济南市大气能见度特征及其影响因素分析

依据济南市2011~2014年大气能见度、PM_(2.5)、气态污染物(SO_2、NO_2、CO、O_3)和相对湿度(RH)的连续在线监测数据,应用频数统计分析、相关性分析和多元线性归回分析等统计学方法分析了济南市大气能见度的特征及多元因子对能见度的影响.结果表明,2011~2014年济南市7级能见度(5~10 km)出现的概率均最高,分别为48.6%、39.6%、44.1%和44.3%.3个不同RH区段中(RH≤30%,30%RH≤60%,60%RH≤90%),在30%RH≤60%区段,能见度与细颗粒物的相关性最大.通过多元线性回归分析,能见度与多元因子的相关度序列为RHPM_(2.5)O_3SO_2CONO_2.     

上海市淀山湖区域灰霾天大气颗粒物中碳组分的污染特征

采集了上海市淀山湖区域2015年3月至2016年2月灰霾天大气颗粒物中PM_(2.5)样品,重点分析了其中碳组分的污染特征。结果表明,PM_(2.5)年均质量浓度为(69.01±37.05)μg/m~3,数值与有机碳(OC)、元素碳(EC)和水溶性有机碳(WSOC)显著相关,相关性大小与灰霾程度有关。OC、EC的年均质量浓度分别为(4.46±3.41)μg/m~3和(2.15±1.31)μg/m~3,呈现冬季高、夏季低的趋势,两者显著相关,相关性大小同样与灰霾程度有关。WSOC的年均质量浓度为(2.07±1.40)μg/m~3,春季高于冬季,且灰霾天质量浓度大于非灰霾天相应值。碳组分对大气能见度的影响较大,需得到控制。     

济南市气象要素对大气污染物浓度的影响

利用2014-12-01—2015-11-30期间济南市空气质量的监测数据,运用Spearman秩相关分析法研究该市大气中细颗粒物PM_(2.5)、可吸入颗粒物PM_(10)、臭氧(O_3)的浓度与气象要素之间的相关性,其中气象要素选取温度、相对湿度和风速。结果表明:PM_(2.5)、PM_(10)及O_3与气象要素有显著的相关性,PM_(2.5)、PM_(10)的浓度与相对湿度呈正相关,与温度和风速呈负相关,O_3的浓度与温度和风速呈正相关,与相对湿度呈负相关;PM_(2.5)、PM_(10)浓度的日变化特征呈双峰双谷型,O_3浓度的日变化特征呈单峰单谷型;PM_(2.5)、PM_(10)的浓度在冬季、秋季、春季较大,在夏季较小;O_3的浓度在夏季最大,在冬季、秋季、春季相对较小,O_3已成为影响济南市夏季空气质量的首要污染物。     

广州PM2.5中有机碳和元素碳的污染特征

于2015年6月～2016年5月对广州大气细粒子PM_(2.5)进行持续观察,分析了样品中有机碳(organic carbon,OC)和元素碳(elemental carbon,EC)的含量.结果表明:广州大气PM_(2.5)含量为(66.03±43.11)μg·m~(-3),OC含量为(8.19±5.01)μg·m~(-3),EC含量为(1.75±0.80)μg·m~(-3); OC,EC和总碳(total carbon,TC)占PM_(2.5)的比例分别为16.73%,3.85%和20.58%,表明广州细粒子的碳污染程度较为严重; PM_(2.5),OC和EC污染都呈现冬季春季夏季秋季的特征,与历史研究基本一致; OC,EC相关系数较高(R~2=0.929),表明二者来源较为相近,且PM_(2.5)中EC1占比例最高(45.41%),表明广州燃煤和机动车尾气是重要的污染源;二次有机碳(SOC)为(4.10±3.56)μg·m~(-3),占OC的比例为46.19%,表明广州二次有机碳的排放与形成是碳污染的重要因素.与历史数据相比,广州大气污染情况有所改善,碳气溶胶污染几乎达到历史最低值.     

郑州市城区PM2.5和PM10变化特征及其与气象要素关系研究

利用2018年1月、4月、7月、10月郑州市城区8个监测站点的PM_(2.5)和PM_(10)浓度数据与气象数据,对郑州市城区PM_(2.5)和PM_(10)的时相变化特征及气象要素对其产生的影响进行研究.结果表明:郑州市城区在1月份的PM_(2.5)浓度最高(118.1μg·m~(-3)),污染严重,4月份PM_(10)浓度最高(169.4μg·m~(-3)).通过分析PM_(2.5)和PM_(10)的比值(PM_(2.5)/PM_(10))发现, PM_(2.5)是郑州市城区主要的大气污染物.PM_(2.5)和PM_(10)与气象要素之间的相关分析表明,PM_(2.5)和PM_(10)与气温和露点温度均呈显著负相关(P0.01),PM_(10)与降水呈显著负相关(P0.05),PM_(2.5)与气温之间的相关性(r=-0.441,P0.01)高于PM_(10)和气温的相关性(r=-0.311,P0.01).另外,当风速在2～3 m·s~(-1)时,PM_(10)最低;而风速大于4 m·s~(-1)时,颗粒物浓度增加明显,且对于PM_(10)的增加作用更显著.露点温度与颗粒物浓度之间也存在一定关系,当露点温度大于0℃时,颗粒物浓度会随露点温度的增加而降低.2018年郑州市PM_(2.5)与PM_(10)昼夜变化呈双峰型特征;风速与温度的双重作用导致PM_(2.5)浓度先于PM_(10)达到最高值,而空气湿度和露点温度则是造成04:00时颗粒物较低的主要原因.另外,通过多元回归分析发现,各月份昼夜时段颗粒物浓度主要受温度和相对湿度影响;在各时段中,温度与颗粒物浓度关系最为密切,风速次之,湿度最弱,各气象要素对PM_(2.5)浓度的影响较PM_(10)浓度更大.     

中国工业基地城市群PM2.5时空分布特征及相关性分析

为研究2014年中国四大工业基地25个主要城市的空气质量污染情况,对25个城市2014年1月~2015年2月的数据进行SPSS聚类分析,研究其整体分布情况,并应用统计学和GIS软件分析其主要城市大气颗粒物的污染分布特征,同时利用SPSS软件对大气污染物PM_(10)、SO_2、NO_2、CO、O_3和PM_(2.5)做相关性分析。结果表明:(1)25个城市PM_(2.5)年均质量浓度在32.94~100.23μg·m~(-3)之间,其中分布在40~70μg·m~(-3)之间的城市相对集中,占所有城市的68%,仅3个城市的PM_(2.5)年均质量浓度小于35μg·m~(-3);(2)PM_(2.5)季节变化特征大体表现为冬季秋季春季夏季,重度污染主要集中在12月和1月;(3)从空间分布上看,京津唐污染水平高于其他三个工业基地,珠三角污染水平最低;(4)四大工业基地城市群PM_(2.5)的浓度与PM_(10)、SO_2、NO_2、CO的浓度存在显著相关性。由于温度、气候等原因,在珠三角和长三角O3与PM_(2.5)呈正相关,而在京津唐和辽中南工业基地则呈负相关。     

PM2.5及气象要素对乌鲁木齐市臭氧的影响

利用乌鲁木齐市2016年12月～2017年11月臭氧(O_3)小时浓度数据,分析了乌鲁木齐市近地面O_3浓度变化特征以及PM_(2.5)和气象要素对O_3浓度的影响。结果表明,2016年12月～2017年11月乌鲁木齐市近地面O_3浓度均值为43.74μg·m~(-3),O_3-8 h浓度第90百分位数为119.98μg·m~(-3)。O_3日变化呈"单峰型",09:00为低谷,16:00达到峰值。臭氧浓度在5～9月相对较高,季节变化从高到低依次为:夏季、春季、秋季、冬季。O_3浓度与PM_(2.5)浓度负相关,高温低湿时二者相关性较高。O_3浓度与相对湿度负相关,与气温、日照时数、风速正相关。在低PM_(2.5)、高温、低湿、长日照时数及风速大于3 m·s~(-1)的气象条件下易发生O_3污染。     

上海市大气PM2.5污染特征及相关因素分析

利用2015年上海市大气污染物的监测数据,运用MATLAB7.0、SPSS等软件进行PM_(2.5)质量浓度污染特征、变化规律以及PM_(2.5)与其他污染气体的相关性分析。研究结果显示,2015年上海市PM_(2.5),年平均浓度为53.6μg/m~3,相比基准年2013年,年均浓度下降14%;PM_(2.5)浓度月变化曲线呈U型分布,其中,月均浓度数值1月份达到最高峰,为82.9μg/m~3;季节污染情况为:冬季春季秋季夏季;PM_(2.5)日均浓度值全年波动较为稳定,超标天数占全年比率21.4%。根据AQI指标监测气体的相关性矩阵来看,PM_(2.5)和PM_(10)之间的相关性最大,相关系数为0.919;与CO、NO_2、SO_2等气体均有较强的相关关系。建议上海市应该优化产业结构、加强公共交通建设、采用清洁能源以期实现治污除霾的目标。     

合肥市PM_(2.5)的分布特征及其要素分析

对2013年合肥市的PM_(2.5)质量浓度、各类空气中污染物、气象要素等数据进行统计处理,通过定性、定量分析,得出PM_(2.5)质量浓度与其他各量间的相关性.结果表明,合肥地区雾霾情况较为严重,除7月份外,PM_(2.5)质量浓度超标率超标率均在87%以上,且冬季更为明显.工业较为发达的庐阳区PM_(2.5)质量略浓度高于其他地区.由Pearson相关性分析可知,PM_(2.5)质量浓度与PM_(10)浓度、NO_2浓度、SO_2浓度等有较强相关性;与能见度、温度、风速、平均低云量、降水量等呈负相关性;与逐日平均总云量、平均相对湿度、平均气压无相关性.     

天津武清区PM_(2.5)与气态污染物SO_2及NO_2污染特征研究

利用2016年武清区大气污染物监测数据,研究了武清区PM_(2.5)及SO_2、NO_2等典型大气污染物浓度变化特征和相互关系。结果表明:2016年PM_(2.5)污染较严重,年均浓度分别为73μg·m~(-3),超标1.1倍。大气中SO_2年均值为25μg·m~(-3),NO_2年均值47μg·m~(-3)。冬季及春秋季节大气中存在明显的二次转化过程,大气中的SO_2和NO_2通过转化生成硝酸盐和硫酸盐,对PM_(2.5)浓度变化具有重要影响。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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