全文获取类型
收费全文 | 341篇 |
免费 | 21篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 77篇 |
综合类 | 6篇 |
化学工业 | 19篇 |
机械仪表 | 2篇 |
建筑科学 | 35篇 |
矿业工程 | 1篇 |
能源动力 | 212篇 |
轻工业 | 1篇 |
石油天然气 | 1篇 |
无线电 | 1篇 |
一般工业技术 | 5篇 |
冶金工业 | 1篇 |
原子能技术 | 1篇 |
自动化技术 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 16篇 |
2018年 | 12篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 18篇 |
2013年 | 25篇 |
2012年 | 18篇 |
2011年 | 44篇 |
2010年 | 29篇 |
2009年 | 27篇 |
2008年 | 32篇 |
2007年 | 22篇 |
2006年 | 20篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有366条查询结果,搜索用时 109 毫秒
41.
From viewpoints of the environment and fuel cost reduction, small-scale biomass combined heat and power (CHP) plants are in demand, especially wood-waste fueled system, which are simple to operate and maintenance-free with high thermal efficiency similar to oil fired units. These are requested by wood and other industries located in mountainous region. To meet these requirements, a Stirling engine CHP system combined with simplified biomass combustion process with pulverized wood powder was developed.In an R&D project started in 2004 considering wood powder properties as a fuel, combustion performance and emissions in combustion flue gas were tested using combustion test apparatus with commercial size units. The wood powder combustion system was modified and optimized during the combustion test results, and the design of the demonstration plant combined with 55 kWe Stirling engine power unit was considered. The demonstration plant was finally completed in March of 2006, and test operation has been progressed for the future commercial CHP system.In the wood powder combustion test, wood powder of less than 500 μm is mainly used, and a combustion chamber length of 3 m is applied. In these conditions, the air ratio can be reduced to 1.1 without increasing CO emission of less than 10 ppm and combustion efficiency of 99.9%. In the same conditions, NOx emission is estimated to be less than 120 ppm (6% O2 basis). Wood powder was confirmed to have excellent properties as a fuel for Stirling engine CHP system. This paper summarizes the wood powder combustion test, and presents the evaluation of the burner design parameters for the biomass Stirling engine system. 相似文献
42.
43.
热电联供是目前火电机组大幅降低CO2排放的唯一可行途径。针对大型火电机组热电联供,提出了带调节及切除功能的前置低压缸供热方案,可以解决大型机组差胀大的问题,缓解常规方案中较低电负荷或较大热负荷时节流损失、回热系统损失和余速损失的增加。通过对一次和二次再热机组实例的计算定量分析表明,带调节及切除功能的前置低压缸供热方案的经济性更优。 相似文献
44.
45.
46.
47.
Blending H2 with natural gas in spark ignition engines can increase for electric efficiency. In-situ H2 production for spark ignition engines fuelled by natural gas has therefore been investigated recently, and reformed exhaust gas recirculation (RGR) has been identified a potentially advantageous approach: RGR uses the steam and O2 contained in exhaust gases under lean combustion, for reforming natural gas and producing H2, CO, and CO2. In this paper, an alternative approach is introduced: air gas reforming circulation (AGRC). AGRC uses directly the O2 contained in air, rendering the chemical pathway comparable to partial oxidation. Formulations based on palladium and platinum have been selected as potential catalysts. With AGRC, the concentrations of the constituents of the reformed gas are approximately 25% hydrogen, 10% carbon monoxide, 8% unconverted hydrocarbons and 55% nitrogen. Experimental results are presented for the electric efficiency and exhaust gas (CO and HC) composition of the overall system (SI engine equipped with AGRC). It is demonstrated that the electric efficiency can increase for specific ratios of air to natural gas over the catalyst. Although the electric efficiency gain with AGRC is modest at around 0.2%, AGRC can be cost effective because of its straightforward and inexpensive implementation. Misfiring and knock were both not observed in the tests reported here. Nevertheless, technical means of avoiding knock are described by adjusting the main flow of natural gas and the additional flow of AGRC. 相似文献
48.
Yasmine Ammar Sharon JoyceRosemary Norman Yaodong WangAnthony P. Roskilly 《Applied Energy》2012,89(1):3-20
Thermal energy loss in the process industry is a significant issue due to the high temperatures and multiple heat intensive processes involved. High-grade thermal energy is typically recovered within processes. However, lower grade heat is often rejected to the environment.The benefits of capturing and utilising low grade thermal energy are highly dependent on the qualities and properties of the heat in the waste streams. The temperature of the low grade heat stream is the most important parameter, as the effective use of the residual heat or the efficiency of energy recovery from the low grade heat sources will mainly depend on the temperature difference between the source and a suitable sink, e.g. another process or space heating/cooling. In general, the temperatures of these waste heat sources are too low to produce electricity and direct heat use will depend on whether potential user can be found.This paper presents past and current drivers for heat recovery studies. High and low grade heat sources are defined according to the viability of recovery within the processes. Firstly, high grade heat capture within the processes is reviewed. Then, the focus is on the potential for low grade heat capture outside of the original plant. The paper addresses the potential for low grade heat recovery with regard to new incentives and technological advances. Finally, different aspects which influence the decision making for low grade heat recovery in the process industry are discussed. It is concluded that organisational, financial and economic barriers might be overcome and benefits from a holistic vision could be gained with stronger governmental policy and regulation incentives. 相似文献
49.
50.
Oscar van Vliet Anne Sjoerd BrouwerTakeshi Kuramochi Machteld van den BroekAndré Faaij 《Journal of power sources》2011,196(4):2298-2310
We examine efficiency, costs and greenhouse gas emissions of current and future electric cars (EV), including the impact from charging EV on electricity demand and infrastructure for generation and distribution.Uncoordinated charging would increase national peak load by 7% at 30% penetration rate of EV and household peak load by 54%, which may exceed the capacity of existing electricity distribution infrastructure. At 30% penetration of EV, off-peak charging would result in a 20% higher, more stable base load and no additional peak load at the national level and up to 7% higher peak load at the household level. Therefore, if off-peak charging is successfully introduced, electric driving need not require additional generation capacity, even in case of 100% switch to electric vehicles.GHG emissions from electric driving depend most on the fuel type (coal or natural gas) used in the generation of electricity for charging, and range between 0 g km−1 (using renewables) and 155 g km−1 (using electricity from an old coal-based plant). Based on the generation capacity projected for the Netherlands in 2015, electricity for EV charging would largely be generated using natural gas, emitting 35-77 g CO2 eq km−1.We find that total cost of ownership (TCO) of current EV are uncompetitive with regular cars and series hybrid cars by more than 800 € year−1. TCO of future wheel motor PHEV may become competitive when batteries cost 400 € kWh−1, even without tax incentives, as long as one battery pack can last for the lifespan of the vehicle. However, TCO of future battery powered cars is at least 25% higher than of series hybrid or regular cars. This cost gap remains unless cost of batteries drops to 150 € kWh−1 in the future. Variations in driving cost from charging patterns have negligible influence on TCO.GHG abatement costs using plug-in hybrid cars are currently 400-1400 € tonne−1 CO2 eq and may come down to −100 to 300 € tonne−1. Abatement cost using battery powered cars are currently above 1900 € tonne−1 and are not projected to drop below 300-800 € tonne−1. 相似文献