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101.
102.
温室效应和温室气体减排分析 总被引:3,自引:0,他引:3
人类活动所排放的温室气体在大气层中的不断增加和积累,使地球温室效应变得越来越严重。由于温室气体所造成的气候异常和由此引发的灾害无国界,因此解决温室气体排放是全人类共同的问题。为此,介绍了温室气体和温室效应,以及大气层中CO2浓度变化和世界排放CO2的情况;通过分析说明世界经济高速发展对化石燃料需求的不断增长,是第二次世界大战以来尤其是近20年来大气中CO2浓度快速增长的主要原因。同时还对排放CO2最多的发电和供热、交通运输、房屋建筑3大领域的节能和减排进行了分析,指出解决全球变暖问题需要人类的智慧、良知和理智。 相似文献
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Over the past few years, hydrogen has been recognized as a suitable substitute for present vehicular fuels. This paper covers the economic analysis of one of the most promising hydrogen production methods—using wind energy for producing hydrogen through electrolysis of seawater—with a concentration on the Indian transport sector. The analysis provides insights about several questions such as the advantages of offshore plants over coastal installations, economics of large wind-machine clusters, and comparison of cost of producing hydrogen with competing gasoline. Robustness of results has been checked by developing several scenarios such as fast/slow learning rates for wind systems for determining future trends. Results of this analysis show that use of hydrogen for transportation is not likely to be attractive before 2012, and that too with considerable learning in wind, electrolyzer and hydrogen storage technology. 相似文献
105.
Liao Jianxin Li Yuanzhen Li Tonghong Zhu Xiaomin Zhang Lei State Key Laboratory of Networking Switching Technology Beijing University of Posts Telecommunications Beijing China EBUPT Information Technology Co. Ltd Beijing China Technical University of Madrid Madrid Spain 《中国通信》2010,7(2):65-70
In this paper we analyze connectivity of one-dimensional Vehicular Ad Hoc Networks where vehicle gap distribution can be approximated by an exponential distribution. The probabilities of Vehicular Ad Hoc Network connectivity for difference cases are derived. Furthermore we proof that the nodes in a sub-interval [z1,z1 +Δz] of interval [0, z], z>0 where all the nodes are independently uniform distributed is a Poisson process and the relationship of Vehicle Ad hoc Networks and one-dimensional Ad Hoc networks ... 相似文献
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本文针对我国大城市中心区步行街区建设情况及其引发的交通矛盾,在分析步行街区交通特征的基础上,提出解决步行街区交通组织基本策略,从内部交通网络、内部与周围道路交通衔接、静态交通等方面提出了步行街区的交通组织对策,并从步行街区的布局、道路规划、出入口规划设计等方面探讨了步行街区的交通规划与设计,最后结合福州市三坊七巷步行街区交通组织进行实例分析。 相似文献
108.
《Energy Policy》2015
The CA-TIMES optimization model of the California Energy System (v1.5) is used to understand how California can meet the 2050 targets for greenhouse gas (GHG) emissions (80% below 1990 levels). This model represents energy supply and demand sectors in California and simulates the technology and resource requirements needed to meet projected energy service demands. The model includes assumptions on policy constraints, as well as technology and resource costs and availability. Multiple scenarios are developed to analyze the changes and investments in low-carbon electricity generation, alternative fuels and advanced vehicles in transportation, resource utilization, and efficiency improvements across many sectors. Results show that major energy transformations are needed but that achieving the 80% reduction goal for California is possible at reasonable average carbon reduction cost ($9 to $124/tonne CO2e at 4% discount rate) relative to a baseline scenario. Availability of low-carbon resources such as nuclear power, carbon capture and sequestration (CCS), biofuels, wind and solar generation, and demand reduction all serve to lower the mitigation costs, but CCS is a key technology for achieving the lowest mitigation costs. 相似文献
109.
在亚热带丘陵河谷地小流域范围内地表物质的迁移常可导致不同沉积区物质组成的变化 .从黄泥土→洪积泥砂土→培泥砂土 ,随着搬运距离的增加 ,其粘粒矿物组成发生了一系列的变化 ;高岭石逐渐下降 ,云母逐渐增加 ,蛭石渐趋下降消失 ,而绿泥石则逐渐形成 ;同时赤铁矿、针铁矿也先后下降消失 .矿物的演化与沉积物所处环境的水分条件及溶液中盐基物质和酸碱度变化有关 相似文献
110.
In rail freight transportation, general merchandise freight cars may pass through many classification stations on their route from origin to destination. The Railroad Blocking Problem (RBP) is to reclassify inbound traffic from various origins in the classification stations and put them on outbound trains with the same or close destinations, the objective of the RBP is to minimize the total operating costs of delivering all traffic on the railway network while satisfying the resource and capacity constraints at the stations and the priority constraints for shipments. In this paper, we introduce a new mathematic model which can comprehensively describe the blocking strategy and various combinations of multi-route O–D pairs in large scale railway network. Furthermore, we propose an improved Ant Colony (AC) algorithm for RPB, and a computational experiment derived from the real life instances of coal heavy haul rail network in north China is given. Experimental results verified the validation of the model and effectiveness of the algorithm. 相似文献