流动注射法(FIA)测定水中氨氮

简要介绍了流动注射法(FIA)测定水中氨氮的实验方法。此方法具有分析速度快、准确度和精密度高、污染少等优点,已用于环境分析测试中酚、氰化物、COD、硒、钍等的测定,减少了对实验室环境的污染和人体的危害,成为现代分析的发展趋势。     

微波消解-流动注射法测定海水中总磷

为了实现实时监测近岸海域海水中的总磷水平,采用微波消解-流动注射-紫外分光光度法进行测定,并通过控制程序实现连续测定。优化了消解条件、进液顺序和显色剂质量浓度等实验条件,并在最佳实验条件下测定的海水中总磷浓度与吸光度呈良好线性关系。标准样品检验的相对标准偏差(RSD)为4.095%,样品的加标回收率在95%~98%之间。研究方法稳定性的检测结果显示,零点漂移在±0.1%之内,量程漂移在±3%之内,符合《近岸海域水质自动监测技术规范》(HJ731—2014)的要求。用微波消解-流动注射-紫外分光光度法测定的大连老虎滩表层海水中总磷的质量浓度为0.068 9 mg/L,与国标法(GB/T 12763.4—2007)测定结果(0.069 3 mg/L)无显著性差异。因此,该测定方法可用于快速测定海水中总磷的含量,为实现海水富营养化的预警监测提供可靠数据。     

高盐度水体氰化物的连续流动分析-分光光度耦合法适用性探讨

采用连续流动分析-分光光度耦合法对大辽河高盐度水体氰化物测定的精密度、准确度进行验证,验证结果表明：当高盐度水体中氯化物浓度低于12800mg/L时,耦合方法下氰化物精密度和准确度均低于15%,加标回收率在81.5%～93.5%,满足SL 219—2013《水环境监测规范》对于水体氰化物测定的规范要求,可用于高盐度河流水体氰化物的快速、连续测定。研究成果对于沿海感潮河段高盐度水体氰化物应急和日常监测具有重要的参考意义。     

甲萘酚代替萘乙二胺测定水中苯胺类化合物

在 p H为 1 2的硼砂 -氢氧化钠缓冲液中苯胺类化合物的重氮盐与甲萘酚的显色反应迅速 ,显色液可稳定 2 h以上。用甲萘酚代替萘乙二胺测定苯胺类化合物 ,简便 ,快速 ,稳定。苯胺类化合物的质量浓度在 0 .0 3～ 2 .8mg/L范围内符合比尔定律 ,线性相关系数为 0 .9999。该法与废水中苯胺类化合物标准测定方法相比结果一致     

顺序注射光度法测定水体中正磷酸盐

应用FIAlab-3500顺序注射分析仪,采用钼锑抗分光光度法测定水中的正磷酸盐,对实验参数进行了优化。实验结果表明,正磷酸盐质量浓度在0~5 mg/L范围内与吸光度呈良好线性关系,方程为y=0.112 8x-0.005 1(R2=0.999 2),空白相对标准偏差(RSD)为1.2%,方法的检出限为0.009 3 mg/L。利用该法测定某管网水中正磷酸盐,测得其加标回收率为96%~105%。     

流动注射分析的发展及应用

综述了国内外流动注射分析的发展,以及流动注射分析与分光光度法、电化学分析法、发光分析法、原子光谱法等技术的联用状况。流动注射分析系统具有能实现对污染物的快速定量分析的优点,它与计算机技术的结合可实现环境监测过程中的自动、在线分析,这将成为今后流动注射分析的主要发展趋势。     

Measurement and characterisation of the Digital Divide of Spanish regions at enterprise level. A comparative analysis with the European context

Until now, a reduced number of research is observed on the adoption and use of ICTs in enterprises and on the digital divide (DD) between them at regional scale in Europe. What is meant by DD are the differences in the levels of digital development of the enterprises; being the digital development the degree of adoption and use of ICTs and e-commerce by the firms. The aim of this piece of work is to characterise and measure the DD in the Spanish regions and those in the countries of the European Union based on the data of their enterprises with more than 10 employees which have used ICTs. The methodology is developed in the following stages: 1) Construction of a synthetic index of digital development (Enterprise Digital Development Index –EDDI-) for countries in the EU and Spanish regions. The production of this index is carried out based on the factors obtained with the factor analysis (FA) with the aim of identifying the key variables which define the different EDDI components. These variables come from the “Community survey on ICT usage and e-commerce in enterprises” of Eurostat. 2) Classification of Spanish regions into the groups of European countries with a similar level of EDDI components based on the discriminant analysis. Those groups are previously obtained by using cluster analysis. And 3) Comparative analysis of the DD between the Spanish regions and those in countries of the EU based on EDDI components and the identified groups. The study provides a synthetic index (EDDI) at European scale comprising 3 dimensions which permits obtaining: i) a ranking from more to less digital development of countries and regions permitting the measurement of the DD among them is established; and ii) a typology of European countries and Spanish regions is defined according to the 3 dimensions of EDDI. The main results of this piece of work show that the Spanish regions at enterprise level: i) are in a medium or higher level of digital development than their European counterparts, presenting, furthermore, a lower DD between them in relation to what happens in European countries; ii) stand out for having a higher digital inclusion than European countries in the ICTs related to infrastructures of internet access and for the interaction with the public authorities; and iii) have a digital development deficit in the integration of ICTs for e-commerce.     

注射用甲硫氨酸维生素B1的细菌内毒素检查

为考察注射用甲硫氨酸维生素B₁的细菌内毒素检查法的可行性,采用《中华人民共和国药典》(2005年版)细菌内毒素检查法。结果得知,注射用甲硫氨酸维生素B₁质量浓度为0.25mg/mL的稀释液可用灵敏度为0.25EU/mL的鲎试剂进行细菌内毒素检查,实验中3个批号的注射用甲硫氨酸维生素B₁经检查均符合规定。     

针对AES算法的差分功耗分析研究与实现

为研究AES算法面对差分功耗分析(DPA)的安全性,在指令级分析了微控制器的功耗模型,讨论了差分功耗分析中D函数的选择问题,成功地运用DPA方法攻击了在微控制器上实现的AES算法。最少只需300个明文样本在20 min内即可获取完整的密钥,从而实证了AES算法面对DPA方法攻击时的脆弱性,并揭示了该算法在微控制器实现中的密钥信息泄露点。     

示差折光-HPLC法测定舒血宁注射液中山梨醇的含量

现有检测方法在测定舒血宁注射液中的山梨醇含量时,存在着专属性不强、操作复杂等弊端。针对此问题,建立了示差折光-HPLC测定舒血宁注射液中山梨醇含量的方法。色谱柱为Carbomix Ca-NP 10:8%(7.8mm×300mm),以水为流动相,流速为0.5mL/min,柱温为80℃。结果表明:山梨醇在0.2~2.0mg/mL(r2=0.999 5)质量浓度范围内与峰面积具有良好的线性关系,平均回收率(n=9)为99.9%。该方法简便,专属、重复性好,可作为舒血宁注射液中山梨醇含量的测定方法。     

锅炉房供热量调节运行经济性分析

针对采用量调节的闭式供暖系统,以河北承德某小区为例,运用理论图解的方法对调节并联水泵共用管路阀门和调节并联水泵非共用管路阀门两种运行方案的经济性分析比较,可知当管网流量大于锅炉总循环水量79％时,采用调节并联水泵非共用管路阀门是节约电能的,但采用并联水泵非共用管路阀门调节方案时,对系统的循环水量是有最低限制要求的,否则...     

An analysis of buying center decisions through the salesforce

In this paper we examine whether classical customer surveys that are used to predict group buying decisions can be replaced by the method of interviewing the salesforce. We set up a two-step research approach. In the first step, we examined the predictive performance of different measurement processes in a salesforce survey (self-explicated approach and limit conjoint analysis for the preferences and constant sum scale and for the influence measurement limit conjoint analysis). In the second step, we conducted a classical customer survey using limit conjoint analysis and compared it with the predictions derived from the salesforce survey. Our results show that when surveying the salesforce (1) limit conjoint analysis is superior to the self-explicated approach in measuring preferences. With regard to the measurement of influence, we did not find any significant differences between the two procedures. (2) Our major findings are that the predictions derived from the salesforce survey are not only more practical because of the relatively low costs but that they also outperform those from the customer survey.