我国油站量油技术与油气排放浅析

论述工加油站油气排放控制与运油罐车、地下储罐量油方式的关系,概述了我国加油站量油方式的现状,以及人工测量和液位仪密闭自动测量两种量油方式。综述了电容式液位仪、超声波液位仪和磁致伸缩式液位仪的量油原理、特点及发展趋势,重点介绍了磁致伸缩技术,并结合汽油流转过程中油气密闭性控制的重要性及储油罐的管理要求,展望了未来加油站量油方式的技术发展趋势。     

青海省西宁市与天峻县大气中得克隆与十溴联苯醚的水平与来源

十溴联苯醚(BDE-209)与得克隆(DP)是两种常见的添加型卤代阻燃剂,被广泛应用于各种电子产品中.由于其普遍存在于多种环境介质中,现已成为一种广泛存在的污染物,可能会对人体及生态系统产生潜在的危害.本研究测定了青海省西宁市与海西蒙古族藏族自治州天峻县夏、冬两季大气中BDE-209与DP的水平.结果表明,青海省西宁市夏、冬两季大气中BDE-209的平均水平分别为370 pg·m-3、470 pg·m-3,天峻县为220 pg·m-3、390 pg·m-3,与其他城市和地区相比,属于水平较高的地区.而西宁市大气中DP的平均水平为0.85 pg·m-3、0.25 pg·m-3,天峻县为0.24 pg·m-3、0.16 pg·m-3,西宁市水平高于天峻县,夏季水平高于冬季,与其他地区相比,青海省DP整体水平较低.西宁市与天峻县DP的同分异构体中,anti-DP所占比例分别是0.66±0.04与0.68±0.06,在时间与时空上的变化均不明显.青海省BDE-209与DP呈现弱的负相关性,说明两种污染物在青海省可能没有相同的本地源.     

中国东北主要河流沉积物中多溴二苯醚的含量状况及生态风险分析

为揭示多溴二苯醚(PBDEs)在东北主要河流流域内的污染现状,通过采集该地区流域内表层沉积物样品,采用GC-NCIMS技术对沉积物中41种PBDEs同类物进行分析.结果发现沉积物中BDE209含量低于检出限,其它40种PBDEs同类物总含量(不包含BDE209)范围(干重)为0.91~17.67 ng·g-1.其中第二松花江吉林市上游和下游沉积物样品中PBDEs的检出含量最高,分别为15.86 ng·g-1、17.67 ng·g-1,以BDE207和BDE47为主,分别占PBDEs总量的86.5%和76.6%;其它河流沉积物中各同族体含量差异并不明显.实验结果与国内外最近的文献报道值相比较,再结合生态风险分析显示,东北主要河流沉积物中PBDEs的含量处于低污染水平,目前不存在生态风险.     

Growth and nutrient accumulation of Phragmites australis in relation to water level variation and nutrient loadings in a shallow lake

Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis (reed) by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m 2 . This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.     

科学扩大基层民主努力构建和谐社会

本文认为,民主是一个政党健康发展的根本保证.而对"什么是民主","怎样建设和发展民主"的科学回答则是民主上述功能发挥的基本前提.民主既是对专制和独裁的否定,同时又是对建立在个人自由主义基础上的极端民主化和无政府主义的否定.我们必须在"科学发展观"这一基本理念的统领下进行包括扩大基层民主在内的民主政治建设-在扩大基层民主方面既不能徘徊不前,更不能搞"大跃进";既要整体推进,但又不能搞"一刀切";既要扩大和发展民主,又要讲求和兼顾科学与效率.只有把扩大基层民主置于"科学发展观"这一基本理念之上,才能有助于推进和谐社会建设.     

节约型社会指标体系框架设计与广东节约水平现状评价

节约型社会指标体系贯穿了循环经济的思想，包括减量化、再使用再循环、节约支撑能力、资源禀赋变化与弹性系数等4领域共51个指标。应用该指标体系估算结果表明，广东省节能、节地、节水、节材、减污、资源化等核心指标目前高于全国平均水平，且每年均有所提升。高新技术产业产值占工业总产值比重、第三产业比重、行政管理费用所占GDP在全国属于领先地位，反映广东与其它地区的差异已经从数量的差异发展为结构性差异。GDP质量优于全国平均水平。但能源消费弹性系数反映出粗放型特征没有根本转变。水环境功能区水质达标率偏低，在制度支撑、科技支撑、教育支撑指标等方面亟待改进。     

兵团农五师师部周围主要交通干线噪声污染状况分析

通过对农五师师部周围8条主要交通干线近3年的交通噪声监测与分析,得到各条道路车流量、车速和道路的基本状况,经分析得出,各交通主干道交通压力虽不大,但两侧噪声污染却比较严重,而且污染水平呈逐年上升趋势.     

苏15井水位趋势异常特征与江苏中强地震关系初探

在总结井孔水位异常的中长期、短期(临震)、后效不同阶段特征的基础上,提出三项异常指标:1、水位反向,速率(?)≥-20mm/月,V_(max)≥-40mm/月;2、异常幅度,H≥130mm;3、异常时间,T≥3月。井孔的5次水位趋势异常中,与3次江苏省5～6级中强震和1次南京地区3.1级地方震的对应关系较好,映震能力达0.8,不失为单井预测预报中强地震的一种有效方法而具推广价值。     

Succession in the Abra ovata Community on Soft Grounds of a Newly Flooded Area of the Caspian Sea

Studies on succession in the Abra ovata community inhabiting the flooded area in Sulak Bay, Caspian Sea, that have been carried out since the mid-1980s were continued. It has been found that the pioneer species A. ovata and Cerastoderma glaucum are still dominant in the structure of this community, determining the course of its succession. Its second stage does not fit the framework of the models characteristic of benthic communities. On the one hand, it conforms to the tolerance model: the pioneer species A. ovata, despite its dominance at all stages of succession, has not prevented the spread of other numerous colonizers of the same trophic level. On the other hand, it conforms to the facilitation model: due to their abundance, the pioneer species as grazing species have attracted organisms of a higher trophic level, namely, sturgeons.