Synthesis of ZrSiO4 and Coesite in SiO2-ZrO2 System Under High Pressure
Synthesis of ZrSiO4 and Coesite in SiO2-ZrO2 System
Under High Pressure
XUE Yan-Feng,XU Da-Peng,ZHANG Guang-qiang,ZHOU Xian-feng,
DING Zhan-hui,LIU Xiao-mei and SU Wen-hui
1.College of Physics, Jilin University, Changchun 130012,P. China; 2,Center for the Condensed-Matter
Science and Technology, Harbin Institute of Technology, Harbin 150001, P.R.China;
3.International Center for Materials Physics ,Chinese Academy of Sciences ,Shenyang 110015,P.R.China
Abstract ZrSiO4 and coesite were obtained under high-pressure and high-temperature from the nano precursor of α-SiO2 and ZrO2.XRD and Raman measurements indicate that ZrSiO4 was formed at a temperature higher than 920℃ under a pressure of 3.6 GPa. As the pressure increased to 3.9 GPa, the ZrSiO4 formation temperature was reduced to 815℃. The formation temperature for coesite was 990℃under 3.9 GPa. The lower formation temperature for ZrSiO4, as compared to that for coesite, provided an experimental evidence that the coesite in the Earth’s surface usually occurs as inclusions in ZrSiO4.
Keywords ZrSiO4;Coesite; High pressure synthesis; Mechanical ball milling
1 Introduction
ZrSiO4is widely used in ceramic, foundry, and refractory industries owing to its high thermal conductivity, chemical stability, and the ability to accommodate a number of dopant ions[1]. Coesite is one of the high-pressure polymorphs of SiO2, and natural coesite usually occurs as inclusions in zircon (ZrSiO4) from all types of gneiss[2].
Based on the pressure and temperature of the experimental transformation of α-SiO2to coesite under high static pressure, a hypothesis[3]of plate subduction-exhumation has been presented to explain the formation of the coesite existing in the Earth’s crust in zones of buildup of the Earth’s plates. However, some experiment results indicate that there exists another possible formation mechanism for the coesite in the Earth’s crust[4].As is well known, the coesite is metastable and is easily transformed to α-SiO2 under ambient pressure. The fact that the coesite usually occurs as inclusions in ZrSiO4in the Earth’s crust implies that zircon(ZrSiO4)is the best vessel for coesite. Thus, the investigation of the formation of coesite accompanying ZrSiO4 under high pressure is very helpful for understanding the formation mechanism of the coesite in the Earth’s crust. We adopted a laboratory method combined with mechanical ball milling(MBM)and high static pressure suggested by Su et a1.[4]to prepare ZrSiO4and coesite, and compared their formation temperatures.
2 Experimental
The raw materials used in the experiment were the mixture of α-SiO2and monoclinic ZrO2(m-ZrO2) with a molar ratio of 3：1.A P6 type mechanical ball mill was used for MBM. The rotating speed of the ball-milling vial was 350 r/min. The samples were first milled for 20h, then put into a boron nitride ampoule, which was encased in a graphite crucible, and pressed to the desired pressure of 3.6 and 3.9 GPa for 30 min at different temperatures. A belt-type two-anvil press was used for studying the crystallization of nano samples.
A Rigaku D/max-rA 12 kW X-ray diffractometer with Cu Ka radiation was used to record
the XRD pattern. A JY-HR 800 high-resolution Raman spectroscope was used(λex=632.8 nm). The wave number was corrected by the characteristic peak of single-crystal Si at 520 cm-1; the resolving power was 1 cm-1.
3 Results and Discussion
3.1 Phase Transformation of ZrO2 Treated by MBM
Fig.1 shows the XRD patterns of the mixture of α-SiO2 and m-ZrO2 after being treated for 20h by mechanical ball milling. All diffraction peaks of ZrO2, and SiO2 were broadened and the amorphous peak background was observed in a diffraction angle(2θ) range of about 20°to40°, indicating that a part of the sample has started amorphization. The diffraction peaks of α-SiO2 were still observed. Therefore, it in dicates that α-SiO2 was stable during the MBM process. On the other hand, a new peak at 30.2°was observed. The analysis shows that the (101) diffraction peak of tetragonal ZrO2(t-ZrO2) indicates that part of m-ZrO2was transformed into t-ZrO2. The transformation of m-ZrO2 to t-ZrO2 should be related to the reduction of the grain size of ZrO2[5]. Therefore, the effects of MBM were grain refinement and amorphization of the sample.
Fig.1 XRD patterns of the samples
a. Initial a-quartz；
b. initial m-ZrO2；
c. sample milled for 20 h.
3.2 Synthesis of ZrSiO4 Under High-pressure and at High-temperature
Zircon has a tetragonal structure with the space group I41/amd (a=0.6607 nm and c=0.5981 nm)[6]. The ideal structure consists of chains of edge-sharing, altemating SiO4 tetrahedra, and ZrO8 triangular dodecahedra extending parallel to the crystallographic c axis. The formation temperatures reported for ZrSiO4 synthesized by solid state reaction under ambient condition were above 1 400 ℃[7]. Sol-gel techniques are mostly used to achieve high purity and very reactive powders, which can depress the formation temperature effectually[8].
The XRD patterns of samples synthesized under 3.6 GPa are illustrated in Fig.2. It can be seen that the XRD pattern of the sample prepared at 630℃ is the same as that of the ball milling mixture(Fig.1 curve c). NO ZrSiO4 product was formed. As the temperature increased to 920℃, the diffraction peaks of ZrSiO4 appeared. The formation temperature for ZrSiO4 under pressure 3.6 GPa was considerably lower than that reported for solid state reactions[7] under ambient conditions. When the temperature was increased to 1060℃, all the diffraction peaks of m-ZrO2 disappeared, but the diffraction peaks of t-ZrO2still remained. The grain size of ZrO2 did not diminish, and
grew slowly under high pressure and at high temperature, which can be seen from the XRD results. This suggests that there should be another mechanism governing the formation of Si-O-Zr chemical bonds[9-11]. α-SiO2was stable under 3.6 GPa because superfluous α-SiO2was not transformed into coesite even at a temperature as high as 1200℃.
Fig. 2 XRD patterns of the samples synthesized under 3．6 GPa at different temperatures
a. 630℃；
b. 920℃；e. 1060℃；d. 1200℃．
Itoh[12] suggested that the formation of ZrSiO4 has two processes under ambient conditions：
α-SiO2+t-ZrO2→ZrSiO4 (1)
or c-SiO2+t- ZrO2→ZrSiO4 (2)
Reaction(1) has priority over reaction(2).In this experiment, no other phase of SiO2 appeared and no m-ZrO2 remained under 3.6 GPa suggesting that reaction(1) has priority over reaction(2) even under high pressure. Fig.3 shows the XRD patterns of the samples obtained under 3.9 GPa at different temperatures. When the temperature was 990℃, the product still contained
t-ZrO2[13], but the diffraction peaks of coesite appeared. When the temperature was increased
to1200℃, the diffraction peaks were only contributed from ZrSiO4 and coesite, showing that the reaction is complete.
Fig. 3 XRD patterns of the samples synthesized under 3.9 GPa at different temperatures
a. 815℃；
b. 990℃；
c. 1200℃．
The “fingerprint” effect of Raman spectroscopy has been widely used to study the phase structures of materials, especially those synthesized under high-pressure and high-temperature[l4,15]. The room-temperature micro-Raman spectra of samples are illustrated in Fig.4. Generally, ZrSiO4 has 12 Raman vibrational modes: 2A lg+4B1g+B2g+5E g[16]. Here, we observed four Raman modes.
A strong υ3 peak near 1007 cm-1 is assigned to anti-symmetric stretching of the SiO4 group and has B1g symmetry. The other three peaks at about 974,439, and 355 cm-1 are attributed to the Si-O stretching band(υl: symmetric stretching) with A1g symmetry, the bending mode υ2 with A1g symmetry, and the υ4 mode with E g symmetry, respectively. The observation of the four Raman peaks for all the samples prepared suggests the formation of ZrSiO4 under high pressure and at high temperature.
Fig．4 Raman spectra of the samples synthesized
under high-pressure and high-temperature
a. 3.6 GPa, 1060℃;
b. 3.6 GPa, 1200℃;
c. 3.9GPa, 990℃;
d. 3.9GPa, 1200℃.
3.3 Transformation of α-SiO2 to Coesite
In this experiment, the transformation of α-SiO2 to coesite occurred only under 3.9 GPa (Fig.3 curves b and c). In the Raman spectra shown in Fig.4, the peak at 47l cm-1 observed for samples a and b is assigned to the A1vibration mode of α-SiO2, a characteristic Raman peak of α-SiO2. As the pressure increased to 3.9 GPa, the peak at 471 cm-1 was not observed, while the characteristic Raman peaks of coesite near 524cm-1(sample c) and 526 cm-1(sample d)appeared. This implies that α-SiO2 was transformed into coesite, which is consistent with the analysis of the XRD results.
It should be noted that the transformation temperature and me pressure for α-SiO2 to coesite are respectively higher than the previous reported values for pure α-SiO2[4]. The reasons we suggest are: (1) the starting materials used in this study were a mixture of α-SiO2 and ZrO2. ZrO2 may affect the process of amorphization of α-SiO2 during MBM and there was no intermediate metastable phase[4] of α-SiO2 induced by lower-energy MBM. The intermediate metastable phase of α-SiO2 during the process of MBM has been considered to be the prerequisite condition for producing coesite by a lower condition of high-static-pressure-induced crystallization of amorphous α-SiO2. (2)ZrSiO4 is easily formed under relatively low pressure and temperature, which restrains the transformation of α-SiO2 to coesite.
References
[1]sigh R.N., J.Am.Ceram.Soc.,1990,73(8),2399
[2]Zhang A.D., Liu L., Sun Y., et al., Chin. Sci. Bull., 2004,49(22),2335
[3]Bohlen S.R., Boettcher A.L., J. Geo. Res., 1982,87,7073
[4]Su W.H., Liu S.E., Xu D.P., et a1.,Physical Review B, 2006,73,144110
[5]Garvie R.C., Goss M.F., J. Mater. Sci., 1986,21,1253
[6]Hazen R.M., Finger L.W., J. Geo. Res., 1979,84,6723
[7]Tartaj P., Sevna C.J., Moya J.S., et al., Mater Sci., 1996,31,6089
[8]Chakrabarti S., Sada J., Biswa A., J. Mater. Sci. Left., 1992,11(16),1124
[9]Sirarat K., Piyasan P., Warapom T., et al., Mater. Proc. Teehno1.,2003,136,186
[10]Chen S.G., Yin Y,S., Wang D.P., et al., Chin. Ceram. Soc., 2004,32(6),666
[11]Xie C., Xu Z.L., Yang Q.J., et a1., Chem. Res. Chinese Universities,2005,21(I),48
[12]Itoh T., J Crystal Growth, 1992,125(2),223
[13]Zhang F., Hua W. M., Chem. J. Chinese Universities,1999,20(6),909
[14]Richet P.,Nature, 1988, 331, 56
[15]Li L.P., Li G.S., Che Y.L., et a1.,Chem.Mater.,2000,12,2567
[16]Dawson P., Hargreave M.M., Wilkinson G.D.,J.Phys.C,1971,4(2),240 .
ZrSiO4在高压力下SiO2氧化锆系统中的柯石英的合成
XUE Yan-Feng,XU Da-Peng,ZHANG Guang-qiang,ZHOU Xian-feng,
DING Zhan-hui,LIU Xiao-mei and SU Wen-hui
1.大学的物理, 吉林大学, 长春,130012,体育中国；
2.凝聚物质研究中心科学与技术, 哈尔滨研究所的技术,哈尔滨,150001号；
3.国际中心材料物理, 中国科学院, 沈阳,110015,P.R.China
摘要ZrSiO4和柯石英取自高压和高温下的α-SiO2纳米前体和ZrO2。XRD和拉曼测量结果表明ZrSiO4成立在温度高于3.6压力920℃全球行动纲领。由于压力增加到3.9 GPa，ZrSiO4地层温度降到815℃。柯石英的形成温度是990℃下3.9全球行动纲领。形成温度较低的ZrSiO4，为柯石英，用于提供在地球表面石英通常发生在ZrSiO4中的夹杂物作为实验证据。
关键字ZrSiO4、柯石英、高压合成、机械球磨
1 介绍
ZrSiO4广泛应用于陶瓷、铸造、耐火材料产业由于其高的热导率、化学稳定性和能力来容纳的掺杂离子[1]。柯石英的SiO2，高压多晶型之一，天然石英通常作为包裹体锆石（ZrSiO4）从所有类型的片麻岩[2]。
基于压力和温度的α-SiO2，柯石英静高压下的实验教学改革，板块俯冲折返的假设[3]已提交解释存在的地球板块建设区的地壳的柯石英的形成。不过，一些实验结果表明存在着地球的地壳[4]柯石英的另一种可能形成机制。众所周知，柯石英是亚稳态和轻松地转换为α-SiO2环境压力下。柯石英通常为ZrSiO4在地壳中夹杂物的事实意味着该锆石（ZrSiO4）是柯石英的最佳容器。因此，形成陪同ZrSiO4在高压力下的柯石英的调查是非常有助于我们理解在地壳中石英的形成机制。我们通过与机械球磨（MBM）相结合的实验室方法和高静压提出Su et al[4]。准备ZrSiO4和柯石英，并比较其形成温度。
2 实验
试验中所用的原料是α-SiO2和单斜ZrO2(m-ZrO2) 3：1摩尔比的混合物。A P6类型机械球磨机用于MBM。球磨玻璃瓶的旋转速度是350 r/min。样品被首先铣20小时，然后放入硼氮化安瓿，是装在石墨坩埚，并争取在不同温度下30分钟的3.6和3.9GPa领所需的压力。带式两铁砧新闻用于研究纳米样品的结晶。
理学电机D/max-rA 12 kW 铜Ka辐射x射线衍射仪用来记XRD模式。使用JY-HR 800高分辨率拉曼(λex = 632.8 nm)。波数得到纠正在520cm-1；单结晶硅的特性高峰分辨率是1cm-1。
3 结果和讨论
3.1 相变的氧化锆MBM治疗
图1显示α-SiO2和m-ZrO2的混合物XRD机械球磨处理20小时后。扩大了所有衍射峰的氧化锆和SiO2和非晶峰背景中约20℃到40℃，指示该示例的一部分已启动非晶衍射角(2θ) 范围，被发现。α-SiO2的衍射峰还观察到。因此，它指示该α-SiO2 MBM过程是稳定。另一方面，有人指出在30.2°的新高峰。分析表明，四方氧化锆的(101)衍射峰(t- ZrO2)指示m-ZrO2的一部分变成了t- ZrO2。m-ZrO2和t-ZrO2的转型应减少氧化锆晶粒尺寸的相关[5]。因此MBM的影响了晶粒细化和无定形化的示例。
图 1 XRD 模式的示例
a. 初始α-石英；
b. 初始m-ZrO2；
c. 示例铣20 小时.
3.2 ZrSiO4的高温下高压合成
锆英石有四方的结构与空间组I41/amd (a= 0.6607 nm和c = 0.5981 nm）[6]。理想的结构组成的边缘共享、交替SiO4四面体和扩展晶体学c轴平行的ZrO8三角黄道12链。报告的环境条件下的固相反应合成的ZrSiO4的形成温度高1400 ℃[7]。溶胶-凝胶技术主要用于实现高纯和很被动的粉末，可有效地降低地层温度[8]。
样品XRD合成下3.6 GPa 图2中所示。可以看到的是在630℃编写的示例的XRD模式是球磨浆(图一曲线c)相同。没有ZrSiO4产品成立。温度上升到920℃，ZrSiO4的衍射峰出现。ZrSiO4 3.6压力的形成温度GPa是大大低于报告的环境条件下的固态反应[7]。当温度增加到1060℃时，m-ZrO2衍射峰消失，但是t-ZrO2的衍射峰仍然是。氧化锆晶粒尺寸并没有减少，及高强度的压力和温度高，从XRD结果可以看出，变得缓慢。这表明应该是执政的硅O-Zr化学键[9-11]形成的另一种机制。α-SiO2是稳定下3.6 GPa因为多余的α-SiO2不变成了柯石英甚至在高达1200℃的温度。
图 2 XRD 模式的合成下 3.6 在不同温度下的GPa 的样本
a. 630℃；
b. 920℃；
c. 1060℃；
d. 1200℃．
伊藤[12]建议ZrSiO4 形成了两个进程下环境条件：
α-SiO2+t-ZrO2→ZrSiO4 (1)
或c-SiO2+t- ZrO2→ZrSiO4 (2)
反应(1)在反应(2)的优先级。在这个实验中，没有其他阶段SiO2的出现和没有m-ZrO2仍
下3.6GPa，反应(1)反应(2)，即使在高压力下对拥有优先权。图3显示了示例XRD获得下3.9GPa在不同温度下。当温度是990℃时，产品仍含有t- ZrO2[13]，但柯石英的衍射峰出现。当温度提高到1200 ℃，衍射峰是只从ZrSiO4和柯石英，显示的反应作出贡献已完成。
Fig. 3 XRD模式的合成下3.9在不同温度下的GPa的样本
a. 815℃；
b. 990℃；
c. 1200℃．
“指纹”影响的拉曼光谱技术已广泛应用研究材料的相结构，特别是那些合成在高压和样品高温[l4,15]。图 4 中所示的样品室温度微拉曼光谱。一般情况下，ZrSiO4具有12拉曼振动模式：2A lg+4B1g+B2g+5E g[16]。在这里，我们观察到四拉曼模式。强υ3峰附近1007年cm-1分配给SiO4组称拉伸，B1g对称。约974,439和3551厘米的其他三个高峰期都归于Si—O 伸展带（υl：对称拉伸）与A1g对称、弯曲的模式υ2，A1g对称性和E g对称性的υ4模式分别。四的拉曼峰，编写的所有样本的观察表明ZrSiO4形成高强度的压力和高温。
Fig. 4 拉曼光谱的合成的样本高压和高温下
a. 3.6 GPa, 1060℃;
b. 3.6 GPa, 1200℃;
c. 3.9GPa, 990℃;
d. 3.9GPa, 1200℃.
3.3 转型到柯石英α-SiO2
在这个实验中，α-SiO2，柯石英转化发生下才3.9GPa（图3曲线b和c）。在图4中所示的拉曼光谱，47 lcm-1在山顶观测到样本和b分配特征的拉曼峰值的α-SiO2，α-SiO2 A1振动模式。由于压力增加到3.9 GPa，于471cm-1高峰未看到，同时特性的拉曼峰，近524cm-1 (样品c)柯石英的和526cm-1(样品d)出现。这意味着，α-SiO2转化为柯石英，这是符合XRD结果分析。
应注意到柯石英的α-SiO2的压力的相变温度与我分别较以前的报告值为纯α-SiO2[4]。我们建议的理由是：(1)在这项研究中使用的起始材料是α-SiO2和氧化锆的混合物。氧化锆可能
影响的非晶化α-SiO2 MBM期间，α-SiO2致低能量MBM没有中间亚稳相[4]。中间的亚稳相的α-SiO2 MBM的过程中已被认为是生产柯石英的前提条件的静压力诱导高结晶的非晶α-SiO2低条件。(2) ZrSiO4很容易形成相对较低的压力和温度，从而抑制α-SiO2，柯石英的转型。
参考文献
[1]Sigh R.N., J.Am.Ceram.Soc.,1990,73(8),2399
[2]Zhang A.D., Liu L., Sun Y., et al., Chin. Sci. Bull., 2004,49(22),2335
[3]Bohlen S.R., Boettcher A.L., J. Geo. Res., 1982,87,7073
[4]Su W.H., Liu S.E., Xu D.P., et a1.,Physical Review B, 2006,73,144110
[5]Garvie R.C., Goss M.F., J. Mater. Sci., 1986,21,1253
[6]Hazen R.M., Finger L.W., J. Geo. Res., 1979,84,6723
[7]Tartaj P., Sevna C.J., Moya J.S., et al., Mater Sci., 1996,31,6089
[8]Chakrabarti S., Sada J., Biswa A., J. Mater. Sci. Left., 1992,11(16),1124
[9]Sirarat K., Piyasan P., Warapom T., et al., Mater. Proc. Teehno1.,2003,136,186
[10]Chen S.G., Yin Y,S., Wang D.P., et al., Chin. Ceram. Soc., 2004,32(6),666
[11]Xie C., Xu Z.L., Yang Q.J., et a1., Chem. Res. Chinese Universities,2005,21(I),48
[12]Itoh T., J Crystal Growth, 1992,125(2),223
[13]Zhang F., Hua W. M., Chem. J. Chinese Universities,1999,20(6),909
[14]Richet P.,Nature, 1988, 331, 56
[15]Li L.P., Li G.S., Che Y.L., et a1.,Chem.Mater.,2000,12,2567
[16]Dawson P., Hargreave M.M., Wilkinson G.D.,J.Phys.C,1971,4(2),240 .
专业英语翻译
班级：无机082
姓名：姜鸿羽
学号：20080150
院系：材料科学与工程学院指导老师：李晓生
成绩：
英语中的比较级与最高级 详解
比较级与最高级 1.as...as 与(not) as(so)...as as...as...句型中，as的词性 第一个as是副词，用在形容词和副词的原级前，常译为“同样地”。第二个as是连词，连接与前面句子结构相同的一个句子(相同部分常省略)，可译为“同..... He is as tall as his brother is (tall) . (后面的as 为连词) 只有在否定句中，第一个as才可换为so 改错: He is so tall as his brother.（X） 2.在比较状语从句中，主句和从句的句式结构一般是相同的 与as...as 句式中第二个as一样，than 也是连词。as和than这两个连词后面的从句的结构与前面的句子大部分情况下结构是相同的，相同部分可以省略。 He picked more apples than she did. 完整的表达为: He picked more apples than she picked apples. 后而的picked apples和前面相同，用did 替代。 He walked as slowly as she did.完整表达为: He walked as slowly as she walked slowly. she后面walked slowly与前面相同，用did替代。
3.谓语的替代 在as和than 引导的比较状语从句中，由于句式同前面 主句相同，为避免重复，常把主句中出现而从句中又出现的动词用do的适当形式来代替。 John speaks German as fluently as Mary does. 4.前后的比较对象应一致 不管后面连词是than 还是as,前后的比较对象应一致。The weather of Beijing is colder than Guangzhou. x than前面比较对象是“天气”，than 后面比较对象是“广州”，不能相比较。应改为: The weather of Bejing is colder than that of Guangzhou. 再如: His handwriting is as good as me. 应改为: His handwriting is as good as mine. 5.可以修饰比较级的词 常用来修饰比较级的词或短语有: Much,even,far,a little,a lot,a bit,by far,rather,any,still,a great deal等。 by far的用法: 用于强调，意为“...得多”“最最...”“显然”等，可修饰形容词或副词的比较级和最高级，通常置于其后，但是若比较级或最高级前有冠词，则可置于其前或其后。
The way常见用法
The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
人教版(新目标)初中英语形容词与副词的比较级与最高级
人教版（新目标）初中英语形容词与副词的比较级与最高级 （一）规则变化： 1．绝大多数的单音节和少数双音节词，加词尾-er ，-est tall—taller—tallest 2．以不发音的e结尾的单音节词和少数以-le结尾的双音节词只加-r，-st nice—nicer—nicest , able—abler—ablest 3．以一个辅音字母结尾的重读闭音节词或少数双音节词，双写结尾的辅音字母，再加-er，-est big—bigger—biggest 4．以辅音字母加y结尾的双音节词，改y为i再加-er，-est easy—easier—easiest 5．少数以-er，-ow结尾的双音节词末尾加-er，-est clever—cleverer—cleverest, narrow—narrower—narrowest 6．其他双音节词和多音节词，在前面加more，most来构成比较级和最高级 easily—more easily—most easily （二）不规则变化 常见的有： good / well—better—best ; bad (ly)/ ill—worse—worst ; old—older/elder—oldest/eldest many / much—more—most ; little—less—least ; far—farther/further—farthest/furthest
用法： 1．原级比较：as + adj./adv. +as（否定为not so/as + adj./adv. +as）当as… as中间有名字时，采用as + adj. + a + n.或as + many / much + n. This is as good an example as the other is . I can carry as much paper as you can. 表示倍数的词或其他程度副词做修饰语时放在as的前面 This room is twice as big as that one. 倍数+as+adj.+as = 倍数+the +n.+of Your room is twice as larger as mine. = Your room is twice the size of mine. 2．比较级+ than 比较级前可加程度状语much, still, even, far, a lot, a little, three years. five times,20%等 He is three years older than I (am). 表示“（两个中）较……的那个”时，比较级前常加the（后面有名字时前面才能加冠词） He is the taller of the two brothers. / He is taller than his two brothers. Which is larger, Canada or Australia? / Which is the larger country, Canada or Australia? 可用比较级形式表示最高级概念，关键是要用或或否定词等把一事物（或人）与其他同类事物（或人）相分离 He is taller than any other boy / anybody else.
英语中的比较级和最高级
大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基础上变化的。分为规则变化和不规则变化。 规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加 -er 和 -est 构成。 great (原级) (比较级) (最高级) 2) 以 -e 结尾的单音节形容词的比较级和最高级是在词尾加 -r 和 -st 构成。wide (原级) (比较级) (最高级) 3)少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和 -est 构成。 clever(原级) (比较级) (最高级) 4) 以 -y 结尾,但 -y 前是辅音字母的形容词的比较级和最高级是把 -y 去掉,加上 -ier 和-est 构成. happy (原形) (比较级) (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该辅音字母然后再加 -er和-est。 big (原级) (比较级) (最高级) 6) 双音节和多音节形容词的比较级和最高级需用more 和 most 加在形容词前面来构成。 beautiful (原级) (比较级) (比较级) difficult (原级) (最高级) (最高级) 常用的不规则变化的形容词的比较级和最高级: 原级------比较级------最高级 good------better------best many------more------most much------more------most bad------worse------worst far------farther, further------farthest, furthest 形容词前如加 less 和 least 则表示"较不"和"最不 形容词比较级的用法: 形容词的比较级用于两个人或事物的比较,其结构形式如下: 主语+谓语(系动词)+ 形容词比较级+than+ 对比成分。也就是, 含有形容词比较级的主句+than+从句。注意从句常常省去意义上和主句相同的部分, 而只剩下对比的成分。
The way的用法及其含义(二)
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
英语比较级和最高级的用法归纳
英语比较级和最高级的用法归纳 在学习英语过程中，会遇到很多的语法问题，比如比较级和最高级的用法，对于 这些语法你能够掌握吗？下面是小编整理的英语比较级和最高级的用法，欢迎阅读！ 英语比较级和最高级的用法 一、形容词、副词的比较级和最高级的构成规则 1.一般单音节词和少数以-er，-ow结尾的双音节词，比较级在后面加-er，最高级 在后面加-est; (1)单音节词 如：small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest (2)双音节词 如：clever→cleverer→cleverest narrow→narrower→narrowest 2.以不发音e结尾的单音节词，比较在原级后加-r，最高级在原级后加-st; 如：large→larger→largest nice→nicer→nicest able→abler→ablest 3.在重读闭音节(即：辅音+元音+辅音)中，先双写末尾的辅音字母，比较级加-er，最高级加-est; 如：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4.以“辅音字母+y”结尾的双音节词，把y改为i，比较级加-er，最高级加-est; 如：easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5.其他双音节词和多音节词，比较级在前面加more，最高级在前面加most; 如：bea utiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily 注意：(1)形容词最高级前通常必须用定冠词 the，副词最高级前可不用。 例句： The Sahara is the biggest desert in the world. (2) 形容词most前面没有the，不表示最高级的含义，只表示"非常"。 It is a most important problem. =It is a very important problem.
(完整版)the的用法
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
英语比较级和最高级的用法
More than的用法 A. “More than+名词”表示“不仅仅是” 1)Modern science is more than a large amount of information. 2)Jason is more than a lecturer; he is a writer, too. 3) We need more than material wealth to build our country.建设我们国家，不仅仅需要物质财富. B. “More than+数词”含“以上”或“不止”之意，如： 4)I have known David for more than 20 years. 5)Let's carry out the test with more than the sample copy. 6) More than one person has made this suggestion. 不止一人提过这个建议. C. “More than+形容词”等于“很”或“非常”的意思，如： 7)In doing scientific experiments, one must be more than careful with the instruments. 8)I assure you I am more than glad to help you. D. more than + (that)从句，其基本意义是“超过（=over）”，但可译成“简直不”“远非”.难以，完全不能（其后通常连用情态动词can） 9) That is more than I can understand . 那非我所能懂的. 10) That is more than I can tell. 那事我实在不明白。 11) The heat there was more than he could stand. 那儿的炎热程度是他所不能忍受的 此外，“more than”也在一些惯用语中出现，如： more...than 的用法 1. 比……多，比……更 He has more books than me. 他的书比我多。 He is more careful than the others. 他比其他人更仔细。 2. 与其……不如 He is more lucky than clever. 与其说他聪明，不如说他幸运。 He is more （a）scholar than （a）teacher. 与其说他是位教师，不如说他是位学者。 注：该句型主要用于同一个人或物在两个不同性质或特征等方面的比较，其中的比较级必须用加more 的形式，不能用加词尾-er 的形式。 No more than/not more than 1. no more than 的意思是“仅仅”“只有”“最多不超过”，强调少。如： --This test takes no more than thirty minutes. 这个测验只要30分钟。 --The pub was no more than half full. 该酒吧的上座率最多不超过五成。-For thirty years，he had done no more than he （had）needed to. 30年来，他只干了他需要干的工作。 2. not more than 为more than （多于）的否定式，其意为“不多于”“不超过”。如：Not more than 10 guests came to her birthday party. 来参加她的生日宴会的客人不超过十人。 比较： She has no more than three hats. 她只有3顶帽子。（太少了） She has not more than three hats. 她至多有3顶帽子。（也许不到3顶帽子） I have no more than five yuan in my pocket. 我口袋里的钱最多不过5元。（言其少） I have not more than five yuan in my pocket. 我口袋里的钱不多于5元。（也许不到5元） more than, less than 的用法 1. （指数量）不到，不足 It’s less than half an hour’s drive from here. 开车到那里不到半个钟头。 In less than an hour he finished the work. 没要上一个小时，他就完成了工作。 2. 比……（小）少 She eats less than she should. 她吃得比她应该吃的少。 Half the group felt they spent less than average. 半数人觉得他们的花费低于平均水平。 more…than,/no more than/not more than (1)Mr．Li is ________ a professor; he is also a famous scientist． (2)As I had ________ five dollars with me, I couldn’t afford the new jacket then． (3)He had to work at the age of ________ twelve． (4)There were ________ ten chairs in the room．However, the number of the children is twelve． (5)If you tel l your father what you’ve done, he’ll be ________ angry． (6)－What did you think of this novel? －I was disappointed to find it ________ interesting ________ that one． 倍数表达法 1. “倍数+形容词（或副词）的比较级+than+从句”表示“A比B大（长、高、宽等）多少倍” This rope is twice longer than that one.这根绳是那根绳的三倍（比那根绳长两倍）。The car runs twice faster than that truck.这辆小车的速度比那辆卡车快两倍（是那辆卡车的三倍）。 2. “倍数+as+形容词或副词的原级+as+从句”表示“A正好是B的多少倍”。
“the way+从句”结构的意义及用法
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
初中英语比较级和最高级讲解与练习
初中英语比较级和最高级讲解与练习 形容词比较级和最高级 一．绝大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 1. 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 2. 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基 础上变化的。分为规则变化和不规则变化。 二．形容词比较级和最高级规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加-er 和-est 构成。 great (原级) greater(比较级) greatest(最高级) 2) 以-e 结尾的单音节形容词的比较级和最高级是在词尾加-r 和-st 构成。 wide (原级) wider (比较级) widest (最高级) 3) 少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和-est构成。 clever(原级) cleverer(比较级) cleverest(最高级)， slow(原级) slower(比较级) slowest (最高级) 4) 以-y 结尾,但-y 前是辅音字母的形容词的比较级和最高级是把-y 去掉,加上-ier 和-est 构成. happy (原形) happier (比较级) happiest (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该 辅音字母然后再加-er和-est。 原形比较级最高级原形比较级最高级 big bigger biggest hot hotter hottest red redder reddest thin thinner thinnest 6) 双音节和多音节形容词的比较级和最高级需用more 和most 加在形容词前面来构 成。 原形比较级最高级 careful careful more careful most careful difficult more difficult most difficult delicious more delicious most delicious 7)常用的不规则变化的形容词的比较级和最高级: 原级比较级最高级 good better best 好的 well better best 身体好的 bad worse worst 坏的 ill worse worst 病的 many more most 许多 much more most 许多 few less least 少数几个 little less least 少数一点儿 （little littler littlest 小的） far further furthest 远（指更进一步，深度。亦可指更远） far farther farthest 远（指更远，路程）
way 用法
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
英语比较级和最高级
形容词比较级和最高级的形式 一、形容词比较级和最高级的构成 形容词的比较级和最高级变化形式规则如下 构成法原级比较级最高级 ①一般单音节词末尾加 er 和 est strong stronger strongest ②单音节词如果以 e结尾，只加 r 和 st strange stranger strangest ③闭音节单音节词如末尾只有一个辅音字母， 须先双写这个辅音字母，再加 er和 est sad big hot sadder bigger hotter saddest biggest hottest ④少数以 y, er(或 ure), ow, ble结尾的双音节词， 末尾加 er和 est(以 y结尾的词，如 y前是辅音字母， 把y变成i，再加 er和 est，以 e结尾的词仍 只加 r和 st) angry Clever Narrow Noble angrier Cleverer narrower nobler angriest cleverest narrowest noblest ⑤其他双音节和多音节词都在前面加单词more和most different more different most different 1) The most high 〔A〕mountain in 〔B〕the world is Mount Everest，which is situated 〔C〕in Nepal and is twenty nine thousand one hundred and fourty one feet high 〔D〕 . 2) This house is spaciouser 〔A〕than that 〔B〕white 〔C〕one I bought in Rapid City，South Dakota 〔D〕last year. 3) Research in the social 〔A〕sciences often proves difficulter 〔B〕than similar 〔C〕work in the physical 〔D〕sciences. 二、形容词比较级或最高级的特殊形式：
高中英语的比较级和最高级用法总结
比较级和最高级 1.在形容词词尾加上―er‖ ―est‖ 构成比较级、最高级： bright（明亮的）—brighter—brightest broad（广阔的）—broader—broadest cheap（便宜的）—cheaper—cheapest clean（干净的）—cleaner—cleanest clever（聪明的）—cleverer—cleverest cold（寒冷的）—colder—coldest cool（凉的）—cooler—coolest dark（黑暗的）—darker—darkest dear（贵的）—dearer—dearest deep（深的）—deeper—deepest fast（迅速的）—faster—fastest few（少的）—fewer—fewest great（伟大的）—greater—greatest hard（困难的,硬的）—harder—hardest high（高的）—higher—highest kind（善良的）—kinder—kindest light（轻的）—lighter—lightest long（长的）—longer—longest loud（响亮的）—louder—loudest low（低的）—lower—lowest near（近的）—nearer—nearest new（新的）—newer—newest poor（穷的）—poorer—poorest quick（快的）—quicker—quickest quiet（安静的）—quieter—quietest rich（富裕的）—richer—richest short（短的）—shorter—shortest slow（慢的）—slower—slowest small（小的）—smaller—smallest smart（聪明的）—smarter—smartest soft（柔软的）—softer—softest strong（强壮的）—stronger—strongest sweet（甜的）—sweeter—sweetest tall（高的）-taller-tallest thick（厚的）—thicker—thickest warm（温暖的）—warmer—warmest weak（弱的）—weaker—weakest young（年轻的）—younger—youngest 2.双写最后一个字母,再加上―er‖ ―est‖构成比较级、最高级： big（大的）—bigger—biggest fat（胖的）—fatter—fattest hot（热的）—hotter—hottest red（红的）—redder—reddest sad（伤心的）—sadder—saddest thin（瘦的）—thinner—thinnest wet（湿的）—wetter—wettest mad（疯的）—madder—maddest 3.以不发音的字母e结尾的形容词,加上―r‖ ―st‖ 构成比较级、最高级：able（能干的）—abler—ablest brave（勇敢的）—braver—bravest close（接近的）—closer—closest fine（好的,完美的）—finer—finest large（巨大的）—larger—largest late（迟的）—later—latest nice（好的）—nicer—nicest ripe（成熟的）—riper—ripest
The way的用法及其含义(一)
The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.
(完整版)初中英语比较级和最高级的用法
英语语法---比较级和最高级的用法 在英语中通常用下列方式表示的词:在形容词或副词前加more(如 more natural,more clearly )或加后缀 -er(newer,sooner )。典型的是指形容词或副词所表示的质、量或关系的增加。英语句子中，将比较两个主体的方法叫做“比较句型”。其中，像“A比B更……”的表达方式称为比较级；而“A最……”的表达方式则称为最高级。组成句子的方式是将形容词或副词变化成比较级或最高级的形态。 一、形容词、副词的比较级和最高级的构成规则 1．一般单音节词和少数以-er，-ow结尾的双音节词，比较级在后面加-er，最高级在后面加-est； （1）单音节词 如：small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest （2）双音节词 如：clever→cleverer→cleverest narrow→narrower→narrowest 2．以不发音e结尾的单音节词，比较在原级后加-r，最高级在原级后加-st； 如：large→larger→largest nice→nicer→nicest able→abler→ablest 3．在重读闭音节（即：辅音＋元音＋辅音）中，先双写末尾的辅音字母，比较级加-er，最高级加-est； 如：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4．以“辅音字母＋y”结尾的双音节词，把y改为i，比较级加-er，最高级加-est； 如：easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5．其他双音节词和多音节词，比较级在前面加more，最高级在前面加most； 如：beautiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily