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排序方式: 共有193条查询结果,搜索用时 46 毫秒
21.
在本文,我们研究谱半径至多为$\sqrt[r]{2+\sqrt{5}}$的超图.我们得到此种超图必须具有一个基普结构,这与Woo-Neumaier在2007年对谱半径至多为$\frac{3}{2}\sqrt{2}$的图的分类结果类似. 相似文献
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利用图的匹配多项式及其最大实数根的性质证明了树T(1,1,n,2,1)及补图匹配唯一的充要条件是n≠1,2,5,8. 相似文献
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Yuxin Wang Huafei Sun Shoudong Huang Yang Song 《Mathematical Methods in the Applied Sciences》2020,43(2):486-511
This paper focuses on using the first curvature κ(t) of trajectory to describe the stability of linear time-invariant system. We extend the results for two and three-dimensional systems (Wang, Sun, Song et al, arXiv:1808.00290) to n-dimensional systems. We prove that for a system , (a) if there exists a measurable set whose Lebesgue measure is greater than zero, such that or does not exist for any initial value in this set, then the zero solution of the system is stable; (b) if the matrix A is invertible, and there exists a measurable set whose Lebesgue measure is greater than zero, such that for any initial value in this set, then the zero solution of the system is asymptotically stable. 相似文献
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In this study, new chalcone compound 1 , new phthalonitrile derivatives 2 and 3, new copper(II), manganese(III) phthalocyanines bearing chalcone groups at peripheral or nonperipheral positions were synthesized. Electrochemistry of tetra-(4-{(2 E )-3-[2-fluoro-4-(trifluoromethyl)phenyl]prop-2-enoyl}phenoxy) substituted Co(II)Pc and Mn(III)Pcs were studied with cyclic voltammetry (CV) to determine the redox properties of the phthalocyanines. According to the results, while the CuPcs 2a and 3a showed two Pc based reduction reactions and one Pc based oxidation reaction, MnPcs 2b and 3b gave two metal-based reduction reactions. All the redox processes are shifted toward positive potentials as a result of the increased electron-withdrawing ability of the trifluoromethyl substituents. 相似文献
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Near infrared spectroscopy (NIRS) is an emerging, non-invasive, multi-index, simple preparation of sample process analytical technique suitable for cotton quality assessment. Cotton impurities not only affect the quality of seed cotton and lint cotton but also the quality of textiles. These impurities can occur during harvest and in the stage of postharvest handing, especially during pack house operations. In such a global and competitive marketplace, it is necessary to explore rapid, accurate, and precise cotton quality measurement techniques which require less expensive instrumentation, exhibit increased flexibility versatility, and perform both laboratory measurements and non-laboratory (at-line or field) measurements. Some reports have been published on the use of NIRS technology for inspecting cotton impurity contents, micronaire, and cotton fiber quality. This article condenses a representative selection of recent research in order to observe the significant progresses in how NIRS technology is applied to inspection of cotton impurity and cotton fiber. Additionally, the drawbacks and obstacles of NIRS for quality measurement in cotton are summarized and the trends are discussed. 相似文献
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超短脉冲强激光与团簇的相互作用已被证明能够产生能量高达MeV量级的高能离子和中子以及非常强的X射线辐射。广阔好原子团簇在超短脉冲强激光场的作用下的加热、电离和膨胀等机制,对这种相互作用的深入研究可能会对激光核聚变和X射线激光等应用领域产生重大影响。 相似文献
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ZHANG Zhan-Jun LIU Yi-Min MAN Zhong-Xiao 《理论物理通讯》2005,44(11)
We present a method to teleport multi-qubit quantum information in an easy way from a sender to a receiver via the control of many agents in a network. Only when all the agents collaborate with the quantum information receiver can the unknown states in the sender‘s qubits be fully reconstructed in the receiver‘s qubits. In our method,agents‘s control parameters are obtained via quantum entanglement swapping. As the realization of the many-agent controlled teleportation is concerned, compared to the recent method [C.P. Yang, et al., Phys. Rev. A 70 (2004) 022329],our present method considerably reduces the preparation difficulty of initial states and the identification difficulty of entangled states, moreover, it does not need local Hadamard operations and it is more feasible in technology. 相似文献