平行光管主反射镜组件的非线性有限元分析

为了提高对光学仪器中光机结构分析的精度,引入了非线性分析方法,用非线性有限元法研究了某平行光管主镜组件存在的非线性问题。介绍了产生结构非线性的主要来源,并在接触理论的基础上对主反射镜组件进行了合理的有限元建模。采用接触非线性分析方法对螺钉预紧时反射镜的响应及在自重和温度载荷作用下反射镜的变形进行了分析。将线性和非线性分析结果与实际结果进行了对比,结果表明,采用接触非线性分析方法对反射镜组件进行工程分析减小了分析误差。因此,在工程分析中,对某些接触部位采用非线性分析方法可以提高分析精度,得到的结果更加符合实际。     

基于经验模态分解滤波的低频振荡Prony分析

传统Prony法在分析低频振荡时对输入信号要求较高,存在着对噪声敏感的弱点.因此提出一种经验模态分解滤波和改进Prony法相结合的低频振荡分析方法.该方法先用经验模态分解对低频振荡信号进行自适应滤波,再用改进Prony法对滤波后的信号进行分析.其中,改进Prony法有效阶数用归一化奇异值法确定.将该方法分别用于分析试验信号和IEEE 4机系统振荡信号,并与基于低通滤波器的Prony分析进行比较.结果表明,在较大噪声环境下,该方法仍然能相对准确的辨识出低频振荡主导模式,验证了其有效性. 关键词： 低频振荡 经验模态分解 改进Prony法 归一化奇异值法     

大学物理教学中量纲分析与应用

量纲分析是重要的半定量分析方法之一,在大学物理教学实践中,要培养和倡导学生在学习中灵活应用量纲分析解决问题,使教学更丰富和直观.本文介绍量纲分析的基本理论及怎样将量纲分析方法贯穿于教学中.     

光机系统分析方法

为了使光学仪器能在恶劣的环境下正常工作，需要对其进行详尽的工程分析。对光机系统的分析方法，包括传统分析方法、集成分析方法和统一分析方法进行了研究，说明了它们的工作原理及实现的具体步骤，分别列举了它们的优缺点。进一步指出在集成分析中热弹性分析需要解决的问题及Zernike多项式拟合中需要注意的问题，归纳了使用统一分析方法时需要特别注意的问题。在比较了3种方法优缺点的基础上，对光机分析方法进行了展望，得出集成分析方法在很长一段时间内将是光机系统分析的主要方法的结论。     

小波分析在遥测信号处理中的应用

综述了小波分析的发展现状,通过对比小波变换与短时傅里叶变换之间的差异,指出小波分析是一种多分辨分析方法,特别适合于非平稳信号的分析与处理,并且应用该方法对遥测速变信号进行处理,取得了较好的效果。     

Deterministic-statistical analysis of a structural-acoustic system

The purpose of this paper is to develop an efficient approach for vibro-acoustic analysis. Being simple and representative, an exited plate-acoustic system is selected as a validation case for the vibro-acoustic analysis as the system presents one two-dimensional statistical component (modal dense structure panel—plate) connected to the other component (deterministic acoustic volume—cavity) through the area junction over a surface domain, rather than at a line boundary. Potential industrial applications of the system vibro-acoustic analysis would be in acoustic modelling of vehicle body panels such as the cabin roof panel, and door panels for the boom noise analysis.A new deterministic-statistical analysis approach is proposed from a combination or hybrid of deterministic analysis and statistical energy analysis (SEA) approaches. General theory of the new deterministic-statistical analysis approach is introduced. The main advantage of the new deterministic-statistical analysis approach is its possibility in place of the time consuming Monte Carlo simulation. In order to illustrate and validate the new deterministic-statistical analysis approach, three approaches of the deterministic analysis, the statistical energy analysis and the new deterministic-statistical analysis are then applied to conduct the plate-acoustic system modelling, and their results will be compared. The vibro-acoustic energy coupling characteristic of the plate-acoustic system will be studied. The most suitable frequency range for the new approach will be identified in consideration of computational accuracy, information and speed.     

拉曼光谱的荧光背景扣除及其用于药物聚类分析

拉曼光谱分析中,由于有机分子或样品中污染物的荧光影响,常会使拉曼光谱产生高背景信号,以致其拉曼光谱吸收信号被淹没。利用自行开发的软件包baselineWavelet,本文对醋酸泼尼松片和格列本脲片的拉曼光谱进行了荧光背景扣除研究,采用主成分分析和随机森林算法对它们进行聚类分析,得到了较好的结果。通过这2种药物的拉曼光谱聚类分析结果,检验了该背景扣除算法的有效性和准确性,并讨论了荧光背景对拉曼光谱聚类分析的影响。结果说明,荧光背景对拉曼光谱聚类分析影响很大,在分析前必须预先扣除。     

Application of Information Technologies and Programming Methods of Embedded Systems for Complex Intellectual Analysis

An information model is outlined, which represents an intelligent system of metallographic analysis in the form of a set of subsystems, the interaction of which ensures the performance of metallographic analysis functions. The structure of the information storage subsystem for metallographic analysis is presented. The deployment model of an intelligent metallographic analysis system is proposed and described. The paper outlines the approach to the presentation of an expert subsystem for metallographic quality control of metals based on a neural network. The process of finding a close precedent in metallographic analysis with reference to a multilayer neural network is described. An intelligent metallographic analysis system is described, which based on proposed information model. A specialized software of an intelligent metallographic analysis system is presented. The functioning results of the developed system for processing images of steel microstructures to determine the steel quantitative parameters is presented.     

六组点堆中子动力学方程组的同伦分析解

鉴于目前六组点堆中子动力学方程仍然无法获得解析解,本文尝试将同伦分析方法应用于六组缓发中子动力方程组的求解,获得了它的级数解析解,并对级数解析解算法的有效性进行了检验.结果表明,该级数解析解算法从计算时间和精度上都能达到工程应用的要求,可适宜于反应堆中子动力学控制的设计分析和仿真计算.     

An efficient numerical approach to electrostatic microelectromechanical system simulation

Computational analysis of electrostatic microelectromechanical systems (MEMS) requires an electrostatic analysis to compute the electrostatic forces acting on micromechanical structures and a mechanical analysis to compute the deformation of micromechanical structures. Typically, the mechanical analysis is performed on an undeformed geometry. However, the electrostatic analysis is performed on the deformed position of microstructures. In this paper, a new efficient approach to self-consistent analysis of electrostatic MEMS in the small deformation case is presented. In this approach, when the microstructures undergo small deformations, the surface charge densities on the deformed geometry can be computed without updating the geometry of the microstructures. This algorithm is based on the linear mode shapes of a microstructure as basis functions. A boundary integral equation for the electrostatic problem is expanded into a Taylor series around the undeformed configuration, and a new coupled-field equation is presented. This approach is validated by comparing its results with the results available in the literature and ANSYS solutions, and shows attractive features comparable to ANSYS.     

Cryptographic Algorithm Using Newton-Raphson Method and General Bischi-Naimzadah Duopoly System

Image encryption is an excellent method for the protection of image content. Most authors used the permutation-substitution model to encrypt/decrypt the image. Chaos-based image encryption methods are used in this model to shuffle the rows/columns and change the pixel values. In parallel, authors proposed permutation using non-chaotic methods and have displayed good results in comparison to chaos-based methods. In the current article, a new image encryption algorithm is designed using combination of Newton-Raphson’s method (non-chaotic) and general Bischi-Naimzadah duopoly system as a hyperchaotic two-dimensional map. The plain image is first shuffled by using Newton-Raphson’s method. Next, a secret matrix with the same size of the plain image is created using general Bischi-Naimzadah duopoly system. Finally, the XOR between the secret matrix and the shuffled image is calculated and then the cipher image is obtained. Several security experiments are executed to measure the efficiency of the proposed algorithm, such as key space analysis, correlation coefficients analysis, histogram analysis, entropy analysis, differential attacks analysis, key sensitivity analysis, robustness analysis, chosen plaintext attack analysis, computational analysis, and NIST statistical Tests. Compared to many recent algorithms, the proposed algorithm has good security efficiency.     

基于近红外光谱油分检测的玉米单倍体鉴别方法研究

目前,在单倍体育种技术中,可先使用低场核磁共振方法定量测得玉米单倍体与二倍体的油分,再依据二者油分差异鉴别单倍体,该方法在实际育种工作中已取得初步应用,但核磁共振鉴别单倍体方法存在速度慢、价格贵、维护难等缺点,难以获得大范围应用。近红外光谱技术有诸多优点并在各领域取得广泛应用,相关研究也表明该技术可用于玉米单倍体的定性鉴别,但是目前该方法用于鉴别单倍体实验研究时涉及的玉米品种相对较少,对于某些品种识别效果较差,且内部机理类似于黑盒,难以指明单倍体、二倍体两类种子是依据何种物质的差别进行区分,有时难以获得农业领域专家认可。根据花粉直感效应的原理,玉米单倍体与二倍体存在明显的油分区别,通过油分鉴别单倍体原理直观明白,易于被业内专家接受。因此,提出了一种先定量得到油分,再依据定量分析所得油分进行分类的方法,即首先使用玉米单籽粒的近红外光谱定量回归分析得到各籽粒的油分含量,再利用定量分析所得的油分值,并使用最小平方误差方法对单倍体、二倍体混合籽粒进行定性分类。实验结果表明近红外定量分析方法的识别精度与核磁共振方法相当,与几种定性分析方法比较,在训练集规模相同时,近红外定量分析方法所得识别率优于几种定性分析方法,进一步表明近红外定量分析方法鉴别单倍体具有一定优势,可满足育种行业精度要求,能够为尽快实现单倍体工程化育种提供保障。     

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Helium cooled ceramic breeder test blanket module (HCCB TBM) was introduced. The TBM system is mainly composed of test blanket, helium coolant system, tritium extraction system, coolant purification system, tritium measurement system and neutron activation system. The structural safety analysis of TBM mainly includes electromagnetic safety analysis, thermal-hydraulic safety analysis and neutronics safety analysis. The material safety analysis of TBM is divided into safety analysis of structural material, safety analysis of functional materials, such as tritium permeation barrier and tritium treatment materials. The research progress made by scholars at home and abroad in the above-mentioned security analysis research work was summarized, and the future safety analysis of the TBM tritium system was looked forward to, with a view to providing reference for the safety design of tritium systems.     

常见金属离子含量的测定及烟草聚类分析研究

对5个烟叶产区的88个烟草样品, 利用火焰光度法和原子吸收光谱法分别测定其钾和镁、钠、锰、铁和锌的含量,应用模糊c-均值(FCM)聚类分析与系统聚类分析对这些样品分类。结果表明,模糊聚类分析对于烟草产地的判断具有积极的指导意义,其判断的准确性优于系统聚类分析。     

基于数据库进行乏燃料鉴别的多元统计分析研究

近年来,随着国际核军控形势的变化,包含防扩散、防核恐及核安保的多边国际军控合作越来越受到重视.核取证技术作为防扩散、防核恐及核安保的一项核心技术,在对涉核非法活动的威慑、阻止以及响应方面具有重要作用,值得深入研究.目前针对核取证技术的研究较多,主要集中于材料的表征和数据的解读.其中解读作为核取证研究技术中最重要的一环,所面对的对象是多种多样的,包括铀矿石、黄饼、核燃料、乏燃料等,而其中乏燃料由于其潜在的威胁越来越受到重视.本文聚焦于在核取证场景中利用多元统计分析方法进行乏燃料鉴别的研究,主要是利用因子分析、判别分析和回归分析方法对乏燃料组分进行分析,研究各方法的适用范围,并为未来可能的利用数据库进行乏燃料鉴别的工作提供理论依据与可行方案,为相关核取证溯源工作的顺利开展提供支撑.     

QCD analysis of experimental polarized deep-inelastic-scattering data

A detailed review of the current state of investigations into polarized deep inelastic scattering (DIS) is presented. Special attention is given to the methods of the QCD analysis of experimental data on these processes and to the methods of extrapolation of polarized structure functions and polarized quark distributions in the regions inaccessible to current experiments. In the case of pure inclusive processes, the QCD analysis of all worldwide data, including the latest COMPASS data, is presented in detail. Special attention is given to such important components of the nucleon-spin problem as the polarized strangeness and polarized gluon distribution. The features of SIDIS processes are considered; in particular, the role of fragmentation functions in the analysis of the semi-inclusive data is discussed. The methods of extracting the fragmentation functions from experimental data are considered in detail, and the corresponding results are presented. The results of analysis of the existing semi-inclusive polarized data both in the QCD leading order and in the next-to-leading order are considered. Special attention is given to non-standard, so-called difference asymmetries, which make it possible to minimize the dependence of results of analysis on the fragmentation functions. The current methods of QCD analysis of semi-inclusive polarized data are critically reviewed. An alternative method of QCD analysis of semi-inclusive data is presented for next-to-leading order QCD. Advantages of the method in practical applications are illustrated by the example of analysis of the HERMES data.     

拉曼光谱在水质分析中的应用:展望及系统设计

拉曼散射光谱是一种研究物质结构强有力的工具,目前已经逐渐应用于许多领域,但在水质分析方面的应用讨论尚少。本文首先对拉曼光谱应用于水质分析的可行性及优越性进行了分析,并在此基础上设计了一套新型的应用微机和进经神经网络实现的拉曼光谱水质分析系统,以达到对水质进行高效、准确的定性和定量分析的目的。     

Seismic response of bridge piers on elasto-plastic Winkler foundation allowed to uplift

When the bridge piers with shallow foundation are subject to intensive earthquake excitations, uplift of foundations will occur and the foundation soil will partly become plastic. It is very difficult to use an accurate method to simulate the uplifting and yielding of supporting soil. An improved Winkler foundation model, which could be used to consider the uplift and yield, was employed in the analysis. The 1940 El Centro earthquake record is inputted to a rigid pier with shallow foundation so that the non-linear history response is obtained. From the non-linear analysis, it is concluded that the non-linear effect is very remarkable when uplifting and yielding of supporting soil are considered. Compared with the linear analysis, the stiffness of bridge pier-soil system degrades in each cycle after considering uplifting and yielding. It is shown that the non-linear analysis can get larger rotational angles and smaller bending moments compared with the linear analysis.     

基于接触非线性分析方法的反射镜组件工程分析

工程中将实际的非线性系统近似为线性系统,用线性分析方法对所研究的对象进行分析往往会带来较大的求解误差。介绍了产生结构非线性的主要因素,并在接触理论基础上,对某空间相机反射镜组件进行了合理的有限元建模。采用接触非线性分析方法对螺钉预紧时反射镜的响应及在自重和温度载荷作用下反射镜的变形进行了分析。通过比较线性分析与非线性分析的结果表明:采用非线性分析的结果更接近实际;在空间相机的工程分析中,对某些接触部位采用非线性的分析方法可以提高分析精度。     

氦冷固态增殖实验包层安全分析研究进展综述

介绍了氦冷固态增殖实验包层(HCCB TBM)系统,该系统主要由TBM 包层、氦冷却系统、氚提取系统、冷却剂净化系统、氚计量系统和中子活化系统等组成。TBM 结构安全分析主要包括电磁安全分析、热工水力安全分析和中子学安全分析,TBM 材料安全分析主要包括结构材料安全分析、阻氚涂层和氚处理等功能材料安全分析。对国内外学者在上述安全分析研究工作中取得的研究进展进行综述,并对TBM 未来的安全分析工作进行展望,以期对其安全设计提供参考。