Impact of China’s Air Pollution Prevention and Control Action Plan on PM2.5 chemical composition over eastern China

China promulgated the Air Pollution Prevention and Control Action Plan(the Action Plan)in 2013 and developed stringent control measures to mitigate fine particulate matter(PM2.5) pollution.Here,we investigated the PM2.5 chemical composition changes over eastern China associated with the Action Plan during 2013-2017 using satellite-based PM2.5 chemical composition data derived using CMAQ simulations and satellite inputs.The PM2.5 concentrations decreased considerably during this time as a result of the reductions in all chemical species in PM2.5.The population-weighted mean concentrations over eastern China decreased from 11.1 to 6.7μgm-3 for SO42-,13.8-13.1μgm-3 for NO3-,7.4-5.8μgm-3 for NH4+,9.9-8.4μgm-3 for OM,4.6-3.8μg m-3 for BC and 12.9-9.6μg m-3 for other species in PM2.5.SO42-had the largest reduction of 40%,while NO3-had the lowest reduction of 5%,resulting in a greater fraction of NO3-and a smaller fraction of SO42-in PM2.5.Among the three key regions,Beijing-Tianjin-Hebei had the largest reduction in PM2.5 and its chemical compositions.The decrease in SO42-concentrations was in line with the reduction of SO2 emissions,and the major driver of the SO2 emission reductions was the industrial sector.The decrease in NO3 concentrations was limited because the decrease in SO2 emissions and the stable NH3 emissions facilitated the formation of NO3-from HNO3,which partially offset the reduction in NOx emissions driven by the power sector.To mitigate PM2.5 pollution more effectively,future efforts are needed to reduce NH3 emissions.

A Study of China’s Air Pollution Prevention and Control Policy Framework from a Policy Instrument Perspective

Environmental pollution caused by rapid economic development like that seen in China over the past twenty years poses various threats to human health. People have started to place much more of an emphasis on environmental security, working to find a balance between sustainability and economic growth. In recent years, air pollution has emerged as a highly discussed topic of social and environmental relevance in China, due in part to persistent smog that affects everyday life and causes serious harm to human health. Although air pollution is normally associated with human activity, is can be caused by natural processes such as eruptions and forest fires, but is always characterized by the release of certain substances into the atmosphere which, when present in certain concentrations or for given durations, can harm human health, daily life, productivity, and other aspects. In humans, it mainly affects the respiratory system, notably the lungs, as well as the immune system. A series of studies both in China and overseas have shown, in certain cases, even low concentrations of air pollution can pose a great threat to human health. In this study, we conducted an analysis of air quality policies, focusing on the 2018 revision of the People’s Republic of China’s Law on the Prevention and Control of Air Pollution(LPCAP). We utilized the content analysis method and Strauss and Corbin’s grounded theory to construct a policy framework, demarcate analysis units, code and classify policy texts, determine descriptive statistics, and analyze dimensional interactions. We used two dimensions(basic policy instruments classified as demand-, supply-, and environment-side;and air carrying capacity) to quantify and analyze the LPCAP, which enabled us to analyze the deficiencies and conflicts within policy instruments. The results show a higher utilization frequency of environment-side policy instruments, particularly regulation management and strategic measures. This reflects efforts by the government to create a favorable environment for improving air quality. Additionally, supply-side policy instruments are used far less frequently than environment-side policy instruments. Air quality legal policies and pollution control measures mainly consist of environment-side policy instruments;ecological thinking and air quality policies that are based mainly on supply-side and environment-side policy instruments;and social coordination policies that mainly use environment-side policy instruments. Based on the results of this study, we recommend an increase in the number of supply-and demand-side policy instruments, particularly the latter which includes promoting ecological thinking amongst citizens, to optimize and improve air pollution prevention and control policies.

Thoughts on Energy Solutions to Alleviation of Air Pollution during the Heating Period in Key Areas

Since the implementation of the Action Plan for Air Pollution Prevention and Control , all regions of China have steadily promoted the prevention and control of air pollution and achieved results continuously. However, the atmospheric environment in key areas such as Beijing-Tianjin-Hebei region, the Yangtze River Delta region, and Fenwei Plain is still severe, and especially during the heating period heavy pollution occurs frequently, which has become the focus and difficulty of improving the quality of the atmospheric environment and is also the weakest link of China s air pollution control at present. How to alleviate air pollution, how to win the battle of pollution prevention and control, how to hold the fruits of the blue sky defense war, energy consumption is key.

Pollution and Control Measures in Plant Tissue Culture in Orchid Plant

Contamination is a phenomenon that often occurs in the operation of plant tissue culture,and it is also one of the three major problems in plant tissue culture.Compared with browning and vitrification,contamination is more likely to occur,which brings great harm to scientific research and production practice.Its appearance will greatly affect the normal growth and differentiation of tissue culture materials,and will reduce the yield of cultivated plants to a certain extent.Therefore,we cannot underestimate any step in the tissue culture operation.This study summarized the reasons for its occurrence and how to formulate prevention and control measures based on recent research combined with the actual situation.

Research Progress on the Relationship between Air Pollution and Socio-economic Growth in China

Air pollution is a hot issue studied by scholars all over the world.Academic circles generally believe that socio-economic factors such as extensive economic growth,unbalanced proportion of industrial structure and unreasonable energy consumption structure are the main"culprits"of serious air pollution in China.Therefore,the relationship between air pollution and socio-economic growth has very important theoretical and practical significance for air pollution prevention and control and promoting the sustainable and healthy development of cities.Through literature research and summary methods,this paper studies the severity and harmfulness of air pollution in China,and deeply studies the research progress of socio-economic influencing factors of air pollution,environmental Kuznets curve hypothesis of air pollution,decoupling relationship between air pollution and socio-economic growth,so as to provide useful reference for the prevention and control of air pollution.

中国大气污染防治政策与空气污染治理——基于城市级面板数据的实证研究

2013年颁布实施的《大气污染防治行动计划》是我国首个针对环境突出问题开展综合治理的行动计划;为巩固治理效果,应对动态变化的环境问题,2018年国务院进一步发布了《打赢蓝天保卫战三年行动计划》。研究利用中国258个城市2013年1月至2020年9月日度空气污染数据,实证检验了上述两阶段政策对空气质量的影响,并从不同污染物治理效果、时间和区域异质性等角度分析了政策效应的差异。结果指出:第一,“大气十条”和“蓝天保卫战”均显著降低了AQI、PM_(2.5)、PM_(10)、SO_(2)、NO_(2)、CO;第二,相比“大气十条”,“蓝天保卫战”对NO_(2)的减排效应更高,且实现对O_(3)的协同治理;第三,“大气十条”和“蓝天保卫战”对各污染物的减排效应因供暖时期、地区能源资源禀赋呈现出较强的异质性特征。

空间站舱内微量有害气体状态评价和流转分析

文章聚焦于中国空间站长期在轨运行中微量有害气体的整体状态和控制情况,阐述了微量有害气体随舱内物质循环向冷凝水回收净化以及CO_(2)去除和还原等环节流转的规律。通过在轨状态分析、地面比对评估试验结果和流转特性分析,说明中国空间站各净化系统对舱内微量污染物成分进行了有效控制,舱内空气中微量有害气体浓度保持在较低水平。研究旨在为后续微量有害气体净化环节的运行和监测提供指导。

水-气耦合下的土质边坡稳定系数场分析

传统边坡稳定性分析方法仅对潜在滑动面进行整体稳定性评估,无法获取各点的安全系数.基于稳定系数场理论,综合考虑水-气耦合作用,对降雨条件下边坡稳定性进行分析.结果表明:1)稳定系数场法能够直观地体现水-气耦合作用下边坡的具体破坏区域,得到各点的安全系数;2)孔隙气压力对边坡降雨入渗有一定阻碍作用,并且随着降雨时间的推移阻渗效果愈明显,相同条件下降雨40 h时,两相流湿润锋深度较单向流减小了28.6%;3)相同条件下,考虑水-气耦合作用将降低边坡稳定性,以降雨40 h为例,两相流边坡失稳面积约为单向流的1.7倍.因此,在实际工程中对边坡稳定性分析时考虑水-气耦合作用,工程偏于安全.

基于PSO-Elman神经网络的井底风温预测模型

目前井下风温预测大多采用BP神经网络,但其预测精度受学习样本数量的影响,且容易陷入局部最优,Elman神经网络具备局部记忆能力,提高了网络的稳定性和动态适应能力,但仍然存在收敛速度过慢、易陷入局部最优的问题。针对上述问题,采用粒子群优化(PSO)算法对Elman神经网络的权值和阈值进行优化,建立了基于PSO-Elman神经网络的井底风温预测模型。分析得出入风相对湿度、入风温度、地面大气压力和井筒深度是井底风温的主要影响因素,因此将其作为模型的输入数据,模型的输出数据为井底风温。在相同样本数据集下的实验结果表明:Elman模型迭代90次后收敛,PSO-Elman模型迭代41次后收敛,说明PSO-Elman模型收敛速度更快;与BP神经网络模型、支持向量回归模型和Elman模型相比,PSO-Elman模型的预测误差较低,平均绝对误差、均方误差(MSE)、平均绝对百分比误差分别为0.376 0℃,0.278 3,1.95%,决定系数R^(2)为0.992 4,非常接近1,表明预测模型具有良好的预测效果。实例验证结果表明,PSO-Elman模型的相对误差范围为-4.69%~1.27%,绝对误差范围为-1.06~0.29℃,MSE为0.26,整体预测精度可满足井下实际需要。

“大气污染物和温室气体协同控制”政策的实施效果研究

推动减污降碳协同增效是深入打好污染防治攻坚战,实现碳达峰的必然要求。将《大气污染防治行动计划》和《打赢蓝天保卫战三年行动计划》视为一个连贯政策,运用渐进双重差分法探究了于2015和2018年提出的“大气污染物和温室气体协同控制”政策实施效果。研究表明:“大气污染物和温室气体协同控制”政策显著提高了“SO_(2)-CO_(2)”排放强度协同度和“PM-CO_(2)”排放量(强度)协同度,但该政策对“SO_(2)-CO_(2)”排放量协同度无显著影响。机制分析表明,提升政府监管水平、弱化政企关系以及增强企业绿色创新是政策的主要传导机制。异质性分析表明,政策效果在不同能耗水平的城市中具有显著差异,比起高污染上市公司,高耗能中小企业在污染物和CO_(2)的协同减排措施上仍存在较大改善空间。研究结论对我国优化“持续深入打好蓝天保卫战”相关政策提供启示。

食源性致病菌交叉污染风险的数学模拟及精准防控策略研究进展

食源性致病菌交叉污染是食品加工生产、贮藏运输、家庭消费等环节中广泛存在的一种现象,被视为导致食源性疾病暴发的重要原因之一。运用数学模型模拟食源性致病菌在不同食品媒介中的转移情况,能够帮助人们理解食源性致病菌交叉污染的传播规律。进一步将交叉污染模型与微生物风险评估相结合,明确交叉污染发生的关键环节,并配合一系列新型的抗菌涂层设计,将能有效地预防和控制交叉污染的发生。因此,本文首先综述了食品工业及家庭生活中致病菌交叉污染导致的食品安全问题,并详细地概述食源性致病菌交叉污染数学建模的最新研究进展,最后通过全局控制和源头控制两个层面,分别阐述了微生物风险评估与危害分析与关键控制点相结合和抗菌涂层在食源性致病菌交叉污染防控中的应用,并对交叉污染未来的研究方案和控制策略提出了展望。

细菌在反渗透膜生物污染中的作用及防控研究进展

海水反渗透膜的生物污染是海水淡化行业面临的一个世界性难题。查阅近年国内外关于海水淡化系统反渗透膜生物污染的文献以及其他相关资料,对海水淡化系统RO膜上优势细菌群落组成及胞外聚合物在膜生物污染中的作用进行了总结,讨论了与膜污染有关的耐氯菌种并简述了以预处理为主的常见防控方法和使用群体抑制酶为主的生物防治新方法。为解决耐氯菌生物膜难以被杀菌剂去除、处理成本较高等问题,提出未来应针对耐氯菌及其他胞外聚合物分泌能力强的微生物等开展研究,并结合预处理、化学清洗和生物控制等方法设计因地制宜的全面防控方案。

中国设施土壤重金属累积特征与污染阻控技术研究进展

长期集约化耕作导致中国设施土壤重金属累积和面源污染风险增加的状况已引起广泛关注。该研究总结了中国设施土壤重金属累积状况及其来源,发现长期盲目投入肥料及农药是引发设施菜田土壤重金属累积问题的主要原因。目前,设施土壤重金属累积呈现出广泛性和中轻度污染特征,其中镉是主要的污染元素。遵循面源污染治理中“源头预控-过程阻断-末端修复”原则,基于国内外文献综述,该文总结归纳出适用于设施土壤重金属累积特征与污染的联合阻控技术及作用机制。首先在灌溉和肥药投入等源头环节减少重金属输入;其次在作物种植过程中,通过选用重金属低积累特性的蔬菜种类或品种,结合水肥一体化施用大分子有机水溶性肥料或叶面喷施具有阻控重金属作用的营养型阻控剂,抑制作物吸收重金属;最后在末端修复环节,利用具有多元功能的土壤改良剂或微生物菌剂进行土壤钝化修复,或采用具有超重金属富集能力且能提高设施土壤生物多样性的植物作为填闲作物,实现生物修复的目标。该联合阻控技术的原则在于协同考虑污染防治、土壤改良、减肥增效等农学和环境目标,集成土壤修复与改良、水肥一体化、填闲作物栽培等技术,并兼顾设施土壤重金属污染修复工程所面临的投入品成本较高、经济效益不明显、缺失可持续改良导致效果不稳定等问题,优推能够钝化重金属并改良土壤的多功能土壤改良剂以及具有阻控重金属吸收、提高作物抗逆性的多功能有机水溶性肥料。上述措施能解决设施土壤普遍存在的重金属累积问题,提升土壤的安全生产能力,可为设施农业可持续发展提供更有效的技术支撑。

防控条件下的超净光学实验室运行管理探讨

超净光学实验室是开展高精度光学实验的重要基础设施,能够提供良好的温湿度、洁净度等环境条件,保障高精度光学设备、特殊光学元件的正常稳定工作。从设计上,超净光学实验室大都采用类似于中央空调系统的内循环空气过滤加有限新风补风的方案。防控的新情况对超净光学实验室的运行管理提出了新的工作要求。根据精密光谱科学与技术国家重点实验室在防控期间管理超净光学实验室的实际经验进行了总结和梳理,重点探讨了实验人员管理、超净实验室运行维护,实验室消杀和应急预案制定等,这些新的管理方法和经验对于提升实验室运行安全、同时防范化解防控风险,具有很好的参考价值和借鉴意义。

医用超声探头及耦合剂微生物污染的研究现状

随着超声医学技术的发展,超声检查技术被越来越多地应用于临床,在多系统疾病的筛查、诊断和治疗中起到尤为重要的作用。超声技术在急诊超声、重症超声中发展迅速,同时还应用于肺部疾病、妇幼儿科疾病诊疗,颅内压检测、心排血量检测,还可以改变手术形式,使手术方式更加简便。还与数字剪影血管造影相结合治疗急性脑出血、引导经外周静脉穿刺置管术、肿瘤学中阴道消融术等,在众多系统疾病中广泛应用。在极大程度上减轻了患者痛苦,缩短了患者平均住院日,减轻了患者经济及心理压力。与此同时,超声检查技术的发展也使医学发展面临一定问题。由医学超声检查技术引起的相关院内感染时有发生。超声探头及超声耦合剂的使用成为超声检查相关院内感染发生的重要影响因素。因此,本文对将医用超声探头进行消毒处理、正确选择医用超声耦合剂展开综述。

综掘工作面气室降尘技术研究

针对掘进巷道中的粉尘控制问题,传统的长压短抽通风降尘技术存在粉尘扩散区域大、风幕降尘技术存在射流孔易堵塞等弊端。以巴拉素煤矿综掘工作面为工程研究背景,建立了掘进作业过程中的粉尘运动数学模型,得出降低综掘工作面粉尘浓度的关键因素是控制掘进巷道风流场扰动范围及减小粉尘颗粒运动时间。以上述关键因素为依据,在风幕降尘的基础上开发了气室降尘技术,通过在正压风筒末端加装风袖,与风幕共同作用将粉尘封闭在气室区域内,再由负压风机抽出,以提高降尘效率。采用Fluent软件对长压短抽通风降尘、风幕降尘和气室降尘进行模拟对比分析,并优化了气室降尘技术参数。模拟结果表明:采用气室降尘技术时,综掘工作面人体呼吸带位置的粉尘浓度为350 mg/m^(3),较采用长压短抽通风降尘时的600 mg/m^(3)和风幕降尘时的480 mg/m^(3)大幅降低;气室降尘最优技术参数为正压风筒出风口距综掘工作面14 m、负压风筒末端直径0.6 m。在巴拉素煤矿2号煤2号回风大巷综掘工作面进行现场试验,结果表明采用气室降尘时,掘进巷道最低粉尘浓度为118 mg/m^(3),低于采用长压短抽通风降尘时的184 mg/m^(3)和风幕降尘时的156 mg/m^(3),且降尘效率较长压短抽通风降尘平均提高54.8%。

沿空留巷Y型通风瓦斯运移规律及风量调控研究

沿空留巷Y型通风“两进一回”工作面和采空区尾巷存在瓦斯涌出问题,当瓦斯超限时,易诱发瓦斯爆炸等灾害。以山西东瑞煤矿沿空留巷工作面为研究对象,利用Fluent数值模拟软件,模拟沿空留巷Y型通风瓦斯运移基本规律,分析不同通风条件对瓦斯浓度分布的影响。结果表明:增加运输巷道风量使沿空留巷瓦斯浓度降低,增加辅运巷道风量使工作面瓦斯浓度降低;当总风量不变时,2条进风巷道的风量配比对工作面瓦斯浓度影响较大,对采空区瓦斯浓度影响相对较小。随着采煤工作面推进距离的增加,沿空留巷和工作面的瓦斯治理难度上升,最佳通风配比量由运输巷道向辅运巷道倾斜。在煤矿开采过程中,应不断调节进风巷风量配比来预防工作面和尾巷的瓦斯浓度升高,同时,还应提高采空区密闭程度、加强采空区的漏风管理。

不同植物性饲料原料中玉米赤霉烯酮污染状况调查

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