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991.
讨论了非有限链环R=F_p+uF_p+vF_p+uvF_p上的循环码.通过环R上的循环码与多项式环R_n=(F_p+uF_p+vF_p+uvF_p)[x]/(xn-1)的理想的对应关系及对R_n的研究给出了R上循环码的刻画.最后定义了一个Gray映射,并刻画了F_p+uF_p+vF_p+uvF_p上的循环码在该映射下的像. 相似文献
992.
GF(2^8)上快速乘法器及求逆器的设计 总被引:5,自引:2,他引:5
基于多项式乘法理论,采用高层次设计方法,设计并采用FPGA实现了GF(2^8)上8位快速乘法器,并利用该乘法器设计了一个计算GF(2^8)上任一元素的例数的求逆器,该乘法器与求逆器可以应用于RS(255.223)码编/译码器。 相似文献
993.
Ma Jianfeng Wang Yumin Lei Zhenjia 《电子科学学刊(英文版)》1997,14(3):241-246
Trellis structures of block codes are discussed. L-section trellis structures of some BCH codes are presented. A fast maximum likelihood decoding algorithm for BCH codes is proposed correspondingly, the decoding problem of q-ary images of qm-ary block codes is also discussed. The direct-sum partition and the associated decoding algorithms are given for the images. 相似文献
994.
Vanadium pentoxide thin films of various thicknesses have been prepared by sol-gel spin coating method on glass and conducting substrates. X-ray diffraction analysis reveals crystalline nature for the 6–12 layered films (170–310?nm). The crystalline films indicate a preferential orientation of the crystallites along the (200) plane. FTIR studies of the V2O5 xerogel show the presence of V–O–V and V=?O bond confirming the formation of V2O5. The scanning electron microscope images reveal formation of nanostructures in the 6–12 layered films. Optical absorption studies indicate a band gap of 2.2–2.5?eV. Pseudocapacitance behaviour of the V2O5 films was studied using cyclic voltammetric technique and impedance analysis. V2O5 films of thickness 202?nm (8 layers) exhibit a specific capacitance of 346?F/g at a scan rate of 5?mV/s. 相似文献
995.
G. V. Prasad Reddy R. Sandhya K. Laha C. Depres C. Robertson A. K. Bhaduri 《哲学杂志》2013,93(16):1265-1280
AbstractA 3D dislocation dynamics study to ascertain the probable path of stage-I fatigue crack propagation across the persistent slip band (PSB) in austenitic stainless steel is presented. Cyclic plasticity and the resulting crack tip slip displacement (CTSD) are evaluated for cracks of varying length introduced at PSB-center and at two PSB-matrix interfaces. CTSD attains high value at either of the two interfaces irrespective of the proximity of crack front to the grain boundary. Further, a difference in microcrack propagation rate is also observed among the two interfaces. The present results assert microcrack propagation preferrentially along one of the two PSB-matrix interfaces rather than at the PSB-center. A pre-existing PSB dislocation structure localises the cyclic slip for crack lengths up to approximately half of the grain depth for an applied strain range of 2 × 10?4. 相似文献
996.
Olga Serifi Fotios Tsopelas Anna‐Maria Kypreou Maria Ochsenkühn‐Petropoulou Panagiotis Kefalas Anastasia Detsi 《Journal of Physical Organic Chemistry》2013,26(3):226-231
The electrochemical behaviour of 13 chalcone analogues was systematically studied by means of cyclic voltammetry and chronoamperometry at a glassy carbon (GC), gold and platinum working electrodes using two different supporting electrolyte/solvent combinations. It was found that chalcone analogues can be easily oxidized at both GC and gold working electrodes, but not at a platinum electrode. Principal component analysis was further employed to reveal similarities/dissimilarities between oxidation potentials, chronoamperometric signals and ability of the compounds to scavenge the reactive oxygen species H2O2. The study reveals the inverse proportional relationship between the scavenging ability of H2O2, expressed as IC50, and chronoamperometric signal at 800 mV using gold as working electrode. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
997.
ABSTRACTThis work presents an electro-optic effect-based design for the widely used Hamming code for checking single bit errors in the received data. The structure is based on Mach-Zehnder Interferometer, designed using Titanium-diffused Lithium Niobate-based waveguides. The proposed device has been successfully tested using the beam propagation method. For a received 7-bit code, the three simultaneously generated check bits are combined to check the error position. Critical performance parameters like extinction ratio (24.39dB), contrast ratio (25.711dB), insertion loss (0.041dB), and amplitude modulation (0.079dB) calculated for the overall device are within acceptable limits for the feasibility of the device. 相似文献
998.
Cheng-Gang Li Jin-Hai Gao Jie Zhang Wan-Ting Song Shui-Qing Liu Si-Zhuo Gao 《Molecular physics》2013,111(4):382-394
The structures, stabilities and electronic properties of neutral and anionic B3Sin (n?=?1–17) clusters have been systemically investigated on the basis of density functional theory at the B3LYP/6-311?+?G(d) level and CALYPSO structure prediction method. The structural searches show that three boron atoms tend to form B3 triangle encapsulated into Sin cages with the increasing number of silicon atoms. Most of the lowest energy structures can be derived by using the squashed pentagonal bipyramid structure of B3Si4 and B3Si4? as the major building unit. The relative stabilities are studied based on the calculated binding energies, second-order difference of energies and HOMO–LUMO gaps of the lowest energy structures. In addition, Hirshfeld, natural population analysis, Bader approaches and natural electronic configuration are performed to explore the charge transfer. At last, molecular orbital, magnetic properties, IR, Raman and UV–vis spectra are also, respectively, analysed for providing strong support for essential theoretical and experimental research. 相似文献
999.
一种LDPC码在光纤通信系统中的性能分析 总被引:1,自引:1,他引:1
针对超强前向纠错(FEC)技术在光纤通信系统中的应用,文章提出了一种构造简单、编码容易实现的低密度奇偶校验(LDPC)码的构造方法,并仿真验证了该LDPC码在光纤信道环境下的译码性能.与常用的RS(255,239)码相比,在相同的码效率下,所构造的码长为4 080的LDPC码能够获得比RS码高2 dB的编码增益. 相似文献
1000.
G. Sankara Raju Kosuru P. Veeramani 《Numerical Functional Analysis & Optimization》2013,34(7):821-830
We introduce a notion of pointwise cyclic contraction T satisfying TA ? B and TB ? A to obtain the existence of a point x ∈ A, such that d(x, Tx) = dist(A, B), known as a best proximity point for such a map. We also prove that for any x ∈ A, the Picard iteration {T2nx} converges to a best proximity point. 相似文献