Clebsch-Gordan Coefficients for Two-Parameter Deformed Quantum Algebra SU(1,1)q,s(Ⅱ)

Abstract The Bargmann represen tations in the tensor product space of the irreducible representations for the two-parameter deformed quantum algebra SU(1,1)_q,s corresponding to the negative discrete series (b) are introduced, and the corresponding Bargmann expressions for the bases of irreps, the coherent state and the operators are also derived. The Clebsch-Gordan coeficients (CGC) for the two-parameter deformed quantum algebra SU(1,1)_q,s corresponding to the negative discrete series (b) are obtained.     

An intrinsic fiber ring laser based sensor with saturable absorber

A novel configuration of fiber ring laser acoustic sensor, which adopts single-mode fiber as sensing element, is proposed and demonstrated. Linewidth less than 1 kHz is achieved by introducing a segment of erbium-doped fiber in the reflecting arm as saturable absorber. A polarization independent unbalanced Michelson interrogation interferometer and phase generated carrier demodulation technique are adopted to recover signal. Experiments demonstrate that the phase sensitivity is 0.018 rad/nm in good linearity and equivalent minimum detect able length change reaches 19.1 pm.     

多尺度Retinex截断区间对图像质量影响的分析

研究了多尺度Retinex算法对曝光量不足的彩色图像增强处理的结果。改进型多尺度Retinex算法是使用多尺度Retinex增强后在亮度平均值附近以k倍标准差进行截取、拉伸。采用亮度与对比度乘积、图像信息熵等2个判据,实验结果表明在亮度平均值附近k=1倍标准差进行截取后再拉伸得到的图像其2个判据的值都较大,图像最佳。     

Investigation of patch antennas based on drilled PBG structure

The method of finite-difference-time domain (FDTD) was used to study the characteristics of the patch antenna based on drilling air holes in the PBG substrate. The results obtained show that the waves propagating along the substrate surface can be suppressed by the drilled photonic crystal band gap (PBG) structure due to the influence of its forbidden band. The energy of the electromagnetic waves is concentrated mainly in the substrate. As a result, patch antennas based on drilling air holes in the PBG substrate have lower return losses (S11) in comparison with the conventional patch antennas; thus, a high gain is reached and the performance is improved. Due to such the advantages, the use of patch antennas can be extended to such fields as mobile communication, satellite communication, aviation, etc.     

Completely solid-state LD-side-pumped Nd:YAlO<Subscript>3</Subscript> CW blue laser with intracavity frequency tripling

We report a completely solid-state continuous-wave (CW) blue laser operating at 447 nm utilizing intracavity frequency tripling of an LD-side-pumped Nd:YAlO₃ (Nd:YAP) laser operating at 1341.4 nm. An LBO crystal with type-I critical phase matching and a KTP crystal with type-II critical phase matching (CTM) were used for the second harmonic generation (SHG) and the third harmonic generation (THG), respectively. In view of the analysis of the cavity stability, a four-mirror folded cavity was designed and the output characteristics were theoretically analyzed. Experimental characteristics obtained were shown to be in agreement with the theoretical analysis. The maximum output power of the 447 nm CW blue laser reached 114 mW, which corresponds to a red-to-blue conversion efficiency of 9%.     

Novel tissue-engineered vascular patches based on decellularized canine aortas and their recellularization in vitro

Decellularized allo- or xenogeneic vascular grafts have been found to give more promising results than some biodegradable synthetic polymers. However, owing to absence of well-organized cells, especially confluent endothelial cells, their long-term patency is limited. Seeding vessel-originated cells on these grafts may overcome the deficiency. In this study, canine aortas were decellularized and cross-linked. 4′,6-Diamidino-2-phenylindole (DAPI) and Masson’ trichrome staining showed complete removal of cell debris, while structure integrity of extracellular matrix (ECM) was remained. Human umbilical vein endothelial cells (HUVECs) and human umbilical artery smooth muscle cells (HUASMCs) were seeded on these decellularized aorta patches in three manners, ECs alone (EC/O), SMCs alone (SMC/O) and ECs on SMCs layer (EC/SMC). In EC/O and SMC/O, scanning electron microscopy (SEM) examination indicated both cells could form confluent layers on the decellularized patches when seeded at high density, but their morphology and alignment changed with seeding density. In EC/SMC, ECs could grow well on SMCs layer, but their morphology, alignment, and confluence degree were deeply influenced by the density of SMCs beneath.     

Au等离子体M带5f-3d跃迁透射谱的理论模拟

基于细致组态(DCA)方法和跃迁系列群 (UTA) 模型,采用全相对论处理并结合量子亏损理论,计算了金Au激光等离子体的M带5f-3d跃迁的透射谱, 给出了金等离子体在不同电子温度和电子密度的时空电离态特性,平均电离度,离子丰度和离子内各能级的布居数,并模拟出Au等离子体的M 带5f-3d跃迁的细致谱线,其计算结果可对激光等离子体透射谱的电子温度和电子密度进行精密诊断.     

磁各向异性色散介质散射的Pad啨时域有限差分方法分析

根据矩阵Pad啨逼近理论,把磁化色散介质的相对磁导率张量表示成以jω为自变量的矩阵函数形式,用/t代替jω后过渡到时域,再引入离散时域移位算子代替时间微分算子.进而导出磁化色散介质中的磁感应强度B和磁场强度H在离散时域的色散关系,并将其具体应用于旋磁介质,得到了这种磁化色散介质的Pad啨时域有限差分方法的递推表达式.作为验证,用这种方法计算了磁化铁氧体球的后向雷达散射截面,所得结果与文献结果一致.理论推导及算例表明,该方法是正确和有效的.     

Poincar-Chetaev方程的Noether对称性

建立d’AlembertLagrange原理的PoincarChetaev形式,给出原理在无限小变换下的变形形式,由此得到广义Noether等式以及守恒量的形式.举例说明结果的应用.     

Laser-phase determination methods and transfer equations for direct temporal structure measure- ments of atto- and femtosecond XUV pulses

In this paper the laser-phase determination methods and transfer equations are presented to directly reconstruct the detailed temporal structures of ultra-short extreme ultraviolet (xuv) pulses from the measured photoelectron energy spectra (PES). Each transfer equation includes one of PID (proportional-integral-differential) terms of PES. The intensity and instantaneous frequency of attosecond xuv can be retrieved from the integral term of PES. The intensity profiles of narrow bandwidth atto- and femtosecond xuvs can be rebuilt from the proportional and differential terms of PES respectively. The methods and equations may be used to improve time resolutions in measuring ultrashort pulses.