第一篇：機(jī)械制造專(zhuān)業(yè)英語(yǔ)翻譯

Medium-technology robots Medium-technology robots are used primarily for picking and placing and for machine loading and unloading.These robots are a bit more sophisticated than the low-technology robots, as the characteristics described next indicate.媒介技術(shù)的機(jī)器人主要用于拾取和放置機(jī)器裝卸。這些機(jī)器人比低技術(shù)的機(jī)器人更時(shí)髦一點(diǎn)，作為特征表明。

1.Axes.In the majority of case, the medium-technology robots have a greater number oh axes on the manipulator than the low-technology robots have.These robots also have a large work cell, which mean that axis travel is greater.1.軸 在大多數(shù)情況下，媒介技術(shù)的機(jī)器人有更多，軸比低技術(shù)的機(jī)器人機(jī)械手。這些機(jī)器人也有大量的工作單元，意味著軸行程更大。

The number of axe on these robots is increased because of the addition of a wrist.The wrist connected to the end of the robot’s arm gives the system two or three additional axes.The wrist allows the robot to develop movements that the low-technology robot is not capable of.With the addition of the wrist, these robots may have five or six axes of motion.對(duì)這些機(jī)器人斧頭的數(shù)量是因?yàn)閷?duì)手腕的增加。腕關(guān)節(jié)連接到機(jī)器人手臂末端的給出了系統(tǒng)的兩個(gè)或三個(gè)額外的軸。腕關(guān)節(jié)使機(jī)器人發(fā)展運(yùn)動(dòng)，低技術(shù)的機(jī)器人是不能夠。手腕的加入，這些機(jī)器人可能有五或六軸的運(yùn)動(dòng)。

The basic medium-technology robot has three axes, or degrees of freedom, as shown in Fig.21-3A.With the addition of a wrist, as illustrated in Fig.21-3B, three additional axes are added to the robot.These axes are called the roll axis, the bend axis, and the yaw(rotational)axis of the wrist.基本培養(yǎng)基技術(shù)的機(jī)器人有三個(gè)軸，或自由度，如fig.21-3a。隨著手腕的增加，說(shuō)明在fig.21-3b，額外的三軸添加到機(jī)器人。這些軸為軸，軸的彎曲，和偏航（旋轉(zhuǎn)）的手腕軸。

2.Payload.Medium-technology robots have a greater payload capacity than the low-technology robots.These robots are capable of handing weights at the end of the wrist ranging from 68 to 150 kilograms.With this increased payload, these robots are able to replace lifting of heavy parts is required.2.有效載荷

媒介技術(shù)的機(jī)器人有比低技術(shù)的機(jī)器人更大的有效載荷能力。這些機(jī)器人能處理量在手腕的范圍從68到150公斤的結(jié)束。這增加的負(fù)載，這些機(jī)器人能代替大部件吊裝是必須的。

3.Cycle Time.For a medium-technology robot, a movement in the reach axis of 25 to 65 centimeters takes 1.0 second to execute.In a rotation around the center axis, the robot can move at a rate of 150 centimeters per second.However, these robots will have greater cycle times than the low-technology robots.The complex jobs the medium-technology robots are able to perform and the payload at the wrist flange are responsible for the increased cycle time of the robot's operation.3.周期時(shí)間。一個(gè)中等技術(shù)的機(jī)器人，在25軸運(yùn)動(dòng)達(dá)到65厘米需要1秒來(lái)執(zhí)行。在圍繞中心軸旋轉(zhuǎn)，機(jī)器人可以在每秒150厘米的速度移動(dòng)。然而，這些機(jī)器人將有比低技術(shù)的機(jī)器人更大的周期時(shí)間。復(fù)雜的工作中技術(shù)的機(jī)器人是能夠執(zhí)行在手腕凸緣的有效載荷是負(fù)責(zé)增加周期時(shí)間的機(jī)器人的操作。

4.Accuracy.Because of the increased number of axes on medium-technology robots, their accuracy and repeatability are not as good as the accuracy and repeatability of low-technology robots.The main reason is that the several axes must converge on a point.The error that is developed because of several axes having to be positioned creates additional error in the accuracy of the robot.Remember that the low-technology robots only move one axis at a time to reach a programmed position.However, the medium-technology robots are capable of repeating their positional data to meet the requirements of the job.The accuracy of the medium-technology robots can range from as low as 0.2millimeter to as high as 1.3millimeters.These ranges are typical for various medium-technology robots.4.精度.由于對(duì)媒介技術(shù)的機(jī)器人軸數(shù)的增加，其準(zhǔn)確性和可重復(fù)性是不作為的精度和可重復(fù)性低技術(shù)的機(jī)器人一樣好。主要原因是多軸必須收斂于一點(diǎn)的。錯(cuò)誤，是因?yàn)橛袔讉€(gè)軸被定位造成的附加誤差精度的機(jī)器人的開(kāi)發(fā)。記住，低技術(shù)的機(jī)器人只能移動(dòng)一個(gè)軸在同一時(shí)間到達(dá)一個(gè)程序的位置。然而，媒介技術(shù)的機(jī)器人能夠重復(fù)他們的位置數(shù)據(jù)，以滿(mǎn)足工作的要求。

對(duì)媒介技術(shù)機(jī)器人精度的范圍可以從0.2毫米低到1.3毫米高。這些范圍內(nèi)的各種介質(zhì)技術(shù)的機(jī)器人典型。

5.Actuation.Medium-technology robots are driven by two types motors: hydraulic or electric.These two types of actuation are used because of the heavy payload.5.驅(qū)動(dòng).媒介技術(shù)的機(jī)器人是由兩種類(lèi)型：液壓或電動(dòng)馬達(dá)驅(qū)動(dòng)。這兩種類(lèi)型的致動(dòng)是因?yàn)槌林氐呢?fù)荷。

6.Controllers.The controllers found on the medium-technology systems are microprocessor-based.That is, the system can have either an 8-bit or a 16-bit microprocessor.With the increased power of the processor, memory size is also increased.Thus, positional data can be programmed into these robots, stored in memory, and recalled for later jobs.Several jobs can be stored in the controller's memory, thus allowing the robots to service two or more machines in the loading and unloading of parts.These robot controllers also allow the user to change or edit program information.6.控制器.在媒介技術(shù)系統(tǒng)控制器的微處理器。那是，該系統(tǒng)可以有一個(gè)8位或16位的微處理器。隨著增加功率的處理器，內(nèi)存的大小也增加了。因此，位置數(shù)據(jù)可以被編程到這些機(jī)器人，存儲(chǔ)在內(nèi)存中，并為以后工作回顧。

幾種工作可以?xún)?chǔ)存在控制器的存儲(chǔ)器中，從而使機(jī)器人服務(wù)兩個(gè)或兩個(gè)以上的機(jī)器在加載和卸載的部分。這些機(jī)器人控制器還允許用戶(hù)更改或編輯程序的信息。

第二篇：專(zhuān)業(yè)英語(yǔ)翻譯

1)Electricity can be measured in amount and quality.電可以用數(shù)量和質(zhì)量來(lái)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(chǎng)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(jì)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?xún)?chǔ)存在被一絕緣介質(zhì)隔開(kāi)的兩塊金屬板中，這樣的裝置被稱(chēng)為電容器，它儲(chǔ)存電能的能力就被稱(chēng)為電容。電容的測(cè)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(hào)前，應(yīng)先對(duì)其進(jìn)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(yáng)下會(huì)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(jì)一個(gè)新的電子產(chǎn)品之前，我們必須做各種實(shí)驗(yàn)。

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(dòng)。

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(gè)單相開(kāi)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(guò)是三個(gè)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(tái)發(fā)電機(jī)的容量越來(lái)越大，目的就是滿(mǎn)足不斷增長(zhǎng)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(xiǎn)的作用就是保護(hù)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(huà)，這個(gè)系統(tǒng)應(yīng)該使用開(kāi)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(gè)閉環(huán)系統(tǒng)中有一個(gè)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(gè)裝置包括一個(gè)互感器和一個(gè)有兩個(gè)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(guò)金屬，電子的移動(dòng)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(dòng)機(jī)以某一速率同步運(yùn)轉(zhuǎn)，該速率是由電源頻率和定子繞制的級(jí)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(jī)的試驗(yàn)將在本節(jié)中敘述，它主要涉及每臺(tái)電機(jī)在離開(kāi)制造廠(chǎng)前應(yīng)進(jìn)行的試驗(yàn)。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(dòng)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(chǎng)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(kuò)大和更高的電壓等級(jí)為輸電所必需，舊的輸電線(xiàn)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(zhǎng)度相同的線(xiàn)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(wú)法為給定電壓等級(jí)的線(xiàn)路指定確切的容量，這是因?yàn)槿萘咳Q于導(dǎo)線(xiàn)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(jī)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(shì)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(duì)應(yīng)的電量。“A 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(xiàn)路方向每隔一定間隔就交換導(dǎo)線(xiàn)位置，使每根導(dǎo)線(xiàn)都能占據(jù)具有相同輸電距離的其他各導(dǎo)線(xiàn)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(chǔ)存在由一絕緣介質(zhì)隔開(kāi)的兩塊金屬極板內(nèi)。這樣的裝置稱(chēng)之為電容器，其儲(chǔ)存電能的能力稱(chēng)為電容。電容的測(cè)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(hù)由一次系統(tǒng)中此電壓等級(jí)的一次饋線(xiàn)供電。一次系統(tǒng)也給經(jīng)過(guò)單相三線(xiàn)電路為居民用電和商業(yè)用戶(hù)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(xiàn)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(hù)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(dòng)機(jī)器的機(jī)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(wàn)噸標(biāo)準(zhǔn)煤以上的負(fù)荷，被稱(chēng)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(jī)驅(qū)動(dòng)的交流發(fā)電機(jī)，同步電機(jī)是將機(jī)械能轉(zhuǎn)化為電能的設(shè)備，其功率范圍高達(dá)1500MW。

1.Hydropower plants can cause low dissolved oxygen levels in the water, a problem that is harmful to riverbank habitats.水電廠(chǎng)會(huì)導(dǎo)致水中的氧氣溶解度降低——（這是）一個(gè)對(duì)岸邊生存環(huán)境有害的問(wèn)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(guó)，水電在全部電力中所占的比例不到20%，并且，因?yàn)榇蠖鄶?shù)可用的水電資源已被開(kāi)發(fā)，該百分?jǐn)?shù)還會(huì)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(shí)現(xiàn)大站的高效經(jīng)濟(jì)（運(yùn)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(chǎng)通常位于河流或湖泊附近，這是因?yàn)樾枰罅康睦鋮s水在蒸汽從汽輪機(jī)排出時(shí)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(guò)電路時(shí)，要損耗掉一部分能量。（現(xiàn)在分詞短語(yǔ)作狀語(yǔ)）

Doing experiment is of great help to us.做實(shí)驗(yàn)對(duì)我們的學(xué)習(xí)是很有幫助的。（動(dòng)名詞作主語(yǔ)）By changing the resistance，we can change the current.通過(guò)改變電阻，我們就能改變電流。（動(dòng)名詞作介賓）Mechanization is using machines instead of hand labor.機(jī)械化就是用機(jī)器來(lái)代替手工勞動(dòng)。（動(dòng)名詞作表語(yǔ)）

When an electric current flow through a wire it meets some opposition.當(dāng)電流流過(guò)導(dǎo)線(xiàn)時(shí)，它會(huì)遇到某種阻力。（狀語(yǔ)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(yǔ)。（狀語(yǔ)從句）It is possible that we use a computer to solve these complicated problem.我們可以用計(jì)算機(jī)來(lái)解這些復(fù)雜的題目。（表語(yǔ)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(gè)是解析式。（賓語(yǔ)從句）The fact is that radio waves travel as fast as light does.事實(shí)是無(wú)線(xiàn)電波的傳播速度與光速一樣快。（表語(yǔ)從句）The places where small computers can be used appear endless.可以使用小型計(jì)算機(jī)的場(chǎng)合似乎是無(wú)止境的。（定語(yǔ)從句）The instrument that we often use is very good in quality.我們經(jīng)常使用的那臺(tái)儀器質(zhì)量很好。（定語(yǔ)從句）

The places where small computers can be used appear endless.可以使用小型計(jì)算機(jī)的場(chǎng)合似乎是無(wú)止境的。（定語(yǔ)從句）The instrument that we often use is very good in quality.我們經(jīng)常使用的那臺(tái)儀器質(zhì)量很好。（定語(yǔ)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(yǔ)從句）This is how a computer works.這就是計(jì)算機(jī)的工作原理。（賓語(yǔ)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(dòng)。（介賓從句）

The fact that everything around us is matter is known to all.我們周?chē)囊磺袞|西均是物質(zhì)這一事實(shí)是大家都知道的。（同位語(yǔ)從句）Section 2 Exercise 3

Section 3 Exercise3 必須強(qiáng)調(diào)的是線(xiàn)性電阻器是一個(gè)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(mǎi)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(shí)其電壓——電流之比才是恒定的，并且這個(gè)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(xiàn)性電阻器僅僅稱(chēng)為電阻器。只有當(dāng)需要強(qiáng)調(diào)元件性質(zhì)的時(shí)候才使用更長(zhǎng)的形式稱(chēng)呼它。

而對(duì)于任何非線(xiàn)性電阻器我們應(yīng)當(dāng)始終這么稱(chēng)呼它，非線(xiàn)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(gè)電路有兩個(gè)或多個(gè)獨(dú)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(diǎn)分析法或網(wǎng)孔分析法。另一種方法是求出每個(gè)獨(dú)立源對(duì)變量的作用然后把它們進(jìn)行疊加。而這種方法被稱(chēng)為疊加法。疊加法原理表明線(xiàn)性電路某個(gè)元件兩端的電壓（或流過(guò)元件的電流）等于每個(gè)獨(dú)立源單獨(dú)作用時(shí)該元件兩端的電壓（或流過(guò)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(hào)為字母Z，阻抗是一個(gè)具有量綱為歐姆的復(fù)數(shù)量。阻抗不是一個(gè)相量，因此不能通過(guò)把它乘以

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

表現(xiàn)為頻域形式，電容在時(shí)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(shí)域變量。

Section 6 Exercise 3

第三篇：專(zhuān)業(yè)英語(yǔ)翻譯

介紹

硒(Se)是一個(gè)對(duì)人類(lèi)和動(dòng)物而言很重要的微量營(yíng)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(dòng)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?yàn)殇X和鐵氧化物具有較高的表面積和零點(diǎn)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(zhǎng)。Hayes博士(1987年)增加報(bào)道,亞硒酸鹽吸附在吸附劑、針鐵礦(a-FeOOH)，形成一個(gè)內(nèi)球體復(fù)合體，硒酸鹽形成一個(gè)弱外球體，然后硒酸鹽在吸附劑會(huì)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(duì)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(gè)Ph=5.0和0.01M電解質(zhì)溶液被選作等溫、動(dòng)力學(xué)、和吸附實(shí)驗(yàn)。

3.2.2吸附等溫線(xiàn)

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(gè)二元氧化物進(jìn)行振蕩。吸附數(shù)據(jù)通過(guò)Langmuir 等溫線(xiàn)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(xiàn)模型適用于通過(guò)二元氧化系統(tǒng)來(lái)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(gè)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(gè)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(gè)酸度常數(shù)來(lái)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(lèi)似于磷酸鹽,而硒酸鹽是類(lèi)似于硫酸鹽(Hayes 1987，wijnja和Schulthess,2000)，兩個(gè)二元氧化物系統(tǒng)對(duì)亞硒酸鹽的吸附大于硒酸鹽。

對(duì)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(gè)更大的容量，來(lái)源于Al(III)/SiO2體系對(duì)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(duì)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(jī)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(guò)程的機(jī)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(dòng)力學(xué)

描述溶質(zhì)吸附率的吸附動(dòng)力學(xué)控制吸附反應(yīng)的停留時(shí)間是一個(gè)決定吸附效率的重要特征。圖.4表明兩個(gè)二元氧化物系統(tǒng)在不同的時(shí)間間隔和偽二級(jí)動(dòng)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(duì)在Al(III)/SiO2 and Fe(III)/SiO2上的亞硒酸鹽，2 h的接觸會(huì)使95%的亞硒酸鹽被完全除去，吸附也會(huì)接近平衡(圖4a)。個(gè)別的硒酸鹽去除百分比可以達(dá)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(gè)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(dòng)力學(xué)數(shù)據(jù)零、第一、偽第二、二階，拋物線(xiàn)，Elovich模型，評(píng)估r2和假定值，總安裝數(shù)據(jù)沒(méi)有顯示。這個(gè)偽二階動(dòng)力學(xué)模型是最好的模型去描述二元氧化系統(tǒng)的動(dòng)力學(xué)數(shù)據(jù)。表3表明顯示了通過(guò)t/qt的圖形從偽二級(jí)動(dòng)力學(xué)模型得到確切系數(shù)(r2)和其他參數(shù)來(lái)確定V0和qeq所有的媒體價(jià)值。這個(gè)偽二階模型很好的符合了兩個(gè)二元氧化物的系統(tǒng)運(yùn)動(dòng)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(duì)硒酸鹽Al(III)/SiO2具有更高的親和力，在Fe(III)/SiO2上對(duì)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(guò)程中被釋放出來(lái)。因?yàn)閬單猁}強(qiáng)烈的通過(guò)結(jié)合金屬氧化物表面形成更強(qiáng)壯的內(nèi)球面復(fù)合物，在緩慢的過(guò)程中亞硒酸鹽需要花更多的時(shí)間到達(dá)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(méi)有改變。圖5和表4表

明了在樣品上進(jìn)行的硒的K-edge EXAFS在pH=5.0時(shí)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(gè)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(gè)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(gè)二元氧化物系統(tǒng)上(圖5)。這個(gè)距離是與以前在亞硒酸鹽進(jìn)行的EXAFS實(shí)驗(yàn)數(shù)據(jù)達(dá)到了良好的統(tǒng)一，這表明對(duì)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)。基于簡(jiǎn)單的幾何約束，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(gè)Al安裝成Se-Al)在pH=5下是一個(gè)雙配位基、雙核的表面復(fù)合物(鍵長(zhǎng)的范圍是～3.2A)。亞硒酸鹽吸附在其他鋁軸承礦物表面這個(gè)和以前的研究(Hayesetal,1987)達(dá)成良好的協(xié)議，這也報(bào)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(bào)道類(lèi)似的Se-Fe鍵距離是3.29A相應(yīng)的在那個(gè)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(gè)雙配位基的單核表面復(fù)合物的距離是2.80A和一個(gè)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(gè)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(gè)在硒酸鹽吸附樣本的Se-Al距離鍵長(zhǎng)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(gè)內(nèi)球體表面復(fù)合物。然而，Se-Fe的鍵長(zhǎng)(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(zhǎng)比在Al(III)/SiO2的長(zhǎng)。根據(jù)EXAFS原則, x射線(xiàn)吸收原子和周?chē)拥木嚯x就是一個(gè)鍵長(zhǎng)。鍵長(zhǎng)越長(zhǎng)，中心和周?chē)脑拥南嗷プ饔迷饺酢Ｔ贔e(III)/SiO2體系上的亞硒酸鹽和硒酸鹽的Se-金屬鍵長(zhǎng)實(shí)際上是一樣的。鍵長(zhǎng)適合特性的估計(jì)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(jìn)制元氧化物系統(tǒng)上亞硒酸鹽比硒酸鹽形成了更強(qiáng)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(xiàng)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(qiáng)烈聯(lián)系導(dǎo)致其整個(gè)表面電荷比Fe(III)/SiO2更加積極, Al(III)/SiO2對(duì)硒的吸附能力比Fe(III)/SiO2的更強(qiáng)。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(zhǎng), 硒和鐵高親和力導(dǎo)致了之間的鍵長(zhǎng)更短。調(diào)查結(jié)果得出目前的研究的基本意義是在推進(jìn)前沿二元氧化物系統(tǒng)化學(xué)專(zhuān)業(yè)知識(shí)。

第四篇：專(zhuān)業(yè)英語(yǔ)翻譯

樁筏基礎(chǔ)的簡(jiǎn)化設(shè)計(jì)方法

摘要：在筏板基礎(chǔ)本身并不能滿(mǎn)足設(shè)計(jì)要求情況下，可通過(guò)在筏板下增加樁來(lái)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(jiǎn)化計(jì)算方法的過(guò)程，對(duì)樁筏基礎(chǔ)的初步設(shè)計(jì)提供了有用的依據(jù)。它包括兩個(gè)階段：

1.樁筏基礎(chǔ)整體性能的評(píng)價(jià)；

2.單柱荷載作用下的性能評(píng)價(jià)。

第五篇：專(zhuān)業(yè)英語(yǔ)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(qiáng)度和腐殖酸對(duì)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(guò)不同離子強(qiáng)度（100mM氯化鈉和100mM氯化鈣）或PH值（4，5.5，和8）或通過(guò)引入10毫克/升的腐殖酸探討水化學(xué)環(huán)境對(duì)這種相互作用力的影響。當(dāng)粒子裸露時(shí)，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(shí)出現(xiàn)在PH值為8的時(shí)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(guò)進(jìn)行了石英晶體微天平與耗散監(jiān)測(cè)的實(shí)驗(yàn)，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(qiáng)度會(huì)減弱。一個(gè)擴(kuò)展的 DLVO模型和Ohshima理論修改后的版本成功地?cái)M合了原子力顯微鏡得到的數(shù)據(jù)。