水质铜测定的不确定度评定

根据火焰原子吸收分光光度法测定水中铜的含量，分析了测量不确定度的主要来源，即标准曲线不确定度、标准溶液不确定度、测量重复性不确定度。计算得到水中铜的测定结果的合成不确定度为0．098mg／L，扩展不确定度为0．196mg/L。     

离子色谱法测定标样中硫酸根含量的测量不确定度评定

通过对离子色谱法测定标样中硫酸根含量的过程研究,分析了该方法测定结果的不确定度来源,并对各不确定度分量进行了评定.     

水中总磷测量的不确定度评定

采用钼酸铵分光光度法测定水中总磷的含量,分析该法测量不确定度的来源,评定水中总磷的测量不确定度。     

地下水矿化度测定的不确定度评定

分析质量法测量地下水矿化度的测量不确定度来源，评定了地下水矿化度的测量不确定度，在各不确定度中，称量引入的不确定度较大。     

水中氯化物测定的不确定度评定

根据硝酸银滴定法测定水中氯化物的含量，分析了该方法测量不确定度的来源，评定了水中氯化物的测量不确定度，在各不确定度中，以标准溶液配制与样品分析时滴定消耗的硝酸银体积引入的不确定度较大。     

水中阴离子表面活性剂的测量不确定度评定

简要介绍了测量不确定度的概念，运用《测量不确定度评定与表示》的技术规范，通过对阴离子表面活性剂的测定过程，分析了影响阴离子表面活性剂测量不确定度的因素，给出了相对标准不确定度分量，并具体阐明了测量不确定度的评定步骤，得出测量扩展不确定度的结果。     

纳氏试剂分光光度法测定水中氨氮的不确定度评定

通过纳氏试剂分光光度法测定水中氨氮的过程分析，对测定不确定度作出了评估，并得出产生测定不确定度的主要原因。     

气相色谱-质谱法测定水中挥发性有机物的测量不确定度评定

根据测量不确定度评定与表示理论,采用气相色谱一质谱法测定水中挥发性有机物。以氯乙烯为例,通过计算和评定,得出当氯乙烯的测量结果为4．99μg／L时,取包含因子k=2（约95％置信概率）,扩展不确定度U=0．96μg／L。该不确定度评定方法在实际工作中具有较强的实用价值。     

气相色谱法测定甲苯的不确定度评定

以甲苯为例,论述了气相色谱法分析的测量不确定度计算及评定的方法。     

平皿计数法测定细菌总数的不确定度评定

根据细菌总数的测定方法,分析了该方法测量不确定度的来源,评定了水中细菌总数的测量不确定度。     

Determination of Nitrogen Oxides in Auto Exhaust

A new procedure for determining nitrogen oxides in automobile exhaust has been developed. The new procedure was included in a Bureau of Mines comparative study that aimed at evaluating various widely used methods for determining NO_x in auto exhaust. The methods included in the evaluation study follow: (1) Static oxidation in tank (ST method). The method involves oxidation of NO in residence with O₂ in a stainless steel tank. (2) Bureau of Mines method (BM method). The method involves application of the ST procedure in exhaust samples from which the hydrocarbons have been removed by combustion over catalyst. (3) Chevron Research method (CR method), as described in the literature. (4) Phenoldisulfonic acid method (PDS method), as described in the literature. The principal objective of this study was to generate experimental evidence which would lead to defining an optimum procedure for converting NO, present in exhaust gas, into NO₂; this conversion is desired so that the total of NO + NO₂ can be determined quantitatively in the form of NO₂. In pursuing this objective, the procedures prescribed by the foregoing methods were comparatively tested. The results indicated that all four methods are subject to error, the extent of which depends on the conditions employed. The BM method was superior from the standpoint of accuracy because it was less affected by interferences due to hydrocarbon-NO₂ reactions.     

离子选择电极分析法测定标样中氟化物的不确定度评定

通过对离子选择电极法测定标样中氟化物的过程研究，分析了该方法测量不确定度的来源，给出了相对不确定度分量，得出测量扩展不确定度的结果。     

Catalytic Reduction of Nitrogen Oxides in Automobile Exhaust

The catalytic reduction of oxides of nitrogen from leaded automobile exhaust has been demonstrated to be technically feasible. These studies made with copper-containing catalysts are based upon the reducing nature of exhaust caused by the carbon monoxide present. The reaction involves 2 CO + 2 NO → + N₂ + CO₂ + 178.5 Kcal.     

Considerations in Setting Standards for Oxides of Nitrogen

Since 1959 the California Department of Public Health has held responsibility for setting standards for ambient air quality and for motor vehicle emissions. The need for standards for oxides of nitrogen involves consideration both of direct effects and effects resulting from participation in photochemical smog reactions. This paper discusses the various effects of concern and describes the department’s program for establishing air quality standards which will become the basis for vehicle emission standards and serve as guides for control of other sources of oxides of nitrogen.