Mössbauer study of Fe70Cr10C10P10 rapidly quenched alloys

Mössbauer spectroscopy was used to study rapidly quenched Fe₇₀Cr₁₀C₁₀P₁₀ amorphous alloys in order to get information about the effect of some preparation parameters on the structure and properties of the alloys. The results indicate that the Mössbauer spectroscopy can sensitively detect changes with quenching rate in these amorphous alloys. The average magnetic field decreases with increasing thickness of the samples. This cooling rate effect was compared with low temperature relaxation changes of the aged thin samples.     

Structural properties of the 10Be and 10C four-cluster nuclei

The structure functions for the ¹⁰Be and ¹⁰C nuclei are studied in a four-particle approximation (two alpha-particle clusters plus two nucleons). New versions of the αα interaction potential are constructed. Together with the nα, pα, and NN potentials proposed previously, they make it possible to describe the binding energies and radii of the nuclei being considered, along with the S-wave twocluster phase shifts at low energies. General properties of four-particle wave functions are studied, and two basic configurations of the cross and tetrahedron types are revealed in the ¹⁰Be and ¹⁰C nuclei. A detailed analysis of the behavior of the structure functions is performed for these nuclei. The density distributions, form factors, and pair correlation functions are considered. The momentum distributions are obtained for the alpha particles and extra nucleons. The structure functions for the ¹⁰Be and ¹⁰C four-cluster nuclei are compared with those for the ⁶He three-cluster nucleus. The bound states of the nuclei are studied within a high-precision variational approach by using Gaussian bases.     

2009国际物理十大进展

2009年12月21日,英国皇家物理学会（IOP）所属国际知名电子期刊《物理世界》评出2009年度国际物理十大进展．     

氦原子Rydberg态10G—10M磁精细结构的计算

通过自洽迭代求解Hartree方程，得到了氦原子1snl组态下的严格数值解波函数，以此构造LS耦合谱项(支项)波函数作为基矢.采用线性变分法，同时考虑交换作用和Breit-Bethe近似下的磁相互作用项，计算了氦Rydberg态10G—10M系列能级的磁精细结构，计算结果很好地符合已有的实验值.对计算方法的进一步改进提出了设想和讨论. 关键词： 氦原子 Rydberg态 磁精细结构 自洽迭代     

Optical constants of thermally evaporated As10Te10S80 thin films

10 Te₁₀S₈₀ thin films were measured over the wavelength range 300 to 900 nm. A simple method, suggested by Swanepoel, was used for the determination of the optical constants and thickness of the film. The absorption edge is described using the non-direct transition model proposed by Tauc. The effect of one hour’s thermal annealing in the temperatures range 300–475 K on the optical properties of the As₁₀Te₁₀S₈₀ film is reported and explained. Received: 12 May 1997/Accepted: 1 August 1997     

Solution of the10Li-Puzzle

The mass of¹⁰Li has been measured with two different reactions:⁹Be(¹³C,¹²N)¹⁰Li,E _Lab=336 MeV, and¹³C(¹⁴C,¹⁷F)¹⁰Li,E _Lab=337 MeV. The mass excess of 33.445(50) MeV is deduced from theQ-value measurement.¹⁰Li is found to be particle-unstable with respect to one-neutron emission by 0.42(5) MeV. In the analysis of the first reaction a low lying excited state is found at 0.38(8) MeV. This state and the ground state can be most probably identified as the 1⁺/2⁺-doublet coupled from the [π 1p3/2 ?ν 1p 1/2] configuration, the 1⁺-state being the ground state. The (¹³C,¹²N)-reaction populates the 1⁺-state strongly due to a spin-isospin-flip character of the dominant part of the transition amplitude. The 2⁺-member corresponds to the mass given by Wilcox et al. A second excited state is observed at 4.05(10) MeV with a width of 0.7(2) MeV, it can be associated with theν 1d 5/2-strength. The second reaction is fully supporting the interpretation of the ground state doublet. The excited state at 4.05 MeV is not observed in this reaction and indeed it should not, because the reaction does not populate in first order excited neutron configurations. The levels are well described by mean field calculations including pairing correlations. The lowest resonance in the calculations is theν 1/2^?-configuration, whereas theν 1/2⁺-configuration shows at the neutron threshold a strong non-resonant contribution.     

Author index of volume 10

Experimental results show that the Moiré pattern with incoherent illumination should be explained by the spatial frequency components lower than the original one without referring to the cut-off frequency of the observation system. The general Moiré pattern is interpreted by the use of a communication theory approach. The results of this interpretation agree with Oster's indicial equation.     

E10, BE10 and arithmetical chaos in superstring cosmology

It is shown that the neverending oscillatory behavior of the generic solution, near a cosmological singularity, of the massless bosonic sector of superstring theory can be described as a billiard motion within a simplex in nine-dimensional hyperbolic space. The Coxeter group of reflections of this billiard is discrete and is the Weyl group of the hyperbolic Kac-Moody algebra E10 (for type II) or BE10 (for type I or heterotic), which are both arithmetic. These results lead to a proof of the chaotic ("Anosov") nature of the classical cosmological oscillations, and suggest a "chaotic quantum billiard" scenario of vacuum selection in string theory.     

回流式水冷超薄多层镜的研究

从理论和实验上讨论了水冷铜镜变形的规律, 从而设计出多种多层镜, 其中回流式多层镜在0.13MPa通水压力下净吸收86.9W激光功率时, 总变形仅 0.10μm,约为同等条件下普通水冷铜镜变形量的1/40。     

GY-CTNMR-10小型核磁共振成像仪的性能研究

本文对小型核磁共振仪的成像特点作了深入的研究,分析了相关参数的变化对所成图像的影响,得到了小型核磁共振成像的优化规律。随后利用GYCTNMR-10小型核磁共振成像仪,对两种植物样品进行了核磁共振成像,研究表明,实验结果和理论分析非常符合。