【正文】 ough clouds. Then we began going down the hills. It was great fun especially as it gradually became much warmer. In the valleys colourful butterflies flew around us and we saw many yaks and sheep eating green grass. At this point we had to change our caps, coats,gloves and trousers for Tshirts and shorts. In the early evening we always stop to make put up our tent and then we eat. After supper Wang Wei put her head down on her pillow and went to sleep but I stayed awake. At midnight the sky became clearer and the stars grew brighter. It was so quiet. There was almost no wind—only the flames of our fire for pany. As I lay beneath the stars I thought about how far we had already travelled. We will reach Dali in Yunnan Province soon, where our cousins Dao Wei and Yu Hang will join us. We can hardly wait to see them!PART 6 THE END OF OUR JOUNEYCambodia was in many ways similar to Laos, although it has twice the population. At another inn, we talked with a teacher who told us that half of the people in her country couldn’t read or write. Her village couldn’t even afford to build a school, so she had to teach outside under a large tent. When we said goodbye, we all felt very lucky to have studied in on the road, we passed between many hills and forests. Then we came to the plains and entered Phnom Penh,the capital of Cambodia. In many ways it looked like Vientiane and Ho Chi Minh City。 it also had wide streets with trees in rows and old French Vientiane, ships could travel the Mekong River the center of the city we visited the palace and a beautiful white elephant. It can only be seen outside the palace on special days. We ate an early supper and went to see a great temple with floors made of sliver.The next morning our group slept late. We were very tired from the long bike ride the day before. Cycling in the hills had been our couins had the chance to make jokes about Wangwei and me. Perhaps,they said,they were the strong ones!We had lunch at a nice outdoor cafe,then rode out of the city.Two days later we crossed the border into Vietnam. We began to see many more people,but I wasn’t surprised .I read in an atlas before our trip that Vietnam has almost seven times the population of Cambodia. We met a farmer who gave us directions and told us that he grows a new rice crop four times every year so he can feed more also told us that the northern part of his country has many mountains and it is much cooler than here in the south,where it is the flat delta made it easier for us to got warm very we drank lots of water and ate lots of the delta separated into nine smaller days later,after we had passed thousands of rice fields,we came to the sea. We were tired but also in high spirits:our dream to cycle along the Mekong River had finally e true.Unit 4A NIGHT THE EARTH DID’T SLEEP Strange things were happening in the countriside of northest there days the water in the village wells rose and fell, rose and noticed that the well walls had deep cracks in them. A smelly gas came out of the cracks. In the farmeryards,the chickens and even the pigs were too nervous to ran out of the fields looking for places to jumped out of their bowls and about 3:00am on July 28,1976,some people saw bright lights in the sound of the planes could be heard outside the city,who thought little of these events,were asleep as usual that night. At3:42 am everything began to seemed as if the world was at an end!Eleven kilometres directly below the city the greast earthquake of 20th century had begun. It was felt in Beijing,which is more thantwo hundred kilometresHDPE雙壁波紋管生產(chǎn)線項(xiàng)目可行性研究報(bào)告一?概 述我國塑料管產(chǎn)業(yè)正面臨快速發(fā)展的歷史機(jī)遇, 進(jìn)入21世紀(jì)我國塑料管產(chǎn)業(yè)進(jìn)入了一個快速增長的時期,目前全國塑料管產(chǎn)業(yè)的基礎(chǔ)已經(jīng)建立,市場的需求明顯呈飛躍式發(fā)展,技術(shù)的進(jìn)步及塑料管所涉及領(lǐng)域在逐步擴(kuò)大,從20世紀(jì)90年代的塑料管?PEX管?PPR管等新型建材逐步從不認(rèn)識到被接受,以及建設(shè)部及設(shè)計(jì)部門的大力推廣,使塑料管材加工業(yè)呈蓬勃發(fā)展態(tài)勢?但在人們大搞供水?燃?xì)夤軜I(yè)的同時忽視市場潛力巨大的排水管道市場?上世紀(jì)90年代末,我國塑料管在各個市場領(lǐng)域內(nèi)分布狀況,業(yè)內(nèi)權(quán)威人士對此進(jìn)行了分析及對比?如下表:表1:塑料管的應(yīng)用領(lǐng)域中國名稱室外給水管建筑給水管建筑排水管埋地排水管輸氣管電工套管農(nóng)業(yè)用管工業(yè)用管總計(jì)歐洲名稱飲水管采暖/室內(nèi)用管污水/排水管燃?xì)夤茏o(hù)套管農(nóng)業(yè)用管工業(yè)用管—中國1998年估計(jì)產(chǎn)量/萬噸121851510850占塑料管總量的比例%24216102102016100歐洲1997年產(chǎn)量/萬噸占塑料管總量的比例%77100從以上的分析和比較可以明顯看到,我國在建筑排水?電工套管領(lǐng)域發(fā)展的比較好,在地埋管方面的發(fā)展最差,歐洲埋地?%,而我國埋地排水管僅占10%,這些差距說明我國的埋地管還處在起步階段,市場潛力巨大?據(jù)分析,市場潛力最大的領(lǐng)域?qū)⑹沁^去發(fā)展最差的埋地排水管?根據(jù)發(fā)達(dá)國家的經(jīng)驗(yàn),塑料管應(yīng)用量(質(zhì)量計(jì))最大的領(lǐng)域在排水排污管,主要是室外的埋地排水排污管?這是因?yàn)楝F(xiàn)代化的國家需要建設(shè)一個龐大的,遍布城鄉(xiāng)的排水排污管道系統(tǒng),不僅生活排水?工業(yè)排水要進(jìn)入這個管系,體積量更大的雨水也有很大部分需要通過這個排水系統(tǒng)收集和輸送(排水管一般是無壓的,管徑較大)?我國過去在埋地排水領(lǐng)域應(yīng)用塑料管最為落后,原因之一是中國過去對于環(huán)境保護(hù)不夠重視,排水管的建設(shè)投資不足,傳統(tǒng)排水管主要采用價格最低的平接口混泥土管?原因之二是塑料埋地排水管和傳統(tǒng)的混泥土埋地排水管不同,其設(shè)計(jì)施工和驗(yàn)收需要全新的規(guī)范?中國過去對塑料埋地排水管的研究試驗(yàn)不夠,實(shí)際應(yīng)用的經(jīng)驗(yàn)也不足,一直沒有制定出國家級的設(shè)計(jì)施工和驗(yàn)收規(guī)范?因此前些年有多家企業(yè)引進(jìn)塑料埋地排水管生產(chǎn)線后都難以打開市場,停留在做個別試驗(yàn)工程的階段?近幾年,塑料埋地排水管的市場開始起步,一方面是因?yàn)橹袊絹碓街匾暛h(huán)境保護(hù),不少地區(qū)大力治理江河湖海的污染。另一方面對于塑料埋地排水管的研究試驗(yàn)和標(biāo)準(zhǔn)及規(guī)范制定工作也逐步有了進(jìn)展,部分地區(qū)已開始大量應(yīng)用?建設(shè)部專門組織的兩個推廣會上,上海