第一篇：專業(yè)英語翻譯

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主 要因素。另外，其他的設(shè)計特性，如較寬的中央分隔帶和較寬的路肩、路邊無障礙物、大量采用防護欄等也是關(guān)鍵要素。

The higher design speeds(設(shè)計速度)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)計速度導(dǎo)致的長視距是由于大半徑水平曲線和長的豎曲線，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.盡管全國絕大部分高速公路最喜歡這樣的設(shè)計和安全性比較高的水平，但還是有很多地方需要進一步增強。

Safety improvements on freeways can also result in substantial savings in life and property(生命和財產(chǎn))because freeways carry 25 percent of the nation’s total traffic.高速公路安全方面的改善，還會節(jié)約大量的生命財產(chǎn)資源，因為高速公路流量占了全國的總流量的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)計速度是一件重要的安全因素因為大部分的幾何設(shè)計標(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，110千米每小時應(yīng)該作為高速公路主干道的設(shè)計速度，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.對于重建，恢復(fù)鋪新路面工程，設(shè)計速度不應(yīng)該低于平時設(shè)計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，這個設(shè)計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）should be developed.無論選擇多大的設(shè)計速度，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作取決于按照《道路的幾何尺寸的規(guī)定》設(shè)計的適當(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，以及傳達某些規(guī)則和警告，否則，它們不會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.同時保養(yǎng)好的涂有油漆的路面標(biāo)志是可以采用的，厚的，長壽命的標(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毫米相對于100毫米的標(biāo)準(zhǔn)寬度）。更寬的標(biāo)記對老司機尤為有利。

第二篇：專業(yè)英語翻譯

1)Electricity can be measured in amount and quality.電可以用數(shù)量和質(zhì)量來度量。

2)Instrument transformers are installed on the high-voltage equipment.互感器安裝在高壓設(shè)備上。

3)Electric power is generated in power generating stations or plants.電能是在發(fā)電站或發(fā)電廠產(chǎn)生的。

4)The meters are calibrated and the scale is designed to read the value of the desired unit.這些儀表可以被校準(zhǔn)并且設(shè)計了不同的量程，以便讀出期望的數(shù)值。

5)Electrical energy can be stored in two metal plates separated by an insulation medium.Such a device is called a capacitor, and its ability to store electrical energy is termed capacitance.It is measured in Farads.電能可以儲存在被一絕緣介質(zhì)隔開的兩塊金屬板中，這樣的裝置被稱為電容器，它儲存電能的能力就被稱為電容。電容的測量單位是法拉。1)The signal should be filtered before it is amplified.The signal should be filtered before being amplified.放大信號前，應(yīng)先對其進行濾波。

2)An object becomes hot.It is placed in the sun.Once being placed in the sun, an object becomes hot.物體放置在太陽下會變熱。

3)We must do various experiments before a new electronic product is designed.Before designing a new electronic product we must do various experiments.在設(shè)計一個新的電子產(chǎn)品之前，我們必須做各種實驗。

4)Changing resistance is a method for controlling the flow of the current.改變電阻是控制電流的一種方法。

5)Conducting electricity means the flow of electrons through an object.傳導(dǎo)電流意味著電子在物體內(nèi)的流動。

1)The power supply, which is shown in block-diagram in Fig.1, is a single-phase switch-mode inverter.The power supply shown in block-diagram in Fig.1 is a single-phase switch-mode inverter.圖1中用框圖表示的電源是一個單相開關(guān)逆變器。

2)A three-phase circuit, as it was pointed out above, is merely a combination of three single-phase circuits.A three-phase circuit, as pointed out above, is merely a combination of three single-phase circuits.正如上面所指出的那樣，三相電路只不過是三個單相電路的組合。

3)The transistor, which is working with correctly polarities, can work as an amplifier.The transistor working with correctly polarities can work as an amplifier.工作于正確電源極性下的晶體管，作用就像放大器。

1）The capacity of individual generators is larger and larger so that the increasing demand of electric power is satisfied.The capacity of individual generators is larger and larger to satisfy the increasing demand of electric power.單臺發(fā)電機的容量越來越大，目的就是滿足不斷增長的用電需求。2)What does a fuse do? It protects a circuit.The function of a fuse is to protect a circuit.保險的作用就是保護電路。1)If it is possible, the open-loop control approach should be used in this system.If possible, the open-loop control approach should be used in this system.可能的話，這個系統(tǒng)應(yīng)該使用開環(huán)控制方法。

2)As illustrated in Fig.1, there is a feedback element in the closed-loop system.As in Fig.1, there is a feedback element in the closed-loop system.就像圖1所示的那樣，這個閉環(huán)系統(tǒng)中有一個反饋元件。

3)The device includes an instrument transformation and a relay system which has two circuits in it.The device includes an instrument transformation and a

relay system with two circuits in it.這個裝置包括一個互感器和一個有兩個電路的繼電器系統(tǒng)。

1)It has been mentioned above that the electrons in a metal

are able to move freely through the metal, that their motion constitutes an electric current in the metal and that they play an important part in conduction of heat.前面已經(jīng)提到：金屬中電子能自由地通過金屬，電子的移動在金屬中形成了電流，電子在熱傳導(dǎo)中起著重要的作用。

2)The reluctance motor operates synchronously at a speed which is determined by the supply frequency and the number of poles for which the stator is wound.磁阻電動機以某一速率同步運轉(zhuǎn)，該速率是由電源頻率和定子繞制的級數(shù)決定的。

3)The testing of a cross-field generator will be described in this section with chief reference to the tests that are normally taken on every machine before it leaves the makers works.交磁發(fā)電機的試驗將在本節(jié)中敘述，它主要涉及每臺電機在離開制造廠前應(yīng)進行的試驗。1)All radiant energies have wavelike characteristics, which are analogous to those of waves moving through water.All radiant energies have wavelike characteristics analogous to those of waves moving through water.所有的輻射能都具有波的特性，與水中移動的波的特征相似。

2)The instruments present include some digital ones which are relative to DSPs.The instruments present include some digital ones relative to DSPs.到場的儀器中還有一些與DSP有關(guān)的數(shù)字儀器。

1.As the system expands and higher voltage levels become necessary for transmission, the older transmission lines are often relegated to subtransmission function.隨著系統(tǒng)的擴大和更高的電壓等級為輸電所必需，舊的輸電線路往往被移交給中壓輸電功能。

1.Roughly, the capability of lines of the same length varies at a rate somewhat greater than the square of the voltage.粗略的講，長度相同的線路的容量，以比電壓的平方略大的比率變化。

2.No definite capability can be specified for a line of a given voltage, however, because capability is dependent on the thermal limits of the conductor, allowable voltage drop, reliability, and requirements for maintaining synchronism between the machines of the system, which is known as stability.然而，無法為給定電壓等級的線路指定確切的容量，這是因為容量取決于導(dǎo)線的發(fā)熱極限、允許的電壓降落、可靠性和維持系統(tǒng)中的發(fā)電機同步的要求（這被認(rèn)為是穩(wěn)定性）。

1.Capacitance exists between the conductors and is the charge on the conductors per unit of potential difference between them.電容存在于導(dǎo)體之間，等于導(dǎo)體上的電荷（電量）與導(dǎo)體間的電勢差之比。或：電容存在于導(dǎo)體之間，等于導(dǎo)體之間單位電壓對應(yīng)的電量?！癆 per unit of B” 表示 “單位B上的A” 或者“A/B”。

2.Balance of the three phases can be restored by exchanging the positions of the conductors at regular intervals along the line so that each conductor occupies the original position of every other conductor over an equal distance, as shown in Fig.3.1.如圖3.1所示，沿線路方向每隔一定間隔就交換導(dǎo)線位置，使每根導(dǎo)線都能占據(jù)具有相同輸電距離的其他各導(dǎo)線的初始位置，以重建三相平衡。

Electrical energy can be stored in two metal plates separated by an insulating medium.Such a device is called capacitor or condenser.Its ability to store electrical energy is capacitance.It is measured in farads 電能可儲存在由一絕緣介質(zhì)隔開的兩塊金屬極板內(nèi)。這樣的裝置稱之為電容器，其儲存電能的能力稱為電容。電容的測量單位是法拉。

1.Small industrial customers are supplied by primary feeders at this voltage level from the primary system, which also supplies the distribution transformers providing secondary voltages over single-phase three-wire circuits for residential and commercial customers at 120 V/240 V.小型工業(yè)用戶由一次系統(tǒng)中此電壓等級的一次饋線供電。一次系統(tǒng)也給經(jīng)過單相三線電路為居民用電和商業(yè)用戶提供120V/240V二次電壓的配電變壓器供電。

2.As illustrated in Fig.6.1, the aggregated load represented at a transmission substation(bus A)usually includes, in addition to the connected load devices, the effects of substation step-down transformers…

如圖6.1所示，在輸電變電站（母線A）所給出的集合負(fù)荷，除了所連接的負(fù)荷設(shè)備以外，通常還包括變電站降壓變壓器的影響……。

1.Roughly, loads are devices those consume electric energy or electric power consumed by customers mainly in distribution system.粗略的講，負(fù)荷是主要在配電網(wǎng)中消耗電能的設(shè)備或者由用戶消耗的功率。

2.The loads absorb electric energy from the power system and converts it into energy of other forms, which may be heat energy to heat water or to melt irons, or mechanical energy to drive a machine, etc.負(fù)荷從電力系統(tǒng)中吸收電能，并將其轉(zhuǎn)換為其他形式的能量，可能是燒水或溶化鋼鐵的熱能，或者是驅(qū)動機器的機械能等。

3.This kind of loads, especially those consume energy calculated by standard coals more over 10 thousands of tons per year, has a name of high energy consuming loads.這種負(fù)荷，尤其是那些年耗能萬噸標(biāo)準(zhǔn)煤以上的負(fù)荷，被稱為高耗能負(fù)荷。

1.The synchronous machine as an AC generator driven by a

turbine is the device which converts mechanical energy to electrical energy, in powers ranging up to 1500MW.作為由渦輪機驅(qū)動的交流發(fā)電機，同步電機是將機械能轉(zhuǎn)化為電能的設(shè)備，其功率范圍高達1500MW。

1.Hydropower plants can cause low dissolved oxygen levels in the water, a problem that is harmful to riverbank habitats.水電廠會導(dǎo)致水中的氧氣溶解度降低——（這是）一個對岸邊生存環(huán)境有害的問題。

2.For instance, in the United States, water power accounts for less than 20% of the total and that percentage will drop because most of the available sources of water power have been developed.例如，在美國，水電在全部電力中所占的比例不到20%，并且，因為大多數(shù)可用的水電資源已被開發(fā)，該百分?jǐn)?shù)還會下降。

1.Most stations have ratings between 200 MW and 1500 MW so as to attain the high efficiency and economy of a large installation.大多數(shù)電站的額定值在200MW到1500MW之間，以實現(xiàn)大站的高效經(jīng)濟（運行）。

2.Thermal stations are usually located near a river or lake because large quantities of cooling water are needed to condense the steam as it exhausts from the turbines.熱電廠通常位于河流或湖泊附近，這是因為需要大量的冷卻水在蒸汽從汽輪機排出時將其冷凝。

1.Nuclear plants fueled by uranium account for a continually increasing share of the load, but their construction is slow and uncertain because of the difficulty of raising capital to meet the sharply rising cost of construction, constantly increasing safety requirements which cause redesign, public opposition to the operation of the plants, and delays in licensing.Flowing through a circuit, the current will lose part of it energy.當(dāng)電流流過電路時，要損耗掉一部分能量。（現(xiàn)在分詞短語作狀語）

Doing experiment is of great help to us.做實驗對我們的學(xué)習(xí)是很有幫助的。（動名詞作主語）By changing the resistance，we can change the current.通過改變電阻，我們就能改變電流。（動名詞作介賓）Mechanization is using machines instead of hand labor.機械化就是用機器來代替手工勞動。（動名詞作表語）

When an electric current flow through a wire it meets some opposition.當(dāng)電流流過導(dǎo)線時，它會遇到某種阻力。（狀語從句）

Before one studies a system, it is necessary to define and discuss some important terms.在我們學(xué)習(xí)系統(tǒng)之前，必須定義并討論一些重要的術(shù)語。（狀語從句）It is possible that we use a computer to solve these complicated problem.我們可以用計算機來解這些復(fù)雜的題目。（表語從句）

You should determine which of the following functions is analytic.你應(yīng)當(dāng)確定下列函數(shù)中哪一個是解析式。（賓語從句）The fact is that radio waves travel as fast as light does.事實是無線電波的傳播速度與光速一樣快。（表語從句）The places where small computers can be used appear endless.可以使用小型計算機的場合似乎是無止境的。（定語從句）The instrument that we often use is very good in quality.我們經(jīng)常使用的那臺儀器質(zhì)量很好。（定語從句）

The places where small computers can be used appear endless.可以使用小型計算機的場合似乎是無止境的。（定語從句）The instrument that we often use is very good in quality.我們經(jīng)常使用的那臺儀器質(zhì)量很好。（定語從句）

Now we can determine where the slope is zero.現(xiàn)在我們可以求出何處斜率為零。（賓語從句）This is how a computer works.這就是計算機的工作原理。（賓語從句）Electrons always move toward where the potential is higher.電子總是朝向電位較高的地方移動。（介賓從句）

The fact that everything around us is matter is known to all.我們周圍的一切東西均是物質(zhì)這一事實是大家都知道的。（同位語從句）Section 2 Exercise 3

Section 3 Exercise3 必須強調(diào)的是線性電阻器是一個理想的電路元件；它是物理元件的數(shù)學(xué)模型。我們可以很容易地買到或制造電阻器，但很快我們發(fā)現(xiàn)這種物理元件只有當(dāng)電流、電壓或者功率處于特定范圍時其電壓——電流之比才是恒定的，并且這個比值也取決于溫度以及其它環(huán)境因素。我們通常應(yīng)當(dāng)把線性電阻器僅僅稱為電阻器。只有當(dāng)需要強調(diào)元件性質(zhì)的時候才使用更長的形式稱呼它。

而對于任何非線性電阻器我們應(yīng)當(dāng)始終這么稱呼它，非線性電阻器不應(yīng)當(dāng)必然地被視為不需要的元件。

Section 4 Exercise 3 如果一個電路有兩個或多個獨立源，求出具體變量值（電流或電壓）的一種方法是使用節(jié)點分析法或網(wǎng)孔分析法。另一種方法是求出每個獨立源對變量的作用然后把它們進行疊加。而這種方法被稱為疊加法。疊加法原理表明線性電路某個元件兩端的電壓（或流過元件的電流）等于每個獨立源單獨作用時該元件兩端的電壓（或流過元件的電流）的代數(shù)和。Section 5 Exercise 3 相電壓與相電流之比等于電路的阻抗，符號為字母Z，阻抗是一個具有量綱為歐姆的復(fù)數(shù)量。阻抗不是一個相量，因此不能通過把它乘以

并取其實部把它轉(zhuǎn)換成時域形式。但是，我們把電感器看作是通過其電感量L表現(xiàn)為時域形式而通過其阻抗

表現(xiàn)為頻域形式，電容在時域里為電容量C而在頻域里為

，阻抗是某種程度上的頻域變量而非時域變量。

Section 6 Exercise 3

第三篇：專業(yè)英語翻譯

介紹

硒(Se)是一個對人類和動物而言很重要的微量營養(yǎng)素,但是Se毒性和Se缺乏發(fā)生在世界不同的地方(弗蘭肯伯格和本森,1994)。硒能提高活動的自由羥基自由基(OH-)導(dǎo)致高氧化應(yīng)激損害生物(趙et al,200

8)。Se這種基本的或有毒的特性在生物中不僅取決于其濃度狀況,而且也在于其直接影響吸收和生物利用度的化合物(米凱爾森et al，1989;倫茨et al，2008)。在水系統(tǒng)中硒酸鹽和亞硒酸鹽是主要的物質(zhì)(雅各布斯,1989),然而,亞硒酸鹽很容易吸附于土壤礦物質(zhì)，所以高濃度的硒酸鹽是工業(yè)廢水污染水域中主要的硒化合物。

鋁、鐵、硅氧化物是普遍存在于地球地殼的礦物，他們通常被用于除去水中污染物,因為鋁和鐵氧化物具有較高的表面積和零點電荷(i.e,86范圍內(nèi)，在Al(III)/SiO2 中的亞硒酸鹽吸附受電解

質(zhì)濃度影，這并不表示pH值的增長。Hayes博士(1987年)增加報道,亞硒酸鹽吸附在吸附劑、針鐵礦(a-FeOOH)，形成一個內(nèi)球體復(fù)合體，硒酸鹽形成一個弱外球體，然后硒酸鹽在吸附劑會受在電子雙層理論上易溶效應(yīng)的影響。圖2顯示在Al(III)/SiO2體系中，用Al(III)/SiO2比Fe(III)/SiO2對硒酸鹽的和亞硒酸鹽除去效率更大。當(dāng)基本溶液添加到Al(III)/SiO2體系中,鋁和二氧化硅形成配合物以增加二氧化硅帶負(fù)電荷表面的吸附地方。因此一個Ph=5.0和0.01M電解質(zhì)溶液被選作等溫、動力學(xué)、和吸附實驗。

3.2.2吸附等溫線

為了探討吸附能力，一系列的亞硒酸鹽和硒酸鹽溶液和在pH=5下用24h準(zhǔn)備的兩個二元氧化物進行振蕩。吸附數(shù)據(jù)通過Langmuir 等溫線裝備好（r 2> 0.858,P < 0.01(n=7))(圖

3、表2)。相關(guān)系數(shù)表明Langmuir等溫線模型適用于通過二元氧化系統(tǒng)來描述亞硒酸鹽和硒酸鹽的吸附平衡。擬合數(shù)據(jù)顯示，分別地由Al(III)/SiO2吸收硒酸鹽和亞硒酸鹽的最大吸附容量(Qmax)是32.7和11.3毫克/克，由Fe(III)/SiO2吸收硒酸鹽和亞硒酸鹽的 Qmax是 20.4和2.4毫克/克。就硒物種的吸附能力考慮, Al(III)/SiO2和Fe(III)/SiO2似乎比粗鋁或鐵氧化物涂層砂高得多(Lo和Chen,1997，Kuan et al,1998)。兩個二元氧化物系統(tǒng)可以歸于微粒增加了硒物種和吸附劑接觸。

在兩個二元氧化物系統(tǒng)中亞硒酸的吸附能力比硒酸鹽的高，這和基于第一個酸度常數(shù)來區(qū)分各種陰離子親和力的結(jié)果是一致的(Hayes,1987，Hayes et al,1988)。亞硒酸鹽的化學(xué)特性和幾何結(jié)構(gòu)類似于磷酸鹽,而硒酸鹽是類似于硫酸鹽(Hayes 1987，wijnja和Schulthess,2000)，兩個二元氧化物系統(tǒng)對亞硒酸鹽的吸附大于硒酸鹽。

對亞硒酸鹽和硒酸鹽吸附而言，Al(III)/SiO2體系相比Fe(III)/SiO2體系顯示了一個更大的容量，來源于Al(III)/SiO2體系對硒含氧陰離子有更多的正電荷造成的高親和力(圖1)。鐵顆粒在二氧化硅上的沉淀物不能增加任何吸附地方，二氧化硅的帶負(fù)電荷的表面增加了硒含氧陰離子和二氧化硅之間的排斥力。因此，Al(III)/SiO2對硒的Qmax高于Fe(III)/SiO2的(表2)。至于二元氧化物系統(tǒng)吸附亞硒酸鹽和硒酸鹽的機制,之前的光譜研究表明,硒的吸附是鋁-和鐵氧化物形成內(nèi)球面配合物的配位體與羥基在礦物表面交換(Peak,2006)。為了研究吸附過程的機制,我們使樣品遭受到二元氧化物系統(tǒng)吸附的硒的XANES和EXAFS光譜。

3.3吸附動力學(xué)

描述溶質(zhì)吸附率的吸附動力學(xué)控制吸附反應(yīng)的停留時間是一個決定吸附效率的重要特征。圖.4表明兩個二元氧化物系統(tǒng)在不同的時間間隔和偽二級動力學(xué)模型的仿真顯示了硒的吸附數(shù)據(jù)。二元氧化物系統(tǒng)吸附亞硒酸鹽和硒酸鹽的偽平衡方法比那些在鋁或鐵涂料石英沙更為迅猛(Lo and Chen,1997，Kuan et al,1998)。對在Al(III)/SiO2 and Fe(III)/SiO2上的亞硒酸鹽，2 h的接觸會使95%的亞硒酸鹽被完全除去，吸附也會接近平衡(圖4a)。個別的硒酸鹽去除百分比可以達到99，在Al(III)/SiO2和Fe(III)/SiO2中30分鐘可以除去96%，吸附也接近平衡(圖4b)。兩個二元氧化物系統(tǒng)的更大的表面地區(qū)和更小的顆粒尺寸提高吸附反應(yīng)的概率。已安裝的動力學(xué)數(shù)據(jù)零、第一、偽第二、二階，拋物線，Elovich模型，評估r2和假定值，總安裝數(shù)據(jù)沒有顯示。這個偽二階動力學(xué)模型是最好的模型去描述二元氧化系統(tǒng)的動力學(xué)數(shù)據(jù)。表3表明顯示了通過t/qt的圖形從偽二級動力學(xué)模型得到確切系數(shù)(r2)和其他參數(shù)來確定V0和qeq所有的媒體價值。這個偽二階模型很好的符合了兩個二元氧化物的系統(tǒng)運動數(shù)據(jù)(r2 > 0.999,P < 0.001,n=18)。亞硒酸鹽在Al(III)/SiO2上的最初的吸附率是6.25mg/gh，少于硒酸鹽的(57.5mg/gh)，在Fe(III)/SiO2上的亞硒酸鹽和硒酸鹽的比例為8.36比4.89mg/gh。數(shù)據(jù)顯示，對硒酸鹽Al(III)/SiO2具有更高的親和力，在Fe(III)/SiO2上對硒酸鹽的吸附能力大于亞硒酸鹽。不像亞硒酸鹽,上清液pH值是穩(wěn)定的，硒酸鹽平衡濃度的pH值從5.0增加到8.0，表明氫氧離子在吸附過程中被釋放出來。因為亞硒酸鹽強烈的通過結(jié)合金屬氧化物表面形成更強壯的內(nèi)球面復(fù)合物，在緩慢的過程中亞硒酸鹽需要花更多的時間到達平衡(Balistrieri and Chao,1987，Hayes,1987，Neal et al,1987，Zhang and Sparks,1990，Scott and Morgan, 1996)。

3.4XAS數(shù)據(jù)分析

從XANES的吸附反應(yīng)可知，氧化狀態(tài)在硒物種和二元氧化物系統(tǒng)之間相互作用沒有改變。圖5和表4表

明了在樣品上進行的硒的K-edge EXAFS在pH=5.0時亞硒酸鹽在二元氧化物系統(tǒng)的吸附結(jié)論。在圖5a,b上顯示了這個徑向結(jié)構(gòu)功能(RSFs)的傅里葉轉(zhuǎn)換數(shù)據(jù)。在所有亞硒酸樣本中，明確證明在RSFs上有兩個外形：第一外形是Se-O(在1.72A下用3 O安裝)，第二外形Se-Al或Se-Fe在兩個二元氧化物系統(tǒng)上(圖5)。這個距離是與以前在亞硒酸鹽進行的EXAFS實驗數(shù)據(jù)達到了良好的統(tǒng)一，這表明對水合和吸附的亞硒酸鹽的Se-O鍵的距離1.68-1.72 A(Manceau and Charlet,1994，Peak et al,2006，Peak,2006)?；诤唵蔚膸缀渭s束，最好的亞硒酸鹽結(jié)合環(huán)境任務(wù)是在Al(III)/SiO2上(在3.22A下用2個Al安裝成Se-Al)在pH=5下是一個雙配位基、雙核的表面復(fù)合物(鍵長的范圍是～3.2A)。亞硒酸鹽吸附在其他鋁軸承礦物表面這個和以前的研究(Hayesetal,1987)達成良好的協(xié)議，這也報道了雙配位基、雙核的表面絡(luò)合作用。在針鐵礦上有內(nèi)球體硒酸鹽的存在是符合Manceau and Charlet(1994)的工作結(jié)果的他們報道類似的Se-Fe鍵距離是3.29A相應(yīng)的在那個工作結(jié)果是3.31A(表4)。在水合的鐵氧化物(HFO)下，然而，他們發(fā)現(xiàn)他們最好的數(shù)據(jù)是0.4鐵在2.80A和1.8鐵在3.29A描述的。他們確定一個雙配位基的單核表面復(fù)合物的距離是2.80A和一個雙配位基的雙核的表面復(fù)合物的距離是3.29A。亞硒酸鹽在Fe(III)/SiO2上的結(jié)果表明距離為3.05A形成雙配位基的單核表面復(fù)合物。

在二元氧化系統(tǒng)上硒酸鹽局部結(jié)構(gòu)是由EXAFS裝置指導(dǎo)的(表4和圖5b)。在所有的硒酸鹽樣品中,第一個形式是在RSFs上的Se-O(在1.66A用4O裝配)與先前發(fā)表的水合和吸附的硒酸鹽Se-O距離是一致的(Hayes et al,1987，Peak and Sparks,2002)。這個在硒酸鹽吸附樣本的Se-Al距離鍵長及配位數(shù)(3.32A、CN=1)表明研究在Al(III)/SiO2表面的硒酸鹽的協(xié)調(diào)環(huán)境是一個內(nèi)球體表面復(fù)合物。然而，Se-Fe的鍵長(3.04A)表明在Fe(III)/SiO2上的硒酸鹽形成了雙配位基的單核配合物(Hug,1997，Peak and Sparks,2002)。EXAFS擬合數(shù)據(jù)表明硒酸鹽在Fe(III)/SiO2的鍵長比在Al(III)/SiO2的長。根據(jù)EXAFS原則, x射線吸收原子和周圍原子的距離就是一個鍵長。鍵長越長，中心和周圍的原子的相互作用越弱。在Fe(III)/SiO2體系上的亞硒酸鹽和硒酸鹽的Se-金屬鍵長實際上是一樣的。鍵長適合特性的估計精度是±0.02A。Peak和Sparks(2002)表明硒酸鹽在赤鐵礦的形式只有內(nèi)球體表面復(fù)合物，在針鐵礦和重質(zhì)燃料油上是外球體和內(nèi)球面表面復(fù)合物的混合形式。EXAFS結(jié)果表明在Fe(III)/SiO2的硒酸鹽形成內(nèi)球體復(fù)合物。雖然在pH=5.0硒酸鹽和亞硒酸鹽在二元氧化物系統(tǒng)形成內(nèi)球體復(fù)合物,數(shù)據(jù)表明在二進制元氧化物系統(tǒng)上亞硒酸鹽比硒酸鹽形成了更強的表面復(fù)合物。結(jié)論

根據(jù)研究結(jié)果,我們提出在二元氧化物系統(tǒng)上鋁或鐵氧化物可以修改二氧化硅的負(fù)表面電荷,應(yīng)用二元氧化物系統(tǒng)吸附陰離子、硒含氧陰離子。從這項研究中,我們觀察到Al(III)/SiO2和Fe(III)/SiO2從水溶液清除硒含氧陰離子是有效的。然而，Al(III)和SiO2表面強烈聯(lián)系導(dǎo)致其整個表面電荷比Fe(III)/SiO2更加積極, Al(III)/SiO2對硒的吸附能力比Fe(III)/SiO2的更強。在pH=5.0, 在Al(III)/SiO2和Fe(III)/SiO2中的亞硒酸鹽形式內(nèi)球體復(fù)合物，分別地包括雙配位基和單配位基。然而, 在Al(III)/SiO2上的硒酸鹽形成較弱的內(nèi)球體單配位基復(fù)合物，在Fe(III)/SiO2上的硒酸鹽也是這樣的。根據(jù)硒酸鹽的鍵長, 硒和鐵高親和力導(dǎo)致了之間的鍵長更短。調(diào)查結(jié)果得出目前的研究的基本意義是在推進前沿二元氧化物系統(tǒng)化學(xué)專業(yè)知識。

第四篇：專業(yè)英語翻譯

樁筏基礎(chǔ)的簡化設(shè)計方法

摘要：在筏板基礎(chǔ)本身并不能滿足設(shè)計要求情況下，可通過在筏板下增加樁來提高其承載力。合理的布置一定量的樁，可以提高樁筏基礎(chǔ)的承載力和減少總沉降和差異沉降。本文分析了簡化計算方法的過程，對樁筏基礎(chǔ)的初步設(shè)計提供了有用的依據(jù)。它包括兩個階段：

1.樁筏基礎(chǔ)整體性能的評價；

2.單柱荷載作用下的性能評價。

第五篇：專業(yè)英語翻譯

Forces of Interactions between Bare and Polymer-Coated Iron and Silica: Effect of pH, Ionic Strength, and Humic Acids The interactions between a silica substrate and iron particles were investigated using atomic force microscopy-based force spectroscopy(AFM).The micrometer-and nanosized iron particles employed were either bare or coated with carboxymethyl cellulose(CMC), a polymer utilized to stabilize iron particle suspensions.The effect of water chemistry on the forces of interaction was probed by varying ionic strength(with 100 mM NaCl and 100 mM CaCl2)or pH(4, 5.5, and 8)or by introducing 10 mg/L of humic acids(HA).When particles were uncoated, the forces upon approach between silica and iron were attractive at pH 4 and 5.5 and in 100 mM CaCl2 at pH 8, but they were negligible in 100 mM NaCl buffered to pH 8 and repulsive in water buffered to pH 8 and in HA solutions.HA produced electrosteric repulsion between iron particles and silica, likely due to its sorption to iron particles.HA sorption to silica was excluded on the basis of experiments conducted with a quartz-crystal microbalance with dissipation monitoring.Repulsion with CMC-coated iron was attributed to electrosteric forces, which were damped at high ionic strength.An extended DLVO model and a modified version of Ohshima’s theory were successfully utilized to model AFM data.PH、離子強度和腐殖酸對硅與裸露鐵粒子和高分子聚合物包裹鐵粒子之間相互作用的影響 利用以原子力顯微鏡為基礎(chǔ)的光譜法研究石英基片和鐵顆粒之間的相互作用。微米和納米鐵顆粒采用的都是赤裸的或羧甲基纖維素包裹的——一種用于穩(wěn)定鐵顆粒懸浮液的聚合物。通過不同離子強度（100mM氯化鈉和100mM氯化鈣）或PH值（4，5.5，和8）或通過引入10毫克/升的腐殖酸探討水化學(xué)環(huán)境對這種相互作用力的影響。當(dāng)粒子裸露時，硅和鐵的相互接近的吸引力出現(xiàn)在PH值4和5.5。加100mM氯化鈣時出現(xiàn)在PH值為8的時候。但在PH為8的100毫米氯化鈉緩沖溶液中它們是可忽略的，在PH為8的水和腐殖酸溶液中表現(xiàn)為相互排斥。腐殖酸使鐵顆粒和二氧化硅之間產(chǎn)生靜電斥力，可能由于其吸附鐵顆粒。通過進行了石英晶體微天平與耗散監(jiān)測的實驗，腐殖酸吸附硅膠的可能性被排除在外。與羧甲基纖維素包鐵顆粒的斥力是由于靜電力量，這種靜電力在高離子強度會減弱。一個擴展的 DLVO模型和Ohshima理論修改后的版本成功地擬合了原子力顯微鏡得到的數(shù)據(jù)。