【正文】 次開處理 的可能。其電路如圖 3． 11 所示： 檢波電路用 LM733CN 作為全波整流器件。芯片 LM733CN是一個具有兩路 獨立輸入、獨立輸出的寬頻帶圖像放大器。對高頻率噪聲有極好的抑制作用，極高的輸出穩(wěn)定性，非線性范圍小，寬頻帶 (0～ 120MHz)，鉗位輸入范圍寬 (士5． 0V)， 125mW 的低功耗， 200K． Q的高輸入阻抗。 30 第八章結(jié)論與展望 本課題借助脈沖反射式超聲波檢測的原理，融合電子技術(shù)、計算機技術(shù)、邏輯控制技術(shù)等，設(shè)計開發(fā)了一種智能化的超聲波脈沖反射檢測儀器。論文詳細介紹了該儀器的硬件結(jié)構(gòu)和 軟件設(shè)計思想，以及儀器的操作方法、功能實現(xiàn)過程?？朔嗽S多諸如 DC． DC電源不穩(wěn)定、超聲波激勵脈沖的脈寬與探頭不匹配，程控放大后信號失真嚴重、噪聲干擾大和邏輯器件 EPLD 的 I／ O端口信號影響液晶顯示的狀態(tài)檢測等一系列問題?；緦崿F(xiàn)了預定的各項基本功能。 31 8． 1 結(jié)論 (1)全數(shù)字化的設(shè)計方案和盡量采用軟件方法實現(xiàn)硬件功能的設(shè)計方法，大 大簡化了儀器的電路以及電子元氣件的數(shù)量。使得儀器具有體積小、重量輕、結(jié)構(gòu)簡單的特點。 (2)軟、硬件均采用的模塊化設(shè)計方案。這樣的方案 和方法，有利于各個擊 破，大大縮減了儀器的開發(fā)周期；模擬、數(shù)字信號系統(tǒng)的分離設(shè)計，很大程度上減少了相互之間的信號干擾，確保了儀器的穩(wěn)定性和可靠性。 (3)大量采用低噪聲、低漂移、高精度、高可靠性的集成電路芯片。應(yīng)用微 型計算機 MCU面向控制的設(shè)計功能、可編程邏輯器件 EPLD強大的實時處理能 力，使得儀器具有小型化、數(shù)字化、自動化、圖像化、便攜式，而且成本也不高等許多優(yōu)點。 (4)大屏幕的液晶顯示器模塊結(jié)合觸摸式功能鍵盤，以及儀器專用操作軟件實現(xiàn)的中文菜單化的操作界面。主菜單到子菜單的樹狀化操作功能步驟。使得儀器具有非常簡單，而且易于掌握的可視化操作界面、操作方法。 (5)程控的 DC． DC高頻開關(guān)電源模塊，分時響應(yīng)儀器的待機工作狀態(tài)和檢測 工作狀態(tài)，大大節(jié)約能源。再加上儀器中所有的芯片、電子元氣件均盡量采用了合適的速度要求、低功耗的器件。使得儀器的整體功耗低，使用時間長，特別是在室外檢測使用時，能大大提高電池的使用壽命。 32 8． 2 進一步的完善 當然，由于時間和本身技術(shù)水平所限，開發(fā)的儀器還存在一些不足，需要進 一步的完善： (1)超聲波檢測模塊中，接收通道對超聲信號的放大、濾波、噪聲抑制等 功 能還需進一步完善和提高。受 CPU的功能所限，儀器的數(shù)據(jù)處理能力還不夠， 對回波數(shù)據(jù)信息還沒有進一步的二次開發(fā)能力。 (2)軟件系統(tǒng)還需更加完善，軟件程序應(yīng)更簡潔。特別是菜單界面的操作功 能還要提高，要更加人性化、便于檢驗人員操作。 (3)儀器的數(shù)據(jù)存儲能力有限，只能存儲一定量的檢測結(jié)果。 33 參考文獻 [1]金長善，超聲工程 [M]，哈爾濱工業(yè)大學出版社， 1989． [2]王仲生萬小朋，無損檢測診斷現(xiàn)場實用技術(shù)，北京：機械工業(yè)出版社， 2022． [3]團體著者，超聲波 探傷及探傷儀， 1988 [4]全國無損檢測編寫組，超聲波探傷技術(shù)及探傷儀 [砌，國防工業(yè)出版社，1988 [5]鮑海鴻，基于 5l單片機超聲波測距器設(shè)計，中國礦業(yè)大學徐海學院， 2022 [6]馬劍民，金屬部件表面開口裂紋深度超聲測量，電力系統(tǒng)第九界無損檢測年會論文集 [7]李喜孟，無損檢測，北京：機械工業(yè)出版社， 2022 [8]尚志遠主編，檢測聲學原理及應(yīng)用，西北大學出版社， 1996 [9]嚴學華司乃潮，檢測技術(shù)與自動控制工程基礎(chǔ)，北京：化學工業(yè)出版社， 2022 [10]牛曉光郝紅衛(wèi)，李樹軍聚束超聲波探頭的研 制，河北電力試驗研究所 [11]SONIX， UT(Ultrasonic Testing)basic theory and operation， 2022 [12]National Semiconductor， DAC0830／ DAC0832 8． Bit 妒 Compatible，Double Buffered D to A Conveners， May 1999 [13]何希才，傳感器及其應(yīng)用電路 [M]，電子工業(yè)出版社， 2022 [14]張占松．開關(guān)電源的原理與設(shè)計 [M]，北京：電子工業(yè)出版社， 1999 [15]康華 光，電子技術(shù)基礎(chǔ)，北京：高等教育出版社， 1998 [16]劉書明劉斌，高性能模數(shù)與數(shù)模轉(zhuǎn)換器件，西安：西安電子科技大學出版 社 [17]高光天，模數(shù)轉(zhuǎn)換器應(yīng)用技術(shù)，北京：科學出版社， 2022 [18]陳嶺麗馮志華，檢測技術(shù)和系統(tǒng)，北京：清華大學出版社， 2022 [19]楊文龍，單片機原理及應(yīng)用，西安：西安電子科技大學出版社， 2022 [20]馮濤王程，可編程邏輯器件開發(fā)技術(shù) MAX+Plusll 入門與提高，北京：人民郵電出版社， 2022 [21]曾繁泰陳美金， VHDL程序設(shè)計，北京：清華大學出版社， 2022 [22]黃正謹徐堅等， CPLD系統(tǒng)設(shè)計技術(shù)入門與應(yīng)用，電子工業(yè)出版社， 2022 34 [23]祁欣于國良，超聲波 TR探頭的設(shè)計及應(yīng)用，北京：傳感器技術(shù)， 2022 [24]孫長柏，頻差式超聲波管道流量計 [J]工業(yè)儀表與自動化裝置， 1996[25]全國鍋爐壓力容器無損檢測人員資格考核委員會編寫，超聲波探傷，勞動 部鍋爐壓力容器安全雜志社， 1995 ag an employment tribunal clai Emloyment tribunals sort out disagreements between employers and employees. You may need to make a claim to an employment tribunal if: you 35 don39。t agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly. For more informu, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. ation about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept i. If you are worried about how the time limits apply to you If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。t charge you more than 35% of your pensation if you win the case. you39。re clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. The (lack of) air up there Cay man Islandsbased Webb, Watch m the head of Fifa39。s antiracism taskforce, is in London for the Football Association39。s 150th anniversary celebrations and will attend City39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Ya ya Toure, he told BBC Sport. For me it39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s 21 win. Michel Platini, president of European football39。s governing body, has also ordered an immediate investigation into the referee39。s actions. CSKA said they were surprised and disappointed by Toure39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。 May be 36 back in the past, to oneself the paranoid weird belief disillusio