第一篇:專業(yè)英語(yǔ)翻譯部分
僅供參考!發(fā)現(xiàn)錯(cuò)誤請(qǐng)及時(shí)指出!
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Climate plays a very important role in the genesis of a soil.On the global scale, there is an obvious correlation between major soil types and the Koppen climatic classification systems major climate types.At regional and local scales, climate becomes less important in soil formation.Instead, Pedogenesis is more influenced by factors like parent material, topography, vegetation, and time.The two most important climatic variables influencing soil formation are temperature arid moisture.Temperature has direct influence on the weathering of bedrock to produce mineral particles.Rates of bedrock weathering generally increase with higher temperatures.Temperature also influences the activity of soil microorganisms, the frequency and magnitude of soil chemical reactions, and the rate of plant growth, moisture levels in most soils are primarily controlled by the addition of water via precipitation minus the losses due to evapotranspiration.If additions of water from precipitation surpass losses from evapotranspiration, moisture levels in a soil tend to be high.If the water loss due to evapotranspiration exceeds inputs from precipitation, moisture levels in a soil tend to be low.High moisture availability in a soil promotes the weathering, of bedrock and sediments, chemical reactions, and plant growth.The availability of moisture also has an influence on soil pH and the decomposition of organic matter.氣候在土壤形成過程中扮演了重要角色。從全球尺度來看,主要的土壤分類和科彭氣候分類法確定的主要的氣候類型有明星的聯(lián)系。在區(qū)域和地方性的范圍內(nèi),氣候顯得不是那么重要。取而代之的是母質(zhì),地形,植被和時(shí)間。溫度和濕度是影響土壤形成的兩個(gè)重要的變量。溫度直接影響基巖風(fēng)化產(chǎn)生礦物顆粒。溫度越高,基巖轉(zhuǎn)化為礦物顆粒的比例越大。溫度同樣影響土壤微生物的活躍度,土壤化學(xué)反應(yīng)的頻率和數(shù)量,植物生長(zhǎng)的比例。大多數(shù)的土壤濕度是由降水減去蒸發(fā)作用控制的。如果降水超過蒸發(fā)作用消耗的水,土壤濕度就會(huì)很高。如果降水少于蒸發(fā)作用,土壤的濕度就會(huì)變低。土壤內(nèi)大量的可用的水氣會(huì)提升母巖溫度和沉積,化學(xué)反應(yīng),還有植物生長(zhǎng)。微生物也會(huì)影響土壤的PH和有機(jī)物的分解。
Living organisms have a role in a number of processes involved in pedogenesis including organic matter accumulation, profile mixing, and biogeochemical nutrient cycling.Under equilibrium conditions, vegetation and soil are closely linked with each other through nutrient cycling.The cycling of nitrogen and carbon in soils is almost completely controlled by the presence of animals and plants.Through litterfall and the process of decomposition, organisms add humus and nutrients to the soil which influences soil structure and fertility.Surface vegetation also protects the upper layers of a soil from erosion by way of binding the soils surface and reducing the speed of moving wind and water across the ground surface.成土作用過程中,生命體參與了其中的有機(jī)物積累,屬性混合和生物化學(xué)養(yǎng)分的循環(huán)。在平衡條件下,植被和土壤通過彼此的養(yǎng)分循環(huán)緊密聯(lián)系在一起。土壤中的碳氮循環(huán)幾乎都需要?jiǎng)游锖椭参锏膮⑴c控制。通過落葉和分解過程,微生物把腐殖質(zhì)和營(yíng)養(yǎng)成分帶給土壤,也因此影響了土壤的結(jié)構(gòu)和肥力。表層植物也可以固定表層土壤來保護(hù)上層的土壤不被途經(jīng)的風(fēng)和水帶走。
Parent material refers to the rock and mineral materials from which the soils develop.These materials can be derived from residual sediment due to the weathering of bedrock or from sediment transported into an area by way of the erosive forces of wind, water, or ice.Pedogenesis is often faster on transported sediments because the weathering of parent material usually takes a long period of time.The influence of parent material on pedogenesis is usually related to soil texture, soil chemistry, and nutrient cycling.母質(zhì)是指土壤形成所在的巖石和礦物質(zhì)。巖床的風(fēng)化或者由侵蝕力(比如風(fēng),水,冰)帶來的沉積物都可以變?yōu)樾纬赡纲|(zhì)需要的物質(zhì)。外來的沉積物形成的成土作用通常都比較快,因?yàn)轱L(fēng)化母質(zhì)需要很長(zhǎng)一段時(shí)間。母質(zhì)在成土過程中的影響就是它參與了土壤的質(zhì)地,土壤化學(xué)和養(yǎng)分循環(huán)。
The distribution of precipitation on the Earth's surface is generally controlled by the absence or presence of mechanisms that lift air masses to cause saturation.It is also controlled by the amount of water vapor held in the air, which is a function of air temperature.A figure is presented that illustrates global precipitation patterns.氣體上升聚集達(dá)到飽和,是否存在這種飽和基本上決定了地球表面降水的分布。同時(shí),大氣中包含水蒸氣的含量也影響了降水,水蒸氣的含量是由大氣溫度控制的。下面的一組數(shù)字將闡明全球降水模式。
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Evaporation and transpiration are the two processes that move water from the Earth’s surface to its atmosphere.Evaporation is movement of free water to the atmosphere as a gas.It requires large amounts of energy.Transpiration is the movement of water through a plant to the atmosphere.Scientists use the term evapotranspiration to describe both processes.In general, the following four factors control the amount of water entering the atmosphere via these two processes: energy availability;the humidity gradient away from the evaporating surface;the wind speed immediately above the surface;and water availability.Agricultural scientists sometimes refer to two types of evapotranspiration: Actual Evapotranspiration and Potential Evapotranspiration.The growth of crops is a function of water supply.If crops experience drought, yields are reduced.Irrigation can supply crops with supplemental water.By determining both actual evapotranspiration and potential evapotranspiration a farmer can calculate the irrigation water needs of their crops.蒸發(fā)作用和蒸騰作用是把水從地表帶到大氣的最主要的兩個(gè)過程。蒸發(fā)是空余的水變成蒸汽進(jìn)入大氣的移動(dòng)過程。這個(gè)過程需要大量的能量。蒸騰作用是水通過植物進(jìn)入大氣??茖W(xué)家用蒸散作用來統(tǒng)稱這兩個(gè)過程。通常情況下,下面四個(gè)因素影響了這兩個(gè)過程:可利用的能量、蒸發(fā)表面的溫度梯度、蒸發(fā)表面即時(shí)風(fēng)速、可用的水。農(nóng)業(yè)科學(xué)家認(rèn)為蒸散作用有兩種方式:實(shí)際的蒸散和潛在的蒸散。農(nóng)作物生長(zhǎng)是供水的過程。如果作物經(jīng)歷了干旱,就會(huì)導(dǎo)致減產(chǎn)。灌溉可以給作物提供附加的水。如果知道了實(shí)際蒸散和潛在蒸散的量,農(nóng)民就可以計(jì)算作物灌溉需要的水量。
Infiltration is the movement of water from precipitation into the soil layer.Infiltration varies both spatially and temporally due to a number of environmental factors.After a rain, infiltration can create a condition where the soil is completely full of water.This condition is, however, only short-lived as a portion of this water quickly drains(gravitational water)via the force exerted on the water by gravity.The portion that remains is called the field capacity.In the soil, field capacity represents a film of water coating all individual soil particles to a thickness of 0.06 mm.The soil water from 0.0002 to 0.06 mm(known as capillary water)can be removed from the soil through the processes of evaporation and transpiration.Both of these processes operate at the surface.Capillary action moves water from one area in the soil to replace losses in another area(biggest losses tend to be at the surface because of plant consumption and evaporation).This movement of water by capillary action generally creates a homogeneous concentration of water throughout the soil profile.Losses of water stop when the film of water around soil particles reaches 0.0002 mm.Water held from the surface of the soil particles to 0.0002 mm is essentially immobile and can only be completely removed with high temperatures(greater than 100 degrees Celsius).Within the soil system, several different forces influence the storage of water.滲透是水從降水進(jìn)入土壤層的過程。滲透由于一些自然的因素會(huì)發(fā)生空間的和暫時(shí)的變化。下完雨之后,滲透會(huì)形成一個(gè)土壤完全充滿水的情況。但是這種情況只是暫時(shí)的,一部分雨水會(huì)由于重力作用排出。留下的那一部分雨水被稱為土地含水能力。土地含水能力展示給我們一個(gè)水薄膜,在這個(gè)薄膜里,所有相互獨(dú)立的土壤粒子被厚度僅僅為0.06毫米的水包裹著。土壤中0.0002到0.06毫米的水都可以通過蒸散作用排出。所以這些過程都發(fā)生在表面。毛細(xì)作用把水從一個(gè)地方搬運(yùn)到另一個(gè)流失水的地方(最大的水流失應(yīng)該就是植物表面的蒸騰和蒸發(fā))。這種毛細(xì)作用可以報(bào)證土壤內(nèi)的水的濃度是均勻的。土壤粒子包被的水薄膜到0.0002毫米時(shí),水就停止流失。這時(shí)的水本質(zhì)上除了超過100攝氏度的情況是不可移動(dòng)的。在土壤系統(tǒng)內(nèi)部,這幾種力量影響了水的短缺度。
Population Structure / Population Pyramids
The population structure for an area shows the number of males and females within different age groups in the population.This information is displayed as an age-sex or population pyramid.Population pyramids of LEDCs typically have a wide base and a narrow top.This represents a high birth rate and high death rate.Population pyramids of MEDCs typically have a roughly equal distribution of population throughout the age groups.The top obviously gets narrower as a result of deaths.Population pyramids for every country in the world can be found here.Population pyramids are used to show the structure of the population according to age and sex.一個(gè)地方的人口結(jié)構(gòu)告訴我們?cè)摰夭煌挲g段男性和女性的人口數(shù)量。這些信息展示出了一個(gè)年齡-性別或者人口數(shù)量的金字塔。發(fā)展中國(guó)家的人口金字塔通常有很大的根基和很窄的塔尖。這體現(xiàn)了這些國(guó)家的高出生率和高死亡率。發(fā)達(dá)國(guó)家的人口金字塔在不同年齡段大概是均勻分布的。塔尖由于死亡的原因會(huì)稍微窄一些。世界上所有國(guó)家的人口金字塔在這里都可以找到。人口金字塔通常用來展示人口在年齡和性別上的結(jié)構(gòu)。
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The increase of greenhouse gases are the primary causes of the human-induced component of warming.Because of burning of fossil fuels, land clearing and agriculture, the amount of CO2 and other greenhouse gases in the atmosphere have increased by more than a third.Changes this large have historically taken thousands of years, but are now happening over the course of decades.溫室氣體增加的主要原因是人類-誘導(dǎo)氣溫的上升。因?yàn)榛剂系娜紵?,大地沒有植被以及農(nóng)業(yè),大氣中二氧化碳和其他溫室氣體的排放量已經(jīng)上升了1/3。經(jīng)歷這么大的變化曾經(jīng)需要數(shù)千年,但是現(xiàn)在只在近十年內(nèi)就完成了。
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Sea Level Rising.With the melt of ice cap and glaciers, sea level has rised 0.8 to 3.0 millimeter.With large numbers of cities located in coastal areas, this causes serious problems.Beach erosion takes place, particularly on steep banks.Wetlands are lost.This is a picture of Shanghai at present, while this may be the picture of Shanghai several years later.Another serious problem is the threat of salt water intruding into underground fresh water in coastal areas.Millions of people will be forced to leave their homes and homelands.海平面上升。隨著冰蓋和冰川的融化,海平面已經(jīng)上升了0.8到3.0毫米。由于很多城市坐落在沿海地區(qū),這就可能帶來災(zāi)難性的問題。海岸侵蝕開始出現(xiàn),尤其是在陡峭的海岸。濕地逐漸消失。這正是上海現(xiàn)在發(fā)生的,也可能是幾年以后上海出現(xiàn)的景象。另一個(gè)嚴(yán)重的問題是鹽水侵入沿海地區(qū)的底下淡水。數(shù)以萬計(jì)的人民不得不背井離鄉(xiāng)。
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They dominate the country in influence and are the national focal-point.Their sheer size and activity becomes a strong pull factor, bringing additional residents to the city and causing the primate city to become even larger and more disproportional to smaller cities in the country.However, not every country has a primate city, as you'll see from the list below.他們通過影響力支配這個(gè)國(guó)家,是整個(gè)國(guó)家的焦點(diǎn)。他們的規(guī)模大小和活動(dòng)變成一股強(qiáng)大的推動(dòng)力,帶來額外的居民,讓這些首位城市變得更大,以至于跟國(guó)內(nèi)的其他小城市相比有些不協(xié)調(diào)。但是,并不是所有國(guó)家都有這樣一個(gè)首位城市,你可以從下面的表里看出來。
Some scholars define a primate city as one that is larger than the combined populations of the second and third ranked cities in a country.This definition does not represent true primacy, however, as the size of the first ranked city is not disproportionate to the second.一些學(xué)者定義首位城市就是比排名第二和第三位城市人口總和還要多的城市。但是這個(gè)定義沒有體現(xiàn)從城市規(guī)模的角度分析,排名前兩位的城市也是不成比例的,所以并不被認(rèn)可。
The law can be applied to smaller regions as well.For example, California's primate city is Los Angeles, with a metropolitan area population of 16 million, which is more than double the San Francisco metropolitan area of 7 million.Even counties can be examined with regard to the Law of the Primate City.這個(gè)法則可以用到小的區(qū)域。舉個(gè)例子,加州的首位城市是洛杉磯,城市人口達(dá)到1600萬,比舊金山的700高出甚多。甚至村莊也可以用首位城市法則來分析。
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Scope of land consolidation schemes(本段藍(lán)字為不確定部分)
Land consolidation has always been regarded as an instrument or entry point for rural development.Early concepts of rural development were virtually the same as agricultural development because of the predominant role of agriculture in rural areas at the time.Improving the agrarian structure was viewed as being identical to maintaining the social viability in rural areas;what was good for the farmers was good for rural areas.An overall objective of early projects was thus to increase the net income from land holdings by increasing the volume of production and decreasing its costs.With this focus on agricultural development, these projects served to consolidate parcels and enlarge holdings and included provisions such as irrigation and drainage infrastructure to improve water management, construction of rural roads, land levelling, soil improvement measures and changes to land use such as converting agriculturally inferior land into forest land or wetlands.土地合并經(jīng)常被認(rèn)為是發(fā)展農(nóng)村的一個(gè)手段或者切入點(diǎn)。早期的農(nóng)村發(fā)展概念基本上和農(nóng)業(yè)發(fā)展一樣的,因?yàn)槟菚r(shí)候的農(nóng)業(yè)生產(chǎn)占據(jù)了農(nóng)村的主導(dǎo)地位。改進(jìn)農(nóng)業(yè)結(jié)構(gòu)看起來是和保留農(nóng)村地區(qū)社會(huì)生存能力一樣的事情。對(duì)農(nóng)民好也就是對(duì)農(nóng)村地區(qū)好。因此早期項(xiàng)目的總體目標(biāo)是通過增加產(chǎn)量和減少成本,以此增加從土地獲得的凈收益。隨著注意力轉(zhuǎn)移到農(nóng)業(yè)發(fā)展上,這些項(xiàng)目服務(wù)于鞏固捆綁,增大資產(chǎn),還這些規(guī)定:修建灌溉和排水基礎(chǔ)設(shè)施來提升用水管理能力,修建農(nóng)村公路,土地平整,土壤改良措施以及改變土地用途比如說把貧瘠的土地轉(zhuǎn)變?yōu)樯只蛘邼竦亍?/p>
Such agricultural improvements are still essential but rural space is now no longer regarded as one of agricultural production alone.Concepts of rural development have become much broader and have expanded to include increased environmental awareness and a wide range of nonagricultural applications.The emphasis of land consolidation projects has shifted from a focus on restructuring agriculture to one of achieving more efficient multiple use of rural space by balancing the interests of agriculture, landscape, nature conservation, recreation and transportation, especially when land is required for the construction of major roads.這些農(nóng)業(yè)進(jìn)步仍然是必不可少的,但是現(xiàn)在農(nóng)村地區(qū)不再僅僅是農(nóng)業(yè)生產(chǎn)的區(qū)域了。農(nóng)村發(fā)展的概念已經(jīng)變得更加廣闊,已經(jīng)拓展到包含環(huán)境意識(shí)和非農(nóng)業(yè)應(yīng)用的領(lǐng)域。土地合并的項(xiàng)目的重點(diǎn)已經(jīng)不再只關(guān)注農(nóng)業(yè)重組,它上升到通過平衡農(nóng)業(yè)利益,地形,自然保護(hù),娛樂和運(yùn)輸(尤其是需要修建主要干道的時(shí)候)來獲取最大的利益。
Environmental conditions are being given increasing priority.Roads are being constructed to suit the landscape.Water bodies are being restored, often with buffer zones.Land consolidation projects are also used for the protection of wetlands and to change land use patterns especially in areas endangered by frequent floods or soil erosion.人們把環(huán)境情況作為優(yōu)先考慮。修路需要符合地形。水體被修復(fù),一般都還有緩沖區(qū)。土地合并項(xiàng)目經(jīng)常用于保護(hù)濕地,還有改變土地利用模式,特別是在因?yàn)轭l發(fā)的洪水和水土流失致使土地瀕臨消失的地方。
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Leakage
The direct income for an area is the amount of tourist expenditure that remains locally after taxes, profits, and wages are paid outside the area and after imports are purchased;these subtracted amounts are called leakage.In most all-inclusive package tours, about 80% of travelers' expenditures go to the airlines, hotels and other international companies(who often have their headquarters in the travelers' home countries), and not to local businesses or workers.In addition, significant amounts of income actually retained at destination level can leave again through leakage.消費(fèi)者的支出除去稅費(fèi),利潤(rùn),支出的工資以及進(jìn)口所需剩下的一部分,就是旅游目的地的直接收入,也叫做滲漏。在大部分全包價(jià)旅游中,旅游者支出的80%付給了航空公司,酒店和其他國(guó)際公司(通常在旅游者來源國(guó)有分支部門),并不是當(dāng)?shù)氐纳痰昊蛘吖と恕4送?,大量的達(dá)到目標(biāo)水平的收入一般會(huì)經(jīng)過滲漏再次離開當(dāng)?shù)亍?01頁(yè)
Tourism development and the related rise in real estate demand may dramatically increase building costs and land values.Not only does this make it more difficult for local people, especially in developing countries, to meet their basic daily needs, it can also result in a dominance by outsiders in land markets and in-migration that erodes economic opportunities for the locals, eventually disempowering residents.In Costa Rica, close to 65% of the hotels belong to foreigners.Long-term tourists living in second homes, and the so-called amenity migrants(wealthy or retired people and liberal professionals moving to attractive destinations in order to enjoy the atmosphere and peaceful rhythms of life)cause price hikes in their new homes if their numbers attain a certain critical mass.旅游業(yè)的發(fā)展和相關(guān)切實(shí)需要的房地產(chǎn)需求可能戲劇性的促進(jìn)了建筑造假和土地價(jià)值。不止是這些造成了當(dāng)?shù)鼐用?特別是在發(fā)展中國(guó)家-難以得到基本日常所需,還會(huì)導(dǎo)致外來者在土地市場(chǎng)和遷移這些對(duì)當(dāng)?shù)厝藢儆诮?jīng)濟(jì)侵略的領(lǐng)域處于支配地位。在哥斯達(dá)黎加,近60%的酒店屬于外國(guó)人,長(zhǎng)期的游客住在第二個(gè)家,這些所謂的美化城市的居民(富人或者退休的人,還有那些想要享受平靜生活和優(yōu)美環(huán)境的自由主義者)的數(shù)量如果達(dá)到一個(gè)臨界值,就會(huì)引起他們新家附近的價(jià)格飛漲。
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Storm structure
The process by which a disturbance forms and subsequently strengthens into a hurricane depends on at least three conditions.Warm waters and moisture are mentioned above.The third condition is a wind pattern near the ocean surface that spirals air inward.Bands of thunderstorms form, allowing the air to warm further and rise higher into the atmosphere.If the winds at these higher levels are relatively light, this structure can remain intact and allow for additional strengthening.一股躁動(dòng)氣流隨后加強(qiáng)成為颶風(fēng)的過程需要至少3個(gè)條件。溫水和降水是必不可少的,第三個(gè)條件是在海洋表面有內(nèi)螺旋的空氣所形成的風(fēng)。雷電風(fēng)暴的形成,讓空氣溫度升高,然后上升到大氣。如果在這個(gè)更高高度的風(fēng)是相對(duì)輕的,這個(gè)結(jié)構(gòu)還會(huì)保持完整然后繼續(xù)加強(qiáng)。
第二篇:水利專業(yè)英語(yǔ)翻譯部分
Lesson 1 importance of water 水的重要性
Water is best known and most abundant of all chemical compounds occurring in relatively pure form on the earth’s surface.Oxygen, the most abundant chemical element, is present in combination with hydrogen to the extent of 89 percent in water.Water covers about three fourths of the earth's surface and permeates cracks of much solid land.The polar regions are overlaid with vast quantities of ice, and the atmosphere of the earth carries water vapor in quantities from 0.1 percent to 2 percent by weight.It has been estimated that the amount of water in the atmosphere above a square mile of land on a mild summer day is of the order of 50,000 tons.在地球表面以相對(duì)純的形式存在的一切化合物中,水是人們最熟悉的、最豐富的一種化合物。在水中,氧這種最豐富的化學(xué)元素與氫結(jié)合,其含量多達(dá)89%。水覆蓋了地球表面的大約3/4的面積,并充滿了陸地上的許多裂縫。地球的兩極被大量的冰所覆蓋,同時(shí)大氣也挾帶有占其重量0.1%~2%的水蒸氣。據(jù)估計(jì),在溫暖的夏日,每平方英里陸地上空大氣中的水量約為5萬噸。
All life on earth depends upon water, the principal ingredient of living cells.The use of water by man, plants, and animals is universal.Without it there can be no life.Every living thing requires water.Man can go nearly two months without food, but can live only three or four days without water.地球上所有的生命都有賴于水而存在,水是活細(xì)胞的基本組分(要素)。人類、植物和動(dòng)物都得用水。沒有水就沒有生命。每一種生物都需要水。人可以接近兩個(gè)月不吃食物而仍能活著,但不喝水則只能活三四天。
In our homes, whether in the city or in the country, water is essential for cleanliness and health.The average American family uses from 65,000 to 75,000 gallons of water per year for various household purposes.在我們的家庭中,無論是在城市還是農(nóng)村,水對(duì)于衛(wèi)生和健康來說都是必不可少的。美國(guó)家庭的年平均用水量達(dá)6.5~7.5萬加侖。
Water can be considered as the principal raw material and the lowest cost raw material from which most of our farm produces is made.It is essential for the growth of crops and animals and is a very important factor in the production of milk and eggs.Animals and poultry, if constantly supplied with running water, will produce more meat, more milk, and more eggs per pound of food and per hour of labor.水可以被認(rèn)為是最基本的和最廉價(jià)的原料。我們的農(nóng)產(chǎn)品,大部分都是由它構(gòu)成的。水是農(nóng)作物和動(dòng)物生長(zhǎng)的要素,也是奶類和蛋類生產(chǎn)的一個(gè)很重要的因素。動(dòng)物和家禽,如果用流動(dòng)的水來喂養(yǎng),那么每磅飼料和每個(gè)勞動(dòng)小時(shí)會(huì)生產(chǎn)出更多的肉、奶和蛋。
For example, apples are 87% water.The trees on which they grow must have watered many times the weight of the fruit.Potatoes are 75% water.To grow an acre of potatoes tons of water is required.Fish are 80% water.They not only consume water but also must have large volumes of water in which to live.Milk is 88% water.To produce one quart of milk a cow requires from 3.5 to
5.5 quarts of water.Beef is 77% water.To produce a pound of beef an animal must drink many times that much water.If there is a shortage of water, there will be a decline in farm production, just as a shortage of steel will cause a decrease in the production of automobiles.例如,蘋果含87%的水分,蘋果樹就必須吸收比蘋果多許多倍的水分;土豆含75%的水分,那么種植每英畝土豆就需要若干噸水;牛奶含水量為88%,為了生產(chǎn)每夸脫牛奶,母
牛需要3.5~5.5 夸脫的水;牛肉含77%的水,為生產(chǎn)1磅牛肉牛必須飲用許多磅水。如果缺水,就會(huì)使農(nóng)產(chǎn)品減產(chǎn),就像缺乏鋼會(huì)引起汽車產(chǎn)量下降一樣。
In addition to the direct use of water in our homes and on the farm, there are many indirect ways in which water affects our lives.In manufacturing, generation of electric power, transportation, recreation, and in many other ways, water plays a very important role.水除了直接為我們的家庭和農(nóng)場(chǎng)利用外,它還以許多間接的方式對(duì)我們的生活產(chǎn)生影響。在制造、發(fā)電、運(yùn)輸、娛樂以及其他許多行業(yè),水都起著很重要的作用。
Our use of water is increasing rapidly with our growing population.Already there are acute shortages of both surface and underground waters in many locations.Careless pollution and contamination of our streams, lakes, and underground sources has greatly impaired the quality of the water which we do have available.It is therefore of utmost importance for our future that good conservation and sanitary measures be practiced by everyone.我們對(duì)水的利用隨人口的增長(zhǎng)而迅速增加。在許多地方,無論地面水或地下水都已經(jīng)嚴(yán)重短缺了。由于任意污染河流、湖泊和地下水源,已經(jīng)大大地?fù)p害了人們能夠利用的水的水質(zhì)。因此,人人有責(zé)對(duì)水采取保護(hù)措施和衛(wèi)生措施,這對(duì)于我們?nèi)祟惖奈磥硎菢O端重要的。
Lesson 18 evapotranspiration 騰發(fā)量
Evaporation is the transfer of water from the liquid to the vapor state.Transpiration is the process by which plants remove moisture from the soil and release it to the air as vapor.More than half of the precipitation which reaches the land surfaces of the earth is returned to the atmosphere by the combined processes, evapotranspiration.In arid regions evaporation may consume a large portion of the water stored in reservoir.蒸發(fā)是水從液態(tài)變成氣態(tài)的過程。蒸騰是植物將從土壤中吸收的水分以汽體的形式釋放到大氣中去的過程。到達(dá)地面的降雨有一半以上以蒸發(fā)與蒸騰相結(jié)合的形式─騰發(fā),回到大氣中去。在干旱地區(qū),蒸發(fā)可以消耗掉大量的水庫(kù)存水。
The rate of evaporation from a water surface is proportional to the difference between the vapor pressure at the surface and vapor pressure in the overlying air(Dalton ’s law).In still air, the vapor-pressure difference soon becomes small, and evaporation is limited by the rate of diffusion of vapor away from the surface.Turbulence caused by wind and thermal convection transports the vapor from the surface layer and permits evaporation to continue.水面蒸發(fā)率與水表面水氣壓與上層空氣大氣壓的差成比例(道爾頓定律)。在靜止的空氣中,氣壓差不久就變得較小,蒸發(fā)受水面水汽彌散速率的限制。由風(fēng)引起的擾動(dòng)和熱對(duì)流將表層的水變?yōu)樗?,(從而)使蒸發(fā)得以持續(xù)下去。
Transpiration is essentially the evaporation of water from the leaves of plants.Rates of transpiration will, therefore, be about the same as rates of evaporation from a free water surface if the supply of water to the plant is not limited.Estimated free water evaporation may, therefore, be assumed to indicate the potential evapotranspiration from a vegetated soil surface.蒸騰從本質(zhì)上是指水分從植物的葉表面的蒸發(fā),因此,如果植物供水不受限制,蒸騰速率大約等于自由水面的蒸發(fā)率。因此,估計(jì)的自由水面蒸發(fā)量可以假定代表有植物的土壤表面的潛在騰發(fā)量。
The total quantity of transpiration by plants over a long period of time is limited primarily by the availability of water.In areas of abundant rainfall well distributed through the year, all plants will transpire at about the same rates and the differences in total will result from the differences in
the length of the growing seasons for the various species.Where water supply is limited and seasonal, depth of roots becomes very important.Here, shallow-rooted grasses wilt and die when the surface soil becomes dry while deep-rooted trees and plants will continue to withdraw water from lower soil layers.The deeper-rooted vegetation will transpire a greater amount of water in the course of a year.The rate of transpiration is not materially reduced by decreases in soil moisture until the wilting point of the soil is reached.整個(gè)長(zhǎng)時(shí)期的植物蒸騰總量主要受水的可獲得量限制。在雨量充足且年內(nèi)分布均勻的地區(qū),所有植物都將以大致相同的速度蒸騰,蒸騰總量的不同是由于各種植物生育期長(zhǎng)短不同而引起的。對(duì)于供水受限制和季節(jié)性(降雨)的地方,植物根系的深度是很重要的。在這樣的地區(qū),當(dāng)表土變干時(shí),淺根系的草凋萎后便死亡,而根深的樹木和作物將繼續(xù)從深層土壤中吸取水分。深根植物在一年蒸騰過程中將蒸騰掉大量的水分。在土壤含水量達(dá)到凋萎點(diǎn)之前,植物的蒸騰速度實(shí)質(zhì)上不會(huì)因土壤水分的減少而減少。
Evapotranspiration, sometimes called consumptive use or total evaporation describes the total water removed from an area by transpiration and by evaporation from soil, snow, and water surfaces.An estimate of the actual evapotranspiration from an area can be made by subtracting measured outflow from the area(surface and subsurface)from the total water supply(precipitation, surface and subsurface inflow, and imported water).Change in surface and underground storage must be included when significant.騰發(fā)量有時(shí)被稱為耗水量或總蒸騰量,表示某一區(qū)域植物蒸騰、土壤蒸發(fā)、雪蒸發(fā)和自由水面蒸發(fā)的總水量。某一區(qū)域上的實(shí)際騰發(fā)量可以從本區(qū)總的供水量(包括降雨、地面和地下流入量以及引入的水量)減去從本區(qū)實(shí)測(cè)流出量(地表和地下流出量)來進(jìn)行估算。當(dāng)?shù)乇砗偷叵聝?chǔ)存量的變化顯著時(shí)必須包括在騰發(fā)量之內(nèi)。
Several attempts have been made to relate evapotranspiration to climatological data through simple equations such as用最簡(jiǎn)單的方程表示騰發(fā)量與氣象數(shù)據(jù)之間的關(guān)系,人們已經(jīng)進(jìn)行了許多嘗試,如:
Where: is the consumptive use in feet and is the sum of the growing season maximum temperatures less 32oF.With in centimeters and temperatures in degrees Celsius, Eq.(18.1)becomes式中: 表示耗水量,單位是英尺; 代表植物生長(zhǎng)季節(jié)最高溫度減去32oF的累計(jì)值。當(dāng) 以厘米為單位,溫度由oC表示時(shí),方程(18.1)變?yōu)?/p>
Such formulas agree fairly well with average values of annual evapotranspiration over a period of years, but it clear that the evaporative process is too complex to be well defined by a simple temperature function.這些公式與多年某一階段的年平均騰發(fā)量吻合良好。但由于蒸發(fā)過程的復(fù)雜性,很顯然,我們不可能用簡(jiǎn)單的溫度函數(shù)去很好的定義騰發(fā)量。
As indicated before, the potential evapotranspiration from an area can be estimated from the free water evaporation.Actual evapotranspiration equals the potential value as limited by the available moisture.On a natural watershed with many vegetal species, it is reasonable to assume that evapotranspiration rates do vary with soil moisture since shallow-rooted species will cease to transpire before deeper-rooted species.A moisture-accounting procedure can be established using the continuity equation
如前所述,某一區(qū)域的潛在騰發(fā)量可以用自由水面騰發(fā)量來估算。實(shí)際騰發(fā)量等于有效水量受限時(shí)的潛在騰發(fā)量。對(duì)于一個(gè)有多種植物的自然流域,假設(shè)騰發(fā)速率確實(shí)隨土壤水分的變化而變化是合理的。這是因?yàn)闇\根植物將在深根植物前停止蒸騰。我們可以用連續(xù)方程建立水量平衡方程:Where: is precipitation;is surface runoff;is subsurface outflow;is actural
evapotranspiration;is the change in moisture storage.式中: 表示降雨量; 表示地表徑流量; 表示地下流出量; 表示實(shí)際騰發(fā)量; 表示水分儲(chǔ)存的變化。is estimated as(可用下式估算:)
Where: is the computed soil moisture storage on any data and is an assumed maximum soil moisture content.A moisture-accounting procedure of this type may be used to calculate runoff as well as estimate evapotranspiration.式中: 表示任何計(jì)算的土壤水分儲(chǔ)存量; 表示一假定的最大土壤含水量。這個(gè)典型的水量平衡方程可用于計(jì)算徑流量和估算騰發(fā)量。
第三篇:材料成型及控制工程專業(yè)英語(yǔ)翻譯(部分)
第3章的原則塑料成型
3。1熱加工物理冶金
現(xiàn)在公認(rèn)的熱加工物理冶金的原則。在變形過程本身,例如一個(gè)滾動(dòng)的傳遞,加工硬化發(fā)生,但回收和再結(jié)晶過程的動(dòng)態(tài)軟化平衡。這些過程,這是熱激活,導(dǎo)致一個(gè)流動(dòng)應(yīng)力,應(yīng)變率和溫度,以及依賴于應(yīng)變。結(jié)構(gòu)性變化的應(yīng)變與位錯(cuò)密度增加放置在一個(gè)臨界應(yīng)變(εc)奧氏體鋼,鎳和銅合金材料的結(jié)果,直到達(dá)到儲(chǔ)存的能量足夠高時(shí)會(huì)導(dǎo)致動(dòng)態(tài)再結(jié)晶。隨著進(jìn)一步的壓力,動(dòng)態(tài)再結(jié)晶發(fā)生多次新的再結(jié)晶晶粒本身加工硬化儲(chǔ)存能量的臨界水平。這些動(dòng)態(tài)的結(jié)構(gòu)變化離開金屬處于不穩(wěn)定的狀態(tài),并提供靜態(tài)恢復(fù)和靜態(tài)再結(jié)晶變形傳遞后的推動(dòng)力??勺裱o態(tài)再結(jié)晶晶粒的生長(zhǎng),如果溫度足夠高。為了能夠把這些原則運(yùn)用到商業(yè)工作流程,我們需要回答兩個(gè)主要問題:
(一)多久再結(jié)晶后變形傳遞到位;及(b)什么晶粒尺寸再結(jié)晶和晶粒生長(zhǎng)產(chǎn)生?這些問題的答案決定進(jìn)入未來和后續(xù)傳遞物質(zhì)的結(jié)構(gòu),從而影響材料的流動(dòng)應(yīng)力和所需的工作力量。最后,他們確定的熱作產(chǎn)品的結(jié)構(gòu)和性質(zhì)。
3。1。1動(dòng)態(tài)的結(jié)構(gòu)變化
在變形奧氏體在熱加工溫度和恒應(yīng)變速率,觀察應(yīng)力應(yīng)變曲線的特點(diǎn)形式如圖所示。3。1。這些曲線是低合金鋼,扭轉(zhuǎn)測(cè)試,但類似的其它鋼得到扭轉(zhuǎn),緊張,或壓縮測(cè)試奧氏體條件。經(jīng)過初期快速加工硬化曲線通過動(dòng)態(tài)再結(jié)晶的發(fā)生相關(guān)的一個(gè)最大。在流動(dòng)應(yīng)力峰值出現(xiàn)一些低分?jǐn)?shù)的再結(jié)晶后已經(jīng)發(fā)生這樣的峰值應(yīng)變(εp)總是大于臨界應(yīng)變動(dòng)態(tài)recystallization(εc)。兩個(gè)菌株之間的關(guān)系是復(fù)雜的,但它已建議thatεc=αεp(其中α是一個(gè)常數(shù))是一個(gè)合理的近似變形熱工權(quán)益的條件下。然而,α的建議值不同,0.83,0.86,和0.67。它從圖3.1可以看出,εp增加系統(tǒng)與ZenerMn鋼,但較低的值的270和286 kJ / mol的范圍,也被觀察到。Asεc標(biāo)志著亞顆粒有點(diǎn)不發(fā)達(dá),加工硬化和動(dòng)態(tài)恢復(fù)行動(dòng),其中也包含了再結(jié)晶核的變化,在微觀結(jié)構(gòu),它也是一個(gè)靜態(tài)后發(fā)生的結(jié)構(gòu)性變化的臨界應(yīng)變變形。低合金鋼和在圖CMn鋼等。巴勒克拉夫,和摩利臣是指,在較低溫度下進(jìn)行比加熱溫度和測(cè)試溫度0Nεp沒有影響這些顯示的測(cè)試。較高的溫度加熱/測(cè)試結(jié)果前一組,將給予更大的初始晶粒尺寸。顯示蛛網(wǎng)膜下腔出血等,Sakui等,以及羅伯茨等。增加,晶粒尺寸(D0),導(dǎo)致增加inεp,他們的數(shù)據(jù)表明αD0 ^ 1 / 2的詞語(yǔ)和術(shù)語(yǔ)的形式εp關(guān)系 應(yīng)力F)。對(duì)于曲線圖,K = 2,這是與其他鋼變形株<εc觀察值相一致。這種關(guān)系t0.05 = 0。27t0.5和t0.95 = 2.08 T0.5,即重結(jié)晶所得超過為了在時(shí)間的幅度。特征時(shí)間T0.5要么金相或恢復(fù)方法測(cè)量,應(yīng)變的依賴,是幾個(gè)鋼圖所示。3.4。所有的曲線顯示為菌株陡峭的應(yīng)變依存度高達(dá)?0。8εp,適合關(guān)系t0.5αε-M,m的平均值= 4。這個(gè)值也是由鐵素體金屬上的意見。這種關(guān)系是適用的應(yīng)變下限是不確定的靜態(tài)再結(jié)晶臨界應(yīng)變沒有接受過系統(tǒng)的研究。這是<低碳950鋼0.05℃,而Djaic和Jonas觀測(cè)表明一個(gè)值> 0.055為高碳鋼在780 Norrison數(shù)據(jù)表明,鋼℃。很明顯的,這種差異是否產(chǎn)生差異?建議由簡(jiǎn)單依賴溫度或組成的折線圖。3.2可能是不現(xiàn)實(shí)的。這值得進(jìn)一步研究低毒株可應(yīng)用于軋板的最終通過,如前所示,這些可能最終晶粒尺寸上有顯著的影響,如果他們超過靜態(tài)再結(jié)晶臨界應(yīng)變。T0.5陡峭的依賴ε應(yīng)變范圍,莫里森指出,有研究?jī)蓚€(gè)數(shù)量級(jí)的訂單,沒有應(yīng)變率的影響。這是多少有些令人吃驚的,有趣的應(yīng)變率(或Z)在任何特定的應(yīng)變?cè)黾拥牧鲃?dòng)應(yīng)力。預(yù)計(jì)將增加流動(dòng)應(yīng)力增加隨機(jī)的位錯(cuò)密度,減少亞晶尺寸,從而增加儲(chǔ)存的能量,亞晶界提供了最大的貢獻(xiàn)的儲(chǔ)存的能量和應(yīng)變的取向差增加,再結(jié)晶的驅(qū)動(dòng)力將增加。然而,這將增加預(yù)計(jì)將應(yīng)變,線性的,所以更大的應(yīng)變依賴的T0.5也必須出現(xiàn)從核點(diǎn)密度和核率的增加。因此,缺乏應(yīng)變率的影響可能反映儲(chǔ)存的能量和下部結(jié)構(gòu)的發(fā)展在任何應(yīng)變補(bǔ)償效果。這與不銹鋼應(yīng)變率觀察到的效果。
Djaic和Jonas的觀測(cè)結(jié)果表明,突然的變化發(fā)生應(yīng)變依賴于應(yīng)變?0.8εp的獨(dú)立性,如圖所示。3。4。與此對(duì)應(yīng)合理預(yù)計(jì)forεc應(yīng)變的產(chǎn)生是因?yàn)轭A(yù)先存在的重結(jié)晶核總是在變形的結(jié)構(gòu)株更大thanεc。在這些條件下的靜態(tài)再結(jié)晶被稱為
“metadynamic”,以區(qū)別于“古典”的再結(jié)晶后的低時(shí)變形后形成的原子核必須的壓力?;謴?fù)測(cè)量結(jié)果表明,再結(jié)晶動(dòng)力學(xué)可能有污漬后,順利進(jìn)入穩(wěn)定的狀態(tài)顯示后株betweenεc和穩(wěn)定狀態(tài)的發(fā)病的復(fù)雜的形式,直接金相觀察和靜態(tài)再結(jié)晶,Avrami方程的指數(shù)k的價(jià)值下降到?1。這意味著,t0.05 = 0.074 T0.5和t0.95 = 4.33 T0..5島E.靜態(tài)再結(jié)晶所得超過兩個(gè)數(shù)量級(jí),在時(shí)間,使變形過程中動(dòng)態(tài)再結(jié)晶的結(jié)構(gòu)后,株。
3。2亞晶和位錯(cuò)強(qiáng)化
已變形引入的缺陷的強(qiáng)化作用表示贊賞多年,它已被用于提高,特別是在金屬和合金的冷加工技術(shù)實(shí)力水平的一種手段。最近的注意力已經(jīng)通過保留在熱加工材料的子結(jié)構(gòu)在強(qiáng)度增加。例如,一個(gè)控制軋制延伸到較低的溫度下,在微合金鋼的情況下,被稱為屈服強(qiáng)度添加了重大的貢獻(xiàn)。這是通常所帶來的兩階段滾動(dòng)γ+α一個(gè)地區(qū)或氣溫仍然較低,單相鐵素體。在很大程度上取決于困難或回收或再結(jié)晶過程,否則由此產(chǎn)生的結(jié)構(gòu)。其目的是允許一定程度的恢復(fù)進(jìn)行,但防止再結(jié)晶,亞晶界釘扎特意通過沉淀。在微合金鋼中,這通常是由于碳化物和氮化物或碳氮。
第四章塑料加工及成型模具
4。1鍛造
本節(jié)簡(jiǎn)要介紹了鍛造業(yè)和其產(chǎn)品,他們?cè)谖覀兊纳罘绞街械闹匾饔?,突出自己的技術(shù)和經(jīng)濟(jì)意義。
在早期的鍛造天是塑造金屬加熱和錘擊的過程。今天,金屬并不總是鍛造加熱和工作可能由幾種類型的應(yīng)用影響或擠壓力迅速精密重型機(jī)械執(zhí)行。在今天的鍛造行業(yè)的技能和經(jīng)驗(yàn)豐富的forgeman判斷增強(qiáng)調(diào)制解調(diào)器技術(shù)的機(jī)器,產(chǎn)生無與倫比的力量和實(shí)用的金屬部件。鍛造藝術(shù)正在增強(qiáng)在以越來越快的速度的鍛造科學(xué)。因此,機(jī)械零件服務(wù)的要求也越來越嚴(yán)重,鍛造已經(jīng)成為比單純的金屬成型多。鍛造許可證予以細(xì)化和控制,以提供更好的機(jī)械性能的金屬結(jié)構(gòu)。此外,鍛造生產(chǎn)導(dǎo)向,遵循的一部分,因此在材料的最大強(qiáng)度效率的形狀的金屬,可在一個(gè)連續(xù)的“糧食流”。因?yàn)閹缀跛械慕饘倏梢詡卧?,鋁鋯廣泛的組合,機(jī)械和物理性能可滿足要求苛刻的太空時(shí)代的應(yīng)用程序。
從技術(shù)上講,鍛造可給金屬的過程中定義的塑造,提煉,并改善其機(jī)械性能的影響或壓力下,通過控制塑性變形的效用增加。但鍛造的真正含義,可以更清楚地認(rèn)識(shí)到考慮多種方式服務(wù)人類和鍛造件,提供設(shè)計(jì),采購(gòu)和使用它們的重要特征。
鍛件通常是在臨界點(diǎn)的沖擊或壓力-----尤其是在可靠性和人體的安全性受到影響,但在鍛件的形狀,大小和屬性種類繁多的機(jī)器和交通工具上發(fā)現(xiàn)擴(kuò)展了當(dāng)前的應(yīng)用程序列表和未來潛在用途遠(yuǎn)遠(yuǎn)超出了這一點(diǎn)。
從規(guī)模的角度來看,例如,鍛件的范圍可能從微小的收銀部分每盎司加權(quán)分?jǐn)?shù),以大規(guī)模的結(jié)構(gòu)組件加權(quán)數(shù)噸。同樣,鍛件覆蓋幾乎每一個(gè)有用的人的基本配置的形狀。他們可在操作溫度范圍從低溫的水平,超過3 000 ° F和在腐蝕性,環(huán)境,自然可以想出。鍛件經(jīng)濟(jì)競(jìng)爭(zhēng)力與其他類型的相應(yīng)的材料生產(chǎn)的零部件。
雖然不是在國(guó)民生產(chǎn)總值的巨大的商業(yè)鍛造業(yè),它是一個(gè)巨人的貢獻(xiàn)我們的生活和我們的國(guó)防的標(biāo)準(zhǔn)。今天的大部分機(jī)器和交通工具的經(jīng)營(yíng)能力在很大程度上依賴于偽造組件實(shí)現(xiàn)的屬性。沒有他們提供的鍛件和性能特點(diǎn),汽車,飛機(jī),卡車,農(nóng)具,土方機(jī)械,導(dǎo)彈,工業(yè)發(fā)動(dòng)機(jī)和機(jī)器,和國(guó)防的實(shí)現(xiàn),因?yàn)槲覀冎浪麄儠?huì)不會(huì)是可行的。
調(diào)制解調(diào)器制造商展望未來,預(yù)測(cè)行業(yè)未來的需求和發(fā)展的產(chǎn)品和服務(wù),以滿足他們。正在確定新的市場(chǎng),探索新技術(shù),新的方法和流程,細(xì)化。
由于材料的使用效率變得更加必要,鍛件的能力,以最小的重量提供實(shí)力變得更有吸引力。隨著越來越多的使用成本高昂,難以機(jī)合金,相對(duì)精度和鍛件的三維均勻成為較為理想。鍛件產(chǎn)品的過程中,如舊的古代,是為明天的新。
4。1。1閉式模鍛
---封閉生產(chǎn)模具,鈦和鎳鍛造---基合金,這是最嚴(yán)格的航空航天應(yīng)用中指定的,是一個(gè)復(fù)雜的過程順序。一個(gè)最基本的要求是密切坯材料和模具偽造負(fù)責(zé)塑造材料的幾何形狀,質(zhì)量和最終客戶的工程屬性要求的制造商之間的合作。
同時(shí)高溫合金和鈦合金鍛造,必須遵循嚴(yán)格的學(xué)科,獲得溫度控制的程度和需要產(chǎn)生可預(yù)見的“鍛造”式結(jié)構(gòu)令人滿意的回應(yīng),以雇用近固溶溫度變形率當(dāng)前的規(guī)范要求性能良好的平衡。
需要小心控制在實(shí)現(xiàn)“鍛造”結(jié)構(gòu),這是可預(yù)見的和殘余應(yīng)變/粒結(jié)構(gòu)的重復(fù)性的主要因素是:死亡執(zhí)行幾何,模具預(yù)熱溫度,潤(rùn)滑/絕緣;動(dòng)能輸入;持續(xù)監(jiān)測(cè)工件表面溫度。
模具預(yù)熱模具材料的強(qiáng)度所施加的限制。潤(rùn)滑/絕緣需求歧視的使用,如果加以適當(dāng)?shù)淖冃魏凸ぜ膽?yīng)用程序的不同覆蓋率達(dá)到100%,通過部分覆蓋,無潤(rùn)滑。幾杯不同的熔點(diǎn)和粘度進(jìn)行了調(diào)查和用于高溫合金和鈦鍛件。
在跌落沖壓,的動(dòng)能輸入控制是實(shí)現(xiàn)TUP是提出的高度,從而相當(dāng)準(zhǔn)確地確定每個(gè)打擊的能量。打擊的頻率需要小心控制,實(shí)現(xiàn)了平衡,從而將持有偽造一個(gè)窄帶內(nèi)的溫度。要做到在一個(gè)可重復(fù)的方式,涉及監(jiān)督的運(yùn)作和不斷監(jiān)測(cè)工件表面溫度影響的動(dòng)能加熱之間的平衡,自然冷卻,死寒蟬錘操作工和技術(shù)人員之間的密切合作。后者是最小化鍍膜玻璃和蒸汽緩沖底模鍛造有時(shí)會(huì)就走了旋轉(zhuǎn)。在處理在一個(gè)固定的底模鍛造的易用性和速度方面的優(yōu)勢(shì)是顯而易見的,因?yàn)槌^一個(gè)因搬遷已躍升登記模具鍛件的幾秒鐘的延遲,可顯著影響,因?yàn)樽罱K結(jié)果在延遲熱損失。
通過使用技術(shù)描述不寒而栗由于模具接觸的鍛件表面的程度,其表面開裂的潛力和金屬模具接觸面附近的流動(dòng)的限制而產(chǎn)生的效果,可以最小化,從而在許多情況下,實(shí)現(xiàn)了更經(jīng)濟(jì)的使用比鍛造工藝的鍛造及模具在連續(xù)接觸的材料。
4。1。2鍛壓
鍛壓采用塑料金屬變形緩慢的擠壓動(dòng)作,迅速的影響錘子打擊對(duì)比。擠壓的動(dòng)作進(jìn)行完全徹底的工作,整個(gè)節(jié)的一部分被按下的中心。這些壓力機(jī)是垂直型,可通過機(jī)械或液壓操作。機(jī)械壓力機(jī)是更快的操作和大多常用。容量范圍從500噸至10000噸。對(duì)于小記者鍛件。封閉的印象死亡;只有一個(gè)中風(fēng)的RAM通常需要執(zhí)行鍛造的最大壓力是建立中風(fēng)力量形成的金屬。可作為獨(dú)立的單位模具安裝,或可能會(huì)變成一個(gè)單一的塊把所有的模腔。對(duì)于小型鍛件個(gè)人死于單位都比較方便。在銅合金鍛件可以小于鋼草案提出了不同的金屬模具的設(shè)計(jì)有一些區(qū)別。因此,可以產(chǎn)生更復(fù)雜的形狀。這些合金的流動(dòng)以及在模具,很容易擠出。在鍛壓一個(gè)更大的比例投入機(jī)器總工作是傳播比在落錘落錘的影響press.Much,吸收是由機(jī)器和基礎(chǔ)金屬。按金屬減少速度更快,而且經(jīng)營(yíng)成本因此降低。大多數(shù)記者鍛件形狀對(duì)稱,表面是相當(dāng)順利,并提供了更緊密的公差比是由落錘獲得。然而,許多不規(guī)則和復(fù)雜形狀的零件可以是偽造的,更經(jīng)濟(jì)模鍛。其他鍛造工藝制成的部件大小的操作通常用于鍛造壓力機(jī)。
在模鍛,金屬片,大約或大約所需的形狀,是擺之間的模具成品件的確切形式面臨,并被迫采取這種形式,通過繪制模具一起。這種方法被廣泛用于制造鋼和黃銅零件。大錠,現(xiàn)在幾乎都是偽造的液壓機(jī),而不是用蒸汽錘,因?yàn)橛浾咚龅墓ぷ鞯牟粩嗌钊搿4送?,記者可以采取冷卻器錠和可以接近的尺寸。鍛件應(yīng)在大約相同的溫度為滾動(dòng);過程中,提高鋼的滾動(dòng)就像不物理性質(zhì),化學(xué)性質(zhì)。在終鍛重要的是不要有鋼太熱,過熱鋼機(jī)械性能差,遇冷。在加熱鍛造溫度通常是由眼睛判斷,但大量相同的模式,是偽造的一塊是在爐加熱溫度測(cè)溫儀表示,而且往往是自動(dòng)控制。
第5章塑料成型及模具
5。1。1注塑模具
5.1.1一般
注塑成型技術(shù)的處理器的持續(xù)發(fā)展的要求越來越多。注塑成型過程中最重要的問題無疑是正確的注射mold.Because設(shè)計(jì)成型形狀的影響不大,如有的建設(shè)最多樣化的注塑部件的機(jī)器。高效的生產(chǎn)主要取決于注塑模具。
模具的耐久性取決于他們的護(hù)理和治療。由于總是硬化和地面的運(yùn)動(dòng)部件和模具型腔,他們之間產(chǎn)生500000和100000000張。為了便于建設(shè),降低制造成本,注塑模具成為standardized.Some公司提供基本現(xiàn)成的方形或圓形,立即use.Only插入標(biāo)準(zhǔn)或卸料板模具設(shè)計(jì)的基礎(chǔ),那么,必須安裝到基礎(chǔ)。
5。1。2個(gè)基本模具結(jié)構(gòu)
5。1。2。1工作原理
注塑模具基本上由兩個(gè)halfs.One模具的一半包含澆道襯套和熱流道系統(tǒng),噴射系統(tǒng)。成型部分是設(shè)在分界線另一半的房子(ref.To ? DIN)
5。1。2。2單或者多腔模具
要成立一個(gè)關(guān)于在注塑模具型腔的選擇計(jì)算,需要準(zhǔn)確掌握的材料,要處理的注塑機(jī)和模具。
蛀牙和相對(duì)整機(jī)成本decrease.The生產(chǎn)對(duì)于一個(gè)給定的成型零件所需的時(shí)間越來越多的模具成本增加,取決于壁厚,注射速度,回收率,冷卻dolded材料所需的時(shí)間,冷卻模具的能力和保壓時(shí)間期限,如必要的附帶倍,射血時(shí)間,延遲時(shí)間等。因此,決定確定的腔數(shù)取決于:
(1)尺寸(成型零件的數(shù)量,交貨時(shí)間順序)
(2)形狀的模具零件(尺寸質(zhì)量要求)
(3)注塑機(jī)(鎖模力,塑化和注射容量)
(4)模具成本
有幾個(gè)已知的程序計(jì)算腔的經(jīng)濟(jì)。不幸的是,他們是如此不同,這是不可能的凝結(jié)。作為一個(gè)例子:
理論最大。腔數(shù)是:
F2必須等于或比F1小。F1是:注塑模具的注射模成型車間成型車間,造型車間注塑成型注射成形的研磨(地上,地下)磨削,磨光單型腔模具單型腔注射模的多腔腔達(dá)到詞語(yǔ)和術(shù)語(yǔ)的最大數(shù)量模多型腔注射模的阻尼力夾緊力;合模力塑化(使)成為可塑;(使)可塑注射容量注射容量
第6章生活及模具失效
6.1總則
正確選擇模具材料和模具制造技術(shù)的決定,在很大程度上,成型模具的使用壽命。模具可能有許多原因,如尺寸變化因磨損或塑性變形,表面光潔度惡化,潤(rùn)滑故障,開裂或破損,必須更換。在炎熱的印象模鍛,模具失效的主要模式是侵蝕,熱疲勞,機(jī)械疲勞和永久(塑料)變形。
物質(zhì)的侵蝕,也俗稱模具磨損,實(shí)際上是從模具表面的壓力和滑動(dòng)變形材料,耐磨耐模具材料,模具的表面溫度,在模具/材料界面相對(duì)滑動(dòng)速度和性質(zhì)接口層是最重要的因素,影響磨料模具磨損。熱疲勞發(fā)生在熱成型和結(jié)果死印象中的“熱檢查”的表面上。從循環(huán)的熱疲勞結(jié)果產(chǎn)生模具表面因接觸與熱變形材料。這種接觸會(huì)導(dǎo)致表層擴(kuò)大,因?yàn)楹芏傅臏囟忍荻?,表面層受到壓?yīng)力。在足夠高的溫度下,這些壓應(yīng)力可能會(huì)導(dǎo)致變形的表面層。當(dāng)模具表面冷卻,壓力逆轉(zhuǎn)可能發(fā)生的表面層,然后將在緊張。經(jīng)過反復(fù)循環(huán)以這種方式,疲勞會(huì)導(dǎo)致形成一支精干的模式,是公認(rèn)的熱量檢查。模具破損或開裂是由于機(jī)械疲勞和模具重載和局部應(yīng)力高的情況下發(fā)生。模具受到交替強(qiáng)調(diào)由于裝卸用餐的變形過程,這將導(dǎo)致裂紋萌生和最終失敗。
模具壽命和模具失效大大在一個(gè)給定的變形過程中存在的條件下,模具材料的機(jī)械性能的影響。一般來說,最顯著的屬性取決于過程溫度。因此,模具冷成型過程中使用的材料是用于熱成型的完全不同。
在金屬成形過程中使用分立部件生產(chǎn)中的設(shè)計(jì)和制造模具和模具材料的選擇是非常重要的的。模具必須作出適當(dāng)?shù)哪>卟牧系恼{(diào)制解調(diào)器的制造方法,以便在合理的成本提供可接受的模具壽命。通常的成型過程中的經(jīng)濟(jì)的成功取決于模具壽命和死每件的成本生產(chǎn)。對(duì)于一個(gè)給定的的應(yīng)用程序,選擇適當(dāng)?shù)哪>卟牧弦蕾囉谌N類型的變量:
(1)變量相關(guān)的過程本身,包括因素,如大小的模具型腔,型機(jī)和變形速度,初始庫(kù)存的大小和溫度,模具溫度要使用,潤(rùn)滑,生產(chǎn)速度和零部件的數(shù)量將生產(chǎn)。
(2)變量死加載的類型,包括速度加載,島E.,逐步影響或模具和變形的金屬(熱成型,這種接觸的時(shí)間是特別重要的),對(duì)模具的最大負(fù)荷和壓力,最高和最低模具溫度,和負(fù)載周期的死亡將數(shù)量之間的接觸時(shí)間遭受。
(3)模具材料的機(jī)械性能,包括淬透性,沖擊強(qiáng)度,熱強(qiáng)度(如果被認(rèn)為是熱成型)和電阻熱和機(jī)械疲勞。
6.2斷裂準(zhǔn)則
韌性斷裂準(zhǔn)則一般可以代表一個(gè)功能的形式: J F(變形歷史)DF = C其中F是有效的應(yīng)變和C的傷害值。韌性斷裂的共同假設(shè),由式為代表。(1),韌性斷裂時(shí),會(huì)發(fā)生在一個(gè)工件的最大傷害值超過臨界值或“臨界傷害值”。對(duì)于均質(zhì)材料中,這個(gè)關(guān)鍵的傷害值可以被視為一個(gè)材料常數(shù),類似的屈服應(yīng)力或拉伸強(qiáng)度。由于不同的韌性斷裂準(zhǔn)則導(dǎo)致不同的傷害值,臨界傷害值對(duì)應(yīng)不同的韌性斷裂準(zhǔn)則,對(duì)于一個(gè)給定的材料不同。許多實(shí)驗(yàn)研究已進(jìn)行了建立測(cè)試方法來確定成形性和/或斷裂極限圖,并已提出了幾種韌性斷裂準(zhǔn)則。數(shù)學(xué)上派生的韌性斷裂準(zhǔn)則已經(jīng)提出基于實(shí)驗(yàn)觀察。擴(kuò)展的研究一直側(cè)重于測(cè)試使用的有限元分析套件的變形和實(shí)驗(yàn)測(cè)試7韌性斷裂準(zhǔn)則。這項(xiàng)研究得出的結(jié)論是Cockroft和萊瑟姆的標(biāo)準(zhǔn)可能是實(shí)際應(yīng)用的最佳。Cockroft和萊瑟姆的標(biāo)準(zhǔn)如下:(2)其中,F(xiàn)F是有效的斷裂應(yīng)變,A *最大主應(yīng)力和F的有效應(yīng)力。關(guān)鍵的傷害值,C需要實(shí)驗(yàn)驗(yàn)證。C使用獲得的剪切荷載,本文提出,關(guān)鍵值分別為0.5,0.25和0。1。這些值尚未得到實(shí)驗(yàn)驗(yàn)證,但有適當(dāng)說明可能斷裂行為的位置和路徑。
6.4表面處理和潤(rùn)滑油溫鍛模具壽命的影響
在大多數(shù)金屬成形應(yīng)用,表面處理和潤(rùn)滑油的影響模具壽命的主要因素,因?yàn)樗鼈冎苯記Q定了界面摩擦和保溫。在一般情況下,在熱和溫鍛過程中,模具表面硬度下降,而模具的溫度增加在反復(fù)操作,從而誘發(fā)熱軟化。熱軟化的原因,盡管不被改變的形成負(fù)載模具的塑性變形。
6.4.1簡(jiǎn)介
金屬鍛造的過程總是伴隨著熱量的產(chǎn)生。這種由于塑性變形和摩擦界面結(jié)果在一個(gè)復(fù)雜和不斷變化的的溫度場(chǎng)的熱。為了預(yù)測(cè)在鍛造過程中的溫度場(chǎng)是非常重要的,因?yàn)樗鼤?huì)影響潤(rùn)滑條件下,材料變形過程中的行為,成品零件的質(zhì)量和模具的使用壽命。模具的使用壽命是限制磨損,熱裂解和疲勞,塑性變形等已經(jīng)有很多研究項(xiàng)目,探討這些因素的影響刀具壽命。然而,在一般情況下,模具表面硬度下降時(shí),在反復(fù)操作的死亡增加,這引起了溫鍛造工藝熱軟化溫度。熱軟化,加速磨損,熱裂解和疲勞等,模具的塑性變形。
為了提高模具壽命,熱處理已被執(zhí)行的死,以增加表面硬度,表面處理也適用于模具,以減少摩擦,增加保溫。由于表面處理,模具的熱性能改變。
潤(rùn)滑油的作用是減少模具和工件之間的摩擦,并減少在鍛造過程中的傳熱鋼坯模具。石墨,固體潤(rùn)滑劑,噴灑前溫成形過程中死亡或工件。根據(jù)石墨的傳熱系數(shù),從坯的模具,有不同的價(jià)值觀。此外,選擇合適的潤(rùn)滑劑為延長(zhǎng)模具壽命,導(dǎo)致降低傳熱從工件的模具。
影響模具使用壽命的主要因素是表面處理和相關(guān)的熱軟化潤(rùn)滑劑。表面硬度高和窮人的傳熱,使模具壽命延長(zhǎng)。
6.4.2一些研究的結(jié)論
在溫?zé)徨懺?,鋼坯傳熱模具減少模具表面的硬度,從而導(dǎo)致模具的塑性變形。表面處理和潤(rùn)滑劑,影響模具的硬度和傳熱系數(shù)。在這項(xiàng)研究中使用無治療,ionnitrided和氮化碳模具。其表面硬度和熱:
傳熱系數(shù)的測(cè)量,并相互比較。石墨,固體潤(rùn)滑劑,是用來種兩種:油基和水基。表面處理和潤(rùn)滑劑在溫成形溫度范圍的有利條件,導(dǎo)致延長(zhǎng)了模具壽命。結(jié)論如下:
(1)氮化碳死的硬度高于離子氮化和熱軟化實(shí)驗(yàn)結(jié)果沒有處理這些。由于一些研究的結(jié)果,它是確定氮化碳涂層,延長(zhǎng)模具壽命比離子氮化物和無治療是一個(gè)更有用的的。
(2)油基石墨的傳熱系數(shù)比在不同的實(shí)驗(yàn)溫度水性那些更高。特別是在850噸,它被廣泛用來作為熱成型溫度,石油為基礎(chǔ)的所有系數(shù)都高于水基。
(3)氮化碳的傳熱系數(shù)比別人低的離子氮化高于氮化碳,并沒有治療的是最高的。因此,氮化碳死是熱的影響比其他治療。氮化碳的表面硬度高,低傳熱系數(shù)水基石墨碳,氮化物和水基石墨被認(rèn)為是有利可圖的有利條件,在溫成形溫度,根據(jù)目前的研究條件,可以延長(zhǎng)模具壽命。
(4)此外,模具壽命主要是由塑性變形的影響,如殼式時(shí),油基潤(rùn)滑劑是比水更有害。特別是,以石油為主的無治療的情況下,延長(zhǎng)模具壽命不利。第8章的CAD / CAM
8.1計(jì)算機(jī)輔助設(shè)計(jì)和計(jì)算機(jī)輔助制造
縱觀我們的工業(yè)社會(huì)的歷史,許多發(fā)明專利,并已經(jīng)發(fā)展了全新的技術(shù)。惠特尼小號(hào)蒸汽機(jī),和福特的組裝線的可互換的零件,瓦特的概念“,但一個(gè)數(shù)的發(fā)展,最值得一提的是在我們的工業(yè)化時(shí)期。這些發(fā)展中的每個(gè)人都有影響生產(chǎn),因?yàn)槲覀冎浪?,并贏得了這些人應(yīng)該承認(rèn)我們的歷史書。也許是單一的發(fā)展產(chǎn)生了影響比以往任何技術(shù)制造更快速和顯著數(shù)字計(jì)算機(jī)。
由于計(jì)算機(jī)技術(shù)的出現(xiàn),制造的專業(yè)人士都希望自動(dòng)化設(shè)計(jì)流程,并使用自動(dòng)化制造工藝所開發(fā)的數(shù)據(jù)庫(kù)。計(jì)算機(jī)輔助設(shè)計(jì)/計(jì)算機(jī)輔助制造(CAD / CAM),成功地實(shí)施時(shí),應(yīng)刪除“墻”的設(shè)計(jì)和制造組件之間歷來存在。的CAD / CAM是指在設(shè)計(jì)和制造工藝中使用的計(jì)算機(jī)。其他條款的CAD / CAM的問世以來,已開發(fā):
?計(jì)算機(jī)圖形(CG)
?計(jì)算機(jī)輔助工程(CAE)
?計(jì)算機(jī)輔助設(shè)計(jì)和制圖(CADD)
?計(jì)算機(jī)輔助工藝規(guī)劃(CAPP)
這些剝離的所有條款是指具體方面的CAD / CAM的概念。CAD / CAM本身是一個(gè)更廣泛的,更具包容性。這是在自動(dòng)化和集成制造的心臟。的CAD / CAM的一個(gè)主要目標(biāo)是生產(chǎn)可用于制造產(chǎn)品,而產(chǎn)品設(shè)計(jì)開發(fā)的數(shù)據(jù)庫(kù)的數(shù)據(jù)。當(dāng)成功實(shí)施CAD / CAM涉及的一家公司的設(shè)計(jì)和制造元件之間的共同數(shù)據(jù)庫(kù)共享。
交互式計(jì)算機(jī)圖形(ICG)在CAD / CAM的重要作用。通過使用全球?qū)Ш叫l(wèi)星系統(tǒng)國(guó)際委員會(huì),設(shè)計(jì)人員開發(fā)出的產(chǎn)品而存儲(chǔ)數(shù)據(jù)的電子圖形圖像設(shè)計(jì)的圖形圖像。圖形圖像可以在二維(2D),或固體格式。ICG的圖像,使用等基本點(diǎn),線,圓和曲線的幾何特征。一旦創(chuàng)建,這些圖像可以很容易地編輯和操縱各種方式,包括放大,裁減,旋轉(zhuǎn)和運(yùn)動(dòng)。ICG系統(tǒng)有三個(gè)主要部分組成:1)硬件,包括計(jì)算機(jī)和各種外圍設(shè)備;2)軟件,包括計(jì)算機(jī)程序和系統(tǒng)技術(shù)手冊(cè)(目前流行的全球?qū)Ш叫l(wèi)星系統(tǒng)國(guó)際委員會(huì)在CAD / CAM軟件使用包括的AutoCAD,CADKEY,Pro / E的,UG,1GYZ軸定義,在指定的立方測(cè)量面積。來衡量的部分是固定的花崗巖板面,準(zhǔn)備探頭方向。當(dāng)探頭接觸點(diǎn)上的部分,點(diǎn)是指通過軸的關(guān)系。讀者對(duì)每個(gè)軸頭旅游點(diǎn)讀數(shù)的繼承與傳輸點(diǎn)的位置數(shù)據(jù)通訊接口。計(jì)算機(jī),然后計(jì)算出精確的幾何形狀和尺寸的部分信息。這些機(jī)器功能的速度,緩解和準(zhǔn)確性,以及檢查的時(shí)間也相應(yīng)減少。CMM可用于鍛件,鑄件,沖壓件,加工件的過程和最終檢驗(yàn)。
第10章質(zhì)量控制
與管理
10。1簡(jiǎn)介:工藝質(zhì)量與組織質(zhì)量
什么是質(zhì)量?的產(chǎn)品需要多少質(zhì)量?質(zhì)量測(cè)量數(shù)值和/或它也涉及美學(xué)問題呢?特別是什么是“質(zhì)量成本”?此外,有沒有一個(gè)“沒有足夠的質(zhì)量成本”?
首先要回答這些問題,質(zhì)量的定義是必要的。在這接下來的幾節(jié)中,將幾個(gè)定義。
第一個(gè)定義,認(rèn)為設(shè)計(jì)師要求所需的直徑測(cè)量作為制造軸直徑等參數(shù)。這是過程質(zhì)量的一個(gè)方面。
第二個(gè)定義認(rèn)為更具全球性的措施,公司的整體素質(zhì)。這是有關(guān)組織的質(zhì)量或全面質(zhì)量管理(TQM)。美國(guó)的工程師,特別是我們戴明,全面質(zhì)量管理,但日本企業(yè)如豐田,早期的倡導(dǎo)者們熱情申請(qǐng)。幸運(yùn)的是,到1982年,圖書,如湯姆彼得斯在讓美國(guó)制造商意識(shí)到什么,他們已經(jīng)做恢復(fù)美國(guó)制造業(yè)競(jìng)爭(zhēng)力的卓越搜索的:(一個(gè))在工廠質(zhì)量保證,(二)全面質(zhì)量管理在整個(gè)完整的組織,和(C)精簡(jiǎn)管理層次。加爾文(1987)描述了八個(gè)方面的全面質(zhì)量管理,他們也波多里奇獎(jiǎng)和ISO 9000的系統(tǒng)評(píng)價(jià)。
10.2在工廠車間的過程質(zhì)量定量測(cè)量:利用統(tǒng)計(jì)質(zhì)量控制(平三)
工序質(zhì)量是直接相關(guān)的制造過程中的物理,具體而言,其固有的精度和控制。
想象一下,在英國(guó)酒吧玩飛鏢的朋友組。每個(gè)球員是三個(gè)飛鏢。我們的目標(biāo)是到每個(gè)罰球命中靶心。每個(gè)球員都需要轉(zhuǎn)一轉(zhuǎn),然后全面恢復(fù)。多少靶心眼愉快的飲用水和打一個(gè)小時(shí)后,每個(gè)球員的得分?靶心周圍發(fā)生什么類型的聚類?
球員之一,經(jīng)驗(yàn)非常豐富,分?jǐn)?shù)很多靶心眼睛。此外,即使在公牛的眼睛是不打,飛鏢聚集其周圍對(duì)稱的一個(gè)小圓圈,直徑50毫米(2英寸)。
播放二是經(jīng)驗(yàn)不足和分?jǐn)?shù)的一些牛市的眼睛都取得了很大的笑聲,董事會(huì)往往是錯(cuò)過了在地上完全和四處飛濺的飛鏢。
播放四有一個(gè)奇怪的風(fēng)格。計(jì)分板的左側(cè),所有的飛鏢組合在一起。沒有公牛的眼睛取得的。然而,飛鏢2其直徑在25微米。
二是機(jī)不準(zhǔn)確。軸的直徑有一個(gè)更大的傳播,高達(dá)500微米(0.02英寸)直徑25毫米(微米+ I-250)。與前兩鏢玩家,機(jī)兩機(jī)一臺(tái)不到準(zhǔn)確。也許機(jī)兩可用于一些圓柱形零件的粗加工,精度并不重要?;蛘撸匾牡氖?,SQC質(zhì)量保證部可以推薦機(jī)器維修,提高了機(jī)器。
機(jī)已無望的準(zhǔn)確性。有些零件是到目前為止,關(guān)閉了25毫米或1英寸的目標(biāo),質(zhì)量保證部停止任何類型的機(jī)器上生產(chǎn),并開始嚴(yán)重的維護(hù)工作。也許是一個(gè)執(zhí)行機(jī)構(gòu)或絲桿受損,偶爾,機(jī)枝到位的方式,從它所需的設(shè)置。
這里是一個(gè)重要的問題:準(zhǔn)確度和精確度之間的區(qū)別是什么?機(jī)四,四像播放,演示機(jī)一臺(tái),或球員之一相比,這種差異。機(jī)四的結(jié)果顯示了很大的精度。然而,精度體現(xiàn)在錯(cuò)誤的地方。一些與機(jī)器的能力,找到一個(gè)準(zhǔn)確的定位錯(cuò)誤。也許夾具滑倒在一個(gè)批處理運(yùn)行的開始。第一軸是從一開始就的不正確的,但所有的軸的直徑大約集群,不正確的位置。
機(jī)五開始,但工具磨損過程中惡化。SQC的團(tuán)隊(duì)必須認(rèn)識(shí)到日益惡化的因素,并修復(fù)它。
機(jī)六是相當(dāng)不錯(cuò)的整體,但偶爾產(chǎn)生一個(gè)真正的窮人的部分是。也許,這是一個(gè)機(jī)與控制器的錯(cuò)誤,這說明短路,并導(dǎo)致重大錯(cuò)誤不時(shí)。
對(duì)于這個(gè)例子,軸的尺寸數(shù)據(jù),監(jiān)測(cè)和監(jiān)督由質(zhì)量保證部。統(tǒng)計(jì)分析和結(jié)果將在廣泛的計(jì)算機(jī)數(shù)據(jù)庫(kù)中存儲(chǔ)的。
這些統(tǒng)計(jì)質(zhì)量控制(SQC)數(shù)據(jù)庫(kù)保持最高的質(zhì)量保證水平的關(guān)鍵。他們提供的小心機(jī)調(diào)整,機(jī)器維修調(diào)度,及時(shí)報(bào)告錯(cuò)誤或漂流行為,和機(jī)器診斷信息。定一個(gè)特定的機(jī)器維修的建議,也可以綁進(jìn)廠調(diào)度。
這樣的質(zhì)量保證,還可以包括Pokayoke方法。在日本Pokayoke_僅僅意味著“無缺陷”。一些額外的設(shè)備添加到一臺(tái)機(jī)器,以防止從一個(gè)運(yùn)營(yíng)商,像一個(gè)錯(cuò)誤,在錯(cuò)誤的方式加載酒吧,它可應(yīng)用于機(jī)械設(shè)計(jì)。
最后,田口質(zhì)量保證的方法可能包括正式的技術(shù)。Taguchi方法集中在制造產(chǎn)品的噪聲類型,然后進(jìn)行記錄統(tǒng)計(jì)方法,以減少其發(fā)生。此外,田口方法的文件丟失的時(shí)間,消費(fèi)者對(duì)產(chǎn)品的消耗,產(chǎn)品的運(yùn)行和/或它在一些日后維修。所有這些問題,然后追溯到通過工廠的噪聲源和分配成本函數(shù)。
第四篇:期末英語(yǔ)翻譯部分
補(bǔ)全句子: 1.(應(yīng)該適合人類,并有助于人機(jī)合一)Should serve man and contribute to cybernetics 2.(不斷發(fā)新產(chǎn)品,并具備以前計(jì)算機(jī)所不具備的功能)design new machines continuously, which are capable of doing work that earlier computers could not;(在平常活動(dòng)中肩負(fù)起更多的責(zé)任)take over more functions in daily life.3.(預(yù)測(cè)產(chǎn)品和服務(wù)的市場(chǎng)可接受度)predict which products and services the market will bear;(評(píng)估產(chǎn)品生命力的寶貴工具)an invaluable tools for assessing the viability of a product 4.(每當(dāng)DOS執(zhí)行一個(gè)程序)each time DOS executes a program;(當(dāng)你正在通過Microsoft Windowws執(zhí)行多個(gè)程序時(shí))when executing multiple programs via Microsoft Windows 5.(當(dāng)工作難找的時(shí)候)When jobs are scarce;(常常被有經(jīng)驗(yàn)的工人排擠)tend to be pushed out in favor of experienced workers 6.(在這些更強(qiáng)大的目標(biāo)導(dǎo)向的工具方面進(jìn)行投資是有意義的)it is a good time to invest in these more powerful , goal-directed tools 7.(為用戶進(jìn)行內(nèi)容定制)it executes the user’s custom contest;(將處理后的內(nèi)容轉(zhuǎn)換到所用的特定設(shè)備)it then loads the content onto the designated device in use 8.(不懂得與時(shí)俱進(jìn))do not keep up with regulations;(只會(huì)束縛人們的手腳)haue their hand tied 9.1.(是一個(gè)富于變化的領(lǐng)域,包括許多相互作用的組成部分)a diverse field with many interacting components;(賦予信息,激發(fā)對(duì)話)imparts information, stimulates dialogue 10.(從食品,動(dòng)物到植物健康部門的各種專家)a diverse range of experts from the food, animal and plant health sectors 11.(從某種程度上)to a certain extent;(我國(guó)土地資源的后續(xù)利用,食品安全和生態(tài)環(huán)境)follow-up utilizing of land resource, food security and ecological environment of our country 12.(細(xì)菌太小,肉眼看不見).Bacteria are too
small to see with the naked the eye;(以避免細(xì)菌污染)avoid contamination with bacteria 13.(常被用作奶油的代用品)often used as a
substitute for butter
14.(轉(zhuǎn)基因食品)genetically modified food;(轉(zhuǎn)
基因食品優(yōu)點(diǎn))the merit of GM food 15.(加強(qiáng)食品監(jiān)督與管理)strengthen the
supervision and administration of food safety;(維護(hù)好食品市場(chǎng)的秩序)maintain a good order of the food market
16.(采取了一項(xiàng)方案,就是在其投入英國(guó)市場(chǎng)食
品上做標(biāo)注)introduced a labeling scheme for their products in the British market
17.(停止進(jìn)口諸如火腿,肉制品等)suspend the
import of meats such as ham, pork products and others
18.(沒能說服數(shù)百人改掉這一惡習(xí))has failed to
convince hundreds of millions of people to abandon the bad habit 19.(令人質(zhì)疑)raise eyebrows
20.(延伸覆蓋大范圍的市場(chǎng))stretches across a
wide range of markets
21.(擦亮品牌)burnished the brand name 22.(為總裁們完成了一項(xiàng)最大的采購(gòu))have
made the ultimate acquisition for chief executives;(大手筆的花掉220億美元財(cái)富的一部分)splashed some of the $22bn fortune 23.(使谷歌在未來幾年里成為不可忽視的力量)
keep Google the force to be reckoned with for years to come
24.(以13.99的優(yōu)惠價(jià)格搶購(gòu)最新、最喜歡的T
恤衫)snap up your latest favorite T-shirt on sale for $13.99
25.(你將或多或少不得不面對(duì)數(shù)額巨大的出價(jià))
you will be faced with a huge number of offers, to varying degrees
26.(使你在行業(yè)中處于更有利的地位)give you
a competitive advantage in your industry 27.(占谷歌所有搜索查詢的四分之一)accounts
for a quarter of all Google search queries 28.(嘗試區(qū)分人類訪客和自動(dòng)化訪問者或機(jī)器
人)try to distinguish human visitors from automated visitors or robots
29.(富于創(chuàng)新精神的搜索引擎)innovative search engines 30.(提出設(shè)計(jì))come up with a design 31.(堅(jiān)守社會(huì)責(zé)任和保護(hù)自然環(huán)境的承諾)commitment to social responsibility and protecting the environment 32.(為訂立國(guó)際條約和行動(dòng)綱領(lǐng)建立共識(shí))builds consensus towards international treaties and programmes of action 33.(在我們的短暫一生中,最好貢獻(xiàn)莫過于此了)I don’t know of any better service to offer for the short time we are in the world 34.(我們要竭盡全力確?!毒┒甲h定書》生效)We should make every effort to ensure the Kyoto Protocol to come into force 35.(對(duì)生態(tài)環(huán)境影響相對(duì)較?。﹔elatively little effect on the ecological environment;(一項(xiàng)重要政策)an important policy 36.活著的樹木可以吸收碳)Living trees absorb carbon;(大氣中碳的釋放)the release of carbon into the atmosphere 37.(受由污染引起的酸雨影響)is affected by the acid rain caused by pollution 38.(盡管氮無毒且很大程度上不活潑)Although nitrogen is nontoxic and largely inert 39.(由清水狀態(tài)轉(zhuǎn)變?yōu)樵孱愡^量繁殖狀態(tài))from a clear –water state to an algal bloom 40.(毀滅一個(gè)地理上孤立的小族群)wipe out a geographically isolated group 整句翻譯:
41.為實(shí)現(xiàn)這些目標(biāo),在1997年簽署了《京都議定書》,并于2005年開始強(qiáng)制生效。The Kyoto Protocol, which set about realizing those aims, was signed in 1997 and came into force in 2005.42.如果不能重新擬定新的國(guó)際公約,人類將沒有任何機(jī)會(huì)來防治嚴(yán)重的氣候突變問題。Without a new global agreement , there is not much chance of averting serious climate change.43.人們擔(dān)憂的是對(duì)碳排放征稅將使商業(yè)和經(jīng)濟(jì)受到創(chuàng)傷。What is worrying is that carbon taxes will hurt business and the economy.44.請(qǐng)你舉一個(gè)具體的例子,說明你是怎樣對(duì)你所處的環(huán)境進(jìn)行評(píng)估并找到重點(diǎn),以獲得你所期望的結(jié)果的。Provide an example of how you assessed a situation and achieved good results by focusing on the
most important priorities.45.我們決心將每一個(gè)項(xiàng)目的成本降到最低,盡量提高效益。We are determined to minimise the cost of each and every project and to maximize
cost-effectiveness.41.(智商體現(xiàn)一種遺傳的,即可繼承的特質(zhì),或
者是文化傳播的特質(zhì),該特質(zhì)受家長(zhǎng)和社會(huì)經(jīng)濟(jì)地位的影響。無論是哪一種,測(cè)試智商都不能影響社會(huì)的流動(dòng)性).IQ measures a genetic, and therefore heritable, traits or a culturally transmitted trait, influenced by parents and socio-economic status.Either way, testing IQ could not influence social mobility.42.(數(shù)據(jù)已經(jīng)添加或更新在數(shù)據(jù)庫(kù)中,但由于沒
有達(dá)到從屬記錄源中的標(biāo)準(zhǔn)而將無法顯示)43.The data was added or updated in the database,but will not be displayed because it does not satisfy the criteria in the subordinate record source.44.(沒有一種學(xué)科方法證明,暴露于10ppm某
種污染達(dá)24小時(shí)是“安全的”,而暴露在超過那個(gè)污染程度便是“危險(xiǎn)的”)There no scientific way to demonstrate that exposure to a pollutant in a concentration of one hundred parts per million for twenty-four hours is “safe”, while
exposures
above
that
level
ale
“dangerous”.45.(香港大學(xué)非常重視研究工作,專門成立了研
究生院協(xié)調(diào)各學(xué)院的研究教學(xué)工作,確保研究教育的質(zhì)量)With much emphasis on research activities, Hong Kong university has established a Graduate School to co-ordinate research among faculty members and to ensure quality research and education.46.(傳統(tǒng)的看法人為錯(cuò)誤消息框的作用是在用
戶錯(cuò)了時(shí)通知他們。實(shí)際上,大多數(shù)錯(cuò)誤公告的作用是在計(jì)算機(jī)對(duì)指令感到不明時(shí)向用戶報(bào)告)Conventional wisdom has held that error messages tell users when they have made a mistake.Actually, must error bulletins report when the computer gets confused.47.(由于某種原因,越來越多的人逐漸重視飲食
問題。無論因?yàn)榍榫w上的壓力或是身體上的意外創(chuàng)傷,還是由于自信心的緣故,人們似乎都從飲食上尋求慰藉,而不是去尋求專業(yè)幫助)More and more people are developing eating issues for many different reasons.Whether it is because of emotional stress, traumatic incidents, or self-confidence issues ,people seem to run to food for comfort instead of seeking professional help
48.(其他人爭(zhēng)論說,糧食匱乏不是糧食產(chǎn)量的問題,而是政府忽視了農(nóng)業(yè)發(fā)展,未能有效利用糧食援救。而且保護(hù)性的貿(mào)易壁壘使消除饑餓更加困難)Others argue that food insecurity is not an issue of a shortfull in food production but rather that governments have neglected agricultural development ,made ineffective use of food aid ,and ,through protective trade barriers, made hunger alleviation more difficult to attain.49.你是否想過為什么快餐連鎖店能夠立刻做好你所點(diǎn)的菜,而在家里媽媽總是要花費(fèi)幾個(gè)小時(shí)的時(shí)間做飯?答案很簡(jiǎn)單。快餐連鎖店使用了能夠加快烹飪過程的物質(zhì),而科學(xué)證明,這些物質(zhì)有害人體健康,如果長(zhǎng)期食用,會(huì)產(chǎn)生嚴(yán)重的危害。Have you ever wondered as to why the fast food joint are able to provide you with your order in no time whereas mom at home takes hours to cook? The answer lies in the simple fact that in fast food joints substances that enhance the cooking process are used.It has been scientifically proved that these substances are very harmful to health and pose serious threats on continuous consumption.50.這看上去好像是科幻小說中的情節(jié):政府已經(jīng)宣稱克隆動(dòng)物所產(chǎn)的肉和奶是安全的,而今,克隆食品赫然出現(xiàn)在了全國(guó)的食品供應(yīng)鏈中。It sounds like a scenario from a science-fiction novel: The government has declared that meat and dairy from cloned animals is safe.and now cloned products can show up in the nation’s food supply.53 51..如今,食品和藥物管理局(FDA)將要求進(jìn)口商能夠證實(shí)他們外國(guó)的供應(yīng)商正在采取必要的安全防范措施。換句話說,他們應(yīng)該能夠確定來自智利的黑鱸與來自緬因州的龍蝦符合同樣的安全標(biāo)準(zhǔn)。Now, the FDA will
require importers to be able to verify that their foreign suppliers are taking the necessary safety precautions.In other words ,they’ll be able to make sure that sea bass from Chile meets the same safety standards as lobster from Maine.整句翻譯:
52.如果該公司能夠迎接復(fù)雜的、高度精密的生產(chǎn)
和極端期限的挑戰(zhàn),它不僅能提高自身作為行業(yè)翹楚的聲譽(yù),而且還會(huì)打開其他機(jī)會(huì)之門。If this company can meet the challenge of the complex, high-precision production and the tight deadline, it will not only burnish its reputation as industry leader but open up other opportunities.53.BP(英國(guó)石油)令人吃驚的談到其在中國(guó)擴(kuò)
張的雄心。不多,分析師們警告稱,中國(guó)煉油行業(yè)盈利能力不佳意味著在該行業(yè)的任何投資到頭來都可能是不具吸引力的。BP has raised eyebrows by talking about its ambitions for expansion in China.However, analysts warned that the poor profitability of China’s refining industry meant that taking a stake in the sector might prove unattractive.54.即使經(jīng)過幾年溫和增長(zhǎng),股票期權(quán)也能使投資
者獲得可觀收益。Even after a few years of moderate growth, stock options can produce a handsome return for investors.55.空中客車公司(Airbus)與波音公司一直就世
界軍事飛機(jī)合同進(jìn)行一場(chǎng)長(zhǎng)期的殊死戰(zhàn)斗。就在一個(gè)月前在美國(guó),EADS,空中客車的母公司,拿走了波音公司一個(gè)將近四百億美元的空中加油機(jī)合同。Airbus have been fighting a long and bruising battle with Boeing for military aircraft contracts around the world.Just a month ago in the U.S., EADS, the parent company of Airbus , snatched away a nearly 40 billion air tanker contract from Boeing.56.在現(xiàn)在所有語(yǔ)言中沒有一個(gè)詞可以準(zhǔn)確地描
述信息技術(shù)對(duì)人類生活的巨大影響。No word in all languages exists to describe the great impact of information technology on human life.
第五篇:專業(yè)英語(yǔ)翻譯
Freeways,especially those built to Interstate standardsare the safest of the various classes of highways.高速公路,尤其是那些按照州際公路標(biāo)準(zhǔn)建造的是各種公路里面最安全的.While control of access, which limits vehicle conflicts(車輛沖突), isa primary factor in relatively low accident, injury,and fatality rates(事故,死亡率), other design features, such as wide medians and shoulders roadsides clear of obstructions, and the extensive use of protective barriers(護(hù)欄), are key factors as well.出入口控制減少車輛沖突,是獲得較低的交通事故率和傷亡率的一個(gè)主 要因素。另外,其他的設(shè)計(jì)特性,如較寬的中央分隔帶和較寬的路肩、路邊無障礙物、大量采用防護(hù)欄等也是關(guān)鍵要素。
The higher design speeds(設(shè)計(jì)速度)used for freeways result in long sight distances(視距)due to long radiushorizontal curves and long vertical curves, and otherdesirable design features that create a safe drivingenvironment.高速公路采用較高的設(shè)計(jì)速度導(dǎo)致的長(zhǎng)視距是由于大半徑水平曲線和長(zhǎng)的豎曲線,以及其他創(chuàng)造安全的駕駛環(huán)境的適宜的設(shè)計(jì)特性.Although most of the nation’s freeways enjoy this
relatively high level of design and safety, there are many opportunities for further enhancements.盡管全國(guó)絕大部分高速公路最喜歡這樣的設(shè)計(jì)和安全性比較高的水平,但還是有很多地方需要進(jìn)一步增強(qiáng)。
Safety improvements on freeways can also result in substantial savings in life and property(生命和財(cái)產(chǎn))because freeways carry 25 percent of the nation’s total traffic.高速公路安全方面的改善,還會(huì)節(jié)約大量的生命財(cái)產(chǎn)資源,因?yàn)楦咚俟妨髁空剂巳珖?guó)的總流量的25﹪。
Selecting the design speed for a freeway is an important safety element because most geometric criteria(準(zhǔn)則,標(biāo)準(zhǔn))related to or depend on it.選擇高速公路的設(shè)計(jì)速度是一件重要的安全因素因?yàn)榇蟛糠值膸缀卧O(shè)計(jì)標(biāo)準(zhǔn)都是與它相關(guān)或者取決于它
In general, 110 kilometers per hour(km/h)should be the design speed for the mainline of a freeway , but it may need to be lower in areas of severe terrain or heavy development.一般來說,110千米每小時(shí)應(yīng)該作為高速公路主干道的設(shè)計(jì)速度,但是在崎嶇的地區(qū)或者施工難度大的地區(qū)可能需要降低。
For reconstruction, rehabilitation, and resurfacing(3R)
projects, the design speed should not be less than the original design speed or the current legal speed limit of that highway section.對(duì)于重建,恢復(fù)鋪新路面工程,設(shè)計(jì)速度不應(yīng)該低于平時(shí)設(shè)計(jì)速度或者那塊交通干線區(qū)域的目前規(guī)定的速度限制。Design speeds for interchange ramps(立交匝道)depend on the type of ramp selected, for example , loop,diamond, or direct, and the low-volume(低交通量), running speed(行駛速度)of the intersecting highway.立交匝道的設(shè)計(jì)速度取決于砸到的選擇類型,例如,環(huán)形、菱形、直線型以及低交通量,相交交通干線的運(yùn)行速度。Usually, the design speed is established by the most restrictive element of the ramp, typically, the sharpest curve(小半徑曲線).通常,這個(gè)設(shè)計(jì)速度被匝道的最限制的范圍,典型的是小半徑曲線。
Whatever design speed is selected, adequate transitions(轉(zhuǎn)變、過渡)from the freeway proper and at the ramp terminal(末端、末尾)or merge point(合流點(diǎn))should be developed.無論選擇多大的設(shè)計(jì)速度,都應(yīng)該發(fā)展來自高速公路本身的和在匝道末尾或者合流點(diǎn)的合適的過渡。
Safe and efficient traffic operations depend on adequate lane
and shoulder widths as outlined in A Police on Geometric Design of Highways and Streets.安全及高效的交通運(yùn)作取決于按照《道路的幾何尺寸的規(guī)定》設(shè)計(jì)的適當(dāng)?shù)男熊嚲€和路肩寬度。
The need to accommodate more traffic within existing or limited additional right-of-way on high-volume urban freeway has led some agencies to increase capacity by exchange full-lane or shoulder widths for additional travel lanes with reduced widths.在高交通量的城市高速公路上,在已有的或者額外有限的公路用地條件下,容納更多的交通的需求,導(dǎo)致許多機(jī)構(gòu)通過減小車道寬度或者路肩寬度來騰出額外的車道來提高通行能力。
Any proposed use of less-than-full-standard cross-section must be analyzed carefully on a site-by-site basis.Experience indicates that 3.3-m lane can operate safely if there are no other less-than-standard features;however, combined with shoulder-width reductions, substandard sight distance, and other features, 3.3-m lanes may not provide the same safe operation.任何少于全標(biāo)準(zhǔn)道路橫截面的提議都必須建立在充分論證的基礎(chǔ)上。經(jīng)驗(yàn)表明,不考慮其他低于標(biāo)準(zhǔn)的因素,3.3
米得行車道寬足夠保證安全。但是結(jié)合路肩寬度的減少,視距不足及其他因素,3.3米得行車道寬不能提供足夠的安全度。Converting shoulder to travel lanes for additional capacity through a short bottleneck section has been shown to significantly reduce congestion-related accidents on some projects.Removing shoulders for several kilometers, however, has not had the same result.在某些項(xiàng)目中,在短程的瓶頸路段為了額外的通行能力,將路肩轉(zhuǎn)變成行車道能顯著減少由道路擁擠導(dǎo)致的交通事故。然而減少幾公里長(zhǎng)的路肩寬度,得不到同樣的的結(jié)果。
Pavement marking, such as lane lines, edge lines, channelizing lines at interchanges and ramps, and word symbol markings, provide important information to the drivers.路面標(biāo)記,像在立體交道和斜坡處的車道線,邊緣線,通道線以及文字和符號(hào)標(biāo)記,為駕駛員提供重要信息
Pavement markings define separate lanes of traffic traveling in the same direction, inform drivers of lane restrictions, and convey certain regulation and warnings that would not otherwise be clearly understand.路面標(biāo)記定義了單獨(dú)的車道交通朝同一方向行駛,告訴駕駛員該車道限速,以及傳達(dá)某些規(guī)則和警告,否則,它們不會(huì)被駕駛員清楚的明白。
Pavement markings are particularly important at night and during inclement weather, and,therefore, must be retroreflective.While well-maintained painted pavement markings are acceptable, thicker, long-life markings ,such as thermoplastic or performed tapes ,may perform better in wet weather and heavy traffic.同時(shí)保養(yǎng)好的涂有油漆的路面標(biāo)志是可以采用的,厚的,長(zhǎng)壽命的標(biāo)記,像熱塑性塑料或預(yù)成行的條帶,可以在潮濕的空氣和交通繁忙時(shí)表現(xiàn)得更出色。
Some studies have been made regarding the benefits of wider edge line markings(150 to 200 mm versus the standard 100 mm width).The wider markings may particularly benefit older drivers.一些研究已經(jīng)取得了有關(guān)更寬邊緣線方面的好處(150到200毫米相對(duì)于100毫米的標(biāo)準(zhǔn)寬度)。更寬的標(biāo)記對(duì)老司機(jī)尤為有利。