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1.
For an integer , a graph is -hamiltonian if for any vertex subset with , is hamiltonian, and is -hamiltonian connected if for any vertex subset with , is hamiltonian connected. Thomassen in 1984 conjectured that every 4-connected line graph is hamiltonian (see Thomassen, 1986), and Ku?zel and Xiong in 2004 conjectured that every 4-connected line graph is hamiltonian connected (see Ryjá?ek and Vrána, 2011). In Broersma and Veldman (1987), Broersma and Veldman raised the characterization problem of -hamiltonian line graphs. In Lai and Shao (2013), it is conjectured that for , a line graph is -hamiltonian if and only if is -connected. In this paper we prove the following.(i) For an integer , the line graph of a claw-free graph is -hamiltonian if and only if is -connected.(ii) The line graph of a claw-free graph is 1-hamiltonian connected if and only if is 4-connected. 相似文献
2.
A graph G is N2‐locally connected if for every vertex ν in G, the edges not incident with ν but having at least one end adjacent to ν in G induce a connected graph. In 1990, Ryjá?ek conjectured that every 3‐connected N2‐locally connected claw‐free graph is Hamiltonian. This conjecture is proved in this note. © 2004 Wiley Periodicals, Inc. J Graph Theory 48: 142–146, 2005 相似文献
3.
Analysis of flavonoid constituents from leaves of Acanthopanax senticosus harms by electrospray tandem mass spectrometry 总被引:2,自引:0,他引:2
Three known flavonoids, quercetin, quercitrin (quercetin-3-0-rhamnoside) and rutin (quercetin-3-0 rutinoside), have been identified for the first time in the leaves of Acanthopanax senticosus Harms by using electrospray tandem mass spectrometry techniques (ESI-MS(n)). The flavonoid hyperin (quercetin-3-0-beta-galactoside), already known to be present, was also investigated. The diagnostic fragment ions of the aglycone quercetin were obtained in the ESI-MS(n) experiments, and a fragmentation mechanism proposed. 相似文献
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Surface-immobilized protein species deposited in the microarray format have been detected by time-of-flight secondary ion mass spectrometry and by scanning Kelvin nanoprobe. The former method was used to examine the nature of protein deposition on amine-coated glass slides and gold substrates in preparation for Kelvin measurements. Both gallium and SF(5)(+) ion sources were employed to produce positive and negative ion spectra of amino acids and polypeptides. Scanning Kelvin technology has been used to detect antibody-antigen interactions in a label-free protocol through measurement of the surface potential of the biochemical pair on indium tin oxide, amine-treated slides and gold substrates. The results show that good inter-spot reproducibility can be achieved and that deposited areas can be examined for homogeneity at 100 nm resolution. This work represents the first report on surface potential detection in protein microarray technology. 相似文献
7.
Changhong Zhao Mingquan Yang Guoqiang Peng 《Nonlinear Analysis: Real World Applications》2010,11(1):117-121
In this paper the convergence behavior of an epidemic model with time-varying delays are considered. Some sufficient conditions are established to ensure that all solutions of the epidemic model with permitted initial conditions converge exponentially to zero, which are new and complement previously known results. 相似文献
8.
Wang Tingting Yin Rongzhang Ye Mingquan Wan Nan Shi Jiadong 《International Journal of Theoretical Physics》2021,60(4):1507-1515
Based on quantum renormalization group (QRG) method, we investigated quantum coherence and quantum phase transition (QPT) in XXZ chain and XY chain, respectively. The results show that both the geometric quantum coherence and entropic coherecne can accurately indicate the QPT at critical point after enough iteration steps. Moreover, the increasing anisotropy parameter destroys the coherence in the XXZ chain, while enhances it in the XY chain. In addition, focused on the XXZ chain we analyzed the nonanalytic phenomena and scaling behaviors with different theoretical exponents in detail.
相似文献9.
采用傅里叶模方法,分析了单点金刚石铣削后KDP晶体表面小尺度波纹的周期和幅值对单层增透膜折射率、厚度以及透射率的影响。研究表明:膜层最佳折射率在1.22左右,在此折射率条件下,保证透射率大于99%的单层增透膜的理想厚度范围应为180~220 nm,并且折射率和膜厚值的选取基本不受晶体表面小尺度波纹周期和幅值的影响。若只考虑SPDT法加工后KDP晶体表面小尺度波纹周期和幅值的实际范围,透射率基本不受波纹周期的影响,但却会随波纹幅值的增大而加速下降。理想镀膜条件下透射率最大值大于99%,并且通常在99.67%~99.94%之间。 相似文献
10.
珍汕97不育系和保持系水稻花粉发育过程中RNA含量变化的研究 总被引:1,自引:0,他引:1
采用组织化学方法,对珍汕97水稻不育系及保持系的花粉发育过程进行分析,结果表明从幼小的单孢花粉到单核边位出现中央大液泡时期,不育系花粉细胞RNA含量与保持系无显著差异,单核末期不育系开始败育,双核期RNA含量与保持系双核期花粉细胞相比有显著下降,说明RNA含量下降是珍汕97不育系花粉败育的一个重要生理特征,不育系花粉在单核末期以前发育是正常的. 相似文献