燃煤电厂锅炉PM2.5现场实测与排放特征研究

采用自设固定源PM_2.5稀释采集系统对陕西省关中地区多个燃煤电厂烟气中的颗粒物开展了现场实测与样品化学源组分分析。结果表明：4个燃煤电厂PM_2.5、PM₁₀占颗粒物比重差异较大（PM_2.5占比范围为6.92%~54.34%,PM₁₀占比范围为36.36%~73.02%）;4个燃煤电厂数浓度水平最高值（2.0×10⁴~4.0×10⁵个/cm³）差异较大,相差约1个数量级;燃煤电厂PM_2.5小粒径段颗粒物质量浓度占比大多较低,但其对PM_2.5数浓度贡献却很大（最小值>95%）,大粒径段颗粒物则相反;煤粉炉PM₁/PM_2.5较大,占比范围为35.29%~51.35%,循环流化床锅炉PM₁/PM_2.5较小,占比范围为16.62%~21.47%;SO₄^2-是燃煤电厂PM_2.5中最丰富的离子成分,各电厂SO₄^2-占总离子浓度比重范围为50.02~65.52%,Na⁺和Ca²⁺位于第2或第3位;各燃煤电厂主要检出无机元素是Si、Al、Ca、Na、Fe、Na等地壳元素;燃煤电厂PM_2.5、PM₁₀和颗粒物的排放因子范围分别为0.001~0.028 kg/t、0.002~0.086 kg/t、0.003~0.236 kg/t;除尘设施组合越复杂先进,排放因子就可能越小。     

上海市2013年以来空气污染物变化特征

根据上海市环境监测中心网站发布的2013年1月?2015年9月上海市空气污染监测结 果，对PM_2.5、PM₁₀、O₃、NO₂、SO₂、CO共6种污染物的变化特征进行了研究.结果表明：上海空气 污染物PM_2.5、PM₁₀、O₃、NO₂、SO₂、CO浓度在逐年降低，显现出近年来上海空气污染治理初见成 效；在每年的12月前后或冬季，PM_2.5、PM₁₀、NO₂、SO₂、CO浓度最高，在每年的8月前后或夏季浓 度最低；O3浓度在每年的12月或冬季最低，7月前后或夏季最高；PM_2.5、PM₁₀、NO₂、SO₂、CO与O₃之间的互为消长关系，在很大程度上取决于环境条件.     

2016年夏季淮安市大气污染特征及成因分析

根据淮安市2016年6-8月的大气环境监测数据,研究了淮安夏季大气污染特征、成因及应对措施。结果表明：2016年夏季淮安PM_2.5、PM₁₀、SO₂、CO、O₃日最大8 h和NO₂的平均浓度分别为38、68、13、847、138和18 μg m_-3,环境空气质量达标率达到67%,首要污染物为O₃和PM。O₃呈现单峰型日变化特征,PM则呈现三峰型。观测期间受偏东和偏南方向气流影响,O₃污染可能是高空高浓度臭氧混合到地面导致,且同时伴随着高浓度的PM污染。盛行风向城市和排放源区污染控制,可以有效降低城市大气污染物浓度。     

某地区PM2.5与居民呼吸系统疾病及恶性肿瘤死亡的时间序列研究

目的 基于广义相加模型定量分析某地级市大气污染物PM_2.5与居民呼吸系统疾病及恶性肿瘤死亡风险的相关性。方法 收集2016~2018年该地级市逐日PM_2.5浓度数据、气象数据、居民呼吸系统疾病及恶性肿瘤死亡数据，进行描述性统计分析；采用基于Quasi-Poisson回归的广义相加模型（GAM），分析PM_2.5与该市居民呼吸系统疾病和恶性肿瘤死亡风险间的相关关系。结果 2016~2018年该地级市大气PM_2.5日均值为49 μg/m³，共有631 d超出《环境空气质量标准》GB3095-2012污染物浓度一级限值标准，占三年总天数的57.6%；广义相加模型滞后效应（Lag0~Lag7）显示，PM_2.5浓度升高10 μg/m³，呼吸系统疾病死亡率在滞后5 d的影响最大(ER=0.699%（95%CI：0.121%~1.277%）)，恶性肿瘤死亡率在滞后3 d时的影响最大(ER=0.443%（95%CI：0.013%~0.873%）)；寒季（11月~4月）期间，PM_2.5浓度升高10 μg/m³，呼吸系统疾病死亡率在滞后6 d的影响最大(ER=0.952%（95%CI：0.269%~1.635%）)，恶性肿瘤死亡率在滞后1 d时的影响最大(ER=0.819%（95%CI：0.177%~1.461%）)。结论 该地级市PM_2.5浓度升高会引起呼吸系统疾病和恶性肿瘤死亡率增加，特别是在寒季，PM_2.5暴露对呼吸系统疾病的负性效应更显著。     

中国人为源颗粒物排放模型及2001年排放清单估算

颗粒物是影响我国城市空气质量的主要污染物, 且细颗粒物对区域和全球环境系统具有重要影响.了解颗粒物的源排放量及排放特征, 对开展颗粒物研究具有重要意义.文中按经济部门、燃料类型和技术类型对颗粒物排放源进行分类, 建立了一个基于技术的、自下而上的排放模型, 并利用该模型计算出2001年全国主要人为源共向大气排放TSP （总悬浮颗粒物） 2.651×10⁷t, PM₁₀（可吸入颗粒物） 1.712×10⁷t, PM_2.5（细颗粒物）1.210×10⁷t.水泥生产、生物质燃料和燃煤源是最主要的PM2.5排放源, 分别占PM2.5排放总量的35%，26%和20%.颗粒物排放的地区分布极不平衡, 主要集中在东部地区.排放量最大的5个省份为山东、河北、江苏、河南和广东.进一步将排放分配到0.5°×0.5°的网格, 从而为区域大气污染模拟研究提供基础数据.     

杭州市2014年城区大气污染物浓度变化特征观测分析

为了研究杭州市城区大气污染物的浓度变化特征,本文选取了2014年杭州市环境监测中心站空气质量自动监测站的大气污染物浓度数据,并结合地面气象要素资料进行分析,结果表明,在观测期间,杭州市城区大气中的PM_2.5污染状况最严重,日平均浓度的超标率达30.7%;各污染物全年分布呈现明显的季节变化：O₃浓度呈现与该季节气温和太阳辐射强度在全年中的排列相一致的夏、秋、春和冬季依次递减的分布,NO₂则呈现冬高夏低,春秋介于两者之间的分布,SO₂浓度从高到低依次为冬季>春季>秋季>夏季,CO、PM_2.5和PM₁₀浓度都呈现出冬高夏季、春秋季变化平缓的季节变化特征;各污染物浓度日变化呈现不同变化规律：O₃和O_x浓度四季的日变化都呈单峰型分布,浓度峰值都出现在13:00～15:00,SO₂也呈现单峰型分布,在09:00～10:00左右达到峰值,于次日04:00左右达到谷值,NO₂、CO、PM_2.5和PM₁₀浓度的日变化特征类似,呈现双峰型变化,且峰值都与早晚高峰时间基本重合,冬季相对于其他季节首峰值时间推迟一小时左右;利用成对样本T检验进行比较,结果表明：NO₂浓度在17:00～次日09:00工作日均明显高于周末,而在09:00～14:00工作日略低于周末,14:00～17:00浓度基本相等,O₃浓度则在工作日的各时刻均高于周末;气象要素是大气污染物分布的重要影响因子,O₃与气温和风速呈极显著正相关关系,与湿度呈极显著负相关关系,NO₂与之相反,SO₂、CO、PM_2.5和PM₁₀与风速呈现一致的显著负相关关系外,与其他气象要素在不同季节差异性较大,SO₂和PM₁₀与相对湿度呈现极显著负相关关系,CO和PM_2.5与气温和湿度的相关性在不尽相同。     

利用SPAMS研究石家庄市采暖结束前后大气细颗粒物污染特征及成因

2016年3月1日—20日期间,石家庄市区于采暖期结束前后出现两次重污染天气。为探究重污染天气成因,利用位于石家庄市大气自动监测站(20 m)的单颗粒气溶胶质谱仪(SPAMS)对两次重污染天气期间的细颗粒物化学组成进行分析,并结合颗粒物质量浓度和气象条件等对重污染天气成因进行了推定。结果表明,3月采暖期(3月1日—15日)期间共发生为期1d的重度污染天气,主要成因为来自燃煤(贡献率42.6%)和工业工艺源(26.4%)的颗粒物严重累积;采暖期结束后(3月16日—20日)出现了连续3d的重度污染天气,前期主要成因为来自机动车尾气(25.5~25.9%)和工业工艺源(23.0~25.5%)的颗粒物严重累积,后期首要污染源变为燃煤(28.6%)和工业工艺(27.4%)。监测过程中,PM_2.5与气象条件的相关性较高,r_湿度/2.5=0.76,r_{大气压/2.5}=-0.58,r_风速/2.5=-0.65,r_温度/2.5=0.35。综合来看,高湿状态下空气的低压静稳和低空传输,共同促使燃煤及工业工艺源的颗粒物累积,二次转化加剧后导致3月4日的重污染天气;而采暖期结束后,在同样不利于扩散的气象条件下,机动车尾气及工业工艺源的颗粒物累积,二次转化加剧,从而导致3月17和18日污染小高峰;不同于前两日,燃煤和工业工艺源的累积,二次转化加剧,导致了3月19日凌晨的污染小高峰。     

基于可视图的衡阳市大气污染物时间序列分析

为研究大气污染物时间序列的非线性特征,基于2016年1月至2017年12月衡阳市PM2.5和PM₁₀质量浓度时间序列,应用可视图方法将两组时间序列映射到复杂网络中,并研究了相应网络的拓扑性质。结果表明:PM2.5和PM₁₀浓度时间序列网络的平均聚类系数、直径、网络密度和平均路径长度等网络特征参数和统计特征参数基本相同。PM2.5浓度时间序列在局部变化趋于平缓,矩阵图中存在明显聚集现象;PM₁₀浓度时间序列存在多个局部峰值,矩阵图中表现为多个重叠的大正方形。两个时间序列网络的累积度分布都具有幂律特征,网络具有无标度特性。原时间序列具有分形序列特征,赫斯特指数均大于0.5,都是持续性时间序列,表明大气污染物浓度时间序列具有长程记忆性。     

严寒地区城市街谷底层可吸入颗粒物浓度分布

以东北三省的省会城市为代表,对街道峡谷底层的可吸入颗粒物(PM₁₀)的质量浓度进行了实地监测。街谷底层PM₁₀浓度分布状况既受到自然气候条件的制约,又受到以绿化植物为主的街谷设施以及人为活动的强烈影响,二者共同作用下形成了如下特征,为严寒地区城市规划设计以及道路绿化设计提供了理论依据：(1) 街谷设施扰乱了理想状态下的街谷气流,其所影响的范围约在0~22 m之间;(2)PM₁₀浓度在每日的9:00和18:00出现峰值,街谷绿化使颗粒物的扩散延迟了约3 h;(3)季节水平上街谷底层PM₁₀浓度差异显著,冬季高出夏季107 mg?m^_-3;(4)不同绿化郁闭度与疏透度对PM₁₀浓度的垂直分布与水平分布产生的影响,夏季均大于冬季。街谷绿化使PM₁₀滞留在9 m以下、两条隔离带之内的机动车道空间内,而在9~22 m的空间以及隔离带外侧的人行道空间里,颗粒物浓度得到消减;(5)街谷底层PM₁₀日均值与气象参数之间存在显著的线性相关性,相关性顺序为湿度＞温度＞风速。     

济南市冬季大气污染时空分布特征及潜在污染源区分析

利用2016—2018年冬季济南市大气主要污染物和气象监测数据,对大气污染特征及潜在源区进行分析。结果表明：2016—2018年冬季济南市环境空气中可吸入颗粒物PM₁₀和细颗粒物PM_2.5分别占首要污染物的34.7%和63.8%,轻度污染以上天数占总天数的58.6%,冬季高质量浓度PM_2.5导致年均值增加7.5μg/m³;从空间分布来看,PM₁₀与PM_2.5空间分布为天桥区、槐荫区及平阴县质量浓度较高,SO₂则为商河县和济阳区质量浓度偏高,NO₂和CO为济阳区、天桥区和槐荫区质量浓度较高;研究期间NO₂、CO、PM₁₀、PM_2.5的质量浓度呈正相关性,相关系数均在0.7以上,推断交通源、工业燃烧源、燃煤是颗粒物的主要来源;济南市冬季的气团输送为偏南、西北、偏北和偏东4个方向,偏南和偏东气团为影响济南市冬季大气污染主要输送路径。进一步研究潜在源区贡献...     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.