一般的国际核心期刊，我们关注的数据库有：SCI、EI、ISTP，这三种论文都是备受关注、含金量非常高的。今天小刊带大家着重了解下，三大学术检索之一的：EI。EI（工程索引）又分为EI源刊（JA检索）和EI会议（CA检索）。EI期刊即被EI数据库收录的连续性出版物。EI期刊难度与认可度高于EI会议。
可以是中文，但最终提交到国外出版社是英文文章。我们提供翻译服务，但先要确定中文内容合格而录用。
不是的。比如说:中文也有很多大学的学报是SCI,EI收录的。
99%的都是英文的。即使国内大学学报，也是其中的英文版。整个中国，也仅中国科学和科学通报，上面的中文版，才被SCI或EI收录，其它收录的全是英文的。具体可以参考
先是你先好文章，每个期刊都是不一样的。然后就是选择自己合适的期刊投稿就可以了
ei期刊投稿最为首要的一个任务，就是要找到一家好的投稿平台。论文评审是非常严格的，稿件到达后，首先要经编辑部工作人员审查，合格后再送有关评委评审。EI期刊是全球范围内的一个数据库，主要收录工程技术领域的重要文献，包括期刊以及会议文献，另外也收录一些科技报告、专著等。EI收录包括三种类型：被EI核心收录、非核心收录（Pageone收录）、会议论文。
一般在EI官网下载当前出版的最新EI Compendex收录刊源，判断是否被EI收录，之后找到要投期刊的官网，在官网投稿即可，部分期刊可能是邮箱投稿。
稿件E-MAIL：责任编务：冯丽QQ：1661589041★★国际EI会议南京组委会电话： 一、正确掌握论文写作的基木要求及规范化，并注意选择对口的专业期刊投稿，且遵循所投刊物的格式要求，再加上导师能对论文严格把好质量关，则可避免因投稿后反复退修而耽误了论文发表的时间，又可减少稿件在初审阶段就被退稿的可能，从而提高论文的录用率.1. 文章超过8页，这不好，因为中文杂志页数有限制，不希望单篇文章太长2. 另外题目不醒目，缺乏对审稿人的吸引力3. 在实验现象的描述中缺乏对不同条件下不同实验现象的强烈对比4. 在现象解释中图太小，另外引用太多，看不到作者自己的独特看法大家要尽量避免呀！5. 写作前要浏览大量的经典文献、注意学术积累，在这个过程中，还要注重利用网络，特别是一些专业数据库6."一定要有创新点"7. 写作后，要进行校对、调整和仔细琢磨，还要注意新资料的及时补充，最好放几天再看，或请同学来看，这样便于发现问题。8.观点要突出，图形要美观。二、采用目标期刊所要求的格式，文章知识点要有创新点 首先应该看看别人做过的，国内的先看，然后再看看老外做的；另外，新技术一定要留意学，否则很难做出新东西来，国内牛点的刊物 还是比较看中创新 的。题目要有概括性，最好突出自己的工作；摘要很重要，需要反复斟酌，一般要有三方面：目的、方法、结论，还是要体现新；文章格式严格按刊物要求；参考文献要全；行文流畅、图表清晰。1、格式一定要符合所投刊物的要求，这是通过初审的因素之一；2、 参考文献的引用要适当；3、 摘要前言是关键；4、 刚写完后放段时间在修改，会有新的发现.三、科技论文方面的写作方法1、 文章要有条理，尤其是前沿和讨论，要层层深入，环环相扣2、 要注意一些常用化学试剂的写作技巧，如TRIzol.3、 注意写清楚菌种或毒株的背景，这一点很重要4、 文章中如果涉及软件，记得写清楚版本四、论文格式很重要，杂志审稿的一些知识点1、注意论文格式。我国的学报论文格式是有国家标准的，大家不必去仔细读那国标，但是一定要找个权威的本行业的刊物先看看，是什么格式。2、度量衡单位。国家一直在改革，在发表论文时是必须注意的3、参考资料的罗列，各学报要求不同，要注意你发表的那个杂志的要求(其实也有国标的) 1) 参考文献必须有外文的。 2)最好有基金支持。文章只要有一丁点创新就行了，大创新投到中文学报亏大了 3) 老板的名字要挂上。 4) 项目意义一定要清楚。 5)中文审稿件人一般不会看公式推导(工科类)。五、前言特别重要，特别在中文期刊杂志上发表论文 。另一个就是论文的结果与讨论，这是论文的重中之重。因为方法的撰写都不会有什么新意，除非你是发现一个新的方法。我在核心期刊发表论文的时候特别 注意这几个方面，在国外杂志发表 更是如此，参考文献最好是本年的，引用最新的，有利于吸引编辑的眼球！1.题目要新颖2.内容要突出自己的特点3.要注意第一印象，不要犯一些低级的格式错误。4.最后要注意引你所投稿的杂志的文献！5.最重要的是，如果能自己推荐审稿人的，一定要引用她的文献！六、EI核心论文投稿中遇到的问题：我个人认为，现在的中文学报文章都不怎么好：1、投稿周期长、关系稿多，还收很贵的版面费，不合算；2、同样影响的外文期刊，不收版面费，3、要投中文稿件，英文摘要要写好，中文表达要清楚，只要说明白自己做的是什么、为什么这么做、得到了什么结果、同国内外同样工作的比较情况，引用本刊的文章。总结：其一、在日历上制作投稿计划。 如果你不是牛人，权威杂志一投即中的几率是非常非常小的。即使是牛人，这个概率也未见得高（原因后面再叙）。虽然一般来说，投权威要抱定久投不中的思想准 备。在日历上做好什么时候把什么文章投给了什么杂志社的纪录，即不浪费时间，又避免了一稿多投（经济管理的牛杂志就那么几个，说不定审稿人都是重复的， 一 稿多投，难免马失前蹄）。每次寄出的论文挂号信收据直接往日历上贴，简单方便，一目了然。其二、不要因为某个文章一次不中就灰心地投往低级杂志。因为杂志社选题要考虑很多方面，拒稿不一定是因为你的文章不好。可能是因为选题与他人重复，也可能是政策、政治因素和杂志社品味、倾向等。所以同一级的杂志社最好多试几家。其三、时间是金。 节约时间的投稿办法有：用特快专递投稿，如果收入条件允许 ，这也向编辑部显视你重视自己的稿件；利用权威杂志的网上稿件查询系统或者稿件查询电话；千万不要尝试电子邮件的联系，这个是最不保险，最慢的，因为牛杂志没有人有空给你发信。其四、署名做到有的放矢 一些较厉害的期刊杂志一般相对公平，倾向于独立原创，这个时候作为第一作者单独署名会更容易获得青睐。而另一些则更希望获得业内已经有些名气的作者投稿，因此要署名可以拉上相关人士，提高投稿命中率。其五、关于投稿中的附件。在相关领域自己最近发过什么其他牛杂志的文章可以复印下来作为附件发给编辑，或者参加过最近的相关主要学术研讨会的会议记录也可。这些可以视作为有分量的推荐信反映出你的专业学术能力和选题的时效性。其六、关于参考文献将最近看的相关外文资料注明出来，让编辑感觉到你贴近学术前沿的意识和功底。用很多博士和博导的话来说，就是穷尽本领域的相关资料，并写出来。这些资料即使你不能全都仔细看，但是要尽量多地搜索。◆ 作者本人自带全英文论文，全权委托我们修改排版后发表。◆ 作者本人自带中文论文，全权委托我们翻译后排版发表。◆ 作者本人无论文，全权委托我们指导写作（或著作权转让）并发表。◆ 我们负责免费办理教育部查新工作站出具ISTP检索认证的报告证书。
SCI，全称是Science Citation Index，即科学引文索引。它收录的期刊都是档次较高的学术刊物。硕士研究生毕业一般不会有这么高的要求，最多也就是说，毕业前只需要在国内期刊发表一篇论文即可（等级按学校和专业不同略有不同）。这个要求往往只针对报送的研究生。博士研究生可能会要求发SCI检索的论文。但是也有的高校要求发EI检索即可，甚至有的高校博士研究生连EI都不要求。
一般是不要求的，有个好学校可能会要求。博士毕业有的学校都不要求
你就说submited,but not published我看到国外教授是这么写的
这个问题没人可以回答你，因为个学校是不同的，有些学校要求中文，也有些要求外语的，字数5000到2W不等。 我的建议是查找你自己学校的教务处网站，里边肯定有以前几届的要求的。 如果你告诉我你的学校，专业，我可以帮你查。。。
飘过，，，，，，，，，，，，，，，，，，，
当然要用全英文。根据你自己的兴趣写论文更好些，因为论文答辩较容易些。
发表英文论文当然是先写中文再翻译，直接用英文写难度比较大，毕竟要先写草稿才可以写文章，所以，先写中文再翻译。
是的，必须全英文，但还要有一页中文摘要，具体格式可以参考CNKI中国知网等论文网论文，关于方向：1.英语教育类学生（师范类）：英语教学法，英美文学，语言学等方向，教学法方向最简单，但不容易得到优秀论文好评；2.应用英语类学生（非师范类，可以报考科技英语，导游英语，商务英语，翻译英语等）：不能写教法，科技，导游，翻译，英美文化，语言学，商务写作方向论文等，一般文化方向较容易，雷同论文较多。
毕业论文致谢词范文（英文版）
论文致谢词英文一:
I would like to extend my deep gratitude to all those who have offered mepractical, cordial and selfless support in writing this thesis.
Firstly, I am extremely grateful to my supervisor, Prof. Wang Baorong. He guidesme, influences me and helps me in the process of writing this thesis. It is with hispatience, generosity, and encouragement that I finally write, revise and perfect mythesis.
Secondly, I am much obliged to all teachers who ever taught me during the yearsof my postgraduate studies, esp. Prof. Li Changbao, associate Prof. Shao Youxue,associate Prof. Ceng Qunxia, associate Prof. Chen Xianghong and associate Prof.
Teng Chao. It is these distinguished professors who give me the opportunity to walkinto the academic world. To study with them will always be an honor for me and theirinstructions will follow me in my future studies.
Thirdly, my dear friend, Bao Yizong, who has worked in the audio-visual fieldfor more than three years, has also offered me great help. Based on his real experience,I can really catch a glimpse of the subtitling process and subtitlers' workingenvironment, which paves way for an accurate and pragmatic study of Red Sorghum'sEnglish subtitles.
Lastly, I also want to thank my family members, esp. my wife and my lovelydaughter. It is their understanding and patience that make this thesis possible.
论文致谢词英文二:
The completion of the thesis is attributed to many people's support andencouragement.
First and foremost, I want to extend my heartfelt gratitude to my supervisor,Professor Cao Daogen, whose patient guidance, valuable suggestions and constantencouragement make me successfully complete this thesis. His conscientious academicspirit and modest, open-minded personality inspire me both in academic study and dailylife. He gives me much help and advice during the whole process of my writing, whichhas made my accomplishments possible.
Also, I would like to express my sincere gratitude to all the professors who havetaught me in this university. Their instructions have helped broaden my horizon andtheir enlightening teaching has provided me with a solid foundation to accomplish thispaper and will always be of great value for my future career and academic research.
My thanks also go to the authors whose books and articles have given meinspiration in the writing of this paper.
Last but not least, I would like to express my special thanks to my parents, whosecare and support motivate me to move on and make me want to be a better person.
论文致谢词英文三:
Upon finishing this thesis, I would like to express my great gratitude towards allthose who have offered me sincere assistance in the three years.
First and foremost, my hearty thanks go to my supervisor, Professor ZhangRuwen, who has given me insightful suggestions and constant encouragement both inmy study and in my life. Furthermore, Professor Zhang's painstaking teaching andvaluable advice have profoundly contributed to the completion of the present thesis.
Also, I own my thanks to all the professors who have taught and enlightening meduring my studies in the campus, for guiding me in the field of research work, whichis both challenging and fantastic. The experience and profit I obtained will be ofgrand importance to my further studies.
Finally, I am also grateful to my family and friends, who encourage and supportme and share with me my worries, frustrations, and happiness.
英语论文致谢Acknowledgements
论文的最后一段都要写一份论文致谢，用于感谢在校学习过程中给予自己帮助和支持的人，让我们开始论文致谢的写作吧。写论文致谢需要注意哪些问题呢？下面是我为大家整理的英语论文致谢Acknowledgements，仅供参考，希望能够帮助到大家。
英语论文致谢Acknowledgements
First of all, I would like to extend my sincere gratitude to my supervisor, Zhang Hong, for her instructive advice and useful suggestions on my thesis. I am deeply grateful of her help in the completion of this thesis.
High tribute shall be paid to Ms. Geng Li, whose profound knowledge of English triggers my love for this beautiful language and whose earnest attitude tells me how to learn English.
I am also deeply indebted to all the other tutors and teachers in Translation Studies for their direct and indirect help to me.
Special thanks should go to my friends who have put considerable time and effort int o their comments on the draft.
Finally, I am indebted to my parents for their continuous support and encouragement.
Acknowledgements
I would like to express my gratitude to all those who helped me during the writing of this thesis.
My deepest gratitude goes first and foremost to Professor Zhou Yanxia, my supervisor, for his constant encouragement and guidance. He has walked me through all the stages of the writing of this thesis. Without his consistent and illuminating instruction, this thesis could not have reached its present form.
Second, I would like to express my heartfelt gratitude to Professor Wang Jinsheng, who led me into the world of translation. I am also greatly indebted to the professors and teachers at the Department of English: Ms. Wu Qing, Feng Shaozhong and Han Xiaoya, who have instructed and helped me a lot in the past two years.
Last my thanks would go to my beloved family for their loving considerations and great confidence in me all through these years. I also owe my sincere gratitude to my friends and my fellow classmates who gave me their help and time in listening to me and helping me work out my problems during the difficult course of the thesis.
英语的论文致谢范文（精选14篇）
写论文关键的一步是在结尾附上致谢词，其作用主要是对论文写作过程中予以帮助的人表示感谢并记录在案，让我们坐下来好好写写论文致谢吧。那么我们该怎么去写论文致谢呢？以下是我为大家整理的英语的论文致谢，仅供参考，希望能够帮助到大家。
First of all, I would like to express my gratitude to all those who helped me during the writing of this thesis. I gratefully acknowledge the help of my supervisor, Ms zhang, who has offered me valuable suggestions in the academic studies. In the preparation of this thesis， she has spent much time reading through each draft and provided me with inspiring advice. Without her patient instruction, insightful criticism and expert guidance, the completion of this thesis would not have been possible.
Second, I also owe a special debt of gratitude to all the professors in Foreign Languages Institute, from whose devoted teaching and enlightening lectures I have benefited a lot and academically prepared for the thesis.
Last, I should finally like to express my gratitude to my beloved parents who have always been helping me out of difficulties and supporting without a word of complaint.
I would like to express my gratitude to all those who helped me during the writing of this thesis. I gratefully acknowledge the help of my supervisor, Ms. Sun Yanlan, who has offered me valuable suggestions in the academic studies. In the preparation of the thesis， she has spent much time reading through each draft and provided me with inspiring advice. Without her patient instruction, insightful criticism and expert guidance, the completion of this thesis would not have been possible.
I also owe a special debt of gratitude to all the professors in Foreign Languages Institute, from whose devoted teaching and enlightening lectures I have benefited a lot and academically prepared for the thesis.
I should finally like to express my gratitude to my beloved parents who have always been helping me out of difficulties and supporting without a word of complaint.
My study at the College of International Studies will soon come to an end and, at the completion of my graduation thesis; I wish to express my sincere appreciation to all those who have offered me invaluable help during the four years of my undergraduate study here atTai Zhou Institute of Nanjing university of Science and Technology.
Firstly, I would like to express my heartfelt gratitude to my supervisor, Professor Xu Guixiang, for her constant encouragement and guidance. She has walked me through all the stages of the writing of this thesis. Without her consistent and illuminating instruction, this thesis could not have reached its present form.
Secondly, I should give my hearty thanks to all the other faculty members of the Department of English for their patient instructions in various courses and their precious suggestions for my study here.
Lastly, my thanks would go to my beloved family for their loving considerations and great confidence in me all through these years. I also owe my sincere gratitude to my friends and my fellow classmates who gave me their help and time in listening to me and helping me work out my problems during the difficult course of the thesis.
Here I would like to express my gratitude to all the people who helped me during theprocess of my writing this thesis. Without their help, I couldn't have completed the thesis.
First and most important of all，I wish to thank Professor XX from the bottom of myheart for not only her valuable guidance and suggestions but also her constantencouragement, patience and generosity in spending her time on my thesis.
Also special thanks should go to my colleagues and the students involved in the study inNo. 4 Senior High School who offered me consistent support and help to conduct myinvestigation and experiment.
But for them, the study would have never been finished.Meanwhile I would also like to express my heartfelt gratitude to all the respectableprofessors who taught me during my postgraduate studies in Liao Ning Normal University.
In their lessons, I acquired the academic competence needed to take on such a study.Last but not least, I feel like taking this opportunity to express my thanks to my family.Because of their love，care，understanding and encouragement, I can complete my thesiswriting eventually.
Hereby I would like to express my gratitude and appreciation to those who have been ofsupport to this thesis.
First and foremost, I am extremely grateful to my supervisor Jiang Hui, who has beenvery generous with her time in helping me. Her valuable suggestions, rigorous supervisionand constant encouragement have contributed greatly to the completion of this thesis.My appreciation also goes to all the other professors and teachers, who taught me in thepast three years.
I have greatly widened my span of knowledge from their courses.I also want to express my gratitude to my classmates and friends who have supportedand encouraged me.
At last, I am grateful to my dear family for their deep love and constant support. Withoutthem, the thesis would not have been finished
AcknowledgementsMy thanks go to my supervisor, Prof. Liuruiming, who has offered a lot of suggestionsand comments on my paper and polished every page of my draft and has spent much of histime in offering valuable advice and guidance in my writing, and whose intellect insightshave contributed greatly to the completion of this thesis. Had he not devoted his pains-taking efforts to reading patiently each draft and making critical comments, the completionof this thesis would have been impossible.
My special thanks also go to all my teachers in Inner Mongolia Normal Universitywhose inspiring lectures have had an undoubted influence on much of the co ntent of mythesis.
I would like to extend my heartfelt gratitude to the authors whose words I havecited or quoted, and to the scholars upon whose ideas I have freely drawn.
Special thanks should also go to my students for their enthusiasm and cooperationin the survey study.
Finally, I would like to give acknowledgements to my husband, my good friendsand my parents. Their love, care, support and incessant encouragement have helped meovercome many difficulties throughout the thesis writing.
Firstly，I would like to express my sincere tiiankfulness to my supervisor, ProfessorZhang Mingjian, who gives me constant instruction and helpful advice to my thesis. Icould not finish my thesis without his patient guidance and his careful corrections.
Secondly, I want to thank all my teachers for their insightful enlightenment andprofound knowledge which helps improve my English.
Thirdly, I would like to be thankful for the sixty-six students who helped finish thequestionnaires and carry out this experimental research.
I am also really appreciated that my parents give me both financial and spiritualsupport and it is their love and support that help me go further in the road of scholarlyresearch.
My heartfelt thanks to all the teachers who have taught me during three years.They have assisted and provided me with invaluable support while I was pursuing thisresearch. This paper could not have been successfully accomplished without the helpof my supervisor, classmates, friends and my family.
First of all. I owe my sincerely thankful to my supervisor, Prof. Ma Naqin whohas generously offered much help during every stage of my thesis writing. Withouther insightful suggestion on the design of research, her patient guidance and hermeticulous review of each draft, this thesis would not have reached the present form.Her rigorous, scientific approach to academic research and dedication to teaching willundoubtedly influence my future life and my teaching career.
Special thanks to the students majoring in Art Department in NorthwestUniversity for Nationalities, who voluntarily participated in this survey. Withouttheir supports and cooperation, the present thesis is impossible.
Last but not least, my gratitude also goes to my parents, my husbands and myson who have given me continuous support and encouragement during writing thisthesis.
Upon the completion of the thesis, I would like to take this opportunity toexpress my sincere gratitude to my supervisor, Professor Peng Xiaohua, who hasgiven me important guidance on the thesis. Without his help and encouragement,my thesis would have been impossible. Besides his help with my thesis,he hasalso given me much advice on the methods of doing research, which is of greatvalue to my future academic life.
I am also obliged to other teachers whose lectures have broadened my scopeof vision in British and American literature and help me lay a necessaryfoundation for the writing of the thesis. I am also grateful to all the members ofthe faculty and staff in the College of Foreign Languages who have provided mewith a lot of help and guidance.
Last but not least, I would like to express my gratitude to all the friends andfamily members who have offered me help. Without their help,I could not havefinished my study and this thesis.
I would like to take this opportunity to express my deep gratitude to my supervisor,professor Lu yun, who has offered me constructive guidance for the planning of the thesisand invaluable advice and encouragement for its completion and improvement. She is sucha devoted teacher that though busy in her teaching and research, she never hesitates to offerme timely and spiritual support. She spares no effort to read, comment on and polish mythesis.
Besides, I wish to extend my sincere gratitude to all the teachers in the School ofForeign Languages in Guangxi Teachers Education who have taught me and given meunselfish support during my three postgraduate years. It is my great honor to have knownall those respectable teachers.
Furthermore, I would like to thank my classmates, Mao xiang, Zhu Jingyan, Zou qin,etc. They have helped me and encouraged me a lot in my writing. Without them, mypostgraduate life will lose much happiness.
Finally, I feel indebted to my parents, for their understanding and love in life. I lovethem.
I would like express my gratitude to all those who offer great help for my thesis.
First and foremost, my deepest gratitude goes to my supervisor Professor YuMuhong, for his father-like encouragement and guidance. He provided me withabundant suggestions and priceless criticisms for my writing of the thesis. But for hisconstant patient guidance and enlightenment, the thesis would have become a missionimpossible.
My sincere thanks also go to the teachers from the School of Foreign Languages ofZhejiang University of Finance and Economics, who jointly led me into the holy templeof academic field. Here, I want to send my gratefulness to those respected teachers likeProf. Wang Baorong, Prof. Li Changbao, Prof. Chen Xianghong, Prof. Shao Youxue,Prof. Teng Chao, Prof. Cen Qunxia etc. Thank you for your being with me and beingthe witnesses for the birth, growth and perfection of my thesis.
I feel indebted to my parents, without their mental and material support, I couldbarely finish the thesis on time.
Finally, my thanks should be sent to all my classmates, for their endless supportand warm hearts, making me feel like living in a united big family.
I would like to take this opportunity to thank a number of people who haveoffered invaluable assistance in the preparation of the dissertation.
My deepest gratitude goes first and foremost to Professor Luo Ping, mysupervisor, who has walked me through all the stages of the writing of this thesis. Hiscritical comments, constant encouragement and guidance have greatly enlightened menot only on the academic pursuit but also on the morals of being a man. Without hisconsistent and illuminating instruction, this thesis could not have reached its presentstage.
Secondly, I would like to express my heartfelt thanks to all the professors andteachers whose insightful lectures have well prepared me for the completion of thethesis during my pursuit of the Master Degree ofArts at SISU.
I also greatly appreciate the assistance offered by the authors and scholarsmentioned in the bibliography, without whose works, the literature review of mythesis would not have been possible.
Last, I am deeply indebted to my beloved parents and friends, who alwayssupported me, willingly discussed with me, and offered valuable insights. Their helpand support have accompanied me through the difficult course of the thesis andmoments of my life.
I would like to express my gratitude to those who help accomplish this study.
First of all, I thank sincerely my supervisor, Dr. Rita Welsh who always responded my email rapidly and in time with a lot of useful suggestions and comments and encouraged me to complete the study. And I also appreciated the guidance and help from Jane Williams, my previous supervisor.
Secondly, Thanks to my teachers and classmates in HTMI, David Coy, Carlos Oberli, Dorothy Qin, Grigory and Louise Liu, who gave initiative advises and their insight which helped me understand better the topic. Moreover, I would like to give my deeper thanks to my friends, Sophy Wang, Lu Wang, Cissy Niu and James Li, who looked for and made an appointment with top leaders of hotels participating in this study and my special thank is also given to those participants who provided valuable insights and made an important contribution for fulfilling this research.
Finally, I thank all of my family members, especially, my parents and sister for their financial support and encouragement.
acknowledgements
my deepest gratitude goes first and foremost to professor aaa , my supervisor, for her constant encouragement and guidance. she has walked me through all the stages of the writing of this thesis. without her consistent and illuminating instruction, this thesis could not have reached its present form.
second, i would like to express my heartfelt gratitude to professor aaa, who led me into the world of translation. i am also greatly indebted to the professors and teachers at the department of english: professor dddd, professor ssss, who have instructed and helped me a lot in the past two years.
last my thanks would go to my beloved family for their loving considerations and great confidence in me all through these years. i also owe my sincere gratitude to my friends and my fellow classmates who gave me their help and time in listening to me and helping me work out my problems during the difficult course of the thesis.