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41.
Experimental study of inlet manifold water injection on combustion and emissions of an automotive direct injection Diesel engine 总被引:1,自引:0,他引:1
This paper describes an experimental study conducted on a modern high speed common-rail automotive Diesel engine in order to evaluate the effects on combustion and pollutant emissions of water injected as a fine mist in the inlet manifold. 相似文献
42.
The cogeneration of heat and power by means of a fuel cell based CHP unit is a promising option for efficient residential power supply. For most applications natural gas is used as fuel. One main component of such a CHP unit is a fuel processor in order to generate hydrogen from the natural gas with hydrogen thermal power output of about 6 kW. Usually the steam reforming process is used for hydrogen production. In order to meet the heat demand of the endothermic steam reforming process the fuel processor is equipped with a burner, which has to work with natural gas during start up phase and mainly with the low calorific anodic off gas of the fuel cell stack during normal operation.The presented work is focused on aspects of the main pollutant emissions (carbon monoxide and nitrogen oxide) of burners integrated into the reformer. Experimental investigations of two different burners, which were developed and adapted to the steam reformer requirements, in a real fuel processor environment show, that it is possible to operate both burner concepts with high and low calorific gases with very low pollutant emissions in order to compete with emissions of current heating boilers, which are in the range of 15 mg kWh−1 for CO and of 20 mg kWh−1 for NOx by adjusting suitable excess air ratios in the range of 1.2-1.4.But it is also demonstrated, that the efficiency of the fuel processor is influenced by the excess air ratio. An increase of the air ratio from 1.05 to 1.45 leads to an decrease of the efficiency from 80% to 76%. This results in a conflict of objectives between low pollutant emissions and high system efficiencies. The choice of a suitable burner concept and the definition of a suitable operation strategy can be based on the presented results. Additionally, aspects like fuel processor geometry, flame monitoring, pressure drop in the burner feed gas line as well as in the flue gas duct, investment costs and safety items have also to be considered for the burner selection. 相似文献
43.
N. D. Singpurwalla 《技术计量学》2013,55(3):703-711
In this paper an attempt is made to show how certain empirical relationships observed in an analysis of air pollution data can be interpreted using extreme-value theory. In order to accomplish this, it was necessary to determine the limiting distribution of the maximum term of a random series from the lognormal law. Since an explicit development of this limiting distribution including a determination of the normalizing constants, is not available in the literature to the knowledge of this author, an appendix has been devoted to it. Potential applications of the extreme value theory to problems of air quality are pointed out. 相似文献
44.
按照《能源发展"十二五"规划》要求,"十二五"期间,我国煤炭深加工产业已经进入总结现有示范项目经验,并按照能量梯级利用、节能减排等要求稳步开展升级示范的新阶段。本文以我国现代煤化工产业为研究对象,探讨如何通过煤气化、多联产、动力岛优化配置等能量梯级利用先进技术,在兼顾公用工程动力供应可靠性要求的同时提高煤制烯烃等现代煤化工项目的整体能源转化效率,并探索一条既能满足我国当前最严厉环保与排放指导要求,又兼顾经济效益的产业升级新模式。研究认为,通过煤气化技术升级,优化配置动力岛及采用多联产等方案,满足国家对煤化工产业发展的全新要求并实现产业的健康可持续发展是可行的。 相似文献
45.
46.
本文根据贵冶各车间废水排放途径 ,分析了二期一步工程投运后 ,造成总排口排放废水中污染物浓度上升的原因 ,并阐述了我厂对排放废水采取的治理措施及实施效果。 相似文献
47.
Ezra L. Cates Marilyn J. Westphal John H. Cox Jon Calabria Steven C. Patch 《Canadian Metallurgical Quarterly》2009,135(7):511-517
A proprietary storm-water treatment system (Baysaver 1/2?K) was monitored as part of a low impact development project to assess pollutant removal efficiency and to model removal as a function of flow rate, season, and dry time. Twenty six storm events were sampled over a 12-month period and analyzed for total suspended solids, turbidity, conductivity, ammonia/ammonium, nitrate/nitrite, total phosphorus, total Zn, total Pb, and total Cu. The data were analyzed to determine which parameters showed significant removal by the device and whether or not the removal efficiencies were influenced by peak flow rate, season of the year, and/or dry time. Results indicated that the removal of each pollutant analyzed was statistically significant with the exception of conductivity, which showed higher outflow levels resulting in significant release of ions. Regression analyses revealed that all pollutants except for conductivity and total phosphorus showed significant negative relationships to peak flow rate and that conductivity and total Cu reductions were significantly related to the season of the year. 相似文献
48.
The investigation was carried out to reveal the impact of urban street layout on local atmospheric environment through computational fluid dynamics (CFD) numerical simulations using standard k–ε turbulence model. Different street canyon configurations are considered and the flow regimes summarized according to the aspect ratio of the leeward building height and the street width H1/W and the aspect ratio of the leeward building height and the windward building height H1/H2. Three regimes are defined to denote the vortices and characteristics of pollutant dispersion in street canyons according to the parameters H1/W and H1/H2. It is found that the pollutant transport and diffusion is strongly dependent upon the type of flow regime inside the canyon and exchange between canyon and the above roof air. The study indicated that there is a strong influence of the street layout on the wind field and the pollutant dispersion in the street canyon mainly depends on the vortex structure in the canyon. The results are validated against an extensive wind tunnel experimental (Meroney and Rafailidis) [Journal of Wind Engineering and Industrial Aerodynamics, 1996;62:37–56; http://www.mi.uni-hamburg.de] and the simulated results concluded by Sini [Atmospheric Environment 1996;30:2659–77] and Sang [Atmospheric Environment 2002;36:1137–45]. 相似文献
49.
应用小室模型对600MW燃煤锅炉炉内流动、燃烧、传热及污染物排放进行了一维数值仿真研究,得出了炉内温度和各个不同组分沿炉膛高度的分布.不同负荷下的仿真计算表明该模型能够反映不同负荷下炉膛内的热流密度分布的不同,从而弥补了零维模型和三维模拟的不足.仿真结果表明,炉内温度分布的高温区和低温区与各气体成份的分布存在很强的对应关系,同时表明采用小室模型可以对炉内复杂的物理化学过程进行有效的模拟,该模型可为锅炉设计、改造和运行提供理论指导. 相似文献
50.
《International Journal of Hydrogen Energy》2022,47(2):1092-1102
Multiple energy sources are combined to solve the shortage due to more and more energy consumption. Hydrogen as an ideal clean and renewable energy was injected to the porous media burner to realize the utilization with methane simultaneously. The numerical model of double-layer structure imported with multi-step kinetics mechanisms was built to study the effects of hydrogen injecting position and width on the combustion characteristics of methane after the experimental validation. Results indicate that the axial temperatures during the hydrogen injection at the upstream and interface positions were obviously higher than that at the downstream position. With the increasing of hydrogen injection width, the overall temperature gradually decreased, which was corresponding to the decreasing trend of CO and NOx emissions. However, the temperature and pollutant emissions increased as the equivalence ratio of methane and hydrogen increased. In addition, the increasing of methane and hydrogen velocity increased the CO emission and decreased the NOx emission. 相似文献