关于Jacobsthal数和Jacobsthal-Lucas数的r-循环矩阵的行列式和逆

和 是n阶r-循环矩阵, 其中 , 是Jacobsthal数, , 是Jacobsthal-Lucas数, 研究得出了 和 的关于Jacobsthal数和Jacobsthal-Lucas数的行列式的值. 同时, 计算出了矩阵 和 的逆.     

Plasma of Electric Arc Discharge between Melted Electrodes

Plasma of electric arc discharge between melted electrodes was experimentally investigated. Diagnostics of electric arc plasma was carried out. Optical emission and absorption spectroscopy was used to obtain radial profiles of temperature, electron density and neutral atoms concentration. The influence of electrode condition on plasma parameters was evaluated. It was found that the copper vapour in plasma tends to be located at the arc axis.     

Precise Quadrupole Moment of the Doubly Closed Shell Plus One Proton Nucleus 41Sc

In order to precisely determine the |eqQ(⁴¹Sc)/h| of ⁴¹Sc(I ^π=7/2⁻, T _1/2=0.596 s) implanted in a TiO₂ single crystal the electric field gradient tensor and anisotropic chemical shift were determined by detecting the Fourier Transformed Pulse-NMR of ⁴⁵Sc(I ^π=7/2⁻, stable) in the crystal at a high field of 7.0 T and 9.4 T. Combining the new |eqQ(⁴¹Sc)/h| value with the Q(⁴⁵Sc)=−(23.6±0.2) fm², also renewed by using the known atomic hyperfine interaction constants and Sternheimer polarization effect, the |Q(⁴¹Sc;I ^π=7/2⁻,T _1/2=0.596 s)|=(15.6±0.3) fm² has been precisely determined. The value is compared with the theoretical Q(⁴¹Sc) given by a shell model code. This revised version was published online in September 2006 with corrections to the Cover Date.     

Describing Hydrodynamic Particle Removal from Surfaces Using the Particle Reynolds Number

The fundamental processes related to the removal of fine particles from surfaces in a hydrodynamic flow field are not adequately understood. A critical particle Reynolds number approach is proposed to assess these mechanisms for fine particles when surface roughness is small compared to particle diameter. At and above the critical particle Reynolds number, particle removal occurs, while below the critical value, particles remain attached to a surface. The system under consideration consists of glass particles adhering to a glass surface in laminar channel flow. Our results indicate rolling is the removal mechanism, which is in agreement with the literature. Theoretical results of the critical particle Reynolds number model for rolling removal are in general agreement with experimental data when particle size distribution, particle and surface roughness, and system Hamaker constant are taken into account.     

金刚石镀膜装置中的等离子体参数测量

利用平行马赫探针和单探针对金刚石镀膜装置中的等离子体漂移速度、,离子密度及电子温度进行了测量,采用ＣｈｕｎｇＫｙｕ－Ｓｕｎ理论对平行马赫探针数据进行分析得到的马赫数为０．２８,电子温度为５ｅＶ,等离子体流速约为９８０ｍ．ｓ＾－１。单探针测行离子密度在１０＾１８～１０＾２０ｍ＾－３的范围内,电子温度在２－８ｅＶ的范围内。     

用电阻箱自组电桥的桥臂电阻选择

本文分析了用电阻箱作桥臂电阻自组电桥的灵敏度及测量结果不确定度,给出桥臂电阻的选择原则。     

Positron spectra from internal pair conversion observed in 238U + 181Ta collisions

We present new results from measurements and simulations of positron spectra, originating from ²³⁸U + ¹⁸¹Ta collisions at beam energies close to the Coulomb barrier. The measurements were performed using an improved experimental setup at the double-Orange spectrometer of GSI. Particular emphasis is put on the signature of positrons from Internal-Pair-Conversion (IPC) processes in the measured e⁺-energy spectra, following the de-excitation of electromagnetic transitions in the moving Ta-like nucleus. It is shown by Monte Carlo simulations that, for the chosen current sweeping procedure used in the present experiments, positron emission from discrete IPC transitions can lead to rather narrow line structures in the measured energy spectra. The measured positron spectra do not show evidence for line structures within the statistical accuracy achieved, although expected from the intensities of the observed γ-transitions ( E _γ∼ 1250-1600 keV) and theoretical conversion coefficients. This is due to the reduced detection efficiency for IPC positrons, caused by the limited spatial and momentum acceptance of the spectrometer. A comparison with previous results, in which lines have been observed, is presented and the implications are discussed. Received: 27 April 2000 / Accepted: 14 September 2000     

镜象电流选择的唯一性

利用稳恒磁场边值问题解答的唯一性定量和维尔斯特拉斯定理讨论了镜象电流选择的唯一性。     

高功率激光稳定腔选模分析

讨论了在有限菲涅耳数时，稳定凹－凸腔的高功率激光选模特性，研究表明当稳定凹－凸腔工作在临近界稳区时，基模体积显著提高，具有良好的选模效果。