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排序方式: 共有96条查询结果,搜索用时 0 毫秒
1.
基于调研数据,对影响城镇水价收费制度改革的诸多因素进行了order probit模型的计量分析。研究发现,居民水费支出、收入水平和住房面积等因素,对收费制度改革具有显著的影响关系,而环保宣传、地区因素和居民个体特征因素的影响关系不显著。在此基础上,提出了城镇水价收费制度改革的对策建议。  相似文献   
2.
金融控股公司若干问题研究   总被引:1,自引:0,他引:1  
本文在广泛搜集近年来有关资料基础上,对金融控股公司的涵义、特征与必要性、利好与风险、问题与挑战、现状与成绩、模式选择与战略对策等内容进行了简要概述,初步勾画了金融控股公司理论体系的基本框架.  相似文献   
3.
厂长负责制是在发展多种所有制经济成份的背景下,为解决党企不分、以政代企问题而提出来的.实践证明,厂长负责制产生了大量的"穷庙富和尚"现象,应当进行改革.本文认为,只有构建国有资产管理新体制,由人大掌握国有资产的所有权,投资公司掌管投资方向,由企业负责生产经营,加强对国有资产的监管力度,这样才能保证国有企业的正常运行.  相似文献   
4.
基于复杂网络理论的电动汽车充电设施布局合理性研究   总被引:1,自引:0,他引:1  
王文涛  许献元 《技术经济》2017,36(7):97-109
提出了一种基于复杂网络理论构建电动汽车充电设施网络的模型,分别构建了上海、西安、合肥和大连的电动汽车充电设施网络,并分析了其电动汽车充电设施的运营情况以及布局的合理性。通过构建理想情况下的电动汽车充电设施网络,研究电动汽车充电设施网络的发展趋势。仿真结果显示:电动汽车充电设施网络的结构对电动汽车充电设施的利用率和稳定性有显著影响——该研究结果在实际网络中得到了验证。  相似文献   
5.
重庆"钉子户"事件引起了社会的广泛关注。该事件的产生涉及若干《物权法》上的问题,也反映了目前我国城市房屋拆迁制度存在的缺陷。弥补这些缺陷应在《物权法》中明确界定"公共利益"的范围、确定拆迁补偿的规则,从而进一步完善《物权法》中的征收制度。  相似文献   
6.
从我国高校收费的由来至目前高校收费及其管理现状到高校收费管理制度的改革和建议,浅议了在实行高等教育全面收费制度的今天,如何加强高校收费管理,制止各种乱收费现象,并尝试构建切实可行的高校收费管理制度.  相似文献   
7.
介绍了一种基于单片机与专用集成PWM控制器SG3525的锌银蓄电池充电机。在分析锌银蓄电池特性基础上,采用模糊算法控制和单片机智能控制,对充电状态实时监控,并采用分段式充电方案,提高充电稳定性,克服了电压突变等带来的充电假结束或不饱和的缺点。通过在常规的BUCK充电电路中设计2只开关管轮流导通方式,使开关管工作在轮流导通状态,并通过实验进行验证,解决了驱动电路变压器驱动能力问题。  相似文献   
8.
Electric vehicles (EVs) are energy efficient and often presented as a zero-emission transport mode to achieve long-term decarbonization visions in the transport sector. The implementation of a sustainable transportation environment through EV utilization, however, requires the addressing of certain cost and environmental concerns such as limited driving range and battery-charging issues before its full potential can be realized. Nevertheless, a specific type of use of EVs, namely in taxi services, may elicit positive public opinion, as it promises a commitment toward sustainability in urban life. In light of this, this study proposes an integrated approach that combines EV operation with a conceptual design for shared-ride taxi services. As some productivity loss may be naturally expected due to the time spent in charging, it is important to look at whether such performance loss from the passenger and system standpoints can be offset with ingenuity in operational design. In this study, an EV taxi charge-replenishing scheme that can be coupled with a real-time taxi-dispatch algorithm is designed. The proposed EV charging schemes for taxi services are studied via simulations and the effects of the limited driving range and battery-charging details are examined from a system performance viewpoint. The simulation study also reveals illustrative results on the impact of the EV taxi fleet's operation on the charging system. Next, a real-time shared-taxi operation scheme that allows ride sharing with other passengers is proposed to maximize the operational efficiency. The simulation results suggest that the shared-taxi concept can be a viable option to improve on the limitations caused by EV operation. In addition, the importance of projected charging demands and queue delays at different charging locations are also addressed. Some limitations and a future research agenda are also discussed.  相似文献   
9.
In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage data sets that represent US household driving patterns, as well as the automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. Faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.  相似文献   
10.
The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept.  相似文献   
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