产品英语长句子精华版费下载

产品英语长句子精华版费下载 重点长句子 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 compounds早在17世纪末期，罗伯特?波义耳就开始了这项工作，他提出了现在公认的元素概念，大 量的研究使我们对元素及其化合物的性质有了相当的了解。 2、Thus it is possible to arrange the list of elements in tabular form with elements having similar properties placed in vertical columns。于是，将具有类试性质的元素 排成纵列，从而把元素排成表格形式是可能的。 3、However, as is characteristic of most transition elements, they form ions having other charges as well.然而，像许多过渡元素所具有的特点一样，他们也形成具有其他电荷的离子。 4、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.他们形成了各种不同的化合 物，在这一点上我们甚至不能举出任何能表现各族元素典型变化的例子。 5、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 compounds 如果根据各别化合物来了解这么多化合 物的性质和行为，即使是其中的一小部分也是不可能的。 6、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 compound。例如，盐酸归类 为酸，由于已熟悉作为不同类别酸的性质，我们就会立即知道这一类化合物的一般性质。 7、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. 当一种酸碱或盐溶解 在水中，这个溶液将成为电流的导体并且归类为电解质，如果不能使电流通过，这个化合物 被归类为非电解质。 8、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, HSO, HClO.算，按传统的观念，在化学式第一个开头的字母为H，余下的是非24 金属元素的化合物被认为是酸。 9、Just as the characteristic part of an acid is hydroxide ion, so the characteristic part of a base in water solution is the hydroxide ion, OH~.正如特色的部分,所以酸 氢离子特征的一个组成部分,基地在水溶液中离子的氢氧化物,喔~。 10、In these cases the oxidation state of the metal is shown by a Roman numeral in parentheses immediately following the English name of the metal which corresponds to its oxidation number在这种情况下，金属氧化态是紧接着英语名称之后再圆括号中用 罗马数字表示，该数字与金属的氧化数一致。 11、The student should have a good start in learning nomenclature if he has learned the Valence Table 3 which gives both charges on ions and names for the more common ones。 一个学生如果掌握了给出离子电荷和较常见的离子名称的价见表3，他在掌握命名方面就必 定有了有一个好的开端。 12、The older system of naming and one still widely used employs Greek prefixes for both the number of oxygen atoms and that of the other element in the compound. 这 个旧的系统的命名与一个更广泛的应用都雇用了希腊的前缀的数量的氧原子和其他元素的 化合物/ 13、When series of locants containing the same number of terms are compared term by term, that series is "lowest" which contains the lowest number on the occasion 1of the first difference. This principle is applied irrespective of the nature of the substituents. 当逐一比较包含着相同(碳原子)数目的词语的许多位次时，根据第 一个位次差值的理由，含最低数字的是最低者。 14、The characteristic groups listed in Table 11 are always cited by prefixes, as given in the Table, to the name of the parent compound 表11中列出的特征性基团， 对母体化合物名称来说总是按表中所给的前缀加以引用。 15、If any characteristic groups other than those in Table 11 are present, one kind must be cited as suffix, but only one kind在表11的基团外，如果存在着其他特征官 能团，一种，而且只有一种，必定作为后缀一用。 16、Some general classes of compound in the order in which the characteristic groups have decreasing priority for citation as principal group 化合物的一般分类，按特 征官能团能引用作主要基团的递减顺序排列。 17、Of even greater usefulness to the organic chemist is the fact that certain groups of atoms (certain functional groups)give rise to stretching or bending vibrational absorption bands at or near the same wavelength it. regardless of the structure of the remainder of the molecule。 一些原子团(官能团)不管分子其余部分结构如何， 在相同波长产生伸缩和变形震动吸收带，这一类对有机化学家有更大的用处。 18、The literature on the subject of the correlation of structure with infrared absorption spectra is vast, and no attempt will be made here to give complete details. 涉及结构及红外吸收谱关系的文献很多，这里不试图给出全部细节。 19、Some idea of the very limited power of quantum mechanics to make predictions emerges from the list of real systems for which it gives the exact descriptions: +the hydrogen atom and the H ion. 从量子力学给出表列真是体系以准确的描述(如像对2 氢原子和氢离子的描述)这一事实出发，显示出量子力学在进行预言时，其能力十分有限。、 20、When a quantity is defined by an equation, one may dispute the wisdom of the definition, but rarely is there any dispute about its meaning 只用一个(数字) 方程去定义一个(物理)量时，人们可能会议论该定义是否合理，而很少对它的含义提出质 疑。+This is much less true with verbal definitions, as the thriving activity of 2our law courts and diplomatic missions attests.用文字定义该物理量是很难准确度， 就像我们法院和外交使团作证时所富有的灵活性。 21、In this lesson it will be shown how one can predict the equilibrium states of chemical systems from thermodynamic data, and conversely how the experimental measurements on equilibrium states provide useful thermodynamic data. 在这节课里, 我们将展示了一个人如何预测化学系统平衡态热力学数据,从实验测量,相反在如何平衡态 提供有用的热力学数据。 22、The principles of chemical equilibrium apply even to these, and it will be seen that for many of them, the extent of reaction can be expressed quantitatively化 学平衡的原理甚至也适用于被认为是进行完全的反应，显然许多这类反应其反应程度可以定 量地表达。 23、If the concentration of any of the components in the system at equilibrium is changed, the concentrations of the other components will change in such a manner that the defined ratio remains equal to K as long as the temperature does not change 如果平衡时体系中任意主分的浓度改变，那么只要温度不变其他组分的浓度将以保持相等K 固定比例的方式的变化。 24、Therefore, it is common practice when studying the rate in the laboratory to carry out reactions at constant temperature (isothermally), thus eliminating one variable那么只要温度不变其它组分的浓度将保持。 25、In practice. it is usually the concentration of the reactants that are used in determining the over-all rates of reaction'. 实际上，一般正是反应物的浓度，它用 以测定反应的总速率。 26、You can then confirm your suspicion as to the nature of one of the contaminants by deliberately adding some o-xylene to the reagent and obtaining a new vapor-phase chromatogram。然后你可以通过有意加入一些邻-二甲苯到试剂中和得到一个新的气象色谱 图而证实你的关于污染物之一的设想。 27、Thus, it is usually wise to confirm a tentative identification of a compound through its retention time by some other means.通常利用一些其他方法来证实通过化 合物的保留时间的不确定鉴别是明智的。