为了能够精确预测短期电价为市场参与者提供有效的决策指导,首先对电价数据进行水平处理,然后建立BP神经网络(BPNN)和最小二乘支持向量机(LSSVM)组合变权模型(BP LSSVM),同时提出采用遗传算法(GA)对该组合变权模型的权重进行优化,最后...为了能够精确预测短期电价为市场参与者提供有效的决策指导,首先对电价数据进行水平处理,然后建立BP神经网络(BPNN)和最小二乘支持向量机(LSSVM)组合变权模型(BP LSSVM),同时提出采用遗传算法(GA)对该组合变权模型的权重进行优化,最后将权重优化之后的GA BP LSSVM模型应用于美国PJM电力市场的边际电价预测,并与传统的LSSVM与BPNN的预测结果进行比较,结果表明,该组合变权模型能够提供更加精确的预测电价。展开更多
采用激光熔覆设备在不锈钢片和40Cr钢表面制得Al2Co Cr Cu0.5Fe Mo Ni Ti高熵合金涂层,对涂层进行退火和拉伸变形,并采用X射线衍射仪、扫描电子显微镜和显微硬度计对涂层进行测试。结果表明,熔覆涂层经过抛光和王水腐蚀后,显微形貌为胞...采用激光熔覆设备在不锈钢片和40Cr钢表面制得Al2Co Cr Cu0.5Fe Mo Ni Ti高熵合金涂层,对涂层进行退火和拉伸变形,并采用X射线衍射仪、扫描电子显微镜和显微硬度计对涂层进行测试。结果表明,熔覆涂层经过抛光和王水腐蚀后,显微形貌为胞粒状特征。300℃退火对涂层硬度没有影响;500~700℃退火后,涂层硬度提高,说明涂层具有时效硬化效应。涂覆态涂层由bcc单相组成,300℃退火后,涂层保持稳定的相结构。拉伸变形后,涂层的衍射峰强度增加,晶界清晰;硬度则随变形量增加先降低后提高。涂层具有良好的附着性能,除了断口附近出现涂层脱落外,其他位置的涂层都保持良好的附着状态。展开更多
CVD diamond films were synthesized by the chemical vapor deposition method.The crystal boundary was investigated using transmission electron microscopy and scan electron microscopy.The second grains facilitate the mor...CVD diamond films were synthesized by the chemical vapor deposition method.The crystal boundary was investigated using transmission electron microscopy and scan electron microscopy.The second grains facilitate the more compact film formation.No micro-holes are seen among diamond grains in the films but there are micro-holes in the interface of film/substrate.The second grain and the primary grain would keep the twin relationship of<110/70.5°.A lot of micro-twins are observed in fivefold twin grains but there is a zone of non twins which is like a strip along the fivefold twin boundary.Two microtwins keep the twin relationship of<110/70.5° with the fivefold twin matrix.The width and length of microtwins are about 3 nm and 32 nm,respectively.展开更多
文摘为了能够精确预测短期电价为市场参与者提供有效的决策指导,首先对电价数据进行水平处理,然后建立BP神经网络(BPNN)和最小二乘支持向量机(LSSVM)组合变权模型(BP LSSVM),同时提出采用遗传算法(GA)对该组合变权模型的权重进行优化,最后将权重优化之后的GA BP LSSVM模型应用于美国PJM电力市场的边际电价预测,并与传统的LSSVM与BPNN的预测结果进行比较,结果表明,该组合变权模型能够提供更加精确的预测电价。
文摘采用激光熔覆设备在不锈钢片和40Cr钢表面制得Al2Co Cr Cu0.5Fe Mo Ni Ti高熵合金涂层,对涂层进行退火和拉伸变形,并采用X射线衍射仪、扫描电子显微镜和显微硬度计对涂层进行测试。结果表明,熔覆涂层经过抛光和王水腐蚀后,显微形貌为胞粒状特征。300℃退火对涂层硬度没有影响;500~700℃退火后,涂层硬度提高,说明涂层具有时效硬化效应。涂覆态涂层由bcc单相组成,300℃退火后,涂层保持稳定的相结构。拉伸变形后,涂层的衍射峰强度增加,晶界清晰;硬度则随变形量增加先降低后提高。涂层具有良好的附着性能,除了断口附近出现涂层脱落外,其他位置的涂层都保持良好的附着状态。
基金Item Sponsored by the Guangdong Provincial Natural Science Foundation Under Grant No.04300026the Jiangmen Science and Technology Projectthe Project of Jiangmen Polytechnic
文摘CVD diamond films were synthesized by the chemical vapor deposition method.The crystal boundary was investigated using transmission electron microscopy and scan electron microscopy.The second grains facilitate the more compact film formation.No micro-holes are seen among diamond grains in the films but there are micro-holes in the interface of film/substrate.The second grain and the primary grain would keep the twin relationship of<110/70.5°.A lot of micro-twins are observed in fivefold twin grains but there is a zone of non twins which is like a strip along the fivefold twin boundary.Two microtwins keep the twin relationship of<110/70.5° with the fivefold twin matrix.The width and length of microtwins are about 3 nm and 32 nm,respectively.
