Funipuncture for fetocide in late termination of pregnancy

The most widely used method for fetocide in late termination of pregnancy for fetal abnormalities (TOPFA) consists of injecting of potassium chloride (KCl) into the fetal heart and is likely to be painful after 22 weeks of gestation. We studied ten consecutive women undergoing TOPFA between 22 and 38 weeks. This technique for fetocide consisted of a single umbilical vein puncture under ultrasound guidance with injections of sufentanil 5 µg followed by KCl 2 g. No electrocardiographic modifications could be observed and maternal plasma potassium levels did not show any significant variation throughout the procedure. Fetal umbilical phlebotomy for fetal analgesia followed by fetocide therefore appears to be a safe procedure for the mother and allows the fetus to die without pain when late termination of pregnancy (TOP) is indicated. Copyright © 2002 John Wiley & Sons, Ltd.     

区域性“减灾十年初步规划”的编制原则

本文简要介绍区域性“减灾十年初步规划”编制的一般原则，包括规划编制的意义、目的、编制顺序和规划应注意的几个方面，并提出规划成果的实施意见。可供各地编制规划时参考。     

离子液体吸收废印刷线路板热拆解过程中挥发性有机物——基于COSMO-RS模型

模拟废印刷线路板（WPCB）的热拆解过程,分析热拆解过程中的挥发性有机物（VOCs）组分;利用真实溶剂似导体屏蔽（COSMO-RS）模型对浓度较高的污染物进行量子力学模拟,研究离子液体（ILs）组成单元对目标污染物溶解度的影响差异,分析溶解过程中主导分子间作用力类型,确定优选吸收剂;测定不同溶剂进行溶解性,验证模型适用性.结果表明：①乙酸乙酯和环戊酮是浓度较高的VOCs组分,在240和250℃时浓度分别为43.1,153mg/m³和105,252mg/m³,质量百分比总和分别为76.3%和67.3%.②高表面屏蔽电荷密度分布峰、长烷基链阴阳离子和亲电基团的存在可提高乙酸乙酯和环戊酮在ILs中的溶解度.双三氟甲磺酰基亚胺盐（NTf₂^-）类ILs是一类优良吸收剂.静电力和范德华力对溶解过程起主导作用.③COSMO-RS模型可定性和半定量用于预测乙酸乙酯和环戊酮的溶解度.     

Density functional theory (DFT) studies of vanadium-titanium based selective catalytic reduction (SCR) catalysts

Based on density functional theory (DFT) and basic structure models, the chemical reactions on the surface of vanadium-titanium based selective catalytic reduction (SCR) denitrification catalysts were summarized. Reasonable structural models (non-periodic and periodic structural models) are the basis of density functional calculations. A periodic structure model was more appropriate to represent the catalyst surface, and its theoretical calculation results were more comparable with the experimental results than a non-periodic model. It is generally believed that the SCR mechanism where NH₃ and NO react to produce N₂ and H₂O follows an Eley-Rideal type mechanism. NH₂NO was found to be an important intermediate in the SCR reaction, with multiple production routes. Simultaneously, the effects of H₂O, SO₂ and metal on SCR catalysts were also summarized.     

Recent advances in catalytic decomposition of ozone

Ozone (O₃), as a harmful air pollutant, has been of wide concern. Safe, efficient, and economical O₃ removal methods urgently need to be developed. Catalytic decomposition is the most promising method for O₃ removal, especially at room temperature or even subzero temperatures. Great efforts have been made to develop high-efficiency catalysts for O₃ decomposition that can operate at low temperatures, high space velocity and high humidity. First, this review describes the general reaction mechanism of O₃ decomposition on noble metal and transition metal oxide catalysts. Then, progress on the O₃ decomposition performance of various catalysts in the past 30 years is summarized in detail. The main focus is the O₃ decomposition performance of manganese oxides, which are divided into supported manganese oxides and non-supported manganese oxides. Methods to improve the activity, stability, and humidity resistance of manganese oxide catalysts for O₃ decomposition are also summarized. The deactivation mechanisms of manganese oxides under dry and humid conditions are discussed. The O₃ decomposition performance of monolithic catalysts is also summarized from the perspective of industrial applications. Finally, the future development directions and prospects of O₃ catalytic decomposition technology are put forward.     

厦门市冬季PM2.5污染情境识别及其与气象条件的关系

为研究厦门市冬季不同PM_2.5污染情境与气象条件和气团轨迹路径特征的关系,结合PM_2.5观测数据,使用AGAGE（Advanced Global Atmospheric Gases Experiment）统计方法识别2014—2018年冬季厦门市PM_2.5观测值、基线值和污染值情境,通过气象数据统计和气团后向轨迹聚类对不同PM_2.5污染情境下气象条件和气团轨迹路径特征进行探究.结果表明:①厦门市冬季不同PM_2.5污染情境下,ρ（PM_2.5）及PM_2.5污染值情境时长占比均呈波动中下降的趋势,具体表现为冬季PM_2.5观测值、污染值和基线值情境下,ρ（PM_2.5）平均值分别从2014年的42.2、90.7、16.4 μg/m3降至2018年的26.3、56.9、8.8 μg/m3,冬季PM_2.5污染值情境时长占比从2014年的10.2%降至2018年的3.0%.②冬季PM_2.5污染值情境下气象要素呈低风速、低气压、高温度、高相对湿度的特征.③冬季到达厦门市的气团轨迹路径中,局地路径由于大气条件稳定易累积形成PM_2.5污染;偏北路径和西北路径易从临近省份携带污染物输入导致PM_2.5污染,属于重要的外源污染输入路径;沿海路径和偏西路径均属于清洁路径,但沿海路径易在福建省北部与偏北路径重合形成污染输入,加强了偏北路径的污染物输送能力.研究显示,近年来厦门市冬季PM_2.5污染有明显减弱趋势,但不利的气象条件和外来污染输入仍会造成PM_2.5污染的发生.      

油气田在役管道高后果区识别与完整性评价方法

根据油气管道建设与管理的相关标准与规范或导则,针对目前油气田在役管道,明确了其高后果区识别的划分及其在不同标准中的差异以及识别的原则和时间间隔,分别介绍了在管道的相关数据采集的基础上开展地质灾害和第三方破坏造成的管道风险评价方法,管道内外腐蚀的直接评价以及包括剩余强度、剩余寿命和材料在内的管道适用性评价方法,同时给出了这些评价工作所涉及到的相关内容项,对油田管道的完整性管理具有重要的指导作用和应用价值。     

近10年中国三大经济区太阳总辐射特征及其与O3、PM2.5的关系

采用中国地面气象观测站网2007~2016年的辐射日值数据集和中国空气质量在线监测平台2014~2016年逐日观测数据,分析了京津冀、长三角和珠三角近10a太阳总辐射年际和季节变化,近3a臭氧日最大8h平均（O_{3_8h_max}）和细颗粒物（PM_2.5）的污染过程频次变化,通过不同因子及其不同强度等级的分型统计,探讨PM_2.5、O_{3_8h_max}与太阳总辐射的关系.结果表明：京津冀近10a太阳总辐射显著上升,京津冀春季和珠三角夏季太阳总辐射显著上升.三大经济区PM_2.5污染过程年频次均呈现逐年递减,且从北到南递减;O₃污染过程年频次时间上呈现先减后增,空间上京津冀多于长三角和珠三角.三大经济区O_{3_8h_max}与太阳总辐射相关系数均在0.71以上,有较强的正相关;而PM_2.5与太阳总辐射的相关性具有区域差异性.三大经济区不同季节不同太阳总辐射下O_{3_8h_max}与PM_2.5的相关关系差异显著,其中京津冀春夏秋三季O_{3_8h_max}与PM_2.5在强太阳总辐射下有较好的正相关,冬季则存在一定的负相关;长三角四季两者相关性均较弱;珠三角夏季两者正相关最为显著;不同PM_2.5浓度下O_{3_8h_max}与太阳总辐射的线性拟合效果较好,体现出较强的正相关关系,各经济区拟合曲线的倾向率均随PM_2.5升高而增大.PM_2.5>75μg/m³时拟合优度均达到最大.