城市道路机动车不同速度等效排污模型研究

为了向决策者提供科学有效的机动车污染控制措施,分析机动车污染的关键影响因素及机动车污染物排放规律的特征,并据此建立机动车污染排放模型,模拟城市区域或者主要道路的污染物排放.通过对机动车污染物排放量的等效性问题的研究,揭示实际路网机动车污染物排放与机动车不同速度的对应关系,建立机动车污染排放的数学模型,在有效控制机动车污染物排放量的基础上进行交通规划.     

天然气再燃烧还原NO_X的数值模拟

燃烧过程排放的氮氧化物（ＮＯＸ） 气体是危害很大、很难处理的大气污染物．降低燃烧过程中的ＮＯＸ排放有两类方法：一是降低ＮＯＸ的原始形成，第二类是还原已形成的ＮＯＸ；在还原已形成的ＮＯＸ 方法中，再燃烧（即部分燃烧后期喷入燃烧） 是当今世界前景看好的低ＮＯＸ 控制技术，它是利用燃料分级形成还原性气氛迫使ＮＯＸ分解来降低ＮＯＸ 形成的燃烧方法．其中，天然气做为再燃烧料已成功用于商业，并在其它措施的基础上再降低ＮＯＸ５０％ ～７０％ ．叙述了以天然气做为再燃烧料的再燃烧原理和途径，重点论述了采用无限快反应速率模型，并假定模拟烟气为层流或湍流粘性系数为常数的湍流情况下，运用有限差分及多重网格方法，计算出了这一还原反应过程的浓度场，得到了较为合理的结果．     

探索厦门市污染物减排策略和控制方案

正根据厦门市域各类污染源主要污染物排放总量及其对污染负荷贡献的研究,各区域大气主要污染控制指标SO2现有排放量低于环境容量,NOx现有排放量个别区域出现超过环境容量的情况应予以削减,水污染物控制指标在个别流域控制断面出现超过环境容量的情况应予以削减。采纳大气和水环境质量研究结论,本文根据污染排放情况和环境质量目标,提出主要污染物减排策略和控制方案。     

中国城市光化学烟雾污染研究

根据在兰州西固石油化工区,北京燕山石油化工区,北京地区和广州地区开展的光化学烟雾研究,讨论我国城市光化学烟雾的污染状况及其污染特征,探讨光化学烟雾的形成机制,并预测城市光化学烟雾的发展趋势。结果表明,上述地区存在严重的光化学烟雾污染,控制我国光化学烟雾污染的有效途径是降低ＮＯＸ排放;北京中关村大气Ｏ３最大小时浓度不仅逐年增加,而且出现Ｏ３最大值的时间也提前,说明大气光化学活性增强,随着机动车保明量     

珠江三角洲机动车污染控制的情景分析

针对珠江三角洲机动车污染物排放对区域大气环境影响日益突出的特点,以及机动车污染控制的迫切需求,利用情景分析方法对珠江三角洲未来不同机动车污染控制方案进行了分析和比较,并对2010年和2015年机动车保有量和主要污染物NOx、PM10和VOC排放量进行了预测分析。结果表明,在机动车持续快速增加的情况下,实行“禁摩”政策和提高机动车排放控制标准有助于大幅度减少珠江三角洲地区机动车污染物排放总量。     

街道峡谷汽车污染模拟研究

为了评价城市环境质量,需要准确模拟城市街道汽车排放污染物的扩散。该文利用道路边ＣＯ和ＮＯｘ的常年监测数据,系统测试了由丹麦国家环境研究所开发的街区空气污染扩散模式ＯＳＰＭ,分析了影响模拟精度的主要因素。针对北京市街道相对比较开阔的特点,在分析街道涡流和流场特征的基础上,修改了模式中街道风速的拟合关系,将地面风速系数增大到２．８倍,经实测数据验证,模拟效果有明显提高     

试论城市地区机动车污染与控制

本文评述了几个国家和地区机动车污染控制的先进经验,综合分析了我国机动车污染的现状及造成严重污染的原因,初步探讨了削减机动车污染物排放的综合对策与建议。     

中国大气污染控制策略与改进方向评析

中国目前区域复合污染现象突出, 现行大气环境质量管理制度安排无法反映这种污染形势的变化。现行的传统污染控制策略的局限性可以概括为: 单纯以主要污染物减排量作为最终控制目标缺乏有效性; 单一指标控制和属地管理模式使得区域总体和长期控制成本高昂。在总结国外经验的基础上, 提出以下政策建议: 在大气污染控制决策过程中应尽快把目标从减少污染物排放转变为减少环境损害(或提高环境质量效益); 污染控制应从单一污染物控制转向多种污染物控制; 应该基于共同发展、区域联防联控的原则, 建立基于区域大气环境管理的生态补偿机制。     

我国城市机动车污染控制对策初探

近年来,随着全国城市机动车保有量的持续增长,机动车污染物排放总量持续攀升,机动车已成为这些城市空气污染的第一大污染源.本文以广州为案例,探讨了我国城市机动车污染控制对策.     

北京市淘汰高污染排放车辆政策研究

鉴于机动车排放对北京市大气污染贡献较大,需以污染物减排为目标调整机动车控制政策。基于北京市机动车构成和污染贡献率的分析,作者提出优先淘汰高污染排放车辆的措施。该项措施的调控对象是机动车中污染贡献最大的车辆,与控制其他车辆相比,该措施可以在控制同等车辆数的情况下实现更大的环境效果。与"控制新增车辆"和"每周限行一天"措施的对比分析显示,优先淘汰高排放车辆措施具有更大的NOx减排潜力,对控制北京市大气污染及实现"十二五"NOx减排目标具有重要意义。综合考虑车主受偿意愿、机动车污染损害成本、淘汰补贴政策的激励方向以及政府的资金预算约束等方面,提出综合的政策建议,并建议采取单一的淘汰补贴标准,补贴水平应在4000~6000元/辆。优先淘汰高排放车辆政策的优势可以概括为:体现公共政策为环境负责的政策走向,体现政策设计的费用有效性,以及充分发挥经济手段的激励性等。     

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.     

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.     

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).     

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.