排序方式: 共有29条查询结果,搜索用时 31 毫秒
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目的研究面向服务的开放式网格结构基础设施与实现方法。方法分析网格基本特性及面向服务的分布式系统范型的基本思想,以OGSI规范为基础,深入探讨面向服务的网格基础设施的结构、模型、标准及实现技术。结果结合W eb service技术,给出了一种OGSA网格服务模型的实现框架。结论面向服务的网格基础设施能够充分利用成熟的技术与方法,有利于构建大规模的、开放的、具有较高适用性的网格系统,应用前景十分广阔。 相似文献
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本文在条件下,根据自旋玻璃杂质间RKKY短程关联作用,提出二维自旋玻璃的渗流模型,分析转变温区自旋集团的行为,说明磁化率的尖拐状峰值和比热的膝盖状峰值,同时解释两者在磁场下的变化趋势。 相似文献
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Linear dispersion near the Dirac points in the band structure of graphenes can give rise to novel physical properties. We calculate the electronic contribution to the Raman spectra in graphenes, which also shows novel features. In the clean limit, the Raman spectrum in the undoped graphene is linear (with a universal slope against impurity scattering) at low energy due to the linear dispersion near the Dirae points, and it peaks at a position corresponding to the van Hove singularity in the band structure. In a doped graphene, the electronic Raman absorption is forbidden up to a vertical inter-band particle-hole gap. Beyond the gap the spectrum follows the undoped case. In the presence of impurities, absorption within the gap (in the otherwise clean case) is induced, which is identified as the intra-band contribution. The Drude-like intra-band contribution is seen to be comparable to the higher energy inter-band Raman peak. The results are discussed in connection to experiments. 相似文献
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用集体坐标和拉格朗日变分原理为基础的微扰论处理了n+1维旋转对称的sine-Gordon孤子在远离原点处受微扰势作用下的行为。强调孤子的粒子性并从正则方法导出其依赖于位置的广义动量和运动方程。这一方法可以处理一类相当广泛的微扰势而无需其具体形式即可定性地讨论孤子的行为。在无耗散条件下,研究了孤子的速度-位置相空间的特性,分析了诸如回波效应、不稳定不动点和逃逸等各种可能的现象。引入耗散后,得到了修正的运动方程。还讨论了上述结果在大面积Josephson结方面的应用,并与数值计算的结果作了比较,两者符合较好。 相似文献
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We improve a previous theory of doped Mort insulators with duality between pairing and magnetism by a further duality transform. As the result we obtained a quantum Ginzburg-Landau theory describing the Cooper pair condensate and the dual of spin condensate. We address the superconductivity by doping a Mort insulator,which we call the Mort superconductivity. Some fingerprints of such novelty in cuprates are the scaling between neutron resonance energy and superfluid density, and the induced quantized spin moment by vortices or Zn impurity (together with circulating charge super-current to be checked by experiments). 相似文献
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We investigate in underdoped cuprates possible coexistence of the superconducting order at zero momentum and pair density wave(PDW)at momentum Q=(Л,Л)in the presence of a Neel order.By symmetry,the d-wave uniform singlet pairing dS0 can coexist with the d-wave triplet PDW dTq,and the p-wave singlet PDW pSq can coexist with the p-wave uniform triplet pT0.At half filling,we find that the novel pSq+pT0 state is energetically more favorable than the dS0+dTQ state.At finite doping,however,the dS0+dTq state is more favorable.In both types of states,the variational triplet parameters cITq and pT0 are of secondary significance.Our results point to a fully symmetric Z2 quantum spin liquid with spinon Fermi surface in proximity to the Neel order at zero doping,which may not be adiabatically connected to the d-wave singlet superconductivity at finite doping with intertwining d-wave triplet PDW fluctuations and spin moment fluctuations.The results are obtained by variational quantum Monte Carlo simulations. 相似文献
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