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排序方式: 共有913条查询结果,搜索用时 15 毫秒
21.
22.
In operation, risk arising from power transformer faults is of much uncertainty and complicacy. To timely and objectively
control the risks, a transformer risk assessment method based on fuzzy analytic hierarchy process (FAHP) and artificial neural
network (ANN) from the perspective of accuracy and quickness is proposed. An analytic hierarchy process model for the transformer
risk assessment is built by analysis of the risk factors affecting the transformer risk level and the weight relation of each
risk factor in transformer risk calculation is analyzed by application of fuzzy consistency judgment matrix; with utilization
of adaptive ability and nonlinear mapping ability of the ANN, the risk factors with large weights are used as input of neutral
network, and thus intelligent quantitative assessment of transformer risk is realized. The simulation result shows that the
proposed method increases the speed and accuracy of the risk assessment and can provide feasible decision basis for the transformer
risk management and maintenance decisions. 相似文献
23.
A series of Ag, Cu and Co-doped manganese oxide octahedral molecular sieves (OMS-2) were synthesized and evaluated to remove
nitrogen oxides (NO
x
) from cigarette mainstream smoke. The three kinds of catalysts were added to cigarettes for studying the capabilities of
reducing NO
x
from cigarette mainstream smoke. The catalysis and reduction of NO in laboratory were studied. A mechanism for NO
x
catalytic reduction from burning cigarettes with the catalysts adding to cigarettes was described. The catalysts show excellent
catalytic activity for NO
x
removal, especially the Ag-doped OMS-2 catalyst. 0.5% (mass fraction) Ag-doped OMS-2 catalyst has the best ability to remove
NO
x
from cigarette mainstream smoke. The use of Ag-doped OMS-2 as catalyst for removing carcinogenic compounds from cigarette
smoke will be an effective strategy to protect the environment and public health. 相似文献
24.
为解决多源监测信息间可能存在冲突的问题,利用D-S证据理论中的突出关键证据作用、弱化冲突证据影响的折扣系数法,建立了高拱坝多效应量冲突证据融合评价模型,并给出了一个工程实例。该模型可以合理、有效地弱化存在冲突的监测信息对高拱坝安全综合评价的不利影响。 相似文献
25.
随着计算机网络与通信、心理学、人工智能等技术的飞速发展,通过网络进行在线教育的模式越来越受到人们的欢迎。但是绝大多数职高学生因为学习习惯较差、学习方法不当、注意力集中时间较短等原因,通过网络在线学习往往不能取得较好的学习效果。针对这一原因,在前人研究的情感模型的基础上进行完善,引入非认知因素,如学习个体的个性特征、外界刺激等,及时对学生在线学习中情感的变化做出相关的反应,使职高学生在线学习时达到更好的学习效果。 相似文献
26.
Ji-Ming Hu Xiang-Lian Liu Jian-Qing Zhang Chu-Nan Cao 《Progress in Organic Coatings》2006,55(4):388-392
Nd–Fe–B type permanent magnets present excellent magnetic properties. However, they are highly sensitive to the attack of corrosive environment. The aim of the present work is to describe the improvement of corrosion resistance of such magnets by dodecyl trimethoxysilane (DTMS) treatment. Electrochemical impedance spectroscopy (EIS) tests showed that, after treated by either DTMS, phosphate or chromate precursor, the protectiveness of Nd–Fe–B alloys was apparently increased. Corrosion performance of magnet treated with silane only was slightly inferior to those of phosphatized or chromatized ones. However, significant improvement in corrosion protection was achieved after two-step treatments, i.e. by top-coating silane films on phosphate or chromate under-layer. The depth profiles of element concentrations on surfaces measured by secondary ion mass spectroscopy (SIMS) indicate a two-layer surface structure for two-step treated samples. Co-existing of silane and phosphate or chromate was detected in the top-layer, suggesting the interaction between the two components. This results in the formation of more stable structure of hybrid organ–inorganic coatings against the attack of corrosive species. 相似文献
27.
目前织染工业排出的污水一般经活性污泥作用被中和后排放,这种废水处理厂排放出的水因其残余COD,电导率较高仍不适于再利用.通过把重心集中在用纳膜技术与化学氧化法相结合处理经活性污泥处理后的织染废水,筛选出合适的纳滤膜,并对工艺流程及操作条件进行探讨. 相似文献
28.
在NdFeB废料经硫酸溶解回收稀土后的高铁、低钴硫酸溶液中,采用添加铁屑、硫化钠、硫磺的硫化沉淀法回收钴,取得了较好的效果,钴的沉淀率大于99%,且沉淀物中钴含量可达8%(质量分数)。该法的最佳工艺条件是:Fe:Co=1.5,Na2S:Co=2,S:Co=0.5,t=70℃、pH=2,反应及沉淀时间为1h。 相似文献
29.
30.
《International Journal of Hydrogen Energy》2019,44(47):26063-26075
The need of fast regulation of electricity production leads to a number of inconveniences occurred to the electric generation system and the electric market, especially to the nuclear power. A new concept to control nuclear power production is posed in order to allow the regulation of the electricity sent to the grid. This concept proposes the joint operation of a nuclear power plant, a coal power plant with postcombustion capture and a methanation plant. The cost effectiveness of this technology and its capability to reduce the CO2 emissions -consumed in the methanation process- are assessed through the design and economic and environmental analysis of a hybrid facility. Mainly due to the increase of the operating hours of the coal-fired power plant, the environmental feasibility of the initial proposal seems to be limited. However, given that benefits are expected in the medium and long-term (2020–2030) for the Power to Gas facility, a future alternative use is proposed. The target of this new alternative configuration will be the storage of CO2 together with the storage of renewable energy. 相似文献