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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
YANG DeChang REHTANZ C. LI Yong &TANG Wei Institute of Power Systems Power Economics TU-Dortmund Dortmund Germany College of Information Electrical Engineering China Agricultural University Beijing China 《中国科学:信息科学(英文版)》2011,(9)
In this paper,a novel method that integrates the improved empirical mode decomposition(EMD)and signal energy algorithm is proposed to estimate the dominant oscillation parameters and corresponding mode shape.Firstly,the EMD with symmetrical extrema extension(SEE)is utilized to decompose the measured data from wide area measurement system(WAMS)into a finite set of intrinsic mode functions(IMFs).Then,the signal energy algorithm is used to calculate the approximate oscillation parameters of the IMFs.The nodes ... 相似文献
992.
在当今大规模建设保障性住房的背景下,提出保障性住房建设的三种建构模式:水平界面的建构模式——东西向布局、垂直界面的建构模式——高层高密度、混合功能的建构模式.在提高容积率的同时,又不乏对人居环境的考虑,期望能对今后保障性住房的建设提供参考. 相似文献
993.
Parallel architectures involve communication with the aim of fast receiving of complete information at each node. Several architectures have been proposed to overcome the problem of high communicational and computational time complexity for transferring and receiving information. To reduce the complexity of such communication, we have implemented Linear Network Coding (LNC) in the parallel environment. For verification of our approach, we have considered some parallel architecture for implementing network coding approach and examined our results on these networks in a generic environment. We have formulated a standard approach for parallel networks, showing that by applying this approach effect of faulty nodes, information size and communication complexity exponentially decreases with code length. 相似文献
994.
Dietrich Goers Michael E. Spahr Antonio Leone Wolfgang Märkle Petr Novák 《Electrochimica acta》2011,(11):A1478
The local current density related to the exfoliation process of graphite negative electrodes in mixed ethylene carbonate/propylene carbonate electrolytes was controlled by a variation of the current applied to lithium half-cells containing either single type graphite electrodes or electrodes consisting of mixtures of an exfoliating and a non-exfoliating graphite. The partial local current density attributed to graphite passivation and its distribution within the volume of the electrode was found to be a key parameter to explain differences in the exfoliation behaviour observed for graphite electrodes. The local current density is related with a local overpotential which may suppress one of several possible electrochemical processes. In a negative electrode consisting of a mixture of a non-exfoliating and an exfoliating graphite component, the exfoliation of the exfoliation-sensitive graphite component can be completely suppressed when increasing the partial local current density attributed to the graphite exfoliation process above a certain threshold, by either decreasing the amount of exfoliating graphite particles in the electrode or by increasing the total current density, i.e., the specific current. The consideration of the local current density distribution for the electrochemical processes throughout the electrode leads to a more general concept for the graphite passivation behaviour during the first lithium insertion in lithium-ion batteries. 相似文献
995.
Nan Sun Bin Yang Long Wang Jian‐Ming Feng Bo Yin Kai Zhang Ming‐Bo Yang 《Polymer International》2012,61(4):622-630
The dependence of hierarchy in crystalline structures and molecular orientations of high density polyethylene parts with different molecular weights molded by gas‐assisted injection molding (GAIM) was intensively examined by scanning electron microscopy, two‐dimensional wide‐angle X‐ray scattering as well as dynamic rheological measurements. The non‐isothermal crystallization kinetics of the samples were also analyzed with a differential scanning calorimeter at various scanning rates. It was found that oriented lamellar structure, shish‐kebab and common spherulites were formed in different regions of the GAIM samples. The scanning electron microscope observations were consistent with the two‐dimensional wide‐angle X‐ray scattering results and showed that the molecular chains near the mold wall had strong orientation behavior, revealing the distribution of the shear rate of the GAIM process. The differences in crystal morphologies can be attributed to molecular weight differences as well as their responses to the external fields during the GAIM process. The formation mechanism of the shish‐kebab structure under the flow field of GAIM was also explored. Copyright © 2012 Society of Chemical Industry 相似文献
996.
在工业应用中,为了提高系统的抗干扰能力和确保系统安全可靠地运行,往往使用电量隔离技术传输信号。文章提出一种传输直流模拟量的隔离电路。此电路主要由非线性光耦、低通滤波器、脉冲发生电路及控制单元组成。它使用简化的脉冲密度调制原理,跟踪待传输的直流信号,控制脉冲波的输出,将直流信号转换成脉冲,经光耦隔离后送入滤波器还原出原信号。此电路具有体积小、成本低的特点。 相似文献
997.
998.
Jun-Woo ParkKazuki Yoshida Naoki TachikawaKaoru Dokko Masayoshi Watanabe 《Journal of power sources》2011,196(4):2264-2268
The physicochemical and electrochemical properties of the binary ionic liquid (IL), lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) dissolved in N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)amide (DEMETFSA), were investigated. The ionic conductivity of the binary IL decreased with an increase in LiTFSA concentration. The self-diffusion coefficients of Li+, DEME+, and TFSA− dissolved in the IL were measured by using the pulsed-field-gradient spin-echo (PGSE) NMR method. The self-diffusion coefficient of each ionic species was also found to decrease with increasing concentration of LiTFSA. The limiting current density in the IL electrolyte was evaluated by chronoamperometry using symmetric Li|IL|Li cell. The results suggest that the diffusion process of Li(I) in the IL dominates the limiting current density in the cell. The highest limiting current density is achieved at a concentration of 0.64 mol dm−3 of LiTFSA. 相似文献
999.
我国中密度纤维板压机发展概况 总被引:1,自引:0,他引:1
简要介绍了我国中密度纤维板压机的发展,并对中密度纤维板多层压机结构与使用、连续压机的优点等进行了讨论。 相似文献
1000.