pore structure in the Silurian and Permian shales of the Sichuan Basin, China

小学上册英语第四单元综合卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. A __________ is a landform that rises above the surrounding area.2.My grandmother knitted a _________ (毛绒玩具) for me when I was born.3.Natural resources like coal and oil are found in ______ rock.4.I have a _____ of stickers in my book. (collection)5. A mouse can fit through very _______ (小) spaces.6.The capital of Bangladesh is _______.7.Which animal is known for its long tail and ability to climb trees?A. BearB. MonkeyC. ElephantD. LionB8.The ______ is a talented graphic artist.9.The _______ (鸽子) coos softly in the park.10.The parakeet is a small ______ (鸟).11.In a circuit, electricity needs a complete _______.12.How many colors are in a standard rainbow?A. FourB. FiveC. SixD. SevenD13.During summer, I like to go to the ______ (海滩) and build ______ (沙堡). It’s so much fun to play in the ______ (海水).14.The __________ (叶子) turn yellow and fall in the fall.15.She likes to dance ___. (well)16.I enjoy creating ________ in my art class.17.What do you call the study of the Earth?A. BiologyB. GeographyC. HistoryD. PhysicsB18.What is the name of the famous American singer known for her role in "A Star Is Born"?A. Barbra StreisandB. Lady GagaC. AdeleD. Whitney HoustonB19.The __________ (战争的影响) shaped national identities.20. A _______ can be used to measure the speed of a falling object.21. A butterfly flutters gently in the _______ enjoying the sunshine.22.She likes to _____ (read/play) in the park.23.The capital of the Gambia is ________ (班珠尔).24. A ______ (休闲园) offers a peaceful escape.25.Which language is spoken in Brazil?A. SpanishB. PortugueseC. FrenchD. ItalianB26. A chemical reaction requires reactants and produces ______.27. A chemical reaction can involve the formation of ______.28.My grandma has a beautiful _______ (名词). 它在 _______ (地点).29.Which one is a fruit?A. CarrotB. PotatoC. AppleD. LettuceC30.The anemone is home to the _____.31.I enjoy making _________ (手工艺品) using my old _________ (玩具).32. A parrot can learn to ______ words.33.ocean floor) features ridges and valleys. The ____34.Dolphins are very _________. (聪明)35.The ancient Romans used ________ for building strong structures.36.What is the smallest continent?A. AfricaB. AustraliaC. AsiaD. Europe答案:B37.What is the name of the famous ancient Egyptian queen?A. CleopatraB. NefertitiC. HatshepsutD. TutankhamunA38.What is the name of the imaginary line that divides the Earth into Eastern and Western Hemispheres?A. EquatorB. Prime MeridianC. Tropic of CancerD. Tropic of CapricornB39.In a chemical equation, reactants are found on the ______.40. A neutralization reaction produces ______ and water.41.What is the capital of Brazil?A. Rio de JaneiroB. São PauloC. BrasíliaD. SalvadorC42.We made a team with our toy ____. (玩具名称)43.My brother is our family's __________ (乐趣).44.He is very ___. (clever)45.My friend is a _____ (作曲家) who writes music.46._____ (雨林保护) is vital for global biodiversity.47.What do we call a scientist who studies plants?A. BotanistB. ZoologistC. EcologistD. GeologistA48.Which animal is known for building dams?A. BeaverB. OtterC. DuckD. FrogA49.The ant carries food much larger than its ______ (身体).50.What is the color of the sky on a clear day?A. GreenB. BlueC. YellowD. GrayB51.She is my . (她是我的。

In fluence of limestone filler and viscosity-modifying admixture on the shrinkage of self-compacting concreteM.Valcuende a ,⁎,E.Marco a ,C.Parra b ,P.Serna ca Department of Architectural Constructions,Universidad Politécnica of Valencia,Camino de vera s/n,46022Valencia,Spainb Department of Structures and Construction,Universidad Politécnica of Cartagena,Doctor Fleming s/n,30202Cartagena,Spain cInstitute of Science and Concrete Technology,Universidad Politécnica of Valencia,Camino de vera s/n,46022Valencia,Spaina b s t r a c ta r t i c l e i n f o Article history:Received 15March 2011Accepted 17January 2012Keywords:Filler (D)Pore size distribution (B)Shrinkage (C)Self-compacting concreteThe aim of this experimental work is to study shrinkage evolution with age in self-compacting concretes (SCC)made with w/c =0.6and different limestone filler and viscosity-modifying admixture (VMA)contents.The results show that limestone fillers speed up hydration reactions and provide a finer porous structure.As a result,when specimens are hardened under water,SCC made with limestone fillers tends to shrink,since the water only penetrates the outer layers of the specimen,while the interior is subject to self-desiccation.If the concrete contains substantial air content (3.2%)the water finds it easier to penetrate and the concrete swells.When hardening takes place in the open air,autogenous shrinkage in SCC is lower than in normally-vibrated concretes (NVC)and the higher the fines content,the lower the shrinkage.This is more than likely due to the use of limestone filler as addition,finer porous structure and higher amount of absorbed water from the aggregate which compensates for the auto-desiccation of the concrete.On the whole,drying shrinkage in SCC is greater than in NVC.However,when filler is replaced by VMA the porous structure is coarser and shrinkage is reduced by 33%,thanks to the lower capillary pressure.This means that due to the reduction in autogenous and drying shrinkage,SCC made solely with VMA presents 7.7%lower total shrinkage than NVC.In SCC made with limestone filler,total shrinkage is only slightly higher than in NVC,the differences being under 9.2%.©2012Elsevier Ltd.All rights reserved.1.IntroductionTotal shrinkage is the sum of various types of shrinkage:chemical,autogenous,drying and carbonation.Even though changes of temper-ature and carbonation reactions have an effect on shrinkage,this phenomenon is mainly the result of water loss and the reduction of the volume of hydrated products compared with the reacting constituents (cement,active additions and water).During the hydra-tion of cement after the start of setting,chemical shrinkage does not occur freely,since it is hindered by the stiffness of the paste itself,by the granular skeleton and possibly by the reinforcement.As a result,an increasing volume of very fine pores is formed inside the hydrated cement paste which drains water from the coarser capil-laries.If water is not supplied from an external source,as hydration of the cement progresses,the volume of water in the pores decreases,a process which is known as self-desiccation,and water menisci are formed.Due to the water surface tension,as the water content in the capillary pores is reduced,the force of attraction between pore walls is increased,giving rise to increased shrinkage.This shrinkage,known as autogenous shrinkage,is higher at low w/c ratios and be-comes especially signi ficant when the w/c ratio falls below 0.4[1,2].In concrete with a w/c ratio over 0.60,autogenous shrinkage is usual-ly between five and ten times less than that caused by drying,so that its effects are not normally taken into consideration [1].In general,a low w/c ratio and a high cement content cause increased autogenous shrinkage,possibly due to the greater volume of small-diameter pores and the reduction of the available water [3].Before initial setting of the concrete,capillary forces are almost negligible,so that chemical shrinkage is practically the only contributor to autogenous deformation.When water is applied during curing,the water lost from the capillary pores in the concrete is replaced by water from the external source,so that self-desiccation does not occur.However,when the water/binder ratio is very low,even when there is an external water supply,the products formed by hydration may obstruct some capillaries and prevent the water from getting to certain zones in the concrete,in which autogenous shrinkage will also occur.The in-fluence of this phenomenon on total shrinkage depends on the size of the specimen [4].Drying shrinkage is a relatively slow process.The driving force behind it is the loss of water from the pores due to the lower humidity prevailing outside the concrete.The diffusion of water through theCement and Concrete Research 42(2012)583–592⁎Corresponding author.Tel.:+34963877450;fax:+34963877459.E-mail address:mvalcuen@csa.upv.es (M.Valcuende).0008-8846/$–see front matter ©2012Elsevier Ltd.All rights reserved.doi:10.1016/j.cemconres.2012.01.001Contents lists available at SciVerse ScienceDirectCement and Concrete Researchj ou r n a l h o m e p a g e :h t t p ://e e s.e l s e v i e r.c o m /C E MC ON /d e f a ul t.a s pmaterial mainly depends on its porous structure,the size and shape of the specimen,the duration of drying and the prevailing atmospheric conditions[5–7].Highfines and cement content and a higher paste volume than in NVC are normally used in making SCC.Since the cement paste is mainly responsible for changes of volume,the higher the paste content,the greater the shrinkage will be[5,8,9],so that,in theory, SCC is liable to suffer a considerable degree of shrinkage.However, significantly increasing the paste volume does not necessarily lead to greater shrinkage,since other factors also intervene in the process, such as the continuity of the capillary network and the density of the matrix[10].Shrinkage may also be promoted by the retarding effect of the powerful superplasticizers used to make SCC[11–13].In addition,the higher the dosage,the longer the delay in hydration reactions[13].Many authors point out that shrinkage is higher in SCC than NVC [10,11,14–17].However,there are also studies that did notfind sig-nificant differences between both types of concrete[18–23],and even some that found lower shrinkage in SCC[24].However,it shouldbe pointed out that in many of these studies the SCC,unlike the NVC used as a reference,contained a high content of active additions,in order to meet this type of concrete's great need forfines.These addi-tions may affect the concrete's fresh and hardened properties and therefore may also affect its shrinkage.Shrinkage may be increased by increasing the content of silica fume[25–27]or granulated blast furnace slag[28–30].On the other hand,the use offly ash or lime-stonefiller may reduce both autogenous and drying shrinkage [8,9,28,31–33].Some authors consider that the limestonefines con-tent has no influence either on autogenous[10,19,23]or on total shrinkage if the same water/powder ratio is maintained[21].Viscosity-modifying admixtures(VMA)may be used to increase the viscosity of SCC.Some studies have shown that by using VMA more stable concrete is obtained in view of water variations in the mixtures than that obtained withfines only[34,35].This enhanced stability seems to have a bearing on the quality of the aggregate–paste interface,with a denser structure in the transition zone [34,36,37].The major construction chemical industries are at present developing a new family of VMA that will allow SCC to be made with-out additionalfines.With these new admixtures the aim is to obtain a more robust concrete,although this could involve the loss of the ben-efits offines,such as the better particle-packing which leads to a denser cementitious matrix.Bearing in mind the foregoing,the aim of this experimental work was to study shrinkage in SCC made with differing limestonefiller and VMA contents,comparing the results obtained with those obtained from traditionally vibrated concrete.Due to the fact that shrinkage is directly related to the porous structure of the material, the microstructure of the different types of concrete was analysed in order to explain the behaviour observed.2.Experimental programme2.1.Concrete mixtures,materials and mixing procedureSix types of concrete were made:four self-compacting and two normally-vibrated concretes,using different cement,limestonefiller and viscosity-modifying admixture contents.In order to obtain strengths approaching those normally used for building,all of them were manufactured with a0.60w/c ratio.The characteristics of each mix are shown in Table1.The nomenclature used to identify each type of concrete refers to self-compacting(S)or normal(N)type concrete,cement content(300or350kg/m3)and the limestonefiller addition(0,45,90or125kg/m3).To produce the self-compacting concretes,CEM II/A-S42.5N ce-ment was used with crushed limestone aggregates:4/10gravel and 0/3sand.Additionally,limestonefiller was also used.The grading curves of the cement,thefines of coarse andfine aggregates and the filler(particle size b0.063mm)are determined by means of laser dif-fraction(Fig.1).The properties of the aggregates are shown in Table2 and the characteristics and composition of the cement are shown in Table3.The admixtures used were a polycarboxylate-based superplasticizer(Viscocrete3425)and a modified starch-based VMA (Stabilizer4R).The properties of the mixtures are displayed in Table4.Taking as a reference the mixes established for SCC,the corre-sponding reference NVC were made with the same types and amounts of cement.The superplasticizer was in this case a calciumTable1Mixture proportions of concretes.N-300S-300/125N-350S-350/0S-350/45S-350/90Cement(kg/m3)300300350350350350 Limestonefiller(kg/m3)0125004590Water(l)180180210210210210w/c0.60.60.60.60.60.6 Superplasticizer(kg/m3)3.60 5.70 1.05 5.60 5.25 5.08 VMA(kg/m3)000 1.75 1.230 Coarse aggregate(kg/m3)865.9733.6883.9642.4684.3726.4Fine aggregate(kg/m3)1070.61072.7939.01164.91080.1996.5Total aggregates(kg/m3)1936.51806.31822.91807.31764.41722.9Totalfine particles(kg/m3)493.5613.6524.6548.7582.7616.9 Paste volume(dm3)354.6402.8391.1406.3418.6430.4Water absorbed byaggregates andfiller(l)14.3116.3713.2213.9514.7715.59 VMA:viscosity-modifyingadmixture.Fig.1.Grading curves of cement,aggregatefines and limestonefiller.Table2Properties of the aggregates.Type of aggregate Specific gravity(g/dm3)Fines(%)Water absorption(%)Filler limestone 2.65– 1.16Fine sand0/3 2.6314.90.90Gravel4/12 2.70 3.90.54584M.Valcuende et al./Cement and Concrete Research42(2012)583–592lignosulfonate(Sikament175).Its content was adjusted to achieve a slump of90±10mm in the Abrams cone for the two mixtures.The mixing sequence of the concrete was carried out byfirstly adding the aggregates,thefiller and the cement.Once a homogenous mixture was obtained,3/4of the water was added and after mixing for a further minute,the superplasticizer was added with the remaining water.Total mixing time was6min for NVC and8min for SCC made with limestonefiller.In the specific case of SCC with VMA,it was observed that a longer mixing time was required since the initial viscosity of the mixture was much higher,but then gradually re-duced until it stabilised.More specifically,3min after adding the superplasticizer,the VMA was added and mixing continued until completing the total time of12min.2.2.Test programme and methodology2.2.1.Shrinkage testTo determine autogenous shrinkage,total shrinkage and swelling, prismatic specimens measuring100×100×400mm were used.To obtain further information on this phenomenon,setting time(ASTM C403-08),temperature and weight loss were also measured.Thermo-couples were inserted into the centre of the specimens immediately after casting(Fig.2)to determine the evolution of temperature rise due to the hydration reaction.In order to measure shrinkage of the specimens until mould removal(48h),the specimens were made in accordance with the recommendations of the Technical Committee on Autogenous Shrink-age of Concrete of the Japan Concrete Institute[38].A polystyrene sheet(thickness3mm)was placed on the bottom and on both sides of the mould so that free movement of the specimen was not restricted by the mould.A polyesterfilm was also placed on the polysty-rene sheet on all sides of the mould and on the surface of the specimen. At the time of initial setting,the end plates of the mould were removed and two dial gauges were put into place(Fig.3).Later,at the age of48h, the specimens to be used for measuring autogenous shrinkage,drying shrinkage and weight loss were stored in a vertical position inside a cli-matically controlled chamber for more than one year at20°C and50% RH(Fig.4).To determine autogenous shrinkage,half of the specimens were sealed with various layers of plasticfilm to avoid moisture loss. Those used to measure total shrinkage were not sealed.In order to study swelling,some specimens were submerged in water at20°C in containers for a period of90days.Three batches were made from each mix.One specimen for each type of test was made from each batch,the result of each test being the arithmetic mean of the three values obtained.Two150mm diameter×300mm high cylindrical specimens were also made from each batch for compressive strength tests at28days(EN 12390-3:2003).The compressive strength results are shown in Table4.2.2.2.Mercury intrusion porosimetry(MIP)testAt the age of28days,pore size distribution was determined using a Micromeritics AutoPore IV-9500mercury porosimeter with a maximum pressure of60,000psia(414MPa).At this pressure,the smallest pore size into which mercury can be introduced is3nm. This test was carried out on small drilled cores(12mm diameter×23mm high),weighing approximately6g.The cored samples were obtained from100×100×100mm cubic specimens.The samples werefirst dried in an oven at110°C and then immersed in mercury under gradually in-creasing ing this technique,a measure of the total porosity of the sample may also be obtained,as well as the surface area of the pore network.However the MIP technique has certain limitations.First, the assumption that the intruded pores are cylindrical is not fully in agree-ment with the characteristics of real pore structure.Second,the sample must be dried prior to intrusion and this can cause microstructural dam-age.Due to surface tension,when the water evaporates the tensile stress generated by the water menisci in the capillaries causes the collapse of some of thefine pores[39].Moreover,microcracking may be induced in concrete as result of cement hydrates desiccation and as result of differen-tial thermal expansion of the aggregates and hardened cement paste.As aTable3Characteristics and chemical composition of the cement.Type of cement Blainefineness(cm2/g)Strength(28days)(MPa)Composition(%)SiO2Al2O3Fe2O3CaO MgO SO3K2O Na2O Ti2O5P2O5CO2LOICEM II/A-S42.5N385051.123.02 4.93 3.7060.41 2.79 2.460.600.510.330.110.55 1.76Table4Results of the mixture properties.Mix Air content(%)Slumpflow test Compressive strength(28days)(Mpa)Øf(cm)T50(s)N-300 1.1No test No test39.4 N-350 1.5No test No test39.0 S-300/125 3.262 3.540.4 S-350/0 1.167 1.539.6 S-350/450.969 1.236.9 S-350/900.971 1.038.7Fig.2.Measurement of the temperature inside concrete.585M.Valcuende et al./Cement and Concrete Research42(2012)583–592result,capillary porosity increases [39,40]and speci fic surface area of the pores is reduced [41].However,total mercury porosity values are not so much in fluenced by the drying technique [39].A third problem is known as the ink-bottle effect,in which a larger pore is preceded in the intrusion path of the mercury by a smaller neck.This may produce pore size distribution curves with an exaggeratedly high volume of smaller pores and a small volume of larger pores.Despite these limitations,the MIP technique is still a very effective aid for comparing the pore structure and pore network characteristics of different types of cement-based ma-terials.The main characteristics of the pore structure of the concretes under study are given in Table 5.A sample was taken from each of the three batches of each type of concrete.The results shown in Table 5are the arithmetic mean of the three values obtained.3.Results and discussionShrinkage strain and thermal strain due to heat generation during cement hydration are generated simultaneously.The temperature of the concrete was monitored by thermocouples from casting up to the age of 72h (Fig.5).During this period,the temperature change was not very signi ficant (of the order of 4.4K),due to the chemical composition of the cement (low C 3A content)and to the small size of the concrete specimen.In Fig.5it can be seen that the temperature rise occurs during the first day (from 5to 25h),after which it falls to ambient temperature approximately one day later.In order to eliminate the temperature effect,the shrinkage values were corrected considering that Δε=α·ΔT,where Δεis the thermal strain,αis the coef ficient of thermal expansion (1/K)and ΔT is the temperature change (K).In order to determine temperature distribution across the specimen,a 100×100×400mm specimen was also made from each mix,which was broken into four pieces after 24h.Temperature distribution was recorded in each of the three resulting cross-sections by means of a thermographic camera with a resolution of 0.1K (Fig.6).The results show a fairly homogenous distribution,with tem-perature differences throughout the cross-section of less than 0.4K.The strain/time curve corrected for the temperature effect corresponds to the volumetric change of concrete under isothermal conditions.As in other similar studies [4],α=10−5/K was selected.After 60h the temperature variation in the mixtures studied was quite small,so this effect was neglected.The cement hydration rate tended to be a little faster in S-350/90,due to the accelerating effect of limestone filler on cementhydrationFig.3.Measurement of shrinkage before mould removal (age less than 48h).Fig.4.Shrinkage test (age more than 48h).586M.Valcuende et al./Cement and Concrete Research 42(2012)583–592[42–44](Fig.7).As fines content is reduced in the mixture,initial set-ting time increases.Thus,for example,there is a difference of 135min between S-350/90and S-350/45and between S-350/45and S-350/0the difference is 90min.NVC initial setting time was slightly less than SCC made without additional fines (S-350/0),probably due to a reduced content of superplasticizer in the NVC mix.As polycarboxylate-based superplasticizers can have a strong retarding effect,a reduction in superplasticizer content leads to faster setting [11–13].3.1.Concrete pore size distributionFigs.8and 9show the increase in mercury intrusion volume according to the equivalent pore diameter.Pore volume distribution follows a similar pattern in the six mixes.Total pore volume was very similar in all the concretes made with the same cement content (Table 5).The most signi ficant differences between the different mixes are seen to be in the capillary pore volume (0.01–1μm).This is an important aspect,since,according to Kumar and Bhattacharjee [45]although the smallest pores have no effect on the concrete's strength properties,they are directly related to shrinkage and parison of SCC and NVC mixesSCCs show a finer porous structure than NVCs.In N-300the volume of pore size between 0.15and 0.4μm is far higher than in S-300/125(around 130%),with the below-0.15μm pore volume being very similar in both mixes (Fig.8).For the concrete made using 350kg/m 3(Fig.9),the differences between SCC and NVC are lower,which is logical because the volume of paste in both types of concrete is similar (Table 1).In N-350the maximum concentration of pores tends to be around larger pore sizes than in SCCs (mixes S-350/0,S-350/45and S-350/90),with a lower volume of smaller capillary pores and greater volume of large capillary pores.In Figs.8and 9and Table 5it can also be seen that the threshold diameter is lower for SCCs than in the corresponding reference NVCs.This diameter marks the limit from which the highest number of pores is concentrated and therefore is a good indicator of the fineness of the porous structure.Furthermore,average pore diameter is smaller in SCCs and the speci fic surface area of the SCCs is greater than that of the NVCs.These results agree with those obtained in previous work [46].SCCs can therefore be said to show a finer porous structure than NVCs,probably due to the higher content of aggregates in NVCs (in the aggregate/paste interfacial transition zone (ITZ)the porosity is higher and the capillary pores are larger than those in cement paste [47])and to the addition of limestone filler in SCCs which produces the following effects:a)filler effect,b)creation of more nucleation sites (since there are more nucleation sites,the size of portlandite crystals is smaller and therefore porosity is lower since,on the one hand the ITZ is not so thick [48]and on the other,the crystals behave like microcracks that create additional porosity [49]),and c)a small part of the CaCO 3present in the limestone filler promotes the reconversion of monosulfoaluminate to ettringite,leading to an increase of the total volume of the hydrate phase [50–53](as ettringite has a low density and thus a relatively large volume per formula unit).Besides,by using a more powerful super-plasticizer in SCC than in NVC,cement dispersion is enhanced,thus reducing the formation of floccules that leave pores on the inside [54].On the other hand,the vibration involved in NVC enhances bleeding,creating an interconnected network of capillary pores.3.1.2.In fluence of fines and VMA contentThe composition of the three SCC types made with 350kg/m 3of cement differs in the limestone fines and VMA contents.As can beTable 5Pore characteristics of concrete mixtures.N-300S-300/125N-350S-350/0S-350/45S-350/90Total cumulative volume (mm 3/g)53.448.563.964.368.966.1Total speci fic surface area(m 2/g)7.898.278.769.6610.9410.78Average pore diameter (nm)28.223.529.226.925.324.6Threshold diameter (μm)0.40.150.150.150.150.1Total porosity (%)12.5711.5414.5214.6415.4915.76Fig.5.Temperature evolution in the first 72h.Fig.6.Temperature distribution throughout the specimen (thermographytest).Fig.7.Setting time.587M.Valcuende et al./Cement and Concrete Research 42(2012)583–592seen in Fig.9,in S-350/90the threshold diameter is lower than for the other two types of SCCs (S-350/0and S-350/45):0.10μm compared to 0.15μm.Moreover,the volume of large capillary pores (larger than 0.1μm)and macropores (larger than 100μm)is 35.2%less than in S-350/0and 31.7%less than in S-350/45.In other words,the porous structure is finer.This is because of better particle packing afforded by the limestone fines,which broaden the grain-size distri-bution and provide a denser cementitious matrix,since they occupy the spaces between cement particles.Also,since the S-350/90con-crete has a lower aggregate content (Table 1),the aggregate-paste ITZ is smaller and therefore,in accordance with Section 3.1.1,there are fewer large capillary pressive strengthThe compressive strength results are shown in Table 4.Although SCC pore structure is finer than NVC,total pore volume is quite similar,which means that the compressive strength values of all the concretes are also similar,with no statistically signi ficant differences between SCC and NVC.3.3.SwellingAs shown in Fig.10,all the specimens undergo an increase in volume due to water absorption after being submerged in water.However,after the third day,the SCC types containing limestone filler (S-350/45and S-350/90)change their behaviour and start to shrink.This is probably due to the greater fineness of their porous structure,as shown by the MIP tests,so that water is only absorbed by the outer layer of the specimen,while the interior undergoes self-desiccation.In this case,the mean change in specimen length is in fluenced by both swelling and autogenous shrinkage,which occur simultaneously in the cross section.This behaviour was also observed in other studies [55]involving concrete with a low w/c ratio.However,an exception was observed in the case of S-300/125,which did not behave like S-350/45and S-350/90,in spite of having smaller total pore volume,smaller mean pore diameter and similar pore threshold diameter.This could have been due to the consider-able content of trapped air in S-300/125(Table 4)caused by the greater viscosity and lower fluidity of the mixture in fresh state [56].The presence of these macropores facilitates water absorption and thus the swelling of the specimen.The rest of the concrete types all show very similar swelling values with no signi ficant differences.Similarly to S-350/45and S-350/90,deformation pro-gresses rapidly and tends to stabilise after approximately 20days of age.3.4.Autogenous shrinkageFigs.11and 12give the evolution of autogenous shrinkage with time.As expected from concrete made with a w/c ratio of 0.6,this shrinkage is only a small percentage of the total shrinkage in the first few days (Fig.13).However,in the longer term,autogenous shrinkage is not as insigni ficant as some other authors have found [4].As the specimens lose water and approach hygrometric equilibrium with the atmosphere,drying shrinkage slows down and stabilises.However,as cement hydration continues,autogenous shrinkagecarriesFig.8.Pore sizedistribution.Fig.9.Pore sizedistribution.Fig.10.Concrete strain underwater.Fig.11.Autogenous shrinkage.588M.Valcuende et al./Cement and Concrete Research 42(2012)583–592on due to self-desiccation within the specimen,so that after one year the autogenous/total shrinkage ratio increases to between 0.4and 0.55,depending on the type of concrete (Fig.13).parison of SCC and NVC mixesSince SCC is made with a higher volume of paste (Table 1)and has a finer porous structure,in theory it could be expected to undergo greater shrinkage than NVC,given that cement paste is the principal material responsible for changes of volume [5,8,9]and the finer the capillaries the greater the tensile stress generated by the water menisci in the capillaries.However,this did not turn out as expected;the SCC presented less shrinkage than the corresponding reference NVC,the differences being on average between 14.3%for concrete made with 300kg of cement and 19.8%for those made with 350kg.This could be due to various causes.The calcium carbonate present in the limestone filler promotes the reconversion of monosulfoalumi-nate to ettringite (see Section 3.1.1),leading to an increase of the total volume of the hydrate phase [52,53].Also,the filler not involved in the reaction (i.e.most of the filler)behaves like a normal aggregate,hindering shrinkage of the cement paste.On the other hand,as SCC has a finer porous structure,water diffusion from the capillary pore network to the gel pores formed during cement hydration is also slower and this slows down the self-desiccation process in the larger capillary pores,which means that less autogenous shrinkage takes place.Another factor exists which,as far as we are aware,has not been considered in other studies,which is the water absorbed by theaggregates.Since mixes are designed assuming that aggregates are saturated with a dry surface,in the course of concrete self-desiccation the aggregates compensate for the loss of water from the paste with the water they have absorbed.Table 1indicates the quantity of water absorbed by aggregates and filler.It can be seen that the capacity to provide extra water is greater in the SCC mixes than in the corresponding reference NVC mixes and thus the self-desiccation is lower in SCC.The SCC types therefore show less long-term autogenous shrinkage than the NVC.This also explains why in S-350/45and S-350/90water loss in unsealed specimens is higher than in N-350(Fig.14)in spite of the finer porous structure of the former (slower water diffusion),due to the fact that total water content is higher (mix water+water absorbed by aggregates).This can also be veri fied by comparing S-300/125and N-300.3.4.2.In fluence of fines and VMA contentTaking mixes S-350/0,S-350/45and S-350/90as reference,in Fig.12it can be seen that concrete made with VMA only (S-350/0)tends to present higher shrinkage than those made with limestone filler addition:10.7%more than mix S-350/45and 11.6%more than S-350/90.According to the information given in the preceding section,this can be explained by the high water absorption coef ficient of the filler,since the extra water from the filler and aggregates was less in S-350/0than S-350/45and 350/90(Table 1).Also,when VMA is used as a substitute for limestone filler,the favourable effect of the filler on hindering shrinkage disappears,as also does its filler effect,which helps to speed up internal water diffusion and thus also autogenous shrinkage.3.5.Drying shrinkageDrying shrinkage cannot be measured.As many authors have pointed out,this shrinkage is obtained by subtracting autogenous from total shrinkage.However,this process involves a small error,which can be seen in Figs.15and 16in the form of a descent in the curve at advanced ages.This,of course,is impossible,since it would mean that the concrete stops shrinking and starts to swell.The error is due to the fact that in unsealed specimens self-desiccation is less important than in sealed specimens,since when the ambient RH is higher than that in the concrete,a small quantity of water vapour is absorbed by the concrete,which compensates for its self-desiccation.3.5.1.In fluence of fines and VMA contentAs shown in Fig.16,the higher the fines content in SCC mixes (0,45and 90kg/m 3),the higher the shrinkage.At the age of oneyearFig.12.Autogenousshrinkage.Fig.13.Ratio between autogenous shrinkage and totalshrinkage.Fig.14.Weight loss.589M.Valcuende et al./Cement and Concrete Research 42(2012)583–592。

6.2.2 Porosity and DensityHello, everybody, in this Section, we are going to talk about porosity and density.译文：在这一节，我们将讨论气孔率和密度。

When referring to a solid material such as a part made from copper or stainless steel, the word density takes into consideration the microstructures that contains no porosity. By which term we do not mean the voids or vacancies in the atomic structure. In speaking of a solid material we mean the material’s theoretical density or mass density, it is the mass of a material divided by its volume.我们通常说到密度，指的是理论密度，表示结构中不包含气孔。

通过质量除以体积得到。

译文：当提到一种固体材料，尤其是由铜或不锈钢制成的材料时，密度这个词通常会考虑到一个没有气孔率的微观结构，在这个词中，我们指的不是原子结构中的孔洞或空位。

我们通常说到密度，指的是理论密度，表示结构中不包含气孔。

通过质量除以体积得到。

There are two factors influence the density of material. Atomic weight is a major factor in determining the density of the materials. Low-atomic-weight elements have low densities. 影响材料密度的因素有两个。

小学上册英语第6单元期末试卷考试时间：90分钟（总分:140）B卷一、综合题(共计100题共100分)1. 填空题：The teacher encourages _____ (团队合作) in class.2. 听力题：The girl loves to ________.3. 听力题：The _______ of a curve can determine its path.4. 选择题：What is the main ingredient in bread?A. SugarB. FlourC. WaterD. Salt答案: B5. 听力题：I have a ______ of crayons. (box)6. 听力题：Most birds can ______.7. 填空题：A barracuda is a fast and fierce ______ (鱼).8. 填空题：I love to ______ (与他人分享) my knowledge.9. 填空题：The little chick is _______ (刚孵化) from its egg.10. 选择题：What is the name of the story about a girl in a red hood?A. CinderellaB. Little Red Riding HoodC. Snow WhiteD. Sleeping Beauty答案: B11. 填空题：I enjoy having ________ (野餐) in the park.12. 听力题：The butterfly flutters from _____ to flower.13. 填空题:I enjoy creating ________ in my art class.14. 选择题：Which of these is a type of nut?A. AlmondB. PotatoC. AppleD. Carrot答案:A15. 听力题：The capital of Serbia is __________.16. 听力题：The ________ (discussion) raises awareness.17. 听力题：The __________ is a long, narrow country in South America.18. 填空题：The ________ was a significant moment in the history of labor rights.19. 选择题：What do you call a young deer?A. CalfB. FawnC. KitD. Cub20. 选择题：What is the capital city of the Czech Republic?A. PragueB. BrnoC. OstravaD. Plzeň21. 选择题：What is the term for a group of words that expresses a complete thought?A. PhraseB. SentenceC. ClauseD. Paragraph答案: B22. 听力题：The bear hibernates in the cold ____.23. 填空题：Do you like _____ (乌龟)?24. 选择题：What is the main ingredient in risotto?A. RiceB. PastaC. WheatD. Barley25. 填空题：The rabbit is very _______ (活泼).26. 听力题：The chemical formula for sodium sulfate is ______.27. 听力题：A __________ is a chemical reaction that occurs quickly.28. 选择题：What do we call a person who writes books?A. DirectorB. AuthorC. EditorD. Publisher答案:B29. 小老鼠) loves cheese. 填空题：The ___The puppy wagged its _____ when it saw me.31. 选择题：What is the capital city of Canada?A. TorontoB. VancouverC. OttawaD. Montreal32. 填空题：The _______ (小变色龙) can blend into its surroundings.33. 听力题：The main gas produced by plants during photosynthesis is ______.34. 听力题：The chemical formula for lithium hydroxide is ______.35. 选择题：What is the capital of Palau?a. Ngerulmudb. Kororc. Melekeokd. Airai答案:a36. 听力题：I want to learn how to ______ (play) the guitar.37. 填空题：I love reading books. My favorite book is about ________ (动物). It teaches me about ________ (自然).38. 选择题：What is the opposite of 'fast'?A. QuickB. SlowC. SteadyD. Rapid答案:B. Slow39. 填空题：The ________ was a crucial chapter in the narrative of national unity.The ______ (小鹰) watches over its nest from a high ______ (树枝).41. 选择题：Which animal has a long trunk?A. GiraffeB. ElephantC. RhinoD. Hippo42. 选择题：Which animal is known for its black and white stripes?A. TigerB. ZebraC. PandaD. Leopard43. 填空题：The ______ (水循环) plays a role in plant growth.44. 听力题：The concentration of a solution is measured in _____ per liter.45. 填空题：My favorite dish is _______ (披萨).46. 听力题：The cat is _____ on the windowsill. (sitting)47. 听力题：We have ___ (history/math) class today.48. 填空题：The ________ (湿润环境) encourages growth.49. 填空题：My cousin, ______ (我的表兄弟), likes to play video games.50. 听力题：In a chemical reaction, substances are converted into new ____.51. 选择题：What do you call a group of fish?A. SchoolB. PackC. SwarmD. Flock答案:A52. 选择题：What do you wear on your head?A. ShoesB. HatC. GlovesD. Scarf53. 填空题：I have a toy _______ that can race against my friends.54. 选择题：What is the capital of Kiribati?a. Tarawab. Kiritimatic. Abemamad. Butaritari答案:a55. 听力题：The flowers are ______ (beautiful).56. 听力题：The sky is _____ and clear. (blue)57. 选择题：What is the freezing point of water in Celsius?A. 0B. 32C. 100D. -1答案:A58. 填空题：My teacher is very __________ (专注).59. 选择题：What is the capital city of Russia?A. MoscowB. St. PetersburgC. KievD. Warsaw60. 听力题：Chemical formulas provide information about the composition of ______.61. 填空题：I have a collection of toy _____ from different places.62. 听力题：The capital of Kazakhstan is _______.63. 填空题：The _______ (Vietnam War) involved North and South Vietnam with US involvement.64. 听力题：A reaction that releases light is called a ______ reaction.65. 选择题：Which animal is known for building dams?A. BeaverB. OtterC. DuckD. Frog答案:A66. 选择题：Which instrument has keys and is played with fingers?A. GuitarB. DrumC. PianoD. Flute67. 选择题：Which planet is known as the Red Planet?a. Earthb. Venusc. Marsd. Jupiter答案:c68. 填空题：The rabbit has long _______ (耳朵) to hear well.69. 选择题：How many continents are there in the world?A. FiveB. SixC. Seven答案:C70. 填空题：My cousin is my __________. (表兄弟/表姐妹)71. 听力题：The ______ shares her experiences on social media.72. 选择题：What is the name of the famous author who wrote "Pride and Prejudice"?A. Charlotte BrontëB. Jane AustenC. Emily DickinsonD. Virginia Woolf73. 选择题：What do we call a person who makes films?A. DirectorB. ProducerC. FilmmakerD. All of the above74. 填空题：The __________ is the study of the Earth's physical features and how humans interact with them. (地理学)75. 听力题：The chemical formula for potassium perchlorate is _____.76. 选择题：What do you call a collection of essays published together?A. AnthologyB. CollectionC. VolumeD. Book答案: A77. 听力题：The ______ has a long tongue.78. 选择题：What do you call a young deer?A. FawnB. KidD. Calf79. 选择题：What is the capital of Peru?A. LimaB. CuscoC. ArequipaD. Trujillo答案: A80. 填空题：The ________ (大洲) of Africa is very large.81. 听力题：A binary star system can create interesting ______ patterns.82. ts release ______ (香氣) that can repel pests. 填空题：Some pla83. 选择题：What do you call a person who creates art?A. ArtistB. SculptorC. PainterD. All of the above答案: D84. 填空题：I can create a _________ (玩具动物) out of clay.85. 听力题：The __________ can provide insights into the evolution of the Earth's surface.86. 选择题：Which food is made from milk?A. BreadB. CheeseC. RiceD. Meat87. 填空题：In _____ (埃及), you can find many pyramids.88. 听力题：We go ______ during the summer. (swimming)89. 选择题：How many wheels does a car typically have?A. 2B. 3C. 4D. 590. 选择题：What do we call a person who writes books?A. AuthorB. ArtistC. ComposerD. Director答案: A91. 选择题：What do we call the natural satellite that orbits Earth?A. MoonB. StarC. PlanetD. Comet答案：A92. 填空题：The ________ has a sharp smell.93. 听力题：A mixture of sand and salt can be separated by ________.94. ts can be dried for ______ (保存). 填空题：Some fru95. 填空题：A squirrel gathers _______ to prepare for winter.96. 填空题：The ______ (小鸭子) waddles after its mother to the ______ (水边).97. 听力题：My uncle is a skilled ____ (mechanic).98. 填空题：My favorite story is about a _______.99. 选择题：What is 3 x 3?a. 6b. 7c. 8d. 9答案:d100. 听力题：I have a ______ for math and science. (passion)。

四川盆地东部地区下志留统龙马溪组页岩储层特征刘树根;马文辛;LUBA Jansa;黄文明;曾祥亮;张长俊【摘要】四川盆地是中国西南部重要的舍油气盆地,在东部和南部地区下志留统龙马溪组页岩广泛发育.在川东南、鄂西渝东地区的勘探井中志留系具有良好的气显示.研究区龙马溪组厚65 -516m,底部为一套海侵沉积的富含笔石的黑色页岩,龙马溪纽向上和向东砂质和钙质含量增加,演变为浅水陆棚沉积.龙马溪组主要由层状-非层状泥／页岩、白云质粉砂岩、层状钙质泥／页岩、泥质粉砂岩、层状.非层状粉砂质泥／页岩、粉·细粒砂岩、钙质结核、富含有机质非层状页岩8种岩相组成.总有机碳含量(TOC)为0.2％～6.7％.有机质以Ⅱ型干酪根为主,R0为2.4％ - 3.6％.页岩中石英矿物含量在2% -93%,主要呈纹层状或分散状分布,主要为陆源碎屑外源成因.龙马溪组页岩岩心孔隙度为0.58% -0.67%.渗透率为0.Ol×10 -3μm2～0.93×10-3μm2.扫描电镜下龙马溪组页岩微孔隙度为2%左右,主要包括晶间孔和粒内孔,孔隙直径为lOOnm～50μm.页岩储层的形成机理主要为有利矿物组合、成岩作用和有机质热裂解作用.龙马溪组与美国Barnett页岩具有一定差异,主要表现在龙马溪组页岩埋藏较深、热演化程度较高、含气量较低、储层较致密、以陆源成因石英为主.对于评价下志留统龙马溪组页岩气勘探前景而言,今后须重点加强针对龙马溪组底部黑色硅质岩系石英成因、成熟度、埋藏史、含气量等方面的研究,以及进行详细的古地貌和古环境恢复.%The Sichuan basin is an oil-bearing and gas-rich basin with extensive development of the Lower Silurian Longmaxi Formation shale in southwestern China. The gas shows in the shale were identified in exploration wells mainly located between southeastern Sichuan basin and western Hubei-eastern Chongqing. The thickness of the Silurian Longmaxi Formation shale ranges from 65 to 516m. The base ofthe Longmaxi Formation shale is graptolite-rich transgressive black shale. Its thickness increases eastward in the study area, similarly as the sand content in the formation, with the latter also increasing stratigraphically upward. The Longmaxi Formation is comprised by eight lithofacies, including laminated and nonlaminated mudstone/shale, dolomitic siltstone, laminated lime mudstone/shale, argillaceous siltstone, laminated and nonlaminated silty mudstone/shale, fine grained silty sandstone, calcareous concretions and nonlaminated shale enriched organic matter. Longmaxi Formation contains 0. 2% to 6. 7% of organic carbon (TOC). The organic matter is overmature, with Ro 2.4% ~3.6% and dominated by type II-kerogen. Quartz silt, which is the second important component of the shale gas reservoir quality, occurs as laminae and/or disseminated and varies from 2% -93% in the shale. The size of quartz silt ranges from 0. 03 to 0. 05 mm, with terrigenous origin. Porosity measured on core samplesof the shale from the Longmaxi Formation in exploratory wells ranges from 0. 58% to 0.67%. The microporosity observed in the thin sections of the shale is about 2%, and dominated by the intercrystal and intragranular pores, with the pore size ranging from 100nm to 50μm. The formation mechanism of the shale reservoirs includes favorable mineral composition, diagenesis and thermal cracking of organic component There are some differences between Longmaxi Formation shale and Barnett shale in USA. The former is burial deeper, higher degree of thermal evolution, lower gas content, denser, more quartz of terrigenous origin. The prevailing low content of organic matter and highly variable quartz content in theLongmaxi Formation shale suggests there are only marginal conditions for exploration of shale gas resource. However, the high variability in both the content of TOC and quartz in the shale indicates that locally, particularly in the southeastern part of the basin, favorable conditions for shale gas may have developed. More detailed paleogeographic, burial history, gas content and quartz origin studies are needed to better access shale-gas potential of the Silurian Longmaxi Formation shale.【期刊名称】《岩石学报》【年(卷),期】2011(027)008【总页数】14页(P2239-2252)【关键词】下志留统;龙马溪组;页岩气;储层特征;四川盆地东部【作者】刘树根;马文辛;LUBA Jansa;黄文明;曾祥亮;张长俊【作者单位】油气藏地质及开发工程国家重点实验室,成都理工大学,成都610059;油气藏地质及开发工程国家重点实验室,成都理工大学,成都610059;Geological Survey of Canada-Atlantic, Dartmouth. N.S. & Earth Science Department, Dalhousie University, Halifax, Nova Scotia B3H3J4;地质勘探开发研究院,中国石油川庆钻探工程有限公司,成都61005l;油气藏地质及开发工程国家重点实验室,成都理工大学,成都610059;油气藏地质及开发工程国家重点实验室,成都理工大学,成都610059【正文语种】中文【中图分类】P534.4;P618.12页岩气是一种非常规气藏，具有典型的自生自储、近原地成藏富集的特点(Curtis,2002; 张金川等,2004,2008; Boyer et al.,2009; Hill et al.,2007; Jarvie et al.,2004,2007; Jarvie,2008; 刘树根等,2009)。

W ei L i ,Q in Y ue ,Y onghui D eng ,*a nd D ongyuan Z haoO rdered Mesoporous Materials Based on Interfacial Assembly and EngineeringW. Li, Q. Yue, Prof. Y. H. Deng, Prof. D. Y. ZhaoDepartment of Chemistry and Shanghai Key Lab ofMolecular Catalysis and Innovative MaterialsState key Laboratory of MolecularEngineering of PolymersLaboratory of Advanced MaterialsFudan UniversityShanghai 200433, P. R. ChinaE-mail: y hdeng@D OI: 10.1002/adma.2013021841. IntroductionW ith recent progresses made in modern nanoscience andnanotechnology, ordered mesoporous materials have beenone of the hottest research topics in scientifi c communitiesspanned chemistry, materials science, physics and biology. [1–3]That is because ordered mesoporous materials possess fas-cinating properties including regular, uniform and interpen-etrating mesopores, tunable pore sizes, high surface areas aswell as abundant framework compositions. Compared withtheir bulk counterparts, they can interact with atoms, ions, mol-ecules or even larger guest species not only at the external sur-face, but also through the whole internal pore system. [4]As aresult, ordered mesoporous materials exhibit substantial perfor-mance boosts in numerous applications such as adsorption, [5–7]separation, [8]catalysis, [9–11]sensors, [12]drug delivery, [13,14]energyconversion and storage, [15–19]and so on. Since the exciting dis-covery of this new kind of materials based on the supramolec-ular assembly chemistry in the early nineties, [20–22]considerablework has been done to synthesize orderedmesoporous materials with diverse com-positions, morphologies and pore symme-tries; meanwhile, tremendous effort hasbeen devoted to elucidate the mechanismof mesostructure formation and exploretheir applications.T he construction of mesoporous mate-rials is mainly concerned with buildingmonodispersed mesosized (2-50 nm)pore voids and arranging them in a long-range ordered array. [23–25]Generally, twokinds of templates are used to produce themesopores: supramolecular aggregatessuch as surfactant micelle arrays, andrigid preformed mesoporous solids suchas ordered mesoporous silica, carbon, andcolloidal crystals. [26,27]The correspondingsynthesis pathways are commonlydescribed in literatures as soft- and hard-templating (nano-casting) methods, respectively. Noticeably, besides the template,the interface also plays a central role in the processing, becauseit provides a rich and crucial space for the assembly and con-struction of mesostructures. Generally, there are two types ofinterfaces involved in the synthetic system. The fi rst one is atbetween surfactant templates and guest species, which hasbeen extensively investigated by several research groups. [28–32]It suggests that the effective interaction of surfactants-guestspecies is critical to govern the soft-templating route for syn-thesis of ordered mesoporous materials. [24]Although excel-lent progresses have been made on the cooperative assemblyof mesostructures in an aqueous phase system, it has severalinherent drawbacks: i) the resultant products are typically pow-ders with ill-defi ned morphology, precluding their general usein thin fi lms or other shape-based technologies; ii) the prepa-ration of non-siliceous mesoporous materials is more chal-lenging because the hydrolysis and condensation of non-sili-ceous precursors (e.g., metal alkoxides) are generally diffi cultto control; iii) the arranged patterns and sizes of mesoporesare often limited; iv) it is a great challenge to obtain multifunc-tional mesoporous materials through such one-pot cooperativeassembly.A nother important interface is the two-phase (solid, liquidand gas) one in the synthetic system, including liquid-solid, gas-liquid, liquid-liquid, gas-solid, and solid-solid interface, whichhas been well developed for synthesis of mesoporous mate-rials ( F igure1). Compared with one-phase synthesis referringto homogeneous nucleation and growth, the introduction of a O rdered mesoporous materials have inspired prominent research interestdue to their unique properties and functionalities and potential applicationsin adsorption, separation, catalysis, sensors, drug delivery, energy conver-sion and storage, and so on. Thanks to continuous efforts over the past twodecades, great achievements have been made in the synthesis and structuralcharacterization of mesoporous materials. In this review, we summarizerecent progresses in preparing ordered mesoporous materials from theviewpoint of interfacial assembly and engineering. Five interfacial assemblyand synthesis are comprehensively highlighted, including liquid-solidinterfacial assembly, gas-liquid interfacial assembly, liquid-liquid interfacialassembly, gas-solid interfacial synthesis, and solid-solid interfacial synthesis,basics about their synthesis pathways, princples and interface engineeringstrategies.two-phase interface in the system will change growth behaviors of mesoporous materials and lead to the formation of molding or multifunctional mesoporous materials. Thus, above-mentioned drawbacks in one phase could be overwhelmed. For example, mesoporous thin fi lms or membranes have been widely fabri-cated on a substrate via an evaporation-induced self-assembly(EISA) method. [ 33 , 34 ] Multifunctional core-shell structuredmesoporous materials can be obtained by rationally depositingmesoporous shells on well-designed cores. [ 35 , 36 ] In addition, thewell-known hard-templating method for mesoporous materials is also a typical interface reaction. In this case, a fl uid (liquid, or even gas) precursor is fi rst infi ltrated into the nanometer-sized pore channels of solid templates, then converted into a targetnanomaterial by nanostructured confi nement. [ 27 , 37–41 ]Thisinterfacial casting strategy avoids the control of the cooperative assembly between surfactants and guest species, and the so-gel process of guest species, making it quite successful in plenty of mesoporous materials.W an and Zhao have comprehensively summarized the fun-damentals of interactions of surfactant-guest species at theinterface. [ 24 , 42 , 43 ] Thus, it will not be introduced in detail. In thisreview, we aim to review the synthesis of ordered mesoporous materials based on the interfacial assembly and engineering, unless otherwise specifi ed, which refer to the two-phase inter-face. Overall, the discussion of interfacial assembly and synthesis of ordered mesoporous materials will be classifi ed into fi ve cate-gories, including liquid-solid interfacial assembly (Section 2), gas-liquid interfacial assembly (Section 3), liquid-liquid interfacial assembly (Section 4), gas-solid interfacial synthesis (Section 5), and solid-solid interfacial synthesis (Section 6). In each section, we will focus on the synthesis pathways, principles and interface engineering strategies. In the last Section, we like to present a summary and some perspectives on the future developments.W ei Li received his B.S. degree in chemistry from Heilongjiang University under the supervi-sion of Prof. Honggang Fu in 2008. Then, he started his Ph.D. study in chemistry under the supervision of Prof. Dongyuan Zhao at Fudan University. He is interested in synthesis of porous materials and nanostructured materials.Q in Yue received her BS degree in chemistry from Fudan University (2011). She is currently pursuing his PhD under the supervision of Prof. Yonghui Deng at Fudan University. Her research focuses on the designed synthesis and applications of core-shell struc-tured materials.Y onghui Deng received his BS in chemistry from Nanchang University (2000) and PhD in polymer chemistry & physics from Fudan University (2005). He worked as a postdoctoral researcher with Prof. Dongyuan Zhao (2005–2007), and was pro-moted as associate (2007) and full professor (2011) in Fudan University. He has coauthoredover 60 scientifi c papers and fi led 12 patents. His research interests include core–shell nanomaterials, functional porous materials, and their applications in catalysis, and separation, etc.D ongyuan Zhao received his BS (1984) and PhD (1990) from Jilin University. He carried out postdoctoral research at the Weizmann Institute of Science (1993–1994), University of Houston (1995–1996), and University of California at Santa Barbara (1996–1998). He is a Professor (Cheung Kong and Hao Qing Professorship) inFudan University since 1998. He was elected as an acad-emician of the Chinese Academy of Science in 2007, and a member of The WorldAcademy of Science (TWAS) in 2010. His research interests mainly include synthesis and applica-tion of ordered mesoporous materials.F igure 1. T he two-phase interfaces for the synthesis of mesoporous materials, including liquid-solid, gas-liquid, liquid-liquid, gas-solid, and solid-solid interface.infrared spectroscopy (FTIR) and conventional FTIR, and so on.The fi nal mesostructures are affected by several factors such assurfactants and their concentration, inorganic precursors, fi naltreatment, even some apparently negligible parameters (e.g.,water concentration, processing humidity and evaporation tem-peratures). It was found that ordered mesostructures gener-ally formed in the last stage of the solvent evaporation, evenin the aging stage. [52]The interplay inside the guest speciesthemselves appears to be extremely important for the resultantordered mesostructures.2.1.1. General FactorsT hrough the EISA process, uniform homogeneous thin fi lmsare obtained only if the solvent perfectly wets the substrate andis volatile. Generally, the EISA process relies on the use of sol-vents with weak polarity such as ethanol, methanol, tetrahydro-furan (THF). The surfactant templates lose their hydrophilic/hydrophobic properties in the weak-polarity solvents due tothe fact that both hydrophilic and hydrophobic segments caninteract with these solvents. Thus, the self-assembly of sur-factants in the initial solution can be inhibited. In this regard,the assembly can be only induced upon the solvent evaporation.Nonpolar and oily solvents are seldom adopted. For example,in toluene or xylene solution, silica nanowires with adjustablediameters were synthesized with Pluronic P123 and F127 bythe EISA approach. The formation of this kind of arrays cor-responds to the reverse mesophases of surfactants in oilysolvents. [54]M ostly, the EISA process proceeds on the substrate, whichprovides a rich and crucial interface for the self-assembly ofmesostructures. The nature of the substrate plays a vital roleon the resultant mesoporous materials in terms of the mor-phology and mesochannels orientations. Therefore, the selec-tion of a substrate is based on a number of considerations.First, it is necessary to ensure a good affi nity of the substratetoward the template and guest species so as to get a uni-form homogeneous film. Second, the chemical compositionand nanostructure of the substrate are important, which aredirectly related with the mesopores alignments. For example,Hara et al. demonstrated the vertical alignment of silica mes-ochannels by utilizing the π–πinteraction between the organictemplate molecule of a planar discotic liquid crystalline andtwo-dimensional (2D) π-plane of graphite. [55]Moreover, thesubstrate should possess good physical and chemical stabili-ties. Thus, the chemical reaction with the fi lm and themselvesdegradation can be effectively avoided during solidifi ed theframework and the template elimination. Additionally, thethermoshrinkage of the substrate should be paid much atten-tion to preparing ordered mesoporous materials with largeframework shrinkage during the thermal processing, to accom-modate stresses. [56]Obviously, the morphology of the resultantmesoporous materials is directly dependent on the substrate.Generally, planar supports such as glass substrates and/orsilicon wafers are widely used to produce mesoporous fi lms.Other materials presenting with plentiful interfaces can alsobe used as the substrate such as polyether polyol-based polyu-rethane (PU) foams, [57]hierarchical biological materials, [58]col-loidal crystals, [59]and so on.2. Liquid-Solid Interfacial AssemblyA liquid-solid interface has proved a quite versatile interface innature, being useful in the construction and assembly of var-ious functional materials. For example, as a typical example ofliquid-solid interfacial synthesis, Langmuir-Blodgett (LB) tech-nique has been shown to be a high-throughput, low-cost, easilyintegrated method to assemble amphiphilic molecules or nano-sized building blocks to fabricate both closely packed super-structures and well-defined patterns with low density. [44,45]Inaddition, liquid-solid interface has also been widely employed toproduce a wide range of supported catalysts in the industry. [46]Specially, in this section, we will introduce the interfacial syn-thesis of mesoporous materials which takes advantage of theliquid-solid interface.2.1. EISA ProcessE ISA process is a very convenient method to prepare orderedmesoporous materials especially for mesoporous thin fi lms,membranes and monoliths. [33,34,47]It was fi rst used by Brinkerand coworkers in the preparation of mesoporous silica thinfi lms. [48]F igure2illustrates the typical EISA process formesoporous thin fi lms. First, a homogeneous solution with dis-solved templating surfactants and guest precursors is required.Then, the solution is cast on a substrate through chemicalsolution deposition. The self-assembly is triggered by theprogressive evaporation of volatile solvents, giving rise to thetemplate-guest species metastable phase with ordered meso-structures. After a treatment step to stabilize mesostructuredcomposites and increase the porosity through template elimi-nation, ordered mesoporous materials are obtained. Sanchez,Brinker and co-workers have carried out elaborate work oninvestigating this strategy. [48,49]Actually, EISA process is rathercomplex, it involves at least three dynamic steps governed bydifferent parameters: the chemistry associated with initial solu-tion, the processes linked to the layer-deposition technique, andthe treatment aimed at eliminating the template and stabilizingthe mineral networks without systemic pore collapses. Detailedstudies of such process have been conducted for various meso-structured fi lms (e.g., SiO 2-CTAB, [49,50]SiO 2-Pluronics, [51]TiO 2-Pluronics [52,53]) by using various techniques, including in situtime-resolved small-angle x-ray scattering (SAXS), grazingincidence SAXS (GI-SAXS), ellipsometric fourier transformF igure 2.S chematic illustration of a typical EISA process for mesoporousmaterials. The synthesis procedure is shown on the top, the bottomsequence illustrates the cooperative self-assembly of mesostructures.reaction is effectively hindered by protonation of MOH nucleo-philic species, in which small oligomers can retain during theself-assembly process of surfactants. [ 66 , 67 ] The use of additivessuch as acetic acid and acetylacetone is also effective for con-trols of the hydrolysis and condensation. [ 68 , 69 ]F or guiding the selection of precursors in fabricating mesoporous metal oxides with various components via EISA process, an ‘‘acid-base pair’’ concept was proposed for the fi rsttime by Zhao and coworkers. [ 70 ] This concept takes a differentperspective to address the infl uence of inorganic-inorganic interplay on the synthesis of mesoporous materials, in which the inorganic precursors are divided into “acid” and “base” according to their alcoholysis (here, alcohol is used as a sol-vent) behaviors. Inorganic metallic or nonmetallic chlorides are considered as strong ‘‘acids’’ since a large amount of acid is generated during the alcoholysis process. Hydrate metallic salts and inorganic acids (Brønsted acids) are attributed as a medium acidic precursor. Metallic alkoxides and nonmetallicalkoxides (e.g. phosphatides) are assigned as bases because acid substances are seldom generated. In this process, two or more inorganic species are used to self-generate a reaction mediumwith the correct acidity to favor the sol-gel process of solvated products, and give a self-adjusted sol-gel synthesis, and pro-mote the assembly of mesostructured materials. Generally, the ‘‘acid-base’’ pairs formed from strong ‘‘acid’’ and strong ‘‘base’’, or strong ‘‘acid (base)’’ and medium ‘‘base (acid)’’ in non-aqueous media are required. Guided by this concept, a wide variety of well-ordered, large-pore, homogeneous, mul-ticomponent, mesostructured solids have been synthesized, including metal phosphates, silicoaluminophosphates, metal borates, as well as various metal oxides and mixed metal oxides. For example, using phosphorus trichloride and zirconiumpropoxide as inorganic precursors, and triblock-copolymers as templates, ordered mesoporous zirconium phosphates havebeen prepared with surface areas between 78 and 177 m2g − 1 and controllable pore sizes between 2 and 4 nm. This concept, together with the increased understanding on EISA strategy,sol-gel chemistry and organic-inorganic interaction, which areinterdependent of each other, could pave the way for preparingordered mesoporous nonsiliceous oxides. [ 71–73 ]A nother benefi t of this EISA process is that it gives rise to ordered mesoporous polymers and carbons. It was fi rst dem-onstrated by Zhao's group. [ 74 ] Highly ordered mesoporous carbons, denoted as FDU-15 and FDU-16 ( F igure 3), were pre-sented by using commercial triblock copolymers as templates, and water-soluble and low-molecular-weight phenolic resins (resols) as precursors, which are polymerized by phenol and formaldehyde under alkaline conditions. F igure 4illustrates the formation process of the ordered mesoporous carbons. The initial homogeneous solution is prepared by dissolving triblock copolymers and resols in ethanol. The choice of resolas a precursor and triblock copolymer as a template is essen-tial for the successful organization of organic-organic meso-structures because resol has a 3D network structure and plenty of hydroxyl groups (-OH), can interact strongly with the PEO blocks of triblock copolymer templates via hydrogen bonds. The assembly of resols and copolymer templates occurs readily toform ordered mesostructures without macrophase separation.The preferential evaporation of ethanol progressively enrichesThe common techniques for casting initial solution on the substrate include dip coating, [ 48 ] spray coating, [ 60 ] and spincoating, [ 61 ] etc. Dip coating method is to withdraw the substratefrom the coating solution at a certain rate to control the forma-tion of liquid layer on the substrate surface. In spray coating, the solution is pulverized onto the surface of the substrate using an aerosol generator or an atomizer. Spin coating, with a different mechanism, fi rst uniformly disperses the coating solution at the center of a spinning substrate and then the solution droplet is spread by the centrifugal force generated by high-speed rotation. The fi lm is thus formed at the same time of being submitted to a shearing force, applying between both interfaces of the drying solution layer. Among these techniques, dip coating and spin coating are most used due to the low cost of equipment and facile operation.2.1.2. Typical ExamplesT he most successful case of the EISA process is the preparation of continuous mesoporous silica fi lms. [ 62–64 ]In a typical pro-cess, silica precursors (e.g., tetraethyl orthosilicate, TEOS) dis-solved in organic solvent (normally ethanol) are prehydrolyzed with stoichiometric quantity of water (catalyzed by acids, such as HCl) at a temperature of 25–70 ° C . Upon solvent evapora-tion, the silicate species further polymerize and condense. At the fi nal stage of solvent evaporation, high concentrated sur-factants such as cetyltrimethylammoniumboromide (CTAB) or polyethylene-oxide based block copolymers (e.g., Pluronic P123) form liquid-crystal phases in the presence of inorganic oligomers. Simultaneously, the low hydrolysis and crosslinkage degree of silicate species improve the assembly on organic/inorganic interfaces, leading to the formation of ordered meso-structures. The process is extremely fast and needs only several seconds. So far, mesoporous silica thin fi lms with diverse mes-ostructures, compositions, fi lm thickness, as well as tunable porosities have been achieved. Y ang et al . fi rst extended the EISA process to the synthesis of mesoporous metal oxides. [ 65 ] In this non-aqueous sol-gel pro-cess, metal halides were used as the inorganic precursors and amphiphilic block copolymers as templates to generate several large-pore mesoporous metal oxides, including TiO 2,ZrO 2,Nb 2O 5,Ta 2O 5,Al 2O 3,SiO 2,SnO 2,WO 3,HfO 2, and mixed oxides SiAlO y ,Al 2T iO y ,ZrTiO y ,SiTiO y and ZrWO y. The resultant mesoporous metal oxides show relatively thermally stability (about 400 ° C ), narrow pore size distributions, but low surface areas ( <200 m 2 /g), as well as possessed semicrystalline frame-works. The most important feature is alcoholysis of inorganic salts generates M(OEt) n C l m species with a low polymerizationrate, which can slowly react with water in air via hydrolysis and crosslinking to form mesostructures. It is well known that the reactivity of metal alkoxides is much higher than those of sil-icon alkoxides. Therefore, restrained hydrolysis and condensa-tion of the inorganic species appears to be crucial for forming mesophases of most of non-siliceous oxides, because of their strong tendency to precipitate and crystallize into bulk oxide phases directly in aqueous media. Various strategies have been developed to control the reactions, including the optimization of pH, water content in precursor solutions, relative humility. [ 52 ] For example, under strongly acidic condition, the condensationsilicate molecular sieves. This step is rather important for the stability of mesoporous products. It should be noted that the cross-linking and polymerizing processes of the phenolic resin frameworks are separated from the assembly with surfactants. This is an important feature of EISA strategy. It is quite dif-ferent from a cooperative formation assembly mechanism, where the surfactant-directing assembly and polymerization of inorganic oligomers occur cooperatively and simultane-ously. Because of the difference in chemical and thermal sta-bility between the resin and Pluronic copolymers, the templates could be easily removed at low temperatures without destroying the resin framework. The continuous hydrocarbon frameworks of mesoporous resins impart highly stable characteristics for the direct transformation to mesoporous carbon frameworks by heating to 600 ∼ 1400 ° C under an inert atmosphere. From the viewpoint of synthesis, these mesoporous polymers and car-bons are excellent examples to expatiate the EISA process. A series of ordered mesoporous carbons with pore sizes ranging from 2 to 23 nm can be obtained from the well-establishedself-assembly. [ 75–80 ] 2.1.3. Assembly In a Confi ned SpaceA part from the fl at substrate, one can also take advantage ofa physically confi ned environment such as porous anodic alu-minum oxide (AAO) membranes to carry out the EISA processfor the preparation of mesoporous materials with novel meso-structures and morphologies.[ 81] In their synthetic approach ( F igure 5 a ), the initial depositing solutions penetrate into the porous matrices of AAO and are dried until complete evapo-ration of the solvents occurs, the strong interfacial force can induce the resultant mesostructures with the thermodynami-cally stable arrangement.[ 82 ] When small molecular CTAB was used as the structure-directing agent (SDA), the long axis of the mesochannels is aligned with the same long axis of AAO channels showing columnar orientations (Figure 5b ). [ 82 , 83 ] However, when nonionic surfactants, such as Brij 56 and block copoly-mers P123, are used as the SDA, in most cases, the mesochannels are oriented perpen-dicular to the AAO channels and circularly packed like stacked donuts (Figure 5 c and5d ). [ 82 ] In addition, different mesostructures were found depending on confi nement con-ditions imposed by the different diameters of AAO nanochannels, ranging from single chains of spherical mesopores to concentricor chiral helical mesopores. [ 84 , 85 ]Followinga rapid evolution of synthetic techniques, a signifi cant number of different mesoporous materials (e.g., titania, and carbon) with highly regular structures can now be pre-pared within these membranes. [ 86 , 87 ]Anothercommon used confi ned space is 3D colloidalcrystals. [ 88–90 ] Applying the initial depos-iting solutions within these matrixes allowsfor the synthesis of hierarchical materialswith an interconnected, face-centered cubicthe concentration of copolymers and drives the organization of resol-copolymer composites into an ordered liquid-crystal mesophase. Furthermore, curing the resol-copolymer compos-ites at 100 ° C with a long time ( > 24 h) to solidify the polymeric framework yields a rigid hydrocarbon network with three-connected benzene rings through the formation of covalent bonds, the same as silicates in zeolites or/and mesoporous F igure 4. S chematic representation of the EISA procedure used to prepare mesoporous poly-mers and carbon frameworks. Reproduced with permission. [ 74 ] Copyright 2005, Wiley-VCH. F igure 3. T EM images of mesoporous carbons FDU-15 (a, b) and FDU-16(c, d). Reprinted with permission. [ 74 ]Copyright 2005, Wiley-VCH.SDA. Carbonization was followed by etching of the silica template and silica component in the carbon/silica nanocomposites, resulting in the formation of ordered mesoporouscarbon nanospheres. [ 92 ] The resultant carbonnanospheres possessed a bimodal pore size distribution of large and small mesopores of ∼ 6 and 3.1 nm, a high surface area of ∼2445 m 2g − 1 , and a high reversible charge capacityof up to 1200 mAhg − 1 and a good cyclingstability when applied in lithium-sulfur batteries.R ecently, Zhao and coworkers developed a kilogram-scale synthesis of mesoporous materials based on the EISA process by using commercially available PU foam as a sub-strate. [ 93–96 ] It subverts the situation of anal-ysis-scale production by the EISA process on a common 2D substrate. Because PU foam as a substrate possess several advances for the EISA process including: i) the 3D opened macrostructure facilitating the evaporation of the solvent; ii) the abundantly porous struc-ture, rich-surface hydrophilic groups and low density providing a plenty of idea interfaces for the EISA process, which can save a large number of space; iii) the nature of decompo-sition in an inert atmosphere at 300 ∼400 °C and low-cost making the removal of PU foam simple and industrial, and which can occurwith the surfactant elimination, thusavoiding the excessive introduction of impurities and treatment process. For example, ordered mesoporous carbon-silica com-posite monoliths with a diversity of macroporous architecturescan be obtained by applying the initial triconstituent precursorsolution in PU foam ( F igure 6a ). [ 93 ] After impregnation, the initial sol solution can be infused into the interconnecting 3D networks and large macropore voids by capillary and wetting driving forces. During the solvent evaporation, the precursorscan coat onto the struts of the foams because of the stronginteraction between the sol precursors and the surface of thePU foam and the low concentration of the sol. With a further increase of the concentration, the resol precursor and cross-linked silica species can assemble with Pluronic F127 to formmacropore and a mesopore network. For example, Deng et al . used the monodispersed silica colloidal crystals as the substrate to provide the interface for the self-assembly of triblock copoly-mers and soluble resols. [ 91 ] After removing the copolymers and silica scaffolds, hierarchically porous carbons with highly ordered face-centered cubic structure were obtained. The macro-/meso-porous carbon products have tunable macropore sizes of 230-430 nm and interconnected windows with a size of 30-65 nm, a high surface area (up to 760 m 2 /g), a large pore volume ( ∼1.25 cm 3 /g) and a mesopore size ( ∼ 11 nm). Interest-ingly, Schuster et al . used the inverse opal as a template for a triconstituent precursor solution containing resol as a carbon precursor, TEOS as a silica precursor and Pluronic F127 as a F igure 5. a ) Schematic representation of the EISA process proceeding in AAO membranes. Plan-view TEM images of mesoporous silica: b) templated with CTAB, c) templated with Brij 56, and d) templated with Pluronic P123. Reprinted with permission. [ 82 ] Copyright 2006, Wiley-VCH. F igure 6. a ) The scheme of the EISA process by using PU foams as the substrate. b) The photograph of the kilogram-scaled mesoporous carbons.Reproduced with permission, panel (a) [ 93 ] and (b). [ 96] Copyright: 2008 Wiley-VCH (a) and 2011 Elsevier (b).。

唐山“PEP”2024年11版小学4年级上册英语第二单元寒假试卷[含答案]考试时间：90分钟（总分:120）A卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、听力题：The main gas in the atmosphere is _____.2、听力题：The Great Barrier Reef is found off the coast of __________.3、填空题：The engineer, ______ (工程师), builds bridges.4、听力题：The sun sets in the ___ (west/east).5、听力题：A chemical reaction that occurs in living organisms is called ______.6、听力题：The capital of Uzbekistan is __________.7、听力题：The Earth's surface is shaped by both internal and external ______.8、填空题：The __________ (文化表达) reflects identity.9、填空题：The horse gallops across the ______.10、What is the main purpose of a school?A. To playB. To learnD. To sleep11、听力题：The ancient Egyptians built ________ to honor their dead.12、What do you call the person who teaches you at school?A. DoctorB. TeacherC. EngineerD. Chef答案: B13、What do you call the person who flies a plane?A. PilotB. DriverC. CaptainD. Sailor答案:A14、听力填空题：I think it’s essential to have goals in life. They give us direction and purpose. I set goals for myself by __________ and tracking my progress.15、What do we call the story of someone's life?A. FictionB. BiographyC. NovelD. Poem16、Which of these is a type of cloud?A. CumulusB. OceanusC. MountainusD. Forestus17、听力题：A solution with a pH of is considered ______.18、填空题：The __________ (文化遗产) of a country is important to preserve.19、How do you say "mother" in French?A. MèreB. MadreD. Mama20、How many continents are in the world?A. 5B. 6C. 7D. 821、听力题：The chicken lays _____ eggs.22、听力题：A trench is a deep ______ in the ocean floor.23、填空题：We should _______ (保持)我们的环境干净。

恩施来凤—鹤峰地区龙马溪组与大隆组页岩孔隙特征及其控制因素陈林;李明龙;王明华;郭洪涛;刘洪林【期刊名称】《资源环境与工程》【年(卷),期】2017(31)2【摘要】Shale pore structure controls the storage mechanism and seepage behavior of shale gas. The authors study the pore structure of the organic-rich shale,the Dalong Formation of Upper Permian and the Longmaxi Formation of Upper Ordovician-Lower Silurian in Enshi Laifeng-Hefeng area adopted,by field emission scanning electron microscope and low-pressure nitrogen gas adsorption techniques. The results show that the pole of the organic-rich shale in this study area can be divided into 4 tpyes:pore in organic matter,pore between mineral particles,pore between mineral particles and organic matter,and microfracture. The mean specific surface area of shale samples is 10. 01 m2/g,which is more than 5 times that of tight sandstone gas reservoir. And the mean pore volume of samples is 13. 69 cm3/g. The main type of shale pore is blind hole closed at one end with a certain amount of parallel plate-shaped hole and ink bottle-shaped hole. And the fea-ture of shale pore development is controlled by the content of TOC and clay mineral.%页岩孔隙结构控制着页岩气存储机制及其渗流行为.采用场发射扫描电子显微镜、低压氮气吸附技术对恩施来凤—鹤峰地区上二叠统大隆组和上奥陶统—下志留统龙马溪组富有机质页岩的孔隙结构进行研究.结果表明:研究区大隆组和龙马溪组富有机质页岩孔隙主要可以分为4个类别,即有机质中的孔隙、矿物颗粒间的孔隙、矿物颗粒和有机物之间的孔隙以及微裂隙;页岩样品比表面积均值为10.01 m2/g,为致密砂岩气储层比表面积的5倍以上,样品孔容均值为13.69 cm3/g;页岩孔隙类型以一端封闭盲孔为主,同时具有一定量平行板状孔和墨水瓶状孔.页岩孔隙发育特征受控于TOC含量与粘土矿物含量.【总页数】6页(P165-169,188)【作者】陈林;李明龙;王明华;郭洪涛;刘洪林【作者单位】湖北省地质局第二地质大队,湖北恩施 445000;湖北省地质局第二地质大队,湖北恩施 445000;湖北省地质局第二地质大队,湖北恩施 445000;湖北省地质局第二地质大队,湖北恩施 445000;湖北省地质局第二地质大队,湖北恩施445000【正文语种】中文【中图分类】P618.12;P618.13【相关文献】1.页岩微观孔隙特征及源-储关系r——以川东南地区五峰组-龙马溪组为例 [J], 胡宗全;杜伟;彭勇民;赵建华2.四川盆地长宁地区志留系龙马溪组页岩孔隙特征及发育控制因素 [J], 李令;潘仁芳;杨依;吴夏;李生涛3.鄂西鹤峰地区上二叠统大隆组页岩储层特征及资源潜力 [J], 王登;余江浩;陈威;周向辉;张焱林;许露露;周豹;冷双梁;黄佳琪4.复杂构造区页岩气储层特征及含气性控制因素——以湖北来凤—咸丰区块来地1井龙马溪组为例 [J], 郑宇龙;牟传龙;肖朝晖;王秀平;刘小龙;陈尧5.四川盆地涪陵地区五峰组-龙马溪组页岩孔隙特征及演化模式 [J], 胡德高;万云强;方栋梁;叶鑫;徐向;邢磊;崔志恒;张洪茂因版权原因，仅展示原文概要，查看原文内容请购买。