悬浮液进样-原子吸收光谱法测定核桃粉中的钙、铁和锌

采用悬浮液进样技术应用于原子吸收光谱法,测定了核桃粉中的钙、铁和锌的含量.将核桃粉悬浮于琼脂胶体中制成悬浮液,直接喷入空气-乙炔火焰,用标准加入法测定,将实验结果与灰化法结果进行了比较,经t检验,在显著性水平a=0.05时两种方法无显著性差异,相对标准偏差≤6.1%,结果吻合较好.该方法简便,快速,灵敏度高,准确性好.     

Some theoretical aspects of elastic wave modeling with a recently developed spectral element method

A spectral element method has been recently developed for solving elastodynamic problems. The numerical solutions are obtained by using the weak formulation of the elastodynamic equation for heterogeneous media, based on the Galerkin approach applied to a partition, in small subdomains, of the original physical domain. In this work, some mathematical aspects of the method and the associated algorithm implementation are systematically investigated. Two kinds of orthogonal basis functions, constructed with Legendre and Chebyshev polynomials, and their related Gauss-Lobatto collocation points are introduced. The related integration formulas are obtained. The standard error estimations and expansion convergence are discussed. An element-by-element pre-conditioned conjugate gradient linear solver in the space domain and a staggered predictor/multi-corrector algorithm in the time integration are used for strong heterogeneous elastic media. As a consequence, neither the global matrices nor the effective force vector is assembled. When analytical formulas are used for the element quadrature, there is even no need for forming element matrix in order to further save memory without losing much in computational efficiency. The element-by-element algorithm uses an optimal tensor product scheme which makes this method much more efficient than finite-element methods from the point of view of both memory storage and computational time requirements. This work is divided into two parts. The first part mainly focuses on theoretical studies with a simple numerical result for the Che-byshev spectral element, and the second part, mainly with the Legendre spectral element, will give the algorithm implementation, numerical accuracy and efficiency analyses, and then the detailed modeling example comparisons of the proposed spectral element method with a pseudo-spectral method, which will be seen in another work by Lin, Wang and Zhang.     

飞秒脉冲振幅和相位的无干涉条纹重构法测量

对作者所提出的无干涉条纹直接电场重构测量飞秒脉冲的振幅和相位的新方法作出进一步理论分析，并通过实验测量说明该方法的优越性.该方法克服了传统的SPIDER方法的弊病，能得到一组无干涉条纹的图像，排除传统方法必须使用傅里叶变换滤波消除干涉条纹而引进的系统误差，使得该方法能够采用较简便设备且能较准确测量飞秒脉冲强度轮廓和相位.最后给出同一条件下新方法和传统SPIDER方法分别重构的脉冲强度自相关曲线与实验测量结果的比较，以说明新方法的有效性和优越性.     

Instability-free ion acceleration by two laser pulses

We demonstrate the instability-free ion acceleration regime by introducing laser control with two parallel circularly polarized laser pulses at an intensity of I = 6.8 × 10²¹?W/cm², normally incident on a hydrogen foil. The special structure of the equivalent wave front of those two pulses, which contains Gaussian peaks in both sides and a concavity in the centre (2D), can suppress the transverse instabilities and hole boring effects to constrain a high density ion clump in the centre of the foil, leading to an acceleration over a long distance and gain above 1GeV/u for the ion bunches.     

PCB集成化RFID在电能表智能制造中的研究应用

针对目前电能表制造企业在应用条形码作为信息获取方式在实际生产中带来的问题,且现有RFID标签无法满足电能表制造实际应用需求,提出将PCB集成化RFID标签引入到电能表的生产制造中。根据制造企业面临的问题给出了制造系统的具体功能结构,结合PCB集成化RFID阐述了智能化制造系统的应用流程,并对其中PCB集成化RFID标签天线的设计给出了介绍。根据试点应用证明该系统能够提高流水线信息获取效率,减小出错的概率,实现了电能表制造企业生产制造的透明化与后台信息管理的透明化。     

偏瘫患者辅助下肢外骨骼设计与仿真分析

针对偏瘫患者外骨骼康复机器人降低外骨骼质量的要求,设计了一种辅助下肢外骨骼机器人,采用柔索驱动的膝关节,具有结构简单,质量轻的特点。同时利用ADAMS建立了外骨骼关节柔索驱动的动力学模型,绳索模块建立了柔索驱动模型,通过Ariel生物运动分析软件,采集髋、膝、踝关节运动数据,运用Spline函数进行了仿真分析。经过仿真分析柔索驱动在上台阶运动过程中的不同拉簧预紧力和拉簧刚度下传动特性和驱动力矩,为进一步研究设计下肢外骨骼提供依据。     

一种中药荧光指纹图谱的光谱图像构建方法

利用液晶光谱仪通过光谱成像法对黄柏和人参总皂甙进行了荧光光谱图像检测,采用滤波器与像素点定位联用的方法提取有效像素点,获取它们的荧光光谱图像,绘制了相应的中药荧光指纹图谱.结合欧氏距离的判定方法,将滤波器与像素点定位联用法、像素点优选法和背景差分算法所得的荧光指纹图谱进行比较,三种方法的差异由小到大的排序为滤波器与像素点定位联用法,背景差分算法,像素点优选法.说明滤波器与像素点定位联用法所得荧光指纹图谱稳定性最好,谱线最优.实验结果表明该方法可以用于构建中药荧光指纹图谱,从而提出了一种新的用于中药指纹图谱构建中提取有效像素点的可行方法.     

Composite lattice pattern formation in a wide-aperture thin-slice solid-state laser with imperfect reflective ends

We observed self-formations of multiple lasing channels and two-dimensional lasing patterns consisting of composite local modes having different lasing frequencies in a laser-diode-pumped wide-aperture thin-slice solid-state laser with imperfect reflective end surfaces. Global patterns resembling higher-order Hermite-Gaussian modes or possessing N-fold rotational symmetries were experimentally shown to appear due to the standard polished surface roughness of closely spaced reflective ends and nonlinear modal interactions.