The improvement in elasticity is tentatively attributed to the plasticizing effect of onium ions,which contribute to dangling chain formation in the matrix,as well as to conformational effects on the polymer at the clay–matrix interface.

A complete exfoliation of nanoclay was observed in PU nanocomposites with high concentration of nanoclay(up to40%)[23].In this work organoclay was ad-ditionally functionalized with diamine,which served a chain extender under PU nanocomposite formation.Tensile strength and elongation-to-break reaches max-imum at5wt%of nano?ller loading[23].Another study of PU nanocomposites demonstrates that the maximum values of?exural and tensile strengths are obtained at only few percent of a clay content[26].Several PU nanocomposites prepared in [18]were studied in the range of organoclay loading of0–8wt%.Tensile proper-ties demonstrate optimal properties at3–4wt%loading by different organoclays. Ultimate strength and initial modulus have increased in nanocomposites,as well as increased gas barrier properties,the thermal stability of one nanocomposite only increased with increasing clay content[18].

A gradual increase of tensile strength with clay content increase up to5wt% of PU nanocomposites and only slight increase of glass-transition temperature(T g) and slight increase of thermal stability was observed for PU nanocomposites pre-pared in Ref.[31].It was concluded based on WAXD and TEM that PU intercalated into clay galleries[31].

Organically-treated synthetic?uoromica,which is a layered silicate as well,of different size has a modest effect on the properties of PU nanocomposites[3].Ex-foliated in a solvent unmodi?ed clay laponite as a hydrophilic compound interacts with polar soft segments(polyol)in PU like poly(ethylene oxide)or poly(propylene oxide)where as in PU with hydrophobic soft segments like poly(tetramethylene ox-ide)clay interacts with the hard domain(urethane links)[24].Thus,in the?rst case a decrease toughness and elongation-to-break is observed,whereas in the second case an increase of the same properties is observed[24].Such a study gives a better understanding of the nanoclay effect of PU nanocomposites properties.

It is reasonable to expect that the formation of PU nanocomposites leads not only to improvement of all valuable for the user properties of the pristine PU. The PU nanocomposites studied in Ref.[27]demonstrated an increase in the elas-ticity,decrease in damping property,signi?cant increase in thermal stability but demonstrated also a decrease of tensile modulus.Hysteresis results indicate that energy dissipation increases with an organoclay concentration increase[27].Films

284I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

of radiation-curable urethane acrylates demonstrate minor variation of Young’s modulus and tensile strength upon dispersion of organoclay in formulations in the concentration up to5wt%[28].

Some onium salts of organoclay haveω-hydroxyalkyl substituents.The HO–CH2–group can be used to react with isocyanate and,that way,to drag OCN–R be-tween galleries or at least strengthen the interaction between urethane pre-polymer and clay[29,30].A twofold increase of tensile strength and tensile modulus in exfo-liated nanocomposites was obtained[29].In a quite similar way PU nanocomposites are formed by a reaction of IPDI not only with polyol but with HO–CH2–groups within galleries.Probably nanocomposites have an intercalated structure[34].

PU nanocomposites with the photoinitiator(PI)2-hydroxy-2-methyl-1-phenyl-propane-1-one(Darocur1173)were prepared[30].This PI-PU nanocomposite was dispersed in polymerizable resins.Such initiator manifested high ef?ciency. XRD and TEM demonstrated formation of intercalated and exfoliated UV-cured nanocomposites with many good characteristics[30].Photopolymerization occurs inside the organoclay galleries[30].

PU,as well as a number of other polymers,can demonstrate shape recovery after temporary applied stress(shape memory).PU nanocomposites demonstrated the lowest relaxation rate after removal of a stress1wt%of organoclay.The studied PU nanocomposites manifested the highest degree of clay exfoliation namely at 1wt%[33].PU nanocomposites with3and5wt%of organoclay relaxed faster than the pristine PU[33].

A profound improvement of properties PU foam upon addition of5wt%of organoclay was observed[35].

We used organoclay Cloisite?15A of Southern Clay Products[36]as received.

A distance between the galleries in the Closite is3.15nm[21,22].Urethane acry-late oligomers were prepared the usual way:a reaction of polyol with diisocyanate with a subsequent capping of non-reacted isocyanate groups byω-hydroxyalkyl acrylates.Prior to that Cloisite was dispersed in polyol by prolong high shear mixing.Unfortunately,this Cloisite and several other studied nanoclays of a sim-ilar structure ef?ciently catalyze di-and,especially trimerization of common iso-cyanates at elevated temperatures[37]:

(1) Formation of isocyanurate in the case of common diisocyanates TDI and IPDI was demonstrated by IR,with characteristic peaks at1695–1715cm?1[29].Polyol with dispersed organoclay and diisocyanates transforms into a solid or a very viscous

I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290285

https://www.sodocs.net/doc/851592737.html,mon polyisocyanates and their abbreviated names.

product.We have found that among several common commercially available poly-isocyanates only those presented in Scheme1do not react with itself and/or with clay under solventless preparation of PU nanocomposites.

To the best of our knowledge,most of the publications,except Ref.[19],do not report disappearance of–NCO in the presence or organoclay by reaction(1).We believe that reaction(1)is a serious hurdle in the synthesis of PU nanocomposites.

Below we will discuss the properties of urethane acrylate oligomer prepared from a trifunctional polyol,H12MDI(Scheme1)and2-hydroxylethyl acrylate as a cap-ping agent.We will name this oligomer UAO.UAO had0–20.0wt%of Cloisite?15A.We studied UAO as a viscous liquid and as a UV-cured in the presence of a photoinitiator?lm.Figure2presents XRD data on the cured UAO.

The following peak locations2θand corresponding spacing(in nm),presented in parentheses,were observed:0.25?(35.3);1.4?(6.3);2.3?(3.8);4.3?(2.1);7.0?(1.3).Interesting is the absence of a maximum at2.8?(3.15nm)of basal spacing in individual Closite?15A(see above).XRD study gives info on the nanocomposite. Lack of the maxima will mean the complete exfoliation of clay or a high disorder of clay.However,several maxima are observed in Figs2and3.A peak at2θ=0.25?is very close to the direct beam and may be spurious.A broad hump at2θ=20?(approx.0.4nm)is consistent with the bulk polymer portion of a sample.Most probably distances of3.8and6.3nm correspond to the intercalated PU acrylate. TEM and SEM will be used used in addition to XRD to get more accurate picture.

We have studied rheology of urethane acrylate nanocomposites with0,3.2,10.0 and20.0wt%of Closite?15A with an ARES(Advanced Rheometric Expansion System)Rheometer.Measurements were done in the rate sweep,dynamic strain sweep and dynamic frequency sweep modes.

286I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

Figure2.Small-(the left curve)and wide-angle X-ray scatter(the right curve)XRD patterns of UV-cured UAO with10wt%of Closite?15A.

Figure4demonstrates the expected pseudoplastic rheological behavior.Figure5 shows a maximum,which most probably re?ects reversible agglomeration of dis-tributed organoclay particles.At low shear rates particles bump into each other and stick,causing an increase of viscosity.At higher shear rates,these loose agglom-erates break up.In general,rheological measurements revealed a rather complex behavior of UAO/Cloisite nanocomposites.

We compared the physical properties of UV-cured two UAO?lms:with0and with10wt%organoclay.We did not observe signi?cant changes in tensile proper-ties and in T g of the two samples.UAO with10wt%organoclay?nds an application in low gloss furniture coatings.Macroscopic gloss measurements of cured?lms of UAO/organoclay demonstrated a marked decrease in surface gloss,proportionate with clay concentration(15G.U.at60?with4wt%clay,vs90G.U.at60?for pris-tine cured UAO).Unlike the incorporation of common fumed silica matting agents, the resulting matte?nishes were highly resistant to burnishing.It is theorized that intercalated clay particles are embedded in the cured polymer matrix with some of the added durability expected of fully exfoliated organoclay,and yet are suf?-ciently abundant and proximate so as to have a visual impact on cured?lm optical properties.

5.Conclusions and Perspectives

In the present article we aimed to describe the current status of PU nanocomposites research.Colloidal silica and organoclays are the most studied nano?llers which of-ten reinforce PU.The advantage of nano-scale reinforcement is twofold:(1)when

I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290287

Figure3.Expanded small-angle X-ray scatter curve of Fig.2.

nano-scale?llers are homogeneously dispersed in the matrix,a tremendous sur-face area developed that could contribute to polymer chain con?nement,which may lead to higher T g,higher stiffness and tensile strength,increased elongation and an increase of both?exural and tensile modulus,higher HDT,and(2)nano-scale?llers,especially clays,provide an extraordinary zigzag tortuous diffusion path that lead to enhanced barriers for gas penetration for a gas(dioxygen,others), moisture.The enhanced barrier characteristics,chemical resistance,reduced sol-vent uptake and?ame retardancy of clay–polymer nanocomposites originates from the hindered pathways through the nanocomposite[2,9].Usually nanocomposites possess special properties not shared by conventional composites,due primarily to large interfacial are per unit volume or mass of the dispersed phase(e.g.,750m2/g [2]).Current status of nanoscience and nanotechnology does not allow prediction of the‘good’formulations and properties of nanocomposites.Chemist/technologist addresses to the prior art and analogies developing nanocomposites,or runs an ex-ploratory work.

Improved properties of some PU nanocomposites with silica can be obtained un-der high load of the latter,namely10–50wt%[14].Organoclay can be properly dis-solved in the level of3–10wt%in order to obtain enhanced performance[18,19].

288I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

Figure4.Dependence of complex viscosity of UAO vs shear rate(rad/s)in the rate sweep mode at 30?C.UAO did not have organoclay.

Figure5.Dependence of complex viscosity of UAO vs shear rate(rad/s)in the rate sweep mode at 30?C.UAO had10.0wt%of organoclay.

One should avoid precipitation(crashing,gel formation)of silica in a nanocompos-ite.In the case of clay all efforts are made to exfoliate clay in polyol or at least

I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290289 to intercalate polyol into organoclay,and to get a large aspect ratio.The fact of exfoliation can be veri?ed by XRD and by other techniques.

PU can be obtained by two ways:by radiation cure of urethane acrylates oligomers(pre-polymers)or by dark reactions between diisocyanates and polyols. Radiation cure of urethane acrylates oligomers,and UV-cure in particular,has all of the known advantages over dark cure(high rate,low energy consumption,etc.).The presence of nano?ller,especially well dispersed nano?ller,does not inhibit photoin-duced reactions,cf.,e.g.,Refs[28,38].Moreover,photoinitiator intercalated into clay galleries,demonstrates high ef?ciency(Section4).

A stunning and often cited result of the Toyota group[17]on nanocomposites expected to?nd a wide application in automotive industry,‘but this application was stopped because of the high cost’[1].To the best of our knowledge,this work was never reproduced.Nanocomposites are expected to revolutionize polymer technol-ogy.Time will show if it will happen,or not.

Acknowledgements

The authors at Bomar are grateful to J.A.Leon for fruitful discussions.The Columbia author thanks the National Science foundation for its generous support through Grant CHE0717518.

References

1.T.J.Pinnavaia and G.W.Beall,Polymer-Clay Nanocomposites.Wiley,New York,NY(2000).

2.M.Rosoff,Nano-Surface Chemistry.Marcel Dekker,New York,NY(2000).

3.D.R.Paul and L.M.Robeson,Polymer49,3187(2008).

4.B.M.Novak,Adv.Mater.5,422(1993).

5.A.Blumstein,Bull.Chem.Soc.,899(1961).

6.S.C.Jana and S.Jain,in:Proc.59th ANTEC(SPE),V ol.2,p.2180(2001).

7.S.Zhou,L.Wu,J.Sun and W.Shen,https://www.sodocs.net/doc/851592737.html,.Coating.45,33(2002).

8.Z.Wang,P.C.LeBaron and T.J.Pinnavaia,in:8th Int.Conf.on Polymer Additives,An Addition,

p.10(1999).

9.P.C.LeBaron,Z.Wang and T.J.Pinnavaia,Appl.Clay Sci.15,11(1999).

10.C.S.Trianta?llidis,P.C.LeBaron and T.J.Pinnavaia,Chem.Mater.14,4088(2002).

11.M.K.Sanyal,A.Datta and S.Hazra,J.Marcomol.Sci.Pure Appl.Chem.74,1553(2002).

12.Z.S.Petrovi′c and W.Zhang,Mater.Sci.Forum352,171(2000).

13.I.Javni,Z.S.Petrovi′c and A.Waddon,A.Polyurethanes Expo’98.Dallas,TX,September17–20

(1998).

14.Z.S.Petrovi′c,I.Javni,A.Waddon and G.Bánhegyi,J.Appl.Polym.Sci.76,133(2000).

15.Y.Chen,S.Zhou,H.Yang and L.Wu,J.Appl.Polymer Sci.95,1032(2005).

16.J.F.Gerard,H.Kaddami and J.P.Pascault,in:Proceedings Euro?llers97,Manchester,p.407

(1997).

https://www.sodocs.net/doc/851592737.html,uki,Y.Kojima,A.Okada,Y.Fukushima,T.Kurauchi and O.Kamigaito,J.Mater.Res.8,

1179(1993).

18.J.-H.Chang and Y.U.An,J.Polym.Sci.B40,670(2002).

290I.V.Khudyakov et al./Designed Monomers and Polymers12(2009)279–290

19.Z.Wang and T.J.Pinnavaia,Chem.Mater.10,3769(1998).

20.Y.I.Tien and K.H.Wei,J.Appl.Polym.Sci.86,1741(2002).

21.L.Zhu and R.P.Wool,Polymer47,8106(2006).

22.C.H.Dan,M.H.Lee,Y.D.Kim,B.H.Min and J.H.Kim,Polymer47,6718(2006).

23.P.Ni,Q.Wang,J.Li,J.Suo and S.Li,J.Appl.Polymer Sci.99,6(2006).

24.B.Finnigan,P.Halley,K.Jack,A.McDowell,R.Truss,P.Casey,R.Knott and D.Martin,J.Appl.

Polymer Sci.102,128(2006).

25.L.T.J.Korley,S.M.Liff,N.Kumar,G.H.McKinley and P.T.Hammond,Macromolecules39,

7030(2006).

26.W.J.Seo,Y.T.Sung,S.B.Kim,Y.B.Lee,K.H.Choe,S.H.Choe,J.Y.Sung and W.N.Kim,

J.Appl.Polymer Sci.102,3764(2006).

27.J.Jin,M.Song,K.J.Yao and L.Chen,J.Appl.Polymer Sci.99,3677(2006).

28.F.M.Uhl,P.Davuluri,S.-C.Wong and D.C.Webster,Polymer45,6175(2004).

29.A.Pattanayak and S.C.Jana,Polymer46,3275(2005).

30.H.Tan and J.Nie,J.Appl.Polymer Sci.106,2656(2007).

31.A.Pattanayak and S.C.Jana,Polymer46,5183(2005).

32.D.S.Kim,J.-T.Kim and W.B.Woo,J.Appl.Polymer Sci.96,1641(2005).

33.F.Cao and S.C.Jana,Polymer48,3790(2007).

34.S.Solarski,S.Benali,M.Rochery,E.Devaux,M.Alexandre,F.Monteverde and P.Dubois,

J.Appl.Polymer Sci.95,238(2005).

35.X.Cao,L.J.Lee,T.Widya and C.Macosko,Polymer46,775(2005).

36.Southern Clay Company website,https://www.sodocs.net/doc/851592737.html,

37.J.Dodge,in:Synthetic Methods in Step-Growth Polymers,Chapter4,M.E.Rogers and T.E.Long

(Eds),p.197.Wiley,New York,NY(2003).

https://www.sodocs.net/doc/851592737.html,ndry,B.Riedl and P.Blanchet,https://www.sodocs.net/doc/851592737.html,.Coatings62,400(2008).

(完整版)2013-2015年全国卷英语听力材料原文及答案

2015 年普通高等学校招生全国统一考试（全国卷·课标I 卷） 第一节（共5小题;每小题 1.5 分,满分7.5 分） 1. What time isit now? A. 9:10. B.9:50. C.10:00. 2. What does the woman think ofthe weather? A.It?s nice. B. It ?s warm. C. It ?s cold. 3. What will the man do? A. Attend a meeting. B. Give a lecture. C.Leavehis office. 4. What isthe woman?s opinion about the course? A. Toohard. B. Worth taking. C. Very easy. 5. What does the woman want the man do? A. Speaklouder. B. Apologizeto her. C.Turn off the radio. 第二节（共15小题;每小题 1.5分,满分22.5分）听第 6 段材料,回答第6、7 题。 6. How long did Michael stay in China? A. Fivedays. B. One week. C.Twoweeks. 7. Where did Michael go last year? A. Russia.B. Norway. C.India. 听第7 段材料,回答第8、9 题。 8. What food does Sallylike? A. Chicken. B. Fish. C.Eggs. 9. What are the speakersgoing to do? A. Cook dinner. B. Go shopping. C. Order dishes. 听第8段材料,回答第10至12题。 10. Where are the speakers? A. In a hospital. B. In the office. C.At home. 11. When isthe report due? A.Thursday. B.Friday. C.Next Monday. 12. What doesGeorgesuggestStephaniedo with the report? A. Improve it. B. Hand it in later. C.Leaveit with him. 听第9 段材料,回答第13 至16 题。 13. What is the probable relationship between the speakers? A. Salespersonand customer. B. Homeowner and cleaner. C.Husbandand wife. 14. What kind of apartment do the speakersprefer? A. One with two bedrooms. B. Onewithout furniture. C.One near a market. 15. How much rent should one pay for the one-bedroom apartment? A.＄350. B. ＄400. C.＄415. 16. Where isthe apartment the speakerswould like to see? A. On LakeStreet. B. On Market. C.On South Street. 听第10 段材料,回答第17 至20 题。 17. What percentage of the world?s tea exports go to Britain? A. Almost 15%. B. About 30%. C. Over 40%. 18. Whydo tea tasterstaste tea with milk? A. Most British people drink tea that way. B. Teatastes much better with milk. C. Teawith milk is healthy. 19. Who suggestsa price for each tea? A. Teatasters. B. Teaexporters. C.Teacompanies.

道路交通工程专业英语词汇

公路highway 道路road 中英术语对照通行能力traffic capacity 基本通行能力basic traffic capacity 可能通行能力possible traffic capacity 设计通行能力design traffic capacity 公路工程highway engineering 公路网highwaynetwork 公路网密度highwaydensity 公路等级highway classification 公路自然区划climatic zoning for highway 公路用地highway right-of-way 高速公路freeway; expressway 等级公路classified highway 辅道reliefroad 干线公路arterial highway 支线公路feederhighway 专用公路accommodation highway 国家干线公路(国道)national trunk highway 省级干线公路(国道)provincialtrunk highway 县公路(县道)county road 乡公路(乡道)township road 辐射式公路radial highway 环形公路ring highway 绕行公路bypass 交通结构trafficstructure 延误delay 行驶速度running speed 运行速度operating speed 平均速度average speed (设计车速)design speed 交通量trafficvolume 公路交通规划traffic planning 交通调查traffic survey 交通量调查traffic volume survey 起迄点调查(OD调查)origin-destinationstudy 境内交通local traffic 过境交通throughtraffic 交通发生traffic generation 交通分布traffic distribution 交通分配traffic assignment 交通预测trafficprognosis 行车道carriageway 分离式行车道divided carriageway 车道lane 变速车道speed-change lane 加速车道acceleration lane 减速车道deceleration lane 爬坡车道climbing lane 停车道parkinglane 错车道turn-outlane 自行车道cycle path 路侧人行道sidewalk 分隔带lane separator 中央分隔带median divider 中间带centralstrip 路肩shoulder;verge 路缘带marginalstrip 路缘石kerb;curb 侧向余宽lateralclearance路 拱camber;crown 路拱横坡crown slope 公路建筑限界clearance of highway 公路路线highway route 公路线形highwayalignment 平面线形horizontal alignment 纵面线形vertical alignment 线形要素alignment elements 平曲线horizontalcurve 极限最小平曲线半径limitedminimumradiusofhorizontalcurve

(交通运输)公共场所双语标识英文译法第部分道路交通精编

（交通运输）《公共场所双语标识英文译法》第部分道 路交通

（交通运输）《公共场所双语标识英文译法》第部分道 路交通

公共场所双语标识英文译法 EnglishTranslationofPublicSigns 第1部分：道路交通 Part1:RoadSigns 1 范围 DB11/T334的本部分规定了北京市道路交通双语标识英文译法的原则。 本部分适用于北京市道路交通中的英文标识。 2 规范性引用文件 下列文件中的条款通过本部分的引用而成为本部分的条款。凡是注日期的引用文件，其随后所有的修改单（不包括勘误的内容）或修订版均不适用于本部分,然而，鼓励根据本部分达成协议的各方研究是否可使用这些文件的最新版本。凡是不注日期的引用文件，其最新版本适用于本部分。 GB/T16159-1996汉语拼音正词法基本规则 3 术语和定义 下列术语和定义适用于本部分。 地名placenames 人们对各个地理实体赋予的专有名称。 地名专名specificnamesandterms 地名中用来区分各个地理实体的词。 地名通名commonnamesandterms 地名中用来区分地理实体类别的词。

4 总则 4.1 道路交通双语标识的英文译法应符合国际惯例，遵循英语习惯（见附录A）。 4.2 本部分汉语拼音用法应符合GB/T16159的要求。 5 细则 5.1 警告提示信息 警告提示信息的翻译应按照国际惯例，遵循英语习惯，如爬坡车道SteepGrade。 5.2 地名通名 5.2.1 壹般（基本）规定 地名通名通常采用英文直接翻译，英文单词首字母大写，其余小写。 5.2.2 街 5.2.2.1 Avenue(Ave)仅用于长安街CHANG’ANAve，平安大街PING’ANAve和俩广路LIANGGUANGAve。 5.2.2.2 街、大街译为Street(St)，如隆福寺街LONGFUSISt，惠新东街HUIXINEastSt；西单北大街XIDANNorthSt，菜市口大街CAISHIKOUSt。 5.2.2.3 小街、条、巷、夹道壹般情况下译为Alley，当路宽达到壹定规模时可译为St，如东直门北小街DONGZHIMENNorthAlley，横壹条HENGYITIAOAlley，东四十条DONGSISHITIAOSt，后海夹道HOUHAIAlley；斜街译为Byway。 5.2.3 路 5.2.3.1 路译为Road（Rd），如白云路BAIYUNRd。 5.2.3.2 辅路译为SideRoad（SideRd），如京石高速辅路JINGSHIExpwySideRd。 5.2.3.3 高速公路译为Expressway（Expwy），如京津塘高速JINGJINTANGExpwy。

学术综合英语(罗立胜)1-6单元课文翻译

human creations, language may be the most remarkable. Through language we share experience, values, exchange ideas, transmit knowledge, and sustain culture. Indeed, language is vital to sense of reality by giving meaning to events. 在人类所有的创造中，语言也许是影响最为深远的。我们用语言来分享经验，表达(传递？)价值观，交换想法，传播知识，传承文化。事实上，对语言本身的思考也是至关重要的。和通常所认为的不同的是，语言并不只是简单地反映现实，语言在具体描述事件的时候也在帮助我们建立对现实的感知。——语序的调整。 Good speakers have respect for language and know how it works. Words are the tools of a speaker?s craft. They have special uses, just like the tools of any other profession. As a speaker, you should be aware of the meaning of words and know how to use language accurately, clearly,vividly,and appropriately. 好的演讲者对语言很重视，也知道如何让它发挥更好的效果。词语是演讲者演讲的重要“武器”，具有特殊的用途，这和任何其他的工作技艺没什么两样。作为演讲者，必须知道词语的具体含义，也要懂得如何做到用词准确、清晰、生动、适当。 Using language accurately is as vital to a speaker as using numbers accurately to a accountant. Never use a word unless you are sure of its meaning. If you are not sure, look up the word in the dictionary. As you prepare your speeches, ask yourself constantly, “What do I really want to say? What do I really mean?” Choose words that are precise and accurate. 演讲者准确地使用语言和会计准确使用数字是一样重要的。确定词意后再措词。如果不确定，请先查词典。当你在准备演讲的时候，要不断地问自己：“我到底要说什么？我到底想表达什么意思？”用词一定要精准。 Using language clearly allows listeners to grasp your meaning immediately. You can ensure this [by using familiar words （that are known to the average person and require no specialized background）; by choosing concrete words in preference to more abstract ones, and by eliminating verbal clutter]. 用词清晰可以让听众迅速理解你的意思（抓到你的点）。要做到这一点，就要尽量使用一般人都熟悉的不需要专业知识就能懂的词语；多用具象词汇少用抽象词汇；还有要减少口误。 Using language vividly helps bring your speech to life. One way (to make your speech vivid)|is through imagery，or the creation of word pictures. You can develop imagery by using concrete language, simile, and metaphor. Simile is an explicit comparison between things （that are essentially different yet have something in common）; it always contains the words “like”or “as”. Metaphor is an impli cit comparison between things that are different yet have something in common; it does not contain the words “like” or “as”. 生动地用词能让演讲鲜活起来！比喻，这种能产生文字图像的修辞，可以使演讲达到生动的效果。比喻要用具象的语言，分为明喻和隐喻。 明喻是指在本质上有区别但仍然有相同点的事物之间做一个明确的比较，一般句中会含有“像”或“似”。隐喻则是一种隐藏的比较，不会出现like 和as 这些连接词。 Another way to make your speeches vivid is by exploiting the rhythm of language. Four devices for creating rhythm are parallelism, repetition, alliteration, and antithesis. Parallelism is the similar arrangement of a pair or series of related words, phrases, or sentences. Repetition is the use of the same word or set of words at the beginning or end of successive clauses or sentences. Alliteration comes from repeating the initial constant sounds of close or adjoining words. Antithesis is the juxtaposition of

研究生学术综合英语1-6课课文及翻译

Presenting a speech （做演讲） Of all human creations, language may be the most remarkable. Through 在人类所有的创造中，语言也许是影响最为深远的。我们用语言 language we share experience, formulate values, exchange ideas, transmit 来分享经验，表达(传递？)价值观，交换想法，传播知识， knowledge, and sustain culture. Indeed, language is vital to think itself. 传承文化。事实上，对语言本身的思考也是至关重要的。[Contrary to popular belief], language | does not simply mirror reality but also helps to create our sense of reality [by giving meaning to events]. 和通常所认为的不同的是，语言并不只是简单地反映现实，语言在 具体描述事件的时候也在帮助我们建立对现实的感知。 ——语序的调整。 Good speakers have respect for language and know how it works. Words are the tools of a speaker’s craft. They have special uses, just like the tools of any other profession. As a speaker, you should be aware of the meaning of words and know how to use language accurately, clearly,vividly,and appropriately. 好的演讲者对语言很重视，也知道如何让它发挥更好的效果。词语是演讲者演讲的重要“武器”，具有特殊的用途，这和任何其他的工作技艺没什么两样。作为演讲者，必须知道词语的具体含义，也要懂得如何做到用词准确、清晰、生动、适当。 Using language accurately is as vital to a speaker as using numbers accurately to a accountant. Never use a word unless you are sure of its meaning. If you are not sure, look up the word in the dictionary. As you prepare your speeches, ask yourself constantly, “What do I really want to say? What do I really mean?”Choose words that are precise and accurate. 演讲者准确地使用语言和会计准确使用数字是一样重要的。确定词意后再措词。如果不确定，请先查词典。当你在准备演讲的时候，要不断地问自己：“我到底要说什么？我到底想表达什么意思？”用词一定要精准。 Using language clearly allows listeners to grasp your meaning immediately. You can ensure this [by using familiar words （that are known to the average person and require no specialized background）; by choosing concrete words in preference to more abstract ones, and by eliminating verbal clutter]. 用词清晰可以让听众迅速理解你的意思（抓到你的点）。要做到这一点，就要尽量使用一般人都熟悉的不需要专业知识就能懂的词语；多用具象词汇少用抽象词汇；还有要减少口误。 Using language vividly helps bring your speech to life. One way (to make your speech vivid)|is through imagery，or the creation of word pictures. You can develop imagery by using concrete language, simile, and metaphor. Simile is an explicit comparison between things （that are essentially different yet have something in common）; it always contains the words “like”or “as”. Metaphor is an implicit

交通工程专业中英文翻译

河北工程大学交通工程专业 外文翻译 学生姓名：李焘 专业：交通工程 班级：09-02 学号：090240225 指导老师：高爱坤 2013年04月

交通事故分析的可能性和局限性 原文出处：SWOV institute for road safety research Leidschendam（会议记录）关键字：后果;目的;描述;限制;关注;事故分析;可能性 摘要：交通事故的统计数字，尤其国家一级的数据对监控和预测事故的发展，积极或消极检测事故的发展，以及对定义安全目标和评估工业安全特别有益。事故分析是应用非常有限的分析，是前瞻性分析和回顾性分析，能够对新开发的交通安全系统和特殊过程的安全措施进行评价。目前迫切需要一个将实时事故分析与研究相结合的行为。将自动检测和视频录制相结合的研究交通事故的科研论文会比较容易接受。这种类型的研究最终会对交通理念有个完善的认识。 1．简介 本文主要是基于个人的经验，研究有关交通安全、安全分析以及事故分析等在研究中的作用。由这些经验推导出的哲学思考就像通过研究和统计得出的实践观点。而这些调查数字已经在其他地方发表了。 在缺少直接观察的事故中，许多方法论问题的产生，导致不能直接测试对结果持续讨论。通过看事故视频来讨论是富有成效的。事实证明，用来解释事故的大部分有关信息就是事故中缺少的记录。深入研究还无法回忆起所有的必要的用来测试有关事故发生的假设数据，。尤其是车-车相撞发生的车祸，这是在荷兰城市道路交叉口录制的视频，一辆从岔路驶来的汽车与主干路的汽车相撞，下列问题可以问：为什么汽车来自次干路上，突然加速后又几乎停止，撞上了在左侧主路的一辆汽车呢？为什么没有注意到正在驶来的车？是不是因为两车从右边驶来，司机因为前面的交叉为他们提供了可能性而斤斤计较？难道他向左看过，但他认为停在拐角处的绿色货车能让他停下来？当然，交通状况并不复杂。目前这个事故中没有骑自行车或行人在拥挤路口分散他的注意。如果停着的绿色车能够在五分钟内消失，这两辆车可能就不会相撞。在事故发生的相关条件下，几乎不可能观察下一个交通行为，因为交通事故是不可预见的。由于新的视频设备和自动检测事故设备的不断发展，如在收集数据方面不需要很高的成本就能变得越来越逼真。必要的增加数据类型也能更好的解释交通中存在的危险因素。关于事故分析的可能性和限制性的问题是不容易回答的，我们不能确切的分析交通事故。

土木工程专业英语翻译(武汉理工大学出版社段兵廷主编)完整版

第一课土木工程学 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 领域。因为包含范围太广，土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目，土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。计算机成为了现代土木工程师的必备品，因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域，土木工程师规划设计各种类型的结构，包括桥梁，大坝，发电厂，设备支撑，海面上的特殊结构，美国太空计划，发射塔，庞大的天文和无线电望远镜，以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力：自重，风荷载和飓风荷载，建筑材料温度变化引起的胀缩，以及地震荷载。他

研究生学术综合英语课文翻译

Unit1如何发表演说斯蒂芬·卢卡斯 1.在人类创造的万物中，语言可能是最卓越的一项创造。通过语言，我们可以分享经验、阐明价值观念、交流思想、传播知识、传承文化。确实，语言对于思想本身至关重要。和流行的信仰不同的是：语言并不是简单地反映事实，而是通过对事件意义的思考来帮助人们感悟现实。 2.优秀的演说者尊重语言并懂得如何驾驭语言。语言是演说者展示才能的工具，对于他们来说，如同其他职业的工具一样,语言也有特殊的功用。作为一名演说者，你应该意识到话语的意义，并懂得如何准确无误地使用语言，使其表达清楚，趣味横生，恰如其分。 3.如同数字对于会计的重要性一样，准确地使用语言对于演说者至关重要。在没有确切知道一个词语的意思之前，千万不要盲目使用。碰到没有把握的词语，一定要查词典追根究底。当你准备演讲之前，一定要不断地问自己：“我究竟想说些什么？我究竟想表达什么样的意思？”因此，对于一篇演讲稿的用词来说，必须准确无误。 4.语言表达清楚无误，听众就能很快抓住你的意思。鉴于此，演说者应该使用那些对于大多数人来说非常熟悉的词语，这些词语不需要任何专业背景就能够理解；演说者应该使用那些表达具体而不是相对抽象的词语；并且千万不要乱堆砌辞藻，哗众取宠。 5.准确生动地使用语言能够使你的演说贴近生活。有一种方法可以使你的语言更加生动形象，那就是通过展开联想或创造语言图示。通过使用表达具体的词语、明喻或者暗喻等手法可以展开想象。明喻是对事物不同之处的比较，不过有些是相同的：它们总是包含“像……一样”或者“如同……一样”这样的连词。暗喻是一种隐性的比喻，它能够把两个形式不同但是有一些相通之处的事物联系在一起，暗喻不包含“像……一样”或者“如同……一样”这样的连词。 6.另一种让你的演说生动形象的方法是注重语言的节奏感。有四种修辞格可以让你的语言富有节奏感：排比、重复、头韵和对比。排比是将一组或一系列具有相似结构的词语、短语或者句子排列在一起；重复是在一系列短句或者长句的开头或者结尾使用相同的一句话或者一组词语；头韵是指邻近或者相邻的几个句子中的首个词语的辅音字母相同；对比是将一些意思相反的词语或者句子并列在一起，通常使用排比结构。 7.恰当地使用语言是指语言的运用要符合特定的场合、特定的观众和特定的主题。同时，恰当地使用语言还意味着演说者要有自己的语言风格，而不是模仿他人的口吻。如果演说者的语言在各个方面都能够做到恰如其分，那么这篇演说成功的机率就会大大提高。 8.优秀的演说并不是空穴来风、缺乏论据的决断。演说者必须找到强有力的论据来支持其观点。实际上，熟练地使用论据经常是区别一篇优秀演说词和一篇空洞演说词的关键所在。一般来说，通常有三种论据材料：事例、统计数据和证词。 9.在演说过程中，你可以使用一些简明扼要的例子——比如过去发生的一个很具体的事件——有时候，你可以罗列好几个简明的例子，借此增强听众的印象。扩展性的例子——描述、

英语听力原文

Unit 2 Coincidence 大学英语全新版3 听力原文 Exercise 1 Listen to the story and choose the right answers to the questions you hear. Andrew had always wanted to be a doctor. But the tuition for a medical school in 1984 was 15,000 dollars a year, which was more than his family could afford. To help him realize his dream, his father, Mr. Stewart, a real estate agent, began searching the house-for-sale ads in newspapers in order to find extra business. One advertisement that he noted down was for the sale of a house in a nearby town. Mr. Stewart called the owner, rying to persuade him to let him be his agent. Somehow he succeeded and the owner promised that he would come to him if he failed to get a good deal with his present agent. Then they made an appointment to meet and discuss the thing. As good things are never easy to acquire, the time for the appointment had to be changed almost ten times. On the day when they were supposed to meet at 3 o'clock in the afternoon, Mr. Stewart received another call from the owner. His heart sank as he feared there would be another change of time. And so it was. The owner told him that he couldn't make it at three but if he would come right then, they could talk it over. Mr. Stewart was overjoyed.Leaving everything aside, he immediately set out to drive to the house. As he approached the area, he had a strange feeling of having been there before. The streets, the trees, the neighborhood, all looked familiar to him. And when he finally reached the house, something clicked in his mind. ]It used to be the house of his father-in-law! The old man had died fifteen years ago but when he was alive, he had often visited him with his wife and children. He remembered that, like his son Andrew,his father-in-law had also wanted to study medicine and, failing to do so, had always hoped that one of his two daughters or his grandchildren could someday become a doctor. Questions 1. Who are the two main characters in the story you have just heard? 2. How did Mr. Stewart get to know the owner of the house? 3. What problem did Mr. Stewart have? 4. What is the coincidence in the story you have just heard? Passage 2 Exercise 1 Listen to the recording and write down the coincidences mentioned in the text. When he entered the house, Mr. Stewart was even more amazed to find that the house was decorated exactly as he had remembered it. He told the owner about this and the latter became intrigued too. However, they were in for even greater surprises. It so happened that in the middle of their discussion, a postman came to deliver a letter. And the letter was addressed to Mr. Stewart's father-in-law! Were it not for Mr. Stewart's presence there and then, the letter would be returned as no person of that name lived in the house any longer. As the postman demanded a signature on the receipt slip, Mr. Stewart signed for his

土木工程专业英语词汇(整理版)

第一部分必须掌握，第二部分尽量掌握 第一部分： 1 Finite Element Method 有限单元法 2 专业英语Specialty English 3 水利工程Hydraulic Engineering 4 土木工程Civil Engineering 5 地下工程Underground Engineering 6 岩土工程Geotechnical Engineering 7 道路工程Road (Highway) Engineering 8 桥梁工程Bridge Engineering 9 隧道工程Tunnel Engineering 10 工程力学Engineering Mechanics 11 交通工程Traffic Engineering 12 港口工程Port Engineering 13 安全性safety 17木结构timber structure 18 砌体结构masonry structure 19 混凝土结构concrete structure 20 钢结构steelstructure 21 钢-混凝土复合结构steel and concrete composite structure 22 素混凝土plain concrete 23 钢筋混凝土reinforced concrete 24 钢筋rebar 25 预应力混凝土pre-stressed concrete 26 静定结构statically determinate structure 27 超静定结构statically indeterminate structure 28 桁架结构truss structure 29 空间网架结构spatial grid structure 30 近海工程offshore engineering 31 静力学statics 32运动学kinematics 33 动力学dynamics 34 简支梁simply supported beam 35 固定支座fixed bearing 36弹性力学elasticity 37 塑性力学plasticity 38 弹塑性力学elaso-plasticity 39 断裂力学fracture Mechanics 40 土力学soil mechanics 41 水力学hydraulics 42 流体力学fluid mechanics 43 固体力学solid mechanics 44 集中力concentrated force 45 压力pressure 46 静水压力hydrostatic pressure 47 均布压力uniform pressure 48 体力body force 49 重力gravity 50 线荷载line load 51 弯矩bending moment 52 torque 扭矩 53 应力stress 54 应变stain 55 正应力normal stress 56 剪应力shearing stress 57 主应力principal stress 58 变形deformation 59 内力internal force 60 偏移量挠度deflection 61 settlement 沉降 62 屈曲失稳buckle 63 轴力axial force 64 允许应力allowable stress 65 疲劳分析fatigue analysis 66 梁beam 67 壳shell 68 板plate 69 桥bridge 70 桩pile 71 主动土压力active earth pressure 72 被动土压力passive earth pressure 73 承载力load-bearing capacity 74 水位water Height 75 位移displacement 76 结构力学structural mechanics 77 材料力学material mechanics 78 经纬仪altometer 79 水准仪level 80 学科discipline 81 子学科sub-discipline 82 期刊journal ,periodical 83文献literature 84 ISSN International Standard Serial Number 国际标准刊号 85 ISBN International Standard Book Number 国际标准书号 86 卷volume 87 期number 88 专著monograph 89 会议论文集Proceeding 90 学位论文thesis, dissertation 91 专利patent 92 档案档案室archive 93 国际学术会议conference 94 导师advisor 95 学位论文答辩defense of thesis 96 博士研究生doctorate student 97 研究生postgraduate 98 EI Engineering Index 工程索引 99 SCI Science Citation Index 科学引文索引

土木工程专业英语课文原文及对照翻译

土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020

Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and