基于解耦差分泽尼克待定系数法的二维横向剪切波面重建算法

横向剪切干涉术是一种自参考干涉计量技术,其原理是被检测波前与其自身被剪开的波前之间在重叠范围内相干涉,由干涉图得到两相互剪切波前的波前差,通过波面重建算法得到待测波面.在波面重建算法中,泽尼克待定系数法是其中的一种.分析了横向剪切干涉技术的测量原理;提出了一种新的基于解耦差分泽尼克待定系数法的二维横向剪切波面重建算法....     

A note on the examination of isospin effects in multi-dimensional Langevin fission dynamics

In [W. Ye, F. Wu, H.W. Yang, Phys. Lett. B 647 (2007) 118] prescission protons and α particles of high-isospin ²⁰⁶Pb were shown to be almost independent of the dissipation strength ks$k_s$. Subsequently, in [P.N. Nadtochy, et al., Phys. Lett. B 685 (2010) 258] prescission light charged particles (LCPs) were shown to have approximately the same sensitivity as neutrons to ks$k_s$ for ²⁰⁶Pb and ²⁰⁴Hg nuclei. In this Letter we point out that the reason for the apparent contradictory conclusions is that the authors in the latter did not compute the changes in the absolute yields of prescission LCPs multiplicities with increasing ks$k_s$ and compare them with typical experimental uncertainties. It is shown that the expected changes are very small in the case of neutron-rich ²⁰⁶Pb and ²⁰⁴Hg systems, which are within experimental error bars. This indicates that, from the viewpoint of experiment, LCPs emission of ²⁰⁶Pb and ²⁰⁴Hg is insensitive to dissipation.     

A facile method to synthesize magnetic polymer nanospheres with multifunctional groups

Magnetic poly(styrene methyl methacrylate)/Fe₃O₄ nanospheres with ester groups were prepared by a modified one-step mini-emulsion polymerization in the presence of Fe₃O₄ ferrofluids. The effects of monomer dose, surfactant content, ferrofluid concentration and initiator content on the particle characteristics such as the size, morphology and magnetic properties were investigated by Fourier-transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis and vibrating sample magnetometer. The results indicated that magnetic nanospheres were superparamagnetic with high saturation magnetization of 51.0 emu/g and corresponding magnetite content of 61.5 wt%. Subsequently, magnetic nanospheres with carboxyl and amino groups were also obtained by hydrolysis and ammonolysis reaction. These magnetic nanospheres with multifunctional groups have biomedical applications.     

Efficient scheme for the preparation of symmetric Dicke states via cross-Kerr nonlinearity

A scheme is proposed for generating maximally entangled Dicke states among four modes. The scheme only uses Kerr medium and homodyne measurements on coherent light fields, which can be efficiently made in quantum optical laboratories. The scheme can be generalized to produce maximally entangled 2k-qubit states.     

Fissility effects on evaporation residue spin distributions

Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the spin distribution of evaporation residue cross sections of nuclei ¹⁹⁰Os and ²¹⁰Po which have the same neutron-to-proton ratio N/Z$N/Z$ but have a difference in fissility. We find that a large fissility enhances the sensitivity of the residue spin distribution to pre-saddle friction substantially. The results suggest that on the experimental side, to obtain accurate information of pre-saddle dissipation strength by measuring the evaporation residue spin distribution it is optimal to populate among various compound systems with equal N/Z$N/Z$ those with high fissility.     

Quantum game interpretation for a special case of Parrondo’s paradox

By using the discrete Markov chain method, Parrondo’s paradox is studied by means of theoretical analysis and computer simulation, built on the case of game AB played in alternation with modulus M=4. We find that such a case does not have a definite stationary probability distribution and that payoffs of the game depend on the parity of the initial capital. Besides, this paper reveals the phenomenon that “processing in order produces non-deterministic results, while a random process produces deterministic results”. The quantum game method is used in a further study. The results show that the explanation of the game corresponding to a stationary probability distribution is that the probability of the initial capital has reached parity.     

Spin characters of generalized symmetric groups

In 1911 Schur computed the spin character values of the symmetric group using two important ingredients: the first one later became famously known as the Schur Q-functions and the second one was certain creative construction of the projective characters on Clifford algebras. In the context of the McKay correspondence and affine Lie algebras, the first part was generalized to all wreath products by the vertex operator calculus in Frenkel et al. (Duke Math J 111:51–96, 2002) where a large part of the character table was produced. The current paper generalizes the second part and provides the missing projective character values for the wreath product of the symmetric group with a finite abelian group. Our approach relies on Mackey–Wigner’s little groups to construct irreducible modules. In particular, projective modules and spin character values of all classical Weyl groups are obtained.     

ChemInform Abstract: High Pressure Superconducting Phase of BI3: An ab initio Study.

The high pressure crystal structure of BI₃ with space group P2₁/c consisting of B₂I₆ dimers is determined using an ab initio evolutionary algorithm for crystal structure prediction in conjunction with density functional theory.     

The solution of problems of the stability of three-dimensional convective flows in a closed rectangular cavity by the collocation method

The use of the collocation method, with collocation points at the zeroes of a Chebyshev polynomial, to solve spatial problems of the stability of convective flows, is described. The fluid occupies a closed rectangular cavity on the boundaries of which conditions of the first, second and third kind can be specified. Using a differential matrix constructed at the collocation points, the spectral problem is transformed into an extended eigenvector problem that is solved numerically. The Rayleigh problem in a closed layer is solved for different values of the ratio of the sides of the rectangular cavity. The calculations presented are compared with the results of the solution of non-linear equations and also with the experimental and theoretical data of other authors.