【導(dǎo)讀】隨著天然氣和煤氣的大量使用，每一座居民大樓都被天然氣所“籠罩”。時(shí)天然氣也是潛在的“危險(xiǎn)品”一旦發(fā)生大面積泄漏，處理不及時(shí)就可能引發(fā)大爆炸，給居民的生命財(cái)產(chǎn)的安全帶來(lái)巨大的威脅。我們需要一個(gè)解決的辦法，使用天然氣報(bào)。警器是對(duì)付天燃?xì)膺@一無(wú)形殺手的重要手段之一。強(qiáng)等優(yōu)，而且價(jià)格低廉使用壽命長(zhǎng)。其與LM358連接，將氣體信號(hào)轉(zhuǎn)換為單片機(jī)可識(shí)。之則為正常狀態(tài)。同時(shí)，該報(bào)警器還有溫度檢測(cè)功能。

　　

【正文】 ********************************************** DELAY: MOV R5,10 。延時(shí) 5ms D1: MOV R6,248 DJNZ R6,$ DJNZ R5,D1 RET *************************************************************** 定時(shí)器 TO ************************************************************* INTTR0： PUSH ACC MOV TL0， 0B0H MOV TH0， 3CH INC COUNT MOV A,COUNT CJNE A,20， RETURN1 MOV COUNT,0 CPL SPEAK RETUN1： POP ACC RETI ************************************************************** TABLE: DB 3FH,06H,5BH,4FH,66H。段碼表 DB 6DH,7DH,07H,7FH,6FH END 畢業(yè)設(shè)計(jì)用紙 第 30頁(yè) 共 30 頁(yè) 致謝 歷時(shí)一個(gè)多月畢業(yè)設(shè)計(jì)終于落下帷幕，首先要感謝 何成平 指導(dǎo)老師在我整個(gè)設(shè)計(jì)過(guò)程中的細(xì)心指導(dǎo)。首次接觸如此系統(tǒng)的設(shè)計(jì)，開(kāi)始無(wú)論是選題還是整體設(shè)計(jì)框架及格式的排版等都一無(wú)所知無(wú)從入手，是 何成平指導(dǎo) 老師的精心指導(dǎo)才給我指明了方向。 從設(shè)計(jì)的選題到資料的搜集直至最后設(shè)計(jì)的修改的整個(gè)過(guò)程中，花費(fèi)了 何 老師很多的寶貴時(shí)間和精力，在此向?qū)煴硎局孕牡馗兄x！ 在此也向幫助過(guò)我的其他老師和同學(xué)致以誠(chéng)摯的感謝。 通過(guò)這次畢業(yè)設(shè)計(jì)不僅提高了我獨(dú)立思考問(wèn)題 、 解決問(wèn)題的能力而且培養(yǎng)了認(rèn)真嚴(yán)謹(jǐn)，一絲不茍的學(xué)習(xí)態(tài)度 ， 增強(qiáng)了很克服困難和挫折的信心 。由于經(jīng)驗(yàn)匱乏，能力有限，設(shè)計(jì)中難免有許多考慮不周全的地方，希望各位老師多加指 導(dǎo) 。再次真誠(chéng)感謝所有幫助過(guò)我的老師同學(xué)。 畢業(yè)設(shè)計(jì)用紙 第 31頁(yè) 共 30 頁(yè) 請(qǐng)您刪除一下內(nèi)容， O(∩ _∩ )O謝謝！??！ Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the sevenday Chinese National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may bee more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and acmodation prices, with the possibility that there will be no rooms available. It is also mon that you39。 ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the weeklong holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the uping Golden Week it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the remended travelling route, China Inner Mongolia Arxan — Hailar — Manzhouli. It is also the joint of the four prairies across the SinoMongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of geous colors all the year round the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name Haren Arxan means hot holy water in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the country39。s largest virgin forest, and known for its spring and ecological environment, Arxan is marveled at by many tourists as the purest land on earth. You cannot miss out the Autumn of Arxan. It is definitely the best with brightlycolored scenery full of emotions. Autumn in the northern part of the country es earlier than the South. A September rain followed by the footprints of Autumn brings more colors to the once emerald green mountain and blooming grassland. Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. The silver birch turns golden, while the larch is still proudly green. You will find yourself drowned in the intoxicating red of the wild fruits as well as the glamour of flowers in full blown. And your heart will be lingering on the woods as it39。s time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sisterinlaw. But she disliked and abused him, and the boy w