关于压缩算子的不变子空间

证明关于压缩算子的如下不变子空间定理：如果T是Hilbert空间H上的压缩算子,且集合Z’={λ∈D;存在z∈H,使得‖z‖=1,且‖（λ-T）z‖＜1/3(1-‖λ‖}是开单位圆D的控制集,那么T有非平凡的不变子空间,这个定理包含了S.Brown,B.Chevreau,C.fPearcy和B.Beauzamy的两个重要结果作为特殊情况,特别是,为个定理包含了S.Brown等人的Hilbert空间上的每个具有厚谱的压缩算子都有平凡的不变子空间这个重要结果作为特殊情况。     

关于S~1上扩张映射的拓扑熵的改进

对文献 [1 ]中圆周上扩张映射的拓扑熵的结论给予了改进 ,得到了结论 :设 f∈ Cr(S1 ,S1 )是扩张映射 ,则 ent(f) =log|deg(f) |.     

Paraelectric--ferroelectric interface dynamics induced by latent heat transfer and irreversibility of ferroelectric phase transitions

The temperature gradients that arise in the paraelectric--ferroelectric interface dynamics induced by the latent heat transfer are studied from the point of view that a ferroelectric phase transition is a stationary, thermal-electric coupled transport process. The local entropy production is derived for a ferroelectric phase transition system from the Gibbs equation. Three types of regions in the system are described well by using the Onsager relations and the principle of minimum entropy production. The theoretical results coincides with the experimental ones.     

Relative entropy as a measure of entanglement for Gaussian states

In this paper, we derive an explicit analytic expression of the relative entropy between two general Gaussian states. In the restriction of the set for Gaussian states and with the help of relative entropy formula and Peres--Simon separability criterion, one can conveniently obtain the relative entropy entanglement for Gaussian states. As an example, the relative entanglement for a two-mode squeezed thermal state has been obtained.     

Entanglement in a system of two two-level atoms interacting with a single-mode field

We investigate the entanglement in a system of two coupling atoms interacting with a single-mode field by means of quantum information entropy theory. The quantum entanglement between the two atoms and the coherent field is discussed by using the quantum reduced entropy, and the entanglement between the two coupling atoms is also investigated by using the quantum relative entropy. In addition, the influences of the atomic dipole--dipole interaction intensity and the average photon number of the coherent field on the degree of the entanglement is examined. The results show that the evolution of the degree of entanglement between the two atoms and the field is just opposite to that of the degree of entanglement between the two atoms. And the properties of the quantum entanglement in the system rely on the atomic dipole--dipole interaction and the average photon number of the coherent field.     

A Possible Generalized Form of Jarzynski Equality

The crucial condition in the derivation of the Jarzynski equality （JE） from the fluctuation theorem is that the time integral of the phase space contraction factor can be exactly expressed as the entropy production resulting from the heat absorbed by the system from the thermal bath. For the system violating this condition, a more general form of JE may exist. This existence is verified by three Gedanken experiments and numerical simulations, and may be confirmed by the real experiment in the nanoscale.     

（Anti-）de Sitter Black Hole Entropy and Generalized Uncertainty Principle

We generalize the method that is used to study corrections to Cardy-Verlinde formula due to generalized uncertainty principle and discuss corrections to Cardy-Verlinde formula due to generalized uncertainty principle in （anti）- de Sitter space. Because in de Sitter black hole spacetime the radiation temperature of the black hole horizon is different from the one of the cosmological horizon, this spacetime is a thermodynamical non-equilibrium spacetime.     

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分析了圆柱、柱锥形及回形纳米碳管弹簧在轴向载荷作用下的变形,给出了它们轴向刚 度$K_{\rm p}$的统一表达式. 为验证$K_{\rm p}$公式的有效性,还将圆柱形碳管纳米弹簧$K_{\rm p}$ 的理论解和相应的试验结果、有限元结果进行了比较. 结果发现,碳管纳米弹簧的$K_{\rm p}$ 理论解和试验结果、有限元结果均较为接近.     

皮肤组织压缩行为与热损伤的相关性

皮肤组织生物热力学是一门涉及生物传热、烧伤、生物力学和生理神经学等的高度交叉的新兴学科.皮肤组织的热力学性能表征对皮肤组织生物热力学的建立和完善以及许多医学应用领域都具有相当重要的作用.然而,目前对于皮肤组织力学性质和温度之间的量化关系却几乎没有开展研究,试图揭示高温引发的热损伤对皮肤组织力学性能影响的研究也相当少.该文重点描述了猪皮在各种热损伤度下的压缩行为,讨论了与热损伤与皮肤压缩行为的相关性及机理.结果表明:皮肤的刚度随热损伤度的提高而下降,并且具有不同损伤度下的应变速率敏感性,这些特性主要是由皮肤的水合作用变化所引起的.     

Generalized Uncertainty Principle and Black Hole Entropy of Higher-Dimensional de Sitter Spacetime

Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-- Hawking black hole entropy. In particular, many researchers have expressed a vested interest in the coetticient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty prlnciple and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is positive. This result is different from the known result at present. Our method is valid not only for four-dimensional spacetimes but also for higher-dimensional spacetimes. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the entropy correction of the complicated spacetime.