天然有机质与重金属相互作用的分析方法进展

由于NOM(natural organic matter,天然有机质)种类及来源的多样性及其结构和性质的复杂性,导致NOM与重金属之间的相互作用存在一定的不确定性. 针对NOM与重金属之间相互作用的一系列分析方法,重点阐述了谱学分析有关分析方法、等温滴定微量热法、溶出伏安法、zeta电位变化分析以及高效体积排阻色谱法等,这些方法从NOM的谱学特征、zeta电位、分子量、热力学参数及电化学性质等方面对二者之间的相互作用进行深入研究,取得了一定进展,但也存在不足. 针对各分析方法的特点及其局限性,建议今后联合使用多种方法分析NOM与重金属之间的相互作用机制;通过确定不同影响因素对二者结合作用的大小和权重,建立多因素影响下二者相互作用的模型,以定性、定量分析天然水体中NOM与重金属的相互作用.      

试论实验技术物资的采购与管理

在高等职业技术院校的教学、科研和实验中所使用的实验技术物资种类繁多,性质各异.为适应教学和科研的需要,实验技术物资一般分为低值易耗品和高值耐用品两大类.文章客观而科学地分析了上述两类物资的采购和管理方法.     

超积累植物在时空、科属内的分布特点及寻找方法

探讨了超积累植物在时空、科属内的分布特点和正常植物演化出镍超积累特性必备的 2个基本条件 ,介绍了国外 2种常用的寻找超积累植物的方法。     

美国NIST元素汞发生器的基准溯源传递方法

综述了美国NIST元素汞发生器的基准溯源传递方法,通过在输出的汞标准气体中混合加入已知高纯度的201Hg0气体（201Hg2＋标准溶液还原雾化）,并采用同位素稀释电感耦合等离子体/质谱法（IDICP/MS）测量加标后201Hg/202Hg同位素丰度比例,计算出待溯源元素汞发生器输出的Hg0 质量浓度.该过程实现了从元素汞一级标准物质SRM 3133到201Hg2＋标准溶液,再到元素汞发生器输出标准气体的溯源传递,完成了从NIST元素汞基准到仪器供应商生产基准的一级溯源传递,为建立符合我国需求的元素汞溯源传递方法和形成元素汞发生器溯源传递能力提供借鉴.     

采用商业混合菌种测定BOD5的可行性

通过实验,对比研究了采用商业混合菌种（Polyseed）改进传统方法测定BOD5的可行性。研究结果表明,相比于采用地表水作为接种水的传统方法,采用进口商业混合菌种配制接种稀释水BOD5（空白值）更稳定,可以改进传统BOD5测定方法,使得日常监测工作更为便捷。     

区域环境空气质量预报的一般方法和基本原则

为响应公众服务和环境管理对环境空气质量预报的迫切需求,中国环境监测总站率先在京津冀区域开展了区域环境空气质量预报测试。结合目前积累的预报经验和国内外相关研究,探索出区域空气质量预报的一般方法和基本原则,讨论了客观订正环节中大气扩散条件、污染源排放、物理化学过程和空气质量变化规律的分析方法及系统建立、结果确定、天气控制形势分析和信息表述等基本原则,以期为各地开展环境空气质量预报提供技术参考。     

Integral transform solutions for atmospheric pollutant dispersion

A transient two-dimensional advection–diffusion model describing the turbulent dispersion of pollutants in the atmosphere has been solved via the Generalized Integral Transform Technique (GITT), by two different schemes. The first approach performs numerical integration of the transformed system using available routines for initial value problems with automatic error control. In spite of the time-consuming character of such a scheme, its flexibility allows the handling of problems involving time-dependent meteorological parameters such as wind speed and eddy diffusivities. The second approach works fully analytically being thus intrinsically more robust and economic, although not directly applicable in dealing with time-dependent parameters. For the test problem used in this work, both methods agree very well with each other, as well as with a known analytical solution for a simpler formulation used as benchmark. The impact of the longitudinal diffusivity on the stiffness of the ordinary differential equation (ODE) system arising from the integral transformation has been assessed through the processing time demanded to solve it when the numerical approach is used. The observed CPU times show that the analytical approach is clearly preferable unless the problem involves time-dependent parameters.     

水质 色度测定——稀释倍数法探讨

稀释倍数法是测定污水色度的国家标准方法,通过对稀释次数、稀释方法的比较实验等对色度的测定方法进行探讨,提出几点体会,在色度的测定中有一定的实用性。     

The Seasonal Variation of the Concentrations of Ozone, Sulfur Dioxide, and Nitrogen Oxides in Two Nigerian Cities

A combination of multivariate statistical methods including factor analysis, principal component analysis, principal component regression, and multiple linear regression (MLR) were employed to evaluate the influence of seasons on the concentrations of ozone, sulfur (IV) oxide, and oxides of nitrogen in ambient air of Nigerian cities of Lagos and Ilorin. The former city is located in the coastal area, and it is highly congested with a high intensity of marine, vehicular, and industrial activities, and the latter city is a medium size town, located in the central guinea savannah zone of Nigeria. Samples were collected using a high-volume sampler from near the ground at various sites of diverse human and industrial activities, during wet and dry seasons from 2003 to 2006. The PCA reveals three distinct groupings during the day for all data, which is a reflection of different factors contributing to the atmospheric chemistry of these cities. The predicted ozone concentration values by MLR agree fairly well with the measured data. The dependence of ozone on meteorological parameters including relative humidity, air temperature, and sun exposure and the precursor pollutants depends on weather and the anthropogenic activities. The results for the two cities indicate that reduction in the level of NO₂ is accompanied by an increase in the level of ozone, suggesting the interconversion between the two via photochemical activity.     

臭氧一级校准数据读取方式对校准的影响研究

臭氧标准参考光度计同时采用串口连接模式、模拟信号连接模式和仪器数据存储-手动输入模式3种数据读取方式对臭氧二级传递标准进行一级校准,比较不同数据读取方式对校准结果的影响。串口连接模式和仪器数据存储-手动输入模式所得到校准曲线的斜率和截距具有很好的一致性,相差较小。经修正转化截距后的模拟信号连接模式所得到的斜率和截距相对于其他2种数据读取方式有一定的差别,但也在校准指标以内。