The economy of the fishing industry is suffering from high fuel prices. Considerable efforts are invested in methods to increase the energy efficiency of fishing vessels and reducing the oil consumption per kilo of ca...The economy of the fishing industry is suffering from high fuel prices. Considerable efforts are invested in methods to increase the energy efficiency of fishing vessels and reducing the oil consumption per kilo of catch that may be as high as 0.6 to 0.7 liter oil per kilo catch. It is primarily the fact that sailing and fishing are on two very different speeds that cause these high fuel consumptions. This is called the two-speed problem and it is the trawlers that are hit hardest by it. The essence of the two-speed problem is that a hydraulic efficiency of only 28% can be expected in trawling speed, when it would be 67% if the ship is sailing at optimum speed all the time. Hydrodynamical analysis shows that an average hydraulic efficiency of only 41% can be expected for a trawler. There is no simple remedy for this, but it is possible to use a technology developed in the hydropower industry, i.e. a draft tube, or a diffuser, to recover energy that would otherwise be lost when trawling. A draft of tube the same length as the propellers diameter could mean fuel savings of 10%, a draft tube twice as long 20%. The difficulty is to find a way to get the draft tube out of the water during sailing with a vessel-specific mechanical design that is not a part of the fluid dynamics of the problem and not discussed in the paper.展开更多
The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was ...The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was established by the method of whole life cycle. The energy consumption of the rural residential buildings in different stages was analyzed through quantitative method in this model. At the same time, the corresponding energy efficiency assessment system was developed.展开更多
TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its el...TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs.展开更多
为提高电力用户能效评估的客观性和准确性,并满足用户对于用电能效及时反馈调整的需求,提出一种在边缘架构下实时动态评估电力用户能效的方法。在构建边缘侧评估框架的基础上,首先,基于“压力-状态-响应”概念模型分析指标间的动态逻辑...为提高电力用户能效评估的客观性和准确性,并满足用户对于用电能效及时反馈调整的需求,提出一种在边缘架构下实时动态评估电力用户能效的方法。在构建边缘侧评估框架的基础上,首先,基于“压力-状态-响应”概念模型分析指标间的动态逻辑关系,从多维度选取动态评价指标,构建用户能效评估指标集合。考虑到边缘节点存储资源的受限,从集合中抽象出指标的重要性、均衡性、独立性三重指标属性进行量化,通过影响度和优化度模型对3种属性的量化值进行融合,并采用合作博弈论优选边缘侧精简指标集,从而有效地对边缘侧数据去冗余。其次,基于CRITIC(criteria importance though intercrieria correlation)权重计算法,充分利用指标的数据信息,对本方法所提指标赋予更为客观的权重系数。最后,通过改进灰色TOPSIS(technique for order preference by similarity to an ideal solution)评估方法构造绝对理想解,以有效避免用户数量动态变化时所产生的逆排序问题,引入的灰色关联度可弥补传统方法中欧式判据无法准确衡量用户优劣性的缺陷。结果表明,所提边缘能效评估方法不仅大幅降低了数据存储的需求,评估结果的可靠性和鲁棒性也得到了充分保证,这对于减少数据上传规模、快速完成用户能效评价方面具有明显优势。展开更多
文摘The economy of the fishing industry is suffering from high fuel prices. Considerable efforts are invested in methods to increase the energy efficiency of fishing vessels and reducing the oil consumption per kilo of catch that may be as high as 0.6 to 0.7 liter oil per kilo catch. It is primarily the fact that sailing and fishing are on two very different speeds that cause these high fuel consumptions. This is called the two-speed problem and it is the trawlers that are hit hardest by it. The essence of the two-speed problem is that a hydraulic efficiency of only 28% can be expected in trawling speed, when it would be 67% if the ship is sailing at optimum speed all the time. Hydrodynamical analysis shows that an average hydraulic efficiency of only 41% can be expected for a trawler. There is no simple remedy for this, but it is possible to use a technology developed in the hydropower industry, i.e. a draft tube, or a diffuser, to recover energy that would otherwise be lost when trawling. A draft of tube the same length as the propellers diameter could mean fuel savings of 10%, a draft tube twice as long 20%. The difficulty is to find a way to get the draft tube out of the water during sailing with a vessel-specific mechanical design that is not a part of the fluid dynamics of the problem and not discussed in the paper.
文摘The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was established by the method of whole life cycle. The energy consumption of the rural residential buildings in different stages was analyzed through quantitative method in this model. At the same time, the corresponding energy efficiency assessment system was developed.
基金Supported by the National High Technology Research and Development Programme of China （No. 2007AA01Z221, 2009AA01Z246） and the National Natural Science Foundation of China （No. 60832009）.
基金the support from the Brook Byers Institute for Sustainable Systems,Hightower ChairGeorgia Research Alliance at the Georgia Institute of Technology。
文摘TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs.
文摘为提高电力用户能效评估的客观性和准确性,并满足用户对于用电能效及时反馈调整的需求,提出一种在边缘架构下实时动态评估电力用户能效的方法。在构建边缘侧评估框架的基础上,首先,基于“压力-状态-响应”概念模型分析指标间的动态逻辑关系,从多维度选取动态评价指标,构建用户能效评估指标集合。考虑到边缘节点存储资源的受限,从集合中抽象出指标的重要性、均衡性、独立性三重指标属性进行量化,通过影响度和优化度模型对3种属性的量化值进行融合,并采用合作博弈论优选边缘侧精简指标集,从而有效地对边缘侧数据去冗余。其次,基于CRITIC(criteria importance though intercrieria correlation)权重计算法,充分利用指标的数据信息,对本方法所提指标赋予更为客观的权重系数。最后,通过改进灰色TOPSIS(technique for order preference by similarity to an ideal solution)评估方法构造绝对理想解,以有效避免用户数量动态变化时所产生的逆排序问题,引入的灰色关联度可弥补传统方法中欧式判据无法准确衡量用户优劣性的缺陷。结果表明,所提边缘能效评估方法不仅大幅降低了数据存储的需求,评估结果的可靠性和鲁棒性也得到了充分保证,这对于减少数据上传规模、快速完成用户能效评价方面具有明显优势。
