环境工程专业英语第四单元阅读资料翻译.doc

any chemical analysis consists of four clearly definable steps:1 collection and preservation of the sample; 2 preparation or pretreatment of the sample for analysis; 3 analytical evaluation ; 4 presentation of the resulting data in a meaningful form. The present status of environmental analysis is discussed in terms of these steps in the following任何化学分析包括四个明确定义的步骤：1收集和保存的样品2准备或预处理的样品进行分析;3分析评价; 4介绍一个有意义的形式所产生的数据。环境分析的现状是讨论在以下这些步骤sample collection . the type of sample collected depends entirely on the type of information required. thus ,a monitoring operation may require collection and analysis of a sample in real time so that little opportunity exists for preconcentration of the chemical species being determined样品采集。收集样本的类型完全取决于所需的信息类型。因此，监控操作可能需要实时收集和分析样品，因此，很少有机会为确定化学物质的富集存在in such case ,considerable sensitivity constraints are placed on the analytical method. alternatively,it may be satisfactory if the sample is collected and accumulated over a period of several hours or even days prior to removal to the laboratory for analytical evaluation. 在这种情况下，相当敏感约束放在分析方法。另外，它可能是令人满意的，如果样本收集和分析评价实验室搬迁之前的几个小时甚至几天的时间积累。in such situations,the requirements placed upon the subsequent analytical technique are less stringent insofar as sufficient material may be collected for even quite insensitive technique to function effectively在这种情况下，放置后，后续的分析技术的要求不那么严格足够的材料就可以收集，甚至不敏感的技术，有效地发挥作用。relatively few environmental analyses are actually conducted in real time due to the fact that the levels of most pollutants in the environment are too low for presently available instrumentation to detect. probably the most effective real-time analyzer presently available is a nuclei counter which determines the number of aerosol nuclei or particles present in the atmosphere相对较少的环境分析，实际上是进行实时由于这样的事实，现有仪器检测，环境中的污染物含量太低。可能是现有最有效的实时分析仪是一个核计数器，这就决定了核气溶胶或颗粒存在于大气中的数量。such an instrument can be mounted on an aircraft and used to locate the presence of a plume emitted form some air-polluting source. 这种仪器可安装在飞机上，用于定位存在某种形式的空气污染源排放一个羽A much more common approach to sample collection involves accumulation of the chemical species to a level where a subsequent analytical is capable of performing a precise and accurate analytical evaluation. 一个更加通用的方法来收集样本涉及化学物质的积累水平，在随后的分析是能够执行精确和准确的分析评价。such cumulative collection procedures have the advantage that they can ,at least in theory, collect as much material as may be required for so me subsequent operation.累计收集程序的优势，他们可以，至少在理论上，收集尽可能多的材料，可能需要一些后续操作。On the other hand, they have the responsibility of maintaining the sample. this second consideration is not trivial since sample stabilization is probably one of the more important (and indeed most neglected) aspects of an environmental analysis。另一方面，他们有责任维护样品。这第二个考虑是不平凡的，因为样品的稳定可能是更重要的（确实是最容易被忽视的）环境分析的方面之一。as a general rule ,preservation of the authenticity of a solid sample is comparatively straightforward ;however ,changes in gaseous and liquid samples following collection are extremely common so than considerable emphasis must be placed upon stabilization and preservation of these types of samples .作为一般规则，固体样品的真实性保存相对简单，然而，在以下收集的气体和液体样本的变化是极为常见的，所以比相当的重视，必须放在稳定和保存这些类型的样品后。bulk collection of solids is comparatively straightforward since a selected portion of material such as soil , tree roots ,leaves ,or biological organisms may readily be collected by using some predetermined criterion for the selection . it is important ,however ,to specify the size or amount of sample which should be collected . such decisions are determined almost entirely by the heterogeneity of the sample in question ,and the only general statement that can be made is that the sampling statistics should be designed to ensure that this heterogeneity is averaged out by the sampling method and criteria employed . 散装固体收集是比较简单的，因为所选的材料，如土壤的一部分，树的根，叶，或生物可随时选择使用一些预先确定的标准的收集。然而，重要的是指定大小或应收集的样品量。这样的决定几乎完全取决于问题样本的异质性，只是一般的语句，可以是抽样统计，以确保这种异质性是平均抽样方法和采用的标准设计应。collection of liquid samples is comparatively straightforward insofar as such samples are usually collected in bulk液体样品的收集比较简单，只要这种样品通常是散装收集the main considerations involved are the extent to which the sample is representative of the system in question and the nature of the container employed for collecting the liquid .in this latter regard ,it is noted that many dissolved inorganic ions show a strong tendency to adsorb on glass container walls所涉及的主要考虑的范围内，该样本是代表系统中的问题和采用容器用于收集液体的性质，在这后一个方面，它指出，许多溶解的无机离子表现出很强的吸附倾向上玻璃容器壁organic species show comparatively little tendency to absorb on glass container walls but adsorb quite readily on many types of plastic有机物种显示了相对较少的倾向，很容易地吸收在玻璃容器壁，但吸附多种类型的塑料。collection of gaseous samples can be achieved in a number of ways . the most obvious is simply to collect a gaseous sample ( usually polluted air or some atmospheric emission stream ) in a container which may consist of an evacuated glass or steel bulb or possibly a small balloon made of a substance which exhibits little tendency to adsorb species form the sample可以实现多种方式收集气体样品。最明显的是简单的收集真空玻璃或钢灯泡或小的倾向吸附物种形成的一种物质，它可能是一个小气球，其中可能包括在一个容器中的气态样品（通常是污染的空气或一些大气排放流）样本the methods employed for collection of environmental samples vary depending upon the physical state of the material in question . in all cases , however , the basic philosophical concept is to collect , accumulate ,and stabilize materia over a period of time for subsequent analysis , or , in the case is real-time monitoring , to present the sample essentially as it occurs in the environment to some form of selective analytical sensing or evaluation device . 收集环境样品中所采用的方法不尽相同，取决于身体状态有问题的材料。然而，在所有情况下，基本的哲学概念是收集，积累，并稳定一段时间，供后续分析本草，或在实时监控，目前样品基本上，因为它发生在环境一些选择性的分析检测或评估设备的形式。probably the most neglected yet most important aspect of an environmental analysis involves the selection , collection ,and analysis of a sample which is represent a heterogeneous system .similarly ,a small sample may result in poor precision and accuracy of the eventual analytical evaluation technique because of the presence of only a small number of atoms or molecules of the species being determined .it is of vital importance , therefore , to ensure that the size of the sample collected , together with its method and point of collection ,be given serious consideration in any environmental analysis . 可能是环境分析的最容易被忽视而又最重要的方面涉及的选择，收集和分析，这是代表了异构系统的样本，同样的，一个小样本，可能会导致因为在贫穷的精度和最终的分析评价技术的准确性因此，只有少数被确定物种的原子或分子的存在，它是至关重要的，以确保样本的大小，其方法和收集点收集，给予认真考虑任何环境分析。considerable research has been conducted into the question of sampling statistics , and sound guidelines have been established for the procedures which must be employed in obtaining an authentic sample相当多的研究已进行了抽样统计的问题，和程序必须在获得一个真实的样品已建立了健全的指引。sample pretreatment . it is often necessary to modify a collected sample in some way so as to prepare it for subsequent analysis . usually , this involves separation of matrix material or of individual molecular species. 样品预处理。它往往是必要的，以某种方式修改收集的样本，以供后续分析准备。通常，这涉及到基质材料或个别分子的分离。analytical evaluation. the actual analytical evaluation step of the overall analytical scheme is generally the most widely recognized and highly emphasized aspect of an environmental analysis. nevertheless, the analytical evaluation can only be successful in providing the numbers necessary to describe an environmental system provided that the other steps in the analytical sequence are suitably designed and performed分析评价。整体分析方法的实际分析评价步骤一般是环境分析的最广泛认可和高度强调的一个方面。然而，分析评价只能成功提供必要的数字来描述环境管理体系提供适当的设计和执行，分析序列中的其他步骤。the analytical evaluation process is usually required to recognize the analytical species of intrest and to determine the amount of that species which is present. two general approaches are normally employed. the first involves analysis of a composite sample utilizing techniques ( primarily spectroscopic ) which are capable of recognizing specific characteristics of elements and compounds present in a complex mixture. the second approach involves physical separation of molecular species into separate compartments in time or space followed by selective or specific identification of the components thus separated. 分析评价过程中通常需要承认的利益分析的物种，并确定这是目前该物种的数量。通常采用两种常用的方法。第一，涉及利用的技术（主要是光谱）是能够认识到一种复杂的混合物中的元素和化合物的具体特点的复合样品的分析。第二种方法涉及物理分子种类分离成单独的选择性分离组件或特定的识别在时间或空间的车厢。data presentation . it is usually necessary to modify raw analytical results so as to present them in a form which can provide meaningful information to the user .commonly, either tabular or graphical representation is used .in either case ,however ,it is essential to include both averages and ranges of multiple measurements and to estimate the precision associated with singles measurements.数据演示