fulltext
ORIGINAL PAPER
Complete sequence and gene organization of the mitochondrial genome of Siamensis Crocodile (Crocodylus siamensis )
Xuefeng Ji ?Xiaobing Wu ?Peng Yan ?George Amato
Received:26October 2006/Accepted:17January 2007óSpringer Science+Business Media B.V.2007
Abstract The complete sequence of mitochondrial genome of Siamensis Crocodile (Crocodylus siamensis )is determined by using PCR ampli?cation,clone and primer-walking sequencing methods.The genome is 16836bp in size,containing 13protein-coding,2ribo-somal and 22transfer RNA genes.The mtDNA gen-ome of Siamensis Crocodile is similar to most vertebrates in gene component,order,orientation,tRNA structure,low percentage of guanine and high percentage of thymine.The nonstandard stop codes (T)in two protein genes (Cox III and Cyt b )are more than those of most vertebrates.Transfer RNA genes range in length from 61to 76nucleotides,and their planar structure present characteristic clover leaf,except for tRNA-Ser (AGY)because of lacking the ‘‘DHU’’arm.
Keywords Crocodylus siamensis áGenome áMitochondrial áStructure
Introduction
The animal mitochondria gene content is highly con-served,which usually encodes 13proteins,2ribosomal
RNAs (rRNAs),and 22transfer RNAs (tRNAs).The gene order is also highly conserved among most ver-tebrates [1].However,gene loss and gene rearrange-ment have been found in some taxa [2].Comparisons of mitochondrial systems are useful for modeling gen-ome evolution and phylogenetic inference [3].They include gene content and gene arrangement,base composition,modes of replication and transcription,protein,tRNA and rRNA gene secondary structures,and genetic codon variations.These features are cur-rently more accessible for study in the much smaller and simpler mitochondrial genomes [3,4].During the last 10years,mitochondrial genome sequence and gene arrangement comparisons were employed as powerful new tools for resolving ancient phylogenetic relationships [2,3,5–7].
According to the traditional classi?cation based on morphology,Crocodylia is divided into three major groups:the Family Alligatoridae (Alligator ,Caiman ,Melanosuchus ,and Paleosuchus ),the Family Croco-dylidae (Crocodylus ,Osteolaemus ,Tomistoma ),and the Family Gavialidae,which includes only one spe-cies,Gavialis gangeticus [8].Crocodylus siamensis belongs to genus Crocodylus ,Family Crocodylidae.As a freshwater crocodilian (a group that also includes alligators,caimans and the gharial),Crocodylus siam-ensis is one of the most endangered crocodiles in the wild,which is widely bred in captivity [9].At present there are seven crocodilian species with their mito-chondrial genomes having been completely sequenced [6,7,10–13].But the data is not enough to explain the phylogenetic relationships of crocodilians.So we se-quenced the complete sequence of mitochondrial genome of Crocodylus siamensis and analyzed its gene organization.
X.Ji áX.Wu (&)áP.Yan
College of Life Sciences,Anhui Key Laboratory
of Conservation and Exploration for Important Biological Resource,Anhui Normal University,Wuhu 241000,China e-mail:wuxb@https://www.360docs.net/doc/d87890539.html,
G.Amato
Molecular Systematics Laboratory,American Museum of Natural History,New York,NY,USA
Mol Biol Rep
DOI 10.1007/s11033-007-9062-x
Materials and methods
Samples and sequencing
Crocodylus siamensis samples were obtained from the specimen storeroom of College of Life Sciences in Anhui Normal University.The fresh blood was stored at–80°C.
Mitochondrial DNA was extracted following the procedure described in Arnason et al.[14].Extracted DNA was diluted10times and stored at–20°C until use as a template for polymerase chain reaction(PCR). The primers for PCR and sequencing were designed based on the complete mtDNA sequences of Alligator mississippiensis(The GenBank accession number is Y13113),Alligator sinensi s(The GenBank accession number is AF511507)and Caiman crocodilus(The GenBank accession number is AJ404872).By using ClustalX1.8[15]we designed66primers(Table1)for the PCR ampli?cation(synthesized by Shanghai San-gon Biotechnology Co.,Ltd.,Shanghai,China).The length of ampli?ed products is from900bp to1200bp. All overlaps between the products were con?rmed by direct sequencing of PCR products ampli?ed from the puri?ed mtDNA template.The whole mitochondrial genome was read at least two times.
PCR reactions were conducted on a PTC-200 thermal cycler with the following conditions:an initial denaturation step of95°C(3min)followed by34 cycles of95°C(30s),49–60°C(30s),and72°C(90s) followed by72°C for10min.The PCR products were separated by electrophoresis in1%agarose gels,then were puried by PCR Cleanup Kit(V-gene,Biotech-nology Limited,Hangzhou,China)and sequenced with ABI3730(Shanghai Sangon Biotechnology Co.,Ltd.,Shanghai,China).At last we got the complete mtDNA sequences of Crocodylus siamensis. The determined nucleotide sequences are deposited
Table1Sequencing primers used in the analysis of Crocodylus niloticus and Crocodylus siamensis mitochondrial genomes
Primer name Upper primer sequence(5￠?3￠)Lower primer sequence(5￠?3￠)Anneal temperature(°C) Pn1AATATGTACACACCGCCCGTC ATTACGCTACCTTYGCACG53.0
Pn3GGCCTAACATACGAATGACT CGTTTGGCGAARGCAGAT52.0
Pn6TCTGGTTATCACTCTCACG GACTAAATCRAGCTTTCGC50.9
Pn8CACTAGCAGAAACAAACCG CTTCTGGTACTCAGAAGTG52.0
Pn9GCATAAAACTTCCACCCTC GTTGAAKGATCCTCGTTC50.0
Pn13CGACCTCGATGTTGGATCAG ATAGTGTGAACAGCCCTGC54.0
Pn16GCTCAACTTACACATGCA TTCCAAGCACACCTTCCG50.0
Pn19CTTCCCACAACACTTCCT TTTCTTGGACGTCTGAGG53.0
nle1CAGCGCAACCCTAACACGAT TCACGGACGTGAATGAGTGA54.0
nle3CCTAATCATCTTCTCATGGAC GGTCTCTTGTTTTGTAATGGC53.0
nle4AATCTGGGCGAGCTACTAGC CCTTAGGTAGAGGTTGAGTC54.0
nle5GACCAGTCCGACTTTCATGT GACTTAACGCCCGTGTTCTGT53.0
nle12GATTGGGTCATTAATCTCCATA TTCAMGGTCAGGGTCATGTTTT52.0
nle14CAACCTGCTTAACAACCGC GGAGACTCATAGTAATGTG51.0
nle15ATGGTTCTTGCAGCGATCCT ATGCCTACTCCYTCTCAGCC54.0
nle17CACTGCTAATACCCAACGA TGGCTGAGCTCTGTTCGGA53.5
nle18CATATCACCAGGGCTATCAAC TATGGAGATTAATGACCCAATC52.0
nle20CTGTACCAATACAGCACTTCC ATTATGGCAGCCATAGCCCC56.0
nle21CATTAGCTTCACGCTAGACA GTGGTTGAGCCTTATTGGT52.0
nle23CTCAATCTATTGATGAGGCTC TGTGACATGGAACTTTGGCT52.0
nle24TATCCTGCTGACTACTACCA GAGGTGATGAATGCGCTTA53.0
cp4CCCACCTGATAGACCAAACA GCGTTCGTGGAGGAAGAT52.0
cp5CTTCCCACAACACTTCCT AGTACTGTTGCTAGCCA53.0
cp6TTAGCCTACTCATCCGACC TGGTTCGAGGTGAAGTG51.0
L16GAACCATTCGGCTATATAGGA GGCTCTTCGTAGGTGTGAT53.1
L17CCTACGGATCAACATTC GTCAATAGGGAGCCATGA54.0
L18ACCATGCCAACATCAGCCAAGCT GTCTAAAGTCCAAGTGAG50.0
P78CGCCTGTTTACCAAAAACAT ACGTGATACTGAGTTCAGA53.0
CS1GAGAATTACGAGCAACTTGC CATCTTTCCCTTGCGGTACT53.0
CS3GAGCCTATTCTTTTACCTACGA GTTGGTATAGGATTGGGTCTCC54.0
CS4GATACCACGACGATATTCC GATCACTTATGTCCTGGC52.0
CS5TACGAACGAACACACTCACG GAGTGTAATAGGGCTGATAC52.0
CS6CCTAAAACCTCTGCTCATGC CTGGTTTAATGTGGTCTGGT52.0
Respectively and Y=C or T,R=A or G,K=G or T,M=A or C
Mol Biol Rep
in the DDBJ/EMBL/GenBank nucleotide sequence databases with the accession number DQ353946. Gene identi?cation and sequence analysis
With the analysis of DNAStar(Version 5.01)and Sequin(Version 5.35),12Heavy-strand encoded protein-coding genes and one Light-strand encoded protein-coding gene were obtained.By the software of tRNA Scan-SE1.21(https://www.360docs.net/doc/d87890539.html,/tRNA Scan-SE),21transfer RNA(tRNA)genes were found. The sequences were aligned by using ClustalX1.8[15], and then were corrected by using DNASIS 3.5 (Hitachi).After checking the position of the tRNA-Ser (AGC)and rRNA genes,the positions of the rest genes were revised and determined.
Results and discussion
Characteristics of the crocodilian mitochondrial genomes
The total length of the mtDNA molecular is16836bp. 31protein-coding genes,22tRNA genes,2rRNA genes,and one control region were identi?ed in the mitochondrial genome of Crocodylus siamensis (Fig.1).
The overall base composition of the H-strand is A: 32.01%(5389bp);T:24.76%(4168bp);C:28.47% (4793bp);G:14.77%(2486bp).The relative order of
nucleotide composition is A>C>T>G,with A being the most represented base(32.12%)and the least of G(14.74%).Similar to cases reported in other ver-tebrate mitochondrial genomes[16,17],the base compositions of mtDNAs were skewed,with more A–T base pairs(56.77%)than G–C(43.23%)base pairs.The skew of AT is0.13,which is higher than that of GC(–0.32).As other vertebrate mtDNAs,overlap and noncoding bases in some genes were also be ob-served.In Crocodylus siamensis,the total size of the overlap of six times is71bp.Of the71bp,the ATPase 8gene and ATPase6gene shared the22bp overlap, and NADH5and NADH6overlap by44bp.The total length of noncoding spacer nucleotides is222bp.The longest noncoding region of56bp,is located between Cyt b and tRNA-Thr.
Protein-coding genes
The13protein-coding genes in Crocodylus siamensis are11380bp.The longest one is NADH5(1854bp)gene,whereas the shortest one is ATPase8(162bp) gene.
In Crocodylus siamensis mtDNA,ATG is the translation initiation codon in7of the13protein-coding genes.The start codon ATA occurs in the NADH1,NADH3,NADH5,while COX I and NADH4L begin with the nonstandard start codons GTG and ACC,respectively.In other crocodilians sequenced,the nonstandard start codons(ACC,AGC, ACT,ACA,ATC)occur in the NADH4L,which is a probable result of highly evolving rate.Standard ter-mination codon TAA occur in10genes,however, AGG is found in NADH1.Incomplete termination codon T occurs in COX III and Cyt b.
tRNA and rRNA gene
Sequences of all22tRNA genes can be folded into a canonical cloverleaf secondary structure with the exception of tRNA-Ser(AGY),which loses‘‘DHU’’arm.These tRNAs range in size from61to76
nucle-
Mol Biol Rep
otides.Figure2shows all the secondary structures of 22tRNAs.
Noncoding sequences
The control region of mtDNA in Crocodylus siam-ensis is1108bp,which locates between the tRNA-Phe and12S rRNA genes(Fig.1).The general structure and conserved sequences of the crocodil-ian mitochondrial control region were comprehen-sively analyzed by Ray and Densmore[18].In crocodilians,domain II is the most conserved part of D-loop and contains several conserved sequence boxes characterize in other vertebrates;domain III is the most variable part of D-loop and contains several interesting sequence motifs,including tan-demly repeated sequences and a long poly-A (Crocodilydae)or poly-C(Alligatoridae);domain I tending to be shorter than the same region in mam-mals and birds,contains sequences similar in structure to both the goose-hairpin and termination associated sequences(TAS),so it is more conservative than domain III.
The origin of L-strand replication(OLR),which usually locates in a cluster of?ve tRNA genes: tRNA Trp-tRNA Ala-tRNA Asn-tRNA Cys-tRNA Tyr(WAN-CY)in vertebrates,lacks in the mtDNA of Crocodylus siamensis.Thus,the absence of OLR appears to be a common characteristic of all crocodilians.The OLR region between Asn-tRNA and Cys-tRNA,which
has Mol Biol Rep
the potential to fold into a stable stem-loop secondary structure,only has‘‘AATATT’’6bp in Crocodylus siamensis.The absence of OLR is probable the result of rearrangement of tRNA.
The control region of Crocodylus siamensis mtDNA is similar with the others vertebrates,which is a most variable part of the mitochondrial genome.But this variable part still has some typical characteristic,for instance,microsatellite sequences and repetitive sequences(5￠-CAACCTAGGCCAAAATAGGAA GAAATTTTAAAAAATTTT-3￠,39bp repeat four times).These features,which found in the control region are the origin of heavy strand(H-strand)rep-lication and the promoters for both heavy and light strand(L-strand)transcription[19–21]. Acknowledgements This work was supported by National Natural Science Foundation of China(NSFC,No.30470244),the Foundations for Excellent Youth in Anhui Province(04043409) and Key Laboratory of Biotic Environment and Ecological safety in Anhui
Province. Mol Biol Rep
References
1.Boore JL(1999)Animal mitochondrial genomes.Nucleic
Acids Res27(8):1767–1780
2.Rest JS,Ast JC,Austin CC,Waddell PJ,Tibbetts EA,Hay
JM,Mindell DP(2003)Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome.
Mol Phylogenet Evol29(2):289–297
3.Boore JL(2004)Complete mitochondrial genome sequence
of Urechis caupo,a representative of the phylum Echiura.
BMC Genomics5(1):67
4.Garesse R,Carrodeguas JA,Santiago J,Perez ML,Marco R,
Vallejo CG(1997)Artemia mitochondrial genome:molecular
biology and evolutive https://www.360docs.net/doc/d87890539.html,p Biochem Phys-iol B Biochem Mol Biol117(3):357–366
5.Zardoya R,Meyer A(1998)Complete mitochondrial gen-
ome suggests diapsid af?nities of turtles.Proc Natl Acad Sci USA95(24):14226–14231
6.Janke A,Erpenbeck D,Nilsson M,Arnason U(2001)The
mitochondrial genomes of the iguana(Iguana iguana)and the caiman(Caiman crocodylus):implications for amniote phylogeny.Proc Biol Sci268(1467):623–631
7.Wu XB,Wang YQ,Zhou KY,Zhu WQ,Nie JS,Wang CL
(2003)The complete mitochondrial genome sequence of Chinese alligator and the phylogeny of crocodiles.Chin Sci Bull48(18):1954–1958
8.Mook CC(1921)Note on the postcranial skeleton in the
Crocodilia.Bull Am Mus Nat Hist XLIV:67–100
9.Temsiripong Y,P.Ratanakorn(2001)A review for reintro-
duction program of Siamese crocodile in Thailand.Pro-ceedings of the Regional Working Meeting of the Crocodile Specialist Group,Guangzhou,China,IUCN-The World Conservation Union,Gland,Switzerland and Cambridge UK.Temsiripong,Y.Re-introduction of the Siamese croc-odile.CSG Newsletter;20(1),pp10–13
10.Janke A,Arnason U(1997)The complete mitochondrial
genome of Alligator mississippiensis and the separation be-tween recent archosauria(birds and crocodiles).Mol Biol Evol14:1266–1272
11.Janke A,Gullberg A,Hughes S,Aggarwal RK,Arnason U
(2005)Mitogenomic analyses place the gharial(Gavialis gangeticus)on the crocodile tree and provide pre-K/T divergence times for most crocodilians.J Mol Evol 61(5):620–626
12.Ji XF,Wu XB,Li Y,Yan P,Amato G(2006)The mito-
chondrial genome of Crocodylus niloticus with implications for phylogenetic relationships among crocodilian species.
Acta Zool Sinica52(4):810–818
13.Li Y,Wu XB,Ji XF,Yan P,Amato G(2006)The complete
mitochondrial genome of the Salt-water Crocodile(Croco-dylus porosus)and phylogeny of crocodiles.Acta Genet Sinica2
14.Arnason U,Gullberg A,Widegren B(1991)The complete
nucleotide sequence of the mitochondrial DNA of the?n whale,Balaenoptera physalus.J Mol Evol33(6):556–568 15.Thompson JD,Gibson TJ,Plewniak F,Jeanmougin F,Hig-
gins DG(1997)The CLUSTAL X windows interface:?exi-ble strategies for multiple sequence alignment aided by quality analysis tools.Nucleic Acids Res25(24):4876–4882 16.Wolstenholme DR(1992)Animal mitochondrial DNA:
structure and evolution.Int Rev Cytol141:173–216
17.Asakawa S,Kumazawa Y,Araki T,Himeno H,Miura K,
Watanabe K(1991)Strand-speci?c nucleotide composition bias in echinoderm and vertebrate mitochondrial genomes.
J Mol Evol32:511–520
18.Ray DA,Densmore L(2002)The Crocodilian mitochondrial
control region:general structure,conserved sequences and evolutionary implications.J Exp Zool294(4):334–345
19.Clayton DA(1982)Replication of animal mitochondrial
DNA.Cell28(4):693–705
20.Clayton DA(1984)Transcription of the mammalian mito-
chondrial genome.Annu Rev Biochem53:573–594
21.Wong TW,Clayton DA(1985)In vitro replication of human
mitochondrial DNA:accurate initiation at the origin of light-strand synthesis.Cell42(3):951–958
Table2Locations of genes and noncoding regions in the mito-
chondrial genome of Crocodylus siamensis
Gene/region Nucleotide no.Size(bp)aa
From to
12S rRNA1985985
tRNA-Val986105469
16S rRNA105526511597
tRNA-Leu(UUR)2653272876
NADH127293691963320
tRNA-Ile3690376172
tRNA-Gln(L)3760383071
tRNA-Met3833390068
NADH2390549601056351
tRNA-Trp4961503474
tRNA-Ala(L)5037510569
tRNA-Asn(L)5107517973
tRNA-Cys(L)5186525166
tRNA-Tyr(L)5252532271
Cox I532468801557518
tRNA-Ser(UCN)(L)6901697070
tRNA-Asp6974704471
Cox II70457728684227
tRNA-Lys7730780374
ATPase87805796616253
ATPase679458640696231
Cox III86409423784261
tRNA-Gly9424949370
NADH394949841348115
tRNA-Arg9852992069
NADH4L99241021729497
NADH410211115841374457
tRNA-Ser(AGY)116141167461
tRNA-His116921176170
tRNA-Leu(CUN)117891185971
NADH511863137161854617
NADH6(L)1367314200528175
tRNA-Glu(L)142011427171
Cyt b14287154421156385
tRNA-Thr154991557072
tRNA-Pro(L)155821564968
tRNA-Phe156601572869
D-loop15729168361108
Mol Biol Rep
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这学期就用了！开题报告、文献检索账号、文献综述、外文翻译、抄袭检测软件、论文目录，都在这了都在这了，有备无患，拿去吧！！来源：齐祥涛的日志 开题报告、文献综述、外文翻译、论文反抄袭软件、论文目录，就差论文正文了，其他都全了！！ 开题报告主要包括以下几个方面： （一）论文名称 论文名称就是课题的名字 第一，名称要准确、规范。准确就是论文的名称要把论文研究的问题是什么，研究的对象是什么交待清楚，论文的名称一定要和研究的内容相一致，不能太大，也不能太小，要准确地把你研究的对象、问题概括出来。 第二，名称要简洁，不能太长。不管是论文或者课题，名称都不能太长，能不要的字就尽量不要，一般不要超过20个字。 （二）论文研究的目的、意义 研究的目的、意义也就是为什么要研究、研究它有什么价值。这一般可以先从现实需要方面去论述，指出现实当中存在这个问题，需要去研究，去解决，本论文的研究有什么实际作用，然后，再写论文的理论和学术价值。这些都要写得具体一点，有针对性一点，不能漫无边际地空喊口号。主要内容包括：⑴研究的有关背景(课题的提出)：即根据什么、受什么启发而搞这项研究。⑵通过分析本地（校）的教育教学实际，指出为什么要研究该课题，研究的价值，要解决的问题。 （三）本论文国内外研究的历史和现状（文献综述）。 规范些应该有，如果是小课题可以省略。一般包括：掌握其研究的广度、深度、已取得的成果；寻找有待进一步研究的问题，从而确定本课题研究的平台(起点)、研究的特色或突破点。 （四）论文研究的指导思想 指导思想就是在宏观上应坚持什么方向，符合什么要求等，这个方向或要求可以是哲学、政治理论，也可以是政府的教育发展规划，也可以是有关研究问题的指导性意见等。 （五）论文写作的目标 论文写作的目标也就是课题最后要达到的具体目的,要解决哪些具体问题，也就是本论文研究要达到的预定目标：即本论文写作的目标定位，确定目标时要紧扣课题,用词要准确、精练、明了。 常见存在问题是：不写研究目标；目标扣题不紧；目标用词不准确；目标定得过高, 对预定的目标没有进行研究或无法进行研究。 确定论文写作目标时，一方面要考虑课题本身的要求，另一方面要考率实际的工作条件与工作水平。 （六）论文的基本内容
英语翻译常用句型
翻译中常见的句型 1．否定句型 1）部分否定。其否定意义只局限于整体中的一部分。其形式：“概括词all, every等+not+谓语动词”。常用于该句型词：all, both, everybody, everywhere, always, altogether, entirely, wholly等。 All is not gold that glitters. I do not wholly agree. 2) 完全否定。其形式：no, none 等否定词+肯定式谓语。常用于该句型词：no, none, nobody, nothing, nowhere, never, neither, nowhere, nowise, 等。还有一种句型：all等概括词+肯定式谓语+否定意义的词。 No words can describe the scene. 任何言词均不能描绘那景色。 All his plan came to nothing. 3)双重否定 a.主语+cannot+ help/refrain/keep + from + v-ing He could not help showing his pleasure.他不由得喜形于色。 b.主语+cannot+ but/choose but/ help but +do They can not choose but admit that they are wrong. c.(there be) not +主语+but+谓语 (There is )Nobody but has his faults. 人人都有缺点。 2．判断句型 1）强调判断句 a.主语+be+ no/none +other than/but +表语（强调内容） The tall figure that I saw was none other than our commander. b.主语+be+ nothing+(else)but/ else than/ less than+ 表语 Genius is nothing but labor and diligence.天才只不过是劳动加勤奋而已。 c.it is/was +强调部分+that/ who +从句 It is I who am to blame. 2) 正反判断句 a.主语+be +not+表语a, but +表语b What I admire in Columbus is not his discovered a world, but his having gone to search for it on the faith of an opinion. b.(it is) not… that(who) …, but…that (who) Not that we are afraid of them, but that they are afraid of us. 3)比较判断句： a.主语+be less+表语a +than表语b / more+表语b+表语a Experience shows that success is due less to abilities than to zeal. b.主语+be+表语b+ rather than+表语a He is an artist rather than a philosopher. c.主语+be+ not so much +表语a+ as+表语b It is so much advice as approval that he seeks. 他寻求的与其说是忠告，不如说是忠告。3．倍数表示句型： a.主语+be+倍数+that of 被比较对象/ as +形容词+as+被比较对象
英语翻译常用句型(加精)
英语翻译常考句型详解 1.It is not that…but that… 这不是说…，而是说… 「例文」It is not that the scales in the one case, and the balance in the other, differ in the principles of their construction or manner of working; but that the latter is much finer apparatus and of couse much more accurate in its measurement than the former. 「译文」这并不是说在一种情况下所使用的磅秤和在另一种情况下所使用的天平在构造原理上或工作方式上存在差别，而是说与前者相比，后者是一种更精密得多的装置，因而在计量上必然更加准确。 2.nothing else than 完全是，实在是 「例文」What the man said was nothing else than nonsense. 「译文」那个人讲的话完全是一派胡言。 3.as引导的特殊状语从句，翻译时做定语从句处理。 「例文」We hope the measures to control prices, as they have been taken by the government, will succeed. 「译文」我们希望，政府已经采取的控制物价的措施将取得成功。 4.名词+or+名词结构中，or后的名词是同位语，应译为即…；或者称…. 「例文」Moreover， technology includes techniques , or ways to do things , as well as the manchines that may or may not be necessary to apply them. 「译文」再者，除机器外技术还包括技艺，即制作方法，而运用这些记忆并不一定都需要机器。 5.more…than…结构有三种译法：than连接肯定形式的从句时，该从句译为否定句；在比较的基础上表示选择关系时，可译为与其说…不如说；进行同类比较时，译成比…更. 「例文」The complexity of the human situation and injustice of the social order demand far more fundamental changes in the basic structure of society itself than some politicians are willing to admit in their speeches. 「译文」人类社会形势的复杂性和社会制度的不公正性要求对社会基本结构进行彻底变革，而一些政客口头上是很不愿意承认这一点的。 「分析」这是一个主从复合句，连词than前为主句，than后为从句。虽然本句是进行程度上的比较，但从句意义是否定的， 故译成否定句。 6.no more …than 与not… any more than no more …than 与not… any more than同义，不可简单地看成是more …than的否定形式。具体地说，这一结构可能是带有一定的感情色彩的否定形式，也可能是一种较特殊的类比形式。其翻译方法有二；表示同类否定比较时，可译为不比…更或都…同样不；表示比喻关系时，可译为正如…不，…也不. 「例文」The food on the ship was no better than on any other ship on which Billy had sailed. 「译文」这条船上(供应的)食品并不如比利工作过的其他船上的(食品)好。(括号里的词是可以省略的。) 「分析」这是一个主从复合句、主句是The food …no better , than on any other ship 是省略了比较对象的比较状语从句，从句on which引导的定语从句修饰先行词ship.本句中no more… than用于同类否定的比较，可译为不如…. 7.not so much as与其说…不如说… 「例文」Science moves forward, they say, not so much through the insights of great men of genius as because of more ordinary things like improved techniques and tools. 「译文」新学派科学家说，科学的发展与其说源于天才伟人的真知灼见，不如说源于改进了的技术和工具等等更为普遍的东西。 「分析」这是一个主从复合句。插入语they say是主句，Science moves forward,……and tools是宾语从句。not so much……as 连接的是状语，as引导的状语从句中，由于上下文清楚，主谓语都省略了，即as(sciencemoves forward.)because of……not so much……as也可译为与其说……不如说……，它所表达的逻辑关系和more than有相似之处，也是在比较的基础上进行判断和选择，被比较的事物也同属一个范畴。所不同的是，more……than表示前重后轻的逻辑关系，而not so much… as和less than表示前轻后重的逻辑关系，这两个结构中信息重心落在句尾，因此不必倒过来译，只须按原文的词序顺译即可。
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英语高考常用句型翻译
?高中英语常用50句句型翻译 1、你没有必要提前预定音乐会的票（need n.） There is no need for you to book the ticket for the concert in advance. 2、在专家面前班门弄斧是没有好处的(good n. show) It is no good showing off in the presence of so many experts. 3、如果你不能集中精神学习，熬夜是没有用的(use) It is no use staying up late if you can’t focus your attention on your study. 4、抱怨交通状况是浪费时间(waste) It’s a waste of time making complaints about the transportation system. 5、我觉得你有必要在应聘之前接受一些训练(it) I find it necessary for you to have some training before you apply for a new job. 6、我突然想起来我忘记提醒班长集合的时间了(occur) It suddenly occurred to me that i forgot to remind the monitor of the gathering time. 7、似乎John对於赢得胜利没有什麽信心，你最好对他说些鼓励的话 It seems that John is not very’d better say a few encouraging words to him. 8、第一眼见到她，我就忍不住爱上她了(the first time) The first time i saw her, i couldn’t help falling in love with her. 9、你在阅读上花时间越多，取得进步越大 The more time you spend in reading, the more rapid progress you will make. 10、他获得成功的原因是他从不丧失信心，从不半途而废(halfway) The reason why he achieved success was that he never lost heart and gave up halfway. 11、重要的不是你说些什麽而是你如何演讲(matter) What matters is not what’s in your speech but how you deliver your speech. 12、再努力一下，你就能成功(effort) Make another effort, and you’ll succeed. 13、尽管教学经验不足，他总是全力以赴的满足学生的需求(spare) In spite of the fact that he lacks teaching experience, he spares no effort to meet the demand of his student. 14、不可否认，他的勇气和坚持为他赢得了很高的声誉(deny)
国外论文免费下载网站
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旅游的社会影响【外文翻译】
外文翻译 原文 The Social Impacts Of Tourism Material Source:https://www.360docs.net/doc/d87890539.html,/1117/1/fulltext.pdf Author:A. J. Haley,Tim Snaith,Graham Miller Within tourism literature it has been widely-documented that urban tourism has been continually neglected as an area of research (Ashworth 1989), and consequently remains devoid of a developed understanding or research base (Law 1993; Page 1995). One of the explanations for this is that the uniqueness of individual cities makes reliable comparisons difficult, with a sizeable portion of the literature centered on individual case studies. Thus, this study responds to the call for the development of valid and reliable studies supported by longitudinal and comparative data collection techniques. The authors feel that research into social impact assessment has jumped too quickly from description to modeling and there is need to conduct studies that will provide longitudinal and comparative data. It was felt that without an approach of this nature, any proposed understanding would merely add to the fragmented picture of urban tourism research. Hence, the purpose of this study is to identify and examine the attitudes of residents in Bath, UK towards tourism development and the paper aims to establish a benchmark study for Bath, enabling future longitudinal and comparative analyses of host attitudes. It is also anticipated that future comparative analysis with other historic cities could establish a basis for theory development and the development of flexible modeling tools regarding the social impacts of tourism on residents of historic and related cities in the United Kingdom. Tourism Marketing Tourism Marketing means the tourism product or travel service providers in identifying the manufacturer on the basis of the needs of tourists, by identifying its target market and can provide the design of appropriate tourism products, services and projects to meet these market requirements process. Tourism Marketing integration of communication and dissemination of Focus. Tourism Brand Integrated Marketing is still the dominant form of tourism marketing.Tourism brand of integrated marketing, is the dominant form of tourism
六级翻译常用句型归纳汇总.
六级翻译常用句型归纳汇总 1. During the meeting,hardly had he begun to speak when the audience interrupted him.(他一开始说话,就被听众打断了 2. Surrounded by the police, the kidnappers had no choices but to surrender on the spot.(没有选择,只能投降 3. The concerned mother thrilled at the news of her son having been admitted to the university.(她的儿子被大学入取了 4. The lecture was so boring that the students couldn’t help yawning.(学生忍不住打起哈欠 5. I will be very grateful if you could be kind enough to give me a ride to school.(好心载我一程去学校 6. Unless you sign a contract with the insurance company for your goods, you are not entitled to a repayment for the goods damaged in delivery. (除非你和保险公司签订了货物保险合同 7. It is reported that local health organization was established 25 years ago(据说当地的卫生组织 25年前就成立了 8. Mr s.Smith shut the window lest the noise outside (should interfere with her son’s sleep(外面的噪声会影响她儿子睡觉 9. The new mayor was charged with failure to fulfill his promise to decrease the inflation rate(未能履行他降低通货膨胀率的承诺 10. When confronted with such question, my mind goes blank(每当我遇到这类问题,我脑袋一片空白 , and I can hardly remember my won date of birth.
论文参考方法
开题报告、文献综述、外文翻译、论文反抄袭软件、论文目录，就差论文正文了，其他都全了！！ 开题报告主要包括以下几个方面： （一）论文名称 论文名称就是课题的名字 第一，名称要准确、规范。准确就是论文的名称要把论文研究的问题是什么，研究的对象是什么交待清楚，论文的名称一定要和研究的内容相一致，不能太大，也不能太小，要准确地把你研究的对象、问题概括出来。 第二，名称要简洁，不能太长。不管是论文或者课题，名称都不能太长，能不要的字就尽量不要，一般不要超过20个字。 （二）论文研究的目的、意义 研究的目的、意义也就是为什么要研究、研究它有什么价值。这一般可以先从现实需要方面去论述，指出现实当中存在这个问题，需要去研究，去解决，本论文的研究有什么实际作用，然后，再写论文的理论和学术价值。这些都要写得具体一点，有针对性一点，不能漫无边际地空喊口号。主要内容包括：⑴研究的有关背景(课题的提出)：即根据什么、受什么启发而搞这项研究。⑵通过分析本地（校）的教育教学实际，指出为什么要研究该课题，研究的价值，要解决的问题。 （三）本论文国内外研究的历史和现状（文献综述）。 规范些应该有，如果是小课题可以省略。一般包括：掌握其研究的广度、深度、已取得的成果；寻找有待进一步研究的问题，从而确定本课题研究的平台(起点)、研究的特色或突破点。 （四）论文研究的指导思想 指导思想就是在宏观上应坚持什么方向，符合什么要求等，这个方向或要求可以是哲学、政治理论，也可以是政府的教育发展规划，也可以是有关研究问题的指导性意见等。 （五）论文写作的目标 论文写作的目标也就是课题最后要达到的具体目的,要解决哪些具体问题，也就是本论文研究要达到的预定目标：即本论文写作的目标定位，确定目标时要紧扣课题,用词要准确、精练、明了。 常见存在问题是：不写研究目标；目标扣题不紧；目标用词不准确；目标定得过高, 对预定的目标没有进行研究或无法进行研究。 确定论文写作目标时，一方面要考虑课题本身的要求，另一方面要考率实际的工作条件与工作水平。 （六）论文的基本内容
fulltext翻译
J Appl Electrochem (2009) 39:577-582 DOI 10.1007/s10800-008-9695-z ORIGINAL PAPER Electrochemical treatment of pharmaceutical azo dye amaranth from waste water Rajeev Jain . Nidhi Sharma . Keisham Radhapyari Received: 25 February 2008/Accepted: 13 0ctober 2008/Published online: I November 2008 @ Springer Science+Business Media B.V. 2008 Abstract The electrochemical behavior of pharmaceuti- cal azo dye amaranth has been investigated in distilled water and Britton-Robinson buffer. One well-defined irreversible cathodic peak is observed. This may be attributed to the reduction of the -N=N- group. Calculation of the number of electrons transferred in the reduction process has been performed and a reduction mechanism proposed. Results indicate that the electrode process is diffusion controlled. The cathodic peak in the case of controlled potential electrolysis is found to reduce substantially with a decrease in color and absorbance. The reaction has first order kinetics with k value 5.75 x10-2 abs min-l. The effciency of different electrode materials (platinum and steel) for decolorisation is compared. Chemical oxygen demand (COD) decreases substan- tially from 2,680 t0 96 ppm at platinum and t0 142 ppm at steel. This translates t0 97% COD removal at platinum and 95% at steel. Keywords Electrochemical treatment . Amaranth Azo dye . Industrial effluents . CV, COD I Introduction Azo dyes continue to be a source of pollution from industrial processes which employ dyes to color paper, R. Jain . N. Sharma . K. Radhapyari School of Studies in Chemistry, Jiwaji University Gwalior 474011, India e-mail: raj eevj ain54 @ yahoo.co.in plastics, foodstuffs, pharmaceutical products, and natural and artificial fibers [1, 2]. It is reported that approximately 5 tonnes of dye discharge from dye and coloration industries every year [3]. The release of such compounds into the environment is of great concern due to their toxicity, mutagenicity, carcinogenicity, and bio-transformation products [4-6]. Hence. much research has focused on methods of azo dye destruction. Many treatment processes have been investigated extensively to treat wastewaters such as chemical precipitation [7], adsorption [8], biological treatment [9], photocatalytic degradation [10, 11], electro- catalytic oxidation [12], ozonation [13], Fentons' reaction
翻译常考句型
1.It is not that…but that… 这不是说…，而是说… 「例文」It is not that the scales in the one case, and the balance in the other, differ in the principles of their construction or manner of working; but that the latter is much finer apparatus and of couse much more accurate in its measurement than the former. 「译文」这并不是说在一种情况下所使用的磅秤和在另一种情况下所使用的天平在构造原理上或工作方式上存在差别，而是说与前者相比，后者是一种更精密得多的装置，因而在计量上必然更加准确。 2.nothing else than 完全是，实在是 「例文」What the man said was nothing else than nonsense. 「译文」那个人讲的话完全是一派胡言。 3.as引导的特殊状语从句，翻译时做定语从句处理。 「例文」We hope the measures to control prices, as they have been taken by the government, will succeed. 「译文」我们希望，政府已经采取的控制物价的措施将取得成功。 4.名词+or+名词结构中，or后的名词是同位语，应译为即…；或者称…. 「例文」Moreover，technology includes techniques , or ways to do things , as well as the manchines that may or may not be necessary to apply them. 「译文」再者，除机器外技术还包括技艺，即制作方法，而运用这些记忆并不一定都需要机器。 5.more…than…结构有三种译法：than连接肯定形式的从句时，该从句译为否定句；在比较的基础上表示选择关系时，可译为与其说…不如说；进行同类比较时，译成比…更. 「例文」The complexity of the human situation and injustice of the social order demand far more fundamental changes in the basic structure of society itself than some politicians are willing to admit in their speeches. 「译文」人类社会形势的复杂性和社会制度的不公正性要求对社会基本结构进行彻底变革，而一些政客口头上是很不愿意承认这一点的。 「分析」这是一个主从复合句，连词than前为主句，than后为从句。虽然本句是进行程度上的比较，但从句意义是否定的，故译成否定句。
常见句型翻译
常见句型翻译 定语从句的译法 I、译成前置定语 1. To be sure, a great rebuilding project would give jobs to many of those people who need them. 诚然，一个宏伟的重建计划也许能为许多需要工作的人提供就业机会。 2. This is the solider who just returned from the front. 这是刚从前线回来的战士。 3.成都, 一个你来了就不想离开的城市。 Chengdu—A city you will never want to say goodbye after arrival. 4. In recent years, however, people have begun to become aware that cities are also areas where there is a concentration of problems. 可是，近几年来人们开始意识到城市也是问题成堆的地方。 当然，有些起附加说明作用的非限制性定语从句，对先行词也有不同程度的修饰限制作用，有时也可以译为前置定语。 5. The sun, which had hidden all day, now came out in all its splendor. 那个整天躲在云层里的太阳,现在又光芒四射地露面了。 6. He liked his sister, who was warm and pleasant, but he did not like his brother, who was aloof and arrogant. 他喜欢热情愉快的妹妹，而不喜欢冷漠高傲的哥哥。 II . 译成后置定语 A、一些结构比较复杂，或者意思上有较强的独立性的限制性定语从句，通常可译为后置的并列句。采取这种译法往往要重复关系代词所代替的词，比如：有时可在此词之前加指示词“这”、“这些”或人称代词“他”、“他们”等等，来使译文明确。 7. This volume is prepared as examples for writing compositions which, as it were, has been taken as a difficult task. 本书旨在为写作提供范例，可以说写作是一个难题。 8. Matter is composed of molecules that are composed of atoms. 物质是由分子组成的，而分子又是由原子组成的。 9. But listen, I met a man, who said you could solve this problem. 听着，我遇见一个人，这个人说你是有权解决这个问题的。 10. Day light comes from the sun, which is a mass of hot, glowing gas. 日光来自太阳，太阳是一团炽热、发光的气体。 B、非限制性定语从句与先行词的关系不十分密切，只是对先行词加以说明，描述或解释，或对整个句子所陈述的事实或现象加以总结、补充说明，其前都有逗号分开。在汉译时一般译为后置并列分句。如： 11.He blamed me for everything, which I thought very unfair. 他把一切错误都归罪于我，我认为这很不公平。 12. These books, which are only a small part of my collection, I picked up in American. 这些书是我在美国买的,它们在我的藏书中只占一小部分。 13. She was very patient towards the children, which her husband seldom was. 她对孩子们很耐心，而她丈夫却很少这样。