高效毛细管电泳法分离检测环境水样中的钙、钠、镁离子

采用高效毛细管电泳法对环境水样中溶解态的钙、镁、钠等金属离子进行分离检测。研究了络合剂α—HIBA的添加及其浓度、背景吸收质浓度、缓冲液pH、进样时间及电压对电泳分离中金属离子的迁移时间、分离度、峰形等参数的影响，确定了最佳实验条件。将该法用于环境水样中金属离子的检测，4．5min内钙、镁、钠3种金属离子完全分离，且试样预处理简单，重现性良好，回收率为94．8％～105．8％。与原子发射光谱相比，两种方法的相关性较好。     

EFFECT OF PRICE ON THE RESIDENTIAL DEMAND FOR WATER WITHIN AN AGENCY1

ABSTRACT: This paper develops a model that can be used to forecast the residential elasticity of demand for water within a district. Long-term water conservation programs and revenue and cost decisions hinge crucially on a determination of this elasticity. This study then pools cross-sectional (census) and time series data to generate elasticity forecasts for the Oakland urban area.     

INFLUENCE OF WELL WATER QUALITY VARIABILITY ON SAMPLING DECISIONS AND MONITORING1

ABSTRACT: Local governmental agencies responsible for decisions in ground water quality management need not only data on ground water quality but they also must understand the relationship of accuracies and risks associated with this data as related to the number of wells to sample. In this report we address this problem by using the philosophical doctrines of probabilism and relativism with simple statistical procedures. This requires a reasonable estimate of the population variance in a quality parameter for a given management-unit area, and requires that the decisionmaker formulate constraints with an acceptable standard error of the sample mean and be willing to accept some level of probability of being Wrong. This technique is illustrated using a 21-year data base of well water chemical data in a 653 km² ground water quality study area in the San Joaquin Valley of California.     

SAMPLE UNCERTAINTY IN FLOOD LEVEE DESIGN: BAYESIAN VERSUS NON-BAYESIAN METHODS1

ABSTRACT: Bayesian and non-Bayesian flood levee design methods that account for the uncertainty due to limited record length are compared using a case study. The first method, Bayesian decision theory (BDT), imbeds the uncertainty in the parameters of the yearly peak stage into a loss function. The optimum design of the flood levee, called Bayes design, corresponds to the minimum expected loss, called Bayes risk. The second method, induced safety algorithm (ISA), computes a margin of safety to be added to either an existing levee or a levee designed by classical benefit-cost analysis. The design decision is shown to fluctuate as different record lengths are considered. For short record lengths, BDT, which takes small sample bias into account, appears to yield a more conservative design than ISA. On the other hand, ISA, which is simple to implement, seems to be preferable to BDT for longer record lengths.     

固相萃取—气相色谱法测定水样中痕量正构烷烃的研究

以正构烷烃为目标化合物,研究了影响固相萃取效率的某些因素,采用双柱串联模式评价了固定相的保留效果,探讨了有机改性剂对固相萃取效率的重要影响及作用机理,建立了水样中痕量正构烷烃的分析方法.在实验条件下,对于正构烷烃含量为250(g/I的水样,方法的平均回收率为98.5%,相对标准偏差为9.9%(n=5).     

黄铜药筒盂坯的液态模锻

应用液态模锻工艺生产药简及弹体盂坯,具有简化工序、生产率高、提高材料利用率及降低能耗等优点,此文从消除铸件气孔和疏松缺陷,细化晶粒等方面简要地讨论了液态模锻黄铜盂坯的性能,并概略地分析了液态模锻生产黄铜盂坯的工艺和模具问题。     

盐酸萘乙二胺法测定NO_2环境标准样品的改进

通过对测定环境空气中NO2盐酸萘乙二胺方法的改进实验,提出低浓度环境标准样品和环境空气样品中NO2测定方法改进意见。     

稻壳（炭）棒分析方法

考察了稻壳（炭）棒试样的制备方法以及试样湿存水，挥发份，灰份及固定碳的分析方法，建立了分析标准，可做为企业标准用于配合分析中。     

汽车后桥壳的液压胀形工艺及模具设计

汽车后桥壳主要由冲压—焊接和铸造这两种工艺方法生产而成.此文讨论了一种新型的汽车后桥壳生产工艺,轴向加压的液压胀形法,并讨论了它的工艺制定及模具设计的一些基本方法,对汽车后轿壳的液压胀形工艺的进一步完善和发展提供了一定的基础.最后,还推测了液压胀形这种新型的工艺方法和发展方向.     

铜合金坯饼光饰废液治理研究

根据铜合金坯饼生产线产生废液的性质 ,用盐析法使有机物浊化析出 ,用中和法使重金属离子沉淀析出。工程运行表明处理后的废水可以达到国家排放标准