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排序方式: 共有1570条查询结果,搜索用时 31 毫秒
71.
文章介绍了一种不使用蓄电池的风能并网电能互补LED路灯照明系统。白天风能并网发电;夜晚风能发电供路灯使用,并由电网电源补充夜晚风能发电的不足部分;系统无储能蓄电池,路灯使用LED作光源,可广泛应用于公园广场景点市郊公路住宅小区等的照明。  相似文献   
72.
针对当前摩托车单向器组件主要采用手工装配、装配效率低、随机性大、无法对装配过程实现有效管理控制的情况,为了易于对零件装配过程进行实时监测和提高生产效率,开发了一种智能摩托车单向器自动装配机。介绍了摩托车单向器自动装配机的上料系统、装配系统、检测系统和落料系统的机械结构,重点阐述了设备的气动系统设计,并进行了实验研究。结果表明,该设备可实现组成单向器的5种零件自动上料和装配,同时降低了操作人员的劳动强度,生产效率提高约50%。其气动系统噪音小、工作可靠,可应用于摩托车单向器的大批量生产。研究结果可为其他相似异形零件自动装配机的开发提供参考。  相似文献   
73.
ABSTRACT

Significant interest exists in the potential for electric vehicles (EVs) to be a source of greenhouse gas (GHG) abatement. In order to establish the extent to which EVs will deliver abatement, however, a realistic understanding of the electricity and transport sector GHG emissions impacts arising from different approaches to integrating EVs into the power system is required. A key issue in this regard is the extent to which GHG emissions are a function of where and when EV charging will be enabled (or disabled) by the provision of recharging infrastructure and implementation of charging management strategies by the electricity industry. This article presents an investigation of the GHG emissions arising from electricity and gasoline consumption by plug-in hybrid EVs under a range of standard EV-power system integration scenarios. An assessment framework is presented, and GHG emissions from EV use are assessed for the New South Wales (NSW) and South Australian (SA) pools of the Australian National Electricity Market (NEM) using retrospective electricity system generation data for 2011. Results highlight that there is a range of possible outcomes depending on the integration scenario and emissions accounting approach used. This range illustrates value of a temporally explicit assessment approach in capturing the temporal alignment of electricity sector emission intensity and EV charging. Results also show the importance of a clean electricity generation mix in order for EVs to provide a GHG abatement benefit beyond what would be achieved by a hybrid (but non-plug-in) vehicle. The extent to which overnight charging in NSW is observed to produce higher emissions relative to unmanaged charging also illustrates a possible trade-off between GHG emissions and benefits for electricity industry from EV charging at times of low demand.  相似文献   
74.
The Brazilian cities as well as many of the large urban centers in the world continue to expand, increasing the demand for mobility and transport, while, at the same time, the same cities are investing in greenhouse gas (GHG) mitigation to avoid climate change. Brazil's urbanization rate increased from 26% in 1940 to almost 70% in 1980. During this period, the Brazilian population tripled and the urban population multiplied by seven. In 2010, the transport sector in São Paulo accounted for 71% of the total emissions released by the energy sector. Ethanol has been considered a fuel with less greenhouse gas emissions, when compared with fossil fuels. However, ethanol production would have to double to meet the expected demand. Electric vehicles (EVs) market is expanding around the world, and is also an option to reduce the transport emissions, if powered by clean electricity. To assess whether the adoption of EVs might bring more benefits than the current ethanol, we develop prospective scenarios supported by the Long-range Energy Alternatives Planning (LEAP) simulation tool, taking a bottom-up tank-to-wheel approach to consider the CO2 emissions of car in São Paulo. The scenario considering a substitution of 25% of gasoline-powered cars by EV in 2030 showed a reduction in energy consumption and CO2 emissions, around 15% and 26% respectively in that year in comparison with 2015. We discuss the interplay between ethanol and EV, also considering emission coefficients from life cycle analysis conducted in Brazil, and concluded EV will have higher positive impact on climate change mitigation than ethanol.  相似文献   
75.
闫存富 《现代经济》2009,(11):85-86
数控机床故障诊断与维修课程是培养数控技术实用型人才的一门重要专业课,它的教学效果直接影响到数控技术人才的培养规格和质量。本文结合自己从事数控机床故障诊断与维修的教学及工作经验,介绍在数控机床故障诊断与维修教学中的一些方法和体会。  相似文献   
76.
利用模糊系统中的模糊规则和SVM中内积函数之间的关系,通过支持向量机对训练样本进行学习,由支持向量确定模糊规则,构建基于规则的模糊分类器。对人脸图像做独立成分分析,提取有利于分类的面部特征的主要独立成分。该模糊系统在ORL人脸库上的实验结果表明,该方法同样适合解决小样本、非线性、高维模式的分类问题。  相似文献   
77.
Humans are unable to effectively handle machines that have poor interface and interaction patterns. The Automated Teller Machine (ATM) is one of the machines that is most frequently operated by a wide spectrum of people. Hence, it is common to apply Human–Computer Interaction (HCI) technology in the design of ATMs. User–ATM interaction, however, has barriers such as a user’s working memory limit, lower literacy level, or lack of awareness and access. Moreover, the diversity of interfaces hurt user motivation, perception, and experience significantly. For example, each bank has its own ATM design targeting its customers only and, thus, when clients of other banks come across such a machine, they suffer from cognitive burden and commit many errors. To this end, we conduct an analytical survey of ATMs used in Pakistan through user analysis and heuristics analysis. We figure out the influence of design diversity and user perception on ATM users’ cognitive stress with the cognitive walkthrough analysis on the survey. We also uncover a realism-usability gap by reviewing the sampled ATM screens from the viewpoint of HCI heuristics. Finally, we suggest the guidelines on the cross-ATM design, characterized by the standardized fast-cash menu and the fail-safe mechanism for novices. This study demonstrates that users are reluctant to switch out of their comfort zones, due to learning costs and a lack of motivation. Therefore, we should design public systems in a very standardized way, which becomes more crucial for a user’s cognitive relief as interface and design patterns are becoming more diverse in our daily lives.  相似文献   
78.
王晖 《价值工程》2012,31(34):30-32
随着社会主义市场经济的发展以及科学技术的进步,电气自动化技术的应用越来越广泛。但在现实生活中,有很多不利的因素影响着电力系统的正常运转。因此,在电气自动化应用的过程中,将无功补偿技术应用其中,不仅可以提升电气自动化技术的经济性与安全性,而且可以减少电力浪费现象的发生。  相似文献   
79.
玻璃纤维筋是一种非常适用于NOMST工法的材料。文章介绍了玻璃纤维筋的物理力学性质。以珠江三角洲城际轨道交通广州至佛山段土建12标(西朗—鹤洞)盾构区间工程为应用背景,介绍了玻璃纤维筋围护桩的施工技术及盾构机采用NOMST工法直接切削玻璃纤维筋围护桩洞门进洞的施工技术。初步探讨了进洞过程中盾构推力对车站接收端墙的作用,采用有限元法进行了模拟分析,并在此基础上提出了NOMST工法进洞时盾构推力的确定方法。  相似文献   
80.
文章以AMADA公司生产的RG系列折弯机为例,介绍下动式折弯机几何精度调整的方法,为同类设备精度调整提供了参考。  相似文献   
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