电器防雷滤波技术探讨

我国是雷电多发地区,在我们日常生活中电器经常会被雷电击坏或不能正常工作。本文就产品设计中我们常采用的一种既防雷又解决滤波的防雷滤波技术讨论,并加以验证。     

OH^—,CO3^2—和HCO3^—碱度测定中S^2—的掩蔽方法研究

用酸碱指示剂滴定法测定废水的中的OH－，CO3^2-,HCO3^-碱度时，S^2-对测定有干扰，此干扰可用H2O2掩蔽。     

ICP——AES法在第二级观测As189.042nm分析线的干扰图

用ICP──AES法获得Ag、Al、Ba、Cr、Fe、Mg、Ni、Ph筹8个元素对As189．042×2nm分析线的干扰图，并测定了干扰程度。实验结果表明；浓度为As含量100倍的Ag、Ba、Fe、Mg、Ni、Ph对As分拆线几乎没有影响，而浓度为As含量100倍的Al和Cr对As分析线有一定的干扰．提出了校正和消除Al、Cr干扰的一些方法。     

Accelerated seeded precipitation pre-treatment of municipal wastewater to reduce scaling

Membrane based treatment processes are very effective in removing salt from wastewater, but are hindered by calcium scale deposit formation. This study investigates the feasibility of removing calcium from treated sewage wastewater using accelerated seeded precipitation. The rate of calcium removal was measured during bench scale batch mode seeded precipitation experiments at pH 9.5 using various quantities of calcium carbonate as seed material. The results indicate that accelerated seeded precipitation may be a feasible option for the decrease of calcium in reverse osmosis concentrate streams during the desalination of treated sewage wastewater for irrigation purposes, promising decreased incidence of scaling and the option to control the sodium adsorption ratio and nutritional properties of the desalted water. It was found that accelerated seeded precipitation of calcium from treated sewage wastewater was largely ineffective if carried out without pre-treatment of the wastewater. Evidence was presented that suggests that phosphate may be a major interfering substance for the seeded precipitation of calcium from this type of wastewater. A pH adjustment to 9.5 followed by a 1-h equilibration period was found to be an effective pre-treatment for the removal of interferences. Calcium carbonate seed addition at 10 g l⁻¹ to wastewater that had been pre-treated in this way was found to result in calcium precipitation from supersaturated level at 60 mg l⁻¹ to saturated level at 5 mg l⁻¹. Approximately 90% reduction of the calcium level occurred 5 min after seed addition. A further 10% reduction was achieved 30 min after seed addition.     

好氧污泥颗粒化过程的影响因素分析

影响好氧颗粒污泥性质的因素多且复杂,具有灰色系统的特点.应用了灰色关联分析方法对好氧颗粒污泥的重要参数污泥体积指数(SVI)、沉降速率、颗粒粒径和污泥浓度(MLSS)进行了关联影响分析.结果表明:对颗粒污泥SVI的影响顺序为沉降速率＞颗粒粒径＞ MLSS,说明沉降速率对活性污泥的形态转变和颗粒化过程的作用最明显,SVI可作为评判颗粒化进程的一个理想指标;沉降速率对MLSS的影响最弱;颗粒粒径的最佳值为1.3～1.5 mm,此时,颗粒粒径对SVI降低的贡献最大,从而使颗粒污泥的沉降性能得到很大改善,并且使MLSS达到最大.     

土氡测量在地质灾害勘测中的干扰实验研究

对土氡勘测中来自测量过程、勘测场地条件、气象因素方面的常见干扰进行了实验研究，探讨了干扰机理，指出了定性及部分定量排除干扰的方法。     

电磁干扰场强的测量不确定度评定

根据《测量不确定度评定与表示》JJF1059—1999及《电磁干扰不确定度评定指南》,针对电磁干扰场强的测量进行了不确定度分析。     

尼尔基水利枢纽施工干扰区生态环境修复与景观规划设计

大型水利工程的建设无疑为人们的生产生活带来了安全与保障,但其施工对生态环境的破坏同样不可小觑。本文结合尼尔基水利枢纽施工干扰区的实际情况,探讨水利枢纽施工干扰区生态环境修复与景观规划设计的理念与指导思想,从植物选择、水体处理与分区设计3个方面介绍了尼尔基水利枢纽施工干扰区生态环境修复与景观规划设计的主体方案构思。     

A resource-based approach to modelling the dynamics of interacting populations

The procedure for modelling the growth of single-species populations [Sakanoue, S., 2007. Extended logistic model for growth of single-species populations. Ecol. Model. 205, 159–168] is improved to be applicable to the study of the dynamics of interacting populations. The improved procedure is based on three assumptions: resource availability changes with population size as a variable, resource supply to populations and population demand for resources are defined as functions of resource availability and population size, and the variables of resource availability and population size shift in the supply function attracted to the demand function. These assumptions are organized into three equations. The equations can generate the dynamics models of plant, herbivore, and detritivore populations, and their own resources. The models can be used to describe prey–predator dynamics. They naturally contain nonlinear terms for the predator’s numerical and functional responses. Depending on the terms, the fluctuations in resource availability and population size stabilize. The three equations can also generate the dynamics models of different populations consuming the same resources. The analysis of zero isoclines of the models shows that a superior population can be simply defined as one with a higher intrinsic rate of natural increase, that a stable coexistence may be realized with the intraspecific interference or the interspecific facilitation of superiors, and that the interspecific interference or the intraspecific facilitation of inferiors may make the coexistence unstable and the inferiors winners depending on their initial population size.