基于GIS的有毒气体储罐泄漏扩散及其过程模拟

为动态模拟有毒气体储罐泄漏扩散事故（toxic gas vessel leakage and dispersion,以下简称为TLD）的扩散过程,基于高斯点源瞬时泄漏模型,添加时间因子,将TLD的泄漏过程转换为一系列瞬时点源泄漏的叠加过程,从而获得任意时刻、任意位置的有毒气体浓度分布方程。以某氯气泄漏事故为例,模拟了有毒气体的扩散过程。结果表明,在初始阶段有毒气体储罐泄漏扩散的影响范围是逐步增大的;泄漏持续到一定时间,扩散过程趋于稳定;若假设泄漏条件不变,则此后的扩散过程类似于连续泄漏,影响范围保持不变。经与ALOHA软件的计算结果对比,两者在泄漏5分钟以后的模拟结果基本一致,本文所述模型模拟计算结果可信。     

全自动固相萃取-超高效液相色谱串联质谱法测定地表水中18种头孢菌素

建立了超高效液相色谱串联质谱（UPLC-MS/MS） 法测定地表水中18种头孢菌素的方法。采用全自动固相萃取技术进行前处理,地表水样经HLB固相萃取小柱富集后,用10%（V/V）的甲酸溶液（溶剂为甲醇）洗脱。优选BEH Shield RP18（1.7μm,2.1mm×100mm） 色谱柱进行分离,在电喷雾正离子（ESI+）模式下电离,多反应模式（MRM）下检测,外标法定量。结果表明：18种头孢菌素在5.0～100 μg/L 范围内线性关系良好,相关系数（r）均＞0.999,方法检出限为0.5～1.8 ng/L,测定下限为2.0～7.2 ng/L。对地表水样品进行加标回收实验,18种头孢菌素的相对标准偏差（RSD）为0.5%～14.5%,加标回收率为64.3%～92.8%。该方法自动化程度高,结果稳定可靠,适用于地表水中头孢菌素的测定。     

上海浦东新区城区大气PM2.5中水溶性离子污染特征研究

为研究大气中细颗粒物(PM2.5)在中低浓度水平下的污染特征及来源,于2018-2020年在上海市浦东新区采用在线气体组分及气溶胶监测系统对大气ρ(PM2.5)及其水溶性离子的质量浓度进行了在线连续观测.结果表明,2018-2020年ρ(PM2 5)变化总体均呈现冬季较高,春、秋季其次,夏季较低的特征.PM2.5中水溶...     

高沼气综采工作面瓦斯抽放方法的研究

应用采场三维瓦斯流动理论，论述了高沼气综采工作面邻近层瓦斯抽放的基本原理。提出了俯采综采工作面邻近层瓦斯的抽放方法，以及用一条边界专用瓦斯巷道，集中抽放钻孔一侧多区段无煤柱综采工作面对应时期邻近层瓦斯的方法。此方法应用于城子河煤矿三个综采工作面，瓦斯抽出率均在４０％以上，最高达７２％。     

ATOMI射频氦等离子体原子发射光谱用于毛细管气相色谱检测(英文)

1　IntroductionInmodernanalyticalchemistry ,chromatographyandemissionspectroscopyandtheircombinedusearebecominganincreasinglyimportanttechniqueforthemeasurementofenvironmentalpollu tants.AtomicemissiondetectorusedinGCcanprovidehighlysensitiveandselectiver…     

Specific association of 36Cl with low molecular weight humic substances in soils

Soils initially contaminated with ³⁶Cl in the chloride form were subjected to solid–liquid extractions using a variety of reagents including deionised water and 1 M sodium hydroxide (NaOH). 1 M NaOH was found to result in the greatest recovery of ³⁶Cl from the soils, a result which provided initial evidence that radioactive chlorine became attached to humic substances present naturally within the soils. Deionised water and 1 M NaOH extracts were subjected to analysis involving separation by gel filtration chromatography (GFC). It was found that ³⁶Cl in 1 M NaOH extracts associated preferentially with low molecular weight (LMW) fractions of humic substances whereas, in deionised water extracts, ³⁶Cl appeared to be present exclusively in the chloride form. Previous literature evidence, mainly from highly organic forest soils, suggests that conversion of stable chlorine from chloride to organic forms can occur as a result of biological action. The present paper also presents good evidence for the specific attachment of stable chlorine (³⁷Cl) to a LMW humic fraction, again demonstrated using GFC separation. Current risk assessments of the deep geological disposal of solid radioactive wastes containing ³⁶Cl typically assume a very low degree of sorption based on the notion that the predominant environmental species of radiochlorine is chloride. This paper concludes with a brief discussion on the implications of organochlorine formation in the biosphere for assessment of the radiological impact of deep geological disposal of solid radioactive wastes.     

加油站模糊数学安全评价模型及应用

笔者针对目前汽车加油站事故的多发性及其安全的重要性 ,指出了目前加油站安全评价方法的不足 ,提出对于加油站这个复杂的多因素、多变量、多层次人机系统应该考虑采用模糊数学的方法来进行安全评价 ,以得到符合实际加油站安全现状的评价结果。通过分析影响加油站安全的各个因素以及因素之间的相互联系 ,建立了较合理的加油站安全评价指标体系 ;并根据现场经验给出了各相关安全因素的权重 ,运用模糊数学方法建立了加油站安全评价模型 ;同时通过实例验证 ,该安全评价模型的评价结果符合实际情况 ,有较强的实际应用性     

液化石油气瓶站气体泄漏爆炸危险性研究

针对某个城市居民区的液化气瓶站,采用数值模拟方法计算在液化气钢瓶发生泄漏后,液化石油气发生爆炸对瓶站和周围建筑的冲击波和温度的影响;分析冲击波对建筑可能造成的损坏情况;根据模拟分析结果,提出了改进液化气瓶站安全性的技术措施。笔者计算和分析的结果及提出的安全技术措施,为保障周围建筑和人员安全提供了技术依据。     

Dilution with air to minimise consequences of toxic/flammable gas releases

Dilution has long been considered a solution to many problems of toxic/flammable material releases. It implies diluting to a concentration that is below physiologically dangerous levels for a toxic substance (generally below TLV), or to a level below LFL for a flammable material release, ensuring that the process adopted for dilution does not itself enhance the risks.

In this paper, we discuss the dilution of a gaseous release by deliberate and cautious mixing with air to reduce its concentration to a harmless level. The idea bears its origin to the Bhopal Gas Tragedy where some families saved themselves by turning the ceiling fans on when MIC reached their bedrooms at the dead of very cold night on December 2–3, 1984. The air pushed in by the fans diluted the MIC to below the harm level.

Some of the advantages of using air dilution are: no cost of air, no air storage needed, no need to treat the air after use as in case of water curtains; required equipment, its maintenance and staff training in its use are very likely to cost less than in other ways of handling a release.

Air dilution may not be feasible in all cases, such as gaseous release within a congested equipment layout, release that forms a liquid pool, etc. The method needs to be evaluated for each case.     

Heavy gas dispersion by water spray curtains: A research methodology

The mitigation of the consequences of accidental releases of dangerous toxic and/or flammable cloud is a serious concern in the petro-chemical and gas industries. Nowadays, the water-curtain is recognized as a useful technique to mitigate a heavy gas cloud. The paper presents a research methodology, which has been established and undertaken to quantify the forced dispersion factor provided by a water-curtain with respect to its configuration.

The method involves medium-scale field tests, Wind-Gallery tests and numerical simulations. These different approaches are discussed and exemplified by typical results emphasizing the observed concentration reduction due to the water-curtain.