【正文】 n the air obstacles on his wayto return immediately the ultrasonic reflected wave received by the receiver immediatelystop the in the air as the propagation velocity of 340m / s according tothe timer records the time t we can calculate the distance between the launch distancebarrier s that is: s 340t / Ranging System for the Second Circuit Design ‐8‐ 畢業(yè)設(shè)計(jì)（論文）英文翻譯 System is characterized by singlechip microputer to control the use of ultrasonictransmitter and ultrasonic receiver since the launch from time to time singlechip selectionof 8751 economictouse and the chip has 4K of ROM to facilitate diagram shown in Figure 1 circuit principle diagram ‐9‐ 畢業(yè)設(shè)計(jì)（論文） 40 kHz ultrasonic pulse generated with the launch Ranging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40its operating voltage of the pulse signal is 40kHz which by the singlechip implementationof the following procedures to : mov 14h 12h ultrasonic firing continued 200mshere: cpl output 40kHz square wave nop nop nop djnz 14h here ret Ranging in front of singlechip termination circuit input port single chipimplementation of the above procedure the port in a 40kHz pulse output signal afteramplification transistor T the drive to launch the first ultrasonic UCM40T issued 40kHzultrasonic pulse and the continued launch of the right and the left side ofthe circuit respectively then input port and the working principle and circuit infront of the same Reception and processing of ultrasonic Used to receive the first launch of the first pair UCM40R the ultrasonic pulsemodulation signal into an alternating voltage the opamp amplification IC1A and afterpolarization IC1B to is locked loop with audio decoder chip LM567 internalvoltagecontrolled oscillator center frequency of f0 1/ capacitor C4 determinetheir target in the launch of the carrier frequency on theLM567 input signal is greater than 25mV the output from the high jump 8 feet into alowlevel as interrupt request signals to the singlechip in front of singlechip termination circuit output port INT0 interrupt thehighest priority right or left location of the output circuit with output gate IC3A accessINT1 port singlechip while singlechip and received input IC3A interrupted ‐10‐ 畢業(yè)設(shè)計(jì)（論文）英文翻譯by the process to identify the source of inquiry to deal with interrupt priority level for thefirst left right of the source code is as follows:receive1: push psw push acc clr ex1 related external interrupt 1 jnb right pin to 0 ranging from right to interrupt serviceroutine circuit jnb left pin to 0 to the left ranging circuit interruptservice routinereturn: SETB EX1 open external interrupt 1 pop acc pop psw retiright:...right location entrance circuit interrupt service routine Ajmp Returnleft:...left Ranging entrance circuit interrupt service routine Ajmp The calculation of ultrasonic propagation time When you start firing at the same time start the singlechip circuitry within the timerT0 the use of timer counting function records the time and the launch of ultrasonicreflected wave received you receive the ultrasonic reflected wave the receivercircuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates asignal singlechip microputer in response to external interrupt request theimplementation of the external interrupt service subroutine read the time differencecalculating the of its source code is as follows:RECEIVE0: PUSH PSW PUSH ACC CLR EX0 related external interrupt 0.第三篇：食品安全外文文獻(xiàn)翻譯(適用于畢業(yè)論文外文翻譯+中英文對照)w 論食品供應(yīng)鏈管理和食品質(zhì)量安全上世紀(jì)90年代以來,供應(yīng)鏈管理已成為學(xué)術(shù)界和實(shí)業(yè)界關(guān)注的熱門話題,特別是供應(yīng)鏈管理成功地應(yīng)用于IBM、Pamp。因此，它不僅可用于移動(dòng)機(jī)器人，還可用在其它檢測系統(tǒng)中。結(jié)論 對所要求測量范圍 30cm200cm 內(nèi)的平面物體做了多次測量發(fā)現(xiàn)，且重復(fù)性好。主程序完成初始化工作、各路超聲波發(fā)射和接收順序的控制。第六步：通過公式計(jì)算距離 y。測量過零時(shí)間與回波的振幅。根據(jù)第二部的數(shù)據(jù)設(shè)定時(shí)間窗。第四步：設(shè)置回波放大器的所得來規(guī)格輸出，假定是 3 伏。第二步：根據(jù)公式改變回波放大器的獲得量直到回?fù)鼙粰z測到。其部分源程序如下：RECEIVE0： PUSH PSW PUSH ACC CLR EX0 ； 關(guān)外部中斷 0 MOV R7 TH0 ； 讀取時(shí)間值 MOV R6 TL0 CLR C MOV A R6 SUBB A 0BBH； 計(jì)算時(shí)間差 MOV 31H A ； 存儲(chǔ)結(jié)果 MOV A R7 SUBB A 3CH MOV 30H A SETB EX0 ； 開外部中斷 0 POP ACC ‐4‐ 畢業(yè)設(shè)計(jì)（論文）英文翻譯 POP PSW RETI對于一個(gè)平坦的目標(biāo)，距離測量包括兩個(gè)階段:粗糙的測量和精細(xì)測量。部分源程序如下：receive1：push psw push acc clr ex1； 關(guān)外部中斷 1 jnb ； 引腳為 0轉(zhuǎn)至右測距電路中斷服務(wù)程序 ‐3‐ 畢業(yè)設(shè)計(jì)（論文）英文翻譯 jnb ； 引腳為 0轉(zhuǎn)至左測距電路中斷服務(wù)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(wù)程序入口 ajmp returnleft：...； 左測距電路中斷服務(wù)程序入口 ajmp 計(jì)算超聲波傳播時(shí)間 在啟動(dòng)發(fā)射電路的同時(shí)啟動(dòng)單片機(jī)內(nèi)部的定時(shí)器 T0，利用定時(shí)器的計(jì)數(shù)功能記錄超聲波發(fā)射的時(shí)間和收到反射波的時(shí)間。是帶有鎖 定環(huán)的音頻譯碼集成塊LM567，內(nèi)部的壓控振蕩器的中心頻率 f01/，電容 C4 決定其鎖定帶寬。右側(cè)和左側(cè)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。‐1‐畢業(yè)設(shè)計(jì)（論文）英文翻譯 圖 1 電路原理圖 ‐2‐ 畢業(yè)設(shè)計(jì)（論文） 40kHz 脈沖的產(chǎn)生與超聲波發(fā)射 測距系統(tǒng)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(hào)，這由單片機(jī)執(zhí)行下面程序來產(chǎn)生。超聲波在空氣中的傳播速度為 340m/s，根據(jù)計(jì)時(shí)器記錄的時(shí)間 t，就可以計(jì)算出發(fā)射點(diǎn)距障礙物的距離s，即：s340t/2超聲波測距系統(tǒng)的電路設(shè)計(jì) 系統(tǒng)的特點(diǎn)是利用單片機(jī)控制超聲波的發(fā)射和對超聲波自發(fā)射至接收往返時(shí)間的計(jì)時(shí)，單片機(jī)選用 C51，經(jīng)濟(jì)易用，且片內(nèi)有 4K 的 ROM，便于編程。強(qiáng)度較強(qiáng)的脈沖會(huì)比強(qiáng)度較弱的脈沖超過界限的時(shí)間早點(diǎn)，因此我們會(huì)認(rèn)為強(qiáng)度較強(qiáng)的脈沖屬于較近的物體。進(jìn)一步說，從脈沖起始點(diǎn)到剛好超過界限之間的時(shí)間段隨著脈沖的強(qiáng)度而改變。這個(gè)界限恰恰選于噪音水平之上，然而脈沖到達(dá)時(shí)間被定義為脈沖信號(hào)剛好超過界限的第一時(shí)刻。反之，如果兩電極間未外加電壓，當(dāng)共振板接收到超聲波 時(shí)，將壓迫壓電晶片作振動(dòng)，將機(jī)械能轉(zhuǎn)換為電信號(hào)，這時(shí)它就成為超聲波接收器了。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)，它有兩個(gè)壓電晶片和一個(gè)共振板。因此，設(shè)計(jì)好的超聲波測距儀就顯得非常重要了。而設(shè)計(jì)研制箱涵排水疏通移動(dòng)機(jī)器人的自動(dòng)控制系統(tǒng)，保證機(jī)器人在箱涵中自由排污疏通，是箱涵排污疏通機(jī)器人的設(shè)計(jì)研制的核心部分。因此，經(jīng)常出現(xiàn)開挖已經(jīng)建設(shè)好的建筑設(shè)施來改造排水系統(tǒng)的現(xiàn)象。關(guān)鍵詞：超聲波，測距儀，單片機(jī)前言 隨著科技的發(fā)展，人們生活水平的提高，城市發(fā)展建設(shè)加快，城市給排水系統(tǒng)也有較大發(fā)展，其狀況不斷改善。因此，深入研究超聲的測距理論和方法具有重要的實(shí)踐意義。stone, used for lithography。llerBrockmann, who designed posters in a severe yet accessible manner typical of the 1950s and 1960s From road signs to technical schematics, from interoffice memorandums to reference manuals, graphic design enhances transfer of is enhanced by improving the visual presentation of can also aid in selling a product or idea through effective visual is applied to products and elements of pany identity like logos, colors, and these are defined as branding(see also advertising).Branding has increasingly bee important in the range of services offered by many graphic designers, alongside corporate identity, and the terms are often used are designed to present subjects such as geography, science, and publications have layouts which illustrate theories and mon example of graphics in use to educate is diagrams of