化学专业英语版翻译

化学专业英语版翻译
化学专业英语版翻译

01T H E E L E M E N T S A N D T H E P E R I O D I C T A B L E

01 元素和元素周期表

The number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal to the atomic number, Z. The total mass of an atom is determined very nearly by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z.

质子的数量在一个原子的核被称为原子序数,或质子数、周淑金、电子的数量在一个电中性原子也等于原子序数松山机场的总质量的原子做出很近的总

数的质子和中子在它的核心。这个总数被称为大量胡逸舟、中子的数量在一个原子,中子数,给出了a - z的数量。

The term element refers to, a pure substance with atoms all of a single kind. To the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 are known; there are 107 chemical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example:

这个术语是指元素,一个纯物质与原子组成一个单一的善良。在药房“客气”

原子的原子数来确定它,因为它的性质是决定其化学行为。目前所有原子和Z = 1 a到Z = 107是知道的;有107种化学元素。每一种化学元素起了一个名字和独特的象征。对于大多数元素都仅仅是一个象征的英文名称缩写形式,一个或两个字母组成,例如:

oxygen==O nitrogen == N neon==Ne magnesium == Mg

氮氧= = = = N霓虹灯啊= = = =不镁镁

Some elements,which have been known for a long time,have symbols based on their Latin names, for example:

一些元素,长久以来,根据他们的拉丁名字符号,例如:

iron==Fe(ferrum) copper==Cu(cuprum) lead==Pb(plumbum)

铁= =铁(铁)的铜= =铜(缓蚀剂)引线= =铅(铅)

A complete listing of the elements may be found in Table 1.

一个完整的上市的元素可以被发现于表1。

Beginning in the late seventeenth century with the work of Robert Boyle, who proposed the presently accepted concept of an element, numerous investigations produced a considerable knowledge of the properties of elements and their compounds1. In 1869, D.Mendeleev and L. Meyer, working independently, proposed the periodic law. In modern form, the law states that the properties of the elements are periodic functions of their atomic numbers. In other words, when the elements are listed in order of increasing atomic number, elements having closely similar properties will

fall at definite intervals along the list. Thus it is possible to arrange the list of elements in tabular form with elements having similar properties placed in vertical columns2. Such an arrangement is called a periodic

在十七世纪后期开始的工作罗伯特·波以耳,提出当前一个元素的接受和运用的概念,产生了可观的知识大量调查的特性及其compounds1元素。在1869年,D.Mendeleev和l .迈耶,独立工作能力,提出了周期性的律法。在现代形式,法律规定的特性是周期函数的元素的原子编号。换句话说,当元素的顺序列出增加原子序数、元素有相近的财产落在了明确的间隔沿名单。由此,我们有可能安排的名单表格元素的元素有相似的性质columns2放置在垂直。这样的安排被称为一个周期

Each horizontal row of elements constitutes a period. It should be noted that the lengths of the periods vary. There is a very short period containing only 2 elements, followed by two short periods of 8 elements each, and then two long periods of 18 elements each. The next period includes 32 elements, and the last period is apparently incomplete. With this arrangement, elements in the same vertical column have similar characteristics. These columns constitute the chemical families or groups. The groups headed by the members of the two 8-element periods are designated as main group elements, and the members of the other groups are called transition or inner transition elements.

每个水平排的元素构成一段时间。但应该注意的是,不同长度的时期。这是一个非常短只包含二元素,后面跟着两个短的每8元素,然后两个长期的18个元

素组成。下一个阶段包括32元素,最后一期明显不完整的。这样的安排、元素在同一垂直柱有相似的特点。这些圆柱构成化学家庭或组。这个团体的成员为首的两8-element时期为主要集团指定的元素,其他组的成员被称为过渡或内在过渡元素。

In the periodic table, a heavy stepped line divides the elements into metals and nonmetals. Elements to the left of this line (with the exception of hydrogen) are metals, while those to the right are nonmetals. This division is for convenience only; elements bordering the line—the metalloids-have properties characteristic of - both metals and nonmetals. It may be seen that most of the elements, including all the transition and inner transition elements, are metals.

在元素周期表,沉重的走线分元素到金属以及非金属矿物等。元素的左本线(除氢)是金属,而那些右边是非金属矿物等。这个师为方便使

用,metalloids-have接壤的line-the元素的性质特点——两者都是金属以及非金属矿物等。这可以被看见,大部分的元素,包括所有的过渡和内在过渡元素,是金属。

Except for hydrogen, a gas, the elements of group IA make up the alkali metal family. They are very reactive metals, and they are never found in the elemental state in nature. However, their compounds are widespread. All the members of the alkali metal family, form ions having a charge of 1+ only. In contrast, the elements of group IB —copper, silver, and gold—are comparatively inert. They are similar to the alkali metals in that they exist

as 1+ ions in many of their compounds. However, as is characteristic of most transition elements, they form ions having other charges as well.

除了氢气、气体、集团的元素是构成了碱金属的家庭。他们是非常活泼的金属,他们永远都不会被发现在国家自然元素。然而,他们的化合物是广泛的。所有成员的碱金属的家庭,形成离子有一个负责1 +而已。相比之下,IB

-copper组元素,白银和gold-are较为活跃的。他们与碱性金属存在1 +离子在他们的许多化合物。然而,从大多数过渡元素的特征,它们形成离子有其它的费用。

The elements of group IIA are known as the alkaline earth metals. Their characteristic ionic charge is 2+. These metals, particularly the last two members of the group, are almost as reactive as the alkali metals. The group IIB elements—zinc, cadmium, and mercury are less reactive than are those of group II A5, but are more reactive than the neighboring elements of group IB. The characteristic charge on their ions is also 2+. 集团的元素IIA被称为碱性地球金属。其特点是离子电荷2 +。这些金属,特别是最后两队中成员的,几乎是作为反应碱性金属。集团elements-zinc IIB 铅、镉、汞更少的反应比第二组A5,但是比较无功比相邻元素。特点集团建筑费用记在他们的离子也是2 +。

With the exception of boron, group IIIA elements are also fairly reactive metals. Aluminum appears to be inert toward reaction with air, but this behavior stems from the fact that the metal forms a thin, invisible film of aluminum oxide on the surface, which protects the bulk of the metal from

further oxidation. The metals of group IIIA form ions of 3+ charge. Group IIIB consists of the metals scandium, yttrium, lanthanum, and actinium.

除了硼、集团IIIA元素相当活性金属。铝似乎反应惰性向空气,但这种行为的根源是金属形成薄、隐形氧化铝膜的表面上,即保护大量的金属的进一步氧化。金属离子组的3 + IIIA形式的费用。由金属集团希望scandium、钇、稀土镧系,actinium。

Group IVA consists of a nonmetal, carbon, two metalloids, silicon and germanium, and two metals, tin and lead. Each of these elements forms some compounds with formulas which indicate that four other atoms are present per group IVA atom, as, for example, carbon tetrachloride, GCl4. The group IVB metals —titanium, zirconium, and hafnium —also forms compounds in which each group IVB atom is combined with four other atoms; these compounds are nonelectrolytes when pure.

集团外语由一个非金属、碳、两个非金属等、硅和锗,和两个金属、锡、铅。这些要素的每一个物质形成一些计算公式表明,其他四个原子每组目前外语原子的,例如,四氯化碳GCl4。IVB金属集团-titanium、锆、hafnium化合物在那时间也形式每组IVB原子结合四个其他原子,这些化合物是nonelectrolytes纯。

The elements of group V A include three nonmetals —nitrogen, phosphorus, and arsenic—and two metals —antimony and bismuth. Although compounds with the formulas N2O5, PCl5, and AsCl5 exist, none of them is ionic. These elements do form compounds-nitrides,

phosphides, and arsenides —in which ions having charges of minus three occur. The elements of group VB are all metals. These elements form such a variety of different compounds that their characteristics are not easily generalized.

元素的一组包含三个非金属- V氮、磷、arsenic-and两种金属锑、铋。- - - - - - -虽然物质N2O5公式,PCl5,AsCl5存在,其中没有一个是离子。这些元素compounds-nitrides形式,phosphides,arsenides—离子有指控减三发生。VB 的元素都是金属集团。这些元素形态的各种不同的化合物,其特点是不易推广。

With the exception of polonium, the elements of group VIA are typical nonmetals. They are sometimes known, as the, chalcogens, from the Greek word meaning "ash formers". In their binary compounds with metals they exist as ions having a charge of 2-. The elements of group ⅦA are all nonmetals and are known as the halogens. from the Greek term meaning "salt formers. ”They are the most reactive nonmetals and are capable of reacting with practically all the metals and with most nonmetals, including each other.

除了钋的元素组上通过是典型的非金属矿物等。他们有时是已知的,因

为,chalcogens,从希腊单词意思是“灰的建设者”。在他们的二元化合物存在与金属离子有一个负责2 -。ⅦA的元素都是非金属和组被称为非卤素。从希腊术语,意即“盐成形机。“他们是最无功等,能够反应几乎所有的金属和大多数非金属,包括对方。

The elements of groups ⅥB, ⅦB, and VIIIB are all metals. They form such a wide Variety of compounds that it is not practical at this point to present any examples as being typical of the behavior of the respective groups.

组织ⅥB的元素,ⅦB,VIIIB都是金属。它们形成这么多各种各样的化合物,它是不切合实际的在这一点上,以目前的典型实例的行为作为各自的组。

The periodicity of chemical behavior is illustrated by the fact that. excluding the first period, each period begins with a very reactive metal. Successive element along the period show decreasing metallic character, eventually becoming nonmetals, and finally, in group ⅦA, a very reactive nonmetal is found. Each period ends with a member of the noble gas family.

化学行为的周期性的事实说明了。除了第一周期,每一个周期开始于一个非常活泼的金属。沿着周期连续元素显示减少金属而言,最终成为非金属,最后,在集团ⅦA,一个很活泼的非金属元素。每一个时期的结尾是一个惰性气体元素。

02 THE NONMETAL ELEMENTS

02非金属元素

We noted earlier. that -nonmetals exhibit properties that are greatly different from those of the metals. As a rule, the nonmetals are poor conductors of electricity (graphitic carbon is an exception) and heat; they are brittle, are often intensely colored, and show an unusually wide range

of melting and boiling points. Their molecular structures, usually involving ordinary covalent bonds, vary from the simple diatomic molecules of H2, Cl2, I2, and N2 to the giant molecules of diamond, silicon and boron.

我们前面所指出的。-nonmetals展览财产,大大不同于其他的金属。作为一个规则,是电的不良导体非金属(石墨碳例外)和热量,他们是易碎的,通常是强烈的颜色,并表现出异常广泛的融化和沸点。他们的分子结构,通常是包括了普通的共价债券的变化,从简单的双原子分子的H2,含,i和N2期的大分子钻石、硅和硼。

The nonmetals that are gases at room temperature are the low-molecular weight diatomic molecules and the noble gases that exert very small intermolecular forces. As the molecular weight increases, we encounter a liquid (Br2) and a solid (I2) whose vapor pressures also indicate small intermolecular forces. Certain properties of a few nonmetals are listed in Table 2.

气体的非金属,室温低分子物重量的双原子分子和高尚的气体时发挥非常小的力量。随着分子量的增大,我们遇到了一个液体(Br2)和一个固体(i)的蒸气压也表明小的电子的力量。一些非金属的某些性质都列在表2。

Table 2- Molecular Weights and Melting Points of Certain Nonmetals

表2——分子量和熔点的某些非金属矿物等

Diatomic Molecules Molecular Weight Melting Point °C Color

双原子分子分子量的熔点°c的颜色

H2 2 -239.1' None

h2 2 -英尺没有

N2 28 -210 None

28 -——任何n2

F2 38 -223 Pale yellow

f2 38 -年-淡黄色

O2 32 -218 Pale blue

o2 32 - -浅蓝色

Cl2 71 -102 Yellow —green

71 -年-含黄色——绿色

Br2 160 -7.3 Red —brown

br2 160 -——红-棕色

I2 254 113 Gray—black

254 113 gray-black i

Simple diatomic molecules are not formed by the heavier members of Groups V and VI at ordinary conditions. This is in direct contrast to the first members of these groups, N2 and O2. The difference arises because of the lower stability of πbonds formed from p orbitals of the third and higher main energy levels as opposed to the second main energy level2. The larger atomic radii and more dense electron clouds of elements of the

third period and higher do not allow good parallel overlap of p orbitals necessary for a strong πbond. This is a general phenomenon —strong πbonds are formed only between elements of the second period. Thus, elemental nitrogen and oxygen form stable molecules with both σand

πbonds, but other members of their groups form more stable structures based on σbonds only at ordinary conditions. Note3 that Group VII elements form diatomic molecules, but πbonds are not required for saturation of valence.

简单的双原子分子并未形成群体的成员由重五和六,在普通的条件。这直接对比这两组的第一个成员,氮气和氧气。差别产生因为较低的稳定的轨道上形成的π债券p第三和更高的主要能量水平相对于level2第二大能源。较大的原子半径和电子云致密元素的三期和更高的不允许平行的轨道上重叠好必要的强pπ债券。这是一个普遍的现象——是强壮π债券只有元素之间形成的第二期。因此,元素氮、氧和形成稳定的分子和πσ债券,但各自小组的其他成员,形成稳定结构基于σ债券只有在普通的条件。Note3那群七元素形成双原子分子,但π债券饱和度不需要价。

Sulfur exhibits allotropic forms. Solid sulfur exists in two crystalline forms and in an amorphous form. Rhombic sulfur is obtained by crystallization from a suitable solution, such as CS2, and it melts at 112°C. Monoclinic sulfur is formed by cooling melted sulfur and it melts at 119°C. Both forms of crystalline sulfur melt into S-gamma, which is composed of S8 molecules. The S8 molecules are puckered rings and survive heating to

about 160°C. Above 160°C, the S8 rings break open, and some of these fragments combine with each other to form a highly viscous mixture of irregularly shaped coils. At a range of higher temperatures the liquid sulfur becomes so viscous that it will not pour from its container. The color also changes from straw yellow at sulfur's melting point to a deep

reddish-brown as it becomes more viscous.

allotropic硫展品形式。固硫存在于两水晶形式和一种无定形的形式。菱形硫得到结晶从适当的解决办法,如CS2,在112°C的融化。Monoclinic硫是由硫和融化冷却融化在119°C。两种形式的水晶融入S-gamma硫组成的S8的分子。S8的分子环和生存眯加热到160°C。超过160°C,破S8环,其中的一些片段相互结合形成一个高粘度的混合的形状不规则的线圈。在一系列的高温液体硫变得如此粘性,它将不可浇上从它的容器。从颜色变化也在硫的稻草黄色熔点到深红褐色也变得较粘稠。

As4 the boiling point of 444 °C is approached, the large-coiled molecules of sulfur are partially degraded and the liquid sulfur decreases in viscosity. If the hot liquid sulfur is quenched by pouring it into cold water, the amorphous form of sulfur is produced. The structure of amorphous sulfur consists of large-coiled helices with eight sulfur atoms to each turn of the helix; the overall nature of amorphous sulfur is described as3 rubbery because it stretches much like ordinary rubber. In a few hours the amorphous sulfur reverts to small rhombic crystals and its rubbery property disappears.

As4沸点444°C走近时,大硫分子部分分解和液体硫的粘度下降。如果把热的液体硫倒它熄灭跳进冰冷的水里,就会产生无定形硫。无定形硫的结构和八大螺旋状物的硫螺旋的每一次转身,总体性质描述的非晶态硫橡胶as3,因为它像普通橡胶延伸。在几小时无定形硫小菱形晶体和它的弹性性质就消失了。

Sulfur, an important raw material in industrial chemistry, occurs as the free element, as SO2 in volcanic regions, as H2S in mineral waters, and in a variety of sulfide ores such as iron pyrite FeS2, zinc blende ZnS, galena PbS and such, and in common formations of gypsum CaSO4 ? 2H2O, anhydrite CaSO4, and barytes BaSO4 ? 2H2O. Sulfur, in one form or another, is used in large quantities for making sulfuric acid, fertilizers, insecticides, and paper.

硫、重要原料工业化学,发生在当自由的元素,因为中SO2的火山区,H2S矿泉水、和用各种各样的硫化矿石硫铁矿FeS2如铁、锌blende ZnS,PbS方铅矿等,共同形成的石膏CaSO4?2 H2O,CaSO4硬石膏,barytes BaSO4?2

H2O。硫、或另一种形式,用于大量制造硫酸、肥料、杀虫剂、和纸张。Sulfur in the form of SO2 obtained in the roasting of sulfide ores is recovered and converted to sulfuric acid, although in previous years much of this SO2 was discarded through exceptionally tall smokestacks. Fortunately, it is now economically favorable to recover these gases, thus greatly reducing this type of atmospheric pollution. A typical roasting reaction involves the change:

硫的形式获得焙烧的SO2在硫化矿石被恢复和转化为硫酸,尽管在过去几年许多这样的异常高二氧化硫被摒弃通过烟囱。幸运的是,现在经济有利的恢复这些气体,从而大幅度地减少这种污染大气。一个典型的焙烧反应涉及改变: 2 ZnS + 3 O2—2 ZnO + 2 SO2

2 ZnS +

3 O2-2氧化锌+ 2二氧化硫

Phosphorus, below 800℃consists of tetratomic molecules, P4. Its molecular structure provides for a covalence of three, as may be expected from the three unpaired p electrons in its atomic structure, and each atom is attached to three others6. Instead of a strictly orthogonal orientation, with the three bonds 90°to each other, the bond angles are only 60°. This supposedly strained structure is stabilized by the mutual interaction of the four atoms (each atom is bonded to the other three), but it is chemically the most active form of phosphorus. This form of phosphorus, the white modification, is spontaneously combustible in air. When heated to 260°C it changes to red phosphorus, whose structure is obscure. Red phosphorus is stable in air but, like all forms of phosphorus, it should be handled carefully because of its tendency to migrate to the bones when ingested, resulting in serious physiological damage.

磷、低于800℃由tetratomic分子,第四名。其分子结构提供价电子的三个,

就可以从三个未成对预期在p电子的原子结构,每一个原子都是三others6相连。而不是一个严格的正交方向,与这三个彼此90°的债券,债券只有60°角。这种被认为是紧张的结构稳定的相互作用的四个原子(每一个原子都是保税

的其他三个),但是它是最活跃的化学形态磷的含量。这种形式的磷、白色的修改,很自然地被易燃空气中。当加热到260°C它改变红磷,其结构是费解的。红色是在空气中磷稳定。但是,就像所有形式的磷,它应该谨慎处理因其迁移到骨头倾向摄入体内后,导致严重的生理伤害。

Elemental carbon exists in one of two crystalline structures —diamond and graphite. The diamond structure, based on tetrahedral bonding of hybridized sp3 orbitals, is encountered among Group IV elements. We may expect that as the bond length increases, the hardness of the diamond-type crystal decreases. Although the tetrahedral structure persists among the elements in this group —carbon, silicon, germanium, and gray tin —the interatomic distances increase from 1.54 A for carbon to 2.80 A for gray tin. Consequently . the bond strengths among the four elements range from very strong to quite weak. In fact, gray tin is so soft that it exists in the form of microcrystals or merely as a powder. Typical of the Group IV diamond-type crystalline elements, it is a nonconductor and shows other nonmetallic properties7.

元素碳存在于两种水晶的结构——金刚石和石墨。金刚石结构、基于四面体的连接的突变sp3的轨道中遇到第四组元素。我们可以希望粘结长度增加,硬度降低diamond-type水晶。虽然四面体结构的持续的元素中在这个集团-碳、硅、锗,和灰色锡-原子距离由1.54提高到2.80 A为炭灰色锡。因此。之间的粘结强度四大元素范围从很强很虚弱。事实上,灰色的锡是柔软的,它的形式存在microcrystals或只是一种粉末。第四组diamond-type典型的水晶

元素,它是一个nonconductor和其他非金属properties7显示。

DS

06无机化合物的分类

The Classes of Compounds

这类化合物

Thousands and tens of thousands of compounds are known to the chemist today. It would be impossible to learn properties and behavior of even a fraction of this number if it had to be done on the basis of individual compounds1. Fortunately, most chemical compounds can be grouped together in a few classes. Then, if we can properly classify a compound . we are at once aware of the general properties of the compound from knowledge of the properties of that class or group of compounds. For example. HCl is classed as an acid. and by becoming familiar with the behavior of acids as a distinct class, we are at once aware of the general properties of the compound2. A great many of the compounds we are to study may be classified as acids, bases, salts, metallic oxides, or nonmetallic oxides. Of these five classes of compounds, the first three —acids, bases, and salts — are by far the most important3?

成千成千上万的化合物已知的化学家今天。它将不可能学会性质和行为的数量甚至一小部分如果必须完成个人compounds1的基础上。幸运的是,大多数化合物可以组合在一起在几类。然后,如果我们能正确地区分一种化合物。我们就立即意识到综合性能的复合知识性质的那堂课或一组化合物。为例。被

列为濒临盐酸酸。和熟悉的行为,酸作为一个特殊的类,我们马上意识到综合性能的compound2。有许多化合物我们学习可分为酸、碱、盐、金属氧化物或非金属氧化物。这五类化合物,排在前三位的-酸、碱、盐——是迄今为止最important3?

When an acid, base, or salt is dissolved in water the resulting solution is a conductor of the electric current and is termed an electrolyte. If no conduction of current occurs, the compound is known as a nonelectrolyte. 当一个酸、碱、盐溶于水产生的解决办法是导体电流,也可以被称为电解质。如果没有传导电流发生时,复合是众所周知的nonelectrolyte。Classification of Common Compounds

常见的化合物分类

By looking at the chemical formulas we may classify many common compounds in the following way.

通过观察化学公式中我们可根据许多常见化合物以如下的方式。

1. Acids, in the conventional sense, may be recognized by noting that the

H is written first in the formula and that the rest of the compound is generally nonmetallic. Ex., HCl, H2SO4, HClO.

1。酸,用常规的感觉,会被注意到的H首先被写在公式和其他非金属化合物一般。例、盐酸、硫酸、HClO。

2. Conventional bases have OH radicals written last in the formula. The first part of the formula is usually a metal. Ex., NaOH, Ca(OH)2, Fe(OH)3,

2。传统的基地激进分子持续哦写公式。第一部分公式的通常是一种金属。例、氢氧化钠、钙(OH)2、铁(OH)3,

3. A salt consists of a metal, written first, combined with a non-metal or radical written last in a formula. Ex., NaCl, Fe2(SO4)3, Ca(ClO)2.

3。盐是由金属,写第一,再加上一个非金属或根本写最后在一个公式。例、氯化钠、导管(SO4)3、钙(ClO)2 .

4. Oxides are compounds containing oxygen and only one other element. 4。氧化合物和氧化物,只有一个元素。

If the element other than oxygen is a nonmetal, the oxide is classed as a nonmetal oxide or an acidic anhydride. The latter name comes about because water added to nonmetal oxides under certain conditions produces acids. Likewise, if water is removed from an acid containing oxygen, the acid anhydride (without water) results.

如果硅氧是一种非金属以外,氧化物被归类为非金属氧化物或酸性酐。后者的名字是由于水加到非金属氧化物在一定条件下产生的酸。同样地,如果水是远离含氧酸的,酸酐(无水)的结果。

The other class of oxides, metallic oxides or basic anhydrides, consist of oxygen combined with a metal. When water is added under proper conditions to basic anhydrides, bases result and vice versa. Acids

另一类氧化物、金属氧化物或基本anhydrides,由氧结合一种金属。当水补充基本anhydrides在合适的条件下,立足结果,反之亦然。酸

All acids in the conventional sense contain hydrogen, which may be replaced by metals. The negative portion of the acid molecule is composed of a nonmetal or a radical (negative valence group). These negative valence groups (except oxide and hydroxide)are often referred to as acid radicals. All acids are covalent compounds in which the atoms are held together by a sharing of electrons. When an acid is dissolved in water, ions are formed as a result of the transfer of a hydrogen ion(proton) from the acid molecule to the water molecule---for example,

所有传统意义上的酸含氢,并可能被取代的金属。负部分的酸分子由一个或一个激进的非金属(负价组)。这些消极价组(除氧化物和氢氧化物)常被称为酸激进分子。酸是一种化合物,所有的共价原子是抱着一个共享的电子。当一种酸溶解在水中,离子形成的氢离子的转移(质子)分子与水分子酸- - - - - - - -例如,

This is a case of coordinate valence, in which an unused pair of electrons from the water molecule combines with a hydrogen ion to form a hydronium ion. The hydronium ion is a hydrated hydrogen ion or proton (H+ *H2O) and, while the ionization of acids in aqueous solution depends on its formation, we shall ordinarily use the simple H+ in writing equations. Such equations are thereby simplified and easier to balance.

这是一例坐标价,未使用的一对电子的从水分子结合形成一个氢离子,离子的印象。离子水合离子的一个氢离子或质子(H + * H2O),而电离酸在水溶液中形成取决于它,我们通常使用简单H +写作方程。这类方程的简化,从而更容

易被平衡。

The chief characteristic of an acid is its ability to furnish hydrogen ions (protons); therefore. an acid is usually defined as a substance which may furnish protons.

主要特点的能力是一种酸提供氢离子(即质子),因此。酸是一种物质,通常定义为可能提供质子。

Properties of Acids. In general, aqueous'solulions of acids are characterized by the following properties;

性能的酸。一般来说,水'solulions酸具有下列性质;

1. They have a sour taste. Lemons . oranges . and other citrus fruits owe their sour taste to' the presence of citric acid; the taste of sour milk is due to the presence of lactic acid.

1。他们有一种酸味。柠檬。桔子。和其他柑橘类水果欠他们的酸味的存在的味道柠檬酸,酸奶是由于乳酸的存在。

2. They turn blue litmus paper red. Litmus is a dye which has a red color in acid solution and a blue color in basic solution; paper which has been soaked in litmus is referred to as litmus paper. Substances of this type, which enable us to determine whether a given solution is acid or basic, are called indicators. Methyl orange and phenolphthalein are other indicators frequently used by chemists.

2。红色石蕊纸他们变成了蓝色。这是一种染料石蕊有一个红色的颜色在酸

化学专业英语(修订版)翻译

01 THE ELEMENTS AND THE PERIODIC TABLE 01 元素和元素周期表 The number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal to the atomic number, Z. The total mass of an atom is determined very nearly by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z. 质子的数量在一个原子的核被称为原子序数,或质子数、周淑金、电子的数量在一个电中性原子也等于原子序数松山机场的总质量的原子做出很近的总数的质子和中子在它的核心。这个总数被称为大量胡逸舟、中子的数量在一个原子,中子数,给出了a - z的数量。 The term element refers to, a pure substance with atoms all of a single kind. T o the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 are known; there are 107 chemical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example: 这个术语是指元素,一个纯物质与原子组成一个单一的善良。在药房“客气”原子的原子数来确定它,因为它的性质是决定其化学行为。目前所有原子和Z = 1 a到Z = 107是知道的;有107种化学元素。每一种化学元素起了一个名字和独特的象征。对于大多数元素都仅仅是一个象征的英文名称缩写形式,一个或两个字母组成,例如: oxygen==O nitrogen == N neon==Ne magnesium == Mg

化学专业英语翻译1

01.THE ELEMENTS AND THE PERIODIC TABLE 01元素和元素周期 表。 The number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal to the atomic number, Z. The total mass of an atom is determined very nearly by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z. 原子核中的质子数的原子称为原子序数,或质子数,卓电子数的电中性的原子也等于原子序数Z,总质量的原子是非常接近的总数量的质子和中子在原子核。这被称为质量数,这个数的原子中的中子,中子数,给出了所有的数量 The term element refers to, a pure substance with atoms all of a single kind. To the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 are known; there are 107 chemical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form of

《化学工程与工艺专业英语》课文翻译 完整版

Unit 1 Chemical Industry 化学工业 1.Origins of the Chemical Industry Although the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin‘s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939). 1.化学工业的起源 尽管化学品的使用可以追溯到古代文明时代,我们所谓的现代化学工业的发展却是非常近代(才开始的)。可以认为它起源于工业革命其间,大约在1800年,并发展成为为其它工业部门提供化学原料的产业。比如制肥皂所用的碱,棉布生产所用的漂白粉,玻璃制造业所用的硅及Na2CO3. 我们会注意到所有这些都是无机物。有机化学工业的开始是在十九世纪六十年代以William Henry Perkin 发现第一种合成染料—苯胺紫并加以开发利用为标志的。20世纪初,德国花费大量资金用于实用化学方面的重点研究,到1914年,德国的化学工业在世界化学产品市场上占有75%的份额。这要归因于新染料的发现以及硫酸的接触法生产和氨的哈伯生产工艺的发展。而后者需要较大的技术突破使得化学反应第一次可以在非常高的压力条件下进行。这方面所取得的成绩对德国很有帮助。特别是由于1914年第一次世界大仗的爆发,对以氮为基础的化合物的需求飞速增长。这种深刻的改变一直持续到战后(1918-1939)。 date bake to/from: 回溯到 dated: 过时的,陈旧的 stand sb. in good stead: 对。。。很有帮助

化学化工专业英语(课本内容)

第二章科技英语构词法 词是构成句子的要素,对词意理解的好坏直接关系到翻译的质量。 所谓构词法即词的构成方法,即词在结构上的规律。科技英语构词特点是外来语多(很多来自希腊语和拉丁语);第二个特点是构词方法多,除了非科技英语中常用的三种构词法—转化、派生及合成法外,还普遍采用压缩法、混成法、符号法和字母象形法。 2.1转化法(Conversion) 由一种词类转化成另一种词类,叫转化法。例如: water(n.水)→water(v.浇水) charge(n.电荷) →charge(v.充电) yield(n.产率) →yield(v.生成) dry(a.干的) →dry(v.烘干) slow(a.慢的) →slow(v.减慢) back(ad.在后、向后) →back(v.使后退、倒车) square(n.正方形) →square(a.正方形的) 2.2派生法(Derivation) 通过加前、后缀构成一新词。派生法是化工类科技英语中最常用的构词法。 例如“烷烃”就是用前缀(如拉丁或希腊前缀)表示分子中碳原子数再加上“-ane”作词尾构成的。若将词尾变成“-ane”、“-yne”、“-ol”、“-al”、“-yl”,则分别表示“烯”、“炔”、“醇”、“醛”、“基”、等。依此类推,从而构成千成种化学物质名词。常遇到这样的情况,许多化学化工名词在字典上查不到,全若掌握这种构词法,能过其前、后缀分别代表的意思,合在一起即是该词的意义。下面通过表1举例说明。需要注意的是,表中物质的数目词头除前四个另有名称外,其它均为表上的数目词头。 本书附录为化学化工专业常用词根及前后缀。此外还可参阅《英汉化学化工词汇》(第三版)附录中的“英汉对照有机基名表”、“西文化学名词中常用的数止词头”及“英汉对照有机词尾表”。 据估计,知道一个前缀可帮助人们认识450个英语单词。一名科技工作者至少要知道近50个前缀和30个后缀。这对扩大科技词汇量,增强自由阅读能力,提高翻译质量和加快翻译速度都是大有裨益的。 2.3合成法(Composition) 由两个或更多的词合成一个词,叫合成法。有时需加连字符。 如副词+过去分词well-known 著名的 名词+名词carbon steel 碳钢 rust-resistance 防锈 名词+过去分词computer-oriented 研制计算机的 介词+名词by-product 副产物 动词+副词makeup 化妆品 check-up 检查 形容词+名词atomic weight 原子量 periodic table 周期表 动词+代词+副词pick-me-up 兴奋剂 副词+介词+名词out-of-door 户外 2.4压缩法(Shortening) (1)只取词头字母 这种方法在科技英语中较常用。

应用化学专业英语翻译完整篇

1 Unit5元素周期表 As our picture of the atom becomes more detailed 随着我们对原子的描述越来越详尽,我们发现我们陷入了进退两难之境。有超过100多中元素要处理,我们怎么能记的住所有的信息?有一种方法就是使用元素周期表。这个周期表包含元素的所有信息。它记录了元素中所含的质子数和电子数,它能让我们算出大多数元素的同位素的中子数。它甚至有各个元素原子的电子怎么排列。最神奇的是,周期表是在人们不知道原子中存在质子、中子和电子的情况下发明的。Not long after Dalton presented his model for atom( )在道尔顿提出他的原子模型(原子是是一个不可分割的粒子,其质量决定了它的身份)不久,化学家门开始根据原子的质量将原子列表。在制定像这些元素表时候,他们观察到在元素中的格局分布。例如,人们可以清楚的看到在具体间隔的元素有着相似的性质。在当时知道的大约60种元素中,第二个和第九个表现出相似的性质,第三个和第十个,第四个和第十一个等都具有相似的性质。 In 1869,Dmitri Ivanovich Mendeleev,a Russian chemist, 在1869年,Dmitri Ivanovich Mendeleev ,一个俄罗斯的化学家,发表了他的元素周期表。Mendeleev通过考虑原子重量和元素的某些特性的周期性准备了他的周期表。这些元素的排列顺序先是按原子质量的增加,,一些情况中, Mendeleev把稍微重写的元素放在轻的那个前面.他这样做只是为了同一列中的元素能具有相似的性质.例如,他把碲(原子质量为128)防在碘(原子质量为127)前面因为碲性质上和硫磺和硒相似, 而碘和氯和溴相似. Mendeleev left a number of gaps in his table.Instead of Mendeleev在他的周期表中留下了一些空白。他非但没有将那些空白看成是缺憾,反而大胆的预测还存在着仍未被发现的元素。更进一步,他甚至预测出那些一些缺失元素的性质出来。在接下来的几年里,随着新元素的发现,里面的许多空格都被填满。这些性质也和Mendeleev所预测的极为接近。这巨大创新的预计值导致了Mendeleev的周期表为人们所接受。 It is known that properties of an element depend mainly on the number of electrons in the outermost energy level of the atoms of the element. 我们现在所知道的元素的性质主要取决于元素原子最外层能量能级的电子数。钠原子最外层能量能级(第三层)有一个电子,锂原子最外层能量能级(第二层)有一个电子。钠和锂的化学性质相似。氦原子和氖原子外层能级上是满的,这两种都是惰性气体,也就是他们不容易进行化学反应。很明显,有着相同电子结构(电子分布)的元素的不仅有着相似的化学性质,而且某些结构也表现比其他元素稳定(不那么活泼) In Mendeleev’s table,the elements were arranged by atomic weights for 在Mendeleev的表中,元素大部分是按照原子数来排列的,这个排列揭示了化学性质的周期性。因为电子数决定元素的化学性质,电子数也应该(现在也确实)决定周期表的顺序。在现代的周期表中,元素是根据原子质量来排列的。记住,这个数字表示了在元素的中性原子中的质子数和电子数。现在的周期表是按照原子数的递增排列,Mendeleev的周期表是按照原子质量的递增排列,彼此平行是由于原子量的增加。只有在一些情况下(Mendeleev注释的那样)重量和顺序不符合。因为原子质量是质子和中子质量的加和,故原子量并不完全随原子序数的增加而增加。原子序数低的原子的中子数有可能比原子序数高的原

化工英文文献翻译

Heavy Oil Development Technology of Liaohe Oilfield Han Yun (Scientific Research Information Department Exploration&Development Research Institute,Liaohe Oilfield Company) Liaohe Oilfield,the largest heavy oil production base in China,features in various reservoir types,deep burial,and wide range of crude oil viscosity.For many years,a series of technologies have been developed for different oil products and reservoir types of the oilfield,of which water flooding,foam slug drive,steam stimulation,steam drive,and SAGD are the main technologies. After continuous improvement,they have been further developed and played an important role in the development of heavy oil in the oilfield. Liaohe Oilfield is abundant in heavy oil resources,46%of the total proved reserves of Liaohe Oilfield Company. Horizontally the resources concentrates in the West Depression and the southern plunging belt of the Central Uplift in Liaohe Rift. Vertically,it is mainly distributed in Paleocene Shahejie Formation(ES). The distinctive geological feature of Liaohe 0ilfield is manifested in three aspects:first,the heavy oil reservoirs are deeply buried and 80%of them are buried more than 900m deep;second,the heavy oil viscosity ranges widely.For most of the reservoirs.the dead oil viscosity ranges in 100~100000mPa·s with the maximum 650000mPa·s.Third the reservoir types are various with complicated oil—water relationship,most of the reservoirs are edge water and bosom water reservoirs and there are also edge water reservoirs,top water reservoirs and bosom water reservoirs.For more than 20 years of development,Liaohe Oilfield has developed series of heavy oil development technologies for different oil products and different types of reservoirs,such as water flooding, foam slug drive,steam stimulation steam drive and SAGD.The most difficult issues have been overcome in the development of the super

《化学工程与工艺专业英语》课文翻译Unit 21 Chemical Industry and Environment

Unit 21 Chemical Industry and Environment 化学工业与环境 How can we reduce the amount of waste that is produced? And how we close the loop by redirecting spent materials and products into programs of recycling? All of these questions must be answered through careful research in the coming years as we strive to keep civilization in balance with nature. 我们怎样才能减少产生废物的数量?我们怎样才能使废弃物质和商品纳入循环使用的程序?所有这些问题必须要在未来的几年里通过仔细的研究得到解决,这样我们才能保持文明与自然的平衡。 1.Atmospheric Chemistry Coal-burning power plants, as well as some natural processes, deliver sulfur compounds to the stratosphere, where oxidation produces sulfuric acid particles that reflect away some of the incoming visible solar radiation. In the troposphere, nitrogen oxides produced by the combustion of fossil fuels combine with many organic molecules under the influence of sunlight to produce urban smog. The volatile hydrocarbon isoprene, well known as a building block of synthetic rubber, is also produced naturally in forests. And the chlorofluorocarbons, better known as CFCs, are inert in automobile air conditioners and home refrigerators but come apart under ultraviolet bombardment in the mid-stratosphere with devastating effect on the earth’s stratospheric ozone layer. The globally averaged atmospheric concentration of stratospheric ozone itself is only 3 parts in 10 million, but it has played a crucial protective role in the development of all biological life through its absorption of potentially harmful shout-wavelength solar ultraviolet radiation. 1.大气化学 燃煤发电厂像一些自然过程一样,也会释放硫化合物到大气层中,在那里氧化作用产生硫酸颗粒能反射入射进来的可见太阳辐射。在对流层,化石燃料燃烧所产生的氮氧化物在阳光的影响下与许多有机物分子结合产生都市烟雾。挥发的碳氢化合物异戊二烯,也就是众所周知的合成橡胶的结构单元,可以在森林中天然产生含氯氟烃。我们所熟悉的CFCs,在汽车空调和家用冰箱里是惰性的,但在中平流层内在紫外线的照射下回发生分解从而对地球大气臭氧层造成破坏,全球大气层中臭氧的平均浓度只有3ppm,但它对所有生命体的生长发育都起了关键的保护作用,因为是它吸收了太阳光线中有害的短波紫外辐射。 During the past 20 years, public attention has been focused on ways that mankind has caused changes in the atmosphere: acid rain, stratospheric zone depletion, greenhouse warming, and the increased oxidizing capacity of the atmosphere. We have known for generations that human activity has affected the nearby surroundings, but only gradually have we noticed such effects as acid rain on a regional then on an intercontinental scale. With the problem of ozone depletion and concerns about global warming, we have now truly entered an era of global change, but the underlying scientific facts have not yet been fully established. 在过去的二十年中,公众的注意力集中在人类对大气层的改变:酸雨、平流层臭氧空洞、温室现象,以及大气的氧化能力增强,前几代人已经知道,人类的活动会对邻近的环境造成影响,但意识到像酸雨这样的效应将由局部扩展到洲际范围则是慢慢发现的。随着臭氧空洞问题的出现,考虑到对全球的威胁,我们已真正进入到全球话改变的时代,但是基本的

应用化学专业英语第二版万有志主编版课后答案和课文翻译

Unit 1 The RootsofChemistry I.Comprehension. 1。C 2. B3.D 4. C 5. B II。Make asentence out of each item by rearranging the wordsin brackets. 1.Thepurification of anorganic compoundis usually a matter of considerabledifficulty, and itis necessary to employ various methods for thispurpose。 2.Science is an ever-increasing body ofaccumulated and systematized knowledge and isalsoan activity bywhic hknowledge isgenerated。 3.Life,after all, is only chemistry,in fact, a small example of c hemistry observed onasingle mundane planet。 4.Peopleare made of molecules; someof themolecules in p eople are rather simple whereas othersarehighly complex。 5.Chemistry isever presentin ourlives from birth todeathbecause without chemistrythere isneither life nor death. 6.Mathematics appears to be almost as humankindand al so permeatesall aspects of human life, although manyof us are notfully awareofthis. III。Translation. 1.(a)chemicalprocess (b) natural science(c)the techni que of distillation 2.Itis theatoms that makeupiron, water,oxygen and the like/andso on/andsoforth/and otherwise. 3.Chemistry hasa very long history, infact,human a ctivity in chemistrygoes back to prerecorded times/predating recorded times. 4.According to/Fromthe evaporation ofwater,people know /realized that liquidscan turn/be/changeinto gases undercertain conditions/circumstance/environment。 5.Youmustknow the propertiesofthe materialbefore y ou use it. IV.Translation 化学是三种基础自然科学之一,另外两种是物理和生物.自从宇宙大爆炸以来,化学过程持续进行,甚至地球上生命的出现可能也是化学过程的结果。人们也许认为生命是三步进化的最终结果,第一步非常快,其余两步相当慢.这三步

机电一体化中英文对照外文翻译文献

中英文对照外文翻译文献 (文档含英文原文和中文翻译) By integration of machinery development The modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation, in mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management system has had the huge change, caused the industrial production to enter into “the integration of machinery” by “the machinery electrification” for the characteristic development phase. First, the integration of machinery outline Integration of machinery is refers in the organization new owner function, the power function, in the information processing functio n and the control function introduces the electronic technology, u nifies the system the mechanism and the computerization design and the software which constitutes always to call.

化学专业英语

精心整理一、元素和单质的命名 “元素”和“单质”的英文意思都是“element”,有时为了区别,在强调“单质”时可用“freeelement”。因此,单质的英文名称与元素的英文名称是一样的。下面给出的既是元素的名称,同时又是单质的名称。 或用后缀-ous表示低价,-ic表示高价。 如FeO:iron(II)oxide或ferrous oxideFe2O3:iron(III)oxide或ferric oxide Cu2O:copper(I)oxide或cuprous oxide CuO:copper(II)oxide或cupric oxide 2.化合物负电荷部分的读法: 2.1二元化合物: 常见的二元化合物有卤化物,氧化物,硫化物,氮化物,磷化物,碳化物,金属氢化物等,命名时需要使用后缀-ide, 如:fluoride,chloride,bromide,iodide,oxide,sulfide,nitride,phosphide,carbide,hydride;OH-的名称也是用后缀-ide:hydroxide, 非金属氢化物不用此后缀,而是将其看成其它二元化合物(见2。2);非最低价的二元化合

物还要加前缀,如O22-:peroxideO2-:superoxide 举例:NaF:sodiumfluoride AlCl3:aluminiumchloride Mg2N3:magnesiumnitride Ag2S:silversulfide CaC2:calciumcarbide Fe(OH)2:iron(II)hydroxide 有些物质常用俗称,如NOnitricoxideN2Onitrousoxide 2.2非金属氢化物 除了水和氨气使用俗称water,ammonia以外,其它的非金属氢化物都用系统名称,命名规则根据化学式的写法不同而有所不同。对于卤族和氧族氢化物,H在化学式中写在前面,因此将其看成另一元素的二元化合物。 举例:HFhydrogenfluorideHClhydrogenchloride HBrhydrogenbromideHIhydrogeniodide CH4 H 高某酸 举例: H HPO3 正盐:根据化学式从左往右分别读出阳离子和阴离子的名称。 如FeSO4iron(II)sulfateKMnO4potassiumpermanganate 酸式盐:同正盐的读法,酸根中的H读做hydrogen,氢原子的个数用前缀表示。 如NaHCO3:sodiumhydrogencarbonate或sodiumbicarbonate NaH2PO4:sodiumdihydrogenphosphate 复盐:同正盐的读法,并且阳离子按英文名称的第一个字母顺序读。 如KNaCO3:potassiumsodiumcarbonate NaNH4HPO4:ammoniumsodiumhydrogenphosphate 水合盐:结晶水读做water或hydrate 如AlCl3.6H2O:aluminumchloride6-water或aluminumchloridehexahydrate AlK(SO4)212H2Oaluminiumpotassiumsulphate12-water

《化学工程与工艺专业英语》课文翻译

Unit1化学工业的研究和开发 One of the main发达国家化学工业飞速发展的一个重要原因就是它在研究和开发方面的投入commitmen t和投资investmen t。通常是销售收入的5%,而研究密集型分支如制药,投入则加倍。要强调这里我们所提出的百分数不是指利润而是指销售收入,也就是说全部回收的钱,其中包括要付出原材料费,企业管理费,员工工资等等。过去这笔巨大的投资支付得很好,使得许多有用的和有价值的产品被投放市场,包括一些合成高聚物如尼龙和聚脂,药品和杀虫剂。尽管近年来进入市场的新产品大为减少,而且在衰退时期研究部门通常是最先被裁减的部门,在研究和开发方面的投资仍然保持在较高的水平。 化学工业technology industry是高技术工业,它需要利用电子学和工程学的最新成果。计算机被广泛应用,从化工厂的自动控制a utomatic control,到新化合物结构的分子模拟,再到实验室分析仪器的控制。 Individual manufacturing一个制造厂的生产量很不一样,精细化工领域每年只有几吨,而巨型企业如化肥厂和石油化工厂有可能高达500,000吨。后者需要巨大的资金投入,因为一个这样规模的工厂要花费2亿5千万美元,再加上自动控制设备的普遍应用,就不难解释为什么化工厂是资金密集型企业而不是劳动力密集型企业。 The major大部分化学公司是真正的跨国公司multinational,他们在世界上的许多国家进行销售和开发市场,他们在许多国家都有制造厂。这种国际间的合作理念,或全球一体化,是化学工业中发展的趋势。大公司通过在别的国家建造制造厂或者是收购已有的工厂进行扩张。 Unit 2工业研究和开发的类型 The applied通常在生产中完成的实用型的或有目的性的研究和开发可以分为好几类,我们对此加以简述。它们是:(1)产品开发;(2)工艺开发;(3)工艺改进;(4)应用开发;每一类下还有许多分支。我们对每一类举一个典型的例子来加以说明。在化学工业的不同部门内每类的工作重点有很大的不同。 (1)产品开发。product development产品开发不仅包括一种新药的发明和生产,还包括,比如说,给一种汽车发动机提供更长时效的抗氧化添加剂。这种开发的产品已经使(发动机)的服务期限在最近的十年中从3000英里提高到6000、9000现在已提高到12000英里。请注意,大部分的买家所需要的是化工产品能创造出来的效果,亦即某种特殊的用途。,或称聚四氟乙烯()被购买是因为它能使炒菜锅、盆表面不粘,易于清洗。(2)工艺开发process development。工艺开发不仅包括为一种全新的产品设计一套制造工艺,还包括为现有的产品设计新的工艺或方案。而要进行后者时可能源于下面的一个或几个原因:新技术的利用、原材料的获得或价格发生了变化。氯乙烯单聚物的制造就是这样的一个例子。它的制造方法随着经济、技术和原材料的变化改变了好几次。另一个刺激因素是需求的显著增加。因而销售量对生产流程的经济效益有很大影响。早期的制造就为此提供了一个很好的例子。 The ability of能预防战争中因伤口感染引发的败血症,因而在第二次世界大战(1939-1945)中,pencillin的需求量非常大,需要大量生产。而在那时,只能用在瓶装牛奶表面发酵的方法小量的生产。英国和美国投入了巨大的人力物力联合进行研制和开发,对生产流程做出了两个重大的改进。首先用一个不同的菌株—黄霉菌代替普通的青霉,它的产量要比后者高得多。第二个重大的流程开发是引进了深层发酵过程。只要在培养液中持续通入大量纯化空气,发酵就能在所有部位进行。这使生产能力大大地增加,达到现代容量超过5000升的不锈钢发酵器。而在第一次世界大战中,死于伤口感染的士兵比直接死于战场上的人还要多。注意到这一点不能不让我们心存感激。 Process development for a new product对一个新产品进行开发要考虑产品生产的规模、产生的副产品以及分离/回收,产品所要求的纯度。在开发阶段利用中试车间(最大容量可达100升)获得的数据设计实际的制造厂是非常宝贵的,例如石油化工或氨的生产。要先建立一个中试车间,运转并测试流程以获得更多的数据。他们需要测试产品的性质,如杀虫剂,或进行消费评估,如一种新的聚合物。 Note that by-products注意,副产品对于化学过程的经济效益也有很大的影响。酚的生产就是一个有代表性的例子。早期的方法,苯磺酸方法,由于它的副产品亚硫酸钠需求枯竭而变的过时。亚硫酸钠需回收和废置成为生产过程附加的费用,增加了生产酚的成本。相反,异丙基苯方法,在经济效益方面优于所有其他方法就在于市场对于它的副产品丙酮的迫切需求。丙酮的销售所得降低了酚的生产成本。 A major part对一个新产品进行工艺开发的一个重要部分是通过设计把废品减到最低,或尽可能地防止可能的污染,这样做带来的经济利益和对环境的益处是显而易见的。 Finally it should be noted that最后要注意,工业开发需要包括化学家、化学工程师、电子和机械工程师这样一支庞大队伍的协同合作才能取得成功。 (3)process improvement工艺改进。工艺改进与正在进行的工艺有关。它可能出现了某个问题使生产停止。在这种情形下,就面临着很大的压力要尽快地解决问题以便生产重新开始,因为故障期耗费资财。 然而,更为常见的commonly,工艺改进是为了提高生产过程的利润。这可以通过很多途径实现。例如通过优化流程提高产量,引进新的催化剂提高效能,或降低生产过程所需要的能量。可说明后者的一个例子是在生产氨的过程中涡轮压缩机的引进。这使生产氨的成本(主要是电)从每吨6.66美元下降到0.56美元。通过工艺的改善提高产品质量也会为产品打开新的市场。 然而,近年来in rencent years,最重要的工艺改进行为主要是减少生产过程对环境的影响,亦即防止生产过程所引起的污染。很明显,有两个相关连的因素推动这样做。第一,公众对化学产品的安全性及其对环境所产生影响的关注以及由此而制订出来的法律;第二,生产者必须花钱对废物进行处理以便它能安全地清除,比如说,排放到河水中。显然这是生产过程的又一笔费用,它将增加所生产化学产品的成本。通过减少废物数量提高效益其潜能是不言而喻的。 然而,请注意note,with a plant对于一个已经建好并正在运行的工厂来说,只能做一些有限的改变来达到上述目的。因此,上面所提到的减少废品的重要性应在新公厂的设计阶段加以考虑。近年来另一个当务之急是保护能源及降低能源消耗。 (4)application development应用开发。显然发掘一个产品新的用处或新的用途能拓宽它的获利渠道。这不仅能创造更多的收入,而且由于产量的增加使单元生产成本降低,从而使利润提高。举例来说,早期是用来制造唱片和塑料雨衣的,后来的用途扩展到塑料薄膜,特别是工程上所使用的管子和排水槽。 我们已经强调emphasis了化学产品是由于它们的效果,或特殊的用途、用处而得以售出这个事实。这就意味着化工产品公司的技术销售代表与顾客之间应有密切的联系。对顾客的技术支持水平往往是赢得销售的一个重要的因素。进行研究和开发的化学家们为这些应用开发提供了帮助。33的制造就是一个例子。它最开始是用来做含氟氯烃的替代物作冷冻剂的。然而近来发现它还可以用作从植物中萃取出来的天然物质的溶解剂。当它作为制冷剂被制造时,固然没有预计到这一点,但它显然也是应用开发的一个例子 。 Unit3设计 Based on the experience and data根据在实验室和中试车间获得的经验和数据,一组工程师集中起来设计工业化的车间。化学工程师的职责就是详细说明所有过程中的流速和条件,设备类型和尺寸,制造材料,流程构造,控制系统,环境保护系统以及其它相关技术参数。这是一个责任重大的工作。 The design stage设计阶段是大把金钱花进去的时候。一个常规的化工流程可能需要五千万到一亿美元的资金投入,有许多的事情要做。化学工程师是做出很多决定的人之一。当你身处其位时,你会对自己曾经努力学习而能运用自己的方法和智慧处理这些问题感到欣慰。 设计阶段design stage的产物是很多图纸: (1)工艺流程图flow sheets。是显示所有设备的图纸。要标出所有的流线和规定的条件(流速、温度、压力、构造、粘度、密度等)。 (2)管道及设备图piping and instrumentation。标明drawings所有设备(包括尺寸、喷嘴位置和材料)、所有管道(包括大小、控制阀、控制器)以及所有安全系统(包括安全阀、安全膜位置和大小、火舌管、安全操作规则)。 (3)仪器设备说明书equipmen specification sheet s。详细说明所有设备准确的空间尺度、操作参数、构造材料、耐腐蚀性、操作温度和压力、最大和最小流速以及诸如此类等等。这些规格说明书应交给中标的设备制造厂以进行设备生产。 3.建造construction After the equipment manufactures当设备制造把设备的所有部分都做好了以后,这些东西要运到工厂所在地(有时这是后勤部门颇具挑战性的任务,尤其对象运输分馏塔这样大型的船只来说)。建造阶段要把所有的部件装配成完整的工厂,首先要做的就是在地面打洞并倾入混凝土,为大型设备及建筑物打下基础(比如控制室、流程分析实验室、维修车间)。 完成了第一步initial activities,就开始安装设备的主要部分以及钢铁上层建筑。要装配热交换器、泵、压缩机、管道、测量元件、自动控制阀。控制系统的线路和管道连接在控制室和操作间之间。电线、开关、变换器需装备在马达上以驱动泵和压缩机。生产设备安装完毕后,化学工程师的职责就是检查它们是否连接完好,每部分是否正常工作。

相关文档
最新文档