城市轨道交通PPP项目政府补贴模式对比研究

近年来,国内城市轨道交通项目往往采用PPP模式运作,PPP模式中可行性缺口补助机制采用不同的政府补贴模式应根据不同项目的特点决定。该文理论研究分析了PPP项目回报机制、补贴模式及其模型,并结合案例分析对比了不同补贴模式的特点及适用范围,旨在为轨道交通PPP项目选择合理的补贴模式,从而提高轨道交通项目运作效率,更好地发挥社会公共服务水平提供借鉴。     

基于模糊TOPSIS法的综合管廊项目PPP模式下风险评价管理分析

综合管廊建设项目属于市政综合基础设施建设项目，目前其主要问题是资金的问题，仅仅靠政府财政支持很难实现大规模建设，而PPP建设模式是近年来政府引入社会资本到社会公共基础设施建设中的新形式，PPP的引入为我国的社会基础设施建设发展提供了新机会。本文从投资者的角度出发，研究了PPP模式下综合管廊项目投资建设风险的影响因子，并确定了23个关键性的风险指标，构建出风险评价指标体系。运用模糊TOPSIS方法模型分析调查问卷的数据，计算出风险评价体系中的各项指标权重，同时结合工程案例，对所构建的综合管廊项目在PPP模式下的风险评价指标体系进行实际运用，并提出了风险管理控制办法。该方法最终将定性与定量因素很好地结合起来，对综合管廊项目PPP模式下投资方案进行风险评价，评价结果具有工程实践性，能够帮助投资者有效地评判和规避风险。     

PPP高速公路项目政府担保价值研究

交通基础设施项目具有投资高、风险高的特点.为了刺激社会资本的参与,政府基于交通需求量进行担保以降低交通基础设施项目的风险、实现共赢.首先,运用实物期权理论,探讨政府对高速公路基础设施交通量进行上下限担保的期权特性,并在风险共担的视阈下运用改进的Shapley值方法确定政府对超过交通量担保上限所带来的超额收益的分配比例;然后,结合应用Black-Scholes期权定价公式,对交通量波动条件下高速公路PPP项目的政府双边担保价值进行研究;最后,通过算例分析测度PPP高速公路项目的担保价值.     

公私合作制交通工程项目风险管理

交通工程采用公私合作制（PPP）模式有很多优点,同时也伴随着大量风险和障碍．分析了交通工程PPP项目存在的主要风险及其后果,提出了减轻公私双方风险的原则和方法,并按照风险公平分担的基本原则,即由最具控制能力且控制成本最低的那方承担风险,所得回报与所承担风险匹配,给出了不同风险的分担策略以减少项目成本和提高项目成功的可能性,提出了PPP项目风险度量的风险指数模型及其计算过程和方法．     

基于SNA的PPP项目风险及扩散机制研究

在对PPP项目风险因素进行系统识别和分析的基础上,以PPP项目常见风险因素为研究对象,通过网络化的视角建立了PPP项目风险因素关系网络模型.运用专家调查法和社会网络分析法更加系统地分析了PPP项目实施过程中可能面临的风险及各风险之间关系、传播机制,寻找出了PPP项目中关键的风险因素,发现其风险因素连锁反应链及起到关键中介作用的桥节点.本研究为PPP项目风险分析提供了一种形象化、针对性的创新研究范式,同时有助于PPP项目实施过程中风险管控.     

城市轨道交通PPP项目运营补贴测算

城市轨道交通(urban rail transit,URT,简称城轨)所具有的准经营性和准公共物品属性决定了政府和社会资本合作(public-private partnership,PPP)开发城轨项目具有一定的合理性。该文对采用PPP模式开发城轨项目进行分析,探讨开发城轨项目产生的外部效益与政府补贴之间的关系。在此基础上,参考政府指导性文件的要求,提出了城轨项目年度运营补贴的计算模型,对2012年北京地铁4号线政府运营补贴支出数额进行了测算;同时采用"有无对比法",以2012年北京地铁4号线为例,对其外部效益进行了测算。结果表明:2012年北京地铁4号线政府运营补贴支出数额明显低于该项目同年各项外部效益之和,说明该项目的政府运营补贴合理。     

交通基础设施PPP项目中政府治理对社会资本参与的影响研究——基于世界银行PPI数据库的实证分析

交通基础设施建设的相对不足如今已经成为制约许多国家经济发展的瓶颈.PPP模式的引入在一定程度上缓解了政府对交通基础设施建设的资金使用矛盾,而政府所扮演的角色也直接影响到PPP项目的成败.本文主要目的是确定政府治理对于社会资本参与交通基础设施PPP合作项目程度的决定因素.从世界银行PPI数据库中选取包含了低等及中等收入的发展中国家从1990—2017年共计7195个PPP项目的详细数据进行实证检验,建立了衡量政府治理能力的五个指标体系和以合同为基础的社会资本参与度四个等级,研究了政府治理对社会资本参与的影响.研究结果表明,公共部门的质量越高,私人参与交通基础设施的程度越大.     

基于产业组织理论的公私合营项目绩效改善路径研究

近年来,政府—社会合作模式(ppp)广受关注,但效果不尽人意。本文首先通过梳理文献总结出可改善的和不可改善的PPP项目绩效影响因素,又将可改善的绩效影响因素分成项目环境因素与项目管理因素,然后研究产业组织理论中SCP范式的适用条件以及其对于PPP行业的适用性,最后,使用SCP范式分析环境因素、管理因素和绩效关系,得到了PPP项目的EMP分析框架,进而提出PPP项目绩效改善的基本路径。研究结果表明,项目环境因素是影响PPP项目绩效的根本因素,管理因素为影响PPP项目绩效的直接因素。     

我国廉租房PPP模式风险分担分析——基于马科维茨模型

本文通过对廉租房项目PPP模式的风险进行识别分析,采用马科维茨模型对廉租房项目PPP模式的风险分担进行量化分析,并结合行为经济学的相关理论,放宽模型的的约束条件,最后得出接近实际建设和应用的廉租房项目PPP模式风险分担模型。     

基于结构方程的海绵城市PPP项目融资关键风险研究

海绵城市的建设可以有效的应对城市洪水和水资源短缺的现象,通过PPP的模式发展有效的解决了海绵城市建设所面对的资金缺口,促进了我国城市的可持续发展。因此,针对解决海绵城市PPP项目融资关键风险的相关研究留有空白的问题,采用结构方程模型(SEM)对海绵城市PPP相关风险进行了验证性因素分析(CFA),得到了其中的关键风险因素,以期为地方政府采取相应管理措施促进海绵城市项目的可持续发展提供参考,为私人资本减轻海绵城市PPP融资项目的风险提供帮助。     

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).     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.