工程论文英文发表
1. 阅读10 篇文献，总结100 个常用句型和常用短语。经常复习。注意，文献作者必须是以英文为母语者，文献内容要与你的专业有关。这属于平时看文献的副产品。 2. 找3-5 篇技术路线和统计方法与你的课题接近的文章，精读。写出论文的草稿。要按照标题、作者、摘要、背景、目的、材料、方法、结果、讨论、致谢、参考文献、图例、图、表、照片和说明的统一格式来写。这样做的好处是从它可以方便地改成任何杂志的格式。 3. 针对论文的每一部分，尤其是某种具体方法、要讨论的某一具体方面，各找5-8 篇文献阅读，充实完善。这里讨论的只涉及英文表达，也只推荐给缺乏英文写作经验的人。 我有范文
有一个《海外英语》，还有《青春岁月》这两个刊物可以刊出全英文稿件，除此以外，英语专业的也可以考虑，比如《校园英语》之类
把论文写成英文的然后投稿
现在都市场化了。有专门的润色公司。而且英文期刊一大丢。知网检索的英文期刊800多块一篇。百度jissr你就知道。
工程类英文期刊
国际英文期刊在中国地区已被众多省市广泛认可，用途较多，越来越多的作者选择将学术成果发表在国际英文期刊上。中国部分部委及多数省市的管理机构或高校均有政策不同程度的认可、支持学者在国际英文期刊发表研究论文。国际英文期刊制度灵活，信息化程度较高，作者可以根据所在部委系统、省市单位的具体政策来具体选择合适的国际英文期刊，快速获得首发权和评审资格，以保护自己的研究成果，推动学术交流。
国外著名土木工程相关期刊列表(SCI/EI)
1，Advances in Structural Engineering
2，ACI Journal of Materials
3，ACI Structural Journal
4，Automation in Construction
5，Buildings and Structures
6，Canadian Geotechnical Journal ISSN: 0008-3674
7，Canadian Journal of Civil Engineerin
8，Computational Mechanics
9，Computers and Structures
10，Computers and Geotechnics ISSN: 0266-352X
11，Cement and Concrete Research
12，Computer Methods in Applied Mechanics and Engineering
13，Communications in Numerical Methods in Engineering
14 Earthquake Engineering and Structural Dynamics
15，Earthquake Spectrum
对应的中文翻译：
1、结构工程进展
2、ACI材料杂志
3、ACI结构期刊
4、施工自动化
5、建筑物和构筑物
6、《加拿大岩土工程杂志》，编号:0008-3674
7、加拿大土木工程杂志
8、计算力学
9、计算机和结构
10、计算机和岩土工程学会编号:0266-352X
11、水泥与混凝土研究
12、应用力学和工程中的计算机方法
13、工程中数值方法的交流
14地震工程和结构动力学
15、地震谱
国内有关土木工程的核心期刊：
1，岩土工程学报；建筑结构学报；土木工程学报；岩石力学与工程学报；建筑结构
2，工业建筑；哈尔滨建筑大学学报；中国给水排水；岩土力学；给水排水
3，施工技术 ；建筑技术；世界建筑；建筑科学；世界地震工程；建筑学报
4，工程勘察；城市规划；暖通空调；西安建筑科技大学学报，自然科学版；水文地质工程地质
5，建筑机械；四川建筑科学研究；重庆建筑大学学报；新型建筑材料；空间结构；城市规划汇刊
国外著名土木工程相关期刊列表(SCI/EI)国际重要学术期刊推荐表序号 国际重要学术期刊名称（SCI、EI检索源）1 Advances in Structural Engineering2 ACI Journal of Materials3 ACI Structural Journal4 Automation in Construction5 Buildings and Structures6 Canadian Geotechnical Journal ISSN: 0008-36747 Canadian Journal of Civil Engineering8 Computational Mechanics9 Computers and Structures10 Computers and Geotechnics ISSN: 0266-352X11 Cement and Concrete Research12 Computer Methods in Applied Mechanics and Engineering13 Communications in Numerical Methods in Engineering14 Earthquake Engineering and Structural Dynamics15 Earthquake Spectrum16 Engineering Geology17 Engineering Analysis with Boundary Elements18 Engineering Structures19 Geotechnique ISSN:0016-850520 Ground Engineering21 Geotextiles and Geomembranes22 International Journal of Impact Engineering ISSN: 0734-743X23 International Journal for Numerical and Analytical Methods in Geomechanics ISSN: 0363-906124 International Journal for Numerical Methods in Engineering25 International Journal of Rock Mechanics and Mining Sciences ISSN: 1365-160926 International Journal of Solids and Structures27 International Journal of Steel Structures28 International Journal of Space Structures29 International Journal of the Geotechnical Structures30 Journal of Applied Mechanics, ASME31 Journal of Bridge Engineering , ASCE32 Journal of Computing in Civil Engineering, ASCE33 Journal of Composites for Engineering, ASCE34 Journal of Constructional Steel Research35 Journal of Engineering Mechanics, ASCE36 Journal of Geodynamics ISSN: 0264-370737 Journal of Geotechnical and Geoenvironmental Engineering, ASCE ISSN: 1019-24138 Journal of Sound and Vibration39 Journal of Steel & Composite Structures40 Journal of Structural Engineering, ASCE41 Journal of Wind Engineering & Industrial Aerodynamics Wind and Structures42 Journal of Construction and Management43 Preceding of Civil Engineering Bailing and Bridge Structures44 Reliability Engineering & System Safety ISSN: 0951-832045 Rock Mechanics and Rock Engineering ISSN: 0723-263246 Shock and Vibration ISSN: 1070-962247 Soils and Foundations ISSN: 0038-080648 Soil Dynamics and Earthquake Engineering49 Structural Engineers50 Structural Engineering and Mechanics51 The Structural Design of Tall Buildings52 Thin-walled Structures53 The Magazine of Concrete Research54 Tunnelling and Underground Space Technology55 Wind and Structures-An International Journal56 Finite Elements in Analysis and Design注：1.以上是否被SCI、EI检索期刊为准。2.除以上学术期刊外，学科认为是国际重要学术期刊，且被SCI、EI检索，专家组可认定为国际重要学术期刊
msea是美国办理的期刊。
msea属于金属材料和冶金领域的权威期刊，在80本冶金期刊中排名第8。MSEA是我们领域的一个传统期刊，应该说，其国际影响力排在Acta Mater.和Metall.Mater. Trans. A之后，也算是比较有影响力的期刊。
MSEA为Materials Science and Engineering:A的缩写，为爱思唯尔旗下的英文期刊。
msea介绍：
MSEA是SCI工程技术类2区期刊。MSEA 2015-2016年度影响因子：2.647。Materials Science and Engineering A，IF：5.234；国人占比：53.57%；自引率：15.46%；领域：纳米科技材料综合冶金工程。
MSEA也属于金属材料和冶金领域的权威期刊，在80本冶金期刊中排名第8。
土木工程论文发表英文
土木工程专业的英文论文格式
导语：土木工程专业的英文的论文格式包括哪些内容呢?土木工程是建造各类工程设施的科学技术的统称。下面是我分享的土木工程专业的英文的论文格式，欢迎阅读!
土木工程专业的英文论文格式均以美国土木工程师协会出版社发布的标准格式为准。
英语论文用激光打印机打印，打印稿为黑白稿，彩色打印件会影响出版效果。
版心：a4纸，上、下页边距3.5 cm，左、右页边距均为3.25 mm。论文内容宽不得超过14.5cm， 长不得超过22.5cm。
字体和字号：正文，标题，作者联络信息和图表中的文字均为times new roman 12号字。可以跟据需要使用同类字体中的粗体，斜体。
行距：单倍行距。
页码： 论文正文和文后所附图例都需添加页码。页码为阿拉伯数字，位于页面下方居中。
文体： 文章应语法正确，技术用词准确。标题应该以最简洁的语言概括文章内容。如果标题较长，请采用title: subtitle的形式。
数学公式：文中的数学公式不得手写，必须打印。公式如果在文中多次被引用，应该编号。公式之间，公式和正文之间都应该空一行。 单位： 文中所用的度量衡单位应为国际单位。可在括号内，单位对应表中列出其他单位。有关国际单位的使用(standard practice for use of the international system of units)可以通过电话1-向asce索取。其他相关使用参考文献，如anmc metric editorial guide， 5th ed，1992 可向美国国家公制协会 索取(american national metric council， 1735n. lynn street， suite 950， arlington， va 22209-2022)
图表：
标题说明和图例：插入的图表应该以出现顺序编号(figure 1，figure 2，table 1，table 2)。图的说明和标题，包括图的序号应该位于图的下方。表的说明和标题，包括表的序号应该位于表格上方。
位置： 图可以插入到正文中，或者集中放在文章最后。如果在正文中插入图，尽量放在页面的.顶部或尾部。不要选择文字环绕图形的对齐方式，可选择上下环绕方式。
底纹： 插图中不要选择带阴影或底纹，否则会影响印刷效果。
照片：如果文中需要附上照片，在文中出现照片的地方贴上其黑白光面冲洗照片，标题说明位于照片下方。照片将和正文一起缩印，请不要提供彩色照片，以免影响印刷效果。
扫描图： 印刷后的扫描图不如原件清晰。如果文中有扫描图，请提供灰色色标扫描图。
作者联络信息：请用横线和正文隔开。联络信息可以为一位作者或所有作者的，包括以下内容：作者全名;所属学会;学历或授予的荣誉;所在单位;通讯地址和电子邮箱;电话和传真。
参考文献： 所有参考文献为单倍行距，放在文章最后，按照第一作者姓氏的字母顺序排列。如有同一作者的两篇以上文献，按出版年代先后排列。正文中引用参考文献时，作者和出版年代应该放入括号内。由于上标缩印后会变小，难于辨认，正文中不使用上标标注参考文献。所列出的参考文献应当在正文中都有所引用，如果正文中没有引用，请将文献列入文章最后的附加信息(additional information)部分，或者相关材料(related materials)部分。
1.《建筑结构制图标准》GB/T50105-2001
2.《建筑结构荷载规范》GB5009-2001(2006版)
3.《混凝土结构设计规范》GB50010-2002
4.《建筑地基基础设计规范》GB5007-2002
5.《砌体结构设计规范》GB5003-2001
6.《建筑抗震设计规范》GB5011-2001
7.《钢结构设计规范》GB50017-2003
8.《建筑结构构造资料》(合订本)，中国建筑工业出版社，1998年。
9.《混凝土结构构造手册》，中国建筑工业出版社，2002年。
10.《地基基础设计手册》，上海科技出版社，1998年。
11.《混凝土结构设计手册》，中国建筑工业出版社，2002年。
12.《建筑结构静力计算手册》，中国建筑工业出版社，1999年
13.《建筑结构强制性国家标准》(简装本)，中国建筑工业出版社，2001年9月
14. 任全宏、常建军.钢筋混凝土多层框架结构房屋结构设计中应注意的几个问题。陕西建筑2007，145(7).
15. 范俊梅. 钢筋混凝土多层框架结构设计问题分析. 科技资讯2008，3.
16. Basic Principles for Reinforced Concrete Structure Design
17.建筑、结构设计有关图集资料以及专业课程教材等。
土木工程的英文是Civil Engineering ,直译是民用工程，它是建造各种工程的统称。它既指建设的对象，即建造在地上，地下，水中的工程设施，也指应用的材料设备和进行的勘测，设计施工，保养，维修等专业技术。土木工程随着人类社会的进步而发展，至今已经演变成为大型综合性的学科，它已经出许多分支，如：建筑工程，铁路工程，道路工程，桥梁工程，特种工程结构，给水排水工程，港口工程，水利工程，环境工程等学科。土木工程共有六个专业：建筑学，城市规划，土木工程，建筑环境与设备工程，给水排水工程和道路桥梁工程。土木工程作为一个重要的基础学科，有其重要的属性：综合性，社会性，实践性，统一性。土木工程为国民经济的发展和人民生活的改善提供了重要的物质技术基础，对众多产业的振兴发挥了促进作用，工程建设是形成固定资产的基本生产过程，因此，建筑业和房地产成为许多国家和地区的经济支柱之一。.古代的土木工程有很长的时间跨度，大致从公元前500年新石器时代出现原始的土木工程活动到16世纪末意大利的文艺复兴，导致土木工程走上迅速发展的道路为止，前后经历了两千多年。在这段时间内，由于科学理论发展及其缓慢，土木工程也没有突破习惯的发展。从17世纪中页开始到20 世纪40年代第二次世界大战结束为止的300年间，国外的建筑取得了长足的进步。土木工程进入了定量分析阶段。一些理论的发展，新材料的出现，新工具的发明，都使土木工程科学日渐完善和成熟。到了近代，二战结束之后，许多国家经济起飞，现代科学日益进步，从而为进一步发展提供了强大的动力和物质基础。人们生活水平的不断提高，必然要求越来越舒适的居住环境，在这种情况下，建筑的发展直接推动了土木工程的发展。总的来说土木工程是一门古老的学科，它已经取得了巨大的成就，未来的土木工程将在人们的生活中占据更重要的地位。地球环境的日益恶化，人口的不断增加，人们为了争取生存，为了争取更舒适的生存环境，必将更加重视土木工程。在不久的将来，一些重大项目将会陆续兴建，插入云霄的摩天大楼，横跨大样的桥梁，更加方便的交通将不是梦想。科技的发展，以及地球不断恶化的环境必将促使土木工程向太空和海洋发展，为人类提供更广阔的生存空间。近年来，工程材料主要是钢筋，混凝土，木材和砖材，在未来，传统材料将得到改观，一些全新的更加适合建筑的材料将问世，尤其是化学合成材料将推动建筑走向更高点。同时，设计方法的精确化，设计工作的自动化，信息和智能话技术的全面引入，将会是人们有一个更加舒适的居住环境。一句话，理论的发展，新材料的出现，计算机的应用，高新技术的引入等都将使土木工程有一个新的飞跃.English is the Civil Engineering Civil Engineering, civil engineering is literally, it is the construction of the project collectively. It means building objects that the construction on the ground, underground, water works facilities, equipment and materials to use in surveying, design construction, maintenance, repair and other professional skills. Civil Engineering with the progress of the human society, has been transformed into large integrated disciplines, it has a number of branches, such as : construction, rail projects, road projects, bridge projects, special project structure, water drainage works, the port project, water, environmental engineering disciplines. A total of six professional Civil Engineering : architecture, urban planning, civil engineering, construction and environmental engineering equipment, water drainage works and road bridge project.Civil Engineering as an important foundation subjects, its important attribute : an integrated, social, practicality, uniformity. Civil Engineering for the development of the national economy and improve the living standards of the people provided important material and technological foundation for the revitalization of many industries played a catalytic role in the construction of fixed assets is a basic production process, the construction and real estate in many countries and regions become a pillar of the economyAncient Civil Engineering has a long time span, roughly 500 years before Christ from the original date in civil engineering activities to the 16 century Italian Renaissance, resulting in the rapid development of the Civil Engineering on the road today, and has experienced more than 2,000 years. During this period, due to the development of scientific theories and slow, there is no breakthrough in civil engineering practices.Century from 17 pages to 40 years in the 20th century end of the Second World War 300 years, foreign construction made great strides. Civil Engineering has entered a phase of quantitative analysis. Some theoretical development, the emergence of new materials, new tools of invention, the Civil Engineering Science is perfection and maturity. In modern times, after the end of World War II, many countries economic takeoff, the increasing advances of modern science, so as to provide a powerful impetus to further development and material basis. People's living conditions continue to improve, more and more comfortable living environment for the inevitable in the circumstances, the construction of development directly to the Civil Engineering development.
The urban river embankment discuss the ecological constructionAnonymous XXXXXXXXAbstract: the urban river embankment construction as the object, discuss the current social background, analyses and compares the river embankment design of traditional methods and characteristics of ecological methods, and puts forward three modes of ecological design and their advantages and disadvantages, and expounds the present situation of the ecological construction in domestic bank and future prospects.Keywords: the bank; Ecology; Design way; Domestic situationText:A, backgroundRiver Banks part is the amphibious interlaced transition belt, has the remarkable edge effect. Here are active substances, nutrient and energy flow, offer a habitat for a variety of creatures. Natural state Banks often species richness, productivity high.The traditional embankment design often single ?一、背景河流的堤岸部分是水陆交错的过渡地带，具有显著的边缘效应。这里有活跃的物质、养分和能量的流动，为多种生物提供了栖息地。自然状态下的堤岸往往物种丰富、生产力高。传统的堤岸设计往往会单纯从防洪角度出发，采用土堤或者土石混合堆砌起来高高的堤岸。它的优点在于高度的可靠性，结构设计后加起防护堤岸抗流水冲刷能力显著增强。对于洪水暴发频繁、侵蚀严重的区段，这样的设计无可厚非，而对于一般河流堤岸的修建，这样的设计则显得缺乏环境的美化和绿化，同时也破坏许多对生态起重要作用的自然因素，如破坏植被与河床间的联系，造成冲刷侵蚀转移等。另外，河流作为城市风貌不可多得的珍惜资源，也是城市风貌的特色要素，它的景观塑造显得十分必要。同时，堤岸景观建设必然使滨河地区土地价值提升，滨水开发的高投资回报的特点更增强了对城市堤岸景观建设的需求。二、需求——堤岸的生态化建设河流堤岸作为城市中最邻近河流的区域，是城市与河流的衔接线，它的景观规划是提高城市生活品质的需要，也是丰富城市景观的需要。生态化建设，它的根本思路是运用自然本身抗干扰和自我修复的能力来处理人与自然的关系。生态设计方法不同于传统用人工的结构和形式来取代自然的方法，而是用自然的结构和形式来顺应自然的进程。将河岸与河道在生态上联系起来，也就实现了物质、养分、能量的交流：对于生物，它提供了合适的栖息地；植物根系可固着土壤，枝叶可截留雨水，过滤地表迳流，抵抗流水冲刷，从而起到保护堤岸、增加堤岸结构的稳定性、净化水质、涵养水源的作用，而且随着时间的推移，这些作用被不断加强。同时，生态化建设以自然的外貌出现，容易与环境取得协调，造价也较低，不需要长期的维护管理。三、河流堤岸生态化设计方式河流堤岸生态化设计，要遵守生态设计的原则，注重地方性、保护与节约自然资本、让自然做功、显露自然，主要体现在对地域气候环境、河流地质地貌、水文变化的适应，对河流生态环境的考虑，对堤岸地形的处理和对筑堤材料的选择和构造方式方面。1） 人工类：传统方法是采用块石或混凝土块砖等堆砌。可在此基础上加以改进以适应河流景观设计的需求。a) 块石或混凝土块砖干砌，不用砂浆。这样在砌块之间就留有空隙，为后期滨河植物的生长提供了空间。随着时间的推移，堤岸会逐渐呈现出自然的风貌。b) 堤岸采用台阶式分级，台阶面上的空间加以利用，种植植物。当然这两种改进方法对于河岸处现有植被仍存在一定的不良影响，人工痕迹也过于明显。2） 自然类：充分利用堤岸植被原型，可直接将适用于滨河地带生长的植被种植于堤岸上，利用植物的根、茎、叶来稳固堤岸，防止侵蚀、控制沉积的同时也为生物提供了栖息地。3） 人工自然相结合综合了以上两种方法的优点，具有人工结构的稳定性和自然的外貌，见效快、生态效益好，以下为常见的两种类型：a) 种植植物的堆石将由大小不同的石块组成的堆石置于与水接触的土壤表面，再把活体切枝插入石堆中使斜坡更加稳定。根系可提高强度，植被可遮盖石块，使堤岸外貌更加自然。b) 与植物结合使用的插孔式混凝土块将预制的混凝土块以连锁的形式置于岸底的浅渠中，再将植物切枝或植株扦插于混凝土块之间和堤岸上部，其上覆土压实，再播种草本植物。堤岸生态化建设也存在一定的局限性。如：选用的材料及建造方法不同，堤岸的防护能力相差很大，需要运用多学科知识认真分析，这就为设计人员提出了更大的挑战；建造初期若受到强烈干扰，则会影响到以后防护作用的发挥等。这也就对河流堤岸的生态化设计提出了更高的要求。四、国内现状1）省会城市在我国省会城市及计划单列市中有近80％进行了堤岸景观规划。（参考文献[3]）城 市 项目名称 城 市 项目名称北 京 长河城市水系统综合治理 南 宁 堤岸园工程长 沙 湘江风光带 宁 波 滨江大道沿江景观工程成 都 府南河绿化工程 上 海 外滩、陆家嘴滨江大道福 州 闵江江滨公园 沈 阳 浑河观光旅游带广 州 珠江二沙段堤岸景观、芳村长堤建设 太 原 汾河公园贵 阳 南明河景观绿化工程 天 津 海河堤岸改造工程哈尔滨 松花江南岸沿江风景长廊 武 汉 汉口江滩一二期工程昆 明 盘龙江中段滨水生态景观建设 西 安 灞河大水大绿工程兰 州 黄河风情线 重 庆 南滨路滨江旅游观光大道从规划后建成情况看，这些城市河流堤岸景观项目都得到了当地政府与市民的肯定。在这些项目中，堤岸既可成为当地最具吸引力的城市公园，如太原的汾河公园和福州的江滨公园；堤岸也可成为市民日常休闲活动的热点地段，如南宁的堤路园和武汉的汉口江滩工程；堤岸还可成为城市最具特色的地段，如重庆的南滨路滨江旅游观光大道；堤岸更可成为城市旅游的热点，如上海的外滩和陆家嘴滨江大道。总之，经过景观规划的堤岸已成为当地最具特色的地区。从建设效果看，相对堤岸的原来面貌而言，统计资料中的这些景观工程都是较成功的，都成为当地城市关注的热点，成为当地政府的政绩工程，成为当地的民心工程。城市河流堤岸通过景观规划，有效地改善了滨河地段的环境，并带动滨河地段的开发。但必须清醒地认识到，这些城市堤岸景观项目规划并非尽善尽美，也存在这样或那样的问题，仍有待完善。2）中小城市城市经济实力的强大决定了其城市建设水平的高标准和高水平。中小城市河流堤岸景观与统计资料中的城市存在较大的差距，存在更多的问题。特别是由于资金问题，堤岸景观是，纯人工，状态的钢筋混凝土防洪堤，或保持自然防洪状态的土石堤，没有经过景观规划，易造成城市资源的极大浪费。五、前景目前，河流景观建设，特别是城市河流景观建设，在中国正方兴未艾；在发达国家中也是一个久盛不衰的话题。 回顾发达国家河流景观建设的历史，自20世纪70年代以来，随着人们环境意识的普遍增强，重视河流景观的生态功能已成为一个时代的呼唤，河流景观建设的生态设计方法也已得到了空前的重视和发展。他山之石可以攻玉，借鉴发达国家已经形成的成熟的理念和做法，可以使我们少走弯路，搭上隆隆前进的生态建设之车。
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Control of Parallel Inverters in Distributed AC Power Systems with Consideration of Line Impedance Effect在分布式交流电力系统中考虑连线阻抗影响时的并联逆变器控制 论文发到你的邮箱了
用于分布式在线UPS中的并联逆变器的一种无线控制器A Wireless Controller for Parallel Inverters in Distributed Online UPS SystemsJosep M. Guerrero', Luis Garcia de Vicufia", Jose Matas'*, Jaume Miret", and Miguel Castilla". Departament #Enginyeria de Sistemes, Automatica i Informhtica Industrial. Universitat Polithica de CatalunyaC. Comte d'Urgell, 187.08036 -Barcelona. Spain. Email: .. Departament #Enginyeria Electrbnica. Universitat Polit6cnica de CatalunyaAV. Victor BaLguer s/n. 08800I - Vilanova i la Geltrh. SpainAbsiract - In this paper, a novel controller for parallelconnectedonline-UPS inverters without control wireinterconnections is presented. The wireless control technique isbased on the well-known droop method, which consists inintroducing P-oand Q-V schemes into the inverters, in order toshare properly the power drawn to the loads. The droop methodhas been widely used in applications of load sharing betweendifferent parallel-connected inverters. However, this methodhas several drawbacks that limited its application, such as atrade-off between output-voltage regulation and power sharingaccuracy, slow transient response, and frequency and phasedeviation. This last disadvantage makes impracticable themethod in online-UPS systems, since in this case every modulemust be in phase with the utility ac mains. To overcome theselimitations, we propose a novel control scheme, endowing to theparalleled-UPS system a proper transient response, strictlyfrequency and phase synchronization with the ac mains, andexcellent power sharing. Simulation and experimental resultsare reported confirming the validity of the proposed approach.1. INTRODUCTIONThe parallel operation of distributed Uninterruptible PowerSupplies (UPS) is presented as a suitable solution to supplycritical and sensitive loads, when high reliability and poweravailability are required. In the last years, many controlschemes for parallel-connected inverters has been raised,which are derived from parallel-schemes of dc-dc converters[I], such as the master-slave control [2], or the democraticcontrol [3]. In contrast, novel control schemes have beenappeared recently, such as the chain-structure control [4], orthe distributed control [ 5 ] . However, all these schemes needcontrol interconnections between modules and, hence, thereliability of the system is reduced since they can be a sourceof noise and failures. Moreover, these communication wireslimited the physical situation ofthe modules [6].In this sense, several control techniques has been proposedwithout control interconnections, such as the droop method.In this method, the control loop achieves good power sharingmaking tight adjustments over the output voltage frequencyand amplitude of the inverter, with the objective tocompensate the active and reactive power unbalances [7].This concept is derived from the power system theory, inwhich the frequency of a generator drops when the powerdrawn to the utility line increases [8].0-7803-7906-3/03/$17.00 02003 IEEE. 1637However, this control approach has an inherent trade-offbetween voltage regulation and power sharing. In addition,this method exhibits slow dynamic-response, since it requireslow-pass filters to calculate the average value of the activeand reactive power. Hence, the stability and the dynamics ofthe whole system are hardly influenced by the characteristicsof these filters and by the value of the droop coefficients,which are bounded by the maximum allowed deviations ofthe output voltage amplitude and frequency.Besides, when active power increases, the droopcharacteristic causes a frequency deviation from the nominalvalue and, consequently, it results in a variable phasedifference between the mains and the inverter output voltage.This fact can be a problem when the bypass switch mustconnect the utility line directly to the critical bus in stead ofits phase difference. In [9], two possibilities are presented inorder to achieve phase synchronization for parallel lineinteractiveUPS systems. The first one is to locate a particularmodule near the bypass switch, which must to synchronizethe output voltage to the mains while supporting overloadcondition before switch on. The second possibility is to waitfor the instant when phase matching is produced to connectthe bypass.However, the mentioned two folds cannot be applied to aparallel online-UPS system, since maximum transfer timeought to be less than a % of line period, and all the modulesmust be always synchronized with the mains when it ispresent. Hence, the modules should be prepared to transferdirectly the energy from the mains to the critical bus in caseof overload or failure [lo].In our previous works [11][12], we proposed differentcontrol schemes to overcome several limitations of theconventional droop method. However, these controllers bythemselves are inappropriate to apply to a parallel online-UPS system. In this paper, a novel wireless control scheme isproposed to parallel different online UPS modules with highperformance and restricted requirements. The controllerprovides: 1) proper transient response; 2) power sharingaccuracy; 3) stable frequency operation; and 4) good phasematching between the output-voltage and the utility line.Thus, this new approach is especially suitable for paralleled-UPS systems with true redundancy, high reliability andpower availability. Simulation and experimental results arereported, confirming the validity of this control scheme.Fig. 1. Equivalenl cimuif ofan invener connecled 10 a bust"Fig. 2. P-odraop function.11. REVlEW OF THE CONVENTIONAL DROOP METHODFig. 1 shows the equivalent circuit of an inverter connectedto a common bus through coupled impedance. When thisimpedance is inductive, the active and reactive powers drawnto the load can be expressed asEVcosQ - V2 Q=where Xis the output reactance of an inverter; Q is the phaseangle between the output voltage of the inverter and thevoltage of the common bus; E and V are the amplitude of theoutput voltage of the inverter and the bus voltage,respectively.From the above equations it can be derived that the activepower P is predominately dependent on the power angle Q,while the reactive power Q mostly depends on the outputvoltageamplitude. Consequently, most of wireless-control ofparalleled-inverters uses the conventional droop method,which introduces the following droops in the amplitude Eand the frequency U of the inverter output voltageu = w -mP (3)E = E ' - n Q , (4)being W* and E' the output voltage frequency and amplitudeat no load, respectively; m and n are the droop coefficientsfor the frequency and amplitude, respectively.Furthermore, a coupled inductance is needed between theinverter output and the critical bus that fixes the outputimpedance, in order to ensure a proper power flow. However,it is bulky and increase:; the size and the cost of the UPSmodules. In addition, tho output voltage is highly distortedwhen supplying nonlinezr loads since the output impedanceis a pure inductance.It is well known that if droop coefficients are increased,then good power sharing is achieved at the expense ofdegrading the voltage regulation (see Fig. 2).The inherent trade-off of this scheme restricts thementioned coefficients, which can be a serious limitation interms of transient response, power sharing accuracy, andsystem stability.On the other hand, lo carry out the droop functions,expressed by (3) and (4), it is necessary to calculate theaverage value over one line-cycle of the output active andreactive instantaneous power. This can be implemented bymeans of low pass filters with a smaller bandwidth than thatof the closed-loop inverter. Consequently, the powercalculation filters and droop coefficients determine, to a largeextent, the dynamics and the stability of the paralleledinvertersystem [ 131.In conclusion, the droop method has several intrinsicproblems to be applied 1.0 a wireless paralleled-system ofonline UPS, which can he summed-up as follows:Static trade-off between the output-voltage regulation(frequency and amplitude) and the power-sharingaccuracy (active an4d reactive).2) Limited transient response. The system dynamicsdepends on the power-calculation filter characteristics,the droop coefficients, and the output impedances.Lost of ac mains synchronization. The frequency andphase deviations, due to the frequency droop, makeimpracticable this method to a parallel-connectedonline UPS system, in which every UPS should becontinuously synchronized to the public ac supply.1)3)111. PROPOSED CONTROL FOR PARALLEL ONLINE UPSINVERTERSIn this work, we will try to overcome the above limitationsand to synthesize a novel control strategy withoutcommunication wires that could be appropriate to highperformanceparalleled industrial UPS. The objective is toconnect online UPS inverters in parallel without usingcontrol interconnections. This kind of systems, also namedinverter-preferred, should be continuously synchronized tothe utility line. When an overload or an inverter failureoccurs, a static bypass switch may connect the input line tothe load, bypassing the inve:rter [14][15].Fig. 3 shows the general diagram of a distributed onlineUPS system. This system consists of two buses: the utilitybus, which is connected lo the public ac mains; and thesecure bus, connected to the distributed critical loads. Theinterface between these buses is based on a number of onlineUPS modules connected in parallel, which providescontinuously power to the: loads [16]. The UPS modulesinclude a rectifier, a set of batteries, an inverter, and a staticbypass switch.11638Q ac mainsutility busI I Ij distributed loads !Fig. 3. Online distributed UPS system.syposr /I 4(4Fig. 4. Operation modes of an online UPS.(a) Normal operation. (b) Bypass operation. (c) Mains failureThe main operation modes of a distributed online UPS1) Normal operation: The power flows to the load, fromthe utility through the distributed UPS units.2) Mains failure: When the public ac mains fails, theUPS inverters supply the power to the loads, from thebatteries, without disruption.Bypass operation: When an overload situation occurs,the bypass switch must connect the critical busdirectly to the ac mains, in order to guarantee thecontinuous supply of the loads, avoiding the damageof the UPS modules.For this reason, the output-voltage waveform should besynchronized to the mains, when this last is present.system are listed below (see Fig. 5):3)Nevertheless, as we state before, the conventional droopmethod can not satisfy the need for synchronization with theutility, due to the frequency variation of the inverters, whichprovokes a phase deviation.To obtain the required performance, we present a transientP-w droop without frequency-deviation in steady-state,proposed previously by OUT in [ 111w=o -mP (5)where is the active power signal without the dccomponent,which is done by. -I t -1sP= p ,( s + t - ' ) ( s + o , )being zthe time constant of the transient droop action.The transient droop function ensures a stable frequencyregulation under steady-state conditions, and 'at the sametime, achieves active power balance by adjusting thefrequency of the modules during a load transient. Besides, toadjust the phase of the modules we propose an additionalsynchronizing loop, yieldingo=w'-m%k,A$, (7)where A$ is the phase difference between the inverter and themains; and k, is the proportional constant of the frequencyadjust. The steady-state frequency reference w* can beobtained by measuring the utility line frequency.The second term of the previous equality trends to zero insteady state, leading tow = w' - k4($ -@'), (8)being $and $* the phase angles of the output voltage inverterand the utility mains, respectively.Taking into account that w = d $ / d t , we can obtain thenext differential equation, which is stable fork, positived$ *dt dt- + km$ = - + k,$' . (9)Thus, when phase difference increases, frequency willdecrease slightly and, hence, all :he UPS modules will besynchronized with the utility, while sharing the power drawnto the loads.IV. CONTROLLIEMRP LEMENTATIONFig. 5 depicts the block diagram of the proposedcontroller. The average active power P , without the dccomponent, can be obtained by means of multiplying theoutput voltage by the output current, and filtering the product........................................................................................io",.LSj'nchronirorion loop.......................................................................................Fig. 5. Block diagram of the proposed controller.using a band-pass filter. In a similar way, the averagereactive power is obtained, hut in this case the output-voltagemust be delayed 90 degrees, and using a low-pass filter.In order to adjust the output voltage frequency, equation(7) is implemented, which corresponds to the frequencymains drooped by two transient-terms: the transient activepower signal term; and the phase difference term, whichis added in order to synchronize the output voltage with theac mains, in a phase-locked loop (PLL) fashion. The outputvoltageamplitude is regulated by using the conventionaldroop method (4).Finally, the physical coupled inductance can be avoided byusing a virtual inductor [17]. This concept consists inemulated an inductance behavior, by drooping the outputvoltage proportionally to the time derivative of the outputcurrent. However, when supplying nonlinear loads, the highordercurrent-harmonics can increase too much the outputvoltageTHD. This can be easily solved by using a high-passfilter instead of a pure-derivative term of the output current,which is useful to share linear and nonlinear loads [I 1][12].Furthermore, the proper design of this output inductance canreduce, to a large extent, the unbalance line-impedanceimpact over the power sharing accuracy.v. SIMULATION AND EXPERIMENTARELS ULTSThe proposed control scheme, (4) and (7), was simulatedwith the parameters listed in Table 1 and the scheme shownin Fig. 6, for a two paralleled inverters system. Thecoefficients m, n, T, and kv were chosen to ensure stability,proper transient response and good phase matching. Fig. 7shows the waveforms of the frequency, circulating currents,phase difference between the modules and the utility line,and the evolution of the active and reactive powers. Note theexcellent synchronization between the modules and theACmiiinr 4 j. ...L...I.P...S...1... ..........................B...u...n...r.r..r..e..s... ................................... iFig. 6. Parallel operation oftwa online UPS modules,mains, and, at the same time, the good power sharingobtained. This characteristik let us to apply the controller tothe online UPS paralleled systems.Two I-kVA UPS modules were built and tested in order toshow the validity of the proposed approach. Each UPSinverter consisted of a single-phase IGBT full-bridge with aswitching frequency of 20 kHz and an LC output filter, withthe following parameters: 1. = 1 mH, C = 20 WF, Vi" = 400V,v, = 220 V, I50 Hz. The controllers of these inverters werebased on three loops: an inner current-loop, an outer PIcontroller that ensures voltage regulation, and the loadsharingcontroller, based on (4) and (7). The last controllerwas implemented by means of a TMS320LF2407A, fixedpoint40 MHz digital sigrial processor (DSP) from TexasInstruments (see Fig. 8), using the parameters listed in TableI. The DSP-controller also includes a PLL block in order tosynchronize the inverter with the common bus. When thisoccurs, the static bypass switch is tumed on, and the droopbasedcontrol is initiated.1640big 7 Wa\cfc)rms for twu.invencr, ;mnectcd in parallel. rpchrontred io Ihc ac mdnl.(a) Frequencics ufhoth UPS (b) Clrculattng currcni among modulcs. (CJ Phmc d!Nercn;: betucen ihc UPS a#>dth e ai mum(d) Ikiril uf the phze diNmncc (e) md (0 Activc and rcactlw pouerr "I ooih UPSNote that the iimc-acs arc deliheratcly JiNercni due in thc disiinct timuion*uni) ofthe \ inrblrr1641TABLEI.PARAMETEROSF THE PARALLELESDYS TEM.Filter Order I IFilter Cut-off Frequency I 0, I 10 I ragsFig. 8 shows the output-current transient response of theUPS inverters. First, the two UPS are operating in parallelwithout load. Notice that a small reactive current is circlingbetween the modules, due to the measurement mismatches.Then, a nonlinear load, with a crest factor of 3, is connectedsuddenly. This result shows the good dynamics and loadsharingof the paralleled system when sharing a nonlinearload.Fig. 8. Output current for the two paralleled UPS, during the connection of Bcommon nonlinear load with a crest factor of 3. (Axis-x: 20 mddiv. Axis-y:5 Mdiv.).VI. CONCLUSIONSIn this paper, a novel load-sharing controller for parallelconnectedonline UPS systems, was proposed. The controlleris based on the droop method, which avoids the use ofcontrol interconnections. In a sharp contrast with theconventional droop method, the controller presented is ableto keep the output-voltage frequency and phase strictlysynchronized with the utility ac mains, while maintaininggood load sharing for linear and nonlinear loads. This fact letus to extend the droop method to paralleled online UPS.On the other hand, the proposed controller emulates aspecial kind of impedance, avoiding the use of a physicalcoupled inductance. Th.e results reported here show theeffectiveness of the proposed approach.
我有一篇我本科毕设的小论文，英文中文都有，而且是我人工翻译的，8000字左右。你要的话PM我。我是电气工程及其自动化专业的。《Analysis of thyristor-controlled phase shifter applied in damping power system oscillations》
通信工程发表英文论文
基于WIN CE的ADSL线路参数研究ADSL line parameters research based on WIN CE CE (also known officially as Windows Embedded CE since version 6.0[2][3], and sometimes abbreviated WinCE) is a variation of Microsoft's Windows operating system for minimalistic computers and embedded systems. Windows CE is a distinctly different kernel, rather than a trimmed-down version of desktop Windows. It is not to be confused with Windows XP Embedded which is NT-based. It is supported on Intel x86 and compatibles, MIPS, ARM, and Hitachi SuperH processors.FeaturesWindows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of memory. Devices are often configured without disk storage, and may be configured as a “closed” system that does not allow for end-user extension (for instance, it can be burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. It supports 256 priority levels and uses priority inheritance for dealing with priority inversion. The fundamental unit of execution is the thread. This helps to simplify the interface and improve execution time.Microsoft has stated that the ‘CE’ is not an intentional initialism, but many people believe CE stands for ‘Consumer Electronics’ or ‘Compact Edition’; users often disparagingly called it “Wince”.[4] Microsoft says it implies a number of Windows CE design precepts, including “Compact, Connectable, Compatible, Companion, and Efficient.”[5] The first version, known during development under the codename “Pegasus”, featured a Windows-like GUI and a number of Microsoft's popular applications, all trimmed down for smaller storage, memory, and speed of the palmtops of the day.Since then, Windows CE has evolved into a component-based, embedded, real-time operating system. It is no longer targeted solely at hand-held computers. Many platforms have been based on the core Windows CE operating system, including Microsoft's AutoPC, Pocket PC 2000, Pocket PC 2002, Windows Mobile 2003, Windows Mobile 2003 SE, Windows Mobile 5.0, Windows Mobile 6, Smartphone 2002, Smartphone 2003 and many industrial devices and embedded systems. Windows CE even powered select games for the Sega Dreamcast, was the operating system of the controversial Gizmondo handheld, and can partially run on modified Microsoft Xbox game consoles.A distinctive feature of Windows CE compared to other Microsoft operating systems is that large parts of it are offered in source code form. First, source code was offered to several vendors, so they could adjust it to their hardware. Then products like Platform Builder (an integrated environment for Windows CE OS image creation and integration, or customized operating system designs based on CE) offered several components in source code form to the general public. However, a number of core components that do not need adaptation to specific hardware environments (other than the CPU family) are still distributed in binary form only.Development toolsVisual StudioLate versions of Microsoft Visual Studio support projects for Windows CE / Windows Mobile, producing executable programs and platform images either as an emulator or attached by cable to an actual mobile device. A mobile device is not necessary to develop a CE program. The .NET Compact Framework supports a subset of the .NET Framework with projects in C# and VB.NET, but not Managed C++.Platform BuilderThis programming tool is used for building the platform (BSP + Kernel), device drivers (shared source or custom made) and also the application. This is a one step environment to get the system up and running. One can also use Platform Builder to export an SDK (standard development kit) for the target microprocessor (SuperH, x86, MIPS, ARM etc.) to be used with another associated tool set named below.Embedded Visual C++ (eVC)The Embedded Visual C++ tool is for development of embedded application for Windows CE based devices. This tool can be used standalone using the SDK exported from Platform Builder or using the Platform Builder using the Platform Manager connectivity setup.Relationship to Windows Mobile, Pocket PC, and SmartPhoneOften Windows CE, Windows Mobile, and Pocket PC are used interchangeably. This practice is not entirely accurate. Windows CE is a modular/componentized operating system that serves as the foundation of several classes of devices. Some of these modules provide subsets of other components' features (e.g. varying levels of windowing support; DCOM vs COM), others which are mutually exclusive (Bitmap or TrueType font support), and others which add additional features to another component. One can buy a kit (the Platform Builder) which contains all these components and the tools with which to develop a custom platform. Applications such as Excel Mobile/Pocket Excel are not part of this kit. The older Handheld PC version of Pocket Word and several other older applications are included as samples, however.Windows Mobile is best described as a subset of platforms based on a Windows CE underpinning. Currently, Pocket PC (now called Windows Mobile Classic), SmartPhone (Windows Mobile Standard), and PocketPC Phone Edition (Windows Mobile Professional) are the three main platforms under the Windows Mobile umbrella. Each platform utilizes different components of Windows CE, as well as supplemental features and applications suited for their respective devices.Pocket PC and Windows Mobile is a Microsoft-defined custom platform for general PDA use, and consists of a Microsoft-defined set of minimum profiles (Professional Edition, Premium Edition) of software and hardware that is supported. The rules for manufacturing a Pocket PC device are stricter than those for producing a custom Windows CE-based platform. The defining characteristics of the Pocket PC are the digitizer as the primary Human Interface Device and its extremely portable size.The SmartPhone platform is a feature rich OS and interface for cellular phone handsets. SmartPhone offers productivity features to business users, such as email, as well as multimedia capabilities for consumers. The SmartPhone interface relies heavily on joystick navigation and PhonePad input. Devices running SmartPhone do not include a touchscreen interface. SmartPhone devices generally resemble other cellular handset form factors, whereas most Phone Edition devices use a PDA form factor with a larger display.Windows Mobile 5 supports USB 2.0 and new devices running this OS will also conform to the USB Mass Storage Class, meaning the storage on PPC can be accessed from any USB-equipped PC, without requiring any extra software, except requiring a compliant host. In other words, you can use it as a flash drive.Competing productsCompetitors to consumer CE based PDA platforms like Pocket PC – the main application of Windows CE – are Java, Symbian OS, Palm OS, iPhone OS and Linux based packages like Qtopia Embedded Linux environment from Trolltech, Convergent Linux Platform from a La Mobile, and Access Linux Platform from Orange and Access.The secondary usage of CE is in devices in need of graphical user interfaces, (point of sale terminals, media centers, web tablets, thin clients) as the main selling point CE is the look and feel being similar to desktop Windows. The competition is Windows XP, Linux and graphical packages for simpler embedded operating systems.Being an RTOS, Windows CE is also theoretically a competitor to any realtime operating system in the embedded space, like VxWorks, ITRON or eCos. The dominating method, however, of mixing Windows look and feel with realtime on the same hardware, is to run double operating systems using some virtualization technology, like TRANGO Hypervisor from TRANGO Virtual Processors or Intime from TenAsys in the case of Windows, and OS Ware from VirtualLogix, Padded Cell from Green Hills Software, OKL4 from Open Kernel Labs, TRANGO Hypervisor from TRANGO Virtual Processors, RTS Hypervisor from Real-Time Systems or PikeOS from Sysgo, in case of the competition.---------Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call. A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same time. Because phone lines vary in quality and were not originally engineered with DSL in mind, it can generally only be used over short distances, typically less than 3mi (5.5 km) [William Stallings' book].At the telephone exchange the line generally terminates at a DSLAM where another frequency splitter separates the voice band signal for the conventional phone network. Data carried by the ADSL is typically routed over the telephone company's data network and eventually reaches a conventional internet network. In the UK under British Telecom the data network in question is its ATM network which in turn sends it to its IP network IP Colossus.The distinguishing characteristic of ADSL over other forms of DSL is that the volume of data flow is greater in one direction than the other, i.e. it is asymmetric. Providers usually market ADSL as a service for consumers to connect to the Internet in a relatively passive mode: able to use the higher speed direction for the "download" from the Internet but not needing to run servers that would require high speed in the other direction.There are both technical and marketing reasons why ADSL is in many places the most common type offered to home users. On the technical side, there is likely to be more crosstalk from other circuits at the DSLAM end (where the wires from many local loops are close to each other) than at the customer premises. Thus the upload signal is weakest at the noisiest part of the local loop, while the download signal is strongest at the noisiest part of the local loop. It therefore makes technical sense to have the DSLAM transmit at a higher bit rate than does the modem on the customer end. Since the typical home user in fact does prefer a higher download speed, the telephone companies chose to make a virtue out of necessity, hence ADSL. On the marketing side, limiting upload speeds limits the attractiveness of this service to business customers, often causing them to purchase higher cost Digital Signal 1 services instead. In this fashion, it segments the digital communications market between business and home usersHow ADSL worksOn the wireCurrently, most ADSL communication is full duplex. Full duplex ADSL communication is usually achieved on a wire pair by either frequency division duplex (FDD), echo canceling duplex (ECD), or time division duplexing (TDD). FDM uses two separate frequency bands, referred to as the upstream and downstream bands. The upstream band is used for communication from the end user to the telephone central office. The downstream band is used for communicating from the central office to the end user. With standard ADSL (annex A), the band from 25.875 kHz to 138 kHz is used for upstream communication, while 138 kHz – 1104 kHz is used for downstream communication. Each of these is further divided into smaller frequency channels of 4.3125 kHz. During initial training, the ADSL modem tests which of the available channels have an acceptable signal-to-noise ratio. The distance from the telephone exchange, noise on the copper wire, or interference from AM radio stations may introduce errors on some frequencies. By keeping the channels small, a high error rate on one frequency thus need not render the line unusable: the channel will not be used, merely resulting in reduced throughput on an otherwise functional ADSL connection.Vendors may support usage of higher frequencies as a proprietary extension to the standard. However, this requires matching vendor-supplied equipment on both ends of the line, and will likely result in crosstalk issues that affect other lines in the same bundle.There is a direct relationship between the number of channels available and the throughput capacity of the ADSL connection. The exact data capacity per channel depends on the modulation method used.[edit] ModulationADSL initially existed in two flavours (similar to VDSL), namely CAP and DMT. CAP was the de facto standard for ADSL deployments up until 1996, deployed in 90 percent of ADSL installs at the time. However, DMT was chosen for the first ITU-T ADSL standards, G.992.1 and G.992.2 (also called G.dmt and G.lite respectively). Therefore all modern installations of ADSL are based on the DMT modulation scheme.Annexes J and M shift the upstream/downstream frequency split up to 276 kHz (from 138 kHz used in the commonly deployed annex A) in order to boost upstream rates. Additionally, the "all-digital-loop" variants of ADSL2 and ADSL2+ (annexes I and J) support an extra 256 kbit/s of upstream if the bandwidth normally used for POTS voice calls is allocated for ADSL usage.While the ADSL access utilizes the 1.1 MHz band, ADSL2+ utilizes the 2.2 MHz band.The downstream and upstream rates displayed are theoretical maxima. Note also that because Digital subscriber line access multiplexers and ADSL modems may have been implemented based on differing or incomplete standards some manufacturers may advertise different speeds. For example, Ericsson has several devices that support non-standard upstream speeds of up to 2 Mbit/s in ADSL2 and ADSL2+.[edit] Installation issuesDue to the way it uses the frequency spectrum, ADSL deployment presents some issues. It is necessary to install appropriate frequency filters at the customer's premises, to avoid interferences with the voice service, while at the same time taking care to keep a clean signal level for the ADSL connection.In the early days of DSL, installation required a technician to visit the premises. A splitter was installed near the demarcation point, from which a dedicated data line was installed. This way, the DSL signal is separated earlier and is not attenuated inside the customer premises. However, this procedure is costly, and also caused problems with customers complaining about having to wait for the technician to perform the installation. As a result, many DSL vendors started offering a self-install option, in which they ship equipment and instructions to the customer. Instead of separating the DSL signal at the demarcation point, the opposite is done: the DSL signal is "filtered off" at each phone outlet by use of a low pass filter, also known as microfilter. This method does not require any rewiring inside the customer premises.A side effect of the move to the self-install model is that the DSL signal can be degraded, especially if more than 5 voiceband devices are connected to the line. The DSL signal is now present on all telephone wiring in the building, causing attenuation and echo. A way to circumvent this is to go back to the original model, and install one filter upstream from all telephone jacks in the building, except for the jack to which the DSL modem will be connected. Since this requires wiring changes by the customer and may not work on some household telephone wiring, it is rarely done. It is usually much easier to install filters at each telephone jack that is in use.
可以投稿到《电子设计工程》科技核心期刊 很容易 交钱就能发的那种
论文发表的方法是：选定想要发表的论文期刊，找到该期刊的投稿方式并投稿，部分期刊要求书面形式投稿，大部分是采用电子稿件形式。在审稿通过以后即可将论文发表在期刊上。
普通刊物（省级、国家级）审核时间为一周，高质量的杂志，审核时间为14-20天。核心期刊审核时间一般为4个月，须经过初审、复审、终审三道程序。
国家没有对期刊进行级别划分。但各单位一般根据期刊的主管单位的级别来对期刊划为省级期刊和国家级期刊。省级期刊主管单位是省级单位。国家级期刊主管单位是国家部门或直属部门。
扩展资料：
发表论文的作用：
1、评职称；研究生毕业需要；教师、医护人员、科研院所的人员、企业员工等晋升高一级的职称时，发表期刊论文是作为一项必须的参考指标。
2、申报基金、课题：教育、科技、卫生系统每年申报的国家自然科学基金项目、其它各种基金项目、各种研究课题时，发表论文是作为基金或课题完成的一种研究成果的结论性展示。
3、世界性基础领域的研究，比如在医学、数学、物理、化学、生命科学等领域开展的基础性研究，公开发表论文是对最新科技科学研究成果、研究方法的一种展示和报道。以推动整个社会的科技进步等。
参考资料来源：百度百科—论文