中英文對照資料外文翻譯文獻(編輯修改稿)

　

【文章內容簡介】 er items screenprinted for scientific journals to news reporting, the presentation of opinion and facts is often improved with graphics and thoughtful positions of visual informationknown as information , magazines, blogs, television and film documentaries may use graphic design to inform and the advent of the web, information designers with experience in interactive tools such as Adobe Flash are increasingly being used to illustrate the background to news graphic design project may involve the stylization and presentation of existing text and either preexisting imagery or images developed by the graphic example, a newspaper story begins with the journalists and photojournalists and then bees the graphic designer39。s job to organize the page into a reasonable layout and determine if any other graphic elements should be a magazine article or advertisement, often the graphic designer or art director will mission photographers or illustrators to create original pieces just to be incorporated into the design design practice has been extended to the modern puter, for example in the use of WYSIWYG user interfaces, often referred to as interactive design, or multimedia any graphic elements may be applied to a design, the graphic elements must be originated by means of visual art graphics are often(but not always)developed 4 by a graphic arts include works which are primarily visual in nature using anything from traditional media, to photography or puter generated design principles may be applied to each graphic art element individually as well as to the final is the art, craft and techniques of type design, modifying type glyphs, and arranging glyphs(characters)are created and modified using a variety of illustration arrangement of type is the selection of typefaces, point size, line length, leading(line spacing)and letter is performed by typesetters, positors, typographers, graphic artists, art directors, and clerical the Digital Age, typography was a specialized opened up typography to new generations of visual designers and lay layout is the part of graphic design that deals in the arrangement and style treatment of elements(content)on a from early illuminated pages in handcopied books of the Middle Ages and proceeding down to intricate modern magazine and catalog layouts, proper page design has long been a consideration in printed print media, elements usually consist of type(text), images(pictures), and occasionally placeholder graphics for elements that are not printed with ink such as die/laser cutting, foil stamping or blind designers are often involved in interface design, such as web design and software design when end user interactivity is a design consideration of the layout or visual munication skills with the interactive munication skills of user interaction and online branding, graphic designers often work with software developers and web developers to create both the look and feel of a web site or software application and enhance the interactive experience of the user or web site is the process of making artworks by printing on paper and other materials or in the case of monotyping, the process is capable of producing multiples of the same piece, which is called a piece is not a copy but an original since it is not a reproduction of another work of art and is technically known as an or drawing, on the other hand, create a unique original piece of are created from a single original surface, known technically as a types of matrices include: plates of metal, usually copper or zinc for engraving or etching。stone, used for lithography。blocks of wood for woodcuts, linoleum for linocuts and fabric plates for there are many other kinds, discussed printed from a single第二篇：超聲波測距畢業論文中英文對照資料外文翻譯文獻超聲波測距畢業論文中英文對照資料外文翻譯文獻超聲波測距 中英文對照資料外文翻譯 超聲測距系統設計 原文出處：傳感器文摘 布拉福德:1993年 第13頁摘要：超聲測距技術在工業現場、車輛導航、水聲工程等領域都具有廣泛的應用價值，目前已應用于物位測量、機器人自動導航以及空氣中與水下的目標探測、識別、定位等場合。因此，深入研究超聲的測距理論和方法具有重要的實踐意義。為了進一步提高測距的精確度，滿足工程人員對測量精度、測距量程和測距儀使用的要求，本文研制了一套基于單片機的便攜式超聲測距系統。關鍵詞：超聲波，測距儀，單片機前言 隨著科技的發展，人們生活水平的提高，城市發展建設加快，城市給排水系統也有較大發展，其狀況不斷改善。但是，由于歷史原因合成時間住的許多不可預見因素，城市給排水系統，特別是排水系統往往落后于城市建設。因此，經常出現開挖已經建設好的建筑設施來改造排水系統的現象。城市污水給人們帶來了困擾，因此箱涵的排污疏通對大城市給排水系統污水處理，人們生活舒適顯得非常重要。而設計研制箱涵排水疏通移動機器人的自動控制系統，保證機器人在箱涵中自由排污疏通，是箱涵排污疏通機器人的設計研制的核心部分?？刂葡到y核心部分就是超聲波測距儀的研制。因此，設計好的超聲波測距儀就顯得非常重要了。 壓電式超聲波發生器原理 畢業設計（論文）英文翻譯 壓電式超聲波發生器實際上是利用壓電晶體的諧振來工作的。超聲波發生器內部結構，它有兩個壓電晶片和一個共振板。當它的兩極外加脈沖信號，其頻率等于壓電晶片的固有振蕩頻率時，壓電晶片將會發生共振，并帶動共振板振動，便產生超聲波。反之，如果兩電極間未外加電壓，當共振板接收到超聲波 時，將壓迫壓電晶片作振動，將機械能轉換為電信號，這時它就成為超聲波接收器了。測量脈沖到達時間的傳統方法是以擁有固定參數的接收信號開端為基礎的。這個界限恰恰選于噪音水平之上，然而脈沖到達時間被定義為脈沖信號剛好超過界限的第一時刻。一個物體的脈沖強度很大程度上取決于這個物體的自然屬性尺寸還有它與傳感器的距離。進一步說，從脈沖起始點到剛好超過界限之間的時間段隨著脈沖的強度而改變。結果，一種錯誤便出現了——兩個擁有不同強度的脈沖在不同時間超過界限卻在同一時間到達。強度較強的脈沖會比強度較弱的脈沖超過界限的時間早點，因此我們會認為強度較強的脈沖屬于較近的物體。 超聲波測距原理 超聲波發射器向某一方向發射超聲波，在發射時刻的同時開始計時，超聲波在空氣中傳播，途中碰到障礙物就立即返回來，超聲波接收器收到反射波就立即停止計時。超聲波在空氣中的傳播速度為 340m/s，根據計時器記錄的時間 t，就可以計算出發射點距障礙物的距離s，即：s340t/2超聲波測距系統的電路設計 系統的特點是利用單片機控制超聲波的發射和對超聲波自發射至接收往返時間的計時，單片機選用 C51，經濟易用，且片內有 4K 的 ROM，便于編程。電路原理圖如圖 1 所示。‐1‐畢業設計（論文）英文翻譯 圖 1 電路原理圖 ‐2‐ 畢業設計（論文） 40kHz 脈沖的產生與超聲波發射 測距系統中的超聲波傳感器采用 UCM40 的壓電陶瓷傳感器，它的工作電壓是40kHz 的脈沖信號，這由單片機執行下面程序來產生。puzel： mov 14h 12h；超聲波發射持續 200mshere： cpl ； 輸出 40kHz 方波 nop ； nop ； nop ； djnz 14h，here； ret 前方測距電路的輸入端接單片機 端口，單片機執行上面的程序后，在 40kHz 的脈沖信號，經過三極管 T 放大，驅動超聲波發射頭 UCM40T，發出 40kHz 的脈沖超聲波，且持續發射 200ms。右側和左側測 距電路的輸入端分別接 和 端口，工作原理與前方測距電路相同。 超聲波的接收與處理 接收頭采用與發射頭配對的 UCM40R，將超聲波調制脈沖變為交變電壓信號，經 IC2運算放大器 IC1A 和 IC1B 兩極放大后加至 IC2。是帶有鎖 定環的音頻譯碼集成塊LM567，內部的壓控振蕩器的中心頻率 f01/，電容 C4 決定其鎖定帶寬。調節 R8 在發射的載頻上，則 LM567 輸入信號大于 25mV，輸出端 8 腳由高電平躍變為低電平，作為中斷請求信號， INT0 端口，中斷優先級最高，左、右測距電路的輸出通過與門 IC3A 的輸出接單片機 INT1 端口，同時單片機 和 接到 IC3A的輸入端，中斷源的識別由程序查詢來處理，中斷優先級為先右后左。部分源程序如下：receive1：push psw push acc clr ex1； 關外部中斷 1 jnb ； 引腳為 0轉至右測距電路中斷服務程序 ‐3‐ 畢業設計（論文）英文翻譯 jnb ； 引腳為 0轉至左測距電路中斷服務程序return： SETB EX1； 開外部中斷 1 pop acc pop psw retiright：...； 右測距電路中斷服務程序入口 ajmp returnleft：...； 左測距電路中斷服務程序入口 ajmp 計算超聲波傳播時間 在啟動發射電路的同時啟動單片機內部的定時器 T0，利用定時器的計數功能記錄超聲波發射的時間和收到反射波的時間。當收到超聲波反射波時，接收電路 輸出