Spin-crossover phenomena of the assembled iron complexes by enclathrating an organic molecule

Assembled complex, Fe(bpa)₂(NCX)₂ (bpa=1,2-bis(4-pyridyl)ethane; X=S, Se, BH₃) enclathrated diphenylmethane. The skeletons were interpenetrating structures for NCS and NCSe complexes, while 2D grid structure was obtained for NCBH₃ complex. The assembled iron complexes showed spin-crossover phenomena by enclathrating diphenylmethane. The ratio of spin transition and the transition temperature depended on the assembled structure.     

Buffer phenomenon in systems with one and a half degrees of freedom

The buffer phenomenon is established for some classical mechanics problems that are described by pendulum-type equations with time-periodic small additive terms. This phenomenon is as follows: the systems under consideration can have an arbitrary fixed number of stable periodic modes if the system parameters are properly chosen.     

Influence of dielectric microcavity on the spontaneous emission rate of atom: a perspective on the closed-orbit theory of photons

The formulas of the quantum electrodynamics have been applied to calculate the spontaneous emission rate of excited atom in dielectric microcavity.The results exhibit damping oscillating Patterns which depend sensitively on the scaling parameter and geometrical structure.Compared with the case that the emitting atom is immersed in dielectric,the spontaneous emission rate is depressed obviously and the center or the mean value of the oscillations is intimately related to the real refractive index of the local position where the atom is.In order to explain this phenomenon,we utilize the closed-orbit theory to deal with the classical trajectories of the emitted photon.and extract the corresponding frequencies of the oscillations by Fourier transform.It is found that the oscillations can be represented in terms of the closed-orbits of the photon motion constrained in dielectric microcavity,thus providing another perspective on the spontaneous emission of atom sandwiched by dielectric slabs.     

Photon-induced switching and tunneling phenomena in a YBCO thin film junction

In the persistent photoconductivity (PPC) phenomenon, illumination of a YBa₂Cu₃O_6.5 thin film junction with a 1mW He−Ne laser leads to the decrease of the critical voltage (similar to the threshold voltage). The decrease of the critical voltage was reversed by illumination with incandescent light. The critical voltage across the junction was experimentally decreased and increased by alternating illumination between He−Ne laser and incandescent light. We also observed visible quenching of the photo-induced state using a 5mW He−Ne laser. Finally, the threshold behavior of the junction was destroyed by illuminating it with incandescent light.     

The Kunze-Stein phenomenon associated with Jacobi transforms

Recently A. D. Ionescu (2000) established the endpoint estimate for the Kunze-Stein phenomenon, which states that if is a noncompact connected semisimple Lie group of real rank one with finite center, then

In this paper, we will prove the corresponding result for the Jacobi transform. Our method is analytical, in which we do not use the structure of Lie groups.

     

Lanczos-Like σ-Factors for Reducing the Gibbs Phenomenon in General Orthogonal Expansions and Other Representations

The first attempt for reducing the Gibbs phenomenon in an orthogonalexpansion, besides the usual one of Fourier series, is due to Cooke in1927–1928 for the Fourier Bessel series.However, his work was limited tothe well-known Fejer averaging of the series. For the past 10 years or so,we have tried a parallel to the more effective Lanczos-type localaveraging method of the Fourier series. As expected, such efforts werehindered by the lack of realizable tools for the general orthogonalexpansion that parallels the familiar simple ones of the Fourier seriesand transforms. During the past 3 years, we have succeeded in developinga simple direct method of filtering the Gibbs phenomenon in Fourier--Besselseries, Hankel transforms representation, and a number of orthogonalpolynomials series expansions. This parallels the equivalent result ofLanczos, which he obtained for his local averaging with the help ofthe (Fourier) convolution theorem.     

Heat capacity of MnBr2·4H2O near the antiferromagnetic transition temperature

Heat capacity of MnBr₂·4H₂O has been measured in the critical region around the Neel temperature. The data can be fitted, over a restricted range of |t|⩽10⁻², to the asymptotic power law. The critical exponents and the amplitudesA andA′ are not consistent with any theoretic predictions. However when scaling constraints are imposed, their values agree with the parameters of Ising model. Corrections to scaling are necessary to extend the range of the fit to |t|>10⁻². The correction terms are asymmetric giving −1·15±0·25 as the ratio of the amplitudes of the lowest order correction terms,D andD′ above and belowT _c. This value is in agreement with the recent predictions of the renormalisation group theory.     

Probability calculations on the auto-annihilation of radiation damage in LiF

Simplified models are presented, simulating the irradiation of lithium fluoride single crystals. In these models the evolution of the primary defect concentration versus the number of Frenkel pairs, induced at random in the lattice, is studied from a statistical point of view. The maximum defect concentration follows as a consequence of postulated annihilation volumes in which a newly created primary recombines with one of its antidefects. The fact whether single or di-atomic interstitials are considered has only a minor effect on the maximum defect retention.     

毛细上升公式的推导方法及其在方形毛细管中的应用

归纳了文献中导出圆形毛细管液柱上升高度计算公式的方法;明确指出了采用受力分析导出毛细上升高度公式时,对伸展力进行简化处理的原理以及其中所隐含的基本假设;从流体力学角度对液柱上升速率和高度进行了讨论.分3种情况对液柱在方形毛细管中上升的现象进行了系统分析,得出了一些重要的结论.     

Study of insulating electrical conductivity in hydrogenated amorphous silicon-nickel alloys at very low temperature

On the insulating side of the metal-insulator transition (MIT), the study of the effect of low temperatures T on the electrical transport in amorphous silicon-nickel alloys a-Si_1−yNi_y:H exhibits that the electrical conductivity follows, at the beginning, the Efros-Shklovskii Variable Range Hopping regime (ES VRH) with T^−1/2. This behaviour showed that long range electron-electron interaction reduces the Density Of State of carriers (DOS) at the Fermi level and creates the Coulomb gap (CG). For T higher than a critical value of temperature T_C, we obtained the Mott Variable Range Hopping regime with T^−1/4, indicating that the DOS becomes almost constant in the vicinity of the Fermi level. The critical temperature T_C decreases with the content of nickel in the alloys.