新型显微成像光谱仪系统中线阵针孔离焦研究

显微成像光谱仪技术是最近新兴的一种生物组织检测方法,它可以广泛应用在生物医学检测,疑难病症分析、预防、诊断中,已经成为当今生物组织检测领域研究的热点。提出了一种新型的基于线阵针孔阵列的激光扫描共焦显微成像光谱仪系统LP-LSCMIS方案,介绍了其工作原理及优点,讨论了该装置中线阵针孔阵列离焦对系统性能的影响,分析了离焦对生物组织荧光图像的光谱分辨和自体荧光光谱的调制深度的影响。推导出了光谱分辨和调制深度与离焦量的关系式。结果表明,离焦对仪器的性能有较大的影响,因此在装置装调时要求有更高精度的调整机构。     

光源偏振度对光纤陀螺零漂影响的研究

以Y波导集成光学调制器保偏型干涉式光纤陀螺作为研究对象,根据各光学元器件的参数建立了各器件的琼斯矩阵以及光路传输模型,在此基础上进行了光路偏振误差的理论分析。通过推导,得到了保偏型干涉式光纤陀螺的偏振误差表达式,并首次分析了光源偏振度对光纤陀螺零漂的影响。借助光源尾纤输出的光谱,对由0%~3%之间呈线性变化的偏振度以及对经实验测试的光源偏振度的实际值引起的偏振模式耦合误差的零漂值进行了仿真计算。结果表明,当光路中其它参数不变时,由光源偏振度变化引起的零漂值为0.001°/h,满足了高精度光纤陀螺的精度要求。     

新颖的高功率L-波段掺铒光纤超荧光光源

研究了L-波段超荧光在光纤中的产生机理,设计了一种带光纤圈反射器的双级双程前向输出L-波段光源结构,通过对两级采用掺铒浓度不同的光纤并优化其长度及两级泵浦光功率,实验中获得了功率高达19.86mW(12.98dBm)、中心波长为1577.421nm的L-波段(1555-1620nm)超荧光光源。实现了低浓度掺铒光纤起诱导光及改善光谱的作用,高浓度光纤为主要发光源,采用光纤圈反射器提高了泵浦光的利用效率、光源的平坦度及稳定性。同时分析了结构中各个参量对光源各方面性能的影响,对光源的设计具有指导意义。     

HIRFL注入器PIG离子源的研制

本文介绍了兰州重离子加速器(HIRFL)的注入器(SFC)所用PIG离子源的研制和改进工作,使用新研制的PIG源,已在注人器SFC上获得了5μA的O_(16)~(5+)及10μA的C_(16)~(4+)的离子束。     

一种检验定性指标的有效方法

介绍了一种检验定性指标的有效方法,可用于确定产品的合格率和评价检验人员的检验水平。用该方法分析了某厂产品的一项实际指标,合格率为91 4%,还对该厂10名检验员的检验水平作了客观的评价。     

位置参数估计量的损失函数之估计

本文考虑损失函数的估计问题,分别对于球对称分布和均匀分布情形给出了其参数的J-S型估计量的损失之估计,它们满足[1]中提出的条件(Ⅰ)和(Ⅱ).     

最大似然方法和Bayes方法在结构方程模型分析中的讨论(英文)

本文通过模拟研究,讨论了最大似然方法和Bayes方法在分析结构方程模型中的相似点和不同之处。     

A new algorithm for fixed design regression and denoising

In this paper, we present a new algorithm to estimate a regression function in a fixed design regression model, by piecewise (standard and trigonometric) polynomials computed with an automatic choice of the knots of the subdivision and of the degrees of the polynomials on each sub-interval. First we give the theoretical background underlying the method: the theoretical performances of our penalized least-squares estimator are based on non-asymptotic evaluations of a mean-square type risk. Then we explain how the algorithm is built and possibly accelerated (to face the case when the number of observations is great), how the penalty term is chosen and why it contains some constants requiring an empirical calibration. Lastly, a comparison with some well-known or recent wavelet methods is made: this brings out that our algorithm behaves in a very competitive way in term of denoising and of compression.     

Covariance estimation under spatial dependence

Correlated multivariate processes have a dependence structure which must be taken into account when estimating the covariance matrix. The natural estimator of the covariance matrix is introduced and is shown that to be biased under the dependence structure. This bias is studied under two different asymptotic models, namely increasing the domain by increasing the number of observations, and increasing the number of observations in the fixed domain. Using the first asymptotic model, we quantify the convergence rate of the bias and of the covariance between the components of the estimated covariance matrix. The second asymptotic model serves to derive a fast and accurate bias correction. As shown, under mild hypotheses, the asymptotic normality of the estimated covariance matrix holds and can be used to test whether the bias is significant, for example, in the sense that the eigenvectors of the estimated and true covariance matrices are significantly different.     

内源全息术的原理和数学描述

以往的全息术在对原子成像时,在相干光源、探测器空间分辨和信号强度三个方面遇到了难以克服的困难. 阐述了内源全息术克服这些困难的原理,研究了内源全息术的记录和再现全过程,推导出内源球面全息图的再现公式,并在散射因子球对称近似和能量无关近似下,推导出以δ函数表示原子全息再现像的解析表达式. 关键词： 内源全息术 同步辐射 晶体结构 傅里叶变换