Estimating the amount and distribution of radon flux density from the soil surface in China

Based on an idealized model, both the annual and the seasonal radon ((222)Rn) flux densities from the soil surface at 1099 sites in China were estimated by linking a database of soil (226)Ra content and a global ecosystems database. Digital maps of the (222)Rn flux density in China were constructed in a spatial resolution of 25 km x 25 km by interpolation among the estimated data. An area-weighted annual average (222)Rn flux density from the soil surface across China was estimated to be 29.7+/-9.4 mBq m(-2)s(-1). Both regional and seasonal variations in the (222)Rn flux densities are significant in China. Annual average flux densities in the southeastern and northwestern China are generally higher than those in other regions of China, because of high soil (226)Ra content in the southeastern area and high soil aridity in the northwestern one. The seasonal average flux density is generally higher in summer/spring than winter, since relatively higher soil temperature and lower soil water saturation in summer/spring than other seasons are common in China.     

炼油污水三泥脱水装置调试运行

炼油污水处理装置的三泥脱水实验表明,剩余污泥的脱水性能最好。根据实验结果,将浮渣与剩余污泥按比例混合进行脱水,连续少量掺入油泥,调整转速与混凝剂用量后取得较好的脱水效果。在离心机处理量13～15m3/h,离转速3000r/min,差转速5～7r/min,混凝剂量5kg/h的工况下,离心机所产泥饼含水率<85%、滤液ρ(COD)<800mg/L。脱水处理直接成本19.6元/m3。     

基于污染物总量控制的流域预警体系构建研究

文章通过对中国目前水环境质量现状分析,指出流域环境预警体系建立的必要性,并选择总量控制指标作为预警体系的评价指标。利用层次分析法建立基于污染物总量控制的流域预警体系,确定预警因子的权重和评分标准。设立临界状态,不良状态预警、缓慢恶化预警和迅速恶化预警4个级别,为建立流域环境质量预警体系提供借鉴。     

内蒙古自治区应急监测预警体系建设思路

随着内蒙古自治区经济的飞速发展,带来了一系列的环境风险问题。自治区也应该建立与之相配套的应急监测预警体系,本文着重介绍了该体系建设的相关内容。     

硅铁炉生产工艺及烟气处理

硅铁电炉目前应用比较广泛,分析硅铁的生产工艺和烟气处理不仅是完成节能减排的需要,也是保护环境的重要手段。     

我国大气VOCs监测现状及挑战

对我国开展大气VOCs监测的必要性、监测现状以及主要使用的监测方法进行了分析。目前,我国已初步建立了大气VOCs手工与自动监测网络,主要采用预浓缩-热脱附-气相色谱-质谱/氢火焰离子化检测器法进行PAMS组分和TO-15组分分析,利用高效液相色谱法进行13种醛、酮类组分分析。目前大气VOCs监测还存在数据质量、灵敏度有待提高,不同设备或方法监测结果一致性较差等问题。为此在VOCs监测过程中应进一步加强质量保证与质量控制,并尝试通过提高预浓缩装置除水和干扰物效率、提升进样量等多种手段提高监测灵敏度。     

地方政府投融资平台信息披露问题研究

地方政府投融资平台在促进地方经济发展，推动城市化进程，应对国际金融危机等方面发挥了重要作用。但由于缺乏统一的管理，各地方政府投融资平台财务状况披露不公开、不透明，债务风险急剧扩大，引起了有关部门和专家学者的高度关注。各地方政府应将融资平台的各种信息，特别是债务情况，定期向主管部门报告，建立地方投融资平台信用评价方法，使得投融资平台朝着健康、良性的方向发展。     

Estimation of explosion energy based on fragment characteristics

Explosions of vessels containing high pressure gases or superheated liquids are a common accident in the chemical industry. Fragments are the most information-rich physical evidence in accident analysis. A method is presented to calculate the total explosion energy based on the characteristics of fragments from the scene of an accident, such as mass, horizontal displacement, etc. The implicit expressions of the initial velocity can be obtained through analysing the trajectory equations of the fragments and the data obtained from the scene of the accident. The total energy is calculated from the relationship between the total explosion energy and the kinetic energy of the fragment. During the calculation there are some uncertain parameters, e.g., the energy factor and the initial angle. To solve the parameter uncertainties, a Monte-Carlo simulation is introduced. Analysis of an industrial accident shows that it is feasible to estimate the total explosion energy using the maximum probability density interval with the proposed methodology.     

农用地资源修正法定级之技术路线探讨——以佛山市高明区为例

目前我国农用地资源定级很少运用修正法，少数学者对修正法定级做过尝试性的实证研究工作，以期探讨修正法定级技术路线的科学性与可行性。在前人研究的基础上，以佛山高明区为例，探讨了修正法定级之修正基础的确定、修正因素的选择、修正系数的计算、定级指数的确定等几个关键技术步骤，提出了以农用地自然质量等指数作为修正基础，采用标准化方法对修正因素分值进行订正，用连乘法计算农用地质量定级指数来划分农用地级别的修正法定级的技术路线，并与因素法定级的成果进行对比分析与验证。     

输煤皮带负压吸尘设备及系统的改进研究

分析了输煤皮带负压吸尘设备及系统目前存在的主要问题 ,详细介绍了对该系统的改进措施和实际情况。