城市交通规划与环境保护的协调对策探讨

城市的发展与城市交通联系密切,城市交通在为城市发展做出贡献的同时,也引发了若干环境污染问题。首先分析了我国道路交通系统现状特点,并尝试找出影响交通发展的原因;其次列举了城市交通带来的环境问题。在此基础上,从城市交通规划的角度提出通过城市道路网系统的优化与建设、交通方式结构优化、交通总量控制、交通管理等来控制交通污染的策略,实现可持续发展的城市交通规划,满足城市交通可持续发展的要求。     

基于能源消耗的城市交通结构优化

为支持可持续发展交通运输系统规划的理论体系的创立,引入交通容量、环境容量和方式能耗的概念,提出基于能源消耗的城市交通结构优化的思路、模型与方法,并进行了应用实例研究。该模型融入了影响城市交通结构的各种因素,使其最优解既能满足经济发展带来的交通需求,又能使交通的环境影响和资源消耗最小化,从而为可持续发展的交通运输系统的规划提供了可行的理论与方法。     

基于低碳模式下的城市交通结构优化模型研究

建立城市可持续发展的交通运输系统,不但要考虑交通出行效率目标最大化,还要使交通系统的资源消耗最小,环境污染最低。本文在以打造低碳城市的发展模式,针对出行的机动性和可达性,同时考虑环境容量、土地利用等约束条件来建立交通结构优化模型。     

城市客运交通供需结构非均衡SD模型

针对城市交通系统的复杂性与动态性,采用系统动力学方法,对城市各交通方式的需求与供给进行了影响因素分析。在确定研究主体模块的基础上,确定了系统边界,绘制因果关系图,并根据各影响因子的因果反馈关系绘制系统流图,选用有效的函数关系建立动力学方程,构建了城市交通结构的系统动力学模型(System Dynamics Model,简称SD模型)。通过分析各交通方式供需非均衡的形成机理与发展趋势,结合样本城市的交通发展状况,以VENSIM为平台进行了仿真分析。研究结果表明,不同交通方式的供给与需求是在非均衡的动态变化中维持相对均衡。     

南京市近期机动车发展规划研究

该课题以实现我市城市道路交通供应与需求协调平衡为目标,综合应用定量、定性分析技术,提出我市机动车交通需求与城市经济发展、城市客货运需求发展、城市道路交通设施供应规模相协调的合理发展模式,以及市区机动车拥有与使用的控制发展政策与措施,以实现城市交通可持续发展目标。该课题研究对机动车发展规划理论与方法进行了系统而有益的探索。     

沈阳市交通可持续发展水平综合分析

城市交通与城市人口规模、人口密度、布局形态以及市民生活方式等城市社会因素密切相关。城市人口规模、人口密度决定了城市交通需求,反过来,城市交通基础设施的规模和水平也影响和限制着城市人口规模的扩张程度和城市人口密度的变化。城市交通受经济、社会、资源与环境诸多因素影响。由于现有统计数据和相关资料的不完全,本文从实际出发在交通、经济、社会、资源和环境等方面选取21个指标对沈阳市交通可持续发展水平进行综合分析。     

基于出行的城市客运交通环境系统优化研究

构建了基于出行结构的城市客运交通环境系统优化模型。在系统分析的基础上, 使用系统动力学方法模拟城市客运交通环境系统的发展;建立线性优化模型求解在城市的资源环境等约束条件下, 以交通综合效率最大化为目标的最优出行结构;根据二者的结果, 设计城市交通发展的不同情景, 进行二次模拟;建立灰色关联评价模型对情景分析结果进行综合评价, 在社会经济条件支撑、政策可行、资源环境压力最小化的前提下, 得到城市客运交通环境系统出行结构的优化结果。最后通过北京市的案例研究, 验证了模型的有效性。     

城市客运结构评价体系及评价方法

根据系统分析原理和城市客运结构特性,从交通功能、经济效益、环境效益三方面建立了城市客运结构综合评价指标体系,探讨了不同交通方式特征指标的量化方法。根据最大效用理论与灰色系统理论的关联度原理,提出了城市现状客运结构与局部最优客运结构贴近度概念。依据3个不同子目标在综合评价中影响程度不同,通过加权计算,得到城市客运结构的综合评价模型。结合西安城市客运结构现状进行了实证分析,结果表明,该评价方法简便实用。     

基于交通环境承载力的城市人口容量预测研究——以太原市为例

城市人口容量研究不仅是城市总体规划的主要内容,对于城市控制性详细规划也起着一定的指导作用。道路交通资源作为承载人口的重要载体,本身具有一定的承载能力。基于交通环境承载力的城市人口容量研究对城市可持续发展有着重要的意义。本文以太原市为例,从道路交通资源承载角度,运用太原市交通模型,以城市交通系统车行道容量估算方法与OD反推两种方法为基底研究手段,结合太原市交通模型开发报告与太原市城市交通发展规划方式划分结果,进行基于交通环境的城市人口容量预测研究,运用此两种模型方法得到太原市规划年极限交通环境承载力条件下的人口容量,对比分析预测结果,论证该模型方法的可行性,并分析两种预测方法的适用性。     

综合客运枢纽旅客换乘交通方式分担模型

为了解客运换乘枢纽旅客交通方式选择分担率,对换乘枢纽旅客交通方式选择影响因素进行分析,认为交通方式选择是道路交通网络基础特性、公共交通配套设施布局特性等客观因素以及旅客出行特性、旅客偏好等主观因素相互作用直至均衡的过程。依据效用最大化理论,在交通方式选择行为模型的基础上,引入感知和态度2个心理变量,构建了随机效用函数模型,并对模型求解。选取某换乘枢纽站的3种交通方式为调查对象,抽样调查了各交通方式的属性值,量化分析了各因素对交通方式选择作用的大小,对各交通方式的分担率进行了计算。研究结果表明:效用最大化能很好地反映旅客在选择交通方式时的决策过程,从旅客的个体出发,综合考虑旅客个体行为能较为客观地计算出不同交通方式的分担量,模型具有较好的实用性。     

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.